src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Charaters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base32",
 203   US"base32d",
 204   US"base62",
 205   US"base62d",
 206   US"base64",
 207   US"base64d",
 208   US"domain",
 209   US"escape",
 210   US"eval",
 211   US"eval10",
 212   US"expand",
 213   US"h",
 214   US"hash",
 215   US"hex2b64",
 216   US"hexquote",
 217   US"ipv6denorm",
 218   US"ipv6norm",
 219   US"l",
 220   US"lc",
 221   US"length",
 222   US"listcount",
 223   US"listnamed",
 224   US"mask",
 225   US"md5",
 226   US"nh",
 227   US"nhash",
 228   US"quote",
 229   US"randint",
 230   US"rfc2047",
 231   US"rfc2047d",
 232   US"rxquote",
 233   US"s",
 234   US"sha1",
 235   US"sha256",
 236   US"sha3",
 237   US"stat",
 238   US"str2b64",
 239   US"strlen",
 240   US"substr",
 241   US"uc",
 242   US"utf8clean" };
 243
 244 enum {
 245   EOP_ADDRESS =  nelem(op_table_underscore),
 246   EOP_ADDRESSES,
 247   EOP_BASE32,
 248   EOP_BASE32D,
 249   EOP_BASE62,
 250   EOP_BASE62D,
 251   EOP_BASE64,
 252   EOP_BASE64D,
 253   EOP_DOMAIN,
 254   EOP_ESCAPE,
 255   EOP_EVAL,
 256   EOP_EVAL10,
 257   EOP_EXPAND,
 258   EOP_H,
 259   EOP_HASH,
 260   EOP_HEX2B64,
 261   EOP_HEXQUOTE,
 262   EOP_IPV6DENORM,
 263   EOP_IPV6NORM,
 264   EOP_L,
 265   EOP_LC,
 266   EOP_LENGTH,
 267   EOP_LISTCOUNT,
 268   EOP_LISTNAMED,
 269   EOP_MASK,
 270   EOP_MD5,
 271   EOP_NH,
 272   EOP_NHASH,
 273   EOP_QUOTE,
 274   EOP_RANDINT,
 275   EOP_RFC2047,
 276   EOP_RFC2047D,
 277   EOP_RXQUOTE,
 278   EOP_S,
 279   EOP_SHA1,
 280   EOP_SHA256,
 281   EOP_SHA3,
 282   EOP_STAT,
 283   EOP_STR2B64,
 284   EOP_STRLEN,
 285   EOP_SUBSTR,
 286   EOP_UC,
 287   EOP_UTF8CLEAN };
 288
 289
 290 /* Table of condition names, and corresponding switch numbers. The names must
 291 be in alphabetical order. */
 292
 293 static uschar *cond_table[] = {
 294   US"<",
 295   US"<=",
 296   US"=",
 297   US"==",     /* Backward compatibility */
 298   US">",
 299   US">=",
 300   US"acl",
 301   US"and",
 302   US"bool",
 303   US"bool_lax",
 304   US"crypteq",
 305   US"def",
 306   US"eq",
 307   US"eqi",
 308   US"exists",
 309   US"first_delivery",
 310   US"forall",
 311   US"forany",
 312   US"ge",
 313   US"gei",
 314   US"gt",
 315   US"gti",
 316   US"inlist",
 317   US"inlisti",
 318   US"isip",
 319   US"isip4",
 320   US"isip6",
 321   US"ldapauth",
 322   US"le",
 323   US"lei",
 324   US"lt",
 325   US"lti",
 326   US"match",
 327   US"match_address",
 328   US"match_domain",
 329   US"match_ip",
 330   US"match_local_part",
 331   US"or",
 332   US"pam",
 333   US"pwcheck",
 334   US"queue_running",
 335   US"radius",
 336   US"saslauthd"
 337 };
 338
 339 enum {
 340   ECOND_NUM_L,
 341   ECOND_NUM_LE,
 342   ECOND_NUM_E,
 343   ECOND_NUM_EE,
 344   ECOND_NUM_G,
 345   ECOND_NUM_GE,
 346   ECOND_ACL,
 347   ECOND_AND,
 348   ECOND_BOOL,
 349   ECOND_BOOL_LAX,
 350   ECOND_CRYPTEQ,
 351   ECOND_DEF,
 352   ECOND_STR_EQ,
 353   ECOND_STR_EQI,
 354   ECOND_EXISTS,
 355   ECOND_FIRST_DELIVERY,
 356   ECOND_FORALL,
 357   ECOND_FORANY,
 358   ECOND_STR_GE,
 359   ECOND_STR_GEI,
 360   ECOND_STR_GT,
 361   ECOND_STR_GTI,
 362   ECOND_INLIST,
 363   ECOND_INLISTI,
 364   ECOND_ISIP,
 365   ECOND_ISIP4,
 366   ECOND_ISIP6,
 367   ECOND_LDAPAUTH,
 368   ECOND_STR_LE,
 369   ECOND_STR_LEI,
 370   ECOND_STR_LT,
 371   ECOND_STR_LTI,
 372   ECOND_MATCH,
 373   ECOND_MATCH_ADDRESS,
 374   ECOND_MATCH_DOMAIN,
 375   ECOND_MATCH_IP,
 376   ECOND_MATCH_LOCAL_PART,
 377   ECOND_OR,
 378   ECOND_PAM,
 379   ECOND_PWCHECK,
 380   ECOND_QUEUE_RUNNING,
 381   ECOND_RADIUS,
 382   ECOND_SASLAUTHD
 383 };
 384
 385
 386 /* Types of table entry */
 387
 388 enum vtypes {
 389   vtype_int,            /* value is address of int */
 390   vtype_filter_int,     /* ditto, but recognized only when filtering */
 391   vtype_ino,            /* value is address of ino_t (not always an int) */
 392   vtype_uid,            /* value is address of uid_t (not always an int) */
 393   vtype_gid,            /* value is address of gid_t (not always an int) */
 394   vtype_bool,           /* value is address of bool */
 395   vtype_stringptr,      /* value is address of pointer to string */
 396   vtype_msgbody,        /* as stringptr, but read when first required */
 397   vtype_msgbody_end,    /* ditto, the end of the message */
 398   vtype_msgheaders,     /* the message's headers, processed */
 399   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 400   vtype_localpart,      /* extract local part from string */
 401   vtype_domain,         /* extract domain from string */
 402   vtype_string_func,    /* value is string returned by given function */
 403   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 404   vtype_tode,           /* value not used; generate tod in epoch format */
 405   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 406   vtype_todf,           /* value not used; generate full tod */
 407   vtype_todl,           /* value not used; generate log tod */
 408   vtype_todlf,          /* value not used; generate log file datestamp tod */
 409   vtype_todzone,        /* value not used; generate time zone only */
 410   vtype_todzulu,        /* value not used; generate zulu tod */
 411   vtype_reply,          /* value not used; get reply from headers */
 412   vtype_pid,            /* value not used; result is pid */
 413   vtype_host_lookup,    /* value not used; get host name */
 414   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 415   vtype_pspace,         /* partition space; value is T/F for spool/log */
 416   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 417   vtype_cert            /* SSL certificate */
 418   #ifndef DISABLE_DKIM
 419   ,vtype_dkim           /* Lookup of value in DKIM signature */
 420   #endif
 421 };
 422
 423 /* Type for main variable table */
 424
 425 typedef struct {
 426   const char *name;
 427   enum vtypes type;
 428   void       *value;
 429 } var_entry;
 430
 431 /* Type for entries pointing to address/length pairs. Not currently
 432 in use. */
 433
 434 typedef struct {
 435   uschar **address;
 436   int  *length;
 437 } alblock;
 438
 439 static uschar * fn_recipients(void);
 440
 441 /* This table must be kept in alphabetical order. */
 442
 443 static var_entry var_table[] = {
 444   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 445      they will be confused with user-creatable ACL variables. */
 446   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 447   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 448   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 449   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 450   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 451   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 452   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 453   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 454   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 455   { "acl_narg",            vtype_int,         &acl_narg },
 456   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 457   { "address_data",        vtype_stringptr,   &deliver_address_data },
 458   { "address_file",        vtype_stringptr,   &address_file },
 459   { "address_pipe",        vtype_stringptr,   &address_pipe },
 460   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 461   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 462   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 463   { "authentication_failed",vtype_int,        &authentication_failed },
 464 #ifdef WITH_CONTENT_SCAN
 465   { "av_failed",           vtype_int,         &av_failed },
 466 #endif
 467 #ifdef EXPERIMENTAL_BRIGHTMAIL
 468   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 469   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 470   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 471   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 472 #endif
 473   { "body_linecount",      vtype_int,         &body_linecount },
 474   { "body_zerocount",      vtype_int,         &body_zerocount },
 475   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 476   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 477   { "caller_gid",          vtype_gid,         &real_gid },
 478   { "caller_uid",          vtype_uid,         &real_uid },
 479   { "callout_address",     vtype_stringptr,   &callout_address },
 480   { "compile_date",        vtype_stringptr,   &version_date },
 481   { "compile_number",      vtype_stringptr,   &version_cnumber },
 482   { "config_dir",          vtype_stringptr,   &config_main_directory },
 483   { "config_file",         vtype_stringptr,   &config_main_filename },
 484   { "csa_status",          vtype_stringptr,   &csa_status },
 485 #ifdef EXPERIMENTAL_DCC
 486   { "dcc_header",          vtype_stringptr,   &dcc_header },
 487   { "dcc_result",          vtype_stringptr,   &dcc_result },
 488 #endif
 489 #ifndef DISABLE_DKIM
 490   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 491   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 492   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 493   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 494   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 495   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 496   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 497   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 498   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 499   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 500   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 501   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 502   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 503   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 504   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 505   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 506   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 507   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 508   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 509   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 510   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 511 #endif
 512 #ifdef EXPERIMENTAL_DMARC
 513   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 514   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 515   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 516   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 517   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 518 #endif
 519   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 520   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 521   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 522   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 523   { "domain",              vtype_stringptr,   &deliver_domain },
 524   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 525 #ifndef DISABLE_EVENT
 526   { "event_data",          vtype_stringptr,   &event_data },
 527
 528   /*XXX want to use generic vars for as many of these as possible*/
 529   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 530
 531   { "event_name",          vtype_stringptr,   &event_name },
 532 #endif
 533   { "exim_gid",            vtype_gid,         &exim_gid },
 534   { "exim_path",           vtype_stringptr,   &exim_path },
 535   { "exim_uid",            vtype_uid,         &exim_uid },
 536   { "exim_version",        vtype_stringptr,   &version_string },
 537   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 538   { "home",                vtype_stringptr,   &deliver_home },
 539   { "host",                vtype_stringptr,   &deliver_host },
 540   { "host_address",        vtype_stringptr,   &deliver_host_address },
 541   { "host_data",           vtype_stringptr,   &host_data },
 542   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 543   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 544   { "host_port",           vtype_int,         &deliver_host_port },
 545   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 546   { "inode",               vtype_ino,         &deliver_inode },
 547   { "interface_address",   vtype_stringptr,   &interface_address },
 548   { "interface_port",      vtype_int,         &interface_port },
 549   { "item",                vtype_stringptr,   &iterate_item },
 550   #ifdef LOOKUP_LDAP
 551   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 552   #endif
 553   { "load_average",        vtype_load_avg,    NULL },
 554   { "local_part",          vtype_stringptr,   &deliver_localpart },
 555   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 556   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 557   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 558   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 559   { "local_user_gid",      vtype_gid,         &local_user_gid },
 560   { "local_user_uid",      vtype_uid,         &local_user_uid },
 561   { "localhost_number",    vtype_int,         &host_number },
 562   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 563   { "log_space",           vtype_pspace,      (void *)FALSE },
 564   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 565   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 566 #ifdef WITH_CONTENT_SCAN
 567   { "malware_name",        vtype_stringptr,   &malware_name },
 568 #endif
 569   { "max_received_linelength", vtype_int,     &max_received_linelength },
 570   { "message_age",         vtype_int,         &message_age },
 571   { "message_body",        vtype_msgbody,     &message_body },
 572   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 573   { "message_body_size",   vtype_int,         &message_body_size },
 574   { "message_exim_id",     vtype_stringptr,   &message_id },
 575   { "message_headers",     vtype_msgheaders,  NULL },
 576   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 577   { "message_id",          vtype_stringptr,   &message_id },
 578   { "message_linecount",   vtype_int,         &message_linecount },
 579   { "message_size",        vtype_int,         &message_size },
 580 #ifdef SUPPORT_I18N
 581   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 582 #endif
 583 #ifdef WITH_CONTENT_SCAN
 584   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 585   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 586   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 587   { "mime_charset",        vtype_stringptr,   &mime_charset },
 588   { "mime_content_description", vtype_stringptr, &mime_content_description },
 589   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 590   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 591   { "mime_content_size",   vtype_int,         &mime_content_size },
 592   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 593   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 594   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 595   { "mime_filename",       vtype_stringptr,   &mime_filename },
 596   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 597   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 598   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 599   { "mime_part_count",     vtype_int,         &mime_part_count },
 600 #endif
 601   { "n0",                  vtype_filter_int,  &filter_n[0] },
 602   { "n1",                  vtype_filter_int,  &filter_n[1] },
 603   { "n2",                  vtype_filter_int,  &filter_n[2] },
 604   { "n3",                  vtype_filter_int,  &filter_n[3] },
 605   { "n4",                  vtype_filter_int,  &filter_n[4] },
 606   { "n5",                  vtype_filter_int,  &filter_n[5] },
 607   { "n6",                  vtype_filter_int,  &filter_n[6] },
 608   { "n7",                  vtype_filter_int,  &filter_n[7] },
 609   { "n8",                  vtype_filter_int,  &filter_n[8] },
 610   { "n9",                  vtype_filter_int,  &filter_n[9] },
 611   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 612   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 613   { "originator_gid",      vtype_gid,         &originator_gid },
 614   { "originator_uid",      vtype_uid,         &originator_uid },
 615   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 616   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 617   { "pid",                 vtype_pid,         NULL },
 618 #ifndef DISABLE_PRDR
 619   { "prdr_requested",      vtype_bool,        &prdr_requested },
 620 #endif
 621   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 622 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 623   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 624   { "proxy_external_port", vtype_int,         &proxy_external_port },
 625   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 626   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 627   { "proxy_session",       vtype_bool,        &proxy_session },
 628 #endif
 629   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 630   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 631   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 632   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 633   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 634   { "queue_name",          vtype_stringptr,   &queue_name },
 635   { "rcpt_count",          vtype_int,         &rcpt_count },
 636   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 637   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 638   { "received_count",      vtype_int,         &received_count },
 639   { "received_for",        vtype_stringptr,   &received_for },
 640   { "received_ip_address", vtype_stringptr,   &interface_address },
 641   { "received_port",       vtype_int,         &interface_port },
 642   { "received_protocol",   vtype_stringptr,   &received_protocol },
 643   { "received_time",       vtype_int,         &received_time },
 644   { "recipient_data",      vtype_stringptr,   &recipient_data },
 645   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 646   { "recipients",          vtype_string_func, &fn_recipients },
 647   { "recipients_count",    vtype_int,         &recipients_count },
 648 #ifdef WITH_CONTENT_SCAN
 649   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 650 #endif
 651   { "reply_address",       vtype_reply,       NULL },
 652   { "return_path",         vtype_stringptr,   &return_path },
 653   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 654   { "router_name",         vtype_stringptr,   &router_name },
 655   { "runrc",               vtype_int,         &runrc },
 656   { "self_hostname",       vtype_stringptr,   &self_hostname },
 657   { "sender_address",      vtype_stringptr,   &sender_address },
 658   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 659   { "sender_address_domain", vtype_domain,    &sender_address },
 660   { "sender_address_local_part", vtype_localpart, &sender_address },
 661   { "sender_data",         vtype_stringptr,   &sender_data },
 662   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 663   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 664   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 665   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 666   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 667   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 668   { "sender_host_name",    vtype_host_lookup, NULL },
 669   { "sender_host_port",    vtype_int,         &sender_host_port },
 670   { "sender_ident",        vtype_stringptr,   &sender_ident },
 671   { "sender_rate",         vtype_stringptr,   &sender_rate },
 672   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 673   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 674   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 675   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 676   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 677   { "sending_port",        vtype_int,         &sending_port },
 678   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 679   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 680   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 681   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 682   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 683   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 684   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 685   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 686   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 687   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 688   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 689   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 690   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 691   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 692   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 693 #ifdef WITH_CONTENT_SCAN
 694   { "spam_action",         vtype_stringptr,   &spam_action },
 695   { "spam_bar",            vtype_stringptr,   &spam_bar },
 696   { "spam_report",         vtype_stringptr,   &spam_report },
 697   { "spam_score",          vtype_stringptr,   &spam_score },
 698   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 699 #endif
 700 #ifdef EXPERIMENTAL_SPF
 701   { "spf_guess",           vtype_stringptr,   &spf_guess },
 702   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 703   { "spf_received",        vtype_stringptr,   &spf_received },
 704   { "spf_result",          vtype_stringptr,   &spf_result },
 705   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 706 #endif
 707   { "spool_directory",     vtype_stringptr,   &spool_directory },
 708   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 709   { "spool_space",         vtype_pspace,      (void *)TRUE },
 710 #ifdef EXPERIMENTAL_SRS
 711   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 712   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 713   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 714   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 715   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 716   { "srs_status",          vtype_stringptr,   &srs_status },
 717 #endif
 718   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 719
 720   /* The non-(in,out) variables are now deprecated */
 721   { "tls_bits",            vtype_int,         &tls_in.bits },
 722   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 723   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 724
 725   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 726   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 727   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 728   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 729   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 730   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 731   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 732 #if defined(SUPPORT_TLS)
 733   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 734 #endif
 735   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 736   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 737   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 738 #ifdef EXPERIMENTAL_DANE
 739   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 740 #endif
 741   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 742   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 743   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 744   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 745 #if defined(SUPPORT_TLS)
 746   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 747 #endif
 748 #ifdef EXPERIMENTAL_DANE
 749   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 750 #endif
 751
 752   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 753 #if defined(SUPPORT_TLS)
 754   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 755 #endif
 756
 757   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 758   { "tod_epoch",           vtype_tode,        NULL },
 759   { "tod_epoch_l",         vtype_todel,       NULL },
 760   { "tod_full",            vtype_todf,        NULL },
 761   { "tod_log",             vtype_todl,        NULL },
 762   { "tod_logfile",         vtype_todlf,       NULL },
 763   { "tod_zone",            vtype_todzone,     NULL },
 764   { "tod_zulu",            vtype_todzulu,     NULL },
 765   { "transport_name",      vtype_stringptr,   &transport_name },
 766   { "value",               vtype_stringptr,   &lookup_value },
 767   { "verify_mode",         vtype_stringptr,   &verify_mode },
 768   { "version_number",      vtype_stringptr,   &version_string },
 769   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 770   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 771   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 772   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 773   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 774   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 775 };
 776
 777 static int var_table_size = nelem(var_table);
 778 static uschar var_buffer[256];
 779 static BOOL malformed_header;
 780
 781 /* For textual hashes */
 782
 783 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 784                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 785                                "0123456789";
 786
 787 enum { HMAC_MD5, HMAC_SHA1 };
 788
 789 /* For numeric hashes */
 790
 791 static unsigned int prime[] = {
 792   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 793  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 794  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 795
 796 /* For printing modes in symbolic form */
 797
 798 static uschar *mtable_normal[] =
 799   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 800
 801 static uschar *mtable_setid[] =
 802   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 803
 804 static uschar *mtable_sticky[] =
 805   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 806
 807
 808
 809 /*************************************************
 810 *           Tables for UTF-8 support             *
 811 *************************************************/
 812
 813 /* Table of the number of extra characters, indexed by the first character
 814 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 815 0x3d. */
 816
 817 static uschar utf8_table1[] = {
 818   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 819   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 820   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 821   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 822
 823 /* These are the masks for the data bits in the first byte of a character,
 824 indexed by the number of additional bytes. */
 825
 826 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 827
 828 /* Get the next UTF-8 character, advancing the pointer. */
 829
 830 #define GETUTF8INC(c, ptr) \
 831   c = *ptr++; \
 832   if ((c & 0xc0) == 0xc0) \
 833     { \
 834     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 835     int s = 6*a; \
 836     c = (c & utf8_table2[a]) << s; \
 837     while (a-- > 0) \
 838       { \
 839       s -= 6; \
 840       c |= (*ptr++ & 0x3f) << s; \
 841       } \
 842     }
 843
 844
 845
 846 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 847
 848 /*************************************************
 849 *           Binary chop search on a table        *
 850 *************************************************/
 851
 852 /* This is used for matching expansion items and operators.
 853
 854 Arguments:
 855   name        the name that is being sought
 856   table       the table to search
 857   table_size  the number of items in the table
 858
 859 Returns:      the offset in the table, or -1
 860 */
 861
 862 static int
 863 chop_match(uschar *name, uschar **table, int table_size)
 864 {
 865 uschar **bot = table;
 866 uschar **top = table + table_size;
 867
 868 while (top > bot)
 869   {
 870   uschar **mid = bot + (top - bot)/2;
 871   int c = Ustrcmp(name, *mid);
 872   if (c == 0) return mid - table;
 873   if (c > 0) bot = mid + 1; else top = mid;
 874   }
 875
 876 return -1;
 877 }
 878
 879
 880
 881 /*************************************************
 882 *          Check a condition string              *
 883 *************************************************/
 884
 885 /* This function is called to expand a string, and test the result for a "true"
 886 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 887 forced fail or lookup defer.
 888
 889 We used to release all store used, but this is not not safe due
 890 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 891 is reasonably careful to release what it can.
 892
 893 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 894
 895 Arguments:
 896   condition     the condition string
 897   m1            text to be incorporated in panic error
 898   m2            ditto
 899
 900 Returns:        TRUE if condition is met, FALSE if not
 901 */
 902
 903 BOOL
 904 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 905 {
 906 int rc;
 907 uschar *ss = expand_string(condition);
 908 if (ss == NULL)
 909   {
 910   if (!expand_string_forcedfail && !search_find_defer)
 911     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 912       "for %s %s: %s", condition, m1, m2, expand_string_message);
 913   return FALSE;
 914   }
 915 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 916   strcmpic(ss, US"false") != 0;
 917 return rc;
 918 }
 919
 920
 921
 922
 923 /*************************************************
 924 *        Pseudo-random number generation         *
 925 *************************************************/
 926
 927 /* Pseudo-random number generation.  The result is not "expected" to be
 928 cryptographically strong but not so weak that someone will shoot themselves
 929 in the foot using it as a nonce in some email header scheme or whatever
 930 weirdness they'll twist this into.  The result should ideally handle fork().
 931
 932 However, if we're stuck unable to provide this, then we'll fall back to
 933 appallingly bad randomness.
 934
 935 If SUPPORT_TLS is defined then this will not be used except as an emergency
 936 fallback.
