src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Charaters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base62",
 203   US"base62d",
 204   US"base64",
 205   US"base64d",
 206   US"domain",
 207   US"escape",
 208   US"eval",
 209   US"eval10",
 210   US"expand",
 211   US"h",
 212   US"hash",
 213   US"hex2b64",
 214   US"hexquote",
 215   US"ipv6denorm",
 216   US"ipv6norm",
 217   US"l",
 218   US"lc",
 219   US"length",
 220   US"listcount",
 221   US"listnamed",
 222   US"mask",
 223   US"md5",
 224   US"nh",
 225   US"nhash",
 226   US"quote",
 227   US"randint",
 228   US"rfc2047",
 229   US"rfc2047d",
 230   US"rxquote",
 231   US"s",
 232   US"sha1",
 233   US"sha256",
 234   US"stat",
 235   US"str2b64",
 236   US"strlen",
 237   US"substr",
 238   US"uc",
 239   US"utf8clean" };
 240
 241 enum {
 242   EOP_ADDRESS =  nelem(op_table_underscore),
 243   EOP_ADDRESSES,
 244   EOP_BASE62,
 245   EOP_BASE62D,
 246   EOP_BASE64,
 247   EOP_BASE64D,
 248   EOP_DOMAIN,
 249   EOP_ESCAPE,
 250   EOP_EVAL,
 251   EOP_EVAL10,
 252   EOP_EXPAND,
 253   EOP_H,
 254   EOP_HASH,
 255   EOP_HEX2B64,
 256   EOP_HEXQUOTE,
 257   EOP_IPV6DENORM,
 258   EOP_IPV6NORM,
 259   EOP_L,
 260   EOP_LC,
 261   EOP_LENGTH,
 262   EOP_LISTCOUNT,
 263   EOP_LISTNAMED,
 264   EOP_MASK,
 265   EOP_MD5,
 266   EOP_NH,
 267   EOP_NHASH,
 268   EOP_QUOTE,
 269   EOP_RANDINT,
 270   EOP_RFC2047,
 271   EOP_RFC2047D,
 272   EOP_RXQUOTE,
 273   EOP_S,
 274   EOP_SHA1,
 275   EOP_SHA256,
 276   EOP_STAT,
 277   EOP_STR2B64,
 278   EOP_STRLEN,
 279   EOP_SUBSTR,
 280   EOP_UC,
 281   EOP_UTF8CLEAN };
 282
 283
 284 /* Table of condition names, and corresponding switch numbers. The names must
 285 be in alphabetical order. */
 286
 287 static uschar *cond_table[] = {
 288   US"<",
 289   US"<=",
 290   US"=",
 291   US"==",     /* Backward compatibility */
 292   US">",
 293   US">=",
 294   US"acl",
 295   US"and",
 296   US"bool",
 297   US"bool_lax",
 298   US"crypteq",
 299   US"def",
 300   US"eq",
 301   US"eqi",
 302   US"exists",
 303   US"first_delivery",
 304   US"forall",
 305   US"forany",
 306   US"ge",
 307   US"gei",
 308   US"gt",
 309   US"gti",
 310   US"inlist",
 311   US"inlisti",
 312   US"isip",
 313   US"isip4",
 314   US"isip6",
 315   US"ldapauth",
 316   US"le",
 317   US"lei",
 318   US"lt",
 319   US"lti",
 320   US"match",
 321   US"match_address",
 322   US"match_domain",
 323   US"match_ip",
 324   US"match_local_part",
 325   US"or",
 326   US"pam",
 327   US"pwcheck",
 328   US"queue_running",
 329   US"radius",
 330   US"saslauthd"
 331 };
 332
 333 enum {
 334   ECOND_NUM_L,
 335   ECOND_NUM_LE,
 336   ECOND_NUM_E,
 337   ECOND_NUM_EE,
 338   ECOND_NUM_G,
 339   ECOND_NUM_GE,
 340   ECOND_ACL,
 341   ECOND_AND,
 342   ECOND_BOOL,
 343   ECOND_BOOL_LAX,
 344   ECOND_CRYPTEQ,
 345   ECOND_DEF,
 346   ECOND_STR_EQ,
 347   ECOND_STR_EQI,
 348   ECOND_EXISTS,
 349   ECOND_FIRST_DELIVERY,
 350   ECOND_FORALL,
 351   ECOND_FORANY,
 352   ECOND_STR_GE,
 353   ECOND_STR_GEI,
 354   ECOND_STR_GT,
 355   ECOND_STR_GTI,
 356   ECOND_INLIST,
 357   ECOND_INLISTI,
 358   ECOND_ISIP,
 359   ECOND_ISIP4,
 360   ECOND_ISIP6,
 361   ECOND_LDAPAUTH,
 362   ECOND_STR_LE,
 363   ECOND_STR_LEI,
 364   ECOND_STR_LT,
 365   ECOND_STR_LTI,
 366   ECOND_MATCH,
 367   ECOND_MATCH_ADDRESS,
 368   ECOND_MATCH_DOMAIN,
 369   ECOND_MATCH_IP,
 370   ECOND_MATCH_LOCAL_PART,
 371   ECOND_OR,
 372   ECOND_PAM,
 373   ECOND_PWCHECK,
 374   ECOND_QUEUE_RUNNING,
 375   ECOND_RADIUS,
 376   ECOND_SASLAUTHD
 377 };
 378
 379
 380 /* Types of table entry */
 381
 382 enum vtypes {
 383   vtype_int,            /* value is address of int */
 384   vtype_filter_int,     /* ditto, but recognized only when filtering */
 385   vtype_ino,            /* value is address of ino_t (not always an int) */
 386   vtype_uid,            /* value is address of uid_t (not always an int) */
 387   vtype_gid,            /* value is address of gid_t (not always an int) */
 388   vtype_bool,           /* value is address of bool */
 389   vtype_stringptr,      /* value is address of pointer to string */
 390   vtype_msgbody,        /* as stringptr, but read when first required */
 391   vtype_msgbody_end,    /* ditto, the end of the message */
 392   vtype_msgheaders,     /* the message's headers, processed */
 393   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 394   vtype_localpart,      /* extract local part from string */
 395   vtype_domain,         /* extract domain from string */
 396   vtype_string_func,    /* value is string returned by given function */
 397   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 398   vtype_tode,           /* value not used; generate tod in epoch format */
 399   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 400   vtype_todf,           /* value not used; generate full tod */
 401   vtype_todl,           /* value not used; generate log tod */
 402   vtype_todlf,          /* value not used; generate log file datestamp tod */
 403   vtype_todzone,        /* value not used; generate time zone only */
 404   vtype_todzulu,        /* value not used; generate zulu tod */
 405   vtype_reply,          /* value not used; get reply from headers */
 406   vtype_pid,            /* value not used; result is pid */
 407   vtype_host_lookup,    /* value not used; get host name */
 408   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 409   vtype_pspace,         /* partition space; value is T/F for spool/log */
 410   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 411   vtype_cert            /* SSL certificate */
 412   #ifndef DISABLE_DKIM
 413   ,vtype_dkim           /* Lookup of value in DKIM signature */
 414   #endif
 415 };
 416
 417 /* Type for main variable table */
 418
 419 typedef struct {
 420   const char *name;
 421   enum vtypes type;
 422   void       *value;
 423 } var_entry;
 424
 425 /* Type for entries pointing to address/length pairs. Not currently
 426 in use. */
 427
 428 typedef struct {
 429   uschar **address;
 430   int  *length;
 431 } alblock;
 432
 433 static uschar * fn_recipients(void);
 434
 435 /* This table must be kept in alphabetical order. */
 436
 437 static var_entry var_table[] = {
 438   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 439      they will be confused with user-creatable ACL variables. */
 440   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 441   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 442   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 443   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 444   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 445   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 446   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 447   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 448   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 449   { "acl_narg",            vtype_int,         &acl_narg },
 450   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 451   { "address_data",        vtype_stringptr,   &deliver_address_data },
 452   { "address_file",        vtype_stringptr,   &address_file },
 453   { "address_pipe",        vtype_stringptr,   &address_pipe },
 454   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 455   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 456   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 457   { "authentication_failed",vtype_int,        &authentication_failed },
 458 #ifdef WITH_CONTENT_SCAN
 459   { "av_failed",           vtype_int,         &av_failed },
 460 #endif
 461 #ifdef EXPERIMENTAL_BRIGHTMAIL
 462   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 463   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 464   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 465   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 466 #endif
 467   { "body_linecount",      vtype_int,         &body_linecount },
 468   { "body_zerocount",      vtype_int,         &body_zerocount },
 469   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 470   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 471   { "caller_gid",          vtype_gid,         &real_gid },
 472   { "caller_uid",          vtype_uid,         &real_uid },
 473   { "callout_address",     vtype_stringptr,   &callout_address },
 474   { "compile_date",        vtype_stringptr,   &version_date },
 475   { "compile_number",      vtype_stringptr,   &version_cnumber },
 476   { "config_dir",          vtype_stringptr,   &config_main_directory },
 477   { "config_file",         vtype_stringptr,   &config_main_filename },
 478   { "csa_status",          vtype_stringptr,   &csa_status },
 479 #ifdef EXPERIMENTAL_DCC
 480   { "dcc_header",          vtype_stringptr,   &dcc_header },
 481   { "dcc_result",          vtype_stringptr,   &dcc_result },
 482 #endif
 483 #ifdef WITH_OLD_DEMIME
 484   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 485   { "demime_reason",       vtype_stringptr,   &demime_reason },
 486 #endif
 487 #ifndef DISABLE_DKIM
 488   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 489   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 490   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 491   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 492   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 493   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 494   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 495   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 496   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 497   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 498   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 499   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 500   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 501   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 502   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 503   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 504   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 505   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 506   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 507   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 508   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 509 #endif
 510 #ifdef EXPERIMENTAL_DMARC
 511   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 512   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 513   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 514   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 515   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 516 #endif
 517   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 518   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 519   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 520   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 521   { "domain",              vtype_stringptr,   &deliver_domain },
 522   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 523 #ifndef DISABLE_EVENT
 524   { "event_data",          vtype_stringptr,   &event_data },
 525
 526   /*XXX want to use generic vars for as many of these as possible*/
 527   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 528
 529   { "event_name",          vtype_stringptr,   &event_name },
 530 #endif
 531   { "exim_gid",            vtype_gid,         &exim_gid },
 532   { "exim_path",           vtype_stringptr,   &exim_path },
 533   { "exim_uid",            vtype_uid,         &exim_uid },
 534   { "exim_version",        vtype_stringptr,   &version_string },
 535 #ifdef WITH_OLD_DEMIME
 536   { "found_extension",     vtype_stringptr,   &found_extension },
 537 #endif
 538   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 539   { "home",                vtype_stringptr,   &deliver_home },
 540   { "host",                vtype_stringptr,   &deliver_host },
 541   { "host_address",        vtype_stringptr,   &deliver_host_address },
 542   { "host_data",           vtype_stringptr,   &host_data },
 543   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 544   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 545   { "host_port",           vtype_int,         &deliver_host_port },
 546   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 547   { "inode",               vtype_ino,         &deliver_inode },
 548   { "interface_address",   vtype_stringptr,   &interface_address },
 549   { "interface_port",      vtype_int,         &interface_port },
 550   { "item",                vtype_stringptr,   &iterate_item },
 551   #ifdef LOOKUP_LDAP
 552   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 553   #endif
 554   { "load_average",        vtype_load_avg,    NULL },
 555   { "local_part",          vtype_stringptr,   &deliver_localpart },
 556   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 557   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 558   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 559   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 560   { "local_user_gid",      vtype_gid,         &local_user_gid },
 561   { "local_user_uid",      vtype_uid,         &local_user_uid },
 562   { "localhost_number",    vtype_int,         &host_number },
 563   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 564   { "log_space",           vtype_pspace,      (void *)FALSE },
 565   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 566   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 567 #ifdef WITH_CONTENT_SCAN
 568   { "malware_name",        vtype_stringptr,   &malware_name },
 569 #endif
 570   { "max_received_linelength", vtype_int,     &max_received_linelength },
 571   { "message_age",         vtype_int,         &message_age },
 572   { "message_body",        vtype_msgbody,     &message_body },
 573   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 574   { "message_body_size",   vtype_int,         &message_body_size },
 575   { "message_exim_id",     vtype_stringptr,   &message_id },
 576   { "message_headers",     vtype_msgheaders,  NULL },
 577   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 578   { "message_id",          vtype_stringptr,   &message_id },
 579   { "message_linecount",   vtype_int,         &message_linecount },
 580   { "message_size",        vtype_int,         &message_size },
 581 #ifdef SUPPORT_I18N
 582   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 583 #endif
 584 #ifdef WITH_CONTENT_SCAN
 585   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 586   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 587   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 588   { "mime_charset",        vtype_stringptr,   &mime_charset },
 589   { "mime_content_description", vtype_stringptr, &mime_content_description },
 590   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 591   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 592   { "mime_content_size",   vtype_int,         &mime_content_size },
 593   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 594   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 595   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 596   { "mime_filename",       vtype_stringptr,   &mime_filename },
 597   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 598   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 599   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 600   { "mime_part_count",     vtype_int,         &mime_part_count },
 601 #endif
 602   { "n0",                  vtype_filter_int,  &filter_n[0] },
 603   { "n1",                  vtype_filter_int,  &filter_n[1] },
 604   { "n2",                  vtype_filter_int,  &filter_n[2] },
 605   { "n3",                  vtype_filter_int,  &filter_n[3] },
 606   { "n4",                  vtype_filter_int,  &filter_n[4] },
 607   { "n5",                  vtype_filter_int,  &filter_n[5] },
 608   { "n6",                  vtype_filter_int,  &filter_n[6] },
 609   { "n7",                  vtype_filter_int,  &filter_n[7] },
 610   { "n8",                  vtype_filter_int,  &filter_n[8] },
 611   { "n9",                  vtype_filter_int,  &filter_n[9] },
 612   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 613   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 614   { "originator_gid",      vtype_gid,         &originator_gid },
 615   { "originator_uid",      vtype_uid,         &originator_uid },
 616   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 617   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 618   { "pid",                 vtype_pid,         NULL },
 619 #ifndef DISABLE_PRDR
 620   { "prdr_requested",      vtype_bool,        &prdr_requested },
 621 #endif
 622   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 623 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 624   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 625   { "proxy_external_port", vtype_int,         &proxy_external_port },
 626   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 627   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 628   { "proxy_session",       vtype_bool,        &proxy_session },
 629 #endif
 630   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 631   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 632   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 633   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 634   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 635   { "rcpt_count",          vtype_int,         &rcpt_count },
 636   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 637   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 638   { "received_count",      vtype_int,         &received_count },
 639   { "received_for",        vtype_stringptr,   &received_for },
 640   { "received_ip_address", vtype_stringptr,   &interface_address },
 641   { "received_port",       vtype_int,         &interface_port },
 642   { "received_protocol",   vtype_stringptr,   &received_protocol },
 643   { "received_time",       vtype_int,         &received_time },
 644   { "recipient_data",      vtype_stringptr,   &recipient_data },
 645   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 646   { "recipients",          vtype_string_func, &fn_recipients },
 647   { "recipients_count",    vtype_int,         &recipients_count },
 648 #ifdef WITH_CONTENT_SCAN
 649   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 650 #endif
 651   { "reply_address",       vtype_reply,       NULL },
 652   { "return_path",         vtype_stringptr,   &return_path },
 653   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 654   { "router_name",         vtype_stringptr,   &router_name },
 655   { "runrc",               vtype_int,         &runrc },
 656   { "self_hostname",       vtype_stringptr,   &self_hostname },
 657   { "sender_address",      vtype_stringptr,   &sender_address },
 658   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 659   { "sender_address_domain", vtype_domain,    &sender_address },
 660   { "sender_address_local_part", vtype_localpart, &sender_address },
 661   { "sender_data",         vtype_stringptr,   &sender_data },
 662   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 663   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 664   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 665   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 666   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 667   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 668   { "sender_host_name",    vtype_host_lookup, NULL },
 669   { "sender_host_port",    vtype_int,         &sender_host_port },
 670   { "sender_ident",        vtype_stringptr,   &sender_ident },
 671   { "sender_rate",         vtype_stringptr,   &sender_rate },
 672   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 673   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 674   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 675   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 676   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 677   { "sending_port",        vtype_int,         &sending_port },
 678   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 679   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 680   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 681   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 682   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 683   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 684   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 685   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 686   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 687   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 688   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 689   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 690   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 691   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 692   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 693 #ifdef WITH_CONTENT_SCAN
 694   { "spam_action",         vtype_stringptr,   &spam_action },
 695   { "spam_bar",            vtype_stringptr,   &spam_bar },
 696   { "spam_report",         vtype_stringptr,   &spam_report },
 697   { "spam_score",          vtype_stringptr,   &spam_score },
 698   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 699 #endif
 700 #ifdef EXPERIMENTAL_SPF
 701   { "spf_guess",           vtype_stringptr,   &spf_guess },
 702   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 703   { "spf_received",        vtype_stringptr,   &spf_received },
 704   { "spf_result",          vtype_stringptr,   &spf_result },
 705   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 706 #endif
 707   { "spool_directory",     vtype_stringptr,   &spool_directory },
 708   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 709   { "spool_space",         vtype_pspace,      (void *)TRUE },
 710 #ifdef EXPERIMENTAL_SRS
 711   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 712   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 713   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 714   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 715   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 716   { "srs_status",          vtype_stringptr,   &srs_status },
 717 #endif
 718   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 719
 720   /* The non-(in,out) variables are now deprecated */
 721   { "tls_bits",            vtype_int,         &tls_in.bits },
 722   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 723   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 724
 725   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 726   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 727   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 728   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 729   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 730   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 731   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 732 #if defined(SUPPORT_TLS)
 733   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 734 #endif
 735   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 736   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 737   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 738 #ifdef EXPERIMENTAL_DANE
 739   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 740 #endif
 741   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 742   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 743   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 744   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 745 #if defined(SUPPORT_TLS)
 746   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 747 #endif
 748 #ifdef EXPERIMENTAL_DANE
 749   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 750 #endif
 751
 752   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 753 #if defined(SUPPORT_TLS)
 754   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 755 #endif
 756
 757   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 758   { "tod_epoch",           vtype_tode,        NULL },
 759   { "tod_epoch_l",         vtype_todel,       NULL },
 760   { "tod_full",            vtype_todf,        NULL },
 761   { "tod_log",             vtype_todl,        NULL },
 762   { "tod_logfile",         vtype_todlf,       NULL },
 763   { "tod_zone",            vtype_todzone,     NULL },
 764   { "tod_zulu",            vtype_todzulu,     NULL },
 765   { "transport_name",      vtype_stringptr,   &transport_name },
 766   { "value",               vtype_stringptr,   &lookup_value },
 767   { "verify_mode",         vtype_stringptr,   &verify_mode },
 768   { "version_number",      vtype_stringptr,   &version_string },
 769   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 770   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 771   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 772   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 773   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 774   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 775 };
 776
 777 static int var_table_size = nelem(var_table);
 778 static uschar var_buffer[256];
 779 static BOOL malformed_header;
 780
 781 /* For textual hashes */
 782
 783 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 784                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 785                                "0123456789";
 786
 787 enum { HMAC_MD5, HMAC_SHA1 };
 788
 789 /* For numeric hashes */
 790
 791 static unsigned int prime[] = {
 792   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 793  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 794  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 795
 796 /* For printing modes in symbolic form */
 797
 798 static uschar *mtable_normal[] =
 799   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 800
 801 static uschar *mtable_setid[] =
 802   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 803
 804 static uschar *mtable_sticky[] =
 805   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 806
 807
 808
 809 /*************************************************
 810 *           Tables for UTF-8 support             *
 811 *************************************************/
 812
 813 /* Table of the number of extra characters, indexed by the first character
 814 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 815 0x3d. */
 816
 817 static uschar utf8_table1[] = {
 818   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 819   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 820   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 821   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 822
 823 /* These are the masks for the data bits in the first byte of a character,
 824 indexed by the number of additional bytes. */
 825
 826 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 827
 828 /* Get the next UTF-8 character, advancing the pointer. */
 829
 830 #define GETUTF8INC(c, ptr) \
 831   c = *ptr++; \
 832   if ((c & 0xc0) == 0xc0) \
 833     { \
 834     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 835     int s = 6*a; \
 836     c = (c & utf8_table2[a]) << s; \
 837     while (a-- > 0) \
 838       { \
 839       s -= 6; \
 840       c |= (*ptr++ & 0x3f) << s; \
 841       } \
 842     }
 843
 844
 845 /*************************************************
 846 *           Binary chop search on a table        *
 847 *************************************************/
 848
 849 /* This is used for matching expansion items and operators.
 850
 851 Arguments:
 852   name        the name that is being sought
 853   table       the table to search
 854   table_size  the number of items in the table
 855
 856 Returns:      the offset in the table, or -1
 857 */
 858
 859 static int
 860 chop_match(uschar *name, uschar **table, int table_size)
 861 {
 862 uschar **bot = table;
 863 uschar **top = table + table_size;
 864
 865 while (top > bot)
 866   {
 867   uschar **mid = bot + (top - bot)/2;
 868   int c = Ustrcmp(name, *mid);
 869   if (c == 0) return mid - table;
 870   if (c > 0) bot = mid + 1; else top = mid;
 871   }
 872
 873 return -1;
 874 }
 875
 876
 877
 878 /*************************************************
 879 *          Check a condition string              *
 880 *************************************************/
 881
 882 /* This function is called to expand a string, and test the result for a "true"
 883 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 884 forced fail or lookup defer.
 885
 886 We used to release all store used, but this is not not safe due
 887 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 888 is reasonably careful to release what it can.
 889
 890 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 891
 892 Arguments:
 893   condition     the condition string
 894   m1            text to be incorporated in panic error
 895   m2            ditto
 896
 897 Returns:        TRUE if condition is met, FALSE if not
 898 */
 899
 900 BOOL
 901 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 902 {
 903 int rc;
 904 uschar *ss = expand_string(condition);
 905 if (ss == NULL)
 906   {
 907   if (!expand_string_forcedfail && !search_find_defer)
 908     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 909       "for %s %s: %s", condition, m1, m2, expand_string_message);
 910   return FALSE;
 911   }
 912 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 913   strcmpic(ss, US"false") != 0;
 914 return rc;
 915 }
 916
 917
 918
 919
 920 /*************************************************
 921 *        Pseudo-random number generation         *
 922 *************************************************/
 923
 924 /* Pseudo-random number generation.  The result is not "expected" to be
 925 cryptographically strong but not so weak that someone will shoot themselves
 926 in the foot using it as a nonce in some email header scheme or whatever
 927 weirdness they'll twist this into.  The result should ideally handle fork().
 928
 929 However, if we're stuck unable to provide this, then we'll fall back to
 930 appallingly bad randomness.
 931
 932 If SUPPORT_TLS is defined then this will not be used except as an emergency
 933 fallback.
 934
 935 Arguments:
 936   max       range maximum
 937 Returns     a random number in range [0, max-1]
 938 */
 939
 940 #ifdef SUPPORT_TLS
 941 # define vaguely_random_number vaguely_random_number_fallback
 942 #endif
 943 int
 944 vaguely_random_number(int max)
 945 {
 946 #ifdef SUPPORT_TLS
 947 # undef vaguely_random_number
 948 #endif
 949   static pid_t pid = 0;
 950   pid_t p2;
 951 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 952   struct timeval tv;
 953 #endif
 954
 955   p2 = getpid();
 956   if (p2 != pid)
 957     {
 958     if (pid != 0)
 959       {
 960
 961 #ifdef HAVE_ARC4RANDOM
 962       /* cryptographically strong randomness, common on *BSD platforms, not
 963       so much elsewhere.  Alas. */
 964 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 965       arc4random_stir();
 966 #endif
 967 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 968 #ifdef HAVE_SRANDOMDEV
 969       /* uses random(4) for seeding */
 970       srandomdev();
 971 #else
 972       gettimeofday(&tv, NULL);
 973       srandom(tv.tv_sec | tv.tv_usec | getpid());
 974 #endif
 975 #else
 976       /* Poor randomness and no seeding here */
 977 #endif
 978
 979       }
 980     pid = p2;
 981     }
 982
 983 #ifdef HAVE_ARC4RANDOM
 984   return arc4random() % max;
 985 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 986   return random() % max;
 987 #else
 988   /* This one returns a 16-bit number, definitely not crypto-strong */
 989   return random_number(max);
 990 #endif
 991 }
 992
 993
 994
 995
 996 /*************************************************
 997 *             Pick out a name from a string      *
 998 *************************************************/
 999
1000 /* If the name is too long, it is silently truncated.
1001
1002 Arguments:
1003   name      points to a buffer into which to put the name
1004   max       is the length of the buffer
1005   s         points to the first alphabetic character of the name
1006   extras    chars other than alphanumerics to permit
1007
1008 Returns:    pointer to the first character after the name
1009
1010 Note: The test for *s != 0 in the while loop is necessary because
1011 Ustrchr() yields non-NULL if the character is zero (which is not something
1012 I expected). */
1013
1014 static const uschar *
1015 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1016 {
1017 int ptr = 0;
1018 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1019   {
1020   if (ptr < max-1) name[ptr++] = *s;
1021   s++;
1022   }
1023 name[ptr] = 0;
1024 return s;
1025 }
1026
1027
1028
1029 /*************************************************
1030 *     Pick out the rest of a header name         *
1031 *************************************************/
1032
1033 /* A variable name starting $header_ (or just $h_ for those who like
1034 abbreviations) might not be the complete header name because headers can
1035 contain any printing characters in their names, except ':'. This function is
1036 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1037 on the end, if the name was terminated by white space.
