src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 # ifndef SUPPORT_CRYPTEQ
  21 #  define SUPPORT_CRYPTEQ
  22 # endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 # include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 # ifdef CRYPT_H
  31 #  include <crypt.h>
  32 # endif
  33 # ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 # endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Characters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"authresults",
 107   US"certextract",
 108   US"dlfunc",
 109   US"env",
 110   US"extract",
 111   US"filter",
 112   US"hash",
 113   US"hmac",
 114   US"if",
 115 #ifdef SUPPORT_I18N
 116   US"imapfolder",
 117 #endif
 118   US"length",
 119   US"listextract",
 120   US"listquote",
 121   US"lookup",
 122   US"map",
 123   US"nhash",
 124   US"perl",
 125   US"prvs",
 126   US"prvscheck",
 127   US"readfile",
 128   US"readsocket",
 129   US"reduce",
 130   US"run",
 131   US"sg",
 132   US"sort",
 133 #ifdef EXPERIMENTAL_SRS_NATIVE
 134   US"srs_encode",
 135 #endif
 136   US"substr",
 137   US"tr" };
 138
 139 enum {
 140   EITEM_ACL,
 141   EITEM_AUTHRESULTS,
 142   EITEM_CERTEXTRACT,
 143   EITEM_DLFUNC,
 144   EITEM_ENV,
 145   EITEM_EXTRACT,
 146   EITEM_FILTER,
 147   EITEM_HASH,
 148   EITEM_HMAC,
 149   EITEM_IF,
 150 #ifdef SUPPORT_I18N
 151   EITEM_IMAPFOLDER,
 152 #endif
 153   EITEM_LENGTH,
 154   EITEM_LISTEXTRACT,
 155   EITEM_LISTQUOTE,
 156   EITEM_LOOKUP,
 157   EITEM_MAP,
 158   EITEM_NHASH,
 159   EITEM_PERL,
 160   EITEM_PRVS,
 161   EITEM_PRVSCHECK,
 162   EITEM_READFILE,
 163   EITEM_READSOCK,
 164   EITEM_REDUCE,
 165   EITEM_RUN,
 166   EITEM_SG,
 167   EITEM_SORT,
 168 #ifdef EXPERIMENTAL_SRS_NATIVE
 169   EITEM_SRS_ENCODE,
 170 #endif
 171   EITEM_SUBSTR,
 172   EITEM_TR };
 173
 174 /* Tables of operator names, and corresponding switch numbers. The names must be
 175 in alphabetical order. There are two tables, because underscore is used in some
 176 cases to introduce arguments, whereas for other it is part of the name. This is
 177 an historical mis-design. */
 178
 179 static uschar *op_table_underscore[] = {
 180   US"from_utf8",
 181   US"local_part",
 182   US"quote_local_part",
 183   US"reverse_ip",
 184   US"time_eval",
 185   US"time_interval"
 186 #ifdef SUPPORT_I18N
 187  ,US"utf8_domain_from_alabel",
 188   US"utf8_domain_to_alabel",
 189   US"utf8_localpart_from_alabel",
 190   US"utf8_localpart_to_alabel"
 191 #endif
 192   };
 193
 194 enum {
 195   EOP_FROM_UTF8,
 196   EOP_LOCAL_PART,
 197   EOP_QUOTE_LOCAL_PART,
 198   EOP_REVERSE_IP,
 199   EOP_TIME_EVAL,
 200   EOP_TIME_INTERVAL
 201 #ifdef SUPPORT_I18N
 202  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 203   EOP_UTF8_DOMAIN_TO_ALABEL,
 204   EOP_UTF8_LOCALPART_FROM_ALABEL,
 205   EOP_UTF8_LOCALPART_TO_ALABEL
 206 #endif
 207   };
 208
 209 static uschar *op_table_main[] = {
 210   US"address",
 211   US"addresses",
 212   US"base32",
 213   US"base32d",
 214   US"base62",
 215   US"base62d",
 216   US"base64",
 217   US"base64d",
 218   US"bless",
 219   US"domain",
 220   US"escape",
 221   US"escape8bit",
 222   US"eval",
 223   US"eval10",
 224   US"expand",
 225   US"h",
 226   US"hash",
 227   US"hex2b64",
 228   US"hexquote",
 229   US"ipv6denorm",
 230   US"ipv6norm",
 231   US"l",
 232   US"lc",
 233   US"length",
 234   US"listcount",
 235   US"listnamed",
 236   US"mask",
 237   US"md5",
 238   US"nh",
 239   US"nhash",
 240   US"quote",
 241   US"randint",
 242   US"rfc2047",
 243   US"rfc2047d",
 244   US"rxquote",
 245   US"s",
 246   US"sha1",
 247   US"sha2",
 248   US"sha256",
 249   US"sha3",
 250   US"stat",
 251   US"str2b64",
 252   US"strlen",
 253   US"substr",
 254   US"uc",
 255   US"utf8clean" };
 256
 257 enum {
 258   EOP_ADDRESS =  nelem(op_table_underscore),
 259   EOP_ADDRESSES,
 260   EOP_BASE32,
 261   EOP_BASE32D,
 262   EOP_BASE62,
 263   EOP_BASE62D,
 264   EOP_BASE64,
 265   EOP_BASE64D,
 266   EOP_BLESS,
 267   EOP_DOMAIN,
 268   EOP_ESCAPE,
 269   EOP_ESCAPE8BIT,
 270   EOP_EVAL,
 271   EOP_EVAL10,
 272   EOP_EXPAND,
 273   EOP_H,
 274   EOP_HASH,
 275   EOP_HEX2B64,
 276   EOP_HEXQUOTE,
 277   EOP_IPV6DENORM,
 278   EOP_IPV6NORM,
 279   EOP_L,
 280   EOP_LC,
 281   EOP_LENGTH,
 282   EOP_LISTCOUNT,
 283   EOP_LISTNAMED,
 284   EOP_MASK,
 285   EOP_MD5,
 286   EOP_NH,
 287   EOP_NHASH,
 288   EOP_QUOTE,
 289   EOP_RANDINT,
 290   EOP_RFC2047,
 291   EOP_RFC2047D,
 292   EOP_RXQUOTE,
 293   EOP_S,
 294   EOP_SHA1,
 295   EOP_SHA2,
 296   EOP_SHA256,
 297   EOP_SHA3,
 298   EOP_STAT,
 299   EOP_STR2B64,
 300   EOP_STRLEN,
 301   EOP_SUBSTR,
 302   EOP_UC,
 303   EOP_UTF8CLEAN };
 304
 305
 306 /* Table of condition names, and corresponding switch numbers. The names must
 307 be in alphabetical order. */
 308
 309 static uschar *cond_table[] = {
 310   US"<",
 311   US"<=",
 312   US"=",
 313   US"==",     /* Backward compatibility */
 314   US">",
 315   US">=",
 316   US"acl",
 317   US"and",
 318   US"bool",
 319   US"bool_lax",
 320   US"crypteq",
 321   US"def",
 322   US"eq",
 323   US"eqi",
 324   US"exists",
 325   US"first_delivery",
 326   US"forall",
 327   US"forall_json",
 328   US"forall_jsons",
 329   US"forany",
 330   US"forany_json",
 331   US"forany_jsons",
 332   US"ge",
 333   US"gei",
 334   US"gt",
 335   US"gti",
 336 #ifdef EXPERIMENTAL_SRS_NATIVE
 337   US"inbound_srs",
 338 #endif
 339   US"inlist",
 340   US"inlisti",
 341   US"isip",
 342   US"isip4",
 343   US"isip6",
 344   US"ldapauth",
 345   US"le",
 346   US"lei",
 347   US"lt",
 348   US"lti",
 349   US"match",
 350   US"match_address",
 351   US"match_domain",
 352   US"match_ip",
 353   US"match_local_part",
 354   US"or",
 355   US"pam",
 356   US"pwcheck",
 357   US"queue_running",
 358   US"radius",
 359   US"saslauthd"
 360 };
 361
 362 enum {
 363   ECOND_NUM_L,
 364   ECOND_NUM_LE,
 365   ECOND_NUM_E,
 366   ECOND_NUM_EE,
 367   ECOND_NUM_G,
 368   ECOND_NUM_GE,
 369   ECOND_ACL,
 370   ECOND_AND,
 371   ECOND_BOOL,
 372   ECOND_BOOL_LAX,
 373   ECOND_CRYPTEQ,
 374   ECOND_DEF,
 375   ECOND_STR_EQ,
 376   ECOND_STR_EQI,
 377   ECOND_EXISTS,
 378   ECOND_FIRST_DELIVERY,
 379   ECOND_FORALL,
 380   ECOND_FORALL_JSON,
 381   ECOND_FORALL_JSONS,
 382   ECOND_FORANY,
 383   ECOND_FORANY_JSON,
 384   ECOND_FORANY_JSONS,
 385   ECOND_STR_GE,
 386   ECOND_STR_GEI,
 387   ECOND_STR_GT,
 388   ECOND_STR_GTI,
 389 #ifdef EXPERIMENTAL_SRS_NATIVE
 390   ECOND_INBOUND_SRS,
 391 #endif
 392   ECOND_INLIST,
 393   ECOND_INLISTI,
 394   ECOND_ISIP,
 395   ECOND_ISIP4,
 396   ECOND_ISIP6,
 397   ECOND_LDAPAUTH,
 398   ECOND_STR_LE,
 399   ECOND_STR_LEI,
 400   ECOND_STR_LT,
 401   ECOND_STR_LTI,
 402   ECOND_MATCH,
 403   ECOND_MATCH_ADDRESS,
 404   ECOND_MATCH_DOMAIN,
 405   ECOND_MATCH_IP,
 406   ECOND_MATCH_LOCAL_PART,
 407   ECOND_OR,
 408   ECOND_PAM,
 409   ECOND_PWCHECK,
 410   ECOND_QUEUE_RUNNING,
 411   ECOND_RADIUS,
 412   ECOND_SASLAUTHD
 413 };
 414
 415
 416 /* Types of table entry */
 417
 418 enum vtypes {
 419   vtype_int,            /* value is address of int */
 420   vtype_filter_int,     /* ditto, but recognized only when filtering */
 421   vtype_ino,            /* value is address of ino_t (not always an int) */
 422   vtype_uid,            /* value is address of uid_t (not always an int) */
 423   vtype_gid,            /* value is address of gid_t (not always an int) */
 424   vtype_bool,           /* value is address of bool */
 425   vtype_stringptr,      /* value is address of pointer to string */
 426   vtype_msgbody,        /* as stringptr, but read when first required */
 427   vtype_msgbody_end,    /* ditto, the end of the message */
 428   vtype_msgheaders,     /* the message's headers, processed */
 429   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 430   vtype_localpart,      /* extract local part from string */
 431   vtype_domain,         /* extract domain from string */
 432   vtype_string_func,    /* value is string returned by given function */
 433   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 434   vtype_tode,           /* value not used; generate tod in epoch format */
 435   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 436   vtype_todf,           /* value not used; generate full tod */
 437   vtype_todl,           /* value not used; generate log tod */
 438   vtype_todlf,          /* value not used; generate log file datestamp tod */
 439   vtype_todzone,        /* value not used; generate time zone only */
 440   vtype_todzulu,        /* value not used; generate zulu tod */
 441   vtype_reply,          /* value not used; get reply from headers */
 442   vtype_pid,            /* value not used; result is pid */
 443   vtype_host_lookup,    /* value not used; get host name */
 444   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 445   vtype_pspace,         /* partition space; value is T/F for spool/log */
 446   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 447   vtype_cert            /* SSL certificate */
 448   #ifndef DISABLE_DKIM
 449   ,vtype_dkim           /* Lookup of value in DKIM signature */
 450   #endif
 451 };
 452
 453 /* Type for main variable table */
 454
 455 typedef struct {
 456   const char *name;
 457   enum vtypes type;
 458   void       *value;
 459 } var_entry;
 460
 461 /* Type for entries pointing to address/length pairs. Not currently
 462 in use. */
 463
 464 typedef struct {
 465   uschar **address;
 466   int  *length;
 467 } alblock;
 468
 469 static uschar * fn_recipients(void);
 470 typedef uschar * stringptr_fn_t(void);
 471 static uschar * fn_queue_size(void);
 472
 473 /* This table must be kept in alphabetical order. */
 474
 475 static var_entry var_table[] = {
 476   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 477      they will be confused with user-creatable ACL variables. */
 478   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 479   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 480   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 481   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 482   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 483   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 484   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 485   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 486   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 487   { "acl_narg",            vtype_int,         &acl_narg },
 488   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 489   { "address_data",        vtype_stringptr,   &deliver_address_data },
 490   { "address_file",        vtype_stringptr,   &address_file },
 491   { "address_pipe",        vtype_stringptr,   &address_pipe },
 492 #ifdef EXPERIMENTAL_ARC
 493   { "arc_domains",         vtype_string_func, (void *) &fn_arc_domains },
 494   { "arc_oldest_pass",     vtype_int,         &arc_oldest_pass },
 495   { "arc_state",           vtype_stringptr,   &arc_state },
 496   { "arc_state_reason",    vtype_stringptr,   &arc_state_reason },
 497 #endif
 498   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 499   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 500   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 501   { "authentication_failed",vtype_int,        &authentication_failed },
 502 #ifdef WITH_CONTENT_SCAN
 503   { "av_failed",           vtype_int,         &av_failed },
 504 #endif
 505 #ifdef EXPERIMENTAL_BRIGHTMAIL
 506   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 507   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 508   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 509   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 510 #endif
 511   { "body_linecount",      vtype_int,         &body_linecount },
 512   { "body_zerocount",      vtype_int,         &body_zerocount },
 513   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 514   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 515   { "caller_gid",          vtype_gid,         &real_gid },
 516   { "caller_uid",          vtype_uid,         &real_uid },
 517   { "callout_address",     vtype_stringptr,   &callout_address },
 518   { "compile_date",        vtype_stringptr,   &version_date },
 519   { "compile_number",      vtype_stringptr,   &version_cnumber },
 520   { "config_dir",          vtype_stringptr,   &config_main_directory },
 521   { "config_file",         vtype_stringptr,   &config_main_filename },
 522   { "csa_status",          vtype_stringptr,   &csa_status },
 523 #ifdef EXPERIMENTAL_DCC
 524   { "dcc_header",          vtype_stringptr,   &dcc_header },
 525   { "dcc_result",          vtype_stringptr,   &dcc_result },
 526 #endif
 527 #ifndef DISABLE_DKIM
 528   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 529   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 530   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 531   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 532   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 533   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 534   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 535   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 536   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 537   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 538   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 539   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 540   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 541   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 542   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 543   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 544   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 545   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 546   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 547   { "dkim_verify_reason",  vtype_stringptr,   &dkim_verify_reason },
 548   { "dkim_verify_status",  vtype_stringptr,   &dkim_verify_status },
 549 #endif
 550 #ifdef SUPPORT_DMARC
 551   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 552   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 553   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 554   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 555 #endif
 556   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 557   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 558   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 559   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 560   { "domain",              vtype_stringptr,   &deliver_domain },
 561   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 562 #ifndef DISABLE_EVENT
 563   { "event_data",          vtype_stringptr,   &event_data },
 564
 565   /*XXX want to use generic vars for as many of these as possible*/
 566   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 567
 568   { "event_name",          vtype_stringptr,   &event_name },
 569 #endif
 570   { "exim_gid",            vtype_gid,         &exim_gid },
 571   { "exim_path",           vtype_stringptr,   &exim_path },
 572   { "exim_uid",            vtype_uid,         &exim_uid },
 573   { "exim_version",        vtype_stringptr,   &version_string },
 574   { "headers_added",       vtype_string_func, (void *) &fn_hdrs_added },
 575   { "home",                vtype_stringptr,   &deliver_home },
 576   { "host",                vtype_stringptr,   &deliver_host },
 577   { "host_address",        vtype_stringptr,   &deliver_host_address },
 578   { "host_data",           vtype_stringptr,   &host_data },
 579   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 580   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 581   { "host_port",           vtype_int,         &deliver_host_port },
 582   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 583   { "inode",               vtype_ino,         &deliver_inode },
 584   { "interface_address",   vtype_stringptr,   &interface_address },
 585   { "interface_port",      vtype_int,         &interface_port },
 586   { "item",                vtype_stringptr,   &iterate_item },
 587   #ifdef LOOKUP_LDAP
 588   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 589   #endif
 590   { "load_average",        vtype_load_avg,    NULL },
 591   { "local_part",          vtype_stringptr,   &deliver_localpart },
 592   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 593   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 594   { "local_part_prefix_v", vtype_stringptr,   &deliver_localpart_prefix_v },
 595   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 596   { "local_part_suffix_v", vtype_stringptr,   &deliver_localpart_suffix_v },
 597   { "local_part_verified", vtype_stringptr,   &deliver_localpart_verified },
 598 #ifdef HAVE_LOCAL_SCAN
 599   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 600 #endif
 601   { "local_user_gid",      vtype_gid,         &local_user_gid },
 602   { "local_user_uid",      vtype_uid,         &local_user_uid },
 603   { "localhost_number",    vtype_int,         &host_number },
 604   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 605   { "log_space",           vtype_pspace,      (void *)FALSE },
 606   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 607   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 608 #ifdef WITH_CONTENT_SCAN
 609   { "malware_name",        vtype_stringptr,   &malware_name },
 610 #endif
 611   { "max_received_linelength", vtype_int,     &max_received_linelength },
 612   { "message_age",         vtype_int,         &message_age },
 613   { "message_body",        vtype_msgbody,     &message_body },
 614   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 615   { "message_body_size",   vtype_int,         &message_body_size },
 616   { "message_exim_id",     vtype_stringptr,   &message_id },
 617   { "message_headers",     vtype_msgheaders,  NULL },
 618   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 619   { "message_id",          vtype_stringptr,   &message_id },
 620   { "message_linecount",   vtype_int,         &message_linecount },
 621   { "message_size",        vtype_int,         &message_size },
 622 #ifdef SUPPORT_I18N
 623   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 624 #endif
 625 #ifdef WITH_CONTENT_SCAN
 626   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 627   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 628   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 629   { "mime_charset",        vtype_stringptr,   &mime_charset },
 630   { "mime_content_description", vtype_stringptr, &mime_content_description },
 631   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 632   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 633   { "mime_content_size",   vtype_int,         &mime_content_size },
 634   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 635   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 636   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 637   { "mime_filename",       vtype_stringptr,   &mime_filename },
 638   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 639   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 640   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 641   { "mime_part_count",     vtype_int,         &mime_part_count },
 642 #endif
 643   { "n0",                  vtype_filter_int,  &filter_n[0] },
 644   { "n1",                  vtype_filter_int,  &filter_n[1] },
 645   { "n2",                  vtype_filter_int,  &filter_n[2] },
 646   { "n3",                  vtype_filter_int,  &filter_n[3] },
 647   { "n4",                  vtype_filter_int,  &filter_n[4] },
 648   { "n5",                  vtype_filter_int,  &filter_n[5] },
 649   { "n6",                  vtype_filter_int,  &filter_n[6] },
 650   { "n7",                  vtype_filter_int,  &filter_n[7] },
 651   { "n8",                  vtype_filter_int,  &filter_n[8] },
 652   { "n9",                  vtype_filter_int,  &filter_n[9] },
 653   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 654   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 655   { "originator_gid",      vtype_gid,         &originator_gid },
 656   { "originator_uid",      vtype_uid,         &originator_uid },
 657   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 658   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 659   { "pid",                 vtype_pid,         NULL },
 660 #ifndef DISABLE_PRDR
 661   { "prdr_requested",      vtype_bool,        &prdr_requested },
 662 #endif
 663   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 664 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 665   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 666   { "proxy_external_port", vtype_int,         &proxy_external_port },
 667   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 668   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 669   { "proxy_session",       vtype_bool,        &proxy_session },
 670 #endif
 671   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 672   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 673   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 674   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 675   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 676   { "queue_name",          vtype_stringptr,   &queue_name },
 677   { "queue_size",          vtype_string_func, &fn_queue_size },
 678   { "rcpt_count",          vtype_int,         &rcpt_count },
 679   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 680   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 681   { "received_count",      vtype_int,         &received_count },
 682   { "received_for",        vtype_stringptr,   &received_for },
 683   { "received_ip_address", vtype_stringptr,   &interface_address },
 684   { "received_port",       vtype_int,         &interface_port },
 685   { "received_protocol",   vtype_stringptr,   &received_protocol },
 686   { "received_time",       vtype_int,         &received_time.tv_sec },
 687   { "recipient_data",      vtype_stringptr,   &recipient_data },
 688   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 689   { "recipients",          vtype_string_func, (void *) &fn_recipients },
 690   { "recipients_count",    vtype_int,         &recipients_count },
 691 #ifdef WITH_CONTENT_SCAN
 692   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 693 #endif
 694   { "reply_address",       vtype_reply,       NULL },
 695   { "return_path",         vtype_stringptr,   &return_path },
 696   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 697   { "router_name",         vtype_stringptr,   &router_name },
 698   { "runrc",               vtype_int,         &runrc },
 699   { "self_hostname",       vtype_stringptr,   &self_hostname },
 700   { "sender_address",      vtype_stringptr,   &sender_address },
 701   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 702   { "sender_address_domain", vtype_domain,    &sender_address },
 703   { "sender_address_local_part", vtype_localpart, &sender_address },
 704   { "sender_data",         vtype_stringptr,   &sender_data },
 705   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 706   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 707   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 708   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 709   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 710   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 711   { "sender_host_name",    vtype_host_lookup, NULL },
 712   { "sender_host_port",    vtype_int,         &sender_host_port },
 713   { "sender_ident",        vtype_stringptr,   &sender_ident },
 714   { "sender_rate",         vtype_stringptr,   &sender_rate },
 715   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 716   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 717   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 718   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 719   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 720   { "sending_port",        vtype_int,         &sending_port },
 721   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 722   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 723   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 724   { "smtp_command_history", vtype_string_func, (void *) &smtp_cmd_hist },
 725   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 726   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 727   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 728   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 729   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 730   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 731   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 732   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 733   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 734   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 735   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 736   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 737 #ifdef WITH_CONTENT_SCAN
 738   { "spam_action",         vtype_stringptr,   &spam_action },
 739   { "spam_bar",            vtype_stringptr,   &spam_bar },
 740   { "spam_report",         vtype_stringptr,   &spam_report },
 741   { "spam_score",          vtype_stringptr,   &spam_score },
 742   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 743 #endif
 744 #ifdef SUPPORT_SPF
 745   { "spf_guess",           vtype_stringptr,   &spf_guess },
 746   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 747   { "spf_received",        vtype_stringptr,   &spf_received },
 748   { "spf_result",          vtype_stringptr,   &spf_result },
 749   { "spf_result_guessed",  vtype_bool,        &spf_result_guessed },
 750   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 751 #endif
 752   { "spool_directory",     vtype_stringptr,   &spool_directory },
 753   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 754   { "spool_space",         vtype_pspace,      (void *)TRUE },
 755 #ifdef EXPERIMENTAL_SRS
 756   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 757   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 758   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 759   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 760 #endif
 761 #if defined(EXPERIMENTAL_SRS) || defined(EXPERIMENTAL_SRS_NATIVE)
 762   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 763 #endif
 764 #ifdef EXPERIMENTAL_SRS
 765   { "srs_status",          vtype_stringptr,   &srs_status },
 766 #endif
 767   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 768
 769   /* The non-(in,out) variables are now deprecated */
 770   { "tls_bits",            vtype_int,         &tls_in.bits },
 771   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 772   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 773
 774   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 775   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 776   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 777   { "tls_in_cipher_std",   vtype_stringptr,   &tls_in.cipher_stdname },
 778   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 779   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 780   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 781   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 782 #ifdef EXPERIMENTAL_TLS_RESUME
 783   { "tls_in_resumption",   vtype_int,         &tls_in.resumption },
 784 #endif
 785 #ifndef DISABLE_TLS
 786   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 787 #endif
 788   { "tls_in_ver",          vtype_stringptr,   &tls_in.ver },
 789   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 790   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 791   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 792   { "tls_out_cipher_std",  vtype_stringptr,   &tls_out.cipher_stdname },
 793 #ifdef SUPPORT_DANE
 794   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 795 #endif
 796   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 797   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 798   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 799   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 800 #ifdef EXPERIMENTAL_TLS_RESUME
 801   { "tls_out_resumption",  vtype_int,         &tls_out.resumption },
 802 #endif
 803 #ifndef DISABLE_TLS
 804   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 805 #endif
 806 #ifdef SUPPORT_DANE
 807   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 808 #endif
 809   { "tls_out_ver",         vtype_stringptr,   &tls_out.ver },
 810
 811   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 812 #ifndef DISABLE_TLS
 813   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 814 #endif
 815
 816   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 817   { "tod_epoch",           vtype_tode,        NULL },
 818   { "tod_epoch_l",         vtype_todel,       NULL },
 819   { "tod_full",            vtype_todf,        NULL },
 820   { "tod_log",             vtype_todl,        NULL },
 821   { "tod_logfile",         vtype_todlf,       NULL },
 822   { "tod_zone",            vtype_todzone,     NULL },
 823   { "tod_zulu",            vtype_todzulu,     NULL },
 824   { "transport_name",      vtype_stringptr,   &transport_name },
 825   { "value",               vtype_stringptr,   &lookup_value },
 826   { "verify_mode",         vtype_stringptr,   &verify_mode },
 827   { "version_number",      vtype_stringptr,   &version_string },
 828   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 829   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 830   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 831   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 832   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 833   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 834 };
 835
 836 static int var_table_size = nelem(var_table);
 837 static uschar var_buffer[256];
 838 static BOOL malformed_header;
 839
 840 /* For textual hashes */
 841
 842 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 843                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 844                                "0123456789";
 845
 846 enum { HMAC_MD5, HMAC_SHA1 };
 847
 848 /* For numeric hashes */
 849
 850 static unsigned int prime[] = {
 851   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 852  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 853  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 854
 855 /* For printing modes in symbolic form */
 856
 857 static uschar *mtable_normal[] =
 858   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 859
 860 static uschar *mtable_setid[] =
 861   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 862
 863 static uschar *mtable_sticky[] =
 864   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 865
 866 /* flags for find_header() */
 867 #define FH_EXISTS_ONLY  BIT(0)
 868 #define FH_WANT_RAW     BIT(1)
 869 #define FH_WANT_LIST    BIT(2)
 870
 871
 872 /*************************************************
 873 *           Tables for UTF-8 support             *
 874 *************************************************/
 875
 876 /* Table of the number of extra characters, indexed by the first character
 877 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 878 0x3d. */
 879
 880 static uschar utf8_table1[] = {
 881   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 882   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 883   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 884   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 885
 886 /* These are the masks for the data bits in the first byte of a character,
 887 indexed by the number of additional bytes. */
 888
 889 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 890
 891 /* Get the next UTF-8 character, advancing the pointer. */
 892
 893 #define GETUTF8INC(c, ptr) \
 894   c = *ptr++; \
 895   if ((c & 0xc0) == 0xc0) \
 896     { \
 897     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 898     int s = 6*a; \
 899     c = (c & utf8_table2[a]) << s; \
 900     while (a-- > 0) \
 901       { \
 902       s -= 6; \
 903       c |= (*ptr++ & 0x3f) << s; \
 904       } \
 905     }
 906
 907
 908
 909 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 910
 911 /*************************************************
 912 *           Binary chop search on a table        *
 913 *************************************************/
 914
 915 /* This is used for matching expansion items and operators.
 916
 917 Arguments:
 918   name        the name that is being sought
 919   table       the table to search
 920   table_size  the number of items in the table
 921
 922 Returns:      the offset in the table, or -1
 923 */
 924
 925 static int
 926 chop_match(uschar *name, uschar **table, int table_size)
 927 {
 928 uschar **bot = table;
 929 uschar **top = table + table_size;
 930
 931 while (top > bot)
 932   {
 933   uschar **mid = bot + (top - bot)/2;
 934   int c = Ustrcmp(name, *mid);
 935   if (c == 0) return mid - table;
 936   if (c > 0) bot = mid + 1; else top = mid;
 937   }
 938
 939 return -1;
 940 }
 941
 942
 943
 944 /*************************************************
 945 *          Check a condition string              *
 946 *************************************************/
 947
 948 /* This function is called to expand a string, and test the result for a "true"
 949 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 950 forced fail or lookup defer.
 951
 952 We used to release all store used, but this is not not safe due
 953 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 954 is reasonably careful to release what it can.
 955
 956 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 957
 958 Arguments:
 959   condition     the condition string
 960   m1            text to be incorporated in panic error
 961   m2            ditto
 962
 963 Returns:        TRUE if condition is met, FALSE if not
 964 */
 965
 966 BOOL
 967 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 968 {
 969 uschar * ss = expand_string(condition);
 970 if (!ss)
 971   {
 972   if (!f.expand_string_forcedfail && !f.search_find_defer)
 973     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 974       "for %s %s: %s", condition, m1, m2, expand_string_message);
 975   return FALSE;
 976   }
 977 return *ss && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 978   strcmpic(ss, US"false") != 0;
 979 }
 980
 981
 982
 983
 984 /*************************************************
 985 *        Pseudo-random number generation         *
 986 *************************************************/
 987
 988 /* Pseudo-random number generation.  The result is not "expected" to be
 989 cryptographically strong but not so weak that someone will shoot themselves
 990 in the foot using it as a nonce in some email header scheme or whatever
 991 weirdness they'll twist this into.  The result should ideally handle fork().
 992
 993 However, if we're stuck unable to provide this, then we'll fall back to
 994 appallingly bad randomness.
 995
 996 If DISABLE_TLS is not defined then this will not be used except as an emergency
 997 fallback.
 998
 999 Arguments:
1000   max       range maximum
1001 Returns     a random number in range [0, max-1]
1002 */
1003
1004 #ifndef DISABLE_TLS
1005 # define vaguely_random_number vaguely_random_number_fallback
1006 #endif
1007 int
1008 vaguely_random_number(int max)
1009 {
1010 #ifndef DISABLE_TLS
1011 # undef vaguely_random_number
1012 #endif
1013 static pid_t pid = 0;
1014 pid_t p2;
1015
1016 if ((p2 = getpid()) != pid)
1017   {
1018   if (pid != 0)
1019     {
1020
1021 #ifdef HAVE_ARC4RANDOM
1022     /* cryptographically strong randomness, common on *BSD platforms, not
1023     so much elsewhere.  Alas. */
1024 # ifndef NOT_HAVE_ARC4RANDOM_STIR
1025     arc4random_stir();
1026 # endif
1027 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
1028 # ifdef HAVE_SRANDOMDEV
1029     /* uses random(4) for seeding */
1030     srandomdev();
1031 # else
1032     {
1033     struct timeval tv;
1034     gettimeofday(&tv, NULL);
1035     srandom(tv.tv_sec | tv.tv_usec | getpid());
1036     }
1037 # endif
1038 #else
1039     /* Poor randomness and no seeding here */
1040 #endif
1041
1042     }
1043   pid = p2;
1044   }
1045
1046 #ifdef HAVE_ARC4RANDOM
1047 return arc4random() % max;
1048 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
1049 return random() % max;
1050 #else
1051 /* This one returns a 16-bit number, definitely not crypto-strong */
1052 return random_number(max);
1053 #endif
1054 }
1055
1056
1057
1058
1059 /*************************************************
1060 *             Pick out a name from a string      *
1061 *************************************************/
1062
1063 /* If the name is too long, it is silently truncated.
1064
1065 Arguments:
1066   name      points to a buffer into which to put the name
1067   max       is the length of the buffer
1068   s         points to the first alphabetic character of the name
1069   extras    chars other than alphanumerics to permit
1070
1071 Returns:    pointer to the first character after the name
1072
1073 Note: The test for *s != 0 in the while loop is necessary because
1074 Ustrchr() yields non-NULL if the character is zero (which is not something
1075 I expected). */
1076
1077 static const uschar *
1078 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1079 {
1080 int ptr = 0;
1081 while (*s && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1082   {
1083   if (ptr < max-1) name[ptr++] = *s;
1084   s++;
1085   }
1086 name[ptr] = 0;
1087 return s;
1088 }
1089
1090
1091
1092 /*************************************************
1093 *     Pick out the rest of a header name         *
1094 *************************************************/
1095
1096 /* A variable name starting $header_ (or just $h_ for those who like
1097 abbreviations) might not be the complete header name because headers can
1098 contain any printing characters in their names, except ':'. This function is
1099 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1100 on the end, if the name was terminated by white space.
