src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   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.  Charaters 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"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef EXPERIMENTAL_INTERNATIONAL
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef EXPERIMENTAL_INTERNATIONAL
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef EXPERIMENTAL_INTERNATIONAL
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef EXPERIMENTAL_INTERNATIONAL
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base62",
 203   US"base62d",
 204   US"domain",
 205   US"escape",
 206   US"eval",
 207   US"eval10",
 208   US"expand",
 209   US"h",
 210   US"hash",
 211   US"hex2b64",
 212   US"hexquote",
 213   US"ipv6denorm",
 214   US"ipv6norm",
 215   US"l",
 216   US"lc",
 217   US"length",
 218   US"listcount",
 219   US"listnamed",
 220   US"mask",
 221   US"md5",
 222   US"nh",
 223   US"nhash",
 224   US"quote",
 225   US"randint",
 226   US"rfc2047",
 227   US"rfc2047d",
 228   US"rxquote",
 229   US"s",
 230   US"sha1",
 231   US"sha256",
 232   US"stat",
 233   US"str2b64",
 234   US"strlen",
 235   US"substr",
 236   US"uc",
 237   US"utf8clean" };
 238
 239 enum {
 240   EOP_ADDRESS =  nelem(op_table_underscore),
 241   EOP_ADDRESSES,
 242   EOP_BASE62,
 243   EOP_BASE62D,
 244   EOP_DOMAIN,
 245   EOP_ESCAPE,
 246   EOP_EVAL,
 247   EOP_EVAL10,
 248   EOP_EXPAND,
 249   EOP_H,
 250   EOP_HASH,
 251   EOP_HEX2B64,
 252   EOP_HEXQUOTE,
 253   EOP_IPV6DENORM,
 254   EOP_IPV6NORM,
 255   EOP_L,
 256   EOP_LC,
 257   EOP_LENGTH,
 258   EOP_LISTCOUNT,
 259   EOP_LISTNAMED,
 260   EOP_MASK,
 261   EOP_MD5,
 262   EOP_NH,
 263   EOP_NHASH,
 264   EOP_QUOTE,
 265   EOP_RANDINT,
 266   EOP_RFC2047,
 267   EOP_RFC2047D,
 268   EOP_RXQUOTE,
 269   EOP_S,
 270   EOP_SHA1,
 271   EOP_SHA256,
 272   EOP_STAT,
 273   EOP_STR2B64,
 274   EOP_STRLEN,
 275   EOP_SUBSTR,
 276   EOP_UC,
 277   EOP_UTF8CLEAN };
 278
 279
 280 /* Table of condition names, and corresponding switch numbers. The names must
 281 be in alphabetical order. */
 282
 283 static uschar *cond_table[] = {
 284   US"<",
 285   US"<=",
 286   US"=",
 287   US"==",     /* Backward compatibility */
 288   US">",
 289   US">=",
 290   US"acl",
 291   US"and",
 292   US"bool",
 293   US"bool_lax",
 294   US"crypteq",
 295   US"def",
 296   US"eq",
 297   US"eqi",
 298   US"exists",
 299   US"first_delivery",
 300   US"forall",
 301   US"forany",
 302   US"ge",
 303   US"gei",
 304   US"gt",
 305   US"gti",
 306   US"inlist",
 307   US"inlisti",
 308   US"isip",
 309   US"isip4",
 310   US"isip6",
 311   US"ldapauth",
 312   US"le",
 313   US"lei",
 314   US"lt",
 315   US"lti",
 316   US"match",
 317   US"match_address",
 318   US"match_domain",
 319   US"match_ip",
 320   US"match_local_part",
 321   US"or",
 322   US"pam",
 323   US"pwcheck",
 324   US"queue_running",
 325   US"radius",
 326   US"saslauthd"
 327 };
 328
 329 enum {
 330   ECOND_NUM_L,
 331   ECOND_NUM_LE,
 332   ECOND_NUM_E,
 333   ECOND_NUM_EE,
 334   ECOND_NUM_G,
 335   ECOND_NUM_GE,
 336   ECOND_ACL,
 337   ECOND_AND,
 338   ECOND_BOOL,
 339   ECOND_BOOL_LAX,
 340   ECOND_CRYPTEQ,
 341   ECOND_DEF,
 342   ECOND_STR_EQ,
 343   ECOND_STR_EQI,
 344   ECOND_EXISTS,
 345   ECOND_FIRST_DELIVERY,
 346   ECOND_FORALL,
 347   ECOND_FORANY,
 348   ECOND_STR_GE,
 349   ECOND_STR_GEI,
 350   ECOND_STR_GT,
 351   ECOND_STR_GTI,
 352   ECOND_INLIST,
 353   ECOND_INLISTI,
 354   ECOND_ISIP,
 355   ECOND_ISIP4,
 356   ECOND_ISIP6,
 357   ECOND_LDAPAUTH,
 358   ECOND_STR_LE,
 359   ECOND_STR_LEI,
 360   ECOND_STR_LT,
 361   ECOND_STR_LTI,
 362   ECOND_MATCH,
 363   ECOND_MATCH_ADDRESS,
 364   ECOND_MATCH_DOMAIN,
 365   ECOND_MATCH_IP,
 366   ECOND_MATCH_LOCAL_PART,
 367   ECOND_OR,
 368   ECOND_PAM,
 369   ECOND_PWCHECK,
 370   ECOND_QUEUE_RUNNING,
 371   ECOND_RADIUS,
 372   ECOND_SASLAUTHD
 373 };
 374
 375
 376 /* Types of table entry */
 377
 378 enum vtypes {
 379   vtype_int,            /* value is address of int */
 380   vtype_filter_int,     /* ditto, but recognized only when filtering */
 381   vtype_ino,            /* value is address of ino_t (not always an int) */
 382   vtype_uid,            /* value is address of uid_t (not always an int) */
 383   vtype_gid,            /* value is address of gid_t (not always an int) */
 384   vtype_bool,           /* value is address of bool */
 385   vtype_stringptr,      /* value is address of pointer to string */
 386   vtype_msgbody,        /* as stringptr, but read when first required */
 387   vtype_msgbody_end,    /* ditto, the end of the message */
 388   vtype_msgheaders,     /* the message's headers, processed */
 389   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 390   vtype_localpart,      /* extract local part from string */
 391   vtype_domain,         /* extract domain from string */
 392   vtype_string_func,    /* value is string returned by given function */
 393   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 394   vtype_tode,           /* value not used; generate tod in epoch format */
 395   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 396   vtype_todf,           /* value not used; generate full tod */
 397   vtype_todl,           /* value not used; generate log tod */
 398   vtype_todlf,          /* value not used; generate log file datestamp tod */
 399   vtype_todzone,        /* value not used; generate time zone only */
 400   vtype_todzulu,        /* value not used; generate zulu tod */
 401   vtype_reply,          /* value not used; get reply from headers */
 402   vtype_pid,            /* value not used; result is pid */
 403   vtype_host_lookup,    /* value not used; get host name */
 404   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 405   vtype_pspace,         /* partition space; value is T/F for spool/log */
 406   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 407   vtype_cert            /* SSL certificate */
 408   #ifndef DISABLE_DKIM
 409   ,vtype_dkim           /* Lookup of value in DKIM signature */
 410   #endif
 411 };
 412
 413 /* Type for main variable table */
 414
 415 typedef struct {
 416   const char *name;
 417   enum vtypes type;
 418   void       *value;
 419 } var_entry;
 420
 421 /* Type for entries pointing to address/length pairs. Not currently
 422 in use. */
 423
 424 typedef struct {
 425   uschar **address;
 426   int  *length;
 427 } alblock;
 428
 429 static uschar * fn_recipients(void);
 430
 431 /* This table must be kept in alphabetical order. */
 432
 433 static var_entry var_table[] = {
 434   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 435      they will be confused with user-creatable ACL variables. */
 436   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 437   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 438   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 439   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 440   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 441   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 442   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 443   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 444   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 445   { "acl_narg",            vtype_int,         &acl_narg },
 446   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 447   { "address_data",        vtype_stringptr,   &deliver_address_data },
 448   { "address_file",        vtype_stringptr,   &address_file },
 449   { "address_pipe",        vtype_stringptr,   &address_pipe },
 450   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 451   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 452   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 453   { "authentication_failed",vtype_int,        &authentication_failed },
 454 #ifdef WITH_CONTENT_SCAN
 455   { "av_failed",           vtype_int,         &av_failed },
 456 #endif
 457 #ifdef EXPERIMENTAL_BRIGHTMAIL
 458   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 459   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 460   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 461   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 462 #endif
 463   { "body_linecount",      vtype_int,         &body_linecount },
 464   { "body_zerocount",      vtype_int,         &body_zerocount },
 465   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 466   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 467   { "caller_gid",          vtype_gid,         &real_gid },
 468   { "caller_uid",          vtype_uid,         &real_uid },
 469   { "callout_address",     vtype_stringptr,   &callout_address },
 470   { "compile_date",        vtype_stringptr,   &version_date },
 471   { "compile_number",      vtype_stringptr,   &version_cnumber },
 472   { "config_dir",          vtype_stringptr,   &config_main_directory },
 473   { "config_file",         vtype_stringptr,   &config_main_filename },
 474   { "csa_status",          vtype_stringptr,   &csa_status },
 475 #ifdef EXPERIMENTAL_DCC
 476   { "dcc_header",          vtype_stringptr,   &dcc_header },
 477   { "dcc_result",          vtype_stringptr,   &dcc_result },
 478 #endif
 479 #ifdef WITH_OLD_DEMIME
 480   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 481   { "demime_reason",       vtype_stringptr,   &demime_reason },
 482 #endif
 483 #ifndef DISABLE_DKIM
 484   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 485   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 486   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 487   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 488   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 489   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 490   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 491   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 492   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 493   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 494   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 495   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 496   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 497   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 498   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 499   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 500   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 501   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 502   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 503   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 504 #endif
 505 #ifdef EXPERIMENTAL_DMARC
 506   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 507   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 508   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 509   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 510   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 511 #endif
 512   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 513   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 514   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 515   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 516   { "domain",              vtype_stringptr,   &deliver_domain },
 517   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 518 #ifdef EXPERIMENTAL_EVENT
 519   { "event_data",          vtype_stringptr,   &event_data },
 520
 521   /*XXX want to use generic vars for as many of these as possible*/
 522   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 523
 524   { "event_name",          vtype_stringptr,   &event_name },
 525 #endif
 526   { "exim_gid",            vtype_gid,         &exim_gid },
 527   { "exim_path",           vtype_stringptr,   &exim_path },
 528   { "exim_uid",            vtype_uid,         &exim_uid },
 529   { "exim_version",        vtype_stringptr,   &version_string },
 530 #ifdef WITH_OLD_DEMIME
 531   { "found_extension",     vtype_stringptr,   &found_extension },
 532 #endif
 533   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 534   { "home",                vtype_stringptr,   &deliver_home },
 535   { "host",                vtype_stringptr,   &deliver_host },
 536   { "host_address",        vtype_stringptr,   &deliver_host_address },
 537   { "host_data",           vtype_stringptr,   &host_data },
 538   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 539   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 540   { "host_port",           vtype_int,         &deliver_host_port },
 541   { "inode",               vtype_ino,         &deliver_inode },
 542   { "interface_address",   vtype_stringptr,   &interface_address },
 543   { "interface_port",      vtype_int,         &interface_port },
 544   { "item",                vtype_stringptr,   &iterate_item },
 545   #ifdef LOOKUP_LDAP
 546   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 547   #endif
 548   { "load_average",        vtype_load_avg,    NULL },
 549   { "local_part",          vtype_stringptr,   &deliver_localpart },
 550   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 551   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 552   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 553   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 554   { "local_user_gid",      vtype_gid,         &local_user_gid },
 555   { "local_user_uid",      vtype_uid,         &local_user_uid },
 556   { "localhost_number",    vtype_int,         &host_number },
 557   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 558   { "log_space",           vtype_pspace,      (void *)FALSE },
 559   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 560   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 561 #ifdef WITH_CONTENT_SCAN
 562   { "malware_name",        vtype_stringptr,   &malware_name },
 563 #endif
 564   { "max_received_linelength", vtype_int,     &max_received_linelength },
 565   { "message_age",         vtype_int,         &message_age },
 566   { "message_body",        vtype_msgbody,     &message_body },
 567   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 568   { "message_body_size",   vtype_int,         &message_body_size },
 569   { "message_exim_id",     vtype_stringptr,   &message_id },
 570   { "message_headers",     vtype_msgheaders,  NULL },
 571   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 572   { "message_id",          vtype_stringptr,   &message_id },
 573   { "message_linecount",   vtype_int,         &message_linecount },
 574   { "message_size",        vtype_int,         &message_size },
 575 #ifdef EXPERIMENTAL_INTERNATIONAL
 576   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 577 #endif
 578 #ifdef WITH_CONTENT_SCAN
 579   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 580   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 581   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 582   { "mime_charset",        vtype_stringptr,   &mime_charset },
 583   { "mime_content_description", vtype_stringptr, &mime_content_description },
 584   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 585   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 586   { "mime_content_size",   vtype_int,         &mime_content_size },
 587   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 588   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 589   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 590   { "mime_filename",       vtype_stringptr,   &mime_filename },
 591   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 592   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 593   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 594   { "mime_part_count",     vtype_int,         &mime_part_count },
 595 #endif
 596   { "n0",                  vtype_filter_int,  &filter_n[0] },
 597   { "n1",                  vtype_filter_int,  &filter_n[1] },
 598   { "n2",                  vtype_filter_int,  &filter_n[2] },
 599   { "n3",                  vtype_filter_int,  &filter_n[3] },
 600   { "n4",                  vtype_filter_int,  &filter_n[4] },
 601   { "n5",                  vtype_filter_int,  &filter_n[5] },
 602   { "n6",                  vtype_filter_int,  &filter_n[6] },
 603   { "n7",                  vtype_filter_int,  &filter_n[7] },
 604   { "n8",                  vtype_filter_int,  &filter_n[8] },
 605   { "n9",                  vtype_filter_int,  &filter_n[9] },
 606   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 607   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 608   { "originator_gid",      vtype_gid,         &originator_gid },
 609   { "originator_uid",      vtype_uid,         &originator_uid },
 610   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 611   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 612   { "pid",                 vtype_pid,         NULL },
 613 #ifndef DISABLE_PRDR
 614   { "prdr_requested",      vtype_bool,        &prdr_requested },
 615 #endif
 616   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 617 #ifdef EXPERIMENTAL_PROXY
 618   { "proxy_host_address",  vtype_stringptr,   &proxy_host_address },
 619   { "proxy_host_port",     vtype_int,         &proxy_host_port },
 620   { "proxy_session",       vtype_bool,        &proxy_session },
 621   { "proxy_target_address",vtype_stringptr,   &proxy_target_address },
 622   { "proxy_target_port",   vtype_int,         &proxy_target_port },
 623 #endif
 624   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 625   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 626   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 627   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 628   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 629   { "rcpt_count",          vtype_int,         &rcpt_count },
 630   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 631   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 632   { "received_count",      vtype_int,         &received_count },
 633   { "received_for",        vtype_stringptr,   &received_for },
 634   { "received_ip_address", vtype_stringptr,   &interface_address },
 635   { "received_port",       vtype_int,         &interface_port },
 636   { "received_protocol",   vtype_stringptr,   &received_protocol },
 637   { "received_time",       vtype_int,         &received_time },
 638   { "recipient_data",      vtype_stringptr,   &recipient_data },
 639   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 640   { "recipients",          vtype_string_func, &fn_recipients },
 641   { "recipients_count",    vtype_int,         &recipients_count },
 642 #ifdef WITH_CONTENT_SCAN
 643   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 644 #endif
 645   { "reply_address",       vtype_reply,       NULL },
 646   { "return_path",         vtype_stringptr,   &return_path },
 647   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 648   { "router_name",         vtype_stringptr,   &router_name },
 649   { "runrc",               vtype_int,         &runrc },
 650   { "self_hostname",       vtype_stringptr,   &self_hostname },
 651   { "sender_address",      vtype_stringptr,   &sender_address },
 652   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 653   { "sender_address_domain", vtype_domain,    &sender_address },
 654   { "sender_address_local_part", vtype_localpart, &sender_address },
 655   { "sender_data",         vtype_stringptr,   &sender_data },
 656   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 657   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 658   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 659   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 660   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 661   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 662   { "sender_host_name",    vtype_host_lookup, NULL },
 663   { "sender_host_port",    vtype_int,         &sender_host_port },
 664   { "sender_ident",        vtype_stringptr,   &sender_ident },
 665   { "sender_rate",         vtype_stringptr,   &sender_rate },
 666   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 667   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 668   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 669   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 670   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 671   { "sending_port",        vtype_int,         &sending_port },
 672   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 673   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 674   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 675   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 676   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 677   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 678   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 679   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 680   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 681   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 682   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 683   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 684   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 685   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 686   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 687 #ifdef WITH_CONTENT_SCAN
 688   { "spam_action",         vtype_stringptr,   &spam_action },
 689   { "spam_bar",            vtype_stringptr,   &spam_bar },
 690   { "spam_report",         vtype_stringptr,   &spam_report },
 691   { "spam_score",          vtype_stringptr,   &spam_score },
 692   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 693 #endif
 694 #ifdef EXPERIMENTAL_SPF
 695   { "spf_guess",           vtype_stringptr,   &spf_guess },
 696   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 697   { "spf_received",        vtype_stringptr,   &spf_received },
 698   { "spf_result",          vtype_stringptr,   &spf_result },
 699   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 700 #endif
 701   { "spool_directory",     vtype_stringptr,   &spool_directory },
 702   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 703   { "spool_space",         vtype_pspace,      (void *)TRUE },
 704 #ifdef EXPERIMENTAL_SRS
 705   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 706   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 707   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 708   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 709   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 710   { "srs_status",          vtype_stringptr,   &srs_status },
 711 #endif
 712   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 713
 714   /* The non-(in,out) variables are now deprecated */
 715   { "tls_bits",            vtype_int,         &tls_in.bits },
 716   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 717   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 718
 719   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 720   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 721   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 722   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 723   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 724   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 725   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 726 #if defined(SUPPORT_TLS)
 727   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 728 #endif
 729   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 730   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 731   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 732 #ifdef EXPERIMENTAL_DANE
 733   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 734 #endif
 735   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 736   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 737   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 738   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 739 #if defined(SUPPORT_TLS)
 740   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 741 #endif
 742 #ifdef EXPERIMENTAL_DANE
 743   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 744 #endif
 745
 746   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 747 #if defined(SUPPORT_TLS)
 748   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 749 #endif
 750
 751   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 752   { "tod_epoch",           vtype_tode,        NULL },
 753   { "tod_epoch_l",         vtype_todel,       NULL },
 754   { "tod_full",            vtype_todf,        NULL },
 755   { "tod_log",             vtype_todl,        NULL },
 756   { "tod_logfile",         vtype_todlf,       NULL },
 757   { "tod_zone",            vtype_todzone,     NULL },
 758   { "tod_zulu",            vtype_todzulu,     NULL },
 759   { "transport_name",      vtype_stringptr,   &transport_name },
 760   { "value",               vtype_stringptr,   &lookup_value },
 761   { "verify_mode",         vtype_stringptr,   &verify_mode },
 762   { "version_number",      vtype_stringptr,   &version_string },
 763   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 764   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 765   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 766   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 767   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 768   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 769 };
 770
 771 static int var_table_size = nelem(var_table);
 772 static uschar var_buffer[256];
 773 static BOOL malformed_header;
 774
 775 /* For textual hashes */
 776
 777 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 778                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 779                                "0123456789";
 780
 781 enum { HMAC_MD5, HMAC_SHA1 };
 782
 783 /* For numeric hashes */
 784
 785 static unsigned int prime[] = {
 786   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 787  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 788  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 789
 790 /* For printing modes in symbolic form */
 791
 792 static uschar *mtable_normal[] =
 793   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 794
 795 static uschar *mtable_setid[] =
 796   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 797
 798 static uschar *mtable_sticky[] =
 799   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 800
 801
 802
 803 /*************************************************
 804 *           Tables for UTF-8 support             *
 805 *************************************************/
 806
 807 /* Table of the number of extra characters, indexed by the first character
 808 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 809 0x3d. */
 810
 811 static uschar utf8_table1[] = {
 812   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 813   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 814   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 815   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 816
 817 /* These are the masks for the data bits in the first byte of a character,
 818 indexed by the number of additional bytes. */
 819
 820 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 821
 822 /* Get the next UTF-8 character, advancing the pointer. */
 823
 824 #define GETUTF8INC(c, ptr) \
 825   c = *ptr++; \
 826   if ((c & 0xc0) == 0xc0) \
 827     { \
 828     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 829     int s = 6*a; \
 830     c = (c & utf8_table2[a]) << s; \
 831     while (a-- > 0) \
 832       { \
 833       s -= 6; \
 834       c |= (*ptr++ & 0x3f) << s; \
 835       } \
 836     }
 837
 838
 839 /*************************************************
 840 *           Binary chop search on a table        *
 841 *************************************************/
 842
 843 /* This is used for matching expansion items and operators.
 844
 845 Arguments:
 846   name        the name that is being sought
 847   table       the table to search
 848   table_size  the number of items in the table
 849
 850 Returns:      the offset in the table, or -1
 851 */
 852
 853 static int
 854 chop_match(uschar *name, uschar **table, int table_size)
 855 {
 856 uschar **bot = table;
 857 uschar **top = table + table_size;
 858
 859 while (top > bot)
 860   {
 861   uschar **mid = bot + (top - bot)/2;
 862   int c = Ustrcmp(name, *mid);
 863   if (c == 0) return mid - table;
 864   if (c > 0) bot = mid + 1; else top = mid;
 865   }
 866
 867 return -1;
 868 }
 869
 870
 871
 872 /*************************************************
 873 *          Check a condition string              *
 874 *************************************************/
 875
 876 /* This function is called to expand a string, and test the result for a "true"
 877 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 878 forced fail or lookup defer.
 879
 880 We used to release all store used, but this is not not safe due
 881 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 882 is reasonably careful to release what it can.
 883
 884 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 885
 886 Arguments:
 887   condition     the condition string
 888   m1            text to be incorporated in panic error
 889   m2            ditto
 890
 891 Returns:        TRUE if condition is met, FALSE if not
 892 */
 893
 894 BOOL
 895 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 896 {
 897 int rc;
 898 uschar *ss = expand_string(condition);
 899 if (ss == NULL)
 900   {
 901   if (!expand_string_forcedfail && !search_find_defer)
 902     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 903       "for %s %s: %s", condition, m1, m2, expand_string_message);
 904   return FALSE;
 905   }
 906 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 907   strcmpic(ss, US"false") != 0;
 908 return rc;
 909 }
 910
 911
 912
 913
 914 /*************************************************
 915 *        Pseudo-random number generation         *
 916 *************************************************/
 917
 918 /* Pseudo-random number generation.  The result is not "expected" to be
 919 cryptographically strong but not so weak that someone will shoot themselves
 920 in the foot using it as a nonce in some email header scheme or whatever
 921 weirdness they'll twist this into.  The result should ideally handle fork().
 922
 923 However, if we're stuck unable to provide this, then we'll fall back to
 924 appallingly bad randomness.
 925
 926 If SUPPORT_TLS is defined then this will not be used except as an emergency
 927 fallback.
 928
 929 Arguments:
 930   max       range maximum
 931 Returns     a random number in range [0, max-1]
 932 */
 933
 934 #ifdef SUPPORT_TLS
 935 # define vaguely_random_number vaguely_random_number_fallback
 936 #endif
 937 int
 938 vaguely_random_number(int max)
 939 {
 940 #ifdef SUPPORT_TLS
 941 # undef vaguely_random_number
 942 #endif
 943   static pid_t pid = 0;
 944   pid_t p2;
 945 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 946   struct timeval tv;
 947 #endif
 948
 949   p2 = getpid();
 950   if (p2 != pid)
 951     {
 952     if (pid != 0)
 953       {
 954
 955 #ifdef HAVE_ARC4RANDOM
 956       /* cryptographically strong randomness, common on *BSD platforms, not
 957       so much elsewhere.  Alas. */
 958 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 959       arc4random_stir();
 960 #endif
 961 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 962 #ifdef HAVE_SRANDOMDEV
 963       /* uses random(4) for seeding */
 964       srandomdev();
 965 #else
 966       gettimeofday(&tv, NULL);
 967       srandom(tv.tv_sec | tv.tv_usec | getpid());
 968 #endif
 969 #else
 970       /* Poor randomness and no seeding here */
 971 #endif
 972
 973       }
 974     pid = p2;
 975     }
 976
 977 #ifdef HAVE_ARC4RANDOM
 978   return arc4random() % max;
 979 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 980   return random() % max;
 981 #else
 982   /* This one returns a 16-bit number, definitely not crypto-strong */
 983   return random_number(max);
 984 #endif
 985 }
 986
 987
 988
 989
 990 /*************************************************
 991 *             Pick out a name from a string      *
 992 *************************************************/
 993
 994 /* If the name is too long, it is silently truncated.
 995
 996 Arguments:
 997   name      points to a buffer into which to put the name
 998   max       is the length of the buffer
 999   s         points to the first alphabetic character of the name
1000   extras    chars other than alphanumerics to permit
1001
1002 Returns:    pointer to the first character after the name
1003
1004 Note: The test for *s != 0 in the while loop is necessary because
1005 Ustrchr() yields non-NULL if the character is zero (which is not something
1006 I expected). */
1007
1008 static const uschar *
1009 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1010 {
1011 int ptr = 0;
1012 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1013   {
1014   if (ptr < max-1) name[ptr++] = *s;
1015   s++;
1016   }
1017 name[ptr] = 0;
1018 return s;
1019 }
1020
1021
1022
1023 /*************************************************
1024 *     Pick out the rest of a header name         *
1025 *************************************************/
1026
1027 /* A variable name starting $header_ (or just $h_ for those who like
1028 abbreviations) might not be the complete header name because headers can
1029 contain any printing characters in their names, except ':'. This function is
1030 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1031 on the end, if the name was terminated by white space.