1038
1039 Arguments:
1040   name      points to a buffer in which the name read so far exists
1041   max       is the length of the buffer
1042   s         points to the first character after the name so far, i.e. the
1043             first non-alphameric character after $header_xxxxx
1044
1045 Returns:    a pointer to the first character after the header name
1046 */
1047
1048 static const uschar *
1049 read_header_name(uschar *name, int max, const uschar *s)
1050 {
1051 int prelen = Ustrchr(name, '_') - name + 1;
1052 int ptr = Ustrlen(name) - prelen;
1053 if (ptr > 0) memmove(name, name+prelen, ptr);
1054 while (mac_isgraph(*s) && *s != ':')
1055   {
1056   if (ptr < max-1) name[ptr++] = *s;
1057   s++;
1058   }
1059 if (*s == ':') s++;
1060 name[ptr++] = ':';
1061 name[ptr] = 0;
1062 return s;
1063 }
1064
1065
1066
1067 /*************************************************
1068 *           Pick out a number from a string      *
1069 *************************************************/
1070
1071 /* Arguments:
1072   n     points to an integer into which to put the number
1073   s     points to the first digit of the number
1074
1075 Returns:  a pointer to the character after the last digit
1076 */
1077 /*XXX consider expanding to int_eximarith_t.  But the test for
1078 "overbig numbers" in 0002 still needs to overflow it. */
1079
1080 static uschar *
1081 read_number(int *n, uschar *s)
1082 {
1083 *n = 0;
1084 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1085 return s;
1086 }
1087
1088 static const uschar *
1089 read_cnumber(int *n, const uschar *s)
1090 {
1091 *n = 0;
1092 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1093 return s;
1094 }
1095
1096
1097
1098 /*************************************************
1099 *        Extract keyed subfield from a string    *
1100 *************************************************/
1101
1102 /* The yield is in dynamic store; NULL means that the key was not found.
1103
1104 Arguments:
1105   key       points to the name of the key
1106   s         points to the string from which to extract the subfield
1107
1108 Returns:    NULL if the subfield was not found, or
1109             a pointer to the subfield's data
1110 */
1111
1112 static uschar *
1113 expand_getkeyed(uschar *key, const uschar *s)
1114 {
1115 int length = Ustrlen(key);
1116 while (isspace(*s)) s++;
1117
1118 /* Loop to search for the key */
1119
1120 while (*s != 0)
1121   {
1122   int dkeylength;
1123   uschar *data;
1124   const uschar *dkey = s;
1125
1126   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1127   dkeylength = s - dkey;
1128   while (isspace(*s)) s++;
1129   if (*s == '=') while (isspace((*(++s))));
1130
1131   data = string_dequote(&s);
1132   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1133     return data;
1134
1135   while (isspace(*s)) s++;
1136   }
1137
1138 return NULL;
1139 }
1140
1141
1142
1143 static var_entry *
1144 find_var_ent(uschar * name)
1145 {
1146 int first = 0;
1147 int last = var_table_size;
1148
1149 while (last > first)
1150   {
1151   int middle = (first + last)/2;
1152   int c = Ustrcmp(name, var_table[middle].name);
1153
1154   if (c > 0) { first = middle + 1; continue; }
1155   if (c < 0) { last = middle; continue; }
1156   return &var_table[middle];
1157   }
1158 return NULL;
1159 }
1160
1161 /*************************************************
1162 *   Extract numbered subfield from string        *
1163 *************************************************/
1164
1165 /* Extracts a numbered field from a string that is divided by tokens - for
1166 example a line from /etc/passwd is divided by colon characters.  First field is
1167 numbered one.  Negative arguments count from the right. Zero returns the whole
1168 string. Returns NULL if there are insufficient tokens in the string
1169
1170 ***WARNING***
1171 Modifies final argument - this is a dynamically generated string, so that's OK.
1172
1173 Arguments:
1174   field       number of field to be extracted,
1175                 first field = 1, whole string = 0, last field = -1
1176   separators  characters that are used to break string into tokens
1177   s           points to the string from which to extract the subfield
1178
1179 Returns:      NULL if the field was not found,
1180               a pointer to the field's data inside s (modified to add 0)
1181 */
1182
1183 static uschar *
1184 expand_gettokened (int field, uschar *separators, uschar *s)
1185 {
1186 int sep = 1;
1187 int count;
1188 uschar *ss = s;
1189 uschar *fieldtext = NULL;
1190
1191 if (field == 0) return s;
1192
1193 /* Break the line up into fields in place; for field > 0 we stop when we have
1194 done the number of fields we want. For field < 0 we continue till the end of
1195 the string, counting the number of fields. */
1196
1197 count = (field > 0)? field : INT_MAX;
1198
1199 while (count-- > 0)
1200   {
1201   size_t len;
1202
1203   /* Previous field was the last one in the string. For a positive field
1204   number, this means there are not enough fields. For a negative field number,
1205   check that there are enough, and scan back to find the one that is wanted. */
1206
1207   if (sep == 0)
1208     {
1209     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1210     if ((-field) == (INT_MAX - count - 1)) return s;
1211     while (field++ < 0)
1212       {
1213       ss--;
1214       while (ss[-1] != 0) ss--;
1215       }
1216     fieldtext = ss;
1217     break;
1218     }
1219
1220   /* Previous field was not last in the string; save its start and put a
1221   zero at its end. */
1222
1223   fieldtext = ss;
1224   len = Ustrcspn(ss, separators);
1225   sep = ss[len];
1226   ss[len] = 0;
1227   ss += len + 1;
1228   }
1229
1230 return fieldtext;
1231 }
1232
1233
1234 static uschar *
1235 expand_getlistele(int field, const uschar * list)
1236 {
1237 const uschar * tlist= list;
1238 int sep= 0;
1239 uschar dummy;
1240
1241 if(field<0)
1242   {
1243   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1244   sep= 0;
1245   }
1246 if(field==0) return NULL;
1247 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1248 return string_nextinlist(&list, &sep, NULL, 0);
1249 }
1250
1251
1252 /* Certificate fields, by name.  Worry about by-OID later */
1253 /* Names are chosen to not have common prefixes */
1254
1255 #ifdef SUPPORT_TLS
1256 typedef struct
1257 {
1258 uschar * name;
1259 int      namelen;
1260 uschar * (*getfn)(void * cert, uschar * mod);
1261 } certfield;
1262 static certfield certfields[] =
1263 {                       /* linear search; no special order */
1264   { US"version",         7,  &tls_cert_version },
1265   { US"serial_number",   13, &tls_cert_serial_number },
1266   { US"subject",         7,  &tls_cert_subject },
1267   { US"notbefore",       9,  &tls_cert_not_before },
1268   { US"notafter",        8,  &tls_cert_not_after },
1269   { US"issuer",          6,  &tls_cert_issuer },
1270   { US"signature",       9,  &tls_cert_signature },
1271   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1272   { US"subj_altname",    12, &tls_cert_subject_altname },
1273   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1274   { US"crl_uri",         7,  &tls_cert_crl_uri },
1275 };
1276
1277 static uschar *
1278 expand_getcertele(uschar * field, uschar * certvar)
1279 {
1280 var_entry * vp;
1281 certfield * cp;
1282
1283 if (!(vp = find_var_ent(certvar)))
1284   {
1285   expand_string_message =
1286     string_sprintf("no variable named \"%s\"", certvar);
1287   return NULL;          /* Unknown variable name */
1288   }
1289 /* NB this stops us passing certs around in variable.  Might
1290 want to do that in future */
1291 if (vp->type != vtype_cert)
1292   {
1293   expand_string_message =
1294     string_sprintf("\"%s\" is not a certificate", certvar);
1295   return NULL;          /* Unknown variable name */
1296   }
1297 if (!*(void **)vp->value)
1298   return NULL;
1299
1300 if (*field >= '0' && *field <= '9')
1301   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1302
1303 for(cp = certfields;
1304     cp < certfields + nelem(certfields);
1305     cp++)
1306   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1307     {
1308     uschar * modifier = *(field += cp->namelen) == ','
1309       ? ++field : NULL;
1310     return (*cp->getfn)( *(void **)vp->value, modifier );
1311     }
1312
1313 expand_string_message =
1314   string_sprintf("bad field selector \"%s\" for certextract", field);
1315 return NULL;
1316 }
1317 #endif  /*SUPPORT_TLS*/
1318
1319 /*************************************************
1320 *        Extract a substring from a string       *
1321 *************************************************/
1322
1323 /* Perform the ${substr or ${length expansion operations.
1324
1325 Arguments:
1326   subject     the input string
1327   value1      the offset from the start of the input string to the start of
1328                 the output string; if negative, count from the right.
1329   value2      the length of the output string, or negative (-1) for unset
1330                 if value1 is positive, unset means "all after"
1331                 if value1 is negative, unset means "all before"
1332   len         set to the length of the returned string
1333
1334 Returns:      pointer to the output string, or NULL if there is an error
1335 */
1336
1337 static uschar *
1338 extract_substr(uschar *subject, int value1, int value2, int *len)
1339 {
1340 int sublen = Ustrlen(subject);
1341
1342 if (value1 < 0)    /* count from right */
1343   {
1344   value1 += sublen;
1345
1346   /* If the position is before the start, skip to the start, and adjust the
1347   length. If the length ends up negative, the substring is null because nothing
1348   can precede. This falls out naturally when the length is unset, meaning "all
1349   to the left". */
1350
1351   if (value1 < 0)
1352     {
1353     value2 += value1;
1354     if (value2 < 0) value2 = 0;
1355     value1 = 0;
1356     }
1357
1358   /* Otherwise an unset length => characters before value1 */
1359
1360   else if (value2 < 0)
1361     {
1362     value2 = value1;
1363     value1 = 0;
1364     }
1365   }
1366
1367 /* For a non-negative offset, if the starting position is past the end of the
1368 string, the result will be the null string. Otherwise, an unset length means
1369 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1370
1371 else
1372   {
1373   if (value1 > sublen)
1374     {
1375     value1 = sublen;
1376     value2 = 0;
1377     }
1378   else if (value2 < 0) value2 = sublen;
1379   }
1380
1381 /* Cut the length down to the maximum possible for the offset value, and get
1382 the required characters. */
1383
1384 if (value1 + value2 > sublen) value2 = sublen - value1;
1385 *len = value2;
1386 return subject + value1;
1387 }
1388
1389
1390
1391
1392 /*************************************************
1393 *            Old-style hash of a string          *
1394 *************************************************/
1395
1396 /* Perform the ${hash expansion operation.
1397
1398 Arguments:
1399   subject     the input string (an expanded substring)
1400   value1      the length of the output string; if greater or equal to the
1401                 length of the input string, the input string is returned
1402   value2      the number of hash characters to use, or 26 if negative
1403   len         set to the length of the returned string
1404
1405 Returns:      pointer to the output string, or NULL if there is an error
1406 */
1407
1408 static uschar *
1409 compute_hash(uschar *subject, int value1, int value2, int *len)
1410 {
1411 int sublen = Ustrlen(subject);
1412
1413 if (value2 < 0) value2 = 26;
1414 else if (value2 > Ustrlen(hashcodes))
1415   {
1416   expand_string_message =
1417     string_sprintf("hash count \"%d\" too big", value2);
1418   return NULL;
1419   }
1420
1421 /* Calculate the hash text. We know it is shorter than the original string, so
1422 can safely place it in subject[] (we know that subject is always itself an
1423 expanded substring). */
1424
1425 if (value1 < sublen)
1426   {
1427   int c;
1428   int i = 0;
1429   int j = value1;
1430   while ((c = (subject[j])) != 0)
1431     {
1432     int shift = (c + j++) & 7;
1433     subject[i] ^= (c << shift) | (c >> (8-shift));
1434     if (++i >= value1) i = 0;
1435     }
1436   for (i = 0; i < value1; i++)
1437     subject[i] = hashcodes[(subject[i]) % value2];
1438   }
1439 else value1 = sublen;
1440
1441 *len = value1;
1442 return subject;
1443 }
1444
1445
1446
1447
1448 /*************************************************
1449 *             Numeric hash of a string           *
1450 *************************************************/
1451
1452 /* Perform the ${nhash expansion operation. The first characters of the
1453 string are treated as most important, and get the highest prime numbers.
1454
1455 Arguments:
1456   subject     the input string
1457   value1      the maximum value of the first part of the result
1458   value2      the maximum value of the second part of the result,
1459                 or negative to produce only a one-part result
1460   len         set to the length of the returned string
1461
1462 Returns:  pointer to the output string, or NULL if there is an error.
1463 */
1464
1465 static uschar *
1466 compute_nhash (uschar *subject, int value1, int value2, int *len)
1467 {
1468 uschar *s = subject;
1469 int i = 0;
1470 unsigned long int total = 0; /* no overflow */
1471
1472 while (*s != 0)
1473   {
1474   if (i == 0) i = nelem(prime) - 1;
1475   total += prime[i--] * (unsigned int)(*s++);
1476   }
1477
1478 /* If value2 is unset, just compute one number */
1479
1480 if (value2 < 0)
1481   {
1482   s = string_sprintf("%d", total % value1);
1483   }
1484
1485 /* Otherwise do a div/mod hash */
1486
1487 else
1488   {
1489   total = total % (value1 * value2);
1490   s = string_sprintf("%d/%d", total/value2, total % value2);
1491   }
1492
1493 *len = Ustrlen(s);
1494 return s;
1495 }
1496
1497
1498
1499
1500
1501 /*************************************************
1502 *     Find the value of a header or headers      *
1503 *************************************************/
1504
1505 /* Multiple instances of the same header get concatenated, and this function
1506 can also return a concatenation of all the header lines. When concatenating
1507 specific headers that contain lists of addresses, a comma is inserted between
1508 them. Otherwise we use a straight concatenation. Because some messages can have
1509 pathologically large number of lines, there is a limit on the length that is
1510 returned. Also, to avoid massive store use which would result from using
1511 string_cat() as it copies and extends strings, we do a preliminary pass to find
1512 out exactly how much store will be needed. On "normal" messages this will be
1513 pretty trivial.
1514
1515 Arguments:
1516   name          the name of the header, without the leading $header_ or $h_,
1517                 or NULL if a concatenation of all headers is required
1518   exists_only   TRUE if called from a def: test; don't need to build a string;
1519                 just return a string that is not "" and not "0" if the header
1520                 exists
1521   newsize       return the size of memory block that was obtained; may be NULL
1522                 if exists_only is TRUE
1523   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1524                 other than concatenating, will be done on the header. Also used
1525                 for $message_headers_raw.
1526   charset       name of charset to translate MIME words to; used only if
1527                 want_raw is false; if NULL, no translation is done (this is
1528                 used for $bh_ and $bheader_)
1529
1530 Returns:        NULL if the header does not exist, else a pointer to a new
1531                 store block
1532 */
1533
1534 static uschar *
1535 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1536   uschar *charset)
1537 {
1538 BOOL found = name == NULL;
1539 int comma = 0;
1540 int len = found? 0 : Ustrlen(name);
1541 int i;
1542 uschar *yield = NULL;
1543 uschar *ptr = NULL;
1544
1545 /* Loop for two passes - saves code repetition */
1546
1547 for (i = 0; i < 2; i++)
1548   {
1549   int size = 0;
1550   header_line *h;
1551
1552   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1553     {
1554     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1555       {
1556       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1557         {
1558         int ilen;
1559         uschar *t;
1560
1561         if (exists_only) return US"1";      /* don't need actual string */
1562         found = TRUE;
1563         t = h->text + len;                  /* text to insert */
1564         if (!want_raw)                      /* unless wanted raw, */
1565           while (isspace(*t)) t++;          /* remove leading white space */
1566         ilen = h->slen - (t - h->text);     /* length to insert */
1567
1568         /* Unless wanted raw, remove trailing whitespace, including the
1569         newline. */
1570
1571         if (!want_raw)
1572           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1573
1574         /* Set comma = 1 if handling a single header and it's one of those
1575         that contains an address list, except when asked for raw headers. Only
1576         need to do this once. */
1577
1578         if (!want_raw && name != NULL && comma == 0 &&
1579             Ustrchr("BCFRST", h->type) != NULL)
1580           comma = 1;
1581
1582         /* First pass - compute total store needed; second pass - compute
1583         total store used, including this header. */
1584
1585         size += ilen + comma + 1;  /* +1 for the newline */
1586
1587         /* Second pass - concatentate the data, up to a maximum. Note that
1588         the loop stops when size hits the limit. */
1589
1590         if (i != 0)
1591           {
1592           if (size > header_insert_maxlen)
1593             {
1594             ilen -= size - header_insert_maxlen - 1;
1595             comma = 0;
1596             }
1597           Ustrncpy(ptr, t, ilen);
1598           ptr += ilen;
1599
1600           /* For a non-raw header, put in the comma if needed, then add
1601           back the newline we removed above, provided there was some text in
1602           the header. */
1603
1604           if (!want_raw && ilen > 0)
1605             {
1606             if (comma != 0) *ptr++ = ',';
1607             *ptr++ = '\n';
1608             }
1609           }
1610         }
1611       }
1612     }
1613
1614   /* At end of first pass, return NULL if no header found. Then truncate size
1615   if necessary, and get the buffer to hold the data, returning the buffer size.
1616   */
1617
1618   if (i == 0)
1619     {
1620     if (!found) return NULL;
1621     if (size > header_insert_maxlen) size = header_insert_maxlen;
1622     *newsize = size + 1;
1623     ptr = yield = store_get(*newsize);
1624     }
1625   }
1626
1627 /* That's all we do for raw header expansion. */
1628
1629 if (want_raw)
1630   {
1631   *ptr = 0;
1632   }
1633
1634 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1635 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1636 function can return an error with decoded data if the charset translation
1637 fails. If decoding fails, it returns NULL. */
1638
1639 else
1640   {
1641   uschar *decoded, *error;
1642   if (ptr > yield && ptr[-1] == '\n') ptr--;
1643   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1644   *ptr = 0;
1645   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1646     newsize, &error);
1647   if (error != NULL)
1648     {
1649     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1650       "    input was: %s\n", error, yield);
1651     }
1652   if (decoded != NULL) yield = decoded;
1653   }
1654
1655 return yield;
1656 }
1657
1658
1659
1660
1661 /*************************************************
1662 *               Return list of recipients        *
1663 *************************************************/
1664 /* A recipients list is available only during system message filtering,
1665 during ACL processing after DATA, and while expanding pipe commands
1666 generated from a system filter, but not elsewhere. */
1667
1668 static uschar *
1669 fn_recipients(void)
1670 {
1671 if (!enable_dollar_recipients) return NULL; else
1672   {
1673   int size = 128;
1674   int ptr = 0;
1675   int i;
1676   uschar * s = store_get(size);
1677   for (i = 0; i < recipients_count; i++)
1678     {
1679     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1680     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1681       Ustrlen(recipients_list[i].address));
1682     }
1683   s[ptr] = 0;     /* string_cat() leaves room */
1684   return s;
1685   }
1686 }
1687
1688
1689 /*************************************************
1690 *               Find value of a variable         *
1691 *************************************************/
1692
1693 /* The table of variables is kept in alphabetic order, so we can search it
1694 using a binary chop. The "choplen" variable is nothing to do with the binary
1695 chop.
1696
1697 Arguments:
1698   name          the name of the variable being sought
1699   exists_only   TRUE if this is a def: test; passed on to find_header()
1700   skipping      TRUE => skip any processing evaluation; this is not the same as
1701                   exists_only because def: may test for values that are first
1702                   evaluated here
1703   newsize       pointer to an int which is initially zero; if the answer is in
1704                 a new memory buffer, *newsize is set to its size
1705
1706 Returns:        NULL if the variable does not exist, or
1707                 a pointer to the variable's contents, or
1708                 something non-NULL if exists_only is TRUE
1709 */
1710
1711 static uschar *
1712 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1713 {
1714 var_entry * vp;
1715 uschar *s, *domain;
1716 uschar **ss;
1717 void * val;
1718
1719 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1720 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1721 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1722 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1723 (this gave backwards compatibility at the changeover). There may be built-in
1724 variables whose names start acl_ but they should never start in this way. This
1725 slightly messy specification is a consequence of the history, needless to say.
1726
1727 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1728 set, in which case give an error. */
1729
1730 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1731      !isalpha(name[5]))
1732   {
1733   tree_node *node =
1734     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1735   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1736   }
1737
1738 /* Handle $auth<n> variables. */
1739
1740 if (Ustrncmp(name, "auth", 4) == 0)
1741   {
1742   uschar *endptr;
1743   int n = Ustrtoul(name + 4, &endptr, 10);
1744   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1745     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1746   }
1747 else if (Ustrncmp(name, "regex", 5) == 0)
1748   {
1749   uschar *endptr;
1750   int n = Ustrtoul(name + 5, &endptr, 10);
1751   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1752     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1753   }
1754
1755 /* For all other variables, search the table */
1756
1757 if (!(vp = find_var_ent(name)))
1758   return NULL;          /* Unknown variable name */
1759
1760 /* Found an existing variable. If in skipping state, the value isn't needed,
1761 and we want to avoid processing (such as looking up the host name). */
1762
1763 if (skipping)
1764   return US"";
1765
1766 val = vp->value;
1767 switch (vp->type)
1768   {
1769   case vtype_filter_int:
1770     if (!filter_running) return NULL;
1771     /* Fall through */
1772     /* VVVVVVVVVVVV */
1773   case vtype_int:
1774     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1775     return var_buffer;
1776
1777   case vtype_ino:
1778     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1779     return var_buffer;
1780
1781   case vtype_gid:
1782     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1783     return var_buffer;
1784
1785   case vtype_uid:
1786     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1787     return var_buffer;
1788
1789   case vtype_bool:
1790     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1791     return var_buffer;
1792
1793   case vtype_stringptr:                      /* Pointer to string */
1794     return (s = *((uschar **)(val))) ? s : US"";
1795
1796   case vtype_pid:
1797     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1798     return var_buffer;
1799
1800   case vtype_load_avg:
1801     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1802     return var_buffer;
1803
1804   case vtype_host_lookup:                    /* Lookup if not done so */
1805     if (sender_host_name == NULL && sender_host_address != NULL &&
1806         !host_lookup_failed && host_name_lookup() == OK)
1807       host_build_sender_fullhost();
1808     return (sender_host_name == NULL)? US"" : sender_host_name;
1809
1810   case vtype_localpart:                      /* Get local part from address */
1811     s = *((uschar **)(val));
1812     if (s == NULL) return US"";
1813     domain = Ustrrchr(s, '@');
1814     if (domain == NULL) return s;
1815     if (domain - s > sizeof(var_buffer) - 1)
1816       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1817           " in string expansion", sizeof(var_buffer));
1818     Ustrncpy(var_buffer, s, domain - s);
1819     var_buffer[domain - s] = 0;
1820     return var_buffer;
1821
1822   case vtype_domain:                         /* Get domain from address */
1823     s = *((uschar **)(val));
1824     if (s == NULL) return US"";
1825     domain = Ustrrchr(s, '@');
1826     return (domain == NULL)? US"" : domain + 1;
1827
1828   case vtype_msgheaders:
1829     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1830
1831   case vtype_msgheaders_raw:
1832     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1833
1834   case vtype_msgbody:                        /* Pointer to msgbody string */
1835   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1836     ss = (uschar **)(val);
1837     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1838       {
1839       uschar *body;
1840       off_t start_offset = SPOOL_DATA_START_OFFSET;
1841       int len = message_body_visible;
1842       if (len > message_size) len = message_size;
1843       *ss = body = store_malloc(len+1);
1844       body[0] = 0;
1845       if (vp->type == vtype_msgbody_end)
1846         {
1847         struct stat statbuf;
1848         if (fstat(deliver_datafile, &statbuf) == 0)
1849           {
1850           start_offset = statbuf.st_size - len;
1851           if (start_offset < SPOOL_DATA_START_OFFSET)
1852             start_offset = SPOOL_DATA_START_OFFSET;
1853           }
1854         }
1855       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1856         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1857           strerror(errno));
1858       len = read(deliver_datafile, body, len);
1859       if (len > 0)
1860         {
1861         body[len] = 0;
1862         if (message_body_newlines)   /* Separate loops for efficiency */
1863           while (len > 0)
1864             { if (body[--len] == 0) body[len] = ' '; }
1865         else
1866           while (len > 0)
1867             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1868         }
1869       }
1870     return (*ss == NULL)? US"" : *ss;
1871
1872   case vtype_todbsdin:                       /* BSD inbox time of day */
1873     return tod_stamp(tod_bsdin);
1874
1875   case vtype_tode:                           /* Unix epoch time of day */
1876     return tod_stamp(tod_epoch);
1877
1878   case vtype_todel:                          /* Unix epoch/usec time of day */
1879     return tod_stamp(tod_epoch_l);
1880
1881   case vtype_todf:                           /* Full time of day */
1882     return tod_stamp(tod_full);
1883
1884   case vtype_todl:                           /* Log format time of day */
1885     return tod_stamp(tod_log_bare);            /* (without timezone) */
1886
1887   case vtype_todzone:                        /* Time zone offset only */
1888     return tod_stamp(tod_zone);
1889
1890   case vtype_todzulu:                        /* Zulu time */
1891     return tod_stamp(tod_zulu);
1892
1893   case vtype_todlf:                          /* Log file datestamp tod */
1894     return tod_stamp(tod_log_datestamp_daily);
1895
1896   case vtype_reply:                          /* Get reply address */
1897     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1898       headers_charset);
1899     if (s != NULL) while (isspace(*s)) s++;
1900     if (s == NULL || *s == 0)
1901       {
1902       *newsize = 0;                            /* For the *s==0 case */
1903       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1904       }
1905     if (s != NULL)
1906       {
1907       uschar *t;
1908       while (isspace(*s)) s++;
1909       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1910       while (t > s && isspace(t[-1])) t--;
1911       *t = 0;
1912       }
1913     return (s == NULL)? US"" : s;
1914
1915   case vtype_string_func:
1916     {
1917     uschar * (*fn)() = val;
1918     return fn();
1919     }
1920
1921   case vtype_pspace:
1922     {
1923     int inodes;
1924     sprintf(CS var_buffer, "%d",
1925       receive_statvfs(val == (void *)TRUE, &inodes));
1926     }
1927   return var_buffer;
1928
1929   case vtype_pinodes:
1930     {
1931     int inodes;
1932     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1933     sprintf(CS var_buffer, "%d", inodes);
1934     }
1935   return var_buffer;
1936
1937   case vtype_cert:
1938     return *(void **)val ? US"<cert>" : US"";
1939
1940 #ifndef DISABLE_DKIM
1941   case vtype_dkim:
1942     return dkim_exim_expand_query((int)(long)val);
1943 #endif
1944
1945   }
1946
1947 return NULL;  /* Unknown variable. Silences static checkers. */
1948 }
1949
1950
1951
1952
1953 void
1954 modify_variable(uschar *name, void * value)
1955 {
1956 var_entry * vp;
1957 if ((vp = find_var_ent(name))) vp->value = value;
1958 return;          /* Unknown variable name, fail silently */
1959 }
1960
1961
1962
1963
1964
1965 /*************************************************
1966 *           Read and expand substrings           *
1967 *************************************************/
1968
1969 /* This function is called to read and expand argument substrings for various
1970 expansion items. Some have a minimum requirement that is less than the maximum;
1971 in these cases, the first non-present one is set to NULL.
