src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   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"base32",
 203   US"base32d",
 204   US"base62",
 205   US"base62d",
 206   US"base64",
 207   US"base64d",
 208   US"domain",
 209   US"escape",
 210   US"eval",
 211   US"eval10",
 212   US"expand",
 213   US"h",
 214   US"hash",
 215   US"hex2b64",
 216   US"hexquote",
 217   US"ipv6denorm",
 218   US"ipv6norm",
 219   US"l",
 220   US"lc",
 221   US"length",
 222   US"listcount",
 223   US"listnamed",
 224   US"mask",
 225   US"md5",
 226   US"nh",
 227   US"nhash",
 228   US"quote",
 229   US"randint",
 230   US"rfc2047",
 231   US"rfc2047d",
 232   US"rxquote",
 233   US"s",
 234   US"sha1",
 235   US"sha256",
 236   US"sha3",
 237   US"stat",
 238   US"str2b64",
 239   US"strlen",
 240   US"substr",
 241   US"uc",
 242   US"utf8clean" };
 243
 244 enum {
 245   EOP_ADDRESS =  nelem(op_table_underscore),
 246   EOP_ADDRESSES,
 247   EOP_BASE32,
 248   EOP_BASE32D,
 249   EOP_BASE62,
 250   EOP_BASE62D,
 251   EOP_BASE64,
 252   EOP_BASE64D,
 253   EOP_DOMAIN,
 254   EOP_ESCAPE,
 255   EOP_EVAL,
 256   EOP_EVAL10,
 257   EOP_EXPAND,
 258   EOP_H,
 259   EOP_HASH,
 260   EOP_HEX2B64,
 261   EOP_HEXQUOTE,
 262   EOP_IPV6DENORM,
 263   EOP_IPV6NORM,
 264   EOP_L,
 265   EOP_LC,
 266   EOP_LENGTH,
 267   EOP_LISTCOUNT,
 268   EOP_LISTNAMED,
 269   EOP_MASK,
 270   EOP_MD5,
 271   EOP_NH,
 272   EOP_NHASH,
 273   EOP_QUOTE,
 274   EOP_RANDINT,
 275   EOP_RFC2047,
 276   EOP_RFC2047D,
 277   EOP_RXQUOTE,
 278   EOP_S,
 279   EOP_SHA1,
 280   EOP_SHA256,
 281   EOP_SHA3,
 282   EOP_STAT,
 283   EOP_STR2B64,
 284   EOP_STRLEN,
 285   EOP_SUBSTR,
 286   EOP_UC,
 287   EOP_UTF8CLEAN };
 288
 289
 290 /* Table of condition names, and corresponding switch numbers. The names must
 291 be in alphabetical order. */
 292
 293 static uschar *cond_table[] = {
 294   US"<",
 295   US"<=",
 296   US"=",
 297   US"==",     /* Backward compatibility */
 298   US">",
 299   US">=",
 300   US"acl",
 301   US"and",
 302   US"bool",
 303   US"bool_lax",
 304   US"crypteq",
 305   US"def",
 306   US"eq",
 307   US"eqi",
 308   US"exists",
 309   US"first_delivery",
 310   US"forall",
 311   US"forany",
 312   US"ge",
 313   US"gei",
 314   US"gt",
 315   US"gti",
 316   US"inlist",
 317   US"inlisti",
 318   US"isip",
 319   US"isip4",
 320   US"isip6",
 321   US"ldapauth",
 322   US"le",
 323   US"lei",
 324   US"lt",
 325   US"lti",
 326   US"match",
 327   US"match_address",
 328   US"match_domain",
 329   US"match_ip",
 330   US"match_local_part",
 331   US"or",
 332   US"pam",
 333   US"pwcheck",
 334   US"queue_running",
 335   US"radius",
 336   US"saslauthd"
 337 };
 338
 339 enum {
 340   ECOND_NUM_L,
 341   ECOND_NUM_LE,
 342   ECOND_NUM_E,
 343   ECOND_NUM_EE,
 344   ECOND_NUM_G,
 345   ECOND_NUM_GE,
 346   ECOND_ACL,
 347   ECOND_AND,
 348   ECOND_BOOL,
 349   ECOND_BOOL_LAX,
 350   ECOND_CRYPTEQ,
 351   ECOND_DEF,
 352   ECOND_STR_EQ,
 353   ECOND_STR_EQI,
 354   ECOND_EXISTS,
 355   ECOND_FIRST_DELIVERY,
 356   ECOND_FORALL,
 357   ECOND_FORANY,
 358   ECOND_STR_GE,
 359   ECOND_STR_GEI,
 360   ECOND_STR_GT,
 361   ECOND_STR_GTI,
 362   ECOND_INLIST,
 363   ECOND_INLISTI,
 364   ECOND_ISIP,
 365   ECOND_ISIP4,
 366   ECOND_ISIP6,
 367   ECOND_LDAPAUTH,
 368   ECOND_STR_LE,
 369   ECOND_STR_LEI,
 370   ECOND_STR_LT,
 371   ECOND_STR_LTI,
 372   ECOND_MATCH,
 373   ECOND_MATCH_ADDRESS,
 374   ECOND_MATCH_DOMAIN,
 375   ECOND_MATCH_IP,
 376   ECOND_MATCH_LOCAL_PART,
 377   ECOND_OR,
 378   ECOND_PAM,
 379   ECOND_PWCHECK,
 380   ECOND_QUEUE_RUNNING,
 381   ECOND_RADIUS,
 382   ECOND_SASLAUTHD
 383 };
 384
 385
 386 /* Types of table entry */
 387
 388 enum vtypes {
 389   vtype_int,            /* value is address of int */
 390   vtype_filter_int,     /* ditto, but recognized only when filtering */
 391   vtype_ino,            /* value is address of ino_t (not always an int) */
 392   vtype_uid,            /* value is address of uid_t (not always an int) */
 393   vtype_gid,            /* value is address of gid_t (not always an int) */
 394   vtype_bool,           /* value is address of bool */
 395   vtype_stringptr,      /* value is address of pointer to string */
 396   vtype_msgbody,        /* as stringptr, but read when first required */
 397   vtype_msgbody_end,    /* ditto, the end of the message */
 398   vtype_msgheaders,     /* the message's headers, processed */
 399   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 400   vtype_localpart,      /* extract local part from string */
 401   vtype_domain,         /* extract domain from string */
 402   vtype_string_func,    /* value is string returned by given function */
 403   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 404   vtype_tode,           /* value not used; generate tod in epoch format */
 405   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 406   vtype_todf,           /* value not used; generate full tod */
 407   vtype_todl,           /* value not used; generate log tod */
 408   vtype_todlf,          /* value not used; generate log file datestamp tod */
 409   vtype_todzone,        /* value not used; generate time zone only */
 410   vtype_todzulu,        /* value not used; generate zulu tod */
 411   vtype_reply,          /* value not used; get reply from headers */
 412   vtype_pid,            /* value not used; result is pid */
 413   vtype_host_lookup,    /* value not used; get host name */
 414   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 415   vtype_pspace,         /* partition space; value is T/F for spool/log */
 416   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 417   vtype_cert            /* SSL certificate */
 418   #ifndef DISABLE_DKIM
 419   ,vtype_dkim           /* Lookup of value in DKIM signature */
 420   #endif
 421 };
 422
 423 /* Type for main variable table */
 424
 425 typedef struct {
 426   const char *name;
 427   enum vtypes type;
 428   void       *value;
 429 } var_entry;
 430
 431 /* Type for entries pointing to address/length pairs. Not currently
 432 in use. */
 433
 434 typedef struct {
 435   uschar **address;
 436   int  *length;
 437 } alblock;
 438
 439 static uschar * fn_recipients(void);
 440
 441 /* This table must be kept in alphabetical order. */
 442
 443 static var_entry var_table[] = {
 444   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 445      they will be confused with user-creatable ACL variables. */
 446   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 447   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 448   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 449   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 450   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 451   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 452   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 453   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 454   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 455   { "acl_narg",            vtype_int,         &acl_narg },
 456   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 457   { "address_data",        vtype_stringptr,   &deliver_address_data },
 458   { "address_file",        vtype_stringptr,   &address_file },
 459   { "address_pipe",        vtype_stringptr,   &address_pipe },
 460   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 461   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 462   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 463   { "authentication_failed",vtype_int,        &authentication_failed },
 464 #ifdef WITH_CONTENT_SCAN
 465   { "av_failed",           vtype_int,         &av_failed },
 466 #endif
 467 #ifdef EXPERIMENTAL_BRIGHTMAIL
 468   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 469   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 470   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 471   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 472 #endif
 473   { "body_linecount",      vtype_int,         &body_linecount },
 474   { "body_zerocount",      vtype_int,         &body_zerocount },
 475   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 476   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 477   { "caller_gid",          vtype_gid,         &real_gid },
 478   { "caller_uid",          vtype_uid,         &real_uid },
 479   { "callout_address",     vtype_stringptr,   &callout_address },
 480   { "compile_date",        vtype_stringptr,   &version_date },
 481   { "compile_number",      vtype_stringptr,   &version_cnumber },
 482   { "config_dir",          vtype_stringptr,   &config_main_directory },
 483   { "config_file",         vtype_stringptr,   &config_main_filename },
 484   { "csa_status",          vtype_stringptr,   &csa_status },
 485 #ifdef EXPERIMENTAL_DCC
 486   { "dcc_header",          vtype_stringptr,   &dcc_header },
 487   { "dcc_result",          vtype_stringptr,   &dcc_result },
 488 #endif
 489 #ifndef DISABLE_DKIM
 490   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 491   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 492   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 493   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 494   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 495   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 496   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 497   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 498   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 499   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 500   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 501   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 502   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 503   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 504   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 505   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 506   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 507   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 508   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 509   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 510   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 511 #endif
 512 #ifdef EXPERIMENTAL_DMARC
 513   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 514   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 515   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 516   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 517   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 518 #endif
 519   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 520   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 521   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 522   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 523   { "domain",              vtype_stringptr,   &deliver_domain },
 524   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 525 #ifndef DISABLE_EVENT
 526   { "event_data",          vtype_stringptr,   &event_data },
 527
 528   /*XXX want to use generic vars for as many of these as possible*/
 529   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 530
 531   { "event_name",          vtype_stringptr,   &event_name },
 532 #endif
 533   { "exim_gid",            vtype_gid,         &exim_gid },
 534   { "exim_path",           vtype_stringptr,   &exim_path },
 535   { "exim_uid",            vtype_uid,         &exim_uid },
 536   { "exim_version",        vtype_stringptr,   &version_string },
 537   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 538   { "home",                vtype_stringptr,   &deliver_home },
 539   { "host",                vtype_stringptr,   &deliver_host },
 540   { "host_address",        vtype_stringptr,   &deliver_host_address },
 541   { "host_data",           vtype_stringptr,   &host_data },
 542   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 543   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 544   { "host_port",           vtype_int,         &deliver_host_port },
 545   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 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   { "queue_name",          vtype_stringptr,   &queue_name },
 635   { "rcpt_count",          vtype_int,         &rcpt_count },
 636   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 637   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 638   { "received_count",      vtype_int,         &received_count },
 639   { "received_for",        vtype_stringptr,   &received_for },
 640   { "received_ip_address", vtype_stringptr,   &interface_address },
 641   { "received_port",       vtype_int,         &interface_port },
 642   { "received_protocol",   vtype_stringptr,   &received_protocol },
 643   { "received_time",       vtype_int,         &received_time },
 644   { "recipient_data",      vtype_stringptr,   &recipient_data },
 645   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 646   { "recipients",          vtype_string_func, &fn_recipients },
 647   { "recipients_count",    vtype_int,         &recipients_count },
 648 #ifdef WITH_CONTENT_SCAN
 649   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 650 #endif
 651   { "reply_address",       vtype_reply,       NULL },
 652   { "return_path",         vtype_stringptr,   &return_path },
 653   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 654   { "router_name",         vtype_stringptr,   &router_name },
 655   { "runrc",               vtype_int,         &runrc },
 656   { "self_hostname",       vtype_stringptr,   &self_hostname },
 657   { "sender_address",      vtype_stringptr,   &sender_address },
 658   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 659   { "sender_address_domain", vtype_domain,    &sender_address },
 660   { "sender_address_local_part", vtype_localpart, &sender_address },
 661   { "sender_data",         vtype_stringptr,   &sender_data },
 662   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 663   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 664   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 665   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 666   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 667   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 668   { "sender_host_name",    vtype_host_lookup, NULL },