 937
 938 Arguments:
 939   max       range maximum
 940 Returns     a random number in range [0, max-1]
 941 */
 942
 943 #ifdef SUPPORT_TLS
 944 # define vaguely_random_number vaguely_random_number_fallback
 945 #endif
 946 int
 947 vaguely_random_number(int max)
 948 {
 949 #ifdef SUPPORT_TLS
 950 # undef vaguely_random_number
 951 #endif
 952   static pid_t pid = 0;
 953   pid_t p2;
 954 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 955   struct timeval tv;
 956 #endif
 957
 958   p2 = getpid();
 959   if (p2 != pid)
 960     {
 961     if (pid != 0)
 962       {
 963
 964 #ifdef HAVE_ARC4RANDOM
 965       /* cryptographically strong randomness, common on *BSD platforms, not
 966       so much elsewhere.  Alas. */
 967 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 968       arc4random_stir();
 969 #endif
 970 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 971 #ifdef HAVE_SRANDOMDEV
 972       /* uses random(4) for seeding */
 973       srandomdev();
 974 #else
 975       gettimeofday(&tv, NULL);
 976       srandom(tv.tv_sec | tv.tv_usec | getpid());
 977 #endif
 978 #else
 979       /* Poor randomness and no seeding here */
 980 #endif
 981
 982       }
 983     pid = p2;
 984     }
 985
 986 #ifdef HAVE_ARC4RANDOM
 987   return arc4random() % max;
 988 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 989   return random() % max;
 990 #else
 991   /* This one returns a 16-bit number, definitely not crypto-strong */
 992   return random_number(max);
 993 #endif
 994 }
 995
 996
 997
 998
 999 /*************************************************
1000 *             Pick out a name from a string      *
1001 *************************************************/
1002
1003 /* If the name is too long, it is silently truncated.
1004
1005 Arguments:
1006   name      points to a buffer into which to put the name
1007   max       is the length of the buffer
1008   s         points to the first alphabetic character of the name
1009   extras    chars other than alphanumerics to permit
1010
1011 Returns:    pointer to the first character after the name
1012
1013 Note: The test for *s != 0 in the while loop is necessary because
1014 Ustrchr() yields non-NULL if the character is zero (which is not something
1015 I expected). */
1016
1017 static const uschar *
1018 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1019 {
1020 int ptr = 0;
1021 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1022   {
1023   if (ptr < max-1) name[ptr++] = *s;
1024   s++;
1025   }
1026 name[ptr] = 0;
1027 return s;
1028 }
1029
1030
1031
1032 /*************************************************
1033 *     Pick out the rest of a header name         *
1034 *************************************************/
1035
1036 /* A variable name starting $header_ (or just $h_ for those who like
1037 abbreviations) might not be the complete header name because headers can
1038 contain any printing characters in their names, except ':'. This function is
1039 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1040 on the end, if the name was terminated by white space.
1041
1042 Arguments:
1043   name      points to a buffer in which the name read so far exists
1044   max       is the length of the buffer
1045   s         points to the first character after the name so far, i.e. the
1046             first non-alphameric character after $header_xxxxx
1047
1048 Returns:    a pointer to the first character after the header name
1049 */
1050
1051 static const uschar *
1052 read_header_name(uschar *name, int max, const uschar *s)
1053 {
1054 int prelen = Ustrchr(name, '_') - name + 1;
1055 int ptr = Ustrlen(name) - prelen;
1056 if (ptr > 0) memmove(name, name+prelen, ptr);
1057 while (mac_isgraph(*s) && *s != ':')
1058   {
1059   if (ptr < max-1) name[ptr++] = *s;
1060   s++;
1061   }
1062 if (*s == ':') s++;
1063 name[ptr++] = ':';
1064 name[ptr] = 0;
1065 return s;
1066 }
1067
1068
1069
1070 /*************************************************
1071 *           Pick out a number from a string      *
1072 *************************************************/
1073
1074 /* Arguments:
1075   n     points to an integer into which to put the number
1076   s     points to the first digit of the number
1077
1078 Returns:  a pointer to the character after the last digit
1079 */
1080 /*XXX consider expanding to int_eximarith_t.  But the test for
1081 "overbig numbers" in 0002 still needs to overflow it. */
1082
1083 static uschar *
1084 read_number(int *n, uschar *s)
1085 {
1086 *n = 0;
1087 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1088 return s;
1089 }
1090
1091 static const uschar *
1092 read_cnumber(int *n, const uschar *s)
1093 {
1094 *n = 0;
1095 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1096 return s;
1097 }
1098
1099
1100
1101 /*************************************************
1102 *        Extract keyed subfield from a string    *
1103 *************************************************/
1104
1105 /* The yield is in dynamic store; NULL means that the key was not found.
1106
1107 Arguments:
1108   key       points to the name of the key
1109   s         points to the string from which to extract the subfield
1110
1111 Returns:    NULL if the subfield was not found, or
1112             a pointer to the subfield's data
1113 */
1114
1115 static uschar *
1116 expand_getkeyed(uschar *key, const uschar *s)
1117 {
1118 int length = Ustrlen(key);
1119 while (isspace(*s)) s++;
1120
1121 /* Loop to search for the key */
1122
1123 while (*s != 0)
1124   {
1125   int dkeylength;
1126   uschar *data;
1127   const uschar *dkey = s;
1128
1129   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1130   dkeylength = s - dkey;
1131   while (isspace(*s)) s++;
1132   if (*s == '=') while (isspace((*(++s))));
1133
1134   data = string_dequote(&s);
1135   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1136     return data;
1137
1138   while (isspace(*s)) s++;
1139   }
1140
1141 return NULL;
1142 }
1143
1144
1145
1146 static var_entry *
1147 find_var_ent(uschar * name)
1148 {
1149 int first = 0;
1150 int last = var_table_size;
1151
1152 while (last > first)
1153   {
1154   int middle = (first + last)/2;
1155   int c = Ustrcmp(name, var_table[middle].name);
1156
1157   if (c > 0) { first = middle + 1; continue; }
1158   if (c < 0) { last = middle; continue; }
1159   return &var_table[middle];
1160   }
1161 return NULL;
1162 }
1163
1164 /*************************************************
1165 *   Extract numbered subfield from string        *
1166 *************************************************/
1167
1168 /* Extracts a numbered field from a string that is divided by tokens - for
1169 example a line from /etc/passwd is divided by colon characters.  First field is
1170 numbered one.  Negative arguments count from the right. Zero returns the whole
1171 string. Returns NULL if there are insufficient tokens in the string
1172
1173 ***WARNING***
1174 Modifies final argument - this is a dynamically generated string, so that's OK.
1175
1176 Arguments:
1177   field       number of field to be extracted,
1178                 first field = 1, whole string = 0, last field = -1
1179   separators  characters that are used to break string into tokens
1180   s           points to the string from which to extract the subfield
1181
1182 Returns:      NULL if the field was not found,
1183               a pointer to the field's data inside s (modified to add 0)
1184 */
1185
1186 static uschar *
1187 expand_gettokened (int field, uschar *separators, uschar *s)
1188 {
1189 int sep = 1;
1190 int count;
1191 uschar *ss = s;
1192 uschar *fieldtext = NULL;
1193
1194 if (field == 0) return s;
1195
1196 /* Break the line up into fields in place; for field > 0 we stop when we have
1197 done the number of fields we want. For field < 0 we continue till the end of
1198 the string, counting the number of fields. */
1199
1200 count = (field > 0)? field : INT_MAX;
1201
1202 while (count-- > 0)
1203   {
1204   size_t len;
1205
1206   /* Previous field was the last one in the string. For a positive field
1207   number, this means there are not enough fields. For a negative field number,
1208   check that there are enough, and scan back to find the one that is wanted. */
1209
1210   if (sep == 0)
1211     {
1212     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1213     if ((-field) == (INT_MAX - count - 1)) return s;
1214     while (field++ < 0)
1215       {
1216       ss--;
1217       while (ss[-1] != 0) ss--;
1218       }
1219     fieldtext = ss;
1220     break;
1221     }
1222
1223   /* Previous field was not last in the string; save its start and put a
1224   zero at its end. */
1225
1226   fieldtext = ss;
1227   len = Ustrcspn(ss, separators);
1228   sep = ss[len];
1229   ss[len] = 0;
1230   ss += len + 1;
1231   }
1232
1233 return fieldtext;
1234 }
1235
1236
1237 static uschar *
1238 expand_getlistele(int field, const uschar * list)
1239 {
1240 const uschar * tlist= list;
1241 int sep= 0;
1242 uschar dummy;
1243
1244 if(field<0)
1245   {
1246   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1247   sep= 0;
1248   }
1249 if(field==0) return NULL;
1250 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1251 return string_nextinlist(&list, &sep, NULL, 0);
1252 }
1253
1254
1255 /* Certificate fields, by name.  Worry about by-OID later */
1256 /* Names are chosen to not have common prefixes */
1257
1258 #ifdef SUPPORT_TLS
1259 typedef struct
1260 {
1261 uschar * name;
1262 int      namelen;
1263 uschar * (*getfn)(void * cert, uschar * mod);
1264 } certfield;
1265 static certfield certfields[] =
1266 {                       /* linear search; no special order */
1267   { US"version",         7,  &tls_cert_version },
1268   { US"serial_number",   13, &tls_cert_serial_number },
1269   { US"subject",         7,  &tls_cert_subject },
1270   { US"notbefore",       9,  &tls_cert_not_before },
1271   { US"notafter",        8,  &tls_cert_not_after },
1272   { US"issuer",          6,  &tls_cert_issuer },
1273   { US"signature",       9,  &tls_cert_signature },
1274   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1275   { US"subj_altname",    12, &tls_cert_subject_altname },
1276   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1277   { US"crl_uri",         7,  &tls_cert_crl_uri },
1278 };
1279
1280 static uschar *
1281 expand_getcertele(uschar * field, uschar * certvar)
1282 {
1283 var_entry * vp;
1284 certfield * cp;
1285
1286 if (!(vp = find_var_ent(certvar)))
1287   {
1288   expand_string_message =
1289     string_sprintf("no variable named \"%s\"", certvar);
1290   return NULL;          /* Unknown variable name */
1291   }
1292 /* NB this stops us passing certs around in variable.  Might
1293 want to do that in future */
1294 if (vp->type != vtype_cert)
1295   {
1296   expand_string_message =
1297     string_sprintf("\"%s\" is not a certificate", certvar);
1298   return NULL;          /* Unknown variable name */
1299   }
1300 if (!*(void **)vp->value)
1301   return NULL;
1302
1303 if (*field >= '0' && *field <= '9')
1304   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1305
1306 for(cp = certfields;
1307     cp < certfields + nelem(certfields);
1308     cp++)
1309   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1310     {
1311     uschar * modifier = *(field += cp->namelen) == ','
1312       ? ++field : NULL;
1313     return (*cp->getfn)( *(void **)vp->value, modifier );
1314     }
1315
1316 expand_string_message =
1317   string_sprintf("bad field selector \"%s\" for certextract", field);
1318 return NULL;
1319 }
1320 #endif  /*SUPPORT_TLS*/
1321
1322 /*************************************************
1323 *        Extract a substring from a string       *
1324 *************************************************/
1325
1326 /* Perform the ${substr or ${length expansion operations.
1327
1328 Arguments:
1329   subject     the input string
1330   value1      the offset from the start of the input string to the start of
1331                 the output string; if negative, count from the right.
1332   value2      the length of the output string, or negative (-1) for unset
1333                 if value1 is positive, unset means "all after"
1334                 if value1 is negative, unset means "all before"
1335   len         set to the length of the returned string
1336
1337 Returns:      pointer to the output string, or NULL if there is an error
1338 */
1339
1340 static uschar *
1341 extract_substr(uschar *subject, int value1, int value2, int *len)
1342 {
1343 int sublen = Ustrlen(subject);
1344
1345 if (value1 < 0)    /* count from right */
1346   {
1347   value1 += sublen;
1348
1349   /* If the position is before the start, skip to the start, and adjust the
1350   length. If the length ends up negative, the substring is null because nothing
1351   can precede. This falls out naturally when the length is unset, meaning "all
1352   to the left". */
1353
1354   if (value1 < 0)
1355     {
1356     value2 += value1;
1357     if (value2 < 0) value2 = 0;
1358     value1 = 0;
1359     }
1360
1361   /* Otherwise an unset length => characters before value1 */
1362
1363   else if (value2 < 0)
1364     {
1365     value2 = value1;
1366     value1 = 0;
1367     }
1368   }
1369
1370 /* For a non-negative offset, if the starting position is past the end of the
1371 string, the result will be the null string. Otherwise, an unset length means
1372 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1373
1374 else
1375   {
1376   if (value1 > sublen)
1377     {
1378     value1 = sublen;
1379     value2 = 0;
1380     }
1381   else if (value2 < 0) value2 = sublen;
1382   }
1383
1384 /* Cut the length down to the maximum possible for the offset value, and get
1385 the required characters. */
1386
1387 if (value1 + value2 > sublen) value2 = sublen - value1;
1388 *len = value2;
1389 return subject + value1;
1390 }
1391
1392
1393
1394
1395 /*************************************************
1396 *            Old-style hash of a string          *
1397 *************************************************/
1398
1399 /* Perform the ${hash expansion operation.
1400
1401 Arguments:
1402   subject     the input string (an expanded substring)
1403   value1      the length of the output string; if greater or equal to the
1404                 length of the input string, the input string is returned
1405   value2      the number of hash characters to use, or 26 if negative
1406   len         set to the length of the returned string
1407
1408 Returns:      pointer to the output string, or NULL if there is an error
1409 */
1410
1411 static uschar *
1412 compute_hash(uschar *subject, int value1, int value2, int *len)
1413 {
1414 int sublen = Ustrlen(subject);
1415
1416 if (value2 < 0) value2 = 26;
1417 else if (value2 > Ustrlen(hashcodes))
1418   {
1419   expand_string_message =
1420     string_sprintf("hash count \"%d\" too big", value2);
1421   return NULL;
1422   }
1423
1424 /* Calculate the hash text. We know it is shorter than the original string, so
1425 can safely place it in subject[] (we know that subject is always itself an
1426 expanded substring). */
1427
1428 if (value1 < sublen)
1429   {
1430   int c;
1431   int i = 0;
1432   int j = value1;
1433   while ((c = (subject[j])) != 0)
1434     {
1435     int shift = (c + j++) & 7;
1436     subject[i] ^= (c << shift) | (c >> (8-shift));
1437     if (++i >= value1) i = 0;
1438     }
1439   for (i = 0; i < value1; i++)
1440     subject[i] = hashcodes[(subject[i]) % value2];
1441   }
1442 else value1 = sublen;
1443
1444 *len = value1;
1445 return subject;
1446 }
1447
1448
1449
1450
1451 /*************************************************
1452 *             Numeric hash of a string           *
1453 *************************************************/
1454
1455 /* Perform the ${nhash expansion operation. The first characters of the
1456 string are treated as most important, and get the highest prime numbers.
1457
1458 Arguments:
1459   subject     the input string
1460   value1      the maximum value of the first part of the result
1461   value2      the maximum value of the second part of the result,
1462                 or negative to produce only a one-part result
1463   len         set to the length of the returned string
1464
1465 Returns:  pointer to the output string, or NULL if there is an error.
1466 */
1467
1468 static uschar *
1469 compute_nhash (uschar *subject, int value1, int value2, int *len)
1470 {
1471 uschar *s = subject;
1472 int i = 0;
1473 unsigned long int total = 0; /* no overflow */
1474
1475 while (*s != 0)
1476   {
1477   if (i == 0) i = nelem(prime) - 1;
1478   total += prime[i--] * (unsigned int)(*s++);
1479   }
1480
1481 /* If value2 is unset, just compute one number */
1482
1483 if (value2 < 0)
1484   {
1485   s = string_sprintf("%d", total % value1);
1486   }
1487
1488 /* Otherwise do a div/mod hash */
1489
1490 else
1491   {
1492   total = total % (value1 * value2);
1493   s = string_sprintf("%d/%d", total/value2, total % value2);
1494   }
1495
1496 *len = Ustrlen(s);
1497 return s;
1498 }
1499
1500
1501
1502
1503
1504 /*************************************************
1505 *     Find the value of a header or headers      *
1506 *************************************************/
1507
1508 /* Multiple instances of the same header get concatenated, and this function
1509 can also return a concatenation of all the header lines. When concatenating
1510 specific headers that contain lists of addresses, a comma is inserted between
1511 them. Otherwise we use a straight concatenation. Because some messages can have
1512 pathologically large number of lines, there is a limit on the length that is
1513 returned. Also, to avoid massive store use which would result from using
1514 string_cat() as it copies and extends strings, we do a preliminary pass to find
1515 out exactly how much store will be needed. On "normal" messages this will be
1516 pretty trivial.
1517
1518 Arguments:
1519   name          the name of the header, without the leading $header_ or $h_,
1520                 or NULL if a concatenation of all headers is required
1521   exists_only   TRUE if called from a def: test; don't need to build a string;
1522                 just return a string that is not "" and not "0" if the header
1523                 exists
1524   newsize       return the size of memory block that was obtained; may be NULL
1525                 if exists_only is TRUE
1526   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1527                 other than concatenating, will be done on the header. Also used
1528                 for $message_headers_raw.
1529   charset       name of charset to translate MIME words to; used only if
1530                 want_raw is false; if NULL, no translation is done (this is
1531                 used for $bh_ and $bheader_)
1532
1533 Returns:        NULL if the header does not exist, else a pointer to a new
1534                 store block
1535 */
1536
1537 static uschar *
1538 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1539   uschar *charset)
1540 {
1541 BOOL found = name == NULL;
1542 int comma = 0;
1543 int len = found? 0 : Ustrlen(name);
1544 int i;
1545 uschar *yield = NULL;
1546 uschar *ptr = NULL;
1547
1548 /* Loop for two passes - saves code repetition */
1549
1550 for (i = 0; i < 2; i++)
1551   {
1552   int size = 0;
1553   header_line *h;
1554
1555   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1556     {
1557     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1558       {
1559       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1560         {
1561         int ilen;
1562         uschar *t;
1563
1564         if (exists_only) return US"1";      /* don't need actual string */
1565         found = TRUE;
1566         t = h->text + len;                  /* text to insert */
1567         if (!want_raw)                      /* unless wanted raw, */
1568           while (isspace(*t)) t++;          /* remove leading white space */
1569         ilen = h->slen - (t - h->text);     /* length to insert */
1570
1571         /* Unless wanted raw, remove trailing whitespace, including the
1572         newline. */
1573
1574         if (!want_raw)
1575           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1576
1577         /* Set comma = 1 if handling a single header and it's one of those
1578         that contains an address list, except when asked for raw headers. Only
1579         need to do this once. */
1580
1581         if (!want_raw && name != NULL && comma == 0 &&
1582             Ustrchr("BCFRST", h->type) != NULL)
1583           comma = 1;
1584
1585         /* First pass - compute total store needed; second pass - compute
1586         total store used, including this header. */
1587
1588         size += ilen + comma + 1;  /* +1 for the newline */
1589
1590         /* Second pass - concatentate the data, up to a maximum. Note that
1591         the loop stops when size hits the limit. */
1592
1593         if (i != 0)
1594           {
1595           if (size > header_insert_maxlen)
1596             {
1597             ilen -= size - header_insert_maxlen - 1;
1598             comma = 0;
1599             }
1600           Ustrncpy(ptr, t, ilen);
1601           ptr += ilen;
1602
1603           /* For a non-raw header, put in the comma if needed, then add
1604           back the newline we removed above, provided there was some text in
1605           the header. */
1606
1607           if (!want_raw && ilen > 0)
1608             {
1609             if (comma != 0) *ptr++ = ',';
1610             *ptr++ = '\n';
1611             }
1612           }
1613         }
1614       }
1615     }
1616
1617   /* At end of first pass, return NULL if no header found. Then truncate size
1618   if necessary, and get the buffer to hold the data, returning the buffer size.
1619   */
1620
1621   if (i == 0)
1622     {
1623     if (!found) return NULL;
1624     if (size > header_insert_maxlen) size = header_insert_maxlen;
1625     *newsize = size + 1;
1626     ptr = yield = store_get(*newsize);
1627     }
1628   }
1629
1630 /* That's all we do for raw header expansion. */
1631
1632 if (want_raw)
1633   {
1634   *ptr = 0;
1635   }
1636
1637 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1638 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1639 function can return an error with decoded data if the charset translation
1640 fails. If decoding fails, it returns NULL. */
1641
1642 else
1643   {
1644   uschar *decoded, *error;
1645   if (ptr > yield && ptr[-1] == '\n') ptr--;
1646   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1647   *ptr = 0;
1648   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1649     newsize, &error);
1650   if (error != NULL)
1651     {
1652     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1653       "    input was: %s\n", error, yield);
1654     }
1655   if (decoded != NULL) yield = decoded;
1656   }
1657
1658 return yield;
1659 }
1660
1661
1662
1663
1664 /*************************************************
1665 *               Return list of recipients        *
1666 *************************************************/
1667 /* A recipients list is available only during system message filtering,
1668 during ACL processing after DATA, and while expanding pipe commands
1669 generated from a system filter, but not elsewhere. */
1670
1671 static uschar *
1672 fn_recipients(void)
1673 {
1674 if (!enable_dollar_recipients) return NULL; else
1675   {
1676   int size = 128;
1677   int ptr = 0;
1678   int i;
1679   uschar * s = store_get(size);
1680   for (i = 0; i < recipients_count; i++)
1681     {
1682     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1683     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1684     }
1685   s[ptr] = 0;     /* string_cat() leaves room */
1686   return s;
1687   }
1688 }
1689
1690
1691 /*************************************************
1692 *               Find value of a variable         *
1693 *************************************************/
1694
1695 /* The table of variables is kept in alphabetic order, so we can search it
1696 using a binary chop. The "choplen" variable is nothing to do with the binary
1697 chop.
1698
1699 Arguments:
1700   name          the name of the variable being sought
1701   exists_only   TRUE if this is a def: test; passed on to find_header()
1702   skipping      TRUE => skip any processing evaluation; this is not the same as
1703                   exists_only because def: may test for values that are first
1704                   evaluated here
1705   newsize       pointer to an int which is initially zero; if the answer is in
1706                 a new memory buffer, *newsize is set to its size
1707
1708 Returns:        NULL if the variable does not exist, or
1709                 a pointer to the variable's contents, or
1710                 something non-NULL if exists_only is TRUE
1711 */
1712
1713 static uschar *
1714 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1715 {
1716 var_entry * vp;
1717 uschar *s, *domain;
1718 uschar **ss;
1719 void * val;
1720
1721 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1722 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1723 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1724 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1725 (this gave backwards compatibility at the changeover). There may be built-in
1726 variables whose names start acl_ but they should never start in this way. This
1727 slightly messy specification is a consequence of the history, needless to say.