1972
1973 Arguments:
1974   sub        points to vector of pointers to set
1975   n          maximum number of substrings
1976   m          minimum required
1977   sptr       points to current string pointer
1978   skipping   the skipping flag
1979   check_end  if TRUE, check for final '}'
1980   name       name of item, for error message
1981   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1982              the store.
1983
1984 Returns:     0 OK; string pointer updated
1985              1 curly bracketing error (too few arguments)
1986              2 too many arguments (only if check_end is set); message set
1987              3 other error (expansion failure)
1988 */
1989
1990 static int
1991 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1992   BOOL check_end, uschar *name, BOOL *resetok)
1993 {
1994 int i;
1995 const uschar *s = *sptr;
1996
1997 while (isspace(*s)) s++;
1998 for (i = 0; i < n; i++)
1999   {
2000   if (*s != '{')
2001     {
2002     if (i < m) return 1;
2003     sub[i] = NULL;
2004     break;
2005     }
2006   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok);
2007   if (sub[i] == NULL) return 3;
2008   if (*s++ != '}') return 1;
2009   while (isspace(*s)) s++;
2010   }
2011 if (check_end && *s++ != '}')
2012   {
2013   if (s[-1] == '{')
2014     {
2015     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
2016       "(max is %d)", name, n);
2017     return 2;
2018     }
2019   return 1;
2020   }
2021
2022 *sptr = s;
2023 return 0;
2024 }
2025
2026
2027
2028
2029 /*************************************************
2030 *     Elaborate message for bad variable         *
2031 *************************************************/
2032
2033 /* For the "unknown variable" message, take a look at the variable's name, and
2034 give additional information about possible ACL variables. The extra information
2035 is added on to expand_string_message.
2036
2037 Argument:   the name of the variable
2038 Returns:    nothing
2039 */
2040
2041 static void
2042 check_variable_error_message(uschar *name)
2043 {
2044 if (Ustrncmp(name, "acl_", 4) == 0)
2045   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2046     (name[4] == 'c' || name[4] == 'm')?
2047       (isalpha(name[5])?
2048         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2049         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2050       ) :
2051       US"user-defined ACL variables must start acl_c or acl_m");
2052 }
2053
2054
2055
2056 /*
2057 Load args from sub array to globals, and call acl_check().
2058 Sub array will be corrupted on return.
2059
2060 Returns:       OK         access is granted by an ACCEPT verb
2061                DISCARD    access is granted by a DISCARD verb
2062                FAIL       access is denied
2063                FAIL_DROP  access is denied; drop the connection
2064                DEFER      can't tell at the moment
2065                ERROR      disaster
2066 */
2067 static int
2068 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2069 {
2070 int i;
2071 int sav_narg = acl_narg;
2072 int ret;
2073 uschar * dummy_logmsg;
2074 extern int acl_where;
2075
2076 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2077 for (i = 0; i < nsub && sub[i+1]; i++)
2078   {
2079   uschar * tmp = acl_arg[i];
2080   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2081   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2082   }
2083 acl_narg = i;
2084 while (i < nsub)
2085   {
2086   sub[i+1] = acl_arg[i];
2087   acl_arg[i++] = NULL;
2088   }
2089
2090 DEBUG(D_expand)
2091   debug_printf("expanding: acl: %s  arg: %s%s\n",
2092     sub[0],
2093     acl_narg>0 ? acl_arg[0] : US"<none>",
2094     acl_narg>1 ? " +more"   : "");
2095
2096 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2097
2098 for (i = 0; i < nsub; i++)
2099   acl_arg[i] = sub[i+1];        /* restore old args */
2100 acl_narg = sav_narg;
2101
2102 return ret;
2103 }
2104
2105
2106
2107
2108 /*************************************************
2109 *        Read and evaluate a condition           *
2110 *************************************************/
2111
2112 /*
2113 Arguments:
2114   s        points to the start of the condition text
2115   resetok  points to a BOOL which is written false if it is unsafe to
2116            free memory. Certain condition types (acl) may have side-effect
2117            allocation which must be preserved.
2118   yield    points to a BOOL to hold the result of the condition test;
2119            if NULL, we are just reading through a condition that is
2120            part of an "or" combination to check syntax, or in a state
2121            where the answer isn't required
2122
2123 Returns:   a pointer to the first character after the condition, or
2124            NULL after an error
2125 */
2126
2127 static const uschar *
2128 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2129 {
2130 BOOL testfor = TRUE;
2131 BOOL tempcond, combined_cond;
2132 BOOL *subcondptr;
2133 BOOL sub2_honour_dollar = TRUE;
2134 int i, rc, cond_type, roffset;
2135 int_eximarith_t num[2];
2136 struct stat statbuf;
2137 uschar name[256];
2138 const uschar *sub[10];
2139
2140 const pcre *re;
2141 const uschar *rerror;
2142
2143 for (;;)
2144   {
2145   while (isspace(*s)) s++;
2146   if (*s == '!') { testfor = !testfor; s++; } else break;
2147   }
2148
2149 /* Numeric comparisons are symbolic */
2150
2151 if (*s == '=' || *s == '>' || *s == '<')
2152   {
2153   int p = 0;
2154   name[p++] = *s++;
2155   if (*s == '=')
2156     {
2157     name[p++] = '=';
2158     s++;
2159     }
2160   name[p] = 0;
2161   }
2162
2163 /* All other conditions are named */
2164
2165 else s = read_name(name, 256, s, US"_");
2166
2167 /* If we haven't read a name, it means some non-alpha character is first. */
2168
2169 if (name[0] == 0)
2170   {
2171   expand_string_message = string_sprintf("condition name expected, "
2172     "but found \"%.16s\"", s);
2173   return NULL;
2174   }
2175
2176 /* Find which condition we are dealing with, and switch on it */
2177
2178 cond_type = chop_match(name, cond_table, nelem(cond_table));
2179 switch(cond_type)
2180   {
2181   /* def: tests for a non-empty variable, or for the existence of a header. If
2182   yield == NULL we are in a skipping state, and don't care about the answer. */
2183
2184   case ECOND_DEF:
2185   if (*s != ':')
2186     {
2187     expand_string_message = US"\":\" expected after \"def\"";
2188     return NULL;
2189     }
2190
2191   s = read_name(name, 256, s+1, US"_");
2192
2193   /* Test for a header's existence. If the name contains a closing brace
2194   character, this may be a user error where the terminating colon has been
2195   omitted. Set a flag to adjust a subsequent error message in this case. */
2196
2197   if (Ustrncmp(name, "h_", 2) == 0 ||
2198       Ustrncmp(name, "rh_", 3) == 0 ||
2199       Ustrncmp(name, "bh_", 3) == 0 ||
2200       Ustrncmp(name, "header_", 7) == 0 ||
2201       Ustrncmp(name, "rheader_", 8) == 0 ||
2202       Ustrncmp(name, "bheader_", 8) == 0)
2203     {
2204     s = read_header_name(name, 256, s);
2205     /* {-for-text-editors */
2206     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2207     if (yield != NULL) *yield =
2208       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2209     }
2210
2211   /* Test for a variable's having a non-empty value. A non-existent variable
2212   causes an expansion failure. */
2213
2214   else
2215     {
2216     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2217     if (value == NULL)
2218       {
2219       expand_string_message = (name[0] == 0)?
2220         string_sprintf("variable name omitted after \"def:\"") :
2221         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2222       check_variable_error_message(name);
2223       return NULL;
2224       }
2225     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2226     }
2227
2228   return s;
2229
2230
2231   /* first_delivery tests for first delivery attempt */
2232
2233   case ECOND_FIRST_DELIVERY:
2234   if (yield != NULL) *yield = deliver_firsttime == testfor;
2235   return s;
2236
2237
2238   /* queue_running tests for any process started by a queue runner */
2239
2240   case ECOND_QUEUE_RUNNING:
2241   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2242   return s;
2243
2244
2245   /* exists:  tests for file existence
2246        isip:  tests for any IP address
2247       isip4:  tests for an IPv4 address
2248       isip6:  tests for an IPv6 address
2249         pam:  does PAM authentication
2250      radius:  does RADIUS authentication
2251    ldapauth:  does LDAP authentication
2252     pwcheck:  does Cyrus SASL pwcheck authentication
2253   */
2254
2255   case ECOND_EXISTS:
2256   case ECOND_ISIP:
2257   case ECOND_ISIP4:
2258   case ECOND_ISIP6:
2259   case ECOND_PAM:
2260   case ECOND_RADIUS:
2261   case ECOND_LDAPAUTH:
2262   case ECOND_PWCHECK:
2263
2264   while (isspace(*s)) s++;
2265   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2266
2267   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2268   if (sub[0] == NULL) return NULL;
2269   /* {-for-text-editors */
2270   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2271
2272   if (yield == NULL) return s;   /* No need to run the test if skipping */
2273
2274   switch(cond_type)
2275     {
2276     case ECOND_EXISTS:
2277     if ((expand_forbid & RDO_EXISTS) != 0)
2278       {
2279       expand_string_message = US"File existence tests are not permitted";
2280       return NULL;
2281       }
2282     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2283     break;
2284
2285     case ECOND_ISIP:
2286     case ECOND_ISIP4:
2287     case ECOND_ISIP6:
2288     rc = string_is_ip_address(sub[0], NULL);
2289     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2290              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2291     break;
2292
2293     /* Various authentication tests - all optionally compiled */
2294
2295     case ECOND_PAM:
2296     #ifdef SUPPORT_PAM
2297     rc = auth_call_pam(sub[0], &expand_string_message);
2298     goto END_AUTH;
2299     #else
2300     goto COND_FAILED_NOT_COMPILED;
2301     #endif  /* SUPPORT_PAM */
2302
2303     case ECOND_RADIUS:
2304     #ifdef RADIUS_CONFIG_FILE
2305     rc = auth_call_radius(sub[0], &expand_string_message);
2306     goto END_AUTH;
2307     #else
2308     goto COND_FAILED_NOT_COMPILED;
2309     #endif  /* RADIUS_CONFIG_FILE */
2310
2311     case ECOND_LDAPAUTH:
2312     #ifdef LOOKUP_LDAP
2313       {
2314       /* Just to keep the interface the same */
2315       BOOL do_cache;
2316       int old_pool = store_pool;
2317       store_pool = POOL_SEARCH;
2318       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2319         &expand_string_message, &do_cache);
2320       store_pool = old_pool;
2321       }
2322     goto END_AUTH;
2323     #else
2324     goto COND_FAILED_NOT_COMPILED;
2325     #endif  /* LOOKUP_LDAP */
2326
2327     case ECOND_PWCHECK:
2328     #ifdef CYRUS_PWCHECK_SOCKET
2329     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2330     goto END_AUTH;
2331     #else
2332     goto COND_FAILED_NOT_COMPILED;
2333     #endif  /* CYRUS_PWCHECK_SOCKET */
2334
2335     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2336         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2337     END_AUTH:
2338     if (rc == ERROR || rc == DEFER) return NULL;
2339     *yield = (rc == OK) == testfor;
2340     #endif
2341     }
2342   return s;
2343
2344
2345   /* call ACL (in a conditional context).  Accept true, deny false.
2346   Defer is a forced-fail.  Anything set by message= goes to $value.
2347   Up to ten parameters are used; we use the braces round the name+args
2348   like the saslauthd condition does, to permit a variable number of args.
2349   See also the expansion-item version EITEM_ACL and the traditional
2350   acl modifier ACLC_ACL.
2351   Since the ACL may allocate new global variables, tell our caller to not
2352   reclaim memory.
2353   */
2354
2355   case ECOND_ACL:
2356     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2357     {
2358     uschar *sub[10];
2359     uschar *user_msg;
2360     BOOL cond = FALSE;
2361     int size = 0;
2362     int ptr = 0;
2363
2364     while (isspace(*s)) s++;
2365     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2366
2367     switch(read_subs(sub, nelem(sub), 1,
2368       &s, yield == NULL, TRUE, US"acl", resetok))
2369       {
2370       case 1: expand_string_message = US"too few arguments or bracketing "
2371         "error for acl";
2372       case 2:
2373       case 3: return NULL;
2374       }
2375
2376     *resetok = FALSE;
2377     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2378         {
2379         case OK:
2380           cond = TRUE;
2381         case FAIL:
2382           lookup_value = NULL;
2383           if (user_msg)
2384             {
2385             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2386             lookup_value[ptr] = '\0';
2387             }
2388           *yield = cond == testfor;
2389           break;
2390
2391         case DEFER:
2392           expand_string_forcedfail = TRUE;
2393         default:
2394           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2395           return NULL;
2396         }
2397     return s;
2398     }
2399
2400
2401   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2402
2403      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2404
2405   However, the last two are optional. That is why the whole set is enclosed
2406   in their own set of braces. */
2407
2408   case ECOND_SASLAUTHD:
2409 #ifndef CYRUS_SASLAUTHD_SOCKET
2410     goto COND_FAILED_NOT_COMPILED;
2411 #else
2412     {
2413     uschar *sub[4];
2414     while (isspace(*s)) s++;
2415     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2416     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2417                     resetok))
2418       {
2419       case 1: expand_string_message = US"too few arguments or bracketing "
2420         "error for saslauthd";
2421       case 2:
2422       case 3: return NULL;
2423       }
2424     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2425     if (yield != NULL)
2426       {
2427       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2428         &expand_string_message);
2429       if (rc == ERROR || rc == DEFER) return NULL;
2430       *yield = (rc == OK) == testfor;
2431       }
2432     return s;
2433     }
2434 #endif /* CYRUS_SASLAUTHD_SOCKET */
2435
2436
2437   /* symbolic operators for numeric and string comparison, and a number of
2438   other operators, all requiring two arguments.
2439
2440   crypteq:           encrypts plaintext and compares against an encrypted text,
2441                        using crypt(), crypt16(), MD5 or SHA-1
2442   inlist/inlisti:    checks if first argument is in the list of the second
2443   match:             does a regular expression match and sets up the numerical
2444                        variables if it succeeds
2445   match_address:     matches in an address list
2446   match_domain:      matches in a domain list
2447   match_ip:          matches a host list that is restricted to IP addresses
2448   match_local_part:  matches in a local part list
2449   */
2450
2451   case ECOND_MATCH_ADDRESS:
2452   case ECOND_MATCH_DOMAIN:
2453   case ECOND_MATCH_IP:
2454   case ECOND_MATCH_LOCAL_PART:
2455 #ifndef EXPAND_LISTMATCH_RHS
2456     sub2_honour_dollar = FALSE;
2457 #endif
2458     /* FALLTHROUGH */
2459
2460   case ECOND_CRYPTEQ:
2461   case ECOND_INLIST:
2462   case ECOND_INLISTI:
2463   case ECOND_MATCH:
2464
2465   case ECOND_NUM_L:     /* Numerical comparisons */
2466   case ECOND_NUM_LE:
2467   case ECOND_NUM_E:
2468   case ECOND_NUM_EE:
2469   case ECOND_NUM_G:
2470   case ECOND_NUM_GE:
2471
2472   case ECOND_STR_LT:    /* String comparisons */
2473   case ECOND_STR_LTI:
2474   case ECOND_STR_LE:
2475   case ECOND_STR_LEI:
2476   case ECOND_STR_EQ:
2477   case ECOND_STR_EQI:
2478   case ECOND_STR_GT:
2479   case ECOND_STR_GTI:
2480   case ECOND_STR_GE:
2481   case ECOND_STR_GEI:
2482
2483   for (i = 0; i < 2; i++)
2484     {
2485     /* Sometimes, we don't expand substrings; too many insecure configurations
2486     created using match_address{}{} and friends, where the second param
2487     includes information from untrustworthy sources. */
2488     BOOL honour_dollar = TRUE;
2489     if ((i > 0) && !sub2_honour_dollar)
2490       honour_dollar = FALSE;
2491
2492     while (isspace(*s)) s++;
2493     if (*s != '{')
2494       {
2495       if (i == 0) goto COND_FAILED_CURLY_START;
2496       expand_string_message = string_sprintf("missing 2nd string in {} "
2497         "after \"%s\"", name);
2498       return NULL;
2499       }
2500     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2501         honour_dollar, resetok);
2502     if (sub[i] == NULL) return NULL;
2503     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2504
2505     /* Convert to numerical if required; we know that the names of all the
2506     conditions that compare numbers do not start with a letter. This just saves
2507     checking for them individually. */
2508
2509     if (!isalpha(name[0]) && yield != NULL)
2510       {
2511       if (sub[i][0] == 0)
2512         {
2513         num[i] = 0;
2514         DEBUG(D_expand)
2515           debug_printf("empty string cast to zero for numerical comparison\n");
2516         }
2517       else
2518         {
2519         num[i] = expanded_string_integer(sub[i], FALSE);
2520         if (expand_string_message != NULL) return NULL;
2521         }
2522       }
2523     }
2524
2525   /* Result not required */
2526
2527   if (yield == NULL) return s;
2528
2529   /* Do an appropriate comparison */
2530
2531   switch(cond_type)
2532     {
2533     case ECOND_NUM_E:
2534     case ECOND_NUM_EE:
2535     tempcond = (num[0] == num[1]);
2536     break;
2537
2538     case ECOND_NUM_G:
2539     tempcond = (num[0] > num[1]);
2540     break;
2541
2542     case ECOND_NUM_GE:
2543     tempcond = (num[0] >= num[1]);
2544     break;
2545
2546     case ECOND_NUM_L:
2547     tempcond = (num[0] < num[1]);
2548     break;
2549
2550     case ECOND_NUM_LE:
2551     tempcond = (num[0] <= num[1]);
2552     break;
2553
2554     case ECOND_STR_LT:
2555     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2556     break;
2557
2558     case ECOND_STR_LTI:
2559     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2560     break;
2561
2562     case ECOND_STR_LE:
2563     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2564     break;
2565
2566     case ECOND_STR_LEI:
2567     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2568     break;
2569
2570     case ECOND_STR_EQ:
2571     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2572     break;
2573
2574     case ECOND_STR_EQI:
2575     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2576     break;
2577
2578     case ECOND_STR_GT:
2579     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2580     break;
2581
2582     case ECOND_STR_GTI:
2583     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2584     break;
2585
2586     case ECOND_STR_GE:
2587     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2588     break;
2589
2590     case ECOND_STR_GEI:
2591     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2592     break;
2593
2594     case ECOND_MATCH:   /* Regular expression match */
2595     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2596       NULL);
2597     if (re == NULL)
2598       {
2599       expand_string_message = string_sprintf("regular expression error in "
2600         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2601       return NULL;
2602       }
2603     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2604     break;
2605
2606     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2607     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2608     goto MATCHED_SOMETHING;
2609
2610     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2611     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2612       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2613     goto MATCHED_SOMETHING;
2614
2615     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2616     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2617       {
2618       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2619         sub[0]);
2620       return NULL;
2621       }
2622     else
2623       {
2624       unsigned int *nullcache = NULL;
2625       check_host_block cb;
2626
2627       cb.host_name = US"";
2628       cb.host_address = sub[0];
2629
2630       /* If the host address starts off ::ffff: it is an IPv6 address in
2631       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2632       addresses. */
2633
2634       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2635         cb.host_address + 7 : cb.host_address;
2636
2637       rc = match_check_list(
2638              &sub[1],                   /* the list */
2639              0,                         /* separator character */
2640              &hostlist_anchor,          /* anchor pointer */
2641              &nullcache,                /* cache pointer */
2642              check_host,                /* function for testing */
2643              &cb,                       /* argument for function */
2644              MCL_HOST,                  /* type of check */
2645              sub[0],                    /* text for debugging */
2646              NULL);                     /* where to pass back data */
2647       }
2648     goto MATCHED_SOMETHING;
2649
2650     case ECOND_MATCH_LOCAL_PART:
2651     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2652       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2653     /* Fall through */
2654     /* VVVVVVVVVVVV */
2655     MATCHED_SOMETHING:
2656     switch(rc)
2657       {
2658       case OK:
2659       tempcond = TRUE;
2660       break;
2661
2662       case FAIL:
2663       tempcond = FALSE;
2664       break;
2665
2666       case DEFER:
2667       expand_string_message = string_sprintf("unable to complete match "
2668         "against \"%s\": %s", sub[1], search_error_message);
2669       return NULL;
2670       }
2671
2672     break;
2673
2674     /* Various "encrypted" comparisons. If the second string starts with
2675     "{" then an encryption type is given. Default to crypt() or crypt16()
2676     (build-time choice). */
2677     /* }-for-text-editors */
2678
2679     case ECOND_CRYPTEQ:
2680     #ifndef SUPPORT_CRYPTEQ
2681     goto COND_FAILED_NOT_COMPILED;
2682     #else
2683     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2684       {
2685       int sublen = Ustrlen(sub[1]+5);
2686       md5 base;
2687       uschar digest[16];
2688
2689       md5_start(&base);
2690       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2691
2692       /* If the length that we are comparing against is 24, the MD5 digest
2693       is expressed as a base64 string. This is the way LDAP does it. However,
2694       some other software uses a straightforward hex representation. We assume
2695       this if the length is 32. Other lengths fail. */
2696
2697       if (sublen == 24)
2698         {
2699         uschar *coded = b64encode((uschar *)digest, 16);
2700         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2701           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2702         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2703         }
2704       else if (sublen == 32)
2705         {
2706         int i;
2707         uschar coded[36];
2708         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2709         coded[32] = 0;
2710         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2711           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2712         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2713         }
2714       else
2715         {
2716         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2717           "fail\n  crypted=%s\n", sub[1]+5);
2718         tempcond = FALSE;
2719         }
2720       }
2721
2722     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2723       {
2724       int sublen = Ustrlen(sub[1]+6);
2725       sha1 base;
2726       uschar digest[20];
2727
2728       sha1_start(&base);
2729       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2730
2731       /* If the length that we are comparing against is 28, assume the SHA1
2732       digest is expressed as a base64 string. If the length is 40, assume a
2733       straightforward hex representation. Other lengths fail. */
2734
2735       if (sublen == 28)
2736         {
2737         uschar *coded = b64encode((uschar *)digest, 20);
2738         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2739           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2740         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2741         }
2742       else if (sublen == 40)
2743         {
2744         int i;
2745         uschar coded[44];
2746         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2747         coded[40] = 0;
2748         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2749           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2750         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2751         }
2752       else
2753         {
2754         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2755           "fail\n  crypted=%s\n", sub[1]+6);
2756         tempcond = FALSE;
2757         }
2758       }
2759
2760     else   /* {crypt} or {crypt16} and non-{ at start */
2761            /* }-for-text-editors */
2762       {
2763       int which = 0;
2764       uschar *coded;
2765
2766       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2767         {
2768         sub[1] += 7;
2769         which = 1;
2770         }
2771       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2772         {
2773         sub[1] += 9;
2774         which = 2;
2775         }
2776       else if (sub[1][0] == '{')                /* }-for-text-editors */
2777         {
2778         expand_string_message = string_sprintf("unknown encryption mechanism "
2779           "in \"%s\"", sub[1]);
2780         return NULL;
2781         }
2782
2783       switch(which)
2784         {
2785         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2786         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2787         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2788         }
2789
2790       #define STR(s) # s
2791       #define XSTR(s) STR(s)
2792       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2793         "  subject=%s\n  crypted=%s\n",
2794         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2795         coded, sub[1]);
2796       #undef STR
2797       #undef XSTR
2798
2799       /* If the encrypted string contains fewer than two characters (for the
2800       salt), force failure. Otherwise we get false positives: with an empty
2801       string the yield of crypt() is an empty string! */
2802
2803       if (coded)
2804         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2805       else if (errno == EINVAL)
2806         tempcond = FALSE;
2807       else
2808         {
2809         expand_string_message = string_sprintf("crypt error: %s\n",
2810           US strerror(errno));
2811         return NULL;
2812         }
2813       }
2814     break;
2815     #endif  /* SUPPORT_CRYPTEQ */
2816
2817     case ECOND_INLIST:
2818     case ECOND_INLISTI:
2819       {
2820       const uschar * list = sub[1];
2821       int sep = 0;
2822       uschar *save_iterate_item = iterate_item;
2823       int (*compare)(const uschar *, const uschar *);
2824
2825       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2826
2827       tempcond = FALSE;
2828       compare = cond_type == ECOND_INLISTI
2829         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2830
2831       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2832         if (compare(sub[0], iterate_item) == 0)
2833           {
2834           tempcond = TRUE;
2835           break;
2836           }
2837       iterate_item = save_iterate_item;
2838       }
2839
2840     }   /* Switch for comparison conditions */
2841
2842   *yield = tempcond == testfor;
2843   return s;    /* End of comparison conditions */
2844
2845
2846   /* and/or: computes logical and/or of several conditions */
2847
2848   case ECOND_AND:
2849   case ECOND_OR:
2850   subcondptr = (yield == NULL)? NULL : &tempcond;
2851   combined_cond = (cond_type == ECOND_AND);
2852
2853   while (isspace(*s)) s++;
2854   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2855
2856   for (;;)
2857     {
2858     while (isspace(*s)) s++;
2859     /* {-for-text-editors */
2860     if (*s == '}') break;
2861     if (*s != '{')                                      /* }-for-text-editors */
2862       {
2863       expand_string_message = string_sprintf("each subcondition "
2864         "inside an \"%s{...}\" condition must be in its own {}", name);
2865       return NULL;
2866       }
2867
2868     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2869       {
2870       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2871         expand_string_message, name);
2872       return NULL;
2873       }
2874     while (isspace(*s)) s++;
2875
2876     /* {-for-text-editors */
2877     if (*s++ != '}')
2878       {
2879       /* {-for-text-editors */
2880       expand_string_message = string_sprintf("missing } at end of condition "
2881         "inside \"%s\" group", name);
2882       return NULL;
2883       }
2884
2885     if (yield != NULL)
2886       {
2887       if (cond_type == ECOND_AND)
2888         {
2889         combined_cond &= tempcond;
2890         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2891         }                                       /* evaluate any more */
2892       else
2893         {
2894         combined_cond |= tempcond;
2895         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2896         }                                       /* evaluate any more */
2897       }
2898     }
2899
2900   if (yield != NULL) *yield = (combined_cond == testfor);
2901   return ++s;
2902
2903
2904   /* forall/forany: iterates a condition with different values */
2905
2906   case ECOND_FORALL:
2907   case ECOND_FORANY:
2908     {
2909     const uschar * list;
2910     int sep = 0;
2911     uschar *save_iterate_item = iterate_item;
2912
2913     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2914
2915     while (isspace(*s)) s++;
2916     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2917     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2918     if (sub[0] == NULL) return NULL;
2919     /* {-for-text-editors */
2920     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2921
2922     while (isspace(*s)) s++;
2923     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2924
2925     sub[1] = s;
2926
2927     /* Call eval_condition once, with result discarded (as if scanning a
2928     "false" part). This allows us to find the end of the condition, because if
2929     the list it empty, we won't actually evaluate the condition for real. */
2930
2931     if (!(s = eval_condition(sub[1], resetok, NULL)))
2932       {
2933       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2934         expand_string_message, name);
2935       return NULL;
2936       }
2937     while (isspace(*s)) s++;
2938
2939     /* {-for-text-editors */
2940     if (*s++ != '}')
2941       {
2942       /* {-for-text-editors */
2943       expand_string_message = string_sprintf("missing } at end of condition "
2944         "inside \"%s\"", name);
2945       return NULL;
2946       }
2947
2948     if (yield != NULL) *yield = !testfor;
2949     list = sub[0];
2950     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2951       {
2952       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2953       if (!eval_condition(sub[1], resetok, &tempcond))
2954         {
2955         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2956           expand_string_message, name);
2957         iterate_item = save_iterate_item;
2958         return NULL;
2959         }
2960       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2961         tempcond? "true":"false");
2962
2963       if (yield != NULL) *yield = (tempcond == testfor);
2964       if (tempcond == (cond_type == ECOND_FORANY)) break;
2965       }
2966
2967     iterate_item = save_iterate_item;
2968     return s;
2969     }
2970
2971
2972   /* The bool{} expansion condition maps a string to boolean.