1101
1102 Arguments:
1103   name      points to a buffer in which the name read so far exists
1104   max       is the length of the buffer
1105   s         points to the first character after the name so far, i.e. the
1106             first non-alphameric character after $header_xxxxx
1107
1108 Returns:    a pointer to the first character after the header name
1109 */
1110
1111 static const uschar *
1112 read_header_name(uschar *name, int max, const uschar *s)
1113 {
1114 int prelen = Ustrchr(name, '_') - name + 1;
1115 int ptr = Ustrlen(name) - prelen;
1116 if (ptr > 0) memmove(name, name+prelen, ptr);
1117 while (mac_isgraph(*s) && *s != ':')
1118   {
1119   if (ptr < max-1) name[ptr++] = *s;
1120   s++;
1121   }
1122 if (*s == ':') s++;
1123 name[ptr++] = ':';
1124 name[ptr] = 0;
1125 return s;
1126 }
1127
1128
1129
1130 /*************************************************
1131 *           Pick out a number from a string      *
1132 *************************************************/
1133
1134 /* Arguments:
1135   n     points to an integer into which to put the number
1136   s     points to the first digit of the number
1137
1138 Returns:  a pointer to the character after the last digit
1139 */
1140 /*XXX consider expanding to int_eximarith_t.  But the test for
1141 "overbig numbers" in 0002 still needs to overflow it. */
1142
1143 static uschar *
1144 read_number(int *n, uschar *s)
1145 {
1146 *n = 0;
1147 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1148 return s;
1149 }
1150
1151 static const uschar *
1152 read_cnumber(int *n, const uschar *s)
1153 {
1154 *n = 0;
1155 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1156 return s;
1157 }
1158
1159
1160
1161 /*************************************************
1162 *        Extract keyed subfield from a string    *
1163 *************************************************/
1164
1165 /* The yield is in dynamic store; NULL means that the key was not found.
1166
1167 Arguments:
1168   key       points to the name of the key
1169   s         points to the string from which to extract the subfield
1170
1171 Returns:    NULL if the subfield was not found, or
1172             a pointer to the subfield's data
1173 */
1174
1175 uschar *
1176 expand_getkeyed(const uschar * key, const uschar * s)
1177 {
1178 int length = Ustrlen(key);
1179 Uskip_whitespace(&s);
1180
1181 /* Loop to search for the key */
1182
1183 while (*s)
1184   {
1185   int dkeylength;
1186   uschar * data;
1187   const uschar * dkey = s;
1188
1189   while (*s && *s != '=' && !isspace(*s)) s++;
1190   dkeylength = s - dkey;
1191   if (Uskip_whitespace(&s) == '=') while (isspace(*++s));
1192
1193   data = string_dequote(&s);
1194   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1195     return data;
1196
1197   Uskip_whitespace(&s);
1198   }
1199
1200 return NULL;
1201 }
1202
1203
1204
1205 static var_entry *
1206 find_var_ent(uschar * name)
1207 {
1208 int first = 0;
1209 int last = var_table_size;
1210
1211 while (last > first)
1212   {
1213   int middle = (first + last)/2;
1214   int c = Ustrcmp(name, var_table[middle].name);
1215
1216   if (c > 0) { first = middle + 1; continue; }
1217   if (c < 0) { last = middle; continue; }
1218   return &var_table[middle];
1219   }
1220 return NULL;
1221 }
1222
1223 /*************************************************
1224 *   Extract numbered subfield from string        *
1225 *************************************************/
1226
1227 /* Extracts a numbered field from a string that is divided by tokens - for
1228 example a line from /etc/passwd is divided by colon characters.  First field is
1229 numbered one.  Negative arguments count from the right. Zero returns the whole
1230 string. Returns NULL if there are insufficient tokens in the string
1231
1232 ***WARNING***
1233 Modifies final argument - this is a dynamically generated string, so that's OK.
1234
1235 Arguments:
1236   field       number of field to be extracted,
1237                 first field = 1, whole string = 0, last field = -1
1238   separators  characters that are used to break string into tokens
1239   s           points to the string from which to extract the subfield
1240
1241 Returns:      NULL if the field was not found,
1242               a pointer to the field's data inside s (modified to add 0)
1243 */
1244
1245 static uschar *
1246 expand_gettokened (int field, uschar *separators, uschar *s)
1247 {
1248 int sep = 1;
1249 int count;
1250 uschar *ss = s;
1251 uschar *fieldtext = NULL;
1252
1253 if (field == 0) return s;
1254
1255 /* Break the line up into fields in place; for field > 0 we stop when we have
1256 done the number of fields we want. For field < 0 we continue till the end of
1257 the string, counting the number of fields. */
1258
1259 count = (field > 0)? field : INT_MAX;
1260
1261 while (count-- > 0)
1262   {
1263   size_t len;
1264
1265   /* Previous field was the last one in the string. For a positive field
1266   number, this means there are not enough fields. For a negative field number,
1267   check that there are enough, and scan back to find the one that is wanted. */
1268
1269   if (sep == 0)
1270     {
1271     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1272     if ((-field) == (INT_MAX - count - 1)) return s;
1273     while (field++ < 0)
1274       {
1275       ss--;
1276       while (ss[-1] != 0) ss--;
1277       }
1278     fieldtext = ss;
1279     break;
1280     }
1281
1282   /* Previous field was not last in the string; save its start and put a
1283   zero at its end. */
1284
1285   fieldtext = ss;
1286   len = Ustrcspn(ss, separators);
1287   sep = ss[len];
1288   ss[len] = 0;
1289   ss += len + 1;
1290   }
1291
1292 return fieldtext;
1293 }
1294
1295
1296 static uschar *
1297 expand_getlistele(int field, const uschar * list)
1298 {
1299 const uschar * tlist = list;
1300 int sep = 0;
1301 uschar dummy;
1302
1303 if (field < 0)
1304   {
1305   for (field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1306   sep = 0;
1307   }
1308 if (field == 0) return NULL;
1309 while (--field > 0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1310 return string_nextinlist(&list, &sep, NULL, 0);
1311 }
1312
1313
1314 /* Certificate fields, by name.  Worry about by-OID later */
1315 /* Names are chosen to not have common prefixes */
1316
1317 #ifndef DISABLE_TLS
1318 typedef struct
1319 {
1320 uschar * name;
1321 int      namelen;
1322 uschar * (*getfn)(void * cert, uschar * mod);
1323 } certfield;
1324 static certfield certfields[] =
1325 {                       /* linear search; no special order */
1326   { US"version",         7,  &tls_cert_version },
1327   { US"serial_number",   13, &tls_cert_serial_number },
1328   { US"subject",         7,  &tls_cert_subject },
1329   { US"notbefore",       9,  &tls_cert_not_before },
1330   { US"notafter",        8,  &tls_cert_not_after },
1331   { US"issuer",          6,  &tls_cert_issuer },
1332   { US"signature",       9,  &tls_cert_signature },
1333   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1334   { US"subj_altname",    12, &tls_cert_subject_altname },
1335   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1336   { US"crl_uri",         7,  &tls_cert_crl_uri },
1337 };
1338
1339 static uschar *
1340 expand_getcertele(uschar * field, uschar * certvar)
1341 {
1342 var_entry * vp;
1343
1344 if (!(vp = find_var_ent(certvar)))
1345   {
1346   expand_string_message =
1347     string_sprintf("no variable named \"%s\"", certvar);
1348   return NULL;          /* Unknown variable name */
1349   }
1350 /* NB this stops us passing certs around in variable.  Might
1351 want to do that in future */
1352 if (vp->type != vtype_cert)
1353   {
1354   expand_string_message =
1355     string_sprintf("\"%s\" is not a certificate", certvar);
1356   return NULL;          /* Unknown variable name */
1357   }
1358 if (!*(void **)vp->value)
1359   return NULL;
1360
1361 if (*field >= '0' && *field <= '9')
1362   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1363
1364 for (certfield * cp = certfields;
1365      cp < certfields + nelem(certfields);
1366      cp++)
1367   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1368     {
1369     uschar * modifier = *(field += cp->namelen) == ','
1370       ? ++field : NULL;
1371     return (*cp->getfn)( *(void **)vp->value, modifier );
1372     }
1373
1374 expand_string_message =
1375   string_sprintf("bad field selector \"%s\" for certextract", field);
1376 return NULL;
1377 }
1378 #endif  /*DISABLE_TLS*/
1379
1380 /*************************************************
1381 *        Extract a substring from a string       *
1382 *************************************************/
1383
1384 /* Perform the ${substr or ${length expansion operations.
1385
1386 Arguments:
1387   subject     the input string
1388   value1      the offset from the start of the input string to the start of
1389                 the output string; if negative, count from the right.
1390   value2      the length of the output string, or negative (-1) for unset
1391                 if value1 is positive, unset means "all after"
1392                 if value1 is negative, unset means "all before"
1393   len         set to the length of the returned string
1394
1395 Returns:      pointer to the output string, or NULL if there is an error
1396 */
1397
1398 static uschar *
1399 extract_substr(uschar *subject, int value1, int value2, int *len)
1400 {
1401 int sublen = Ustrlen(subject);
1402
1403 if (value1 < 0)    /* count from right */
1404   {
1405   value1 += sublen;
1406
1407   /* If the position is before the start, skip to the start, and adjust the
1408   length. If the length ends up negative, the substring is null because nothing
1409   can precede. This falls out naturally when the length is unset, meaning "all
1410   to the left". */
1411
1412   if (value1 < 0)
1413     {
1414     value2 += value1;
1415     if (value2 < 0) value2 = 0;
1416     value1 = 0;
1417     }
1418
1419   /* Otherwise an unset length => characters before value1 */
1420
1421   else if (value2 < 0)
1422     {
1423     value2 = value1;
1424     value1 = 0;
1425     }
1426   }
1427
1428 /* For a non-negative offset, if the starting position is past the end of the
1429 string, the result will be the null string. Otherwise, an unset length means
1430 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1431
1432 else
1433   {
1434   if (value1 > sublen)
1435     {
1436     value1 = sublen;
1437     value2 = 0;
1438     }
1439   else if (value2 < 0) value2 = sublen;
1440   }
1441
1442 /* Cut the length down to the maximum possible for the offset value, and get
1443 the required characters. */
1444
1445 if (value1 + value2 > sublen) value2 = sublen - value1;
1446 *len = value2;
1447 return subject + value1;
1448 }
1449
1450
1451
1452
1453 /*************************************************
1454 *            Old-style hash of a string          *
1455 *************************************************/
1456
1457 /* Perform the ${hash expansion operation.
1458
1459 Arguments:
1460   subject     the input string (an expanded substring)
1461   value1      the length of the output string; if greater or equal to the
1462                 length of the input string, the input string is returned
1463   value2      the number of hash characters to use, or 26 if negative
1464   len         set to the length of the returned string
1465
1466 Returns:      pointer to the output string, or NULL if there is an error
1467 */
1468
1469 static uschar *
1470 compute_hash(uschar *subject, int value1, int value2, int *len)
1471 {
1472 int sublen = Ustrlen(subject);
1473
1474 if (value2 < 0) value2 = 26;
1475 else if (value2 > Ustrlen(hashcodes))
1476   {
1477   expand_string_message =
1478     string_sprintf("hash count \"%d\" too big", value2);
1479   return NULL;
1480   }
1481
1482 /* Calculate the hash text. We know it is shorter than the original string, so
1483 can safely place it in subject[] (we know that subject is always itself an
1484 expanded substring). */
1485
1486 if (value1 < sublen)
1487   {
1488   int c;
1489   int i = 0;
1490   int j = value1;
1491   while ((c = (subject[j])) != 0)
1492     {
1493     int shift = (c + j++) & 7;
1494     subject[i] ^= (c << shift) | (c >> (8-shift));
1495     if (++i >= value1) i = 0;
1496     }
1497   for (i = 0; i < value1; i++)
1498     subject[i] = hashcodes[(subject[i]) % value2];
1499   }
1500 else value1 = sublen;
1501
1502 *len = value1;
1503 return subject;
1504 }
1505
1506
1507
1508
1509 /*************************************************
1510 *             Numeric hash of a string           *
1511 *************************************************/
1512
1513 /* Perform the ${nhash expansion operation. The first characters of the
1514 string are treated as most important, and get the highest prime numbers.
1515
1516 Arguments:
1517   subject     the input string
1518   value1      the maximum value of the first part of the result
1519   value2      the maximum value of the second part of the result,
1520                 or negative to produce only a one-part result
1521   len         set to the length of the returned string
1522
1523 Returns:  pointer to the output string, or NULL if there is an error.
1524 */
1525
1526 static uschar *
1527 compute_nhash (uschar *subject, int value1, int value2, int *len)
1528 {
1529 uschar *s = subject;
1530 int i = 0;
1531 unsigned long int total = 0; /* no overflow */
1532
1533 while (*s != 0)
1534   {
1535   if (i == 0) i = nelem(prime) - 1;
1536   total += prime[i--] * (unsigned int)(*s++);
1537   }
1538
1539 /* If value2 is unset, just compute one number */
1540
1541 if (value2 < 0)
1542   s = string_sprintf("%lu", total % value1);
1543
1544 /* Otherwise do a div/mod hash */
1545
1546 else
1547   {
1548   total = total % (value1 * value2);
1549   s = string_sprintf("%lu/%lu", total/value2, total % value2);
1550   }
1551
1552 *len = Ustrlen(s);
1553 return s;
1554 }
1555
1556
1557
1558
1559
1560 /*************************************************
1561 *     Find the value of a header or headers      *
1562 *************************************************/
1563
1564 /* Multiple instances of the same header get concatenated, and this function
1565 can also return a concatenation of all the header lines. When concatenating
1566 specific headers that contain lists of addresses, a comma is inserted between
1567 them. Otherwise we use a straight concatenation. Because some messages can have
1568 pathologically large number of lines, there is a limit on the length that is
1569 returned.
1570
1571 Arguments:
1572   name          the name of the header, without the leading $header_ or $h_,
1573                 or NULL if a concatenation of all headers is required
1574   newsize       return the size of memory block that was obtained; may be NULL
1575                 if exists_only is TRUE
1576   flags         FH_EXISTS_ONLY
1577                   set if called from a def: test; don't need to build a string;
1578                   just return a string that is not "" and not "0" if the header
1579                   exists
1580                 FH_WANT_RAW
1581                   set if called for $rh_ or $rheader_ items; no processing,
1582                   other than concatenating, will be done on the header. Also used
1583                   for $message_headers_raw.
1584                 FH_WANT_LIST
1585                   Double colon chars in the content, and replace newline with
1586                   colon between each element when concatenating; returning a
1587                   colon-sep list (elements might contain newlines)
1588   charset       name of charset to translate MIME words to; used only if
1589                 want_raw is false; if NULL, no translation is done (this is
1590                 used for $bh_ and $bheader_)
1591
1592 Returns:        NULL if the header does not exist, else a pointer to a new
1593                 store block
1594 */
1595
1596 static uschar *
1597 find_header(uschar *name, int *newsize, unsigned flags, uschar *charset)
1598 {
1599 BOOL found = !name;
1600 int len = name ? Ustrlen(name) : 0;
1601 BOOL comma = FALSE;
1602 gstring * g = NULL;
1603
1604 for (header_line * h = header_list; h; h = h->next)
1605   if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1606     if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1607       {
1608       uschar * s, * t;
1609       size_t inc;
1610
1611       if (flags & FH_EXISTS_ONLY)
1612         return US"1";  /* don't need actual string */
1613
1614       found = TRUE;
1615       s = h->text + len;                /* text to insert */
1616       if (!(flags & FH_WANT_RAW))       /* unless wanted raw, */
1617         Uskip_whitespace(&s);           /* remove leading white space */
1618       t = h->text + h->slen;            /* end-point */
1619
1620       /* Unless wanted raw, remove trailing whitespace, including the
1621       newline. */
1622
1623       if (flags & FH_WANT_LIST)
1624         while (t > s && t[-1] == '\n') t--;
1625       else if (!(flags & FH_WANT_RAW))
1626         {
1627         while (t > s && isspace(t[-1])) t--;
1628
1629         /* Set comma if handling a single header and it's one of those
1630         that contains an address list, except when asked for raw headers. Only
1631         need to do this once. */
1632
1633         if (name && !comma && Ustrchr("BCFRST", h->type)) comma = TRUE;
1634         }
1635
1636       /* Trim the header roughly if we're approaching limits */
1637       inc = t - s;
1638       if (gstring_length(g) + inc > header_insert_maxlen)
1639         inc = header_insert_maxlen - gstring_length(g);
1640
1641       /* For raw just copy the data; for a list, add the data as a colon-sep
1642       list-element; for comma-list add as an unchecked comma,newline sep
1643       list-elemment; for other nonraw add as an unchecked newline-sep list (we
1644       stripped trailing WS above including the newline). We ignore the potential
1645       expansion due to colon-doubling, just leaving the loop if the limit is met
1646       or exceeded. */
1647
1648       if (flags & FH_WANT_LIST)
1649         g = string_append_listele_n(g, ':', s, (unsigned)inc);
1650       else if (flags & FH_WANT_RAW)
1651         g = string_catn(g, s, (unsigned)inc);
1652       else if (inc > 0)
1653         g = string_append2_listele_n(g, comma ? US",\n" : US"\n",
1654           s, (unsigned)inc);
1655
1656       if (gstring_length(g) >= header_insert_maxlen) break;
1657       }
1658
1659 if (!found) return NULL;        /* No header found */
1660 if (!g) return US"";
1661
1662 /* That's all we do for raw header expansion. */
1663
1664 *newsize = g->size;
1665 if (flags & FH_WANT_RAW)
1666   return string_from_gstring(g);
1667
1668 /* Otherwise do RFC 2047 decoding, translating the charset if requested.
1669 The rfc2047_decode2() function can return an error with decoded data if the
1670 charset translation fails. If decoding fails, it returns NULL. */
1671
1672 else
1673   {
1674   uschar * error, * decoded = rfc2047_decode2(string_from_gstring(g),
1675     check_rfc2047_length, charset, '?', NULL, newsize, &error);
1676   if (error)
1677     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1678       "    input was: %s\n", error, g->s);
1679   return decoded ? decoded : string_from_gstring(g);
1680   }
1681 }
1682
1683
1684
1685
1686 /* Append a "local" element to an Authentication-Results: header
1687 if this was a non-smtp message.
1688 */
1689
1690 static gstring *
1691 authres_local(gstring * g, const uschar * sysname)
1692 {
1693 if (!f.authentication_local)
1694   return g;
1695 g = string_append(g, 3, US";\n\tlocal=pass (non-smtp, ", sysname, US")");
1696 if (authenticated_id) g = string_append(g, 2, " u=", authenticated_id);
1697 return g;
1698 }
1699
1700
1701 /* Append an "iprev" element to an Authentication-Results: header
1702 if we have attempted to get the calling host's name.
1703 */
1704
1705 static gstring *
1706 authres_iprev(gstring * g)
1707 {
1708 if (sender_host_name)
1709   g = string_append(g, 3, US";\n\tiprev=pass (", sender_host_name, US")");
1710 else if (host_lookup_deferred)
1711   g = string_catn(g, US";\n\tiprev=temperror", 19);
1712 else if (host_lookup_failed)
1713   g = string_catn(g, US";\n\tiprev=fail", 13);
1714 else
1715   return g;
1716
1717 if (sender_host_address)
1718   g = string_append(g, 2, US" smtp.remote-ip=", sender_host_address);
1719 return g;
1720 }
1721
1722
1723
1724 /*************************************************
1725 *               Return list of recipients        *
1726 *************************************************/
1727 /* A recipients list is available only during system message filtering,
1728 during ACL processing after DATA, and while expanding pipe commands
1729 generated from a system filter, but not elsewhere. */
1730
1731 static uschar *
1732 fn_recipients(void)
1733 {
1734 uschar * s;
1735 gstring * g = NULL;
1736
1737 if (!f.enable_dollar_recipients) return NULL;
1738
1739 for (int i = 0; i < recipients_count; i++)
1740   {
1741   s = recipients_list[i].address;
1742   g = string_append2_listele_n(g, US", ", s, Ustrlen(s));
1743   }
1744 return g ? g->s : NULL;
1745 }
1746
1747
1748 /*************************************************
1749 *               Return size of queue             *
1750 *************************************************/
1751 /* Ask the daemon for the queue size */
1752
1753 static uschar *
1754 fn_queue_size(void)
1755 {
1756 struct sockaddr_un sa_un = {.sun_family = AF_UNIX};
1757 uschar buf[16];
1758 int fd;
1759 ssize_t len;
1760 const uschar * where;
1761 #ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1762 uschar * sname;
1763 #endif
1764 fd_set fds;
1765 struct timeval tv;
1766
1767 if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
1768   {
1769   DEBUG(D_expand) debug_printf(" socket: %s\n", strerror(errno));
1770   return NULL;
1771   }
1772
1773 #ifdef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1774 sa_un.sun_path[0] = 0;  /* Abstract local socket addr - Linux-specific? */
1775 len = offsetof(struct sockaddr_un, sun_path) + 1
1776   + snprintf(sa_un.sun_path+1, sizeof(sa_un.sun_path)-1, "exim_%d", getpid());
1777 #else
1778 sname = string_sprintf("%s/p_%d", spool_directory, getpid());
1779 len = offsetof(struct sockaddr_un, sun_path)
1780   + snprintf(sa_un.sun_path, sizeof(sa_un.sun_path), "%s", sname);
1781 #endif
1782
1783 if (bind(fd, (const struct sockaddr *)&sa_un, len) < 0)
1784   { where = US"bind"; goto bad; }
1785
1786 #ifdef notdef
1787 debug_printf("local addr '%s%s'\n",
1788   *sa_un.sun_path ? "" : "@",
1789   sa_un.sun_path + (*sa_un.sun_path ? 0 : 1));
1790 #endif
1791
1792 #ifdef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1793 sa_un.sun_path[0] = 0;  /* Abstract local socket addr - Linux-specific? */
1794 len = offsetof(struct sockaddr_un, sun_path) + 1
1795   + snprintf(sa_un.sun_path+1, sizeof(sa_un.sun_path)-1, "%s",
1796               expand_string(notifier_socket));
1797 #else
1798 len = offsetof(struct sockaddr_un, sun_path)
1799   + snprintf(sa_un.sun_path, sizeof(sa_un.sun_path), "%s",
1800               expand_string(notifier_socket));
1801 #endif
1802
1803 if (connect(fd, (const struct sockaddr *)&sa_un, len) < 0)
1804   { where = US"connect"; goto bad2; }
1805
1806 buf[0] = NOTIFY_QUEUE_SIZE_REQ;
1807 if (send(fd, buf, 1, 0) < 0) { where = US"send"; goto bad; }
1808
1809 FD_ZERO(&fds); FD_SET(fd, &fds);
1810 tv.tv_sec = 2; tv.tv_usec = 0;
1811 if (select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tv) != 1)
1812   {
1813   DEBUG(D_expand) debug_printf("no daemon response; using local evaluation\n");
1814   len = snprintf(CS buf, sizeof(buf), "%u", queue_count_cached());
1815   }
1816 else if ((len = recv(fd, buf, sizeof(buf), 0)) < 0)
1817   { where = US"recv"; goto bad2; }
1818
1819 close(fd);
1820 #ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1821 Uunlink(sname);
1822 #endif
1823 return string_copyn(buf, len);
1824
1825 bad2:
1826 #ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1827   Uunlink(sname);
1828 #endif
1829 bad:
1830   close(fd);
1831   DEBUG(D_expand) debug_printf(" %s: %s\n", where, strerror(errno));
1832   return NULL;
1833 }
1834
1835
1836 /*************************************************
1837 *               Find value of a variable         *
1838 *************************************************/
1839
1840 /* The table of variables is kept in alphabetic order, so we can search it
1841 using a binary chop. The "choplen" variable is nothing to do with the binary
1842 chop.
1843
1844 Arguments:
1845   name          the name of the variable being sought
1846   exists_only   TRUE if this is a def: test; passed on to find_header()
1847   skipping      TRUE => skip any processing evaluation; this is not the same as
1848                   exists_only because def: may test for values that are first
1849                   evaluated here
1850   newsize       pointer to an int which is initially zero; if the answer is in
1851                 a new memory buffer, *newsize is set to its size
1852
1853 Returns:        NULL if the variable does not exist, or
1854                 a pointer to the variable's contents, or
1855                 something non-NULL if exists_only is TRUE
1856 */
1857
1858 static uschar *
1859 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1860 {
1861 var_entry * vp;
1862 uschar *s, *domain;
1863 uschar **ss;
1864 void * val;
1865
1866 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1867 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1868 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1869 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1870 (this gave backwards compatibility at the changeover). There may be built-in
1871 variables whose names start acl_ but they should never start in this way. This
1872 slightly messy specification is a consequence of the history, needless to say.
1873
1874 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1875 set, in which case give an error. */
1876
1877 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1878      !isalpha(name[5]))
1879   {
1880   tree_node * node =
1881     tree_search(name[4] == 'c' ? acl_var_c : acl_var_m, name + 4);
1882   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1883   }
1884 else if (Ustrncmp(name, "r_", 2) == 0)
1885   {
1886   tree_node * node = tree_search(router_var, name + 2);
1887   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1888   }
1889
1890 /* Handle $auth<n> variables. */
1891
1892 if (Ustrncmp(name, "auth", 4) == 0)
1893   {
1894   uschar *endptr;
1895   int n = Ustrtoul(name + 4, &endptr, 10);
1896   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1897     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1898   }
1899 else if (Ustrncmp(name, "regex", 5) == 0)
1900   {
1901   uschar *endptr;
1902   int n = Ustrtoul(name + 5, &endptr, 10);
1903   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1904     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1905   }
1906
1907 /* For all other variables, search the table */
1908
1909 if (!(vp = find_var_ent(name)))
1910   return NULL;          /* Unknown variable name */
1911
1912 /* Found an existing variable. If in skipping state, the value isn't needed,
1913 and we want to avoid processing (such as looking up the host name). */
1914
1915 if (skipping)
1916   return US"";
1917
1918 val = vp->value;
1919 switch (vp->type)
1920   {
1921   case vtype_filter_int:
1922     if (!f.filter_running) return NULL;
1923     /* Fall through */
1924     /* VVVVVVVVVVVV */
1925   case vtype_int:
1926     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1927     return var_buffer;
1928
1929   case vtype_ino:
1930     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1931     return var_buffer;
1932
1933   case vtype_gid:
1934     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1935     return var_buffer;
1936
1937   case vtype_uid:
1938     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1939     return var_buffer;
1940
1941   case vtype_bool:
1942     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1943     return var_buffer;
1944
1945   case vtype_stringptr:                      /* Pointer to string */
1946     return (s = *((uschar **)(val))) ? s : US"";
1947
1948   case vtype_pid:
1949     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1950     return var_buffer;
1951
1952   case vtype_load_avg:
1953     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1954     return var_buffer;
1955
1956   case vtype_host_lookup:                    /* Lookup if not done so */
1957     if (  !sender_host_name && sender_host_address
1958        && !host_lookup_failed && host_name_lookup() == OK)
1959       host_build_sender_fullhost();
1960     return sender_host_name ? sender_host_name : US"";
1961
1962   case vtype_localpart:                      /* Get local part from address */
1963     if (!(s = *((uschar **)(val)))) return US"";
1964     if (!(domain = Ustrrchr(s, '@'))) return s;
1965     if (domain - s > sizeof(var_buffer) - 1)
1966       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1967           " in string expansion", sizeof(var_buffer));
1968     return string_copyn(s, domain - s);
1969
1970   case vtype_domain:                         /* Get domain from address */
1971     if (!(s = *((uschar **)(val)))) return US"";
1972     domain = Ustrrchr(s, '@');
1973     return domain ? domain + 1 : US"";
1974
1975   case vtype_msgheaders:
1976     return find_header(NULL, newsize, exists_only ? FH_EXISTS_ONLY : 0, NULL);
1977
1978   case vtype_msgheaders_raw:
1979     return find_header(NULL, newsize,
1980                 exists_only ? FH_EXISTS_ONLY|FH_WANT_RAW : FH_WANT_RAW, NULL);
1981
1982   case vtype_msgbody:                        /* Pointer to msgbody string */
1983   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1984     ss = (uschar **)(val);
1985     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1986       {
1987       uschar *body;
1988       off_t start_offset = SPOOL_DATA_START_OFFSET;
1989       int len = message_body_visible;
1990       if (len > message_size) len = message_size;
1991       *ss = body = store_malloc(len+1);
1992       body[0] = 0;
1993       if (vp->type == vtype_msgbody_end)
1994         {
1995         struct stat statbuf;
1996         if (fstat(deliver_datafile, &statbuf) == 0)
1997           {
1998           start_offset = statbuf.st_size - len;
1999           if (start_offset < SPOOL_DATA_START_OFFSET)
2000             start_offset = SPOOL_DATA_START_OFFSET;
2001           }
2002         }
2003       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
2004         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
2005           strerror(errno));
2006       len = read(deliver_datafile, body, len);
2007       if (len > 0)
2008         {
2009         body[len] = 0;
2010         if (message_body_newlines)   /* Separate loops for efficiency */
2011           while (len > 0)
2012             { if (body[--len] == 0) body[len] = ' '; }
2013         else
2014           while (len > 0)
2015             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
2016         }
2017       }
2018     return *ss ? *ss : US"";
2019
2020   case vtype_todbsdin:                       /* BSD inbox time of day */
2021     return tod_stamp(tod_bsdin);
2022
2023   case vtype_tode:                           /* Unix epoch time of day */
2024     return tod_stamp(tod_epoch);
2025
2026   case vtype_todel:                          /* Unix epoch/usec time of day */
2027     return tod_stamp(tod_epoch_l);
2028
2029   case vtype_todf:                           /* Full time of day */
2030     return tod_stamp(tod_full);
2031
2032   case vtype_todl:                           /* Log format time of day */
2033     return tod_stamp(tod_log_bare);            /* (without timezone) */
2034
2035   case vtype_todzone:                        /* Time zone offset only */
2036     return tod_stamp(tod_zone);
2037
2038   case vtype_todzulu:                        /* Zulu time */
2039     return tod_stamp(tod_zulu);
2040
2041   case vtype_todlf:                          /* Log file datestamp tod */
2042     return tod_stamp(tod_log_datestamp_daily);
2043
2044   case vtype_reply:                          /* Get reply address */
2045     s = find_header(US"reply-to:", newsize,
2046                 exists_only ? FH_EXISTS_ONLY|FH_WANT_RAW : FH_WANT_RAW,
2047                 headers_charset);
2048     if (s) Uskip_whitespace(&s);
2049     if (!s || !*s)
2050       {
2051       *newsize = 0;                            /* For the *s==0 case */
2052       s = find_header(US"from:", newsize,
2053                 exists_only ? FH_EXISTS_ONLY|FH_WANT_RAW : FH_WANT_RAW,
2054                 headers_charset);
2055       }
2056     if (s)
2057       {
2058       uschar *t;
2059       Uskip_whitespace(&s);
2060       for (t = s; *t; t++) if (*t == '\n') *t = ' ';
2061       while (t > s && isspace(t[-1])) t--;
2062       *t = 0;
2063       }
2064     return s ? s : US"";
2065
2066   case vtype_string_func:
2067     {
2068     stringptr_fn_t * fn = (stringptr_fn_t *) val;
2069     return fn();
2070     }
2071
2072   case vtype_pspace:
2073     {
2074     int inodes;
2075     sprintf(CS var_buffer, PR_EXIM_ARITH,
2076       receive_statvfs(val == (void *)TRUE, &inodes));
2077     }
2078   return var_buffer;
2079
2080   case vtype_pinodes:
2081     {
2082     int inodes;
2083     (void) receive_statvfs(val == (void *)TRUE, &inodes);
2084     sprintf(CS var_buffer, "%d", inodes);
2085     }
2086   return var_buffer;
2087
2088   case vtype_cert:
2089     return *(void **)val ? US"<cert>" : US"";
2090
2091 #ifndef DISABLE_DKIM
2092   case vtype_dkim:
2093     return dkim_exim_expand_query((int)(long)val);
2094 #endif
2095
2096   }
2097
2098 return NULL;  /* Unknown variable. Silences static checkers. */
2099 }
2100
2101
2102
2103
2104 void
2105 modify_variable(uschar *name, void * value)
2106 {
2107 var_entry * vp;
2108 if ((vp = find_var_ent(name))) vp->value = value;
2109 return;          /* Unknown variable name, fail silently */
2110 }
2111
2112
2113
2114
2115
2116
2117 /*************************************************
2118 *           Read and expand substrings           *
2119 *************************************************/
2120
2121 /* This function is called to read and expand argument substrings for various
2122 expansion items. Some have a minimum requirement that is less than the maximum;
2123 in these cases, the first non-present one is set to NULL.
2124
2125 Arguments:
2126   sub        points to vector of pointers to set
2127   n          maximum number of substrings
2128   m          minimum required
2129   sptr       points to current string pointer
2130   skipping   the skipping flag
2131   check_end  if TRUE, check for final '}'
2132   name       name of item, for error message
2133   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
2134              the store.
2135
2136 Returns:     0 OK; string pointer updated
2137              1 curly bracketing error (too few arguments)
2138              2 too many arguments (only if check_end is set); message set
2139              3 other error (expansion failure)
2140 */
2141
2142 static int
2143 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
2144   BOOL check_end, uschar *name, BOOL *resetok)
2145 {
2146 const uschar *s = *sptr;
2147
2148 Uskip_whitespace(&s);
2149 for (int i = 0; i < n; i++)
2150   {
2151   if (*s != '{')
2152     {
2153     if (i < m)
2154       {
2155       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2156         "(min is %d)", name, m);
2157       return 1;
2158       }
2159     sub[i] = NULL;
2160     break;
2161     }
2162   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2163     return 3;
2164   if (*s++ != '}') return 1;
2165   Uskip_whitespace(&s);
2166   }
2167 if (check_end && *s++ != '}')
2168   {
2169   if (s[-1] == '{')
2170     {
2171     expand_string_message = string_sprintf("Too many arguments for '%s' "
2172       "(max is %d)", name, n);
2173     return 2;
2174     }
2175   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2176   return 1;
2177   }
2178
2179 *sptr = s;
2180 return 0;
2181 }
2182
2183
2184
2185
2186 /*************************************************
2187 *     Elaborate message for bad variable         *
2188 *************************************************/
2189
2190 /* For the "unknown variable" message, take a look at the variable's name, and
2191 give additional information about possible ACL variables. The extra information
2192 is added on to expand_string_message.
