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 SUPPORT_I18N
 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 SUPPORT_I18N
 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 SUPPORT_I18N
 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 SUPPORT_I18N
 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"base64",
 205   US"base64d",
 206   US"domain",
 207   US"escape",
 208   US"eval",
 209   US"eval10",
 210   US"expand",
 211   US"h",
 212   US"hash",
 213   US"hex2b64",
 214   US"hexquote",
 215   US"ipv6denorm",
 216   US"ipv6norm",
 217   US"l",
 218   US"lc",
 219   US"length",
 220   US"listcount",
 221   US"listnamed",
 222   US"mask",
 223   US"md5",
 224   US"nh",
 225   US"nhash",
 226   US"quote",
 227   US"randint",
 228   US"rfc2047",
 229   US"rfc2047d",
 230   US"rxquote",
 231   US"s",
 232   US"sha1",
 233   US"sha256",
 234   US"stat",
 235   US"str2b64",
 236   US"strlen",
 237   US"substr",
 238   US"uc",
 239   US"utf8clean" };
 240
 241 enum {
 242   EOP_ADDRESS =  nelem(op_table_underscore),
 243   EOP_ADDRESSES,
 244   EOP_BASE62,
 245   EOP_BASE62D,
 246   EOP_BASE64,
 247   EOP_BASE64D,
 248   EOP_DOMAIN,
 249   EOP_ESCAPE,
 250   EOP_EVAL,
 251   EOP_EVAL10,
 252   EOP_EXPAND,
 253   EOP_H,
 254   EOP_HASH,
 255   EOP_HEX2B64,
 256   EOP_HEXQUOTE,
 257   EOP_IPV6DENORM,
 258   EOP_IPV6NORM,
 259   EOP_L,
 260   EOP_LC,
 261   EOP_LENGTH,
 262   EOP_LISTCOUNT,
 263   EOP_LISTNAMED,
 264   EOP_MASK,
 265   EOP_MD5,
 266   EOP_NH,
 267   EOP_NHASH,
 268   EOP_QUOTE,
 269   EOP_RANDINT,
 270   EOP_RFC2047,
 271   EOP_RFC2047D,
 272   EOP_RXQUOTE,
 273   EOP_S,
 274   EOP_SHA1,
 275   EOP_SHA256,
 276   EOP_STAT,
 277   EOP_STR2B64,
 278   EOP_STRLEN,
 279   EOP_SUBSTR,
 280   EOP_UC,
 281   EOP_UTF8CLEAN };
 282
 283
 284 /* Table of condition names, and corresponding switch numbers. The names must
 285 be in alphabetical order. */
 286
 287 static uschar *cond_table[] = {
 288   US"<",
 289   US"<=",
 290   US"=",
 291   US"==",     /* Backward compatibility */
 292   US">",
 293   US">=",
 294   US"acl",
 295   US"and",
 296   US"bool",
 297   US"bool_lax",
 298   US"crypteq",
 299   US"def",
 300   US"eq",
 301   US"eqi",
 302   US"exists",
 303   US"first_delivery",
 304   US"forall",
 305   US"forany",
 306   US"ge",
 307   US"gei",
 308   US"gt",
 309   US"gti",
 310   US"inlist",
 311   US"inlisti",
 312   US"isip",
 313   US"isip4",
 314   US"isip6",
 315   US"ldapauth",
 316   US"le",
 317   US"lei",
 318   US"lt",
 319   US"lti",
 320   US"match",
 321   US"match_address",
 322   US"match_domain",
 323   US"match_ip",
 324   US"match_local_part",
 325   US"or",
 326   US"pam",
 327   US"pwcheck",
 328   US"queue_running",
 329   US"radius",
 330   US"saslauthd"
 331 };
 332
 333 enum {
 334   ECOND_NUM_L,
 335   ECOND_NUM_LE,
 336   ECOND_NUM_E,
 337   ECOND_NUM_EE,
 338   ECOND_NUM_G,
 339   ECOND_NUM_GE,
 340   ECOND_ACL,
 341   ECOND_AND,
 342   ECOND_BOOL,
 343   ECOND_BOOL_LAX,
 344   ECOND_CRYPTEQ,
 345   ECOND_DEF,
 346   ECOND_STR_EQ,
 347   ECOND_STR_EQI,
 348   ECOND_EXISTS,
 349   ECOND_FIRST_DELIVERY,
 350   ECOND_FORALL,
 351   ECOND_FORANY,
 352   ECOND_STR_GE,
 353   ECOND_STR_GEI,
 354   ECOND_STR_GT,
 355   ECOND_STR_GTI,
 356   ECOND_INLIST,
 357   ECOND_INLISTI,
 358   ECOND_ISIP,
 359   ECOND_ISIP4,
 360   ECOND_ISIP6,
 361   ECOND_LDAPAUTH,
 362   ECOND_STR_LE,
 363   ECOND_STR_LEI,
 364   ECOND_STR_LT,
 365   ECOND_STR_LTI,
 366   ECOND_MATCH,
 367   ECOND_MATCH_ADDRESS,
 368   ECOND_MATCH_DOMAIN,
 369   ECOND_MATCH_IP,
 370   ECOND_MATCH_LOCAL_PART,
 371   ECOND_OR,
 372   ECOND_PAM,
 373   ECOND_PWCHECK,
 374   ECOND_QUEUE_RUNNING,
 375   ECOND_RADIUS,
 376   ECOND_SASLAUTHD
 377 };
 378
 379
 380 /* Types of table entry */
 381
 382 enum vtypes {
 383   vtype_int,            /* value is address of int */
 384   vtype_filter_int,     /* ditto, but recognized only when filtering */
 385   vtype_ino,            /* value is address of ino_t (not always an int) */
 386   vtype_uid,            /* value is address of uid_t (not always an int) */
 387   vtype_gid,            /* value is address of gid_t (not always an int) */
 388   vtype_bool,           /* value is address of bool */
 389   vtype_stringptr,      /* value is address of pointer to string */
 390   vtype_msgbody,        /* as stringptr, but read when first required */
 391   vtype_msgbody_end,    /* ditto, the end of the message */
 392   vtype_msgheaders,     /* the message's headers, processed */
 393   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 394   vtype_localpart,      /* extract local part from string */
 395   vtype_domain,         /* extract domain from string */
 396   vtype_string_func,    /* value is string returned by given function */
 397   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 398   vtype_tode,           /* value not used; generate tod in epoch format */
 399   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 400   vtype_todf,           /* value not used; generate full tod */
 401   vtype_todl,           /* value not used; generate log tod */
 402   vtype_todlf,          /* value not used; generate log file datestamp tod */
 403   vtype_todzone,        /* value not used; generate time zone only */
 404   vtype_todzulu,        /* value not used; generate zulu tod */
 405   vtype_reply,          /* value not used; get reply from headers */
 406   vtype_pid,            /* value not used; result is pid */
 407   vtype_host_lookup,    /* value not used; get host name */
 408   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 409   vtype_pspace,         /* partition space; value is T/F for spool/log */
 410   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 411   vtype_cert            /* SSL certificate */
 412   #ifndef DISABLE_DKIM
 413   ,vtype_dkim           /* Lookup of value in DKIM signature */
 414   #endif
 415 };
 416
 417 /* Type for main variable table */
 418
 419 typedef struct {
 420   const char *name;
 421   enum vtypes type;
 422   void       *value;
 423 } var_entry;
 424
 425 /* Type for entries pointing to address/length pairs. Not currently
 426 in use. */
 427
 428 typedef struct {
 429   uschar **address;
 430   int  *length;
 431 } alblock;
 432
 433 static uschar * fn_recipients(void);
 434
 435 /* This table must be kept in alphabetical order. */
 436
 437 static var_entry var_table[] = {
 438   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 439      they will be confused with user-creatable ACL variables. */
 440   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 441   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 442   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 443   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 444   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 445   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 446   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 447   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 448   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 449   { "acl_narg",            vtype_int,         &acl_narg },
 450   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 451   { "address_data",        vtype_stringptr,   &deliver_address_data },
 452   { "address_file",        vtype_stringptr,   &address_file },
 453   { "address_pipe",        vtype_stringptr,   &address_pipe },
 454   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 455   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 456   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 457   { "authentication_failed",vtype_int,        &authentication_failed },
 458 #ifdef WITH_CONTENT_SCAN
 459   { "av_failed",           vtype_int,         &av_failed },
 460 #endif
 461 #ifdef EXPERIMENTAL_BRIGHTMAIL
 462   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 463   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 464   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 465   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 466 #endif
 467   { "body_linecount",      vtype_int,         &body_linecount },
 468   { "body_zerocount",      vtype_int,         &body_zerocount },
 469   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 470   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 471   { "caller_gid",          vtype_gid,         &real_gid },
 472   { "caller_uid",          vtype_uid,         &real_uid },
 473   { "callout_address",     vtype_stringptr,   &callout_address },
 474   { "compile_date",        vtype_stringptr,   &version_date },
 475   { "compile_number",      vtype_stringptr,   &version_cnumber },
 476   { "config_dir",          vtype_stringptr,   &config_main_directory },
 477   { "config_file",         vtype_stringptr,   &config_main_filename },
 478   { "csa_status",          vtype_stringptr,   &csa_status },
 479 #ifdef EXPERIMENTAL_DCC
 480   { "dcc_header",          vtype_stringptr,   &dcc_header },
 481   { "dcc_result",          vtype_stringptr,   &dcc_result },
 482 #endif
 483 #ifdef WITH_OLD_DEMIME
 484   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 485   { "demime_reason",       vtype_stringptr,   &demime_reason },
 486 #endif
 487 #ifndef DISABLE_DKIM
 488   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 489   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 490   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 491   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 492   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 493   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 494   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 495   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 496   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 497   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 498   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 499   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 500   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 501   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 502   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 503   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 504   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 505   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 506   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 507   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 508   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 509 #endif
 510 #ifdef EXPERIMENTAL_DMARC
 511   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 512   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 513   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 514   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 515   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 516 #endif
 517   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 518   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 519   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 520   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 521   { "domain",              vtype_stringptr,   &deliver_domain },
 522   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 523 #ifndef DISABLE_EVENT
 524   { "event_data",          vtype_stringptr,   &event_data },
 525
 526   /*XXX want to use generic vars for as many of these as possible*/
 527   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 528
 529   { "event_name",          vtype_stringptr,   &event_name },
 530 #endif
 531   { "exim_gid",            vtype_gid,         &exim_gid },
 532   { "exim_path",           vtype_stringptr,   &exim_path },
 533   { "exim_uid",            vtype_uid,         &exim_uid },
 534   { "exim_version",        vtype_stringptr,   &version_string },
 535 #ifdef WITH_OLD_DEMIME
 536   { "found_extension",     vtype_stringptr,   &found_extension },
 537 #endif
 538   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 539   { "home",                vtype_stringptr,   &deliver_home },
 540   { "host",                vtype_stringptr,   &deliver_host },
 541   { "host_address",        vtype_stringptr,   &deliver_host_address },
 542   { "host_data",           vtype_stringptr,   &host_data },
 543   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 544   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 545   { "host_port",           vtype_int,         &deliver_host_port },
 546   { "inode",               vtype_ino,         &deliver_inode },
 547   { "interface_address",   vtype_stringptr,   &interface_address },
 548   { "interface_port",      vtype_int,         &interface_port },
 549   { "item",                vtype_stringptr,   &iterate_item },
 550   #ifdef LOOKUP_LDAP
 551   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 552   #endif
 553   { "load_average",        vtype_load_avg,    NULL },
 554   { "local_part",          vtype_stringptr,   &deliver_localpart },
 555   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 556   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 557   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 558   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 559   { "local_user_gid",      vtype_gid,         &local_user_gid },
 560   { "local_user_uid",      vtype_uid,         &local_user_uid },
 561   { "localhost_number",    vtype_int,         &host_number },
 562   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 563   { "log_space",           vtype_pspace,      (void *)FALSE },
 564   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 565   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 566 #ifdef WITH_CONTENT_SCAN
 567   { "malware_name",        vtype_stringptr,   &malware_name },
 568 #endif
 569   { "max_received_linelength", vtype_int,     &max_received_linelength },
 570   { "message_age",         vtype_int,         &message_age },
 571   { "message_body",        vtype_msgbody,     &message_body },
 572   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 573   { "message_body_size",   vtype_int,         &message_body_size },
 574   { "message_exim_id",     vtype_stringptr,   &message_id },
 575   { "message_headers",     vtype_msgheaders,  NULL },
 576   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 577   { "message_id",          vtype_stringptr,   &message_id },
 578   { "message_linecount",   vtype_int,         &message_linecount },
 579   { "message_size",        vtype_int,         &message_size },
 580 #ifdef SUPPORT_I18N
 581   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 582 #endif
 583 #ifdef WITH_CONTENT_SCAN
 584   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 585   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 586   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 587   { "mime_charset",        vtype_stringptr,   &mime_charset },
 588   { "mime_content_description", vtype_stringptr, &mime_content_description },
 589   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 590   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 591   { "mime_content_size",   vtype_int,         &mime_content_size },
 592   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 593   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 594   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 595   { "mime_filename",       vtype_stringptr,   &mime_filename },