1728
1729 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1730 set, in which case give an error. */
1731
1732 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1733      !isalpha(name[5]))
1734   {
1735   tree_node *node =
1736     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1737   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1738   }
1739
1740 /* Handle $auth<n> variables. */
1741
1742 if (Ustrncmp(name, "auth", 4) == 0)
1743   {
1744   uschar *endptr;
1745   int n = Ustrtoul(name + 4, &endptr, 10);
1746   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1747     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1748   }
1749 else if (Ustrncmp(name, "regex", 5) == 0)
1750   {
1751   uschar *endptr;
1752   int n = Ustrtoul(name + 5, &endptr, 10);
1753   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1754     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1755   }
1756
1757 /* For all other variables, search the table */
1758
1759 if (!(vp = find_var_ent(name)))
1760   return NULL;          /* Unknown variable name */
1761
1762 /* Found an existing variable. If in skipping state, the value isn't needed,
1763 and we want to avoid processing (such as looking up the host name). */
1764
1765 if (skipping)
1766   return US"";
1767
1768 val = vp->value;
1769 switch (vp->type)
1770   {
1771   case vtype_filter_int:
1772     if (!filter_running) return NULL;
1773     /* Fall through */
1774     /* VVVVVVVVVVVV */
1775   case vtype_int:
1776     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1777     return var_buffer;
1778
1779   case vtype_ino:
1780     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1781     return var_buffer;
1782
1783   case vtype_gid:
1784     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1785     return var_buffer;
1786
1787   case vtype_uid:
1788     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1789     return var_buffer;
1790
1791   case vtype_bool:
1792     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1793     return var_buffer;
1794
1795   case vtype_stringptr:                      /* Pointer to string */
1796     return (s = *((uschar **)(val))) ? s : US"";
1797
1798   case vtype_pid:
1799     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1800     return var_buffer;
1801
1802   case vtype_load_avg:
1803     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1804     return var_buffer;
1805
1806   case vtype_host_lookup:                    /* Lookup if not done so */
1807     if (sender_host_name == NULL && sender_host_address != NULL &&
1808         !host_lookup_failed && host_name_lookup() == OK)
1809       host_build_sender_fullhost();
1810     return (sender_host_name == NULL)? US"" : sender_host_name;
1811
1812   case vtype_localpart:                      /* Get local part from address */
1813     s = *((uschar **)(val));
1814     if (s == NULL) return US"";
1815     domain = Ustrrchr(s, '@');
1816     if (domain == NULL) return s;
1817     if (domain - s > sizeof(var_buffer) - 1)
1818       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1819           " in string expansion", sizeof(var_buffer));
1820     Ustrncpy(var_buffer, s, domain - s);
1821     var_buffer[domain - s] = 0;
1822     return var_buffer;
1823
1824   case vtype_domain:                         /* Get domain from address */
1825     s = *((uschar **)(val));
1826     if (s == NULL) return US"";
1827     domain = Ustrrchr(s, '@');
1828     return (domain == NULL)? US"" : domain + 1;
1829
1830   case vtype_msgheaders:
1831     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1832
1833   case vtype_msgheaders_raw:
1834     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1835
1836   case vtype_msgbody:                        /* Pointer to msgbody string */
1837   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1838     ss = (uschar **)(val);
1839     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1840       {
1841       uschar *body;
1842       off_t start_offset = SPOOL_DATA_START_OFFSET;
1843       int len = message_body_visible;
1844       if (len > message_size) len = message_size;
1845       *ss = body = store_malloc(len+1);
1846       body[0] = 0;
1847       if (vp->type == vtype_msgbody_end)
1848         {
1849         struct stat statbuf;
1850         if (fstat(deliver_datafile, &statbuf) == 0)
1851           {
1852           start_offset = statbuf.st_size - len;
1853           if (start_offset < SPOOL_DATA_START_OFFSET)
1854             start_offset = SPOOL_DATA_START_OFFSET;
1855           }
1856         }
1857       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1858         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1859           strerror(errno));
1860       len = read(deliver_datafile, body, len);
1861       if (len > 0)
1862         {
1863         body[len] = 0;
1864         if (message_body_newlines)   /* Separate loops for efficiency */
1865           while (len > 0)
1866             { if (body[--len] == 0) body[len] = ' '; }
1867         else
1868           while (len > 0)
1869             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1870         }
1871       }
1872     return (*ss == NULL)? US"" : *ss;
1873
1874   case vtype_todbsdin:                       /* BSD inbox time of day */
1875     return tod_stamp(tod_bsdin);
1876
1877   case vtype_tode:                           /* Unix epoch time of day */
1878     return tod_stamp(tod_epoch);
1879
1880   case vtype_todel:                          /* Unix epoch/usec time of day */
1881     return tod_stamp(tod_epoch_l);
1882
1883   case vtype_todf:                           /* Full time of day */
1884     return tod_stamp(tod_full);
1885
1886   case vtype_todl:                           /* Log format time of day */
1887     return tod_stamp(tod_log_bare);            /* (without timezone) */
1888
1889   case vtype_todzone:                        /* Time zone offset only */
1890     return tod_stamp(tod_zone);
1891
1892   case vtype_todzulu:                        /* Zulu time */
1893     return tod_stamp(tod_zulu);
1894
1895   case vtype_todlf:                          /* Log file datestamp tod */
1896     return tod_stamp(tod_log_datestamp_daily);
1897
1898   case vtype_reply:                          /* Get reply address */
1899     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1900       headers_charset);
1901     if (s != NULL) while (isspace(*s)) s++;
1902     if (s == NULL || *s == 0)
1903       {
1904       *newsize = 0;                            /* For the *s==0 case */
1905       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1906       }
1907     if (s != NULL)
1908       {
1909       uschar *t;
1910       while (isspace(*s)) s++;
1911       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1912       while (t > s && isspace(t[-1])) t--;
1913       *t = 0;
1914       }
1915     return (s == NULL)? US"" : s;
1916
1917   case vtype_string_func:
1918     {
1919     uschar * (*fn)() = val;
1920     return fn();
1921     }
1922
1923   case vtype_pspace:
1924     {
1925     int inodes;
1926     sprintf(CS var_buffer, "%d",
1927       receive_statvfs(val == (void *)TRUE, &inodes));
1928     }
1929   return var_buffer;
1930
1931   case vtype_pinodes:
1932     {
1933     int inodes;
1934     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1935     sprintf(CS var_buffer, "%d", inodes);
1936     }
1937   return var_buffer;
1938
1939   case vtype_cert:
1940     return *(void **)val ? US"<cert>" : US"";
1941
1942 #ifndef DISABLE_DKIM
1943   case vtype_dkim:
1944     return dkim_exim_expand_query((int)(long)val);
1945 #endif
1946
1947   }
1948
1949 return NULL;  /* Unknown variable. Silences static checkers. */
1950 }
1951
1952
1953
1954
1955 void
1956 modify_variable(uschar *name, void * value)
1957 {
1958 var_entry * vp;
1959 if ((vp = find_var_ent(name))) vp->value = value;
1960 return;          /* Unknown variable name, fail silently */
1961 }
1962
1963
1964
1965
1966
1967 /*************************************************
1968 *           Read and expand substrings           *
1969 *************************************************/
1970
1971 /* This function is called to read and expand argument substrings for various
1972 expansion items. Some have a minimum requirement that is less than the maximum;
1973 in these cases, the first non-present one is set to NULL.
1974
1975 Arguments:
1976   sub        points to vector of pointers to set
1977   n          maximum number of substrings
1978   m          minimum required
1979   sptr       points to current string pointer
1980   skipping   the skipping flag
1981   check_end  if TRUE, check for final '}'
1982   name       name of item, for error message
1983   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1984              the store.
1985
1986 Returns:     0 OK; string pointer updated
1987              1 curly bracketing error (too few arguments)
1988              2 too many arguments (only if check_end is set); message set
1989              3 other error (expansion failure)
1990 */
1991
1992 static int
1993 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1994   BOOL check_end, uschar *name, BOOL *resetok)
1995 {
1996 int i;
1997 const uschar *s = *sptr;
1998
1999 while (isspace(*s)) s++;
2000 for (i = 0; i < n; i++)
2001   {
2002   if (*s != '{')
2003     {
2004     if (i < m)
2005       {
2006       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2007         "(min is %d)", name, m);
2008       return 1;
2009       }
2010     sub[i] = NULL;
2011     break;
2012     }
2013   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2014     return 3;
2015   if (*s++ != '}') return 1;
2016   while (isspace(*s)) s++;
2017   }
2018 if (check_end && *s++ != '}')
2019   {
2020   if (s[-1] == '{')
2021     {
2022     expand_string_message = string_sprintf("Too many arguments for '%s' "
2023       "(max is %d)", name, n);
2024     return 2;
2025     }
2026   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2027   return 1;
2028   }
2029
2030 *sptr = s;
2031 return 0;
2032 }
2033
2034
2035
2036
2037 /*************************************************
2038 *     Elaborate message for bad variable         *
2039 *************************************************/
2040
2041 /* For the "unknown variable" message, take a look at the variable's name, and
2042 give additional information about possible ACL variables. The extra information
2043 is added on to expand_string_message.
2044
2045 Argument:   the name of the variable
2046 Returns:    nothing
2047 */
2048
2049 static void
2050 check_variable_error_message(uschar *name)
2051 {
2052 if (Ustrncmp(name, "acl_", 4) == 0)
2053   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2054     (name[4] == 'c' || name[4] == 'm')?
2055       (isalpha(name[5])?
2056         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2057         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2058       ) :
2059       US"user-defined ACL variables must start acl_c or acl_m");
2060 }
2061
2062
2063
2064 /*
2065 Load args from sub array to globals, and call acl_check().
2066 Sub array will be corrupted on return.
2067
2068 Returns:       OK         access is granted by an ACCEPT verb
2069                DISCARD    access is (apparently) granted by a DISCARD verb
2070                FAIL       access is denied
2071                FAIL_DROP  access is denied; drop the connection
2072                DEFER      can't tell at the moment
2073                ERROR      disaster
2074 */
2075 static int
2076 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2077 {
2078 int i;
2079 int sav_narg = acl_narg;
2080 int ret;
2081 uschar * dummy_logmsg;
2082 extern int acl_where;
2083
2084 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2085 for (i = 0; i < nsub && sub[i+1]; i++)
2086   {
2087   uschar * tmp = acl_arg[i];
2088   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2089   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2090   }
2091 acl_narg = i;
2092 while (i < nsub)
2093   {
2094   sub[i+1] = acl_arg[i];
2095   acl_arg[i++] = NULL;
2096   }
2097
2098 DEBUG(D_expand)
2099   debug_printf("expanding: acl: %s  arg: %s%s\n",
2100     sub[0],
2101     acl_narg>0 ? acl_arg[0] : US"<none>",
2102     acl_narg>1 ? " +more"   : "");
2103
2104 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2105
2106 for (i = 0; i < nsub; i++)
2107   acl_arg[i] = sub[i+1];        /* restore old args */
2108 acl_narg = sav_narg;
2109
2110 return ret;
2111 }
2112
2113
2114
2115
2116 /*************************************************
2117 *        Read and evaluate a condition           *
2118 *************************************************/
2119
2120 /*
2121 Arguments:
2122   s        points to the start of the condition text
2123   resetok  points to a BOOL which is written false if it is unsafe to
2124            free memory. Certain condition types (acl) may have side-effect
2125            allocation which must be preserved.
2126   yield    points to a BOOL to hold the result of the condition test;
2127            if NULL, we are just reading through a condition that is
2128            part of an "or" combination to check syntax, or in a state
2129            where the answer isn't required
2130
2131 Returns:   a pointer to the first character after the condition, or
2132            NULL after an error
2133 */
2134
2135 static const uschar *
2136 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2137 {
2138 BOOL testfor = TRUE;
2139 BOOL tempcond, combined_cond;
2140 BOOL *subcondptr;
2141 BOOL sub2_honour_dollar = TRUE;
2142 int i, rc, cond_type, roffset;
2143 int_eximarith_t num[2];
2144 struct stat statbuf;
2145 uschar name[256];
2146 const uschar *sub[10];
2147
2148 const pcre *re;
2149 const uschar *rerror;
2150
2151 for (;;)
2152   {
2153   while (isspace(*s)) s++;
2154   if (*s == '!') { testfor = !testfor; s++; } else break;
2155   }
2156
2157 /* Numeric comparisons are symbolic */
2158
2159 if (*s == '=' || *s == '>' || *s == '<')
2160   {
2161   int p = 0;
2162   name[p++] = *s++;
2163   if (*s == '=')
2164     {
2165     name[p++] = '=';
2166     s++;
2167     }
2168   name[p] = 0;
2169   }
2170
2171 /* All other conditions are named */
2172
2173 else s = read_name(name, 256, s, US"_");
2174
2175 /* If we haven't read a name, it means some non-alpha character is first. */
2176
2177 if (name[0] == 0)
2178   {
2179   expand_string_message = string_sprintf("condition name expected, "
2180     "but found \"%.16s\"", s);
2181   return NULL;
2182   }
2183
2184 /* Find which condition we are dealing with, and switch on it */
2185
2186 cond_type = chop_match(name, cond_table, nelem(cond_table));
2187 switch(cond_type)
2188   {
2189   /* def: tests for a non-empty variable, or for the existence of a header. If
2190   yield == NULL we are in a skipping state, and don't care about the answer. */
2191
2192   case ECOND_DEF:
2193   if (*s != ':')
2194     {
2195     expand_string_message = US"\":\" expected after \"def\"";
2196     return NULL;
2197     }
2198
2199   s = read_name(name, 256, s+1, US"_");
2200
2201   /* Test for a header's existence. If the name contains a closing brace
2202   character, this may be a user error where the terminating colon has been
2203   omitted. Set a flag to adjust a subsequent error message in this case. */
2204
2205   if (Ustrncmp(name, "h_", 2) == 0 ||
2206       Ustrncmp(name, "rh_", 3) == 0 ||
2207       Ustrncmp(name, "bh_", 3) == 0 ||
2208       Ustrncmp(name, "header_", 7) == 0 ||
2209       Ustrncmp(name, "rheader_", 8) == 0 ||
2210       Ustrncmp(name, "bheader_", 8) == 0)
2211     {
2212     s = read_header_name(name, 256, s);
2213     /* {-for-text-editors */
2214     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2215     if (yield != NULL) *yield =
2216       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2217     }
2218
2219   /* Test for a variable's having a non-empty value. A non-existent variable
2220   causes an expansion failure. */
2221
2222   else
2223     {
2224     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2225     if (value == NULL)
2226       {
2227       expand_string_message = (name[0] == 0)?
2228         string_sprintf("variable name omitted after \"def:\"") :
2229         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2230       check_variable_error_message(name);
2231       return NULL;
2232       }
2233     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2234     }
2235
2236   return s;
2237
2238
2239   /* first_delivery tests for first delivery attempt */
2240
2241   case ECOND_FIRST_DELIVERY:
2242   if (yield != NULL) *yield = deliver_firsttime == testfor;
2243   return s;
2244
2245
2246   /* queue_running tests for any process started by a queue runner */
2247
2248   case ECOND_QUEUE_RUNNING:
2249   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2250   return s;
2251
2252
2253   /* exists:  tests for file existence
2254        isip:  tests for any IP address
2255       isip4:  tests for an IPv4 address
2256       isip6:  tests for an IPv6 address
2257         pam:  does PAM authentication
2258      radius:  does RADIUS authentication
2259    ldapauth:  does LDAP authentication
2260     pwcheck:  does Cyrus SASL pwcheck authentication
2261   */
2262
2263   case ECOND_EXISTS:
2264   case ECOND_ISIP:
2265   case ECOND_ISIP4:
2266   case ECOND_ISIP6:
2267   case ECOND_PAM:
2268   case ECOND_RADIUS:
2269   case ECOND_LDAPAUTH:
2270   case ECOND_PWCHECK:
2271
2272   while (isspace(*s)) s++;
2273   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2274
2275   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2276   if (sub[0] == NULL) return NULL;
2277   /* {-for-text-editors */
2278   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2279
2280   if (yield == NULL) return s;   /* No need to run the test if skipping */
2281
2282   switch(cond_type)
2283     {
2284     case ECOND_EXISTS:
2285     if ((expand_forbid & RDO_EXISTS) != 0)
2286       {
2287       expand_string_message = US"File existence tests are not permitted";
2288       return NULL;
2289       }
2290     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2291     break;
2292
2293     case ECOND_ISIP:
2294     case ECOND_ISIP4:
2295     case ECOND_ISIP6:
2296     rc = string_is_ip_address(sub[0], NULL);
2297     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2298              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2299     break;
2300
2301     /* Various authentication tests - all optionally compiled */
2302
2303     case ECOND_PAM:
2304     #ifdef SUPPORT_PAM
2305     rc = auth_call_pam(sub[0], &expand_string_message);
2306     goto END_AUTH;
2307     #else
2308     goto COND_FAILED_NOT_COMPILED;
2309     #endif  /* SUPPORT_PAM */
2310
2311     case ECOND_RADIUS:
2312     #ifdef RADIUS_CONFIG_FILE
2313     rc = auth_call_radius(sub[0], &expand_string_message);
2314     goto END_AUTH;
2315     #else
2316     goto COND_FAILED_NOT_COMPILED;
2317     #endif  /* RADIUS_CONFIG_FILE */
2318
2319     case ECOND_LDAPAUTH:
2320     #ifdef LOOKUP_LDAP
2321       {
2322       /* Just to keep the interface the same */
2323       BOOL do_cache;
2324       int old_pool = store_pool;
2325       store_pool = POOL_SEARCH;
2326       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2327         &expand_string_message, &do_cache);
2328       store_pool = old_pool;
2329       }
2330     goto END_AUTH;
2331     #else
2332     goto COND_FAILED_NOT_COMPILED;
2333     #endif  /* LOOKUP_LDAP */
2334
2335     case ECOND_PWCHECK:
2336     #ifdef CYRUS_PWCHECK_SOCKET
2337     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2338     goto END_AUTH;
2339     #else
2340     goto COND_FAILED_NOT_COMPILED;
2341     #endif  /* CYRUS_PWCHECK_SOCKET */
2342
2343     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2344         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2345     END_AUTH:
2346     if (rc == ERROR || rc == DEFER) return NULL;
2347     *yield = (rc == OK) == testfor;
2348     #endif
2349     }
2350   return s;
2351
2352
2353   /* call ACL (in a conditional context).  Accept true, deny false.
2354   Defer is a forced-fail.  Anything set by message= goes to $value.
2355   Up to ten parameters are used; we use the braces round the name+args
2356   like the saslauthd condition does, to permit a variable number of args.
2357   See also the expansion-item version EITEM_ACL and the traditional
2358   acl modifier ACLC_ACL.
2359   Since the ACL may allocate new global variables, tell our caller to not
2360   reclaim memory.
2361   */
2362
2363   case ECOND_ACL:
2364     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2365     {
2366     uschar *sub[10];
2367     uschar *user_msg;
2368     BOOL cond = FALSE;
2369     int size = 0;
2370     int ptr = 0;
2371
2372     while (isspace(*s)) s++;
2373     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2374
2375     switch(read_subs(sub, nelem(sub), 1,
2376       &s, yield == NULL, TRUE, US"acl", resetok))
2377       {
2378       case 1: expand_string_message = US"too few arguments or bracketing "
2379         "error for acl";
2380       case 2:
2381       case 3: return NULL;
2382       }
2383
2384     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2385     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2386         {
2387         case OK:
2388           cond = TRUE;
2389         case FAIL:
2390           lookup_value = NULL;
2391           if (user_msg)
2392             {
2393             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2394             lookup_value[ptr] = '\0';
2395             }
2396           *yield = cond == testfor;
2397           break;
2398
2399         case DEFER:
2400           expand_string_forcedfail = TRUE;
2401           /*FALLTHROUGH*/
2402         default:
2403           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2404           return NULL;
2405         }
2406     return s;
2407     }
2408
2409
2410   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2411
2412      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2413
2414   However, the last two are optional. That is why the whole set is enclosed
2415   in their own set of braces. */
2416
2417   case ECOND_SASLAUTHD:
2418 #ifndef CYRUS_SASLAUTHD_SOCKET
2419     goto COND_FAILED_NOT_COMPILED;
2420 #else
2421     {
2422     uschar *sub[4];
2423     while (isspace(*s)) s++;
2424     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2425     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2426                     resetok))
2427       {
2428       case 1: expand_string_message = US"too few arguments or bracketing "
2429         "error for saslauthd";
2430       case 2:
2431       case 3: return NULL;
2432       }
2433     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2434     if (yield != NULL)
2435       {
2436       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2437         &expand_string_message);
2438       if (rc == ERROR || rc == DEFER) return NULL;
2439       *yield = (rc == OK) == testfor;
2440       }
2441     return s;
2442     }
2443 #endif /* CYRUS_SASLAUTHD_SOCKET */
2444
2445
2446   /* symbolic operators for numeric and string comparison, and a number of
2447   other operators, all requiring two arguments.