2973   The values supported should match those supported by the ACL condition
2974   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2975   of true/false.  Note that Router "condition" rules have a different
2976   interpretation, where general data can be used and only a few values
2977   map to FALSE.
2978   Note that readconf.c boolean matching, for boolean configuration options,
2979   only matches true/yes/false/no.
2980   The bool_lax{} condition matches the Router logic, which is much more
2981   liberal. */
2982   case ECOND_BOOL:
2983   case ECOND_BOOL_LAX:
2984     {
2985     uschar *sub_arg[1];
2986     uschar *t, *t2;
2987     uschar *ourname;
2988     size_t len;
2989     BOOL boolvalue = FALSE;
2990     while (isspace(*s)) s++;
2991     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2992     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2993     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2994       {
2995       case 1: expand_string_message = string_sprintf(
2996                   "too few arguments or bracketing error for %s",
2997                   ourname);
2998       /*FALLTHROUGH*/
2999       case 2:
3000       case 3: return NULL;
3001       }
3002     t = sub_arg[0];
3003     while (isspace(*t)) t++;
3004     len = Ustrlen(t);
3005     if (len)
3006       {
3007       /* trailing whitespace: seems like a good idea to ignore it too */
3008       t2 = t + len - 1;
3009       while (isspace(*t2)) t2--;
3010       if (t2 != (t + len))
3011         {
3012         *++t2 = '\0';
3013         len = t2 - t;
3014         }
3015       }
3016     DEBUG(D_expand)
3017       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3018     /* logic for the lax case from expand_check_condition(), which also does
3019     expands, and the logic is both short and stable enough that there should
3020     be no maintenance burden from replicating it. */
3021     if (len == 0)
3022       boolvalue = FALSE;
3023     else if (*t == '-'
3024              ? Ustrspn(t+1, "0123456789") == len-1
3025              : Ustrspn(t,   "0123456789") == len)
3026       {
3027       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3028       /* expand_check_condition only does a literal string "0" check */
3029       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3030         boolvalue = TRUE;
3031       }
3032     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3033       boolvalue = TRUE;
3034     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3035       boolvalue = FALSE;
3036     else if (cond_type == ECOND_BOOL_LAX)
3037       boolvalue = TRUE;
3038     else
3039       {
3040       expand_string_message = string_sprintf("unrecognised boolean "
3041        "value \"%s\"", t);
3042       return NULL;
3043       }
3044     if (yield != NULL) *yield = (boolvalue == testfor);
3045     return s;
3046     }
3047
3048   /* Unknown condition */
3049
3050   default:
3051   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3052   return NULL;
3053   }   /* End switch on condition type */
3054
3055 /* Missing braces at start and end of data */
3056
3057 COND_FAILED_CURLY_START:
3058 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3059 return NULL;
3060
3061 COND_FAILED_CURLY_END:
3062 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3063   name);
3064 return NULL;
3065
3066 /* A condition requires code that is not compiled */
3067
3068 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3069     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3070     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3071 COND_FAILED_NOT_COMPILED:
3072 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3073   name);
3074 return NULL;
3075 #endif
3076 }
3077
3078
3079
3080
3081 /*************************************************
3082 *          Save numerical variables              *
3083 *************************************************/
3084
3085 /* This function is called from items such as "if" that want to preserve and
3086 restore the numbered variables.
3087
3088 Arguments:
3089   save_expand_string    points to an array of pointers to set
3090   save_expand_nlength   points to an array of ints for the lengths
3091
3092 Returns:                the value of expand max to save
3093 */
3094
3095 static int
3096 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3097 {
3098 int i;
3099 for (i = 0; i <= expand_nmax; i++)
3100   {
3101   save_expand_nstring[i] = expand_nstring[i];
3102   save_expand_nlength[i] = expand_nlength[i];
3103   }
3104 return expand_nmax;
3105 }
3106
3107
3108
3109 /*************************************************
3110 *           Restore numerical variables          *
3111 *************************************************/
3112
3113 /* This function restored saved values of numerical strings.
3114
3115 Arguments:
3116   save_expand_nmax      the number of strings to restore
3117   save_expand_string    points to an array of pointers
3118   save_expand_nlength   points to an array of ints
3119
3120 Returns:                nothing
3121 */
3122
3123 static void
3124 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3125   int *save_expand_nlength)
3126 {
3127 int i;
3128 expand_nmax = save_expand_nmax;
3129 for (i = 0; i <= expand_nmax; i++)
3130   {
3131   expand_nstring[i] = save_expand_nstring[i];
3132   expand_nlength[i] = save_expand_nlength[i];
3133   }
3134 }
3135
3136
3137
3138
3139
3140 /*************************************************
3141 *            Handle yes/no substrings            *
3142 *************************************************/
3143
3144 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3145 alternative substrings that depend on whether or not the condition was true,
3146 or the lookup or extraction succeeded. The substrings always have to be
3147 expanded, to check their syntax, but "skipping" is set when the result is not
3148 needed - this avoids unnecessary nested lookups.
3149
3150 Arguments:
3151   skipping       TRUE if we were skipping when this item was reached
3152   yes            TRUE if the first string is to be used, else use the second
3153   save_lookup    a value to put back into lookup_value before the 2nd expansion
3154   sptr           points to the input string pointer
3155   yieldptr       points to the output string pointer
3156   sizeptr        points to the output string size
3157   ptrptr         points to the output string pointer
3158   type           "lookup", "if", "extract", "run", "env", "listextract" or
3159                  "certextract" for error message
3160   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3161                 the store.
3162
3163 Returns:         0 OK; lookup_value has been reset to save_lookup
3164                  1 expansion failed
3165                  2 expansion failed because of bracketing error
3166 */
3167
3168 static int
3169 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3170   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3171 {
3172 int rc = 0;
3173 const uschar *s = *sptr;    /* Local value */
3174 uschar *sub1, *sub2;
3175
3176 /* If there are no following strings, we substitute the contents of $value for
3177 lookups and for extractions in the success case. For the ${if item, the string
3178 "true" is substituted. In the fail case, nothing is substituted for all three
3179 items. */
3180
3181 while (isspace(*s)) s++;
3182 if (*s == '}')
3183   {
3184   if (type[0] == 'i')
3185     {
3186     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
3187     }
3188   else
3189     {
3190     if (yes && lookup_value)
3191       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
3192         Ustrlen(lookup_value));
3193     lookup_value = save_lookup;
3194     }
3195   s++;
3196   goto RETURN;
3197   }
3198
3199 /* The first following string must be braced. */
3200
3201 if (*s++ != '{') goto FAILED_CURLY;
3202
3203 /* Expand the first substring. Forced failures are noticed only if we actually
3204 want this string. Set skipping in the call in the fail case (this will always
3205 be the case if we were already skipping). */
3206
3207 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3208 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3209 expand_string_forcedfail = FALSE;
3210 if (*s++ != '}') goto FAILED_CURLY;
3211
3212 /* If we want the first string, add it to the output */
3213
3214 if (yes)
3215   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
3216
3217 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3218 $value to what it was at the start of the item, so that it has this value
3219 during the second string expansion. For the call from "if" or "run" to this
3220 function, save_lookup is set to lookup_value, so that this statement does
3221 nothing. */
3222
3223 lookup_value = save_lookup;
3224
3225 /* There now follows either another substring, or "fail", or nothing. This
3226 time, forced failures are noticed only if we want the second string. We must
3227 set skipping in the nested call if we don't want this string, or if we were
3228 already skipping. */
3229
3230 while (isspace(*s)) s++;
3231 if (*s == '{')
3232   {
3233   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3234   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3235   expand_string_forcedfail = FALSE;
3236   if (*s++ != '}') goto FAILED_CURLY;
3237
3238   /* If we want the second string, add it to the output */
3239
3240   if (!yes)
3241     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
3242   }
3243
3244 /* If there is no second string, but the word "fail" is present when the use of
3245 the second string is wanted, set a flag indicating it was a forced failure
3246 rather than a syntactic error. Swallow the terminating } in case this is nested
3247 inside another lookup or if or extract. */
3248
3249 else if (*s != '}')
3250   {
3251   uschar name[256];
3252   /* deconst cast ok here as source is s anyway */
3253   s = US read_name(name, sizeof(name), s, US"_");
3254   if (Ustrcmp(name, "fail") == 0)
3255     {
3256     if (!yes && !skipping)
3257       {
3258       while (isspace(*s)) s++;
3259       if (*s++ != '}') goto FAILED_CURLY;
3260       expand_string_message =
3261         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3262       expand_string_forcedfail = TRUE;
3263       goto FAILED;
3264       }
3265     }
3266   else
3267     {
3268     expand_string_message =
3269       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3270     goto FAILED;
3271     }
3272   }
3273
3274 /* All we have to do now is to check on the final closing brace. */
3275
3276 while (isspace(*s)) s++;
3277 if (*s++ == '}') goto RETURN;
3278
3279 /* Get here if there is a bracketing failure */
3280
3281 FAILED_CURLY:
3282 rc++;
3283
3284 /* Get here for other failures */
3285
3286 FAILED:
3287 rc++;
3288
3289 /* Update the input pointer value before returning */
3290
3291 RETURN:
3292 *sptr = s;
3293 return rc;
3294 }
3295
3296
3297
3298
3299 /*************************************************
3300 *    Handle MD5 or SHA-1 computation for HMAC    *
3301 *************************************************/
3302
3303 /* These are some wrapping functions that enable the HMAC code to be a bit
3304 cleaner. A good compiler will spot the tail recursion.
3305
3306 Arguments:
3307   type         HMAC_MD5 or HMAC_SHA1
3308   remaining    are as for the cryptographic hash functions
3309
3310 Returns:       nothing
3311 */
3312
3313 static void
3314 chash_start(int type, void *base)
3315 {
3316 if (type == HMAC_MD5)
3317   md5_start((md5 *)base);
3318 else
3319   sha1_start((sha1 *)base);
3320 }
3321
3322 static void
3323 chash_mid(int type, void *base, uschar *string)
3324 {
3325 if (type == HMAC_MD5)
3326   md5_mid((md5 *)base, string);
3327 else
3328   sha1_mid((sha1 *)base, string);
3329 }
3330
3331 static void
3332 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3333 {
3334 if (type == HMAC_MD5)
3335   md5_end((md5 *)base, string, length, digest);
3336 else
3337   sha1_end((sha1 *)base, string, length, digest);
3338 }
3339
3340
3341
3342
3343
3344 /********************************************************
3345 * prvs: Get last three digits of days since Jan 1, 1970 *
3346 ********************************************************/
3347
3348 /* This is needed to implement the "prvs" BATV reverse
3349    path signing scheme
3350
3351 Argument: integer "days" offset to add or substract to
3352           or from the current number of days.
3353
3354 Returns:  pointer to string containing the last three
3355           digits of the number of days since Jan 1, 1970,
3356           modified by the offset argument, NULL if there
3357           was an error in the conversion.
3358
3359 */
3360
3361 static uschar *
3362 prvs_daystamp(int day_offset)
3363 {
3364 uschar *days = store_get(32);                /* Need at least 24 for cases */
3365 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3366   (time(NULL) + day_offset*86400)/86400);
3367 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3368 }
3369
3370
3371
3372 /********************************************************
3373 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3374 ********************************************************/
3375
3376 /* This is needed to implement the "prvs" BATV reverse
3377    path signing scheme
3378
3379 Arguments:
3380   address RFC2821 Address to use
3381       key The key to use (must be less than 64 characters
3382           in size)
3383   key_num Single-digit key number to use. Defaults to
3384           '0' when NULL.
3385
3386 Returns:  pointer to string containing the first three
3387           bytes of the final hash in hex format, NULL if
3388           there was an error in the process.
3389 */
3390
3391 static uschar *
3392 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3393 {
3394 uschar *hash_source, *p;
3395 int size = 0,offset = 0,i;
3396 sha1 sha1_base;
3397 void *use_base = &sha1_base;
3398 uschar innerhash[20];
3399 uschar finalhash[20];
3400 uschar innerkey[64];
3401 uschar outerkey[64];
3402 uschar *finalhash_hex = store_get(40);
3403
3404 if (key_num == NULL)
3405   key_num = US"0";
3406
3407 if (Ustrlen(key) > 64)
3408   return NULL;
3409
3410 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3411 hash_source = string_cat(hash_source,&size,&offset,daystamp,3);
3412 hash_source = string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3413 hash_source[offset] = '\0';
3414
3415 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3416
3417 memset(innerkey, 0x36, 64);
3418 memset(outerkey, 0x5c, 64);
3419
3420 for (i = 0; i < Ustrlen(key); i++)
3421   {
3422   innerkey[i] ^= key[i];
3423   outerkey[i] ^= key[i];
3424   }
3425
3426 chash_start(HMAC_SHA1, use_base);
3427 chash_mid(HMAC_SHA1, use_base, innerkey);
3428 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3429
3430 chash_start(HMAC_SHA1, use_base);
3431 chash_mid(HMAC_SHA1, use_base, outerkey);
3432 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3433
3434 p = finalhash_hex;
3435 for (i = 0; i < 3; i++)
3436   {
3437   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3438   *p++ = hex_digits[finalhash[i] & 0x0f];
3439   }
3440 *p = '\0';
3441
3442 return finalhash_hex;
3443 }
3444
3445
3446
3447
3448 /*************************************************
3449 *        Join a file onto the output string      *
3450 *************************************************/
3451
3452 /* This is used for readfile/readsock and after a run expansion.
3453 It joins the contents of a file onto the output string, globally replacing
3454 newlines with a given string (optionally).
3455
3456 Arguments:
3457   f            the FILE
3458   yield        pointer to the expandable string
3459   sizep        pointer to the current size
3460   ptrp         pointer to the current position
3461   eol          newline replacement string, or NULL
3462
3463 Returns:       new value of string pointer
3464 */
3465
3466 static uschar *
3467 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3468 {
3469 int eollen = eol ? Ustrlen(eol) : 0;
3470 uschar buffer[1024];
3471
3472 while (Ufgets(buffer, sizeof(buffer), f))
3473   {
3474   int len = Ustrlen(buffer);
3475   if (eol && buffer[len-1] == '\n') len--;
3476   yield = string_cat(yield, sizep, ptrp, buffer, len);
3477   if (buffer[len] != 0)
3478     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3479   }
3480
3481 if (yield) yield[*ptrp] = 0;
3482
3483 return yield;
3484 }
3485
3486
3487
3488
3489 /*************************************************
3490 *          Evaluate numeric expression           *
3491 *************************************************/
3492
3493 /* This is a set of mutually recursive functions that evaluate an arithmetic
3494 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3495 these functions that is called from elsewhere is eval_expr, whose interface is:
3496
3497 Arguments:
3498   sptr        pointer to the pointer to the string - gets updated
3499   decimal     TRUE if numbers are to be assumed decimal
3500   error       pointer to where to put an error message - must be NULL on input
3501   endket      TRUE if ')' must terminate - FALSE for external call
3502
3503 Returns:      on success: the value of the expression, with *error still NULL
3504               on failure: an undefined value, with *error = a message
3505 */
3506
3507 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3508
3509
3510 static int_eximarith_t
3511 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3512 {
3513 uschar *s = *sptr;
3514 int_eximarith_t x = eval_op_or(&s, decimal, error);
3515 if (*error == NULL)
3516   {
3517   if (endket)
3518     {
3519     if (*s != ')')
3520       *error = US"expecting closing parenthesis";
3521     else
3522       while (isspace(*(++s)));
3523     }
3524   else if (*s != 0) *error = US"expecting operator";
3525   }
3526 *sptr = s;
3527 return x;
3528 }
3529
3530
3531 static int_eximarith_t
3532 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3533 {
3534 register int c;
3535 int_eximarith_t n;
3536 uschar *s = *sptr;
3537 while (isspace(*s)) s++;
3538 c = *s;
3539 if (isdigit(c))
3540   {
3541   int count;
3542   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3543   s += count;
3544   switch (tolower(*s))
3545     {
3546     default: break;
3547     case 'k': n *= 1024; s++; break;
3548     case 'm': n *= 1024*1024; s++; break;
3549     case 'g': n *= 1024*1024*1024; s++; break;
3550     }
3551   while (isspace (*s)) s++;
3552   }
3553 else if (c == '(')
3554   {
3555   s++;
3556   n = eval_expr(&s, decimal, error, 1);
3557   }
3558 else
3559   {
3560   *error = US"expecting number or opening parenthesis";
3561   n = 0;
3562   }
3563 *sptr = s;
3564 return n;
3565 }
3566
3567
3568 static int_eximarith_t
3569 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3570 {
3571 uschar *s = *sptr;
3572 int_eximarith_t x;
3573 while (isspace(*s)) s++;
3574 if (*s == '+' || *s == '-' || *s == '~')
3575   {
3576   int op = *s++;
3577   x = eval_op_unary(&s, decimal, error);
3578   if (op == '-') x = -x;
3579     else if (op == '~') x = ~x;
3580   }
3581 else
3582   {
3583   x = eval_number(&s, decimal, error);
3584   }
3585 *sptr = s;
3586 return x;
3587 }
3588
3589
3590 static int_eximarith_t
3591 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3592 {
3593 uschar *s = *sptr;
3594 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3595 if (*error == NULL)
3596   {
3597   while (*s == '*' || *s == '/' || *s == '%')
3598     {
3599     int op = *s++;
3600     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3601     if (*error != NULL) break;
3602     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3603      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3604      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3605      * -N*M is INT_MIN will yielf INT_MIN.
3606      * Since we don't support floating point, this is somewhat simpler.
3607      * Ideally, we'd return an error, but since we overflow for all other
3608      * arithmetic, consistency suggests otherwise, but what's the correct value
3609      * to use?  There is none.
3610      * The C standard guarantees overflow for unsigned arithmetic but signed
3611      * overflow invokes undefined behaviour; in practice, this is overflow
3612      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3613      * that long/longlong larger than int are available, or we could just work
3614      * with larger types.  We should consider whether to guarantee 32bit eval
3615      * and 64-bit working variables, with errors returned.  For now ...
3616      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3617      * can just let the other invalid results occur otherwise, as they have
3618      * until now.  For this one case, we can coerce.
3619      */
3620     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3621       {
3622       DEBUG(D_expand)
3623         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3624             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3625       x = EXIM_ARITH_MAX;
3626       continue;
3627       }
3628     if (op == '*')
3629       x *= y;
3630     else
3631       {
3632       if (y == 0)
3633         {
3634         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3635         x = 0;
3636         break;
3637         }
3638       if (op == '/')
3639         x /= y;
3640       else
3641         x %= y;
3642       }
3643     }
3644   }
3645 *sptr = s;
3646 return x;
3647 }
3648
3649
3650 static int_eximarith_t
3651 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3652 {
3653 uschar *s = *sptr;
3654 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3655 if (*error == NULL)
3656   {
3657   while (*s == '+' || *s == '-')
3658     {
3659     int op = *s++;
3660     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3661     if (*error != NULL) break;
3662     if (op == '+') x += y; else x -= y;
3663     }
3664   }
3665 *sptr = s;
3666 return x;
3667 }
3668
3669
3670 static int_eximarith_t
3671 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3672 {
3673 uschar *s = *sptr;
3674 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3675 if (*error == NULL)
3676   {
3677   while ((*s == '<' || *s == '>') && s[1] == s[0])
3678     {
3679     int_eximarith_t y;
3680     int op = *s++;
3681     s++;
3682     y = eval_op_sum(&s, decimal, error);
3683     if (*error != NULL) break;
3684     if (op == '<') x <<= y; else x >>= y;
3685     }
3686   }
3687 *sptr = s;
3688 return x;
3689 }
3690
3691
3692 static int_eximarith_t
3693 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3694 {
3695 uschar *s = *sptr;
3696 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3697 if (*error == NULL)
3698   {
3699   while (*s == '&')
3700     {
3701     int_eximarith_t y;
3702     s++;
3703     y = eval_op_shift(&s, decimal, error);
3704     if (*error != NULL) break;
3705     x &= y;
3706     }
3707   }
3708 *sptr = s;
3709 return x;
3710 }
3711
3712
3713 static int_eximarith_t
3714 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3715 {
3716 uschar *s = *sptr;
3717 int_eximarith_t x = eval_op_and(&s, decimal, error);
3718 if (*error == NULL)
3719   {
3720   while (*s == '^')
3721     {
3722     int_eximarith_t y;
3723     s++;
3724     y = eval_op_and(&s, decimal, error);
3725     if (*error != NULL) break;
3726     x ^= y;
3727     }
3728   }
3729 *sptr = s;
3730 return x;
3731 }
3732
3733
3734 static int_eximarith_t
3735 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3736 {
3737 uschar *s = *sptr;
3738 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3739 if (*error == NULL)
3740   {
3741   while (*s == '|')
3742     {
3743     int_eximarith_t y;
3744     s++;
3745     y = eval_op_xor(&s, decimal, error);
3746     if (*error != NULL) break;
3747     x |= y;
3748     }
3749   }
3750 *sptr = s;
3751 return x;
3752 }
3753
3754
3755
3756 /*************************************************
3757 *                 Expand string                  *
3758 *************************************************/
3759
3760 /* Returns either an unchanged string, or the expanded string in stacking pool
3761 store. Interpreted sequences are:
3762
3763    \...                    normal escaping rules
3764    $name                   substitutes the variable
3765    ${name}                 ditto
3766    ${op:string}            operates on the expanded string value
3767    ${item{arg1}{arg2}...}  expands the args and then does the business
3768                              some literal args are not enclosed in {}
3769
3770 There are now far too many operators and item types to make it worth listing
3771 them here in detail any more.
3772
3773 We use an internal routine recursively to handle embedded substrings. The
3774 external function follows. The yield is NULL if the expansion failed, and there
3775 are two cases: if something collapsed syntactically, or if "fail" was given
3776 as the action on a lookup failure. These can be distinguised by looking at the
3777 variable expand_string_forcedfail, which is TRUE in the latter case.
3778
3779 The skipping flag is set true when expanding a substring that isn't actually
3780 going to be used (after "if" or "lookup") and it prevents lookups from
3781 happening lower down.
3782
3783 Store usage: At start, a store block of the length of the input plus 64
3784 is obtained. This is expanded as necessary by string_cat(), which might have to
3785 get a new block, or might be able to expand the original. At the end of the
3786 function we can release any store above that portion of the yield block that
3787 was actually used. In many cases this will be optimal.
3788
3789 However: if the first item in the expansion is a variable name or header name,
3790 we reset the store before processing it; if the result is in fresh store, we
3791 use that without copying. This is helpful for expanding strings like
3792 $message_headers which can get very long.
3793
3794 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3795 since resetting the store at the end of the expansion will free store that was
3796 allocated by the plugin code as well as the slop after the expanded string. So
3797 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3798 and, given the acl condition, ${if }. This is an unfortunate consequence of
3799 string expansion becoming too powerful.
3800
3801 Arguments:
3802   string         the string to be expanded
3803   ket_ends       true if expansion is to stop at }
3804   left           if not NULL, a pointer to the first character after the
3805                  expansion is placed here (typically used with ket_ends)
3806   skipping       TRUE for recursive calls when the value isn't actually going
3807                  to be used (to allow for optimisation)
3808   honour_dollar  TRUE if $ is to be expanded,
3809                  FALSE if it's just another character
3810   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3811                  the store.
3812
3813 Returns:         NULL if expansion fails:
3814                    expand_string_forcedfail is set TRUE if failure was forced
3815                    expand_string_message contains a textual error message
3816                  a pointer to the expanded string on success
3817 */
3818
3819 static uschar *
3820 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3821   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3822 {
3823 int ptr = 0;
3824 int size = Ustrlen(string)+ 64;
3825 int item_type;
3826 uschar *yield = store_get(size);
3827 const uschar *s = string;
3828 uschar *save_expand_nstring[EXPAND_MAXN+1];
3829 int save_expand_nlength[EXPAND_MAXN+1];
3830 BOOL resetok = TRUE;
3831
3832 expand_string_forcedfail = FALSE;
3833 expand_string_message = US"";
3834
3835 while (*s != 0)
3836   {
3837   uschar *value;
3838   uschar name[256];
3839
3840   /* \ escapes the next character, which must exist, or else
3841   the expansion fails. There's a special escape, \N, which causes
3842   copying of the subject verbatim up to the next \N. Otherwise,
3843   the escapes are the standard set. */
3844
3845   if (*s == '\\')
3846     {
3847     if (s[1] == 0)
3848       {
3849       expand_string_message = US"\\ at end of string";
3850       goto EXPAND_FAILED;
3851       }
3852
3853     if (s[1] == 'N')
3854       {
3855       const uschar * t = s + 2;
3856       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3857       yield = string_cat(yield, &size, &ptr, t, s - t);
3858       if (*s != 0) s += 2;
3859       }
3860
3861     else
3862       {
3863       uschar ch[1];
3864       ch[0] = string_interpret_escape(&s);
3865       s++;
3866       yield = string_cat(yield, &size, &ptr, ch, 1);
3867       }
3868
3869     continue;
3870     }
3871
3872   /*{*/
3873   /* Anything other than $ is just copied verbatim, unless we are
3874   looking for a terminating } character. */
3875
3876   /*{*/
3877   if (ket_ends && *s == '}') break;
3878
3879   if (*s != '$' || !honour_dollar)
3880     {
3881     yield = string_cat(yield, &size, &ptr, s++, 1);
3882     continue;
3883     }
3884
3885   /* No { after the $ - must be a plain name or a number for string
3886   match variable. There has to be a fudge for variables that are the
3887   names of header fields preceded by "$header_" because header field
3888   names can contain any printing characters except space and colon.