 596   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 597   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 598   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 599   { "mime_part_count",     vtype_int,         &mime_part_count },
 600 #endif
 601   { "n0",                  vtype_filter_int,  &filter_n[0] },
 602   { "n1",                  vtype_filter_int,  &filter_n[1] },
 603   { "n2",                  vtype_filter_int,  &filter_n[2] },
 604   { "n3",                  vtype_filter_int,  &filter_n[3] },
 605   { "n4",                  vtype_filter_int,  &filter_n[4] },
 606   { "n5",                  vtype_filter_int,  &filter_n[5] },
 607   { "n6",                  vtype_filter_int,  &filter_n[6] },
 608   { "n7",                  vtype_filter_int,  &filter_n[7] },
 609   { "n8",                  vtype_filter_int,  &filter_n[8] },
 610   { "n9",                  vtype_filter_int,  &filter_n[9] },
 611   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 612   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 613   { "originator_gid",      vtype_gid,         &originator_gid },
 614   { "originator_uid",      vtype_uid,         &originator_uid },
 615   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 616   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 617   { "pid",                 vtype_pid,         NULL },
 618 #ifndef DISABLE_PRDR
 619   { "prdr_requested",      vtype_bool,        &prdr_requested },
 620 #endif
 621   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 622 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 623   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 624   { "proxy_external_port", vtype_int,         &proxy_external_port },
 625   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 626   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 627   { "proxy_session",       vtype_bool,        &proxy_session },
 628 #endif
 629   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 630   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 631   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 632   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 633   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 634   { "rcpt_count",          vtype_int,         &rcpt_count },
 635   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 636   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 637   { "received_count",      vtype_int,         &received_count },
 638   { "received_for",        vtype_stringptr,   &received_for },
 639   { "received_ip_address", vtype_stringptr,   &interface_address },
 640   { "received_port",       vtype_int,         &interface_port },
 641   { "received_protocol",   vtype_stringptr,   &received_protocol },
 642   { "received_time",       vtype_int,         &received_time },
 643   { "recipient_data",      vtype_stringptr,   &recipient_data },
 644   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 645   { "recipients",          vtype_string_func, &fn_recipients },
 646   { "recipients_count",    vtype_int,         &recipients_count },
 647 #ifdef WITH_CONTENT_SCAN
 648   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 649 #endif
 650   { "reply_address",       vtype_reply,       NULL },
 651   { "return_path",         vtype_stringptr,   &return_path },
 652   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 653   { "router_name",         vtype_stringptr,   &router_name },
 654   { "runrc",               vtype_int,         &runrc },
 655   { "self_hostname",       vtype_stringptr,   &self_hostname },
 656   { "sender_address",      vtype_stringptr,   &sender_address },
 657   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 658   { "sender_address_domain", vtype_domain,    &sender_address },
 659   { "sender_address_local_part", vtype_localpart, &sender_address },
 660   { "sender_data",         vtype_stringptr,   &sender_data },
 661   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 662   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 663   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 664   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 665   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 666   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 667   { "sender_host_name",    vtype_host_lookup, NULL },
 668   { "sender_host_port",    vtype_int,         &sender_host_port },
 669   { "sender_ident",        vtype_stringptr,   &sender_ident },
 670   { "sender_rate",         vtype_stringptr,   &sender_rate },
 671   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 672   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 673   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 674   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 675   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 676   { "sending_port",        vtype_int,         &sending_port },
 677   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 678   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 679   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 680   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 681   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 682   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 683   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 684   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 685   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 686   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 687   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 688   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 689   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 690   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 691   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 692 #ifdef WITH_CONTENT_SCAN
 693   { "spam_action",         vtype_stringptr,   &spam_action },
 694   { "spam_bar",            vtype_stringptr,   &spam_bar },
 695   { "spam_report",         vtype_stringptr,   &spam_report },
 696   { "spam_score",          vtype_stringptr,   &spam_score },
 697   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 698 #endif
 699 #ifdef EXPERIMENTAL_SPF
 700   { "spf_guess",           vtype_stringptr,   &spf_guess },
 701   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 702   { "spf_received",        vtype_stringptr,   &spf_received },
 703   { "spf_result",          vtype_stringptr,   &spf_result },
 704   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 705 #endif
 706   { "spool_directory",     vtype_stringptr,   &spool_directory },
 707   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 708   { "spool_space",         vtype_pspace,      (void *)TRUE },
 709 #ifdef EXPERIMENTAL_SRS
 710   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 711   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 712   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 713   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 714   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 715   { "srs_status",          vtype_stringptr,   &srs_status },
 716 #endif
 717   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 718
 719   /* The non-(in,out) variables are now deprecated */
 720   { "tls_bits",            vtype_int,         &tls_in.bits },
 721   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 722   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 723
 724   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 725   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 726   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 727   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 728   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 729   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 730   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 731 #if defined(SUPPORT_TLS)
 732   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 733 #endif
 734   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 735   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 736   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 737 #ifdef EXPERIMENTAL_DANE
 738   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 739 #endif
 740   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 741   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 742   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 743   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 744 #if defined(SUPPORT_TLS)
 745   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 746 #endif
 747 #ifdef EXPERIMENTAL_DANE
 748   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 749 #endif
 750
 751   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 752 #if defined(SUPPORT_TLS)
 753   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 754 #endif
 755
 756   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 757   { "tod_epoch",           vtype_tode,        NULL },
 758   { "tod_epoch_l",         vtype_todel,       NULL },
 759   { "tod_full",            vtype_todf,        NULL },
 760   { "tod_log",             vtype_todl,        NULL },
 761   { "tod_logfile",         vtype_todlf,       NULL },
 762   { "tod_zone",            vtype_todzone,     NULL },
 763   { "tod_zulu",            vtype_todzulu,     NULL },
 764   { "transport_name",      vtype_stringptr,   &transport_name },
 765   { "value",               vtype_stringptr,   &lookup_value },
 766   { "verify_mode",         vtype_stringptr,   &verify_mode },
 767   { "version_number",      vtype_stringptr,   &version_string },
 768   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 769   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 770   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 771   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 772   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 773   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 774 };
 775
 776 static int var_table_size = nelem(var_table);
 777 static uschar var_buffer[256];
 778 static BOOL malformed_header;
 779
 780 /* For textual hashes */
 781
 782 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 783                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 784                                "0123456789";
 785
 786 enum { HMAC_MD5, HMAC_SHA1 };
 787
 788 /* For numeric hashes */
 789
 790 static unsigned int prime[] = {
 791   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 792  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 793  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 794
 795 /* For printing modes in symbolic form */
 796
 797 static uschar *mtable_normal[] =
 798   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 799
 800 static uschar *mtable_setid[] =
 801   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 802
 803 static uschar *mtable_sticky[] =
 804   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 805
 806
 807
 808 /*************************************************
 809 *           Tables for UTF-8 support             *
 810 *************************************************/
 811
 812 /* Table of the number of extra characters, indexed by the first character
 813 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 814 0x3d. */
 815
 816 static uschar utf8_table1[] = {
 817   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 818   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 819   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 820   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 821
 822 /* These are the masks for the data bits in the first byte of a character,
 823 indexed by the number of additional bytes. */
 824
 825 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 826
 827 /* Get the next UTF-8 character, advancing the pointer. */
 828
 829 #define GETUTF8INC(c, ptr) \
 830   c = *ptr++; \
 831   if ((c & 0xc0) == 0xc0) \
 832     { \
 833     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 834     int s = 6*a; \
 835     c = (c & utf8_table2[a]) << s; \
 836     while (a-- > 0) \
 837       { \
 838       s -= 6; \
 839       c |= (*ptr++ & 0x3f) << s; \
 840       } \
 841     }
 842
 843
 844 /*************************************************
 845 *           Binary chop search on a table        *
 846 *************************************************/
 847
 848 /* This is used for matching expansion items and operators.
 849
 850 Arguments:
 851   name        the name that is being sought
 852   table       the table to search
 853   table_size  the number of items in the table
 854
 855 Returns:      the offset in the table, or -1
 856 */
 857
 858 static int
 859 chop_match(uschar *name, uschar **table, int table_size)
 860 {
 861 uschar **bot = table;
 862 uschar **top = table + table_size;
 863
 864 while (top > bot)
 865   {
 866   uschar **mid = bot + (top - bot)/2;
 867   int c = Ustrcmp(name, *mid);
 868   if (c == 0) return mid - table;
 869   if (c > 0) bot = mid + 1; else top = mid;
 870   }
 871
 872 return -1;
 873 }
 874
 875
 876
 877 /*************************************************
 878 *          Check a condition string              *
 879 *************************************************/
 880
 881 /* This function is called to expand a string, and test the result for a "true"
 882 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 883 forced fail or lookup defer.
 884
 885 We used to release all store used, but this is not not safe due
 886 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 887 is reasonably careful to release what it can.
 888
 889 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 890
 891 Arguments:
 892   condition     the condition string
 893   m1            text to be incorporated in panic error
 894   m2            ditto
 895
 896 Returns:        TRUE if condition is met, FALSE if not
 897 */
 898
 899 BOOL
 900 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 901 {
 902 int rc;
 903 uschar *ss = expand_string(condition);
 904 if (ss == NULL)
 905   {
 906   if (!expand_string_forcedfail && !search_find_defer)
 907     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 908       "for %s %s: %s", condition, m1, m2, expand_string_message);
 909   return FALSE;
 910   }
 911 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 912   strcmpic(ss, US"false") != 0;
 913 return rc;
 914 }
 915
 916
 917
 918
 919 /*************************************************
 920 *        Pseudo-random number generation         *
 921 *************************************************/
 922
 923 /* Pseudo-random number generation.  The result is not "expected" to be
 924 cryptographically strong but not so weak that someone will shoot themselves
 925 in the foot using it as a nonce in some email header scheme or whatever
 926 weirdness they'll twist this into.  The result should ideally handle fork().
 927
 928 However, if we're stuck unable to provide this, then we'll fall back to
 929 appallingly bad randomness.
 930
 931 If SUPPORT_TLS is defined then this will not be used except as an emergency
 932 fallback.