2448
2449   crypteq:           encrypts plaintext and compares against an encrypted text,
2450                        using crypt(), crypt16(), MD5 or SHA-1
2451   inlist/inlisti:    checks if first argument is in the list of the second
2452   match:             does a regular expression match and sets up the numerical
2453                        variables if it succeeds
2454   match_address:     matches in an address list
2455   match_domain:      matches in a domain list
2456   match_ip:          matches a host list that is restricted to IP addresses
2457   match_local_part:  matches in a local part list
2458   */
2459
2460   case ECOND_MATCH_ADDRESS:
2461   case ECOND_MATCH_DOMAIN:
2462   case ECOND_MATCH_IP:
2463   case ECOND_MATCH_LOCAL_PART:
2464 #ifndef EXPAND_LISTMATCH_RHS
2465     sub2_honour_dollar = FALSE;
2466 #endif
2467     /* FALLTHROUGH */
2468
2469   case ECOND_CRYPTEQ:
2470   case ECOND_INLIST:
2471   case ECOND_INLISTI:
2472   case ECOND_MATCH:
2473
2474   case ECOND_NUM_L:     /* Numerical comparisons */
2475   case ECOND_NUM_LE:
2476   case ECOND_NUM_E:
2477   case ECOND_NUM_EE:
2478   case ECOND_NUM_G:
2479   case ECOND_NUM_GE:
2480
2481   case ECOND_STR_LT:    /* String comparisons */
2482   case ECOND_STR_LTI:
2483   case ECOND_STR_LE:
2484   case ECOND_STR_LEI:
2485   case ECOND_STR_EQ:
2486   case ECOND_STR_EQI:
2487   case ECOND_STR_GT:
2488   case ECOND_STR_GTI:
2489   case ECOND_STR_GE:
2490   case ECOND_STR_GEI:
2491
2492   for (i = 0; i < 2; i++)
2493     {
2494     /* Sometimes, we don't expand substrings; too many insecure configurations
2495     created using match_address{}{} and friends, where the second param
2496     includes information from untrustworthy sources. */
2497     BOOL honour_dollar = TRUE;
2498     if ((i > 0) && !sub2_honour_dollar)
2499       honour_dollar = FALSE;
2500
2501     while (isspace(*s)) s++;
2502     if (*s != '{')
2503       {
2504       if (i == 0) goto COND_FAILED_CURLY_START;
2505       expand_string_message = string_sprintf("missing 2nd string in {} "
2506         "after \"%s\"", name);
2507       return NULL;
2508       }
2509     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2510         honour_dollar, resetok);
2511     if (sub[i] == NULL) return NULL;
2512     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2513
2514     /* Convert to numerical if required; we know that the names of all the
2515     conditions that compare numbers do not start with a letter. This just saves
2516     checking for them individually. */
2517
2518     if (!isalpha(name[0]) && yield != NULL)
2519       if (sub[i][0] == 0)
2520         {
2521         num[i] = 0;
2522         DEBUG(D_expand)
2523           debug_printf("empty string cast to zero for numerical comparison\n");
2524         }
2525       else
2526         {
2527         num[i] = expanded_string_integer(sub[i], FALSE);
2528         if (expand_string_message != NULL) return NULL;
2529         }
2530     }
2531
2532   /* Result not required */
2533
2534   if (yield == NULL) return s;
2535
2536   /* Do an appropriate comparison */
2537
2538   switch(cond_type)
2539     {
2540     case ECOND_NUM_E:
2541     case ECOND_NUM_EE:
2542     tempcond = (num[0] == num[1]);
2543     break;
2544
2545     case ECOND_NUM_G:
2546     tempcond = (num[0] > num[1]);
2547     break;
2548
2549     case ECOND_NUM_GE:
2550     tempcond = (num[0] >= num[1]);
2551     break;
2552
2553     case ECOND_NUM_L:
2554     tempcond = (num[0] < num[1]);
2555     break;
2556
2557     case ECOND_NUM_LE:
2558     tempcond = (num[0] <= num[1]);
2559     break;
2560
2561     case ECOND_STR_LT:
2562     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2563     break;
2564
2565     case ECOND_STR_LTI:
2566     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2567     break;
2568
2569     case ECOND_STR_LE:
2570     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2571     break;
2572
2573     case ECOND_STR_LEI:
2574     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2575     break;
2576
2577     case ECOND_STR_EQ:
2578     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2579     break;
2580
2581     case ECOND_STR_EQI:
2582     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2583     break;
2584
2585     case ECOND_STR_GT:
2586     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2587     break;
2588
2589     case ECOND_STR_GTI:
2590     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2591     break;
2592
2593     case ECOND_STR_GE:
2594     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2595     break;
2596
2597     case ECOND_STR_GEI:
2598     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2599     break;
2600
2601     case ECOND_MATCH:   /* Regular expression match */
2602     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2603       NULL);
2604     if (re == NULL)
2605       {
2606       expand_string_message = string_sprintf("regular expression error in "
2607         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2608       return NULL;
2609       }
2610     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2611     break;
2612
2613     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2614     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2615     goto MATCHED_SOMETHING;
2616
2617     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2618     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2619       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2620     goto MATCHED_SOMETHING;
2621
2622     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2623     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2624       {
2625       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2626         sub[0]);
2627       return NULL;
2628       }
2629     else
2630       {
2631       unsigned int *nullcache = NULL;
2632       check_host_block cb;
2633
2634       cb.host_name = US"";
2635       cb.host_address = sub[0];
2636
2637       /* If the host address starts off ::ffff: it is an IPv6 address in
2638       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2639       addresses. */
2640
2641       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2642         cb.host_address + 7 : cb.host_address;
2643
2644       rc = match_check_list(
2645              &sub[1],                   /* the list */
2646              0,                         /* separator character */
2647              &hostlist_anchor,          /* anchor pointer */
2648              &nullcache,                /* cache pointer */
2649              check_host,                /* function for testing */
2650              &cb,                       /* argument for function */
2651              MCL_HOST,                  /* type of check */
2652              sub[0],                    /* text for debugging */
2653              NULL);                     /* where to pass back data */
2654       }
2655     goto MATCHED_SOMETHING;
2656
2657     case ECOND_MATCH_LOCAL_PART:
2658     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2659       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2660     /* Fall through */
2661     /* VVVVVVVVVVVV */
2662     MATCHED_SOMETHING:
2663     switch(rc)
2664       {
2665       case OK:
2666       tempcond = TRUE;
2667       break;
2668
2669       case FAIL:
2670       tempcond = FALSE;
2671       break;
2672
2673       case DEFER:
2674       expand_string_message = string_sprintf("unable to complete match "
2675         "against \"%s\": %s", sub[1], search_error_message);
2676       return NULL;
2677       }
2678
2679     break;
2680
2681     /* Various "encrypted" comparisons. If the second string starts with
2682     "{" then an encryption type is given. Default to crypt() or crypt16()
2683     (build-time choice). */
2684     /* }-for-text-editors */
2685
2686     case ECOND_CRYPTEQ:
2687     #ifndef SUPPORT_CRYPTEQ
2688     goto COND_FAILED_NOT_COMPILED;
2689     #else
2690     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2691       {
2692       int sublen = Ustrlen(sub[1]+5);
2693       md5 base;
2694       uschar digest[16];
2695
2696       md5_start(&base);
2697       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2698
2699       /* If the length that we are comparing against is 24, the MD5 digest
2700       is expressed as a base64 string. This is the way LDAP does it. However,
2701       some other software uses a straightforward hex representation. We assume
2702       this if the length is 32. Other lengths fail. */
2703
2704       if (sublen == 24)
2705         {
2706         uschar *coded = b64encode(digest, 16);
2707         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2708           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2709         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2710         }
2711       else if (sublen == 32)
2712         {
2713         int i;
2714         uschar coded[36];
2715         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2716         coded[32] = 0;
2717         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2718           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2719         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2720         }
2721       else
2722         {
2723         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2724           "fail\n  crypted=%s\n", sub[1]+5);
2725         tempcond = FALSE;
2726         }
2727       }
2728
2729     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2730       {
2731       int sublen = Ustrlen(sub[1]+6);
2732       hctx h;
2733       uschar digest[20];
2734
2735       sha1_start(&h);
2736       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2737
2738       /* If the length that we are comparing against is 28, assume the SHA1
2739       digest is expressed as a base64 string. If the length is 40, assume a
2740       straightforward hex representation. Other lengths fail. */
2741
2742       if (sublen == 28)
2743         {
2744         uschar *coded = b64encode(digest, 20);
2745         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2746           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2747         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2748         }
2749       else if (sublen == 40)
2750         {
2751         int i;
2752         uschar coded[44];
2753         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2754         coded[40] = 0;
2755         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2756           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2757         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2758         }
2759       else
2760         {
2761         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2762           "fail\n  crypted=%s\n", sub[1]+6);
2763         tempcond = FALSE;
2764         }
2765       }
2766
2767     else   /* {crypt} or {crypt16} and non-{ at start */
2768            /* }-for-text-editors */
2769       {
2770       int which = 0;
2771       uschar *coded;
2772
2773       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2774         {
2775         sub[1] += 7;
2776         which = 1;
2777         }
2778       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2779         {
2780         sub[1] += 9;
2781         which = 2;
2782         }
2783       else if (sub[1][0] == '{')                /* }-for-text-editors */
2784         {
2785         expand_string_message = string_sprintf("unknown encryption mechanism "
2786           "in \"%s\"", sub[1]);
2787         return NULL;
2788         }
2789
2790       switch(which)
2791         {
2792         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2793         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2794         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2795         }
2796
2797       #define STR(s) # s
2798       #define XSTR(s) STR(s)
2799       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2800         "  subject=%s\n  crypted=%s\n",
2801         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2802         coded, sub[1]);
2803       #undef STR
2804       #undef XSTR
2805
2806       /* If the encrypted string contains fewer than two characters (for the
2807       salt), force failure. Otherwise we get false positives: with an empty
2808       string the yield of crypt() is an empty string! */
2809
2810       if (coded)
2811         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2812       else if (errno == EINVAL)
2813         tempcond = FALSE;
2814       else
2815         {
2816         expand_string_message = string_sprintf("crypt error: %s\n",
2817           US strerror(errno));
2818         return NULL;
2819         }
2820       }
2821     break;
2822     #endif  /* SUPPORT_CRYPTEQ */
2823
2824     case ECOND_INLIST:
2825     case ECOND_INLISTI:
2826       {
2827       const uschar * list = sub[1];
2828       int sep = 0;
2829       uschar *save_iterate_item = iterate_item;
2830       int (*compare)(const uschar *, const uschar *);
2831
2832       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2833
2834       tempcond = FALSE;
2835       compare = cond_type == ECOND_INLISTI
2836         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2837
2838       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2839         if (compare(sub[0], iterate_item) == 0)
2840           {
2841           tempcond = TRUE;
2842           break;
2843           }
2844       iterate_item = save_iterate_item;
2845       }
2846
2847     }   /* Switch for comparison conditions */
2848
2849   *yield = tempcond == testfor;
2850   return s;    /* End of comparison conditions */
2851
2852
2853   /* and/or: computes logical and/or of several conditions */
2854
2855   case ECOND_AND:
2856   case ECOND_OR:
2857   subcondptr = (yield == NULL)? NULL : &tempcond;
2858   combined_cond = (cond_type == ECOND_AND);
2859
2860   while (isspace(*s)) s++;
2861   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2862
2863   for (;;)
2864     {
2865     while (isspace(*s)) s++;
2866     /* {-for-text-editors */
2867     if (*s == '}') break;
2868     if (*s != '{')                                      /* }-for-text-editors */
2869       {
2870       expand_string_message = string_sprintf("each subcondition "
2871         "inside an \"%s{...}\" condition must be in its own {}", name);
2872       return NULL;
2873       }
2874
2875     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2876       {
2877       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2878         expand_string_message, name);
2879       return NULL;
2880       }
2881     while (isspace(*s)) s++;
2882
2883     /* {-for-text-editors */
2884     if (*s++ != '}')
2885       {
2886       /* {-for-text-editors */
2887       expand_string_message = string_sprintf("missing } at end of condition "
2888         "inside \"%s\" group", name);
2889       return NULL;
2890       }
2891
2892     if (yield != NULL)
2893       {
2894       if (cond_type == ECOND_AND)
2895         {
2896         combined_cond &= tempcond;
2897         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2898         }                                       /* evaluate any more */
2899       else
2900         {
2901         combined_cond |= tempcond;
2902         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2903         }                                       /* evaluate any more */
2904       }
2905     }
2906
2907   if (yield != NULL) *yield = (combined_cond == testfor);
2908   return ++s;
2909
2910
2911   /* forall/forany: iterates a condition with different values */
2912
2913   case ECOND_FORALL:
2914   case ECOND_FORANY:
2915     {
2916     const uschar * list;
2917     int sep = 0;
2918     uschar *save_iterate_item = iterate_item;
2919
2920     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2921
2922     while (isspace(*s)) s++;
2923     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2924     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2925     if (sub[0] == NULL) return NULL;
2926     /* {-for-text-editors */
2927     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2928
2929     while (isspace(*s)) s++;
2930     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2931
2932     sub[1] = s;
2933
2934     /* Call eval_condition once, with result discarded (as if scanning a
2935     "false" part). This allows us to find the end of the condition, because if
2936     the list it empty, we won't actually evaluate the condition for real. */
2937
2938     if (!(s = eval_condition(sub[1], resetok, NULL)))
2939       {
2940       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2941         expand_string_message, name);
2942       return NULL;
2943       }
2944     while (isspace(*s)) s++;
2945
2946     /* {-for-text-editors */
2947     if (*s++ != '}')
2948       {
2949       /* {-for-text-editors */
2950       expand_string_message = string_sprintf("missing } at end of condition "
2951         "inside \"%s\"", name);
2952       return NULL;
2953       }
2954
2955     if (yield != NULL) *yield = !testfor;
2956     list = sub[0];
2957     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2958       {
2959       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2960       if (!eval_condition(sub[1], resetok, &tempcond))
2961         {
2962         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2963           expand_string_message, name);
2964         iterate_item = save_iterate_item;
2965         return NULL;
2966         }
2967       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2968         tempcond? "true":"false");
2969
2970       if (yield != NULL) *yield = (tempcond == testfor);
2971       if (tempcond == (cond_type == ECOND_FORANY)) break;
2972       }
2973
2974     iterate_item = save_iterate_item;
2975     return s;
2976     }
2977
2978
2979   /* The bool{} expansion condition maps a string to boolean.
2980   The values supported should match those supported by the ACL condition
2981   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2982   of true/false.  Note that Router "condition" rules have a different
2983   interpretation, where general data can be used and only a few values
2984   map to FALSE.
2985   Note that readconf.c boolean matching, for boolean configuration options,
2986   only matches true/yes/false/no.
2987   The bool_lax{} condition matches the Router logic, which is much more
2988   liberal. */
2989   case ECOND_BOOL:
2990   case ECOND_BOOL_LAX:
2991     {
2992     uschar *sub_arg[1];
2993     uschar *t, *t2;
2994     uschar *ourname;
2995     size_t len;
2996     BOOL boolvalue = FALSE;
2997     while (isspace(*s)) s++;
2998     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2999     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3000     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3001       {
3002       case 1: expand_string_message = string_sprintf(
3003                   "too few arguments or bracketing error for %s",
3004                   ourname);
3005       /*FALLTHROUGH*/
3006       case 2:
3007       case 3: return NULL;
3008       }
3009     t = sub_arg[0];
3010     while (isspace(*t)) t++;
3011     len = Ustrlen(t);
3012     if (len)
3013       {
3014       /* trailing whitespace: seems like a good idea to ignore it too */
3015       t2 = t + len - 1;
3016       while (isspace(*t2)) t2--;
3017       if (t2 != (t + len))
3018         {
3019         *++t2 = '\0';
3020         len = t2 - t;
3021         }
3022       }
3023     DEBUG(D_expand)
3024       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3025     /* logic for the lax case from expand_check_condition(), which also does
3026     expands, and the logic is both short and stable enough that there should
3027     be no maintenance burden from replicating it. */
3028     if (len == 0)
3029       boolvalue = FALSE;
3030     else if (*t == '-'
3031              ? Ustrspn(t+1, "0123456789") == len-1
3032              : Ustrspn(t,   "0123456789") == len)
3033       {
3034       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3035       /* expand_check_condition only does a literal string "0" check */
3036       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3037         boolvalue = TRUE;
3038       }
3039     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3040       boolvalue = TRUE;
3041     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3042       boolvalue = FALSE;
3043     else if (cond_type == ECOND_BOOL_LAX)
3044       boolvalue = TRUE;
3045     else
3046       {
3047       expand_string_message = string_sprintf("unrecognised boolean "
3048        "value \"%s\"", t);
3049       return NULL;
3050       }
3051     if (yield != NULL) *yield = (boolvalue == testfor);
3052     return s;
3053     }
3054
3055   /* Unknown condition */
3056
3057   default:
3058   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3059   return NULL;
3060   }   /* End switch on condition type */
3061
3062 /* Missing braces at start and end of data */
3063
3064 COND_FAILED_CURLY_START:
3065 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3066 return NULL;
3067
3068 COND_FAILED_CURLY_END:
3069 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3070   name);
3071 return NULL;
3072
3073 /* A condition requires code that is not compiled */
3074
3075 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3076     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3077     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3078 COND_FAILED_NOT_COMPILED:
3079 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3080   name);
3081 return NULL;
3082 #endif
3083 }
3084
3085
3086
3087
3088 /*************************************************
3089 *          Save numerical variables              *
3090 *************************************************/
3091
3092 /* This function is called from items such as "if" that want to preserve and
3093 restore the numbered variables.
3094
3095 Arguments:
3096   save_expand_string    points to an array of pointers to set
3097   save_expand_nlength   points to an array of ints for the lengths
3098
3099 Returns:                the value of expand max to save
3100 */
3101
3102 static int
3103 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3104 {
3105 int i;
3106 for (i = 0; i <= expand_nmax; i++)
3107   {
3108   save_expand_nstring[i] = expand_nstring[i];
3109   save_expand_nlength[i] = expand_nlength[i];
3110   }
3111 return expand_nmax;
3112 }
3113
3114
3115
3116 /*************************************************
3117 *           Restore numerical variables          *
3118 *************************************************/
3119
3120 /* This function restored saved values of numerical strings.
3121
3122 Arguments:
3123   save_expand_nmax      the number of strings to restore
3124   save_expand_string    points to an array of pointers
3125   save_expand_nlength   points to an array of ints
3126
3127 Returns:                nothing
3128 */
3129
3130 static void
3131 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3132   int *save_expand_nlength)
3133 {
3134 int i;
3135 expand_nmax = save_expand_nmax;
3136 for (i = 0; i <= expand_nmax; i++)
3137   {
3138   expand_nstring[i] = save_expand_nstring[i];
3139   expand_nlength[i] = save_expand_nlength[i];
3140   }
3141 }
3142
3143
3144
3145
3146
3147 /*************************************************
3148 *            Handle yes/no substrings            *
3149 *************************************************/
3150
3151 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3152 alternative substrings that depend on whether or not the condition was true,
3153 or the lookup or extraction succeeded. The substrings always have to be
3154 expanded, to check their syntax, but "skipping" is set when the result is not
3155 needed - this avoids unnecessary nested lookups.
3156
3157 Arguments:
3158   skipping       TRUE if we were skipping when this item was reached
3159   yes            TRUE if the first string is to be used, else use the second
3160   save_lookup    a value to put back into lookup_value before the 2nd expansion
3161   sptr           points to the input string pointer
3162   yieldptr       points to the output string pointer
3163   sizeptr        points to the output string size
3164   ptrptr         points to the output string pointer
3165   type           "lookup", "if", "extract", "run", "env", "listextract" or
3166                  "certextract" for error message
3167   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3168                 the store.
3169
3170 Returns:         0 OK; lookup_value has been reset to save_lookup
3171                  1 expansion failed
3172                  2 expansion failed because of bracketing error
3173 */
3174
3175 static int
3176 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3177   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3178 {
3179 int rc = 0;
3180 const uschar *s = *sptr;    /* Local value */
3181 uschar *sub1, *sub2;
3182 const uschar * errwhere;
3183
3184 /* If there are no following strings, we substitute the contents of $value for
3185 lookups and for extractions in the success case. For the ${if item, the string
3186 "true" is substituted. In the fail case, nothing is substituted for all three
3187 items. */
3188
3189 while (isspace(*s)) s++;
3190 if (*s == '}')
3191   {
3192   if (type[0] == 'i')
3193     {
3194     if (yes) *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3195     }
3196   else
3197     {
3198     if (yes && lookup_value)
3199       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3200     lookup_value = save_lookup;
3201     }
3202   s++;
3203   goto RETURN;
3204   }
3205
3206 /* The first following string must be braced. */
3207
3208 if (*s++ != '{')
3209   {
3210   errwhere = US"'yes' part did not start with '{'";
3211   goto FAILED_CURLY;
3212   }
3213
3214 /* Expand the first substring. Forced failures are noticed only if we actually
3215 want this string. Set skipping in the call in the fail case (this will always
3216 be the case if we were already skipping). */
3217
3218 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3219 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3220 expand_string_forcedfail = FALSE;
3221 if (*s++ != '}')
3222   {
3223   errwhere = US"'yes' part did not end with '}'";
3224   goto FAILED_CURLY;
3225   }
3226
3227 /* If we want the first string, add it to the output */
3228
3229 if (yes)
3230   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3231
3232 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3233 $value to what it was at the start of the item, so that it has this value
3234 during the second string expansion. For the call from "if" or "run" to this
3235 function, save_lookup is set to lookup_value, so that this statement does
3236 nothing. */
3237
3238 lookup_value = save_lookup;
3239
3240 /* There now follows either another substring, or "fail", or nothing. This
3241 time, forced failures are noticed only if we want the second string. We must
3242 set skipping in the nested call if we don't want this string, or if we were
3243 already skipping. */
3244
3245 while (isspace(*s)) s++;
3246 if (*s == '{')
3247   {
3248   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3249   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3250   expand_string_forcedfail = FALSE;
3251   if (*s++ != '}')
3252     {
3253     errwhere = US"'no' part did not start with '{'";
3254     goto FAILED_CURLY;
3255     }
3256
3257   /* If we want the second string, add it to the output */
3258
3259   if (!yes)
3260     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3261   }
3262
3263 /* If there is no second string, but the word "fail" is present when the use of
3264 the second string is wanted, set a flag indicating it was a forced failure
3265 rather than a syntactic error. Swallow the terminating } in case this is nested
3266 inside another lookup or if or extract. */
3267
3268 else if (*s != '}')
3269   {
3270   uschar name[256];
3271   /* deconst cast ok here as source is s anyway */
3272   s = US read_name(name, sizeof(name), s, US"_");
3273   if (Ustrcmp(name, "fail") == 0)
3274     {
3275     if (!yes && !skipping)
3276       {
3277       while (isspace(*s)) s++;
3278       if (*s++ != '}')
3279         {
3280         errwhere = US"did not close with '}' after forcedfail";
3281         goto FAILED_CURLY;
3282         }
3283       expand_string_message =
3284         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3285       expand_string_forcedfail = TRUE;
3286       goto FAILED;
3287       }
3288     }
3289   else
3290     {
3291     expand_string_message =
3292       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3293     goto FAILED;
3294     }
3295   }
3296
3297 /* All we have to do now is to check on the final closing brace. */
3298
3299 while (isspace(*s)) s++;
3300 if (*s++ != '}')
3301   {
3302   errwhere = US"did not close with '}'";
3303   goto FAILED_CURLY;
3304   }
3305
3306
3307 RETURN:
3308 /* Update the input pointer value before returning */
3309 *sptr = s;
3310 return rc;
3311
3312 FAILED_CURLY:
3313   /* Get here if there is a bracketing failure */
3314   expand_string_message = string_sprintf(
3315     "curly-bracket problem in conditional yes/no parsing: %s\n"
3316     " remaining string is '%s'", errwhere, --s);
3317   rc = 2;
3318   goto RETURN;
3319
3320 FAILED:
3321   /* Get here for other failures */
3322   rc = 1;
3323   goto RETURN;
3324 }
3325
3326
3327
3328
3329 /*************************************************
3330 *    Handle MD5 or SHA-1 computation for HMAC    *
3331 *************************************************/
3332
3333 /* These are some wrapping functions that enable the HMAC code to be a bit
3334 cleaner. A good compiler will spot the tail recursion.
3335
3336 Arguments:
3337   type         HMAC_MD5 or HMAC_SHA1
3338   remaining    are as for the cryptographic hash functions
3339
3340 Returns:       nothing
3341 */
3342
3343 static void
3344 chash_start(int type, void *base)
3345 {
3346 if (type == HMAC_MD5)
3347   md5_start((md5 *)base);
3348 else
3349   sha1_start((hctx *)base);
3350 }
3351
3352 static void
3353 chash_mid(int type, void *base, uschar *string)
3354 {
3355 if (type == HMAC_MD5)
3356   md5_mid((md5 *)base, string);
3357 else
3358   sha1_mid((hctx *)base, string);
3359 }
3360
3361 static void
3362 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3363 {
3364 if (type == HMAC_MD5)
3365   md5_end((md5 *)base, string, length, digest);
3366 else
3367   sha1_end((hctx *)base, string, length, digest);
3368 }
3369
3370
3371
3372
3373
3374 /********************************************************
3375 * prvs: Get last three digits of days since Jan 1, 1970 *
3376 ********************************************************/
3377
3378 /* This is needed to implement the "prvs" BATV reverse
3379    path signing scheme
3380
3381 Argument: integer "days" offset to add or substract to
3382           or from the current number of days.
3383
3384 Returns:  pointer to string containing the last three
3385           digits of the number of days since Jan 1, 1970,
3386           modified by the offset argument, NULL if there
3387           was an error in the conversion.
3388
3389 */
3390
3391 static uschar *
3392 prvs_daystamp(int day_offset)
3393 {
3394 uschar *days = store_get(32);                /* Need at least 24 for cases */
3395 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3396   (time(NULL) + day_offset*86400)/86400);
3397 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3398 }
3399
3400
3401
3402 /********************************************************
3403 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3404 ********************************************************/
3405
3406 /* This is needed to implement the "prvs" BATV reverse
3407    path signing scheme
3408
3409 Arguments:
3410   address RFC2821 Address to use
3411       key The key to use (must be less than 64 characters
3412           in size)
3413   key_num Single-digit key number to use. Defaults to
3414           '0' when NULL.
3415
3416 Returns:  pointer to string containing the first three
3417           bytes of the final hash in hex format, NULL if
3418           there was an error in the process.