 669   { "sender_host_port",    vtype_int,         &sender_host_port },
 670   { "sender_ident",        vtype_stringptr,   &sender_ident },
 671   { "sender_rate",         vtype_stringptr,   &sender_rate },
 672   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 673   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 674   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 675   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 676   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 677   { "sending_port",        vtype_int,         &sending_port },
 678   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 679   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 680   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 681   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 682   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 683   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 684   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 685   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 686   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 687   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 688   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 689   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 690   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 691   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 692   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 693 #ifdef WITH_CONTENT_SCAN
 694   { "spam_action",         vtype_stringptr,   &spam_action },
 695   { "spam_bar",            vtype_stringptr,   &spam_bar },
 696   { "spam_report",         vtype_stringptr,   &spam_report },
 697   { "spam_score",          vtype_stringptr,   &spam_score },
 698   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 699 #endif
 700 #ifdef EXPERIMENTAL_SPF
 701   { "spf_guess",           vtype_stringptr,   &spf_guess },
 702   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 703   { "spf_received",        vtype_stringptr,   &spf_received },
 704   { "spf_result",          vtype_stringptr,   &spf_result },
 705   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 706 #endif
 707   { "spool_directory",     vtype_stringptr,   &spool_directory },
 708   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 709   { "spool_space",         vtype_pspace,      (void *)TRUE },
 710 #ifdef EXPERIMENTAL_SRS
 711   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 712   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 713   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 714   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 715   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 716   { "srs_status",          vtype_stringptr,   &srs_status },
 717 #endif
 718   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 719
 720   /* The non-(in,out) variables are now deprecated */
 721   { "tls_bits",            vtype_int,         &tls_in.bits },
 722   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 723   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 724
 725   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 726   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 727   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 728   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 729   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 730   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 731   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 732 #if defined(SUPPORT_TLS)
 733   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 734 #endif
 735   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 736   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 737   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 738 #ifdef EXPERIMENTAL_DANE
 739   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 740 #endif
 741   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 742   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 743   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 744   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 745 #if defined(SUPPORT_TLS)
 746   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 747 #endif
 748 #ifdef EXPERIMENTAL_DANE
 749   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 750 #endif
 751
 752   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 753 #if defined(SUPPORT_TLS)
 754   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 755 #endif
 756
 757   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 758   { "tod_epoch",           vtype_tode,        NULL },
 759   { "tod_epoch_l",         vtype_todel,       NULL },
 760   { "tod_full",            vtype_todf,        NULL },
 761   { "tod_log",             vtype_todl,        NULL },
 762   { "tod_logfile",         vtype_todlf,       NULL },
 763   { "tod_zone",            vtype_todzone,     NULL },
 764   { "tod_zulu",            vtype_todzulu,     NULL },
 765   { "transport_name",      vtype_stringptr,   &transport_name },
 766   { "value",               vtype_stringptr,   &lookup_value },
 767   { "verify_mode",         vtype_stringptr,   &verify_mode },
 768   { "version_number",      vtype_stringptr,   &version_string },
 769   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 770   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 771   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 772   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 773   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 774   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 775 };
 776
 777 static int var_table_size = nelem(var_table);
 778 static uschar var_buffer[256];
 779 static BOOL malformed_header;
 780
 781 /* For textual hashes */
 782
 783 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 784                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 785                                "0123456789";
 786
 787 enum { HMAC_MD5, HMAC_SHA1 };
 788
 789 /* For numeric hashes */
 790
 791 static unsigned int prime[] = {
 792   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 793  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 794  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 795
 796 /* For printing modes in symbolic form */
 797
 798 static uschar *mtable_normal[] =
 799   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 800
 801 static uschar *mtable_setid[] =
 802   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 803
 804 static uschar *mtable_sticky[] =
 805   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 806
 807
 808
 809 /*************************************************
 810 *           Tables for UTF-8 support             *
 811 *************************************************/
 812
 813 /* Table of the number of extra characters, indexed by the first character
 814 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 815 0x3d. */
 816
 817 static uschar utf8_table1[] = {
 818   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 819   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 820   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 821   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 822
 823 /* These are the masks for the data bits in the first byte of a character,
 824 indexed by the number of additional bytes. */
 825
 826 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 827
 828 /* Get the next UTF-8 character, advancing the pointer. */
 829
 830 #define GETUTF8INC(c, ptr) \
 831   c = *ptr++; \
 832   if ((c & 0xc0) == 0xc0) \
 833     { \
 834     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 835     int s = 6*a; \
 836     c = (c & utf8_table2[a]) << s; \
 837     while (a-- > 0) \
 838       { \
 839       s -= 6; \
 840       c |= (*ptr++ & 0x3f) << s; \
 841       } \
 842     }
 843
 844
 845
 846 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 847
 848 /*************************************************
 849 *           Binary chop search on a table        *
 850 *************************************************/
 851
 852 /* This is used for matching expansion items and operators.
 853
 854 Arguments:
 855   name        the name that is being sought
 856   table       the table to search
 857   table_size  the number of items in the table
 858
 859 Returns:      the offset in the table, or -1
 860 */
 861
 862 static int
 863 chop_match(uschar *name, uschar **table, int table_size)
 864 {
 865 uschar **bot = table;
 866 uschar **top = table + table_size;
 867
 868 while (top > bot)
 869   {
 870   uschar **mid = bot + (top - bot)/2;
 871   int c = Ustrcmp(name, *mid);
 872   if (c == 0) return mid - table;
 873   if (c > 0) bot = mid + 1; else top = mid;
 874   }
 875
 876 return -1;
 877 }
 878
 879
 880
 881 /*************************************************
 882 *          Check a condition string              *
 883 *************************************************/
 884
 885 /* This function is called to expand a string, and test the result for a "true"
 886 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 887 forced fail or lookup defer.
 888
 889 We used to release all store used, but this is not not safe due
 890 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 891 is reasonably careful to release what it can.
 892
 893 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 894
 895 Arguments:
 896   condition     the condition string
 897   m1            text to be incorporated in panic error
 898   m2            ditto
 899
 900 Returns:        TRUE if condition is met, FALSE if not
 901 */
 902
 903 BOOL
 904 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 905 {
 906 int rc;
 907 uschar *ss = expand_string(condition);
 908 if (ss == NULL)
 909   {
 910   if (!expand_string_forcedfail && !search_find_defer)
 911     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 912       "for %s %s: %s", condition, m1, m2, expand_string_message);
 913   return FALSE;
 914   }
 915 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 916   strcmpic(ss, US"false") != 0;
 917 return rc;
 918 }
 919
 920
 921
 922
 923 /*************************************************
 924 *        Pseudo-random number generation         *
 925 *************************************************/
 926
 927 /* Pseudo-random number generation.  The result is not "expected" to be
 928 cryptographically strong but not so weak that someone will shoot themselves
 929 in the foot using it as a nonce in some email header scheme or whatever
 930 weirdness they'll twist this into.  The result should ideally handle fork().
 931
 932 However, if we're stuck unable to provide this, then we'll fall back to
 933 appallingly bad randomness.
 934
 935 If SUPPORT_TLS is defined then this will not be used except as an emergency
 936 fallback.
 937
 938 Arguments:
 939   max       range maximum
 940 Returns     a random number in range [0, max-1]
 941 */
 942
 943 #ifdef SUPPORT_TLS
 944 # define vaguely_random_number vaguely_random_number_fallback
 945 #endif
 946 int
 947 vaguely_random_number(int max)
 948 {
 949 #ifdef SUPPORT_TLS
 950 # undef vaguely_random_number
 951 #endif
 952   static pid_t pid = 0;
 953   pid_t p2;
 954 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 955   struct timeval tv;
 956 #endif
 957
 958   p2 = getpid();
 959   if (p2 != pid)
 960     {
 961     if (pid != 0)
 962       {
 963
 964 #ifdef HAVE_ARC4RANDOM
 965       /* cryptographically strong randomness, common on *BSD platforms, not
 966       so much elsewhere.  Alas. */
 967 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 968       arc4random_stir();
 969 #endif
 970 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 971 #ifdef HAVE_SRANDOMDEV
 972       /* uses random(4) for seeding */
 973       srandomdev();
 974 #else
 975       gettimeofday(&tv, NULL);
 976       srandom(tv.tv_sec | tv.tv_usec | getpid());
 977 #endif
 978 #else
 979       /* Poor randomness and no seeding here */
 980 #endif
 981
 982       }
 983     pid = p2;
 984     }
 985
 986 #ifdef HAVE_ARC4RANDOM
 987   return arc4random() % max;
 988 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 989   return random() % max;
 990 #else
 991   /* This one returns a 16-bit number, definitely not crypto-strong */
 992   return random_number(max);
 993 #endif
 994 }
 995
 996
 997
 998
 999 /*************************************************
1000 *             Pick out a name from a string      *
1001 *************************************************/
1002
1003 /* If the name is too long, it is silently truncated.
1004
1005 Arguments:
1006   name      points to a buffer into which to put the name
1007   max       is the length of the buffer
1008   s         points to the first alphabetic character of the name
1009   extras    chars other than alphanumerics to permit
1010
1011 Returns:    pointer to the first character after the name
1012
1013 Note: The test for *s != 0 in the while loop is necessary because
1014 Ustrchr() yields non-NULL if the character is zero (which is not something
1015 I expected). */
1016
1017 static const uschar *
1018 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1019 {
1020 int ptr = 0;
1021 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1022   {
1023   if (ptr < max-1) name[ptr++] = *s;
1024   s++;
1025   }
1026 name[ptr] = 0;
1027 return s;
1028 }
1029
1030
1031
1032 /*************************************************
1033 *     Pick out the rest of a header name         *
1034 *************************************************/
1035
1036 /* A variable name starting $header_ (or just $h_ for those who like
1037 abbreviations) might not be the complete header name because headers can
1038 contain any printing characters in their names, except ':'. This function is
1039 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1040 on the end, if the name was terminated by white space.