3889   For those that don't like typing this much, "$h_" is a synonym for
3890   "$header_". A non-existent header yields a NULL value; nothing is
3891   inserted. */  /*}*/
3892
3893   if (isalpha((*(++s))))
3894     {
3895     int len;
3896     int newsize = 0;
3897
3898     s = read_name(name, sizeof(name), s, US"_");
3899
3900     /* If this is the first thing to be expanded, release the pre-allocated
3901     buffer. */
3902
3903     if (ptr == 0 && yield != NULL)
3904       {
3905       if (resetok) store_reset(yield);
3906       yield = NULL;
3907       size = 0;
3908       }
3909
3910     /* Header */
3911
3912     if (Ustrncmp(name, "h_", 2) == 0 ||
3913         Ustrncmp(name, "rh_", 3) == 0 ||
3914         Ustrncmp(name, "bh_", 3) == 0 ||
3915         Ustrncmp(name, "header_", 7) == 0 ||
3916         Ustrncmp(name, "rheader_", 8) == 0 ||
3917         Ustrncmp(name, "bheader_", 8) == 0)
3918       {
3919       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3920       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3921       s = read_header_name(name, sizeof(name), s);
3922       value = find_header(name, FALSE, &newsize, want_raw, charset);
3923
3924       /* If we didn't find the header, and the header contains a closing brace
3925       character, this may be a user error where the terminating colon
3926       has been omitted. Set a flag to adjust the error message in this case.
3927       But there is no error here - nothing gets inserted. */
3928
3929       if (value == NULL)
3930         {
3931         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3932         continue;
3933         }
3934       }
3935
3936     /* Variable */
3937
3938     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3939       {
3940       expand_string_message =
3941         string_sprintf("unknown variable name \"%s\"", name);
3942         check_variable_error_message(name);
3943       goto EXPAND_FAILED;
3944       }
3945
3946     /* If the data is known to be in a new buffer, newsize will be set to the
3947     size of that buffer. If this is the first thing in an expansion string,
3948     yield will be NULL; just point it at the new store instead of copying. Many
3949     expansion strings contain just one reference, so this is a useful
3950     optimization, especially for humungous headers. */
3951
3952     len = Ustrlen(value);
3953     if (yield == NULL && newsize != 0)
3954       {
3955       yield = value;
3956       size = newsize;
3957       ptr = len;
3958       }
3959     else yield = string_cat(yield, &size, &ptr, value, len);
3960
3961     continue;
3962     }
3963
3964   if (isdigit(*s))
3965     {
3966     int n;
3967     s = read_cnumber(&n, s);
3968     if (n >= 0 && n <= expand_nmax)
3969       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3970         expand_nlength[n]);
3971     continue;
3972     }
3973
3974   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
3975
3976   if (*s != '{')                                                        /*}*/
3977     {
3978     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
3979     goto EXPAND_FAILED;
3980     }
3981
3982   /* After { there can be various things, but they all start with
3983   an initial word, except for a number for a string match variable. */
3984
3985   if (isdigit((*(++s))))
3986     {
3987     int n;
3988     s = read_cnumber(&n, s);            /*{*/
3989     if (*s++ != '}')
3990       {                                 /*{*/
3991       expand_string_message = US"} expected after number";
3992       goto EXPAND_FAILED;
3993       }
3994     if (n >= 0 && n <= expand_nmax)
3995       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3996         expand_nlength[n]);
3997     continue;
3998     }
3999
4000   if (!isalpha(*s))
4001     {
4002     expand_string_message = US"letter or digit expected after ${";      /*}*/
4003     goto EXPAND_FAILED;
4004     }
4005
4006   /* Allow "-" in names to cater for substrings with negative
4007   arguments. Since we are checking for known names after { this is
4008   OK. */
4009
4010   s = read_name(name, sizeof(name), s, US"_-");
4011   item_type = chop_match(name, item_table, nelem(item_table));
4012
4013   switch(item_type)
4014     {
4015     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4016     If the ACL returns accept or reject we return content set by "message ="
4017     There is currently no limit on recursion; this would have us call
4018     acl_check_internal() directly and get a current level from somewhere.
4019     See also the acl expansion condition ECOND_ACL and the traditional
4020     acl modifier ACLC_ACL.
4021     Assume that the function has side-effects on the store that must be preserved.
4022     */
4023
4024     case EITEM_ACL:
4025       /* ${acl {name} {arg1}{arg2}...} */
4026       {
4027       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4028       uschar *user_msg;
4029
4030       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4031                       &resetok))
4032         {
4033         case 1: goto EXPAND_FAILED_CURLY;
4034         case 2:
4035         case 3: goto EXPAND_FAILED;
4036         }
4037       if (skipping) continue;
4038
4039       resetok = FALSE;
4040       switch(eval_acl(sub, nelem(sub), &user_msg))
4041         {
4042         case OK:
4043         case FAIL:
4044           DEBUG(D_expand)
4045             debug_printf("acl expansion yield: %s\n", user_msg);
4046           if (user_msg)
4047             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
4048           continue;
4049
4050         case DEFER:
4051           expand_string_forcedfail = TRUE;
4052         default:
4053           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4054           goto EXPAND_FAILED;
4055         }
4056       }
4057
4058     /* Handle conditionals - preserve the values of the numerical expansion
4059     variables in case they get changed by a regular expression match in the
4060     condition. If not, they retain their external settings. At the end
4061     of this "if" section, they get restored to their previous values. */
4062
4063     case EITEM_IF:
4064       {
4065       BOOL cond = FALSE;
4066       const uschar *next_s;
4067       int save_expand_nmax =
4068         save_expand_strings(save_expand_nstring, save_expand_nlength);
4069
4070       while (isspace(*s)) s++;
4071       next_s = eval_condition(s, &resetok, skipping? NULL : &cond);
4072       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4073
4074       DEBUG(D_expand)
4075         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
4076           cond? "true" : "false");
4077
4078       s = next_s;
4079
4080       /* The handling of "yes" and "no" result strings is now in a separate
4081       function that is also used by ${lookup} and ${extract} and ${run}. */
4082
4083       switch(process_yesno(
4084                skipping,                     /* were previously skipping */
4085                cond,                         /* success/failure indicator */
4086                lookup_value,                 /* value to reset for string2 */
4087                &s,                           /* input pointer */
4088                &yield,                       /* output pointer */
4089                &size,                        /* output size */
4090                &ptr,                         /* output current point */
4091                US"if",                       /* condition type */
4092                &resetok))
4093         {
4094         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4095         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4096         }
4097
4098       /* Restore external setting of expansion variables for continuation
4099       at this level. */
4100
4101       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4102         save_expand_nlength);
4103       continue;
4104       }
4105
4106 #ifdef SUPPORT_I18N
4107     case EITEM_IMAPFOLDER:
4108       {                         /* ${imapfolder {name}{sep]{specials}} */
4109       uschar *sub_arg[3];
4110       uschar *encoded;
4111
4112       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4113                       &resetok))
4114         {
4115         case 1: goto EXPAND_FAILED_CURLY;
4116         case 2:
4117         case 3: goto EXPAND_FAILED;
4118         }
4119
4120       if (sub_arg[1] == NULL)           /* One argument */
4121         {
4122         sub_arg[1] = US"/";             /* default separator */
4123         sub_arg[2] = NULL;
4124         }
4125       else if (Ustrlen(sub_arg[1]) != 1)
4126         {
4127         expand_string_message =
4128           string_sprintf(
4129                 "IMAP folder separator must be one character, found \"%s\"",
4130                 sub_arg[1]);
4131         goto EXPAND_FAILED;
4132         }
4133
4134       if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4135                           sub_arg[1][0], sub_arg[2], &expand_string_message)))
4136         goto EXPAND_FAILED;
4137       if (!skipping)
4138         yield = string_cat(yield, &size, &ptr, encoded, Ustrlen(encoded));
4139       continue;
4140       }
4141 #endif
4142
4143     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4144     expanding an internal string that isn't actually going to be used. All we
4145     need to do is check the syntax, so don't do a lookup at all. Preserve the
4146     values of the numerical expansion variables in case they get changed by a
4147     partial lookup. If not, they retain their external settings. At the end
4148     of this "lookup" section, they get restored to their previous values. */
4149
4150     case EITEM_LOOKUP:
4151       {
4152       int stype, partial, affixlen, starflags;
4153       int expand_setup = 0;
4154       int nameptr = 0;
4155       uschar *key, *filename;
4156       const uschar *affix;
4157       uschar *save_lookup_value = lookup_value;
4158       int save_expand_nmax =
4159         save_expand_strings(save_expand_nstring, save_expand_nlength);
4160
4161       if ((expand_forbid & RDO_LOOKUP) != 0)
4162         {
4163         expand_string_message = US"lookup expansions are not permitted";
4164         goto EXPAND_FAILED;
4165         }
4166
4167       /* Get the key we are to look up for single-key+file style lookups.
4168       Otherwise set the key NULL pro-tem. */
4169
4170       while (isspace(*s)) s++;
4171       if (*s == '{')                                    /*}*/
4172         {
4173         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4174         if (key == NULL) goto EXPAND_FAILED;            /*{*/
4175         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4176         while (isspace(*s)) s++;
4177         }
4178       else key = NULL;
4179
4180       /* Find out the type of database */
4181
4182       if (!isalpha(*s))
4183         {
4184         expand_string_message = US"missing lookup type";
4185         goto EXPAND_FAILED;
4186         }
4187
4188       /* The type is a string that may contain special characters of various
4189       kinds. Allow everything except space or { to appear; the actual content
4190       is checked by search_findtype_partial. */         /*}*/
4191
4192       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4193         {
4194         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4195         s++;
4196         }
4197       name[nameptr] = 0;
4198       while (isspace(*s)) s++;
4199
4200       /* Now check for the individual search type and any partial or default
4201       options. Only those types that are actually in the binary are valid. */
4202
4203       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4204         &starflags);
4205       if (stype < 0)
4206         {
4207         expand_string_message = search_error_message;
4208         goto EXPAND_FAILED;
4209         }
4210
4211       /* Check that a key was provided for those lookup types that need it,
4212       and was not supplied for those that use the query style. */
4213
4214       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4215         {
4216         if (key == NULL)
4217           {
4218           expand_string_message = string_sprintf("missing {key} for single-"
4219             "key \"%s\" lookup", name);
4220           goto EXPAND_FAILED;
4221           }
4222         }
4223       else
4224         {
4225         if (key != NULL)
4226           {
4227           expand_string_message = string_sprintf("a single key was given for "
4228             "lookup type \"%s\", which is not a single-key lookup type", name);
4229           goto EXPAND_FAILED;
4230           }
4231         }
4232
4233       /* Get the next string in brackets and expand it. It is the file name for
4234       single-key+file lookups, and the whole query otherwise. In the case of
4235       queries that also require a file name (e.g. sqlite), the file name comes
4236       first. */
4237
4238       if (*s != '{') goto EXPAND_FAILED_CURLY;
4239       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4240       if (filename == NULL) goto EXPAND_FAILED;
4241       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4242       while (isspace(*s)) s++;
4243
4244       /* If this isn't a single-key+file lookup, re-arrange the variables
4245       to be appropriate for the search_ functions. For query-style lookups,
4246       there is just a "key", and no file name. For the special query-style +
4247       file types, the query (i.e. "key") starts with a file name. */
4248
4249       if (key == NULL)
4250         {
4251         while (isspace(*filename)) filename++;
4252         key = filename;
4253
4254         if (mac_islookup(stype, lookup_querystyle))
4255           {
4256           filename = NULL;
4257           }
4258         else
4259           {
4260           if (*filename != '/')
4261             {
4262             expand_string_message = string_sprintf(
4263               "absolute file name expected for \"%s\" lookup", name);
4264             goto EXPAND_FAILED;
4265             }
4266           while (*key != 0 && !isspace(*key)) key++;
4267           if (*key != 0) *key++ = 0;
4268           }
4269         }
4270
4271       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4272       the entry was not found. Note that there is no search_close() function.
4273       Files are left open in case of re-use. At suitable places in higher logic,
4274       search_tidyup() is called to tidy all open files. This can save opening
4275       the same file several times. However, files may also get closed when
4276       others are opened, if too many are open at once. The rule is that a
4277       handle should not be used after a second search_open().
4278
4279       Request that a partial search sets up $1 and maybe $2 by passing
4280       expand_setup containing zero. If its value changes, reset expand_nmax,
4281       since new variables will have been set. Note that at the end of this
4282       "lookup" section, the old numeric variables are restored. */
4283
4284       if (skipping)
4285         lookup_value = NULL;
4286       else
4287         {
4288         void *handle = search_open(filename, stype, 0, NULL, NULL);
4289         if (handle == NULL)
4290           {
4291           expand_string_message = search_error_message;
4292           goto EXPAND_FAILED;
4293           }
4294         lookup_value = search_find(handle, filename, key, partial, affix,
4295           affixlen, starflags, &expand_setup);
4296         if (search_find_defer)
4297           {
4298           expand_string_message =
4299             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4300               string_printing2(key, FALSE), search_error_message);
4301           goto EXPAND_FAILED;
4302           }
4303         if (expand_setup > 0) expand_nmax = expand_setup;
4304         }
4305
4306       /* The handling of "yes" and "no" result strings is now in a separate
4307       function that is also used by ${if} and ${extract}. */
4308
4309       switch(process_yesno(
4310                skipping,                     /* were previously skipping */
4311                lookup_value != NULL,         /* success/failure indicator */
4312                save_lookup_value,            /* value to reset for string2 */
4313                &s,                           /* input pointer */
4314                &yield,                       /* output pointer */
4315                &size,                        /* output size */
4316                &ptr,                         /* output current point */
4317                US"lookup",                   /* condition type */
4318                &resetok))
4319         {
4320         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4321         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4322         }
4323
4324       /* Restore external setting of expansion variables for carrying on
4325       at this level, and continue. */
4326
4327       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4328         save_expand_nlength);
4329       continue;
4330       }
4331
4332     /* If Perl support is configured, handle calling embedded perl subroutines,
4333     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4334     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4335     arguments (defined below). */
4336
4337     #define EXIM_PERL_MAX_ARGS 8
4338
4339     case EITEM_PERL:
4340     #ifndef EXIM_PERL
4341     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4342       "is not included in this binary";
4343     goto EXPAND_FAILED;
4344
4345     #else   /* EXIM_PERL */
4346       {
4347       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4348       uschar *new_yield;
4349
4350       if ((expand_forbid & RDO_PERL) != 0)
4351         {
4352         expand_string_message = US"Perl calls are not permitted";
4353         goto EXPAND_FAILED;
4354         }
4355
4356       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4357            US"perl", &resetok))
4358         {
4359         case 1: goto EXPAND_FAILED_CURLY;
4360         case 2:
4361         case 3: goto EXPAND_FAILED;
4362         }
4363
4364       /* If skipping, we don't actually do anything */
4365
4366       if (skipping) continue;
4367
4368       /* Start the interpreter if necessary */
4369
4370       if (!opt_perl_started)
4371         {
4372         uschar *initerror;
4373         if (opt_perl_startup == NULL)
4374           {
4375           expand_string_message = US"A setting of perl_startup is needed when "
4376             "using the Perl interpreter";
4377           goto EXPAND_FAILED;
4378           }
4379         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4380         initerror = init_perl(opt_perl_startup);
4381         if (initerror != NULL)
4382           {
4383           expand_string_message =
4384             string_sprintf("error in perl_startup code: %s\n", initerror);
4385           goto EXPAND_FAILED;
4386           }
4387         opt_perl_started = TRUE;
4388         }
4389
4390       /* Call the function */
4391
4392       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4393       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4394         sub_arg[0], sub_arg + 1);
4395
4396       /* NULL yield indicates failure; if the message pointer has been set to
4397       NULL, the yield was undef, indicating a forced failure. Otherwise the
4398       message will indicate some kind of Perl error. */
4399
4400       if (new_yield == NULL)
4401         {
4402         if (expand_string_message == NULL)
4403           {
4404           expand_string_message =
4405             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4406               "failure", sub_arg[0]);
4407           expand_string_forcedfail = TRUE;
4408           }
4409         goto EXPAND_FAILED;
4410         }
4411
4412       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4413       set during a callback from Perl. */
4414
4415       expand_string_forcedfail = FALSE;
4416       yield = new_yield;
4417       continue;
4418       }
4419     #endif /* EXIM_PERL */
4420
4421     /* Transform email address to "prvs" scheme to use
4422        as BATV-signed return path */
4423
4424     case EITEM_PRVS:
4425       {
4426       uschar *sub_arg[3];
4427       uschar *p,*domain;
4428
4429       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4430         {
4431         case 1: goto EXPAND_FAILED_CURLY;
4432         case 2:
4433         case 3: goto EXPAND_FAILED;
4434         }
4435
4436       /* If skipping, we don't actually do anything */
4437       if (skipping) continue;
4438
4439       /* sub_arg[0] is the address */
4440       domain = Ustrrchr(sub_arg[0],'@');
4441       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4442         {
4443         expand_string_message = US"prvs first argument must be a qualified email address";
4444         goto EXPAND_FAILED;
4445         }
4446
4447       /* Calculate the hash. The second argument must be a single-digit
4448       key number, or unset. */
4449
4450       if (sub_arg[2] != NULL &&
4451           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4452         {
4453         expand_string_message = US"prvs second argument must be a single digit";
4454         goto EXPAND_FAILED;
4455         }
4456
4457       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4458       if (p == NULL)
4459         {
4460         expand_string_message = US"prvs hmac-sha1 conversion failed";
4461         goto EXPAND_FAILED;
4462         }
4463
4464       /* Now separate the domain from the local part */
4465       *domain++ = '\0';
4466
4467       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4468       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4469       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4470       string_cat(yield,&size,&ptr,p,6);
4471       string_cat(yield,&size,&ptr,US"=",1);
4472       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4473       string_cat(yield,&size,&ptr,US"@",1);
4474       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4475
4476       continue;
4477       }
4478
4479     /* Check a prvs-encoded address for validity */
4480
4481     case EITEM_PRVSCHECK:
4482       {
4483       uschar *sub_arg[3];
4484       int mysize = 0, myptr = 0;
4485       const pcre *re;
4486       uschar *p;
4487
4488       /* TF: Ugliness: We want to expand parameter 1 first, then set
4489          up expansion variables that are used in the expansion of
4490          parameter 2. So we clone the string for the first
4491          expansion, where we only expand parameter 1.
4492
4493          PH: Actually, that isn't necessary. The read_subs() function is
4494          designed to work this way for the ${if and ${lookup expansions. I've
4495          tidied the code.
4496       */
4497
4498       /* Reset expansion variables */
4499       prvscheck_result = NULL;
4500       prvscheck_address = NULL;
4501       prvscheck_keynum = NULL;
4502
4503       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4504         {
4505         case 1: goto EXPAND_FAILED_CURLY;
4506         case 2:
4507         case 3: goto EXPAND_FAILED;
4508         }
4509
4510       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4511                               TRUE,FALSE);
4512
4513       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4514         {
4515         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4516         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4517         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4518         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4519         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4520
4521         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4522         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4523         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4524         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4525         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4526
4527         /* Set up expansion variables */
4528         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4529         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4530         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4531         prvscheck_address[myptr] = '\0';
4532         prvscheck_keynum = string_copy(key_num);
4533
4534         /* Now expand the second argument */
4535         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4536           {
4537           case 1: goto EXPAND_FAILED_CURLY;
4538           case 2:
4539           case 3: goto EXPAND_FAILED;
4540           }
4541
4542         /* Now we have the key and can check the address. */
4543
4544         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4545           daystamp);
4546
4547         if (p == NULL)
4548           {
4549           expand_string_message = US"hmac-sha1 conversion failed";
4550           goto EXPAND_FAILED;
4551           }
4552
4553         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4554         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4555
4556         if (Ustrcmp(p,hash) == 0)
4557           {
4558           /* Success, valid BATV address. Now check the expiry date. */
4559           uschar *now = prvs_daystamp(0);
4560           unsigned int inow = 0,iexpire = 1;
4561
4562           (void)sscanf(CS now,"%u",&inow);
4563           (void)sscanf(CS daystamp,"%u",&iexpire);
4564
4565           /* When "iexpire" is < 7, a "flip" has occured.
4566              Adjust "inow" accordingly. */
4567           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4568
4569           if (iexpire >= inow)
4570             {
4571             prvscheck_result = US"1";
4572             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4573             }
4574             else
4575             {
4576             prvscheck_result = NULL;
4577             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4578             }
4579           }
4580         else
4581           {
4582           prvscheck_result = NULL;
4583           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4584           }
4585
4586         /* Now expand the final argument. We leave this till now so that
4587         it can include $prvscheck_result. */
4588
4589         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4590           {
4591           case 1: goto EXPAND_FAILED_CURLY;
4592           case 2:
4593           case 3: goto EXPAND_FAILED;
4594           }
4595
4596         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4597           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4598         else
4599           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4600
4601         /* Reset the "internal" variables afterwards, because they are in
4602         dynamic store that will be reclaimed if the expansion succeeded. */
4603
4604         prvscheck_address = NULL;
4605         prvscheck_keynum = NULL;
4606         }
4607       else
4608         {
4609         /* Does not look like a prvs encoded address, return the empty string.
4610            We need to make sure all subs are expanded first, so as to skip over
4611            the entire item. */
4612
4613         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4614           {
4615           case 1: goto EXPAND_FAILED_CURLY;
4616           case 2:
4617           case 3: goto EXPAND_FAILED;
4618           }
4619         }
4620
4621       continue;
4622       }
4623
4624     /* Handle "readfile" to insert an entire file */
4625
4626     case EITEM_READFILE:
4627       {
4628       FILE *f;
4629       uschar *sub_arg[2];
4630
4631       if ((expand_forbid & RDO_READFILE) != 0)
4632         {
4633         expand_string_message = US"file insertions are not permitted";
4634         goto EXPAND_FAILED;
4635         }
4636
4637       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4638         {
4639         case 1: goto EXPAND_FAILED_CURLY;
4640         case 2:
4641         case 3: goto EXPAND_FAILED;
4642         }
4643
4644       /* If skipping, we don't actually do anything */
4645
4646       if (skipping) continue;
4647
4648       /* Open the file and read it */
4649
4650       f = Ufopen(sub_arg[0], "rb");
4651       if (f == NULL)
4652         {
4653         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4654         goto EXPAND_FAILED;
4655         }
4656
4657       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4658       (void)fclose(f);
4659       continue;
4660       }
4661
4662     /* Handle "readsocket" to insert data from a Unix domain socket */
4663
4664     case EITEM_READSOCK:
4665       {
4666       int fd;
4667       int timeout = 5;
4668       int save_ptr = ptr;
4669       FILE *f;
4670       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4671       uschar *arg;
4672       uschar *sub_arg[4];
4673
4674       if ((expand_forbid & RDO_READSOCK) != 0)
4675         {
4676         expand_string_message = US"socket insertions are not permitted";
4677         goto EXPAND_FAILED;
4678         }
4679
4680       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4681       because there may be a string for expansion on failure. */
4682
4683       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4684         {
4685         case 1: goto EXPAND_FAILED_CURLY;
4686         case 2:                             /* Won't occur: no end check */
4687         case 3: goto EXPAND_FAILED;
4688         }
4689
4690       /* Sort out timeout, if given */
4691
4692       if (sub_arg[2] != NULL)
4693         {
4694         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4695         if (timeout < 0)
4696           {
4697           expand_string_message = string_sprintf("bad time value %s",
4698             sub_arg[2]);
4699           goto EXPAND_FAILED;
4700           }
4701         }
4702       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4703
4704       /* If skipping, we don't actually do anything. Otherwise, arrange to
4705       connect to either an IP or a Unix socket. */
4706
4707       if (!skipping)
4708         {
4709         /* Handle an IP (internet) domain */
4710
4711         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4712           {
4713           int port;
4714           uschar *server_name = sub_arg[0] + 5;
4715           uschar *port_name = Ustrrchr(server_name, ':');
4716
4717           /* Sort out the port */
4718
4719           if (port_name == NULL)
4720             {
4721             expand_string_message =
4722               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4723             goto EXPAND_FAILED;
4724             }
4725           *port_name++ = 0;           /* Terminate server name */
4726
4727           if (isdigit(*port_name))
4728             {
4729             uschar *end;
4730             port = Ustrtol(port_name, &end, 0);
4731             if (end != port_name + Ustrlen(port_name))
4732               {
4733               expand_string_message =
4734                 string_sprintf("invalid port number %s", port_name);
4735               goto EXPAND_FAILED;
4736               }
4737             }
4738           else
4739             {
4740             struct servent *service_info = getservbyname(CS port_name, "tcp");
4741             if (service_info == NULL)
4742               {
4743               expand_string_message = string_sprintf("unknown port \"%s\"",
4744                 port_name);
4745               goto EXPAND_FAILED;
4746               }
4747             port = ntohs(service_info->s_port);
4748             }
4749
4750           if ((fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4751                   timeout, NULL, &expand_string_message)) < 0)
4752               goto SOCK_FAIL;
4753           }
4754
4755         /* Handle a Unix domain socket */
4756
4757         else
4758           {
4759           int rc;
4760           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4761             {
4762             expand_string_message = string_sprintf("failed to create socket: %s",
4763               strerror(errno));
4764             goto SOCK_FAIL;
4765             }
4766
4767           sockun.sun_family = AF_UNIX;
4768           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4769             sub_arg[0]);
4770
4771           sigalrm_seen = FALSE;
4772           alarm(timeout);
4773           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4774           alarm(0);
4775           if (sigalrm_seen)
4776             {
4777             expand_string_message = US "socket connect timed out";
4778             goto SOCK_FAIL;
4779             }
4780           if (rc < 0)
4781             {
4782             expand_string_message = string_sprintf("failed to connect to socket "
4783               "%s: %s", sub_arg[0], strerror(errno));
4784             goto SOCK_FAIL;
4785             }
4786           }
4787
4788         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4789
4790         /* Allow sequencing of test actions */
4791         if (running_in_test_harness) millisleep(100);
4792
4793         /* Write the request string, if not empty */
4794
4795         if (sub_arg[1][0] != 0)
4796           {
4797           int len = Ustrlen(sub_arg[1]);
4798           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4799             sub_arg[1]);
4800           if (write(fd, sub_arg[1], len) != len)
4801             {
4802             expand_string_message = string_sprintf("request write to socket "
4803               "failed: %s", strerror(errno));
4804             goto SOCK_FAIL;
4805             }
4806           }
4807
4808         /* Shut down the sending side of the socket. This helps some servers to
4809         recognise that it is their turn to do some work. Just in case some
4810         system doesn't have this function, make it conditional. */
4811
4812         #ifdef SHUT_WR
4813         shutdown(fd, SHUT_WR);
4814         #endif
4815
4816         if (running_in_test_harness) millisleep(100);
4817
4818         /* Now we need to read from the socket, under a timeout. The function
4819         that reads a file can be used. */
4820
4821         f = fdopen(fd, "rb");
4822         sigalrm_seen = FALSE;
4823         alarm(timeout);
4824         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4825         alarm(0);
4826         (void)fclose(f);
4827
4828         /* After a timeout, we restore the pointer in the result, that is,
4829         make sure we add nothing from the socket. */
4830
4831         if (sigalrm_seen)
4832           {
4833           ptr = save_ptr;
4834           expand_string_message = US "socket read timed out";
4835           goto SOCK_FAIL;
4836           }
4837         }
4838
4839       /* The whole thing has worked (or we were skipping). If there is a
4840       failure string following, we need to skip it. */
4841
4842       if (*s == '{')
4843         {
4844         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4845           goto EXPAND_FAILED;
4846         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4847         while (isspace(*s)) s++;
4848         }
4849       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4850       continue;
4851
4852       /* Come here on failure to create socket, connect socket, write to the
4853       socket, or timeout on reading. If another substring follows, expand and
4854       use it. Otherwise, those conditions give expand errors. */
4855
4856       SOCK_FAIL:
4857       if (*s != '{') goto EXPAND_FAILED;
4858       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4859       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok);
4860       if (arg == NULL) goto EXPAND_FAILED;
4861       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4862       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4863       while (isspace(*s)) s++;
4864       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4865       continue;
4866       }
4867
4868     /* Handle "run" to execute a program. */
4869
4870     case EITEM_RUN:
4871       {
4872       FILE *f;
4873       uschar *arg;
4874       const uschar **argv;
4875       pid_t pid;
4876       int fd_in, fd_out;
4877       int lsize = 0, lptr = 0;
4878
4879       if ((expand_forbid & RDO_RUN) != 0)
4880         {
4881         expand_string_message = US"running a command is not permitted";
4882         goto EXPAND_FAILED;
4883         }
4884
4885       while (isspace(*s)) s++;
4886       if (*s != '{') goto EXPAND_FAILED_CURLY;
4887       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4888       if (arg == NULL) goto EXPAND_FAILED;
4889       while (isspace(*s)) s++;
4890       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4891
4892       if (skipping)   /* Just pretend it worked when we're skipping */
4893         {
4894         runrc = 0;
4895         }
4896       else
4897         {
4898         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4899             arg,                                /* raw command */
4900             FALSE,                              /* don't expand the arguments */
4901             0,                                  /* not relevant when... */
4902             NULL,                               /* no transporting address */
4903             US"${run} expansion",               /* for error messages */
4904             &expand_string_message))            /* where to put error message */
4905           goto EXPAND_FAILED;
4906
4907         /* Create the child process, making it a group leader. */
4908
4909         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
4910           {
4911           expand_string_message =
4912             string_sprintf("couldn't create child process: %s", strerror(errno));
4913           goto EXPAND_FAILED;
4914           }
4915
4916         /* Nothing is written to the standard input. */
4917
4918         (void)close(fd_in);
4919
4920         /* Read the pipe to get the command's output into $value (which is kept
4921         in lookup_value). Read during execution, so that if the output exceeds
4922         the OS pipe buffer limit, we don't block forever. Remember to not release
4923         memory just allocated for $value. */
4924
4925         resetok = FALSE;
4926         f = fdopen(fd_out, "rb");
4927         sigalrm_seen = FALSE;
4928         alarm(60);
4929         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
4930         alarm(0);
4931         (void)fclose(f);
4932
4933         /* Wait for the process to finish, applying the timeout, and inspect its
4934         return code for serious disasters. Simple non-zero returns are passed on.