3419 */
3420
3421 static uschar *
3422 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3423 {
3424 uschar *hash_source, *p;
3425 int size = 0,offset = 0,i;
3426 hctx h;
3427 uschar innerhash[20];
3428 uschar finalhash[20];
3429 uschar innerkey[64];
3430 uschar outerkey[64];
3431 uschar *finalhash_hex = store_get(40);
3432
3433 if (key_num == NULL)
3434   key_num = US"0";
3435
3436 if (Ustrlen(key) > 64)
3437   return NULL;
3438
3439 hash_source = string_catn(NULL, &size, &offset, key_num, 1);
3440 hash_source = string_catn(hash_source, &size, &offset, daystamp, 3);
3441 hash_source = string_cat(hash_source, &size, &offset, address);
3442 hash_source[offset] = '\0';
3443
3444 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3445
3446 memset(innerkey, 0x36, 64);
3447 memset(outerkey, 0x5c, 64);
3448
3449 for (i = 0; i < Ustrlen(key); i++)
3450   {
3451   innerkey[i] ^= key[i];
3452   outerkey[i] ^= key[i];
3453   }
3454
3455 chash_start(HMAC_SHA1, &h);
3456 chash_mid(HMAC_SHA1, &h, innerkey);
3457 chash_end(HMAC_SHA1, &h, hash_source, offset, innerhash);
3458
3459 chash_start(HMAC_SHA1, &h);
3460 chash_mid(HMAC_SHA1, &h, outerkey);
3461 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3462
3463 p = finalhash_hex;
3464 for (i = 0; i < 3; i++)
3465   {
3466   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3467   *p++ = hex_digits[finalhash[i] & 0x0f];
3468   }
3469 *p = '\0';
3470
3471 return finalhash_hex;
3472 }
3473
3474
3475
3476
3477 /*************************************************
3478 *        Join a file onto the output string      *
3479 *************************************************/
3480
3481 /* This is used for readfile/readsock and after a run expansion.
3482 It joins the contents of a file onto the output string, globally replacing
3483 newlines with a given string (optionally).
3484
3485 Arguments:
3486   f            the FILE
3487   yield        pointer to the expandable string
3488   sizep        pointer to the current size
3489   ptrp         pointer to the current position
3490   eol          newline replacement string, or NULL
3491
3492 Returns:       new value of string pointer
3493 */
3494
3495 static uschar *
3496 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3497 {
3498 uschar buffer[1024];
3499
3500 while (Ufgets(buffer, sizeof(buffer), f))
3501   {
3502   int len = Ustrlen(buffer);
3503   if (eol && buffer[len-1] == '\n') len--;
3504   yield = string_catn(yield, sizep, ptrp, buffer, len);
3505   if (eol && buffer[len])
3506     yield = string_cat(yield, sizep, ptrp, eol);
3507   }
3508
3509 if (yield) yield[*ptrp] = 0;
3510
3511 return yield;
3512 }
3513
3514
3515
3516
3517 /*************************************************
3518 *          Evaluate numeric expression           *
3519 *************************************************/
3520
3521 /* This is a set of mutually recursive functions that evaluate an arithmetic
3522 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3523 these functions that is called from elsewhere is eval_expr, whose interface is:
3524
3525 Arguments:
3526   sptr        pointer to the pointer to the string - gets updated
3527   decimal     TRUE if numbers are to be assumed decimal
3528   error       pointer to where to put an error message - must be NULL on input
3529   endket      TRUE if ')' must terminate - FALSE for external call
3530
3531 Returns:      on success: the value of the expression, with *error still NULL
3532               on failure: an undefined value, with *error = a message
3533 */
3534
3535 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3536
3537
3538 static int_eximarith_t
3539 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3540 {
3541 uschar *s = *sptr;
3542 int_eximarith_t x = eval_op_or(&s, decimal, error);
3543 if (*error == NULL)
3544   {
3545   if (endket)
3546     {
3547     if (*s != ')')
3548       *error = US"expecting closing parenthesis";
3549     else
3550       while (isspace(*(++s)));
3551     }
3552   else if (*s != 0) *error = US"expecting operator";
3553   }
3554 *sptr = s;
3555 return x;
3556 }
3557
3558
3559 static int_eximarith_t
3560 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3561 {
3562 register int c;
3563 int_eximarith_t n;
3564 uschar *s = *sptr;
3565 while (isspace(*s)) s++;
3566 c = *s;
3567 if (isdigit(c))
3568   {
3569   int count;
3570   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3571   s += count;
3572   switch (tolower(*s))
3573     {
3574     default: break;
3575     case 'k': n *= 1024; s++; break;
3576     case 'm': n *= 1024*1024; s++; break;
3577     case 'g': n *= 1024*1024*1024; s++; break;
3578     }
3579   while (isspace (*s)) s++;
3580   }
3581 else if (c == '(')
3582   {
3583   s++;
3584   n = eval_expr(&s, decimal, error, 1);
3585   }
3586 else
3587   {
3588   *error = US"expecting number or opening parenthesis";
3589   n = 0;
3590   }
3591 *sptr = s;
3592 return n;
3593 }
3594
3595
3596 static int_eximarith_t
3597 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3598 {
3599 uschar *s = *sptr;
3600 int_eximarith_t x;
3601 while (isspace(*s)) s++;
3602 if (*s == '+' || *s == '-' || *s == '~')
3603   {
3604   int op = *s++;
3605   x = eval_op_unary(&s, decimal, error);
3606   if (op == '-') x = -x;
3607     else if (op == '~') x = ~x;
3608   }
3609 else
3610   {
3611   x = eval_number(&s, decimal, error);
3612   }
3613 *sptr = s;
3614 return x;
3615 }
3616
3617
3618 static int_eximarith_t
3619 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3620 {
3621 uschar *s = *sptr;
3622 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3623 if (*error == NULL)
3624   {
3625   while (*s == '*' || *s == '/' || *s == '%')
3626     {
3627     int op = *s++;
3628     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3629     if (*error != NULL) break;
3630     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3631      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3632      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3633      * -N*M is INT_MIN will yielf INT_MIN.
3634      * Since we don't support floating point, this is somewhat simpler.
3635      * Ideally, we'd return an error, but since we overflow for all other
3636      * arithmetic, consistency suggests otherwise, but what's the correct value
3637      * to use?  There is none.
3638      * The C standard guarantees overflow for unsigned arithmetic but signed
3639      * overflow invokes undefined behaviour; in practice, this is overflow
3640      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3641      * that long/longlong larger than int are available, or we could just work
3642      * with larger types.  We should consider whether to guarantee 32bit eval
3643      * and 64-bit working variables, with errors returned.  For now ...
3644      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3645      * can just let the other invalid results occur otherwise, as they have
3646      * until now.  For this one case, we can coerce.
3647      */
3648     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3649       {
3650       DEBUG(D_expand)
3651         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3652             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3653       x = EXIM_ARITH_MAX;
3654       continue;
3655       }
3656     if (op == '*')
3657       x *= y;
3658     else
3659       {
3660       if (y == 0)
3661         {
3662         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3663         x = 0;
3664         break;
3665         }
3666       if (op == '/')
3667         x /= y;
3668       else
3669         x %= y;
3670       }
3671     }
3672   }
3673 *sptr = s;
3674 return x;
3675 }
3676
3677
3678 static int_eximarith_t
3679 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3680 {
3681 uschar *s = *sptr;
3682 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3683 if (!*error)
3684   {
3685   while (*s == '+' || *s == '-')
3686     {
3687     int op = *s++;
3688     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3689     if (*error) break;
3690     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3691        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3692       {                 /* over-conservative check */
3693       *error = op == '+'
3694         ? US"overflow in sum" : US"overflow in difference";
3695       break;
3696       }
3697     if (op == '+') x += y; else x -= y;
3698     }
3699   }
3700 *sptr = s;
3701 return x;
3702 }
3703
3704
3705 static int_eximarith_t
3706 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3707 {
3708 uschar *s = *sptr;
3709 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3710 if (*error == NULL)
3711   {
3712   while ((*s == '<' || *s == '>') && s[1] == s[0])
3713     {
3714     int_eximarith_t y;
3715     int op = *s++;
3716     s++;
3717     y = eval_op_sum(&s, decimal, error);
3718     if (*error != NULL) break;
3719     if (op == '<') x <<= y; else x >>= y;
3720     }
3721   }
3722 *sptr = s;
3723 return x;
3724 }
3725
3726
3727 static int_eximarith_t
3728 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3729 {
3730 uschar *s = *sptr;
3731 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3732 if (*error == NULL)
3733   {
3734   while (*s == '&')
3735     {
3736     int_eximarith_t y;
3737     s++;
3738     y = eval_op_shift(&s, decimal, error);
3739     if (*error != NULL) break;
3740     x &= y;
3741     }
3742   }
3743 *sptr = s;
3744 return x;
3745 }
3746
3747
3748 static int_eximarith_t
3749 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3750 {
3751 uschar *s = *sptr;
3752 int_eximarith_t x = eval_op_and(&s, decimal, error);
3753 if (*error == NULL)
3754   {
3755   while (*s == '^')
3756     {
3757     int_eximarith_t y;
3758     s++;
3759     y = eval_op_and(&s, decimal, error);
3760     if (*error != NULL) break;
3761     x ^= y;
3762     }
3763   }
3764 *sptr = s;
3765 return x;
3766 }
3767
3768
3769 static int_eximarith_t
3770 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3771 {
3772 uschar *s = *sptr;
3773 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3774 if (*error == NULL)
3775   {
3776   while (*s == '|')
3777     {
3778     int_eximarith_t y;
3779     s++;
3780     y = eval_op_xor(&s, decimal, error);
3781     if (*error != NULL) break;
3782     x |= y;
3783     }
3784   }
3785 *sptr = s;
3786 return x;
3787 }
3788
3789
3790
3791 /*************************************************
3792 *                 Expand string                  *
3793 *************************************************/
3794
3795 /* Returns either an unchanged string, or the expanded string in stacking pool
3796 store. Interpreted sequences are:
3797
3798    \...                    normal escaping rules
3799    $name                   substitutes the variable
3800    ${name}                 ditto
3801    ${op:string}            operates on the expanded string value
3802    ${item{arg1}{arg2}...}  expands the args and then does the business
3803                              some literal args are not enclosed in {}
3804
3805 There are now far too many operators and item types to make it worth listing
3806 them here in detail any more.
3807
3808 We use an internal routine recursively to handle embedded substrings. The
3809 external function follows. The yield is NULL if the expansion failed, and there
3810 are two cases: if something collapsed syntactically, or if "fail" was given
3811 as the action on a lookup failure. These can be distinguised by looking at the
3812 variable expand_string_forcedfail, which is TRUE in the latter case.
3813
3814 The skipping flag is set true when expanding a substring that isn't actually
3815 going to be used (after "if" or "lookup") and it prevents lookups from
3816 happening lower down.
3817
3818 Store usage: At start, a store block of the length of the input plus 64
3819 is obtained. This is expanded as necessary by string_cat(), which might have to
3820 get a new block, or might be able to expand the original. At the end of the
3821 function we can release any store above that portion of the yield block that
3822 was actually used. In many cases this will be optimal.
3823
3824 However: if the first item in the expansion is a variable name or header name,
3825 we reset the store before processing it; if the result is in fresh store, we
3826 use that without copying. This is helpful for expanding strings like
3827 $message_headers which can get very long.
3828
3829 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3830 since resetting the store at the end of the expansion will free store that was
3831 allocated by the plugin code as well as the slop after the expanded string. So
3832 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3833 and, given the acl condition, ${if }. This is an unfortunate consequence of
3834 string expansion becoming too powerful.
3835
3836 Arguments:
3837   string         the string to be expanded
3838   ket_ends       true if expansion is to stop at }
3839   left           if not NULL, a pointer to the first character after the
3840                  expansion is placed here (typically used with ket_ends)
3841   skipping       TRUE for recursive calls when the value isn't actually going
3842                  to be used (to allow for optimisation)
3843   honour_dollar  TRUE if $ is to be expanded,
3844                  FALSE if it's just another character
3845   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3846                  the store.
3847
3848 Returns:         NULL if expansion fails:
3849                    expand_string_forcedfail is set TRUE if failure was forced
3850                    expand_string_message contains a textual error message
3851                  a pointer to the expanded string on success
3852 */
3853
3854 static uschar *
3855 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3856   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3857 {
3858 int ptr = 0;
3859 int size = Ustrlen(string)+ 64;
3860 uschar *yield = store_get(size);
3861 int item_type;
3862 const uschar *s = string;
3863 uschar *save_expand_nstring[EXPAND_MAXN+1];
3864 int save_expand_nlength[EXPAND_MAXN+1];
3865 BOOL resetok = TRUE;
3866
3867 DEBUG(D_expand)
3868   debug_printf("%s: %s\n", skipping ? "   scanning" : "considering", string);
3869
3870 expand_string_forcedfail = FALSE;
3871 expand_string_message = US"";
3872
3873 while (*s != 0)
3874   {
3875   uschar *value;
3876   uschar name[256];
3877
3878   /* \ escapes the next character, which must exist, or else
3879   the expansion fails. There's a special escape, \N, which causes
3880   copying of the subject verbatim up to the next \N. Otherwise,
3881   the escapes are the standard set. */
3882
3883   if (*s == '\\')
3884     {
3885     if (s[1] == 0)
3886       {
3887       expand_string_message = US"\\ at end of string";
3888       goto EXPAND_FAILED;
3889       }
3890
3891     if (s[1] == 'N')
3892       {
3893       const uschar * t = s + 2;
3894       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3895       yield = string_catn(yield, &size, &ptr, t, s - t);
3896       if (*s != 0) s += 2;
3897       }
3898
3899     else
3900       {
3901       uschar ch[1];
3902       ch[0] = string_interpret_escape(&s);
3903       s++;
3904       yield = string_catn(yield, &size, &ptr, ch, 1);
3905       }
3906
3907     continue;
3908     }
3909
3910   /*{*/
3911   /* Anything other than $ is just copied verbatim, unless we are
3912   looking for a terminating } character. */
3913
3914   /*{*/
3915   if (ket_ends && *s == '}') break;
3916
3917   if (*s != '$' || !honour_dollar)
3918     {
3919     yield = string_catn(yield, &size, &ptr, s++, 1);
3920     continue;
3921     }
3922
3923   /* No { after the $ - must be a plain name or a number for string
3924   match variable. There has to be a fudge for variables that are the
3925   names of header fields preceded by "$header_" because header field
3926   names can contain any printing characters except space and colon.
3927   For those that don't like typing this much, "$h_" is a synonym for
3928   "$header_". A non-existent header yields a NULL value; nothing is
3929   inserted. */  /*}*/
3930
3931   if (isalpha((*(++s))))
3932     {
3933     int len;
3934     int newsize = 0;
3935
3936     s = read_name(name, sizeof(name), s, US"_");
3937
3938     /* If this is the first thing to be expanded, release the pre-allocated
3939     buffer. */
3940
3941     if (ptr == 0 && yield != NULL)
3942       {
3943       if (resetok) store_reset(yield);
3944       yield = NULL;
3945       size = 0;
3946       }
3947
3948     /* Header */
3949
3950     if (Ustrncmp(name, "h_", 2) == 0 ||
3951         Ustrncmp(name, "rh_", 3) == 0 ||
3952         Ustrncmp(name, "bh_", 3) == 0 ||
3953         Ustrncmp(name, "header_", 7) == 0 ||
3954         Ustrncmp(name, "rheader_", 8) == 0 ||
3955         Ustrncmp(name, "bheader_", 8) == 0)
3956       {
3957       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3958       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3959       s = read_header_name(name, sizeof(name), s);
3960       value = find_header(name, FALSE, &newsize, want_raw, charset);
3961
3962       /* If we didn't find the header, and the header contains a closing brace
3963       character, this may be a user error where the terminating colon
3964       has been omitted. Set a flag to adjust the error message in this case.
3965       But there is no error here - nothing gets inserted. */
3966
3967       if (value == NULL)
3968         {
3969         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3970         continue;
3971         }
3972       }
3973
3974     /* Variable */
3975
3976     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3977       {
3978       expand_string_message =
3979         string_sprintf("unknown variable name \"%s\"", name);
3980         check_variable_error_message(name);
3981       goto EXPAND_FAILED;
3982       }
3983
3984     /* If the data is known to be in a new buffer, newsize will be set to the
3985     size of that buffer. If this is the first thing in an expansion string,
3986     yield will be NULL; just point it at the new store instead of copying. Many
3987     expansion strings contain just one reference, so this is a useful
3988     optimization, especially for humungous headers. */
3989
3990     len = Ustrlen(value);
3991     if (yield == NULL && newsize != 0)
3992       {
3993       yield = value;
3994       size = newsize;
3995       ptr = len;
3996       }
3997     else yield = string_catn(yield, &size, &ptr, value, len);
3998
3999     continue;
4000     }
4001
4002   if (isdigit(*s))
4003     {
4004     int n;
4005     s = read_cnumber(&n, s);
4006     if (n >= 0 && n <= expand_nmax)
4007       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4008         expand_nlength[n]);
4009     continue;
4010     }
4011
4012   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4013
4014   if (*s != '{')                                                        /*}*/
4015     {
4016     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4017     goto EXPAND_FAILED;
4018     }
4019
4020   /* After { there can be various things, but they all start with
4021   an initial word, except for a number for a string match variable. */
4022
4023   if (isdigit((*(++s))))
4024     {
4025     int n;
4026     s = read_cnumber(&n, s);            /*{*/
4027     if (*s++ != '}')
4028       {                                 /*{*/
4029       expand_string_message = US"} expected after number";
4030       goto EXPAND_FAILED;
4031       }
4032     if (n >= 0 && n <= expand_nmax)
4033       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4034         expand_nlength[n]);
4035     continue;
4036     }
4037
4038   if (!isalpha(*s))
4039     {
4040     expand_string_message = US"letter or digit expected after ${";      /*}*/
4041     goto EXPAND_FAILED;
4042     }
4043
4044   /* Allow "-" in names to cater for substrings with negative
4045   arguments. Since we are checking for known names after { this is
4046   OK. */
4047
4048   s = read_name(name, sizeof(name), s, US"_-");
4049   item_type = chop_match(name, item_table, nelem(item_table));
4050
4051   switch(item_type)
4052     {
4053     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4054     If the ACL returns accept or reject we return content set by "message ="
4055     There is currently no limit on recursion; this would have us call
4056     acl_check_internal() directly and get a current level from somewhere.
4057     See also the acl expansion condition ECOND_ACL and the traditional
4058     acl modifier ACLC_ACL.
4059     Assume that the function has side-effects on the store that must be preserved.
4060     */
4061
4062     case EITEM_ACL:
4063       /* ${acl {name} {arg1}{arg2}...} */
4064       {
4065       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4066       uschar *user_msg;
4067
4068       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4069                       &resetok))
4070         {
4071         case 1: goto EXPAND_FAILED_CURLY;
4072         case 2:
4073         case 3: goto EXPAND_FAILED;
4074         }
4075       if (skipping) continue;
4076
4077       resetok = FALSE;
4078       switch(eval_acl(sub, nelem(sub), &user_msg))
4079         {
4080         case OK:
4081         case FAIL:
4082           DEBUG(D_expand)
4083             debug_printf("acl expansion yield: %s\n", user_msg);
4084           if (user_msg)
4085             yield = string_cat(yield, &size, &ptr, user_msg);
4086           continue;
4087
4088         case DEFER:
4089           expand_string_forcedfail = TRUE;
4090           /*FALLTHROUGH*/
4091         default:
4092           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4093           goto EXPAND_FAILED;
4094         }
4095       }
4096
4097     /* Handle conditionals - preserve the values of the numerical expansion
4098     variables in case they get changed by a regular expression match in the
4099     condition. If not, they retain their external settings. At the end
4100     of this "if" section, they get restored to their previous values. */
4101
4102     case EITEM_IF:
4103       {
4104       BOOL cond = FALSE;
4105       const uschar *next_s;
4106       int save_expand_nmax =
4107         save_expand_strings(save_expand_nstring, save_expand_nlength);
4108
4109       while (isspace(*s)) s++;
4110       next_s = eval_condition(s, &resetok, skipping? NULL : &cond);
4111       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4112
4113       DEBUG(D_expand)
4114         debug_printf("  condition: %.*s\n     result: %s\n",
4115           (int)(next_s - s), s,
4116           cond ? "true" : "false");
4117
4118       s = next_s;
4119
4120       /* The handling of "yes" and "no" result strings is now in a separate
4121       function that is also used by ${lookup} and ${extract} and ${run}. */
4122
4123       switch(process_yesno(
4124                skipping,                     /* were previously skipping */
4125                cond,                         /* success/failure indicator */
4126                lookup_value,                 /* value to reset for string2 */
4127                &s,                           /* input pointer */
4128                &yield,                       /* output pointer */
4129                &size,                        /* output size */
4130                &ptr,                         /* output current point */
4131                US"if",                       /* condition type */
4132                &resetok))
4133         {
4134         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4135         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4136         }
4137
4138       /* Restore external setting of expansion variables for continuation
4139       at this level. */
4140
4141       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4142         save_expand_nlength);
4143       continue;
4144       }
4145
4146 #ifdef SUPPORT_I18N
4147     case EITEM_IMAPFOLDER:
4148       {                         /* ${imapfolder {name}{sep]{specials}} */
4149       uschar *sub_arg[3];
4150       uschar *encoded;
4151
4152       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4153                       &resetok))
4154         {
4155         case 1: goto EXPAND_FAILED_CURLY;
4156         case 2:
4157         case 3: goto EXPAND_FAILED;
4158         }
4159
4160       if (sub_arg[1] == NULL)           /* One argument */
4161         {
4162         sub_arg[1] = US"/";             /* default separator */
4163         sub_arg[2] = NULL;
4164         }
4165       else if (Ustrlen(sub_arg[1]) != 1)
4166         {
4167         expand_string_message =
4168           string_sprintf(
4169                 "IMAP folder separator must be one character, found \"%s\"",
4170                 sub_arg[1]);
4171         goto EXPAND_FAILED;
4172         }
4173
4174       if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4175                           sub_arg[1][0], sub_arg[2], &expand_string_message)))
4176         goto EXPAND_FAILED;
4177       if (!skipping)
4178         yield = string_cat(yield, &size, &ptr, encoded);
4179       continue;
4180       }
4181 #endif
4182
4183     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4184     expanding an internal string that isn't actually going to be used. All we
4185     need to do is check the syntax, so don't do a lookup at all. Preserve the
4186     values of the numerical expansion variables in case they get changed by a
4187     partial lookup. If not, they retain their external settings. At the end
4188     of this "lookup" section, they get restored to their previous values. */
4189
4190     case EITEM_LOOKUP:
4191       {
4192       int stype, partial, affixlen, starflags;
4193       int expand_setup = 0;
4194       int nameptr = 0;
4195       uschar *key, *filename;
4196       const uschar *affix;
4197       uschar *save_lookup_value = lookup_value;
4198       int save_expand_nmax =
4199         save_expand_strings(save_expand_nstring, save_expand_nlength);
4200
4201       if ((expand_forbid & RDO_LOOKUP) != 0)
4202         {
4203         expand_string_message = US"lookup expansions are not permitted";
4204         goto EXPAND_FAILED;
4205         }
4206
4207       /* Get the key we are to look up for single-key+file style lookups.
