src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 # ifndef SUPPORT_CRYPTEQ
  21 #  define SUPPORT_CRYPTEQ
  22 # endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 # include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 # ifdef CRYPT_H
  31 #  include <crypt.h>
  32 # endif
  33 # ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 # endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Characters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"authresults",
 107   US"certextract",
 108   US"dlfunc",
 109   US"env",
 110   US"extract",
 111   US"filter",
 112   US"hash",
 113   US"hmac",
 114   US"if",
 115 #ifdef SUPPORT_I18N
 116   US"imapfolder",
 117 #endif
 118   US"length",
 119   US"listextract",
 120   US"lookup",
 121   US"map",
 122   US"nhash",
 123   US"perl",
 124   US"prvs",
 125   US"prvscheck",
 126   US"readfile",
 127   US"readsocket",
 128   US"reduce",
 129   US"run",
 130   US"sg",
 131   US"sort",
 132   US"substr",
 133   US"tr" };
 134
 135 enum {
 136   EITEM_ACL,
 137   EITEM_AUTHRESULTS,
 138   EITEM_CERTEXTRACT,
 139   EITEM_DLFUNC,
 140   EITEM_ENV,
 141   EITEM_EXTRACT,
 142   EITEM_FILTER,
 143   EITEM_HASH,
 144   EITEM_HMAC,
 145   EITEM_IF,
 146 #ifdef SUPPORT_I18N
 147   EITEM_IMAPFOLDER,
 148 #endif
 149   EITEM_LENGTH,
 150   EITEM_LISTEXTRACT,
 151   EITEM_LOOKUP,
 152   EITEM_MAP,
 153   EITEM_NHASH,
 154   EITEM_PERL,
 155   EITEM_PRVS,
 156   EITEM_PRVSCHECK,
 157   EITEM_READFILE,
 158   EITEM_READSOCK,
 159   EITEM_REDUCE,
 160   EITEM_RUN,
 161   EITEM_SG,
 162   EITEM_SORT,
 163   EITEM_SUBSTR,
 164   EITEM_TR };
 165
 166 /* Tables of operator names, and corresponding switch numbers. The names must be
 167 in alphabetical order. There are two tables, because underscore is used in some
 168 cases to introduce arguments, whereas for other it is part of the name. This is
 169 an historical mis-design. */
 170
 171 static uschar *op_table_underscore[] = {
 172   US"from_utf8",
 173   US"local_part",
 174   US"quote_local_part",
 175   US"reverse_ip",
 176   US"time_eval",
 177   US"time_interval"
 178 #ifdef SUPPORT_I18N
 179  ,US"utf8_domain_from_alabel",
 180   US"utf8_domain_to_alabel",
 181   US"utf8_localpart_from_alabel",
 182   US"utf8_localpart_to_alabel"
 183 #endif
 184   };
 185
 186 enum {
 187   EOP_FROM_UTF8,
 188   EOP_LOCAL_PART,
 189   EOP_QUOTE_LOCAL_PART,
 190   EOP_REVERSE_IP,
 191   EOP_TIME_EVAL,
 192   EOP_TIME_INTERVAL
 193 #ifdef SUPPORT_I18N
 194  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 195   EOP_UTF8_DOMAIN_TO_ALABEL,
 196   EOP_UTF8_LOCALPART_FROM_ALABEL,
 197   EOP_UTF8_LOCALPART_TO_ALABEL
 198 #endif
 199   };
 200
 201 static uschar *op_table_main[] = {
 202   US"address",
 203   US"addresses",
 204   US"base32",
 205   US"base32d",
 206   US"base62",
 207   US"base62d",
 208   US"base64",
 209   US"base64d",
 210   US"domain",
 211   US"escape",
 212   US"escape8bit",
 213   US"eval",
 214   US"eval10",
 215   US"expand",
 216   US"h",
 217   US"hash",
 218   US"hex2b64",
 219   US"hexquote",
 220   US"ipv6denorm",
 221   US"ipv6norm",
 222   US"l",
 223   US"lc",
 224   US"length",
 225   US"listcount",
 226   US"listnamed",
 227   US"mask",
 228   US"md5",
 229   US"nh",
 230   US"nhash",
 231   US"quote",
 232   US"randint",
 233   US"rfc2047",
 234   US"rfc2047d",
 235   US"rxquote",
 236   US"s",
 237   US"sha1",
 238   US"sha256",
 239   US"sha3",
 240   US"stat",
 241   US"str2b64",
 242   US"strlen",
 243   US"substr",
 244   US"uc",
 245   US"utf8clean" };
 246
 247 enum {
 248   EOP_ADDRESS =  nelem(op_table_underscore),
 249   EOP_ADDRESSES,
 250   EOP_BASE32,
 251   EOP_BASE32D,
 252   EOP_BASE62,
 253   EOP_BASE62D,
 254   EOP_BASE64,
 255   EOP_BASE64D,
 256   EOP_DOMAIN,
 257   EOP_ESCAPE,
 258   EOP_ESCAPE8BIT,
 259   EOP_EVAL,
 260   EOP_EVAL10,
 261   EOP_EXPAND,
 262   EOP_H,
 263   EOP_HASH,
 264   EOP_HEX2B64,
 265   EOP_HEXQUOTE,
 266   EOP_IPV6DENORM,
 267   EOP_IPV6NORM,
 268   EOP_L,
 269   EOP_LC,
 270   EOP_LENGTH,
 271   EOP_LISTCOUNT,
 272   EOP_LISTNAMED,
 273   EOP_MASK,
 274   EOP_MD5,
 275   EOP_NH,
 276   EOP_NHASH,
 277   EOP_QUOTE,
 278   EOP_RANDINT,
 279   EOP_RFC2047,
 280   EOP_RFC2047D,
 281   EOP_RXQUOTE,
 282   EOP_S,
 283   EOP_SHA1,
 284   EOP_SHA256,
 285   EOP_SHA3,
 286   EOP_STAT,
 287   EOP_STR2B64,
 288   EOP_STRLEN,
 289   EOP_SUBSTR,
 290   EOP_UC,
 291   EOP_UTF8CLEAN };
 292
 293
 294 /* Table of condition names, and corresponding switch numbers. The names must
 295 be in alphabetical order. */
 296
 297 static uschar *cond_table[] = {
 298   US"<",
 299   US"<=",
 300   US"=",
 301   US"==",     /* Backward compatibility */
 302   US">",
 303   US">=",
 304   US"acl",
 305   US"and",
 306   US"bool",
 307   US"bool_lax",
 308   US"crypteq",
 309   US"def",
 310   US"eq",
 311   US"eqi",
 312   US"exists",
 313   US"first_delivery",
 314   US"forall",
 315   US"forany",
 316   US"ge",
 317   US"gei",
 318   US"gt",
 319   US"gti",
 320   US"inlist",
 321   US"inlisti",
 322   US"isip",
 323   US"isip4",
 324   US"isip6",
 325   US"ldapauth",
 326   US"le",
 327   US"lei",
 328   US"lt",
 329   US"lti",
 330   US"match",
 331   US"match_address",
 332   US"match_domain",
 333   US"match_ip",
 334   US"match_local_part",
 335   US"or",
 336   US"pam",
 337   US"pwcheck",
 338   US"queue_running",
 339   US"radius",
 340   US"saslauthd"
 341 };
 342
 343 enum {
 344   ECOND_NUM_L,
 345   ECOND_NUM_LE,
 346   ECOND_NUM_E,
 347   ECOND_NUM_EE,
 348   ECOND_NUM_G,
 349   ECOND_NUM_GE,
 350   ECOND_ACL,
 351   ECOND_AND,
 352   ECOND_BOOL,
 353   ECOND_BOOL_LAX,
 354   ECOND_CRYPTEQ,
 355   ECOND_DEF,
 356   ECOND_STR_EQ,
 357   ECOND_STR_EQI,
 358   ECOND_EXISTS,
 359   ECOND_FIRST_DELIVERY,
 360   ECOND_FORALL,
 361   ECOND_FORANY,
 362   ECOND_STR_GE,
 363   ECOND_STR_GEI,
 364   ECOND_STR_GT,
 365   ECOND_STR_GTI,
 366   ECOND_INLIST,
 367   ECOND_INLISTI,
 368   ECOND_ISIP,
 369   ECOND_ISIP4,
 370   ECOND_ISIP6,
 371   ECOND_LDAPAUTH,
 372   ECOND_STR_LE,
 373   ECOND_STR_LEI,
 374   ECOND_STR_LT,
 375   ECOND_STR_LTI,
 376   ECOND_MATCH,
 377   ECOND_MATCH_ADDRESS,
 378   ECOND_MATCH_DOMAIN,
 379   ECOND_MATCH_IP,
 380   ECOND_MATCH_LOCAL_PART,
 381   ECOND_OR,
 382   ECOND_PAM,
 383   ECOND_PWCHECK,
 384   ECOND_QUEUE_RUNNING,
 385   ECOND_RADIUS,
 386   ECOND_SASLAUTHD
 387 };
 388
 389
 390 /* Types of table entry */
 391
 392 enum vtypes {
 393   vtype_int,            /* value is address of int */
 394   vtype_filter_int,     /* ditto, but recognized only when filtering */
 395   vtype_ino,            /* value is address of ino_t (not always an int) */
 396   vtype_uid,            /* value is address of uid_t (not always an int) */
 397   vtype_gid,            /* value is address of gid_t (not always an int) */
 398   vtype_bool,           /* value is address of bool */
 399   vtype_stringptr,      /* value is address of pointer to string */
 400   vtype_msgbody,        /* as stringptr, but read when first required */
 401   vtype_msgbody_end,    /* ditto, the end of the message */
 402   vtype_msgheaders,     /* the message's headers, processed */
 403   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 404   vtype_localpart,      /* extract local part from string */
 405   vtype_domain,         /* extract domain from string */
 406   vtype_string_func,    /* value is string returned by given function */
 407   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 408   vtype_tode,           /* value not used; generate tod in epoch format */
 409   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 410   vtype_todf,           /* value not used; generate full tod */
 411   vtype_todl,           /* value not used; generate log tod */
 412   vtype_todlf,          /* value not used; generate log file datestamp tod */
 413   vtype_todzone,        /* value not used; generate time zone only */
 414   vtype_todzulu,        /* value not used; generate zulu tod */
 415   vtype_reply,          /* value not used; get reply from headers */
 416   vtype_pid,            /* value not used; result is pid */
 417   vtype_host_lookup,    /* value not used; get host name */
 418   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 419   vtype_pspace,         /* partition space; value is T/F for spool/log */
 420   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 421   vtype_cert            /* SSL certificate */
 422   #ifndef DISABLE_DKIM
 423   ,vtype_dkim           /* Lookup of value in DKIM signature */
 424   #endif
 425 };
 426
 427 /* Type for main variable table */
 428
 429 typedef struct {
 430   const char *name;
 431   enum vtypes type;
 432   void       *value;
 433 } var_entry;
 434
 435 /* Type for entries pointing to address/length pairs. Not currently
 436 in use. */
 437
 438 typedef struct {
 439   uschar **address;
 440   int  *length;
 441 } alblock;
 442
 443 static uschar * fn_recipients(void);
 444
 445 /* This table must be kept in alphabetical order. */
 446
 447 static var_entry var_table[] = {
 448   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 449      they will be confused with user-creatable ACL variables. */
 450   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 451   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 452   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 453   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 454   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 455   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 456   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 457   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 458   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 459   { "acl_narg",            vtype_int,         &acl_narg },
 460   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 461   { "address_data",        vtype_stringptr,   &deliver_address_data },
 462   { "address_file",        vtype_stringptr,   &address_file },
 463   { "address_pipe",        vtype_stringptr,   &address_pipe },
 464 #ifdef EXPERIMENTAL_ARC
 465   { "arc_domains",         vtype_string_func, &fn_arc_domains },
 466   { "arc_oldest_pass",     vtype_int,         &arc_oldest_pass },
 467   { "arc_state",           vtype_stringptr,   &arc_state },
 468   { "arc_state_reason",    vtype_stringptr,   &arc_state_reason },
 469 #endif
 470   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 471   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 472   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 473   { "authentication_failed",vtype_int,        &authentication_failed },
 474 #ifdef WITH_CONTENT_SCAN
 475   { "av_failed",           vtype_int,         &av_failed },
 476 #endif
 477 #ifdef EXPERIMENTAL_BRIGHTMAIL
 478   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 479   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 480   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 481   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 482 #endif
 483   { "body_linecount",      vtype_int,         &body_linecount },
 484   { "body_zerocount",      vtype_int,         &body_zerocount },
 485   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 486   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 487   { "caller_gid",          vtype_gid,         &real_gid },
 488   { "caller_uid",          vtype_uid,         &real_uid },
 489   { "callout_address",     vtype_stringptr,   &callout_address },
 490   { "compile_date",        vtype_stringptr,   &version_date },
 491   { "compile_number",      vtype_stringptr,   &version_cnumber },
 492   { "config_dir",          vtype_stringptr,   &config_main_directory },
 493   { "config_file",         vtype_stringptr,   &config_main_filename },
 494   { "csa_status",          vtype_stringptr,   &csa_status },
 495 #ifdef EXPERIMENTAL_DCC
 496   { "dcc_header",          vtype_stringptr,   &dcc_header },
 497   { "dcc_result",          vtype_stringptr,   &dcc_result },
 498 #endif
 499 #ifndef DISABLE_DKIM
 500   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 501   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 502   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 503   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 504   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 505   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 506   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 507   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 508   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 509   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 510   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 511   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 512   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 513   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 514   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 515   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 516   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 517   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 518   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 519   { "dkim_verify_reason",  vtype_stringptr,   &dkim_verify_reason },
 520   { "dkim_verify_status",  vtype_stringptr,   &dkim_verify_status },
 521 #endif
 522 #ifdef EXPERIMENTAL_DMARC
 523   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 524   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 525   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 526   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 527 #endif
 528   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 529   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 530   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 531   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 532   { "domain",              vtype_stringptr,   &deliver_domain },
 533   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 534 #ifndef DISABLE_EVENT
 535   { "event_data",          vtype_stringptr,   &event_data },
 536
 537   /*XXX want to use generic vars for as many of these as possible*/
 538   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 539
 540   { "event_name",          vtype_stringptr,   &event_name },
 541 #endif
 542   { "exim_gid",            vtype_gid,         &exim_gid },
 543   { "exim_path",           vtype_stringptr,   &exim_path },
 544   { "exim_uid",            vtype_uid,         &exim_uid },
 545   { "exim_version",        vtype_stringptr,   &version_string },
 546   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 547   { "home",                vtype_stringptr,   &deliver_home },
 548   { "host",                vtype_stringptr,   &deliver_host },
 549   { "host_address",        vtype_stringptr,   &deliver_host_address },
 550   { "host_data",           vtype_stringptr,   &host_data },
 551   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 552   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 553   { "host_port",           vtype_int,         &deliver_host_port },
 554   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 555   { "inode",               vtype_ino,         &deliver_inode },
 556   { "interface_address",   vtype_stringptr,   &interface_address },
 557   { "interface_port",      vtype_int,         &interface_port },
 558   { "item",                vtype_stringptr,   &iterate_item },
 559   #ifdef LOOKUP_LDAP