4935         */
4936
4937         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4938           {
4939           if (sigalrm_seen == TRUE || runrc == -256)
4940             {
4941             expand_string_message = string_sprintf("command timed out");
4942             killpg(pid, SIGKILL);       /* Kill the whole process group */
4943             }
4944
4945           else if (runrc == -257)
4946             expand_string_message = string_sprintf("wait() failed: %s",
4947               strerror(errno));
4948
4949           else
4950             expand_string_message = string_sprintf("command killed by signal %d",
4951               -runrc);
4952
4953           goto EXPAND_FAILED;
4954           }
4955         }
4956
4957       /* Process the yes/no strings; $value may be useful in both cases */
4958
4959       switch(process_yesno(
4960                skipping,                     /* were previously skipping */
4961                runrc == 0,                   /* success/failure indicator */
4962                lookup_value,                 /* value to reset for string2 */
4963                &s,                           /* input pointer */
4964                &yield,                       /* output pointer */
4965                &size,                        /* output size */
4966                &ptr,                         /* output current point */
4967                US"run",                      /* condition type */
4968                &resetok))
4969         {
4970         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4971         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4972         }
4973
4974       continue;
4975       }
4976
4977     /* Handle character translation for "tr" */
4978
4979     case EITEM_TR:
4980       {
4981       int oldptr = ptr;
4982       int o2m;
4983       uschar *sub[3];
4984
4985       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
4986         {
4987         case 1: goto EXPAND_FAILED_CURLY;
4988         case 2:
4989         case 3: goto EXPAND_FAILED;
4990         }
4991
4992       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4993       o2m = Ustrlen(sub[2]) - 1;
4994
4995       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4996         {
4997         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4998         if (m != NULL)
4999           {
5000           int o = m - sub[1];
5001           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5002           }
5003         }
5004
5005       continue;
5006       }
5007
5008     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5009     expanded arguments. */
5010
5011     case EITEM_HASH:
5012     case EITEM_LENGTH:
5013     case EITEM_NHASH:
5014     case EITEM_SUBSTR:
5015       {
5016       int i;
5017       int len;
5018       uschar *ret;
5019       int val[2] = { 0, -1 };
5020       uschar *sub[3];
5021
5022       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5023       Ensure that sub[2] is set in the ${length } case. */
5024
5025       sub[2] = NULL;
5026       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5027              TRUE, name, &resetok))
5028         {
5029         case 1: goto EXPAND_FAILED_CURLY;
5030         case 2:
5031         case 3: goto EXPAND_FAILED;
5032         }
5033
5034       /* Juggle the arguments if there are only two of them: always move the
5035       string to the last position and make ${length{n}{str}} equivalent to
5036       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5037
5038       if (sub[2] == NULL)
5039         {
5040         sub[2] = sub[1];
5041         sub[1] = NULL;
5042         if (item_type == EITEM_LENGTH)
5043           {
5044           sub[1] = sub[0];
5045           sub[0] = NULL;
5046           }
5047         }
5048
5049       for (i = 0; i < 2; i++)
5050         {
5051         if (sub[i] == NULL) continue;
5052         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5053         if (*ret != 0 || (i != 0 && val[i] < 0))
5054           {
5055           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5056             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5057           goto EXPAND_FAILED;
5058           }
5059         }
5060
5061       ret =
5062         (item_type == EITEM_HASH)?
5063           compute_hash(sub[2], val[0], val[1], &len) :
5064         (item_type == EITEM_NHASH)?
5065           compute_nhash(sub[2], val[0], val[1], &len) :
5066           extract_substr(sub[2], val[0], val[1], &len);
5067
5068       if (ret == NULL) goto EXPAND_FAILED;
5069       yield = string_cat(yield, &size, &ptr, ret, len);
5070       continue;
5071       }
5072
5073     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5074     This code originally contributed by Steve Haslam. It currently supports
5075     the use of MD5 and SHA-1 hashes.
5076
5077     We need some workspace that is large enough to handle all the supported
5078     hash types. Use macros to set the sizes rather than be too elaborate. */
5079
5080     #define MAX_HASHLEN      20
5081     #define MAX_HASHBLOCKLEN 64
5082
5083     case EITEM_HMAC:
5084       {
5085       uschar *sub[3];
5086       md5 md5_base;
5087       sha1 sha1_base;
5088       void *use_base;
5089       int type, i;
5090       int hashlen;      /* Number of octets for the hash algorithm's output */
5091       int hashblocklen; /* Number of octets the hash algorithm processes */
5092       uschar *keyptr, *p;
5093       unsigned int keylen;
5094
5095       uschar keyhash[MAX_HASHLEN];
5096       uschar innerhash[MAX_HASHLEN];
5097       uschar finalhash[MAX_HASHLEN];
5098       uschar finalhash_hex[2*MAX_HASHLEN];
5099       uschar innerkey[MAX_HASHBLOCKLEN];
5100       uschar outerkey[MAX_HASHBLOCKLEN];
5101
5102       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5103         {
5104         case 1: goto EXPAND_FAILED_CURLY;
5105         case 2:
5106         case 3: goto EXPAND_FAILED;
5107         }
5108
5109       if (Ustrcmp(sub[0], "md5") == 0)
5110         {
5111         type = HMAC_MD5;
5112         use_base = &md5_base;
5113         hashlen = 16;
5114         hashblocklen = 64;
5115         }
5116       else if (Ustrcmp(sub[0], "sha1") == 0)
5117         {
5118         type = HMAC_SHA1;
5119         use_base = &sha1_base;
5120         hashlen = 20;
5121         hashblocklen = 64;
5122         }
5123       else
5124         {
5125         expand_string_message =
5126           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5127         goto EXPAND_FAILED;
5128         }
5129
5130       keyptr = sub[1];
5131       keylen = Ustrlen(keyptr);
5132
5133       /* If the key is longer than the hash block length, then hash the key
5134       first */
5135
5136       if (keylen > hashblocklen)
5137         {
5138         chash_start(type, use_base);
5139         chash_end(type, use_base, keyptr, keylen, keyhash);
5140         keyptr = keyhash;
5141         keylen = hashlen;
5142         }
5143
5144       /* Now make the inner and outer key values */
5145
5146       memset(innerkey, 0x36, hashblocklen);
5147       memset(outerkey, 0x5c, hashblocklen);
5148
5149       for (i = 0; i < keylen; i++)
5150         {
5151         innerkey[i] ^= keyptr[i];
5152         outerkey[i] ^= keyptr[i];
5153         }
5154
5155       /* Now do the hashes */
5156
5157       chash_start(type, use_base);
5158       chash_mid(type, use_base, innerkey);
5159       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5160
5161       chash_start(type, use_base);
5162       chash_mid(type, use_base, outerkey);
5163       chash_end(type, use_base, innerhash, hashlen, finalhash);
5164
5165       /* Encode the final hash as a hex string */
5166
5167       p = finalhash_hex;
5168       for (i = 0; i < hashlen; i++)
5169         {
5170         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5171         *p++ = hex_digits[finalhash[i] & 0x0f];
5172         }
5173
5174       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
5175         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
5176
5177       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
5178       }
5179
5180     continue;
5181
5182     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5183     We have to save the numerical variables and restore them afterwards. */
5184
5185     case EITEM_SG:
5186       {
5187       const pcre *re;
5188       int moffset, moffsetextra, slen;
5189       int roffset;
5190       int emptyopt;
5191       const uschar *rerror;
5192       uschar *subject;
5193       uschar *sub[3];
5194       int save_expand_nmax =
5195         save_expand_strings(save_expand_nstring, save_expand_nlength);
5196
5197       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5198         {
5199         case 1: goto EXPAND_FAILED_CURLY;
5200         case 2:
5201         case 3: goto EXPAND_FAILED;
5202         }
5203
5204       /* Compile the regular expression */
5205
5206       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5207         NULL);
5208
5209       if (re == NULL)
5210         {
5211         expand_string_message = string_sprintf("regular expression error in "
5212           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5213         goto EXPAND_FAILED;
5214         }
5215
5216       /* Now run a loop to do the substitutions as often as necessary. It ends
5217       when there are no more matches. Take care over matches of the null string;
5218       do the same thing as Perl does. */
5219
5220       subject = sub[0];
5221       slen = Ustrlen(sub[0]);
5222       moffset = moffsetextra = 0;
5223       emptyopt = 0;
5224
5225       for (;;)
5226         {
5227         int ovector[3*(EXPAND_MAXN+1)];
5228         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5229           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5230         int nn;
5231         uschar *insert;
5232
5233         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5234         is not necessarily the end. We want to repeat the match from one
5235         character further along, but leaving the basic offset the same (for
5236         copying below). We can't be at the end of the string - that was checked
5237         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5238         finished; copy the remaining string and end the loop. */
5239
5240         if (n < 0)
5241           {
5242           if (emptyopt != 0)
5243             {
5244             moffsetextra = 1;
5245             emptyopt = 0;
5246             continue;
5247             }
5248           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5249           break;
5250           }
5251
5252         /* Match - set up for expanding the replacement. */
5253
5254         if (n == 0) n = EXPAND_MAXN + 1;
5255         expand_nmax = 0;
5256         for (nn = 0; nn < n*2; nn += 2)
5257           {
5258           expand_nstring[expand_nmax] = subject + ovector[nn];
5259           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5260           }
5261         expand_nmax--;
5262
5263         /* Copy the characters before the match, plus the expanded insertion. */
5264
5265         yield = string_cat(yield, &size, &ptr, subject + moffset,
5266           ovector[0] - moffset);
5267         insert = expand_string(sub[2]);
5268         if (insert == NULL) goto EXPAND_FAILED;
5269         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5270
5271         moffset = ovector[1];
5272         moffsetextra = 0;
5273         emptyopt = 0;
5274
5275         /* If we have matched an empty string, first check to see if we are at
5276         the end of the subject. If so, the loop is over. Otherwise, mimic
5277         what Perl's /g options does. This turns out to be rather cunning. First
5278         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5279         string at the same point. If this fails (picked up above) we advance to
5280         the next character. */
5281
5282         if (ovector[0] == ovector[1])
5283           {
5284           if (ovector[0] == slen) break;
5285           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5286           }
5287         }
5288
5289       /* All done - restore numerical variables. */
5290
5291       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5292         save_expand_nlength);
5293       continue;
5294       }
5295
5296     /* Handle keyed and numbered substring extraction. If the first argument
5297     consists entirely of digits, then a numerical extraction is assumed. */
5298
5299     case EITEM_EXTRACT:
5300       {
5301       int i;
5302       int j = 2;
5303       int field_number = 1;
5304       BOOL field_number_set = FALSE;
5305       uschar *save_lookup_value = lookup_value;
5306       uschar *sub[3];
5307       int save_expand_nmax =
5308         save_expand_strings(save_expand_nstring, save_expand_nlength);
5309
5310       /* While skipping we cannot rely on the data for expansions being
5311       available (eg. $item) hence cannot decide on numeric vs. keyed.
5312       Just read as many arguments as there are. */
5313
5314       if (skipping)
5315         {
5316         while (isspace(*s)) s++;
5317         while (*s == '{')
5318           {
5319           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5320             goto EXPAND_FAILED;                                 /*{*/
5321           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5322           while (isspace(*s)) s++;
5323           }
5324         if (*s != '}')
5325           goto EXPAND_FAILED_CURLY;
5326         }
5327
5328       else for (i = 0; i < j; i++) /* Read the proper number of arguments */
5329         {
5330         while (isspace(*s)) s++;
5331         if (*s == '{')                                          /*}*/
5332           {
5333           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5334           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5335           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5336
5337           /* After removal of leading and trailing white space, the first
5338           argument must not be empty; if it consists entirely of digits
5339           (optionally preceded by a minus sign), this is a numerical
5340           extraction, and we expect 3 arguments. */
5341
5342           if (i == 0)
5343             {
5344             int len;
5345             int x = 0;
5346             uschar *p = sub[0];
5347
5348             while (isspace(*p)) p++;
5349             sub[0] = p;
5350
5351             len = Ustrlen(p);
5352             while (len > 0 && isspace(p[len-1])) len--;
5353             p[len] = 0;
5354
5355             if (*p == 0)
5356               {
5357               expand_string_message = US"first argument of \"extract\" must "
5358                 "not be empty";
5359               goto EXPAND_FAILED;
5360               }
5361
5362             if (*p == '-')
5363               {
5364               field_number = -1;
5365               p++;
5366               }
5367             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5368             if (*p == 0)
5369               {
5370               field_number *= x;
5371               j = 3;               /* Need 3 args */
5372               field_number_set = TRUE;
5373               }
5374             }
5375           }
5376         else goto EXPAND_FAILED_CURLY;
5377         }
5378
5379       /* Extract either the numbered or the keyed substring into $value. If
5380       skipping, just pretend the extraction failed. */
5381
5382       lookup_value = skipping? NULL : field_number_set?
5383         expand_gettokened(field_number, sub[1], sub[2]) :
5384         expand_getkeyed(sub[0], sub[1]);
5385
5386       /* If no string follows, $value gets substituted; otherwise there can
5387       be yes/no strings, as for lookup or if. */
5388
5389       switch(process_yesno(
5390                skipping,                     /* were previously skipping */
5391                lookup_value != NULL,         /* success/failure indicator */
5392                save_lookup_value,            /* value to reset for string2 */
5393                &s,                           /* input pointer */
5394                &yield,                       /* output pointer */
5395                &size,                        /* output size */
5396                &ptr,                         /* output current point */
5397                US"extract",                  /* condition type */
5398                &resetok))
5399         {
5400         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5401         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5402         }
5403
5404       /* All done - restore numerical variables. */
5405
5406       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5407         save_expand_nlength);
5408
5409       continue;
5410       }
5411
5412     /* return the Nth item from a list */
5413
5414     case EITEM_LISTEXTRACT:
5415       {
5416       int i;
5417       int field_number = 1;
5418       uschar *save_lookup_value = lookup_value;
5419       uschar *sub[2];
5420       int save_expand_nmax =
5421         save_expand_strings(save_expand_nstring, save_expand_nlength);
5422
5423       /* Read the field & list arguments */
5424
5425       for (i = 0; i < 2; i++)
5426         {
5427         while (isspace(*s)) s++;
5428         if (*s != '{')                                  /*}*/
5429           goto EXPAND_FAILED_CURLY;
5430
5431         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5432         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5433         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5434
5435         /* After removal of leading and trailing white space, the first
5436         argument must be numeric and nonempty. */
5437
5438         if (i == 0)
5439           {
5440           int len;
5441           int x = 0;
5442           uschar *p = sub[0];
5443
5444           while (isspace(*p)) p++;
5445           sub[0] = p;
5446
5447           len = Ustrlen(p);
5448           while (len > 0 && isspace(p[len-1])) len--;
5449           p[len] = 0;
5450
5451           if (!*p && !skipping)
5452             {
5453             expand_string_message = US"first argument of \"listextract\" must "
5454               "not be empty";
5455             goto EXPAND_FAILED;
5456             }
5457
5458           if (*p == '-')
5459             {
5460             field_number = -1;
5461             p++;
5462             }
5463           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5464           if (*p)
5465             {
5466             expand_string_message = US"first argument of \"listextract\" must "
5467               "be numeric";
5468             goto EXPAND_FAILED;
5469             }
5470           field_number *= x;
5471           }
5472         }
5473
5474       /* Extract the numbered element into $value. If
5475       skipping, just pretend the extraction failed. */
5476
5477       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5478
5479       /* If no string follows, $value gets substituted; otherwise there can
5480       be yes/no strings, as for lookup or if. */
5481
5482       switch(process_yesno(
5483                skipping,                     /* were previously skipping */
5484                lookup_value != NULL,         /* success/failure indicator */
5485                save_lookup_value,            /* value to reset for string2 */
5486                &s,                           /* input pointer */
5487                &yield,                       /* output pointer */
5488                &size,                        /* output size */
5489                &ptr,                         /* output current point */
5490                US"listextract",              /* condition type */
5491                &resetok))
5492         {
5493         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5494         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5495         }
5496
5497       /* All done - restore numerical variables. */
5498
5499       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5500         save_expand_nlength);
5501
5502       continue;
5503       }
5504
5505 #ifdef SUPPORT_TLS
5506     case EITEM_CERTEXTRACT:
5507       {
5508       uschar *save_lookup_value = lookup_value;
5509       uschar *sub[2];
5510       int save_expand_nmax =
5511         save_expand_strings(save_expand_nstring, save_expand_nlength);
5512
5513       /* Read the field argument */
5514       while (isspace(*s)) s++;
5515       if (*s != '{')                                    /*}*/
5516         goto EXPAND_FAILED_CURLY;
5517       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5518       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5519       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5520       /* strip spaces fore & aft */
5521       {
5522       int len;
5523       uschar *p = sub[0];
5524
5525       while (isspace(*p)) p++;
5526       sub[0] = p;
5527
5528       len = Ustrlen(p);
5529       while (len > 0 && isspace(p[len-1])) len--;
5530       p[len] = 0;
5531       }
5532
5533       /* inspect the cert argument */
5534       while (isspace(*s)) s++;
5535       if (*s != '{')                                    /*}*/
5536         goto EXPAND_FAILED_CURLY;
5537       if (*++s != '$')
5538         {
5539         expand_string_message = US"second argument of \"certextract\" must "
5540           "be a certificate variable";
5541         goto EXPAND_FAILED;
5542         }
5543       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5544       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5545       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5546
5547       if (skipping)
5548         lookup_value = NULL;
5549       else
5550         {
5551         lookup_value = expand_getcertele(sub[0], sub[1]);
5552         if (*expand_string_message) goto EXPAND_FAILED;
5553         }
5554       switch(process_yesno(
5555                skipping,                     /* were previously skipping */
5556                lookup_value != NULL,         /* success/failure indicator */
5557                save_lookup_value,            /* value to reset for string2 */
5558                &s,                           /* input pointer */
5559                &yield,                       /* output pointer */
5560                &size,                        /* output size */
5561                &ptr,                         /* output current point */
5562                US"certextract",              /* condition type */
5563                &resetok))
5564         {
5565         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5566         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5567         }
5568
5569       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5570         save_expand_nlength);
5571       continue;
5572       }
5573 #endif  /*SUPPORT_TLS*/
5574
5575     /* Handle list operations */
5576
5577     case EITEM_FILTER:
5578     case EITEM_MAP:
5579     case EITEM_REDUCE:
5580       {
5581       int sep = 0;
5582       int save_ptr = ptr;
5583       uschar outsep[2] = { '\0', '\0' };
5584       const uschar *list, *expr, *temp;
5585       uschar *save_iterate_item = iterate_item;
5586       uschar *save_lookup_value = lookup_value;
5587
5588       while (isspace(*s)) s++;
5589       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5590
5591       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5592       if (list == NULL) goto EXPAND_FAILED;
5593       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5594
5595       if (item_type == EITEM_REDUCE)
5596         {
5597         uschar * t;
5598         while (isspace(*s)) s++;
5599         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5600         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5601         if (!t) goto EXPAND_FAILED;
5602         lookup_value = t;
5603         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5604         }
5605
5606       while (isspace(*s)) s++;
5607       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5608
5609       expr = s;
5610
5611       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5612       if scanning a "false" part). This allows us to find the end of the
5613       condition, because if the list is empty, we won't actually evaluate the
5614       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5615       the normal internal expansion function. */
5616
5617       if (item_type == EITEM_FILTER)
5618         {
5619         temp = eval_condition(expr, &resetok, NULL);
5620         if (temp != NULL) s = temp;
5621         }
5622       else
5623         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5624
5625       if (temp == NULL)
5626         {
5627         expand_string_message = string_sprintf("%s inside \"%s\" item",
5628           expand_string_message, name);
5629         goto EXPAND_FAILED;
5630         }
5631
5632       while (isspace(*s)) s++;
5633       if (*s++ != '}')
5634         {                                               /*{*/
5635         expand_string_message = string_sprintf("missing } at end of condition "
5636           "or expression inside \"%s\"", name);
5637         goto EXPAND_FAILED;
5638         }
5639
5640       while (isspace(*s)) s++;                          /*{*/
5641       if (*s++ != '}')
5642         {                                               /*{*/
5643         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5644           name);
5645         goto EXPAND_FAILED;
5646         }
5647
5648       /* If we are skipping, we can now just move on to the next item. When
5649       processing for real, we perform the iteration. */
5650
5651       if (skipping) continue;
5652       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5653         {
5654         *outsep = (uschar)sep;      /* Separator as a string */
5655
5656         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5657
5658         if (item_type == EITEM_FILTER)
5659           {
5660           BOOL condresult;
5661           if (eval_condition(expr, &resetok, &condresult) == NULL)
5662             {
5663             iterate_item = save_iterate_item;
5664             lookup_value = save_lookup_value;
5665             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5666               expand_string_message, name);
5667             goto EXPAND_FAILED;
5668             }
5669           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5670             condresult? "true":"false");
5671           if (condresult)
5672             temp = iterate_item;    /* TRUE => include this item */
5673           else
5674             continue;               /* FALSE => skip this item */
5675           }
5676
5677         /* EITEM_MAP and EITEM_REDUCE */
5678
5679         else
5680           {
5681           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5682           temp = t;
5683           if (temp == NULL)
5684             {
5685             iterate_item = save_iterate_item;
5686             expand_string_message = string_sprintf("%s inside \"%s\" item",
5687               expand_string_message, name);
5688             goto EXPAND_FAILED;
5689             }
5690           if (item_type == EITEM_REDUCE)
5691             {
5692             lookup_value = t;         /* Update the value of $value */
5693             continue;                 /* and continue the iteration */
5694             }
5695           }
5696
5697         /* We reach here for FILTER if the condition is true, always for MAP,
5698         and never for REDUCE. The value in "temp" is to be added to the output
5699         list that is being created, ensuring that any occurrences of the
5700         separator character are doubled. Unless we are dealing with the first
5701         item of the output list, add in a space if the new item begins with the
5702         separator character, or is an empty string. */
5703
5704         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5705           yield = string_cat(yield, &size, &ptr, US" ", 1);
5706
5707         /* Add the string in "temp" to the output list that we are building,
5708         This is done in chunks by searching for the separator character. */
5709
5710         for (;;)
5711           {
5712           size_t seglen = Ustrcspn(temp, outsep);
5713             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5714
5715           /* If we got to the end of the string we output one character
5716           too many; backup and end the loop. Otherwise arrange to double the
5717           separator. */
5718
5719           if (temp[seglen] == '\0') { ptr--; break; }
5720           yield = string_cat(yield, &size, &ptr, outsep, 1);
5721           temp += seglen + 1;
5722           }
5723
5724         /* Output a separator after the string: we will remove the redundant
5725         final one at the end. */
5726
5727         yield = string_cat(yield, &size, &ptr, outsep, 1);
5728         }   /* End of iteration over the list loop */
5729
5730       /* REDUCE has generated no output above: output the final value of
5731       $value. */
5732
5733       if (item_type == EITEM_REDUCE)
5734         {
5735         yield = string_cat(yield, &size, &ptr, lookup_value,
5736           Ustrlen(lookup_value));
5737         lookup_value = save_lookup_value;  /* Restore $value */
5738         }
5739
5740       /* FILTER and MAP generate lists: if they have generated anything, remove
5741       the redundant final separator. Even though an empty item at the end of a
5742       list does not count, this is tidier. */
5743
5744       else if (ptr != save_ptr) ptr--;
5745
5746       /* Restore preserved $item */
5747
5748       iterate_item = save_iterate_item;
5749       continue;
5750       }
5751
5752     case EITEM_SORT:
5753       {
5754       int sep = 0;
5755       const uschar *srclist, *cmp, *xtract;
5756       uschar *srcitem;
5757       const uschar *dstlist = NULL, *dstkeylist = NULL;
5758       uschar * tmp;
5759       uschar *save_iterate_item = iterate_item;
5760
5761       while (isspace(*s)) s++;
5762       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5763
5764       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5765       if (!srclist) goto EXPAND_FAILED;
5766       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5767
5768       while (isspace(*s)) s++;
5769       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5770
5771       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5772       if (!cmp) goto EXPAND_FAILED;
5773       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5774
5775       while (isspace(*s)) s++;
5776       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5777
5778       xtract = s;
5779       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5780       if (!tmp) goto EXPAND_FAILED;
5781       xtract = string_copyn(xtract, s - xtract);
5782
5783       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5784                                                         /*{*/
5785       if (*s++ != '}')
5786         {                                               /*{*/
5787         expand_string_message = US"missing } at end of \"sort\"";
5788         goto EXPAND_FAILED;
5789         }
5790
5791       if (skipping) continue;
5792
5793       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5794         {
5795         uschar * dstitem;
5796         uschar * newlist = NULL;
5797         uschar * newkeylist = NULL;
5798         uschar * srcfield;
5799
5800         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
5801
5802         /* extract field for comparisons */