 933
 934 Arguments:
 935   max       range maximum
 936 Returns     a random number in range [0, max-1]
 937 */
 938
 939 #ifdef SUPPORT_TLS
 940 # define vaguely_random_number vaguely_random_number_fallback
 941 #endif
 942 int
 943 vaguely_random_number(int max)
 944 {
 945 #ifdef SUPPORT_TLS
 946 # undef vaguely_random_number
 947 #endif
 948   static pid_t pid = 0;
 949   pid_t p2;
 950 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 951   struct timeval tv;
 952 #endif
 953
 954   p2 = getpid();
 955   if (p2 != pid)
 956     {
 957     if (pid != 0)
 958       {
 959
 960 #ifdef HAVE_ARC4RANDOM
 961       /* cryptographically strong randomness, common on *BSD platforms, not
 962       so much elsewhere.  Alas. */
 963 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 964       arc4random_stir();
 965 #endif
 966 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 967 #ifdef HAVE_SRANDOMDEV
 968       /* uses random(4) for seeding */
 969       srandomdev();
 970 #else
 971       gettimeofday(&tv, NULL);
 972       srandom(tv.tv_sec | tv.tv_usec | getpid());
 973 #endif
 974 #else
 975       /* Poor randomness and no seeding here */
 976 #endif
 977
 978       }
 979     pid = p2;
 980     }
 981
 982 #ifdef HAVE_ARC4RANDOM
 983   return arc4random() % max;
 984 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 985   return random() % max;
 986 #else
 987   /* This one returns a 16-bit number, definitely not crypto-strong */
 988   return random_number(max);
 989 #endif
 990 }
 991
 992
 993
 994
 995 /*************************************************
 996 *             Pick out a name from a string      *
 997 *************************************************/
 998
 999 /* If the name is too long, it is silently truncated.
1000
1001 Arguments:
1002   name      points to a buffer into which to put the name
1003   max       is the length of the buffer
1004   s         points to the first alphabetic character of the name
1005   extras    chars other than alphanumerics to permit
1006
1007 Returns:    pointer to the first character after the name
1008
1009 Note: The test for *s != 0 in the while loop is necessary because
1010 Ustrchr() yields non-NULL if the character is zero (which is not something
1011 I expected). */
1012
1013 static const uschar *
1014 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1015 {
1016 int ptr = 0;
1017 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1018   {
1019   if (ptr < max-1) name[ptr++] = *s;
1020   s++;
1021   }
1022 name[ptr] = 0;
1023 return s;
1024 }
1025
1026
1027
1028 /*************************************************
1029 *     Pick out the rest of a header name         *
1030 *************************************************/
1031
1032 /* A variable name starting $header_ (or just $h_ for those who like
1033 abbreviations) might not be the complete header name because headers can
1034 contain any printing characters in their names, except ':'. This function is
1035 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1036 on the end, if the name was terminated by white space.
1037
1038 Arguments:
1039   name      points to a buffer in which the name read so far exists
1040   max       is the length of the buffer
1041   s         points to the first character after the name so far, i.e. the
1042             first non-alphameric character after $header_xxxxx
1043
1044 Returns:    a pointer to the first character after the header name
1045 */
1046
1047 static const uschar *
1048 read_header_name(uschar *name, int max, const uschar *s)
1049 {
1050 int prelen = Ustrchr(name, '_') - name + 1;
1051 int ptr = Ustrlen(name) - prelen;
1052 if (ptr > 0) memmove(name, name+prelen, ptr);
1053 while (mac_isgraph(*s) && *s != ':')
1054   {
1055   if (ptr < max-1) name[ptr++] = *s;
1056   s++;
1057   }
1058 if (*s == ':') s++;
1059 name[ptr++] = ':';
1060 name[ptr] = 0;
1061 return s;
1062 }
1063
1064
1065
1066 /*************************************************
1067 *           Pick out a number from a string      *
1068 *************************************************/
1069
1070 /* Arguments:
1071   n     points to an integer into which to put the number
1072   s     points to the first digit of the number
1073
1074 Returns:  a pointer to the character after the last digit
1075 */
1076 /*XXX consider expanding to int_eximarith_t.  But the test for
1077 "overbig numbers" in 0002 still needs to overflow it. */
1078
1079 static uschar *
1080 read_number(int *n, uschar *s)
1081 {
1082 *n = 0;
1083 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1084 return s;
1085 }
1086
1087 static const uschar *
1088 read_cnumber(int *n, const uschar *s)
1089 {
1090 *n = 0;
1091 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1092 return s;
1093 }
1094
1095
1096
1097 /*************************************************
1098 *        Extract keyed subfield from a string    *
1099 *************************************************/
1100
1101 /* The yield is in dynamic store; NULL means that the key was not found.
1102
1103 Arguments:
1104   key       points to the name of the key
1105   s         points to the string from which to extract the subfield
1106
1107 Returns:    NULL if the subfield was not found, or
1108             a pointer to the subfield's data
1109 */
1110
1111 static uschar *
1112 expand_getkeyed(uschar *key, const uschar *s)
1113 {
1114 int length = Ustrlen(key);
1115 while (isspace(*s)) s++;
1116
1117 /* Loop to search for the key */
1118
1119 while (*s != 0)
1120   {
1121   int dkeylength;
1122   uschar *data;
1123   const uschar *dkey = s;
1124
1125   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1126   dkeylength = s - dkey;
1127   while (isspace(*s)) s++;
1128   if (*s == '=') while (isspace((*(++s))));
1129
1130   data = string_dequote(&s);
1131   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1132     return data;
1133
1134   while (isspace(*s)) s++;
1135   }
1136
1137 return NULL;
1138 }
1139
1140
1141
1142 static var_entry *
1143 find_var_ent(uschar * name)
1144 {
1145 int first = 0;
1146 int last = var_table_size;
1147
1148 while (last > first)
1149   {
1150   int middle = (first + last)/2;
1151   int c = Ustrcmp(name, var_table[middle].name);
1152
1153   if (c > 0) { first = middle + 1; continue; }
1154   if (c < 0) { last = middle; continue; }
1155   return &var_table[middle];
1156   }
1157 return NULL;
1158 }
1159
1160 /*************************************************
1161 *   Extract numbered subfield from string        *
1162 *************************************************/
1163
1164 /* Extracts a numbered field from a string that is divided by tokens - for
1165 example a line from /etc/passwd is divided by colon characters.  First field is
1166 numbered one.  Negative arguments count from the right. Zero returns the whole
1167 string. Returns NULL if there are insufficient tokens in the string
1168
1169 ***WARNING***
1170 Modifies final argument - this is a dynamically generated string, so that's OK.
1171
1172 Arguments:
1173   field       number of field to be extracted,
1174                 first field = 1, whole string = 0, last field = -1
1175   separators  characters that are used to break string into tokens
1176   s           points to the string from which to extract the subfield
1177
1178 Returns:      NULL if the field was not found,
1179               a pointer to the field's data inside s (modified to add 0)
1180 */
1181
1182 static uschar *
1183 expand_gettokened (int field, uschar *separators, uschar *s)
1184 {
1185 int sep = 1;
1186 int count;
1187 uschar *ss = s;
1188 uschar *fieldtext = NULL;
1189
1190 if (field == 0) return s;
1191
1192 /* Break the line up into fields in place; for field > 0 we stop when we have
1193 done the number of fields we want. For field < 0 we continue till the end of
1194 the string, counting the number of fields. */
1195
1196 count = (field > 0)? field : INT_MAX;
1197
1198 while (count-- > 0)
1199   {
1200   size_t len;
1201
1202   /* Previous field was the last one in the string. For a positive field
1203   number, this means there are not enough fields. For a negative field number,
1204   check that there are enough, and scan back to find the one that is wanted. */
1205
1206   if (sep == 0)
1207     {
1208     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1209     if ((-field) == (INT_MAX - count - 1)) return s;
1210     while (field++ < 0)
1211       {
1212       ss--;
1213       while (ss[-1] != 0) ss--;
1214       }
1215     fieldtext = ss;
1216     break;
1217     }
1218
1219   /* Previous field was not last in the string; save its start and put a
1220   zero at its end. */
1221
1222   fieldtext = ss;
1223   len = Ustrcspn(ss, separators);
1224   sep = ss[len];
1225   ss[len] = 0;
1226   ss += len + 1;
1227   }
1228
1229 return fieldtext;
1230 }
1231
1232
1233 static uschar *
1234 expand_getlistele(int field, const uschar * list)
1235 {
1236 const uschar * tlist= list;
1237 int sep= 0;
1238 uschar dummy;
1239
1240 if(field<0)
1241   {
1242   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1243   sep= 0;
1244   }
1245 if(field==0) return NULL;
1246 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1247 return string_nextinlist(&list, &sep, NULL, 0);
1248 }
1249
1250
1251 /* Certificate fields, by name.  Worry about by-OID later */
1252 /* Names are chosen to not have common prefixes */
1253
1254 #ifdef SUPPORT_TLS
1255 typedef struct
1256 {
1257 uschar * name;
1258 int      namelen;
1259 uschar * (*getfn)(void * cert, uschar * mod);
1260 } certfield;
1261 static certfield certfields[] =
1262 {                       /* linear search; no special order */
1263   { US"version",         7,  &tls_cert_version },
1264   { US"serial_number",   13, &tls_cert_serial_number },
1265   { US"subject",         7,  &tls_cert_subject },
1266   { US"notbefore",       9,  &tls_cert_not_before },
1267   { US"notafter",        8,  &tls_cert_not_after },
1268   { US"issuer",          6,  &tls_cert_issuer },
1269   { US"signature",       9,  &tls_cert_signature },
1270   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1271   { US"subj_altname",    12, &tls_cert_subject_altname },
1272   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1273   { US"crl_uri",         7,  &tls_cert_crl_uri },
1274 };
1275
1276 static uschar *
1277 expand_getcertele(uschar * field, uschar * certvar)
1278 {
1279 var_entry * vp;
1280 certfield * cp;
1281
1282 if (!(vp = find_var_ent(certvar)))
1283   {
1284   expand_string_message =
1285     string_sprintf("no variable named \"%s\"", certvar);
1286   return NULL;          /* Unknown variable name */
1287   }
1288 /* NB this stops us passing certs around in variable.  Might
1289 want to do that in future */
1290 if (vp->type != vtype_cert)
1291   {
1292   expand_string_message =
1293     string_sprintf("\"%s\" is not a certificate", certvar);
1294   return NULL;          /* Unknown variable name */
1295   }
1296 if (!*(void **)vp->value)
1297   return NULL;
1298
1299 if (*field >= '0' && *field <= '9')
1300   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1301
1302 for(cp = certfields;
1303     cp < certfields + nelem(certfields);
1304     cp++)
1305   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1306     {
1307     uschar * modifier = *(field += cp->namelen) == ','
1308       ? ++field : NULL;
1309     return (*cp->getfn)( *(void **)vp->value, modifier );
1310     }
1311
1312 expand_string_message =
1313   string_sprintf("bad field selector \"%s\" for certextract", field);
1314 return NULL;
1315 }
1316 #endif  /*SUPPORT_TLS*/
1317
1318 /*************************************************
1319 *        Extract a substring from a string       *
1320 *************************************************/
1321
1322 /* Perform the ${substr or ${length expansion operations.
1323
1324 Arguments:
1325   subject     the input string
1326   value1      the offset from the start of the input string to the start of
1327                 the output string; if negative, count from the right.