 560   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 561   #endif
 562   { "load_average",        vtype_load_avg,    NULL },
 563   { "local_part",          vtype_stringptr,   &deliver_localpart },
 564   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 565   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 566   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 567 #ifdef HAVE_LOCAL_SCAN
 568   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 569 #endif
 570   { "local_user_gid",      vtype_gid,         &local_user_gid },
 571   { "local_user_uid",      vtype_uid,         &local_user_uid },
 572   { "localhost_number",    vtype_int,         &host_number },
 573   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 574   { "log_space",           vtype_pspace,      (void *)FALSE },
 575   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 576   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 577 #ifdef WITH_CONTENT_SCAN
 578   { "malware_name",        vtype_stringptr,   &malware_name },
 579 #endif
 580   { "max_received_linelength", vtype_int,     &max_received_linelength },
 581   { "message_age",         vtype_int,         &message_age },
 582   { "message_body",        vtype_msgbody,     &message_body },
 583   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 584   { "message_body_size",   vtype_int,         &message_body_size },
 585   { "message_exim_id",     vtype_stringptr,   &message_id },
 586   { "message_headers",     vtype_msgheaders,  NULL },
 587   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 588   { "message_id",          vtype_stringptr,   &message_id },
 589   { "message_linecount",   vtype_int,         &message_linecount },
 590   { "message_size",        vtype_int,         &message_size },
 591 #ifdef SUPPORT_I18N
 592   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 593 #endif
 594 #ifdef WITH_CONTENT_SCAN
 595   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 596   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 597   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 598   { "mime_charset",        vtype_stringptr,   &mime_charset },
 599   { "mime_content_description", vtype_stringptr, &mime_content_description },
 600   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 601   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 602   { "mime_content_size",   vtype_int,         &mime_content_size },
 603   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 604   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 605   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 606   { "mime_filename",       vtype_stringptr,   &mime_filename },
 607   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 608   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 609   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 610   { "mime_part_count",     vtype_int,         &mime_part_count },
 611 #endif
 612   { "n0",                  vtype_filter_int,  &filter_n[0] },
 613   { "n1",                  vtype_filter_int,  &filter_n[1] },
 614   { "n2",                  vtype_filter_int,  &filter_n[2] },
 615   { "n3",                  vtype_filter_int,  &filter_n[3] },
 616   { "n4",                  vtype_filter_int,  &filter_n[4] },
 617   { "n5",                  vtype_filter_int,  &filter_n[5] },
 618   { "n6",                  vtype_filter_int,  &filter_n[6] },
 619   { "n7",                  vtype_filter_int,  &filter_n[7] },
 620   { "n8",                  vtype_filter_int,  &filter_n[8] },
 621   { "n9",                  vtype_filter_int,  &filter_n[9] },
 622   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 623   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 624   { "originator_gid",      vtype_gid,         &originator_gid },
 625   { "originator_uid",      vtype_uid,         &originator_uid },
 626   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 627   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 628   { "pid",                 vtype_pid,         NULL },
 629 #ifndef DISABLE_PRDR
 630   { "prdr_requested",      vtype_bool,        &prdr_requested },
 631 #endif
 632   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 633 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 634   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 635   { "proxy_external_port", vtype_int,         &proxy_external_port },
 636   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 637   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 638   { "proxy_session",       vtype_bool,        &proxy_session },
 639 #endif
 640   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 641   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 642   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 643   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 644   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 645   { "queue_name",          vtype_stringptr,   &queue_name },
 646   { "rcpt_count",          vtype_int,         &rcpt_count },
 647   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 648   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 649   { "received_count",      vtype_int,         &received_count },
 650   { "received_for",        vtype_stringptr,   &received_for },
 651   { "received_ip_address", vtype_stringptr,   &interface_address },
 652   { "received_port",       vtype_int,         &interface_port },
 653   { "received_protocol",   vtype_stringptr,   &received_protocol },
 654   { "received_time",       vtype_int,         &received_time.tv_sec },
 655   { "recipient_data",      vtype_stringptr,   &recipient_data },
 656   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 657   { "recipients",          vtype_string_func, &fn_recipients },
 658   { "recipients_count",    vtype_int,         &recipients_count },
 659 #ifdef WITH_CONTENT_SCAN
 660   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 661 #endif
 662   { "reply_address",       vtype_reply,       NULL },
 663   { "return_path",         vtype_stringptr,   &return_path },
 664   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 665   { "router_name",         vtype_stringptr,   &router_name },
 666   { "runrc",               vtype_int,         &runrc },
 667   { "self_hostname",       vtype_stringptr,   &self_hostname },
 668   { "sender_address",      vtype_stringptr,   &sender_address },
 669   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 670   { "sender_address_domain", vtype_domain,    &sender_address },
 671   { "sender_address_local_part", vtype_localpart, &sender_address },
 672   { "sender_data",         vtype_stringptr,   &sender_data },
 673   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 674   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 675   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 676   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 677   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 678   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 679   { "sender_host_name",    vtype_host_lookup, NULL },
 680   { "sender_host_port",    vtype_int,         &sender_host_port },
 681   { "sender_ident",        vtype_stringptr,   &sender_ident },
 682   { "sender_rate",         vtype_stringptr,   &sender_rate },
 683   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 684   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 685   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 686   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 687   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 688   { "sending_port",        vtype_int,         &sending_port },
 689   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 690   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 691   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 692   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 693   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 694   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 695   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 696   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 697   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 698   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 699   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 700   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 701   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 702   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 703   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 704   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 705 #ifdef WITH_CONTENT_SCAN
 706   { "spam_action",         vtype_stringptr,   &spam_action },
 707   { "spam_bar",            vtype_stringptr,   &spam_bar },
 708   { "spam_report",         vtype_stringptr,   &spam_report },
 709   { "spam_score",          vtype_stringptr,   &spam_score },
 710   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 711 #endif
 712 #ifdef SUPPORT_SPF
 713   { "spf_guess",           vtype_stringptr,   &spf_guess },
 714   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 715   { "spf_received",        vtype_stringptr,   &spf_received },
 716   { "spf_result",          vtype_stringptr,   &spf_result },
 717   { "spf_result_guessed",  vtype_bool,        &spf_result_guessed },
 718   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 719 #endif
 720   { "spool_directory",     vtype_stringptr,   &spool_directory },
 721   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 722   { "spool_space",         vtype_pspace,      (void *)TRUE },
 723 #ifdef EXPERIMENTAL_SRS
 724   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 725   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 726   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 727   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 728   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 729   { "srs_status",          vtype_stringptr,   &srs_status },
 730 #endif
 731   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 732
 733   /* The non-(in,out) variables are now deprecated */
 734   { "tls_bits",            vtype_int,         &tls_in.bits },
 735   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 736   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 737
 738   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 739   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 740   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 741   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 742   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 743   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 744   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 745 #if defined(SUPPORT_TLS)
 746   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 747 #endif
 748   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 749   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 750   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 751 #ifdef SUPPORT_DANE
 752   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 753 #endif
 754   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 755   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 756   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 757   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 758 #if defined(SUPPORT_TLS)
 759   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 760 #endif
 761 #ifdef SUPPORT_DANE
 762   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 763 #endif
 764
 765   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 766 #if defined(SUPPORT_TLS)
 767   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 768 #endif
 769
 770   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 771   { "tod_epoch",           vtype_tode,        NULL },
 772   { "tod_epoch_l",         vtype_todel,       NULL },
 773   { "tod_full",            vtype_todf,        NULL },
 774   { "tod_log",             vtype_todl,        NULL },
 775   { "tod_logfile",         vtype_todlf,       NULL },
 776   { "tod_zone",            vtype_todzone,     NULL },
 777   { "tod_zulu",            vtype_todzulu,     NULL },
 778   { "transport_name",      vtype_stringptr,   &transport_name },
 779   { "value",               vtype_stringptr,   &lookup_value },
 780   { "verify_mode",         vtype_stringptr,   &verify_mode },
 781   { "version_number",      vtype_stringptr,   &version_string },
 782   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 783   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 784   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 785   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 786   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 787   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 788 };
 789
 790 static int var_table_size = nelem(var_table);
 791 static uschar var_buffer[256];
 792 static BOOL malformed_header;
 793
 794 /* For textual hashes */
 795
 796 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 797                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 798                                "0123456789";
 799
 800 enum { HMAC_MD5, HMAC_SHA1 };
 801
 802 /* For numeric hashes */
 803
 804 static unsigned int prime[] = {
 805   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 806  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 807  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 808
 809 /* For printing modes in symbolic form */
 810
 811 static uschar *mtable_normal[] =
 812   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 813
 814 static uschar *mtable_setid[] =
 815   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 816
 817 static uschar *mtable_sticky[] =
 818   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 819
 820
 821
 822 /*************************************************
 823 *           Tables for UTF-8 support             *
 824 *************************************************/
 825
 826 /* Table of the number of extra characters, indexed by the first character
 827 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 828 0x3d. */
 829
 830 static uschar utf8_table1[] = {
 831   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 832   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 833   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 834   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 835
 836 /* These are the masks for the data bits in the first byte of a character,
 837 indexed by the number of additional bytes. */
 838
 839 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 840
 841 /* Get the next UTF-8 character, advancing the pointer. */
 842
 843 #define GETUTF8INC(c, ptr) \
 844   c = *ptr++; \
 845   if ((c & 0xc0) == 0xc0) \
 846     { \
 847     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 848     int s = 6*a; \
 849     c = (c & utf8_table2[a]) << s; \
 850     while (a-- > 0) \
 851       { \
 852       s -= 6; \
 853       c |= (*ptr++ & 0x3f) << s; \
 854       } \
 855     }
 856
 857
 858
 859 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 860
 861 /*************************************************
 862 *           Binary chop search on a table        *
 863 *************************************************/
 864
 865 /* This is used for matching expansion items and operators.