1032
1033 Arguments:
1034   name      points to a buffer in which the name read so far exists
1035   max       is the length of the buffer
1036   s         points to the first character after the name so far, i.e. the
1037             first non-alphameric character after $header_xxxxx
1038
1039 Returns:    a pointer to the first character after the header name
1040 */
1041
1042 static const uschar *
1043 read_header_name(uschar *name, int max, const uschar *s)
1044 {
1045 int prelen = Ustrchr(name, '_') - name + 1;
1046 int ptr = Ustrlen(name) - prelen;
1047 if (ptr > 0) memmove(name, name+prelen, ptr);
1048 while (mac_isgraph(*s) && *s != ':')
1049   {
1050   if (ptr < max-1) name[ptr++] = *s;
1051   s++;
1052   }
1053 if (*s == ':') s++;
1054 name[ptr++] = ':';
1055 name[ptr] = 0;
1056 return s;
1057 }
1058
1059
1060
1061 /*************************************************
1062 *           Pick out a number from a string      *
1063 *************************************************/
1064
1065 /* Arguments:
1066   n     points to an integer into which to put the number
1067   s     points to the first digit of the number
1068
1069 Returns:  a pointer to the character after the last digit
1070 */
1071
1072 static uschar *
1073 read_number(int *n, uschar *s)
1074 {
1075 *n = 0;
1076 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1077 return s;
1078 }
1079
1080 static const uschar *
1081 read_cnumber(int *n, const uschar *s)
1082 {
1083 *n = 0;
1084 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1085 return s;
1086 }
1087
1088
1089
1090 /*************************************************
1091 *        Extract keyed subfield from a string    *
1092 *************************************************/
1093
1094 /* The yield is in dynamic store; NULL means that the key was not found.
1095
1096 Arguments:
1097   key       points to the name of the key
1098   s         points to the string from which to extract the subfield
1099
1100 Returns:    NULL if the subfield was not found, or
1101             a pointer to the subfield's data
1102 */
1103
1104 static uschar *
1105 expand_getkeyed(uschar *key, const uschar *s)
1106 {
1107 int length = Ustrlen(key);
1108 while (isspace(*s)) s++;
1109
1110 /* Loop to search for the key */
1111
1112 while (*s != 0)
1113   {
1114   int dkeylength;
1115   uschar *data;
1116   const uschar *dkey = s;
1117
1118   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1119   dkeylength = s - dkey;
1120   while (isspace(*s)) s++;
1121   if (*s == '=') while (isspace((*(++s))));
1122
1123   data = string_dequote(&s);
1124   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1125     return data;
1126
1127   while (isspace(*s)) s++;
1128   }
1129
1130 return NULL;
1131 }
1132
1133
1134
1135 static var_entry *
1136 find_var_ent(uschar * name)
1137 {
1138 int first = 0;
1139 int last = var_table_size;
1140
1141 while (last > first)
1142   {
1143   int middle = (first + last)/2;
1144   int c = Ustrcmp(name, var_table[middle].name);
1145
1146   if (c > 0) { first = middle + 1; continue; }
1147   if (c < 0) { last = middle; continue; }
1148   return &var_table[middle];
1149   }
1150 return NULL;
1151 }
1152
1153 /*************************************************
1154 *   Extract numbered subfield from string        *
1155 *************************************************/
1156
1157 /* Extracts a numbered field from a string that is divided by tokens - for
1158 example a line from /etc/passwd is divided by colon characters.  First field is
1159 numbered one.  Negative arguments count from the right. Zero returns the whole
1160 string. Returns NULL if there are insufficient tokens in the string
1161
1162 ***WARNING***
1163 Modifies final argument - this is a dynamically generated string, so that's OK.
1164
1165 Arguments:
1166   field       number of field to be extracted,
1167                 first field = 1, whole string = 0, last field = -1
1168   separators  characters that are used to break string into tokens
1169   s           points to the string from which to extract the subfield
1170
1171 Returns:      NULL if the field was not found,
1172               a pointer to the field's data inside s (modified to add 0)
1173 */
1174
1175 static uschar *
1176 expand_gettokened (int field, uschar *separators, uschar *s)
1177 {
1178 int sep = 1;
1179 int count;
1180 uschar *ss = s;
1181 uschar *fieldtext = NULL;
1182
1183 if (field == 0) return s;
1184
1185 /* Break the line up into fields in place; for field > 0 we stop when we have
1186 done the number of fields we want. For field < 0 we continue till the end of
1187 the string, counting the number of fields. */
1188
1189 count = (field > 0)? field : INT_MAX;
1190
1191 while (count-- > 0)
1192   {
1193   size_t len;
1194
1195   /* Previous field was the last one in the string. For a positive field
1196   number, this means there are not enough fields. For a negative field number,
1197   check that there are enough, and scan back to find the one that is wanted. */
1198
1199   if (sep == 0)
1200     {
1201     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1202     if ((-field) == (INT_MAX - count - 1)) return s;
1203     while (field++ < 0)
1204       {
1205       ss--;
1206       while (ss[-1] != 0) ss--;
1207       }
1208     fieldtext = ss;
1209     break;
1210     }
1211
1212   /* Previous field was not last in the string; save its start and put a
1213   zero at its end. */
1214
1215   fieldtext = ss;
1216   len = Ustrcspn(ss, separators);
1217   sep = ss[len];
1218   ss[len] = 0;
1219   ss += len + 1;
1220   }
1221
1222 return fieldtext;
1223 }
1224
1225
1226 static uschar *
1227 expand_getlistele(int field, const uschar * list)
1228 {
1229 const uschar * tlist= list;
1230 int sep= 0;
1231 uschar dummy;
1232
1233 if(field<0)
1234   {
1235   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1236   sep= 0;
1237   }
1238 if(field==0) return NULL;
1239 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1240 return string_nextinlist(&list, &sep, NULL, 0);
1241 }
1242
1243
1244 /* Certificate fields, by name.  Worry about by-OID later */
1245 /* Names are chosen to not have common prefixes */
1246
1247 #ifdef SUPPORT_TLS
1248 typedef struct
1249 {
1250 uschar * name;
1251 int      namelen;
1252 uschar * (*getfn)(void * cert, uschar * mod);
1253 } certfield;
1254 static certfield certfields[] =
1255 {                       /* linear search; no special order */
1256   { US"version",         7,  &tls_cert_version },
1257   { US"serial_number",   13, &tls_cert_serial_number },
1258   { US"subject",         7,  &tls_cert_subject },
1259   { US"notbefore",       9,  &tls_cert_not_before },
1260   { US"notafter",        8,  &tls_cert_not_after },
1261   { US"issuer",          6,  &tls_cert_issuer },
1262   { US"signature",       9,  &tls_cert_signature },
1263   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1264   { US"subj_altname",    12, &tls_cert_subject_altname },
1265   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1266   { US"crl_uri",         7,  &tls_cert_crl_uri },
1267 };
1268
1269 static uschar *
1270 expand_getcertele(uschar * field, uschar * certvar)
1271 {
1272 var_entry * vp;
1273 certfield * cp;
1274
1275 if (!(vp = find_var_ent(certvar)))
1276   {
1277   expand_string_message =
1278     string_sprintf("no variable named \"%s\"", certvar);
1279   return NULL;          /* Unknown variable name */
1280   }
1281 /* NB this stops us passing certs around in variable.  Might
1282 want to do that in future */
1283 if (vp->type != vtype_cert)
1284   {
1285   expand_string_message =
1286     string_sprintf("\"%s\" is not a certificate", certvar);
1287   return NULL;          /* Unknown variable name */
1288   }
1289 if (!*(void **)vp->value)
1290   return NULL;
1291
1292 if (*field >= '0' && *field <= '9')
1293   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1294
1295 for(cp = certfields;
1296     cp < certfields + nelem(certfields);
1297     cp++)
1298   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1299     {
1300     uschar * modifier = *(field += cp->namelen) == ','
1301       ? ++field : NULL;
1302     return (*cp->getfn)( *(void **)vp->value, modifier );
1303     }
1304
1305 expand_string_message =
1306   string_sprintf("bad field selector \"%s\" for certextract", field);
1307 return NULL;
1308 }
1309 #endif  /*SUPPORT_TLS*/
1310
1311 /*************************************************
1312 *        Extract a substring from a string       *
1313 *************************************************/
1314
1315 /* Perform the ${substr or ${length expansion operations.
1316
1317 Arguments:
1318   subject     the input string
1319   value1      the offset from the start of the input string to the start of
1320                 the output string; if negative, count from the right.
1321   value2      the length of the output string, or negative (-1) for unset
1322                 if value1 is positive, unset means "all after"
1323                 if value1 is negative, unset means "all before"
1324   len         set to the length of the returned string
1325
1326 Returns:      pointer to the output string, or NULL if there is an error
1327 */
1328
1329 static uschar *
1330 extract_substr(uschar *subject, int value1, int value2, int *len)
1331 {
1332 int sublen = Ustrlen(subject);
1333
1334 if (value1 < 0)    /* count from right */
1335   {
1336   value1 += sublen;
1337
1338   /* If the position is before the start, skip to the start, and adjust the
1339   length. If the length ends up negative, the substring is null because nothing
1340   can precede. This falls out naturally when the length is unset, meaning "all
1341   to the left". */
1342
1343   if (value1 < 0)
1344     {
1345     value2 += value1;
1346     if (value2 < 0) value2 = 0;
1347     value1 = 0;
1348     }
1349
1350   /* Otherwise an unset length => characters before value1 */
1351
1352   else if (value2 < 0)
1353     {
1354     value2 = value1;
1355     value1 = 0;
1356     }
1357   }
1358
1359 /* For a non-negative offset, if the starting position is past the end of the
1360 string, the result will be the null string. Otherwise, an unset length means
1361 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1362
1363 else
1364   {
1365   if (value1 > sublen)
1366     {
1367     value1 = sublen;
1368     value2 = 0;
1369     }
1370   else if (value2 < 0) value2 = sublen;
1371   }
1372
1373 /* Cut the length down to the maximum possible for the offset value, and get
1374 the required characters. */
1375
1376 if (value1 + value2 > sublen) value2 = sublen - value1;
1377 *len = value2;
1378 return subject + value1;
1379 }
1380
1381
1382
1383
1384 /*************************************************
1385 *            Old-style hash of a string          *
1386 *************************************************/
1387
1388 /* Perform the ${hash expansion operation.
1389
1390 Arguments:
1391   subject     the input string (an expanded substring)
1392   value1      the length of the output string; if greater or equal to the
1393                 length of the input string, the input string is returned
1394   value2      the number of hash characters to use, or 26 if negative
1395   len         set to the length of the returned string
1396
1397 Returns:      pointer to the output string, or NULL if there is an error
1398 */
1399
1400 static uschar *
1401 compute_hash(uschar *subject, int value1, int value2, int *len)
1402 {
1403 int sublen = Ustrlen(subject);
1404
1405 if (value2 < 0) value2 = 26;
1406 else if (value2 > Ustrlen(hashcodes))
1407   {
1408   expand_string_message =
1409     string_sprintf("hash count \"%d\" too big", value2);
1410   return NULL;
1411   }
1412
1413 /* Calculate the hash text. We know it is shorter than the original string, so
1414 can safely place it in subject[] (we know that subject is always itself an
1415 expanded substring). */
1416
1417 if (value1 < sublen)
1418   {
1419   int c;
1420   int i = 0;
1421   int j = value1;
1422   while ((c = (subject[j])) != 0)
1423     {
1424     int shift = (c + j++) & 7;
1425     subject[i] ^= (c << shift) | (c >> (8-shift));
1426     if (++i >= value1) i = 0;
1427     }
1428   for (i = 0; i < value1; i++)
1429     subject[i] = hashcodes[(subject[i]) % value2];
1430   }
1431 else value1 = sublen;
1432
1433 *len = value1;
1434 return subject;
1435 }
1436
1437
1438
1439
1440 /*************************************************
1441 *             Numeric hash of a string           *
1442 *************************************************/
1443
1444 /* Perform the ${nhash expansion operation. The first characters of the
1445 string are treated as most important, and get the highest prime numbers.
1446
1447 Arguments:
1448   subject     the input string
1449   value1      the maximum value of the first part of the result
1450   value2      the maximum value of the second part of the result,
1451                 or negative to produce only a one-part result
1452   len         set to the length of the returned string
1453
1454 Returns:  pointer to the output string, or NULL if there is an error.
1455 */
1456
1457 static uschar *
1458 compute_nhash (uschar *subject, int value1, int value2, int *len)
1459 {
1460 uschar *s = subject;
1461 int i = 0;
1462 unsigned long int total = 0; /* no overflow */
1463
1464 while (*s != 0)
1465   {
1466   if (i == 0) i = nelem(prime) - 1;
1467   total += prime[i--] * (unsigned int)(*s++);
1468   }
1469
1470 /* If value2 is unset, just compute one number */
1471
1472 if (value2 < 0)
1473   {
1474   s = string_sprintf("%d", total % value1);
1475   }
1476
1477 /* Otherwise do a div/mod hash */
1478
1479 else
1480   {
1481   total = total % (value1 * value2);
1482   s = string_sprintf("%d/%d", total/value2, total % value2);
1483   }
1484
1485 *len = Ustrlen(s);
1486 return s;
1487 }
1488
1489
1490
1491
1492
1493 /*************************************************
1494 *     Find the value of a header or headers      *
1495 *************************************************/
1496
1497 /* Multiple instances of the same header get concatenated, and this function
1498 can also return a concatenation of all the header lines. When concatenating
1499 specific headers that contain lists of addresses, a comma is inserted between
1500 them. Otherwise we use a straight concatenation. Because some messages can have
1501 pathologically large number of lines, there is a limit on the length that is
1502 returned. Also, to avoid massive store use which would result from using
1503 string_cat() as it copies and extends strings, we do a preliminary pass to find
1504 out exactly how much store will be needed. On "normal" messages this will be
1505 pretty trivial.
1506
1507 Arguments:
1508   name          the name of the header, without the leading $header_ or $h_,
1509                 or NULL if a concatenation of all headers is required
1510   exists_only   TRUE if called from a def: test; don't need to build a string;
1511                 just return a string that is not "" and not "0" if the header
1512                 exists
1513   newsize       return the size of memory block that was obtained; may be NULL
1514                 if exists_only is TRUE
1515   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1516                 other than concatenating, will be done on the header. Also used
1517                 for $message_headers_raw.
1518   charset       name of charset to translate MIME words to; used only if
1519                 want_raw is false; if NULL, no translation is done (this is
1520                 used for $bh_ and $bheader_)
1521
1522 Returns:        NULL if the header does not exist, else a pointer to a new
1523                 store block
1524 */
1525
1526 static uschar *
1527 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1528   uschar *charset)
1529 {
1530 BOOL found = name == NULL;
1531 int comma = 0;
1532 int len = found? 0 : Ustrlen(name);
1533 int i;
1534 uschar *yield = NULL;
1535 uschar *ptr = NULL;
1536
1537 /* Loop for two passes - saves code repetition */
1538
1539 for (i = 0; i < 2; i++)
1540   {
1541   int size = 0;
1542   header_line *h;
1543
1544   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1545     {
1546     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1547       {
1548       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1549         {
1550         int ilen;
1551         uschar *t;
1552
1553         if (exists_only) return US"1";      /* don't need actual string */
1554         found = TRUE;
1555         t = h->text + len;                  /* text to insert */
1556         if (!want_raw)                      /* unless wanted raw, */
1557           while (isspace(*t)) t++;          /* remove leading white space */
1558         ilen = h->slen - (t - h->text);     /* length to insert */
1559
1560         /* Unless wanted raw, remove trailing whitespace, including the
1561         newline. */
1562
1563         if (!want_raw)
1564           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1565
1566         /* Set comma = 1 if handling a single header and it's one of those
1567         that contains an address list, except when asked for raw headers. Only
1568         need to do this once. */
1569
1570         if (!want_raw && name != NULL && comma == 0 &&
1571             Ustrchr("BCFRST", h->type) != NULL)
1572           comma = 1;
1573
1574         /* First pass - compute total store needed; second pass - compute
1575         total store used, including this header. */
1576
1577         size += ilen + comma + 1;  /* +1 for the newline */
1578
1579         /* Second pass - concatentate the data, up to a maximum. Note that
1580         the loop stops when size hits the limit. */
1581
1582         if (i != 0)
1583           {
1584           if (size > header_insert_maxlen)
1585             {
1586             ilen -= size - header_insert_maxlen - 1;
1587             comma = 0;
1588             }
1589           Ustrncpy(ptr, t, ilen);
1590           ptr += ilen;
1591
1592           /* For a non-raw header, put in the comma if needed, then add
1593           back the newline we removed above, provided there was some text in
1594           the header. */
1595
1596           if (!want_raw && ilen > 0)
1597             {
1598             if (comma != 0) *ptr++ = ',';
1599             *ptr++ = '\n';
1600             }
1601           }
1602         }
1603       }
1604     }
1605
1606   /* At end of first pass, return NULL if no header found. Then truncate size
1607   if necessary, and get the buffer to hold the data, returning the buffer size.
1608   */
1609
1610   if (i == 0)
1611     {
1612     if (!found) return NULL;
1613     if (size > header_insert_maxlen) size = header_insert_maxlen;
1614     *newsize = size + 1;
1615     ptr = yield = store_get(*newsize);
1616     }
1617   }
1618
1619 /* That's all we do for raw header expansion. */
1620
1621 if (want_raw)
1622   {
1623   *ptr = 0;
1624   }
1625
1626 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1627 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1628 function can return an error with decoded data if the charset translation
1629 fails. If decoding fails, it returns NULL. */
1630
1631 else
1632   {
1633   uschar *decoded, *error;
1634   if (ptr > yield && ptr[-1] == '\n') ptr--;
1635   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1636   *ptr = 0;
1637   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1638     newsize, &error);
1639   if (error != NULL)
1640     {
1641     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1642       "    input was: %s\n", error, yield);
1643     }
1644   if (decoded != NULL) yield = decoded;
1645   }
1646
1647 return yield;
1648 }
1649
1650
1651
1652
1653 /*************************************************
1654 *               Return list of recipients        *
1655 *************************************************/
1656 /* A recipients list is available only during system message filtering,
1657 during ACL processing after DATA, and while expanding pipe commands
1658 generated from a system filter, but not elsewhere. */
1659
1660 static uschar *
1661 fn_recipients(void)
1662 {
1663 if (!enable_dollar_recipients) return NULL; else
1664   {
1665   int size = 128;
1666   int ptr = 0;
1667   int i;
1668   uschar * s = store_get(size);
1669   for (i = 0; i < recipients_count; i++)
1670     {
1671     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1672     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1673       Ustrlen(recipients_list[i].address));
1674     }
1675   s[ptr] = 0;     /* string_cat() leaves room */
1676   return s;
1677   }
1678 }
1679
1680
1681 /*************************************************
1682 *               Find value of a variable         *
1683 *************************************************/
1684
1685 /* The table of variables is kept in alphabetic order, so we can search it
1686 using a binary chop. The "choplen" variable is nothing to do with the binary
1687 chop.
1688
1689 Arguments:
1690   name          the name of the variable being sought
1691   exists_only   TRUE if this is a def: test; passed on to find_header()
1692   skipping      TRUE => skip any processing evaluation; this is not the same as
1693                   exists_only because def: may test for values that are first
1694                   evaluated here
1695   newsize       pointer to an int which is initially zero; if the answer is in
1696                 a new memory buffer, *newsize is set to its size
1697
1698 Returns:        NULL if the variable does not exist, or
1699                 a pointer to the variable's contents, or
1700                 something non-NULL if exists_only is TRUE
1701 */
1702
1703 static uschar *
1704 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1705 {
1706 var_entry * vp;
1707 uschar *s, *domain;
1708 uschar **ss;
1709 void * val;
1710
1711 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1712 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1713 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1714 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1715 (this gave backwards compatibility at the changeover). There may be built-in
1716 variables whose names start acl_ but they should never start in this way. This
1717 slightly messy specification is a consequence of the history, needless to say.
1718
1719 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1720 set, in which case give an error. */
1721
1722 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1723      !isalpha(name[5]))
1724   {
1725   tree_node *node =
1726     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1727   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1728   }
1729
1730 /* Handle $auth<n> variables. */
1731
1732 if (Ustrncmp(name, "auth", 4) == 0)
1733   {
1734   uschar *endptr;
1735   int n = Ustrtoul(name + 4, &endptr, 10);
1736   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1737     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1738   }
1739 else if (Ustrncmp(name, "regex", 5) == 0)
1740   {
1741   uschar *endptr;
1742   int n = Ustrtoul(name + 5, &endptr, 10);
1743   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1744     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1745   }
1746
1747 /* For all other variables, search the table */
1748
1749 if (!(vp = find_var_ent(name)))
1750   return NULL;          /* Unknown variable name */
1751
1752 /* Found an existing variable. If in skipping state, the value isn't needed,
1753 and we want to avoid processing (such as looking up the host name). */
1754
1755 if (skipping)
1756   return US"";
1757
1758 val = vp->value;
1759 switch (vp->type)
1760   {
1761   case vtype_filter_int:
1762   if (!filter_running) return NULL;
1763   /* Fall through */
1764   /* VVVVVVVVVVVV */
1765   case vtype_int:
1766   sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1767   return var_buffer;
1768
1769   case vtype_ino:
1770   sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1771   return var_buffer;
1772
1773   case vtype_gid:
1774   sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1775   return var_buffer;
1776
1777   case vtype_uid:
1778   sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1779   return var_buffer;
1780
1781   case vtype_bool:
1782   sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1783   return var_buffer;
1784
1785   case vtype_stringptr:                      /* Pointer to string */
1786   s = *((uschar **)(val));
1787   return (s == NULL)? US"" : s;
1788
1789   case vtype_pid:
1790   sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1791   return var_buffer;
1792
1793   case vtype_load_avg:
1794   sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1795   return var_buffer;
1796
1797   case vtype_host_lookup:                    /* Lookup if not done so */
1798   if (sender_host_name == NULL && sender_host_address != NULL &&
1799       !host_lookup_failed && host_name_lookup() == OK)
1800     host_build_sender_fullhost();
1801   return (sender_host_name == NULL)? US"" : sender_host_name;
1802
1803   case vtype_localpart:                      /* Get local part from address */
1804   s = *((uschar **)(val));
1805   if (s == NULL) return US"";
1806   domain = Ustrrchr(s, '@');
1807   if (domain == NULL) return s;
1808   if (domain - s > sizeof(var_buffer) - 1)
1809     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1810         " in string expansion", sizeof(var_buffer));
1811   Ustrncpy(var_buffer, s, domain - s);
1812   var_buffer[domain - s] = 0;
1813   return var_buffer;
1814
1815   case vtype_domain:                         /* Get domain from address */
1816   s = *((uschar **)(val));
1817   if (s == NULL) return US"";
1818   domain = Ustrrchr(s, '@');
1819   return (domain == NULL)? US"" : domain + 1;
1820
1821   case vtype_msgheaders:
1822   return find_header(NULL, exists_only, newsize, FALSE, NULL);
1823
1824   case vtype_msgheaders_raw:
1825   return find_header(NULL, exists_only, newsize, TRUE, NULL);
1826
1827   case vtype_msgbody:                        /* Pointer to msgbody string */
1828   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1829   ss = (uschar **)(val);
1830   if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1831     {
1832     uschar *body;
1833     off_t start_offset = SPOOL_DATA_START_OFFSET;
1834     int len = message_body_visible;
1835     if (len > message_size) len = message_size;
1836     *ss = body = store_malloc(len+1);
1837     body[0] = 0;
1838     if (vp->type == vtype_msgbody_end)
1839       {
1840       struct stat statbuf;
1841       if (fstat(deliver_datafile, &statbuf) == 0)
1842         {
1843         start_offset = statbuf.st_size - len;
1844         if (start_offset < SPOOL_DATA_START_OFFSET)
1845           start_offset = SPOOL_DATA_START_OFFSET;
1846         }
1847       }
1848     lseek(deliver_datafile, start_offset, SEEK_SET);
1849     len = read(deliver_datafile, body, len);
1850     if (len > 0)
1851       {
1852       body[len] = 0;
1853       if (message_body_newlines)   /* Separate loops for efficiency */
1854         {
1855         while (len > 0)
1856           { if (body[--len] == 0) body[len] = ' '; }
1857         }
1858       else
1859         {
1860         while (len > 0)
1861           { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1862         }
1863       }
1864     }
1865   return (*ss == NULL)? US"" : *ss;
1866
1867   case vtype_todbsdin:                       /* BSD inbox time of day */
1868   return tod_stamp(tod_bsdin);
1869
1870   case vtype_tode:                           /* Unix epoch time of day */
1871   return tod_stamp(tod_epoch);
1872
1873   case vtype_todel:                          /* Unix epoch/usec time of day */
1874   return tod_stamp(tod_epoch_l);
1875
1876   case vtype_todf:                           /* Full time of day */
1877   return tod_stamp(tod_full);
1878
1879   case vtype_todl:                           /* Log format time of day */
1880   return tod_stamp(tod_log_bare);            /* (without timezone) */
1881
1882   case vtype_todzone:                        /* Time zone offset only */
1883   return tod_stamp(tod_zone);
1884
1885   case vtype_todzulu:                        /* Zulu time */
1886   return tod_stamp(tod_zulu);
1887
1888   case vtype_todlf:                          /* Log file datestamp tod */
1889   return tod_stamp(tod_log_datestamp_daily);
1890
1891   case vtype_reply:                          /* Get reply address */
1892   s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1893     headers_charset);
1894   if (s != NULL) while (isspace(*s)) s++;
1895   if (s == NULL || *s == 0)
1896     {
1897     *newsize = 0;                            /* For the *s==0 case */
1898     s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1899     }
1900   if (s != NULL)
1901     {
1902     uschar *t;
1903     while (isspace(*s)) s++;
1904     for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1905     while (t > s && isspace(t[-1])) t--;
1906     *t = 0;
1907     }
1908   return (s == NULL)? US"" : s;
1909
1910   case vtype_string_func:
1911     {
1912     uschar * (*fn)() = val;
1913     return fn();
1914     }
1915
1916   case vtype_pspace:
1917     {
1918     int inodes;
1919     sprintf(CS var_buffer, "%d",
1920       receive_statvfs(val == (void *)TRUE, &inodes));
1921     }
1922   return var_buffer;
1923
1924   case vtype_pinodes:
1925     {
1926     int inodes;
1927     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1928     sprintf(CS var_buffer, "%d", inodes);
1929     }
1930   return var_buffer;
1931
1932   case vtype_cert:
1933   return *(void **)val ? US"<cert>" : US"";
1934
1935   #ifndef DISABLE_DKIM
1936   case vtype_dkim:
1937   return dkim_exim_expand_query((int)(long)val);
1938   #endif
1939
1940   }
1941
1942 return NULL;  /* Unknown variable. Silences static checkers. */
1943 }
1944
1945
1946
1947
1948 void
1949 modify_variable(uschar *name, void * value)
1950 {
1951 var_entry * vp;
1952 if ((vp = find_var_ent(name))) vp->value = value;
1953 return;          /* Unknown variable name, fail silently */
1954 }
1955
1956
1957
1958
1959
1960 /*************************************************
1961 *           Read and expand substrings           *
1962 *************************************************/
1963
1964 /* This function is called to read and expand argument substrings for various
1965 expansion items. Some have a minimum requirement that is less than the maximum;
1966 in these cases, the first non-present one is set to NULL.