1041
1042 Arguments:
1043   name      points to a buffer in which the name read so far exists
1044   max       is the length of the buffer
1045   s         points to the first character after the name so far, i.e. the
1046             first non-alphameric character after $header_xxxxx
1047
1048 Returns:    a pointer to the first character after the header name
1049 */
1050
1051 static const uschar *
1052 read_header_name(uschar *name, int max, const uschar *s)
1053 {
1054 int prelen = Ustrchr(name, '_') - name + 1;
1055 int ptr = Ustrlen(name) - prelen;
1056 if (ptr > 0) memmove(name, name+prelen, ptr);
1057 while (mac_isgraph(*s) && *s != ':')
1058   {
1059   if (ptr < max-1) name[ptr++] = *s;
1060   s++;
1061   }
1062 if (*s == ':') s++;
1063 name[ptr++] = ':';
1064 name[ptr] = 0;
1065 return s;
1066 }
1067
1068
1069
1070 /*************************************************
1071 *           Pick out a number from a string      *
1072 *************************************************/
1073
1074 /* Arguments:
1075   n     points to an integer into which to put the number
1076   s     points to the first digit of the number
1077
1078 Returns:  a pointer to the character after the last digit
1079 */
1080 /*XXX consider expanding to int_eximarith_t.  But the test for
1081 "overbig numbers" in 0002 still needs to overflow it. */
1082
1083 static uschar *
1084 read_number(int *n, uschar *s)
1085 {
1086 *n = 0;
1087 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1088 return s;
1089 }
1090
1091 static const uschar *
1092 read_cnumber(int *n, const uschar *s)
1093 {
1094 *n = 0;
1095 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1096 return s;
1097 }
1098
1099
1100
1101 /*************************************************
1102 *        Extract keyed subfield from a string    *
1103 *************************************************/
1104
1105 /* The yield is in dynamic store; NULL means that the key was not found.
1106
1107 Arguments:
1108   key       points to the name of the key
1109   s         points to the string from which to extract the subfield
1110
1111 Returns:    NULL if the subfield was not found, or
1112             a pointer to the subfield's data
1113 */
1114
1115 static uschar *
1116 expand_getkeyed(uschar *key, const uschar *s)
1117 {
1118 int length = Ustrlen(key);
1119 while (isspace(*s)) s++;
1120
1121 /* Loop to search for the key */
1122
1123 while (*s != 0)
1124   {
1125   int dkeylength;
1126   uschar *data;
1127   const uschar *dkey = s;
1128
1129   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1130   dkeylength = s - dkey;
1131   while (isspace(*s)) s++;
1132   if (*s == '=') while (isspace((*(++s))));
1133
1134   data = string_dequote(&s);
1135   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1136     return data;
1137
1138   while (isspace(*s)) s++;
1139   }
1140
1141 return NULL;
1142 }
1143
1144
1145
1146 static var_entry *
1147 find_var_ent(uschar * name)
1148 {
1149 int first = 0;
1150 int last = var_table_size;
1151
1152 while (last > first)
1153   {
1154   int middle = (first + last)/2;
1155   int c = Ustrcmp(name, var_table[middle].name);
1156
1157   if (c > 0) { first = middle + 1; continue; }
1158   if (c < 0) { last = middle; continue; }
1159   return &var_table[middle];
1160   }
1161 return NULL;
1162 }
1163
1164 /*************************************************
1165 *   Extract numbered subfield from string        *
1166 *************************************************/
1167
1168 /* Extracts a numbered field from a string that is divided by tokens - for
1169 example a line from /etc/passwd is divided by colon characters.  First field is
1170 numbered one.  Negative arguments count from the right. Zero returns the whole
1171 string. Returns NULL if there are insufficient tokens in the string
1172
1173 ***WARNING***
1174 Modifies final argument - this is a dynamically generated string, so that's OK.
1175
1176 Arguments:
1177   field       number of field to be extracted,
1178                 first field = 1, whole string = 0, last field = -1
1179   separators  characters that are used to break string into tokens
1180   s           points to the string from which to extract the subfield
1181
1182 Returns:      NULL if the field was not found,
1183               a pointer to the field's data inside s (modified to add 0)
1184 */
1185
1186 static uschar *
1187 expand_gettokened (int field, uschar *separators, uschar *s)
1188 {
1189 int sep = 1;
1190 int count;
1191 uschar *ss = s;
1192 uschar *fieldtext = NULL;
1193
1194 if (field == 0) return s;
1195
1196 /* Break the line up into fields in place; for field > 0 we stop when we have
1197 done the number of fields we want. For field < 0 we continue till the end of
1198 the string, counting the number of fields. */
1199
1200 count = (field > 0)? field : INT_MAX;
1201
1202 while (count-- > 0)
1203   {
1204   size_t len;
1205
1206   /* Previous field was the last one in the string. For a positive field
1207   number, this means there are not enough fields. For a negative field number,
1208   check that there are enough, and scan back to find the one that is wanted. */
1209
1210   if (sep == 0)
1211     {
1212     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1213     if ((-field) == (INT_MAX - count - 1)) return s;
1214     while (field++ < 0)
1215       {
1216       ss--;
1217       while (ss[-1] != 0) ss--;
1218       }
1219     fieldtext = ss;
1220     break;
1221     }
1222
1223   /* Previous field was not last in the string; save its start and put a
1224   zero at its end. */
1225
1226   fieldtext = ss;
1227   len = Ustrcspn(ss, separators);
1228   sep = ss[len];
1229   ss[len] = 0;
1230   ss += len + 1;
1231   }
1232
1233 return fieldtext;
1234 }
1235
1236
1237 static uschar *
1238 expand_getlistele(int field, const uschar * list)
1239 {
1240 const uschar * tlist= list;
1241 int sep= 0;
1242 uschar dummy;
1243
1244 if(field<0)
1245   {
1246   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1247   sep= 0;
1248   }
1249 if(field==0) return NULL;
1250 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1251 return string_nextinlist(&list, &sep, NULL, 0);
1252 }
1253
1254
1255 /* Certificate fields, by name.  Worry about by-OID later */
1256 /* Names are chosen to not have common prefixes */
1257
1258 #ifdef SUPPORT_TLS
1259 typedef struct
1260 {
1261 uschar * name;
1262 int      namelen;
1263 uschar * (*getfn)(void * cert, uschar * mod);
1264 } certfield;
1265 static certfield certfields[] =
1266 {                       /* linear search; no special order */
1267   { US"version",         7,  &tls_cert_version },
1268   { US"serial_number",   13, &tls_cert_serial_number },
1269   { US"subject",         7,  &tls_cert_subject },
1270   { US"notbefore",       9,  &tls_cert_not_before },
1271   { US"notafter",        8,  &tls_cert_not_after },
1272   { US"issuer",          6,  &tls_cert_issuer },
1273   { US"signature",       9,  &tls_cert_signature },
1274   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1275   { US"subj_altname",    12, &tls_cert_subject_altname },
1276   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1277   { US"crl_uri",         7,  &tls_cert_crl_uri },
1278 };
1279
1280 static uschar *
1281 expand_getcertele(uschar * field, uschar * certvar)
1282 {
1283 var_entry * vp;
1284 certfield * cp;
1285
1286 if (!(vp = find_var_ent(certvar)))
1287   {
1288   expand_string_message =
1289     string_sprintf("no variable named \"%s\"", certvar);
1290   return NULL;          /* Unknown variable name */
1291   }
1292 /* NB this stops us passing certs around in variable.  Might
1293 want to do that in future */
1294 if (vp->type != vtype_cert)
1295   {
1296   expand_string_message =
1297     string_sprintf("\"%s\" is not a certificate", certvar);
1298   return NULL;          /* Unknown variable name */
1299   }
1300 if (!*(void **)vp->value)
1301   return NULL;
1302
1303 if (*field >= '0' && *field <= '9')
1304   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1305
1306 for(cp = certfields;
1307     cp < certfields + nelem(certfields);
1308     cp++)
1309   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1310     {
1311     uschar * modifier = *(field += cp->namelen) == ','
1312       ? ++field : NULL;
1313     return (*cp->getfn)( *(void **)vp->value, modifier );
1314     }
1315
1316 expand_string_message =
1317   string_sprintf("bad field selector \"%s\" for certextract", field);
1318 return NULL;
1319 }
1320 #endif  /*SUPPORT_TLS*/
1321
1322 /*************************************************
1323 *        Extract a substring from a string       *
1324 *************************************************/
1325
1326 /* Perform the ${substr or ${length expansion operations.
1327
1328 Arguments:
1329   subject     the input string
1330   value1      the offset from the start of the input string to the start of
1331                 the output string; if negative, count from the right.
1332   value2      the length of the output string, or negative (-1) for unset
1333                 if value1 is positive, unset means "all after"
1334                 if value1 is negative, unset means "all before"
1335   len         set to the length of the returned string
1336
1337 Returns:      pointer to the output string, or NULL if there is an error
1338 */
1339
1340 static uschar *
1341 extract_substr(uschar *subject, int value1, int value2, int *len)
1342 {
1343 int sublen = Ustrlen(subject);
1344
1345 if (value1 < 0)    /* count from right */
1346   {
1347   value1 += sublen;
1348
1349   /* If the position is before the start, skip to the start, and adjust the
1350   length. If the length ends up negative, the substring is null because nothing
1351   can precede. This falls out naturally when the length is unset, meaning "all
1352   to the left". */
1353
1354   if (value1 < 0)
1355     {
1356     value2 += value1;
1357     if (value2 < 0) value2 = 0;
1358     value1 = 0;
1359     }
1360
1361   /* Otherwise an unset length => characters before value1 */
1362
1363   else if (value2 < 0)
1364     {
1365     value2 = value1;
1366     value1 = 0;
1367     }
1368   }
1369
1370 /* For a non-negative offset, if the starting position is past the end of the
1371 string, the result will be the null string. Otherwise, an unset length means
1372 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1373
1374 else
1375   {
1376   if (value1 > sublen)
1377     {
1378     value1 = sublen;
1379     value2 = 0;
1380     }
1381   else if (value2 < 0) value2 = sublen;
1382   }
1383
1384 /* Cut the length down to the maximum possible for the offset value, and get
1385 the required characters. */
1386
1387 if (value1 + value2 > sublen) value2 = sublen - value1;
1388 *len = value2;
1389 return subject + value1;
1390 }
1391
1392
1393
1394
1395 /*************************************************
1396 *            Old-style hash of a string          *
1397 *************************************************/
1398
1399 /* Perform the ${hash expansion operation.