 866
 867 Arguments:
 868   name        the name that is being sought
 869   table       the table to search
 870   table_size  the number of items in the table
 871
 872 Returns:      the offset in the table, or -1
 873 */
 874
 875 static int
 876 chop_match(uschar *name, uschar **table, int table_size)
 877 {
 878 uschar **bot = table;
 879 uschar **top = table + table_size;
 880
 881 while (top > bot)
 882   {
 883   uschar **mid = bot + (top - bot)/2;
 884   int c = Ustrcmp(name, *mid);
 885   if (c == 0) return mid - table;
 886   if (c > 0) bot = mid + 1; else top = mid;
 887   }
 888
 889 return -1;
 890 }
 891
 892
 893
 894 /*************************************************
 895 *          Check a condition string              *
 896 *************************************************/
 897
 898 /* This function is called to expand a string, and test the result for a "true"
 899 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 900 forced fail or lookup defer.
 901
 902 We used to release all store used, but this is not not safe due
 903 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 904 is reasonably careful to release what it can.
 905
 906 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 907
 908 Arguments:
 909   condition     the condition string
 910   m1            text to be incorporated in panic error
 911   m2            ditto
 912
 913 Returns:        TRUE if condition is met, FALSE if not
 914 */
 915
 916 BOOL
 917 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 918 {
 919 int rc;
 920 uschar *ss = expand_string(condition);
 921 if (ss == NULL)
 922   {
 923   if (!expand_string_forcedfail && !search_find_defer)
 924     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 925       "for %s %s: %s", condition, m1, m2, expand_string_message);
 926   return FALSE;
 927   }
 928 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 929   strcmpic(ss, US"false") != 0;
 930 return rc;
 931 }
 932
 933
 934
 935
 936 /*************************************************
 937 *        Pseudo-random number generation         *
 938 *************************************************/
 939
 940 /* Pseudo-random number generation.  The result is not "expected" to be
 941 cryptographically strong but not so weak that someone will shoot themselves
 942 in the foot using it as a nonce in some email header scheme or whatever
 943 weirdness they'll twist this into.  The result should ideally handle fork().
 944
 945 However, if we're stuck unable to provide this, then we'll fall back to
 946 appallingly bad randomness.
 947
 948 If SUPPORT_TLS is defined then this will not be used except as an emergency
 949 fallback.
 950
 951 Arguments:
 952   max       range maximum
 953 Returns     a random number in range [0, max-1]
 954 */
 955
 956 #ifdef SUPPORT_TLS
 957 # define vaguely_random_number vaguely_random_number_fallback
 958 #endif
 959 int
 960 vaguely_random_number(int max)
 961 {
 962 #ifdef SUPPORT_TLS
 963 # undef vaguely_random_number
 964 #endif
 965   static pid_t pid = 0;
 966   pid_t p2;
 967 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 968   struct timeval tv;
 969 #endif
 970
 971   p2 = getpid();
 972   if (p2 != pid)
 973     {
 974     if (pid != 0)
 975       {
 976
 977 #ifdef HAVE_ARC4RANDOM
 978       /* cryptographically strong randomness, common on *BSD platforms, not
 979       so much elsewhere.  Alas. */
 980 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 981       arc4random_stir();
 982 #endif
 983 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 984 #ifdef HAVE_SRANDOMDEV
 985       /* uses random(4) for seeding */
 986       srandomdev();
 987 #else
 988       gettimeofday(&tv, NULL);
 989       srandom(tv.tv_sec | tv.tv_usec | getpid());
 990 #endif
 991 #else
 992       /* Poor randomness and no seeding here */
 993 #endif
 994
 995       }
 996     pid = p2;
 997     }
 998
 999 #ifdef HAVE_ARC4RANDOM
1000   return arc4random() % max;
1001 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
1002   return random() % max;
1003 #else
1004   /* This one returns a 16-bit number, definitely not crypto-strong */
1005   return random_number(max);
1006 #endif
1007 }
1008
1009
1010
1011
1012 /*************************************************
1013 *             Pick out a name from a string      *
1014 *************************************************/
1015
1016 /* If the name is too long, it is silently truncated.
1017
1018 Arguments:
1019   name      points to a buffer into which to put the name
1020   max       is the length of the buffer
1021   s         points to the first alphabetic character of the name
1022   extras    chars other than alphanumerics to permit
1023
1024 Returns:    pointer to the first character after the name
1025
1026 Note: The test for *s != 0 in the while loop is necessary because
1027 Ustrchr() yields non-NULL if the character is zero (which is not something
1028 I expected). */
1029
1030 static const uschar *
1031 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1032 {
1033 int ptr = 0;
1034 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1035   {
1036   if (ptr < max-1) name[ptr++] = *s;
1037   s++;
1038   }
1039 name[ptr] = 0;
1040 return s;
1041 }
1042
1043
1044
1045 /*************************************************
1046 *     Pick out the rest of a header name         *
1047 *************************************************/
1048
1049 /* A variable name starting $header_ (or just $h_ for those who like
1050 abbreviations) might not be the complete header name because headers can
1051 contain any printing characters in their names, except ':'. This function is
1052 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1053 on the end, if the name was terminated by white space.
1054
1055 Arguments:
1056   name      points to a buffer in which the name read so far exists
1057   max       is the length of the buffer
1058   s         points to the first character after the name so far, i.e. the
1059             first non-alphameric character after $header_xxxxx
1060
1061 Returns:    a pointer to the first character after the header name
1062 */
1063
1064 static const uschar *
1065 read_header_name(uschar *name, int max, const uschar *s)
1066 {
1067 int prelen = Ustrchr(name, '_') - name + 1;
1068 int ptr = Ustrlen(name) - prelen;
1069 if (ptr > 0) memmove(name, name+prelen, ptr);
1070 while (mac_isgraph(*s) && *s != ':')
1071   {
1072   if (ptr < max-1) name[ptr++] = *s;
1073   s++;
1074   }
1075 if (*s == ':') s++;
1076 name[ptr++] = ':';
1077 name[ptr] = 0;
1078 return s;
1079 }
1080
1081
1082
1083 /*************************************************
1084 *           Pick out a number from a string      *
1085 *************************************************/
1086
1087 /* Arguments:
1088   n     points to an integer into which to put the number
1089   s     points to the first digit of the number
1090
1091 Returns:  a pointer to the character after the last digit
1092 */
1093 /*XXX consider expanding to int_eximarith_t.  But the test for
1094 "overbig numbers" in 0002 still needs to overflow it. */
1095
1096 static uschar *
1097 read_number(int *n, uschar *s)
1098 {
1099 *n = 0;
1100 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1101 return s;
1102 }
1103
1104 static const uschar *
1105 read_cnumber(int *n, const uschar *s)
1106 {
1107 *n = 0;
1108 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1109 return s;
1110 }
1111
1112
1113
1114 /*************************************************
1115 *        Extract keyed subfield from a string    *
1116 *************************************************/
1117
1118 /* The yield is in dynamic store; NULL means that the key was not found.
1119
1120 Arguments:
1121   key       points to the name of the key
1122   s         points to the string from which to extract the subfield
1123
1124 Returns:    NULL if the subfield was not found, or
1125             a pointer to the subfield's data
1126 */
1127
1128 static uschar *
1129 expand_getkeyed(uschar *key, const uschar *s)
1130 {
1131 int length = Ustrlen(key);
1132 while (isspace(*s)) s++;
1133
1134 /* Loop to search for the key */
1135
1136 while (*s != 0)
1137   {
1138   int dkeylength;
1139   uschar *data;
1140   const uschar *dkey = s;
1141
1142   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1143   dkeylength = s - dkey;
1144   while (isspace(*s)) s++;
1145   if (*s == '=') while (isspace((*(++s))));
1146
1147   data = string_dequote(&s);
1148   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1149     return data;
1150
1151   while (isspace(*s)) s++;
1152   }
1153
1154 return NULL;
1155 }
1156
1157
1158
1159 static var_entry *
1160 find_var_ent(uschar * name)
1161 {
1162 int first = 0;
1163 int last = var_table_size;
1164
1165 while (last > first)
1166   {
1167   int middle = (first + last)/2;
1168   int c = Ustrcmp(name, var_table[middle].name);
1169
1170   if (c > 0) { first = middle + 1; continue; }
1171   if (c < 0) { last = middle; continue; }
1172   return &var_table[middle];
1173   }
1174 return NULL;
1175 }
1176
1177 /*************************************************
1178 *   Extract numbered subfield from string        *
1179 *************************************************/
1180
1181 /* Extracts a numbered field from a string that is divided by tokens - for
1182 example a line from /etc/passwd is divided by colon characters.  First field is
1183 numbered one.  Negative arguments count from the right. Zero returns the whole
1184 string. Returns NULL if there are insufficient tokens in the string
1185
1186 ***WARNING***
1187 Modifies final argument - this is a dynamically generated string, so that's OK.
1188
1189 Arguments:
1190   field       number of field to be extracted,
1191                 first field = 1, whole string = 0, last field = -1
1192   separators  characters that are used to break string into tokens
1193   s           points to the string from which to extract the subfield
1194
1195 Returns:      NULL if the field was not found,
1196               a pointer to the field's data inside s (modified to add 0)
1197 */
1198
1199 static uschar *
1200 expand_gettokened (int field, uschar *separators, uschar *s)
1201 {
1202 int sep = 1;
1203 int count;
1204 uschar *ss = s;
1205 uschar *fieldtext = NULL;
1206
1207 if (field == 0) return s;
1208
1209 /* Break the line up into fields in place; for field > 0 we stop when we have
1210 done the number of fields we want. For field < 0 we continue till the end of
1211 the string, counting the number of fields. */
1212
1213 count = (field > 0)? field : INT_MAX;
1214
1215 while (count-- > 0)
1216   {
1217   size_t len;
1218
1219   /* Previous field was the last one in the string. For a positive field
1220   number, this means there are not enough fields. For a negative field number,
1221   check that there are enough, and scan back to find the one that is wanted. */
1222
1223   if (sep == 0)
1224     {
1225     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1226     if ((-field) == (INT_MAX - count - 1)) return s;
1227     while (field++ < 0)
1228       {
1229       ss--;
1230       while (ss[-1] != 0) ss--;
1231       }
1232     fieldtext = ss;
1233     break;
1234     }
1235
1236   /* Previous field was not last in the string; save its start and put a
1237   zero at its end. */
1238
1239   fieldtext = ss;
1240   len = Ustrcspn(ss, separators);
1241   sep = ss[len];
1242   ss[len] = 0;
1243   ss += len + 1;
1244   }
1245
1246 return fieldtext;
1247 }
1248
1249
1250 static uschar *
1251 expand_getlistele(int field, const uschar * list)
1252 {
1253 const uschar * tlist= list;
1254 int sep= 0;
1255 uschar dummy;
1256
1257 if(field<0)
1258   {
1259   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1260   sep= 0;
1261   }
1262 if(field==0) return NULL;
1263 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1264 return string_nextinlist(&list, &sep, NULL, 0);
1265 }
1266
1267
1268 /* Certificate fields, by name.  Worry about by-OID later */
1269 /* Names are chosen to not have common prefixes */
1270
1271 #ifdef SUPPORT_TLS
1272 typedef struct
1273 {
1274 uschar * name;
1275 int      namelen;
1276 uschar * (*getfn)(void * cert, uschar * mod);
1277 } certfield;
1278 static certfield certfields[] =
1279 {                       /* linear search; no special order */
1280   { US"version",         7,  &tls_cert_version },
1281   { US"serial_number",   13, &tls_cert_serial_number },
1282   { US"subject",         7,  &tls_cert_subject },
1283   { US"notbefore",       9,  &tls_cert_not_before },
1284   { US"notafter",        8,  &tls_cert_not_after },
1285   { US"issuer",          6,  &tls_cert_issuer },
1286   { US"signature",       9,  &tls_cert_signature },
1287   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1288   { US"subj_altname",    12, &tls_cert_subject_altname },
1289   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1290   { US"crl_uri",         7,  &tls_cert_crl_uri },
1291 };
1292
1293 static uschar *
1294 expand_getcertele(uschar * field, uschar * certvar)
1295 {
1296 var_entry * vp;
1297 certfield * cp;
1298
1299 if (!(vp = find_var_ent(certvar)))
1300   {
1301   expand_string_message =
1302     string_sprintf("no variable named \"%s\"", certvar);
1303   return NULL;          /* Unknown variable name */
1304   }
1305 /* NB this stops us passing certs around in variable.  Might
1306 want to do that in future */
1307 if (vp->type != vtype_cert)
1308   {
1309   expand_string_message =
1310     string_sprintf("\"%s\" is not a certificate", certvar);
1311   return NULL;          /* Unknown variable name */
1312   }
1313 if (!*(void **)vp->value)
1314   return NULL;
1315
1316 if (*field >= '0' && *field <= '9')
1317   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1318
1319 for(cp = certfields;
1320     cp < certfields + nelem(certfields);
1321     cp++)
1322   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1323     {
1324     uschar * modifier = *(field += cp->namelen) == ','
1325       ? ++field : NULL;
1326     return (*cp->getfn)( *(void **)vp->value, modifier );
1327     }
1328
1329 expand_string_message =
1330   string_sprintf("bad field selector \"%s\" for certextract", field);
1331 return NULL;
1332 }
1333 #endif  /*SUPPORT_TLS*/
1334
1335 /*************************************************
1336 *        Extract a substring from a string       *
1337 *************************************************/
1338
1339 /* Perform the ${substr or ${length expansion operations.