1967
1968 Arguments:
1969   sub        points to vector of pointers to set
1970   n          maximum number of substrings
1971   m          minimum required
1972   sptr       points to current string pointer
1973   skipping   the skipping flag
1974   check_end  if TRUE, check for final '}'
1975   name       name of item, for error message
1976   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1977              the store.
1978
1979 Returns:     0 OK; string pointer updated
1980              1 curly bracketing error (too few arguments)
1981              2 too many arguments (only if check_end is set); message set
1982              3 other error (expansion failure)
1983 */
1984
1985 static int
1986 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1987   BOOL check_end, uschar *name, BOOL *resetok)
1988 {
1989 int i;
1990 const uschar *s = *sptr;
1991
1992 while (isspace(*s)) s++;
1993 for (i = 0; i < n; i++)
1994   {
1995   if (*s != '{')
1996     {
1997     if (i < m) return 1;
1998     sub[i] = NULL;
1999     break;
2000     }
2001   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok);
2002   if (sub[i] == NULL) return 3;
2003   if (*s++ != '}') return 1;
2004   while (isspace(*s)) s++;
2005   }
2006 if (check_end && *s++ != '}')
2007   {
2008   if (s[-1] == '{')
2009     {
2010     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
2011       "(max is %d)", name, n);
2012     return 2;
2013     }
2014   return 1;
2015   }
2016
2017 *sptr = s;
2018 return 0;
2019 }
2020
2021
2022
2023
2024 /*************************************************
2025 *     Elaborate message for bad variable         *
2026 *************************************************/
2027
2028 /* For the "unknown variable" message, take a look at the variable's name, and
2029 give additional information about possible ACL variables. The extra information
2030 is added on to expand_string_message.
2031
2032 Argument:   the name of the variable
2033 Returns:    nothing
2034 */
2035
2036 static void
2037 check_variable_error_message(uschar *name)
2038 {
2039 if (Ustrncmp(name, "acl_", 4) == 0)
2040   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2041     (name[4] == 'c' || name[4] == 'm')?
2042       (isalpha(name[5])?
2043         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2044         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2045       ) :
2046       US"user-defined ACL variables must start acl_c or acl_m");
2047 }
2048
2049
2050
2051 /*
2052 Load args from sub array to globals, and call acl_check().
2053 Sub array will be corrupted on return.
2054
2055 Returns:       OK         access is granted by an ACCEPT verb
2056                DISCARD    access is granted by a DISCARD verb
2057                FAIL       access is denied
2058                FAIL_DROP  access is denied; drop the connection
2059                DEFER      can't tell at the moment
2060                ERROR      disaster
2061 */
2062 static int
2063 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2064 {
2065 int i;
2066 int sav_narg = acl_narg;
2067 int ret;
2068 uschar * dummy_logmsg;
2069 extern int acl_where;
2070
2071 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2072 for (i = 0; i < nsub && sub[i+1]; i++)
2073   {
2074   uschar * tmp = acl_arg[i];
2075   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2076   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2077   }
2078 acl_narg = i;
2079 while (i < nsub)
2080   {
2081   sub[i+1] = acl_arg[i];
2082   acl_arg[i++] = NULL;
2083   }
2084
2085 DEBUG(D_expand)
2086   debug_printf("expanding: acl: %s  arg: %s%s\n",
2087     sub[0],
2088     acl_narg>0 ? acl_arg[0] : US"<none>",
2089     acl_narg>1 ? " +more"   : "");
2090
2091 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2092
2093 for (i = 0; i < nsub; i++)
2094   acl_arg[i] = sub[i+1];        /* restore old args */
2095 acl_narg = sav_narg;
2096
2097 return ret;
2098 }
2099
2100
2101
2102
2103 /*************************************************
2104 *        Read and evaluate a condition           *
2105 *************************************************/
2106
2107 /*
2108 Arguments:
2109   s        points to the start of the condition text
2110   resetok  points to a BOOL which is written false if it is unsafe to
2111            free memory. Certain condition types (acl) may have side-effect
2112            allocation which must be preserved.
2113   yield    points to a BOOL to hold the result of the condition test;
2114            if NULL, we are just reading through a condition that is
2115            part of an "or" combination to check syntax, or in a state
2116            where the answer isn't required
2117
2118 Returns:   a pointer to the first character after the condition, or
2119            NULL after an error
2120 */
2121
2122 static const uschar *
2123 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2124 {
2125 BOOL testfor = TRUE;
2126 BOOL tempcond, combined_cond;
2127 BOOL *subcondptr;
2128 BOOL sub2_honour_dollar = TRUE;
2129 int i, rc, cond_type, roffset;
2130 int_eximarith_t num[2];
2131 struct stat statbuf;
2132 uschar name[256];
2133 const uschar *sub[10];
2134
2135 const pcre *re;
2136 const uschar *rerror;
2137
2138 for (;;)
2139   {
2140   while (isspace(*s)) s++;
2141   if (*s == '!') { testfor = !testfor; s++; } else break;
2142   }
2143
2144 /* Numeric comparisons are symbolic */
2145
2146 if (*s == '=' || *s == '>' || *s == '<')
2147   {
2148   int p = 0;
2149   name[p++] = *s++;
2150   if (*s == '=')
2151     {
2152     name[p++] = '=';
2153     s++;
2154     }
2155   name[p] = 0;
2156   }
2157
2158 /* All other conditions are named */
2159
2160 else s = read_name(name, 256, s, US"_");
2161
2162 /* If we haven't read a name, it means some non-alpha character is first. */
2163
2164 if (name[0] == 0)
2165   {
2166   expand_string_message = string_sprintf("condition name expected, "
2167     "but found \"%.16s\"", s);
2168   return NULL;
2169   }
2170
2171 /* Find which condition we are dealing with, and switch on it */
2172
2173 cond_type = chop_match(name, cond_table, nelem(cond_table));
2174 switch(cond_type)
2175   {
2176   /* def: tests for a non-empty variable, or for the existence of a header. If
2177   yield == NULL we are in a skipping state, and don't care about the answer. */
2178
2179   case ECOND_DEF:
2180   if (*s != ':')
2181     {
2182     expand_string_message = US"\":\" expected after \"def\"";
2183     return NULL;
2184     }
2185
2186   s = read_name(name, 256, s+1, US"_");
2187
2188   /* Test for a header's existence. If the name contains a closing brace
2189   character, this may be a user error where the terminating colon has been
2190   omitted. Set a flag to adjust a subsequent error message in this case. */
2191
2192   if (Ustrncmp(name, "h_", 2) == 0 ||
2193       Ustrncmp(name, "rh_", 3) == 0 ||
2194       Ustrncmp(name, "bh_", 3) == 0 ||
2195       Ustrncmp(name, "header_", 7) == 0 ||
2196       Ustrncmp(name, "rheader_", 8) == 0 ||
2197       Ustrncmp(name, "bheader_", 8) == 0)
2198     {
2199     s = read_header_name(name, 256, s);
2200     /* {-for-text-editors */
2201     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2202     if (yield != NULL) *yield =
2203       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2204     }
2205
2206   /* Test for a variable's having a non-empty value. A non-existent variable
2207   causes an expansion failure. */
2208
2209   else
2210     {
2211     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2212     if (value == NULL)
2213       {
2214       expand_string_message = (name[0] == 0)?
2215         string_sprintf("variable name omitted after \"def:\"") :
2216         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2217       check_variable_error_message(name);
2218       return NULL;
2219       }
2220     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2221     }
2222
2223   return s;
2224
2225
2226   /* first_delivery tests for first delivery attempt */
2227
2228   case ECOND_FIRST_DELIVERY:
2229   if (yield != NULL) *yield = deliver_firsttime == testfor;
2230   return s;
2231
2232
2233   /* queue_running tests for any process started by a queue runner */
2234
2235   case ECOND_QUEUE_RUNNING:
2236   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2237   return s;
2238
2239
2240   /* exists:  tests for file existence
2241        isip:  tests for any IP address
2242       isip4:  tests for an IPv4 address
2243       isip6:  tests for an IPv6 address
2244         pam:  does PAM authentication
2245      radius:  does RADIUS authentication
2246    ldapauth:  does LDAP authentication
2247     pwcheck:  does Cyrus SASL pwcheck authentication
2248   */
2249
2250   case ECOND_EXISTS:
2251   case ECOND_ISIP:
2252   case ECOND_ISIP4:
2253   case ECOND_ISIP6:
2254   case ECOND_PAM:
2255   case ECOND_RADIUS:
2256   case ECOND_LDAPAUTH:
2257   case ECOND_PWCHECK:
2258
2259   while (isspace(*s)) s++;
2260   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2261
2262   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2263   if (sub[0] == NULL) return NULL;
2264   /* {-for-text-editors */
2265   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2266
2267   if (yield == NULL) return s;   /* No need to run the test if skipping */
2268
2269   switch(cond_type)
2270     {
2271     case ECOND_EXISTS:
2272     if ((expand_forbid & RDO_EXISTS) != 0)
2273       {
2274       expand_string_message = US"File existence tests are not permitted";
2275       return NULL;
2276       }
2277     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2278     break;
2279
2280     case ECOND_ISIP:
2281     case ECOND_ISIP4:
2282     case ECOND_ISIP6:
2283     rc = string_is_ip_address(sub[0], NULL);
2284     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2285              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2286     break;
2287
2288     /* Various authentication tests - all optionally compiled */
2289
2290     case ECOND_PAM:
2291     #ifdef SUPPORT_PAM
2292     rc = auth_call_pam(sub[0], &expand_string_message);
2293     goto END_AUTH;
2294     #else
2295     goto COND_FAILED_NOT_COMPILED;
2296     #endif  /* SUPPORT_PAM */
2297
2298     case ECOND_RADIUS:
2299     #ifdef RADIUS_CONFIG_FILE
2300     rc = auth_call_radius(sub[0], &expand_string_message);
2301     goto END_AUTH;
2302     #else
2303     goto COND_FAILED_NOT_COMPILED;
2304     #endif  /* RADIUS_CONFIG_FILE */
2305
2306     case ECOND_LDAPAUTH:
2307     #ifdef LOOKUP_LDAP
2308       {
2309       /* Just to keep the interface the same */
2310       BOOL do_cache;
2311       int old_pool = store_pool;
2312       store_pool = POOL_SEARCH;
2313       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2314         &expand_string_message, &do_cache);
2315       store_pool = old_pool;
2316       }
2317     goto END_AUTH;
2318     #else
2319     goto COND_FAILED_NOT_COMPILED;
2320     #endif  /* LOOKUP_LDAP */
2321
2322     case ECOND_PWCHECK:
2323     #ifdef CYRUS_PWCHECK_SOCKET
2324     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2325     goto END_AUTH;
2326     #else
2327     goto COND_FAILED_NOT_COMPILED;
2328     #endif  /* CYRUS_PWCHECK_SOCKET */
2329
2330     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2331         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2332     END_AUTH:
2333     if (rc == ERROR || rc == DEFER) return NULL;
2334     *yield = (rc == OK) == testfor;
2335     #endif
2336     }
2337   return s;
2338
2339
2340   /* call ACL (in a conditional context).  Accept true, deny false.
2341   Defer is a forced-fail.  Anything set by message= goes to $value.
2342   Up to ten parameters are used; we use the braces round the name+args
2343   like the saslauthd condition does, to permit a variable number of args.
2344   See also the expansion-item version EITEM_ACL and the traditional
2345   acl modifier ACLC_ACL.
2346   Since the ACL may allocate new global variables, tell our caller to not
2347   reclaim memory.
2348   */
2349
2350   case ECOND_ACL:
2351     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2352     {
2353     uschar *sub[10];
2354     uschar *user_msg;
2355     BOOL cond = FALSE;
2356     int size = 0;
2357     int ptr = 0;
2358
2359     while (isspace(*s)) s++;
2360     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2361
2362     switch(read_subs(sub, nelem(sub), 1,
2363       &s, yield == NULL, TRUE, US"acl", resetok))
2364       {
2365       case 1: expand_string_message = US"too few arguments or bracketing "
2366         "error for acl";
2367       case 2:
2368       case 3: return NULL;
2369       }
2370
2371     *resetok = FALSE;
2372     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2373         {
2374         case OK:
2375           cond = TRUE;
2376         case FAIL:
2377           lookup_value = NULL;
2378           if (user_msg)
2379             {
2380             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2381             lookup_value[ptr] = '\0';
2382             }
2383           *yield = cond == testfor;
2384           break;
2385
2386         case DEFER:
2387           expand_string_forcedfail = TRUE;
2388         default:
2389           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2390           return NULL;
2391         }
2392     return s;
2393     }
2394
2395
2396   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2397
2398      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2399
2400   However, the last two are optional. That is why the whole set is enclosed
2401   in their own set of braces. */
2402
2403   case ECOND_SASLAUTHD:
2404 #ifndef CYRUS_SASLAUTHD_SOCKET
2405     goto COND_FAILED_NOT_COMPILED;
2406 #else
2407     {
2408     uschar *sub[4];
2409     while (isspace(*s)) s++;
2410     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2411     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2412                     resetok))
2413       {
2414       case 1: expand_string_message = US"too few arguments or bracketing "
2415         "error for saslauthd";
2416       case 2:
2417       case 3: return NULL;
2418       }
2419     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2420     if (yield != NULL)
2421       {
2422       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2423         &expand_string_message);
2424       if (rc == ERROR || rc == DEFER) return NULL;
2425       *yield = (rc == OK) == testfor;
2426       }
2427     return s;
2428     }
2429 #endif /* CYRUS_SASLAUTHD_SOCKET */
2430
2431
2432   /* symbolic operators for numeric and string comparison, and a number of
2433   other operators, all requiring two arguments.
2434
2435   crypteq:           encrypts plaintext and compares against an encrypted text,
2436                        using crypt(), crypt16(), MD5 or SHA-1
2437   inlist/inlisti:    checks if first argument is in the list of the second
2438   match:             does a regular expression match and sets up the numerical
2439                        variables if it succeeds
2440   match_address:     matches in an address list
2441   match_domain:      matches in a domain list
2442   match_ip:          matches a host list that is restricted to IP addresses
2443   match_local_part:  matches in a local part list
2444   */
2445
2446   case ECOND_MATCH_ADDRESS:
2447   case ECOND_MATCH_DOMAIN:
2448   case ECOND_MATCH_IP:
2449   case ECOND_MATCH_LOCAL_PART:
2450 #ifndef EXPAND_LISTMATCH_RHS
2451     sub2_honour_dollar = FALSE;
2452 #endif
2453     /* FALLTHROUGH */
2454
2455   case ECOND_CRYPTEQ:
2456   case ECOND_INLIST:
2457   case ECOND_INLISTI:
2458   case ECOND_MATCH:
2459
2460   case ECOND_NUM_L:     /* Numerical comparisons */
2461   case ECOND_NUM_LE:
2462   case ECOND_NUM_E:
2463   case ECOND_NUM_EE:
2464   case ECOND_NUM_G:
2465   case ECOND_NUM_GE:
2466
2467   case ECOND_STR_LT:    /* String comparisons */
2468   case ECOND_STR_LTI:
2469   case ECOND_STR_LE:
2470   case ECOND_STR_LEI:
2471   case ECOND_STR_EQ:
2472   case ECOND_STR_EQI:
2473   case ECOND_STR_GT:
2474   case ECOND_STR_GTI:
2475   case ECOND_STR_GE:
2476   case ECOND_STR_GEI:
2477
2478   for (i = 0; i < 2; i++)
2479     {
2480     /* Sometimes, we don't expand substrings; too many insecure configurations
2481     created using match_address{}{} and friends, where the second param
2482     includes information from untrustworthy sources. */
2483     BOOL honour_dollar = TRUE;
2484     if ((i > 0) && !sub2_honour_dollar)
2485       honour_dollar = FALSE;
2486
2487     while (isspace(*s)) s++;
2488     if (*s != '{')
2489       {
2490       if (i == 0) goto COND_FAILED_CURLY_START;
2491       expand_string_message = string_sprintf("missing 2nd string in {} "
2492         "after \"%s\"", name);
2493       return NULL;
2494       }
2495     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2496         honour_dollar, resetok);
2497     if (sub[i] == NULL) return NULL;
2498     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2499
2500     /* Convert to numerical if required; we know that the names of all the
2501     conditions that compare numbers do not start with a letter. This just saves
2502     checking for them individually. */
2503
2504     if (!isalpha(name[0]) && yield != NULL)
2505       {
2506       if (sub[i][0] == 0)
2507         {
2508         num[i] = 0;
2509         DEBUG(D_expand)
2510           debug_printf("empty string cast to zero for numerical comparison\n");
2511         }
2512       else
2513         {
2514         num[i] = expanded_string_integer(sub[i], FALSE);
2515         if (expand_string_message != NULL) return NULL;
2516         }
2517       }
2518     }
2519
2520   /* Result not required */
2521
2522   if (yield == NULL) return s;
2523
2524   /* Do an appropriate comparison */
2525
2526   switch(cond_type)
2527     {
2528     case ECOND_NUM_E:
2529     case ECOND_NUM_EE:
2530     tempcond = (num[0] == num[1]);
2531     break;
2532
2533     case ECOND_NUM_G:
2534     tempcond = (num[0] > num[1]);
2535     break;
2536
2537     case ECOND_NUM_GE:
2538     tempcond = (num[0] >= num[1]);
2539     break;
2540
2541     case ECOND_NUM_L:
2542     tempcond = (num[0] < num[1]);
2543     break;
2544
2545     case ECOND_NUM_LE:
2546     tempcond = (num[0] <= num[1]);
2547     break;
2548
2549     case ECOND_STR_LT:
2550     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2551     break;
2552
2553     case ECOND_STR_LTI:
2554     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2555     break;
2556
2557     case ECOND_STR_LE:
2558     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2559     break;
2560
2561     case ECOND_STR_LEI:
2562     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2563     break;
2564
2565     case ECOND_STR_EQ:
2566     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2567     break;
2568
2569     case ECOND_STR_EQI:
2570     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2571     break;
2572
2573     case ECOND_STR_GT:
2574     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2575     break;
2576
2577     case ECOND_STR_GTI:
2578     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2579     break;
2580
2581     case ECOND_STR_GE:
2582     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2583     break;
2584
2585     case ECOND_STR_GEI:
2586     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2587     break;
2588
2589     case ECOND_MATCH:   /* Regular expression match */
2590     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2591       NULL);
2592     if (re == NULL)
2593       {
2594       expand_string_message = string_sprintf("regular expression error in "
2595         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2596       return NULL;
2597       }
2598     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2599     break;
2600
2601     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2602     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2603     goto MATCHED_SOMETHING;
2604
2605     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2606     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2607       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2608     goto MATCHED_SOMETHING;
2609
2610     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2611     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2612       {
2613       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2614         sub[0]);
2615       return NULL;
2616       }
2617     else
2618       {
2619       unsigned int *nullcache = NULL;
2620       check_host_block cb;
2621
2622       cb.host_name = US"";
2623       cb.host_address = sub[0];
2624
2625       /* If the host address starts off ::ffff: it is an IPv6 address in
2626       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2627       addresses. */
2628
2629       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2630         cb.host_address + 7 : cb.host_address;
2631
2632       rc = match_check_list(
2633              &sub[1],                   /* the list */
2634              0,                         /* separator character */
2635              &hostlist_anchor,          /* anchor pointer */
2636              &nullcache,                /* cache pointer */
2637              check_host,                /* function for testing */
2638              &cb,                       /* argument for function */
2639              MCL_HOST,                  /* type of check */
2640              sub[0],                    /* text for debugging */
2641              NULL);                     /* where to pass back data */
2642       }
2643     goto MATCHED_SOMETHING;
2644
2645     case ECOND_MATCH_LOCAL_PART:
2646     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2647       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2648     /* Fall through */
2649     /* VVVVVVVVVVVV */
2650     MATCHED_SOMETHING:
2651     switch(rc)
2652       {
2653       case OK:
2654       tempcond = TRUE;
2655       break;
2656
2657       case FAIL:
2658       tempcond = FALSE;
2659       break;
2660
2661       case DEFER:
2662       expand_string_message = string_sprintf("unable to complete match "
2663         "against \"%s\": %s", sub[1], search_error_message);
2664       return NULL;
2665       }
2666
2667     break;
2668
2669     /* Various "encrypted" comparisons. If the second string starts with
2670     "{" then an encryption type is given. Default to crypt() or crypt16()
2671     (build-time choice). */
2672     /* }-for-text-editors */
2673
2674     case ECOND_CRYPTEQ:
2675     #ifndef SUPPORT_CRYPTEQ
2676     goto COND_FAILED_NOT_COMPILED;
2677     #else
2678     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2679       {
2680       int sublen = Ustrlen(sub[1]+5);
2681       md5 base;
2682       uschar digest[16];
2683
2684       md5_start(&base);
2685       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2686
2687       /* If the length that we are comparing against is 24, the MD5 digest
2688       is expressed as a base64 string. This is the way LDAP does it. However,
2689       some other software uses a straightforward hex representation. We assume
2690       this if the length is 32. Other lengths fail. */
2691
2692       if (sublen == 24)
2693         {
2694         uschar *coded = auth_b64encode((uschar *)digest, 16);
2695         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2696           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2697         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2698         }
2699       else if (sublen == 32)
2700         {
2701         int i;
2702         uschar coded[36];
2703         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2704         coded[32] = 0;
2705         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2706           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2707         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2708         }
2709       else
2710         {
2711         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2712           "fail\n  crypted=%s\n", sub[1]+5);
2713         tempcond = FALSE;
2714         }
2715       }
2716
2717     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2718       {
2719       int sublen = Ustrlen(sub[1]+6);
2720       sha1 base;
2721       uschar digest[20];
2722
2723       sha1_start(&base);
2724       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2725
2726       /* If the length that we are comparing against is 28, assume the SHA1
2727       digest is expressed as a base64 string. If the length is 40, assume a
2728       straightforward hex representation. Other lengths fail. */
2729
2730       if (sublen == 28)
2731         {
2732         uschar *coded = auth_b64encode((uschar *)digest, 20);
2733         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2734           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2735         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2736         }
2737       else if (sublen == 40)
2738         {
2739         int i;
2740         uschar coded[44];
2741         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2742         coded[40] = 0;
2743         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2744           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2745         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2746         }
2747       else
2748         {
2749         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2750           "fail\n  crypted=%s\n", sub[1]+6);
2751         tempcond = FALSE;
2752         }
2753       }
2754
2755     else   /* {crypt} or {crypt16} and non-{ at start */
2756            /* }-for-text-editors */
2757       {
2758       int which = 0;
2759       uschar *coded;
2760
2761       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2762         {
2763         sub[1] += 7;
2764         which = 1;
2765         }
2766       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2767         {
2768         sub[1] += 9;
2769         which = 2;
2770         }
2771       else if (sub[1][0] == '{')                /* }-for-text-editors */
2772         {
2773         expand_string_message = string_sprintf("unknown encryption mechanism "
2774           "in \"%s\"", sub[1]);
2775         return NULL;
2776         }
2777
2778       switch(which)
2779         {
2780         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2781         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2782         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2783         }
2784
2785       #define STR(s) # s
2786       #define XSTR(s) STR(s)
2787       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2788         "  subject=%s\n  crypted=%s\n",
2789         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2790         coded, sub[1]);
2791       #undef STR
2792       #undef XSTR
2793
2794       /* If the encrypted string contains fewer than two characters (for the
2795       salt), force failure. Otherwise we get false positives: with an empty
2796       string the yield of crypt() is an empty string! */
2797
2798       tempcond = (Ustrlen(sub[1]) < 2)? FALSE :
2799         (Ustrcmp(coded, sub[1]) == 0);
2800       }
2801     break;
2802     #endif  /* SUPPORT_CRYPTEQ */
2803
2804     case ECOND_INLIST:
2805     case ECOND_INLISTI:
2806       {
2807       const uschar * list = sub[1];
2808       int sep = 0;
2809       uschar *save_iterate_item = iterate_item;
2810       int (*compare)(const uschar *, const uschar *);
2811
2812       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2813
2814       tempcond = FALSE;
2815       compare = cond_type == ECOND_INLISTI
2816         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2817
2818       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2819         if (compare(sub[0], iterate_item) == 0)
2820           {
2821           tempcond = TRUE;
2822           break;
2823           }
2824       iterate_item = save_iterate_item;
2825       }
2826
2827     }   /* Switch for comparison conditions */
2828
2829   *yield = tempcond == testfor;
2830   return s;    /* End of comparison conditions */
2831
2832
2833   /* and/or: computes logical and/or of several conditions */
2834
2835   case ECOND_AND:
2836   case ECOND_OR:
2837   subcondptr = (yield == NULL)? NULL : &tempcond;
2838   combined_cond = (cond_type == ECOND_AND);
2839
2840   while (isspace(*s)) s++;
2841   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2842
2843   for (;;)
2844     {
2845     while (isspace(*s)) s++;
2846     /* {-for-text-editors */
2847     if (*s == '}') break;
2848     if (*s != '{')                                      /* }-for-text-editors */
2849       {
2850       expand_string_message = string_sprintf("each subcondition "
2851         "inside an \"%s{...}\" condition must be in its own {}", name);
2852       return NULL;
2853       }
2854
2855     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2856       {
2857       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2858         expand_string_message, name);
2859       return NULL;
2860       }
2861     while (isspace(*s)) s++;
2862
2863     /* {-for-text-editors */
2864     if (*s++ != '}')
2865       {
2866       /* {-for-text-editors */
2867       expand_string_message = string_sprintf("missing } at end of condition "
2868         "inside \"%s\" group", name);
2869       return NULL;
2870       }
2871
2872     if (yield != NULL)
2873       {
2874       if (cond_type == ECOND_AND)
2875         {
2876         combined_cond &= tempcond;
2877         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2878         }                                       /* evaluate any more */
2879       else
2880         {
2881         combined_cond |= tempcond;
2882         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2883         }                                       /* evaluate any more */
2884       }
2885     }
2886
2887   if (yield != NULL) *yield = (combined_cond == testfor);
2888   return ++s;
2889
2890
2891   /* forall/forany: iterates a condition with different values */
2892
2893   case ECOND_FORALL:
2894   case ECOND_FORANY:
2895     {
2896     const uschar * list;
2897     int sep = 0;
2898     uschar *save_iterate_item = iterate_item;
2899
2900     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2901
2902     while (isspace(*s)) s++;
2903     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2904     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2905     if (sub[0] == NULL) return NULL;
2906     /* {-for-text-editors */
2907     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2908
2909     while (isspace(*s)) s++;
2910     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2911
2912     sub[1] = s;
2913
2914     /* Call eval_condition once, with result discarded (as if scanning a
2915     "false" part). This allows us to find the end of the condition, because if
2916     the list it empty, we won't actually evaluate the condition for real. */
2917
2918     if (!(s = eval_condition(sub[1], resetok, NULL)))
2919       {
2920       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2921         expand_string_message, name);
2922       return NULL;
2923       }
2924     while (isspace(*s)) s++;
2925
2926     /* {-for-text-editors */
2927     if (*s++ != '}')
2928       {
2929       /* {-for-text-editors */
2930       expand_string_message = string_sprintf("missing } at end of condition "
2931         "inside \"%s\"", name);
2932       return NULL;
2933       }
2934
2935     if (yield != NULL) *yield = !testfor;
2936     list = sub[0];
2937     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2938       {
2939       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2940       if (!eval_condition(sub[1], resetok, &tempcond))
2941         {
2942         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2943           expand_string_message, name);
2944         iterate_item = save_iterate_item;
2945         return NULL;
2946         }
2947       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2948         tempcond? "true":"false");
2949
2950       if (yield != NULL) *yield = (tempcond == testfor);
2951       if (tempcond == (cond_type == ECOND_FORANY)) break;
2952       }
2953
2954     iterate_item = save_iterate_item;
2955     return s;
2956     }
2957
2958
2959   /* The bool{} expansion condition maps a string to boolean.