1328   value2      the length of the output string, or negative (-1) for unset
1329                 if value1 is positive, unset means "all after"
1330                 if value1 is negative, unset means "all before"
1331   len         set to the length of the returned string
1332
1333 Returns:      pointer to the output string, or NULL if there is an error
1334 */
1335
1336 static uschar *
1337 extract_substr(uschar *subject, int value1, int value2, int *len)
1338 {
1339 int sublen = Ustrlen(subject);
1340
1341 if (value1 < 0)    /* count from right */
1342   {
1343   value1 += sublen;
1344
1345   /* If the position is before the start, skip to the start, and adjust the
1346   length. If the length ends up negative, the substring is null because nothing
1347   can precede. This falls out naturally when the length is unset, meaning "all
1348   to the left". */
1349
1350   if (value1 < 0)
1351     {
1352     value2 += value1;
1353     if (value2 < 0) value2 = 0;
1354     value1 = 0;
1355     }
1356
1357   /* Otherwise an unset length => characters before value1 */
1358
1359   else if (value2 < 0)
1360     {
1361     value2 = value1;
1362     value1 = 0;
1363     }
1364   }
1365
1366 /* For a non-negative offset, if the starting position is past the end of the
1367 string, the result will be the null string. Otherwise, an unset length means
1368 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1369
1370 else
1371   {
1372   if (value1 > sublen)
1373     {
1374     value1 = sublen;
1375     value2 = 0;
1376     }
1377   else if (value2 < 0) value2 = sublen;
1378   }
1379
1380 /* Cut the length down to the maximum possible for the offset value, and get
1381 the required characters. */
1382
1383 if (value1 + value2 > sublen) value2 = sublen - value1;
1384 *len = value2;
1385 return subject + value1;
1386 }
1387
1388
1389
1390
1391 /*************************************************
1392 *            Old-style hash of a string          *
1393 *************************************************/
1394
1395 /* Perform the ${hash expansion operation.
1396
1397 Arguments:
1398   subject     the input string (an expanded substring)
1399   value1      the length of the output string; if greater or equal to the
1400                 length of the input string, the input string is returned
1401   value2      the number of hash characters to use, or 26 if negative
1402   len         set to the length of the returned string
1403
1404 Returns:      pointer to the output string, or NULL if there is an error
1405 */
1406
1407 static uschar *
1408 compute_hash(uschar *subject, int value1, int value2, int *len)
1409 {
1410 int sublen = Ustrlen(subject);
1411
1412 if (value2 < 0) value2 = 26;
1413 else if (value2 > Ustrlen(hashcodes))
1414   {
1415   expand_string_message =
1416     string_sprintf("hash count \"%d\" too big", value2);
1417   return NULL;
1418   }
1419
1420 /* Calculate the hash text. We know it is shorter than the original string, so
1421 can safely place it in subject[] (we know that subject is always itself an
1422 expanded substring). */
1423
1424 if (value1 < sublen)
1425   {
1426   int c;
1427   int i = 0;
1428   int j = value1;
1429   while ((c = (subject[j])) != 0)
1430     {
1431     int shift = (c + j++) & 7;
1432     subject[i] ^= (c << shift) | (c >> (8-shift));
1433     if (++i >= value1) i = 0;
1434     }
1435   for (i = 0; i < value1; i++)
1436     subject[i] = hashcodes[(subject[i]) % value2];
1437   }
1438 else value1 = sublen;
1439
1440 *len = value1;
1441 return subject;
1442 }
1443
1444
1445
1446
1447 /*************************************************
1448 *             Numeric hash of a string           *
1449 *************************************************/
1450
1451 /* Perform the ${nhash expansion operation. The first characters of the
1452 string are treated as most important, and get the highest prime numbers.
1453
1454 Arguments:
1455   subject     the input string
1456   value1      the maximum value of the first part of the result
1457   value2      the maximum value of the second part of the result,
1458                 or negative to produce only a one-part result
1459   len         set to the length of the returned string
1460
1461 Returns:  pointer to the output string, or NULL if there is an error.
1462 */
1463
1464 static uschar *
1465 compute_nhash (uschar *subject, int value1, int value2, int *len)
1466 {
1467 uschar *s = subject;
1468 int i = 0;
1469 unsigned long int total = 0; /* no overflow */
1470
1471 while (*s != 0)
1472   {
1473   if (i == 0) i = nelem(prime) - 1;
1474   total += prime[i--] * (unsigned int)(*s++);
1475   }
1476
1477 /* If value2 is unset, just compute one number */
1478
1479 if (value2 < 0)
1480   {
1481   s = string_sprintf("%d", total % value1);
1482   }
1483
1484 /* Otherwise do a div/mod hash */
1485
1486 else
1487   {
1488   total = total % (value1 * value2);
1489   s = string_sprintf("%d/%d", total/value2, total % value2);
1490   }
1491
1492 *len = Ustrlen(s);
1493 return s;
1494 }
1495
1496
1497
1498
1499
1500 /*************************************************
1501 *     Find the value of a header or headers      *
1502 *************************************************/
1503
1504 /* Multiple instances of the same header get concatenated, and this function
1505 can also return a concatenation of all the header lines. When concatenating
1506 specific headers that contain lists of addresses, a comma is inserted between
1507 them. Otherwise we use a straight concatenation. Because some messages can have
1508 pathologically large number of lines, there is a limit on the length that is
1509 returned. Also, to avoid massive store use which would result from using
1510 string_cat() as it copies and extends strings, we do a preliminary pass to find
1511 out exactly how much store will be needed. On "normal" messages this will be
1512 pretty trivial.
1513
1514 Arguments:
1515   name          the name of the header, without the leading $header_ or $h_,
1516                 or NULL if a concatenation of all headers is required
1517   exists_only   TRUE if called from a def: test; don't need to build a string;
1518                 just return a string that is not "" and not "0" if the header
1519                 exists
1520   newsize       return the size of memory block that was obtained; may be NULL
1521                 if exists_only is TRUE
1522   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1523                 other than concatenating, will be done on the header. Also used
1524                 for $message_headers_raw.
1525   charset       name of charset to translate MIME words to; used only if
1526                 want_raw is false; if NULL, no translation is done (this is
1527                 used for $bh_ and $bheader_)
1528
1529 Returns:        NULL if the header does not exist, else a pointer to a new
1530                 store block
1531 */
1532
1533 static uschar *
1534 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1535   uschar *charset)
1536 {
1537 BOOL found = name == NULL;
1538 int comma = 0;
1539 int len = found? 0 : Ustrlen(name);
1540 int i;
1541 uschar *yield = NULL;
1542 uschar *ptr = NULL;
1543
1544 /* Loop for two passes - saves code repetition */
1545
1546 for (i = 0; i < 2; i++)
1547   {
1548   int size = 0;
1549   header_line *h;
1550
1551   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1552     {
1553     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1554       {
1555       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1556         {
1557         int ilen;
1558         uschar *t;
1559
1560         if (exists_only) return US"1";      /* don't need actual string */
1561         found = TRUE;
1562         t = h->text + len;                  /* text to insert */
1563         if (!want_raw)                      /* unless wanted raw, */
1564           while (isspace(*t)) t++;          /* remove leading white space */
1565         ilen = h->slen - (t - h->text);     /* length to insert */
1566
1567         /* Unless wanted raw, remove trailing whitespace, including the
1568         newline. */
1569
1570         if (!want_raw)
1571           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1572
1573         /* Set comma = 1 if handling a single header and it's one of those
1574         that contains an address list, except when asked for raw headers. Only
1575         need to do this once. */
1576
1577         if (!want_raw && name != NULL && comma == 0 &&
1578             Ustrchr("BCFRST", h->type) != NULL)
1579           comma = 1;
1580
1581         /* First pass - compute total store needed; second pass - compute
1582         total store used, including this header. */
1583
1584         size += ilen + comma + 1;  /* +1 for the newline */
1585
1586         /* Second pass - concatentate the data, up to a maximum. Note that
1587         the loop stops when size hits the limit. */
1588
1589         if (i != 0)
1590           {
1591           if (size > header_insert_maxlen)
1592             {
1593             ilen -= size - header_insert_maxlen - 1;
1594             comma = 0;
1595             }
1596           Ustrncpy(ptr, t, ilen);
1597           ptr += ilen;
1598
1599           /* For a non-raw header, put in the comma if needed, then add
1600           back the newline we removed above, provided there was some text in
1601           the header. */
1602
1603           if (!want_raw && ilen > 0)
1604             {
1605             if (comma != 0) *ptr++ = ',';
1606             *ptr++ = '\n';
1607             }
1608           }
1609         }
1610       }
1611     }
1612
1613   /* At end of first pass, return NULL if no header found. Then truncate size
1614   if necessary, and get the buffer to hold the data, returning the buffer size.
1615   */
1616
1617   if (i == 0)
1618     {
1619     if (!found) return NULL;
1620     if (size > header_insert_maxlen) size = header_insert_maxlen;
1621     *newsize = size + 1;
1622     ptr = yield = store_get(*newsize);
1623     }
1624   }
1625
1626 /* That's all we do for raw header expansion. */
1627
1628 if (want_raw)
1629   {
1630   *ptr = 0;
1631   }
1632
1633 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1634 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1635 function can return an error with decoded data if the charset translation
1636 fails. If decoding fails, it returns NULL. */
1637
1638 else
1639   {
1640   uschar *decoded, *error;
1641   if (ptr > yield && ptr[-1] == '\n') ptr--;
1642   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1643   *ptr = 0;
1644   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1645     newsize, &error);
1646   if (error != NULL)
1647     {
1648     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1649       "    input was: %s\n", error, yield);
1650     }
1651   if (decoded != NULL) yield = decoded;
1652   }
1653
1654 return yield;
1655 }
1656
1657
1658
1659
1660 /*************************************************
1661 *               Return list of recipients        *
1662 *************************************************/
1663 /* A recipients list is available only during system message filtering,
1664 during ACL processing after DATA, and while expanding pipe commands
1665 generated from a system filter, but not elsewhere. */
1666
1667 static uschar *
1668 fn_recipients(void)
1669 {
1670 if (!enable_dollar_recipients) return NULL; else
1671   {
1672   int size = 128;
1673   int ptr = 0;
1674   int i;
1675   uschar * s = store_get(size);
1676   for (i = 0; i < recipients_count; i++)
1677     {
1678     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1679     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1680       Ustrlen(recipients_list[i].address));
1681     }
1682   s[ptr] = 0;     /* string_cat() leaves room */
1683   return s;
1684   }
1685 }
1686
1687
1688 /*************************************************
1689 *               Find value of a variable         *
1690 *************************************************/
1691
1692 /* The table of variables is kept in alphabetic order, so we can search it
1693 using a binary chop. The "choplen" variable is nothing to do with the binary
1694 chop.
1695
1696 Arguments:
1697   name          the name of the variable being sought
1698   exists_only   TRUE if this is a def: test; passed on to find_header()
1699   skipping      TRUE => skip any processing evaluation; this is not the same as
1700                   exists_only because def: may test for values that are first
1701                   evaluated here
1702   newsize       pointer to an int which is initially zero; if the answer is in
1703                 a new memory buffer, *newsize is set to its size
1704
1705 Returns:        NULL if the variable does not exist, or
1706                 a pointer to the variable's contents, or
1707                 something non-NULL if exists_only is TRUE
1708 */
1709
1710 static uschar *
1711 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1712 {
1713 var_entry * vp;
1714 uschar *s, *domain;
1715 uschar **ss;
1716 void * val;
1717
1718 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1719 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1720 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1721 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1722 (this gave backwards compatibility at the changeover). There may be built-in
1723 variables whose names start acl_ but they should never start in this way. This
1724 slightly messy specification is a consequence of the history, needless to say.
