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