2960   The values supported should match those supported by the ACL condition
2961   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2962   of true/false.  Note that Router "condition" rules have a different
2963   interpretation, where general data can be used and only a few values
2964   map to FALSE.
2965   Note that readconf.c boolean matching, for boolean configuration options,
2966   only matches true/yes/false/no.
2967   The bool_lax{} condition matches the Router logic, which is much more
2968   liberal. */
2969   case ECOND_BOOL:
2970   case ECOND_BOOL_LAX:
2971     {
2972     uschar *sub_arg[1];
2973     uschar *t, *t2;
2974     uschar *ourname;
2975     size_t len;
2976     BOOL boolvalue = FALSE;
2977     while (isspace(*s)) s++;
2978     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2979     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2980     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2981       {
2982       case 1: expand_string_message = string_sprintf(
2983                   "too few arguments or bracketing error for %s",
2984                   ourname);
2985       /*FALLTHROUGH*/
2986       case 2:
2987       case 3: return NULL;
2988       }
2989     t = sub_arg[0];
2990     while (isspace(*t)) t++;
2991     len = Ustrlen(t);
2992     if (len)
2993       {
2994       /* trailing whitespace: seems like a good idea to ignore it too */
2995       t2 = t + len - 1;
2996       while (isspace(*t2)) t2--;
2997       if (t2 != (t + len))
2998         {
2999         *++t2 = '\0';
3000         len = t2 - t;
3001         }
3002       }
3003     DEBUG(D_expand)
3004       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3005     /* logic for the lax case from expand_check_condition(), which also does
3006     expands, and the logic is both short and stable enough that there should
3007     be no maintenance burden from replicating it. */
3008     if (len == 0)
3009       boolvalue = FALSE;
3010     else if (*t == '-'
3011              ? Ustrspn(t+1, "0123456789") == len-1
3012              : Ustrspn(t,   "0123456789") == len)
3013       {
3014       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3015       /* expand_check_condition only does a literal string "0" check */
3016       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3017         boolvalue = TRUE;
3018       }
3019     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3020       boolvalue = TRUE;
3021     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3022       boolvalue = FALSE;
3023     else if (cond_type == ECOND_BOOL_LAX)
3024       boolvalue = TRUE;
3025     else
3026       {
3027       expand_string_message = string_sprintf("unrecognised boolean "
3028        "value \"%s\"", t);
3029       return NULL;
3030       }
3031     if (yield != NULL) *yield = (boolvalue == testfor);
3032     return s;
3033     }
3034
3035   /* Unknown condition */
3036
3037   default:
3038   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3039   return NULL;
3040   }   /* End switch on condition type */
3041
3042 /* Missing braces at start and end of data */
3043
3044 COND_FAILED_CURLY_START:
3045 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3046 return NULL;
3047
3048 COND_FAILED_CURLY_END:
3049 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3050   name);
3051 return NULL;
3052
3053 /* A condition requires code that is not compiled */
3054
3055 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3056     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3057     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3058 COND_FAILED_NOT_COMPILED:
3059 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3060   name);
3061 return NULL;
3062 #endif
3063 }
3064
3065
3066
3067
3068 /*************************************************
3069 *          Save numerical variables              *
3070 *************************************************/
3071
3072 /* This function is called from items such as "if" that want to preserve and
3073 restore the numbered variables.
3074
3075 Arguments:
3076   save_expand_string    points to an array of pointers to set
3077   save_expand_nlength   points to an array of ints for the lengths
3078
3079 Returns:                the value of expand max to save
3080 */
3081
3082 static int
3083 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3084 {
3085 int i;
3086 for (i = 0; i <= expand_nmax; i++)
3087   {
3088   save_expand_nstring[i] = expand_nstring[i];
3089   save_expand_nlength[i] = expand_nlength[i];
3090   }
3091 return expand_nmax;
3092 }
3093
3094
3095
3096 /*************************************************
3097 *           Restore numerical variables          *
3098 *************************************************/
3099
3100 /* This function restored saved values of numerical strings.
3101
3102 Arguments:
3103   save_expand_nmax      the number of strings to restore
3104   save_expand_string    points to an array of pointers
3105   save_expand_nlength   points to an array of ints
3106
3107 Returns:                nothing
3108 */
3109
3110 static void
3111 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3112   int *save_expand_nlength)
3113 {
3114 int i;
3115 expand_nmax = save_expand_nmax;
3116 for (i = 0; i <= expand_nmax; i++)
3117   {
3118   expand_nstring[i] = save_expand_nstring[i];
3119   expand_nlength[i] = save_expand_nlength[i];
3120   }
3121 }
3122
3123
3124
3125
3126
3127 /*************************************************
3128 *            Handle yes/no substrings            *
3129 *************************************************/
3130
3131 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3132 alternative substrings that depend on whether or not the condition was true,
3133 or the lookup or extraction succeeded. The substrings always have to be
3134 expanded, to check their syntax, but "skipping" is set when the result is not
3135 needed - this avoids unnecessary nested lookups.
3136
3137 Arguments:
3138   skipping       TRUE if we were skipping when this item was reached
3139   yes            TRUE if the first string is to be used, else use the second
3140   save_lookup    a value to put back into lookup_value before the 2nd expansion
3141   sptr           points to the input string pointer
3142   yieldptr       points to the output string pointer
3143   sizeptr        points to the output string size
3144   ptrptr         points to the output string pointer
3145   type           "lookup" or "if" or "extract" or "run", for error message
3146   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3147                 the store.
3148
3149 Returns:         0 OK; lookup_value has been reset to save_lookup
3150                  1 expansion failed
3151                  2 expansion failed because of bracketing error
3152 */
3153
3154 static int
3155 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3156   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3157 {
3158 int rc = 0;
3159 const uschar *s = *sptr;    /* Local value */
3160 uschar *sub1, *sub2;
3161
3162 /* If there are no following strings, we substitute the contents of $value for
3163 lookups and for extractions in the success case. For the ${if item, the string
3164 "true" is substituted. In the fail case, nothing is substituted for all three
3165 items. */
3166
3167 while (isspace(*s)) s++;
3168 if (*s == '}')
3169   {
3170   if (type[0] == 'i')
3171     {
3172     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
3173     }
3174   else
3175     {
3176     if (yes && lookup_value != NULL)
3177       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
3178         Ustrlen(lookup_value));
3179     lookup_value = save_lookup;
3180     }
3181   s++;
3182   goto RETURN;
3183   }
3184
3185 /* The first following string must be braced. */
3186
3187 if (*s++ != '{') goto FAILED_CURLY;
3188
3189 /* Expand the first substring. Forced failures are noticed only if we actually
3190 want this string. Set skipping in the call in the fail case (this will always
3191 be the case if we were already skipping). */
3192
3193 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3194 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3195 expand_string_forcedfail = FALSE;
3196 if (*s++ != '}') goto FAILED_CURLY;
3197
3198 /* If we want the first string, add it to the output */
3199
3200 if (yes)
3201   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
3202
3203 /* If this is called from a lookup or an extract, we want to restore $value to
3204 what it was at the start of the item, so that it has this value during the
3205 second string expansion. For the call from "if" or "run" to this function,
3206 save_lookup is set to lookup_value, so that this statement does nothing. */
3207
3208 lookup_value = save_lookup;
3209
3210 /* There now follows either another substring, or "fail", or nothing. This
3211 time, forced failures are noticed only if we want the second string. We must
3212 set skipping in the nested call if we don't want this string, or if we were
3213 already skipping. */
3214
3215 while (isspace(*s)) s++;
3216 if (*s == '{')
3217   {
3218   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3219   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3220   expand_string_forcedfail = FALSE;
3221   if (*s++ != '}') goto FAILED_CURLY;
3222
3223   /* If we want the second string, add it to the output */
3224
3225   if (!yes)
3226     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
3227   }
3228
3229 /* If there is no second string, but the word "fail" is present when the use of
3230 the second string is wanted, set a flag indicating it was a forced failure
3231 rather than a syntactic error. Swallow the terminating } in case this is nested
3232 inside another lookup or if or extract. */
3233
3234 else if (*s != '}')
3235   {
3236   uschar name[256];
3237   /* deconst cast ok here as source is s anyway */
3238   s = US read_name(name, sizeof(name), s, US"_");
3239   if (Ustrcmp(name, "fail") == 0)
3240     {
3241     if (!yes && !skipping)
3242       {
3243       while (isspace(*s)) s++;
3244       if (*s++ != '}') goto FAILED_CURLY;
3245       expand_string_message =
3246         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3247       expand_string_forcedfail = TRUE;
3248       goto FAILED;
3249       }
3250     }
3251   else
3252     {
3253     expand_string_message =
3254       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3255     goto FAILED;
3256     }
3257   }
3258
3259 /* All we have to do now is to check on the final closing brace. */
3260
3261 while (isspace(*s)) s++;
3262 if (*s++ == '}') goto RETURN;
3263
3264 /* Get here if there is a bracketing failure */
3265
3266 FAILED_CURLY:
3267 rc++;
3268
3269 /* Get here for other failures */
3270
3271 FAILED:
3272 rc++;
3273
3274 /* Update the input pointer value before returning */
3275
3276 RETURN:
3277 *sptr = s;
3278 return rc;
3279 }
3280
3281
3282
3283
3284 /*************************************************
3285 *    Handle MD5 or SHA-1 computation for HMAC    *
3286 *************************************************/
3287
3288 /* These are some wrapping functions that enable the HMAC code to be a bit
3289 cleaner. A good compiler will spot the tail recursion.
3290
3291 Arguments:
3292   type         HMAC_MD5 or HMAC_SHA1
3293   remaining    are as for the cryptographic hash functions
3294
3295 Returns:       nothing
3296 */
3297
3298 static void
3299 chash_start(int type, void *base)
3300 {
3301 if (type == HMAC_MD5)
3302   md5_start((md5 *)base);
3303 else
3304   sha1_start((sha1 *)base);
3305 }
3306
3307 static void
3308 chash_mid(int type, void *base, uschar *string)
3309 {
3310 if (type == HMAC_MD5)
3311   md5_mid((md5 *)base, string);
3312 else
3313   sha1_mid((sha1 *)base, string);
3314 }
3315
3316 static void
3317 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3318 {
3319 if (type == HMAC_MD5)
3320   md5_end((md5 *)base, string, length, digest);
3321 else
3322   sha1_end((sha1 *)base, string, length, digest);
3323 }
3324
3325
3326
3327
3328
3329 /********************************************************
3330 * prvs: Get last three digits of days since Jan 1, 1970 *
3331 ********************************************************/
3332
3333 /* This is needed to implement the "prvs" BATV reverse
3334    path signing scheme
3335
3336 Argument: integer "days" offset to add or substract to
3337           or from the current number of days.
3338
3339 Returns:  pointer to string containing the last three
3340           digits of the number of days since Jan 1, 1970,
3341           modified by the offset argument, NULL if there
3342           was an error in the conversion.
3343
3344 */
3345
3346 static uschar *
3347 prvs_daystamp(int day_offset)
3348 {
3349 uschar *days = store_get(32);                /* Need at least 24 for cases */
3350 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3351   (time(NULL) + day_offset*86400)/86400);
3352 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3353 }
3354
3355
3356
3357 /********************************************************
3358 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3359 ********************************************************/
3360
3361 /* This is needed to implement the "prvs" BATV reverse
3362    path signing scheme
3363
3364 Arguments:
3365   address RFC2821 Address to use
3366       key The key to use (must be less than 64 characters
3367           in size)
3368   key_num Single-digit key number to use. Defaults to
3369           '0' when NULL.
3370
3371 Returns:  pointer to string containing the first three
3372           bytes of the final hash in hex format, NULL if
3373           there was an error in the process.
3374 */
3375
3376 static uschar *
3377 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3378 {
3379 uschar *hash_source, *p;
3380 int size = 0,offset = 0,i;
3381 sha1 sha1_base;
3382 void *use_base = &sha1_base;
3383 uschar innerhash[20];
3384 uschar finalhash[20];
3385 uschar innerkey[64];
3386 uschar outerkey[64];
3387 uschar *finalhash_hex = store_get(40);
3388
3389 if (key_num == NULL)
3390   key_num = US"0";
3391
3392 if (Ustrlen(key) > 64)
3393   return NULL;
3394
3395 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3396 string_cat(hash_source,&size,&offset,daystamp,3);
3397 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3398 hash_source[offset] = '\0';
3399
3400 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3401
3402 memset(innerkey, 0x36, 64);
3403 memset(outerkey, 0x5c, 64);
3404
3405 for (i = 0; i < Ustrlen(key); i++)
3406   {
3407   innerkey[i] ^= key[i];
3408   outerkey[i] ^= key[i];
3409   }
3410
3411 chash_start(HMAC_SHA1, use_base);
3412 chash_mid(HMAC_SHA1, use_base, innerkey);
3413 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3414
3415 chash_start(HMAC_SHA1, use_base);
3416 chash_mid(HMAC_SHA1, use_base, outerkey);
3417 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3418
3419 p = finalhash_hex;
3420 for (i = 0; i < 3; i++)
3421   {
3422   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3423   *p++ = hex_digits[finalhash[i] & 0x0f];
3424   }
3425 *p = '\0';
3426
3427 return finalhash_hex;
3428 }
3429
3430
3431
3432
3433 /*************************************************
3434 *        Join a file onto the output string      *
3435 *************************************************/
3436
3437 /* This is used for readfile and after a run expansion. It joins the contents
3438 of a file onto the output string, globally replacing newlines with a given
3439 string (optionally). The file is closed at the end.
3440
3441 Arguments:
3442   f            the FILE
3443   yield        pointer to the expandable string
3444   sizep        pointer to the current size
3445   ptrp         pointer to the current position
3446   eol          newline replacement string, or NULL
3447
3448 Returns:       new value of string pointer
3449 */
3450
3451 static uschar *
3452 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3453 {
3454 int eollen;
3455 uschar buffer[1024];
3456
3457 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3458
3459 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3460   {
3461   int len = Ustrlen(buffer);
3462   if (eol != NULL && buffer[len-1] == '\n') len--;
3463   yield = string_cat(yield, sizep, ptrp, buffer, len);
3464   if (buffer[len] != 0)
3465     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3466   }
3467
3468 if (yield != NULL) yield[*ptrp] = 0;
3469
3470 return yield;
3471 }
3472
3473
3474
3475
3476 /*************************************************
3477 *          Evaluate numeric expression           *
3478 *************************************************/
3479
3480 /* This is a set of mutually recursive functions that evaluate an arithmetic
3481 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3482 these functions that is called from elsewhere is eval_expr, whose interface is:
3483
3484 Arguments:
3485   sptr        pointer to the pointer to the string - gets updated
3486   decimal     TRUE if numbers are to be assumed decimal
3487   error       pointer to where to put an error message - must be NULL on input
3488   endket      TRUE if ')' must terminate - FALSE for external call
3489
3490 Returns:      on success: the value of the expression, with *error still NULL
3491               on failure: an undefined value, with *error = a message
3492 */
3493
3494 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3495
3496
3497 static int_eximarith_t
3498 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3499 {
3500 uschar *s = *sptr;
3501 int_eximarith_t x = eval_op_or(&s, decimal, error);
3502 if (*error == NULL)
3503   {
3504   if (endket)
3505     {
3506     if (*s != ')')
3507       *error = US"expecting closing parenthesis";
3508     else
3509       while (isspace(*(++s)));
3510     }
3511   else if (*s != 0) *error = US"expecting operator";
3512   }
3513 *sptr = s;
3514 return x;
3515 }
3516
3517
3518 static int_eximarith_t
3519 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3520 {
3521 register int c;
3522 int_eximarith_t n;
3523 uschar *s = *sptr;
3524 while (isspace(*s)) s++;
3525 c = *s;
3526 if (isdigit(c))
3527   {
3528   int count;
3529   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3530   s += count;
3531   switch (tolower(*s))
3532     {
3533     default: break;
3534     case 'k': n *= 1024; s++; break;
3535     case 'm': n *= 1024*1024; s++; break;
3536     case 'g': n *= 1024*1024*1024; s++; break;
3537     }
3538   while (isspace (*s)) s++;
3539   }
3540 else if (c == '(')
3541   {
3542   s++;
3543   n = eval_expr(&s, decimal, error, 1);
3544   }
3545 else
3546   {
3547   *error = US"expecting number or opening parenthesis";
3548   n = 0;
3549   }
3550 *sptr = s;
3551 return n;
3552 }
3553
3554
3555 static int_eximarith_t
3556 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3557 {
3558 uschar *s = *sptr;
3559 int_eximarith_t x;
3560 while (isspace(*s)) s++;
3561 if (*s == '+' || *s == '-' || *s == '~')
3562   {
3563   int op = *s++;
3564   x = eval_op_unary(&s, decimal, error);
3565   if (op == '-') x = -x;
3566     else if (op == '~') x = ~x;
3567   }
3568 else
3569   {
3570   x = eval_number(&s, decimal, error);
3571   }
3572 *sptr = s;
3573 return x;
3574 }
3575
3576
3577 static int_eximarith_t
3578 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3579 {
3580 uschar *s = *sptr;
3581 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3582 if (*error == NULL)
3583   {
3584   while (*s == '*' || *s == '/' || *s == '%')
3585     {
3586     int op = *s++;
3587     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3588     if (*error != NULL) break;
3589     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3590      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3591      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3592      * -N*M is INT_MIN will yielf INT_MIN.
3593      * Since we don't support floating point, this is somewhat simpler.
3594      * Ideally, we'd return an error, but since we overflow for all other
3595      * arithmetic, consistency suggests otherwise, but what's the correct value
3596      * to use?  There is none.
3597      * The C standard guarantees overflow for unsigned arithmetic but signed
3598      * overflow invokes undefined behaviour; in practice, this is overflow
3599      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3600      * that long/longlong larger than int are available, or we could just work
3601      * with larger types.  We should consider whether to guarantee 32bit eval
3602      * and 64-bit working variables, with errors returned.  For now ...
3603      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3604      * can just let the other invalid results occur otherwise, as they have
3605      * until now.  For this one case, we can coerce.
3606      */
3607     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3608       {
3609       DEBUG(D_expand)
3610         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3611             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3612       x = EXIM_ARITH_MAX;
3613       continue;
3614       }
3615     if (op == '*')
3616       x *= y;
3617     else
3618       {
3619       if (y == 0)
3620         {
3621         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3622         x = 0;
3623         break;
3624         }
3625       if (op == '/')
3626         x /= y;
3627       else
3628         x %= y;
3629       }
3630     }
3631   }
3632 *sptr = s;
3633 return x;
3634 }
3635
3636
3637 static int_eximarith_t
3638 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3639 {
3640 uschar *s = *sptr;
3641 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3642 if (*error == NULL)
3643   {
3644   while (*s == '+' || *s == '-')
3645     {
3646     int op = *s++;
3647     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3648     if (*error != NULL) break;
3649     if (op == '+') x += y; else x -= y;
3650     }
3651   }
3652 *sptr = s;
3653 return x;
3654 }
3655
3656
3657 static int_eximarith_t
3658 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3659 {
3660 uschar *s = *sptr;
3661 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3662 if (*error == NULL)
3663   {
3664   while ((*s == '<' || *s == '>') && s[1] == s[0])
3665     {
3666     int_eximarith_t y;
3667     int op = *s++;
3668     s++;
3669     y = eval_op_sum(&s, decimal, error);
3670     if (*error != NULL) break;
3671     if (op == '<') x <<= y; else x >>= y;
3672     }
3673   }
3674 *sptr = s;
3675 return x;
3676 }
3677
3678
3679 static int_eximarith_t
3680 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3681 {
3682 uschar *s = *sptr;
3683 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3684 if (*error == NULL)
3685   {
3686   while (*s == '&')
3687     {
3688     int_eximarith_t y;
3689     s++;
3690     y = eval_op_shift(&s, decimal, error);
3691     if (*error != NULL) break;
3692     x &= y;
3693     }
3694   }
3695 *sptr = s;
3696 return x;
3697 }
3698
3699
3700 static int_eximarith_t
3701 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3702 {
3703 uschar *s = *sptr;
3704 int_eximarith_t x = eval_op_and(&s, decimal, error);
3705 if (*error == NULL)
3706   {
3707   while (*s == '^')
3708     {
3709     int_eximarith_t y;
3710     s++;
3711     y = eval_op_and(&s, decimal, error);
3712     if (*error != NULL) break;
3713     x ^= y;
3714     }
3715   }
3716 *sptr = s;
3717 return x;
3718 }
3719
3720
3721 static int_eximarith_t
3722 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3723 {
3724 uschar *s = *sptr;
3725 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3726 if (*error == NULL)
3727   {
3728   while (*s == '|')
3729     {
3730     int_eximarith_t y;
3731     s++;
3732     y = eval_op_xor(&s, decimal, error);
3733     if (*error != NULL) break;
3734     x |= y;
3735     }
3736   }
3737 *sptr = s;
3738 return x;
3739 }
3740
3741
3742
3743 /*************************************************
3744 *                 Expand string                  *
3745 *************************************************/
3746
3747 /* Returns either an unchanged string, or the expanded string in stacking pool
3748 store. Interpreted sequences are:
3749
3750    \...                    normal escaping rules
3751    $name                   substitutes the variable
3752    ${name}                 ditto
3753    ${op:string}            operates on the expanded string value
3754    ${item{arg1}{arg2}...}  expands the args and then does the business
3755                              some literal args are not enclosed in {}
3756
3757 There are now far too many operators and item types to make it worth listing
3758 them here in detail any more.
3759
3760 We use an internal routine recursively to handle embedded substrings. The
3761 external function follows. The yield is NULL if the expansion failed, and there
3762 are two cases: if something collapsed syntactically, or if "fail" was given
3763 as the action on a lookup failure. These can be distinguised by looking at the
3764 variable expand_string_forcedfail, which is TRUE in the latter case.
3765
3766 The skipping flag is set true when expanding a substring that isn't actually
3767 going to be used (after "if" or "lookup") and it prevents lookups from
3768 happening lower down.
3769
3770 Store usage: At start, a store block of the length of the input plus 64
3771 is obtained. This is expanded as necessary by string_cat(), which might have to
3772 get a new block, or might be able to expand the original. At the end of the
3773 function we can release any store above that portion of the yield block that
3774 was actually used. In many cases this will be optimal.
3775
3776 However: if the first item in the expansion is a variable name or header name,
3777 we reset the store before processing it; if the result is in fresh store, we
3778 use that without copying. This is helpful for expanding strings like
3779 $message_headers which can get very long.
3780
3781 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3782 since resetting the store at the end of the expansion will free store that was
3783 allocated by the plugin code as well as the slop after the expanded string. So
3784 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3785 and, given the acl condition, ${if }. This is an unfortunate consequence of
3786 string expansion becoming too powerful.
3787
3788 Arguments:
3789   string         the string to be expanded
3790   ket_ends       true if expansion is to stop at }
3791   left           if not NULL, a pointer to the first character after the
3792                  expansion is placed here (typically used with ket_ends)
3793   skipping       TRUE for recursive calls when the value isn't actually going
3794                  to be used (to allow for optimisation)
3795   honour_dollar  TRUE if $ is to be expanded,
3796                  FALSE if it's just another character
3797   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3798                  the store.