1400
1401 Arguments:
1402   subject     the input string (an expanded substring)
1403   value1      the length of the output string; if greater or equal to the
1404                 length of the input string, the input string is returned
1405   value2      the number of hash characters to use, or 26 if negative
1406   len         set to the length of the returned string
1407
1408 Returns:      pointer to the output string, or NULL if there is an error
1409 */
1410
1411 static uschar *
1412 compute_hash(uschar *subject, int value1, int value2, int *len)
1413 {
1414 int sublen = Ustrlen(subject);
1415
1416 if (value2 < 0) value2 = 26;
1417 else if (value2 > Ustrlen(hashcodes))
1418   {
1419   expand_string_message =
1420     string_sprintf("hash count \"%d\" too big", value2);
1421   return NULL;
1422   }
1423
1424 /* Calculate the hash text. We know it is shorter than the original string, so
1425 can safely place it in subject[] (we know that subject is always itself an
1426 expanded substring). */
1427
1428 if (value1 < sublen)
1429   {
1430   int c;
1431   int i = 0;
1432   int j = value1;
1433   while ((c = (subject[j])) != 0)
1434     {
1435     int shift = (c + j++) & 7;
1436     subject[i] ^= (c << shift) | (c >> (8-shift));
1437     if (++i >= value1) i = 0;
1438     }
1439   for (i = 0; i < value1; i++)
1440     subject[i] = hashcodes[(subject[i]) % value2];
1441   }
1442 else value1 = sublen;
1443
1444 *len = value1;
1445 return subject;
1446 }
1447
1448
1449
1450
1451 /*************************************************
1452 *             Numeric hash of a string           *
1453 *************************************************/
1454
1455 /* Perform the ${nhash expansion operation. The first characters of the
1456 string are treated as most important, and get the highest prime numbers.
1457
1458 Arguments:
1459   subject     the input string
1460   value1      the maximum value of the first part of the result
1461   value2      the maximum value of the second part of the result,
1462                 or negative to produce only a one-part result
1463   len         set to the length of the returned string
1464
1465 Returns:  pointer to the output string, or NULL if there is an error.
1466 */
1467
1468 static uschar *
1469 compute_nhash (uschar *subject, int value1, int value2, int *len)
1470 {
1471 uschar *s = subject;
1472 int i = 0;
1473 unsigned long int total = 0; /* no overflow */
1474
1475 while (*s != 0)
1476   {
1477   if (i == 0) i = nelem(prime) - 1;
1478   total += prime[i--] * (unsigned int)(*s++);
1479   }
1480
1481 /* If value2 is unset, just compute one number */
1482
1483 if (value2 < 0)
1484   {
1485   s = string_sprintf("%d", total % value1);
1486   }
1487
1488 /* Otherwise do a div/mod hash */
1489
1490 else
1491   {
1492   total = total % (value1 * value2);
1493   s = string_sprintf("%d/%d", total/value2, total % value2);
1494   }
1495
1496 *len = Ustrlen(s);
1497 return s;
1498 }
1499
1500
1501
1502
1503
1504 /*************************************************
1505 *     Find the value of a header or headers      *
1506 *************************************************/
1507
1508 /* Multiple instances of the same header get concatenated, and this function
1509 can also return a concatenation of all the header lines. When concatenating
1510 specific headers that contain lists of addresses, a comma is inserted between
1511 them. Otherwise we use a straight concatenation. Because some messages can have
1512 pathologically large number of lines, there is a limit on the length that is
1513 returned. Also, to avoid massive store use which would result from using
1514 string_cat() as it copies and extends strings, we do a preliminary pass to find
1515 out exactly how much store will be needed. On "normal" messages this will be
1516 pretty trivial.
1517
1518 Arguments:
1519   name          the name of the header, without the leading $header_ or $h_,
1520                 or NULL if a concatenation of all headers is required
1521   exists_only   TRUE if called from a def: test; don't need to build a string;
1522                 just return a string that is not "" and not "0" if the header
1523                 exists
1524   newsize       return the size of memory block that was obtained; may be NULL
1525                 if exists_only is TRUE
1526   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1527                 other than concatenating, will be done on the header. Also used
1528                 for $message_headers_raw.
1529   charset       name of charset to translate MIME words to; used only if
1530                 want_raw is false; if NULL, no translation is done (this is
1531                 used for $bh_ and $bheader_)
1532
1533 Returns:        NULL if the header does not exist, else a pointer to a new
1534                 store block
1535 */
1536
1537 static uschar *
1538 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1539   uschar *charset)
1540 {
1541 BOOL found = name == NULL;
1542 int comma = 0;
1543 int len = found? 0 : Ustrlen(name);
1544 int i;
1545 uschar *yield = NULL;
1546 uschar *ptr = NULL;
1547
1548 /* Loop for two passes - saves code repetition */
1549
1550 for (i = 0; i < 2; i++)
1551   {
1552   int size = 0;
1553   header_line *h;
1554
1555   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1556     {
1557     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1558       {
1559       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1560         {
1561         int ilen;
1562         uschar *t;
1563
1564         if (exists_only) return US"1";      /* don't need actual string */
1565         found = TRUE;
1566         t = h->text + len;                  /* text to insert */
1567         if (!want_raw)                      /* unless wanted raw, */
1568           while (isspace(*t)) t++;          /* remove leading white space */
1569         ilen = h->slen - (t - h->text);     /* length to insert */
1570
1571         /* Unless wanted raw, remove trailing whitespace, including the
1572         newline. */
1573
1574         if (!want_raw)
1575           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1576
1577         /* Set comma = 1 if handling a single header and it's one of those
1578         that contains an address list, except when asked for raw headers. Only
1579         need to do this once. */
1580
1581         if (!want_raw && name != NULL && comma == 0 &&
1582             Ustrchr("BCFRST", h->type) != NULL)
1583           comma = 1;
1584
1585         /* First pass - compute total store needed; second pass - compute
1586         total store used, including this header. */
1587
1588         size += ilen + comma + 1;  /* +1 for the newline */
1589
1590         /* Second pass - concatentate the data, up to a maximum. Note that
1591         the loop stops when size hits the limit. */
1592
1593         if (i != 0)
1594           {
1595           if (size > header_insert_maxlen)
1596             {
1597             ilen -= size - header_insert_maxlen - 1;
1598             comma = 0;
1599             }
1600           Ustrncpy(ptr, t, ilen);
1601           ptr += ilen;
1602
1603           /* For a non-raw header, put in the comma if needed, then add
1604           back the newline we removed above, provided there was some text in
1605           the header. */
1606
1607           if (!want_raw && ilen > 0)
1608             {
1609             if (comma != 0) *ptr++ = ',';
1610             *ptr++ = '\n';
1611             }
1612           }
1613         }
1614       }
1615     }
1616
1617   /* At end of first pass, return NULL if no header found. Then truncate size
1618   if necessary, and get the buffer to hold the data, returning the buffer size.
1619   */
1620
1621   if (i == 0)
1622     {
1623     if (!found) return NULL;
1624     if (size > header_insert_maxlen) size = header_insert_maxlen;
1625     *newsize = size + 1;
1626     ptr = yield = store_get(*newsize);
1627     }
1628   }
1629
1630 /* That's all we do for raw header expansion. */
1631
1632 if (want_raw)
1633   {
1634   *ptr = 0;
1635   }
1636
1637 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1638 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1639 function can return an error with decoded data if the charset translation
1640 fails. If decoding fails, it returns NULL. */
1641
1642 else
1643   {
1644   uschar *decoded, *error;
1645   if (ptr > yield && ptr[-1] == '\n') ptr--;
1646   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1647   *ptr = 0;
1648   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1649     newsize, &error);
1650   if (error != NULL)
1651     {
1652     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1653       "    input was: %s\n", error, yield);
1654     }
1655   if (decoded != NULL) yield = decoded;
1656   }
1657
1658 return yield;
1659 }
1660
1661
1662
1663
1664 /*************************************************
1665 *               Return list of recipients        *
1666 *************************************************/
1667 /* A recipients list is available only during system message filtering,
1668 during ACL processing after DATA, and while expanding pipe commands
1669 generated from a system filter, but not elsewhere. */
1670
1671 static uschar *
1672 fn_recipients(void)
1673 {
1674 if (!enable_dollar_recipients) return NULL; else
1675   {
1676   int size = 128;
1677   int ptr = 0;
1678   int i;
1679   uschar * s = store_get(size);
1680   for (i = 0; i < recipients_count; i++)
1681     {
1682     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1683     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1684     }
1685   s[ptr] = 0;     /* string_cat() leaves room */
1686   return s;
1687   }
1688 }
1689
1690
1691 /*************************************************
1692 *               Find value of a variable         *
1693 *************************************************/
1694
1695 /* The table of variables is kept in alphabetic order, so we can search it
1696 using a binary chop. The "choplen" variable is nothing to do with the binary
1697 chop.
1698
1699 Arguments:
1700   name          the name of the variable being sought
1701   exists_only   TRUE if this is a def: test; passed on to find_header()
1702   skipping      TRUE => skip any processing evaluation; this is not the same as
1703                   exists_only because def: may test for values that are first
1704                   evaluated here
1705   newsize       pointer to an int which is initially zero; if the answer is in
1706                 a new memory buffer, *newsize is set to its size
1707
1708 Returns:        NULL if the variable does not exist, or
1709                 a pointer to the variable's contents, or
1710                 something non-NULL if exists_only is TRUE
1711 */
1712
1713 static uschar *
1714 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1715 {
1716 var_entry * vp;
1717 uschar *s, *domain;
1718 uschar **ss;
1719 void * val;
1720
1721 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1722 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1723 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1724 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1725 (this gave backwards compatibility at the changeover). There may be built-in
1726 variables whose names start acl_ but they should never start in this way. This
1727 slightly messy specification is a consequence of the history, needless to say.