1340
1341 Arguments:
1342   subject     the input string
1343   value1      the offset from the start of the input string to the start of
1344                 the output string; if negative, count from the right.
1345   value2      the length of the output string, or negative (-1) for unset
1346                 if value1 is positive, unset means "all after"
1347                 if value1 is negative, unset means "all before"
1348   len         set to the length of the returned string
1349
1350 Returns:      pointer to the output string, or NULL if there is an error
1351 */
1352
1353 static uschar *
1354 extract_substr(uschar *subject, int value1, int value2, int *len)
1355 {
1356 int sublen = Ustrlen(subject);
1357
1358 if (value1 < 0)    /* count from right */
1359   {
1360   value1 += sublen;
1361
1362   /* If the position is before the start, skip to the start, and adjust the
1363   length. If the length ends up negative, the substring is null because nothing
1364   can precede. This falls out naturally when the length is unset, meaning "all
1365   to the left". */
1366
1367   if (value1 < 0)
1368     {
1369     value2 += value1;
1370     if (value2 < 0) value2 = 0;
1371     value1 = 0;
1372     }
1373
1374   /* Otherwise an unset length => characters before value1 */
1375
1376   else if (value2 < 0)
1377     {
1378     value2 = value1;
1379     value1 = 0;
1380     }
1381   }
1382
1383 /* For a non-negative offset, if the starting position is past the end of the
1384 string, the result will be the null string. Otherwise, an unset length means
1385 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1386
1387 else
1388   {
1389   if (value1 > sublen)
1390     {
1391     value1 = sublen;
1392     value2 = 0;
1393     }
1394   else if (value2 < 0) value2 = sublen;
1395   }
1396
1397 /* Cut the length down to the maximum possible for the offset value, and get
1398 the required characters. */
1399
1400 if (value1 + value2 > sublen) value2 = sublen - value1;
1401 *len = value2;
1402 return subject + value1;
1403 }
1404
1405
1406
1407
1408 /*************************************************
1409 *            Old-style hash of a string          *
1410 *************************************************/
1411
1412 /* Perform the ${hash expansion operation.
1413
1414 Arguments:
1415   subject     the input string (an expanded substring)
1416   value1      the length of the output string; if greater or equal to the
1417                 length of the input string, the input string is returned
1418   value2      the number of hash characters to use, or 26 if negative
1419   len         set to the length of the returned string
1420
1421 Returns:      pointer to the output string, or NULL if there is an error
1422 */
1423
1424 static uschar *
1425 compute_hash(uschar *subject, int value1, int value2, int *len)
1426 {
1427 int sublen = Ustrlen(subject);
1428
1429 if (value2 < 0) value2 = 26;
1430 else if (value2 > Ustrlen(hashcodes))
1431   {
1432   expand_string_message =
1433     string_sprintf("hash count \"%d\" too big", value2);
1434   return NULL;
1435   }
1436
1437 /* Calculate the hash text. We know it is shorter than the original string, so
1438 can safely place it in subject[] (we know that subject is always itself an
1439 expanded substring). */
1440
1441 if (value1 < sublen)
1442   {
1443   int c;
1444   int i = 0;
1445   int j = value1;
1446   while ((c = (subject[j])) != 0)
1447     {
1448     int shift = (c + j++) & 7;
1449     subject[i] ^= (c << shift) | (c >> (8-shift));
1450     if (++i >= value1) i = 0;
1451     }
1452   for (i = 0; i < value1; i++)
1453     subject[i] = hashcodes[(subject[i]) % value2];
1454   }
1455 else value1 = sublen;
1456
1457 *len = value1;
1458 return subject;
1459 }
1460
1461
1462
1463
1464 /*************************************************
1465 *             Numeric hash of a string           *
1466 *************************************************/
1467
1468 /* Perform the ${nhash expansion operation. The first characters of the
1469 string are treated as most important, and get the highest prime numbers.
1470
1471 Arguments:
1472   subject     the input string
1473   value1      the maximum value of the first part of the result
1474   value2      the maximum value of the second part of the result,
1475                 or negative to produce only a one-part result
1476   len         set to the length of the returned string
1477
1478 Returns:  pointer to the output string, or NULL if there is an error.
1479 */
1480
1481 static uschar *
1482 compute_nhash (uschar *subject, int value1, int value2, int *len)
1483 {
1484 uschar *s = subject;
1485 int i = 0;
1486 unsigned long int total = 0; /* no overflow */
1487
1488 while (*s != 0)
1489   {
1490   if (i == 0) i = nelem(prime) - 1;
1491   total += prime[i--] * (unsigned int)(*s++);
1492   }
1493
1494 /* If value2 is unset, just compute one number */
1495
1496 if (value2 < 0)
1497   s = string_sprintf("%lu", total % value1);
1498
1499 /* Otherwise do a div/mod hash */
1500
1501 else
1502   {
1503   total = total % (value1 * value2);
1504   s = string_sprintf("%lu/%lu", total/value2, total % value2);
1505   }
1506
1507 *len = Ustrlen(s);
1508 return s;
1509 }
1510
1511
1512
1513
1514
1515 /*************************************************
1516 *     Find the value of a header or headers      *
1517 *************************************************/
1518
1519 /* Multiple instances of the same header get concatenated, and this function
1520 can also return a concatenation of all the header lines. When concatenating
1521 specific headers that contain lists of addresses, a comma is inserted between
1522 them. Otherwise we use a straight concatenation. Because some messages can have
1523 pathologically large number of lines, there is a limit on the length that is
1524 returned. Also, to avoid massive store use which would result from using
1525 string_cat() as it copies and extends strings, we do a preliminary pass to find
1526 out exactly how much store will be needed. On "normal" messages this will be
1527 pretty trivial.
1528
1529 Arguments:
1530   name          the name of the header, without the leading $header_ or $h_,
1531                 or NULL if a concatenation of all headers is required
1532   exists_only   TRUE if called from a def: test; don't need to build a string;
1533                 just return a string that is not "" and not "0" if the header
1534                 exists
1535   newsize       return the size of memory block that was obtained; may be NULL
1536                 if exists_only is TRUE
1537   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1538                 other than concatenating, will be done on the header. Also used
1539                 for $message_headers_raw.
1540   charset       name of charset to translate MIME words to; used only if
1541                 want_raw is false; if NULL, no translation is done (this is
1542                 used for $bh_ and $bheader_)
1543
1544 Returns:        NULL if the header does not exist, else a pointer to a new
1545                 store block
1546 */
1547
1548 static uschar *
1549 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1550   uschar *charset)
1551 {
1552 BOOL found = name == NULL;
1553 int comma = 0;
1554 int len = found? 0 : Ustrlen(name);
1555 int i;
1556 uschar *yield = NULL;
1557 uschar *ptr = NULL;
1558
1559 /* Loop for two passes - saves code repetition */
1560
1561 for (i = 0; i < 2; i++)
1562   {
1563   int size = 0;
1564   header_line *h;
1565
1566   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1567     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1568       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1569         {
1570         int ilen;
1571         uschar *t;
1572
1573         if (exists_only) return US"1";      /* don't need actual string */
1574         found = TRUE;
1575         t = h->text + len;                  /* text to insert */
1576         if (!want_raw)                      /* unless wanted raw, */
1577           while (isspace(*t)) t++;          /* remove leading white space */
1578         ilen = h->slen - (t - h->text);     /* length to insert */
1579
1580         /* Unless wanted raw, remove trailing whitespace, including the
1581         newline. */
1582
1583         if (!want_raw)
1584           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1585
1586         /* Set comma = 1 if handling a single header and it's one of those
1587         that contains an address list, except when asked for raw headers. Only
1588         need to do this once. */
1589
1590         if (!want_raw && name && comma == 0 &&
1591             Ustrchr("BCFRST", h->type) != NULL)
1592           comma = 1;
1593
1594         /* First pass - compute total store needed; second pass - compute
1595         total store used, including this header. */
1596
1597         size += ilen + comma + 1;  /* +1 for the newline */
1598
1599         /* Second pass - concatenate the data, up to a maximum. Note that
1600         the loop stops when size hits the limit. */
1601
1602         if (i != 0)
1603           {
1604           if (size > header_insert_maxlen)
1605             {
1606             ilen -= size - header_insert_maxlen - 1;
1607             comma = 0;
1608             }
1609           Ustrncpy(ptr, t, ilen);
1610           ptr += ilen;
1611
1612           /* For a non-raw header, put in the comma if needed, then add
1613           back the newline we removed above, provided there was some text in
1614           the header. */
1615
1616           if (!want_raw && ilen > 0)
1617             {
1618             if (comma != 0) *ptr++ = ',';
1619             *ptr++ = '\n';
1620             }
1621           }
1622         }
1623
1624   /* At end of first pass, return NULL if no header found. Then truncate size
1625   if necessary, and get the buffer to hold the data, returning the buffer size.
1626   */
1627
1628   if (i == 0)
1629     {
1630     if (!found) return NULL;
1631     if (size > header_insert_maxlen) size = header_insert_maxlen;
1632     *newsize = size + 1;
1633     ptr = yield = store_get(*newsize);
1634     }
1635   }
1636
1637 /* That's all we do for raw header expansion. */
1638
1639 if (want_raw)
1640   *ptr = 0;
1641
1642 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1643 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1644 function can return an error with decoded data if the charset translation
1645 fails. If decoding fails, it returns NULL. */
1646
1647 else
1648   {
1649   uschar *decoded, *error;
1650   if (ptr > yield && ptr[-1] == '\n') ptr--;
1651   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1652   *ptr = 0;
1653   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1654     newsize, &error);
1655   if (error != NULL)
1656     {
1657     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1658       "    input was: %s\n", error, yield);
1659     }
1660   if (decoded != NULL) yield = decoded;
1661   }
1662
1663 return yield;
1664 }
1665
1666
1667
1668
1669 /* Append a "local" element to an Autherntication-Results: header
1670 if this was a non-smtp message.
1671 */
1672
1673 static gstring *
1674 authres_local(gstring * g, const uschar * sysname)
1675 {
1676 if (!authentication_local)
1677   return g;
1678 g = string_append(g, 3, US";\n\tlocal=pass (non-smtp, ", sysname, US")");
1679 if (authenticated_id) g = string_append(g, 2, " u=", authenticated_id);
1680 return g;
1681 }
1682
1683
1684 /* Append an "iprev" element to an Autherntication-Results: header
1685 if we have attempted to get the calling host's name.