5803         iterate_item = srcitem;
5804         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5805                                           TRUE, &resetok))
5806            || !*srcfield)
5807           {
5808           expand_string_message = string_sprintf(
5809               "field-extract in sort: \"%s\"", xtract);
5810           goto EXPAND_FAILED;
5811           }
5812
5813         /* Insertion sort */
5814
5815         /* copy output list until new-item < list-item */
5816         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5817           {
5818           uschar * dstfield;
5819           uschar * expr;
5820           BOOL before;
5821
5822           /* field for comparison */
5823           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5824             goto sort_mismatch;
5825
5826           /* build and run condition string */
5827           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
5828
5829           DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
5830           if (!eval_condition(expr, &resetok, &before))
5831             {
5832             expand_string_message = string_sprintf("comparison in sort: %s",
5833                 expr);
5834             goto EXPAND_FAILED;
5835             }
5836
5837           if (before)
5838             {
5839             /* New-item sorts before this dst-item.  Append new-item,
5840             then dst-item, then remainder of dst list. */
5841
5842             newlist = string_append_listele(newlist, sep, srcitem);
5843             newkeylist = string_append_listele(newkeylist, sep, srcfield);
5844             srcitem = NULL;
5845
5846             newlist = string_append_listele(newlist, sep, dstitem);
5847             newkeylist = string_append_listele(newkeylist, sep, dstfield);
5848
5849             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5850               {
5851               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5852                 goto sort_mismatch;
5853               newlist = string_append_listele(newlist, sep, dstitem);
5854               newkeylist = string_append_listele(newkeylist, sep, dstfield);
5855               }
5856
5857             break;
5858             }
5859
5860           newlist = string_append_listele(newlist, sep, dstitem);
5861           newkeylist = string_append_listele(newkeylist, sep, dstfield);
5862           }
5863
5864         /* If we ran out of dstlist without consuming srcitem, append it */
5865         if (srcitem)
5866           {
5867           newlist = string_append_listele(newlist, sep, srcitem);
5868           newkeylist = string_append_listele(newkeylist, sep, srcfield);
5869           }
5870
5871         dstlist = newlist;
5872         dstkeylist = newkeylist;
5873
5874         DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
5875         DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
5876         }
5877
5878       if (dstlist)
5879         yield = string_cat(yield, &size, &ptr, dstlist, Ustrlen(dstlist));
5880
5881       /* Restore preserved $item */
5882       iterate_item = save_iterate_item;
5883       continue;
5884
5885       sort_mismatch:
5886         expand_string_message = US"Internal error in sort (list mismatch)";
5887         goto EXPAND_FAILED;
5888       }
5889
5890
5891     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
5892     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5893     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5894     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5895
5896     #define EXPAND_DLFUNC_MAX_ARGS 8
5897
5898     case EITEM_DLFUNC:
5899 #ifndef EXPAND_DLFUNC
5900       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
5901         "is not included in this binary";
5902       goto EXPAND_FAILED;
5903
5904 #else   /* EXPAND_DLFUNC */
5905       {
5906       tree_node *t;
5907       exim_dlfunc_t *func;
5908       uschar *result;
5909       int status, argc;
5910       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5911
5912       if ((expand_forbid & RDO_DLFUNC) != 0)
5913         {
5914         expand_string_message =
5915           US"dynamically-loaded functions are not permitted";
5916         goto EXPAND_FAILED;
5917         }
5918
5919       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5920            TRUE, US"dlfunc", &resetok))
5921         {
5922         case 1: goto EXPAND_FAILED_CURLY;
5923         case 2:
5924         case 3: goto EXPAND_FAILED;
5925         }
5926
5927       /* If skipping, we don't actually do anything */
5928
5929       if (skipping) continue;
5930
5931       /* Look up the dynamically loaded object handle in the tree. If it isn't
5932       found, dlopen() the file and put the handle in the tree for next time. */
5933
5934       t = tree_search(dlobj_anchor, argv[0]);
5935       if (t == NULL)
5936         {
5937         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5938         if (handle == NULL)
5939           {
5940           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5941             argv[0], dlerror());
5942           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5943           goto EXPAND_FAILED;
5944           }
5945         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5946         Ustrcpy(t->name, argv[0]);
5947         t->data.ptr = handle;
5948         (void)tree_insertnode(&dlobj_anchor, t);
5949         }
5950
5951       /* Having obtained the dynamically loaded object handle, look up the
5952       function pointer. */
5953
5954       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5955       if (func == NULL)
5956         {
5957         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5958           "%s", argv[1], argv[0], dlerror());
5959         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5960         goto EXPAND_FAILED;
5961         }
5962
5963       /* Call the function and work out what to do with the result. If it
5964       returns OK, we have a replacement string; if it returns DEFER then
5965       expansion has failed in a non-forced manner; if it returns FAIL then
5966       failure was forced; if it returns ERROR or any other value there's a
5967       problem, so panic slightly. In any case, assume that the function has
5968       side-effects on the store that must be preserved. */
5969
5970       resetok = FALSE;
5971       result = NULL;
5972       for (argc = 0; argv[argc] != NULL; argc++);
5973       status = func(&result, argc - 2, &argv[2]);
5974       if(status == OK)
5975         {
5976         if (result == NULL) result = US"";
5977         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5978         continue;
5979         }
5980       else
5981         {
5982         expand_string_message = result == NULL ? US"(no message)" : result;
5983         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5984           else if(status != FAIL)
5985             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5986               argv[0], argv[1], status, expand_string_message);
5987         goto EXPAND_FAILED;
5988         }
5989       }
5990 #endif /* EXPAND_DLFUNC */
5991
5992     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
5993       {
5994       uschar * key;
5995       uschar *save_lookup_value = lookup_value;
5996
5997       while (isspace(*s)) s++;
5998       if (*s != '{')                                    /*}*/
5999         goto EXPAND_FAILED;
6000
6001       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6002       if (!key) goto EXPAND_FAILED;                     /*{*/
6003       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
6004
6005       lookup_value = US getenv(CS key);
6006
6007       switch(process_yesno(
6008                skipping,                     /* were previously skipping */
6009                lookup_value != NULL,         /* success/failure indicator */
6010                save_lookup_value,            /* value to reset for string2 */
6011                &s,                           /* input pointer */
6012                &yield,                       /* output pointer */
6013                &size,                        /* output size */
6014                &ptr,                         /* output current point */
6015                US"env",                      /* condition type */
6016                &resetok))
6017         {
6018         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6019         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6020         }
6021       continue;
6022       }
6023     }   /* EITEM_* switch */
6024
6025   /* Control reaches here if the name is not recognized as one of the more
6026   complicated expansion items. Check for the "operator" syntax (name terminated
6027   by a colon). Some of the operators have arguments, separated by _ from the
6028   name. */
6029
6030   if (*s == ':')
6031     {
6032     int c;
6033     uschar *arg = NULL;
6034     uschar *sub;
6035     var_entry *vp = NULL;
6036
6037     /* Owing to an historical mis-design, an underscore may be part of the
6038     operator name, or it may introduce arguments.  We therefore first scan the
6039     table of names that contain underscores. If there is no match, we cut off
6040     the arguments and then scan the main table. */
6041
6042     if ((c = chop_match(name, op_table_underscore,
6043                         nelem(op_table_underscore))) < 0)
6044       {
6045       arg = Ustrchr(name, '_');
6046       if (arg != NULL) *arg = 0;
6047       c = chop_match(name, op_table_main, nelem(op_table_main));
6048       if (c >= 0) c += nelem(op_table_underscore);
6049       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6050       }
6051
6052     /* Deal specially with operators that might take a certificate variable
6053     as we do not want to do the usual expansion. For most, expand the string.*/
6054     switch(c)
6055       {
6056 #ifdef SUPPORT_TLS
6057       case EOP_MD5:
6058       case EOP_SHA1:
6059       case EOP_SHA256:
6060       case EOP_BASE64:
6061         if (s[1] == '$')
6062           {
6063           const uschar * s1 = s;
6064           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6065                   FALSE, &resetok);
6066           if (!sub)       goto EXPAND_FAILED;           /*{*/
6067           if (*s1 != '}') goto EXPAND_FAILED_CURLY;
6068           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6069             {
6070             s = s1+1;
6071             break;
6072             }
6073           vp = NULL;
6074           }
6075         /*FALLTHROUGH*/
6076 #endif
6077       default:
6078         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6079         if (!sub) goto EXPAND_FAILED;
6080         s++;
6081         break;
6082       }
6083
6084     /* If we are skipping, we don't need to perform the operation at all.
6085     This matters for operations like "mask", because the data may not be
6086     in the correct format when skipping. For example, the expression may test
6087     for the existence of $sender_host_address before trying to mask it. For
6088     other operations, doing them may not fail, but it is a waste of time. */
6089
6090     if (skipping && c >= 0) continue;
6091
6092     /* Otherwise, switch on the operator type */
6093
6094     switch(c)
6095       {
6096       case EOP_BASE62:
6097         {
6098         uschar *t;
6099         unsigned long int n = Ustrtoul(sub, &t, 10);
6100         if (*t != 0)
6101           {
6102           expand_string_message = string_sprintf("argument for base62 "
6103             "operator is \"%s\", which is not a decimal number", sub);
6104           goto EXPAND_FAILED;
6105           }
6106         t = string_base62(n);
6107         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6108         continue;
6109         }
6110
6111       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6112
6113       case EOP_BASE62D:
6114         {
6115         uschar buf[16];
6116         uschar *tt = sub;
6117         unsigned long int n = 0;
6118         while (*tt != 0)
6119           {
6120           uschar *t = Ustrchr(base62_chars, *tt++);
6121           if (t == NULL)
6122             {
6123             expand_string_message = string_sprintf("argument for base62d "
6124               "operator is \"%s\", which is not a base %d number", sub,
6125               BASE_62);
6126             goto EXPAND_FAILED;
6127             }
6128           n = n * BASE_62 + (t - base62_chars);
6129           }
6130         (void)sprintf(CS buf, "%ld", n);
6131         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
6132         continue;
6133         }
6134
6135       case EOP_EXPAND:
6136         {
6137         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6138         if (expanded == NULL)
6139           {
6140           expand_string_message =
6141             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6142               expand_string_message);
6143           goto EXPAND_FAILED;
6144           }
6145         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
6146         continue;
6147         }
6148
6149       case EOP_LC:
6150         {
6151         int count = 0;
6152         uschar *t = sub - 1;
6153         while (*(++t) != 0) { *t = tolower(*t); count++; }
6154         yield = string_cat(yield, &size, &ptr, sub, count);
6155         continue;
6156         }
6157
6158       case EOP_UC:
6159         {
6160         int count = 0;
6161         uschar *t = sub - 1;
6162         while (*(++t) != 0) { *t = toupper(*t); count++; }
6163         yield = string_cat(yield, &size, &ptr, sub, count);
6164         continue;
6165         }
6166
6167       case EOP_MD5:
6168 #ifdef SUPPORT_TLS
6169         if (vp && *(void **)vp->value)
6170           {
6171           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6172           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6173           }
6174         else
6175 #endif
6176           {
6177           md5 base;
6178           uschar digest[16];
6179           int j;
6180           char st[33];
6181           md5_start(&base);
6182           md5_end(&base, sub, Ustrlen(sub), digest);
6183           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6184           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
6185           }
6186         continue;
6187
6188       case EOP_SHA1:
6189 #ifdef SUPPORT_TLS
6190         if (vp && *(void **)vp->value)
6191           {
6192           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6193           yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6194           }
6195         else
6196 #endif
6197           {
6198           sha1 base;
6199           uschar digest[20];
6200           int j;
6201           char st[41];
6202           sha1_start(&base);
6203           sha1_end(&base, sub, Ustrlen(sub), digest);
6204           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6205           yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
6206           }
6207         continue;
6208
6209       case EOP_SHA256:
6210 #ifdef SUPPORT_TLS
6211         if (vp && *(void **)vp->value)
6212           {
6213           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6214           yield = string_cat(yield, &size, &ptr, cp, (int)Ustrlen(cp));
6215           }
6216         else
6217 #endif
6218           expand_string_message = US"sha256 only supported for certificates";
6219         continue;
6220
6221       /* Convert hex encoding to base64 encoding */
6222
6223       case EOP_HEX2B64:
6224         {
6225         int c = 0;
6226         int b = -1;
6227         uschar *in = sub;
6228         uschar *out = sub;
6229         uschar *enc;
6230
6231         for (enc = sub; *enc != 0; enc++)
6232           {
6233           if (!isxdigit(*enc))
6234             {
6235             expand_string_message = string_sprintf("\"%s\" is not a hex "
6236               "string", sub);
6237             goto EXPAND_FAILED;
6238             }
6239           c++;
6240           }
6241
6242         if ((c & 1) != 0)
6243           {
6244           expand_string_message = string_sprintf("\"%s\" contains an odd "
6245             "number of characters", sub);
6246           goto EXPAND_FAILED;
6247           }
6248
6249         while ((c = *in++) != 0)
6250           {
6251           if (isdigit(c)) c -= '0';
6252           else c = toupper(c) - 'A' + 10;
6253           if (b == -1)
6254             {
6255             b = c << 4;
6256             }
6257           else
6258             {
6259             *out++ = b | c;
6260             b = -1;
6261             }
6262           }
6263
6264         enc = b64encode(sub, out - sub);
6265         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
6266         continue;
6267         }
6268
6269       /* Convert octets outside 0x21..0x7E to \xXX form */
6270
6271       case EOP_HEXQUOTE:
6272         {
6273         uschar *t = sub - 1;
6274         while (*(++t) != 0)
6275           {
6276           if (*t < 0x21 || 0x7E < *t)
6277             yield = string_cat(yield, &size, &ptr,
6278               string_sprintf("\\x%02x", *t), 4);
6279           else
6280             yield = string_cat(yield, &size, &ptr, t, 1);
6281           }
6282         continue;
6283         }
6284
6285       /* count the number of list elements */
6286
6287       case EOP_LISTCOUNT:
6288         {
6289         int cnt = 0;
6290         int sep = 0;
6291         uschar * cp;
6292         uschar buffer[256];
6293
6294         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6295         cp = string_sprintf("%d", cnt);
6296         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
6297         continue;
6298         }
6299
6300       /* expand a named list given the name */
6301       /* handles nested named lists; requotes as colon-sep list */
6302
6303       case EOP_LISTNAMED:
6304         {
6305         tree_node *t = NULL;
6306         const uschar * list;
6307         int sep = 0;
6308         uschar * item;
6309         uschar * suffix = US"";
6310         BOOL needsep = FALSE;
6311         uschar buffer[256];
6312
6313         if (*sub == '+') sub++;
6314         if (arg == NULL)        /* no-argument version */
6315           {
6316           if (!(t = tree_search(addresslist_anchor, sub)) &&
6317               !(t = tree_search(domainlist_anchor,  sub)) &&
6318               !(t = tree_search(hostlist_anchor,    sub)))
6319             t = tree_search(localpartlist_anchor, sub);
6320           }
6321         else switch(*arg)       /* specific list-type version */
6322           {
6323           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6324           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6325           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6326           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6327           default:
6328             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6329             goto EXPAND_FAILED;
6330           }
6331
6332         if(!t)
6333           {
6334           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6335             sub, !arg?""
6336               : *arg=='a'?"address "
6337               : *arg=='d'?"domain "
6338               : *arg=='h'?"host "
6339               : *arg=='l'?"localpart "
6340               : 0);
6341           goto EXPAND_FAILED;
6342           }
6343
6344         list = ((namedlist_block *)(t->data.ptr))->string;
6345
6346         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6347           {
6348           uschar * buf = US" : ";
6349           if (needsep)
6350             yield = string_cat(yield, &size, &ptr, buf, 3);
6351           else
6352             needsep = TRUE;
6353
6354           if (*item == '+')     /* list item is itself a named list */
6355             {
6356             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6357             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6358             }
6359           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6360             {
6361             char * cp;
6362             char tok[3];
6363             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6364             while ((cp= strpbrk((const char *)item, tok)))
6365               {
6366               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
6367               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6368                 {
6369                 yield = string_cat(yield, &size, &ptr, US"::", 2);
6370                 item = (uschar *)cp;
6371                 }
6372               else              /* sep in item; should already be doubled; emit once */
6373                 {
6374                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
6375                 if (*cp == sep) cp++;
6376                 item = (uschar *)cp;
6377                 }
6378               }
6379             }
6380           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
6381           }
6382         continue;
6383         }
6384
6385       /* mask applies a mask to an IP address; for example the result of
6386       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6387
6388       case EOP_MASK:
6389         {
6390         int count;
6391         uschar *endptr;
6392         int binary[4];
6393         int mask, maskoffset;
6394         int type = string_is_ip_address(sub, &maskoffset);
6395         uschar buffer[64];
6396
6397         if (type == 0)
6398           {
6399           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6400            sub);
6401           goto EXPAND_FAILED;
6402           }
6403
6404         if (maskoffset == 0)
6405           {
6406           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6407             sub);
6408           goto EXPAND_FAILED;
6409           }
6410
6411         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6412
6413         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6414           {
6415           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6416             sub);
6417           goto EXPAND_FAILED;
6418           }
6419
6420         /* Convert the address to binary integer(s) and apply the mask */
6421
6422         sub[maskoffset] = 0;
6423         count = host_aton(sub, binary);
6424         host_mask(count, binary, mask);
6425
6426         /* Convert to masked textual format and add to output. */
6427
6428         yield = string_cat(yield, &size, &ptr, buffer,
6429           host_nmtoa(count, binary, mask, buffer, '.'));
6430         continue;
6431         }
6432
6433       case EOP_IPV6NORM:
6434       case EOP_IPV6DENORM:
6435         {
6436         int type = string_is_ip_address(sub, NULL);
6437         int binary[4];
6438         uschar buffer[44];
6439
6440         switch (type)
6441           {
6442           case 6:
6443             (void) host_aton(sub, binary);
6444             break;
6445
6446           case 4:       /* convert to IPv4-mapped IPv6 */
6447             binary[0] = binary[1] = 0;
6448             binary[2] = 0x0000ffff;
6449             (void) host_aton(sub, binary+3);
6450             break;
6451
6452           case 0:
6453             expand_string_message =
6454               string_sprintf("\"%s\" is not an IP address", sub);
6455             goto EXPAND_FAILED;
6456           }
6457
6458         yield = string_cat(yield, &size, &ptr, buffer,
6459                   c == EOP_IPV6NORM
6460                     ? ipv6_nmtoa(binary, buffer)
6461                     : host_nmtoa(4, binary, -1, buffer, ':')
6462                   );
6463         continue;
6464         }
6465
6466       case EOP_ADDRESS:
6467       case EOP_LOCAL_PART:
6468       case EOP_DOMAIN:
6469         {
6470         uschar *error;
6471         int start, end, domain;
6472         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6473           FALSE);
6474         if (t != NULL)
6475           {
6476           if (c != EOP_DOMAIN)
6477             {
6478             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6479             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
6480             }
6481           else if (domain != 0)
6482             {
6483             domain += start;
6484             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
6485             }
6486           }
6487         continue;
6488         }
6489
6490       case EOP_ADDRESSES:
6491         {
6492         uschar outsep[2] = { ':', '\0' };
6493         uschar *address, *error;
6494         int save_ptr = ptr;
6495         int start, end, domain;  /* Not really used */
6496
6497         while (isspace(*sub)) sub++;
6498         if (*sub == '>') { *outsep = *++sub; ++sub; }
6499         parse_allow_group = TRUE;
6500
6501         for (;;)
6502           {
6503           uschar *p = parse_find_address_end(sub, FALSE);
6504           uschar saveend = *p;
6505           *p = '\0';
6506           address = parse_extract_address(sub, &error, &start, &end, &domain,
6507             FALSE);
6508           *p = saveend;
6509
6510           /* Add the address to the output list that we are building. This is
6511           done in chunks by searching for the separator character. At the
6512           start, unless we are dealing with the first address of the output
6513           list, add in a space if the new address begins with the separator
6514           character, or is an empty string. */
6515
6516           if (address != NULL)
6517             {
6518             if (ptr != save_ptr && address[0] == *outsep)
6519               yield = string_cat(yield, &size, &ptr, US" ", 1);
6520
6521             for (;;)
6522               {
6523               size_t seglen = Ustrcspn(address, outsep);
6524               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
6525
6526               /* If we got to the end of the string we output one character
6527               too many. */
6528
6529               if (address[seglen] == '\0') { ptr--; break; }
6530               yield = string_cat(yield, &size, &ptr, outsep, 1);
6531               address += seglen + 1;
6532               }
6533
6534             /* Output a separator after the string: we will remove the
6535             redundant final one at the end. */
6536
6537             yield = string_cat(yield, &size, &ptr, outsep, 1);
6538             }
6539
6540           if (saveend == '\0') break;
6541           sub = p + 1;
6542           }
6543
6544         /* If we have generated anything, remove the redundant final
6545         separator. */
6546
6547         if (ptr != save_ptr) ptr--;
6548         parse_allow_group = FALSE;
6549         continue;
6550         }
6551
6552
6553       /* quote puts a string in quotes if it is empty or contains anything
6554       other than alphamerics, underscore, dot, or hyphen.
6555
6556       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6557       be quoted in order to be a valid local part.
6558
6559       In both cases, newlines and carriage returns are converted into \n and \r
6560       respectively */
6561
6562       case EOP_QUOTE:
6563       case EOP_QUOTE_LOCAL_PART:
6564       if (arg == NULL)
6565         {
6566         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6567         uschar *t = sub - 1;
6568
6569         if (c == EOP_QUOTE)
6570           {
6571           while (!needs_quote && *(++t) != 0)
6572             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6573           }
6574         else  /* EOP_QUOTE_LOCAL_PART */
6575           {
6576           while (!needs_quote && *(++t) != 0)
6577             needs_quote = !isalnum(*t) &&
6578               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6579               (*t != '.' || t == sub || t[1] == 0);
6580           }
6581
6582         if (needs_quote)
6583           {
6584           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6585           t = sub - 1;
6586           while (*(++t) != 0)
6587             {
6588             if (*t == '\n')
6589               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
6590             else if (*t == '\r')
6591               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
6592             else
6593               {
6594               if (*t == '\\' || *t == '"')
6595                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
6596               yield = string_cat(yield, &size, &ptr, t, 1);
6597               }
6598             }
6599           yield = string_cat(yield, &size, &ptr, US"\"", 1);
6600           }
6601         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6602         continue;
6603         }
6604
6605       /* quote_lookuptype does lookup-specific quoting */
6606
6607       else
6608         {
6609         int n;
6610         uschar *opt = Ustrchr(arg, '_');
6611
6612         if (opt != NULL) *opt++ = 0;
6613
6614         n = search_findtype(arg, Ustrlen(arg));
6615         if (n < 0)
6616           {
6617           expand_string_message = search_error_message;
6618           goto EXPAND_FAILED;
6619           }
6620
6621         if (lookup_list[n]->quote != NULL)
6622           sub = (lookup_list[n]->quote)(sub, opt);
6623         else if (opt != NULL) sub = NULL;
6624
6625         if (sub == NULL)
6626           {
6627           expand_string_message = string_sprintf(
6628             "\"%s\" unrecognized after \"${quote_%s\"",
6629             opt, arg);
6630           goto EXPAND_FAILED;
6631           }
6632
6633         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
6634         continue;
6635         }
6636
6637       /* rx quote sticks in \ before any non-alphameric character so that
6638       the insertion works in a regular expression. */
6639
6640       case EOP_RXQUOTE:
6641         {
6642         uschar *t = sub - 1;
6643         while (*(++t) != 0)
6644           {
6645           if (!isalnum(*t))
6646             yield = string_cat(yield, &size, &ptr, US"\\", 1);
6647           yield = string_cat(yield, &size, &ptr, t, 1);
6648           }
6649         continue;
6650         }
6651
6652       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6653       prescribed by the RFC, if there are characters that need to be encoded */
6654
6655       case EOP_RFC2047:
6656         {
6657         uschar buffer[2048];
6658         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6659           buffer, sizeof(buffer), FALSE);
6660         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
6661         continue;
6662         }
6663
6664       /* RFC 2047 decode */
6665
6666       case EOP_RFC2047D:
6667         {
6668         int len;
6669         uschar *error;
6670         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6671           headers_charset, '?', &len, &error);
6672         if (error != NULL)
6673           {
6674           expand_string_message = error;
6675           goto EXPAND_FAILED;
6676           }
6677         yield = string_cat(yield, &size, &ptr, decoded, len);
6678         continue;
6679         }
6680
6681       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6682       underscores */
6683
6684       case EOP_FROM_UTF8:
6685         {
6686         while (*sub != 0)
6687           {
6688           int c;
6689           uschar buff[4];
6690           GETUTF8INC(c, sub);
6691           if (c > 255) c = '_';
6692           buff[0] = c;
6693           yield = string_cat(yield, &size, &ptr, buff, 1);
6694           }
6695         continue;
6696         }
6697
6698           /* replace illegal UTF-8 sequences by replacement character  */
6699
6700       #define UTF8_REPLACEMENT_CHAR US"?"