1728
1729 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1730 set, in which case give an error. */
1731
1732 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1733      !isalpha(name[5]))
1734   {
1735   tree_node *node =
1736     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1737   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1738   }
1739
1740 /* Handle $auth<n> variables. */
1741
1742 if (Ustrncmp(name, "auth", 4) == 0)
1743   {
1744   uschar *endptr;
1745   int n = Ustrtoul(name + 4, &endptr, 10);
1746   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1747     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1748   }
1749 else if (Ustrncmp(name, "regex", 5) == 0)
1750   {
1751   uschar *endptr;
1752   int n = Ustrtoul(name + 5, &endptr, 10);
1753   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1754     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1755   }
1756
1757 /* For all other variables, search the table */
1758
1759 if (!(vp = find_var_ent(name)))
1760   return NULL;          /* Unknown variable name */
1761
1762 /* Found an existing variable. If in skipping state, the value isn't needed,
1763 and we want to avoid processing (such as looking up the host name). */
1764
1765 if (skipping)
1766   return US"";
1767
1768 val = vp->value;
1769 switch (vp->type)
1770   {
1771   case vtype_filter_int:
1772     if (!filter_running) return NULL;
1773     /* Fall through */
1774     /* VVVVVVVVVVVV */
1775   case vtype_int:
1776     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1777     return var_buffer;
1778
1779   case vtype_ino:
1780     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1781     return var_buffer;
1782
1783   case vtype_gid:
1784     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1785     return var_buffer;
1786
1787   case vtype_uid:
1788     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1789     return var_buffer;
1790
1791   case vtype_bool:
1792     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1793     return var_buffer;
1794
1795   case vtype_stringptr:                      /* Pointer to string */
1796     return (s = *((uschar **)(val))) ? s : US"";
1797
1798   case vtype_pid:
1799     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1800     return var_buffer;
1801
1802   case vtype_load_avg:
1803     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1804     return var_buffer;
1805
1806   case vtype_host_lookup:                    /* Lookup if not done so */
1807     if (sender_host_name == NULL && sender_host_address != NULL &&
1808         !host_lookup_failed && host_name_lookup() == OK)
1809       host_build_sender_fullhost();
1810     return (sender_host_name == NULL)? US"" : sender_host_name;
1811
1812   case vtype_localpart:                      /* Get local part from address */
1813     s = *((uschar **)(val));
1814     if (s == NULL) return US"";
1815     domain = Ustrrchr(s, '@');
1816     if (domain == NULL) return s;
1817     if (domain - s > sizeof(var_buffer) - 1)
1818       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1819           " in string expansion", sizeof(var_buffer));
1820     Ustrncpy(var_buffer, s, domain - s);
1821     var_buffer[domain - s] = 0;
1822     return var_buffer;
1823
1824   case vtype_domain:                         /* Get domain from address */
1825     s = *((uschar **)(val));
1826     if (s == NULL) return US"";
1827     domain = Ustrrchr(s, '@');
1828     return (domain == NULL)? US"" : domain + 1;
1829
1830   case vtype_msgheaders:
1831     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1832
1833   case vtype_msgheaders_raw:
1834     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1835
1836   case vtype_msgbody:                        /* Pointer to msgbody string */
1837   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1838     ss = (uschar **)(val);
1839     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1840       {
1841       uschar *body;
1842       off_t start_offset = SPOOL_DATA_START_OFFSET;
1843       int len = message_body_visible;
1844       if (len > message_size) len = message_size;
1845       *ss = body = store_malloc(len+1);
1846       body[0] = 0;
1847       if (vp->type == vtype_msgbody_end)
1848         {
1849         struct stat statbuf;
1850         if (fstat(deliver_datafile, &statbuf) == 0)
1851           {
1852           start_offset = statbuf.st_size - len;
1853           if (start_offset < SPOOL_DATA_START_OFFSET)
1854             start_offset = SPOOL_DATA_START_OFFSET;
1855           }
1856         }
1857       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1858         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1859           strerror(errno));
1860       len = read(deliver_datafile, body, len);
1861       if (len > 0)
1862         {
1863         body[len] = 0;
1864         if (message_body_newlines)   /* Separate loops for efficiency */
1865           while (len > 0)
1866             { if (body[--len] == 0) body[len] = ' '; }
1867         else
1868           while (len > 0)
1869             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1870         }
1871       }
1872     return (*ss == NULL)? US"" : *ss;
1873
1874   case vtype_todbsdin:                       /* BSD inbox time of day */
1875     return tod_stamp(tod_bsdin);
1876
1877   case vtype_tode:                           /* Unix epoch time of day */
1878     return tod_stamp(tod_epoch);
1879
1880   case vtype_todel:                          /* Unix epoch/usec time of day */
1881     return tod_stamp(tod_epoch_l);
1882
1883   case vtype_todf:                           /* Full time of day */
1884     return tod_stamp(tod_full);
1885
1886   case vtype_todl:                           /* Log format time of day */
1887     return tod_stamp(tod_log_bare);            /* (without timezone) */
1888
1889   case vtype_todzone:                        /* Time zone offset only */
1890     return tod_stamp(tod_zone);
1891
1892   case vtype_todzulu:                        /* Zulu time */
1893     return tod_stamp(tod_zulu);
1894
1895   case vtype_todlf:                          /* Log file datestamp tod */
1896     return tod_stamp(tod_log_datestamp_daily);
1897
1898   case vtype_reply:                          /* Get reply address */
1899     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1900       headers_charset);
1901     if (s != NULL) while (isspace(*s)) s++;
1902     if (s == NULL || *s == 0)
1903       {
1904       *newsize = 0;                            /* For the *s==0 case */
1905       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1906       }
1907     if (s != NULL)
1908       {
1909       uschar *t;
1910       while (isspace(*s)) s++;
1911       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1912       while (t > s && isspace(t[-1])) t--;
1913       *t = 0;
1914       }
1915     return (s == NULL)? US"" : s;
1916
1917   case vtype_string_func:
1918     {
1919     uschar * (*fn)() = val;
1920     return fn();
1921     }
1922
1923   case vtype_pspace:
1924     {
1925     int inodes;
1926     sprintf(CS var_buffer, "%d",
1927       receive_statvfs(val == (void *)TRUE, &inodes));
1928     }
1929   return var_buffer;
1930
1931   case vtype_pinodes:
1932     {
1933     int inodes;
1934     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1935     sprintf(CS var_buffer, "%d", inodes);
1936     }
1937   return var_buffer;
1938
1939   case vtype_cert:
1940     return *(void **)val ? US"<cert>" : US"";
1941
1942 #ifndef DISABLE_DKIM
1943   case vtype_dkim:
1944     return dkim_exim_expand_query((int)(long)val);
1945 #endif
1946
1947   }
1948
1949 return NULL;  /* Unknown variable. Silences static checkers. */
1950 }
1951
1952
1953
1954
1955 void
1956 modify_variable(uschar *name, void * value)
1957 {
1958 var_entry * vp;
1959 if ((vp = find_var_ent(name))) vp->value = value;
1960 return;          /* Unknown variable name, fail silently */
1961 }
1962
1963
1964
1965
1966
1967 /*************************************************
1968 *           Read and expand substrings           *
1969 *************************************************/
1970
1971 /* This function is called to read and expand argument substrings for various
1972 expansion items. Some have a minimum requirement that is less than the maximum;
1973 in these cases, the first non-present one is set to NULL.
1974
1975 Arguments:
1976   sub        points to vector of pointers to set
1977   n          maximum number of substrings
1978   m          minimum required
1979   sptr       points to current string pointer
1980   skipping   the skipping flag
1981   check_end  if TRUE, check for final '}'
1982   name       name of item, for error message
1983   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1984              the store.
1985
1986 Returns:     0 OK; string pointer updated
1987              1 curly bracketing error (too few arguments)
1988              2 too many arguments (only if check_end is set); message set
1989              3 other error (expansion failure)
1990 */
1991
1992 static int
1993 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1994   BOOL check_end, uschar *name, BOOL *resetok)
1995 {
1996 int i;
1997 const uschar *s = *sptr;
1998
1999 while (isspace(*s)) s++;
2000 for (i = 0; i < n; i++)
2001   {
2002   if (*s != '{')
2003     {
2004     if (i < m)
2005       {
2006       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2007         "(min is %d)", name, m);
2008       return 1;
2009       }
2010     sub[i] = NULL;
2011     break;
2012     }
2013   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2014     return 3;
2015   if (*s++ != '}') return 1;
2016   while (isspace(*s)) s++;
2017   }
2018 if (check_end && *s++ != '}')
2019   {
2020   if (s[-1] == '{')
2021     {
2022     expand_string_message = string_sprintf("Too many arguments for '%s' "
2023       "(max is %d)", name, n);
2024     return 2;
2025     }
2026   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2027   return 1;
2028   }
2029
2030 *sptr = s;
2031 return 0;
2032 }
2033
2034
2035
2036
2037 /*************************************************
2038 *     Elaborate message for bad variable         *
2039 *************************************************/
2040
2041 /* For the "unknown variable" message, take a look at the variable's name, and
2042 give additional information about possible ACL variables. The extra information
2043 is added on to expand_string_message.
2044
2045 Argument:   the name of the variable
2046 Returns:    nothing
2047 */
2048
2049 static void
2050 check_variable_error_message(uschar *name)
2051 {
2052 if (Ustrncmp(name, "acl_", 4) == 0)
2053   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2054     (name[4] == 'c' || name[4] == 'm')?
2055       (isalpha(name[5])?
2056         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2057         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2058       ) :
2059       US"user-defined ACL variables must start acl_c or acl_m");
2060 }
2061
2062
2063
2064 /*
2065 Load args from sub array to globals, and call acl_check().
2066 Sub array will be corrupted on return.
2067
2068 Returns:       OK         access is granted by an ACCEPT verb
2069                DISCARD    access is (apparently) granted by a DISCARD verb
2070                FAIL       access is denied
2071                FAIL_DROP  access is denied; drop the connection
2072                DEFER      can't tell at the moment
2073                ERROR      disaster
2074 */
2075 static int
2076 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2077 {
2078 int i;
2079 int sav_narg = acl_narg;
2080 int ret;
2081 uschar * dummy_logmsg;
2082 extern int acl_where;
2083
2084 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2085 for (i = 0; i < nsub && sub[i+1]; i++)
2086   {
2087   uschar * tmp = acl_arg[i];
2088   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2089   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2090   }
2091 acl_narg = i;
2092 while (i < nsub)
2093   {
2094   sub[i+1] = acl_arg[i];
2095   acl_arg[i++] = NULL;
2096   }
2097
2098 DEBUG(D_expand)
2099   debug_printf("expanding: acl: %s  arg: %s%s\n",
2100     sub[0],
2101     acl_narg>0 ? acl_arg[0] : US"<none>",
2102     acl_narg>1 ? " +more"   : "");
2103
2104 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2105
2106 for (i = 0; i < nsub; i++)
2107   acl_arg[i] = sub[i+1];        /* restore old args */
2108 acl_narg = sav_narg;
2109
2110 return ret;
2111 }
2112
2113
2114
2115
2116 /*************************************************
2117 *        Read and evaluate a condition           *
2118 *************************************************/
2119
2120 /*
2121 Arguments:
2122   s        points to the start of the condition text
2123   resetok  points to a BOOL which is written false if it is unsafe to
2124            free memory. Certain condition types (acl) may have side-effect
2125            allocation which must be preserved.
2126   yield    points to a BOOL to hold the result of the condition test;
2127            if NULL, we are just reading through a condition that is
2128            part of an "or" combination to check syntax, or in a state
2129            where the answer isn't required
2130
2131 Returns:   a pointer to the first character after the condition, or
2132            NULL after an error
2133 */
2134
2135 static const uschar *
2136 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2137 {
2138 BOOL testfor = TRUE;
2139 BOOL tempcond, combined_cond;
2140 BOOL *subcondptr;
2141 BOOL sub2_honour_dollar = TRUE;
2142 int i, rc, cond_type, roffset;
2143 int_eximarith_t num[2];
2144 struct stat statbuf;
2145 uschar name[256];
2146 const uschar *sub[10];
2147
2148 const pcre *re;
2149 const uschar *rerror;
2150
2151 for (;;)
2152   {
2153   while (isspace(*s)) s++;
2154   if (*s == '!') { testfor = !testfor; s++; } else break;
2155   }
2156
2157 /* Numeric comparisons are symbolic */
2158
2159 if (*s == '=' || *s == '>' || *s == '<')
2160   {
2161   int p = 0;
2162   name[p++] = *s++;
2163   if (*s == '=')
2164     {
2165     name[p++] = '=';
2166     s++;
2167     }
2168   name[p] = 0;
2169   }
2170
2171 /* All other conditions are named */
2172
2173 else s = read_name(name, 256, s, US"_");
2174
2175 /* If we haven't read a name, it means some non-alpha character is first. */
2176
2177 if (name[0] == 0)
2178   {
2179   expand_string_message = string_sprintf("condition name expected, "
2180     "but found \"%.16s\"", s);
2181   return NULL;
2182   }
2183
2184 /* Find which condition we are dealing with, and switch on it */
2185
2186 cond_type = chop_match(name, cond_table, nelem(cond_table));
2187 switch(cond_type)
2188   {
2189   /* def: tests for a non-empty variable, or for the existence of a header. If
2190   yield == NULL we are in a skipping state, and don't care about the answer. */
2191
2192   case ECOND_DEF:
2193   if (*s != ':')
2194     {
2195     expand_string_message = US"\":\" expected after \"def\"";
2196     return NULL;
2197     }
2198
2199   s = read_name(name, 256, s+1, US"_");
2200
2201   /* Test for a header's existence. If the name contains a closing brace
2202   character, this may be a user error where the terminating colon has been
2203   omitted. Set a flag to adjust a subsequent error message in this case. */
2204
2205   if (Ustrncmp(name, "h_", 2) == 0 ||
2206       Ustrncmp(name, "rh_", 3) == 0 ||
2207       Ustrncmp(name, "bh_", 3) == 0 ||
2208       Ustrncmp(name, "header_", 7) == 0 ||
2209       Ustrncmp(name, "rheader_", 8) == 0 ||
2210       Ustrncmp(name, "bheader_", 8) == 0)
2211     {
2212     s = read_header_name(name, 256, s);
2213     /* {-for-text-editors */
2214     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2215     if (yield != NULL) *yield =
2216       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2217     }
2218
2219   /* Test for a variable's having a non-empty value. A non-existent variable
2220   causes an expansion failure. */
2221
2222   else
2223     {
2224     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2225     if (value == NULL)
2226       {
2227       expand_string_message = (name[0] == 0)?