1686 */
1687
1688 static gstring *
1689 authres_iprev(gstring * g)
1690 {
1691 if (sender_host_name)
1692   return string_append(g, sender_host_address ? 5 : 3,
1693     US";\n\tiprev=pass (", sender_host_name, US")",
1694     US" smtp.client-ip=", sender_host_address);
1695 if (host_lookup_deferred)
1696   return string_catn(g, US";\n\tiprev=temperror", 19);
1697 if (host_lookup_failed)
1698   return string_catn(g, US";\n\tiprev=fail", 13);
1699 return g;
1700 }
1701
1702
1703
1704 /*************************************************
1705 *               Return list of recipients        *
1706 *************************************************/
1707 /* A recipients list is available only during system message filtering,
1708 during ACL processing after DATA, and while expanding pipe commands
1709 generated from a system filter, but not elsewhere. */
1710
1711 static uschar *
1712 fn_recipients(void)
1713 {
1714 gstring * g = NULL;
1715 int i;
1716
1717 if (!enable_dollar_recipients) return NULL;
1718
1719 for (i = 0; i < recipients_count; i++)
1720   {
1721   /*XXX variant of list_appendele? */
1722   if (i != 0) g = string_catn(g, US", ", 2);
1723   g = string_cat(g, recipients_list[i].address);
1724   }
1725 return string_from_gstring(g);
1726 }
1727
1728
1729 /*************************************************
1730 *               Find value of a variable         *
1731 *************************************************/
1732
1733 /* The table of variables is kept in alphabetic order, so we can search it
1734 using a binary chop. The "choplen" variable is nothing to do with the binary
1735 chop.
1736
1737 Arguments:
1738   name          the name of the variable being sought
1739   exists_only   TRUE if this is a def: test; passed on to find_header()
1740   skipping      TRUE => skip any processing evaluation; this is not the same as
1741                   exists_only because def: may test for values that are first
1742                   evaluated here
1743   newsize       pointer to an int which is initially zero; if the answer is in
1744                 a new memory buffer, *newsize is set to its size
1745
1746 Returns:        NULL if the variable does not exist, or
1747                 a pointer to the variable's contents, or
1748                 something non-NULL if exists_only is TRUE
1749 */
1750
1751 static uschar *
1752 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1753 {
1754 var_entry * vp;
1755 uschar *s, *domain;
1756 uschar **ss;
1757 void * val;
1758
1759 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1760 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1761 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1762 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1763 (this gave backwards compatibility at the changeover). There may be built-in
1764 variables whose names start acl_ but they should never start in this way. This
1765 slightly messy specification is a consequence of the history, needless to say.
1766
1767 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1768 set, in which case give an error. */
1769
1770 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1771      !isalpha(name[5]))
1772   {
1773   tree_node *node =
1774     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1775   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1776   }
1777
1778 /* Handle $auth<n> variables. */
1779
1780 if (Ustrncmp(name, "auth", 4) == 0)
1781   {
1782   uschar *endptr;
1783   int n = Ustrtoul(name + 4, &endptr, 10);
1784   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1785     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1786   }
1787 else if (Ustrncmp(name, "regex", 5) == 0)
1788   {
1789   uschar *endptr;
1790   int n = Ustrtoul(name + 5, &endptr, 10);
1791   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1792     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1793   }
1794
1795 /* For all other variables, search the table */
1796
1797 if (!(vp = find_var_ent(name)))
1798   return NULL;          /* Unknown variable name */
1799
1800 /* Found an existing variable. If in skipping state, the value isn't needed,
1801 and we want to avoid processing (such as looking up the host name). */
1802
1803 if (skipping)
1804   return US"";
1805
1806 val = vp->value;
1807 switch (vp->type)
1808   {
1809   case vtype_filter_int:
1810     if (!filter_running) return NULL;
1811     /* Fall through */
1812     /* VVVVVVVVVVVV */
1813   case vtype_int:
1814     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1815     return var_buffer;
1816
1817   case vtype_ino:
1818     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1819     return var_buffer;
1820
1821   case vtype_gid:
1822     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1823     return var_buffer;
1824
1825   case vtype_uid:
1826     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1827     return var_buffer;
1828
1829   case vtype_bool:
1830     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1831     return var_buffer;
1832
1833   case vtype_stringptr:                      /* Pointer to string */
1834     return (s = *((uschar **)(val))) ? s : US"";
1835
1836   case vtype_pid:
1837     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1838     return var_buffer;
1839
1840   case vtype_load_avg:
1841     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1842     return var_buffer;
1843
1844   case vtype_host_lookup:                    /* Lookup if not done so */
1845     if (  !sender_host_name && sender_host_address
1846        && !host_lookup_failed && host_name_lookup() == OK)
1847       host_build_sender_fullhost();
1848     return sender_host_name ? sender_host_name : US"";
1849
1850   case vtype_localpart:                      /* Get local part from address */
1851     s = *((uschar **)(val));
1852     if (s == NULL) return US"";
1853     domain = Ustrrchr(s, '@');
1854     if (domain == NULL) return s;
1855     if (domain - s > sizeof(var_buffer) - 1)
1856       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1857           " in string expansion", sizeof(var_buffer));
1858     Ustrncpy(var_buffer, s, domain - s);
1859     var_buffer[domain - s] = 0;
1860     return var_buffer;
1861
1862   case vtype_domain:                         /* Get domain from address */
1863     s = *((uschar **)(val));
1864     if (s == NULL) return US"";
1865     domain = Ustrrchr(s, '@');
1866     return (domain == NULL)? US"" : domain + 1;
1867
1868   case vtype_msgheaders:
1869     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1870
1871   case vtype_msgheaders_raw:
1872     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1873
1874   case vtype_msgbody:                        /* Pointer to msgbody string */
1875   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1876     ss = (uschar **)(val);
1877     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1878       {
1879       uschar *body;
1880       off_t start_offset = SPOOL_DATA_START_OFFSET;
1881       int len = message_body_visible;
1882       if (len > message_size) len = message_size;
1883       *ss = body = store_malloc(len+1);
1884       body[0] = 0;
1885       if (vp->type == vtype_msgbody_end)
1886         {
1887         struct stat statbuf;
1888         if (fstat(deliver_datafile, &statbuf) == 0)
1889           {
1890           start_offset = statbuf.st_size - len;
1891           if (start_offset < SPOOL_DATA_START_OFFSET)
1892             start_offset = SPOOL_DATA_START_OFFSET;
1893           }
1894         }
1895       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1896         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1897           strerror(errno));
1898       len = read(deliver_datafile, body, len);
1899       if (len > 0)
1900         {
1901         body[len] = 0;
1902         if (message_body_newlines)   /* Separate loops for efficiency */
1903           while (len > 0)
1904             { if (body[--len] == 0) body[len] = ' '; }
1905         else
1906           while (len > 0)
1907             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1908         }
1909       }
1910     return *ss ? *ss : US"";
1911
1912   case vtype_todbsdin:                       /* BSD inbox time of day */
1913     return tod_stamp(tod_bsdin);
1914
1915   case vtype_tode:                           /* Unix epoch time of day */
1916     return tod_stamp(tod_epoch);
1917
1918   case vtype_todel:                          /* Unix epoch/usec time of day */
1919     return tod_stamp(tod_epoch_l);
1920
1921   case vtype_todf:                           /* Full time of day */
1922     return tod_stamp(tod_full);
1923
1924   case vtype_todl:                           /* Log format time of day */
1925     return tod_stamp(tod_log_bare);            /* (without timezone) */
1926
1927   case vtype_todzone:                        /* Time zone offset only */
1928     return tod_stamp(tod_zone);
1929
1930   case vtype_todzulu:                        /* Zulu time */
1931     return tod_stamp(tod_zulu);
1932
1933   case vtype_todlf:                          /* Log file datestamp tod */
1934     return tod_stamp(tod_log_datestamp_daily);
1935
1936   case vtype_reply:                          /* Get reply address */
1937     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1938       headers_charset);
1939     if (s) while (isspace(*s)) s++;
1940     if (!s || !*s)
1941       {
1942       *newsize = 0;                            /* For the *s==0 case */
1943       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1944       }
1945     if (s)
1946       {
1947       uschar *t;
1948       while (isspace(*s)) s++;
1949       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1950       while (t > s && isspace(t[-1])) t--;
1951       *t = 0;
1952       }
1953     return s ? s : US"";
1954
1955   case vtype_string_func:
1956     {
1957     uschar * (*fn)() = val;
1958     return fn();
1959     }
1960
1961   case vtype_pspace:
1962     {
1963     int inodes;
1964     sprintf(CS var_buffer, "%d",
1965       receive_statvfs(val == (void *)TRUE, &inodes));
1966     }
1967   return var_buffer;
1968
1969   case vtype_pinodes:
1970     {
1971     int inodes;
1972     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1973     sprintf(CS var_buffer, "%d", inodes);
1974     }
1975   return var_buffer;
1976
1977   case vtype_cert:
1978     return *(void **)val ? US"<cert>" : US"";
1979
1980 #ifndef DISABLE_DKIM
1981   case vtype_dkim:
1982     return dkim_exim_expand_query((int)(long)val);
1983 #endif
1984
1985   }
1986
1987 return NULL;  /* Unknown variable. Silences static checkers. */
1988 }
1989
1990
1991
1992
1993 void
1994 modify_variable(uschar *name, void * value)
1995 {
1996 var_entry * vp;
1997 if ((vp = find_var_ent(name))) vp->value = value;
1998 return;          /* Unknown variable name, fail silently */
1999 }
2000
2001
2002
2003
2004
2005
2006 /*************************************************
2007 *           Read and expand substrings           *
2008 *************************************************/
2009
2010 /* This function is called to read and expand argument substrings for various
2011 expansion items. Some have a minimum requirement that is less than the maximum;
2012 in these cases, the first non-present one is set to NULL.
2013
2014 Arguments:
2015   sub        points to vector of pointers to set
2016   n          maximum number of substrings
2017   m          minimum required
2018   sptr       points to current string pointer
2019   skipping   the skipping flag
2020   check_end  if TRUE, check for final '}'
2021   name       name of item, for error message
2022   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
2023              the store.
2024
2025 Returns:     0 OK; string pointer updated
2026              1 curly bracketing error (too few arguments)
2027              2 too many arguments (only if check_end is set); message set
2028              3 other error (expansion failure)
2029 */
2030
2031 static int
2032 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
2033   BOOL check_end, uschar *name, BOOL *resetok)
2034 {
2035 int i;
2036 const uschar *s = *sptr;
2037
2038 while (isspace(*s)) s++;
2039 for (i = 0; i < n; i++)
2040   {
2041   if (*s != '{')
2042     {
2043     if (i < m)
2044       {
2045       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2046         "(min is %d)", name, m);
2047       return 1;
2048       }
2049     sub[i] = NULL;
2050     break;
2051     }
2052   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2053     return 3;
2054   if (*s++ != '}') return 1;
2055   while (isspace(*s)) s++;
2056   }
2057 if (check_end && *s++ != '}')
2058   {
2059   if (s[-1] == '{')
2060     {
2061     expand_string_message = string_sprintf("Too many arguments for '%s' "
2062       "(max is %d)", name, n);
2063     return 2;
2064     }
2065   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2066   return 1;
2067   }
2068
2069 *sptr = s;
2070 return 0;
2071 }
2072
2073
2074
2075
2076 /*************************************************
2077 *     Elaborate message for bad variable         *
2078 *************************************************/
2079
2080 /* For the "unknown variable" message, take a look at the variable's name, and
2081 give additional information about possible ACL variables. The extra information
2082 is added on to expand_string_message.
2083
2084 Argument:   the name of the variable
2085 Returns:    nothing
2086 */
2087
2088 static void
2089 check_variable_error_message(uschar *name)
2090 {
2091 if (Ustrncmp(name, "acl_", 4) == 0)
2092   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2093     (name[4] == 'c' || name[4] == 'm')?
2094       (isalpha(name[5])?