1725
1726 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1727 set, in which case give an error. */
1728
1729 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1730      !isalpha(name[5]))
1731   {
1732   tree_node *node =
1733     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1734   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1735   }
1736
1737 /* Handle $auth<n> variables. */
1738
1739 if (Ustrncmp(name, "auth", 4) == 0)
1740   {
1741   uschar *endptr;
1742   int n = Ustrtoul(name + 4, &endptr, 10);
1743   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1744     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1745   }
1746 else if (Ustrncmp(name, "regex", 5) == 0)
1747   {
1748   uschar *endptr;
1749   int n = Ustrtoul(name + 5, &endptr, 10);
1750   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1751     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1752   }
1753
1754 /* For all other variables, search the table */
1755
1756 if (!(vp = find_var_ent(name)))
1757   return NULL;          /* Unknown variable name */
1758
1759 /* Found an existing variable. If in skipping state, the value isn't needed,
1760 and we want to avoid processing (such as looking up the host name). */
1761
1762 if (skipping)
1763   return US"";
1764
1765 val = vp->value;
1766 switch (vp->type)
1767   {
1768   case vtype_filter_int:
1769     if (!filter_running) return NULL;
1770     /* Fall through */
1771     /* VVVVVVVVVVVV */
1772   case vtype_int:
1773     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1774     return var_buffer;
1775
1776   case vtype_ino:
1777     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1778     return var_buffer;
1779
1780   case vtype_gid:
1781     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1782     return var_buffer;
1783
1784   case vtype_uid:
1785     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1786     return var_buffer;
1787
1788   case vtype_bool:
1789     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1790     return var_buffer;
1791
1792   case vtype_stringptr:                      /* Pointer to string */
1793     return (s = *((uschar **)(val))) ? s : US"";
1794
1795   case vtype_pid:
1796     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1797     return var_buffer;
1798
1799   case vtype_load_avg:
1800     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1801     return var_buffer;
1802
1803   case vtype_host_lookup:                    /* Lookup if not done so */
1804     if (sender_host_name == NULL && sender_host_address != NULL &&
1805         !host_lookup_failed && host_name_lookup() == OK)
1806       host_build_sender_fullhost();
1807     return (sender_host_name == NULL)? US"" : sender_host_name;
1808
1809   case vtype_localpart:                      /* Get local part from address */
1810     s = *((uschar **)(val));
1811     if (s == NULL) return US"";
1812     domain = Ustrrchr(s, '@');
1813     if (domain == NULL) return s;
1814     if (domain - s > sizeof(var_buffer) - 1)
1815       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1816           " in string expansion", sizeof(var_buffer));
1817     Ustrncpy(var_buffer, s, domain - s);
1818     var_buffer[domain - s] = 0;
1819     return var_buffer;
1820
1821   case vtype_domain:                         /* Get domain from address */
1822     s = *((uschar **)(val));
1823     if (s == NULL) return US"";
1824     domain = Ustrrchr(s, '@');
1825     return (domain == NULL)? US"" : domain + 1;
1826
1827   case vtype_msgheaders:
1828     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1829
1830   case vtype_msgheaders_raw:
1831     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1832
1833   case vtype_msgbody:                        /* Pointer to msgbody string */
1834   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1835     ss = (uschar **)(val);
1836     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1837       {
1838       uschar *body;
1839       off_t start_offset = SPOOL_DATA_START_OFFSET;
1840       int len = message_body_visible;
1841       if (len > message_size) len = message_size;
1842       *ss = body = store_malloc(len+1);
1843       body[0] = 0;
1844       if (vp->type == vtype_msgbody_end)
1845         {
1846         struct stat statbuf;
1847         if (fstat(deliver_datafile, &statbuf) == 0)
1848           {
1849           start_offset = statbuf.st_size - len;
1850           if (start_offset < SPOOL_DATA_START_OFFSET)
1851             start_offset = SPOOL_DATA_START_OFFSET;
1852           }
1853         }
1854       lseek(deliver_datafile, start_offset, SEEK_SET);
1855       len = read(deliver_datafile, body, len);
1856       if (len > 0)
1857         {
1858         body[len] = 0;
1859         if (message_body_newlines)   /* Separate loops for efficiency */
1860           while (len > 0)
1861             { if (body[--len] == 0) body[len] = ' '; }
1862         else
1863           while (len > 0)
1864             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1865         }
1866       }
1867     return (*ss == NULL)? US"" : *ss;
1868
1869   case vtype_todbsdin:                       /* BSD inbox time of day */
1870     return tod_stamp(tod_bsdin);
1871
1872   case vtype_tode:                           /* Unix epoch time of day */
1873     return tod_stamp(tod_epoch);
1874
1875   case vtype_todel:                          /* Unix epoch/usec time of day */
1876     return tod_stamp(tod_epoch_l);
1877
1878   case vtype_todf:                           /* Full time of day */
1879     return tod_stamp(tod_full);
1880
1881   case vtype_todl:                           /* Log format time of day */
1882     return tod_stamp(tod_log_bare);            /* (without timezone) */
1883
1884   case vtype_todzone:                        /* Time zone offset only */
1885     return tod_stamp(tod_zone);
1886
1887   case vtype_todzulu:                        /* Zulu time */
1888     return tod_stamp(tod_zulu);
1889
1890   case vtype_todlf:                          /* Log file datestamp tod */
1891     return tod_stamp(tod_log_datestamp_daily);
1892
1893   case vtype_reply:                          /* Get reply address */
1894     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1895       headers_charset);
1896     if (s != NULL) while (isspace(*s)) s++;
1897     if (s == NULL || *s == 0)
1898       {
1899       *newsize = 0;                            /* For the *s==0 case */
1900       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1901       }
1902     if (s != NULL)
1903       {
1904       uschar *t;
1905       while (isspace(*s)) s++;
1906       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1907       while (t > s && isspace(t[-1])) t--;
1908       *t = 0;
1909       }
1910     return (s == NULL)? US"" : s;
1911
1912   case vtype_string_func:
1913     {
1914     uschar * (*fn)() = val;
1915     return fn();
1916     }
1917
1918   case vtype_pspace:
1919     {
1920     int inodes;
1921     sprintf(CS var_buffer, "%d",
1922       receive_statvfs(val == (void *)TRUE, &inodes));
1923     }
1924   return var_buffer;
1925
1926   case vtype_pinodes:
1927     {
1928     int inodes;
1929     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1930     sprintf(CS var_buffer, "%d", inodes);
1931     }
1932   return var_buffer;
1933
1934   case vtype_cert:
1935     return *(void **)val ? US"<cert>" : US"";
1936
1937 #ifndef DISABLE_DKIM
1938   case vtype_dkim:
1939     return dkim_exim_expand_query((int)(long)val);
1940 #endif
1941
1942   }
1943
1944 return NULL;  /* Unknown variable. Silences static checkers. */
1945 }
1946
1947
1948
1949
1950 void
1951 modify_variable(uschar *name, void * value)
1952 {
1953 var_entry * vp;
1954 if ((vp = find_var_ent(name))) vp->value = value;
1955 return;          /* Unknown variable name, fail silently */
1956 }
1957
1958
1959
1960
1961
1962 /*************************************************
1963 *           Read and expand substrings           *
1964 *************************************************/
1965
1966 /* This function is called to read and expand argument substrings for various
1967 expansion items. Some have a minimum requirement that is less than the maximum;
1968 in these cases, the first non-present one is set to NULL.
1969
1970 Arguments:
1971   sub        points to vector of pointers to set
1972   n          maximum number of substrings
1973   m          minimum required
1974   sptr       points to current string pointer
1975   skipping   the skipping flag
1976   check_end  if TRUE, check for final '}'
1977   name       name of item, for error message
1978   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1979              the store.
1980
1981 Returns:     0 OK; string pointer updated
1982              1 curly bracketing error (too few arguments)
1983              2 too many arguments (only if check_end is set); message set
1984              3 other error (expansion failure)
1985 */
1986
1987 static int
1988 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1989   BOOL check_end, uschar *name, BOOL *resetok)
1990 {
1991 int i;
1992 const uschar *s = *sptr;
1993
1994 while (isspace(*s)) s++;
1995 for (i = 0; i < n; i++)
1996   {
1997   if (*s != '{')
1998     {
1999     if (i < m) return 1;
2000     sub[i] = NULL;
2001     break;
2002     }
2003   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok);
2004   if (sub[i] == NULL) return 3;
2005   if (*s++ != '}') return 1;
2006   while (isspace(*s)) s++;
2007   }
2008 if (check_end && *s++ != '}')
2009   {
2010   if (s[-1] == '{')
2011     {
2012     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
2013       "(max is %d)", name, n);
2014     return 2;
2015     }
2016   return 1;
2017   }
2018
2019 *sptr = s;
2020 return 0;
2021 }
2022
2023
2024
2025
2026 /*************************************************
2027 *     Elaborate message for bad variable         *
2028 *************************************************/
2029
2030 /* For the "unknown variable" message, take a look at the variable's name, and
2031 give additional information about possible ACL variables. The extra information
2032 is added on to expand_string_message.
2033
2034 Argument:   the name of the variable
2035 Returns:    nothing
2036 */
2037
2038 static void
2039 check_variable_error_message(uschar *name)
2040 {
2041 if (Ustrncmp(name, "acl_", 4) == 0)
2042   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2043     (name[4] == 'c' || name[4] == 'm')?
2044       (isalpha(name[5])?
2045         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2046         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2047       ) :
2048       US"user-defined ACL variables must start acl_c or acl_m");
2049 }
2050
2051
2052
2053 /*
2054 Load args from sub array to globals, and call acl_check().
2055 Sub array will be corrupted on return.
2056
2057 Returns:       OK         access is granted by an ACCEPT verb
2058                DISCARD    access is granted by a DISCARD verb
2059                FAIL       access is denied
2060                FAIL_DROP  access is denied; drop the connection
2061                DEFER      can't tell at the moment
2062                ERROR      disaster
2063 */
2064 static int
2065 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2066 {
2067 int i;
2068 int sav_narg = acl_narg;
2069 int ret;
2070 uschar * dummy_logmsg;
2071 extern int acl_where;
2072
2073 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2074 for (i = 0; i < nsub && sub[i+1]; i++)
2075   {
2076   uschar * tmp = acl_arg[i];
2077   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2078   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2079   }
2080 acl_narg = i;
2081 while (i < nsub)
2082   {
2083   sub[i+1] = acl_arg[i];
2084   acl_arg[i++] = NULL;
2085   }
2086
2087 DEBUG(D_expand)
2088   debug_printf("expanding: acl: %s  arg: %s%s\n",
2089     sub[0],
2090     acl_narg>0 ? acl_arg[0] : US"<none>",
2091     acl_narg>1 ? " +more"   : "");
2092
2093 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2094
2095 for (i = 0; i < nsub; i++)
2096   acl_arg[i] = sub[i+1];        /* restore old args */
2097 acl_narg = sav_narg;
2098
2099 return ret;
2100 }
2101
2102
2103
2104
2105 /*************************************************
2106 *        Read and evaluate a condition           *
2107 *************************************************/
2108
2109 /*
2110 Arguments:
2111   s        points to the start of the condition text
2112   resetok  points to a BOOL which is written false if it is unsafe to
2113            free memory. Certain condition types (acl) may have side-effect
2114            allocation which must be preserved.