2228         string_sprintf("variable name omitted after \"def:\"") :
2229         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2230       check_variable_error_message(name);
2231       return NULL;
2232       }
2233     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2234     }
2235
2236   return s;
2237
2238
2239   /* first_delivery tests for first delivery attempt */
2240
2241   case ECOND_FIRST_DELIVERY:
2242   if (yield != NULL) *yield = deliver_firsttime == testfor;
2243   return s;
2244
2245
2246   /* queue_running tests for any process started by a queue runner */
2247
2248   case ECOND_QUEUE_RUNNING:
2249   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2250   return s;
2251
2252
2253   /* exists:  tests for file existence
2254        isip:  tests for any IP address
2255       isip4:  tests for an IPv4 address
2256       isip6:  tests for an IPv6 address
2257         pam:  does PAM authentication
2258      radius:  does RADIUS authentication
2259    ldapauth:  does LDAP authentication
2260     pwcheck:  does Cyrus SASL pwcheck authentication
2261   */
2262
2263   case ECOND_EXISTS:
2264   case ECOND_ISIP:
2265   case ECOND_ISIP4:
2266   case ECOND_ISIP6:
2267   case ECOND_PAM:
2268   case ECOND_RADIUS:
2269   case ECOND_LDAPAUTH:
2270   case ECOND_PWCHECK:
2271
2272   while (isspace(*s)) s++;
2273   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2274
2275   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2276   if (sub[0] == NULL) return NULL;
2277   /* {-for-text-editors */
2278   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2279
2280   if (yield == NULL) return s;   /* No need to run the test if skipping */
2281
2282   switch(cond_type)
2283     {
2284     case ECOND_EXISTS:
2285     if ((expand_forbid & RDO_EXISTS) != 0)
2286       {
2287       expand_string_message = US"File existence tests are not permitted";
2288       return NULL;
2289       }
2290     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2291     break;
2292
2293     case ECOND_ISIP:
2294     case ECOND_ISIP4:
2295     case ECOND_ISIP6:
2296     rc = string_is_ip_address(sub[0], NULL);
2297     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2298              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2299     break;
2300
2301     /* Various authentication tests - all optionally compiled */
2302
2303     case ECOND_PAM:
2304     #ifdef SUPPORT_PAM
2305     rc = auth_call_pam(sub[0], &expand_string_message);
2306     goto END_AUTH;
2307     #else
2308     goto COND_FAILED_NOT_COMPILED;
2309     #endif  /* SUPPORT_PAM */
2310
2311     case ECOND_RADIUS:
2312     #ifdef RADIUS_CONFIG_FILE
2313     rc = auth_call_radius(sub[0], &expand_string_message);
2314     goto END_AUTH;
2315     #else
2316     goto COND_FAILED_NOT_COMPILED;
2317     #endif  /* RADIUS_CONFIG_FILE */
2318
2319     case ECOND_LDAPAUTH:
2320     #ifdef LOOKUP_LDAP
2321       {
2322       /* Just to keep the interface the same */
2323       BOOL do_cache;
2324       int old_pool = store_pool;
2325       store_pool = POOL_SEARCH;
2326       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2327         &expand_string_message, &do_cache);
2328       store_pool = old_pool;
2329       }
2330     goto END_AUTH;
2331     #else
2332     goto COND_FAILED_NOT_COMPILED;
2333     #endif  /* LOOKUP_LDAP */
2334
2335     case ECOND_PWCHECK:
2336     #ifdef CYRUS_PWCHECK_SOCKET
2337     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2338     goto END_AUTH;
2339     #else
2340     goto COND_FAILED_NOT_COMPILED;
2341     #endif  /* CYRUS_PWCHECK_SOCKET */
2342
2343     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2344         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2345     END_AUTH:
2346     if (rc == ERROR || rc == DEFER) return NULL;
2347     *yield = (rc == OK) == testfor;
2348     #endif
2349     }
2350   return s;
2351
2352
2353   /* call ACL (in a conditional context).  Accept true, deny false.
2354   Defer is a forced-fail.  Anything set by message= goes to $value.
2355   Up to ten parameters are used; we use the braces round the name+args
2356   like the saslauthd condition does, to permit a variable number of args.
2357   See also the expansion-item version EITEM_ACL and the traditional
2358   acl modifier ACLC_ACL.
2359   Since the ACL may allocate new global variables, tell our caller to not
2360   reclaim memory.
2361   */
2362
2363   case ECOND_ACL:
2364     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2365     {
2366     uschar *sub[10];
2367     uschar *user_msg;
2368     BOOL cond = FALSE;
2369     int size = 0;
2370     int ptr = 0;
2371
2372     while (isspace(*s)) s++;
2373     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2374
2375     switch(read_subs(sub, nelem(sub), 1,
2376       &s, yield == NULL, TRUE, US"acl", resetok))
2377       {
2378       case 1: expand_string_message = US"too few arguments or bracketing "
2379         "error for acl";
2380       case 2:
2381       case 3: return NULL;
2382       }
2383
2384     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2385     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2386         {
2387         case OK:
2388           cond = TRUE;
2389         case FAIL:
2390           lookup_value = NULL;
2391           if (user_msg)
2392             {
2393             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2394             lookup_value[ptr] = '\0';
2395             }
2396           *yield = cond == testfor;
2397           break;
2398
2399         case DEFER:
2400           expand_string_forcedfail = TRUE;
2401           /*FALLTHROUGH*/
2402         default:
2403           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2404           return NULL;
2405         }
2406     return s;
2407     }
2408
2409
2410   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2411
2412      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2413
2414   However, the last two are optional. That is why the whole set is enclosed
2415   in their own set of braces. */
2416
2417   case ECOND_SASLAUTHD:
2418 #ifndef CYRUS_SASLAUTHD_SOCKET
2419     goto COND_FAILED_NOT_COMPILED;
2420 #else
2421     {
2422     uschar *sub[4];
2423     while (isspace(*s)) s++;
2424     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2425     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2426                     resetok))
2427       {
2428       case 1: expand_string_message = US"too few arguments or bracketing "
2429         "error for saslauthd";
2430       case 2:
2431       case 3: return NULL;
2432       }
2433     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2434     if (yield != NULL)
2435       {
2436       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2437         &expand_string_message);
2438       if (rc == ERROR || rc == DEFER) return NULL;
2439       *yield = (rc == OK) == testfor;
2440       }
2441     return s;
2442     }
2443 #endif /* CYRUS_SASLAUTHD_SOCKET */
2444
2445
2446   /* symbolic operators for numeric and string comparison, and a number of
2447   other operators, all requiring two arguments.