4208       Otherwise set the key NULL pro-tem. */
4209
4210       while (isspace(*s)) s++;
4211       if (*s == '{')                                    /*}*/
4212         {
4213         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4214         if (!key) goto EXPAND_FAILED;                   /*{{*/
4215         if (*s++ != '}')
4216           {
4217           expand_string_message = US"missing '}' after lookup key";
4218           goto EXPAND_FAILED_CURLY;
4219           }
4220         while (isspace(*s)) s++;
4221         }
4222       else key = NULL;
4223
4224       /* Find out the type of database */
4225
4226       if (!isalpha(*s))
4227         {
4228         expand_string_message = US"missing lookup type";
4229         goto EXPAND_FAILED;
4230         }
4231
4232       /* The type is a string that may contain special characters of various
4233       kinds. Allow everything except space or { to appear; the actual content
4234       is checked by search_findtype_partial. */         /*}*/
4235
4236       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4237         {
4238         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4239         s++;
4240         }
4241       name[nameptr] = 0;
4242       while (isspace(*s)) s++;
4243
4244       /* Now check for the individual search type and any partial or default
4245       options. Only those types that are actually in the binary are valid. */
4246
4247       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4248         &starflags);
4249       if (stype < 0)
4250         {
4251         expand_string_message = search_error_message;
4252         goto EXPAND_FAILED;
4253         }
4254
4255       /* Check that a key was provided for those lookup types that need it,
4256       and was not supplied for those that use the query style. */
4257
4258       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4259         {
4260         if (key == NULL)
4261           {
4262           expand_string_message = string_sprintf("missing {key} for single-"
4263             "key \"%s\" lookup", name);
4264           goto EXPAND_FAILED;
4265           }
4266         }
4267       else
4268         {
4269         if (key != NULL)
4270           {
4271           expand_string_message = string_sprintf("a single key was given for "
4272             "lookup type \"%s\", which is not a single-key lookup type", name);
4273           goto EXPAND_FAILED;
4274           }
4275         }
4276
4277       /* Get the next string in brackets and expand it. It is the file name for
4278       single-key+file lookups, and the whole query otherwise. In the case of
4279       queries that also require a file name (e.g. sqlite), the file name comes
4280       first. */
4281
4282       if (*s != '{')
4283         {
4284         expand_string_message = US"missing '{' for lookup file-or-query arg";
4285         goto EXPAND_FAILED_CURLY;
4286         }
4287       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4288       if (filename == NULL) goto EXPAND_FAILED;
4289       if (*s++ != '}')
4290         {
4291         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4292         goto EXPAND_FAILED_CURLY;
4293         }
4294       while (isspace(*s)) s++;
4295
4296       /* If this isn't a single-key+file lookup, re-arrange the variables
4297       to be appropriate for the search_ functions. For query-style lookups,
4298       there is just a "key", and no file name. For the special query-style +
4299       file types, the query (i.e. "key") starts with a file name. */
4300
4301       if (!key)
4302         {
4303         while (isspace(*filename)) filename++;
4304         key = filename;
4305
4306         if (mac_islookup(stype, lookup_querystyle))
4307           filename = NULL;
4308         else
4309           {
4310           if (*filename != '/')
4311             {
4312             expand_string_message = string_sprintf(
4313               "absolute file name expected for \"%s\" lookup", name);
4314             goto EXPAND_FAILED;
4315             }
4316           while (*key != 0 && !isspace(*key)) key++;
4317           if (*key != 0) *key++ = 0;
4318           }
4319         }
4320
4321       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4322       the entry was not found. Note that there is no search_close() function.
4323       Files are left open in case of re-use. At suitable places in higher logic,
4324       search_tidyup() is called to tidy all open files. This can save opening
4325       the same file several times. However, files may also get closed when
4326       others are opened, if too many are open at once. The rule is that a
4327       handle should not be used after a second search_open().
4328
4329       Request that a partial search sets up $1 and maybe $2 by passing
4330       expand_setup containing zero. If its value changes, reset expand_nmax,
4331       since new variables will have been set. Note that at the end of this
4332       "lookup" section, the old numeric variables are restored. */
4333
4334       if (skipping)
4335         lookup_value = NULL;
4336       else
4337         {
4338         void *handle = search_open(filename, stype, 0, NULL, NULL);
4339         if (handle == NULL)
4340           {
4341           expand_string_message = search_error_message;
4342           goto EXPAND_FAILED;
4343           }
4344         lookup_value = search_find(handle, filename, key, partial, affix,
4345           affixlen, starflags, &expand_setup);
4346         if (search_find_defer)
4347           {
4348           expand_string_message =
4349             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4350               string_printing2(key, FALSE), search_error_message);
4351           goto EXPAND_FAILED;
4352           }
4353         if (expand_setup > 0) expand_nmax = expand_setup;
4354         }
4355
4356       /* The handling of "yes" and "no" result strings is now in a separate
4357       function that is also used by ${if} and ${extract}. */
4358
4359       switch(process_yesno(
4360                skipping,                     /* were previously skipping */
4361                lookup_value != NULL,         /* success/failure indicator */
4362                save_lookup_value,            /* value to reset for string2 */
4363                &s,                           /* input pointer */
4364                &yield,                       /* output pointer */
4365                &size,                        /* output size */
4366                &ptr,                         /* output current point */
4367                US"lookup",                   /* condition type */
4368                &resetok))
4369         {
4370         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4371         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4372         }
4373
4374       /* Restore external setting of expansion variables for carrying on
4375       at this level, and continue. */
4376
4377       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4378         save_expand_nlength);
4379       continue;
4380       }
4381
4382     /* If Perl support is configured, handle calling embedded perl subroutines,
4383     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4384     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4385     arguments (defined below). */
4386
4387     #define EXIM_PERL_MAX_ARGS 8
4388
4389     case EITEM_PERL:
4390     #ifndef EXIM_PERL
4391     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4392       "is not included in this binary";
4393     goto EXPAND_FAILED;
4394
4395     #else   /* EXIM_PERL */
4396       {
4397       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4398       uschar *new_yield;
4399
4400       if ((expand_forbid & RDO_PERL) != 0)
4401         {
4402         expand_string_message = US"Perl calls are not permitted";
4403         goto EXPAND_FAILED;
4404         }
4405
4406       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4407            US"perl", &resetok))
4408         {
4409         case 1: goto EXPAND_FAILED_CURLY;
4410         case 2:
4411         case 3: goto EXPAND_FAILED;
4412         }
4413
4414       /* If skipping, we don't actually do anything */
4415
4416       if (skipping) continue;
4417
4418       /* Start the interpreter if necessary */
4419
4420       if (!opt_perl_started)
4421         {
4422         uschar *initerror;
4423         if (opt_perl_startup == NULL)
4424           {
4425           expand_string_message = US"A setting of perl_startup is needed when "
4426             "using the Perl interpreter";
4427           goto EXPAND_FAILED;
4428           }
4429         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4430         initerror = init_perl(opt_perl_startup);
4431         if (initerror != NULL)
4432           {
4433           expand_string_message =
4434             string_sprintf("error in perl_startup code: %s\n", initerror);
4435           goto EXPAND_FAILED;
4436           }
4437         opt_perl_started = TRUE;
4438         }
4439
4440       /* Call the function */
4441
4442       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4443       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4444         sub_arg[0], sub_arg + 1);
4445
4446       /* NULL yield indicates failure; if the message pointer has been set to
4447       NULL, the yield was undef, indicating a forced failure. Otherwise the
4448       message will indicate some kind of Perl error. */
4449
4450       if (new_yield == NULL)
4451         {
4452         if (expand_string_message == NULL)
4453           {
4454           expand_string_message =
4455             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4456               "failure", sub_arg[0]);
4457           expand_string_forcedfail = TRUE;
4458           }
4459         goto EXPAND_FAILED;
4460         }
4461
4462       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4463       set during a callback from Perl. */
4464
4465       expand_string_forcedfail = FALSE;
4466       yield = new_yield;
4467       continue;
4468       }
4469     #endif /* EXIM_PERL */
4470
4471     /* Transform email address to "prvs" scheme to use
4472        as BATV-signed return path */
4473
4474     case EITEM_PRVS:
4475       {
4476       uschar *sub_arg[3];
4477       uschar *p,*domain;
4478
4479       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4480         {
4481         case 1: goto EXPAND_FAILED_CURLY;
4482         case 2:
4483         case 3: goto EXPAND_FAILED;
4484         }
4485
4486       /* If skipping, we don't actually do anything */
4487       if (skipping) continue;
4488
4489       /* sub_arg[0] is the address */
4490       domain = Ustrrchr(sub_arg[0],'@');
4491       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4492         {
4493         expand_string_message = US"prvs first argument must be a qualified email address";
4494         goto EXPAND_FAILED;
4495         }
4496
4497       /* Calculate the hash. The second argument must be a single-digit
4498       key number, or unset. */
4499
4500       if (sub_arg[2] != NULL &&
4501           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4502         {
4503         expand_string_message = US"prvs second argument must be a single digit";
4504         goto EXPAND_FAILED;
4505         }
4506
4507       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4508       if (p == NULL)
4509         {
4510         expand_string_message = US"prvs hmac-sha1 conversion failed";
4511         goto EXPAND_FAILED;
4512         }
4513
4514       /* Now separate the domain from the local part */
4515       *domain++ = '\0';
4516
4517       yield = string_catn(yield, &size, &ptr, US"prvs=", 5);
4518       yield = string_catn(yield, &size, &ptr, sub_arg[2] ? sub_arg[2] : US"0", 1);
4519       yield = string_catn(yield, &size, &ptr, prvs_daystamp(7), 3);
4520       yield = string_catn(yield, &size, &ptr, p, 6);
4521       yield = string_catn(yield, &size, &ptr, US"=", 1);
4522       yield = string_cat (yield, &size, &ptr, sub_arg[0]);
4523       yield = string_catn(yield, &size, &ptr, US"@", 1);
4524       yield = string_cat (yield, &size, &ptr, domain);
4525
4526       continue;
4527       }
4528
4529     /* Check a prvs-encoded address for validity */
4530
4531     case EITEM_PRVSCHECK:
4532       {
4533       uschar *sub_arg[3];
4534       int mysize = 0, myptr = 0;
4535       const pcre *re;
4536       uschar *p;
4537
4538       /* TF: Ugliness: We want to expand parameter 1 first, then set
4539          up expansion variables that are used in the expansion of
4540          parameter 2. So we clone the string for the first
4541          expansion, where we only expand parameter 1.
4542
4543          PH: Actually, that isn't necessary. The read_subs() function is
4544          designed to work this way for the ${if and ${lookup expansions. I've
4545          tidied the code.
4546       */
4547
4548       /* Reset expansion variables */
4549       prvscheck_result = NULL;
4550       prvscheck_address = NULL;
4551       prvscheck_keynum = NULL;
4552
4553       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4554         {
4555         case 1: goto EXPAND_FAILED_CURLY;
4556         case 2:
4557         case 3: goto EXPAND_FAILED;
4558         }
4559
4560       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4561                               TRUE,FALSE);
4562
4563       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4564         {
4565         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4566         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4567         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4568         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4569         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4570
4571         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4572         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4573         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4574         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4575         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4576
4577         /* Set up expansion variables */
4578         prvscheck_address = string_cat (NULL, &mysize, &myptr, local_part);
4579         prvscheck_address = string_catn(prvscheck_address, &mysize, &myptr, US"@", 1);
4580         prvscheck_address = string_cat (prvscheck_address, &mysize, &myptr, domain);
4581         prvscheck_address[myptr] = '\0';
4582         prvscheck_keynum = string_copy(key_num);
4583
4584         /* Now expand the second argument */
4585         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4586           {
4587           case 1: goto EXPAND_FAILED_CURLY;
4588           case 2:
4589           case 3: goto EXPAND_FAILED;
4590           }
4591
4592         /* Now we have the key and can check the address. */
4593
4594         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4595           daystamp);
4596
4597         if (p == NULL)
4598           {
4599           expand_string_message = US"hmac-sha1 conversion failed";
4600           goto EXPAND_FAILED;
4601           }
4602
4603         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4604         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4605
4606         if (Ustrcmp(p,hash) == 0)
4607           {
4608           /* Success, valid BATV address. Now check the expiry date. */
4609           uschar *now = prvs_daystamp(0);
4610           unsigned int inow = 0,iexpire = 1;
4611
4612           (void)sscanf(CS now,"%u",&inow);
4613           (void)sscanf(CS daystamp,"%u",&iexpire);
4614
4615           /* When "iexpire" is < 7, a "flip" has occured.
4616              Adjust "inow" accordingly. */
4617           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4618
4619           if (iexpire >= inow)
4620             {
4621             prvscheck_result = US"1";
4622             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4623             }
4624             else
4625             {
4626             prvscheck_result = NULL;
4627             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4628             }
4629           }
4630         else
4631           {
4632           prvscheck_result = NULL;
4633           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4634           }
4635
4636         /* Now expand the final argument. We leave this till now so that
4637         it can include $prvscheck_result. */
4638
4639         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4640           {
4641           case 1: goto EXPAND_FAILED_CURLY;
4642           case 2:
4643           case 3: goto EXPAND_FAILED;
4644           }
4645
4646         yield = string_cat(yield, &size, &ptr,
4647           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4648
4649         /* Reset the "internal" variables afterwards, because they are in
4650         dynamic store that will be reclaimed if the expansion succeeded. */
4651
4652         prvscheck_address = NULL;
4653         prvscheck_keynum = NULL;
4654         }
4655       else
4656         {
4657         /* Does not look like a prvs encoded address, return the empty string.
4658            We need to make sure all subs are expanded first, so as to skip over
4659            the entire item. */
4660
4661         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4662           {
4663           case 1: goto EXPAND_FAILED_CURLY;
4664           case 2:
4665           case 3: goto EXPAND_FAILED;
4666           }
4667         }
4668
4669       continue;
4670       }
4671
4672     /* Handle "readfile" to insert an entire file */
4673
4674     case EITEM_READFILE:
4675       {
4676       FILE *f;
4677       uschar *sub_arg[2];
4678
4679       if ((expand_forbid & RDO_READFILE) != 0)
4680         {
4681         expand_string_message = US"file insertions are not permitted";
4682         goto EXPAND_FAILED;
4683         }
4684
4685       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4686         {
4687         case 1: goto EXPAND_FAILED_CURLY;
4688         case 2:
4689         case 3: goto EXPAND_FAILED;
4690         }
4691
4692       /* If skipping, we don't actually do anything */
4693
4694       if (skipping) continue;
4695
4696       /* Open the file and read it */
4697
4698       f = Ufopen(sub_arg[0], "rb");
4699       if (f == NULL)
4700         {
4701         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4702         goto EXPAND_FAILED;
4703         }
4704
4705       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4706       (void)fclose(f);
4707       continue;
4708       }
4709
4710     /* Handle "readsocket" to insert data from a Unix domain socket */
4711
4712     case EITEM_READSOCK:
4713       {
4714       int fd;
4715       int timeout = 5;
4716       int save_ptr = ptr;
4717       FILE *f;
4718       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4719       uschar *arg;
4720       uschar *sub_arg[4];
4721
4722       if ((expand_forbid & RDO_READSOCK) != 0)
4723         {
4724         expand_string_message = US"socket insertions are not permitted";
4725         goto EXPAND_FAILED;
4726         }
4727
4728       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4729       because there may be a string for expansion on failure. */
4730
4731       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4732         {
4733         case 1: goto EXPAND_FAILED_CURLY;
4734         case 2:                             /* Won't occur: no end check */
4735         case 3: goto EXPAND_FAILED;
4736         }
4737
4738       /* Sort out timeout, if given */
4739
4740       if (sub_arg[2] != NULL)
4741         {
4742         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4743         if (timeout < 0)
4744           {
4745           expand_string_message = string_sprintf("bad time value %s",
4746             sub_arg[2]);
4747           goto EXPAND_FAILED;
4748           }
4749         }
4750       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4751
4752       /* If skipping, we don't actually do anything. Otherwise, arrange to
4753       connect to either an IP or a Unix socket. */
4754
4755       if (!skipping)
4756         {
4757         /* Handle an IP (internet) domain */
4758
4759         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4760           {
4761           int port;
4762           uschar *server_name = sub_arg[0] + 5;
4763           uschar *port_name = Ustrrchr(server_name, ':');
4764
4765           /* Sort out the port */
4766
4767           if (port_name == NULL)
4768             {
4769             expand_string_message =
4770               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4771             goto EXPAND_FAILED;
4772             }
4773           *port_name++ = 0;           /* Terminate server name */
4774
4775           if (isdigit(*port_name))
4776             {
4777             uschar *end;
4778             port = Ustrtol(port_name, &end, 0);
4779             if (end != port_name + Ustrlen(port_name))
4780               {
4781               expand_string_message =
4782                 string_sprintf("invalid port number %s", port_name);
4783               goto EXPAND_FAILED;
4784               }
4785             }
4786           else
4787             {
4788             struct servent *service_info = getservbyname(CS port_name, "tcp");
4789             if (service_info == NULL)
4790               {
4791               expand_string_message = string_sprintf("unknown port \"%s\"",
4792                 port_name);
4793               goto EXPAND_FAILED;
4794               }
4795             port = ntohs(service_info->s_port);
4796             }
4797
4798           if ((fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4799                   timeout, NULL, &expand_string_message)) < 0)
4800               goto SOCK_FAIL;
4801           }
4802
4803         /* Handle a Unix domain socket */
4804
4805         else
4806           {
4807           int rc;
4808           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4809             {
4810             expand_string_message = string_sprintf("failed to create socket: %s",
4811               strerror(errno));
4812             goto SOCK_FAIL;
4813             }
4814
4815           sockun.sun_family = AF_UNIX;
4816           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4817             sub_arg[0]);
4818
4819           sigalrm_seen = FALSE;
4820           alarm(timeout);
4821           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4822           alarm(0);
4823           if (sigalrm_seen)
4824             {
4825             expand_string_message = US "socket connect timed out";
4826             goto SOCK_FAIL;
4827             }
4828           if (rc < 0)
4829             {
4830             expand_string_message = string_sprintf("failed to connect to socket "
4831               "%s: %s", sub_arg[0], strerror(errno));
4832             goto SOCK_FAIL;
4833             }
4834           }
4835
4836         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4837
4838         /* Allow sequencing of test actions */
4839         if (running_in_test_harness) millisleep(100);
4840
4841         /* Write the request string, if not empty */
4842
4843         if (sub_arg[1][0] != 0)
4844           {
4845           int len = Ustrlen(sub_arg[1]);
4846           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4847             sub_arg[1]);
4848           if (write(fd, sub_arg[1], len) != len)
4849             {
4850             expand_string_message = string_sprintf("request write to socket "
4851               "failed: %s", strerror(errno));
4852             goto SOCK_FAIL;
4853             }
4854           }
4855
4856         /* Shut down the sending side of the socket. This helps some servers to
4857         recognise that it is their turn to do some work. Just in case some
4858         system doesn't have this function, make it conditional. */
4859
4860         #ifdef SHUT_WR
4861         shutdown(fd, SHUT_WR);
4862         #endif
4863
4864         if (running_in_test_harness) millisleep(100);
4865
4866         /* Now we need to read from the socket, under a timeout. The function
4867         that reads a file can be used. */
4868
4869         f = fdopen(fd, "rb");
4870         sigalrm_seen = FALSE;
4871         alarm(timeout);
4872         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4873         alarm(0);
4874         (void)fclose(f);
4875
4876         /* After a timeout, we restore the pointer in the result, that is,
4877         make sure we add nothing from the socket. */
4878
4879         if (sigalrm_seen)
4880           {
4881           ptr = save_ptr;
4882           expand_string_message = US "socket read timed out";
4883           goto SOCK_FAIL;
4884           }
4885         }
4886
4887       /* The whole thing has worked (or we were skipping). If there is a
4888       failure string following, we need to skip it. */
4889
4890       if (*s == '{')
4891         {
4892         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4893           goto EXPAND_FAILED;
4894         if (*s++ != '}')
4895           {
4896           expand_string_message = US"missing '}' closing failstring for readsocket";
4897           goto EXPAND_FAILED_CURLY;
4898           }
4899         while (isspace(*s)) s++;
4900         }
4901
4902     readsock_done:
4903       if (*s++ != '}')
4904         {
4905         expand_string_message = US"missing '}' closing readsocket";
4906         goto EXPAND_FAILED_CURLY;
4907         }
4908       continue;
4909
4910       /* Come here on failure to create socket, connect socket, write to the
4911       socket, or timeout on reading. If another substring follows, expand and
4912       use it. Otherwise, those conditions give expand errors. */
4913
4914       SOCK_FAIL:
4915       if (*s != '{') goto EXPAND_FAILED;
4916       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4917       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4918         goto EXPAND_FAILED;
4919       yield = string_cat(yield, &size, &ptr, arg);
4920       if (*s++ != '}')
4921         {
4922         expand_string_message = US"missing '}' closing failstring for readsocket";
4923         goto EXPAND_FAILED_CURLY;
4924         }
4925       while (isspace(*s)) s++;
4926       goto readsock_done;
4927       }
4928
4929     /* Handle "run" to execute a program. */
4930
4931     case EITEM_RUN:
4932       {
4933       FILE *f;
4934       uschar *arg;
4935       const uschar **argv;
4936       pid_t pid;
4937       int fd_in, fd_out;
4938       int lsize = 0, lptr = 0;
4939
4940       if ((expand_forbid & RDO_RUN) != 0)
4941         {
4942         expand_string_message = US"running a command is not permitted";
4943         goto EXPAND_FAILED;
4944         }
4945
4946       while (isspace(*s)) s++;
4947       if (*s != '{')
4948         {
4949         expand_string_message = US"missing '{' for command arg of run";
4950         goto EXPAND_FAILED_CURLY;
4951         }
4952       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4953       if (arg == NULL) goto EXPAND_FAILED;
4954       while (isspace(*s)) s++;
4955       if (*s++ != '}')
4956         {
4957         expand_string_message = US"missing '}' closing command arg of run";
4958         goto EXPAND_FAILED_CURLY;
4959         }
4960
4961       if (skipping)   /* Just pretend it worked when we're skipping */
4962         runrc = 0;
4963       else
4964         {
4965         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4966             arg,                                /* raw command */
4967             FALSE,                              /* don't expand the arguments */
4968             0,                                  /* not relevant when... */
4969             NULL,                               /* no transporting address */
4970             US"${run} expansion",               /* for error messages */
4971             &expand_string_message))            /* where to put error message */
4972           goto EXPAND_FAILED;
4973
4974         /* Create the child process, making it a group leader. */
4975
4976         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
4977           {
4978           expand_string_message =
4979             string_sprintf("couldn't create child process: %s", strerror(errno));
4980           goto EXPAND_FAILED;
4981           }
4982
4983         /* Nothing is written to the standard input. */
4984
4985         (void)close(fd_in);
4986
4987         /* Read the pipe to get the command's output into $value (which is kept
4988         in lookup_value). Read during execution, so that if the output exceeds
4989         the OS pipe buffer limit, we don't block forever. Remember to not release
4990         memory just allocated for $value. */
4991
4992         resetok = FALSE;
4993         f = fdopen(fd_out, "rb");
4994         sigalrm_seen = FALSE;
4995         alarm(60);
4996         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
4997         alarm(0);
4998         (void)fclose(f);
4999
5000         /* Wait for the process to finish, applying the timeout, and inspect its
5001         return code for serious disasters. Simple non-zero returns are passed on.