2115   yield    points to a BOOL to hold the result of the condition test;
2116            if NULL, we are just reading through a condition that is
2117            part of an "or" combination to check syntax, or in a state
2118            where the answer isn't required
2119
2120 Returns:   a pointer to the first character after the condition, or
2121            NULL after an error
2122 */
2123
2124 static const uschar *
2125 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2126 {
2127 BOOL testfor = TRUE;
2128 BOOL tempcond, combined_cond;
2129 BOOL *subcondptr;
2130 BOOL sub2_honour_dollar = TRUE;
2131 int i, rc, cond_type, roffset;
2132 int_eximarith_t num[2];
2133 struct stat statbuf;
2134 uschar name[256];
2135 const uschar *sub[10];
2136
2137 const pcre *re;
2138 const uschar *rerror;
2139
2140 for (;;)
2141   {
2142   while (isspace(*s)) s++;
2143   if (*s == '!') { testfor = !testfor; s++; } else break;
2144   }
2145
2146 /* Numeric comparisons are symbolic */
2147
2148 if (*s == '=' || *s == '>' || *s == '<')
2149   {
2150   int p = 0;
2151   name[p++] = *s++;
2152   if (*s == '=')
2153     {
2154     name[p++] = '=';
2155     s++;
2156     }
2157   name[p] = 0;
2158   }
2159
2160 /* All other conditions are named */
2161
2162 else s = read_name(name, 256, s, US"_");
2163
2164 /* If we haven't read a name, it means some non-alpha character is first. */
2165
2166 if (name[0] == 0)
2167   {
2168   expand_string_message = string_sprintf("condition name expected, "
2169     "but found \"%.16s\"", s);
2170   return NULL;
2171   }
2172
2173 /* Find which condition we are dealing with, and switch on it */
2174
2175 cond_type = chop_match(name, cond_table, nelem(cond_table));
2176 switch(cond_type)
2177   {
2178   /* def: tests for a non-empty variable, or for the existence of a header. If
2179   yield == NULL we are in a skipping state, and don't care about the answer. */
2180
2181   case ECOND_DEF:
2182   if (*s != ':')
2183     {
2184     expand_string_message = US"\":\" expected after \"def\"";
2185     return NULL;
2186     }
2187
2188   s = read_name(name, 256, s+1, US"_");
2189
2190   /* Test for a header's existence. If the name contains a closing brace
2191   character, this may be a user error where the terminating colon has been
2192   omitted. Set a flag to adjust a subsequent error message in this case. */
2193
2194   if (Ustrncmp(name, "h_", 2) == 0 ||
2195       Ustrncmp(name, "rh_", 3) == 0 ||
2196       Ustrncmp(name, "bh_", 3) == 0 ||
2197       Ustrncmp(name, "header_", 7) == 0 ||
2198       Ustrncmp(name, "rheader_", 8) == 0 ||
2199       Ustrncmp(name, "bheader_", 8) == 0)
2200     {
2201     s = read_header_name(name, 256, s);
2202     /* {-for-text-editors */
2203     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2204     if (yield != NULL) *yield =
2205       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2206     }
2207
2208   /* Test for a variable's having a non-empty value. A non-existent variable
2209   causes an expansion failure. */
2210
2211   else
2212     {
2213     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2214     if (value == NULL)
2215       {
2216       expand_string_message = (name[0] == 0)?
2217         string_sprintf("variable name omitted after \"def:\"") :
2218         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2219       check_variable_error_message(name);
2220       return NULL;
2221       }
2222     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2223     }
2224
2225   return s;
2226
2227
2228   /* first_delivery tests for first delivery attempt */
2229
2230   case ECOND_FIRST_DELIVERY:
2231   if (yield != NULL) *yield = deliver_firsttime == testfor;
2232   return s;
2233
2234
2235   /* queue_running tests for any process started by a queue runner */
2236
2237   case ECOND_QUEUE_RUNNING:
2238   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2239   return s;
2240
2241
2242   /* exists:  tests for file existence
2243        isip:  tests for any IP address
2244       isip4:  tests for an IPv4 address
2245       isip6:  tests for an IPv6 address
2246         pam:  does PAM authentication
2247      radius:  does RADIUS authentication
2248    ldapauth:  does LDAP authentication
2249     pwcheck:  does Cyrus SASL pwcheck authentication
2250   */
2251
2252   case ECOND_EXISTS:
2253   case ECOND_ISIP:
2254   case ECOND_ISIP4:
2255   case ECOND_ISIP6:
2256   case ECOND_PAM:
2257   case ECOND_RADIUS:
2258   case ECOND_LDAPAUTH:
2259   case ECOND_PWCHECK:
2260
2261   while (isspace(*s)) s++;
2262   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2263
2264   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2265   if (sub[0] == NULL) return NULL;
2266   /* {-for-text-editors */
2267   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2268
2269   if (yield == NULL) return s;   /* No need to run the test if skipping */
2270
2271   switch(cond_type)
2272     {
2273     case ECOND_EXISTS:
2274     if ((expand_forbid & RDO_EXISTS) != 0)
2275       {
2276       expand_string_message = US"File existence tests are not permitted";
2277       return NULL;
2278       }
2279     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2280     break;
2281
2282     case ECOND_ISIP:
2283     case ECOND_ISIP4:
2284     case ECOND_ISIP6:
2285     rc = string_is_ip_address(sub[0], NULL);
2286     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2287              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2288     break;
2289
2290     /* Various authentication tests - all optionally compiled */
2291
2292     case ECOND_PAM:
2293     #ifdef SUPPORT_PAM
2294     rc = auth_call_pam(sub[0], &expand_string_message);
2295     goto END_AUTH;
2296     #else
2297     goto COND_FAILED_NOT_COMPILED;
2298     #endif  /* SUPPORT_PAM */
2299
2300     case ECOND_RADIUS:
2301     #ifdef RADIUS_CONFIG_FILE
2302     rc = auth_call_radius(sub[0], &expand_string_message);
2303     goto END_AUTH;
2304     #else
2305     goto COND_FAILED_NOT_COMPILED;
2306     #endif  /* RADIUS_CONFIG_FILE */
2307
2308     case ECOND_LDAPAUTH:
2309     #ifdef LOOKUP_LDAP
2310       {
2311       /* Just to keep the interface the same */
2312       BOOL do_cache;
2313       int old_pool = store_pool;
2314       store_pool = POOL_SEARCH;
2315       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2316         &expand_string_message, &do_cache);
2317       store_pool = old_pool;
2318       }
2319     goto END_AUTH;
2320     #else
2321     goto COND_FAILED_NOT_COMPILED;
2322     #endif  /* LOOKUP_LDAP */
2323
2324     case ECOND_PWCHECK:
2325     #ifdef CYRUS_PWCHECK_SOCKET
2326     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2327     goto END_AUTH;
2328     #else
2329     goto COND_FAILED_NOT_COMPILED;
2330     #endif  /* CYRUS_PWCHECK_SOCKET */
2331
2332     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2333         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2334     END_AUTH:
2335     if (rc == ERROR || rc == DEFER) return NULL;
2336     *yield = (rc == OK) == testfor;
2337     #endif
2338     }
2339   return s;
2340
2341
2342   /* call ACL (in a conditional context).  Accept true, deny false.
2343   Defer is a forced-fail.  Anything set by message= goes to $value.
2344   Up to ten parameters are used; we use the braces round the name+args
2345   like the saslauthd condition does, to permit a variable number of args.
2346   See also the expansion-item version EITEM_ACL and the traditional
2347   acl modifier ACLC_ACL.
2348   Since the ACL may allocate new global variables, tell our caller to not
2349   reclaim memory.
2350   */
2351
2352   case ECOND_ACL:
2353     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2354     {
2355     uschar *sub[10];
2356     uschar *user_msg;
2357     BOOL cond = FALSE;
2358     int size = 0;
2359     int ptr = 0;
2360
2361     while (isspace(*s)) s++;
2362     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2363
2364     switch(read_subs(sub, nelem(sub), 1,
2365       &s, yield == NULL, TRUE, US"acl", resetok))
2366       {
2367       case 1: expand_string_message = US"too few arguments or bracketing "
2368         "error for acl";
2369       case 2:
2370       case 3: return NULL;
2371       }
2372
2373     *resetok = FALSE;
2374     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2375         {
2376         case OK:
2377           cond = TRUE;
2378         case FAIL:
2379           lookup_value = NULL;
2380           if (user_msg)
2381             {
2382             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2383             lookup_value[ptr] = '\0';
2384             }
2385           *yield = cond == testfor;
2386           break;
2387
2388         case DEFER:
2389           expand_string_forcedfail = TRUE;
2390         default:
2391           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2392           return NULL;
2393         }
2394     return s;
2395     }
2396
2397
2398   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2399
2400      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2401
2402   However, the last two are optional. That is why the whole set is enclosed
2403   in their own set of braces. */
2404
2405   case ECOND_SASLAUTHD:
2406 #ifndef CYRUS_SASLAUTHD_SOCKET
2407     goto COND_FAILED_NOT_COMPILED;
2408 #else
2409     {
2410     uschar *sub[4];
2411     while (isspace(*s)) s++;
2412     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2413     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2414                     resetok))
2415       {
2416       case 1: expand_string_message = US"too few arguments or bracketing "
2417         "error for saslauthd";
2418       case 2:
2419       case 3: return NULL;
2420       }
2421     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2422     if (yield != NULL)
2423       {
2424       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2425         &expand_string_message);
2426       if (rc == ERROR || rc == DEFER) return NULL;
2427       *yield = (rc == OK) == testfor;
2428       }
2429     return s;
2430     }
2431 #endif /* CYRUS_SASLAUTHD_SOCKET */
2432
2433
2434   /* symbolic operators for numeric and string comparison, and a number of
2435   other operators, all requiring two arguments.