2448
2449   crypteq:           encrypts plaintext and compares against an encrypted text,
2450                        using crypt(), crypt16(), MD5 or SHA-1
2451   inlist/inlisti:    checks if first argument is in the list of the second
2452   match:             does a regular expression match and sets up the numerical
2453                        variables if it succeeds
2454   match_address:     matches in an address list
2455   match_domain:      matches in a domain list
2456   match_ip:          matches a host list that is restricted to IP addresses
2457   match_local_part:  matches in a local part list
2458   */
2459
2460   case ECOND_MATCH_ADDRESS:
2461   case ECOND_MATCH_DOMAIN:
2462   case ECOND_MATCH_IP:
2463   case ECOND_MATCH_LOCAL_PART:
2464 #ifndef EXPAND_LISTMATCH_RHS
2465     sub2_honour_dollar = FALSE;
2466 #endif
2467     /* FALLTHROUGH */
2468
2469   case ECOND_CRYPTEQ:
2470   case ECOND_INLIST:
2471   case ECOND_INLISTI:
2472   case ECOND_MATCH:
2473
2474   case ECOND_NUM_L:     /* Numerical comparisons */
2475   case ECOND_NUM_LE:
2476   case ECOND_NUM_E:
2477   case ECOND_NUM_EE:
2478   case ECOND_NUM_G:
2479   case ECOND_NUM_GE:
2480
2481   case ECOND_STR_LT:    /* String comparisons */
2482   case ECOND_STR_LTI:
2483   case ECOND_STR_LE:
2484   case ECOND_STR_LEI:
2485   case ECOND_STR_EQ:
2486   case ECOND_STR_EQI:
2487   case ECOND_STR_GT:
2488   case ECOND_STR_GTI:
2489   case ECOND_STR_GE:
2490   case ECOND_STR_GEI:
2491
2492   for (i = 0; i < 2; i++)
2493     {
2494     /* Sometimes, we don't expand substrings; too many insecure configurations
2495     created using match_address{}{} and friends, where the second param
2496     includes information from untrustworthy sources. */
2497     BOOL honour_dollar = TRUE;
2498     if ((i > 0) && !sub2_honour_dollar)
2499       honour_dollar = FALSE;
2500
2501     while (isspace(*s)) s++;
2502     if (*s != '{')
2503       {
2504       if (i == 0) goto COND_FAILED_CURLY_START;
2505       expand_string_message = string_sprintf("missing 2nd string in {} "
2506         "after \"%s\"", name);
2507       return NULL;
2508       }
2509     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2510         honour_dollar, resetok);
2511     if (sub[i] == NULL) return NULL;
2512     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2513
2514     /* Convert to numerical if required; we know that the names of all the
2515     conditions that compare numbers do not start with a letter. This just saves
2516     checking for them individually. */
2517
2518     if (!isalpha(name[0]) && yield != NULL)
2519       if (sub[i][0] == 0)
2520         {
2521         num[i] = 0;
2522         DEBUG(D_expand)
2523           debug_printf("empty string cast to zero for numerical comparison\n");
2524         }
2525       else
2526         {
2527         num[i] = expanded_string_integer(sub[i], FALSE);
2528         if (expand_string_message != NULL) return NULL;
2529         }
2530     }
2531
2532   /* Result not required */
2533
2534   if (yield == NULL) return s;
2535
2536   /* Do an appropriate comparison */
2537
2538   switch(cond_type)
2539     {
2540     case ECOND_NUM_E:
2541     case ECOND_NUM_EE:
2542     tempcond = (num[0] == num[1]);
2543     break;
2544
2545     case ECOND_NUM_G:
2546     tempcond = (num[0] > num[1]);
2547     break;
2548
2549     case ECOND_NUM_GE:
2550     tempcond = (num[0] >= num[1]);
2551     break;
2552
2553     case ECOND_NUM_L:
2554     tempcond = (num[0] < num[1]);
2555     break;
2556
2557     case ECOND_NUM_LE:
2558     tempcond = (num[0] <= num[1]);
2559     break;
2560
2561     case ECOND_STR_LT:
2562     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2563     break;
2564
2565     case ECOND_STR_LTI:
2566     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2567     break;
2568
2569     case ECOND_STR_LE:
2570     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2571     break;
2572
2573     case ECOND_STR_LEI:
2574     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2575     break;
2576
2577     case ECOND_STR_EQ:
2578     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2579     break;
2580
2581     case ECOND_STR_EQI:
2582     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2583     break;
2584
2585     case ECOND_STR_GT:
2586     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2587     break;
2588
2589     case ECOND_STR_GTI:
2590     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2591     break;
2592
2593     case ECOND_STR_GE:
2594     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2595     break;
2596
2597     case ECOND_STR_GEI:
2598     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2599     break;
2600
2601     case ECOND_MATCH:   /* Regular expression match */
2602     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2603       NULL);
2604     if (re == NULL)
2605       {
2606       expand_string_message = string_sprintf("regular expression error in "
2607         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2608       return NULL;
2609       }
2610     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2611     break;
2612
2613     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2614     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2615     goto MATCHED_SOMETHING;
2616
2617     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2618     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2619       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2620     goto MATCHED_SOMETHING;
2621
2622     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2623     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2624       {
2625       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2626         sub[0]);
2627       return NULL;
2628       }
2629     else
2630       {
2631       unsigned int *nullcache = NULL;
2632       check_host_block cb;
2633
2634       cb.host_name = US"";
2635       cb.host_address = sub[0];
2636
2637       /* If the host address starts off ::ffff: it is an IPv6 address in
2638       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2639       addresses. */
2640
2641       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2642         cb.host_address + 7 : cb.host_address;
2643
2644       rc = match_check_list(
2645              &sub[1],                   /* the list */
2646              0,                         /* separator character */
2647              &hostlist_anchor,          /* anchor pointer */
2648              &nullcache,                /* cache pointer */
2649              check_host,                /* function for testing */
2650              &cb,                       /* argument for function */
2651              MCL_HOST,                  /* type of check */
2652              sub[0],                    /* text for debugging */
2653              NULL);                     /* where to pass back data */
2654       }
2655     goto MATCHED_SOMETHING;
2656
2657     case ECOND_MATCH_LOCAL_PART:
2658     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2659       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2660     /* Fall through */
2661     /* VVVVVVVVVVVV */
2662     MATCHED_SOMETHING:
2663     switch(rc)
2664       {
2665       case OK:
2666       tempcond = TRUE;
2667       break;
2668
2669       case FAIL:
2670       tempcond = FALSE;
2671       break;
2672
2673       case DEFER:
2674       expand_string_message = string_sprintf("unable to complete match "
2675         "against \"%s\": %s", sub[1], search_error_message);
2676       return NULL;
2677       }
2678
2679     break;
2680
2681     /* Various "encrypted" comparisons. If the second string starts with
2682     "{" then an encryption type is given. Default to crypt() or crypt16()
2683     (build-time choice). */
2684     /* }-for-text-editors */
2685
2686     case ECOND_CRYPTEQ:
2687     #ifndef SUPPORT_CRYPTEQ
2688     goto COND_FAILED_NOT_COMPILED;
2689     #else
2690     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2691       {
2692       int sublen = Ustrlen(sub[1]+5);
2693       md5 base;
2694       uschar digest[16];
2695
2696       md5_start(&base);
2697       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2698
2699       /* If the length that we are comparing against is 24, the MD5 digest
2700       is expressed as a base64 string. This is the way LDAP does it. However,
2701       some other software uses a straightforward hex representation. We assume
2702       this if the length is 32. Other lengths fail. */
2703
2704       if (sublen == 24)
2705         {
2706         uschar *coded = b64encode(digest, 16);
2707         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2708           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2709         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2710         }
2711       else if (sublen == 32)
2712         {
2713         int i;
2714         uschar coded[36];
2715         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2716         coded[32] = 0;
2717         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2718           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2719         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2720         }
2721       else
2722         {
2723         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2724           "fail\n  crypted=%s\n", sub[1]+5);
2725         tempcond = FALSE;
2726         }
2727       }
2728
2729     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2730       {
2731       int sublen = Ustrlen(sub[1]+6);
2732       hctx h;
2733       uschar digest[20];
2734
2735       sha1_start(&h);
2736       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2737
2738       /* If the length that we are comparing against is 28, assume the SHA1
2739       digest is expressed as a base64 string. If the length is 40, assume a
2740       straightforward hex representation. Other lengths fail. */
2741
2742       if (sublen == 28)
2743         {
2744         uschar *coded = b64encode(digest, 20);
2745         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2746           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2747         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2748         }
2749       else if (sublen == 40)
2750         {
2751         int i;
2752         uschar coded[44];
2753         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2754         coded[40] = 0;
2755         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2756           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2757         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2758         }
2759       else
2760         {
2761         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2762           "fail\n  crypted=%s\n", sub[1]+6);
2763         tempcond = FALSE;
2764         }
2765       }
2766
2767     else   /* {crypt} or {crypt16} and non-{ at start */
2768            /* }-for-text-editors */
2769       {
2770       int which = 0;
2771       uschar *coded;
2772
2773       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2774         {
2775         sub[1] += 7;
2776         which = 1;
2777         }
2778       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2779         {
2780         sub[1] += 9;
2781         which = 2;
2782         }
2783       else if (sub[1][0] == '{')                /* }-for-text-editors */
2784         {
2785         expand_string_message = string_sprintf("unknown encryption mechanism "
2786           "in \"%s\"", sub[1]);
2787         return NULL;
2788         }
2789
2790       switch(which)
2791         {
2792         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2793         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2794         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2795         }
2796
2797       #define STR(s) # s
2798       #define XSTR(s) STR(s)
2799       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2800         "  subject=%s\n  crypted=%s\n",
2801         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2802         coded, sub[1]);
2803       #undef STR
2804       #undef XSTR
2805
2806       /* If the encrypted string contains fewer than two characters (for the
2807       salt), force failure. Otherwise we get false positives: with an empty
2808       string the yield of crypt() is an empty string! */
2809
2810       if (coded)
2811         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2812       else if (errno == EINVAL)
2813         tempcond = FALSE;
2814       else
2815         {
2816         expand_string_message = string_sprintf("crypt error: %s\n",
2817           US strerror(errno));
2818         return NULL;
2819         }
2820       }
2821     break;
2822     #endif  /* SUPPORT_CRYPTEQ */
2823
2824     case ECOND_INLIST:
2825     case ECOND_INLISTI:
2826       {
2827       const uschar * list = sub[1];
2828       int sep = 0;
2829       uschar *save_iterate_item = iterate_item;
2830       int (*compare)(const uschar *, const uschar *);
2831
2832       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2833
2834       tempcond = FALSE;
2835       compare = cond_type == ECOND_INLISTI
2836         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2837
2838       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2839         if (compare(sub[0], iterate_item) == 0)
2840           {
2841           tempcond = TRUE;
2842           break;
2843           }
2844       iterate_item = save_iterate_item;
2845       }
2846
2847     }   /* Switch for comparison conditions */
2848
2849   *yield = tempcond == testfor;
2850   return s;    /* End of comparison conditions */
2851
2852
2853   /* and/or: computes logical and/or of several conditions */
2854
2855   case ECOND_AND:
2856   case ECOND_OR:
2857   subcondptr = (yield == NULL)? NULL : &tempcond;
2858   combined_cond = (cond_type == ECOND_AND);
2859
2860   while (isspace(*s)) s++;
2861   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2862
2863   for (;;)
2864     {
2865     while (isspace(*s)) s++;
2866     /* {-for-text-editors */
2867     if (*s == '}') break;
2868     if (*s != '{')                                      /* }-for-text-editors */
2869       {
2870       expand_string_message = string_sprintf("each subcondition "
2871         "inside an \"%s{...}\" condition must be in its own {}", name);
2872       return NULL;
2873       }
2874
2875     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2876       {
2877       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2878         expand_string_message, name);
2879       return NULL;
2880       }
2881     while (isspace(*s)) s++;
2882
2883     /* {-for-text-editors */
2884     if (*s++ != '}')
2885       {
2886       /* {-for-text-editors */
2887       expand_string_message = string_sprintf("missing } at end of condition "
2888         "inside \"%s\" group", name);
2889       return NULL;
2890       }
2891
2892     if (yield != NULL)
2893       {
2894       if (cond_type == ECOND_AND)
2895         {
2896         combined_cond &= tempcond;
2897         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2898         }                                       /* evaluate any more */
2899       else
2900         {
2901         combined_cond |= tempcond;
2902         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2903         }                                       /* evaluate any more */
2904       }
2905     }
2906
2907   if (yield != NULL) *yield = (combined_cond == testfor);
2908   return ++s;
2909
2910
2911   /* forall/forany: iterates a condition with different values */
2912
2913   case ECOND_FORALL:
2914   case ECOND_FORANY:
2915     {
2916     const uschar * list;
2917     int sep = 0;
2918     uschar *save_iterate_item = iterate_item;
2919
2920     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2921
2922     while (isspace(*s)) s++;
2923     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2924     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2925     if (sub[0] == NULL) return NULL;
2926     /* {-for-text-editors */
2927     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2928
2929     while (isspace(*s)) s++;
2930     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2931
2932     sub[1] = s;
2933
2934     /* Call eval_condition once, with result discarded (as if scanning a
2935     "false" part). This allows us to find the end of the condition, because if
2936     the list it empty, we won't actually evaluate the condition for real. */
2937
2938     if (!(s = eval_condition(sub[1], resetok, NULL)))
2939       {
2940       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2941         expand_string_message, name);
2942       return NULL;
2943       }
2944     while (isspace(*s)) s++;
2945
2946     /* {-for-text-editors */
2947     if (*s++ != '}')
2948       {
2949       /* {-for-text-editors */
2950       expand_string_message = string_sprintf("missing } at end of condition "
2951         "inside \"%s\"", name);
2952       return NULL;
2953       }
2954
2955     if (yield != NULL) *yield = !testfor;
2956     list = sub[0];
2957     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2958       {
2959       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2960       if (!eval_condition(sub[1], resetok, &tempcond))
2961         {
2962         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2963           expand_string_message, name);
2964         iterate_item = save_iterate_item;
2965         return NULL;
2966         }
2967       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2968         tempcond? "true":"false");
2969
2970       if (yield != NULL) *yield = (tempcond == testfor);
2971       if (tempcond == (cond_type == ECOND_FORANY)) break;
2972       }
2973
2974     iterate_item = save_iterate_item;
2975     return s;
2976     }
2977
2978
2979   /* The bool{} expansion condition maps a string to boolean.