2193
2194 Argument:   the name of the variable
2195 Returns:    nothing
2196 */
2197
2198 static void
2199 check_variable_error_message(uschar *name)
2200 {
2201 if (Ustrncmp(name, "acl_", 4) == 0)
2202   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2203     (name[4] == 'c' || name[4] == 'm')?
2204       (isalpha(name[5])?
2205         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2206         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2207       ) :
2208       US"user-defined ACL variables must start acl_c or acl_m");
2209 }
2210
2211
2212
2213 /*
2214 Load args from sub array to globals, and call acl_check().
2215 Sub array will be corrupted on return.
2216
2217 Returns:       OK         access is granted by an ACCEPT verb
2218                DISCARD    access is (apparently) granted by a DISCARD verb
2219                FAIL       access is denied
2220                FAIL_DROP  access is denied; drop the connection
2221                DEFER      can't tell at the moment
2222                ERROR      disaster
2223 */
2224 static int
2225 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2226 {
2227 int i;
2228 int sav_narg = acl_narg;
2229 int ret;
2230 uschar * dummy_logmsg;
2231 extern int acl_where;
2232
2233 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2234 for (i = 0; i < nsub && sub[i+1]; i++)
2235   {
2236   uschar * tmp = acl_arg[i];
2237   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2238   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2239   }
2240 acl_narg = i;
2241 while (i < nsub)
2242   {
2243   sub[i+1] = acl_arg[i];
2244   acl_arg[i++] = NULL;
2245   }
2246
2247 DEBUG(D_expand)
2248   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2249     sub[0],
2250     acl_narg>0 ? acl_arg[0] : US"<none>",
2251     acl_narg>1 ? " +more"   : "");
2252
2253 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2254
2255 for (i = 0; i < nsub; i++)
2256   acl_arg[i] = sub[i+1];        /* restore old args */
2257 acl_narg = sav_narg;
2258
2259 return ret;
2260 }
2261
2262
2263
2264
2265 /* Return pointer to dewrapped string, with enclosing specified chars removed.
2266 The given string is modified on return.  Leading whitespace is skipped while
2267 looking for the opening wrap character, then the rest is scanned for the trailing
2268 (non-escaped) wrap character.  A backslash in the string will act as an escape.
2269
2270 A nul is written over the trailing wrap, and a pointer to the char after the
2271 leading wrap is returned.
2272
2273 Arguments:
2274   s     String for de-wrapping
2275   wrap  Two-char string, the first being the opener, second the closer wrapping
2276         character
2277 Return:
2278   Pointer to de-wrapped string, or NULL on error (with expand_string_message set).
2279 */
2280
2281 static uschar *
2282 dewrap(uschar * s, const uschar * wrap)
2283 {
2284 uschar * p = s;
2285 unsigned depth = 0;
2286 BOOL quotesmode = wrap[0] == wrap[1];
2287
2288 if (Uskip_whitespace(&p) == *wrap)
2289   {
2290   s = ++p;
2291   wrap++;
2292   while (*p)
2293     {
2294     if (*p == '\\') p++;
2295     else if (!quotesmode && *p == wrap[-1]) depth++;
2296     else if (*p == *wrap)
2297       if (depth == 0)
2298         {
2299         *p = '\0';
2300         return s;
2301         }
2302       else
2303         depth--;
2304     p++;
2305     }
2306   }
2307 expand_string_message = string_sprintf("missing '%c'", *wrap);
2308 return NULL;
2309 }
2310
2311
2312 /* Pull off the leading array or object element, returning
2313 a copy in an allocated string.  Update the list pointer.
2314
2315 The element may itself be an abject or array.
2316 Return NULL when the list is empty.
2317 */
2318
2319 static uschar *
2320 json_nextinlist(const uschar ** list)
2321 {
2322 unsigned array_depth = 0, object_depth = 0;
2323 const uschar * s = *list, * item;
2324
2325 skip_whitespace(&s);
2326
2327 for (item = s;
2328      *s && (*s != ',' || array_depth != 0 || object_depth != 0);
2329      s++)
2330   switch (*s)
2331     {
2332     case '[': array_depth++; break;
2333     case ']': array_depth--; break;
2334     case '{': object_depth++; break;
2335     case '}': object_depth--; break;
2336     }
2337 *list = *s ? s+1 : s;
2338 if (item == s) return NULL;
2339 item = string_copyn(item, s - item);
2340 DEBUG(D_expand) debug_printf_indent("  json ele: '%s'\n", item);
2341 return US item;
2342 }
2343
2344
2345
2346 /************************************************/
2347 /*  Return offset in ops table, or -1 if not found.
2348 Repoint to just after the operator in the string.
2349
2350 Argument:
2351  ss     string representation of operator
2352  opname split-out operator name
2353 */
2354
2355 static int
2356 identify_operator(const uschar ** ss, uschar ** opname)
2357 {
2358 const uschar * s = *ss;
2359 uschar name[256];
2360
2361 /* Numeric comparisons are symbolic */
2362
2363 if (*s == '=' || *s == '>' || *s == '<')
2364   {
2365   int p = 0;
2366   name[p++] = *s++;
2367   if (*s == '=')
2368     {
2369     name[p++] = '=';
2370     s++;
2371     }
2372   name[p] = 0;
2373   }
2374
2375 /* All other conditions are named */
2376
2377 else
2378   s = read_name(name, sizeof(name), s, US"_");
2379 *ss = s;
2380
2381 /* If we haven't read a name, it means some non-alpha character is first. */
2382
2383 if (!name[0])
2384   {
2385   expand_string_message = string_sprintf("condition name expected, "
2386     "but found \"%.16s\"", s);
2387   return -1;
2388   }
2389 if (opname)
2390   *opname = string_copy(name);
2391
2392 return chop_match(name, cond_table, nelem(cond_table));
2393 }
2394
2395
2396 /*************************************************
2397 *    Handle MD5 or SHA-1 computation for HMAC    *
2398 *************************************************/
2399
2400 /* These are some wrapping functions that enable the HMAC code to be a bit
2401 cleaner. A good compiler will spot the tail recursion.
2402
2403 Arguments:
2404   type         HMAC_MD5 or HMAC_SHA1
2405   remaining    are as for the cryptographic hash functions
2406
2407 Returns:       nothing
2408 */
2409
2410 static void
2411 chash_start(int type, void * base)
2412 {
2413 if (type == HMAC_MD5)
2414   md5_start((md5 *)base);
2415 else
2416   sha1_start((hctx *)base);
2417 }
2418
2419 static void
2420 chash_mid(int type, void * base, const uschar * string)
2421 {
2422 if (type == HMAC_MD5)
2423   md5_mid((md5 *)base, string);
2424 else
2425   sha1_mid((hctx *)base, string);
2426 }
2427
2428 static void
2429 chash_end(int type, void * base, const uschar * string, int length,
2430   uschar * digest)
2431 {
2432 if (type == HMAC_MD5)
2433   md5_end((md5 *)base, string, length, digest);
2434 else
2435   sha1_end((hctx *)base, string, length, digest);
2436 }
2437
2438
2439
2440
2441 #ifdef EXPERIMENTAL_SRS_NATIVE
2442 /* Do an hmac_md5.  The result is _not_ nul-terminated, and is sized as
2443 the smaller of a full hmac_md5 result (16 bytes) or the supplied output buffer.
2444
2445 Arguments:
2446         key     encoding key, nul-terminated
2447         src     data to be hashed, nul-terminated
2448         buf     output buffer
2449         len     size of output buffer
2450 */
2451
2452 static void
2453 hmac_md5(const uschar * key, const uschar * src, uschar * buf, unsigned len)
2454 {
2455 md5 md5_base;
2456 const uschar * keyptr;
2457 uschar * p;
2458 unsigned int keylen;
2459
2460 #define MD5_HASHLEN      16
2461 #define MD5_HASHBLOCKLEN 64
2462
2463 uschar keyhash[MD5_HASHLEN];
2464 uschar innerhash[MD5_HASHLEN];
2465 uschar finalhash[MD5_HASHLEN];
2466 uschar innerkey[MD5_HASHBLOCKLEN];
2467 uschar outerkey[MD5_HASHBLOCKLEN];
2468
2469 keyptr = key;
2470 keylen = Ustrlen(keyptr);
2471
2472 /* If the key is longer than the hash block length, then hash the key
2473 first */
2474
2475 if (keylen > MD5_HASHBLOCKLEN)
2476   {
2477   chash_start(HMAC_MD5, &md5_base);
2478   chash_end(HMAC_MD5, &md5_base, keyptr, keylen, keyhash);
2479   keyptr = keyhash;
2480   keylen = MD5_HASHLEN;
2481   }
2482
2483 /* Now make the inner and outer key values */
2484
2485 memset(innerkey, 0x36, MD5_HASHBLOCKLEN);
2486 memset(outerkey, 0x5c, MD5_HASHBLOCKLEN);
2487
2488 for (int i = 0; i < keylen; i++)
2489   {
2490   innerkey[i] ^= keyptr[i];
2491   outerkey[i] ^= keyptr[i];
2492   }
2493
2494 /* Now do the hashes */
2495
2496 chash_start(HMAC_MD5, &md5_base);
2497 chash_mid(HMAC_MD5, &md5_base, innerkey);
2498 chash_end(HMAC_MD5, &md5_base, src, Ustrlen(src), innerhash);
2499
2500 chash_start(HMAC_MD5, &md5_base);
2501 chash_mid(HMAC_MD5, &md5_base, outerkey);
2502 chash_end(HMAC_MD5, &md5_base, innerhash, MD5_HASHLEN, finalhash);
2503
2504 /* Encode the final hash as a hex string, limited by output buffer size */
2505
2506 p = buf;
2507 for (int i = 0, j = len; i < MD5_HASHLEN; i++)
2508   {
2509   if (j-- <= 0) break;
2510   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
2511   if (j-- <= 0) break;
2512   *p++ = hex_digits[finalhash[i] & 0x0f];
2513   }
2514 return;
2515 }
2516 #endif /*EXPERIMENTAL_SRS_NATIVE*/
2517
2518
2519 /*************************************************
2520 *        Read and evaluate a condition           *
2521 *************************************************/
2522
2523 /*
2524 Arguments:
2525   s        points to the start of the condition text
2526   resetok  points to a BOOL which is written false if it is unsafe to
2527            free memory. Certain condition types (acl) may have side-effect
2528            allocation which must be preserved.
2529   yield    points to a BOOL to hold the result of the condition test;
2530            if NULL, we are just reading through a condition that is
2531            part of an "or" combination to check syntax, or in a state
2532            where the answer isn't required
2533
2534 Returns:   a pointer to the first character after the condition, or
2535            NULL after an error
2536 */
2537
2538 static const uschar *
2539 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2540 {
2541 BOOL testfor = TRUE;
2542 BOOL tempcond, combined_cond;
2543 BOOL *subcondptr;
2544 BOOL sub2_honour_dollar = TRUE;
2545 BOOL is_forany, is_json, is_jsons;
2546 int rc, cond_type, roffset;
2547 int_eximarith_t num[2];
2548 struct stat statbuf;
2549 uschar * opname;
2550 uschar name[256];
2551 const uschar *sub[10];
2552
2553 const pcre *re;
2554 const uschar *rerror;
2555
2556 for (;;)
2557   if (Uskip_whitespace(&s) == '!') { testfor = !testfor; s++; } else break;
2558
2559 switch(cond_type = identify_operator(&s, &opname))
2560   {
2561   /* def: tests for a non-empty variable, or for the existence of a header. If
2562   yield == NULL we are in a skipping state, and don't care about the answer. */
2563
2564   case ECOND_DEF:
2565     {
2566     uschar * t;
2567
2568     if (*s != ':')
2569       {
2570       expand_string_message = US"\":\" expected after \"def\"";
2571       return NULL;
2572       }
2573
2574     s = read_name(name, sizeof(name), s+1, US"_");
2575
2576     /* Test for a header's existence. If the name contains a closing brace
2577     character, this may be a user error where the terminating colon has been
2578     omitted. Set a flag to adjust a subsequent error message in this case. */
2579
2580     if (  ( *(t = name) == 'h'
2581           || (*t == 'r' || *t == 'l' || *t == 'b') && *++t == 'h'
2582           )
2583        && (*++t == '_' || Ustrncmp(t, "eader_", 6) == 0)
2584        )
2585       {
2586       s = read_header_name(name, sizeof(name), s);
2587       /* {-for-text-editors */
2588       if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2589       if (yield) *yield =
2590         (find_header(name, NULL, FH_EXISTS_ONLY, NULL) != NULL) == testfor;
2591       }
2592
2593     /* Test for a variable's having a non-empty value. A non-existent variable
2594     causes an expansion failure. */
2595
2596     else
2597       {
2598       if (!(t = find_variable(name, TRUE, yield == NULL, NULL)))
2599         {
2600         expand_string_message = name[0]
2601           ? string_sprintf("unknown variable \"%s\" after \"def:\"", name)
2602           : US"variable name omitted after \"def:\"";
2603         check_variable_error_message(name);
2604         return NULL;
2605         }
2606       if (yield) *yield = (t[0] != 0) == testfor;
2607       }
2608
2609     return s;
2610     }
2611
2612
2613   /* first_delivery tests for first delivery attempt */
2614
2615   case ECOND_FIRST_DELIVERY:
2616   if (yield) *yield = f.deliver_firsttime == testfor;
2617   return s;
2618
2619
2620   /* queue_running tests for any process started by a queue runner */
2621
2622   case ECOND_QUEUE_RUNNING:
2623   if (yield) *yield = (queue_run_pid != (pid_t)0) == testfor;
2624   return s;
2625
2626
2627   /* exists:  tests for file existence
2628        isip:  tests for any IP address
2629       isip4:  tests for an IPv4 address
2630       isip6:  tests for an IPv6 address
2631         pam:  does PAM authentication
2632      radius:  does RADIUS authentication
2633    ldapauth:  does LDAP authentication
2634     pwcheck:  does Cyrus SASL pwcheck authentication
2635   */
2636
2637   case ECOND_EXISTS:
2638   case ECOND_ISIP:
2639   case ECOND_ISIP4:
2640   case ECOND_ISIP6:
2641   case ECOND_PAM:
2642   case ECOND_RADIUS:
2643   case ECOND_LDAPAUTH:
2644   case ECOND_PWCHECK:
2645
2646   if (Uskip_whitespace(&s) != '{') goto COND_FAILED_CURLY_START; /* }-for-text-editors */
2647
2648   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2649   if (!sub[0]) return NULL;
2650   /* {-for-text-editors */
2651   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2652
2653   if (!yield) return s;   /* No need to run the test if skipping */
2654
2655   switch(cond_type)
2656     {
2657     case ECOND_EXISTS:
2658     if ((expand_forbid & RDO_EXISTS) != 0)
2659       {
2660       expand_string_message = US"File existence tests are not permitted";
2661       return NULL;
2662       }
2663     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2664     break;
2665
2666     case ECOND_ISIP:
2667     case ECOND_ISIP4:
2668     case ECOND_ISIP6:
2669     rc = string_is_ip_address(sub[0], NULL);
2670     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2671              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2672     break;
2673
2674     /* Various authentication tests - all optionally compiled */
2675
2676     case ECOND_PAM:
2677     #ifdef SUPPORT_PAM
2678     rc = auth_call_pam(sub[0], &expand_string_message);
2679     goto END_AUTH;
2680     #else
2681     goto COND_FAILED_NOT_COMPILED;
2682     #endif  /* SUPPORT_PAM */
2683
2684     case ECOND_RADIUS:
2685     #ifdef RADIUS_CONFIG_FILE
2686     rc = auth_call_radius(sub[0], &expand_string_message);
2687     goto END_AUTH;
2688     #else
2689     goto COND_FAILED_NOT_COMPILED;
2690     #endif  /* RADIUS_CONFIG_FILE */
2691
2692     case ECOND_LDAPAUTH:
2693     #ifdef LOOKUP_LDAP
2694       {
2695       /* Just to keep the interface the same */
2696       BOOL do_cache;
2697       int old_pool = store_pool;
2698       store_pool = POOL_SEARCH;
2699       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2700         &expand_string_message, &do_cache);
2701       store_pool = old_pool;
2702       }
2703     goto END_AUTH;
2704     #else
2705     goto COND_FAILED_NOT_COMPILED;
2706     #endif  /* LOOKUP_LDAP */
2707
2708     case ECOND_PWCHECK:
2709     #ifdef CYRUS_PWCHECK_SOCKET
2710     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2711     goto END_AUTH;
2712     #else
2713     goto COND_FAILED_NOT_COMPILED;
2714     #endif  /* CYRUS_PWCHECK_SOCKET */
2715
2716     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2717         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2718     END_AUTH:
2719     if (rc == ERROR || rc == DEFER) return NULL;
2720     *yield = (rc == OK) == testfor;
2721     #endif
2722     }
2723   return s;
2724
2725
2726   /* call ACL (in a conditional context).  Accept true, deny false.
2727   Defer is a forced-fail.  Anything set by message= goes to $value.
2728   Up to ten parameters are used; we use the braces round the name+args
2729   like the saslauthd condition does, to permit a variable number of args.
2730   See also the expansion-item version EITEM_ACL and the traditional
2731   acl modifier ACLC_ACL.
2732   Since the ACL may allocate new global variables, tell our caller to not
2733   reclaim memory.
2734   */
2735
2736   case ECOND_ACL:
2737     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2738     {
2739     uschar *sub[10];
2740     uschar *user_msg;
2741     BOOL cond = FALSE;
2742
2743     Uskip_whitespace(&s);
2744     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2745
2746     switch(read_subs(sub, nelem(sub), 1,
2747       &s, yield == NULL, TRUE, name, resetok))
2748       {
2749       case 1: expand_string_message = US"too few arguments or bracketing "
2750         "error for acl";
2751       case 2:
2752       case 3: return NULL;
2753       }
2754
2755     if (yield)
2756       {
2757       int rc;
2758       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2759       switch(rc = eval_acl(sub, nelem(sub), &user_msg))
2760         {
2761         case OK:
2762           cond = TRUE;
2763         case FAIL:
2764           lookup_value = NULL;
2765           if (user_msg)
2766             lookup_value = string_copy(user_msg);
2767           *yield = cond == testfor;
2768           break;
2769
2770         case DEFER:
2771           f.expand_string_forcedfail = TRUE;
2772           /*FALLTHROUGH*/
2773         default:
2774           expand_string_message = string_sprintf("%s from acl \"%s\"",
2775             rc_names[rc], sub[0]);
2776           return NULL;
2777         }
2778       }
2779     return s;
2780     }
2781
2782
2783   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2784
2785      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2786
2787   However, the last two are optional. That is why the whole set is enclosed
2788   in their own set of braces. */
2789
2790   case ECOND_SASLAUTHD:
2791 #ifndef CYRUS_SASLAUTHD_SOCKET
2792     goto COND_FAILED_NOT_COMPILED;
2793 #else
2794     {
2795     uschar *sub[4];
2796     Uskip_whitespace(&s);
2797     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2798     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, name,
2799                     resetok))
2800       {
2801       case 1: expand_string_message = US"too few arguments or bracketing "
2802         "error for saslauthd";
2803       case 2:
2804       case 3: return NULL;
2805       }
2806     if (!sub[2]) sub[3] = NULL;  /* realm if no service */
2807     if (yield)
2808       {
2809       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2810         &expand_string_message);
2811       if (rc == ERROR || rc == DEFER) return NULL;
2812       *yield = (rc == OK) == testfor;
2813       }
2814     return s;
2815     }
2816 #endif /* CYRUS_SASLAUTHD_SOCKET */
2817
2818
2819   /* symbolic operators for numeric and string comparison, and a number of
2820   other operators, all requiring two arguments.
2821
2822   crypteq:           encrypts plaintext and compares against an encrypted text,
2823                        using crypt(), crypt16(), MD5 or SHA-1
2824   inlist/inlisti:    checks if first argument is in the list of the second
2825   match:             does a regular expression match and sets up the numerical
2826                        variables if it succeeds
2827   match_address:     matches in an address list
2828   match_domain:      matches in a domain list
2829   match_ip:          matches a host list that is restricted to IP addresses
2830   match_local_part:  matches in a local part list
2831   */
2832
2833   case ECOND_MATCH_ADDRESS:
2834   case ECOND_MATCH_DOMAIN:
2835   case ECOND_MATCH_IP:
2836   case ECOND_MATCH_LOCAL_PART:
2837 #ifndef EXPAND_LISTMATCH_RHS
2838     sub2_honour_dollar = FALSE;
2839 #endif
2840     /* FALLTHROUGH */
2841
2842   case ECOND_CRYPTEQ:
2843   case ECOND_INLIST:
2844   case ECOND_INLISTI:
2845   case ECOND_MATCH:
2846
2847   case ECOND_NUM_L:     /* Numerical comparisons */
2848   case ECOND_NUM_LE:
2849   case ECOND_NUM_E:
2850   case ECOND_NUM_EE:
2851   case ECOND_NUM_G:
2852   case ECOND_NUM_GE:
2853
2854   case ECOND_STR_LT:    /* String comparisons */
2855   case ECOND_STR_LTI:
2856   case ECOND_STR_LE:
2857   case ECOND_STR_LEI:
2858   case ECOND_STR_EQ:
2859   case ECOND_STR_EQI:
2860   case ECOND_STR_GT:
2861   case ECOND_STR_GTI:
2862   case ECOND_STR_GE:
2863   case ECOND_STR_GEI:
2864
2865   for (int i = 0; i < 2; i++)
2866     {
2867     /* Sometimes, we don't expand substrings; too many insecure configurations
2868     created using match_address{}{} and friends, where the second param
2869     includes information from untrustworthy sources. */
2870     BOOL honour_dollar = TRUE;
2871     if ((i > 0) && !sub2_honour_dollar)
2872       honour_dollar = FALSE;
2873
2874     if (Uskip_whitespace(&s) != '{')
2875       {
2876       if (i == 0) goto COND_FAILED_CURLY_START;
2877       expand_string_message = string_sprintf("missing 2nd string in {} "
2878         "after \"%s\"", opname);
2879       return NULL;
2880       }
2881     if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2882         honour_dollar, resetok)))
2883       return NULL;
2884     DEBUG(D_expand) if (i == 1 && !sub2_honour_dollar && Ustrchr(sub[1], '$'))
2885       debug_printf_indent("WARNING: the second arg is NOT expanded,"
2886                         " for security reasons\n");
2887     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2888
2889     /* Convert to numerical if required; we know that the names of all the
2890     conditions that compare numbers do not start with a letter. This just saves
2891     checking for them individually. */
2892
2893     if (!isalpha(opname[0]) && yield)
2894       if (sub[i][0] == 0)
2895         {
2896         num[i] = 0;
2897         DEBUG(D_expand)
2898           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2899         }
2900       else
2901         {
2902         num[i] = expanded_string_integer(sub[i], FALSE);
2903         if (expand_string_message) return NULL;
2904         }
2905     }
2906
2907   /* Result not required */
2908
2909   if (!yield) return s;
2910
2911   /* Do an appropriate comparison */
2912
2913   switch(cond_type)
2914     {
2915     case ECOND_NUM_E:
2916     case ECOND_NUM_EE:
2917     tempcond = (num[0] == num[1]);
2918     break;
2919
2920     case ECOND_NUM_G:
2921     tempcond = (num[0] > num[1]);
2922     break;
2923
2924     case ECOND_NUM_GE:
2925     tempcond = (num[0] >= num[1]);
2926     break;
2927
2928     case ECOND_NUM_L:
2929     tempcond = (num[0] < num[1]);
2930     break;
2931
2932     case ECOND_NUM_LE:
2933     tempcond = (num[0] <= num[1]);
2934     break;
2935
2936     case ECOND_STR_LT:
2937     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2938     break;
2939
2940     case ECOND_STR_LTI:
2941     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2942     break;
2943
2944     case ECOND_STR_LE:
2945     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2946     break;
2947
2948     case ECOND_STR_LEI:
2949     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2950     break;
2951
2952     case ECOND_STR_EQ:
2953     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2954     break;
2955
2956     case ECOND_STR_EQI:
2957     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2958     break;
2959
2960     case ECOND_STR_GT:
2961     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2962     break;
2963
2964     case ECOND_STR_GTI:
2965     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2966     break;
2967
2968     case ECOND_STR_GE:
2969     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2970     break;
2971
2972     case ECOND_STR_GEI:
2973     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2974     break;
2975
2976     case ECOND_MATCH:   /* Regular expression match */
2977     if (!(re = pcre_compile(CS sub[1], PCRE_COPT, CCSS &rerror,
2978                             &roffset, NULL)))
2979       {
2980       expand_string_message = string_sprintf("regular expression error in "
2981         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2982       return NULL;
2983       }
2984     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2985     break;
2986
2987     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2988     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2989     goto MATCHED_SOMETHING;
2990
2991     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2992     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2993       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2994     goto MATCHED_SOMETHING;
2995
2996     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2997     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2998       {
2999       expand_string_message = string_sprintf("\"%s\" is not an IP address",
3000         sub[0]);
3001       return NULL;
3002       }
3003     else
3004       {
3005       unsigned int *nullcache = NULL;
3006       check_host_block cb;
3007
3008       cb.host_name = US"";
3009       cb.host_address = sub[0];
3010
3011       /* If the host address starts off ::ffff: it is an IPv6 address in
3012       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3013       addresses. */
3014
3015       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
3016         cb.host_address + 7 : cb.host_address;
3017
3018       rc = match_check_list(
3019              &sub[1],                   /* the list */
3020              0,                         /* separator character */
3021              &hostlist_anchor,          /* anchor pointer */
3022              &nullcache,                /* cache pointer */
3023              check_host,                /* function for testing */
3024              &cb,                       /* argument for function */
3025              MCL_HOST,                  /* type of check */
3026              sub[0],                    /* text for debugging */
3027              NULL);                     /* where to pass back data */
3028       }
3029     goto MATCHED_SOMETHING;
3030
3031     case ECOND_MATCH_LOCAL_PART:
3032     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
3033       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
3034     /* Fall through */
3035     /* VVVVVVVVVVVV */
3036     MATCHED_SOMETHING:
3037     switch(rc)
3038       {
3039       case OK:
3040       tempcond = TRUE;
3041       break;
3042
3043       case FAIL:
3044       tempcond = FALSE;
3045       break;
3046
3047       case DEFER:
3048       expand_string_message = string_sprintf("unable to complete match "
3049         "against \"%s\": %s", sub[1], search_error_message);
3050       return NULL;
3051       }
3052
3053     break;
3054
3055     /* Various "encrypted" comparisons. If the second string starts with
3056     "{" then an encryption type is given. Default to crypt() or crypt16()
3057     (build-time choice). */
3058     /* }-for-text-editors */
3059
3060     case ECOND_CRYPTEQ:
3061     #ifndef SUPPORT_CRYPTEQ
3062     goto COND_FAILED_NOT_COMPILED;
3063     #else
3064     if (strncmpic(sub[1], US"{md5}", 5) == 0)
3065       {
3066       int sublen = Ustrlen(sub[1]+5);
3067       md5 base;
3068       uschar digest[16];
3069
3070       md5_start(&base);
3071       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
3072
3073       /* If the length that we are comparing against is 24, the MD5 digest
3074       is expressed as a base64 string. This is the way LDAP does it. However,
3075       some other software uses a straightforward hex representation. We assume
3076       this if the length is 32. Other lengths fail. */
3077
3078       if (sublen == 24)
3079         {
3080         uschar *coded = b64encode(CUS digest, 16);
3081         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
3082           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
3083         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
3084         }
3085       else if (sublen == 32)
3086         {
3087         uschar coded[36];
3088         for (int i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
3089         coded[32] = 0;
3090         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
3091           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
3092         tempcond = (strcmpic(coded, sub[1]+5) == 0);
3093         }
3094       else
3095         {
3096         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
3097           "fail\n  crypted=%s\n", sub[1]+5);
3098         tempcond = FALSE;
3099         }
3100       }
3101
3102     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
3103       {
3104       int sublen = Ustrlen(sub[1]+6);
3105       hctx h;
3106       uschar digest[20];
3107
3108       sha1_start(&h);
3109       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
3110
3111       /* If the length that we are comparing against is 28, assume the SHA1
3112       digest is expressed as a base64 string. If the length is 40, assume a
3113       straightforward hex representation. Other lengths fail. */
3114
3115       if (sublen == 28)
3116         {
3117         uschar *coded = b64encode(CUS digest, 20);
3118         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
3119           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
3120         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
3121         }
3122       else if (sublen == 40)
3123         {
3124         uschar coded[44];
3125         for (int i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
3126         coded[40] = 0;
3127         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
3128           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
3129         tempcond = (strcmpic(coded, sub[1]+6) == 0);
3130         }
3131       else
3132         {
3133         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
3134           "fail\n  crypted=%s\n", sub[1]+6);
3135         tempcond = FALSE;
3136         }
3137       }
3138
3139     else   /* {crypt} or {crypt16} and non-{ at start */
3140            /* }-for-text-editors */
3141       {
3142       int which = 0;
3143       uschar *coded;
3144
3145       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
3146         {
3147         sub[1] += 7;
3148         which = 1;
3149         }
3150       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
3151         {
3152         sub[1] += 9;
3153         which = 2;
3154         }
3155       else if (sub[1][0] == '{')                /* }-for-text-editors */
3156         {
3157         expand_string_message = string_sprintf("unknown encryption mechanism "
3158           "in \"%s\"", sub[1]);
3159         return NULL;
3160         }
3161
3162       switch(which)
3163         {
3164         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
3165         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
3166         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
3167         }
3168
3169       #define STR(s) # s
3170       #define XSTR(s) STR(s)
3171       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
3172         "  subject=%s\n  crypted=%s\n",
3173         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
3174         coded, sub[1]);
3175       #undef STR
3176       #undef XSTR
3177
3178       /* If the encrypted string contains fewer than two characters (for the
3179       salt), force failure. Otherwise we get false positives: with an empty
3180       string the yield of crypt() is an empty string! */
3181
3182       if (coded)
3183         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
3184       else if (errno == EINVAL)
3185         tempcond = FALSE;
3186       else
3187         {
3188         expand_string_message = string_sprintf("crypt error: %s\n",
3189           US strerror(errno));
3190         return NULL;
3191         }
3192       }
3193     break;
3194     #endif  /* SUPPORT_CRYPTEQ */
3195
3196     case ECOND_INLIST:
3197     case ECOND_INLISTI:
3198       {
3199       const uschar * list = sub[1];
3200       int sep = 0;
3201       uschar *save_iterate_item = iterate_item;
3202       int (*compare)(const uschar *, const uschar *);
3203
3204       DEBUG(D_expand) debug_printf_indent("condition: %s  item: %s\n", opname, sub[0]);
3205
3206       tempcond = FALSE;
3207       compare = cond_type == ECOND_INLISTI
3208         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
3209
3210       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
3211         {
3212         DEBUG(D_expand) debug_printf_indent(" compare %s\n", iterate_item);
3213         if (compare(sub[0], iterate_item) == 0)
3214           {
3215           tempcond = TRUE;
3216           break;
3217           }
3218         }
3219       iterate_item = save_iterate_item;
3220       }
3221
3222     }   /* Switch for comparison conditions */
3223
3224   *yield = tempcond == testfor;
3225   return s;    /* End of comparison conditions */
3226
3227
3228   /* and/or: computes logical and/or of several conditions */
3229
3230   case ECOND_AND:
3231   case ECOND_OR:
3232   subcondptr = (yield == NULL) ? NULL : &tempcond;
3233   combined_cond = (cond_type == ECOND_AND);
3234
3235   Uskip_whitespace(&s);
3236   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3237
3238   for (;;)
3239     {
3240     /* {-for-text-editors */
3241     if (Uskip_whitespace(&s) == '}') break;
3242     if (*s != '{')                                      /* }-for-text-editors */
3243       {
3244       expand_string_message = string_sprintf("each subcondition "
3245         "inside an \"%s{...}\" condition must be in its own {}", opname);
3246       return NULL;
3247       }
3248
3249     if (!(s = eval_condition(s+1, resetok, subcondptr)))
3250       {
3251       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
3252         expand_string_message, opname);
3253       return NULL;
3254       }
3255     Uskip_whitespace(&s);
3256
3257     /* {-for-text-editors */
3258     if (*s++ != '}')
3259       {
3260       /* {-for-text-editors */
3261       expand_string_message = string_sprintf("missing } at end of condition "
3262         "inside \"%s\" group", opname);
3263       return NULL;
3264       }
3265
3266     if (yield)
3267       if (cond_type == ECOND_AND)
3268         {
3269         combined_cond &= tempcond;
3270         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
3271         }                                       /* evaluate any more */
3272       else
3273         {
3274         combined_cond |= tempcond;
3275         if (combined_cond) subcondptr = NULL;   /* once true, don't */
3276         }                                       /* evaluate any more */
3277     }
3278
3279   if (yield) *yield = (combined_cond == testfor);
3280   return ++s;
3281
3282
3283   /* forall/forany: iterates a condition with different values */
3284
3285   case ECOND_FORALL:      is_forany = FALSE;  is_json = FALSE; is_jsons = FALSE; goto FORMANY;
3286   case ECOND_FORANY:      is_forany = TRUE;   is_json = FALSE; is_jsons = FALSE; goto FORMANY;
3287   case ECOND_FORALL_JSON: is_forany = FALSE;  is_json = TRUE;  is_jsons = FALSE; goto FORMANY;
3288   case ECOND_FORANY_JSON: is_forany = TRUE;   is_json = TRUE;  is_jsons = FALSE; goto FORMANY;
3289   case ECOND_FORALL_JSONS: is_forany = FALSE; is_json = TRUE;  is_jsons = TRUE;  goto FORMANY;
3290   case ECOND_FORANY_JSONS: is_forany = TRUE;  is_json = TRUE;  is_jsons = TRUE;  goto FORMANY;
3291
3292   FORMANY:
3293     {
3294     const uschar * list;
3295     int sep = 0;
3296     uschar *save_iterate_item = iterate_item;
3297
3298     DEBUG(D_expand) debug_printf_indent("condition: %s\n", opname);
3299
3300     Uskip_whitespace(&s);
3301     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
3302     if (!(sub[0] = expand_string_internal(s, TRUE, &s, yield == NULL, TRUE, resetok)))
3303       return NULL;
3304     /* {-for-text-editors */
3305     if (*s++ != '}') goto COND_FAILED_CURLY_END;
3306
3307     Uskip_whitespace(&s);
3308     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
3309
3310     sub[1] = s;
3311
3312     /* Call eval_condition once, with result discarded (as if scanning a
3313     "false" part). This allows us to find the end of the condition, because if
3314     the list it empty, we won't actually evaluate the condition for real. */
3315
3316     if (!(s = eval_condition(sub[1], resetok, NULL)))
3317       {
3318       expand_string_message = string_sprintf("%s inside \"%s\" condition",
3319         expand_string_message, opname);
3320       return NULL;
3321       }
3322     Uskip_whitespace(&s);
3323
3324     /* {-for-text-editors */
3325     if (*s++ != '}')
3326       {
3327       /* {-for-text-editors */
3328       expand_string_message = string_sprintf("missing } at end of condition "
3329         "inside \"%s\"", opname);
3330       return NULL;
3331       }
3332
3333     if (yield) *yield = !testfor;
3334     list = sub[0];
3335     if (is_json) list = dewrap(string_copy(list), US"[]");
3336     while ((iterate_item = is_json
3337       ? json_nextinlist(&list) : string_nextinlist(&list, &sep, NULL, 0)))
3338       {
3339       if (is_jsons)
3340         if (!(iterate_item = dewrap(iterate_item, US"\"\"")))
3341           {
3342           expand_string_message =
3343             string_sprintf("%s wrapping string result for extract jsons",
3344               expand_string_message);
3345           iterate_item = save_iterate_item;
3346           return NULL;
3347           }
3348
3349       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", opname, iterate_item);
3350       if (!eval_condition(sub[1], resetok, &tempcond))
3351         {
3352         expand_string_message = string_sprintf("%s inside \"%s\" condition",
3353           expand_string_message, opname);
3354         iterate_item = save_iterate_item;
3355         return NULL;
3356         }
3357       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", opname,
3358         tempcond? "true":"false");
3359
3360       if (yield) *yield = (tempcond == testfor);
3361       if (tempcond == is_forany) break;
3362       }
3363
3364     iterate_item = save_iterate_item;
3365     return s;
3366     }
3367
3368
3369   /* The bool{} expansion condition maps a string to boolean.