2095         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2096         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2097       ) :
2098       US"user-defined ACL variables must start acl_c or acl_m");
2099 }
2100
2101
2102
2103 /*
2104 Load args from sub array to globals, and call acl_check().
2105 Sub array will be corrupted on return.
2106
2107 Returns:       OK         access is granted by an ACCEPT verb
2108                DISCARD    access is (apparently) granted by a DISCARD verb
2109                FAIL       access is denied
2110                FAIL_DROP  access is denied; drop the connection
2111                DEFER      can't tell at the moment
2112                ERROR      disaster
2113 */
2114 static int
2115 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2116 {
2117 int i;
2118 int sav_narg = acl_narg;
2119 int ret;
2120 uschar * dummy_logmsg;
2121 extern int acl_where;
2122
2123 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2124 for (i = 0; i < nsub && sub[i+1]; i++)
2125   {
2126   uschar * tmp = acl_arg[i];
2127   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2128   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2129   }
2130 acl_narg = i;
2131 while (i < nsub)
2132   {
2133   sub[i+1] = acl_arg[i];
2134   acl_arg[i++] = NULL;
2135   }
2136
2137 DEBUG(D_expand)
2138   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2139     sub[0],
2140     acl_narg>0 ? acl_arg[0] : US"<none>",
2141     acl_narg>1 ? " +more"   : "");
2142
2143 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2144
2145 for (i = 0; i < nsub; i++)
2146   acl_arg[i] = sub[i+1];        /* restore old args */
2147 acl_narg = sav_narg;
2148
2149 return ret;
2150 }
2151
2152
2153
2154
2155 /*************************************************
2156 *        Read and evaluate a condition           *
2157 *************************************************/
2158
2159 /*
2160 Arguments:
2161   s        points to the start of the condition text
2162   resetok  points to a BOOL which is written false if it is unsafe to
2163            free memory. Certain condition types (acl) may have side-effect
2164            allocation which must be preserved.
2165   yield    points to a BOOL to hold the result of the condition test;
2166            if NULL, we are just reading through a condition that is
2167            part of an "or" combination to check syntax, or in a state
2168            where the answer isn't required
2169
2170 Returns:   a pointer to the first character after the condition, or
2171            NULL after an error
2172 */
2173
2174 static const uschar *
2175 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2176 {
2177 BOOL testfor = TRUE;
2178 BOOL tempcond, combined_cond;
2179 BOOL *subcondptr;
2180 BOOL sub2_honour_dollar = TRUE;
2181 int i, rc, cond_type, roffset;
2182 int_eximarith_t num[2];
2183 struct stat statbuf;
2184 uschar name[256];
2185 const uschar *sub[10];
2186
2187 const pcre *re;
2188 const uschar *rerror;
2189
2190 for (;;)
2191   {
2192   while (isspace(*s)) s++;
2193   if (*s == '!') { testfor = !testfor; s++; } else break;
2194   }
2195
2196 /* Numeric comparisons are symbolic */
2197
2198 if (*s == '=' || *s == '>' || *s == '<')
2199   {
2200   int p = 0;
2201   name[p++] = *s++;
2202   if (*s == '=')
2203     {
2204     name[p++] = '=';
2205     s++;
2206     }
2207   name[p] = 0;
2208   }
2209
2210 /* All other conditions are named */
2211
2212 else s = read_name(name, 256, s, US"_");
2213
2214 /* If we haven't read a name, it means some non-alpha character is first. */
2215
2216 if (name[0] == 0)
2217   {
2218   expand_string_message = string_sprintf("condition name expected, "
2219     "but found \"%.16s\"", s);
2220   return NULL;
2221   }
2222
2223 /* Find which condition we are dealing with, and switch on it */
2224
2225 cond_type = chop_match(name, cond_table, nelem(cond_table));
2226 switch(cond_type)
2227   {
2228   /* def: tests for a non-empty variable, or for the existence of a header. If
2229   yield == NULL we are in a skipping state, and don't care about the answer. */
2230
2231   case ECOND_DEF:
2232   if (*s != ':')
2233     {
2234     expand_string_message = US"\":\" expected after \"def\"";
2235     return NULL;
2236     }
2237
2238   s = read_name(name, 256, s+1, US"_");
2239
2240   /* Test for a header's existence. If the name contains a closing brace
2241   character, this may be a user error where the terminating colon has been
2242   omitted. Set a flag to adjust a subsequent error message in this case. */
2243
2244   if (Ustrncmp(name, "h_", 2) == 0 ||
2245       Ustrncmp(name, "rh_", 3) == 0 ||
2246       Ustrncmp(name, "bh_", 3) == 0 ||
2247       Ustrncmp(name, "header_", 7) == 0 ||
2248       Ustrncmp(name, "rheader_", 8) == 0 ||
2249       Ustrncmp(name, "bheader_", 8) == 0)
2250     {
2251     s = read_header_name(name, 256, s);
2252     /* {-for-text-editors */
2253     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2254     if (yield != NULL) *yield =
2255       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2256     }
2257
2258   /* Test for a variable's having a non-empty value. A non-existent variable
2259   causes an expansion failure. */
2260
2261   else
2262     {
2263     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2264     if (value == NULL)
2265       {
2266       expand_string_message = (name[0] == 0)?
2267         string_sprintf("variable name omitted after \"def:\"") :
2268         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2269       check_variable_error_message(name);
2270       return NULL;
2271       }
2272     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2273     }
2274
2275   return s;
2276
2277
2278   /* first_delivery tests for first delivery attempt */
2279
2280   case ECOND_FIRST_DELIVERY:
2281   if (yield != NULL) *yield = deliver_firsttime == testfor;
2282   return s;
2283
2284
2285   /* queue_running tests for any process started by a queue runner */
2286
2287   case ECOND_QUEUE_RUNNING:
2288   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2289   return s;
2290
2291
2292   /* exists:  tests for file existence
2293        isip:  tests for any IP address
2294       isip4:  tests for an IPv4 address
2295       isip6:  tests for an IPv6 address
2296         pam:  does PAM authentication
2297      radius:  does RADIUS authentication
2298    ldapauth:  does LDAP authentication
2299     pwcheck:  does Cyrus SASL pwcheck authentication
2300   */
2301
2302   case ECOND_EXISTS:
2303   case ECOND_ISIP:
2304   case ECOND_ISIP4:
2305   case ECOND_ISIP6:
2306   case ECOND_PAM:
2307   case ECOND_RADIUS:
2308   case ECOND_LDAPAUTH:
2309   case ECOND_PWCHECK:
2310
2311   while (isspace(*s)) s++;
2312   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2313
2314   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2315   if (sub[0] == NULL) return NULL;
2316   /* {-for-text-editors */
2317   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2318
2319   if (yield == NULL) return s;   /* No need to run the test if skipping */
2320
2321   switch(cond_type)
2322     {
2323     case ECOND_EXISTS:
2324     if ((expand_forbid & RDO_EXISTS) != 0)
2325       {
2326       expand_string_message = US"File existence tests are not permitted";
2327       return NULL;
2328       }
2329     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2330     break;
2331
2332     case ECOND_ISIP:
2333     case ECOND_ISIP4:
2334     case ECOND_ISIP6:
2335     rc = string_is_ip_address(sub[0], NULL);
2336     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2337              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2338     break;
2339
2340     /* Various authentication tests - all optionally compiled */
2341
2342     case ECOND_PAM:
2343     #ifdef SUPPORT_PAM
2344     rc = auth_call_pam(sub[0], &expand_string_message);
2345     goto END_AUTH;
2346     #else
2347     goto COND_FAILED_NOT_COMPILED;
2348     #endif  /* SUPPORT_PAM */
2349
2350     case ECOND_RADIUS:
2351     #ifdef RADIUS_CONFIG_FILE
2352     rc = auth_call_radius(sub[0], &expand_string_message);
2353     goto END_AUTH;
2354     #else
2355     goto COND_FAILED_NOT_COMPILED;
2356     #endif  /* RADIUS_CONFIG_FILE */
2357
2358     case ECOND_LDAPAUTH:
2359     #ifdef LOOKUP_LDAP
2360       {
2361       /* Just to keep the interface the same */
2362       BOOL do_cache;
2363       int old_pool = store_pool;
2364       store_pool = POOL_SEARCH;
2365       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2366         &expand_string_message, &do_cache);
2367       store_pool = old_pool;
2368       }
2369     goto END_AUTH;
2370     #else
2371     goto COND_FAILED_NOT_COMPILED;
2372     #endif  /* LOOKUP_LDAP */
2373
2374     case ECOND_PWCHECK:
2375     #ifdef CYRUS_PWCHECK_SOCKET
2376     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2377     goto END_AUTH;
2378     #else
2379     goto COND_FAILED_NOT_COMPILED;
2380     #endif  /* CYRUS_PWCHECK_SOCKET */
2381
2382     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2383         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2384     END_AUTH:
2385     if (rc == ERROR || rc == DEFER) return NULL;
2386     *yield = (rc == OK) == testfor;
2387     #endif
2388     }
2389   return s;
2390
2391
2392   /* call ACL (in a conditional context).  Accept true, deny false.
2393   Defer is a forced-fail.  Anything set by message= goes to $value.
2394   Up to ten parameters are used; we use the braces round the name+args
2395   like the saslauthd condition does, to permit a variable number of args.
2396   See also the expansion-item version EITEM_ACL and the traditional
2397   acl modifier ACLC_ACL.
2398   Since the ACL may allocate new global variables, tell our caller to not
2399   reclaim memory.
2400   */
2401
2402   case ECOND_ACL:
2403     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2404     {
2405     uschar *sub[10];
2406     uschar *user_msg;
2407     BOOL cond = FALSE;
2408
2409     while (isspace(*s)) s++;
2410     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2411
2412     switch(read_subs(sub, nelem(sub), 1,
2413       &s, yield == NULL, TRUE, US"acl", resetok))
2414       {
2415       case 1: expand_string_message = US"too few arguments or bracketing "
2416         "error for acl";
2417       case 2:
2418       case 3: return NULL;
2419       }
2420
2421     if (yield != NULL)
2422       {
2423       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2424       switch(eval_acl(sub, nelem(sub), &user_msg))
2425         {
2426         case OK:
2427           cond = TRUE;
2428         case FAIL:
2429           lookup_value = NULL;
2430           if (user_msg)
2431             lookup_value = string_copy(user_msg);
2432           *yield = cond == testfor;
2433           break;
2434
2435         case DEFER:
2436           expand_string_forcedfail = TRUE;
2437           /*FALLTHROUGH*/
2438         default:
2439           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2440           return NULL;
2441         }
2442       }
2443     return s;
2444     }
2445
2446
2447   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2448
2449      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2450
2451   However, the last two are optional. That is why the whole set is enclosed
2452   in their own set of braces. */
2453
2454   case ECOND_SASLAUTHD:
2455 #ifndef CYRUS_SASLAUTHD_SOCKET
2456     goto COND_FAILED_NOT_COMPILED;
2457 #else
2458     {
2459     uschar *sub[4];
2460     while (isspace(*s)) s++;
2461     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2462     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2463                     resetok))
2464       {
2465       case 1: expand_string_message = US"too few arguments or bracketing "
2466         "error for saslauthd";
2467       case 2:
2468       case 3: return NULL;
2469       }
2470     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2471     if (yield != NULL)
2472       {
2473       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2474         &expand_string_message);
2475       if (rc == ERROR || rc == DEFER) return NULL;
2476       *yield = (rc == OK) == testfor;
2477       }
2478     return s;
2479     }
2480 #endif /* CYRUS_SASLAUTHD_SOCKET */
2481
2482
2483   /* symbolic operators for numeric and string comparison, and a number of
2484   other operators, all requiring two arguments.