3799
3800 Returns:         NULL if expansion fails:
3801                    expand_string_forcedfail is set TRUE if failure was forced
3802                    expand_string_message contains a textual error message
3803                  a pointer to the expanded string on success
3804 */
3805
3806 static uschar *
3807 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3808   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3809 {
3810 int ptr = 0;
3811 int size = Ustrlen(string)+ 64;
3812 int item_type;
3813 uschar *yield = store_get(size);
3814 const uschar *s = string;
3815 uschar *save_expand_nstring[EXPAND_MAXN+1];
3816 int save_expand_nlength[EXPAND_MAXN+1];
3817 BOOL resetok = TRUE;
3818
3819 expand_string_forcedfail = FALSE;
3820 expand_string_message = US"";
3821
3822 while (*s != 0)
3823   {
3824   uschar *value;
3825   uschar name[256];
3826
3827   /* \ escapes the next character, which must exist, or else
3828   the expansion fails. There's a special escape, \N, which causes
3829   copying of the subject verbatim up to the next \N. Otherwise,
3830   the escapes are the standard set. */
3831
3832   if (*s == '\\')
3833     {
3834     if (s[1] == 0)
3835       {
3836       expand_string_message = US"\\ at end of string";
3837       goto EXPAND_FAILED;
3838       }
3839
3840     if (s[1] == 'N')
3841       {
3842       const uschar * t = s + 2;
3843       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3844       yield = string_cat(yield, &size, &ptr, t, s - t);
3845       if (*s != 0) s += 2;
3846       }
3847
3848     else
3849       {
3850       uschar ch[1];
3851       ch[0] = string_interpret_escape(&s);
3852       s++;
3853       yield = string_cat(yield, &size, &ptr, ch, 1);
3854       }
3855
3856     continue;
3857     }
3858
3859   /*{*/
3860   /* Anything other than $ is just copied verbatim, unless we are
3861   looking for a terminating } character. */
3862
3863   /*{*/
3864   if (ket_ends && *s == '}') break;
3865
3866   if (*s != '$' || !honour_dollar)
3867     {
3868     yield = string_cat(yield, &size, &ptr, s++, 1);
3869     continue;
3870     }
3871
3872   /* No { after the $ - must be a plain name or a number for string
3873   match variable. There has to be a fudge for variables that are the
3874   names of header fields preceded by "$header_" because header field
3875   names can contain any printing characters except space and colon.
3876   For those that don't like typing this much, "$h_" is a synonym for
3877   "$header_". A non-existent header yields a NULL value; nothing is
3878   inserted. */  /*}*/
3879
3880   if (isalpha((*(++s))))
3881     {
3882     int len;
3883     int newsize = 0;
3884
3885     s = read_name(name, sizeof(name), s, US"_");
3886
3887     /* If this is the first thing to be expanded, release the pre-allocated
3888     buffer. */
3889
3890     if (ptr == 0 && yield != NULL)
3891       {
3892       if (resetok) store_reset(yield);
3893       yield = NULL;
3894       size = 0;
3895       }
3896
3897     /* Header */
3898
3899     if (Ustrncmp(name, "h_", 2) == 0 ||
3900         Ustrncmp(name, "rh_", 3) == 0 ||
3901         Ustrncmp(name, "bh_", 3) == 0 ||
3902         Ustrncmp(name, "header_", 7) == 0 ||
3903         Ustrncmp(name, "rheader_", 8) == 0 ||
3904         Ustrncmp(name, "bheader_", 8) == 0)
3905       {
3906       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3907       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3908       s = read_header_name(name, sizeof(name), s);
3909       value = find_header(name, FALSE, &newsize, want_raw, charset);
3910
3911       /* If we didn't find the header, and the header contains a closing brace
3912       character, this may be a user error where the terminating colon
3913       has been omitted. Set a flag to adjust the error message in this case.
3914       But there is no error here - nothing gets inserted. */
3915
3916       if (value == NULL)
3917         {
3918         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3919         continue;
3920         }
3921       }
3922
3923     /* Variable */
3924
3925     else
3926       {
3927       value = find_variable(name, FALSE, skipping, &newsize);
3928       if (value == NULL)
3929         {
3930         expand_string_message =
3931           string_sprintf("unknown variable name \"%s\"", name);
3932           check_variable_error_message(name);
3933         goto EXPAND_FAILED;
3934         }
3935       }
3936
3937     /* If the data is known to be in a new buffer, newsize will be set to the
3938     size of that buffer. If this is the first thing in an expansion string,
3939     yield will be NULL; just point it at the new store instead of copying. Many
3940     expansion strings contain just one reference, so this is a useful
3941     optimization, especially for humungous headers. */
3942
3943     len = Ustrlen(value);
3944     if (yield == NULL && newsize != 0)
3945       {
3946       yield = value;
3947       size = newsize;
3948       ptr = len;
3949       }
3950     else yield = string_cat(yield, &size, &ptr, value, len);
3951
3952     continue;
3953     }
3954
3955   if (isdigit(*s))
3956     {
3957     int n;
3958     s = read_cnumber(&n, s);
3959     if (n >= 0 && n <= expand_nmax)
3960       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3961         expand_nlength[n]);
3962     continue;
3963     }
3964
3965   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
3966
3967   if (*s != '{')                                                        /*}*/
3968     {
3969     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
3970     goto EXPAND_FAILED;
3971     }
3972
3973   /* After { there can be various things, but they all start with
3974   an initial word, except for a number for a string match variable. */
3975
3976   if (isdigit((*(++s))))
3977     {
3978     int n;
3979     s = read_cnumber(&n, s);            /*{*/
3980     if (*s++ != '}')
3981       {                                 /*{*/
3982       expand_string_message = US"} expected after number";
3983       goto EXPAND_FAILED;
3984       }
3985     if (n >= 0 && n <= expand_nmax)
3986       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3987         expand_nlength[n]);
3988     continue;
3989     }
3990
3991   if (!isalpha(*s))
3992     {
3993     expand_string_message = US"letter or digit expected after ${";      /*}*/
3994     goto EXPAND_FAILED;
3995     }
3996
3997   /* Allow "-" in names to cater for substrings with negative
3998   arguments. Since we are checking for known names after { this is
3999   OK. */
4000
4001   s = read_name(name, sizeof(name), s, US"_-");
4002   item_type = chop_match(name, item_table, nelem(item_table));
4003
4004   switch(item_type)
4005     {
4006     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4007     If the ACL returns accept or reject we return content set by "message ="
4008     There is currently no limit on recursion; this would have us call
4009     acl_check_internal() directly and get a current level from somewhere.
4010     See also the acl expansion condition ECOND_ACL and the traditional
4011     acl modifier ACLC_ACL.
4012     Assume that the function has side-effects on the store that must be preserved.
4013     */
4014
4015     case EITEM_ACL:
4016       /* ${acl {name} {arg1}{arg2}...} */
4017       {
4018       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4019       uschar *user_msg;
4020
4021       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4022                       &resetok))
4023         {
4024         case 1: goto EXPAND_FAILED_CURLY;
4025         case 2:
4026         case 3: goto EXPAND_FAILED;
4027         }
4028       if (skipping) continue;
4029
4030       resetok = FALSE;
4031       switch(eval_acl(sub, nelem(sub), &user_msg))
4032         {
4033         case OK:
4034         case FAIL:
4035           DEBUG(D_expand)
4036             debug_printf("acl expansion yield: %s\n", user_msg);
4037           if (user_msg)
4038             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
4039           continue;
4040
4041         case DEFER:
4042           expand_string_forcedfail = TRUE;
4043         default:
4044           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4045           goto EXPAND_FAILED;
4046         }
4047       }
4048
4049     /* Handle conditionals - preserve the values of the numerical expansion
4050     variables in case they get changed by a regular expression match in the
4051     condition. If not, they retain their external settings. At the end
4052     of this "if" section, they get restored to their previous values. */
4053
4054     case EITEM_IF:
4055       {
4056       BOOL cond = FALSE;
4057       const uschar *next_s;
4058       int save_expand_nmax =
4059         save_expand_strings(save_expand_nstring, save_expand_nlength);
4060
4061       while (isspace(*s)) s++;
4062       next_s = eval_condition(s, &resetok, skipping? NULL : &cond);
4063       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4064
4065       DEBUG(D_expand)
4066         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
4067           cond? "true" : "false");
4068
4069       s = next_s;
4070
4071       /* The handling of "yes" and "no" result strings is now in a separate
4072       function that is also used by ${lookup} and ${extract} and ${run}. */
4073
4074       switch(process_yesno(
4075                skipping,                     /* were previously skipping */
4076                cond,                         /* success/failure indicator */
4077                lookup_value,                 /* value to reset for string2 */
4078                &s,                           /* input pointer */
4079                &yield,                       /* output pointer */
4080                &size,                        /* output size */
4081                &ptr,                         /* output current point */
4082                US"if",                       /* condition type */
4083                &resetok))
4084         {
4085         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4086         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4087         }
4088
4089       /* Restore external setting of expansion variables for continuation
4090       at this level. */
4091
4092       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4093         save_expand_nlength);
4094       continue;
4095       }
4096
4097 #ifdef EXPERIMENTAL_INTERNATIONAL
4098     case EITEM_IMAPFOLDER:
4099       {                         /* ${imapfolder {name}{sep]{specials}} */
4100       uschar *sub_arg[3];
4101       uschar *encoded;
4102
4103       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4104                       &resetok))
4105         {
4106         case 1: goto EXPAND_FAILED_CURLY;
4107         case 2:
4108         case 3: goto EXPAND_FAILED;
4109         }
4110
4111       if (sub_arg[1] == NULL)           /* One argument */
4112         {
4113         sub_arg[1] = US"/";             /* default separator */
4114         sub_arg[2] = NULL;
4115         }
4116       else if (Ustrlen(sub_arg[1]) != 1)
4117         {
4118         expand_string_message =
4119           string_sprintf(
4120                 "IMAP folder separator must be one character, found \"%s\"",
4121                 sub_arg[1]);
4122         goto EXPAND_FAILED;
4123         }
4124
4125       if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4126                           sub_arg[1][0], sub_arg[2], &expand_string_message)))
4127         goto EXPAND_FAILED;
4128       if (!skipping)
4129         yield = string_cat(yield, &size, &ptr, encoded, Ustrlen(encoded));
4130       continue;
4131       }
4132 #endif
4133
4134     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4135     expanding an internal string that isn't actually going to be used. All we
4136     need to do is check the syntax, so don't do a lookup at all. Preserve the
4137     values of the numerical expansion variables in case they get changed by a
4138     partial lookup. If not, they retain their external settings. At the end
4139     of this "lookup" section, they get restored to their previous values. */
4140
4141     case EITEM_LOOKUP:
4142       {
4143       int stype, partial, affixlen, starflags;
4144       int expand_setup = 0;
4145       int nameptr = 0;
4146       uschar *key, *filename;
4147       const uschar *affix;
4148       uschar *save_lookup_value = lookup_value;
4149       int save_expand_nmax =
4150         save_expand_strings(save_expand_nstring, save_expand_nlength);
4151
4152       if ((expand_forbid & RDO_LOOKUP) != 0)
4153         {
4154         expand_string_message = US"lookup expansions are not permitted";
4155         goto EXPAND_FAILED;
4156         }
4157
4158       /* Get the key we are to look up for single-key+file style lookups.
4159       Otherwise set the key NULL pro-tem. */
4160
4161       while (isspace(*s)) s++;
4162       if (*s == '{')                                    /*}*/
4163         {
4164         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4165         if (key == NULL) goto EXPAND_FAILED;            /*{*/
4166         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4167         while (isspace(*s)) s++;
4168         }
4169       else key = NULL;
4170
4171       /* Find out the type of database */
4172
4173       if (!isalpha(*s))
4174         {
4175         expand_string_message = US"missing lookup type";
4176         goto EXPAND_FAILED;
4177         }
4178
4179       /* The type is a string that may contain special characters of various
4180       kinds. Allow everything except space or { to appear; the actual content
4181       is checked by search_findtype_partial. */         /*}*/
4182
4183       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4184         {
4185         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4186         s++;
4187         }
4188       name[nameptr] = 0;
4189       while (isspace(*s)) s++;
4190
4191       /* Now check for the individual search type and any partial or default
4192       options. Only those types that are actually in the binary are valid. */
4193
4194       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4195         &starflags);
4196       if (stype < 0)
4197         {
4198         expand_string_message = search_error_message;
4199         goto EXPAND_FAILED;
4200         }
4201
4202       /* Check that a key was provided for those lookup types that need it,
4203       and was not supplied for those that use the query style. */
4204
4205       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4206         {
4207         if (key == NULL)
4208           {
4209           expand_string_message = string_sprintf("missing {key} for single-"
4210             "key \"%s\" lookup", name);
4211           goto EXPAND_FAILED;
4212           }
4213         }
4214       else
4215         {
4216         if (key != NULL)
4217           {
4218           expand_string_message = string_sprintf("a single key was given for "
4219             "lookup type \"%s\", which is not a single-key lookup type", name);
4220           goto EXPAND_FAILED;
4221           }
4222         }
4223
4224       /* Get the next string in brackets and expand it. It is the file name for
4225       single-key+file lookups, and the whole query otherwise. In the case of
4226       queries that also require a file name (e.g. sqlite), the file name comes
4227       first. */
4228
4229       if (*s != '{') goto EXPAND_FAILED_CURLY;
4230       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4231       if (filename == NULL) goto EXPAND_FAILED;
4232       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4233       while (isspace(*s)) s++;
4234
4235       /* If this isn't a single-key+file lookup, re-arrange the variables
4236       to be appropriate for the search_ functions. For query-style lookups,
4237       there is just a "key", and no file name. For the special query-style +
4238       file types, the query (i.e. "key") starts with a file name. */
4239
4240       if (key == NULL)
4241         {
4242         while (isspace(*filename)) filename++;
4243         key = filename;
4244
4245         if (mac_islookup(stype, lookup_querystyle))
4246           {
4247           filename = NULL;
4248           }
4249         else
4250           {
4251           if (*filename != '/')
4252             {
4253             expand_string_message = string_sprintf(
4254               "absolute file name expected for \"%s\" lookup", name);
4255             goto EXPAND_FAILED;
4256             }
4257           while (*key != 0 && !isspace(*key)) key++;
4258           if (*key != 0) *key++ = 0;
4259           }
4260         }
4261
4262       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4263       the entry was not found. Note that there is no search_close() function.
4264       Files are left open in case of re-use. At suitable places in higher logic,
4265       search_tidyup() is called to tidy all open files. This can save opening
4266       the same file several times. However, files may also get closed when
4267       others are opened, if too many are open at once. The rule is that a
4268       handle should not be used after a second search_open().
4269
4270       Request that a partial search sets up $1 and maybe $2 by passing
4271       expand_setup containing zero. If its value changes, reset expand_nmax,
4272       since new variables will have been set. Note that at the end of this
4273       "lookup" section, the old numeric variables are restored. */
4274
4275       if (skipping)
4276         lookup_value = NULL;
4277       else
4278         {
4279         void *handle = search_open(filename, stype, 0, NULL, NULL);
4280         if (handle == NULL)
4281           {
4282           expand_string_message = search_error_message;
4283           goto EXPAND_FAILED;
4284           }
4285         lookup_value = search_find(handle, filename, key, partial, affix,
4286           affixlen, starflags, &expand_setup);
4287         if (search_find_defer)
4288           {
4289           expand_string_message =
4290             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4291               string_printing2(key, FALSE), search_error_message);
4292           goto EXPAND_FAILED;
4293           }
4294         if (expand_setup > 0) expand_nmax = expand_setup;
4295         }
4296
4297       /* The handling of "yes" and "no" result strings is now in a separate
4298       function that is also used by ${if} and ${extract}. */
4299
4300       switch(process_yesno(
4301                skipping,                     /* were previously skipping */
4302                lookup_value != NULL,         /* success/failure indicator */
4303                save_lookup_value,            /* value to reset for string2 */
4304                &s,                           /* input pointer */
4305                &yield,                       /* output pointer */
4306                &size,                        /* output size */
4307                &ptr,                         /* output current point */
4308                US"lookup",                   /* condition type */
4309                &resetok))
4310         {
4311         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4312         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4313         }
4314
4315       /* Restore external setting of expansion variables for carrying on
4316       at this level, and continue. */
4317
4318       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4319         save_expand_nlength);
4320       continue;
4321       }
4322
4323     /* If Perl support is configured, handle calling embedded perl subroutines,
4324     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4325     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4326     arguments (defined below). */
4327
4328     #define EXIM_PERL_MAX_ARGS 8
4329
4330     case EITEM_PERL:
4331     #ifndef EXIM_PERL
4332     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4333       "is not included in this binary";
4334     goto EXPAND_FAILED;
4335
4336     #else   /* EXIM_PERL */
4337       {
4338       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4339       uschar *new_yield;
4340
4341       if ((expand_forbid & RDO_PERL) != 0)
4342         {
4343         expand_string_message = US"Perl calls are not permitted";
4344         goto EXPAND_FAILED;
4345         }
4346
4347       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4348            US"perl", &resetok))
4349         {
4350         case 1: goto EXPAND_FAILED_CURLY;
4351         case 2:
4352         case 3: goto EXPAND_FAILED;
4353         }
4354
4355       /* If skipping, we don't actually do anything */
4356
4357       if (skipping) continue;
4358
4359       /* Start the interpreter if necessary */
4360
4361       if (!opt_perl_started)
4362         {
4363         uschar *initerror;
4364         if (opt_perl_startup == NULL)
4365           {
4366           expand_string_message = US"A setting of perl_startup is needed when "
4367             "using the Perl interpreter";
4368           goto EXPAND_FAILED;
4369           }
4370         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4371         initerror = init_perl(opt_perl_startup);
4372         if (initerror != NULL)
4373           {
4374           expand_string_message =
4375             string_sprintf("error in perl_startup code: %s\n", initerror);
4376           goto EXPAND_FAILED;
4377           }
4378         opt_perl_started = TRUE;
4379         }
4380
4381       /* Call the function */
4382
4383       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4384       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4385         sub_arg[0], sub_arg + 1);
4386
4387       /* NULL yield indicates failure; if the message pointer has been set to
4388       NULL, the yield was undef, indicating a forced failure. Otherwise the
4389       message will indicate some kind of Perl error. */
4390
4391       if (new_yield == NULL)
4392         {
4393         if (expand_string_message == NULL)
4394           {
4395           expand_string_message =
4396             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4397               "failure", sub_arg[0]);
4398           expand_string_forcedfail = TRUE;
4399           }
4400         goto EXPAND_FAILED;
4401         }
4402
4403       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4404       set during a callback from Perl. */
4405
4406       expand_string_forcedfail = FALSE;
4407       yield = new_yield;
4408       continue;
4409       }
4410     #endif /* EXIM_PERL */
4411
4412     /* Transform email address to "prvs" scheme to use
4413        as BATV-signed return path */
4414
4415     case EITEM_PRVS:
4416       {
4417       uschar *sub_arg[3];
4418       uschar *p,*domain;
4419
4420       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4421         {
4422         case 1: goto EXPAND_FAILED_CURLY;
4423         case 2:
4424         case 3: goto EXPAND_FAILED;
4425         }
4426
4427       /* If skipping, we don't actually do anything */
4428       if (skipping) continue;
4429
4430       /* sub_arg[0] is the address */
4431       domain = Ustrrchr(sub_arg[0],'@');
4432       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4433         {
4434         expand_string_message = US"prvs first argument must be a qualified email address";
4435         goto EXPAND_FAILED;
4436         }
4437
4438       /* Calculate the hash. The second argument must be a single-digit
4439       key number, or unset. */
4440
4441       if (sub_arg[2] != NULL &&
4442           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4443         {
4444         expand_string_message = US"prvs second argument must be a single digit";
4445         goto EXPAND_FAILED;
4446         }
4447
4448       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4449       if (p == NULL)
4450         {
4451         expand_string_message = US"prvs hmac-sha1 conversion failed";
4452         goto EXPAND_FAILED;
4453         }
4454
4455       /* Now separate the domain from the local part */
4456       *domain++ = '\0';
4457
4458       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4459       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4460       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4461       string_cat(yield,&size,&ptr,p,6);
4462       string_cat(yield,&size,&ptr,US"=",1);
4463       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4464       string_cat(yield,&size,&ptr,US"@",1);
4465       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4466
4467       continue;
4468       }
4469
4470     /* Check a prvs-encoded address for validity */
4471
4472     case EITEM_PRVSCHECK:
4473       {
4474       uschar *sub_arg[3];
4475       int mysize = 0, myptr = 0;
4476       const pcre *re;
4477       uschar *p;
4478
4479       /* TF: Ugliness: We want to expand parameter 1 first, then set
4480          up expansion variables that are used in the expansion of
4481          parameter 2. So we clone the string for the first
4482          expansion, where we only expand parameter 1.
4483
4484          PH: Actually, that isn't necessary. The read_subs() function is
4485          designed to work this way for the ${if and ${lookup expansions. I've
4486          tidied the code.
4487       */
4488
4489       /* Reset expansion variables */
4490       prvscheck_result = NULL;
4491       prvscheck_address = NULL;
4492       prvscheck_keynum = NULL;
4493
4494       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4495         {
4496         case 1: goto EXPAND_FAILED_CURLY;
4497         case 2:
4498         case 3: goto EXPAND_FAILED;
4499         }
4500
4501       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4502                               TRUE,FALSE);
4503
4504       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4505         {
4506         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4507         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4508         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4509         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4510         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4511
4512         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4513         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4514         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4515         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4516         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4517
4518         /* Set up expansion variables */
4519         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4520         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4521         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4522         prvscheck_address[myptr] = '\0';
4523         prvscheck_keynum = string_copy(key_num);
4524
4525         /* Now expand the second argument */
4526         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4527           {
4528           case 1: goto EXPAND_FAILED_CURLY;
4529           case 2:
4530           case 3: goto EXPAND_FAILED;
4531           }
4532
4533         /* Now we have the key and can check the address. */
4534
4535         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4536           daystamp);
4537
4538         if (p == NULL)
4539           {
4540           expand_string_message = US"hmac-sha1 conversion failed";
4541           goto EXPAND_FAILED;
4542           }
4543
4544         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4545         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4546
4547         if (Ustrcmp(p,hash) == 0)
4548           {
4549           /* Success, valid BATV address. Now check the expiry date. */
4550           uschar *now = prvs_daystamp(0);
4551           unsigned int inow = 0,iexpire = 1;
4552
4553           (void)sscanf(CS now,"%u",&inow);
4554           (void)sscanf(CS daystamp,"%u",&iexpire);
4555
4556           /* When "iexpire" is < 7, a "flip" has occured.
4557              Adjust "inow" accordingly. */
4558           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4559
4560           if (iexpire >= inow)
4561             {
4562             prvscheck_result = US"1";
4563             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4564             }
4565             else
4566             {
4567             prvscheck_result = NULL;
4568             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4569             }
4570           }
4571         else
4572           {
4573           prvscheck_result = NULL;
4574           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4575           }
4576
4577         /* Now expand the final argument. We leave this till now so that
4578         it can include $prvscheck_result. */
4579
4580         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4581           {
4582           case 1: goto EXPAND_FAILED_CURLY;
4583           case 2:
4584           case 3: goto EXPAND_FAILED;
4585           }
4586
4587         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4588           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4589         else
4590           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4591
4592         /* Reset the "internal" variables afterwards, because they are in
4593         dynamic store that will be reclaimed if the expansion succeeded. */
4594
4595         prvscheck_address = NULL;
4596         prvscheck_keynum = NULL;
4597         }
4598       else
4599         {
4600         /* Does not look like a prvs encoded address, return the empty string.