2436
2437   crypteq:           encrypts plaintext and compares against an encrypted text,
2438                        using crypt(), crypt16(), MD5 or SHA-1
2439   inlist/inlisti:    checks if first argument is in the list of the second
2440   match:             does a regular expression match and sets up the numerical
2441                        variables if it succeeds
2442   match_address:     matches in an address list
2443   match_domain:      matches in a domain list
2444   match_ip:          matches a host list that is restricted to IP addresses
2445   match_local_part:  matches in a local part list
2446   */
2447
2448   case ECOND_MATCH_ADDRESS:
2449   case ECOND_MATCH_DOMAIN:
2450   case ECOND_MATCH_IP:
2451   case ECOND_MATCH_LOCAL_PART:
2452 #ifndef EXPAND_LISTMATCH_RHS
2453     sub2_honour_dollar = FALSE;
2454 #endif
2455     /* FALLTHROUGH */
2456
2457   case ECOND_CRYPTEQ:
2458   case ECOND_INLIST:
2459   case ECOND_INLISTI:
2460   case ECOND_MATCH:
2461
2462   case ECOND_NUM_L:     /* Numerical comparisons */
2463   case ECOND_NUM_LE:
2464   case ECOND_NUM_E:
2465   case ECOND_NUM_EE:
2466   case ECOND_NUM_G:
2467   case ECOND_NUM_GE:
2468
2469   case ECOND_STR_LT:    /* String comparisons */
2470   case ECOND_STR_LTI:
2471   case ECOND_STR_LE:
2472   case ECOND_STR_LEI:
2473   case ECOND_STR_EQ:
2474   case ECOND_STR_EQI:
2475   case ECOND_STR_GT:
2476   case ECOND_STR_GTI:
2477   case ECOND_STR_GE:
2478   case ECOND_STR_GEI:
2479
2480   for (i = 0; i < 2; i++)
2481     {
2482     /* Sometimes, we don't expand substrings; too many insecure configurations
2483     created using match_address{}{} and friends, where the second param
2484     includes information from untrustworthy sources. */
2485     BOOL honour_dollar = TRUE;
2486     if ((i > 0) && !sub2_honour_dollar)
2487       honour_dollar = FALSE;
2488
2489     while (isspace(*s)) s++;
2490     if (*s != '{')
2491       {
2492       if (i == 0) goto COND_FAILED_CURLY_START;
2493       expand_string_message = string_sprintf("missing 2nd string in {} "
2494         "after \"%s\"", name);
2495       return NULL;
2496       }
2497     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2498         honour_dollar, resetok);
2499     if (sub[i] == NULL) return NULL;
2500     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2501
2502     /* Convert to numerical if required; we know that the names of all the
2503     conditions that compare numbers do not start with a letter. This just saves
2504     checking for them individually. */
2505
2506     if (!isalpha(name[0]) && yield != NULL)
2507       {
2508       if (sub[i][0] == 0)
2509         {
2510         num[i] = 0;
2511         DEBUG(D_expand)
2512           debug_printf("empty string cast to zero for numerical comparison\n");
2513         }
2514       else
2515         {
2516         num[i] = expanded_string_integer(sub[i], FALSE);
2517         if (expand_string_message != NULL) return NULL;
2518         }
2519       }
2520     }
2521
2522   /* Result not required */
2523
2524   if (yield == NULL) return s;
2525
2526   /* Do an appropriate comparison */
2527
2528   switch(cond_type)
2529     {
2530     case ECOND_NUM_E:
2531     case ECOND_NUM_EE:
2532     tempcond = (num[0] == num[1]);
2533     break;
2534
2535     case ECOND_NUM_G:
2536     tempcond = (num[0] > num[1]);
2537     break;
2538
2539     case ECOND_NUM_GE:
2540     tempcond = (num[0] >= num[1]);
2541     break;
2542
2543     case ECOND_NUM_L:
2544     tempcond = (num[0] < num[1]);
2545     break;
2546
2547     case ECOND_NUM_LE:
2548     tempcond = (num[0] <= num[1]);
2549     break;
2550
2551     case ECOND_STR_LT:
2552     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2553     break;
2554
2555     case ECOND_STR_LTI:
2556     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2557     break;
2558
2559     case ECOND_STR_LE:
2560     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2561     break;
2562
2563     case ECOND_STR_LEI:
2564     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2565     break;
2566
2567     case ECOND_STR_EQ:
2568     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2569     break;
2570
2571     case ECOND_STR_EQI:
2572     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2573     break;
2574
2575     case ECOND_STR_GT:
2576     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2577     break;
2578
2579     case ECOND_STR_GTI:
2580     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2581     break;
2582
2583     case ECOND_STR_GE:
2584     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2585     break;
2586
2587     case ECOND_STR_GEI:
2588     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2589     break;
2590
2591     case ECOND_MATCH:   /* Regular expression match */
2592     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2593       NULL);
2594     if (re == NULL)
2595       {
2596       expand_string_message = string_sprintf("regular expression error in "
2597         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2598       return NULL;
2599       }
2600     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2601     break;
2602
2603     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2604     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2605     goto MATCHED_SOMETHING;
2606
2607     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2608     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2609       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2610     goto MATCHED_SOMETHING;
2611
2612     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2613     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2614       {
2615       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2616         sub[0]);
2617       return NULL;
2618       }
2619     else
2620       {
2621       unsigned int *nullcache = NULL;
2622       check_host_block cb;
2623
2624       cb.host_name = US"";
2625       cb.host_address = sub[0];
2626
2627       /* If the host address starts off ::ffff: it is an IPv6 address in
2628       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2629       addresses. */
2630
2631       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2632         cb.host_address + 7 : cb.host_address;
2633
2634       rc = match_check_list(
2635              &sub[1],                   /* the list */
2636              0,                         /* separator character */
2637              &hostlist_anchor,          /* anchor pointer */
2638              &nullcache,                /* cache pointer */
2639              check_host,                /* function for testing */
2640              &cb,                       /* argument for function */
2641              MCL_HOST,                  /* type of check */
2642              sub[0],                    /* text for debugging */
2643              NULL);                     /* where to pass back data */
2644       }
2645     goto MATCHED_SOMETHING;
2646
2647     case ECOND_MATCH_LOCAL_PART:
2648     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2649       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2650     /* Fall through */
2651     /* VVVVVVVVVVVV */
2652     MATCHED_SOMETHING:
2653     switch(rc)
2654       {
2655       case OK:
2656       tempcond = TRUE;
2657       break;
2658
2659       case FAIL:
2660       tempcond = FALSE;
2661       break;
2662
2663       case DEFER:
2664       expand_string_message = string_sprintf("unable to complete match "
2665         "against \"%s\": %s", sub[1], search_error_message);
2666       return NULL;
2667       }
2668
2669     break;
2670
2671     /* Various "encrypted" comparisons. If the second string starts with
2672     "{" then an encryption type is given. Default to crypt() or crypt16()
2673     (build-time choice). */
2674     /* }-for-text-editors */
2675
2676     case ECOND_CRYPTEQ:
2677     #ifndef SUPPORT_CRYPTEQ
2678     goto COND_FAILED_NOT_COMPILED;
2679     #else
2680     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2681       {
2682       int sublen = Ustrlen(sub[1]+5);
2683       md5 base;
2684       uschar digest[16];
2685
2686       md5_start(&base);
2687       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2688
2689       /* If the length that we are comparing against is 24, the MD5 digest
2690       is expressed as a base64 string. This is the way LDAP does it. However,
2691       some other software uses a straightforward hex representation. We assume
2692       this if the length is 32. Other lengths fail. */
2693
2694       if (sublen == 24)
2695         {
2696         uschar *coded = b64encode((uschar *)digest, 16);
2697         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2698           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2699         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2700         }
2701       else if (sublen == 32)
2702         {
2703         int i;
2704         uschar coded[36];
2705         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2706         coded[32] = 0;
2707         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2708           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2709         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2710         }
2711       else
2712         {
2713         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2714           "fail\n  crypted=%s\n", sub[1]+5);
2715         tempcond = FALSE;
2716         }
2717       }
2718
2719     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2720       {
2721       int sublen = Ustrlen(sub[1]+6);
2722       sha1 base;
2723       uschar digest[20];
2724
2725       sha1_start(&base);
2726       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2727
2728       /* If the length that we are comparing against is 28, assume the SHA1
2729       digest is expressed as a base64 string. If the length is 40, assume a
2730       straightforward hex representation. Other lengths fail. */
2731
2732       if (sublen == 28)
2733         {
2734         uschar *coded = b64encode((uschar *)digest, 20);
2735         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2736           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2737         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2738         }
2739       else if (sublen == 40)
2740         {
2741         int i;
2742         uschar coded[44];
2743         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2744         coded[40] = 0;
2745         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2746           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2747         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2748         }
2749       else
2750         {
2751         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2752           "fail\n  crypted=%s\n", sub[1]+6);
2753         tempcond = FALSE;
2754         }
2755       }
2756
2757     else   /* {crypt} or {crypt16} and non-{ at start */
2758            /* }-for-text-editors */
2759       {
2760       int which = 0;
2761       uschar *coded;
2762
2763       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2764         {
2765         sub[1] += 7;
2766         which = 1;
2767         }
2768       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2769         {
2770         sub[1] += 9;
2771         which = 2;
2772         }
2773       else if (sub[1][0] == '{')                /* }-for-text-editors */
2774         {
2775         expand_string_message = string_sprintf("unknown encryption mechanism "
2776           "in \"%s\"", sub[1]);
2777         return NULL;
2778         }
2779
2780       switch(which)
2781         {
2782         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2783         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2784         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2785         }
2786
2787       #define STR(s) # s
2788       #define XSTR(s) STR(s)
2789       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2790         "  subject=%s\n  crypted=%s\n",
2791         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2792         coded, sub[1]);
2793       #undef STR
2794       #undef XSTR
2795
2796       /* If the encrypted string contains fewer than two characters (for the
2797       salt), force failure. Otherwise we get false positives: with an empty
2798       string the yield of crypt() is an empty string! */
2799
2800       if (coded)
2801         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2802       else if (errno == EINVAL)
2803         tempcond = FALSE;
2804       else
2805         {
2806         expand_string_message = string_sprintf("crypt error: %s\n",
2807           US strerror(errno));
2808         return NULL;
2809         }
2810       }
2811     break;
2812     #endif  /* SUPPORT_CRYPTEQ */
2813
2814     case ECOND_INLIST:
2815     case ECOND_INLISTI:
2816       {
2817       const uschar * list = sub[1];
2818       int sep = 0;
2819       uschar *save_iterate_item = iterate_item;
2820       int (*compare)(const uschar *, const uschar *);
2821
2822       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2823
2824       tempcond = FALSE;
2825       compare = cond_type == ECOND_INLISTI
2826         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2827
2828       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2829         if (compare(sub[0], iterate_item) == 0)
2830           {
2831           tempcond = TRUE;
2832           break;
2833           }
2834       iterate_item = save_iterate_item;
2835       }
2836
2837     }   /* Switch for comparison conditions */
2838
2839   *yield = tempcond == testfor;
2840   return s;    /* End of comparison conditions */
2841
2842
2843   /* and/or: computes logical and/or of several conditions */
2844
2845   case ECOND_AND:
2846   case ECOND_OR:
2847   subcondptr = (yield == NULL)? NULL : &tempcond;
2848   combined_cond = (cond_type == ECOND_AND);
2849
2850   while (isspace(*s)) s++;
2851   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2852
2853   for (;;)
2854     {
2855     while (isspace(*s)) s++;
2856     /* {-for-text-editors */
2857     if (*s == '}') break;
2858     if (*s != '{')                                      /* }-for-text-editors */
2859       {
2860       expand_string_message = string_sprintf("each subcondition "
2861         "inside an \"%s{...}\" condition must be in its own {}", name);
2862       return NULL;
2863       }
2864
2865     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2866       {
2867       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2868         expand_string_message, name);
2869       return NULL;
2870       }
2871     while (isspace(*s)) s++;
2872
2873     /* {-for-text-editors */
2874     if (*s++ != '}')
2875       {
2876       /* {-for-text-editors */
2877       expand_string_message = string_sprintf("missing } at end of condition "
2878         "inside \"%s\" group", name);
2879       return NULL;
2880       }
2881
2882     if (yield != NULL)
2883       {
2884       if (cond_type == ECOND_AND)
2885         {
2886         combined_cond &= tempcond;
2887         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2888         }                                       /* evaluate any more */
2889       else
2890         {
2891         combined_cond |= tempcond;
2892         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2893         }                                       /* evaluate any more */
2894       }
2895     }
2896
2897   if (yield != NULL) *yield = (combined_cond == testfor);
2898   return ++s;
2899
2900
2901   /* forall/forany: iterates a condition with different values */
2902
2903   case ECOND_FORALL:
2904   case ECOND_FORANY:
2905     {
2906     const uschar * list;
2907     int sep = 0;
2908     uschar *save_iterate_item = iterate_item;
2909
2910     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2911
2912     while (isspace(*s)) s++;
2913     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2914     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2915     if (sub[0] == NULL) return NULL;
2916     /* {-for-text-editors */
2917     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2918
2919     while (isspace(*s)) s++;
2920     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2921
2922     sub[1] = s;
2923
2924     /* Call eval_condition once, with result discarded (as if scanning a
2925     "false" part). This allows us to find the end of the condition, because if
2926     the list it empty, we won't actually evaluate the condition for real. */
2927
2928     if (!(s = eval_condition(sub[1], resetok, NULL)))
2929       {
2930       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2931         expand_string_message, name);
2932       return NULL;
2933       }
2934     while (isspace(*s)) s++;
2935
2936     /* {-for-text-editors */
2937     if (*s++ != '}')
2938       {
2939       /* {-for-text-editors */
2940       expand_string_message = string_sprintf("missing } at end of condition "
2941         "inside \"%s\"", name);
2942       return NULL;
2943       }
2944
2945     if (yield != NULL) *yield = !testfor;
2946     list = sub[0];
2947     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2948       {
2949       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2950       if (!eval_condition(sub[1], resetok, &tempcond))
2951         {
2952         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2953           expand_string_message, name);
2954         iterate_item = save_iterate_item;
2955         return NULL;
2956         }
2957       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2958         tempcond? "true":"false");
2959
2960       if (yield != NULL) *yield = (tempcond == testfor);
2961       if (tempcond == (cond_type == ECOND_FORANY)) break;
2962       }
2963
2964     iterate_item = save_iterate_item;
2965     return s;
2966     }
2967
2968
2969   /* The bool{} expansion condition maps a string to boolean.