2485
2486   crypteq:           encrypts plaintext and compares against an encrypted text,
2487                        using crypt(), crypt16(), MD5 or SHA-1
2488   inlist/inlisti:    checks if first argument is in the list of the second
2489   match:             does a regular expression match and sets up the numerical
2490                        variables if it succeeds
2491   match_address:     matches in an address list
2492   match_domain:      matches in a domain list
2493   match_ip:          matches a host list that is restricted to IP addresses
2494   match_local_part:  matches in a local part list
2495   */
2496
2497   case ECOND_MATCH_ADDRESS:
2498   case ECOND_MATCH_DOMAIN:
2499   case ECOND_MATCH_IP:
2500   case ECOND_MATCH_LOCAL_PART:
2501 #ifndef EXPAND_LISTMATCH_RHS
2502     sub2_honour_dollar = FALSE;
2503 #endif
2504     /* FALLTHROUGH */
2505
2506   case ECOND_CRYPTEQ:
2507   case ECOND_INLIST:
2508   case ECOND_INLISTI:
2509   case ECOND_MATCH:
2510
2511   case ECOND_NUM_L:     /* Numerical comparisons */
2512   case ECOND_NUM_LE:
2513   case ECOND_NUM_E:
2514   case ECOND_NUM_EE:
2515   case ECOND_NUM_G:
2516   case ECOND_NUM_GE:
2517
2518   case ECOND_STR_LT:    /* String comparisons */
2519   case ECOND_STR_LTI:
2520   case ECOND_STR_LE:
2521   case ECOND_STR_LEI:
2522   case ECOND_STR_EQ:
2523   case ECOND_STR_EQI:
2524   case ECOND_STR_GT:
2525   case ECOND_STR_GTI:
2526   case ECOND_STR_GE:
2527   case ECOND_STR_GEI:
2528
2529   for (i = 0; i < 2; i++)
2530     {
2531     /* Sometimes, we don't expand substrings; too many insecure configurations
2532     created using match_address{}{} and friends, where the second param
2533     includes information from untrustworthy sources. */
2534     BOOL honour_dollar = TRUE;
2535     if ((i > 0) && !sub2_honour_dollar)
2536       honour_dollar = FALSE;
2537
2538     while (isspace(*s)) s++;
2539     if (*s != '{')
2540       {
2541       if (i == 0) goto COND_FAILED_CURLY_START;
2542       expand_string_message = string_sprintf("missing 2nd string in {} "
2543         "after \"%s\"", name);
2544       return NULL;
2545       }
2546     if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2547         honour_dollar, resetok)))
2548       return NULL;
2549     DEBUG(D_expand) if (i == 1 && !sub2_honour_dollar && Ustrchr(sub[1], '$'))
2550       debug_printf_indent("WARNING: the second arg is NOT expanded,"
2551                         " for security reasons\n");
2552     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2553
2554     /* Convert to numerical if required; we know that the names of all the
2555     conditions that compare numbers do not start with a letter. This just saves
2556     checking for them individually. */
2557
2558     if (!isalpha(name[0]) && yield != NULL)
2559       if (sub[i][0] == 0)
2560         {
2561         num[i] = 0;
2562         DEBUG(D_expand)
2563           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2564         }
2565       else
2566         {
2567         num[i] = expanded_string_integer(sub[i], FALSE);
2568         if (expand_string_message != NULL) return NULL;
2569         }
2570     }
2571
2572   /* Result not required */
2573
2574   if (yield == NULL) return s;
2575
2576   /* Do an appropriate comparison */
2577
2578   switch(cond_type)
2579     {
2580     case ECOND_NUM_E:
2581     case ECOND_NUM_EE:
2582     tempcond = (num[0] == num[1]);
2583     break;
2584
2585     case ECOND_NUM_G:
2586     tempcond = (num[0] > num[1]);
2587     break;
2588
2589     case ECOND_NUM_GE:
2590     tempcond = (num[0] >= num[1]);
2591     break;
2592
2593     case ECOND_NUM_L:
2594     tempcond = (num[0] < num[1]);
2595     break;
2596
2597     case ECOND_NUM_LE:
2598     tempcond = (num[0] <= num[1]);
2599     break;
2600
2601     case ECOND_STR_LT:
2602     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2603     break;
2604
2605     case ECOND_STR_LTI:
2606     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2607     break;
2608
2609     case ECOND_STR_LE:
2610     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2611     break;
2612
2613     case ECOND_STR_LEI:
2614     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2615     break;
2616
2617     case ECOND_STR_EQ:
2618     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2619     break;
2620
2621     case ECOND_STR_EQI:
2622     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2623     break;
2624
2625     case ECOND_STR_GT:
2626     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2627     break;
2628
2629     case ECOND_STR_GTI:
2630     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2631     break;
2632
2633     case ECOND_STR_GE:
2634     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2635     break;
2636
2637     case ECOND_STR_GEI:
2638     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2639     break;
2640
2641     case ECOND_MATCH:   /* Regular expression match */
2642     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2643       NULL);
2644     if (re == NULL)
2645       {
2646       expand_string_message = string_sprintf("regular expression error in "
2647         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2648       return NULL;
2649       }
2650     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2651     break;
2652
2653     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2654     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2655     goto MATCHED_SOMETHING;
2656
2657     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2658     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2659       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2660     goto MATCHED_SOMETHING;
2661
2662     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2663     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2664       {
2665       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2666         sub[0]);
2667       return NULL;
2668       }
2669     else
2670       {
2671       unsigned int *nullcache = NULL;
2672       check_host_block cb;
2673
2674       cb.host_name = US"";
2675       cb.host_address = sub[0];
2676
2677       /* If the host address starts off ::ffff: it is an IPv6 address in
2678       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2679       addresses. */
2680
2681       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2682         cb.host_address + 7 : cb.host_address;
2683
2684       rc = match_check_list(
2685              &sub[1],                   /* the list */
2686              0,                         /* separator character */
2687              &hostlist_anchor,          /* anchor pointer */
2688              &nullcache,                /* cache pointer */
2689              check_host,                /* function for testing */
2690              &cb,                       /* argument for function */
2691              MCL_HOST,                  /* type of check */
2692              sub[0],                    /* text for debugging */
2693              NULL);                     /* where to pass back data */
2694       }
2695     goto MATCHED_SOMETHING;
2696
2697     case ECOND_MATCH_LOCAL_PART:
2698     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2699       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2700     /* Fall through */
2701     /* VVVVVVVVVVVV */
2702     MATCHED_SOMETHING:
2703     switch(rc)
2704       {
2705       case OK:
2706       tempcond = TRUE;
2707       break;
2708
2709       case FAIL:
2710       tempcond = FALSE;
2711       break;
2712
2713       case DEFER:
2714       expand_string_message = string_sprintf("unable to complete match "
2715         "against \"%s\": %s", sub[1], search_error_message);
2716       return NULL;
2717       }
2718
2719     break;
2720
2721     /* Various "encrypted" comparisons. If the second string starts with
2722     "{" then an encryption type is given. Default to crypt() or crypt16()
2723     (build-time choice). */
2724     /* }-for-text-editors */
2725
2726     case ECOND_CRYPTEQ:
2727     #ifndef SUPPORT_CRYPTEQ
2728     goto COND_FAILED_NOT_COMPILED;
2729     #else
2730     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2731       {
2732       int sublen = Ustrlen(sub[1]+5);
2733       md5 base;
2734       uschar digest[16];
2735
2736       md5_start(&base);
2737       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2738
2739       /* If the length that we are comparing against is 24, the MD5 digest
2740       is expressed as a base64 string. This is the way LDAP does it. However,
2741       some other software uses a straightforward hex representation. We assume
2742       this if the length is 32. Other lengths fail. */
2743
2744       if (sublen == 24)
2745         {
2746         uschar *coded = b64encode(digest, 16);
2747         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2748           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2749         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2750         }
2751       else if (sublen == 32)
2752         {
2753         int i;
2754         uschar coded[36];
2755         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2756         coded[32] = 0;
2757         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2758           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2759         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2760         }
2761       else
2762         {
2763         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2764           "fail\n  crypted=%s\n", sub[1]+5);
2765         tempcond = FALSE;
2766         }
2767       }
2768
2769     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2770       {
2771       int sublen = Ustrlen(sub[1]+6);
2772       hctx h;
2773       uschar digest[20];
2774
2775       sha1_start(&h);
2776       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2777
2778       /* If the length that we are comparing against is 28, assume the SHA1
2779       digest is expressed as a base64 string. If the length is 40, assume a
2780       straightforward hex representation. Other lengths fail. */
2781
2782       if (sublen == 28)
2783         {
2784         uschar *coded = b64encode(digest, 20);
2785         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2786           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2787         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2788         }
2789       else if (sublen == 40)
2790         {
2791         int i;
2792         uschar coded[44];
2793         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2794         coded[40] = 0;
2795         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2796           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2797         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2798         }
2799       else
2800         {
2801         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2802           "fail\n  crypted=%s\n", sub[1]+6);
2803         tempcond = FALSE;
2804         }
2805       }
2806
2807     else   /* {crypt} or {crypt16} and non-{ at start */
2808            /* }-for-text-editors */
2809       {
2810       int which = 0;
2811       uschar *coded;
2812
2813       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2814         {
2815         sub[1] += 7;
2816         which = 1;
2817         }
2818       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2819         {
2820         sub[1] += 9;
2821         which = 2;
2822         }
2823       else if (sub[1][0] == '{')                /* }-for-text-editors */
2824         {
2825         expand_string_message = string_sprintf("unknown encryption mechanism "
2826           "in \"%s\"", sub[1]);
2827         return NULL;
2828         }
2829
2830       switch(which)
2831         {
2832         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2833         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2834         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2835         }
2836
2837       #define STR(s) # s
2838       #define XSTR(s) STR(s)
2839       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2840         "  subject=%s\n  crypted=%s\n",
2841         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2842         coded, sub[1]);
2843       #undef STR
2844       #undef XSTR
2845
2846       /* If the encrypted string contains fewer than two characters (for the
2847       salt), force failure. Otherwise we get false positives: with an empty
2848       string the yield of crypt() is an empty string! */
2849
2850       if (coded)
2851         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2852       else if (errno == EINVAL)
2853         tempcond = FALSE;
2854       else
2855         {
2856         expand_string_message = string_sprintf("crypt error: %s\n",
2857           US strerror(errno));
2858         return NULL;
2859         }
2860       }
2861     break;
2862     #endif  /* SUPPORT_CRYPTEQ */
2863
2864     case ECOND_INLIST:
2865     case ECOND_INLISTI:
2866       {
2867       const uschar * list = sub[1];
2868       int sep = 0;
2869       uschar *save_iterate_item = iterate_item;
2870       int (*compare)(const uschar *, const uschar *);
2871
2872       DEBUG(D_expand) debug_printf_indent("condition: %s  item: %s\n", name, sub[0]);
2873
2874       tempcond = FALSE;
2875       compare = cond_type == ECOND_INLISTI
2876         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2877
2878       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2879         {
2880         DEBUG(D_expand) debug_printf_indent(" compare %s\n", iterate_item);
2881         if (compare(sub[0], iterate_item) == 0)
2882           {
2883           tempcond = TRUE;
2884           break;
2885           }
2886         }
2887       iterate_item = save_iterate_item;
2888       }
2889
2890     }   /* Switch for comparison conditions */
2891
2892   *yield = tempcond == testfor;
2893   return s;    /* End of comparison conditions */
2894
2895
2896   /* and/or: computes logical and/or of several conditions */
2897
2898   case ECOND_AND:
2899   case ECOND_OR:
2900   subcondptr = (yield == NULL)? NULL : &tempcond;
2901   combined_cond = (cond_type == ECOND_AND);
2902
2903   while (isspace(*s)) s++;
2904   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2905
2906   for (;;)
2907     {
2908     while (isspace(*s)) s++;
2909     /* {-for-text-editors */
2910     if (*s == '}') break;
2911     if (*s != '{')                                      /* }-for-text-editors */
2912       {
2913       expand_string_message = string_sprintf("each subcondition "
2914         "inside an \"%s{...}\" condition must be in its own {}", name);
2915       return NULL;
2916       }
2917
2918     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2919       {
2920       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2921         expand_string_message, name);
2922       return NULL;
2923       }
2924     while (isspace(*s)) s++;
2925
2926     /* {-for-text-editors */
2927     if (*s++ != '}')
2928       {
2929       /* {-for-text-editors */
2930       expand_string_message = string_sprintf("missing } at end of condition "
2931         "inside \"%s\" group", name);
2932       return NULL;
2933       }
2934
2935     if (yield != NULL)
2936       {
2937       if (cond_type == ECOND_AND)
2938         {
2939         combined_cond &= tempcond;
2940         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2941         }                                       /* evaluate any more */
2942       else
2943         {
2944         combined_cond |= tempcond;
2945         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2946         }                                       /* evaluate any more */
2947       }
2948     }
2949
2950   if (yield != NULL) *yield = (combined_cond == testfor);
2951   return ++s;
2952
2953
2954   /* forall/forany: iterates a condition with different values */
2955
2956   case ECOND_FORALL:
2957   case ECOND_FORANY:
2958     {
2959     const uschar * list;
2960     int sep = 0;
2961     uschar *save_iterate_item = iterate_item;
2962
2963     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2964
2965     while (isspace(*s)) s++;
2966     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2967     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2968     if (sub[0] == NULL) return NULL;
2969     /* {-for-text-editors */
2970     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2971
2972     while (isspace(*s)) s++;
2973     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2974
2975     sub[1] = s;
2976
2977     /* Call eval_condition once, with result discarded (as if scanning a
2978     "false" part). This allows us to find the end of the condition, because if
2979     the list it empty, we won't actually evaluate the condition for real. */
2980
2981     if (!(s = eval_condition(sub[1], resetok, NULL)))
2982       {
2983       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2984         expand_string_message, name);
2985       return NULL;
2986       }
2987     while (isspace(*s)) s++;
2988
2989     /* {-for-text-editors */
2990     if (*s++ != '}')
2991       {
2992       /* {-for-text-editors */
2993       expand_string_message = string_sprintf("missing } at end of condition "
2994         "inside \"%s\"", name);
2995       return NULL;
2996       }
2997
2998     if (yield != NULL) *yield = !testfor;
2999     list = sub[0];
3000     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
3001       {
3002       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
3003       if (!eval_condition(sub[1], resetok, &tempcond))
3004         {
3005         expand_string_message = string_sprintf("%s inside \"%s\" condition",
3006           expand_string_message, name);
3007         iterate_item = save_iterate_item;
3008         return NULL;
3009         }
3010       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
3011         tempcond? "true":"false");
3012
3013       if (yield != NULL) *yield = (tempcond == testfor);
3014       if (tempcond == (cond_type == ECOND_FORANY)) break;
3015       }
3016
3017     iterate_item = save_iterate_item;
3018     return s;
3019     }
3020
3021
3022   /* The bool{} expansion condition maps a string to boolean.