4601            We need to make sure all subs are expanded first, so as to skip over
4602            the entire item. */
4603
4604         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4605           {
4606           case 1: goto EXPAND_FAILED_CURLY;
4607           case 2:
4608           case 3: goto EXPAND_FAILED;
4609           }
4610         }
4611
4612       continue;
4613       }
4614
4615     /* Handle "readfile" to insert an entire file */
4616
4617     case EITEM_READFILE:
4618       {
4619       FILE *f;
4620       uschar *sub_arg[2];
4621
4622       if ((expand_forbid & RDO_READFILE) != 0)
4623         {
4624         expand_string_message = US"file insertions are not permitted";
4625         goto EXPAND_FAILED;
4626         }
4627
4628       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4629         {
4630         case 1: goto EXPAND_FAILED_CURLY;
4631         case 2:
4632         case 3: goto EXPAND_FAILED;
4633         }
4634
4635       /* If skipping, we don't actually do anything */
4636
4637       if (skipping) continue;
4638
4639       /* Open the file and read it */
4640
4641       f = Ufopen(sub_arg[0], "rb");
4642       if (f == NULL)
4643         {
4644         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4645         goto EXPAND_FAILED;
4646         }
4647
4648       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4649       (void)fclose(f);
4650       continue;
4651       }
4652
4653     /* Handle "readsocket" to insert data from a Unix domain socket */
4654
4655     case EITEM_READSOCK:
4656       {
4657       int fd;
4658       int timeout = 5;
4659       int save_ptr = ptr;
4660       FILE *f;
4661       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4662       uschar *arg;
4663       uschar *sub_arg[4];
4664
4665       if ((expand_forbid & RDO_READSOCK) != 0)
4666         {
4667         expand_string_message = US"socket insertions are not permitted";
4668         goto EXPAND_FAILED;
4669         }
4670
4671       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4672       because there may be a string for expansion on failure. */
4673
4674       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4675         {
4676         case 1: goto EXPAND_FAILED_CURLY;
4677         case 2:                             /* Won't occur: no end check */
4678         case 3: goto EXPAND_FAILED;
4679         }
4680
4681       /* Sort out timeout, if given */
4682
4683       if (sub_arg[2] != NULL)
4684         {
4685         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4686         if (timeout < 0)
4687           {
4688           expand_string_message = string_sprintf("bad time value %s",
4689             sub_arg[2]);
4690           goto EXPAND_FAILED;
4691           }
4692         }
4693       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4694
4695       /* If skipping, we don't actually do anything. Otherwise, arrange to
4696       connect to either an IP or a Unix socket. */
4697
4698       if (!skipping)
4699         {
4700         /* Handle an IP (internet) domain */
4701
4702         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4703           {
4704           int port;
4705           uschar *server_name = sub_arg[0] + 5;
4706           uschar *port_name = Ustrrchr(server_name, ':');
4707
4708           /* Sort out the port */
4709
4710           if (port_name == NULL)
4711             {
4712             expand_string_message =
4713               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4714             goto EXPAND_FAILED;
4715             }
4716           *port_name++ = 0;           /* Terminate server name */
4717
4718           if (isdigit(*port_name))
4719             {
4720             uschar *end;
4721             port = Ustrtol(port_name, &end, 0);
4722             if (end != port_name + Ustrlen(port_name))
4723               {
4724               expand_string_message =
4725                 string_sprintf("invalid port number %s", port_name);
4726               goto EXPAND_FAILED;
4727               }
4728             }
4729           else
4730             {
4731             struct servent *service_info = getservbyname(CS port_name, "tcp");
4732             if (service_info == NULL)
4733               {
4734               expand_string_message = string_sprintf("unknown port \"%s\"",
4735                 port_name);
4736               goto EXPAND_FAILED;
4737               }
4738             port = ntohs(service_info->s_port);
4739             }
4740
4741           if ((fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4742                   timeout, NULL, &expand_string_message)) < 0)
4743               goto SOCK_FAIL;
4744           }
4745
4746         /* Handle a Unix domain socket */
4747
4748         else
4749           {
4750           int rc;
4751           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4752             {
4753             expand_string_message = string_sprintf("failed to create socket: %s",
4754               strerror(errno));
4755             goto SOCK_FAIL;
4756             }
4757
4758           sockun.sun_family = AF_UNIX;
4759           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4760             sub_arg[0]);
4761
4762           sigalrm_seen = FALSE;
4763           alarm(timeout);
4764           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4765           alarm(0);
4766           if (sigalrm_seen)
4767             {
4768             expand_string_message = US "socket connect timed out";
4769             goto SOCK_FAIL;
4770             }
4771           if (rc < 0)
4772             {
4773             expand_string_message = string_sprintf("failed to connect to socket "
4774               "%s: %s", sub_arg[0], strerror(errno));
4775             goto SOCK_FAIL;
4776             }
4777           }
4778
4779         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4780
4781         /* Allow sequencing of test actions */
4782         if (running_in_test_harness) millisleep(100);
4783
4784         /* Write the request string, if not empty */
4785
4786         if (sub_arg[1][0] != 0)
4787           {
4788           int len = Ustrlen(sub_arg[1]);
4789           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4790             sub_arg[1]);
4791           if (write(fd, sub_arg[1], len) != len)
4792             {
4793             expand_string_message = string_sprintf("request write to socket "
4794               "failed: %s", strerror(errno));
4795             goto SOCK_FAIL;
4796             }
4797           }
4798
4799         /* Shut down the sending side of the socket. This helps some servers to
4800         recognise that it is their turn to do some work. Just in case some
4801         system doesn't have this function, make it conditional. */
4802
4803         #ifdef SHUT_WR
4804         shutdown(fd, SHUT_WR);
4805         #endif
4806
4807         if (running_in_test_harness) millisleep(100);
4808
4809         /* Now we need to read from the socket, under a timeout. The function
4810         that reads a file can be used. */
4811
4812         f = fdopen(fd, "rb");
4813         sigalrm_seen = FALSE;
4814         alarm(timeout);
4815         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4816         alarm(0);
4817         (void)fclose(f);
4818
4819         /* After a timeout, we restore the pointer in the result, that is,
4820         make sure we add nothing from the socket. */
4821
4822         if (sigalrm_seen)
4823           {
4824           ptr = save_ptr;
4825           expand_string_message = US "socket read timed out";
4826           goto SOCK_FAIL;
4827           }
4828         }
4829
4830       /* The whole thing has worked (or we were skipping). If there is a
4831       failure string following, we need to skip it. */
4832
4833       if (*s == '{')
4834         {
4835         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4836           goto EXPAND_FAILED;
4837         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4838         while (isspace(*s)) s++;
4839         }
4840       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4841       continue;
4842
4843       /* Come here on failure to create socket, connect socket, write to the
4844       socket, or timeout on reading. If another substring follows, expand and
4845       use it. Otherwise, those conditions give expand errors. */
4846
4847       SOCK_FAIL:
4848       if (*s != '{') goto EXPAND_FAILED;
4849       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4850       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok);
4851       if (arg == NULL) goto EXPAND_FAILED;
4852       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4853       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4854       while (isspace(*s)) s++;
4855       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4856       continue;
4857       }
4858
4859     /* Handle "run" to execute a program. */
4860
4861     case EITEM_RUN:
4862       {
4863       FILE *f;
4864       uschar *arg;
4865       const uschar **argv;
4866       pid_t pid;
4867       int fd_in, fd_out;
4868       int lsize = 0;
4869       int lptr = 0;
4870
4871       if ((expand_forbid & RDO_RUN) != 0)
4872         {
4873         expand_string_message = US"running a command is not permitted";
4874         goto EXPAND_FAILED;
4875         }
4876
4877       while (isspace(*s)) s++;
4878       if (*s != '{') goto EXPAND_FAILED_CURLY;
4879       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4880       if (arg == NULL) goto EXPAND_FAILED;
4881       while (isspace(*s)) s++;
4882       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4883
4884       if (skipping)   /* Just pretend it worked when we're skipping */
4885         {
4886         runrc = 0;
4887         }
4888       else
4889         {
4890         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4891             arg,                                /* raw command */
4892             FALSE,                              /* don't expand the arguments */
4893             0,                                  /* not relevant when... */
4894             NULL,                               /* no transporting address */
4895             US"${run} expansion",               /* for error messages */
4896             &expand_string_message))            /* where to put error message */
4897           {
4898           goto EXPAND_FAILED;
4899           }
4900
4901         /* Create the child process, making it a group leader. */
4902
4903         pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4904
4905         if (pid < 0)
4906           {
4907           expand_string_message =
4908             string_sprintf("couldn't create child process: %s", strerror(errno));
4909           goto EXPAND_FAILED;
4910           }
4911
4912         /* Nothing is written to the standard input. */
4913
4914         (void)close(fd_in);
4915
4916         /* Read the pipe to get the command's output into $value (which is kept
4917         in lookup_value). Read during execution, so that if the output exceeds
4918         the OS pipe buffer limit, we don't block forever. */
4919
4920         f = fdopen(fd_out, "rb");
4921         sigalrm_seen = FALSE;
4922         alarm(60);
4923         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4924         alarm(0);
4925         (void)fclose(f);
4926
4927         /* Wait for the process to finish, applying the timeout, and inspect its
4928         return code for serious disasters. Simple non-zero returns are passed on.
4929         */
4930
4931         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4932           {
4933           if (sigalrm_seen == TRUE || runrc == -256)
4934             {
4935             expand_string_message = string_sprintf("command timed out");
4936             killpg(pid, SIGKILL);       /* Kill the whole process group */
4937             }
4938
4939           else if (runrc == -257)
4940             expand_string_message = string_sprintf("wait() failed: %s",
4941               strerror(errno));
4942
4943           else
4944             expand_string_message = string_sprintf("command killed by signal %d",
4945               -runrc);
4946
4947           goto EXPAND_FAILED;
4948           }
4949         }
4950
4951       /* Process the yes/no strings; $value may be useful in both cases */
4952
4953       switch(process_yesno(
4954                skipping,                     /* were previously skipping */
4955                runrc == 0,                   /* success/failure indicator */
4956                lookup_value,                 /* value to reset for string2 */
4957                &s,                           /* input pointer */
4958                &yield,                       /* output pointer */
4959                &size,                        /* output size */
4960                &ptr,                         /* output current point */
4961                US"run",                      /* condition type */
4962                &resetok))
4963         {
4964         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4965         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4966         }
4967
4968       continue;
4969       }
4970
4971     /* Handle character translation for "tr" */
4972
4973     case EITEM_TR:
4974       {
4975       int oldptr = ptr;
4976       int o2m;
4977       uschar *sub[3];
4978
4979       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
4980         {
4981         case 1: goto EXPAND_FAILED_CURLY;
4982         case 2:
4983         case 3: goto EXPAND_FAILED;
4984         }
4985
4986       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4987       o2m = Ustrlen(sub[2]) - 1;
4988
4989       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4990         {
4991         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4992         if (m != NULL)
4993           {
4994           int o = m - sub[1];
4995           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4996           }
4997         }
4998
4999       continue;
5000       }
5001
5002     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5003     expanded arguments. */
5004
5005     case EITEM_HASH:
5006     case EITEM_LENGTH:
5007     case EITEM_NHASH:
5008     case EITEM_SUBSTR:
5009       {
5010       int i;
5011       int len;
5012       uschar *ret;
5013       int val[2] = { 0, -1 };
5014       uschar *sub[3];
5015
5016       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5017       Ensure that sub[2] is set in the ${length } case. */
5018
5019       sub[2] = NULL;
5020       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5021              TRUE, name, &resetok))
5022         {
5023         case 1: goto EXPAND_FAILED_CURLY;
5024         case 2:
5025         case 3: goto EXPAND_FAILED;
5026         }
5027
5028       /* Juggle the arguments if there are only two of them: always move the
5029       string to the last position and make ${length{n}{str}} equivalent to
5030       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5031
5032       if (sub[2] == NULL)
5033         {
5034         sub[2] = sub[1];
5035         sub[1] = NULL;
5036         if (item_type == EITEM_LENGTH)
5037           {
5038           sub[1] = sub[0];
5039           sub[0] = NULL;
5040           }
5041         }
5042
5043       for (i = 0; i < 2; i++)
5044         {
5045         if (sub[i] == NULL) continue;
5046         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5047         if (*ret != 0 || (i != 0 && val[i] < 0))
5048           {
5049           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5050             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5051           goto EXPAND_FAILED;
5052           }
5053         }
5054
5055       ret =
5056         (item_type == EITEM_HASH)?
5057           compute_hash(sub[2], val[0], val[1], &len) :
5058         (item_type == EITEM_NHASH)?
5059           compute_nhash(sub[2], val[0], val[1], &len) :
5060           extract_substr(sub[2], val[0], val[1], &len);
5061
5062       if (ret == NULL) goto EXPAND_FAILED;
5063       yield = string_cat(yield, &size, &ptr, ret, len);
5064       continue;
5065       }
5066
5067     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5068     This code originally contributed by Steve Haslam. It currently supports
5069     the use of MD5 and SHA-1 hashes.
5070
5071     We need some workspace that is large enough to handle all the supported
5072     hash types. Use macros to set the sizes rather than be too elaborate. */
5073
5074     #define MAX_HASHLEN      20
5075     #define MAX_HASHBLOCKLEN 64
5076
5077     case EITEM_HMAC:
5078       {
5079       uschar *sub[3];
5080       md5 md5_base;
5081       sha1 sha1_base;
5082       void *use_base;
5083       int type, i;
5084       int hashlen;      /* Number of octets for the hash algorithm's output */
5085       int hashblocklen; /* Number of octets the hash algorithm processes */
5086       uschar *keyptr, *p;
5087       unsigned int keylen;
5088
5089       uschar keyhash[MAX_HASHLEN];
5090       uschar innerhash[MAX_HASHLEN];
5091       uschar finalhash[MAX_HASHLEN];
5092       uschar finalhash_hex[2*MAX_HASHLEN];
5093       uschar innerkey[MAX_HASHBLOCKLEN];
5094       uschar outerkey[MAX_HASHBLOCKLEN];
5095
5096       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5097         {
5098         case 1: goto EXPAND_FAILED_CURLY;
5099         case 2:
5100         case 3: goto EXPAND_FAILED;
5101         }
5102
5103       if (Ustrcmp(sub[0], "md5") == 0)
5104         {
5105         type = HMAC_MD5;
5106         use_base = &md5_base;
5107         hashlen = 16;
5108         hashblocklen = 64;
5109         }
5110       else if (Ustrcmp(sub[0], "sha1") == 0)
5111         {
5112         type = HMAC_SHA1;
5113         use_base = &sha1_base;
5114         hashlen = 20;
5115         hashblocklen = 64;
5116         }
5117       else
5118         {
5119         expand_string_message =
5120           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5121         goto EXPAND_FAILED;
5122         }
5123
5124       keyptr = sub[1];
5125       keylen = Ustrlen(keyptr);
5126
5127       /* If the key is longer than the hash block length, then hash the key
5128       first */
5129
5130       if (keylen > hashblocklen)
5131         {
5132         chash_start(type, use_base);
5133         chash_end(type, use_base, keyptr, keylen, keyhash);
5134         keyptr = keyhash;
5135         keylen = hashlen;
5136         }
5137
5138       /* Now make the inner and outer key values */
5139
5140       memset(innerkey, 0x36, hashblocklen);
5141       memset(outerkey, 0x5c, hashblocklen);
5142
5143       for (i = 0; i < keylen; i++)
5144         {
5145         innerkey[i] ^= keyptr[i];
5146         outerkey[i] ^= keyptr[i];
5147         }
5148
5149       /* Now do the hashes */
5150
5151       chash_start(type, use_base);
5152       chash_mid(type, use_base, innerkey);
5153       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5154
5155       chash_start(type, use_base);
5156       chash_mid(type, use_base, outerkey);
5157       chash_end(type, use_base, innerhash, hashlen, finalhash);
5158
5159       /* Encode the final hash as a hex string */
5160
5161       p = finalhash_hex;
5162       for (i = 0; i < hashlen; i++)
5163         {
5164         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5165         *p++ = hex_digits[finalhash[i] & 0x0f];
5166         }
5167
5168       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
5169         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
5170
5171       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
5172       }
5173
5174     continue;
5175
5176     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5177     We have to save the numerical variables and restore them afterwards. */
5178
5179     case EITEM_SG:
5180       {
5181       const pcre *re;
5182       int moffset, moffsetextra, slen;
5183       int roffset;
5184       int emptyopt;
5185       const uschar *rerror;
5186       uschar *subject;
5187       uschar *sub[3];
5188       int save_expand_nmax =
5189         save_expand_strings(save_expand_nstring, save_expand_nlength);
5190
5191       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5192         {
5193         case 1: goto EXPAND_FAILED_CURLY;
5194         case 2:
5195         case 3: goto EXPAND_FAILED;
5196         }
5197
5198       /* Compile the regular expression */
5199
5200       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5201         NULL);
5202
5203       if (re == NULL)
5204         {
5205         expand_string_message = string_sprintf("regular expression error in "
5206           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5207         goto EXPAND_FAILED;
5208         }
5209
5210       /* Now run a loop to do the substitutions as often as necessary. It ends
5211       when there are no more matches. Take care over matches of the null string;
5212       do the same thing as Perl does. */
5213
5214       subject = sub[0];
5215       slen = Ustrlen(sub[0]);
5216       moffset = moffsetextra = 0;
5217       emptyopt = 0;
5218
5219       for (;;)
5220         {
5221         int ovector[3*(EXPAND_MAXN+1)];
5222         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5223           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5224         int nn;
5225         uschar *insert;
5226
5227         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5228         is not necessarily the end. We want to repeat the match from one
5229         character further along, but leaving the basic offset the same (for
5230         copying below). We can't be at the end of the string - that was checked
5231         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5232         finished; copy the remaining string and end the loop. */
5233
5234         if (n < 0)
5235           {
5236           if (emptyopt != 0)
5237             {
5238             moffsetextra = 1;
5239             emptyopt = 0;
5240             continue;
5241             }
5242           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5243           break;
5244           }
5245
5246         /* Match - set up for expanding the replacement. */
5247
5248         if (n == 0) n = EXPAND_MAXN + 1;
5249         expand_nmax = 0;
5250         for (nn = 0; nn < n*2; nn += 2)
5251           {
5252           expand_nstring[expand_nmax] = subject + ovector[nn];
5253           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5254           }
5255         expand_nmax--;
5256
5257         /* Copy the characters before the match, plus the expanded insertion. */
5258
5259         yield = string_cat(yield, &size, &ptr, subject + moffset,
5260           ovector[0] - moffset);
5261         insert = expand_string(sub[2]);
5262         if (insert == NULL) goto EXPAND_FAILED;
5263         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5264
5265         moffset = ovector[1];
5266         moffsetextra = 0;
5267         emptyopt = 0;
5268
5269         /* If we have matched an empty string, first check to see if we are at
5270         the end of the subject. If so, the loop is over. Otherwise, mimic
5271         what Perl's /g options does. This turns out to be rather cunning. First
5272         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5273         string at the same point. If this fails (picked up above) we advance to
5274         the next character. */
5275
5276         if (ovector[0] == ovector[1])
5277           {
5278           if (ovector[0] == slen) break;
5279           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5280           }
5281         }
5282
5283       /* All done - restore numerical variables. */
5284
5285       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5286         save_expand_nlength);
5287       continue;
5288       }
5289
5290     /* Handle keyed and numbered substring extraction. If the first argument
5291     consists entirely of digits, then a numerical extraction is assumed. */
5292
5293     case EITEM_EXTRACT:
5294       {
5295       int i;
5296       int j = 2;
5297       int field_number = 1;
5298       BOOL field_number_set = FALSE;
5299       uschar *save_lookup_value = lookup_value;
5300       uschar *sub[3];
5301       int save_expand_nmax =
5302         save_expand_strings(save_expand_nstring, save_expand_nlength);
5303
5304       /* Read the arguments */
5305
5306       for (i = 0; i < j; i++)
5307         {
5308         while (isspace(*s)) s++;
5309         if (*s == '{')                                          /*}*/
5310           {
5311           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5312           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5313           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5314
5315           /* After removal of leading and trailing white space, the first
5316           argument must not be empty; if it consists entirely of digits
5317           (optionally preceded by a minus sign), this is a numerical
5318           extraction, and we expect 3 arguments. */
5319
5320           if (i == 0)
5321             {
5322             int len;
5323             int x = 0;
5324             uschar *p = sub[0];
5325
5326             while (isspace(*p)) p++;
5327             sub[0] = p;
5328
5329             len = Ustrlen(p);
5330             while (len > 0 && isspace(p[len-1])) len--;
5331             p[len] = 0;
5332
5333             if (!skipping)
5334               {
5335               if (*p == 0)
5336                 {
5337                 expand_string_message = US"first argument of \"extract\" must "
5338                   "not be empty";
5339                 goto EXPAND_FAILED;
5340                 }
5341
5342               if (*p == '-')
5343                 {
5344                 field_number = -1;
5345                 p++;
5346                 }
5347               while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5348               if (*p == 0)
5349                 {
5350                 field_number *= x;
5351                 j = 3;               /* Need 3 args */
5352                 field_number_set = TRUE;
5353                 }
5354               }
5355             }
5356           }
5357         else goto EXPAND_FAILED_CURLY;
5358         }
5359
5360       /* Extract either the numbered or the keyed substring into $value. If
5361       skipping, just pretend the extraction failed. */
5362
5363       lookup_value = skipping? NULL : field_number_set?
5364         expand_gettokened(field_number, sub[1], sub[2]) :
5365         expand_getkeyed(sub[0], sub[1]);
5366
5367       /* If no string follows, $value gets substituted; otherwise there can
5368       be yes/no strings, as for lookup or if. */
5369
5370       switch(process_yesno(
5371                skipping,                     /* were previously skipping */
5372                lookup_value != NULL,         /* success/failure indicator */
5373                save_lookup_value,            /* value to reset for string2 */
5374                &s,                           /* input pointer */
5375                &yield,                       /* output pointer */
5376                &size,                        /* output size */
5377                &ptr,                         /* output current point */
5378                US"extract",                  /* condition type */
5379                &resetok))
5380         {
5381         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5382         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5383         }
5384
5385       /* All done - restore numerical variables. */
5386
5387       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5388         save_expand_nlength);
5389
5390       continue;
5391       }
5392
5393     /* return the Nth item from a list */
5394
5395     case EITEM_LISTEXTRACT:
5396       {
5397       int i;
5398       int field_number = 1;
5399       uschar *save_lookup_value = lookup_value;
5400       uschar *sub[2];
5401       int save_expand_nmax =
5402         save_expand_strings(save_expand_nstring, save_expand_nlength);
5403
5404       /* Read the field & list arguments */
5405
5406       for (i = 0; i < 2; i++)
5407         {
5408         while (isspace(*s)) s++;
5409         if (*s != '{')                                  /*}*/
5410           goto EXPAND_FAILED_CURLY;
5411
5412         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5413         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5414         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5415
5416         /* After removal of leading and trailing white space, the first
5417         argument must be numeric and nonempty. */
5418
5419         if (i == 0)
5420           {
5421           int len;
5422           int x = 0;
5423           uschar *p = sub[0];
5424
5425           while (isspace(*p)) p++;
5426           sub[0] = p;
5427
5428           len = Ustrlen(p);
5429           while (len > 0 && isspace(p[len-1])) len--;
5430           p[len] = 0;
5431
5432           if (!*p && !skipping)
5433             {
5434             expand_string_message = US"first argument of \"listextract\" must "
5435               "not be empty";
5436             goto EXPAND_FAILED;
5437             }
5438
5439           if (*p == '-')
5440             {
5441             field_number = -1;
5442             p++;
5443             }
5444           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5445           if (*p)
5446             {
5447             expand_string_message = US"first argument of \"listextract\" must "
5448               "be numeric";
5449             goto EXPAND_FAILED;
5450             }
5451           field_number *= x;
5452           }
5453         }
5454
5455       /* Extract the numbered element into $value. If
5456       skipping, just pretend the extraction failed. */
5457
5458       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5459
5460       /* If no string follows, $value gets substituted; otherwise there can
5461       be yes/no strings, as for lookup or if. */
5462
5463       switch(process_yesno(
5464                skipping,                     /* were previously skipping */
5465                lookup_value != NULL,         /* success/failure indicator */
5466                save_lookup_value,            /* value to reset for string2 */
5467                &s,                           /* input pointer */
5468                &yield,                       /* output pointer */
5469                &size,                        /* output size */
5470                &ptr,                         /* output current point */
5471                US"extract",                  /* condition type */
5472                &resetok))
5473         {
5474         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5475         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5476         }
5477
5478       /* All done - restore numerical variables. */
5479
5480       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5481         save_expand_nlength);
5482
5483       continue;
5484       }
5485
5486 #ifdef SUPPORT_TLS
5487     case EITEM_CERTEXTRACT:
5488       {
5489       uschar *save_lookup_value = lookup_value;
5490       uschar *sub[2];
5491       int save_expand_nmax =
5492         save_expand_strings(save_expand_nstring, save_expand_nlength);
5493
5494       /* Read the field argument */
5495       while (isspace(*s)) s++;
5496       if (*s != '{')                                    /*}*/
5497         goto EXPAND_FAILED_CURLY;
5498       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5499       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5500       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5501       /* strip spaces fore & aft */
5502       {
5503       int len;
5504       uschar *p = sub[0];
5505
5506       while (isspace(*p)) p++;
5507       sub[0] = p;
5508
5509       len = Ustrlen(p);
5510       while (len > 0 && isspace(p[len-1])) len--;
5511       p[len] = 0;
5512       }
5513
5514       /* inspect the cert argument */
5515       while (isspace(*s)) s++;
5516       if (*s != '{')                                    /*}*/
5517         goto EXPAND_FAILED_CURLY;
5518       if (*++s != '$')
5519         {
5520         expand_string_message = US"second argument of \"certextract\" must "
5521           "be a certificate variable";
5522         goto EXPAND_FAILED;
5523         }
5524       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5525       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5526       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5527
5528       if (skipping)
5529         lookup_value = NULL;
5530       else
5531         {
5532         lookup_value = expand_getcertele(sub[0], sub[1]);
5533         if (*expand_string_message) goto EXPAND_FAILED;
5534         }
5535       switch(process_yesno(
5536                skipping,                     /* were previously skipping */
5537                lookup_value != NULL,         /* success/failure indicator */
5538                save_lookup_value,            /* value to reset for string2 */
5539                &s,                           /* input pointer */
5540                &yield,                       /* output pointer */
5541                &size,                        /* output size */
5542                &ptr,                         /* output current point */
5543                US"extract",                  /* condition type */
5544                &resetok))
5545         {
5546         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5547         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5548         }
5549
5550       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5551         save_expand_nlength);
5552       continue;
5553       }
5554 #endif  /*SUPPORT_TLS*/
5555
5556     /* Handle list operations */
5557
5558     case EITEM_FILTER:
5559     case EITEM_MAP:
5560     case EITEM_REDUCE:
5561       {
5562       int sep = 0;
5563       int save_ptr = ptr;
5564       uschar outsep[2] = { '\0', '\0' };
5565       const uschar *list, *expr, *temp;
5566       uschar *save_iterate_item = iterate_item;
5567       uschar *save_lookup_value = lookup_value;
5568
5569       while (isspace(*s)) s++;
5570       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5571
5572       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5573       if (list == NULL) goto EXPAND_FAILED;
5574       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5575
5576       if (item_type == EITEM_REDUCE)
5577         {
5578         uschar * t;
5579         while (isspace(*s)) s++;
5580         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5581         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5582         if (!t) goto EXPAND_FAILED;