5002         */
5003
5004         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5005           {
5006           if (sigalrm_seen || runrc == -256)
5007             {
5008             expand_string_message = string_sprintf("command timed out");
5009             killpg(pid, SIGKILL);       /* Kill the whole process group */
5010             }
5011
5012           else if (runrc == -257)
5013             expand_string_message = string_sprintf("wait() failed: %s",
5014               strerror(errno));
5015
5016           else
5017             expand_string_message = string_sprintf("command killed by signal %d",
5018               -runrc);
5019
5020           goto EXPAND_FAILED;
5021           }
5022         }
5023
5024       /* Process the yes/no strings; $value may be useful in both cases */
5025
5026       switch(process_yesno(
5027                skipping,                     /* were previously skipping */
5028                runrc == 0,                   /* success/failure indicator */
5029                lookup_value,                 /* value to reset for string2 */
5030                &s,                           /* input pointer */
5031                &yield,                       /* output pointer */
5032                &size,                        /* output size */
5033                &ptr,                         /* output current point */
5034                US"run",                      /* condition type */
5035                &resetok))
5036         {
5037         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5038         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5039         }
5040
5041       continue;
5042       }
5043
5044     /* Handle character translation for "tr" */
5045
5046     case EITEM_TR:
5047       {
5048       int oldptr = ptr;
5049       int o2m;
5050       uschar *sub[3];
5051
5052       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5053         {
5054         case 1: goto EXPAND_FAILED_CURLY;
5055         case 2:
5056         case 3: goto EXPAND_FAILED;
5057         }
5058
5059       yield = string_cat(yield, &size, &ptr, sub[0]);
5060       o2m = Ustrlen(sub[2]) - 1;
5061
5062       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
5063         {
5064         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
5065         if (m != NULL)
5066           {
5067           int o = m - sub[1];
5068           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5069           }
5070         }
5071
5072       continue;
5073       }
5074
5075     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5076     expanded arguments. */
5077
5078     case EITEM_HASH:
5079     case EITEM_LENGTH:
5080     case EITEM_NHASH:
5081     case EITEM_SUBSTR:
5082       {
5083       int i;
5084       int len;
5085       uschar *ret;
5086       int val[2] = { 0, -1 };
5087       uschar *sub[3];
5088
5089       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5090       Ensure that sub[2] is set in the ${length } case. */
5091
5092       sub[2] = NULL;
5093       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5094              TRUE, name, &resetok))
5095         {
5096         case 1: goto EXPAND_FAILED_CURLY;
5097         case 2:
5098         case 3: goto EXPAND_FAILED;
5099         }
5100
5101       /* Juggle the arguments if there are only two of them: always move the
5102       string to the last position and make ${length{n}{str}} equivalent to
5103       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5104
5105       if (sub[2] == NULL)
5106         {
5107         sub[2] = sub[1];
5108         sub[1] = NULL;
5109         if (item_type == EITEM_LENGTH)
5110           {
5111           sub[1] = sub[0];
5112           sub[0] = NULL;
5113           }
5114         }
5115
5116       for (i = 0; i < 2; i++)
5117         {
5118         if (sub[i] == NULL) continue;
5119         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5120         if (*ret != 0 || (i != 0 && val[i] < 0))
5121           {
5122           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5123             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5124           goto EXPAND_FAILED;
5125           }
5126         }
5127
5128       ret =
5129         (item_type == EITEM_HASH)?
5130           compute_hash(sub[2], val[0], val[1], &len) :
5131         (item_type == EITEM_NHASH)?
5132           compute_nhash(sub[2], val[0], val[1], &len) :
5133           extract_substr(sub[2], val[0], val[1], &len);
5134
5135       if (ret == NULL) goto EXPAND_FAILED;
5136       yield = string_catn(yield, &size, &ptr, ret, len);
5137       continue;
5138       }
5139
5140     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5141     This code originally contributed by Steve Haslam. It currently supports
5142     the use of MD5 and SHA-1 hashes.
5143
5144     We need some workspace that is large enough to handle all the supported
5145     hash types. Use macros to set the sizes rather than be too elaborate. */
5146
5147     #define MAX_HASHLEN      20
5148     #define MAX_HASHBLOCKLEN 64
5149
5150     case EITEM_HMAC:
5151       {
5152       uschar *sub[3];
5153       md5 md5_base;
5154       hctx sha1_ctx;
5155       void *use_base;
5156       int type, i;
5157       int hashlen;      /* Number of octets for the hash algorithm's output */
5158       int hashblocklen; /* Number of octets the hash algorithm processes */
5159       uschar *keyptr, *p;
5160       unsigned int keylen;
5161
5162       uschar keyhash[MAX_HASHLEN];
5163       uschar innerhash[MAX_HASHLEN];
5164       uschar finalhash[MAX_HASHLEN];
5165       uschar finalhash_hex[2*MAX_HASHLEN];
5166       uschar innerkey[MAX_HASHBLOCKLEN];
5167       uschar outerkey[MAX_HASHBLOCKLEN];
5168
5169       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5170         {
5171         case 1: goto EXPAND_FAILED_CURLY;
5172         case 2:
5173         case 3: goto EXPAND_FAILED;
5174         }
5175
5176       if (!skipping)
5177         {
5178         if (Ustrcmp(sub[0], "md5") == 0)
5179           {
5180           type = HMAC_MD5;
5181           use_base = &md5_base;
5182           hashlen = 16;
5183           hashblocklen = 64;
5184           }
5185         else if (Ustrcmp(sub[0], "sha1") == 0)
5186           {
5187           type = HMAC_SHA1;
5188           use_base = &sha1_ctx;
5189           hashlen = 20;
5190           hashblocklen = 64;
5191           }
5192         else
5193           {
5194           expand_string_message =
5195             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5196           goto EXPAND_FAILED;
5197           }
5198
5199         keyptr = sub[1];
5200         keylen = Ustrlen(keyptr);
5201
5202         /* If the key is longer than the hash block length, then hash the key
5203         first */
5204
5205         if (keylen > hashblocklen)
5206           {
5207           chash_start(type, use_base);
5208           chash_end(type, use_base, keyptr, keylen, keyhash);
5209           keyptr = keyhash;
5210           keylen = hashlen;
5211           }
5212
5213         /* Now make the inner and outer key values */
5214
5215         memset(innerkey, 0x36, hashblocklen);
5216         memset(outerkey, 0x5c, hashblocklen);
5217
5218         for (i = 0; i < keylen; i++)
5219           {
5220           innerkey[i] ^= keyptr[i];
5221           outerkey[i] ^= keyptr[i];
5222           }
5223
5224         /* Now do the hashes */
5225
5226         chash_start(type, use_base);
5227         chash_mid(type, use_base, innerkey);
5228         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5229
5230         chash_start(type, use_base);
5231         chash_mid(type, use_base, outerkey);
5232         chash_end(type, use_base, innerhash, hashlen, finalhash);
5233
5234         /* Encode the final hash as a hex string */
5235
5236         p = finalhash_hex;
5237         for (i = 0; i < hashlen; i++)
5238           {
5239           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5240           *p++ = hex_digits[finalhash[i] & 0x0f];
5241           }
5242
5243         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5244           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5245
5246         yield = string_catn(yield, &size, &ptr, finalhash_hex, hashlen*2);
5247         }
5248       continue;
5249       }
5250
5251     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5252     We have to save the numerical variables and restore them afterwards. */
5253
5254     case EITEM_SG:
5255       {
5256       const pcre *re;
5257       int moffset, moffsetextra, slen;
5258       int roffset;
5259       int emptyopt;
5260       const uschar *rerror;
5261       uschar *subject;
5262       uschar *sub[3];
5263       int save_expand_nmax =
5264         save_expand_strings(save_expand_nstring, save_expand_nlength);
5265
5266       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5267         {
5268         case 1: goto EXPAND_FAILED_CURLY;
5269         case 2:
5270         case 3: goto EXPAND_FAILED;
5271         }
5272
5273       /* Compile the regular expression */
5274
5275       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5276         NULL);
5277
5278       if (re == NULL)
5279         {
5280         expand_string_message = string_sprintf("regular expression error in "
5281           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5282         goto EXPAND_FAILED;
5283         }
5284
5285       /* Now run a loop to do the substitutions as often as necessary. It ends
5286       when there are no more matches. Take care over matches of the null string;
5287       do the same thing as Perl does. */
5288
5289       subject = sub[0];
5290       slen = Ustrlen(sub[0]);
5291       moffset = moffsetextra = 0;
5292       emptyopt = 0;
5293
5294       for (;;)
5295         {
5296         int ovector[3*(EXPAND_MAXN+1)];
5297         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5298           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5299         int nn;
5300         uschar *insert;
5301
5302         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5303         is not necessarily the end. We want to repeat the match from one
5304         character further along, but leaving the basic offset the same (for
5305         copying below). We can't be at the end of the string - that was checked
5306         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5307         finished; copy the remaining string and end the loop. */
5308
5309         if (n < 0)
5310           {
5311           if (emptyopt != 0)
5312             {
5313             moffsetextra = 1;
5314             emptyopt = 0;
5315             continue;
5316             }
5317           yield = string_catn(yield, &size, &ptr, subject+moffset, slen-moffset);
5318           break;
5319           }
5320
5321         /* Match - set up for expanding the replacement. */
5322
5323         if (n == 0) n = EXPAND_MAXN + 1;
5324         expand_nmax = 0;
5325         for (nn = 0; nn < n*2; nn += 2)
5326           {
5327           expand_nstring[expand_nmax] = subject + ovector[nn];
5328           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5329           }
5330         expand_nmax--;
5331
5332         /* Copy the characters before the match, plus the expanded insertion. */
5333
5334         yield = string_catn(yield, &size, &ptr, subject + moffset,
5335           ovector[0] - moffset);
5336         insert = expand_string(sub[2]);
5337         if (insert == NULL) goto EXPAND_FAILED;
5338         yield = string_cat(yield, &size, &ptr, insert);
5339
5340         moffset = ovector[1];
5341         moffsetextra = 0;
5342         emptyopt = 0;
5343
5344         /* If we have matched an empty string, first check to see if we are at
5345         the end of the subject. If so, the loop is over. Otherwise, mimic
5346         what Perl's /g options does. This turns out to be rather cunning. First
5347         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5348         string at the same point. If this fails (picked up above) we advance to
5349         the next character. */
5350
5351         if (ovector[0] == ovector[1])
5352           {
5353           if (ovector[0] == slen) break;
5354           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5355           }
5356         }
5357
5358       /* All done - restore numerical variables. */
5359
5360       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5361         save_expand_nlength);
5362       continue;
5363       }
5364
5365     /* Handle keyed and numbered substring extraction. If the first argument
5366     consists entirely of digits, then a numerical extraction is assumed. */
5367
5368     case EITEM_EXTRACT:
5369       {
5370       int i;
5371       int j;
5372       int field_number = 1;
5373       BOOL field_number_set = FALSE;
5374       uschar *save_lookup_value = lookup_value;
5375       uschar *sub[3];
5376       int save_expand_nmax =
5377         save_expand_strings(save_expand_nstring, save_expand_nlength);
5378
5379       /* While skipping we cannot rely on the data for expansions being
5380       available (eg. $item) hence cannot decide on numeric vs. keyed.
5381       Read a maximum of 5 arguments (inclding the yes/no) */
5382
5383       if (skipping)
5384         {
5385         while (isspace(*s)) s++;
5386         for (j = 5; j > 0 && *s == '{'; j--)
5387           {
5388           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5389             goto EXPAND_FAILED;                                 /*{*/
5390           if (*s++ != '}')
5391             {
5392             expand_string_message = US"missing '{' for arg of extract";
5393             goto EXPAND_FAILED_CURLY;
5394             }
5395           while (isspace(*s)) s++;
5396           }
5397         if (  Ustrncmp(s, "fail", 4) == 0
5398            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5399            )
5400           {
5401           s += 4;
5402           while (isspace(*s)) s++;
5403           }
5404         if (*s != '}')
5405           {
5406           expand_string_message = US"missing '}' closing extract";
5407           goto EXPAND_FAILED_CURLY;
5408           }
5409         }
5410
5411       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5412         {
5413         while (isspace(*s)) s++;
5414         if (*s == '{')                                          /*}*/
5415           {
5416           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5417           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5418           if (*s++ != '}')
5419             {
5420             expand_string_message = string_sprintf(
5421               "missing '}' closing arg %d of extract", i+1);
5422             goto EXPAND_FAILED_CURLY;
5423             }
5424
5425           /* After removal of leading and trailing white space, the first
5426           argument must not be empty; if it consists entirely of digits
5427           (optionally preceded by a minus sign), this is a numerical
5428           extraction, and we expect 3 arguments. */
5429
5430           if (i == 0)
5431             {
5432             int len;
5433             int x = 0;
5434             uschar *p = sub[0];
5435
5436             while (isspace(*p)) p++;
5437             sub[0] = p;
5438
5439             len = Ustrlen(p);
5440             while (len > 0 && isspace(p[len-1])) len--;
5441             p[len] = 0;
5442
5443             if (*p == 0)
5444               {
5445               expand_string_message = US"first argument of \"extract\" must "
5446                 "not be empty";
5447               goto EXPAND_FAILED;
5448               }
5449
5450             if (*p == '-')
5451               {
5452               field_number = -1;
5453               p++;
5454               }
5455             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5456             if (*p == 0)
5457               {
5458               field_number *= x;
5459               j = 3;               /* Need 3 args */
5460               field_number_set = TRUE;
5461               }
5462             }
5463           }
5464         else
5465           {
5466           expand_string_message = string_sprintf(
5467             "missing '{' for arg %d of extract", i+1);
5468           goto EXPAND_FAILED_CURLY;
5469           }
5470         }
5471
5472       /* Extract either the numbered or the keyed substring into $value. If
5473       skipping, just pretend the extraction failed. */
5474
5475       lookup_value = skipping? NULL : field_number_set?
5476         expand_gettokened(field_number, sub[1], sub[2]) :
5477         expand_getkeyed(sub[0], 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"extract",                  /* 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     /* return the Nth item from a list */
5506
5507     case EITEM_LISTEXTRACT:
5508       {
5509       int i;
5510       int field_number = 1;
5511       uschar *save_lookup_value = lookup_value;
5512       uschar *sub[2];
5513       int save_expand_nmax =
5514         save_expand_strings(save_expand_nstring, save_expand_nlength);
5515
5516       /* Read the field & list arguments */
5517
5518       for (i = 0; i < 2; i++)
5519         {
5520         while (isspace(*s)) s++;
5521         if (*s != '{')                                  /*}*/
5522           {
5523           expand_string_message = string_sprintf(
5524             "missing '{' for arg %d of listextract", i+1);
5525           goto EXPAND_FAILED_CURLY;
5526           }
5527
5528         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5529         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5530         if (*s++ != '}')
5531           {
5532           expand_string_message = string_sprintf(
5533             "missing '}' closing arg %d of listextract", i+1);
5534           goto EXPAND_FAILED_CURLY;
5535           }
5536
5537         /* After removal of leading and trailing white space, the first
5538         argument must be numeric and nonempty. */
5539
5540         if (i == 0)
5541           {
5542           int len;
5543           int x = 0;
5544           uschar *p = sub[0];
5545
5546           while (isspace(*p)) p++;
5547           sub[0] = p;
5548
5549           len = Ustrlen(p);
5550           while (len > 0 && isspace(p[len-1])) len--;
5551           p[len] = 0;
5552
5553           if (!*p && !skipping)
5554             {
5555             expand_string_message = US"first argument of \"listextract\" must "
5556               "not be empty";
5557             goto EXPAND_FAILED;
5558             }
5559
5560           if (*p == '-')
5561             {
5562             field_number = -1;
5563             p++;
5564             }
5565           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5566           if (*p)
5567             {
5568             expand_string_message = US"first argument of \"listextract\" must "
5569               "be numeric";
5570             goto EXPAND_FAILED;
5571             }
5572           field_number *= x;
5573           }
5574         }
5575
5576       /* Extract the numbered element into $value. If
5577       skipping, just pretend the extraction failed. */
5578
5579       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5580
5581       /* If no string follows, $value gets substituted; otherwise there can
5582       be yes/no strings, as for lookup or if. */
5583
5584       switch(process_yesno(
5585                skipping,                     /* were previously skipping */
5586                lookup_value != NULL,         /* success/failure indicator */
5587                save_lookup_value,            /* value to reset for string2 */
5588                &s,                           /* input pointer */
5589                &yield,                       /* output pointer */
5590                &size,                        /* output size */
5591                &ptr,                         /* output current point */
5592                US"listextract",              /* condition type */
5593                &resetok))
5594         {
5595         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5596         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5597         }
5598
5599       /* All done - restore numerical variables. */
5600
5601       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5602         save_expand_nlength);
5603
5604       continue;
5605       }
5606
5607 #ifdef SUPPORT_TLS
5608     case EITEM_CERTEXTRACT:
5609       {
5610       uschar *save_lookup_value = lookup_value;
5611       uschar *sub[2];
5612       int save_expand_nmax =
5613         save_expand_strings(save_expand_nstring, save_expand_nlength);
5614
5615       /* Read the field argument */
5616       while (isspace(*s)) s++;
5617       if (*s != '{')                                    /*}*/
5618         {
5619         expand_string_message = US"missing '{' for field arg of certextract";
5620         goto EXPAND_FAILED_CURLY;
5621         }
5622       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5623       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5624       if (*s++ != '}')
5625         {
5626         expand_string_message = US"missing '}' closing field arg of certextract";
5627         goto EXPAND_FAILED_CURLY;
5628         }
5629       /* strip spaces fore & aft */
5630       {
5631       int len;
5632       uschar *p = sub[0];
5633
5634       while (isspace(*p)) p++;
5635       sub[0] = p;
5636
5637       len = Ustrlen(p);
5638       while (len > 0 && isspace(p[len-1])) len--;
5639       p[len] = 0;
5640       }
5641
5642       /* inspect the cert argument */
5643       while (isspace(*s)) s++;
5644       if (*s != '{')                                    /*}*/
5645         {
5646         expand_string_message = US"missing '{' for cert variable arg of certextract";
5647         goto EXPAND_FAILED_CURLY;
5648         }
5649       if (*++s != '$')
5650         {
5651         expand_string_message = US"second argument of \"certextract\" must "
5652           "be a certificate variable";
5653         goto EXPAND_FAILED;
5654         }
5655       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5656       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5657       if (*s++ != '}')
5658         {
5659         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5660         goto EXPAND_FAILED_CURLY;
5661         }
5662
5663       if (skipping)
5664         lookup_value = NULL;
5665       else
5666         {
5667         lookup_value = expand_getcertele(sub[0], sub[1]);
5668         if (*expand_string_message) goto EXPAND_FAILED;
5669         }
5670       switch(process_yesno(
5671                skipping,                     /* were previously skipping */
5672                lookup_value != NULL,         /* success/failure indicator */
5673                save_lookup_value,            /* value to reset for string2 */
5674                &s,                           /* input pointer */
5675                &yield,                       /* output pointer */
5676                &size,                        /* output size */
5677                &ptr,                         /* output current point */
5678                US"certextract",              /* condition type */
5679                &resetok))
5680         {
5681         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5682         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5683         }
5684
5685       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5686         save_expand_nlength);
5687       continue;
5688       }
5689 #endif  /*SUPPORT_TLS*/
5690
5691     /* Handle list operations */
5692
5693     case EITEM_FILTER:
5694     case EITEM_MAP:
5695     case EITEM_REDUCE:
5696       {
5697       int sep = 0;
5698       int save_ptr = ptr;
5699       uschar outsep[2] = { '\0', '\0' };
5700       const uschar *list, *expr, *temp;
5701       uschar *save_iterate_item = iterate_item;
5702       uschar *save_lookup_value = lookup_value;
5703
5704       while (isspace(*s)) s++;
5705       if (*s++ != '{')
5706         {
5707         expand_string_message =
5708           string_sprintf("missing '{' for first arg of %s", name);
5709         goto EXPAND_FAILED_CURLY;
5710         }
5711
5712       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5713       if (list == NULL) goto EXPAND_FAILED;
5714       if (*s++ != '}')
5715         {
5716         expand_string_message =
5717           string_sprintf("missing '}' closing first arg of %s", name);
5718         goto EXPAND_FAILED_CURLY;
5719         }
5720
5721       if (item_type == EITEM_REDUCE)
5722         {
5723         uschar * t;
5724         while (isspace(*s)) s++;
5725         if (*s++ != '{')
5726           {
5727           expand_string_message = US"missing '{' for second arg of reduce";
5728           goto EXPAND_FAILED_CURLY;
5729           }
5730         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5731         if (!t) goto EXPAND_FAILED;
5732         lookup_value = t;
5733         if (*s++ != '}')
5734           {
5735           expand_string_message = US"missing '}' closing second arg of reduce";
5736           goto EXPAND_FAILED_CURLY;
5737           }
5738         }
5739
5740       while (isspace(*s)) s++;
5741       if (*s++ != '{')
5742         {
5743         expand_string_message =
5744           string_sprintf("missing '{' for last arg of %s", name);
5745         goto EXPAND_FAILED_CURLY;
5746         }
5747
5748       expr = s;
5749
5750       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5751       if scanning a "false" part). This allows us to find the end of the
5752       condition, because if the list is empty, we won't actually evaluate the
5753       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5754       the normal internal expansion function. */
5755
5756       if (item_type == EITEM_FILTER)
5757         {
5758         temp = eval_condition(expr, &resetok, NULL);
5759         if (temp != NULL) s = temp;
5760         }
5761       else
5762         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5763
5764       if (temp == NULL)
5765         {
5766         expand_string_message = string_sprintf("%s inside \"%s\" item",
5767           expand_string_message, name);
5768         goto EXPAND_FAILED;
5769         }
5770
5771       while (isspace(*s)) s++;
5772       if (*s++ != '}')
5773         {                                               /*{*/
5774         expand_string_message = string_sprintf("missing } at end of condition "
5775           "or expression inside \"%s\"", name);
5776         goto EXPAND_FAILED;
5777         }
5778
5779       while (isspace(*s)) s++;                          /*{*/
5780       if (*s++ != '}')
5781         {                                               /*{*/
5782         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5783           name);
5784         goto EXPAND_FAILED;
5785         }
5786
5787       /* If we are skipping, we can now just move on to the next item. When
5788       processing for real, we perform the iteration. */
5789
5790       if (skipping) continue;
5791       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5792         {
5793         *outsep = (uschar)sep;      /* Separator as a string */
5794
5795         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5796
5797         if (item_type == EITEM_FILTER)
5798           {
5799           BOOL condresult;
5800           if (eval_condition(expr, &resetok, &condresult) == NULL)
5801             {
5802             iterate_item = save_iterate_item;
5803             lookup_value = save_lookup_value;
5804             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5805               expand_string_message, name);
5806             goto EXPAND_FAILED;
5807             }
5808           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5809             condresult? "true":"false");
5810           if (condresult)
5811             temp = iterate_item;    /* TRUE => include this item */
5812           else
5813             continue;               /* FALSE => skip this item */
5814           }
5815
5816         /* EITEM_MAP and EITEM_REDUCE */
5817
5818         else
5819           {
5820           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5821           temp = t;
5822           if (temp == NULL)
5823             {
5824             iterate_item = save_iterate_item;
5825             expand_string_message = string_sprintf("%s inside \"%s\" item",
5826               expand_string_message, name);
5827             goto EXPAND_FAILED;
5828             }
5829           if (item_type == EITEM_REDUCE)
5830             {
5831             lookup_value = t;         /* Update the value of $value */
5832             continue;                 /* and continue the iteration */
5833             }
5834           }
5835
5836         /* We reach here for FILTER if the condition is true, always for MAP,
5837         and never for REDUCE. The value in "temp" is to be added to the output
5838         list that is being created, ensuring that any occurrences of the
5839         separator character are doubled. Unless we are dealing with the first
5840         item of the output list, add in a space if the new item begins with the
5841         separator character, or is an empty string. */