3023   The values supported should match those supported by the ACL condition
3024   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
3025   of true/false.  Note that Router "condition" rules have a different
3026   interpretation, where general data can be used and only a few values
3027   map to FALSE.
3028   Note that readconf.c boolean matching, for boolean configuration options,
3029   only matches true/yes/false/no.
3030   The bool_lax{} condition matches the Router logic, which is much more
3031   liberal. */
3032   case ECOND_BOOL:
3033   case ECOND_BOOL_LAX:
3034     {
3035     uschar *sub_arg[1];
3036     uschar *t, *t2;
3037     uschar *ourname;
3038     size_t len;
3039     BOOL boolvalue = FALSE;
3040     while (isspace(*s)) s++;
3041     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3042     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3043     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3044       {
3045       case 1: expand_string_message = string_sprintf(
3046                   "too few arguments or bracketing error for %s",
3047                   ourname);
3048       /*FALLTHROUGH*/
3049       case 2:
3050       case 3: return NULL;
3051       }
3052     t = sub_arg[0];
3053     while (isspace(*t)) t++;
3054     len = Ustrlen(t);
3055     if (len)
3056       {
3057       /* trailing whitespace: seems like a good idea to ignore it too */
3058       t2 = t + len - 1;
3059       while (isspace(*t2)) t2--;
3060       if (t2 != (t + len))
3061         {
3062         *++t2 = '\0';
3063         len = t2 - t;
3064         }
3065       }
3066     DEBUG(D_expand)
3067       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3068     /* logic for the lax case from expand_check_condition(), which also does
3069     expands, and the logic is both short and stable enough that there should
3070     be no maintenance burden from replicating it. */
3071     if (len == 0)
3072       boolvalue = FALSE;
3073     else if (*t == '-'
3074              ? Ustrspn(t+1, "0123456789") == len-1
3075              : Ustrspn(t,   "0123456789") == len)
3076       {
3077       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3078       /* expand_check_condition only does a literal string "0" check */
3079       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3080         boolvalue = TRUE;
3081       }
3082     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3083       boolvalue = TRUE;
3084     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3085       boolvalue = FALSE;
3086     else if (cond_type == ECOND_BOOL_LAX)
3087       boolvalue = TRUE;
3088     else
3089       {
3090       expand_string_message = string_sprintf("unrecognised boolean "
3091        "value \"%s\"", t);
3092       return NULL;
3093       }
3094     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3095         boolvalue? "true":"false");
3096     if (yield != NULL) *yield = (boolvalue == testfor);
3097     return s;
3098     }
3099
3100   /* Unknown condition */
3101
3102   default:
3103   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3104   return NULL;
3105   }   /* End switch on condition type */
3106
3107 /* Missing braces at start and end of data */
3108
3109 COND_FAILED_CURLY_START:
3110 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3111 return NULL;
3112
3113 COND_FAILED_CURLY_END:
3114 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3115   name);
3116 return NULL;
3117
3118 /* A condition requires code that is not compiled */
3119
3120 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3121     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3122     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3123 COND_FAILED_NOT_COMPILED:
3124 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3125   name);
3126 return NULL;
3127 #endif
3128 }
3129
3130
3131
3132
3133 /*************************************************
3134 *          Save numerical variables              *
3135 *************************************************/
3136
3137 /* This function is called from items such as "if" that want to preserve and
3138 restore the numbered variables.
3139
3140 Arguments:
3141   save_expand_string    points to an array of pointers to set
3142   save_expand_nlength   points to an array of ints for the lengths
3143
3144 Returns:                the value of expand max to save
3145 */
3146
3147 static int
3148 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3149 {
3150 int i;
3151 for (i = 0; i <= expand_nmax; i++)
3152   {
3153   save_expand_nstring[i] = expand_nstring[i];
3154   save_expand_nlength[i] = expand_nlength[i];
3155   }
3156 return expand_nmax;
3157 }
3158
3159
3160
3161 /*************************************************
3162 *           Restore numerical variables          *
3163 *************************************************/
3164
3165 /* This function restored saved values of numerical strings.
3166
3167 Arguments:
3168   save_expand_nmax      the number of strings to restore
3169   save_expand_string    points to an array of pointers
3170   save_expand_nlength   points to an array of ints
3171
3172 Returns:                nothing
3173 */
3174
3175 static void
3176 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3177   int *save_expand_nlength)
3178 {
3179 int i;
3180 expand_nmax = save_expand_nmax;
3181 for (i = 0; i <= expand_nmax; i++)
3182   {
3183   expand_nstring[i] = save_expand_nstring[i];
3184   expand_nlength[i] = save_expand_nlength[i];
3185   }
3186 }
3187
3188
3189
3190
3191
3192 /*************************************************
3193 *            Handle yes/no substrings            *
3194 *************************************************/
3195
3196 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3197 alternative substrings that depend on whether or not the condition was true,
3198 or the lookup or extraction succeeded. The substrings always have to be
3199 expanded, to check their syntax, but "skipping" is set when the result is not
3200 needed - this avoids unnecessary nested lookups.
3201
3202 Arguments:
3203   skipping       TRUE if we were skipping when this item was reached
3204   yes            TRUE if the first string is to be used, else use the second
3205   save_lookup    a value to put back into lookup_value before the 2nd expansion
3206   sptr           points to the input string pointer
3207   yieldptr       points to the output growable-string pointer
3208   type           "lookup", "if", "extract", "run", "env", "listextract" or
3209                  "certextract" for error message
3210   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3211                 the store.
3212
3213 Returns:         0 OK; lookup_value has been reset to save_lookup
3214                  1 expansion failed
3215                  2 expansion failed because of bracketing error
3216 */
3217
3218 static int
3219 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3220   gstring ** yieldptr, uschar *type, BOOL *resetok)
3221 {
3222 int rc = 0;
3223 const uschar *s = *sptr;    /* Local value */
3224 uschar *sub1, *sub2;
3225 const uschar * errwhere;
3226
3227 /* If there are no following strings, we substitute the contents of $value for
3228 lookups and for extractions in the success case. For the ${if item, the string
3229 "true" is substituted. In the fail case, nothing is substituted for all three
3230 items. */
3231
3232 while (isspace(*s)) s++;
3233 if (*s == '}')
3234   {
3235   if (type[0] == 'i')
3236     {
3237     if (yes && !skipping)
3238       *yieldptr = string_catn(*yieldptr, US"true", 4);
3239     }
3240   else
3241     {
3242     if (yes && lookup_value && !skipping)
3243       *yieldptr = string_cat(*yieldptr, lookup_value);
3244     lookup_value = save_lookup;
3245     }
3246   s++;
3247   goto RETURN;
3248   }
3249
3250 /* The first following string must be braced. */
3251
3252 if (*s++ != '{')
3253   {
3254   errwhere = US"'yes' part did not start with '{'";
3255   goto FAILED_CURLY;
3256   }
3257
3258 /* Expand the first substring. Forced failures are noticed only if we actually
3259 want this string. Set skipping in the call in the fail case (this will always
3260 be the case if we were already skipping). */
3261
3262 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3263 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3264 expand_string_forcedfail = FALSE;
3265 if (*s++ != '}')
3266   {
3267   errwhere = US"'yes' part did not end with '}'";
3268   goto FAILED_CURLY;
3269   }
3270
3271 /* If we want the first string, add it to the output */
3272
3273 if (yes)
3274   *yieldptr = string_cat(*yieldptr, sub1);
3275
3276 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3277 $value to what it was at the start of the item, so that it has this value
3278 during the second string expansion. For the call from "if" or "run" to this
3279 function, save_lookup is set to lookup_value, so that this statement does
3280 nothing. */
3281
3282 lookup_value = save_lookup;
3283
3284 /* There now follows either another substring, or "fail", or nothing. This
3285 time, forced failures are noticed only if we want the second string. We must
3286 set skipping in the nested call if we don't want this string, or if we were
3287 already skipping. */
3288
3289 while (isspace(*s)) s++;
3290 if (*s == '{')
3291   {
3292   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3293   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3294   expand_string_forcedfail = FALSE;
3295   if (*s++ != '}')
3296     {
3297     errwhere = US"'no' part did not start with '{'";
3298     goto FAILED_CURLY;
3299     }
3300
3301   /* If we want the second string, add it to the output */
3302
3303   if (!yes)
3304     *yieldptr = string_cat(*yieldptr, sub2);
3305   }
3306
3307 /* If there is no second string, but the word "fail" is present when the use of
3308 the second string is wanted, set a flag indicating it was a forced failure
3309 rather than a syntactic error. Swallow the terminating } in case this is nested
3310 inside another lookup or if or extract. */
3311
3312 else if (*s != '}')
3313   {
3314   uschar name[256];
3315   /* deconst cast ok here as source is s anyway */
3316   s = US read_name(name, sizeof(name), s, US"_");
3317   if (Ustrcmp(name, "fail") == 0)
3318     {
3319     if (!yes && !skipping)
3320       {
3321       while (isspace(*s)) s++;
3322       if (*s++ != '}')
3323         {
3324         errwhere = US"did not close with '}' after forcedfail";
3325         goto FAILED_CURLY;
3326         }
3327       expand_string_message =
3328         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3329       expand_string_forcedfail = TRUE;
3330       goto FAILED;
3331       }
3332     }
3333   else
3334     {
3335     expand_string_message =
3336       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3337     goto FAILED;
3338     }
3339   }
3340
3341 /* All we have to do now is to check on the final closing brace. */
3342
3343 while (isspace(*s)) s++;
3344 if (*s++ != '}')
3345   {
3346   errwhere = US"did not close with '}'";
3347   goto FAILED_CURLY;
3348   }
3349
3350
3351 RETURN:
3352 /* Update the input pointer value before returning */
3353 *sptr = s;
3354 return rc;
3355
3356 FAILED_CURLY:
3357   /* Get here if there is a bracketing failure */
3358   expand_string_message = string_sprintf(
3359     "curly-bracket problem in conditional yes/no parsing: %s\n"
3360     " remaining string is '%s'", errwhere, --s);
3361