3370   The values supported should match those supported by the ACL condition
3371   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
3372   of true/false.  Note that Router "condition" rules have a different
3373   interpretation, where general data can be used and only a few values
3374   map to FALSE.
3375   Note that readconf.c boolean matching, for boolean configuration options,
3376   only matches true/yes/false/no.
3377   The bool_lax{} condition matches the Router logic, which is much more
3378   liberal. */
3379   case ECOND_BOOL:
3380   case ECOND_BOOL_LAX:
3381     {
3382     uschar *sub_arg[1];
3383     uschar *t, *t2;
3384     uschar *ourname;
3385     size_t len;
3386     BOOL boolvalue = FALSE;
3387
3388     if (Uskip_whitespace(&s) != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
3389     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3390     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3391       {
3392       case 1: expand_string_message = string_sprintf(
3393                   "too few arguments or bracketing error for %s",
3394                   ourname);
3395       /*FALLTHROUGH*/
3396       case 2:
3397       case 3: return NULL;
3398       }
3399     t = sub_arg[0];
3400     Uskip_whitespace(&t);
3401     if ((len = Ustrlen(t)))
3402       {
3403       /* trailing whitespace: seems like a good idea to ignore it too */
3404       t2 = t + len - 1;
3405       while (isspace(*t2)) t2--;
3406       if (t2 != (t + len))
3407         {
3408         *++t2 = '\0';
3409         len = t2 - t;
3410         }
3411       }
3412     DEBUG(D_expand)
3413       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3414     /* logic for the lax case from expand_check_condition(), which also does
3415     expands, and the logic is both short and stable enough that there should
3416     be no maintenance burden from replicating it. */
3417     if (len == 0)
3418       boolvalue = FALSE;
3419     else if (*t == '-'
3420              ? Ustrspn(t+1, "0123456789") == len-1
3421              : Ustrspn(t,   "0123456789") == len)
3422       {
3423       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3424       /* expand_check_condition only does a literal string "0" check */
3425       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3426         boolvalue = TRUE;
3427       }
3428     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3429       boolvalue = TRUE;
3430     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3431       boolvalue = FALSE;
3432     else if (cond_type == ECOND_BOOL_LAX)
3433       boolvalue = TRUE;
3434     else
3435       {
3436       expand_string_message = string_sprintf("unrecognised boolean "
3437        "value \"%s\"", t);
3438       return NULL;
3439       }
3440     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3441         boolvalue? "true":"false");
3442     if (yield) *yield = (boolvalue == testfor);
3443     return s;
3444     }
3445
3446 #ifdef EXPERIMENTAL_SRS_NATIVE
3447   case ECOND_INBOUND_SRS:
3448     /* ${if inbound_srs {local_part}{secret}  {yes}{no}} */
3449     {
3450     uschar * sub[2];
3451     const pcre * re;
3452     int ovec[3*(4+1)];
3453     int n;
3454     uschar cksum[4];
3455     BOOL boolvalue = FALSE;
3456
3457     switch(read_subs(sub, 2, 2, CUSS &s, yield == NULL, FALSE, name, resetok))
3458       {
3459       case 1: expand_string_message = US"too few arguments or bracketing "
3460         "error for inbound_srs";
3461       case 2:
3462       case 3: return NULL;
3463       }
3464
3465     /* Match the given local_part against the SRS-encoded pattern */
3466
3467     re = regex_must_compile(US"^(?i)SRS0=([^=]+)=([A-Z2-7]+)=([^=]*)=(.*)$",
3468                             TRUE, FALSE);
3469     if (pcre_exec(re, NULL, CS sub[0], Ustrlen(sub[0]), 0, PCRE_EOPT,
3470                   ovec, nelem(ovec)) < 0)
3471       {
3472       DEBUG(D_expand) debug_printf("no match for SRS'd local-part pattern\n");
3473       goto srs_result;
3474       }
3475
3476     /* Side-effect: record the decoded recipient */
3477
3478     srs_recipient = string_sprintf("%.*S@%.*S",                 /* lowercased */
3479                       ovec[9]-ovec[8], sub[0] + ovec[8],        /* substring 4 */
3480                       ovec[7]-ovec[6], sub[0] + ovec[6]);       /* substring 3 */
3481
3482     /* If a zero-length secret was given, we're done.  Otherwise carry on
3483     and validate the given SRS local_part againt our secret. */
3484
3485     if (!*sub[1])
3486       {
3487       boolvalue = TRUE;
3488       goto srs_result;
3489       }
3490
3491     /* check the timestamp */
3492       {
3493       struct timeval now;
3494       uschar * ss = sub[0] + ovec[4];   /* substring 2, the timestamp */
3495       long d;
3496
3497       gettimeofday(&now, NULL);
3498       now.tv_sec /= 86400;              /* days since epoch */
3499
3500       /* Decode substring 2 from base32 to a number */
3501
3502       for (d = 0, n = ovec[5]-ovec[4]; n; n--)
3503         {
3504         uschar * t = Ustrchr(base32_chars, *ss++);
3505         d = d * 32 + (t - base32_chars);
3506         }
3507
3508       if (((now.tv_sec - d) & 0x3ff) > 10)      /* days since SRS generated */
3509         {
3510         DEBUG(D_expand) debug_printf("SRS too old\n");
3511         goto srs_result;
3512         }
3513       }
3514
3515     /* check length of substring 1, the offered checksum */
3516
3517     if (ovec[3]-ovec[2] != 4)
3518       {
3519       DEBUG(D_expand) debug_printf("SRS checksum wrong size\n");
3520       goto srs_result;
3521       }
3522
3523     /* Hash the address with our secret, and compare that computed checksum
3524     with the one extracted from the arg */
3525
3526     hmac_md5(sub[1], srs_recipient, cksum, sizeof(cksum));
3527     if (Ustrncmp(cksum, sub[0] + ovec[2], 4) != 0)
3528       {
3529       DEBUG(D_expand) debug_printf("SRS checksum mismatch\n");
3530       goto srs_result;
3531       }
3532     boolvalue = TRUE;
3533
3534 srs_result:
3535     if (yield) *yield = (boolvalue == testfor);
3536     return s;
3537     }
3538 #endif /*EXPERIMENTAL_SRS_NATIVE*/
3539
3540   /* Unknown condition */
3541
3542   default:
3543     if (!expand_string_message || !*expand_string_message)
3544       expand_string_message = string_sprintf("unknown condition \"%s\"", opname);
3545     return NULL;
3546   }   /* End switch on condition type */
3547
3548 /* Missing braces at start and end of data */
3549
3550 COND_FAILED_CURLY_START:
3551 expand_string_message = string_sprintf("missing { after \"%s\"", opname);
3552 return NULL;
3553
3554 COND_FAILED_CURLY_END:
3555 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3556   opname);
3557 return NULL;
3558
3559 /* A condition requires code that is not compiled */
3560
3561 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3562     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3563     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3564 COND_FAILED_NOT_COMPILED:
3565 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3566   opname);
3567 return NULL;
3568 #endif
3569 }
3570
3571
3572
3573
3574 /*************************************************
3575 *          Save numerical variables              *
3576 *************************************************/
3577
3578 /* This function is called from items such as "if" that want to preserve and
3579 restore the numbered variables.
3580
3581 Arguments:
3582   save_expand_string    points to an array of pointers to set
3583   save_expand_nlength   points to an array of ints for the lengths
3584
3585 Returns:                the value of expand max to save
3586 */
3587
3588 static int
3589 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3590 {
3591 for (int i = 0; i <= expand_nmax; i++)
3592   {
3593   save_expand_nstring[i] = expand_nstring[i];
3594   save_expand_nlength[i] = expand_nlength[i];
3595   }
3596 return expand_nmax;
3597 }
3598
3599
3600
3601 /*************************************************
3602 *           Restore numerical variables          *
3603 *************************************************/
3604
3605 /* This function restored saved values of numerical strings.
3606
3607 Arguments:
3608   save_expand_nmax      the number of strings to restore
3609   save_expand_string    points to an array of pointers
3610   save_expand_nlength   points to an array of ints
3611
3612 Returns:                nothing
3613 */
3614
3615 static void
3616 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3617   int *save_expand_nlength)
3618 {
3619 expand_nmax = save_expand_nmax;
3620 for (int i = 0; i <= expand_nmax; i++)
3621   {
3622   expand_nstring[i] = save_expand_nstring[i];
3623   expand_nlength[i] = save_expand_nlength[i];
3624   }
3625 }
3626
3627
3628
3629
3630
3631 /*************************************************
3632 *            Handle yes/no substrings            *
3633 *************************************************/
3634
3635 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3636 alternative substrings that depend on whether or not the condition was true,
3637 or the lookup or extraction succeeded. The substrings always have to be
3638 expanded, to check their syntax, but "skipping" is set when the result is not
3639 needed - this avoids unnecessary nested lookups.
3640
3641 Arguments:
3642   skipping       TRUE if we were skipping when this item was reached
3643   yes            TRUE if the first string is to be used, else use the second
3644   save_lookup    a value to put back into lookup_value before the 2nd expansion
3645   sptr           points to the input string pointer
3646   yieldptr       points to the output growable-string pointer
3647   type           "lookup", "if", "extract", "run", "env", "listextract" or
3648                  "certextract" for error message
3649   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3650                 the store.
3651
3652 Returns:         0 OK; lookup_value has been reset to save_lookup
3653                  1 expansion failed
3654                  2 expansion failed because of bracketing error
3655 */
3656
3657 static int
3658 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3659   gstring ** yieldptr, uschar *type, BOOL *resetok)
3660 {
3661 int rc = 0;
3662 const uschar *s = *sptr;    /* Local value */
3663 uschar *sub1, *sub2;
3664 const uschar * errwhere;
3665
3666 /* If there are no following strings, we substitute the contents of $value for
3667 lookups and for extractions in the success case. For the ${if item, the string
3668 "true" is substituted. In the fail case, nothing is substituted for all three
3669 items. */
3670
3671 if (skip_whitespace(&s) == '}')
3672   {
3673   if (type[0] == 'i')
3674     {
3675     if (yes && !skipping)
3676       *yieldptr = string_catn(*yieldptr, US"true", 4);
3677     }
3678   else
3679     {
3680     if (yes && lookup_value && !skipping)
3681       *yieldptr = string_cat(*yieldptr, lookup_value);
3682     lookup_value = save_lookup;
3683     }
3684   s++;
3685   goto RETURN;
3686   }
3687
3688 /* The first following string must be braced. */
3689
3690 if (*s++ != '{')
3691   {
3692   errwhere = US"'yes' part did not start with '{'";
3693   goto FAILED_CURLY;
3694   }
3695
3696 /* Expand the first substring. Forced failures are noticed only if we actually
3697 want this string. Set skipping in the call in the fail case (this will always
3698 be the case if we were already skipping). */
3699
3700 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3701 if (sub1 == NULL && (yes || !f.expand_string_forcedfail)) goto FAILED;
3702 f.expand_string_forcedfail = FALSE;
3703 if (*s++ != '}')
3704   {
3705   errwhere = US"'yes' part did not end with '}'";
3706   goto FAILED_CURLY;
3707   }
3708
3709 /* If we want the first string, add it to the output */
3710
3711 if (yes)
3712   *yieldptr = string_cat(*yieldptr, sub1);
3713
3714 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3715 $value to what it was at the start of the item, so that it has this value
3716 during the second string expansion. For the call from "if" or "run" to this
3717 function, save_lookup is set to lookup_value, so that this statement does
3718 nothing. */
3719
3720 lookup_value = save_lookup;
3721
3722 /* There now follows either another substring, or "fail", or nothing. This
3723 time, forced failures are noticed only if we want the second string. We must
3724 set skipping in the nested call if we don't want this string, or if we were
3725 already skipping. */
3726
3727 if (skip_whitespace(&s) == '{')
3728   {
3729   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3730   if (sub2 == NULL && (!yes || !f.expand_string_forcedfail)) goto FAILED;
3731   f.expand_string_forcedfail = FALSE;
3732   if (*s++ != '}')
3733     {
3734     errwhere = US"'no' part did not start with '{'";
3735     goto FAILED_CURLY;
3736     }
3737
3738   /* If we want the second string, add it to the output */
3739
3740   if (!yes)
3741     *yieldptr = string_cat(*yieldptr, sub2);
3742   }
3743
3744 /* If there is no second string, but the word "fail" is present when the use of
3745 the second string is wanted, set a flag indicating it was a forced failure
3746 rather than a syntactic error. Swallow the terminating } in case this is nested
3747 inside another lookup or if or extract. */
3748
3749 else if (*s != '}')
3750   {
3751   uschar name[256];
3752   /* deconst cast ok here as source is s anyway */
3753   s = US read_name(name, sizeof(name), s, US"_");
3754   if (Ustrcmp(name, "fail") == 0)
3755     {
3756     if (!yes && !skipping)
3757       {
3758       Uskip_whitespace(&s);
3759       if (*s++ != '}')
3760         {
3761         errwhere = US"did not close with '}' after forcedfail";
3762         goto FAILED_CURLY;
3763         }
3764       expand_string_message =
3765         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3766       f.expand_string_forcedfail = TRUE;
3767       goto FAILED;
3768       }
3769     }
3770   else
3771     {
3772     expand_string_message =
3773       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3774     goto FAILED;
3775     }
3776   }
3777
3778 /* All we have to do now is to check on the final closing brace. */
3779
3780 skip_whitespace(&s);
3781 if (*s++ != '}')
3782   {
3783   errwhere = US"did not close with '}'";
3784   goto FAILED_CURLY;
3785   }
3786
3787
3788 RETURN:
3789 /* Update the input pointer value before returning */
3790 *sptr = s;
3791 return rc;
3792
3793 FAILED_CURLY:
3794   /* Get here if there is a bracketing failure */
3795   expand_string_message = string_sprintf(
3796     "curly-bracket problem in conditional yes/no parsing: %s\n"
3797     " remaining string is '%s'", errwhere, --s);
3798   rc = 2;
3799   goto RETURN;
3800
3801 FAILED:
3802   /* Get here for other failures */
3803   rc = 1;
3804   goto RETURN;
3805 }
3806
3807
3808
3809
3810 /********************************************************
3811 * prvs: Get last three digits of days since Jan 1, 1970 *
3812 ********************************************************/
3813
3814 /* This is needed to implement the "prvs" BATV reverse
3815    path signing scheme
3816
3817 Argument: integer "days" offset to add or substract to
3818           or from the current number of days.
3819
3820 Returns:  pointer to string containing the last three
3821           digits of the number of days since Jan 1, 1970,
3822           modified by the offset argument, NULL if there
3823           was an error in the conversion.
3824
3825 */
3826
3827 static uschar *
3828 prvs_daystamp(int day_offset)
3829 {
3830 uschar *days = store_get(32, FALSE);         /* Need at least 24 for cases */
3831 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3832   (time(NULL) + day_offset*86400)/86400);
3833 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3834 }
3835
3836
3837
3838 /********************************************************
3839 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3840 ********************************************************/
3841
3842 /* This is needed to implement the "prvs" BATV reverse
3843    path signing scheme
3844
3845 Arguments:
3846   address RFC2821 Address to use
3847       key The key to use (must be less than 64 characters
3848           in size)
3849   key_num Single-digit key number to use. Defaults to
3850           '0' when NULL.
3851
3852 Returns:  pointer to string containing the first three
3853           bytes of the final hash in hex format, NULL if
3854           there was an error in the process.
3855 */
3856
3857 static uschar *
3858 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3859 {
3860 gstring * hash_source;
3861 uschar * p;
3862 hctx h;
3863 uschar innerhash[20];
3864 uschar finalhash[20];
3865 uschar innerkey[64];
3866 uschar outerkey[64];
3867 uschar *finalhash_hex;
3868
3869 if (!key_num)
3870   key_num = US"0";
3871
3872 if (Ustrlen(key) > 64)
3873   return NULL;
3874
3875 hash_source = string_catn(NULL, key_num, 1);
3876 hash_source = string_catn(hash_source, daystamp, 3);
3877 hash_source = string_cat(hash_source, address);
3878 (void) string_from_gstring(hash_source);
3879
3880 DEBUG(D_expand)
3881   debug_printf_indent("prvs: hash source is '%s'\n", hash_source->s);
3882
3883 memset(innerkey, 0x36, 64);
3884 memset(outerkey, 0x5c, 64);
3885
3886 for (int i = 0; i < Ustrlen(key); i++)
3887   {
3888   innerkey[i] ^= key[i];
3889   outerkey[i] ^= key[i];
3890   }
3891
3892 chash_start(HMAC_SHA1, &h);
3893 chash_mid(HMAC_SHA1, &h, innerkey);
3894 chash_end(HMAC_SHA1, &h, hash_source->s, hash_source->ptr, innerhash);
3895
3896 chash_start(HMAC_SHA1, &h);
3897 chash_mid(HMAC_SHA1, &h, outerkey);
3898 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3899
3900 /* Hashing is deemed sufficient to de-taint any input data */
3901
3902 p = finalhash_hex = store_get(40, FALSE);
3903 for (int i = 0; i < 3; i++)
3904   {
3905   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3906   *p++ = hex_digits[finalhash[i] & 0x0f];
3907   }
3908 *p = '\0';
3909
3910 return finalhash_hex;
3911 }
3912
3913
3914
3915
3916 /*************************************************
3917 *        Join a file onto the output string      *
3918 *************************************************/
3919
3920 /* This is used for readfile/readsock and after a run expansion.
3921 It joins the contents of a file onto the output string, globally replacing
3922 newlines with a given string (optionally).
3923
3924 Arguments:
3925   f            the FILE
3926   yield        pointer to the expandable string struct
3927   eol          newline replacement string, or NULL
3928
3929 Returns:       new pointer for expandable string, terminated if non-null
3930 */
3931
3932 gstring *
3933 cat_file(FILE *f, gstring *yield, uschar *eol)
3934 {
3935 uschar buffer[1024];
3936
3937 while (Ufgets(buffer, sizeof(buffer), f))
3938   {
3939   int len = Ustrlen(buffer);
3940   if (eol && buffer[len-1] == '\n') len--;
3941   yield = string_catn(yield, buffer, len);
3942   if (eol && buffer[len])
3943     yield = string_cat(yield, eol);
3944   }
3945
3946 (void) string_from_gstring(yield);
3947 return yield;
3948 }
3949
3950
3951 #ifndef DISABLE_TLS
3952 gstring *
3953 cat_file_tls(void * tls_ctx, gstring * yield, uschar * eol)
3954 {
3955 int rc;
3956 uschar buffer[1024];
3957
3958 /*XXX could we read direct into a pre-grown string? */
3959
3960 while ((rc = tls_read(tls_ctx, buffer, sizeof(buffer))) > 0)
3961   for (uschar * s = buffer; rc--; s++)
3962     yield = eol && *s == '\n'
3963       ? string_cat(yield, eol) : string_catn(yield, s, 1);
3964
3965 /* We assume that all errors, and any returns of zero bytes,
3966 are actually EOF. */
3967
3968 (void) string_from_gstring(yield);
3969 return yield;
3970 }
3971 #endif
3972
3973
3974 /*************************************************
3975 *          Evaluate numeric expression           *
3976 *************************************************/
3977
3978 /* This is a set of mutually recursive functions that evaluate an arithmetic
3979 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3980 these functions that is called from elsewhere is eval_expr, whose interface is:
3981
3982 Arguments:
3983   sptr        pointer to the pointer to the string - gets updated
3984   decimal     TRUE if numbers are to be assumed decimal
3985   error       pointer to where to put an error message - must be NULL on input
3986   endket      TRUE if ')' must terminate - FALSE for external call
3987
3988 Returns:      on success: the value of the expression, with *error still NULL
3989               on failure: an undefined value, with *error = a message
3990 */
3991
3992 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3993
3994
3995 static int_eximarith_t
3996 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3997 {
3998 uschar *s = *sptr;
3999 int_eximarith_t x = eval_op_or(&s, decimal, error);
4000
4001 if (!*error)
4002   if (endket)
4003     if (*s != ')')
4004       *error = US"expecting closing parenthesis";
4005     else
4006       while (isspace(*++s));
4007   else if (*s)
4008     *error = US"expecting operator";
4009 *sptr = s;
4010 return x;
4011 }
4012
4013
4014 static int_eximarith_t
4015 eval_number(uschar **sptr, BOOL decimal, uschar **error)
4016 {
4017 int c;
4018 int_eximarith_t n;
4019 uschar *s = *sptr;
4020
4021 if (isdigit((c = Uskip_whitespace(&s))))
4022   {
4023   int count;
4024   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
4025   s += count;
4026   switch (tolower(*s))
4027     {
4028     default: break;
4029     case 'k': n *= 1024; s++; break;
4030     case 'm': n *= 1024*1024; s++; break;
4031     case 'g': n *= 1024*1024*1024; s++; break;
4032     }
4033   Uskip_whitespace(&s);
4034   }
4035 else if (c == '(')
4036   {
4037   s++;
4038   n = eval_expr(&s, decimal, error, 1);
4039   }
4040 else
4041   {
4042   *error = US"expecting number or opening parenthesis";
4043   n = 0;
4044   }
4045 *sptr = s;
4046 return n;
4047 }
4048
4049
4050 static int_eximarith_t
4051 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
4052 {
4053 uschar *s = *sptr;
4054 int_eximarith_t x;
4055 Uskip_whitespace(&s);
4056 if (*s == '+' || *s == '-' || *s == '~')
4057   {
4058   int op = *s++;
4059   x = eval_op_unary(&s, decimal, error);
4060   if (op == '-') x = -x;
4061     else if (op == '~') x = ~x;
4062   }
4063 else
4064   x = eval_number(&s, decimal, error);
4065
4066 *sptr = s;
4067 return x;
4068 }
4069
4070
4071 static int_eximarith_t
4072 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
4073 {
4074 uschar *s = *sptr;
4075 int_eximarith_t x = eval_op_unary(&s, decimal, error);
4076 if (!*error)
4077   {
4078   while (*s == '*' || *s == '/' || *s == '%')
4079     {
4080     int op = *s++;
4081     int_eximarith_t y = eval_op_unary(&s, decimal, error);
4082     if (*error) break;
4083     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
4084      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
4085      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
4086      * -N*M is INT_MIN will yield INT_MIN.
4087      * Since we don't support floating point, this is somewhat simpler.
4088      * Ideally, we'd return an error, but since we overflow for all other
4089      * arithmetic, consistency suggests otherwise, but what's the correct value
4090      * to use?  There is none.
4091      * The C standard guarantees overflow for unsigned arithmetic but signed
4092      * overflow invokes undefined behaviour; in practice, this is overflow
4093      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
4094      * that long/longlong larger than int are available, or we could just work
4095      * with larger types.  We should consider whether to guarantee 32bit eval
4096      * and 64-bit working variables, with errors returned.  For now ...
4097      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
4098      * can just let the other invalid results occur otherwise, as they have
4099      * until now.  For this one case, we can coerce.
4100      */
4101     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
4102       {
4103       DEBUG(D_expand)
4104         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
4105             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
4106       x = EXIM_ARITH_MAX;
4107       continue;
4108       }
4109     if (op == '*')
4110       x *= y;
4111     else
4112       {
4113       if (y == 0)
4114         {
4115         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
4116         x = 0;
4117         break;
4118         }
4119       if (op == '/')
4120         x /= y;
4121       else
4122         x %= y;
4123       }
4124     }
4125   }
4126 *sptr = s;
4127 return x;
4128 }
4129
4130
4131 static int_eximarith_t
4132 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
4133 {
4134 uschar *s = *sptr;
4135 int_eximarith_t x = eval_op_mult(&s, decimal, error);
4136 if (!*error)
4137   {
4138   while (*s == '+' || *s == '-')
4139     {
4140     int op = *s++;
4141     int_eximarith_t y = eval_op_mult(&s, decimal, error);
4142     if (*error) break;
4143     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
4144        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
4145       {                 /* over-conservative check */
4146       *error = op == '+'
4147         ? US"overflow in sum" : US"overflow in difference";
4148       break;
4149       }
4150     if (op == '+') x += y; else x -= y;
4151     }
4152   }
4153 *sptr = s;
4154 return x;
4155 }
4156
4157
4158 static int_eximarith_t
4159 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
4160 {
4161 uschar *s = *sptr;
4162 int_eximarith_t x = eval_op_sum(&s, decimal, error);
4163 if (!*error)
4164   {
4165   while ((*s == '<' || *s == '>') && s[1] == s[0])
4166     {
4167     int_eximarith_t y;
4168     int op = *s++;
4169     s++;
4170     y = eval_op_sum(&s, decimal, error);
4171     if (*error) break;
4172     if (op == '<') x <<= y; else x >>= y;
4173     }
4174   }
4175 *sptr = s;
4176 return x;
4177 }
4178
4179
4180 static int_eximarith_t
4181 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
4182 {
4183 uschar *s = *sptr;
4184 int_eximarith_t x = eval_op_shift(&s, decimal, error);
4185 if (!*error)
4186   {
4187   while (*s == '&')
4188     {
4189     int_eximarith_t y;
4190     s++;
4191     y = eval_op_shift(&s, decimal, error);
4192     if (*error) break;
4193     x &= y;
4194     }
4195   }
4196 *sptr = s;
4197 return x;
4198 }
4199
4200
4201 static int_eximarith_t
4202 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
4203 {
4204 uschar *s = *sptr;
4205 int_eximarith_t x = eval_op_and(&s, decimal, error);
4206 if (!*error)
4207   {
4208   while (*s == '^')
4209     {
4210     int_eximarith_t y;
4211     s++;
4212     y = eval_op_and(&s, decimal, error);
4213     if (*error) break;
4214     x ^= y;
4215     }
4216   }
4217 *sptr = s;
4218 return x;
4219 }
4220
4221
4222 static int_eximarith_t
4223 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
4224 {
4225 uschar *s = *sptr;
4226 int_eximarith_t x = eval_op_xor(&s, decimal, error);
4227 if (!*error)
4228   {
4229   while (*s == '|')
4230     {
4231     int_eximarith_t y;
4232     s++;
4233     y = eval_op_xor(&s, decimal, error);
4234     if (*error) break;
4235     x |= y;
4236     }
4237   }
4238 *sptr = s;
4239 return x;
4240 }
4241
4242
4243
4244 /************************************************/
4245 /* Comparison operation for sort expansion.  We need to avoid
4246 re-expanding the fields being compared, so need a custom routine.
4247
4248 Arguments:
4249  cond_type              Comparison operator code
4250  leftarg, rightarg      Arguments for comparison
4251
4252 Return true iff (leftarg compare rightarg)
4253 */
4254
4255 static BOOL
4256 sortsbefore(int cond_type, BOOL alpha_cond,
4257   const uschar * leftarg, const uschar * rightarg)
4258 {
4259 int_eximarith_t l_num, r_num;
4260
4261 if (!alpha_cond)
4262   {
4263   l_num = expanded_string_integer(leftarg, FALSE);
4264   if (expand_string_message) return FALSE;
4265   r_num = expanded_string_integer(rightarg, FALSE);
4266   if (expand_string_message) return FALSE;
4267
4268   switch (cond_type)
4269     {
4270     case ECOND_NUM_G:   return l_num >  r_num;
4271     case ECOND_NUM_GE:  return l_num >= r_num;
4272     case ECOND_NUM_L:   return l_num <  r_num;
4273     case ECOND_NUM_LE:  return l_num <= r_num;
4274     default: break;
4275     }
4276   }
4277 else
4278   switch (cond_type)
4279     {
4280     case ECOND_STR_LT:  return Ustrcmp (leftarg, rightarg) <  0;
4281     case ECOND_STR_LTI: return strcmpic(leftarg, rightarg) <  0;
4282     case ECOND_STR_LE:  return Ustrcmp (leftarg, rightarg) <= 0;
4283     case ECOND_STR_LEI: return strcmpic(leftarg, rightarg) <= 0;
4284     case ECOND_STR_GT:  return Ustrcmp (leftarg, rightarg) >  0;
4285     case ECOND_STR_GTI: return strcmpic(leftarg, rightarg) >  0;
4286     case ECOND_STR_GE:  return Ustrcmp (leftarg, rightarg) >= 0;
4287     case ECOND_STR_GEI: return strcmpic(leftarg, rightarg) >= 0;
4288     default: break;
4289     }
4290 return FALSE;   /* should not happen */
4291 }
4292
4293
4294 /*************************************************
4295 *                 Expand string                  *
4296 *************************************************/
4297
4298 /* Returns either an unchanged string, or the expanded string in stacking pool
4299 store. Interpreted sequences are:
4300
4301    \...                    normal escaping rules
4302    $name                   substitutes the variable
4303    ${name}                 ditto
4304    ${op:string}            operates on the expanded string value
4305    ${item{arg1}{arg2}...}  expands the args and then does the business
4306                              some literal args are not enclosed in {}
4307
4308 There are now far too many operators and item types to make it worth listing
4309 them here in detail any more.
4310
4311 We use an internal routine recursively to handle embedded substrings. The
4312 external function follows. The yield is NULL if the expansion failed, and there
4313 are two cases: if something collapsed syntactically, or if "fail" was given
4314 as the action on a lookup failure. These can be distinguished by looking at the
4315 variable expand_string_forcedfail, which is TRUE in the latter case.
4316
4317 The skipping flag is set true when expanding a substring that isn't actually
4318 going to be used (after "if" or "lookup") and it prevents lookups from
4319 happening lower down.
4320
4321 Store usage: At start, a store block of the length of the input plus 64
4322 is obtained. This is expanded as necessary by string_cat(), which might have to
4323 get a new block, or might be able to expand the original. At the end of the
4324 function we can release any store above that portion of the yield block that
4325 was actually used. In many cases this will be optimal.
4326
4327 However: if the first item in the expansion is a variable name or header name,
4328 we reset the store before processing it; if the result is in fresh store, we
4329 use that without copying. This is helpful for expanding strings like
4330 $message_headers which can get very long.