5583         lookup_value = t;
5584         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5585         }
5586
5587       while (isspace(*s)) s++;
5588       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5589
5590       expr = s;
5591
5592       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5593       if scanning a "false" part). This allows us to find the end of the
5594       condition, because if the list is empty, we won't actually evaluate the
5595       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5596       the normal internal expansion function. */
5597
5598       if (item_type == EITEM_FILTER)
5599         {
5600         temp = eval_condition(expr, &resetok, NULL);
5601         if (temp != NULL) s = temp;
5602         }
5603       else
5604         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5605
5606       if (temp == NULL)
5607         {
5608         expand_string_message = string_sprintf("%s inside \"%s\" item",
5609           expand_string_message, name);
5610         goto EXPAND_FAILED;
5611         }
5612
5613       while (isspace(*s)) s++;
5614       if (*s++ != '}')
5615         {                                               /*{*/
5616         expand_string_message = string_sprintf("missing } at end of condition "
5617           "or expression inside \"%s\"", name);
5618         goto EXPAND_FAILED;
5619         }
5620
5621       while (isspace(*s)) s++;                          /*{*/
5622       if (*s++ != '}')
5623         {                                               /*{*/
5624         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5625           name);
5626         goto EXPAND_FAILED;
5627         }
5628
5629       /* If we are skipping, we can now just move on to the next item. When
5630       processing for real, we perform the iteration. */
5631
5632       if (skipping) continue;
5633       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5634         {
5635         *outsep = (uschar)sep;      /* Separator as a string */
5636
5637         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5638
5639         if (item_type == EITEM_FILTER)
5640           {
5641           BOOL condresult;
5642           if (eval_condition(expr, &resetok, &condresult) == NULL)
5643             {
5644             iterate_item = save_iterate_item;
5645             lookup_value = save_lookup_value;
5646             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5647               expand_string_message, name);
5648             goto EXPAND_FAILED;
5649             }
5650           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5651             condresult? "true":"false");
5652           if (condresult)
5653             temp = iterate_item;    /* TRUE => include this item */
5654           else
5655             continue;               /* FALSE => skip this item */
5656           }
5657
5658         /* EITEM_MAP and EITEM_REDUCE */
5659
5660         else
5661           {
5662           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5663           temp = t;
5664           if (temp == NULL)
5665             {
5666             iterate_item = save_iterate_item;
5667             expand_string_message = string_sprintf("%s inside \"%s\" item",
5668               expand_string_message, name);
5669             goto EXPAND_FAILED;
5670             }
5671           if (item_type == EITEM_REDUCE)
5672             {
5673             lookup_value = t;         /* Update the value of $value */
5674             continue;                 /* and continue the iteration */
5675             }
5676           }
5677
5678         /* We reach here for FILTER if the condition is true, always for MAP,
5679         and never for REDUCE. The value in "temp" is to be added to the output
5680         list that is being created, ensuring that any occurrences of the
5681         separator character are doubled. Unless we are dealing with the first
5682         item of the output list, add in a space if the new item begins with the
5683         separator character, or is an empty string. */
5684
5685         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5686           yield = string_cat(yield, &size, &ptr, US" ", 1);
5687
5688         /* Add the string in "temp" to the output list that we are building,
5689         This is done in chunks by searching for the separator character. */
5690
5691         for (;;)
5692           {
5693           size_t seglen = Ustrcspn(temp, outsep);
5694             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5695
5696           /* If we got to the end of the string we output one character
5697           too many; backup and end the loop. Otherwise arrange to double the
5698           separator. */
5699
5700           if (temp[seglen] == '\0') { ptr--; break; }
5701           yield = string_cat(yield, &size, &ptr, outsep, 1);
5702           temp += seglen + 1;
5703           }
5704
5705         /* Output a separator after the string: we will remove the redundant
5706         final one at the end. */
5707
5708         yield = string_cat(yield, &size, &ptr, outsep, 1);
5709         }   /* End of iteration over the list loop */
5710
5711       /* REDUCE has generated no output above: output the final value of
5712       $value. */
5713
5714       if (item_type == EITEM_REDUCE)
5715         {
5716         yield = string_cat(yield, &size, &ptr, lookup_value,
5717           Ustrlen(lookup_value));
5718         lookup_value = save_lookup_value;  /* Restore $value */
5719         }
5720
5721       /* FILTER and MAP generate lists: if they have generated anything, remove
5722       the redundant final separator. Even though an empty item at the end of a
5723       list does not count, this is tidier. */
5724
5725       else if (ptr != save_ptr) ptr--;
5726
5727       /* Restore preserved $item */
5728
5729       iterate_item = save_iterate_item;
5730       continue;
5731       }
5732
5733     case EITEM_SORT:
5734       {
5735       int sep = 0;
5736       const uschar *srclist, *cmp, *xtract;
5737       uschar *srcitem;
5738       const uschar *dstlist = NULL, *dstkeylist = NULL;
5739       uschar * tmp;
5740       uschar *save_iterate_item = iterate_item;
5741
5742       while (isspace(*s)) s++;
5743       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5744
5745       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5746       if (!srclist) goto EXPAND_FAILED;
5747       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5748
5749       while (isspace(*s)) s++;
5750       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5751
5752       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5753       if (!cmp) goto EXPAND_FAILED;
5754       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5755
5756       while (isspace(*s)) s++;
5757       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5758
5759       xtract = s;
5760       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5761       if (!tmp) goto EXPAND_FAILED;
5762       xtract = string_copyn(xtract, s - xtract);
5763
5764       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5765                                                         /*{*/
5766       if (*s++ != '}')
5767         {                                               /*{*/
5768         expand_string_message = US"missing } at end of \"sort\"";
5769         goto EXPAND_FAILED;
5770         }
5771
5772       if (skipping) continue;
5773
5774       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5775         {
5776         uschar * dstitem;
5777         uschar * newlist = NULL;
5778         uschar * newkeylist = NULL;
5779         uschar * srcfield;
5780
5781         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
5782
5783         /* extract field for comparisons */
5784         iterate_item = srcitem;
5785         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5786                                           TRUE, &resetok))
5787            || !*srcfield)
5788           {
5789           expand_string_message = string_sprintf(
5790               "field-extract in sort: \"%s\"", xtract);
5791           goto EXPAND_FAILED;
5792           }
5793
5794         /* Insertion sort */
5795
5796         /* copy output list until new-item < list-item */
5797         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5798           {
5799           uschar * dstfield;
5800           uschar * expr;
5801           BOOL before;
5802
5803           /* field for comparison */
5804           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5805             goto sort_mismatch;
5806
5807           /* build and run condition string */
5808           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
5809
5810           DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
5811           if (!eval_condition(expr, &resetok, &before))
5812             {
5813             expand_string_message = string_sprintf("comparison in sort: %s",
5814                 expr);
5815             goto EXPAND_FAILED;
5816             }
5817
5818           if (before)
5819             {
5820             /* New-item sorts before this dst-item.  Append new-item,
5821             then dst-item, then remainder of dst list. */
5822
5823             newlist = string_append_listele(newlist, sep, srcitem);
5824             newkeylist = string_append_listele(newkeylist, sep, srcfield);
5825             srcitem = NULL;
5826
5827             newlist = string_append_listele(newlist, sep, dstitem);
5828             newkeylist = string_append_listele(newkeylist, sep, dstfield);
5829
5830             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5831               {
5832               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5833                 goto sort_mismatch;
5834               newlist = string_append_listele(newlist, sep, dstitem);
5835               newkeylist = string_append_listele(newkeylist, sep, dstfield);
5836               }
5837
5838             break;
5839             }
5840
5841           newlist = string_append_listele(newlist, sep, dstitem);
5842           newkeylist = string_append_listele(newkeylist, sep, dstfield);
5843           }
5844
5845         /* If we ran out of dstlist without consuming srcitem, append it */
5846         if (srcitem)
5847           {
5848           newlist = string_append_listele(newlist, sep, srcitem);
5849           newkeylist = string_append_listele(newkeylist, sep, srcfield);
5850           }
5851
5852         dstlist = newlist;
5853         dstkeylist = newkeylist;
5854
5855         DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
5856         DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
5857         }
5858
5859       if (dstlist)
5860         yield = string_cat(yield, &size, &ptr, dstlist, Ustrlen(dstlist));
5861
5862       /* Restore preserved $item */
5863       iterate_item = save_iterate_item;
5864       continue;
5865
5866       sort_mismatch:
5867         expand_string_message = US"Internal error in sort (list mismatch)";
5868         goto EXPAND_FAILED;
5869       }
5870
5871
5872     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
5873     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5874     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5875     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5876
5877     #define EXPAND_DLFUNC_MAX_ARGS 8
5878
5879     case EITEM_DLFUNC:
5880 #ifndef EXPAND_DLFUNC
5881       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
5882         "is not included in this binary";
5883       goto EXPAND_FAILED;
5884
5885 #else   /* EXPAND_DLFUNC */
5886       {
5887       tree_node *t;
5888       exim_dlfunc_t *func;
5889       uschar *result;
5890       int status, argc;
5891       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5892
5893       if ((expand_forbid & RDO_DLFUNC) != 0)
5894         {
5895         expand_string_message =
5896           US"dynamically-loaded functions are not permitted";
5897         goto EXPAND_FAILED;
5898         }
5899
5900       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5901            TRUE, US"dlfunc", &resetok))
5902         {
5903         case 1: goto EXPAND_FAILED_CURLY;
5904         case 2:
5905         case 3: goto EXPAND_FAILED;
5906         }
5907
5908       /* If skipping, we don't actually do anything */
5909
5910       if (skipping) continue;
5911
5912       /* Look up the dynamically loaded object handle in the tree. If it isn't
5913       found, dlopen() the file and put the handle in the tree for next time. */
5914
5915       t = tree_search(dlobj_anchor, argv[0]);
5916       if (t == NULL)
5917         {
5918         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5919         if (handle == NULL)
5920           {
5921           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5922             argv[0], dlerror());
5923           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5924           goto EXPAND_FAILED;
5925           }
5926         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5927         Ustrcpy(t->name, argv[0]);
5928         t->data.ptr = handle;
5929         (void)tree_insertnode(&dlobj_anchor, t);
5930         }
5931
5932       /* Having obtained the dynamically loaded object handle, look up the
5933       function pointer. */
5934
5935       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5936       if (func == NULL)
5937         {
5938         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5939           "%s", argv[1], argv[0], dlerror());
5940         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5941         goto EXPAND_FAILED;
5942         }
5943
5944       /* Call the function and work out what to do with the result. If it
5945       returns OK, we have a replacement string; if it returns DEFER then
5946       expansion has failed in a non-forced manner; if it returns FAIL then
5947       failure was forced; if it returns ERROR or any other value there's a
5948       problem, so panic slightly. In any case, assume that the function has
5949       side-effects on the store that must be preserved. */
5950
5951       resetok = FALSE;
5952       result = NULL;
5953       for (argc = 0; argv[argc] != NULL; argc++);
5954       status = func(&result, argc - 2, &argv[2]);
5955       if(status == OK)
5956         {
5957         if (result == NULL) result = US"";
5958         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5959         continue;
5960         }
5961       else
5962         {
5963         expand_string_message = result == NULL ? US"(no message)" : result;
5964         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5965           else if(status != FAIL)
5966             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5967               argv[0], argv[1], status, expand_string_message);
5968         goto EXPAND_FAILED;
5969         }
5970       }
5971 #endif /* EXPAND_DLFUNC */
5972
5973     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
5974       {
5975       uschar * key;
5976       uschar *save_lookup_value = lookup_value;
5977
5978       while (isspace(*s)) s++;
5979       if (*s != '{')                                    /*}*/
5980         goto EXPAND_FAILED;
5981
5982       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5983       if (!key) goto EXPAND_FAILED;                     /*{*/
5984       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5985
5986       lookup_value = US getenv(CS key);
5987
5988       switch(process_yesno(
5989                skipping,                     /* were previously skipping */
5990                lookup_value != NULL,         /* success/failure indicator */
5991                save_lookup_value,            /* value to reset for string2 */
5992                &s,                           /* input pointer */
5993                &yield,                       /* output pointer */
5994                &size,                        /* output size */
5995                &ptr,                         /* output current point */
5996                US"env",                      /* condition type */
5997                &resetok))
5998         {
5999         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6000         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6001         }
6002       continue;
6003       }
6004     }   /* EITEM_* switch */
6005
6006   /* Control reaches here if the name is not recognized as one of the more
6007   complicated expansion items. Check for the "operator" syntax (name terminated
6008   by a colon). Some of the operators have arguments, separated by _ from the
6009   name. */
6010
6011   if (*s == ':')
6012     {
6013     int c;
6014     uschar *arg = NULL;
6015     uschar *sub;
6016     var_entry *vp = NULL;
6017
6018     /* Owing to an historical mis-design, an underscore may be part of the
6019     operator name, or it may introduce arguments.  We therefore first scan the
6020     table of names that contain underscores. If there is no match, we cut off
6021     the arguments and then scan the main table. */
6022
6023     if ((c = chop_match(name, op_table_underscore,
6024                         nelem(op_table_underscore))) < 0)
6025       {
6026       arg = Ustrchr(name, '_');
6027       if (arg != NULL) *arg = 0;
6028       c = chop_match(name, op_table_main, nelem(op_table_main));
6029       if (c >= 0) c += nelem(op_table_underscore);
6030       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6031       }
6032
6033     /* Deal specially with operators that might take a certificate variable
6034     as we do not want to do the usual expansion. For most, expand the string.*/
6035     switch(c)
6036       {
6037 #ifdef SUPPORT_TLS
6038       case EOP_MD5:
6039       case EOP_SHA1:
6040       case EOP_SHA256:
6041         if (s[1] == '$')
6042           {
6043           const uschar * s1 = s;
6044           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6045                   FALSE, &resetok);
6046           if (!sub)       goto EXPAND_FAILED;           /*{*/
6047           if (*s1 != '}') goto EXPAND_FAILED_CURLY;
6048           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6049             {
6050             s = s1+1;
6051             break;
6052             }
6053           vp = NULL;
6054           }
6055         /*FALLTHROUGH*/
6056 #endif
6057       default:
6058         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6059         if (!sub) goto EXPAND_FAILED;
6060         s++;
6061         break;
6062       }
6063
6064     /* If we are skipping, we don't need to perform the operation at all.
6065     This matters for operations like "mask", because the data may not be
6066     in the correct format when skipping. For example, the expression may test
6067     for the existence of $sender_host_address before trying to mask it. For
6068     other operations, doing them may not fail, but it is a waste of time. */
6069
6070     if (skipping && c >= 0) continue;
6071
6072     /* Otherwise, switch on the operator type */
6073
6074     switch(c)
6075       {
6076       case EOP_BASE62:
6077         {
6078         uschar *t;
6079         unsigned long int n = Ustrtoul(sub, &t, 10);
6080         if (*t != 0)
6081           {
6082           expand_string_message = string_sprintf("argument for base62 "
6083             "operator is \"%s\", which is not a decimal number", sub);
6084           goto EXPAND_FAILED;
6085           }
6086         t = string_base62(n);
6087         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6088         continue;
6089         }
6090
6091       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6092
6093       case EOP_BASE62D:
6094         {
6095         uschar buf[16];
6096         uschar *tt = sub;
6097         unsigned long int n = 0;
6098         while (*tt != 0)
6099           {
6100           uschar *t = Ustrchr(base62_chars, *tt++);
6101           if (t == NULL)
6102             {
6103             expand_string_message = string_sprintf("argument for base62d "
6104               "operator is \"%s\", which is not a base %d number", sub,
6105               BASE_62);
6106             goto EXPAND_FAILED;
6107             }
6108           n = n * BASE_62 + (t - base62_chars);
6109           }
6110         (void)sprintf(CS buf, "%ld", n);
6111         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
6112         continue;
6113         }
6114
6115       case EOP_EXPAND:
6116         {
6117         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6118         if (expanded == NULL)
6119           {
6120           expand_string_message =
6121             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6122               expand_string_message);
6123           goto EXPAND_FAILED;
6124           }
6125         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
6126         continue;
6127         }
6128
6129       case EOP_LC:
6130         {
6131         int count = 0;
6132         uschar *t = sub - 1;
6133         while (*(++t) != 0) { *t = tolower(*t); count++; }
6134         yield = string_cat(yield, &size, &ptr, sub, count);
6135         continue;
6136         }
6137
6138       case EOP_UC:
6139         {
6140         int count = 0;
6141         uschar *t = sub - 1;
6142         while (*(++t) != 0) { *t = toupper(*t); count++; }
6143         yield = string_cat(yield, &size, &ptr, sub, count);
6144         continue;
6145         }
6146
6147       case EOP_MD5:
6148 #ifdef SUPPORT_TLS
6149         if (vp && *(void **)vp->value)
6150           {
6151           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6152           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6153           }
6154         else
6155 #endif
6156           {
6157           md5 base;
6158           uschar digest[16];
6159           int j;
6160           char st[33];
6161           md5_start(&base);
6162           md5_end(&base, sub, Ustrlen(sub), digest);
6163           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6164           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
6165           }
6166         continue;
6167
6168       case EOP_SHA1:
6169 #ifdef SUPPORT_TLS
6170         if (vp && *(void **)vp->value)
6171           {
6172           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6173           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6174           }
6175         else
6176 #endif
6177           {
6178           sha1 base;
6179           uschar digest[20];
6180           int j;
6181           char st[41];
6182           sha1_start(&base);
6183           sha1_end(&base, sub, Ustrlen(sub), digest);
6184           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6185           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
6186           }
6187         continue;
6188
6189       case EOP_SHA256:
6190 #ifdef SUPPORT_TLS
6191         if (vp && *(void **)vp->value)
6192           {
6193           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6194           yield = string_cat(yield, &size, &ptr, cp, (int)Ustrlen(cp));
6195           }
6196         else
6197 #endif
6198           expand_string_message = US"sha256 only supported for certificates";
6199         continue;
6200
6201       /* Convert hex encoding to base64 encoding */
6202
6203       case EOP_HEX2B64:
6204         {
6205         int c = 0;
6206         int b = -1;
6207         uschar *in = sub;
6208         uschar *out = sub;
6209         uschar *enc;
6210
6211         for (enc = sub; *enc != 0; enc++)
6212           {
6213           if (!isxdigit(*enc))
6214             {
6215             expand_string_message = string_sprintf("\"%s\" is not a hex "
6216               "string", sub);
6217             goto EXPAND_FAILED;
6218             }
6219           c++;
6220           }
6221
6222         if ((c & 1) != 0)
6223           {
6224           expand_string_message = string_sprintf("\"%s\" contains an odd "
6225             "number of characters", sub);
6226           goto EXPAND_FAILED;
6227           }
6228
6229         while ((c = *in++) != 0)
6230           {
6231           if (isdigit(c)) c -= '0';
6232           else c = toupper(c) - 'A' + 10;
6233           if (b == -1)
6234             {
6235             b = c << 4;
6236             }
6237           else
6238             {
6239             *out++ = b | c;
6240             b = -1;
6241             }
6242           }
6243
6244         enc = auth_b64encode(sub, out - sub);
6245         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
6246         continue;
6247         }
6248
6249       /* Convert octets outside 0x21..0x7E to \xXX form */
6250
6251       case EOP_HEXQUOTE:
6252         {
6253         uschar *t = sub - 1;
6254         while (*(++t) != 0)
6255           {
6256           if (*t < 0x21 || 0x7E < *t)
6257             yield = string_cat(yield, &size, &ptr,
6258               string_sprintf("\\x%02x", *t), 4);
6259           else
6260             yield = string_cat(yield, &size, &ptr, t, 1);
6261           }
6262         continue;
6263         }
6264
6265       /* count the number of list elements */
6266
6267       case EOP_LISTCOUNT:
6268         {
6269         int cnt = 0;
6270         int sep = 0;
6271         uschar * cp;
6272         uschar buffer[256];
6273
6274         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6275         cp = string_sprintf("%d", cnt);
6276         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6277         continue;
6278         }
6279
6280       /* expand a named list given the name */
6281       /* handles nested named lists; requotes as colon-sep list */
6282
6283       case EOP_LISTNAMED:
6284         {
6285         tree_node *t = NULL;
6286         const uschar * list;
6287         int sep = 0;
6288         uschar * item;
6289         uschar * suffix = US"";
6290         BOOL needsep = FALSE;
6291         uschar buffer[256];
6292
6293         if (*sub == '+') sub++;
6294         if (arg == NULL)        /* no-argument version */
6295           {
6296           if (!(t = tree_search(addresslist_anchor, sub)) &&
6297               !(t = tree_search(domainlist_anchor,  sub)) &&
6298               !(t = tree_search(hostlist_anchor,    sub)))
6299             t = tree_search(localpartlist_anchor, sub);
6300           }
6301         else switch(*arg)       /* specific list-type version */
6302           {
6303           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6304           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6305           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6306           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6307           default:
6308             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6309             goto EXPAND_FAILED;
6310           }
6311
6312         if(!t)
6313           {
6314           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6315             sub, !arg?""
6316               : *arg=='a'?"address "
6317               : *arg=='d'?"domain "
6318               : *arg=='h'?"host "
6319               : *arg=='l'?"localpart "
6320               : 0);
6321           goto EXPAND_FAILED;
6322           }
6323
6324         list = ((namedlist_block *)(t->data.ptr))->string;
6325
6326         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6327           {
6328           uschar * buf = US" : ";
6329           if (needsep)
6330             yield = string_cat(yield, &size, &ptr, buf, 3);
6331           else
6332             needsep = TRUE;
6333
6334           if (*item == '+')     /* list item is itself a named list */
6335             {
6336             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6337             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6338             }
6339           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6340             {
6341             char * cp;
6342             char tok[3];
6343             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6344             while ((cp= strpbrk((const char *)item, tok)))
6345               {
6346               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
6347               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6348                 {
6349                 yield = string_cat(yield, &size, &ptr, US"::", 2);
6350                 item = (uschar *)cp;
6351                 }
6352               else              /* sep in item; should already be doubled; emit once */
6353                 {
6354                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
6355                 if (*cp == sep) cp++;
6356                 item = (uschar *)cp;
6357                 }
6358               }
6359             }
6360           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
6361           }
6362         continue;
6363         }
6364
6365       /* mask applies a mask to an IP address; for example the result of
6366       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6367
6368       case EOP_MASK:
6369         {
6370         int count;
6371         uschar *endptr;
6372         int binary[4];
6373         int mask, maskoffset;
6374         int type = string_is_ip_address(sub, &maskoffset);
6375         uschar buffer[64];
6376
6377         if (type == 0)
6378           {
6379           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6380            sub);
6381           goto EXPAND_FAILED;
6382           }
6383
6384         if (maskoffset == 0)
6385           {
6386           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6387             sub);
6388           goto EXPAND_FAILED;
6389           }
6390
6391         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6392
6393         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6394           {
6395           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6396             sub);
6397           goto EXPAND_FAILED;
6398           }
6399
6400         /* Convert the address to binary integer(s) and apply the mask */
6401
6402         sub[maskoffset] = 0;
6403         count = host_aton(sub, binary);
6404         host_mask(count, binary, mask);
6405
6406         /* Convert to masked textual format and add to output. */
6407
6408         yield = string_cat(yield, &size, &ptr, buffer,
6409           host_nmtoa(count, binary, mask, buffer, '.'));
6410         continue;
6411         }
6412
6413       case EOP_IPV6NORM:
6414       case EOP_IPV6DENORM:
6415         {
6416         int type = string_is_ip_address(sub, NULL);
6417         int binary[4];
6418         uschar buffer[44];
6419
6420         switch (type)
6421           {
6422           case 6:
6423             (void) host_aton(sub, binary);
6424             break;
6425
6426           case 4:       /* convert to IPv4-mapped IPv6 */
6427             binary[0] = binary[1] = 0;
6428             binary[2] = 0x0000ffff;
6429             (void) host_aton(sub, binary+3);
6430             break;
6431
6432           case 0:
6433             expand_string_message =
6434               string_sprintf("\"%s\" is not an IP address", sub);
6435             goto EXPAND_FAILED;
6436           }
6437
6438         yield = string_cat(yield, &size, &ptr, buffer,
6439                   c == EOP_IPV6NORM
6440                     ? ipv6_nmtoa(binary, buffer)
6441                     : host_nmtoa(4, binary, -1, buffer, ':')
6442                   );
6443         continue;
6444         }
6445
6446       case EOP_ADDRESS:
6447       case EOP_LOCAL_PART:
6448       case EOP_DOMAIN:
6449         {
6450         uschar *error;
6451         int start, end, domain;
6452         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6453           FALSE);
6454         if (t != NULL)
6455           {
6456           if (c != EOP_DOMAIN)
6457             {
6458             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6459             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
6460             }
6461           else if (domain != 0)
6462             {
6463             domain += start;
6464             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
6465             }
6466           }
6467         continue;
6468         }
6469
6470       case EOP_ADDRESSES:
6471         {
6472         uschar outsep[2] = { ':', '\0' };
6473         uschar *address, *error;
6474         int save_ptr = ptr;
6475         int start, end, domain;  /* Not really used */
6476
6477         while (isspace(*sub)) sub++;
6478         if (*sub == '>') { *outsep = *++sub; ++sub; }
6479         parse_allow_group = TRUE;
6480
6481         for (;;)
6482           {
6483           uschar *p = parse_find_address_end(sub, FALSE);
6484           uschar saveend = *p;
6485           *p = '\0';
6486           address = parse_extract_address(sub, &error, &start, &end, &domain,
6487             FALSE);
6488           *p = saveend;
6489
6490           /* Add the address to the output list that we are building. This is
6491           done in chunks by searching for the separator character. At the
6492           start, unless we are dealing with the first address of the output
6493           list, add in a space if the new address begins with the separator
6494           character, or is an empty string. */
6495
6496           if (address != NULL)
6497             {
6498             if (ptr != save_ptr && address[0] == *outsep)
6499               yield = string_cat(yield, &size, &ptr, US" ", 1);
6500
6501             for (;;)
6502               {
6503               size_t seglen = Ustrcspn(address, outsep);
6504               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
6505
6506               /* If we got to the end of the string we output one character
6507               too many. */
6508
6509               if (address[seglen] == '\0') { ptr--; break; }
6510               yield = string_cat(yield, &size, &ptr, outsep, 1);
6511               address += seglen + 1;
6512               }
6513
6514             /* Output a separator after the string: we will remove the
6515             redundant final one at the end. */
6516
6517             yield = string_cat(yield, &size, &ptr, outsep, 1);
6518             }
6519
6520           if (saveend == '\0') break;
6521           sub = p + 1;
6522           }
6523
6524         /* If we have generated anything, remove the redundant final
6525         separator. */
6526
6527         if (ptr != save_ptr) ptr--;
6528         parse_allow_group = FALSE;
6529         continue;
6530         }
6531
6532
6533       /* quote puts a string in quotes if it is empty or contains anything
6534       other than alphamerics, underscore, dot, or hyphen.
6535
6536       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6537       be quoted in order to be a valid local part.
