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