2970   The values supported should match those supported by the ACL condition
2971   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2972   of true/false.  Note that Router "condition" rules have a different
2973   interpretation, where general data can be used and only a few values
2974   map to FALSE.
2975   Note that readconf.c boolean matching, for boolean configuration options,
2976   only matches true/yes/false/no.
2977   The bool_lax{} condition matches the Router logic, which is much more
2978   liberal. */
2979   case ECOND_BOOL:
2980   case ECOND_BOOL_LAX:
2981     {
2982     uschar *sub_arg[1];
2983     uschar *t, *t2;
2984     uschar *ourname;
2985     size_t len;
2986     BOOL boolvalue = FALSE;
2987     while (isspace(*s)) s++;
2988     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2989     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2990     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2991       {
2992       case 1: expand_string_message = string_sprintf(
2993                   "too few arguments or bracketing error for %s",
2994                   ourname);
2995       /*FALLTHROUGH*/
2996       case 2:
2997       case 3: return NULL;
2998       }
2999     t = sub_arg[0];
3000     while (isspace(*t)) t++;
3001     len = Ustrlen(t);
3002     if (len)
3003       {
3004       /* trailing whitespace: seems like a good idea to ignore it too */
3005       t2 = t + len - 1;
3006       while (isspace(*t2)) t2--;
3007       if (t2 != (t + len))
3008         {
3009         *++t2 = '\0';
3010         len = t2 - t;
3011         }
3012       }
3013     DEBUG(D_expand)
3014       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3015     /* logic for the lax case from expand_check_condition(), which also does
3016     expands, and the logic is both short and stable enough that there should
3017     be no maintenance burden from replicating it. */
3018     if (len == 0)
3019       boolvalue = FALSE;
3020     else if (*t == '-'
3021              ? Ustrspn(t+1, "0123456789") == len-1
3022              : Ustrspn(t,   "0123456789") == len)
3023       {
3024       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3025       /* expand_check_condition only does a literal string "0" check */
3026       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3027         boolvalue = TRUE;
3028       }
3029     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3030       boolvalue = TRUE;
3031     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3032       boolvalue = FALSE;
3033     else if (cond_type == ECOND_BOOL_LAX)
3034       boolvalue = TRUE;
3035     else
3036       {
3037       expand_string_message = string_sprintf("unrecognised boolean "
3038        "value \"%s\"", t);
3039       return NULL;
3040       }
3041     if (yield != NULL) *yield = (boolvalue == testfor);
3042     return s;
3043     }
3044
3045   /* Unknown condition */
3046
3047   default:
3048   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3049   return NULL;
3050   }   /* End switch on condition type */
3051
3052 /* Missing braces at start and end of data */
3053
3054 COND_FAILED_CURLY_START:
3055 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3056 return NULL;
3057
3058 COND_FAILED_CURLY_END:
3059 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3060   name);
3061 return NULL;
3062
3063 /* A condition requires code that is not compiled */
3064
3065 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3066     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3067     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3068 COND_FAILED_NOT_COMPILED:
3069 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3070   name);
3071 return NULL;
3072 #endif
3073 }
3074
3075
3076
3077
3078 /*************************************************
3079 *          Save numerical variables              *
3080 *************************************************/
3081
3082 /* This function is called from items such as "if" that want to preserve and
3083 restore the numbered variables.
3084
3085 Arguments:
3086   save_expand_string    points to an array of pointers to set
3087   save_expand_nlength   points to an array of ints for the lengths
3088
3089 Returns:                the value of expand max to save
3090 */
3091
3092 static int
3093 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3094 {
3095 int i;
3096 for (i = 0; i <= expand_nmax; i++)
3097   {
3098   save_expand_nstring[i] = expand_nstring[i];
3099   save_expand_nlength[i] = expand_nlength[i];
3100   }
3101 return expand_nmax;
3102 }
3103
3104
3105
3106 /*************************************************
3107 *           Restore numerical variables          *
3108 *************************************************/
3109
3110 /* This function restored saved values of numerical strings.
3111
3112 Arguments:
3113   save_expand_nmax      the number of strings to restore
3114   save_expand_string    points to an array of pointers
3115   save_expand_nlength   points to an array of ints
3116
3117 Returns:                nothing
3118 */
3119
3120 static void
3121 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3122   int *save_expand_nlength)
3123 {
3124 int i;
3125 expand_nmax = save_expand_nmax;
3126 for (i = 0; i <= expand_nmax; i++)
3127   {
3128   expand_nstring[i] = save_expand_nstring[i];
3129   expand_nlength[i] = save_expand_nlength[i];
3130   }
3131 }
3132
3133
3134
3135
3136
3137 /*************************************************
3138 *            Handle yes/no substrings            *
3139 *************************************************/
3140
3141 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3142 alternative substrings that depend on whether or not the condition was true,
3143 or the lookup or extraction succeeded. The substrings always have to be
3144 expanded, to check their syntax, but "skipping" is set when the result is not
3145 needed - this avoids unnecessary nested lookups.
3146
3147 Arguments:
3148   skipping       TRUE if we were skipping when this item was reached
3149   yes            TRUE if the first string is to be used, else use the second
3150   save_lookup    a value to put back into lookup_value before the 2nd expansion
3151   sptr           points to the input string pointer
3152   yieldptr       points to the output string pointer
3153   sizeptr        points to the output string size
3154   ptrptr         points to the output string pointer
3155   type           "lookup", "if", "extract", "run", "env", "listextract" or
3156                  "certextract" for error message
3157   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3158                 the store.
3159
3160 Returns:         0 OK; lookup_value has been reset to save_lookup
3161                  1 expansion failed
3162                  2 expansion failed because of bracketing error
3163 */
3164
3165 static int
3166 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3167   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3168 {
3169 int rc = 0;
3170 const uschar *s = *sptr;    /* Local value */
3171 uschar *sub1, *sub2;
3172
3173 /* If there are no following strings, we substitute the contents of $value for
3174 lookups and for extractions in the success case. For the ${if item, the string
3175 "true" is substituted. In the fail case, nothing is substituted for all three
3176 items. */
3177
3178 while (isspace(*s)) s++;
3179 if (*s == '}')
3180   {
3181   if (type[0] == 'i')
3182     {
3183     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
3184     }
3185   else
3186     {
3187     if (yes && lookup_value)
3188       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
3189         Ustrlen(lookup_value));
3190     lookup_value = save_lookup;
3191     }
3192   s++;
3193   goto RETURN;
3194   }
3195
3196 /* The first following string must be braced. */
3197
3198 if (*s++ != '{') goto FAILED_CURLY;
3199
3200 /* Expand the first substring. Forced failures are noticed only if we actually
3201 want this string. Set skipping in the call in the fail case (this will always
3202 be the case if we were already skipping). */
3203
3204 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3205 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3206 expand_string_forcedfail = FALSE;
3207 if (*s++ != '}') goto FAILED_CURLY;
3208
3209 /* If we want the first string, add it to the output */
3210
3211 if (yes)
3212   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
3213
3214 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3215 $value to what it was at the start of the item, so that it has this value
3216 during the second string expansion. For the call from "if" or "run" to this
3217 function, save_lookup is set to lookup_value, so that this statement does
3218 nothing. */
3219
3220 lookup_value = save_lookup;
3221
3222 /* There now follows either another substring, or "fail", or nothing. This
3223 time, forced failures are noticed only if we want the second string. We must
3224 set skipping in the nested call if we don't want this string, or if we were
3225 already skipping. */
3226
3227 while (isspace(*s)) s++;
3228 if (*s == '{')
3229   {
3230   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3231   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3232   expand_string_forcedfail = FALSE;
3233   if (*s++ != '}') goto FAILED_CURLY;
3234
3235   /* If we want the second string, add it to the output */
3236
3237   if (!yes)
3238     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
3239   }
3240
3241 /* If there is no second string, but the word "fail" is present when the use of
3242 the second string is wanted, set a flag indicating it was a forced failure
3243 rather than a syntactic error. Swallow the terminating } in case this is nested
3244 inside another lookup or if or extract. */
3245
3246 else if (*s != '}')
3247   {
3248   uschar name[256];
3249   /* deconst cast ok here as source is s anyway */
3250   s = US read_name(name, sizeof(name), s, US"_");
3251   if (Ustrcmp(name, "fail") == 0)
3252     {
3253     if (!yes && !skipping)
3254       {
3255       while (isspace(*s)) s++;
3256       if (*s++ != '}') goto FAILED_CURLY;
3257       expand_string_message =
3258         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3259       expand_string_forcedfail = TRUE;
3260       goto FAILED;
3261       }
3262     }
3263   else
3264     {
3265     expand_string_message =
3266       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3267     goto FAILED;
3268     }
3269   }
3270
3271 /* All we have to do now is to check on the final closing brace. */
3272
3273 while (isspace(*s)) s++;
3274 if (*s++ == '}') goto RETURN;
3275
3276 /* Get here if there is a bracketing failure */
3277
3278 FAILED_CURLY:
3279 rc++;
3280
3281 /* Get here for other failures */
3282
3283 FAILED:
3284 rc++;
3285
3286 /* Update the input pointer value before returning */
3287
3288 RETURN:
3289 *sptr = s;
3290 return rc;
3291 }
3292
3293
3294
3295
3296 /*************************************************
3297 *    Handle MD5 or SHA-1 computation for HMAC    *
3298 *************************************************/
3299
3300 /* These are some wrapping functions that enable the HMAC code to be a bit
3301 cleaner. A good compiler will spot the tail recursion.
3302
3303 Arguments:
3304   type         HMAC_MD5 or HMAC_SHA1
3305   remaining    are as for the cryptographic hash functions
3306
3307 Returns:       nothing
3308 */
3309
3310 static void
3311 chash_start(int type, void *base)
3312 {
3313 if (type == HMAC_MD5)
3314   md5_start((md5 *)base);
3315 else
3316   sha1_start((sha1 *)base);
3317 }
3318
3319 static void
3320 chash_mid(int type, void *base, uschar *string)
3321 {
3322 if (type == HMAC_MD5)
3323   md5_mid((md5 *)base, string);
3324 else
3325   sha1_mid((sha1 *)base, string);
3326 }
3327
3328 static void
3329 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3330 {
3331 if (type == HMAC_MD5)
3332   md5_end((md5 *)base, string, length, digest);
3333 else
3334   sha1_end((sha1 *)base, string, length, digest);
3335 }
3336
3337
3338
3339
3340
3341 /********************************************************
3342 * prvs: Get last three digits of days since Jan 1, 1970 *
3343 ********************************************************/
3344
3345 /* This is needed to implement the "prvs" BATV reverse
3346    path signing scheme
3347
3348 Argument: integer "days" offset to add or substract to
3349           or from the current number of days.
3350
3351 Returns:  pointer to string containing the last three
3352           digits of the number of days since Jan 1, 1970,
3353           modified by the offset argument, NULL if there
3354           was an error in the conversion.
3355
3356 */
3357
3358 static uschar *
3359 prvs_daystamp(int day_offset)
3360 {
3361 uschar *days = store_get(32);                /* Need at least 24 for cases */
3362 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3363   (time(NULL) + day_offset*86400)/86400);
3364 return (Ustrlen(days) >= 3) ? &</