6701
6702       case EOP_UTF8CLEAN:
6703         {
6704         int seq_len = 0, index = 0;
6705         int bytes_left = 0;
6706         long codepoint = -1;
6707         uschar seq_buff[4];                     /* accumulate utf-8 here */
6708
6709         while (*sub != 0)
6710           {
6711           int complete = 0;
6712           uschar c = *sub++;
6713
6714           if (bytes_left)
6715             {
6716             if ((c & 0xc0) != 0x80)
6717                     /* wrong continuation byte; invalidate all bytes */
6718               complete = 1; /* error */
6719             else
6720               {
6721               codepoint = (codepoint << 6) | (c & 0x3f);
6722               seq_buff[index++] = c;
6723               if (--bytes_left == 0)            /* codepoint complete */
6724                 if(codepoint > 0x10FFFF)        /* is it too large? */
6725                   complete = -1;        /* error (RFC3629 limit) */
6726                 else
6727                   {             /* finished; output utf-8 sequence */
6728                   yield = string_cat(yield, &size, &ptr, seq_buff, seq_len);
6729                   index = 0;
6730                   }
6731               }
6732             }
6733           else  /* no bytes left: new sequence */
6734             {
6735             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6736               {
6737               yield = string_cat(yield, &size, &ptr, &c, 1);
6738               continue;
6739               }
6740             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
6741               {
6742               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
6743                 complete = -1;
6744               else
6745                 {
6746                   bytes_left = 1;
6747                   codepoint = c & 0x1f;
6748                 }
6749               }
6750             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
6751               {
6752               bytes_left = 2;
6753               codepoint = c & 0x0f;
6754               }
6755             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
6756               {
6757               bytes_left = 3;
6758               codepoint = c & 0x07;
6759               }
6760             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
6761               complete = -1;
6762
6763             seq_buff[index++] = c;
6764             seq_len = bytes_left + 1;
6765             }           /* if(bytes_left) */
6766
6767           if (complete != 0)
6768             {
6769             bytes_left = index = 0;
6770             yield = string_cat(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
6771             }
6772           if ((complete == 1) && ((c & 0x80) == 0))
6773                         /* ASCII character follows incomplete sequence */
6774               yield = string_cat(yield, &size, &ptr, &c, 1);
6775           }
6776         continue;
6777         }
6778
6779 #ifdef SUPPORT_I18N
6780       case EOP_UTF8_DOMAIN_TO_ALABEL:
6781         {
6782         uschar * error = NULL;
6783         uschar * s = string_domain_utf8_to_alabel(sub, &error);
6784         if (error)
6785           {
6786           expand_string_message = string_sprintf(
6787             "error converting utf8 (%s) to alabel: %s",
6788             string_printing(sub), error);
6789           goto EXPAND_FAILED;
6790           }
6791         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6792         continue;
6793         }
6794
6795       case EOP_UTF8_DOMAIN_FROM_ALABEL:
6796         {
6797         uschar * error = NULL;
6798         uschar * s = string_domain_alabel_to_utf8(sub, &error);
6799         if (error)
6800           {
6801           expand_string_message = string_sprintf(
6802             "error converting alabel (%s) to utf8: %s",
6803             string_printing(sub), error);
6804           goto EXPAND_FAILED;
6805           }
6806         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6807         continue;
6808         }
6809
6810       case EOP_UTF8_LOCALPART_TO_ALABEL:
6811         {
6812         uschar * error = NULL;
6813         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
6814         if (error)
6815           {
6816           expand_string_message = string_sprintf(
6817             "error converting utf8 (%s) to alabel: %s",
6818             string_printing(sub), error);
6819           goto EXPAND_FAILED;
6820           }
6821         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6822         DEBUG(D_expand) debug_printf("yield: '%s'\n", yield);
6823         continue;
6824         }
6825
6826       case EOP_UTF8_LOCALPART_FROM_ALABEL:
6827         {
6828         uschar * error = NULL;
6829         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
6830         if (error)
6831           {
6832           expand_string_message = string_sprintf(
6833             "error converting alabel (%s) to utf8: %s",
6834             string_printing(sub), error);
6835           goto EXPAND_FAILED;
6836           }
6837         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6838         continue;
6839         }
6840 #endif  /* EXPERIMENTAL_INTERNATIONAL */
6841
6842       /* escape turns all non-printing characters into escape sequences. */
6843
6844       case EOP_ESCAPE:
6845         {
6846         const uschar *t = string_printing(sub);
6847         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6848         continue;
6849         }
6850
6851       /* Handle numeric expression evaluation */
6852
6853       case EOP_EVAL:
6854       case EOP_EVAL10:
6855         {
6856         uschar *save_sub = sub;
6857         uschar *error = NULL;
6858         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6859         if (error != NULL)
6860           {
6861           expand_string_message = string_sprintf("error in expression "
6862             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6863               save_sub);
6864           goto EXPAND_FAILED;
6865           }
6866         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6867         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6868         continue;
6869         }
6870
6871       /* Handle time period formating */
6872
6873       case EOP_TIME_EVAL:
6874         {
6875         int n = readconf_readtime(sub, 0, FALSE);
6876         if (n < 0)
6877           {
6878           expand_string_message = string_sprintf("string \"%s\" is not an "
6879             "Exim time interval in \"%s\" operator", sub, name);
6880           goto EXPAND_FAILED;
6881           }
6882         sprintf(CS var_buffer, "%d", n);
6883         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6884         continue;
6885         }
6886
6887       case EOP_TIME_INTERVAL:
6888         {
6889         int n;
6890         uschar *t = read_number(&n, sub);
6891         if (*t != 0) /* Not A Number*/
6892           {
6893           expand_string_message = string_sprintf("string \"%s\" is not a "
6894             "positive number in \"%s\" operator", sub, name);
6895           goto EXPAND_FAILED;
6896           }
6897         t = readconf_printtime(n);
6898         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6899         continue;
6900         }
6901
6902       /* Convert string to base64 encoding */
6903
6904       case EOP_STR2B64:
6905       case EOP_BASE64:
6906         {
6907 #ifdef SUPPORT_TLS
6908         uschar * s = vp && *(void **)vp->value
6909           ? tls_cert_der_b64(*(void **)vp->value)
6910           : b64encode(sub, Ustrlen(sub));
6911 #else
6912         uschar * s = b64encode(sub, Ustrlen(sub));
6913 #endif
6914         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6915         continue;
6916         }
6917
6918       case EOP_BASE64D:
6919         {
6920         uschar * s;
6921         int len = b64decode(sub, &s);
6922         if (len < 0)
6923           {
6924           expand_string_message = string_sprintf("string \"%s\" is not "
6925             "well-formed for \"%s\" operator", sub, name);
6926           goto EXPAND_FAILED;
6927           }
6928         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6929         continue;
6930         }
6931
6932       /* strlen returns the length of the string */
6933
6934       case EOP_STRLEN:
6935         {
6936         uschar buff[24];
6937         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6938         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6939         continue;
6940         }
6941
6942       /* length_n or l_n takes just the first n characters or the whole string,
6943       whichever is the shorter;
6944
6945       substr_m_n, and s_m_n take n characters from offset m; negative m take
6946       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6947       takes the rest, either to the right or to the left.
6948
6949       hash_n or h_n makes a hash of length n from the string, yielding n
6950       characters from the set a-z; hash_n_m makes a hash of length n, but
6951       uses m characters from the set a-zA-Z0-9.
6952
6953       nhash_n returns a single number between 0 and n-1 (in text form), while
6954       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6955       between 0 and n-1 and the second between 0 and m-1. */
6956
6957       case EOP_LENGTH:
6958       case EOP_L:
6959       case EOP_SUBSTR:
6960       case EOP_S:
6961       case EOP_HASH:
6962       case EOP_H:
6963       case EOP_NHASH:
6964       case EOP_NH:
6965         {
6966         int sign = 1;
6967         int value1 = 0;
6968         int value2 = -1;
6969         int *pn;
6970         int len;
6971         uschar *ret;
6972
6973         if (arg == NULL)
6974           {
6975           expand_string_message = string_sprintf("missing values after %s",
6976             name);
6977           goto EXPAND_FAILED;
6978           }
6979
6980         /* "length" has only one argument, effectively being synonymous with
6981         substr_0_n. */
6982
6983         if (c == EOP_LENGTH || c == EOP_L)
6984           {
6985           pn = &value2;
6986           value2 = 0;
6987           }
6988
6989         /* The others have one or two arguments; for "substr" the first may be
6990         negative. The second being negative means "not supplied". */
6991
6992         else
6993           {
6994           pn = &value1;
6995           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6996           }
6997
6998         /* Read up to two numbers, separated by underscores */
6999
7000         ret = arg;
7001         while (*arg != 0)
7002           {
7003           if (arg != ret && *arg == '_' && pn == &value1)
7004             {
7005             pn = &value2;
7006             value2 = 0;
7007             if (arg[1] != 0) arg++;
7008             }
7009           else if (!isdigit(*arg))
7010             {
7011             expand_string_message =
7012               string_sprintf("non-digit after underscore in \"%s\"", name);
7013             goto EXPAND_FAILED;
7014             }
7015           else *pn = (*pn)*10 + *arg++ - '0';
7016           }
7017         value1 *= sign;
7018
7019         /* Perform the required operation */
7020
7021         ret =
7022           (c == EOP_HASH || c == EOP_H)?
7023              compute_hash(sub, value1, value2, &len) :
7024           (c == EOP_NHASH || c == EOP_NH)?
7025              compute_nhash(sub, value1, value2, &len) :
7026              extract_substr(sub, value1, value2, &len);
7027
7028         if (ret == NULL) goto EXPAND_FAILED;
7029         yield = string_cat(yield, &size, &ptr, ret, len);
7030         continue;
7031         }
7032
7033       /* Stat a path */
7034
7035       case EOP_STAT:
7036         {
7037         uschar *s;
7038         uschar smode[12];
7039         uschar **modetable[3];
7040         int i;
7041         mode_t mode;
7042         struct stat st;
7043
7044         if ((expand_forbid & RDO_EXISTS) != 0)
7045           {
7046           expand_string_message = US"Use of the stat() expansion is not permitted";
7047           goto EXPAND_FAILED;
7048           }
7049
7050         if (stat(CS sub, &st) < 0)
7051           {
7052           expand_string_message = string_sprintf("stat(%s) failed: %s",
7053             sub, strerror(errno));
7054           goto EXPAND_FAILED;
7055           }
7056         mode = st.st_mode;
7057         switch (mode & S_IFMT)
7058           {
7059           case S_IFIFO: smode[0] = 'p'; break;
7060           case S_IFCHR: smode[0] = 'c'; break;
7061           case S_IFDIR: smode[0] = 'd'; break;
7062           case S_IFBLK: smode[0] = 'b'; break;
7063           case S_IFREG: smode[0] = '-'; break;
7064           default: smode[0] = '?'; break;
7065           }
7066
7067         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7068         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7069         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7070
7071         for (i = 0; i < 3; i++)
7072           {
7073           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7074           mode >>= 3;
7075           }
7076
7077         smode[10] = 0;
7078         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7079           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7080           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7081           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7082           (long)st.st_gid, st.st_size, (long)st.st_atime,
7083           (long)st.st_mtime, (long)st.st_ctime);
7084         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
7085         continue;
7086         }
7087
7088       /* vaguely random number less than N */
7089
7090       case EOP_RANDINT:
7091         {
7092         int_eximarith_t max;
7093         uschar *s;
7094
7095         max = expanded_string_integer(sub, TRUE);
7096         if (expand_string_message != NULL)
7097           goto EXPAND_FAILED;
7098         s = string_sprintf("%d", vaguely_random_number((int)max));
7099         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
7100         continue;
7101         }
7102
7103       /* Reverse IP, including IPv6 to dotted-nibble */
7104
7105       case EOP_REVERSE_IP:
7106         {
7107         int family, maskptr;
7108         uschar reversed[128];
7109
7110         family = string_is_ip_address(sub, &maskptr);
7111         if (family == 0)
7112           {
7113           expand_string_message = string_sprintf(
7114               "reverse_ip() not given an IP address [%s]", sub);
7115           goto EXPAND_FAILED;
7116           }
7117         invert_address(reversed, sub);
7118         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
7119         continue;
7120         }
7121
7122       /* Unknown operator */
7123
7124       default:
7125       expand_string_message =
7126         string_sprintf("unknown expansion operator \"%s\"", name);
7127       goto EXPAND_FAILED;
7128       }
7129     }
7130
7131   /* Handle a plain name. If this is the first thing in the expansion, release
7132   the pre-allocated buffer. If the result data is known to be in a new buffer,
7133   newsize will be set to the size of that buffer, and we can just point at that
7134   store instead of copying. Many expansion strings contain just one reference,
7135   so this is a useful optimization, especially for humungous headers
7136   ($message_headers). */
7137                                                 /*{*/
7138   if (*s++ == '}')
7139     {
7140     int len;
7141     int newsize = 0;
7142     if (ptr == 0)
7143       {
7144       if (resetok) store_reset(yield);
7145       yield = NULL;
7146       size = 0;
7147       }
7148     value = find_variable(name, FALSE, skipping, &newsize);
7149     if (value == NULL)
7150       {
7151       expand_string_message =
7152         string_sprintf("unknown variable in \"${%s}\"", name);
7153       check_variable_error_message(name);
7154       goto EXPAND_FAILED;
7155       }
7156     len = Ustrlen(value);
7157     if (yield == NULL && newsize != 0)
7158       {
7159       yield = value;
7160       size = newsize;
7161       ptr = len;
7162       }
7163     else yield = string_cat(yield, &size, &ptr, value, len);
7164     continue;
7165     }
7166
7167   /* Else there's something wrong */
7168
7169   expand_string_message =
7170     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7171     "in a variable reference)", name);
7172   goto EXPAND_FAILED;
7173   }
7174
7175 /* If we hit the end of the string when ket_ends is set, there is a missing
7176 terminating brace. */
7177
7178 if (ket_ends && *s == 0)
7179   {
7180   expand_string_message = malformed_header?
7181     US"missing } at end of string - could be header name not terminated by colon"
7182     :
7183     US"missing } at end of string";
7184   goto EXPAND_FAILED;
7185   }
7186
7187 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7188 added to the string. If so, set up an empty string. Add a terminating zero. If
7189 left != NULL, return a pointer to the terminator. */
7190
7191 if (yield == NULL) yield = store_get(1);
7192 yield[ptr] = 0;
7193 if (left != NULL) *left = s;
7194
7195 /* Any stacking store that was used above the final string is no longer needed.
7196 In many cases the final string will be the first one that was got and so there
7197 will be optimal store usage. */
7198
7199 if (resetok) store_reset(yield + ptr + 1);
7200 else if (resetok_p) *resetok_p = FALSE;
7201
7202 DEBUG(D_expand)
7203   {
7204   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
7205     yield);
7206   if (skipping) debug_printf("skipping: result is not used\n");
7207   }
7208 return yield;
7209
7210 /* This is the failure exit: easiest to program with a goto. We still need
7211 to update the pointer to the terminator, for cases of nested calls with "fail".
7212 */
7213
7214 EXPAND_FAILED_CURLY:
7215 expand_string_message = malformed_header?
7216   US"missing or misplaced { or } - could be header name not terminated by colon"
7217   :
7218   US"missing or misplaced { or }";
7219
7220 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7221 that is a bad idea, because expand_string_message is in dynamic store. */
7222
7223 EXPAND_FAILED:
7224 if (left != NULL) *left = s;
7225 DEBUG(D_expand)
7226   {
7227   debug_printf("failed to expand: %s\n", string);
7228   debug_printf("   error message: %s\n", expand_string_message);
7229   if (expand_string_forcedfail) debug_printf("failure was forced\n");
7230   }
7231 if (resetok_p) *resetok_p = resetok;
7232 return NULL;
7233 }
7234
7235
7236 /* This is the external function call. Do a quick check for any expansion
7237 metacharacters, and if there are none, just return the input string.
7238
7239 Argument: the string to be expanded
7240 Returns:  the expanded string, or NULL if expansion failed; if failure was
7241           due to a lookup deferring, search_find_defer will be TRUE
7242 */
7243
7244 uschar *
7245 expand_string(uschar *string)
7246 {
7247 search_find_defer = FALSE;
7248 malformed_header = FALSE;
7249 return (Ustrpbrk(string, "$\\") == NULL)? string :
7250   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7251 }
7252
7253
7254
7255 const uschar *
7256 expand_cstring(const uschar *string)
7257 {
7258 search_find_defer = FALSE;
7259 malformed_header = FALSE;
7260 return (Ustrpbrk(string, "$\\") == NULL)? string :
7261   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7262 }
7263
7264
7265
7266 /*************************************************
7267 *              Expand and copy                   *
7268 *************************************************/
7269
7270 /* Now and again we want to expand a string and be sure that the result is in a
7271 new bit of store. This function does that.
7272 Since we know it has been copied, the de-const cast is safe.
7273
7274 Argument: the string to be expanded
7275 Returns:  the expanded string, always in a new bit of store, or NULL
7276 */
7277
7278 uschar *
7279 expand_string_copy(const uschar *string)
7280 {
7281 const uschar *yield = expand_cstring(string);
7282 if (yield == string) yield = string_copy(string);
7283 return US yield;
7284 }
7285
7286
7287
7288 /*************************************************
7289 *        Expand and interpret as an integer      *
7290 *************************************************/
7291
7292 /* Expand a string, and convert the result into an integer.
7293
7294 Arguments:
7295   string  the string to be expanded
7296   isplus  TRUE if a non-negative number is expected
7297
7298 Returns:  the integer value, or
7299           -1 for an expansion error               ) in both cases, message in
7300           -2 for an integer interpretation error  ) expand_string_message
7301           expand_string_message is set NULL for an OK integer
7302 */
7303
7304 int_eximarith_t
7305 expand_string_integer(uschar *string, BOOL isplus)
7306 {
7307 return expanded_string_integer(expand_string(string), isplus);
7308 }
7309
7310
7311 /*************************************************
7312  *         Interpret string as an integer        *
7313  *************************************************/
7314
7315 /* Convert a string (that has already been expanded) into an integer.
7316
7317 This function is used inside the expansion code.
7318
7319 Arguments:
7320   s       the string to be expanded
7321   isplus  TRUE if a non-negative number is expected
7322
7323 Returns:  the integer value, or
7324           -1 if string is NULL (which implies an expansion error)
7325           -2 for an integer interpretation error
7326           expand_string_message is set NULL for an OK integer
7327 */
7328
7329 static int_eximarith_t
7330 expanded_string_integer(const uschar *s, BOOL isplus)
7331 {
7332 int_eximarith_t value;
7333 uschar *msg = US"invalid integer \"%s\"";
7334 uschar *endptr;
7335
7336 /* If expansion failed, expand_string_message will be set. */
7337
7338 if (s == NULL) return -1;
7339
7340 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7341 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7342 systems, so we set it zero ourselves. */
7343
7344 errno = 0;
7345 expand_string_message = NULL;               /* Indicates no error */
7346
7347 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7348 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7349 the behaviour explicitly.  Stripping leading whitespace is a harmless
7350 noop change since strtol skips it anyway (provided that there is a number
7351 to find at all). */
7352 if (isspace(*s))
7353   {
7354   while (isspace(*s)) ++s;
7355   if (*s == '\0')
7356     {
7357       DEBUG(D_expand)
7358        debug_printf("treating blank string as number 0\n");
7359       return 0;
7360     }
7361   }
7362
7363 value = strtoll(CS s, CSS &endptr, 10);
7364
7365 if (endptr == s)
7366   {
7367   msg = US"integer expected but \"%s\" found";
7368   }
7369 else if (value < 0 && isplus)
7370   {
7371   msg = US"non-negative integer expected but \"%s\" found";
7372   }
7373 else
7374   {
7375   switch (tolower(*endptr))
7376     {
7377     default:
7378       break;
7379     case 'k':
7380       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7381       else value *= 1024;
7382       endptr++;
7383       break;
7384     case 'm':
7385       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7386       else value *= 1024*1024;
7387       endptr++;
7388       break;
7389     case 'g':
7390       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7391       else value *= 1024*1024*1024;
7392       endptr++;
7393       break;
7394     }
7395   if (errno == ERANGE)
7396     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7397   else
7398     {
7399     while (isspace(*endptr)) endptr++;
7400     if (*endptr == 0) return value;
7401     }
7402   }
7403
7404 expand_string_message = string_sprintf(CS msg, s);
7405 return -2;
7406 }
7407
7408
7409 /* These values are usually fixed boolean values, but they are permitted to be
7410 expanded strings.
7411
7412 Arguments:
7413   addr       address being routed
7414   mtype      the module type
7415   mname      the module name
7416   dbg_opt    debug selectors
7417   oname      the option name
7418   bvalue     the router's boolean value
7419   svalue     the router's string value
7420   rvalue     where to put the returned value
7421
7422 Returns:     OK     value placed in rvalue
7423              DEFER  expansion failed
7424 */
7425
7426 int
7427 exp_bool(address_item *addr,
7428   uschar *mtype, uschar *mname, unsigned dbg_opt,
7429   uschar *oname, BOOL bvalue,
7430   uschar *svalue, BOOL *rvalue)
7431 {
7432 uschar *expanded;
7433 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7434
7435 expanded = expand_string(svalue);
7436 if (expanded == NULL)
7437   {
7438   if (expand_string_forcedfail)
7439     {
7440     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7441     *rvalue = bvalue;
7442     return OK;
7443     }
7444   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7445       oname, mname, mtype, expand_string_message);
7446   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7447   return DEFER;
7448   }
7449
7450 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7451   expanded);
7452
7453 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7454   *rvalue = TRUE;
7455 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7456   *rvalue = FALSE;
7457 else
7458   {
7459   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7460     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7461   return DEFER;
7462   }
7463
7464 return OK;
7465 }
7466
7467
7468
7469
7470 /*************************************************
7471 **************************************************
7472 *             Stand-alone test program           *
7473 **************************************************
7474 *************************************************/
7475
7476 #ifdef STAND_ALONE
7477
7478
7479 BOOL
7480 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7481 {
7482 int ovector[3*(EXPAND_MAXN+1)];
7483 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7484   ovector, nelem(ovector));
7485 BOOL yield = n >= 0;
7486 if (n == 0) n = EXPAND_MAXN + 1;
7487 if (yield)
7488   {
7489   int nn;
7490   expand_nmax = (setup < 0)? 0 : setup + 1;
7491   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7492     {
7493     expand_nstring[expand_nmax] = subject + ovector[nn];
7494     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7495     }
7496   expand_nmax--;
7497   }
7498 return yield;
7499 }
7500
7501
7502 int main(int argc, uschar **argv)
7503 {
7504 int i;
7505 uschar buffer[1024];
7506
7507 debug_selector = D_v;
7508 debug_file = stderr;
7509 debug_fd = fileno(debug_file);
7510 big_buffer = malloc(big_buffer_size);
7511
7512 for (i = 1; i < argc; i++)
7513   {
7514   if (argv[i][0] == '+')
7515     {
7516     debug_trace_memory = 2;
7517     argv[i]++;
7518     }
7519   if (isdigit(argv[i][0]))
7520     debug_selector = Ustrtol(argv[i], NULL, 0);
7521   else
7522     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7523         Ustrlen(argv[i]))
7524       {
7525 #ifdef LOOKUP_LDAP
7526       eldap_default_servers = argv[i];
7527 #endif
7528 #ifdef LOOKUP_MYSQL
7529       mysql_servers = argv[i];
7530 #endif
7531 #ifdef LOOKUP_PGSQL
7532       pgsql_servers = argv[i];
7533 #endif
7534 #ifdef LOOKUP_REDIS
7535       redis_servers = argv[i];
7536 #endif
7537       }
7538 #ifdef EXIM_PERL
7539   else opt_perl_startup = argv[i];
7540 #endif
7541   }
7542
7543 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7544
7545 expand_nstring[1] = US"string 1....";
7546 expand_nlength[1] = 8;
7547 expand_nmax = 1;
7548
7549 #ifdef EXIM_PERL
7550 if (opt_perl_startup != NULL)
7551   {
7552   uschar *errstr;
7553   printf("Starting Perl interpreter\n");
7554   errstr = init_perl(opt_perl_startup);
7555   if (errstr != NULL)
7556     {
7557     printf("** error in perl_startup code: %s\n", errstr);
7558     return EXIT_FAILURE;
7559     }
7560   }
7561 #endif /* EXIM_PERL */
7562
7563 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7564   {
7565   void *reset_point = store_get(0);
7566   uschar *yield = expand_string(buffer);
7567   if (yield != NULL)
7568     {
7569     printf("%s\n", yield);
7570     store_reset(reset_point);
7571     }
7572   else
7573     {
7574     if (search_find_defer) printf("search_find deferred\n");
7575     printf("Failed: %s\n", expand_string_message);
7576     if (expand_string_forcedfail) printf("Forced failure\n");
7577     printf("\n");
7578     }
7579   }
7580
7581 search_tidyup();
7582
7583 return 0;
7584 }
7585
7586 #endif
7587
7588 /* vi: aw ai sw=2
7589 */
7590 /* End of expand.c */