4331
4332 There's a problem if a ${dlfunc item has side-effects that cause allocation,
4333 since resetting the store at the end of the expansion will free store that was
4334 allocated by the plugin code as well as the slop after the expanded string. So
4335 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
4336 and, given the acl condition, ${if }. This is an unfortunate consequence of
4337 string expansion becoming too powerful.
4338
4339 Arguments:
4340   string         the string to be expanded
4341   ket_ends       true if expansion is to stop at }
4342   left           if not NULL, a pointer to the first character after the
4343                  expansion is placed here (typically used with ket_ends)
4344   skipping       TRUE for recursive calls when the value isn't actually going
4345                  to be used (to allow for optimisation)
4346   honour_dollar  TRUE if $ is to be expanded,
4347                  FALSE if it's just another character
4348   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
4349                  the store.
4350
4351 Returns:         NULL if expansion fails:
4352                    expand_string_forcedfail is set TRUE if failure was forced
4353                    expand_string_message contains a textual error message
4354                  a pointer to the expanded string on success
4355 */
4356
4357 static uschar *
4358 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
4359   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
4360 {
4361 rmark reset_point = store_mark();
4362 gstring * yield = string_get(Ustrlen(string) + 64);
4363 int item_type;
4364 const uschar *s = string;
4365 uschar *save_expand_nstring[EXPAND_MAXN+1];
4366 int save_expand_nlength[EXPAND_MAXN+1];
4367 BOOL resetok = TRUE;
4368
4369 expand_level++;
4370 DEBUG(D_expand)
4371   DEBUG(D_noutf8)
4372     debug_printf_indent("/%s: %s\n",
4373       skipping ? "---scanning" : "considering", string);
4374   else
4375     debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
4376       skipping
4377       ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
4378       : "considering",
4379       string);
4380
4381 f.expand_string_forcedfail = FALSE;
4382 expand_string_message = US"";
4383
4384 if (is_tainted(string))
4385   {
4386   expand_string_message =
4387     string_sprintf("attempt to expand tainted string '%s'", s);
4388   log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
4389   goto EXPAND_FAILED;
4390   }
4391
4392 while (*s != 0)
4393   {
4394   uschar *value;
4395   uschar name[256];
4396
4397   /* \ escapes the next character, which must exist, or else
4398   the expansion fails. There's a special escape, \N, which causes
4399   copying of the subject verbatim up to the next \N. Otherwise,
4400   the escapes are the standard set. */
4401
4402   if (*s == '\\')
4403     {
4404     if (s[1] == 0)
4405       {
4406       expand_string_message = US"\\ at end of string";
4407       goto EXPAND_FAILED;
4408       }
4409
4410     if (s[1] == 'N')
4411       {
4412       const uschar * t = s + 2;
4413       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
4414       yield = string_catn(yield, t, s - t);
4415       if (*s != 0) s += 2;
4416       }
4417
4418     else
4419       {
4420       uschar ch[1];
4421       ch[0] = string_interpret_escape(&s);
4422       s++;
4423       yield = string_catn(yield, ch, 1);
4424       }
4425
4426     continue;
4427     }
4428
4429   /*{*/
4430   /* Anything other than $ is just copied verbatim, unless we are
4431   looking for a terminating } character. */
4432
4433   /*{*/
4434   if (ket_ends && *s == '}') break;
4435
4436   if (*s != '$' || !honour_dollar)
4437     {
4438     yield = string_catn(yield, s++, 1);
4439     continue;
4440     }
4441
4442   /* No { after the $ - must be a plain name or a number for string
4443   match variable. There has to be a fudge for variables that are the
4444   names of header fields preceded by "$header_" because header field
4445   names can contain any printing characters except space and colon.
4446   For those that don't like typing this much, "$h_" is a synonym for
4447   "$header_". A non-existent header yields a NULL value; nothing is
4448   inserted. */  /*}*/
4449
4450   if (isalpha((*(++s))))
4451     {
4452     int len;
4453     int newsize = 0;
4454     gstring * g = NULL;
4455     uschar * t;
4456
4457     s = read_name(name, sizeof(name), s, US"_");
4458
4459     /* If this is the first thing to be expanded, release the pre-allocated
4460     buffer. */
4461
4462     if (!yield)
4463       g = store_get(sizeof(gstring), FALSE);
4464     else if (yield->ptr == 0)
4465       {
4466       if (resetok) reset_point = store_reset(reset_point);
4467       yield = NULL;
4468       reset_point = store_mark();
4469       g = store_get(sizeof(gstring), FALSE);    /* alloc _before_ calling find_variable() */
4470       }
4471
4472     /* Header */
4473
4474     if (  ( *(t = name) == 'h'
4475           || (*t == 'r' || *t == 'l' || *t == 'b') && *++t == 'h'
4476           )
4477        && (*++t == '_' || Ustrncmp(t, "eader_", 6) == 0)
4478        )
4479       {
4480       unsigned flags = *name == 'r' ? FH_WANT_RAW
4481                       : *name == 'l' ? FH_WANT_RAW|FH_WANT_LIST
4482                       : 0;
4483       uschar * charset = *name == 'b' ? NULL : headers_charset;
4484
4485       s = read_header_name(name, sizeof(name), s);
4486       value = find_header(name, &newsize, flags, charset);
4487
4488       /* If we didn't find the header, and the header contains a closing brace
4489       character, this may be a user error where the terminating colon
4490       has been omitted. Set a flag to adjust the error message in this case.
4491       But there is no error here - nothing gets inserted. */
4492
4493       if (!value)
4494         {
4495         if (Ustrchr(name, '}')) malformed_header = TRUE;
4496         continue;
4497         }
4498       }
4499
4500     /* Variable */
4501
4502     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
4503       {
4504       expand_string_message =
4505         string_sprintf("unknown variable name \"%s\"", name);
4506         check_variable_error_message(name);
4507       goto EXPAND_FAILED;
4508       }
4509
4510     /* If the data is known to be in a new buffer, newsize will be set to the
4511     size of that buffer. If this is the first thing in an expansion string,
4512     yield will be NULL; just point it at the new store instead of copying. Many
4513     expansion strings contain just one reference, so this is a useful
4514     optimization, especially for humungous headers.  We need to use a gstring
4515     structure that is not allocated after that new-buffer, else a later store
4516     reset in the middle of the buffer will make it inaccessible. */
4517
4518     len = Ustrlen(value);
4519     if (!yield && newsize != 0)
4520       {
4521       yield = g;
4522       yield->size = newsize;
4523       yield->ptr = len;
4524       yield->s = value;
4525       }
4526     else
4527       yield = string_catn(yield, value, len);
4528
4529     continue;
4530     }
4531
4532   if (isdigit(*s))
4533     {
4534     int n;
4535     s = read_cnumber(&n, s);
4536     if (n >= 0 && n <= expand_nmax)
4537       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4538     continue;
4539     }
4540
4541   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4542
4543   if (*s != '{')                                                        /*}*/
4544     {
4545     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4546     goto EXPAND_FAILED;
4547     }
4548
4549   /* After { there can be various things, but they all start with
4550   an initial word, except for a number for a string match variable. */
4551
4552   if (isdigit((*(++s))))
4553     {
4554     int n;
4555     s = read_cnumber(&n, s);            /*{*/
4556     if (*s++ != '}')
4557       {                                 /*{*/
4558       expand_string_message = US"} expected after number";
4559       goto EXPAND_FAILED;
4560       }
4561     if (n >= 0 && n <= expand_nmax)
4562       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4563     continue;
4564     }
4565
4566   if (!isalpha(*s))
4567     {
4568     expand_string_message = US"letter or digit expected after ${";      /*}*/
4569     goto EXPAND_FAILED;
4570     }
4571
4572   /* Allow "-" in names to cater for substrings with negative
4573   arguments. Since we are checking for known names after { this is
4574   OK. */
4575
4576   s = read_name(name, sizeof(name), s, US"_-");
4577   item_type = chop_match(name, item_table, nelem(item_table));
4578
4579   switch(item_type)
4580     {
4581     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4582     If the ACL returns accept or reject we return content set by "message ="
4583     There is currently no limit on recursion; this would have us call
4584     acl_check_internal() directly and get a current level from somewhere.
4585     See also the acl expansion condition ECOND_ACL and the traditional
4586     acl modifier ACLC_ACL.
4587     Assume that the function has side-effects on the store that must be preserved.
4588     */
4589
4590     case EITEM_ACL:
4591       /* ${acl {name} {arg1}{arg2}...} */
4592       {
4593       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4594       uschar *user_msg;
4595       int rc;
4596
4597       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, name,
4598                       &resetok))
4599         {
4600         case 1: goto EXPAND_FAILED_CURLY;
4601         case 2:
4602         case 3: goto EXPAND_FAILED;
4603         }
4604       if (skipping) continue;
4605
4606       resetok = FALSE;
4607       switch(rc = eval_acl(sub, nelem(sub), &user_msg))
4608         {
4609         case OK:
4610         case FAIL:
4611           DEBUG(D_expand)
4612             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4613           if (user_msg)
4614             yield = string_cat(yield, user_msg);
4615           continue;
4616
4617         case DEFER:
4618           f.expand_string_forcedfail = TRUE;
4619           /*FALLTHROUGH*/
4620         default:
4621           expand_string_message = string_sprintf("%s from acl \"%s\"",
4622             rc_names[rc], sub[0]);
4623           goto EXPAND_FAILED;
4624         }
4625       }
4626
4627     case EITEM_AUTHRESULTS:
4628       /* ${authresults {mysystemname}} */
4629       {
4630       uschar *sub_arg[1];
4631
4632       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4633                       &resetok))
4634         {
4635         case 1: goto EXPAND_FAILED_CURLY;
4636         case 2:
4637         case 3: goto EXPAND_FAILED;
4638         }
4639
4640       yield = string_append(yield, 3,
4641                         US"Authentication-Results: ", sub_arg[0], US"; none");
4642       yield->ptr -= 6;
4643
4644       yield = authres_local(yield, sub_arg[0]);
4645       yield = authres_iprev(yield);
4646       yield = authres_smtpauth(yield);
4647 #ifdef SUPPORT_SPF
4648       yield = authres_spf(yield);
4649 #endif
4650 #ifndef DISABLE_DKIM
4651       yield = authres_dkim(yield);
4652 #endif
4653 #ifdef SUPPORT_DMARC
4654       yield = authres_dmarc(yield);
4655 #endif
4656 #ifdef EXPERIMENTAL_ARC
4657       yield = authres_arc(yield);
4658 #endif
4659       continue;
4660       }
4661
4662     /* Handle conditionals - preserve the values of the numerical expansion
4663     variables in case they get changed by a regular expression match in the
4664     condition. If not, they retain their external settings. At the end
4665     of this "if" section, they get restored to their previous values. */
4666
4667     case EITEM_IF:
4668       {
4669       BOOL cond = FALSE;
4670       const uschar *next_s;
4671       int save_expand_nmax =
4672         save_expand_strings(save_expand_nstring, save_expand_nlength);
4673
4674       Uskip_whitespace(&s);
4675       if (!(next_s = eval_condition(s, &resetok, skipping ? NULL : &cond)))
4676         goto EXPAND_FAILED;  /* message already set */
4677
4678       DEBUG(D_expand)
4679         DEBUG(D_noutf8)
4680           {
4681           debug_printf_indent("|--condition: %.*s\n", (int)(next_s - s), s);
4682           debug_printf_indent("|-----result: %s\n", cond ? "true" : "false");
4683           }
4684         else
4685           {
4686           debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4687             "condition: %.*s\n",
4688             (int)(next_s - s), s);
4689           debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4690             UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4691             "result: %s\n",
4692             cond ? "true" : "false");
4693           }
4694
4695       s = next_s;
4696
4697       /* The handling of "yes" and "no" result strings is now in a separate
4698       function that is also used by ${lookup} and ${extract} and ${run}. */
4699
4700       switch(process_yesno(
4701                skipping,                     /* were previously skipping */
4702                cond,                         /* success/failure indicator */
4703                lookup_value,                 /* value to reset for string2 */
4704                &s,                           /* input pointer */
4705                &yield,                       /* output pointer */
4706                US"if",                       /* condition type */
4707                &resetok))
4708         {
4709         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4710         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4711         }
4712
4713       /* Restore external setting of expansion variables for continuation
4714       at this level. */
4715
4716       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4717         save_expand_nlength);
4718       continue;
4719       }
4720
4721 #ifdef SUPPORT_I18N
4722     case EITEM_IMAPFOLDER:
4723       {                         /* ${imapfolder {name}{sep]{specials}} */
4724       uschar *sub_arg[3];
4725       uschar *encoded;
4726
4727       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4728                       &resetok))
4729         {
4730         case 1: goto EXPAND_FAILED_CURLY;
4731         case 2:
4732         case 3: goto EXPAND_FAILED;
4733         }
4734
4735       if (!sub_arg[1])                  /* One argument */
4736         {
4737         sub_arg[1] = US"/";             /* default separator */
4738         sub_arg[2] = NULL;
4739         }
4740       else if (Ustrlen(sub_arg[1]) != 1)
4741         {
4742         expand_string_message =
4743           string_sprintf(
4744                 "IMAP folder separator must be one character, found \"%s\"",
4745                 sub_arg[1]);
4746         goto EXPAND_FAILED;
4747         }
4748
4749       if (!skipping)
4750         {
4751         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4752                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4753           goto EXPAND_FAILED;
4754         yield = string_cat(yield, encoded);
4755         }
4756       continue;
4757       }
4758 #endif
4759
4760     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4761     expanding an internal string that isn't actually going to be used. All we
4762     need to do is check the syntax, so don't do a lookup at all. Preserve the
4763     values of the numerical expansion variables in case they get changed by a
4764     partial lookup. If not, they retain their external settings. At the end
4765     of this "lookup" section, they get restored to their previous values. */
4766
4767     case EITEM_LOOKUP:
4768       {
4769       int stype, partial, affixlen, starflags;
4770       int expand_setup = 0;
4771       int nameptr = 0;
4772       uschar *key, *filename;
4773       const uschar * affix, * opts;
4774       uschar *save_lookup_value = lookup_value;
4775       int save_expand_nmax =
4776         save_expand_strings(save_expand_nstring, save_expand_nlength);
4777
4778       if ((expand_forbid & RDO_LOOKUP) != 0)
4779         {
4780         expand_string_message = US"lookup expansions are not permitted";
4781         goto EXPAND_FAILED;
4782         }
4783
4784       /* Get the key we are to look up for single-key+file style lookups.
4785       Otherwise set the key NULL pro-tem. */
4786
4787       if (Uskip_whitespace(&s) == '{')                                  /*}*/
4788         {
4789         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4790         if (!key) goto EXPAND_FAILED;                   /*{{*/
4791         if (*s++ != '}')
4792           {
4793           expand_string_message = US"missing '}' after lookup key";
4794           goto EXPAND_FAILED_CURLY;
4795           }
4796         Uskip_whitespace(&s);
4797         }
4798       else key = NULL;
4799
4800       /* Find out the type of database */
4801
4802       if (!isalpha(*s))
4803         {
4804         expand_string_message = US"missing lookup type";
4805         goto EXPAND_FAILED;
4806         }
4807
4808       /* The type is a string that may contain special characters of various
4809       kinds. Allow everything except space or { to appear; the actual content
4810       is checked by search_findtype_partial. */         /*}*/
4811
4812       while (*s && *s != '{' && !isspace(*s))           /*}*/
4813         {
4814         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4815         s++;
4816         }
4817       name[nameptr] = '\0';
4818       Uskip_whitespace(&s);
4819
4820       /* Now check for the individual search type and any partial or default
4821       options. Only those types that are actually in the binary are valid. */
4822
4823       if ((stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4824           &starflags, &opts)) < 0)
4825         {
4826         expand_string_message = search_error_message;
4827         goto EXPAND_FAILED;
4828         }
4829
4830       /* Check that a key was provided for those lookup types that need it,
4831       and was not supplied for those that use the query style. */
4832
4833       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4834         {
4835         if (!key)
4836           {
4837           expand_string_message = string_sprintf("missing {key} for single-"
4838             "key \"%s\" lookup", name);
4839           goto EXPAND_FAILED;
4840           }
4841         }
4842       else
4843         {
4844         if (key)
4845           {
4846           expand_string_message = string_sprintf("a single key was given for "
4847             "lookup type \"%s\", which is not a single-key lookup type", name);
4848           goto EXPAND_FAILED;
4849           }
4850         }
4851
4852       /* Get the next string in brackets and expand it. It is the file name for
4853       single-key+file lookups, and the whole query otherwise. In the case of
4854       queries that also require a file name (e.g. sqlite), the file name comes
4855       first. */
4856
4857       if (*s != '{')
4858         {
4859         expand_string_message = US"missing '{' for lookup file-or-query arg";
4860         goto EXPAND_FAILED_CURLY;
4861         }
4862       if (!(filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok)))
4863         goto EXPAND_FAILED;
4864       if (*s++ != '}')
4865         {
4866         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4867         goto EXPAND_FAILED_CURLY;
4868         }
4869       Uskip_whitespace(&s);
4870
4871       /* If this isn't a single-key+file lookup, re-arrange the variables
4872       to be appropriate for the search_ functions. For query-style lookups,
4873       there is just a "key", and no file name. For the special query-style +
4874       file types, the query (i.e. "key") starts with a file name. */
4875
4876       if (!key)
4877         {
4878         Uskip_whitespace(&filename);
4879         key = filename;
4880
4881         if (mac_islookup(stype, lookup_querystyle))
4882           filename = NULL;
4883         else
4884           if (*filename == '/')
4885             {
4886             while (*key && !isspace(*key)) key++;
4887             if (*key) *key++ = '\0';
4888             }
4889           else
4890             filename = NULL;
4891         }
4892
4893       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4894       the entry was not found. Note that there is no search_close() function.
4895       Files are left open in case of re-use. At suitable places in higher logic,
4896       search_tidyup() is called to tidy all open files. This can save opening
4897       the same file several times. However, files may also get closed when
4898       others are opened, if too many are open at once. The rule is that a
4899       handle should not be used after a second search_open().
4900
4901       Request that a partial search sets up $1 and maybe $2 by passing
4902       expand_setup containing zero. If its value changes, reset expand_nmax,
4903       since new variables will have been set. Note that at the end of this
4904       "lookup" section, the old numeric variables are restored. */
4905
4906       if (skipping)
4907         lookup_value = NULL;
4908       else
4909         {
4910         void *handle = search_open(filename, stype, 0, NULL, NULL);
4911         if (!handle)
4912           {
4913           expand_string_message = search_error_message;
4914           goto EXPAND_FAILED;
4915           }
4916         lookup_value = search_find(handle, filename, key, partial, affix,
4917           affixlen, starflags, &expand_setup, opts);
4918         if (f.search_find_defer)
4919           {
4920           expand_string_message =
4921             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4922               string_printing2(key, FALSE), search_error_message);
4923           goto EXPAND_FAILED;
4924           }
4925         if (expand_setup > 0) expand_nmax = expand_setup;
4926         }
4927
4928       /* The handling of "yes" and "no" result strings is now in a separate
4929       function that is also used by ${if} and ${extract}. */
4930
4931       switch(process_yesno(
4932                skipping,                     /* were previously skipping */
4933                lookup_value != NULL,         /* success/failure indicator */
4934                save_lookup_value,            /* value to reset for string2 */
4935                &s,                           /* input pointer */
4936                &yield,                       /* output pointer */
4937                US"lookup",                   /* condition type */
4938                &resetok))
4939         {
4940         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4941         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4942         }
4943
4944       /* Restore external setting of expansion variables for carrying on
4945       at this level, and continue. */
4946
4947       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4948         save_expand_nlength);
4949       continue;
4950       }
4951
4952     /* If Perl support is configured, handle calling embedded perl subroutines,
4953     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4954     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4955     arguments (defined below). */
4956
4957     #define EXIM_PERL_MAX_ARGS 8
4958
4959     case EITEM_PERL:
4960     #ifndef EXIM_PERL
4961     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4962       "is not included in this binary";
4963     goto EXPAND_FAILED;
4964
4965     #else   /* EXIM_PERL */
4966       {
4967       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4968       gstring *new_yield;
4969
4970       if ((expand_forbid & RDO_PERL) != 0)
4971         {
4972         expand_string_message = US"Perl calls are not permitted";
4973         goto EXPAND_FAILED;
4974         }
4975
4976       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4977            name, &resetok))
4978         {
4979         case 1: goto EXPAND_FAILED_CURLY;
4980         case 2:
4981         case 3: goto EXPAND_FAILED;
4982         }
4983
4984       /* If skipping, we don't actually do anything */
4985
4986       if (skipping) continue;
4987
4988       /* Start the interpreter if necessary */
4989
4990       if (!opt_perl_started)
4991         {
4992         uschar *initerror;
4993         if (!opt_perl_startup)
4994           {
4995           expand_string_message = US"A setting of perl_startup is needed when "
4996             "using the Perl interpreter";
4997           goto EXPAND_FAILED;
4998           }
4999         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
5000         if ((initerror = init_perl(opt_perl_startup)))
5001           {
5002           expand_string_message =
5003             string_sprintf("error in perl_startup code: %s\n", initerror);
5004           goto EXPAND_FAILED;
5005           }
5006         opt_perl_started = TRUE;
5007         }
5008
5009       /* Call the function */
5010
5011       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
5012       new_yield = call_perl_cat(yield, &expand_string_message,
5013         sub_arg[0], sub_arg + 1);
5014
5015       /* NULL yield indicates failure; if the message pointer has been set to
5016       NULL, the yield was undef, indicating a forced failure. Otherwise the
5017       message will indicate some kind of Perl error. */
5018
5019       if (!new_yield)
5020         {
5021         if (!expand_string_message)
5022           {
5023           expand_string_message =
5024             string_sprintf("Perl subroutine \"%s\" returned undef to force "
5025               "failure", sub_arg[0]);
5026           f.expand_string_forcedfail = TRUE;
5027           }
5028         goto EXPAND_FAILED;
5029         }
5030
5031       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
5032       set during a callback from Perl. */
5033
5034       f.expand_string_forcedfail = FALSE;
5035       yield = new_yield;
5036       continue;
5037       }
5038     #endif /* EXIM_PERL */
5039
5040     /* Transform email address to "prvs" scheme to use
5041        as BATV-signed return path */
5042
5043     case EITEM_PRVS:
5044       {
5045       uschar *sub_arg[3];
5046       uschar *p,*domain;
5047
5048       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, name, &resetok))
5049         {
5050         case 1: goto EXPAND_FAILED_CURLY;
5051         case 2:
5052         case 3: goto EXPAND_FAILED;
5053         }
5054
5055       /* If skipping, we don't actually do anything */
5056       if (skipping) continue;
5057
5058       /* sub_arg[0] is the address */
5059       if (  !(domain = Ustrrchr(sub_arg[0],'@'))
5060          || domain == sub_arg[0] || Ustrlen(domain) == 1)
5061         {
5062         expand_string_message = US"prvs first argument must be a qualified email address";
5063         goto EXPAND_FAILED;
5064         }
5065
5066       /* Calculate the hash. The third argument must be a single-digit
5067       key number, or unset. */
5068
5069       if (  sub_arg[2]
5070          && (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
5071         {
5072         expand_string_message = US"prvs third argument must be a single digit";
5073         goto EXPAND_FAILED;
5074         }
5075
5076       p = prvs_hmac_sha1(sub_arg[0], sub_arg[1], sub_arg[2], prvs_daystamp(7));
5077       if (!p)
5078         {
5079         expand_string_message = US"prvs hmac-sha1 conversion failed";
5080         goto EXPAND_FAILED;
5081         }
5082
5083       /* Now separate the domain from the local part */
5084       *domain++ = '\0';
5085
5086       yield = string_catn(yield, US"prvs=", 5);
5087       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
5088       yield = string_catn(yield, prvs_daystamp(7), 3);
5089       yield = string_catn(yield, p, 6);
5090       yield = string_catn(yield, US"=", 1);
5091       yield = string_cat (yield, sub_arg[0]);
5092       yield = string_catn(yield, US"@", 1);
5093       yield = string_cat (yield, domain);
5094
5095       continue;
5096       }
5097
5098     /* Check a prvs-encoded address for validity */
5099
5100     case EITEM_PRVSCHECK:
5101       {
5102       uschar *sub_arg[3];
5103       gstring * g;
5104       const pcre *re;
5105       uschar *p;
5106
5107       /* TF: Ugliness: We want to expand parameter 1 first, then set
5108          up expansion variables that are used in the expansion of
5109          parameter 2. So we clone the string for the first
5110          expansion, where we only expand parameter 1.
5111
5112          PH: Actually, that isn't necessary. The read_subs() function is
5113          designed to work this way for the ${if and ${lookup expansions. I've
5114          tidied the code.
5115       */
5116
5117       /* Reset expansion variables */
5118       prvscheck_result = NULL;
5119       prvscheck_address = NULL;
5120       prvscheck_keynum = NULL;
5121
5122       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, name, &resetok))
5123         {
5124         case 1: goto EXPAND_FAILED_CURLY;
5125         case 2:
5126         case 3: goto EXPAND_FAILED;
5127         }
5128
5129       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
5130                               TRUE,FALSE);
5131
5132       if (regex_match_and_setup(re,sub_arg[0],0,-1))
5133         {
5134         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
5135         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
5136         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
5137         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
5138         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
5139
5140         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
5141         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
5142         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
5143         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
5144         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
5145
5146         /* Set up expansion variables */
5147         g = string_cat (NULL, local_part);
5148         g = string_catn(g, US"@", 1);
5149         g = string_cat (g, domain);
5150         prvscheck_address = string_from_gstring(g);
5151         prvscheck_keynum = string_copy(key_num);
5152
5153         /* Now expand the second argument */
5154         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, name, &resetok))
5155           {
5156           case 1: goto EXPAND_FAILED_CURLY;
5157           case 2:
5158           case 3: goto EXPAND_FAILED;
5159           }
5160
5161         /* Now we have the key and can check the address. */
5162
5163         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
5164           daystamp);
5165
5166         if (!p)
5167           {
5168           expand_string_message = US"hmac-sha1 conversion failed";
5169           goto EXPAND_FAILED;
5170           }
5171
5172         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
5173         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
5174
5175         if (Ustrcmp(p,hash) == 0)
5176           {
5177           /* Success, valid BATV address. Now check the expiry date. */
5178           uschar *now = prvs_daystamp(0);
5179           unsigned int inow = 0,iexpire = 1;
5180
5181           (void)sscanf(CS now,"%u",&inow);
5182           (void)sscanf(CS daystamp,"%u",&iexpire);
5183
5184           /* When "iexpire" is < 7, a "flip" has occurred.
5185              Adjust "inow" accordingly. */
5186           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
5187
5188           if (iexpire >= inow)
5189             {
5190             prvscheck_result = US"1";
5191             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
5192             }
5193           else
5194             {
5195             prvscheck_result = NULL;
5196             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
5197             }
5198           }
5199         else
5200           {
5201           prvscheck_result = NULL;
5202           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
5203           }
5204
5205         /* Now expand the final argument. We leave this till now so that
5206         it can include $prvscheck_result. */
5207
5208         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, name, &resetok))
5209           {
5210           case 1: goto EXPAND_FAILED_CURLY;
5211           case 2:
5212           case 3: goto EXPAND_FAILED;
5213           }
5214
5215         yield = string_cat(yield,
5216           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
5217
5218         /* Reset the "internal" variables afterwards, because they are in
5219         dynamic store that will be reclaimed if the expansion succeeded. */
5220
5221         prvscheck_address = NULL;
5222         prvscheck_keynum = NULL;
5223         }
5224       else
5225         /* Does not look like a prvs encoded address, return the empty string.
5226            We need to make sure all subs are expanded first, so as to skip over
5227            the entire item. */
5228
5229         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, name, &resetok))
5230           {
5231           case 1: goto EXPAND_FAILED_CURLY;
5232           case 2:
5233           case 3: goto EXPAND_FAILED;
5234           }
5235
5236       continue;
5237       }
5238
5239     /* Handle "readfile" to insert an entire file */
5240
5241     case EITEM_READFILE:
5242       {
5243       FILE *f;
5244       uschar *sub_arg[2];
5245
5246       if ((expand_forbid & RDO_READFILE) != 0)
5247         {
5248         expand_string_message = US"file insertions are not permitted";
5249         goto EXPAND_FAILED;
5250         }
5251
5252       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, name, &resetok))
5253         {
5254         case 1: goto EXPAND_FAILED_CURLY;
5255         case 2:
5256         case 3: goto EXPAND_FAILED;
5257         }
5258
5259       /* If skipping, we don't actually do anything */
5260
5261       if (skipping) continue;
5262
5263       /* Open the file and read it */
5264
5265       if (!(f = Ufopen(sub_arg[0], "rb")))
5266         {
5267         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
5268         goto EXPAND_FAILED;
5269         }
5270
5271       yield = cat_file(f, yield, sub_arg[1]);
5272       (void)fclose(f);
5273       continue;
5274       }
5275
5276     /* Handle "readsocket" to insert data from a socket, either
5277     Inet or Unix domain */
5278
5279     case EITEM_READSOCK:
5280       {
5281       uschar * arg;
5282       uschar * sub_arg[4];
5283
5284       if (expand_forbid & RDO_READSOCK)
5285         {
5286         expand_string_message = US"socket insertions are not permitted";
5287         goto EXPAND_FAILED;
5288         }
5289
5290       /* Read up to 4 arguments, but don't do the end of item check afterwards,
5291       because there may be a string for expansion on failure. */
5292
5293       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, name, &resetok))
5294         {
5295         case 1: goto EXPAND_FAILED_CURLY;
5296         case 2:                             /* Won't occur: no end check */
5297         case 3: goto EXPAND_FAILED;
5298         }
5299
5300       /* If skipping, we don't actually do anything. Otherwise, arrange to
5301       connect to either an IP or a Unix socket. */
5302
5303       if (!skipping)
5304         {
5305         int stype = search_findtype(US"readsock", 8);
5306         gstring * g = NULL;
5307         void * handle;
5308         int expand_setup = -1;
5309         uschar * s;
5310
5311         /* If the reqstr is empty, flag that and set a dummy */
5312
5313         if (!sub_arg[1][0])
5314           {
5315           g = string_append_listele(g, ',', US"send=no");
5316           sub_arg[1] = US"DUMMY";
5317           }
5318
5319         /* Re-marshall the options */
5320
5321         if (sub_arg[2])
5322           {
5323           const uschar * list = sub_arg[2];
5324           uschar * item;
5325           int sep = 0;
5326
5327           /* First option has no tag and is timeout */
5328           if ((item = string_nextinlist(&list, &sep, NULL, 0)))
5329             g = string_append_listele(g, ',',
5330                   string_sprintf("timeout=%s", item));
5331
5332           /* The rest of the options from the expansion */
5333           while ((item = string_nextinlist(&list, &sep, NULL, 0)))
5334             g = string_append_listele(g, ',', item);
5335
5336           /* possibly plus an EOL string */
5337           if (sub_arg[3] && *sub_arg[3])
5338             g = string_append_listele(g, ',',
5339                   string_sprintf("eol=%s", sub_arg[3]));
5340
5341           }
5342
5343         /* Gat a (possibly cached) handle for the connection */
5344
5345         if (!(handle = search_open(sub_arg[0], stype, 0, NULL, NULL)))
5346           {
5347           if (*expand_string_message) goto EXPAND_FAILED;
5348           expand_string_message = search_error_message;
5349           search_error_message = NULL;
5350           goto SOCK_FAIL;
5351           }
5352
5353         /* Get (possibly cached) results for the lookup */
5354         /* sspec: sub_arg[0]  req: sub_arg[1]  opts: g */
5355
5356         if ((s = search_find(handle, sub_arg[0], sub_arg[1], -1, NULL, 0, 0,
5357                                     &expand_setup, string_from_gstring(g))))
5358           yield = string_cat(yield, s);
5359         else if (f.search_find_defer)
5360           {
5361           expand_string_message = search_error_message;
5362           search_error_message = NULL;
5363           goto SOCK_FAIL;
5364           }
5365         else
5366           {     /* should not happen, at present */
5367           expand_string_message = search_error_message;
5368           search_error_message = NULL;
5369           goto SOCK_FAIL;
5370           }
5371         }
5372
5373       /* The whole thing has worked (or we were skipping). If there is a
5374       failure string following, we need to skip it. */
5375
5376       if (*s == '{')
5377         {
5378         if (!expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok))
5379           goto EXPAND_FAILED;
5380         if (*s++ != '}')
5381           {
5382           expand_string_message = US"missing '}' closing failstring for readsocket";
5383           goto EXPAND_FAILED_CURLY;
5384           }
5385         Uskip_whitespace(&s);
5386         }
5387
5388     READSOCK_DONE:
5389       if (*s++ != '}')
5390         {
5391         expand_string_message = US"missing '}' closing readsocket";
5392         goto EXPAND_FAILED_CURLY;
5393         }
5394       continue;
5395
5396       /* Come here on failure to create socket, connect socket, write to the
5397       socket, or timeout on reading. If another substring follows, expand and
5398       use it. Otherwise, those conditions give expand errors. */
5399
5400     SOCK_FAIL:
5401       if (*s != '{') goto EXPAND_FAILED;
5402       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
5403       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
5404         goto EXPAND_FAILED;
5405       yield = string_cat(yield, arg);
5406       if (*s++ != '}')
5407         {
5408         expand_string_message = US"missing '}' closing failstring for readsocket";
5409         goto EXPAND_FAILED_CURLY;
5410         }
5411       Uskip_whitespace(&s);
5412       goto READSOCK_DONE;
5413       }
5414
5415     /* Handle "run" to execute a program. */
5416
5417     case EITEM_RUN:
5418       {
5419       FILE *f;
5420       uschar *arg;
5421       const uschar **argv;
5422       pid_t pid;
5423       int fd_in, fd_out;
5424
5425       if ((expand_forbid & RDO_RUN) != 0)
5426         {
5427         expand_string_message = US"running a command is not permitted";
5428         goto EXPAND_FAILED;
5429         }
5430
5431       Uskip_whitespace(&s);
5432       if (*s != '{')
5433         {
5434         expand_string_message = US"missing '{' for command arg of run";
5435         goto EXPAND_FAILED_CURLY;
5436         }
5437       if (!(arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok)))
5438         goto EXPAND_FAILED;
5439       Uskip_whitespace(&s);
5440       if (*s++ != '}')
5441         {
5442         expand_string_message = US"missing '}' closing command arg of run";
5443         goto EXPAND_FAILED_CURLY;
5444         }
5445
5446       if (skipping)   /* Just pretend it worked when we're skipping */
5447         {
5448         runrc = 0;
5449         lookup_value = NULL;
5450         }
5451       else
5452         {
5453         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5454             arg,                                /* raw command */
5455             FALSE,                              /* don't expand the arguments */
5456             0,                                  /* not relevant when... */
5457             NULL,                               /* no transporting address */
5458             US"${run} expansion",               /* for error messages */
5459             &expand_string_message))            /* where to put error message */
5460           goto EXPAND_FAILED;
5461
5462         /* Create the child process, making it a group leader. */
5463
5464         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE,
5465                               US"expand-run")) < 0)
5466           {
5467           expand_string_message =
5468             string_sprintf("couldn't create child process: %s", strerror(errno));
5469           goto EXPAND_FAILED;
5470           }
5471
5472         /* Nothing is written to the standard input. */
5473
5474         (void)close(fd_in);
5475
5476         /* Read the pipe to get the command's output into $value (which is kept
5477         in lookup_value). Read during execution, so that if the output exceeds
5478         the OS pipe buffer limit, we don't block forever. Remember to not release
5479         memory just allocated for $value. */
5480
5481         resetok = FALSE;
5482         f = fdopen(fd_out, "rb");
5483         sigalrm_seen = FALSE;
5484         ALARM(60);
5485         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5486         ALARM_CLR(0);
5487         (void)fclose(f);
5488
5489         /* Wait for the process to finish, applying the timeout, and inspect its
5490         return code for serious disasters. Simple non-zero returns are passed on.