6538
6539       In both cases, newlines and carriage returns are converted into \n and \r
6540       respectively */
6541
6542       case EOP_QUOTE:
6543       case EOP_QUOTE_LOCAL_PART:
6544       if (arg == NULL)
6545         {
6546         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6547         uschar *t = sub - 1;
6548
6549         if (c == EOP_QUOTE)
6550           {
6551           while (!needs_quote && *(++t) != 0)
6552             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6553           }
6554         else  /* EOP_QUOTE_LOCAL_PART */
6555           {
6556           while (!needs_quote && *(++t) != 0)
6557             needs_quote = !isalnum(*t) &&
6558               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6559               (*t != '.' || t == sub || t[1] == 0);
6560           }
6561
6562         if (needs_quote)
6563           {
6564           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6565           t = sub - 1;
6566           while (*(++t) != 0)
6567             {
6568             if (*t == '\n')
6569               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
6570             else if (*t == '\r')
6571               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
6572             else
6573               {
6574               if (*t == '\\' || *t == '"')
6575                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
6576               yield = string_cat(yield, &size, &ptr, t, 1);
6577               }
6578             }
6579           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6580           }
6581         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6582         continue;
6583         }
6584
6585       /* quote_lookuptype does lookup-specific quoting */
6586
6587       else
6588         {
6589         int n;
6590         uschar *opt = Ustrchr(arg, '_');
6591
6592         if (opt != NULL) *opt++ = 0;
6593
6594         n = search_findtype(arg, Ustrlen(arg));
6595         if (n < 0)
6596           {
6597           expand_string_message = search_error_message;
6598           goto EXPAND_FAILED;
6599           }
6600
6601         if (lookup_list[n]->quote != NULL)
6602           sub = (lookup_list[n]->quote)(sub, opt);
6603         else if (opt != NULL) sub = NULL;
6604
6605         if (sub == NULL)
6606           {
6607           expand_string_message = string_sprintf(
6608             "\"%s\" unrecognized after \"${quote_%s\"",
6609             opt, arg);
6610           goto EXPAND_FAILED;
6611           }
6612
6613         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6614         continue;
6615         }
6616
6617       /* rx quote sticks in \ before any non-alphameric character so that
6618       the insertion works in a regular expression. */
6619
6620       case EOP_RXQUOTE:
6621         {
6622         uschar *t = sub - 1;
6623         while (*(++t) != 0)
6624           {
6625           if (!isalnum(*t))
6626             yield = string_cat(yield, &size, &ptr, US"\\", 1);
6627           yield = string_cat(yield, &size, &ptr, t, 1);
6628           }
6629         continue;
6630         }
6631
6632       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6633       prescribed by the RFC, if there are characters that need to be encoded */
6634
6635       case EOP_RFC2047:
6636         {
6637         uschar buffer[2048];
6638         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6639           buffer, sizeof(buffer), FALSE);
6640         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
6641         continue;
6642         }
6643
6644       /* RFC 2047 decode */
6645
6646       case EOP_RFC2047D:
6647         {
6648         int len;
6649         uschar *error;
6650         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6651           headers_charset, '?', &len, &error);
6652         if (error != NULL)
6653           {
6654           expand_string_message = error;
6655           goto EXPAND_FAILED;
6656           }
6657         yield = string_cat(yield, &size, &ptr, decoded, len);
6658         continue;
6659         }
6660
6661       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6662       underscores */
6663
6664       case EOP_FROM_UTF8:
6665         {
6666         while (*sub != 0)
6667           {
6668           int c;
6669           uschar buff[4];
6670           GETUTF8INC(c, sub);
6671           if (c > 255) c = '_';
6672           buff[0] = c;
6673           yield = string_cat(yield, &size, &ptr, buff, 1);
6674           }
6675         continue;
6676         }
6677
6678           /* replace illegal UTF-8 sequences by replacement character  */
6679
6680       #define UTF8_REPLACEMENT_CHAR US"?"
6681
6682       case EOP_UTF8CLEAN:
6683         {
6684         int seq_len = 0, index = 0;
6685         int bytes_left = 0;
6686         long codepoint = -1;
6687         uschar seq_buff[4];                     /* accumulate utf-8 here */
6688
6689         while (*sub != 0)
6690           {
6691           int complete = 0;
6692           uschar c = *sub++;
6693
6694           if (bytes_left)
6695             {
6696             if ((c & 0xc0) != 0x80)
6697                     /* wrong continuation byte; invalidate all bytes */
6698               complete = 1; /* error */
6699             else
6700               {
6701               codepoint = (codepoint << 6) | (c & 0x3f);
6702               seq_buff[index++] = c;
6703               if (--bytes_left == 0)            /* codepoint complete */
6704                 if(codepoint > 0x10FFFF)        /* is it too large? */
6705                   complete = -1;        /* error (RFC3629 limit) */
6706                 else
6707                   {             /* finished; output utf-8 sequence */
6708                   yield = string_cat(yield, &size, &ptr, seq_buff, seq_len);
6709                   index = 0;
6710                   }
6711               }
6712             }
6713           else  /* no bytes left: new sequence */
6714             {
6715             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6716               {
6717               yield = string_cat(yield, &size, &ptr, &c, 1);
6718               continue;
6719               }
6720             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
6721               {
6722               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
6723                 complete = -1;
6724               else
6725                 {
6726                   bytes_left = 1;
6727                   codepoint = c & 0x1f;
6728                 }
6729               }
6730             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
6731               {
6732               bytes_left = 2;
6733               codepoint = c & 0x0f;
6734               }
6735             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
6736               {
6737               bytes_left = 3;
6738               codepoint = c & 0x07;
6739               }
6740             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
6741               complete = -1;
6742
6743             seq_buff[index++] = c;
6744             seq_len = bytes_left + 1;
6745             }           /* if(bytes_left) */
6746
6747           if (complete != 0)
6748             {
6749             bytes_left = index = 0;
6750             yield = string_cat(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
6751             }
6752           if ((complete == 1) && ((c & 0x80) == 0))
6753                         /* ASCII character follows incomplete sequence */
6754               yield = string_cat(yield, &size, &ptr, &c, 1);
6755           }
6756         continue;
6757         }
6758
6759 #ifdef EXPERIMENTAL_INTERNATIONAL
6760       case EOP_UTF8_DOMAIN_TO_ALABEL:
6761         {
6762         uschar * error = NULL;
6763         uschar * s = string_domain_utf8_to_alabel(sub, &error);
6764         if (error)
6765           {
6766           expand_string_message = string_sprintf(
6767             "error converting utf8 (%s) to alabel: %s",
6768             string_printing(sub), error);
6769           goto EXPAND_FAILED;
6770           }
6771         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6772         continue;
6773         }
6774
6775       case EOP_UTF8_DOMAIN_FROM_ALABEL:
6776         {
6777         uschar * error = NULL;
6778         uschar * s = string_domain_alabel_to_utf8(sub, &error);
6779         if (error)
6780           {
6781           expand_string_message = string_sprintf(
6782             "error converting alabel (%s) to utf8: %s",
6783             string_printing(sub), error);
6784           goto EXPAND_FAILED;
6785           }
6786         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6787         continue;
6788         }
6789
6790       case EOP_UTF8_LOCALPART_TO_ALABEL:
6791         {
6792         uschar * error = NULL;
6793         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
6794         if (error)
6795           {
6796           expand_string_message = string_sprintf(
6797             "error converting utf8 (%s) to alabel: %s",
6798             string_printing(sub), error);
6799           goto EXPAND_FAILED;
6800           }
6801         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6802         DEBUG(D_expand) debug_printf("yield: '%s'\n", yield);
6803         continue;
6804         }
6805
6806       case EOP_UTF8_LOCALPART_FROM_ALABEL:
6807         {
6808         uschar * error = NULL;
6809         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
6810         if (error)
6811           {
6812           expand_string_message = string_sprintf(
6813             "error converting alabel (%s) to utf8: %s",
6814             string_printing(sub), error);
6815           goto EXPAND_FAILED;
6816           }
6817         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6818         continue;
6819         }
6820 #endif  /* EXPERIMENTAL_INTERNATIONAL */
6821
6822       /* escape turns all non-printing characters into escape sequences. */
6823
6824       case EOP_ESCAPE:
6825         {
6826         const uschar *t = string_printing(sub);
6827         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6828         continue;
6829         }
6830
6831       /* Handle numeric expression evaluation */
6832
6833       case EOP_EVAL:
6834       case EOP_EVAL10:
6835         {
6836         uschar *save_sub = sub;
6837         uschar *error = NULL;
6838         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6839         if (error != NULL)
6840           {
6841           expand_string_message = string_sprintf("error in expression "
6842             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6843               save_sub);
6844           goto EXPAND_FAILED;
6845           }
6846         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6847         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6848         continue;
6849         }
6850
6851       /* Handle time period formating */
6852
6853       case EOP_TIME_EVAL:
6854         {
6855         int n = readconf_readtime(sub, 0, FALSE);
6856         if (n < 0)
6857           {
6858           expand_string_message = string_sprintf("string \"%s\" is not an "
6859             "Exim time interval in \"%s\" operator", sub, name);
6860           goto EXPAND_FAILED;
6861           }
6862         sprintf(CS var_buffer, "%d", n);
6863         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6864         continue;
6865         }
6866
6867       case EOP_TIME_INTERVAL:
6868         {
6869         int n;
6870         uschar *t = read_number(&n, sub);
6871         if (*t != 0) /* Not A Number*/
6872           {
6873           expand_string_message = string_sprintf("string \"%s\" is not a "
6874             "positive number in \"%s\" operator", sub, name);
6875           goto EXPAND_FAILED;
6876           }
6877         t = readconf_printtime(n);
6878         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6879         continue;
6880         }
6881
6882       /* Convert string to base64 encoding */
6883
6884       case EOP_STR2B64:
6885         {
6886         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
6887         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
6888         continue;
6889         }
6890
6891       /* strlen returns the length of the string */
6892
6893       case EOP_STRLEN:
6894         {
6895         uschar buff[24];
6896         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6897         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6898         continue;
6899         }
6900
6901       /* length_n or l_n takes just the first n characters or the whole string,
6902       whichever is the shorter;
6903
6904       substr_m_n, and s_m_n take n characters from offset m; negative m take
6905       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6906       takes the rest, either to the right or to the left.
6907
6908       hash_n or h_n makes a hash of length n from the string, yielding n
6909       characters from the set a-z; hash_n_m makes a hash of length n, but
6910       uses m characters from the set a-zA-Z0-9.
6911
6912       nhash_n returns a single number between 0 and n-1 (in text form), while
6913       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6914       between 0 and n-1 and the second between 0 and m-1. */
6915
6916       case EOP_LENGTH:
6917       case EOP_L:
6918       case EOP_SUBSTR:
6919       case EOP_S:
6920       case EOP_HASH:
6921       case EOP_H:
6922       case EOP_NHASH:
6923       case EOP_NH:
6924         {
6925         int sign = 1;
6926         int value1 = 0;
6927         int value2 = -1;
6928         int *pn;
6929         int len;
6930         uschar *ret;
6931
6932         if (arg == NULL)
6933           {
6934           expand_string_message = string_sprintf("missing values after %s",
6935             name);
6936           goto EXPAND_FAILED;
6937           }
6938
6939         /* "length" has only one argument, effectively being synonymous with
6940         substr_0_n. */
6941
6942         if (c == EOP_LENGTH || c == EOP_L)
6943           {
6944           pn = &value2;
6945           value2 = 0;
6946           }
6947
6948         /* The others have one or two arguments; for "substr" the first may be
6949         negative. The second being negative means "not supplied". */
6950
6951         else
6952           {
6953           pn = &value1;
6954           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6955           }
6956
6957         /* Read up to two numbers, separated by underscores */
6958
6959         ret = arg;
6960         while (*arg != 0)
6961           {
6962           if (arg != ret && *arg == '_' && pn == &value1)
6963             {
6964             pn = &value2;
6965             value2 = 0;
6966             if (arg[1] != 0) arg++;
6967             }
6968           else if (!isdigit(*arg))
6969             {
6970             expand_string_message =
6971               string_sprintf("non-digit after underscore in \"%s\"", name);
6972             goto EXPAND_FAILED;
6973             }
6974           else *pn = (*pn)*10 + *arg++ - '0';
6975           }
6976         value1 *= sign;
6977
6978         /* Perform the required operation */
6979
6980         ret =
6981           (c == EOP_HASH || c == EOP_H)?
6982              compute_hash(sub, value1, value2, &len) :
6983           (c == EOP_NHASH || c == EOP_NH)?
6984              compute_nhash(sub, value1, value2, &len) :
6985              extract_substr(sub, value1, value2, &len);
6986
6987         if (ret == NULL) goto EXPAND_FAILED;
6988         yield = string_cat(yield, &size, &ptr, ret, len);
6989         continue;
6990         }
6991
6992       /* Stat a path */
6993
6994       case EOP_STAT:
6995         {
6996         uschar *s;
6997         uschar smode[12];
6998         uschar **modetable[3];
6999         int i;
7000         mode_t mode;
7001         struct stat st;
7002
7003         if ((expand_forbid & RDO_EXISTS) != 0)
7004           {
7005           expand_string_message = US"Use of the stat() expansion is not permitted";
7006           goto EXPAND_FAILED;
7007           }
7008
7009         if (stat(CS sub, &st) < 0)
7010           {
7011           expand_string_message = string_sprintf("stat(%s) failed: %s",
7012             sub, strerror(errno));
7013           goto EXPAND_FAILED;
7014           }
7015         mode = st.st_mode;
7016         switch (mode & S_IFMT)
7017           {
7018           case S_IFIFO: smode[0] = 'p'; break;
7019           case S_IFCHR: smode[0] = 'c'; break;
7020           case S_IFDIR: smode[0] = 'd'; break;
7021           case S_IFBLK: smode[0] = 'b'; break;
7022           case S_IFREG: smode[0] = '-'; break;
7023           default: smode[0] = '?'; break;
7024           }
7025
7026         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7027         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7028         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7029
7030         for (i = 0; i < 3; i++)
7031           {
7032           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7033           mode >>= 3;
7034           }
7035
7036         smode[10] = 0;
7037         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7038           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7039           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7040           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7041           (long)st.st_gid, st.st_size, (long)st.st_atime,
7042           (long)st.st_mtime, (long)st.st_ctime);
7043         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
7044         continue;
7045         }
7046
7047       /* vaguely random number less than N */
7048
7049       case EOP_RANDINT:
7050         {
7051         int_eximarith_t max;
7052         uschar *s;
7053
7054         max = expanded_string_integer(sub, TRUE);
7055         if (expand_string_message != NULL)
7056           goto EXPAND_FAILED;
7057         s = string_sprintf("%d", vaguely_random_number((int)max));
7058         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
7059         continue;
7060         }
7061
7062       /* Reverse IP, including IPv6 to dotted-nibble */
7063
7064       case EOP_REVERSE_IP:
7065         {
7066         int family, maskptr;
7067         uschar reversed[128];
7068
7069         family = string_is_ip_address(sub, &maskptr);
7070         if (family == 0)
7071           {
7072           expand_string_message = string_sprintf(
7073               "reverse_ip() not given an IP address [%s]", sub);
7074           goto EXPAND_FAILED;
7075           }
7076         invert_address(reversed, sub);
7077         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
7078         continue;
7079         }
7080
7081       /* Unknown operator */
7082
7083       default:
7084       expand_string_message =
7085         string_sprintf("unknown expansion operator \"%s\"", name);
7086       goto EXPAND_FAILED;
7087       }
7088     }
7089
7090   /* Handle a plain name. If this is the first thing in the expansion, release
7091   the pre-allocated buffer. If the result data is known to be in a new buffer,
7092   newsize will be set to the size of that buffer, and we can just point at that
7093   store instead of copying. Many expansion strings contain just one reference,
7094   so this is a useful optimization, especially for humungous headers
7095   ($message_headers). */
7096                                                 /*{*/
7097   if (*s++ == '}')
7098     {
7099     int len;
7100     int newsize = 0;
7101     if (ptr == 0)
7102       {
7103       if (resetok) store_reset(yield);
7104       yield = NULL;
7105       size = 0;
7106       }
7107     value = find_variable(name, FALSE, skipping, &newsize);
7108     if (value == NULL)
7109       {
7110       expand_string_message =
7111         string_sprintf("unknown variable in \"${%s}\"", name);
7112       check_variable_error_message(name);
7113       goto EXPAND_FAILED;
7114       }
7115     len = Ustrlen(value);
7116     if (yield == NULL && newsize != 0)
7117       {
7118       yield = value;
7119       size = newsize;
7120       ptr = len;
7121       }
7122     else yield = string_cat(yield, &size, &ptr, value, len);
7123     continue;
7124     }
7125
7126   /* Else there's something wrong */
7127
7128   expand_string_message =
7129     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7130     "in a variable reference)", name);
7131   goto EXPAND_FAILED;
7132   }
7133
7134 /* If we hit the end of the string when ket_ends is set, there is a missing
7135 terminating brace. */
7136
7137 if (ket_ends && *s == 0)
7138   {
7139   expand_string_message = malformed_header?
7140     US"missing } at end of string - could be header name not terminated by colon"
7141     :
7142     US"missing } at end of string";
7143   goto EXPAND_FAILED;
7144   }
7145
7146 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7147 added to the string. If so, set up an empty string. Add a terminating zero. If
7148 left != NULL, return a pointer to the terminator. */
7149
7150 if (yield == NULL) yield = store_get(1);
7151 yield[ptr] = 0;
7152 if (left != NULL) *left = s;
7153
7154 /* Any stacking store that was used above the final string is no longer needed.
7155 In many cases the final string will be the first one that was got and so there
7156 will be optimal store usage. */
7157
7158 if (resetok) store_reset(yield + ptr + 1);
7159 else if (resetok_p) *resetok_p = FALSE;
7160
7161 DEBUG(D_expand)
7162   {
7163   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
7164     yield);
7165   if (skipping) debug_printf("skipping: result is not used\n");
7166   }
7167 return yield;
7168
7169 /* This is the failure exit: easiest to program with a goto. We still need
7170 to update the pointer to the terminator, for cases of nested calls with "fail".
7171 */
7172
7173 EXPAND_FAILED_CURLY:
7174 expand_string_message = malformed_header?
7175   US"missing or misplaced { or } - could be header name not terminated by colon"
7176   :
7177   US"missing or misplaced { or }";
7178
7179 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7180 that is a bad idea, because expand_string_message is in dynamic store. */
7181
7182 EXPAND_FAILED:
7183 if (left != NULL) *left = s;
7184 DEBUG(D_expand)
7185   {
7186   debug_printf("failed to expand: %s\n", string);
7187   debug_printf("   error message: %s\n", expand_string_message);
7188   if (expand_string_forcedfail) debug_printf("failure was forced\n");
7189   }
7190 if (resetok_p) *resetok_p = resetok;
7191 return NULL;
7192 }
7193
7194
7195 /* This is the external function call. Do a quick check for any expansion
7196 metacharacters, and if there are none, just return the input string.
7197
7198 Argument: the string to be expanded
7199 Returns:  the expanded string, or NULL if expansion failed; if failure was
7200           due to a lookup deferring, search_find_defer will be TRUE
7201 */
7202
7203 uschar *
7204 expand_string(uschar *string)
7205 {
7206 search_find_defer = FALSE;
7207 malformed_header = FALSE;
7208 return (Ustrpbrk(string, "$\\") == NULL)? string :
7209   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7210 }
7211
7212
7213
7214 const uschar *
7215 expand_cstring(const uschar *string)
7216 {
7217 search_find_defer = FALSE;
7218 malformed_header = FALSE;
7219 return (Ustrpbrk(string, "$\\") == NULL)? string :
7220   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7221 }
7222
7223
7224
7225 /*************************************************
7226 *              Expand and copy                   *
7227 *************************************************/
7228
7229 /* Now and again we want to expand a string and be sure that the result is in a
7230 new bit of store. This function does that.
7231 Since we know it has been copied, the de-const cast is safe.
7232
7233 Argument: the string to be expanded
7234 Returns:  the expanded string, always in a new bit of store, or NULL
7235 */
7236
7237 uschar *
7238 expand_string_copy(const uschar *string)
7239 {
7240 const uschar *yield = expand_cstring(string);
7241 if (yield == string) yield = string_copy(string);
7242 return US yield;
7243 }
7244
7245
7246
7247 /*************************************************
7248 *        Expand and interpret as an integer      *
7249 *************************************************/
7250
7251 /* Expand a string, and convert the result into an integer.
7252
7253 Arguments:
7254   string  the string to be expanded
7255   isplus  TRUE if a non-negative number is expected
7256
7257 Returns:  the integer value, or
7258           -1 for an expansion error               ) in both cases, message in
7259           -2 for an integer interpretation error  ) expand_string_message
7260           expand_string_message is set NULL for an OK integer
7261 */
7262
7263 int_eximarith_t
7264 expand_string_integer(uschar *string, BOOL isplus)
7265 {
7266 return expanded_string_integer(expand_string(string), isplus);
7267 }
7268
7269
7270 /*************************************************
7271  *         Interpret string as an integer        *
7272  *************************************************/
7273
7274 /* Convert a string (that has already been expanded) into an integer.
7275
7276 This function is used inside the expansion code.
7277
7278 Arguments:
7279   s       the string to be expanded
7280   isplus  TRUE if a non-negative number is expected
7281
7282 Returns:  the integer value, or
7283           -1 if string is NULL (which implies an expansion error)
7284           -2 for an integer interpretation error
7285           expand_string_message is set NULL for an OK integer
7286 */
7287
7288 static int_eximarith_t
7289 expanded_string_integer(const uschar *s, BOOL isplus)
7290 {
7291 int_eximarith_t value;
7292 uschar *msg = US"invalid integer \"%s\"";
7293 uschar *endptr;
7294
7295 /* If expansion failed, expand_string_message will be set. */
7296
7297 if (s == NULL) return -1;
7298
7299 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7300 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7301 systems, so we set it zero ourselves. */
7302
7303 errno = 0;
7304 expand_string_message = NULL;               /* Indicates no error */
7305
7306 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7307 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7308 the behaviour explicitly.  Stripping leading whitespace is a harmless
7309 noop change since strtol skips it anyway (provided that there is a number
7310 to find at all). */
7311 if (isspace(*s))
7312   {
7313   while (isspace(*s)) ++s;
7314   if (*s == '\0')
7315     {
7316       DEBUG(D_expand)
7317        debug_printf("treating blank string as number 0\n");
7318       return 0;
7319     }
7320   }
7321
7322 value = strtoll(CS s, CSS &endptr, 10);
7323
7324 if (endptr == s)
7325   {
7326   msg = US"integer expected but \"%s\" found";
7327   }
7328 else if (value < 0 && isplus)
7329   {
7330   msg = US"non-negative integer expected but \"%s\" found";
7331   }
7332 else
7333   {
7334   switch (tolower(*endptr))
7335     {
7336     default:
7337       break;
7338     case 'k':
7339       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7340       else value *= 1024;
7341       endptr++;
7342       break;
7343     case 'm':
7344       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7345       else value *= 1024*1024;
7346       endptr++;
7347       break;
7348     case 'g':
7349       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7350       else value *= 1024*1024*1024;
7351       endptr++;
7352       break;
7353     }
7354   if (errno == ERANGE)
7355     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7356   else
7357     {
7358     while (isspace(*endptr)) endptr++;
7359     if (*endptr == 0) return value;
7360     }
7361   }
7362
7363 expand_string_message = string_sprintf(CS msg, s);
7364 return -2;
7365 }
7366
7367
7368 /* These values are usually fixed boolean values, but they are permitted to be
7369 expanded strings.
7370
7371 Arguments:
7372   addr       address being routed
7373   mtype      the module type
7374   mname      the module name
7375   dbg_opt    debug selectors
7376   oname      the option name
7377   bvalue     the router's boolean value
7378   svalue     the router's string value
7379   rvalue     where to put the returned value
7380
7381 Returns:     OK     value placed in rvalue
7382              DEFER  expansion failed
7383 */
7384
7385 int
7386 exp_bool(address_item *addr,
7387   uschar *mtype, uschar *mname, unsigned dbg_opt,
7388   uschar *oname, BOOL bvalue,
7389   uschar *svalue, BOOL *rvalue)
7390 {
7391 uschar *expanded;
7392 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7393
7394 expanded = expand_string(svalue);
7395 if (expanded == NULL)
7396   {
7397   if (expand_string_forcedfail)
7398     {
7399     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7400     *rvalue = bvalue;
7401     return OK;
7402     }
7403   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7404       oname, mname, mtype, expand_string_message);
7405   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7406   return DEFER;
7407   }
7408
7409 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7410   expanded);
7411
7412 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7413   *rvalue = TRUE;
7414 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7415   *rvalue = FALSE;
7416 else
7417   {
7418   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7419     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7420   return DEFER;
7421   }
7422
7423 return OK;
7424 }
7425
7426
7427
7428
7429 /*************************************************
7430 **************************************************
7431 *             Stand-alone test program           *
7432 **************************************************
7433 *************************************************/
7434
7435 #ifdef STAND_ALONE
7436
7437
7438 BOOL
7439 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7440 {
7441 int ovector[3*(EXPAND_MAXN+1)];
7442 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7443   ovector, nelem(ovector));
7444 BOOL yield = n >= 0;
7445 if (n == 0) n = EXPAND_MAXN + 1;
7446 if (yield)
7447   {
7448   int nn;
7449   expand_nmax = (setup < 0)? 0 : setup + 1;
7450   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7451     {
7452     expand_nstring[expand_nmax] = subject + ovector[nn];
7453     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7454     }
7455   expand_nmax--;
7456   }
7457 return yield;
7458 }
7459
7460
7461 int main(int argc, uschar **argv)
7462 {
7463 int i;
7464 uschar buffer[1024];
7465
7466 debug_selector = D_v;
7467 debug_file = stderr;
7468 debug_fd = fileno(debug_file);
7469 big_buffer = malloc(big_buffer_size);
7470
7471 for (i = 1; i < argc; i++)
7472   {
7473   if (argv[i][0] == '+')
7474     {
7475     debug_trace_memory = 2;
7476     argv[i]++;
7477     }
7478   if (isdigit(argv[i][0]))
7479     debug_selector = Ustrtol(argv[i], NULL, 0);
7480   else
7481     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7482         Ustrlen(argv[i]))
7483       {
7484       #ifdef LOOKUP_LDAP
7485       eldap_default_servers = argv[i];
7486       #endif
7487       #ifdef LOOKUP_MYSQL
7488       mysql_servers = argv[i];
7489       #endif
7490       #ifdef LOOKUP_PGSQL
7491       pgsql_servers = argv[i];
7492       #endif
7493       #ifdef EXPERIMENTAL_REDIS
7494       redis_servers = argv[i];
7495       #endif
7496       }
7497   #ifdef EXIM_PERL
7498   else opt_perl_startup = argv[i];
7499   #endif
7500   }
7501
7502 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7503
7504 expand_nstring[1] = US"string 1....";
7505 expand_nlength[1] = 8;
7506 expand_nmax = 1;
7507
7508 #ifdef EXIM_PERL
7509 if (opt_perl_startup != NULL)
7510   {
7511   uschar *errstr;
7512   printf("Starting Perl interpreter\n");
7513   errstr = init_perl(opt_perl_startup);
7514   if (errstr != NULL)
7515     {
7516     printf("** error in perl_startup code: %s\n", errstr);
7517     return EXIT_FAILURE;
7518     }
7519   }
7520 #endif /* EXIM_PERL */
7521
7522 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7523   {
7524   void *reset_point = store_get(0);
7525   uschar *yield = expand_string(buffer);
7526   if (yield != NULL)
7527     {
7528     printf("%s\n", yield);
7529     store_reset(reset_point);
7530     }
7531   else
7532     {
7533     if (search_find_defer) printf("search_find deferred\n");
7534     printf("Failed: %s\n", expand_string_message);
7535     if (expand_string_forcedfail) printf("Forced failure\n");
7536     printf("\n");
7537     }
7538   }
7539
7540 search_tidyup();
7541
7542 return 0;
7543 }
7544
7545 #endif
7546
7547 /* vi: aw ai sw=2
7548 */
7549 /* End of expand.c */