2980   The values supported should match those supported by the ACL condition
2981   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2982   of true/false.  Note that Router "condition" rules have a different
2983   interpretation, where general data can be used and only a few values
2984   map to FALSE.
2985   Note that readconf.c boolean matching, for boolean configuration options,
2986   only matches true/yes/false/no.
2987   The bool_lax{} condition matches the Router logic, which is much more
2988   liberal. */
2989   case ECOND_BOOL:
2990   case ECOND_BOOL_LAX:
2991     {
2992     uschar *sub_arg[1];
2993     uschar *t, *t2;
2994     uschar *ourname;
2995     size_t len;
2996     BOOL boolvalue = FALSE;
2997     while (isspace(*s)) s++;
2998     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2999     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3000     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3001       {
3002       case 1: expand_string_message = string_sprintf(
3003                   "too few arguments or bracketing error for %s",
3004                   ourname);
3005       /*FALLTHROUGH*/
3006       case 2:
3007       case 3: return NULL;
3008       }
3009     t = sub_arg[0];
3010     while (isspace(*t)) t++;
3011     len = Ustrlen(t);
3012     if (len)
3013       {
3014       /* trailing whitespace: seems like a good idea to ignore it too */
3015       t2 = t + len - 1;
3016       while (isspace(*t2)) t2--;
3017       if (t2 != (t + len))
3018         {
3019         *++t2 = '\0';
3020         len = t2 - t;
3021         }
3022       }
3023     DEBUG(D_expand)
3024       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3025     /* logic for the lax case from expand_check_condition(), which also does
3026     expands, and the logic is both short and stable enough that there should
3027     be no maintenance burden from replicating it. */
3028     if (len == 0)
3029       boolvalue = FALSE;
3030     else if (*t == '-'
3031              ? Ustrspn(t+1, "0123456789") == len-1
3032              : Ustrspn(t,   "0123456789") == len)
3033       {
3034       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3035       /* expand_check_condition only does a literal string "0" check */
3036       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3037         boolvalue = TRUE;
3038       }
3039     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3040       boolvalue = TRUE;
3041     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3042       boolvalue = FALSE;
3043     else if (cond_type == ECOND_BOOL_LAX)
3044       boolvalue = TRUE;
3045     else
3046       {
3047       expand_string_message = string_sprintf("unrecognised boolean "
3048        "value \"%s\"", t);
3049       return NULL;
3050       }
3051     if (yield != NULL) *yield = (boolvalue == testfor);
3052     return s;
3053     }
3054
3055   /* Unknown condition */
3056
3057   default:
3058   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3059   return NULL;
3060   }   /* End switch on condition type */
3061
3062 /* Missing braces at start and end of data */
3063
3064 COND_FAILED_CURLY_START:
3065 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3066 return NULL;
3067
3068 COND_FAILED_CURLY_END:
3069 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3070   name);
3071 return NULL;
3072
3073 /* A condition requires code that is not compiled */
3074
3075 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3076     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3077     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3078 COND_FAILED_NOT_COMPILED:
3079 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3080   name);
3081 return NULL;
3082 #endif
3083 }
3084
3085
3086
3087
3088 /*************************************************
3089 *          Save numerical variables              *
3090 *************************************************/
3091
3092 /* This function is called from items such as "if" that want to preserve and
3093 restore the numbered variables.
3094
3095 Arguments:
3096   save_expand_string    points to an array of pointers to set
3097   save_expand_nlength   points to an array of ints for the lengths
3098
3099 Returns:                the value of expand max to save
3100 */
3101
3102 static int
3103 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3104 {
3105 int i;
3106 for (i = 0; i <= expand_nmax; i++)
3107   {
3108   save_expand_nstring[i] = expand_nstring[i];
3109   save_expand_nlength[i] = expand_nlength[i];
3110   }
3111 return expand_nmax;
3112 }
3113
3114
3115
3116 /*************************************************
3117 *           Restore numerical variables          *
3118 *************************************************/
3119
3120 /* This function restored saved values of numerical strings.
3121
3122 Arguments:
3123   save_expand_nmax      the number of strings to restore
3124   save_expand_string    points to an array of pointers
3125   save_expand_nlength   points to an array of ints
3126
3127 Returns:                nothing
3128 */
3129
3130 static void
3131 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3132   int *save_expand_nlength)
3133 {
3134 int i;
3135 expand_nmax = save_expand_nmax;
3136 for (i = 0; i <= expand_nmax; i++)
3137   {
3138   expand_nstring[i] = save_expand_nstring[i];
3139   expand_nlength[i] = save_expand_nlength[i];
3140   }
3141 }
3142
3143
3144
3145
3146
3147 /*************************************************
3148 *            Handle yes/no substrings            *
3149 *************************************************/
3150
3151 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3152 alternative substrings that depend on whether or not the condition was true,
3153 or the lookup or extraction succeeded. The substrings always have to be
3154 expanded, to check their syntax, but "skipping" is set when the result is not
3155 needed - this avoids unnecessary nested lookups.
3156
3157 Arguments:
3158   skipping       TRUE if we were skipping when this item was reached
3159   yes            TRUE if the first string is to be used, else use the second
3160   save_lookup    a value to put back into lookup_value before the 2nd expansion
3161   sptr           points to the input string pointer
3162   yieldptr       points to the output string pointer
3163   sizeptr        points to the output string size
3164   ptrptr         points to the output string pointer
3165   type           "lookup", "if", "extract", "run", "env", "listextract" or
3166                  "certextract" for error message
3167   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3168                 the store.
3169
3170 Returns:         0 OK; lookup_value has been reset to save_lookup
3171                  1 expansion failed
3172                  2 expansion failed because of bracketing error
3173 */
3174
3175 static int
3176 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3177   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3178 {
3179 int rc = 0;
3180 const uschar *s = *sptr;    /* Local value */
3181 uschar *sub1, *sub2;
3182 const uschar * errwhere;
3183
3184 /* If there are no following strings, we substitute the contents of $value for
3185 lookups and for extractions in the success case. For the ${if item, the string
3186 "true" is substituted. In the fail case, nothing is substituted for all three
3187 items. */
3188
3189 while (isspace(*s)) s++;
3190 if (*s == '}')
3191   {
3192   if (type[0] == 'i')
3193     {
3194     if (yes) *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3195     }
3196   else
3197     {
3198     if (yes && lookup_value)
3199       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3200     lookup_value = save_lookup;
3201     }
3202   s++;
3203   goto RETURN;
3204   }
3205
3206 /* The first following string must be braced. */
3207
3208 if (*s++ != '{')
3209   {
3210   errwhere = US"'yes' part did not start with '{'";
3211   goto FAILED_CURLY;
3212   }
3213
3214 /* Expand the first substring. Forced failures are noticed only if we actually
3215 want this string. Set skipping in the call in the fail case (this will always
3216 be the case if we were already skipping). */
3217
3218 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3219 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3220 expand_string_forcedfail = FALSE;
3221 if (*s++ != '}')
3222   {
3223   errwhere = US"'yes' part did not end with '}'";
3224   goto FAILED_CURLY;
3225   }
3226
3227 /* If we want the first string, add it to the output */
3228
3229 if (yes)
3230   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3231
3232 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3233 $value to what it was at the start of the item, so that it has this value
3234 during the second string expansion. For the call from "if" or "run" to this
3235 function, save_lookup is set to lookup_value, so that this statement does
3236 nothing. */
3237
3238 lookup_value = save_lookup;
3239
3240 /* There now follows either another substring, or "fail", or nothing. This
3241 time, forced failures are noticed only if we want the second string. We must
3242 set skipping in the nested call if we don't want this string, or if we were
3243 already skipping. */
3244
3245 while (isspace(*s)) s++;
3246 if (*s == '{')
3247   {
3248   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3249   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3250   expand_string_forcedfail = FALSE;
3251   if (*s++ != '}')
3252     {
3253     errwhere = US"'no' part did not start with '{'";
3254     goto FAILED_CURLY;
3255     }
3256
3257   /* If we want the second string, add it to the output */
3258
3259   if (!yes)
3260     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3261   }
3262
3263 /* If there is no second string, but the word "fail" is present when the use of
3264 the second string is wanted, set a flag indicating it was a forced failure
3265 rather than a syntactic error. Swallow the terminating } in case this is nested
3266 inside another lookup or if or extract. */
3267
3268 else if (*s != '}')
3269   {
3270   uschar name[256];
3271   /* deconst cast ok here as source is s anyway */
3272   s = US read_name(name, sizeof(name), s, US"_");
3273   if (Ustrcmp(name, "fail") == 0)
3274     {
3275     if (!yes && !skipping)
3276       {
3277       while (isspace(*s)) s++;
3278       if (*s++ != '}')
3279         {
3280         errwhere = US"did not close with '}' after forcedfail";
3281         goto FAILED_CURLY;
3282         }
3283       expand_string_message =
3284         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3285       expand_string_forcedfail = TRUE;
3286       goto FAILED;
3287       }
3288     }
3289   else
3290     {
3291     expand_string_message =
3292       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3293     goto FAILED;
3294     }
3295   }
3296
3297 /* All we have to do now is to check on the final closing brace. */
3298
3299 while (isspace(*s)) s++;
3300 if (*s++ != '}')
3301   {
3302   errwhere = US"did not close with '}'";
3303   goto FAILED_CURLY;
3304   }
3305
3306
3307 RETURN:
3308 /* Update the input pointer value before returning */
3309 *sptr = s;
3310 return rc;
3311
3312 FAILED_CURLY:
3313   /* Get here if there is a bracketing failure */
3314   expand_string_message = string_sprintf(
3315     "curly-bracket problem in conditional yes/no parsing: %s\n"
3316     " remaining string is '%s'", errwhere, --s);
3317   rc = 2;
3318   goto RETURN;
3319
3320 FAILED:
3321   /* Get here for other failures */
3322   rc = 1;
3323   goto RETURN;
3324 }
3325
3326
3327
3328
3329 /*************************************************
3330 *    Handle MD5 or SHA-1 computation for HMAC    *
3331 *************************************************/
3332
3333 /* These are some wrapping functions that enable the HMAC code to be a bit
3334 cleaner. A good compiler will spot the tail recursion.
3335
3336 Arguments:
3337   type         HMAC_MD5 or HMAC_SHA1
3338   remaining    are as for the cryptographic hash functions
3339
3340 Returns:       nothing
3341 */
3342
3343 static void
3344 chash_start(int type, void *base)
3345 {
3346 if (type == HMAC_MD5)
3347   md5_start((md5 *)base);
3348 else
3349   sha1_start((hctx *)base);
3350 }
3351
3352 static void
3353 chash_mid(int type, void *base, uschar *string)
3354 {
3355 if (type == HMAC_MD5)
3356   md5_mid((md5 *)base, string);
3357 else
3358   sha1_mid((hctx *)base, string);
3359 }
3360
3361 static void
3362 chash_end(int type, void *base, uschar *<