5491         */
5492
5493         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5494           {
5495           if (sigalrm_seen || runrc == -256)
5496             {
5497             expand_string_message = US"command timed out";
5498             killpg(pid, SIGKILL);       /* Kill the whole process group */
5499             }
5500
5501           else if (runrc == -257)
5502             expand_string_message = string_sprintf("wait() failed: %s",
5503               strerror(errno));
5504
5505           else
5506             expand_string_message = string_sprintf("command killed by signal %d",
5507               -runrc);
5508
5509           goto EXPAND_FAILED;
5510           }
5511         }
5512
5513       /* Process the yes/no strings; $value may be useful in both cases */
5514
5515       switch(process_yesno(
5516                skipping,                     /* were previously skipping */
5517                runrc == 0,                   /* success/failure indicator */
5518                lookup_value,                 /* value to reset for string2 */
5519                &s,                           /* input pointer */
5520                &yield,                       /* output pointer */
5521                US"run",                      /* condition type */
5522                &resetok))
5523         {
5524         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5525         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5526         }
5527
5528       continue;
5529       }
5530
5531     /* Handle character translation for "tr" */
5532
5533     case EITEM_TR:
5534       {
5535       int oldptr = gstring_length(yield);
5536       int o2m;
5537       uschar *sub[3];
5538
5539       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5540         {
5541         case 1: goto EXPAND_FAILED_CURLY;
5542         case 2:
5543         case 3: goto EXPAND_FAILED;
5544         }
5545
5546       yield = string_cat(yield, sub[0]);
5547       o2m = Ustrlen(sub[2]) - 1;
5548
5549       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5550         {
5551         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5552         if (m)
5553           {
5554           int o = m - sub[1];
5555           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5556           }
5557         }
5558
5559       continue;
5560       }
5561
5562     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5563     expanded arguments. */
5564
5565     case EITEM_HASH:
5566     case EITEM_LENGTH:
5567     case EITEM_NHASH:
5568     case EITEM_SUBSTR:
5569       {
5570       int len;
5571       uschar *ret;
5572       int val[2] = { 0, -1 };
5573       uschar *sub[3];
5574
5575       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5576       Ensure that sub[2] is set in the ${length } case. */
5577
5578       sub[2] = NULL;
5579       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5580              TRUE, name, &resetok))
5581         {
5582         case 1: goto EXPAND_FAILED_CURLY;
5583         case 2:
5584         case 3: goto EXPAND_FAILED;
5585         }
5586
5587       /* Juggle the arguments if there are only two of them: always move the
5588       string to the last position and make ${length{n}{str}} equivalent to
5589       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5590
5591       if (!sub[2])
5592         {
5593         sub[2] = sub[1];
5594         sub[1] = NULL;
5595         if (item_type == EITEM_LENGTH)
5596           {
5597           sub[1] = sub[0];
5598           sub[0] = NULL;
5599           }
5600         }
5601
5602       for (int i = 0; i < 2; i++) if (sub[i])
5603         {
5604         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5605         if (*ret != 0 || (i != 0 && val[i] < 0))
5606           {
5607           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5608             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5609           goto EXPAND_FAILED;
5610           }
5611         }
5612
5613       ret =
5614         item_type == EITEM_HASH
5615         ?  compute_hash(sub[2], val[0], val[1], &len)
5616         : item_type == EITEM_NHASH
5617         ? compute_nhash(sub[2], val[0], val[1], &len)
5618         : extract_substr(sub[2], val[0], val[1], &len);
5619       if (!ret)
5620         goto EXPAND_FAILED;
5621       yield = string_catn(yield, ret, len);
5622       continue;
5623       }
5624
5625     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5626     This code originally contributed by Steve Haslam. It currently supports
5627     the use of MD5 and SHA-1 hashes.
5628
5629     We need some workspace that is large enough to handle all the supported
5630     hash types. Use macros to set the sizes rather than be too elaborate. */
5631
5632     #define MAX_HASHLEN      20
5633     #define MAX_HASHBLOCKLEN 64
5634
5635     case EITEM_HMAC:
5636       {
5637       uschar *sub[3];
5638       md5 md5_base;
5639       hctx sha1_ctx;
5640       void *use_base;
5641       int type;
5642       int hashlen;      /* Number of octets for the hash algorithm's output */
5643       int hashblocklen; /* Number of octets the hash algorithm processes */
5644       uschar *keyptr, *p;
5645       unsigned int keylen;
5646
5647       uschar keyhash[MAX_HASHLEN];
5648       uschar innerhash[MAX_HASHLEN];
5649       uschar finalhash[MAX_HASHLEN];
5650       uschar finalhash_hex[2*MAX_HASHLEN];
5651       uschar innerkey[MAX_HASHBLOCKLEN];
5652       uschar outerkey[MAX_HASHBLOCKLEN];
5653
5654       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5655         {
5656         case 1: goto EXPAND_FAILED_CURLY;
5657         case 2:
5658         case 3: goto EXPAND_FAILED;
5659         }
5660
5661       if (!skipping)
5662         {
5663         if (Ustrcmp(sub[0], "md5") == 0)
5664           {
5665           type = HMAC_MD5;
5666           use_base = &md5_base;
5667           hashlen = 16;
5668           hashblocklen = 64;
5669           }
5670         else if (Ustrcmp(sub[0], "sha1") == 0)
5671           {
5672           type = HMAC_SHA1;
5673           use_base = &sha1_ctx;
5674           hashlen = 20;
5675           hashblocklen = 64;
5676           }
5677         else
5678           {
5679           expand_string_message =
5680             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5681           goto EXPAND_FAILED;
5682           }
5683
5684         keyptr = sub[1];
5685         keylen = Ustrlen(keyptr);
5686
5687         /* If the key is longer than the hash block length, then hash the key
5688         first */
5689
5690         if (keylen > hashblocklen)
5691           {
5692           chash_start(type, use_base);
5693           chash_end(type, use_base, keyptr, keylen, keyhash);
5694           keyptr = keyhash;
5695           keylen = hashlen;
5696           }
5697
5698         /* Now make the inner and outer key values */
5699
5700         memset(innerkey, 0x36, hashblocklen);
5701         memset(outerkey, 0x5c, hashblocklen);
5702
5703         for (int i = 0; i < keylen; i++)
5704           {
5705           innerkey[i] ^= keyptr[i];
5706           outerkey[i] ^= keyptr[i];
5707           }
5708
5709         /* Now do the hashes */
5710
5711         chash_start(type, use_base);
5712         chash_mid(type, use_base, innerkey);
5713         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5714
5715         chash_start(type, use_base);
5716         chash_mid(type, use_base, outerkey);
5717         chash_end(type, use_base, innerhash, hashlen, finalhash);
5718
5719         /* Encode the final hash as a hex string */
5720
5721         p = finalhash_hex;
5722         for (int i = 0; i < hashlen; i++)
5723           {
5724           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5725           *p++ = hex_digits[finalhash[i] & 0x0f];
5726           }
5727
5728         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5729           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5730
5731         yield = string_catn(yield, finalhash_hex, hashlen*2);
5732         }
5733       continue;
5734       }
5735
5736     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5737     We have to save the numerical variables and restore them afterwards. */
5738
5739     case EITEM_SG:
5740       {
5741       const pcre *re;
5742       int moffset, moffsetextra, slen;
5743       int roffset;
5744       int emptyopt;
5745       const uschar *rerror;
5746       uschar *subject;
5747       uschar *sub[3];
5748       int save_expand_nmax =
5749         save_expand_strings(save_expand_nstring, save_expand_nlength);
5750
5751       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5752         {
5753         case 1: goto EXPAND_FAILED_CURLY;
5754         case 2:
5755         case 3: goto EXPAND_FAILED;
5756         }
5757
5758       /* Compile the regular expression */
5759
5760       if (!(re = pcre_compile(CS sub[1], PCRE_COPT, CCSS &rerror,
5761                               &roffset, NULL)))
5762         {
5763         expand_string_message = string_sprintf("regular expression error in "
5764           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5765         goto EXPAND_FAILED;
5766         }
5767
5768       /* Now run a loop to do the substitutions as often as necessary. It ends
5769       when there are no more matches. Take care over matches of the null string;
5770       do the same thing as Perl does. */
5771
5772       subject = sub[0];
5773       slen = Ustrlen(sub[0]);
5774       moffset = moffsetextra = 0;
5775       emptyopt = 0;
5776
5777       for (;;)
5778         {
5779         int ovector[3*(EXPAND_MAXN+1)];
5780         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5781           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5782         uschar *insert;
5783
5784         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5785         is not necessarily the end. We want to repeat the match from one
5786         character further along, but leaving the basic offset the same (for
5787         copying below). We can't be at the end of the string - that was checked
5788         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5789         finished; copy the remaining string and end the loop. */
5790
5791         if (n < 0)
5792           {
5793           if (emptyopt != 0)
5794             {
5795             moffsetextra = 1;
5796             emptyopt = 0;
5797             continue;
5798             }
5799           yield = string_catn(yield, subject+moffset, slen-moffset);
5800           break;
5801           }
5802
5803         /* Match - set up for expanding the replacement. */
5804
5805         if (n == 0) n = EXPAND_MAXN + 1;
5806         expand_nmax = 0;
5807         for (int nn = 0; nn < n*2; nn += 2)
5808           {
5809           expand_nstring[expand_nmax] = subject + ovector[nn];
5810           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5811           }
5812         expand_nmax--;
5813
5814         /* Copy the characters before the match, plus the expanded insertion. */
5815
5816         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5817         if (!(insert = expand_string(sub[2])))
5818           goto EXPAND_FAILED;
5819         yield = string_cat(yield, insert);
5820
5821         moffset = ovector[1];
5822         moffsetextra = 0;
5823         emptyopt = 0;
5824
5825         /* If we have matched an empty string, first check to see if we are at
5826         the end of the subject. If so, the loop is over. Otherwise, mimic
5827         what Perl's /g options does. This turns out to be rather cunning. First
5828         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5829         string at the same point. If this fails (picked up above) we advance to
5830         the next character. */
5831
5832         if (ovector[0] == ovector[1])
5833           {
5834           if (ovector[0] == slen) break;
5835           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5836           }
5837         }
5838
5839       /* All done - restore numerical variables. */
5840
5841       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5842         save_expand_nlength);
5843       continue;
5844       }
5845
5846     /* Handle keyed and numbered substring extraction. If the first argument
5847     consists entirely of digits, then a numerical extraction is assumed. */
5848
5849     case EITEM_EXTRACT:
5850       {
5851       int field_number = 1;
5852       BOOL field_number_set = FALSE;
5853       uschar *save_lookup_value = lookup_value;
5854       uschar *sub[3];
5855       int save_expand_nmax =
5856         save_expand_strings(save_expand_nstring, save_expand_nlength);
5857
5858       /* On reflection the original behaviour of extract-json for a string
5859       result, leaving it quoted, was a mistake.  But it was already published,
5860       hence the addition of jsons.  In a future major version, make json
5861       work like josons, and withdraw jsons. */
5862
5863       enum {extract_basic, extract_json, extract_jsons} fmt = extract_basic;
5864
5865       /* Check for a format-variant specifier */
5866
5867       if (Uskip_whitespace(&s) != '{')                                  /*}*/
5868         if (Ustrncmp(s, "json", 4) == 0)
5869           if (*(s += 4) == 's')
5870             {fmt = extract_jsons; s++;}
5871           else
5872             fmt = extract_json;
5873
5874       /* While skipping we cannot rely on the data for expansions being
5875       available (eg. $item) hence cannot decide on numeric vs. keyed.
5876       Read a maximum of 5 arguments (including the yes/no) */
5877
5878       if (skipping)
5879         {
5880         for (int j = 5; j > 0 && *s == '{'; j--)                /*'}'*/
5881           {
5882           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5883             goto EXPAND_FAILED;                                 /*'{'*/
5884           if (*s++ != '}')
5885             {
5886             expand_string_message = US"missing '{' for arg of extract";
5887             goto EXPAND_FAILED_CURLY;
5888             }
5889           Uskip_whitespace(&s);
5890           }
5891         if (  Ustrncmp(s, "fail", 4) == 0                       /*'{'*/
5892            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5893            )
5894           {
5895           s += 4;
5896           Uskip_whitespace(&s);
5897           }                                                     /*'{'*/
5898         if (*s != '}')
5899           {
5900           expand_string_message = US"missing '}' closing extract";
5901           goto EXPAND_FAILED_CURLY;
5902           }
5903         }
5904
5905       else for (int i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5906         {
5907         if (Uskip_whitespace(&s) == '{')                                                /*'}'*/
5908           {
5909           if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok)))
5910             goto EXPAND_FAILED;                                 /*'{'*/
5911           if (*s++ != '}')
5912             {
5913             expand_string_message = string_sprintf(
5914               "missing '}' closing arg %d of extract", i+1);
5915             goto EXPAND_FAILED_CURLY;
5916             }
5917
5918           /* After removal of leading and trailing white space, the first
5919           argument must not be empty; if it consists entirely of digits
5920           (optionally preceded by a minus sign), this is a numerical
5921           extraction, and we expect 3 arguments (normal) or 2 (json). */
5922
5923           if (i == 0)
5924             {
5925             int len;
5926             int x = 0;
5927             uschar *p = sub[0];
5928
5929             Uskip_whitespace(&p);
5930             sub[0] = p;
5931
5932             len = Ustrlen(p);
5933             while (len > 0 && isspace(p[len-1])) len--;
5934             p[len] = 0;
5935
5936             if (*p == 0)
5937               {
5938               expand_string_message = US"first argument of \"extract\" must "
5939                 "not be empty";
5940               goto EXPAND_FAILED;
5941               }
5942
5943             if (*p == '-')
5944               {
5945               field_number = -1;
5946               p++;
5947               }
5948             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5949             if (*p == 0)
5950               {
5951               field_number *= x;
5952               if (fmt == extract_basic) j = 3;               /* Need 3 args */
5953               field_number_set = TRUE;
5954               }
5955             }
5956           }
5957         else
5958           {
5959           expand_string_message = string_sprintf(
5960             "missing '{' for arg %d of extract", i+1);
5961           goto EXPAND_FAILED_CURLY;
5962           }
5963         }
5964
5965       /* Extract either the numbered or the keyed substring into $value. If
5966       skipping, just pretend the extraction failed. */
5967
5968       if (skipping)
5969         lookup_value = NULL;
5970       else switch (fmt)
5971         {
5972         case extract_basic:
5973           lookup_value = field_number_set
5974             ? expand_gettokened(field_number, sub[1], sub[2])
5975             : expand_getkeyed(sub[0], sub[1]);
5976           break;
5977
5978         case extract_json:
5979         case extract_jsons:
5980           {
5981           uschar * s, * item;
5982           const uschar * list;
5983
5984           /* Array: Bracket-enclosed and comma-separated.
5985           Object: Brace-enclosed, comma-sep list of name:value pairs */
5986
5987           if (!(s = dewrap(sub[1], field_number_set ? US"[]" : US"{}")))
5988             {
5989             expand_string_message =
5990               string_sprintf("%s wrapping %s for extract json",
5991                 expand_string_message,
5992                 field_number_set ? "array" : "object");
5993             goto EXPAND_FAILED_CURLY;
5994             }
5995
5996           list = s;
5997           if (field_number_set)
5998             {
5999             if (field_number <= 0)
6000               {
6001               expand_string_message = US"first argument of \"extract\" must "
6002                 "be greater than zero";
6003               goto EXPAND_FAILED;
6004               }
6005             while (field_number > 0 && (item = json_nextinlist(&list)))
6006               field_number--;
6007             if ((lookup_value = s = item))
6008               {
6009               while (*s) s++;
6010               while (--s >= lookup_value && isspace(*s)) *s = '\0';
6011               }
6012             }
6013           else
6014             {
6015             lookup_value = NULL;
6016             while ((item = json_nextinlist(&list)))
6017               {
6018               /* Item is:  string name-sep value.  string is quoted.
6019               Dequote the string and compare with the search key. */
6020
6021               if (!(item = dewrap(item, US"\"\"")))
6022                 {
6023                 expand_string_message =
6024                   string_sprintf("%s wrapping string key for extract json",
6025                     expand_string_message);
6026                 goto EXPAND_FAILED_CURLY;
6027                 }
6028               if (Ustrcmp(item, sub[0]) == 0)   /*XXX should be a UTF8-compare */
6029                 {
6030                 s = item + Ustrlen(item) + 1;
6031                 if (Uskip_whitespace(&s) != ':')
6032                   {
6033                   expand_string_message =
6034                     US"missing object value-separator for extract json";
6035                   goto EXPAND_FAILED_CURLY;
6036                   }
6037                 s++;
6038                 Uskip_whitespace(&s);
6039                 lookup_value = s;
6040                 break;
6041                 }
6042               }
6043             }
6044           }
6045
6046           if (  fmt == extract_jsons
6047              && lookup_value
6048              && !(lookup_value = dewrap(lookup_value, US"\"\"")))
6049             {
6050             expand_string_message =
6051               string_sprintf("%s wrapping string result for extract jsons",
6052                 expand_string_message);
6053             goto EXPAND_FAILED_CURLY;
6054             }
6055           break;        /* json/s */
6056         }
6057
6058       /* If no string follows, $value gets substituted; otherwise there can
6059       be yes/no strings, as for lookup or if. */
6060
6061       switch(process_yesno(
6062                skipping,                     /* were previously skipping */
6063                lookup_value != NULL,         /* success/failure indicator */
6064                save_lookup_value,            /* value to reset for string2 */
6065                &s,                           /* input pointer */
6066                &yield,                       /* output pointer */
6067                US"extract",                  /* condition type */
6068                &resetok))
6069         {
6070         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6071         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6072         }
6073
6074       /* All done - restore numerical variables. */
6075
6076       restore_expand_strings(save_expand_nmax, save_expand_nstring,
6077         save_expand_nlength);
6078
6079       continue;
6080       }
6081
6082     /* return the Nth item from a list */
6083
6084     case EITEM_LISTEXTRACT:
6085       {
6086       int field_number = 1;
6087       uschar *save_lookup_value = lookup_value;
6088       uschar *sub[2];
6089       int save_expand_nmax =
6090         save_expand_strings(save_expand_nstring, save_expand_nlength);
6091
6092       /* Read the field & list arguments */
6093
6094       for (int i = 0; i < 2; i++)
6095         {
6096         if (Uskip_whitespace(&s) != '{')                                        /*'}'*/
6097           {
6098           expand_string_message = string_sprintf(
6099             "missing '{' for arg %d of listextract", i+1);
6100           goto EXPAND_FAILED_CURLY;
6101           }
6102
6103         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6104         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
6105         if (*s++ != '}')
6106           {
6107           expand_string_message = string_sprintf(
6108             "missing '}' closing arg %d of listextract", i+1);
6109           goto EXPAND_FAILED_CURLY;
6110           }
6111
6112         /* After removal of leading and trailing white space, the first
6113         argument must be numeric and nonempty. */
6114
6115         if (i == 0)
6116           {
6117           int len;
6118           int x = 0;
6119           uschar *p = sub[0];
6120
6121           Uskip_whitespace(&p);
6122           sub[0] = p;
6123
6124           len = Ustrlen(p);
6125           while (len > 0 && isspace(p[len-1])) len--;
6126           p[len] = 0;
6127
6128           if (!*p && !skipping)
6129             {
6130             expand_string_message = US"first argument of \"listextract\" must "
6131               "not be empty";
6132             goto EXPAND_FAILED;
6133             }
6134
6135           if (*p == '-')
6136             {
6137             field_number = -1;
6138             p++;
6139             }
6140           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
6141           if (*p)
6142             {
6143             expand_string_message = US"first argument of \"listextract\" must "
6144               "be numeric";
6145             goto EXPAND_FAILED;
6146             }
6147           field_number *= x;
6148           }
6149         }
6150
6151       /* Extract the numbered element into $value. If
6152       skipping, just pretend the extraction failed. */
6153
6154       lookup_value = skipping ? NULL : expand_getlistele(field_number, sub[1]);
6155
6156       /* If no string follows, $value gets substituted; otherwise there can
6157       be yes/no strings, as for lookup or if. */
6158
6159       switch(process_yesno(
6160                skipping,                     /* were previously skipping */
6161                lookup_value != NULL,         /* success/failure indicator */
6162                save_lookup_value,            /* value to reset for string2 */
6163                &s,                           /* input pointer */
6164                &yield,                       /* output pointer */
6165                US"listextract",              /* condition type */
6166                &resetok))
6167         {
6168         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6169         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6170         }
6171
6172       /* All done - restore numerical variables. */
6173
6174       restore_expand_strings(save_expand_nmax, save_expand_nstring,
6175         save_expand_nlength);
6176
6177       continue;
6178       }
6179
6180     case EITEM_LISTQUOTE:
6181       {
6182       uschar * sub[2];
6183       switch(read_subs(sub, 2, 2, &s, skipping, TRUE, name, &resetok))
6184         {
6185         case 1: goto EXPAND_FAILED_CURLY;
6186         case 2:
6187         case 3: goto EXPAND_FAILED;
6188         }
6189       for (uschar sep = *sub[0], c; c = *sub[1]; sub[1]++)
6190         {
6191         if (c == sep) yield = string_catn(yield, sub[1], 1);
6192         yield = string_catn(yield, sub[1], 1);
6193         }
6194       continue;
6195       }
6196
6197 #ifndef DISABLE_TLS
6198     case EITEM_CERTEXTRACT:
6199       {
6200       uschar *save_lookup_value = lookup_value;
6201       uschar *sub[2];
6202       int save_expand_nmax =
6203         save_expand_strings(save_expand_nstring, save_expand_nlength);
6204
6205       /* Read the field argument */
6206       if (Uskip_whitespace(&s) != '{')                                  /*}*/
6207         {
6208         expand_string_message = US"missing '{' for field arg of certextract";
6209         goto EXPAND_FAILED_CURLY;
6210         }
6211       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6212       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
6213       if (*s++ != '}')
6214         {
6215         expand_string_message = US"missing '}' closing field arg of certextract";
6216         goto EXPAND_FAILED_CURLY;
6217         }
6218       /* strip spaces fore & aft */
6219       {
6220       int len;
6221       uschar *p = sub[0];
6222
6223       Uskip_whitespace(&p);
6224       sub[0] = p;
6225
6226       len = Ustrlen(p);
6227       while (len > 0 && isspace(p[len-1])) len--;
6228       p[len] = 0;
6229       }
6230
6231       /* inspect the cert argument */
6232       if (Uskip_whitespace(&s) != '{')                                  /*}*/
6233         {
6234         expand_string_message = US"missing '{' for cert variable arg of certextract";
6235         goto EXPAND_FAILED_CURLY;
6236         }
6237       if (*++s != '$')
6238         {
6239         expand_string_message = US"second argument of \"certextract\" must "
6240           "be a certificate variable";
6241         goto EXPAND_FAILED;
6242         }
6243       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
6244       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
6245       if (*s++ != '}')
6246         {
6247         expand_string_message = US"missing '}' closing cert variable arg of certextract";
6248         goto EXPAND_FAILED_CURLY;
6249         }
6250
6251       if (skipping)
6252         lookup_value = NULL;
6253       else
6254         {
6255         lookup_value = expand_getcertele(sub[0], sub[1]);
6256         if (*expand_string_message) goto EXPAND_FAILED;
6257         }
6258       switch(process_yesno(
6259                skipping,                     /* were previously skipping */
6260                lookup_value != NULL,         /* success/failure indicator */
6261                save_lookup_value,            /* value to reset for string2 */
6262                &s,                           /* input pointer */
6263                &yield,                       /* output pointer */
6264                US"certextract",              /* condition type */
6265                &resetok))
6266         {
6267         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6268         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6269         }
6270
6271       restore_expand_strings(save_expand_nmax, save_expand_nstring,
6272         save_expand_nlength);
6273       continue;
6274       }
6275 #endif  /*DISABLE_TLS*/
6276
6277     /* Handle list operations */
6278
6279     case EITEM_FILTER:
6280     case EITEM_MAP:
6281     case EITEM_REDUCE:
6282       {
6283       int sep = 0;
6284       int save_ptr = gstring_length(yield);
6285       uschar outsep[2] = { '\0', '\0' };
6286       const uschar *list, *expr, *temp;
6287       uschar *save_iterate_item = iterate_item;
6288       uschar *save_lookup_value = lookup_value;
6289
6290       Uskip_whitespace(&s);
6291       if (*s++ != '{')
6292         {
6293         expand_string_message =
6294           string_sprintf("missing '{' for first arg of %s", name);
6295         goto EXPAND_FAILED_CURLY;
6296         }
6297
6298       if (!(list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok)))
6299         goto EXPAND_FAILED;
6300       if (*s++ != '}')
6301         {
6302         expand_string_message =
6303           string_sprintf("missing '}' closing first arg of %s", name);
6304         goto EXPAND_FAILED_CURLY;
6305         }
6306
6307       if (item_type == EITEM_REDUCE)
6308         {
6309         uschar * t;
6310         Uskip_whitespace(&s);
6311         if (*s++ != '{')
6312           {
6313           expand_string_message = US"missing '{' for second arg of reduce";
6314           goto EXPAND_FAILED_CURLY;
6315           }
6316         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
6317         if (!t) goto EXPAND_FAILED;
6318         lookup_value = t;
6319         if (*s++ != '}')
6320           {
6321           expand_string_message = US"missing '}' closing second arg of reduce";
6322           goto EXPAND_FAILED_CURLY;
6323           }
6324         }
6325
6326       Uskip_whitespace(&s);
6327       if (*s++ != '{')
6328         {
6329         expand_string_message =
6330           string_sprintf("missing '{' for last arg of %s", name);
6331         goto EXPAND_FAILED_CURLY;
6332         }
6333
6334       expr = s;
6335
6336       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
6337       if scanning a "false" part). This allows us to find the end of the
6338       condition, because if the list is empty, we won't actually evaluate the
6339       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
6340       the normal internal expansion function. */
6341
6342       if (item_type == EITEM_FILTER)
6343         {
6344         if ((temp = eval_condition(expr, &resetok, NULL)))
6345           s = temp;
6346         }
6347       else
6348         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
6349
6350       if (!temp)
6351         {
6352         expand_string_message = string_sprintf("%s inside \"%s\" item",
6353           expand_string_message, name);
6354         goto EXPAND_FAILED;
6355         }
6356
6357       Uskip_whitespace(&s);
6358       if (*s++ != '}')
6359         {                                               /*{*/
6360         expand_string_message = string_sprintf("missing } at end of condition "
6361           "or expression inside \"%s\"; could be an unquoted } in the content",
6362           name);
6363         goto EXPAND_FAILED;
6364         }
6365
6366       Uskip_whitespace(&s);                             /*{*/
6367       if (*s++ != '}')
6368         {                                               /*{*/
6369         expand_string_message = string_sprintf("missing } at end of \"%s\"",
6370           name);
6371         goto EXPAND_FAILED;
6372         }
6373
6374       /* If we are skipping, we can now just move on to the next item. When
6375       processing for real, we perform the iteration. */
6376
6377       if (skipping) continue;
6378       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
6379         {
6380         *outsep = (uschar)sep;      /* Separator as a string */
6381
6382         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
6383                           name, iterate_item, lookup_value);
6384
6385         if (item_type == EITEM_FILTER)
6386           {
6387           BOOL condresult;
6388           if (!eval_condition(expr, &resetok, &condresult))
6389             {
6390             iterate_item = save_iterate_item;
6391             lookup_value = save_lookup_value;
6392             expand_string_message = string_sprintf("%s inside \"%s\" condition",
6393               expand_string_message, name);
6394             goto EXPAND_FAILED;
6395             }
6396           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
6397             condresult? "true":"false");
6398           if (condresult)
6399             temp = iterate_item;    /* TRUE => include this item */
6400           else
6401             continue;               /* FALSE => skip this item */
6402           }
6403
6404         /* EITEM_MAP and EITEM_REDUCE */
6405
6406         else
6407           {
6408           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
6409           temp = t;
6410           if (!temp)
6411             {
6412             iterate_item = save_iterate_item;
6413             expand_string_message = string_sprintf("%s inside \"%s\" item",
6414               expand_string_message, name);
6415             goto EXPAND_FAILED;
6416             }
6417           if (item_type == EITEM_REDUCE)
6418             {
6419             lookup_value = t;         /* Update the value of $value */
6420             continue;                 /* and continue the iteration */
6421             }
6422           }
6423
6424         /* We reach here for FILTER if the condition is true, always for MAP,
6425         and never for REDUCE. The value in "temp" is to be added to the output
6426         list that is being created, ensuring that any occurrences of the
6427         separator character are doubled. Unless we are dealing with the first
6428         item of the output list, add in a space if the new item begins with the
6429         separator character, or is an empty string. */
6430
6431         if (  yield && yield->ptr != save_ptr
6432            && (temp[0] == *outsep || temp[0] == 0))
6433           yield = string_catn(yield, US" ", 1);
6434
6435         /* Add the string in "temp" to the output list that we are building,
6436         This is done in chunks by searching for the separator character. */
6437
6438         for (;;)
6439           {
6440           size_t seglen = Ustrcspn(temp, outsep);
6441
6442           yield = string_catn(yield, temp, seglen + 1);
6443
6444           /* If we got to the end of the string we output one character
6445           too many; backup and end the loop. Otherwise arrange to double the
6446           separator. */
6447
6448           if (temp[seglen] == '\0') { yield->ptr--; break; }
6449           yield = string_catn(yield, outsep, 1);
6450           temp += seglen + 1;
6451           }
6452
6453         /* Output a separator after the string: we will remove the redundant
6454         final one at the end. */
6455
6456         yield = string_catn(yield, outsep, 1);
6457         }   /* End of iteration over the list loop */
6458
6459       /* REDUCE has generated no output above: output the final value of
6460       $value. */
6461
6462       if (item_type == EITEM_REDUCE)
6463         {
6464         yield = string_cat(yield, lookup_value);
6465         lookup_value = save_lookup_value;  /* Restore $value */
6466         }
6467
6468       /* FILTER and MAP generate lists: if they have generated anything, remove
6469       the redundant final separator. Even though an empty item at the end of a
6470       list does not count, this is tidier. */
6471
6472       else if (yield && yield->ptr != save_ptr) yield->ptr--;
6473
6474       /* Restore preserved $item */
6475
6476       iterate_item = save_iterate_item;
6477       continue;
6478       }
6479
6480     case EITEM_SORT:
6481       {
6482       int cond_type;
6483       int sep = 0;
6484       const uschar *srclist, *cmp, *xtract;
6485       uschar * opname, * srcitem;
6486       const uschar *dstlist = NULL, *dstkeylist = NULL;
6487       uschar * tmp;
6488       uschar *save_iterate_item = iterate_item;
6489
6490       Uskip_whitespace(&s);
6491       if (*s++ != '{')
6492         {
6493         expand_string_message = US"missing '{' for list arg of sort";
6494         goto EXPAND_FAILED_CURLY;
6495         }
6496
6497       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
6498       if (!srclist) goto EXPAND_FAILED;
6499       if (*s++ != '}')
6500         {
6501         expand_string_message = US"missing '}' closing list arg of sort";
6502         goto EXPAND_FAILED_CURLY;
6503         }
6504
6505       Uskip_whitespace(&s);
6506       if (*s++ != '{')
6507         {
6508         expand_string_message = US"missing '{' for comparator arg of sort";
6509         goto EXPAND_FAILED_CURLY;
6510         }
6511
6512       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
6513       if (!cmp) goto EXPAND_FAILED;
6514       if (*s++ != '}')
6515         {
6516         expand_string_message = US"missing '}' closing comparator arg of sort";
6517         goto EXPAND_FAILED_CURLY;
6518         }
6519
6520       if ((cond_type = identify_operator(&cmp, &opname)) == -1)
6521         {
6522         if (!expand_string_message)
6523           expand_string_message = string_sprintf("unknown condition \"%s\"", s);
6524         goto EXPAND_FAILED;
6525         }
6526       switch(cond_type)
6527         {
6528         case ECOND_NUM_L: case ECOND_NUM_LE:
6529         case ECOND_NUM_G: case ECOND_NUM_GE:
6530         case ECOND_STR_GE: case ECOND_STR_GEI: case ECOND_STR_GT: case ECOND_STR_GTI:
6531         case ECOND_STR_LE: case ECOND_STR_LEI: case ECOND_STR_LT: case ECOND_STR_LTI:
6532           break;
6533
6534         default:
6535           expand_string_message = US"comparator not handled for sort";
6536           goto EXPAND_FAILED;
6537         }
6538
6539       Uskip_whitespace(&s);
6540       if (*s++ != '{')
6541         {
6542         expand_string_message = US"missing '{' for extractor arg of sort";
6543         goto EXPAND_FAILED_CURLY;
6544         }
6545
6546       xtract = s;
6547       if (!(tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok)))
6548         goto EXPAND_FAILED;
6549       xtract = string_copyn(xtract, s - xtract);
6550
6551       if (*s++ != '}')
6552         {
6553         expand_string_message = US"missing '}' closing extractor arg of sort";
6554         goto EXPAND_FAILED_CURLY;
6555         }
6556                                                         /*{*/
6557       if (*s++ != '}')
6558         {                                               /*{*/
6559         expand_string_message = US"missing } at end of \"sort\"";
6560         goto EXPAND_FAILED;
6561         }
6562
6563       if (skipping) continue;
6564
6565       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
6566         {
6567         uschar * srcfield, * dstitem;
6568         gstring * newlist = NULL;
6569         gstring * newkeylist = NULL;
6570
6571         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6572
6573         /* extract field for comparisons */
6574         iterate_item = srcitem;
6575         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6576                                           TRUE, &resetok))
6577            || !*srcfield)
6578           {
6579           expand_string_message = string_sprintf(
6580               "field-extract in sort: \"%s\"", xtract);
6581           goto EXPAND_FAILED;
6582           }
6583
6584         /* Insertion sort */
6585
6586         /* copy output list until new-item < list-item */
6587         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6588           {
6589           uschar * dstfield;
6590
6591           /* field for comparison */
6592           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6593             goto sort_mismatch;
6594
6595           /* String-comparator names start with a letter; numeric names do not */
6596
6597           if (sortsbefore(cond_type, isalpha(opname[0]),
6598               srcfield, dstfield))
6599             {
6600             /* New-item sorts before this dst-item.  Append new-item,
6601             then dst-item, then remainder of dst list. */
6602
6603             newlist = string_append_listele(newlist, sep, srcitem);
6604             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6605             srcitem = NULL;
6606
6607             newlist = string_append_listele(newlist, sep, dstitem);
6608             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6609
6610 /*XXX why field-at-a-time copy?  Why not just dup the rest of the list? */
6611             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6612               {
6613               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6614                 goto sort_mismatch;
6615               newlist = string_append_listele(newlist, sep, dstitem);
6616               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6617               }
6618
6619             break;
6620             }
6621
6622           newlist = string_append_listele(newlist, sep, dstitem);
6623           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6624           }
6625
6626         /* If we ran out of dstlist without consuming srcitem, append it */
6627         if (srcitem)
6628           {
6629           newlist = string_append_listele(newlist, sep, srcitem);
6630           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6631           }
6632
6633         dstlist = newlist->s;
6634         dstkeylist = newkeylist->s;
6635
6636         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6637         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6638         }
6639
6640       if (dstlist)
6641         yield = string_cat(yield, dstlist);
6642
6643       /* Restore preserved $item */
6644       iterate_item = save_iterate_item;
6645       continue;
6646
6647       sort_mismatch:
6648         expand_string_message = US"Internal error in sort (list mismatch)";
6649         goto EXPAND_FAILED;
6650       }
6651
6652
6653     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6654     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6655     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6656     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6657
6658     #define EXPAND_DLFUNC_MAX_ARGS 8
6659
6660     case EITEM_DLFUNC:
6661 #ifndef EXPAND_DLFUNC
6662       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6663         "is not included in this binary";
6664       goto EXPAND_FAILED;
6665
6666 #else   /* EXPAND_DLFUNC */
6667       {
6668       tree_node *t;
6669       exim_dlfunc_t *func;
6670       uschar *result;
6671       int status, argc;
6672       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6673
6674       if ((expand_forbid & RDO_DLFUNC) != 0)
6675         {
6676         expand_string_message =
6677           US"dynamically-loaded functions are not permitted";
6678         goto EXPAND_FAILED;
6679         }
6680
6681       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6682            TRUE, name, &resetok))
6683         {
6684         case 1: goto EXPAND_FAILED_CURLY;
6685         case 2:
6686         case 3: goto EXPAND_FAILED;
6687         }
6688
6689       /* If skipping, we don't actually do anything */
6690
6691       if (skipping) continue;
6692
6693       /* Look up the dynamically loaded object handle in the tree. If it isn't
6694       found, dlopen() the file and put the handle in the tree for next time. */
6695
6696       if (!(t = tree_search(dlobj_anchor, argv[0])))
6697         {
6698         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6699         if (!handle)
6700           {
6701           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6702             argv[0], dlerror());
6703           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6704           goto EXPAND_FAILED;
6705           }
6706         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]), is_tainted(argv[0]));
6707         Ustrcpy(t->name, argv[0]);
6708         t->data.ptr = handle;
6709         (void)tree_insertnode(&dlobj_anchor, t);
6710         }
6711
6712       /* Having obtained the dynamically loaded object handle, look up the
6713       function pointer. */
6714
6715       if (!(func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1])))
6716         {
6717         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6718           "%s", argv[1], argv[0], dlerror());
6719         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6720         goto EXPAND_FAILED;
6721         }
6722
6723       /* Call the function and work out what to do with the result. If it
6724       returns OK, we have a replacement string; if it returns DEFER then
6725       expansion has failed in a non-forced manner; if it returns FAIL then
6726       failure was forced; if it returns ERROR or any other value there's a
6727       problem, so panic slightly. In any case, assume that the function has
6728       side-effects on the store that must be preserved. */
6729
6730       resetok = FALSE;
6731       result = NULL;
6732       for (argc = 0; argv[argc]; argc++);
6733       status = func(&result, argc - 2, &argv[2]);
6734       if(status == OK)
6735         {
6736         if (!result) result = US"";
6737         yield = string_cat(yield, result);
6738         continue;
6739         }
6740       else
6741         {
6742         expand_string_message = result ? result : US"(no message)";
6743         if (status == FAIL_FORCED)
6744           f.expand_string_forcedfail = TRUE;
6745         else if (status != FAIL)
6746           log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6747               argv[0], argv[1], status, expand_string_message);
6748         goto EXPAND_FAILED;
6749         }
6750       }
6751 #endif /* EXPAND_DLFUNC */
6752
6753     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6754       {
6755       uschar * key;
6756       uschar *save_lookup_value = lookup_value;
6757
6758       if (Uskip_whitespace(&s) != '{')                                  /*}*/
6759         goto EXPAND_FAILED;
6760
6761       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6762       if (!key) goto EXPAND_FAILED;                     /*{*/
6763       if (*s++ != '}')
6764         {
6765         expand_string_message = US"missing '{' for name arg of env";
6766         goto EXPAND_FAILED_CURLY;
6767         }
6768
6769       lookup_value = US getenv(CS key);
6770
6771       switch(process_yesno(
6772                skipping,                     /* were previously skipping */
6773                lookup_value != NULL,         /* success/failure indicator */
6774                save_lookup_value,            /* value to reset for string2 */
6775                &s,                           /* input pointer */
6776                &yield,                       /* output pointer */
6777                US"env",                      /* condition type */
6778                &resetok))
6779         {
6780         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6781         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6782         }
6783       continue;
6784       }
6785
6786 #ifdef EXPERIMENTAL_SRS_NATIVE
6787     case EITEM_SRS_ENCODE:
6788       /* ${srs_encode {secret} {return_path} {orig_domain}} */
6789       {
6790       uschar * sub[3];
6791       uschar cksum[4];
6792
6793       switch (read_subs(sub, 3, 3, CUSS &s, skipping, TRUE, name, &resetok))
6794         {
6795         case 1: goto EXPAND_FAILED_CURLY;
6796         case 2:
6797         case 3: goto EXPAND_FAILED;
6798         }
6799
6800       yield = string_catn(yield, US"SRS0=", 5);
6801
6802       /* ${l_4:${hmac{md5}{SRS_SECRET}{${lc:$return_path}}}}= */
6803       hmac_md5(sub[0], string_copylc(sub[1]), cksum, sizeof(cksum));
6804       yield = string_catn(yield, cksum, sizeof(cksum));
6805       yield = string_catn(yield, US"=", 1);
6806
6807       /* ${base32:${eval:$tod_epoch/86400&0x3ff}}= */
6808         {
6809         struct timeval now;
6810         unsigned long i;
6811         gstring * g = NULL;
6812
6813         gettimeofday(&now, NULL);
6814         for (unsigned long i = (now.tv_sec / 86400) & 0x3ff; i; i >>= 5)
6815           g = string_catn(g, &base32_chars[i & 0x1f], 1);
6816         if (g) while (g->ptr > 0)
6817           yield = string_catn(yield, &g->s[--g->ptr], 1);
6818         }
6819       yield = string_catn(yield, US"=", 1);
6820
6821       /* ${domain:$return_path}=${local_part:$return_path} */
6822         {
6823         int start, end, domain;
6824         uschar * t = parse_extract_address(sub[1], &expand_string_message,
6825                                           &start, &end, &domain, FALSE);
6826         if (!t)
6827           goto EXPAND_FAILED;
6828
6829         if (domain > 0) yield = string_cat(yield, t + domain);
6830         yield = string_catn(yield, US"=", 1);
6831         yield = domain > 0
6832           ? string_catn(yield, t, domain - 1) : string_cat(yield, t);
6833         }
6834
6835       /* @$original_domain */
6836       yield = string_catn(yield, US"@", 1);
6837       yield = string_cat(yield, sub[2]);
6838       continue;
6839       }
6840 #endif /*EXPERIMENTAL_SRS_NATIVE*/
6841     }   /* EITEM_* switch */
6842
6843   /* Control reaches here if the name is not recognized as one of the more
6844   complicated expansion items. Check for the "operator" syntax (name terminated
6845   by a colon). Some of the operators have arguments, separated by _ from the
6846   name. */
6847
6848   if (*s == ':')
6849     {
6850     int c;
6851     uschar *arg = NULL;
6852     uschar *sub;
6853 #ifndef DISABLE_TLS
6854     var_entry *vp = NULL;
6855 #endif
6856
6857     /* Owing to an historical mis-design, an underscore may be part of the
6858     operator name, or it may introduce arguments.  We therefore first scan the
6859     table of names that contain underscores. If there is no match, we cut off
6860     the arguments and then scan the main table. */
6861
6862     if ((c = chop_match(name, op_table_underscore,
6863                         nelem(op_table_underscore))) < 0)
6864       {
6865       if ((arg = Ustrchr(name, '_')))
6866         *arg = 0;
6867       if ((c = chop_match(name, op_table_main, nelem(op_table_main))) >= 0)
6868         c += nelem(op_table_underscore);
6869       if (arg) *arg++ = '_';            /* Put back for error messages */
6870       }
6871
6872     /* Deal specially with operators that might take a certificate variable
6873     as we do not want to do the usual expansion. For most, expand the string.*/
6874     switch(c)
6875       {
6876 #ifndef DISABLE_TLS
6877       case EOP_MD5:
6878       case EOP_SHA1:
6879       case EOP_SHA256:
6880       case EOP_BASE64:
6881         if (s[1] == '$')
6882           {
6883           const uschar * s1 = s;
6884           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6885                   FALSE, &resetok);
6886           if (!sub)       goto EXPAND_FAILED;           /*{*/
6887           if (*s1 != '}')
6888             {
6889             expand_string_message =
6890               string_sprintf("missing '}' closing cert arg of %s", name);
6891             goto EXPAND_FAILED_CURLY;
6892             }
6893           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6894             {
6895             s = s1+1;
6896             break;
6897             }
6898           vp = NULL;
6899           }
6900         /*FALLTHROUGH*/
6901 #endif
6902       default:
6903         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6904         if (!sub) goto EXPAND_FAILED;
6905         s++;
6906         break;
6907       }
6908
6909     /* If we are skipping, we don't need to perform the operation at all.
6910     This matters for operations like "mask", because the data may not be
6911     in the correct format when skipping. For example, the expression may test
6912     for the existence of $sender_host_address before trying to mask it. For
6913     other operations, doing them may not fail, but it is a waste of time. */
6914
6915     if (skipping && c >= 0) continue;
6916
6917     /* Otherwise, switch on the operator type */
6918
6919     switch(c)
6920       {
6921       case EOP_BASE32:
6922         {
6923         uschar *t;
6924         unsigned long int n = Ustrtoul(sub, &t, 10);
6925         gstring * g = NULL;
6926
6927         if (*t != 0)
6928           {
6929           expand_string_message = string_sprintf("argument for base32 "
6930             "operator is \"%s\", which is not a decimal number", sub);
6931           goto EXPAND_FAILED;
6932           }
6933         for ( ; n; n >>= 5)
6934           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6935
6936         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6937         continue;
6938         }
6939
6940       case EOP_BASE32D:
6941         {
6942         uschar *tt = sub;
6943         unsigned long int n = 0;
6944         while (*tt)
6945           {
6946           uschar * t = Ustrchr(base32_chars, *tt++);
6947           if (!t)
6948             {
6949             expand_string_message = string_sprintf("argument for base32d "
6950               "operator is \"%s\", which is not a base 32 number", sub);
6951             goto EXPAND_FAILED;
6952             }
6953           n = n * 32 + (t - base32_chars);
6954           }
6955         yield = string_fmt_append(yield, "%ld", n);
6956         continue;
6957         }
6958
6959       case EOP_BASE62:
6960         {
6961         uschar *t;
6962         unsigned long int n = Ustrtoul(sub, &t, 10);
6963         if (*t != 0)
6964           {
6965           expand_string_message = string_sprintf("argument for base62 "
6966             "operator is \"%s\", which is not a decimal number", sub);
6967           goto EXPAND_FAILED;
6968           }
6969         yield = string_cat(yield, string_base62(n));
6970         continue;
6971         }
6972
6973       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6974
6975       case EOP_BASE62D:
6976         {
6977         uschar *tt = sub;
6978         unsigned long int n = 0;
6979         while (*tt != 0)
6980           {
6981           uschar *t = Ustrchr(base62_chars, *tt++);
6982           if (!t)
6983             {
6984             expand_string_message = string_sprintf("argument for base62d "
6985               "operator is \"%s\", which is not a base %d number", sub,
6986               BASE_62);
6987             goto EXPAND_FAILED;
6988             }
6989           n = n * BASE_62 + (t - base62_chars);
6990           }
6991         yield = string_fmt_append(yield, "%ld", n);
6992         continue;
6993         }
6994
6995       case EOP_BLESS:
6996         /* This is purely for the convenience of the test harness.  Do not enable
6997         it otherwise as it defeats the taint-checking security. */
6998
6999         if (f.running_in_test_harness)
7000           yield = string_cat(yield, is_tainted(sub)
7001                                     ? string_copy_taint(sub, FALSE) : sub);
7002         else
7003           {
7004           DEBUG(D_expand) debug_printf_indent("bless operator not supported\n");
7005           yield = string_cat(yield, sub);
7006           }
7007         continue;
7008
7009       case EOP_EXPAND:
7010         {
7011         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
7012         if (!expanded)
7013           {
7014           expand_string_message =
7015             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
7016               expand_string_message);
7017           goto EXPAND_FAILED;
7018           }
7019         yield = string_cat(yield, expanded);
7020         continue;
7021         }
7022
7023       case EOP_LC:
7024         {
7025         int count = 0;
7026         uschar *t = sub - 1;
7027         while (*(++t) != 0) { *t = tolower(*t); count++; }
7028         yield = string_catn(yield, sub, count);
7029         continue;
7030         }
7031
7032       case EOP_UC:
7033         {
7034         int count = 0;
7035         uschar *t = sub - 1;
7036         while (*(++t) != 0) { *t = toupper(*t); count++; }
7037         yield = string_catn(yield, sub, count);
7038         continue;
7039         }
7040
7041       case EOP_MD5:
7042 #ifndef DISABLE_TLS
7043         if (vp && *(void **)vp->value)
7044           {
7045           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
7046           yield = string_cat(yield, cp);
7047           }
7048         else
7049 #endif
7050           {
7051           md5 base;
7052           uschar digest[16];
7053           md5_start(&base);
7054           md5_end(&base, sub, Ustrlen(sub), digest);
7055           for (int j = 0; j < 16; j++)
7056             yield = string_fmt_append(yield, "%02x", digest[j]);
7057           }
7058         continue;
7059
7060       case EOP_SHA1:
7061 #ifndef DISABLE_TLS
7062         if (vp && *(void **)vp->value)
7063           {
7064           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
7065           yield = string_cat(yield, cp);
7066           }
7067         else
7068 #endif
7069           {
7070           hctx h;
7071           uschar digest[20];
7072           sha1_start(&h);
7073           sha1_end(&h, sub, Ustrlen(sub), digest);
7074           for (int j = 0; j < 20; j++)
7075             yield = string_fmt_append(yield, "%02X", digest[j]);
7076           }
7077         continue;
7078
7079       case EOP_SHA2:
7080       case EOP_SHA256:
7081 #ifdef EXIM_HAVE_SHA2
7082         if (vp && *(void **)vp->value)
7083           if (c == EOP_SHA256)
7084             yield = string_cat(yield, tls_cert_fprt_sha256(*(void **)vp->value));
7085           else
7086             expand_string_message = US"sha2_N not supported with certificates";
7087         else
7088           {
7089           hctx h;
7090           blob b;
7091           hashmethod m = !arg ? HASH_SHA2_256
7092             : Ustrcmp(arg, "256") == 0 ? HASH_SHA2_256
7093             : Ustrcmp(arg, "384") == 0 ? HASH_SHA2_384
7094             : Ustrcmp(arg, "512") == 0 ? HASH_SHA2_512
7095             : HASH_BADTYPE;
7096
7097           if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
7098             {
7099             expand_string_message = US"unrecognised sha2 variant";
7100             goto EXPAND_FAILED;
7101             }
7102
7103           exim_sha_update(&h, sub, Ustrlen(sub));
7104           exim_sha_finish(&h, &b);
7105           while (b.len-- > 0)
7106             yield = string_fmt_append(yield, "%02X", *b.data++);
7107           }
7108 #else
7109           expand_string_message = US"sha256 only supported with TLS";
7110 #endif
7111         continue;
7112
7113       case EOP_SHA3:
7114 #ifdef EXIM_HAVE_SHA3
7115         {
7116         hctx h;
7117         blob b;
7118         hashmethod m = !arg ? HASH_SHA3_256
7119           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
7120           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
7121           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
7122           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
7123           : HASH_BADTYPE;
7124
7125         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
7126           {
7127           expand_string_message = US"unrecognised sha3 variant";
7128           goto EXPAND_FAILED;
7129           }
7130
7131         exim_sha_update(&h, sub, Ustrlen(sub));
7132         exim_sha_finish(&h, &b);
7133         while (b.len-- > 0)
7134           yield = string_fmt_append(yield, "%02X", *b.data++);
7135         }
7136         continue;
7137 #else
7138         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 + or OpenSSL 1.1.1 +";
7139         goto EXPAND_FAILED;
7140 #endif
7141
7142       /* Convert hex encoding to base64 encoding */
7143
7144       case EOP_HEX2B64:
7145         {
7146         int c = 0;
7147         int b = -1;
7148         uschar *in = sub;
7149         uschar *out = sub;
7150         uschar *enc;
7151
7152         for (enc = sub; *enc; enc++)
7153           {
7154           if (!isxdigit(*enc))
7155             {
7156             expand_string_message = string_sprintf("\"%s\" is not a hex "
7157               "string", sub);
7158             goto EXPAND_FAILED;
7159             }
7160           c++;
7161           }
7162
7163         if ((c & 1) != 0)
7164           {
7165           expand_string_message = string_sprintf("\"%s\" contains an odd "
7166             "number of characters", sub);
7167           goto EXPAND_FAILED;
7168           }
7169
7170         while ((c = *in++) != 0)
7171           {
7172           if (isdigit(c)) c -= '0';
7173           else c = toupper(c) - 'A' + 10;
7174           if (b == -1)
7175             b = c << 4;
7176           else
7177             {
7178             *out++ = b | c;
7179             b = -1;
7180             }
7181           }
7182
7183         enc = b64encode(CUS sub, out - sub);
7184         yield = string_cat(yield, enc);
7185         continue;
7186         }
7187
7188       /* Convert octets outside 0x21..0x7E to \xXX form */
7189
7190       case EOP_HEXQUOTE:
7191         {
7192         uschar *t = sub - 1;
7193         while (*(++t) != 0)
7194           {
7195           if (*t < 0x21 || 0x7E < *t)
7196             yield = string_fmt_append(yield, "\\x%02x", *t);
7197           else
7198             yield = string_catn(yield, t, 1);
7199           }
7200         continue;
7201         }
7202
7203       /* count the number of list elements */
7204
7205       case EOP_LISTCOUNT:
7206         {
7207         int cnt = 0;
7208         int sep = 0;
7209         uschar buffer[256];
7210
7211         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer))) cnt++;
7212         yield = string_fmt_append(yield, "%d", cnt);
7213         continue;
7214         }
7215
7216       /* expand a named list given the name */
7217       /* handles nested named lists; requotes as colon-sep list */
7218
7219       case EOP_LISTNAMED:
7220         {
7221         tree_node *t = NULL;
7222         const uschar * list;
7223         int sep = 0;
7224         uschar * item;
7225         uschar * suffix = US"";
7226         BOOL needsep = FALSE;
7227         uschar buffer[256];
7228
7229         if (*sub == '+') sub++;
7230         if (!arg)               /* no-argument version */
7231           {
7232           if (!(t = tree_search(addresslist_anchor, sub)) &&
7233               !(t = tree_search(domainlist_anchor,  sub)) &&
7234               !(t = tree_search(hostlist_anchor,    sub)))
7235             t = tree_search(localpartlist_anchor, sub);
7236           }
7237         else switch(*arg)       /* specific list-type version */
7238           {
7239           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
7240           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
7241           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
7242           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
7243           default:
7244             expand_string_message = US"bad suffix on \"list\" operator";
7245             goto EXPAND_FAILED;
7246           }
7247
7248         if(!t)
7249           {
7250           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
7251             sub, !arg?""
7252               : *arg=='a'?"address "
7253               : *arg=='d'?"domain "
7254               : *arg=='h'?"host "
7255               : *arg=='l'?"localpart "
7256               : 0);
7257           goto EXPAND_FAILED;
7258           }
7259
7260         list = ((namedlist_block *)(t->data.ptr))->string;
7261
7262         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
7263           {
7264           uschar * buf = US" : ";
7265           if (needsep)
7266             yield = string_catn(yield, buf, 3);
7267           else
7268             needsep = TRUE;
7269
7270           if (*item == '+')     /* list item is itself a named list */
7271             {
7272             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
7273             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
7274             }
7275           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
7276             {
7277             char * cp;
7278             char tok[3];
7279             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
7280             while ((cp= strpbrk(CCS item, tok)))
7281               {
7282               yield = string_catn(yield, item, cp - CS item);
7283               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
7284                 {
7285                 yield = string_catn(yield, US"::", 2);
7286                 item = US cp;
7287                 }
7288               else              /* sep in item; should already be doubled; emit once */
7289                 {
7290                 yield = string_catn(yield, US tok, 1);
7291                 if (*cp == sep) cp++;
7292                 item = US cp;
7293                 }
7294               }
7295             }
7296           yield = string_cat(yield, item);
7297           }
7298         continue;
7299         }
7300
7301       /* quote a list-item for the given list-separator */
7302
7303       /* mask applies a mask to an IP address; for example the result of
7304       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
7305
7306       case EOP_MASK:
7307         {
7308         int count;
7309         uschar *endptr;
7310         int binary[4];
7311         int mask, maskoffset;
7312         int type = string_is_ip_address(sub, &maskoffset);
7313         uschar buffer[64];
7314
7315         if (type == 0)
7316           {
7317           expand_string_message = string_sprintf("\"%s\" is not an IP address",
7318            sub);
7319           goto EXPAND_FAILED;
7320           }
7321
7322         if (maskoffset == 0)
7323           {
7324           expand_string_message = string_sprintf("missing mask value in \"%s\"",
7325             sub);
7326           goto EXPAND_FAILED;
7327           }
7328
7329         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
7330
7331         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
7332           {
7333           expand_string_message = string_sprintf("mask value too big in \"%s\"",
7334             sub);
7335           goto EXPAND_FAILED;
7336           }
7337
7338         /* Convert the address to binary integer(s) and apply the mask */
7339
7340         sub[maskoffset] = 0;
7341         count = host_aton(sub, binary);
7342         host_mask(count, binary, mask);
7343
7344         /* Convert to masked textual format and add to output. */
7345
7346         yield = string_catn(yield, buffer,
7347           host_nmtoa(count, binary, mask, buffer, '.'));
7348         continue;
7349         }
7350
7351       case EOP_IPV6NORM:
7352       case EOP_IPV6DENORM:
7353         {
7354         int type = string_is_ip_address(sub, NULL);
7355         int binary[4];
7356         uschar buffer[44];
7357
7358         switch (type)
7359           {
7360           case 6:
7361             (void) host_aton(sub, binary);
7362             break;
7363
7364           case 4:       /* convert to IPv4-mapped IPv6 */
7365             binary[0] = binary[1] = 0;
7366             binary[2] = 0x0000ffff;
7367             (void) host_aton(sub, binary+3);
7368             break;
7369
7370           case 0:
7371             expand_string_message =
7372               string_sprintf("\"%s\" is not an IP address", sub);
7373             goto EXPAND_FAILED;
7374           }
7375
7376         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
7377                     ? ipv6_nmtoa(binary, buffer)
7378                     : host_nmtoa(4, binary, -1, buffer, ':')
7379                   );
7380         continue;
7381         }
7382
7383       case EOP_ADDRESS:
7384       case EOP_LOCAL_PART:
7385       case EOP_DOMAIN:
7386         {
7387         uschar * error;
7388         int start, end, domain;
7389         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
7390           FALSE);
7391         if (t)
7392           if (c != EOP_DOMAIN)
7393             yield = c == EOP_LOCAL_PART && domain > 0
7394               ? string_catn(yield, t, domain - 1)
7395               : string_cat(yield, t);
7396           else if (domain > 0)
7397             yield = string_cat(yield, t + domain);
7398         continue;
7399         }
7400
7401       case EOP_ADDRESSES:
7402         {
7403         uschar outsep[2] = { ':', '\0' };
7404         uschar *address, *error;
7405         int save_ptr = gstring_length(yield);
7406         int start, end, domain;  /* Not really used */
7407
7408         if (Uskip_whitespace(&sub) == '>')
7409           if (*outsep = *++sub) ++sub;
7410           else
7411             {
7412             expand_string_message = string_sprintf("output separator "
7413               "missing in expanding ${addresses:%s}", --sub);
7414             goto EXPAND_FAILED;
7415             }
7416         f.parse_allow_group = TRUE;
7417
7418         for (;;)
7419           {
7420           uschar * p = parse_find_address_end(sub, FALSE);
7421           uschar saveend = *p;
7422           *p = '\0';
7423           address = parse_extract_address(sub, &error, &start, &end, &domain,
7424             FALSE);
7425           *p = saveend;
7426
7427           /* Add the address to the output list that we are building. This is
7428           done in chunks by searching for the separator character. At the
7429           start, unless we are dealing with the first address of the output
7430           list, add in a space if the new address begins with the separator
7431           character, or is an empty string. */
7432
7433           if (address)
7434             {
7435             if (yield && yield->ptr != save_ptr && address[0] == *outsep)
7436               yield = string_catn(yield, US" ", 1);
7437
7438             for (;;)
7439               {
7440               size_t seglen = Ustrcspn(address, outsep);
7441               yield = string_catn(yield, address, seglen + 1);
7442
7443               /* If we got to the end of the string we output one character
7444               too many. */
7445
7446               if (address[seglen] == '\0') { yield->ptr--; break; }
7447               yield = string_catn(yield, outsep, 1);
7448               address += seglen + 1;
7449               }
7450
7451             /* Output a separator after the string: we will remove the
7452             redundant final one at the end. */
7453
7454             yield = string_catn(yield, outsep, 1);
7455             }
7456
7457           if (saveend == '\0') break;
7458           sub = p + 1;
7459           }
7460
7461         /* If we have generated anything, remove the redundant final
7462         separator. */
7463
7464         if (yield && yield->ptr != save_ptr) yield->ptr--;
7465         f.parse_allow_group = FALSE;
7466         continue;
7467         }
7468
7469
7470       /* quote puts a string in quotes if it is empty or contains anything
7471       other than alphamerics, underscore, dot, or hyphen.
7472
7473       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
7474       be quoted in order to be a valid local part.
7475
7476       In both cases, newlines and carriage returns are converted into \n and \r
7477       respectively */
7478
7479       case EOP_QUOTE:
7480       case EOP_QUOTE_LOCAL_PART:
7481       if (!arg)
7482         {
7483         BOOL needs_quote = (!*sub);      /* TRUE for empty string */
7484         uschar *t = sub - 1;
7485
7486         if (c == EOP_QUOTE)
7487           {
7488           while (!needs_quote && *(++t) != 0)
7489             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
7490           }
7491         else  /* EOP_QUOTE_LOCAL_PART */
7492           {
7493           while (!needs_quote && *(++t) != 0)
7494             needs_quote = !isalnum(*t) &&
7495               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
7496               (*t != '.' || t == sub || t[1] == 0);
7497           }
7498
7499         if (needs_quote)
7500           {
7501           yield = string_catn(yield, US"\"", 1);
7502           t = sub - 1;
7503           while (*(++t) != 0)
7504             {
7505             if (*t == '\n')
7506               yield = string_catn(yield, US"\\n", 2);
7507             else if (*t == '\r')
7508               yield = string_catn(yield, US"\\r", 2);
7509             else
7510               {
7511               if (*t == '\\' || *t == '"')
7512                 yield = string_catn(yield, US"\\", 1);
7513               yield = string_catn(yield, t, 1);
7514               }
7515             }
7516           yield = string_catn(yield, US"\"", 1);
7517           }
7518         else yield = string_cat(yield, sub);
7519         continue;
7520         }
7521
7522       /* quote_lookuptype does lookup-specific quoting */
7523
7524       else
7525         {
7526         int n;
7527         uschar *opt = Ustrchr(arg, '_');
7528
7529         if (opt) *opt++ = 0;
7530
7531         if ((n = search_findtype(arg, Ustrlen(arg))) < 0)
7532           {
7533           expand_string_message = search_error_message;
7534           goto EXPAND_FAILED;
7535           }
7536
7537         if (lookup_list[n]->quote)
7538           sub = (lookup_list[n]->quote)(sub, opt);
7539         else if (opt)
7540           sub = NULL;
7541
7542         if (!sub)
7543           {
7544           expand_string_message = string_sprintf(
7545             "\"%s\" unrecognized after \"${quote_%s\"",
7546             opt, arg);
7547           goto EXPAND_FAILED;
7548           }
7549
7550         yield = string_cat(yield, sub);
7551         continue;
7552         }
7553
7554       /* rx quote sticks in \ before any non-alphameric character so that
7555       the insertion works in a regular expression. */
7556
7557       case EOP_RXQUOTE:
7558         {
7559         uschar *t = sub - 1;
7560         while (*(++t) != 0)
7561           {
7562           if (!isalnum(*t))
7563             yield = string_catn(yield, US"\\", 1);
7564           yield = string_catn(yield, t, 1);
7565           }
7566         continue;
7567         }
7568
7569       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
7570       prescribed by the RFC, if there are characters that need to be encoded */
7571
7572       case EOP_RFC2047:
7573         {
7574         uschar buffer[2048];
7575         yield = string_cat(yield,
7576                             parse_quote_2047(sub, Ustrlen(sub), headers_charset,
7577                               buffer, sizeof(buffer), FALSE));
7578         continue;
7579         }
7580
7581       /* RFC 2047 decode */
7582
7583       case EOP_RFC2047D:
7584         {
7585         int len;
7586         uschar *error;
7587         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
7588           headers_charset, '?', &len, &error);
7589         if (error)
7590           {
7591           expand_string_message = error;
7592           goto EXPAND_FAILED;
7593           }
7594         yield = string_catn(yield, decoded, len);
7595         continue;
7596         }
7597
7598       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
7599       underscores */
7600
7601       case EOP_FROM_UTF8:
7602         {
7603         uschar * buff = store_get(4, is_tainted(sub));
7604         while (*sub)
7605           {
7606           int c;
7607           GETUTF8INC(c, sub);
7608           if (c > 255) c = '_';
7609           buff[0] = c;
7610           yield = string_catn(yield, buff, 1);
7611           }
7612         continue;
7613         }
7614
7615       /* replace illegal UTF-8 sequences by replacement character  */
7616
7617       #define UTF8_REPLACEMENT_CHAR US"?"
7618
7619       case EOP_UTF8CLEAN:
7620         {
7621         int seq_len = 0, index = 0;
7622         int bytes_left = 0;
7623         long codepoint = -1;
7624         int complete;
7625         uschar seq_buff[4];                     /* accumulate utf-8 here */
7626
7627         /* Manually track tainting, as we deal in individual chars below */
7628
7629         if (is_tainted(sub))
7630           if (yield->s && yield->ptr)
7631             gstring_rebuffer(yield);
7632           else
7633             yield->s = store_get(yield->size = Ustrlen(sub), TRUE);
7634
7635         /* Check the UTF-8, byte-by-byte */
7636
7637         while (*sub)
7638           {
7639           complete = 0;
7640           uschar c = *sub++;
7641
7642           if (bytes_left)
7643             {
7644             if ((c & 0xc0) != 0x80)
7645                     /* wrong continuation byte; invalidate all bytes */
7646               complete = 1; /* error */
7647             else
7648               {
7649               codepoint = (codepoint << 6) | (c & 0x3f);
7650               seq_buff[index++] = c;
7651               if (--bytes_left == 0)            /* codepoint complete */
7652                 if(codepoint > 0x10FFFF)        /* is it too large? */
7653                   complete = -1;        /* error (RFC3629 limit) */
7654                 else
7655                   {             /* finished; output utf-8 sequence */
7656                   yield = string_catn(yield, seq_buff, seq_len);
7657                   index = 0;
7658                   }
7659               }
7660             }
7661           else  /* no bytes left: new sequence */
7662             {
7663             if(!(c & 0x80))     /* 1-byte sequence, US-ASCII, keep it */
7664               {
7665               yield = string_catn(yield, &c, 1);
7666               continue;
7667               }
7668             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7669               {
7670               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7671                 complete = -1;
7672               else
7673                 {
7674                   bytes_left = 1;
7675                   codepoint = c & 0x1f;
7676                 }
7677               }
7678             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7679               {
7680               bytes_left = 2;
7681               codepoint = c & 0x0f;
7682               }
7683             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7684               {
7685               bytes_left = 3;
7686               codepoint = c & 0x07;
7687               }
7688             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7689               complete = -1;
7690
7691             seq_buff[index++] = c;
7692             seq_len = bytes_left + 1;
7693             }           /* if(bytes_left) */
7694
7695           if (complete != 0)
7696             {
7697             bytes_left = index = 0;
7698             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7699             }
7700           if ((complete == 1) && ((c & 0x80) == 0))
7701                         /* ASCII character follows incomplete sequence */
7702               yield = string_catn(yield, &c, 1);
7703           }
7704         /* If given a sequence truncated mid-character, we also want to report ?
7705         * Eg, ${length_1:フィル} is one byte, not one character, so we expect
7706         * ${utf8clean:${length_1:フィル}} to yield '?' */
7707         if (bytes_left != 0)
7708           yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7709
7710         continue;
7711         }
7712
7713 #ifdef SUPPORT_I18N
7714       case EOP_UTF8_DOMAIN_TO_ALABEL:
7715         {
7716         uschar * error = NULL;
7717         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7718         if (error)
7719           {
7720           expand_string_message = string_sprintf(
7721             "error converting utf8 (%s) to alabel: %s",
7722             string_printing(sub), error);
7723           goto EXPAND_FAILED;
7724           }
7725         yield = string_cat(yield, s);
7726         continue;
7727         }
7728
7729       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7730         {
7731         uschar * error = NULL;
7732         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7733         if (error)
7734           {
7735           expand_string_message = string_sprintf(
7736             "error converting alabel (%s) to utf8: %s",
7737             string_printing(sub), error);
7738           goto EXPAND_FAILED;
7739           }
7740         yield = string_cat(yield, s);
7741         continue;
7742         }
7743
7744       case EOP_UTF8_LOCALPART_TO_ALABEL:
7745         {
7746         uschar * error = NULL;
7747         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7748         if (error)
7749           {
7750           expand_string_message = string_sprintf(
7751             "error converting utf8 (%s) to alabel: %s",
7752             string_printing(sub), error);
7753           goto EXPAND_FAILED;
7754           }
7755         yield = string_cat(yield, s);
7756         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7757         continue;
7758         }
7759
7760       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7761         {
7762         uschar * error = NULL;
7763         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7764         if (error)
7765           {
7766           expand_string_message = string_sprintf(
7767             "error converting alabel (%s) to utf8: %s",
7768             string_printing(sub), error);
7769           goto EXPAND_FAILED;
7770           }
7771         yield = string_cat(yield, s);
7772         continue;
7773         }
7774 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7775
7776       /* escape turns all non-printing characters into escape sequences. */
7777
7778       case EOP_ESCAPE:
7779         {
7780         const uschar * t = string_printing(sub);
7781         yield = string_cat(yield, t);
7782         continue;
7783         }
7784
7785       case EOP_ESCAPE8BIT:
7786         {
7787         uschar c;
7788
7789         for (const uschar * s = sub; (c = *s); s++)
7790           yield = c < 127 && c != '\\'
7791             ? string_catn(yield, s, 1)
7792             : string_fmt_append(yield, "\\%03o", c);
7793         continue;
7794         }
7795
7796       /* Handle numeric expression evaluation */
7797
7798       case EOP_EVAL:
7799       case EOP_EVAL10:
7800         {
7801         uschar *save_sub = sub;
7802         uschar *error = NULL;
7803         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7804         if (error)
7805           {
7806           expand_string_message = string_sprintf("error in expression "
7807             "evaluation: %s (after processing \"%.*s\")", error,
7808             (int)(sub-save_sub), save_sub);
7809           goto EXPAND_FAILED;
7810           }
7811         yield = string_fmt_append(yield, PR_EXIM_ARITH, n);
7812         continue;
7813         }
7814
7815       /* Handle time period formatting */
7816
7817       case EOP_TIME_EVAL:
7818         {
7819         int n = readconf_readtime(sub, 0, FALSE);
7820         if (n < 0)
7821           {
7822           expand_string_message = string_sprintf("string \"%s\" is not an "
7823             "Exim time interval in \"%s\" operator", sub, name);
7824           goto EXPAND_FAILED;
7825           }
7826         yield = string_fmt_append(yield, "%d", n);
7827         continue;
7828         }
7829
7830       case EOP_TIME_INTERVAL:
7831         {
7832         int n;
7833         uschar *t = read_number(&n, sub);
7834         if (*t != 0) /* Not A Number*/
7835           {
7836           expand_string_message = string_sprintf("string \"%s\" is not a "
7837             "positive number in \"%s\" operator", sub, name);
7838           goto EXPAND_FAILED;
7839           }
7840         t = readconf_printtime(n);
7841         yield = string_cat(yield, t);
7842         continue;
7843         }
7844
7845       /* Convert string to base64 encoding */
7846
7847       case EOP_STR2B64:
7848       case EOP_BASE64:
7849         {
7850 #ifndef DISABLE_TLS
7851         uschar * s = vp && *(void **)vp->value
7852           ? tls_cert_der_b64(*(void **)vp->value)
7853           : b64encode(CUS sub, Ustrlen(sub));
7854 #else
7855         uschar * s = b64encode(CUS sub, Ustrlen(sub));
7856 #endif
7857         yield = string_cat(yield, s);
7858         continue;
7859         }
7860
7861       case EOP_BASE64D:
7862         {
7863         uschar * s;
7864         int len = b64decode(sub, &s);
7865         if (len < 0)
7866           {
7867           expand_string_message = string_sprintf("string \"%s\" is not "
7868             "well-formed for \"%s\" operator", sub, name);
7869           goto EXPAND_FAILED;
7870           }
7871         yield = string_cat(yield, s);
7872         continue;
7873         }
7874
7875       /* strlen returns the length of the string */
7876
7877       case EOP_STRLEN:
7878         yield = string_fmt_append(yield, "%d", Ustrlen(sub));
7879         continue;
7880
7881       /* length_n or l_n takes just the first n characters or the whole string,
7882       whichever is the shorter;
7883
7884       substr_m_n, and s_m_n take n characters from offset m; negative m take
7885       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7886       takes the rest, either to the right or to the left.
7887
7888       hash_n or h_n makes a hash of length n from the string, yielding n
7889       characters from the set a-z; hash_n_m makes a hash of length n, but
7890       uses m characters from the set a-zA-Z0-9.
7891
7892       nhash_n returns a single number between 0 and n-1 (in text form), while
7893       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7894       between 0 and n-1 and the second between 0 and m-1. */
7895
7896       case EOP_LENGTH:
7897       case EOP_L:
7898       case EOP_SUBSTR:
7899       case EOP_S:
7900       case EOP_HASH:
7901       case EOP_H:
7902       case EOP_NHASH:
7903       case EOP_NH:
7904         {
7905         int sign = 1;
7906         int value1 = 0;
7907         int value2 = -1;
7908         int *pn;
7909         int len;
7910         uschar *ret;
7911
7912         if (!arg)
7913           {
7914           expand_string_message = string_sprintf("missing values after %s",
7915             name);
7916           goto EXPAND_FAILED;
7917           }
7918
7919         /* "length" has only one argument, effectively being synonymous with
7920         substr_0_n. */
7921
7922         if (c == EOP_LENGTH || c == EOP_L)
7923           {
7924           pn = &value2;
7925           value2 = 0;
7926           }
7927
7928         /* The others have one or two arguments; for "substr" the first may be
7929         negative. The second being negative means "not supplied". */
7930
7931         else
7932           {
7933           pn = &value1;
7934           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7935           }
7936
7937         /* Read up to two numbers, separated by underscores */
7938
7939         ret = arg;
7940         while (*arg != 0)
7941           {
7942           if (arg != ret && *arg == '_' && pn == &value1)
7943             {
7944             pn = &value2;
7945             value2 = 0;
7946             if (arg[1] != 0) arg++;
7947             }
7948           else if (!isdigit(*arg))
7949             {
7950             expand_string_message =
7951               string_sprintf("non-digit after underscore in \"%s\"", name);
7952             goto EXPAND_FAILED;
7953             }
7954           else *pn = (*pn)*10 + *arg++ - '0';
7955           }
7956         value1 *= sign;
7957
7958         /* Perform the required operation */
7959
7960         ret = c == EOP_HASH || c == EOP_H
7961           ? compute_hash(sub, value1, value2, &len)
7962           : c == EOP_NHASH || c == EOP_NH
7963           ? compute_nhash(sub, value1, value2, &len)
7964           : extract_substr(sub, value1, value2, &len);
7965         if (!ret) goto EXPAND_FAILED;
7966
7967         yield = string_catn(yield, ret, len);
7968         continue;
7969         }
7970
7971       /* Stat a path */
7972
7973       case EOP_STAT:
7974         {
7975         uschar smode[12];
7976         uschar **modetable[3];
7977         mode_t mode;
7978         struct stat st;
7979
7980         if (expand_forbid & RDO_EXISTS)
7981           {
7982           expand_string_message = US"Use of the stat() expansion is not permitted";
7983           goto EXPAND_FAILED;
7984           }
7985
7986         if (stat(CS sub, &st) < 0)
7987           {
7988           expand_string_message = string_sprintf("stat(%s) failed: %s",
7989             sub, strerror(errno));
7990           goto EXPAND_FAILED;
7991           }
7992         mode = st.st_mode;
7993         switch (mode & S_IFMT)
7994           {
7995           case S_IFIFO: smode[0] = 'p'; break;
7996           case S_IFCHR: smode[0] = 'c'; break;
7997           case S_IFDIR: smode[0] = 'd'; break;
7998           case S_IFBLK: smode[0] = 'b'; break;
7999           case S_IFREG: smode[0] = '-'; break;
8000           default: smode[0] = '?'; break;
8001           }
8002
8003         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
8004         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
8005         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
8006
8007         for (int i = 0; i < 3; i++)
8008           {
8009           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
8010           mode >>= 3;
8011           }
8012
8013         smode[10] = 0;
8014         yield = string_fmt_append(yield,
8015           "mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
8016           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
8017           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
8018           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
8019           (long)st.st_gid, st.st_size, (long)st.st_atime,
8020           (long)st.st_mtime, (long)st.st_ctime);
8021         continue;
8022         }
8023
8024       /* vaguely random number less than N */
8025
8026       case EOP_RANDINT:
8027         {
8028         int_eximarith_t max = expanded_string_integer(sub, TRUE);
8029
8030         if (expand_string_message)
8031           goto EXPAND_FAILED;
8032         yield = string_fmt_append(yield, "%d", vaguely_random_number((int)max));
8033         continue;
8034         }
8035
8036       /* Reverse IP, including IPv6 to dotted-nibble */
8037
8038       case EOP_REVERSE_IP:
8039         {
8040         int family, maskptr;
8041         uschar reversed[128];
8042
8043         family = string_is_ip_address(sub, &maskptr);
8044         if (family == 0)
8045           {
8046           expand_string_message = string_sprintf(
8047               "reverse_ip() not given an IP address [%s]", sub);
8048           goto EXPAND_FAILED;
8049           }
8050         invert_address(reversed, sub);
8051         yield = string_cat(yield, reversed);
8052         continue;
8053         }
8054
8055       /* Unknown operator */
8056
8057       default:
8058         expand_string_message =
8059           string_sprintf("unknown expansion operator \"%s\"", name);
8060         goto EXPAND_FAILED;
8061       }
8062     }
8063
8064   /* Handle a plain name. If this is the first thing in the expansion, release
8065   the pre-allocated buffer. If the result data is known to be in a new buffer,
8066   newsize will be set to the size of that buffer, and we can just point at that
8067   store instead of copying. Many expansion strings contain just one reference,
8068   so this is a useful optimization, especially for humungous headers
8069   ($message_headers). */
8070                                                 /*{*/
8071   if (*s++ == '}')
8072     {
8073     int len;
8074     int newsize = 0;
8075     gstring * g = NULL;
8076
8077     if (!yield)
8078       g = store_get(sizeof(gstring), FALSE);
8079     else if (yield->ptr == 0)
8080       {
8081       if (resetok) reset_point = store_reset(reset_point);
8082       yield = NULL;
8083       reset_point = store_mark();
8084       g = store_get(sizeof(gstring), FALSE);    /* alloc _before_ calling find_variable() */
8085       }
8086     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
8087       {
8088       expand_string_message =
8089         string_sprintf("unknown variable in \"${%s}\"", name);
8090       check_variable_error_message(name);
8091       goto EXPAND_FAILED;
8092       }
8093     len = Ustrlen(value);
8094     if (!yield && newsize)
8095       {
8096       yield = g;
8097       yield->size = newsize;
8098       yield->ptr = len;
8099       yield->s = value;
8100       }
8101     else
8102       yield = string_catn(yield, value, len);
8103     continue;
8104     }
8105
8106   /* Else there's something wrong */
8107
8108   expand_string_message =
8109     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
8110     "in a variable reference)", name);
8111   goto EXPAND_FAILED;
8112   }
8113
8114 /* If we hit the end of the string when ket_ends is set, there is a missing
8115 terminating brace. */
8116
8117 if (ket_ends && *s == 0)
8118   {
8119   expand_string_message = malformed_header
8120     ? US"missing } at end of string - could be header name not terminated by colon"
8121     : US"missing } at end of string";
8122   goto EXPAND_FAILED;
8123   }
8124
8125 /* Expansion succeeded; yield may still be NULL here if nothing was actually
8126 added to the string. If so, set up an empty string. Add a terminating zero. If
8127 left != NULL, return a pointer to the terminator. */
8128
8129 if (!yield)
8130   yield = string_get(1);
8131 (void) string_from_gstring(yield);
8132 if (left) *left = s;
8133
8134 /* Any stacking store that was used above the final string is no longer needed.
8135 In many cases the final string will be the first one that was got and so there
8136 will be optimal store usage. */
8137
8138 if (resetok) gstring_release_unused(yield);
8139 else if (resetok_p) *resetok_p = FALSE;
8140
8141 DEBUG(D_expand)
8142   {
8143   BOOL tainted = is_tainted(yield->s);
8144   DEBUG(D_noutf8)
8145     {
8146     debug_printf_indent("|--expanding: %.*s\n", (int)(s - string), string);
8147     debug_printf_indent("%sresult: %s\n",
8148       skipping ? "|-----" : "\\_____", yield->s);
8149     if (tainted)
8150       debug_printf_indent("%s     \\__(tainted)\n",
8151         skipping ? "|     " : "      ");
8152     if (skipping)
8153       debug_printf_indent("\\___skipping: result is not used\n");
8154     }
8155   else
8156     {
8157     debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
8158       "expanding: %.*s\n",
8159       (int)(s - string), string);
8160     debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
8161       "result: %s\n",
8162       skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
8163       yield->s);
8164     if (tainted)
8165       debug_printf_indent("%s(tainted)\n",
8166         skipping
8167         ? UTF8_VERT "             " : "           " UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ);
8168     if (skipping)
8169       debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
8170         "skipping: result is not used\n");
8171     }
8172   }
8173 expand_level--;
8174 return yield->s;
8175
8176 /* This is the failure exit: easiest to program with a goto. We still need
8177 to update the pointer to the terminator, for cases of nested calls with "fail".
8178 */
8179
8180 EXPAND_FAILED_CURLY:
8181 if (malformed_header)
8182   expand_string_message =
8183     US"missing or misplaced { or } - could be header name not terminated by colon";
8184
8185 else if (!expand_string_message || !*expand_string_message)
8186   expand_string_message = US"missing or misplaced { or }";
8187
8188 /* At one point, Exim reset the store to yield (if yield was not NULL), but
8189 that is a bad idea, because expand_string_message is in dynamic store. */
8190
8191 EXPAND_FAILED:
8192 if (left) *left = s;
8193 DEBUG(D_expand)
8194   DEBUG(D_noutf8)
8195     {
8196     debug_printf_indent("|failed to expand: %s\n", string);
8197     debug_printf_indent("%serror message: %s\n",
8198       f.expand_string_forcedfail ? "|---" : "\\___", expand_string_message);
8199     if (f.expand_string_forcedfail)
8200       debug_printf_indent("\\failure was forced\n");
8201     }
8202   else
8203     {
8204     debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
8205       string);
8206     debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
8207       "error message: %s\n",
8208       f.expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
8209       expand_string_message);
8210     if (f.expand_string_forcedfail)
8211       debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
8212     }
8213 if (resetok_p && !resetok) *resetok_p = FALSE;
8214 expand_level--;
8215 return NULL;
8216 }
8217
8218
8219 /* This is the external function call. Do a quick check for any expansion
8220 metacharacters, and if there are none, just return the input string.
8221
8222 Argument: the string to be expanded
8223 Returns:  the expanded string, or NULL if expansion failed; if failure was
8224           due to a lookup deferring, search_find_defer will be TRUE
8225 */
8226
8227 const uschar *
8228 expand_cstring(const uschar * string)
8229 {
8230 if (Ustrpbrk(string, "$\\") != NULL)
8231   {
8232   int old_pool = store_pool;
8233   uschar * s;
8234
8235   f.search_find_defer = FALSE;
8236   malformed_header = FALSE;
8237   store_pool = POOL_MAIN;
8238     s = expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
8239   store_pool = old_pool;
8240   return s;
8241   }
8242 return string;
8243 }
8244
8245
8246 uschar *
8247 expand_string(uschar * string)
8248 {
8249 return US expand_cstring(CUS string);
8250 }
8251
8252
8253
8254
8255
8256 /*************************************************
8257 *              Expand and copy                   *
8258 *************************************************/
8259
8260 /* Now and again we want to expand a string and be sure that the result is in a
8261 new bit of store. This function does that.
8262 Since we know it has been copied, the de-const cast is safe.
8263
8264 Argument: the string to be expanded
8265 Returns:  the expanded string, always in a new bit of store, or NULL
8266 */
8267
8268 uschar *
8269 expand_string_copy(const uschar *string)
8270 {
8271 const uschar *yield = expand_cstring(string);
8272 if (yield == string) yield = string_copy(string);
8273 return US yield;
8274 }
8275
8276
8277
8278 /*************************************************
8279 *        Expand and interpret as an integer      *
8280 *************************************************/
8281
8282 /* Expand a string, and convert the result into an integer.
8283
8284 Arguments:
8285   string  the string to be expanded
8286   isplus  TRUE if a non-negative number is expected
8287
8288 Returns:  the integer value, or
8289           -1 for an expansion error               ) in both cases, message in
8290           -2 for an integer interpretation error  ) expand_string_message
8291           expand_string_message is set NULL for an OK integer
8292 */
8293
8294 int_eximarith_t
8295 expand_string_integer(uschar *string, BOOL isplus)
8296 {
8297 return expanded_string_integer(expand_string(string), isplus);
8298 }
8299
8300
8301 /*************************************************
8302  *         Interpret string as an integer        *
8303  *************************************************/
8304
8305 /* Convert a string (that has already been expanded) into an integer.
8306
8307 This function is used inside the expansion code.
8308
8309 Arguments:
8310   s       the string to be expanded
8311   isplus  TRUE if a non-negative number is expected
8312
8313 Returns:  the integer value, or
8314           -1 if string is NULL (which implies an expansion error)
8315           -2 for an integer interpretation error
8316           expand_string_message is set NULL for an OK integer
8317 */
8318
8319 static int_eximarith_t
8320 expanded_string_integer(const uschar *s, BOOL isplus)
8321 {
8322 int_eximarith_t value;
8323 uschar *msg = US"invalid integer \"%s\"";
8324 uschar *endptr;
8325
8326 /* If expansion failed, expand_string_message will be set. */
8327
8328 if (!s) return -1;
8329
8330 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
8331 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
8332 systems, so we set it zero ourselves. */
8333
8334 errno = 0;
8335 expand_string_message = NULL;               /* Indicates no error */
8336
8337 /* Before Exim 4.64, strings consisting entirely of whitespace compared
8338 equal to 0.  Unfortunately, people actually relied upon that, so preserve
8339 the behaviour explicitly.  Stripping leading whitespace is a harmless
8340 noop change since strtol skips it anyway (provided that there is a number
8341 to find at all). */
8342 if (isspace(*s))
8343   if (Uskip_whitespace(&s) == '\0')
8344     {
8345       DEBUG(D_expand)
8346        debug_printf_indent("treating blank string as number 0\n");
8347       return 0;
8348     }
8349
8350 value = strtoll(CS s, CSS &endptr, 10);
8351
8352 if (endptr == s)
8353   msg = US"integer expected but \"%s\" found";
8354 else if (value < 0 && isplus)
8355   msg = US"non-negative integer expected but \"%s\" found";
8356 else
8357   {
8358   switch (tolower(*endptr))
8359     {
8360     default:
8361       break;
8362     case 'k':
8363       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
8364       else value *= 1024;
8365       endptr++;
8366       break;
8367     case 'm':
8368       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
8369       else value *= 1024*1024;
8370       endptr++;
8371       break;
8372     case 'g':
8373       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
8374       else value *= 1024*1024*1024;
8375       endptr++;
8376       break;
8377     }
8378   if (errno == ERANGE)
8379     msg = US"absolute value of integer \"%s\" is too large (overflow)";
8380   else
8381     if (Uskip_whitespace(&endptr) == 0) return value;
8382   }
8383
8384 expand_string_message = string_sprintf(CS msg, s);
8385 return -2;
8386 }
8387
8388
8389 /* These values are usually fixed boolean values, but they are permitted to be
8390 expanded strings.
8391
8392 Arguments:
8393   addr       address being routed
8394   mtype      the module type
8395   mname      the module name
8396   dbg_opt    debug selectors
8397   oname      the option name
8398   bvalue     the router's boolean value
8399   svalue     the router's string value
8400   rvalue     where to put the returned value
8401
8402 Returns:     OK     value placed in rvalue
8403              DEFER  expansion failed
8404 */
8405
8406 int
8407 exp_bool(address_item *addr,
8408   uschar *mtype, uschar *mname, unsigned dbg_opt,
8409   uschar *oname, BOOL bvalue,
8410   uschar *svalue, BOOL *rvalue)
8411 {
8412 uschar *expanded;
8413 if (!svalue) { *rvalue = bvalue; return OK; }
8414
8415 if (!(expanded = expand_string(svalue)))
8416   {
8417   if (f.expand_string_forcedfail)
8418     {
8419     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
8420     *rvalue = bvalue;
8421     return OK;
8422     }
8423   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
8424       oname, mname, mtype, expand_string_message);
8425   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
8426   return DEFER;
8427   }
8428
8429 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
8430   expanded);
8431
8432 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
8433   *rvalue = TRUE;
8434 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
8435   *rvalue = FALSE;
8436 else
8437   {
8438   addr->message = string_sprintf("\"%s\" is not a valid value for the "
8439     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
8440   return DEFER;
8441   }
8442
8443 return OK;
8444 }
8445
8446
8447
8448 /* Avoid potentially exposing a password in a string about to be logged */
8449
8450 uschar *
8451 expand_hide_passwords(uschar * s)
8452 {
8453 return (  (  Ustrstr(s, "failed to expand") != NULL
8454           || Ustrstr(s, "expansion of ")    != NULL
8455           )
8456        && (  Ustrstr(s, "mysql")   != NULL
8457           || Ustrstr(s, "pgsql")   != NULL
8458           || Ustrstr(s, "redis")   != NULL
8459           || Ustrstr(s, "sqlite")  != NULL
8460           || Ustrstr(s, "ldap:")   != NULL
8461           || Ustrstr(s, "ldaps:")  != NULL
8462           || Ustrstr(s, "ldapi:")  != NULL
8463           || Ustrstr(s, "ldapdn:") != NULL
8464           || Ustrstr(s, "ldapm:")  != NULL
8465        )  )
8466   ? US"Temporary internal error" : s;
8467 }
8468
8469
8470 /* Read given named file into big_buffer.  Use for keying material etc.
8471 The content will have an ascii NUL appended.
8472
8473 Arguments:
8474  filename       as it says
8475
8476 Return:  pointer to buffer, or NULL on error.
8477 */
8478
8479 uschar *
8480 expand_file_big_buffer(const uschar * filename)
8481 {
8482 int fd, off = 0, len;
8483
8484 if ((fd = exim_open2(CS filename, O_RDONLY)) < 0)
8485   {
8486   log_write(0, LOG_MAIN | LOG_PANIC, "unable to open file for reading: %s",
8487              filename);
8488   return NULL;
8489   }
8490
8491 do
8492   {
8493   if ((len = read(fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
8494     {
8495     (void) close(fd);
8496     log_write(0, LOG_MAIN|LOG_PANIC, "unable to read file: %s", filename);
8497     return NULL;
8498     }
8499   off += len;
8500   }
8501 while (len > 0);
8502
8503 (void) close(fd);
8504 big_buffer[off] = '\0';
8505 return big_buffer;
8506 }
8507
8508
8509
8510 /*************************************************
8511 * Error-checking for testsuite                   *
8512 *************************************************/
8513 typedef struct {
8514   uschar *      region_start;
8515   uschar *      region_end;
8516   const uschar *var_name;
8517   const uschar *var_data;
8518 } err_ctx;
8519
8520 static void
8521 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
8522 {
8523 err_ctx * e = ctx;
8524 if (var_data >= e->region_start  &&  var_data < e->region_end)
8525   {
8526   e->var_name = CUS var_name;
8527   e->var_data = CUS var_data;
8528   }
8529 }
8530
8531 void
8532 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
8533 {
8534 err_ctx e = { .region_start = ptr, .region_end = US ptr + len,
8535               .var_name = NULL, .var_data = NULL };
8536
8537 /* check acl_ variables */
8538 tree_walk(acl_var_c, assert_variable_notin, &e);
8539 tree_walk(acl_var_m, assert_variable_notin, &e);
8540
8541 /* check auth<n> variables */
8542 for (int i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
8543   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
8544
8545 /* check regex<n> variables */
8546 for (int i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
8547   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
8548
8549 /* check known-name variables */
8550 for (var_entry * v = var_table; v < var_table + var_table_size; v++)
8551   if (v->type == vtype_stringptr)
8552     assert_variable_notin(US v->name, *(USS v->value), &e);
8553
8554 /* check dns and address trees */
8555 tree_walk(tree_dns_fails,     assert_variable_notin, &e);
8556 tree_walk(tree_duplicates,    assert_variable_notin, &e);
8557 tree_walk(tree_nonrecipients, assert_variable_notin, &e);
8558 tree_walk(tree_unusable,      assert_variable_notin, &e);
8559
8560 if (e.var_name)
8561   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
8562     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
8563     e.var_name, filename, linenumber, e.var_data);
8564 }
8565
8566
8567
8568 /*************************************************
8569 **************************************************
8570 *             Stand-alone test program           *
8571 **************************************************
8572 *************************************************/
8573
8574 #ifdef STAND_ALONE
8575
8576
8577 BOOL
8578 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
8579 {
8580 int ovector[3*(EXPAND_MAXN+1)];
8581 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
8582   ovector, nelem(ovector));
8583 BOOL yield = n >= 0;
8584 if (n == 0) n = EXPAND_MAXN + 1;
8585 if (yield)
8586   {
8587   expand_nmax = setup < 0 ? 0 : setup + 1;
8588   for (int nn = setup < 0 ? 0 : 2; nn < n*2; nn += 2)
8589     {
8590     expand_nstring[expand_nmax] = subject + ovector[nn];
8591     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
8592     }
8593   expand_nmax--;
8594   }
8595 return yield;
8596 }
8597
8598
8599 int main(int argc, uschar **argv)
8600 {
8601 uschar buffer[1024];
8602
8603 debug_selector = D_v;
8604 debug_file = stderr;
8605 debug_fd = fileno(debug_file);
8606 big_buffer = malloc(big_buffer_size);
8607
8608 for (int i = 1; i < argc; i++)
8609   {
8610   if (argv[i][0] == '+')
8611     {
8612     debug_trace_memory = 2;
8613     argv[i]++;
8614     }
8615   if (isdigit(argv[i][0]))
8616     debug_selector = Ustrtol(argv[i], NULL, 0);
8617   else
8618     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
8619         Ustrlen(argv[i]))
8620       {
8621 #ifdef LOOKUP_LDAP
8622       eldap_default_servers = argv[i];
8623 #endif
8624 #ifdef LOOKUP_MYSQL
8625       mysql_servers = argv[i];
8626 #endif
8627 #ifdef LOOKUP_PGSQL
8628       pgsql_servers = argv[i];
8629 #endif
8630 #ifdef LOOKUP_REDIS
8631       redis_servers = argv[i];
8632 #endif
8633       }
8634 #ifdef EXIM_PERL
8635   else opt_perl_startup = argv[i];
8636 #endif
8637   }
8638
8639 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
8640
8641 expand_nstring[1] = US"string 1....";
8642 expand_nlength[1] = 8;
8643 expand_nmax = 1;
8644
8645 #ifdef EXIM_PERL
8646 if (opt_perl_startup != NULL)
8647   {
8648   uschar *errstr;
8649   printf("Starting Perl interpreter\n");
8650   errstr = init_perl(opt_perl_startup);
8651   if (errstr != NULL)
8652     {
8653     printf("** error in perl_startup code: %s\n", errstr);
8654     return EXIT_FAILURE;
8655     }
8656   }
8657 #endif /* EXIM_PERL */
8658
8659 /* Thie deliberately regards the input as untainted, so that it can be
8660 expanded; only reasonable since this is a test for string-expansions. */
8661
8662 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
8663   {
8664   rmark reset_point = store_mark();
8665   uschar *yield = expand_string(buffer);
8666   if (yield)
8667     printf("%s\n", yield);
8668   else
8669     {
8670     if (f.search_find_defer) printf("search_find deferred\n");
8671     printf("Failed: %s\n", expand_string_message);
8672     if (f.expand_string_forcedfail) printf("Forced failure\n");
8673     printf("\n");
8674     }
8675   store_reset(reset_point);
8676   }
8677
8678 search_tidyup();
8679
8680 return 0;
8681 }
8682
8683 #endif
8684
8685 /* vi: aw ai sw=2
8686 */
8687 /* End of expand.c */