5842
5843         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5844           yield = string_catn(yield, &size, &ptr, US" ", 1);
5845
5846         /* Add the string in "temp" to the output list that we are building,
5847         This is done in chunks by searching for the separator character. */
5848
5849         for (;;)
5850           {
5851           size_t seglen = Ustrcspn(temp, outsep);
5852
5853           yield = string_catn(yield, &size, &ptr, temp, seglen + 1);
5854
5855           /* If we got to the end of the string we output one character
5856           too many; backup and end the loop. Otherwise arrange to double the
5857           separator. */
5858
5859           if (temp[seglen] == '\0') { ptr--; break; }
5860           yield = string_catn(yield, &size, &ptr, outsep, 1);
5861           temp += seglen + 1;
5862           }
5863
5864         /* Output a separator after the string: we will remove the redundant
5865         final one at the end. */
5866
5867         yield = string_catn(yield, &size, &ptr, outsep, 1);
5868         }   /* End of iteration over the list loop */
5869
5870       /* REDUCE has generated no output above: output the final value of
5871       $value. */
5872
5873       if (item_type == EITEM_REDUCE)
5874         {
5875         yield = string_cat(yield, &size, &ptr, lookup_value);
5876         lookup_value = save_lookup_value;  /* Restore $value */
5877         }
5878
5879       /* FILTER and MAP generate lists: if they have generated anything, remove
5880       the redundant final separator. Even though an empty item at the end of a
5881       list does not count, this is tidier. */
5882
5883       else if (ptr != save_ptr) ptr--;
5884
5885       /* Restore preserved $item */
5886
5887       iterate_item = save_iterate_item;
5888       continue;
5889       }
5890
5891     case EITEM_SORT:
5892       {
5893       int sep = 0;
5894       const uschar *srclist, *cmp, *xtract;
5895       uschar *srcitem;
5896       const uschar *dstlist = NULL, *dstkeylist = NULL;
5897       uschar * tmp;
5898       uschar *save_iterate_item = iterate_item;
5899
5900       while (isspace(*s)) s++;
5901       if (*s++ != '{')
5902         {
5903         expand_string_message = US"missing '{' for list arg of sort";
5904         goto EXPAND_FAILED_CURLY;
5905         }
5906
5907       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5908       if (!srclist) goto EXPAND_FAILED;
5909       if (*s++ != '}')
5910         {
5911         expand_string_message = US"missing '}' closing list arg of sort";
5912         goto EXPAND_FAILED_CURLY;
5913         }
5914
5915       while (isspace(*s)) s++;
5916       if (*s++ != '{')
5917         {
5918         expand_string_message = US"missing '{' for comparator arg of sort";
5919         goto EXPAND_FAILED_CURLY;
5920         }
5921
5922       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5923       if (!cmp) goto EXPAND_FAILED;
5924       if (*s++ != '}')
5925         {
5926         expand_string_message = US"missing '}' closing comparator arg of sort";
5927         goto EXPAND_FAILED_CURLY;
5928         }
5929
5930       while (isspace(*s)) s++;
5931       if (*s++ != '{')
5932         {
5933         expand_string_message = US"missing '{' for extractor arg of sort";
5934         goto EXPAND_FAILED_CURLY;
5935         }
5936
5937       xtract = s;
5938       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5939       if (!tmp) goto EXPAND_FAILED;
5940       xtract = string_copyn(xtract, s - xtract);
5941
5942       if (*s++ != '}')
5943         {
5944         expand_string_message = US"missing '}' closing extractor arg of sort";
5945         goto EXPAND_FAILED_CURLY;
5946         }
5947                                                         /*{*/
5948       if (*s++ != '}')
5949         {                                               /*{*/
5950         expand_string_message = US"missing } at end of \"sort\"";
5951         goto EXPAND_FAILED;
5952         }
5953
5954       if (skipping) continue;
5955
5956       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5957         {
5958         uschar * dstitem;
5959         uschar * newlist = NULL;
5960         uschar * newkeylist = NULL;
5961         uschar * srcfield;
5962
5963         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
5964
5965         /* extract field for comparisons */
5966         iterate_item = srcitem;
5967         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5968                                           TRUE, &resetok))
5969            || !*srcfield)
5970           {
5971           expand_string_message = string_sprintf(
5972               "field-extract in sort: \"%s\"", xtract);
5973           goto EXPAND_FAILED;
5974           }
5975
5976         /* Insertion sort */
5977
5978         /* copy output list until new-item < list-item */
5979         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5980           {
5981           uschar * dstfield;
5982           uschar * expr;
5983           BOOL before;
5984
5985           /* field for comparison */
5986           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5987             goto sort_mismatch;
5988
5989           /* build and run condition string */
5990           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
5991
5992           DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
5993           if (!eval_condition(expr, &resetok, &before))
5994             {
5995             expand_string_message = string_sprintf("comparison in sort: %s",
5996                 expr);
5997             goto EXPAND_FAILED;
5998             }
5999
6000           if (before)
6001             {
6002             /* New-item sorts before this dst-item.  Append new-item,
6003             then dst-item, then remainder of dst list. */
6004
6005             newlist = string_append_listele(newlist, sep, srcitem);
6006             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6007             srcitem = NULL;
6008
6009             newlist = string_append_listele(newlist, sep, dstitem);
6010             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6011
6012             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6013               {
6014               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6015                 goto sort_mismatch;
6016               newlist = string_append_listele(newlist, sep, dstitem);
6017               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6018               }
6019
6020             break;
6021             }
6022
6023           newlist = string_append_listele(newlist, sep, dstitem);
6024           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6025           }
6026
6027         /* If we ran out of dstlist without consuming srcitem, append it */
6028         if (srcitem)
6029           {
6030           newlist = string_append_listele(newlist, sep, srcitem);
6031           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6032           }
6033
6034         dstlist = newlist;
6035         dstkeylist = newkeylist;
6036
6037         DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
6038         DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6039         }
6040
6041       if (dstlist)
6042         yield = string_cat(yield, &size, &ptr, dstlist);
6043
6044       /* Restore preserved $item */
6045       iterate_item = save_iterate_item;
6046       continue;
6047
6048       sort_mismatch:
6049         expand_string_message = US"Internal error in sort (list mismatch)";
6050         goto EXPAND_FAILED;
6051       }
6052
6053
6054     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6055     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6056     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6057     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6058
6059     #define EXPAND_DLFUNC_MAX_ARGS 8
6060
6061     case EITEM_DLFUNC:
6062 #ifndef EXPAND_DLFUNC
6063       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6064         "is not included in this binary";
6065       goto EXPAND_FAILED;
6066
6067 #else   /* EXPAND_DLFUNC */
6068       {
6069       tree_node *t;
6070       exim_dlfunc_t *func;
6071       uschar *result;
6072       int status, argc;
6073       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6074
6075       if ((expand_forbid & RDO_DLFUNC) != 0)
6076         {
6077         expand_string_message =
6078           US"dynamically-loaded functions are not permitted";
6079         goto EXPAND_FAILED;
6080         }
6081
6082       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6083            TRUE, US"dlfunc", &resetok))
6084         {
6085         case 1: goto EXPAND_FAILED_CURLY;
6086         case 2:
6087         case 3: goto EXPAND_FAILED;
6088         }
6089
6090       /* If skipping, we don't actually do anything */
6091
6092       if (skipping) continue;
6093
6094       /* Look up the dynamically loaded object handle in the tree. If it isn't
6095       found, dlopen() the file and put the handle in the tree for next time. */
6096
6097       t = tree_search(dlobj_anchor, argv[0]);
6098       if (t == NULL)
6099         {
6100         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6101         if (handle == NULL)
6102           {
6103           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6104             argv[0], dlerror());
6105           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6106           goto EXPAND_FAILED;
6107           }
6108         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6109         Ustrcpy(t->name, argv[0]);
6110         t->data.ptr = handle;
6111         (void)tree_insertnode(&dlobj_anchor, t);
6112         }
6113
6114       /* Having obtained the dynamically loaded object handle, look up the
6115       function pointer. */
6116
6117       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6118       if (func == NULL)
6119         {
6120         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6121           "%s", argv[1], argv[0], dlerror());
6122         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6123         goto EXPAND_FAILED;
6124         }
6125
6126       /* Call the function and work out what to do with the result. If it
6127       returns OK, we have a replacement string; if it returns DEFER then
6128       expansion has failed in a non-forced manner; if it returns FAIL then
6129       failure was forced; if it returns ERROR or any other value there's a
6130       problem, so panic slightly. In any case, assume that the function has
6131       side-effects on the store that must be preserved. */
6132
6133       resetok = FALSE;
6134       result = NULL;
6135       for (argc = 0; argv[argc] != NULL; argc++);
6136       status = func(&result, argc - 2, &argv[2]);
6137       if(status == OK)
6138         {
6139         if (result == NULL) result = US"";
6140         yield = string_cat(yield, &size, &ptr, result);
6141         continue;
6142         }
6143       else
6144         {
6145         expand_string_message = result == NULL ? US"(no message)" : result;
6146         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6147           else if(status != FAIL)
6148             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6149               argv[0], argv[1], status, expand_string_message);
6150         goto EXPAND_FAILED;
6151         }
6152       }
6153 #endif /* EXPAND_DLFUNC */
6154
6155     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6156       {
6157       uschar * key;
6158       uschar *save_lookup_value = lookup_value;
6159
6160       while (isspace(*s)) s++;
6161       if (*s != '{')                                    /*}*/
6162         goto EXPAND_FAILED;
6163
6164       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6165       if (!key) goto EXPAND_FAILED;                     /*{*/
6166       if (*s++ != '}')
6167         {
6168         expand_string_message = US"missing '{' for name arg of env";
6169         goto EXPAND_FAILED_CURLY;
6170         }
6171
6172       lookup_value = US getenv(CS key);
6173
6174       switch(process_yesno(
6175                skipping,                     /* were previously skipping */
6176                lookup_value != NULL,         /* success/failure indicator */
6177                save_lookup_value,            /* value to reset for string2 */
6178                &s,                           /* input pointer */
6179                &yield,                       /* output pointer */
6180                &size,                        /* output size */
6181                &ptr,                         /* output current point */
6182                US"env",                      /* condition type */
6183                &resetok))
6184         {
6185         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6186         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6187         }
6188       continue;
6189       }
6190     }   /* EITEM_* switch */
6191
6192   /* Control reaches here if the name is not recognized as one of the more
6193   complicated expansion items. Check for the "operator" syntax (name terminated
6194   by a colon). Some of the operators have arguments, separated by _ from the
6195   name. */
6196
6197   if (*s == ':')
6198     {
6199     int c;
6200     uschar *arg = NULL;
6201     uschar *sub;
6202     var_entry *vp = NULL;
6203
6204     /* Owing to an historical mis-design, an underscore may be part of the
6205     operator name, or it may introduce arguments.  We therefore first scan the
6206     table of names that contain underscores. If there is no match, we cut off
6207     the arguments and then scan the main table. */
6208
6209     if ((c = chop_match(name, op_table_underscore,
6210                         nelem(op_table_underscore))) < 0)
6211       {
6212       arg = Ustrchr(name, '_');
6213       if (arg != NULL) *arg = 0;
6214       c = chop_match(name, op_table_main, nelem(op_table_main));
6215       if (c >= 0) c += nelem(op_table_underscore);
6216       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6217       }
6218
6219     /* Deal specially with operators that might take a certificate variable
6220     as we do not want to do the usual expansion. For most, expand the string.*/
6221     switch(c)
6222       {
6223 #ifdef SUPPORT_TLS
6224       case EOP_MD5:
6225       case EOP_SHA1:
6226       case EOP_SHA256:
6227       case EOP_BASE64:
6228         if (s[1] == '$')
6229           {
6230           const uschar * s1 = s;
6231           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6232                   FALSE, &resetok);
6233           if (!sub)       goto EXPAND_FAILED;           /*{*/
6234           if (*s1 != '}')
6235             {
6236             expand_string_message =
6237               string_sprintf("missing '}' closing cert arg of %s", name);
6238             goto EXPAND_FAILED_CURLY;
6239             }
6240           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6241             {
6242             s = s1+1;
6243             break;
6244             }
6245           vp = NULL;
6246           }
6247         /*FALLTHROUGH*/
6248 #endif
6249       default:
6250         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6251         if (!sub) goto EXPAND_FAILED;
6252         s++;
6253         break;
6254       }
6255
6256     /* If we are skipping, we don't need to perform the operation at all.
6257     This matters for operations like "mask", because the data may not be
6258     in the correct format when skipping. For example, the expression may test
6259     for the existence of $sender_host_address before trying to mask it. For
6260     other operations, doing them may not fail, but it is a waste of time. */
6261
6262     if (skipping && c >= 0) continue;
6263
6264     /* Otherwise, switch on the operator type */
6265
6266     switch(c)
6267       {
6268       case EOP_BASE32:
6269         {
6270         uschar *t;
6271         unsigned long int n = Ustrtoul(sub, &t, 10);
6272         uschar * s = NULL;
6273         int sz = 0, i = 0;
6274
6275         if (*t != 0)
6276           {
6277           expand_string_message = string_sprintf("argument for base32 "
6278             "operator is \"%s\", which is not a decimal number", sub);
6279           goto EXPAND_FAILED;
6280           }
6281         for ( ; n; n >>= 5)
6282           s = string_catn(s, &sz, &i, &base32_chars[n & 0x1f], 1);
6283
6284         while (i > 0) yield = string_catn(yield, &size, &ptr, &s[--i], 1);
6285         continue;
6286         }
6287
6288       case EOP_BASE32D:
6289         {
6290         uschar *tt = sub;
6291         unsigned long int n = 0;
6292         uschar * s;
6293         while (*tt)
6294           {
6295           uschar * t = Ustrchr(base32_chars, *tt++);
6296           if (t == NULL)
6297             {
6298             expand_string_message = string_sprintf("argument for base32d "
6299               "operator is \"%s\", which is not a base 32 number", sub);
6300             goto EXPAND_FAILED;
6301             }
6302           n = n * 32 + (t - base32_chars);
6303           }
6304         s = string_sprintf("%ld", n);
6305         yield = string_cat(yield, &size, &ptr, s);
6306         continue;
6307         }
6308
6309       case EOP_BASE62:
6310         {
6311         uschar *t;
6312         unsigned long int n = Ustrtoul(sub, &t, 10);
6313         if (*t != 0)
6314           {
6315           expand_string_message = string_sprintf("argument for base62 "
6316             "operator is \"%s\", which is not a decimal number", sub);
6317           goto EXPAND_FAILED;
6318           }
6319         t = string_base62(n);
6320         yield = string_cat(yield, &size, &ptr, t);
6321         continue;
6322         }
6323
6324       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6325
6326       case EOP_BASE62D:
6327         {
6328         uschar buf[16];
6329         uschar *tt = sub;
6330         unsigned long int n = 0;
6331         while (*tt != 0)
6332           {
6333           uschar *t = Ustrchr(base62_chars, *tt++);
6334           if (t == NULL)
6335             {
6336             expand_string_message = string_sprintf("argument for base62d "
6337               "operator is \"%s\", which is not a base %d number", sub,
6338               BASE_62);
6339             goto EXPAND_FAILED;
6340             }
6341           n = n * BASE_62 + (t - base62_chars);
6342           }
6343         (void)sprintf(CS buf, "%ld", n);
6344         yield = string_cat(yield, &size, &ptr, buf);
6345         continue;
6346         }
6347
6348       case EOP_EXPAND:
6349         {
6350         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6351         if (expanded == NULL)
6352           {
6353           expand_string_message =
6354             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6355               expand_string_message);
6356           goto EXPAND_FAILED;
6357           }
6358         yield = string_cat(yield, &size, &ptr, expanded);
6359         continue;
6360         }
6361
6362       case EOP_LC:
6363         {
6364         int count = 0;
6365         uschar *t = sub - 1;
6366         while (*(++t) != 0) { *t = tolower(*t); count++; }
6367         yield = string_catn(yield, &size, &ptr, sub, count);
6368         continue;
6369         }
6370
6371       case EOP_UC:
6372         {
6373         int count = 0;
6374         uschar *t = sub - 1;
6375         while (*(++t) != 0) { *t = toupper(*t); count++; }
6376         yield = string_catn(yield, &size, &ptr, sub, count);
6377         continue;
6378         }
6379
6380       case EOP_MD5:
6381 #ifdef SUPPORT_TLS
6382         if (vp && *(void **)vp->value)
6383           {
6384           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6385           yield = string_cat(yield, &size, &ptr, cp);
6386           }
6387         else
6388 #endif
6389           {
6390           md5 base;
6391           uschar digest[16];
6392           int j;
6393           char st[33];
6394           md5_start(&base);
6395           md5_end(&base, sub, Ustrlen(sub), digest);
6396           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6397           yield = string_cat(yield, &size, &ptr, US st);
6398           }
6399         continue;
6400
6401       case EOP_SHA1:
6402 #ifdef SUPPORT_TLS
6403         if (vp && *(void **)vp->value)
6404           {
6405           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6406           yield = string_cat(yield, &size, &ptr, cp);
6407           }
6408         else
6409 #endif
6410           {
6411           hctx h;
6412           uschar digest[20];
6413           int j;
6414           char st[41];
6415           sha1_start(&h);
6416           sha1_end(&h, sub, Ustrlen(sub), digest);
6417           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6418           yield = string_catn(yield, &size, &ptr, US st, 40);
6419           }
6420         continue;
6421
6422       case EOP_SHA256:
6423 #ifdef EXIM_HAVE_SHA2
6424         if (vp && *(void **)vp->value)
6425           {
6426           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6427           yield = string_cat(yield, &size, &ptr, cp);
6428           }
6429         else
6430           {
6431           hctx h;
6432           blob b;
6433           char st[3];
6434
6435           exim_sha_init(&h, HASH_SHA256);
6436           exim_sha_update(&h, sub, Ustrlen(sub));
6437           exim_sha_finish(&h, &b);
6438           while (b.len-- > 0)
6439             {
6440             sprintf(st, "%02X", *b.data++);
6441             yield = string_catn(yield, &size, &ptr, US st, 2);
6442             }
6443           }
6444 #else
6445           expand_string_message = US"sha256 only supported with TLS";
6446 #endif
6447         continue;
6448
6449       case EOP_SHA3:
6450 #ifdef EXIM_HAVE_SHA3
6451         {
6452         hctx h;
6453         blob b;
6454         char st[3];
6455         hashmethod m = !arg ? HASH_SHA3_256
6456           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6457           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6458           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6459           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6460           : HASH_BADTYPE;
6461
6462         if (m == HASH_BADTYPE)
6463           {
6464           expand_string_message = US"unrecognised sha3 variant";
6465           goto EXPAND_FAILED;
6466           }
6467
6468         exim_sha_init(&h, m);
6469         exim_sha_update(&h, sub, Ustrlen(sub));
6470         exim_sha_finish(&h, &b);
6471         while (b.len-- > 0)
6472           {
6473           sprintf(st, "%02X", *b.data++);
6474           yield = string_catn(yield, &size, &ptr, US st, 2);
6475           }
6476         }
6477         continue;
6478 #else
6479         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6480         goto EXPAND_FAILED;
6481 #endif
6482
6483       /* Convert hex encoding to base64 encoding */
6484
6485       case EOP_HEX2B64:
6486         {
6487         int c = 0;
6488         int b = -1;
6489         uschar *in = sub;
6490         uschar *out = sub;
6491         uschar *enc;
6492
6493         for (enc = sub; *enc != 0; enc++)
6494           {
6495           if (!isxdigit(*enc))
6496             {
6497             expand_string_message = string_sprintf("\"%s\" is not a hex "
6498               "string", sub);
6499             goto EXPAND_FAILED;
6500             }
6501           c++;
6502           }
6503
6504         if ((c & 1) != 0)
6505           {
6506           expand_string_message = string_sprintf("\"%s\" contains an odd "
6507             "number of characters", sub);
6508           goto EXPAND_FAILED;
6509           }
6510
6511         while ((c = *in++) != 0)
6512           {
6513           if (isdigit(c)) c -= '0';
6514           else c = toupper(c) - 'A' + 10;
6515           if (b == -1)
6516             {
6517             b = c << 4;
6518             }
6519           else
6520             {
6521             *out++ = b | c;
6522             b = -1;
6523             }
6524           }
6525
6526         enc = b64encode(sub, out - sub);
6527         yield = string_cat(yield, &size, &ptr, enc);
6528         continue;
6529         }
6530
6531       /* Convert octets outside 0x21..0x7E to \xXX form */
6532
6533       case EOP_HEXQUOTE:
6534         {
6535         uschar *t = sub - 1;
6536         while (*(++t) != 0)
6537           {
6538           if (*t < 0x21 || 0x7E < *t)
6539             yield = string_catn(yield, &size, &ptr,
6540               string_sprintf("\\x%02x", *t), 4);
6541           else
6542             yield = string_catn(yield, &size, &ptr, t, 1);
6543           }
6544         continue;
6545         }
6546
6547       /* count the number of list elements */
6548
6549       case EOP_LISTCOUNT:
6550         {
6551         int cnt = 0;
6552         int sep = 0;
6553         uschar * cp;
6554         uschar buffer[256];
6555
6556         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6557         cp = string_sprintf("%d", cnt);
6558         yield = string_cat(yield, &size, &ptr, cp);
6559         continue;
6560         }
6561
6562       /* expand a named list given the name */
6563       /* handles nested named lists; requotes as colon-sep list */
6564
6565       case EOP_LISTNAMED:
6566         {
6567         tree_node *t = NULL;
6568         const uschar * list;
6569         int sep = 0;
6570         uschar * item;
6571         uschar * suffix = US"";
6572         BOOL needsep = FALSE;
6573         uschar buffer[256];
6574
6575         if (*sub == '+') sub++;
6576         if (arg == NULL)        /* no-argument version */
6577           {
6578           if (!(t = tree_search(addresslist_anchor, sub)) &&
6579               !(t = tree_search(domainlist_anchor,  sub)) &&
6580               !(t = tree_search(hostlist_anchor,    sub)))
6581             t = tree_search(localpartlist_anchor, sub);
6582           }
6583         else switch(*arg)       /* specific list-type version */
6584           {
6585           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6586           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6587           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6588           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6589           default:
6590             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6591             goto EXPAND_FAILED;
6592           }
6593
6594         if(!t)
6595           {
6596           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6597             sub, !arg?""
6598               : *arg=='a'?"address "
6599               : *arg=='d'?"domain "
6600               : *arg=='h'?"host "
6601               : *arg=='l'?"localpart "
6602               : 0);
6603           goto EXPAND_FAILED;
6604           }
6605
6606         list = ((namedlist_block *)(t->data.ptr))->string;
6607
6608         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6609           {
6610           uschar * buf = US" : ";
6611           if (needsep)
6612             yield = string_catn(yield, &size, &ptr, buf, 3);
6613           else
6614             needsep = TRUE;
6615
6616           if (*item == '+')     /* list item is itself a named list */
6617             {
6618             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6619             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6620             }
6621           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6622             {
6623             char * cp;
6624             char tok[3];
6625             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6626             while ((cp= strpbrk((const char *)item, tok)))
6627               {
6628               yield = string_catn(yield, &size, &ptr, item, cp-(char *)item);
6629               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6630                 {
6631                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6632                 item = (uschar *)cp;
6633                 }
6634               else              /* sep in item; should already be doubled; emit once */
6635                 {
6636                 yield = string_catn(yield, &size, &ptr, (uschar *)tok, 1);
6637                 if (*cp == sep) cp++;
6638                 item = (uschar *)cp;
6639                 }
6640               }
6641             }
6642           yield = string_cat(yield, &size, &ptr, item);
6643           }
6644         continue;
6645         }
6646
6647       /* mask applies a mask to an IP address; for example the result of
6648       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6649
6650       case EOP_MASK:
6651         {
6652         int count;
6653         uschar *endptr;
6654         int binary[4];
6655         int mask, maskoffset;
6656         int type = string_is_ip_address(sub, &maskoffset);
6657         uschar buffer[64];
6658
6659         if (type == 0)
6660           {
6661           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6662            sub);
6663           goto EXPAND_FAILED;
6664           }
6665
6666         if (maskoffset == 0)
6667           {
6668           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6669             sub);
6670           goto EXPAND_FAILED;
6671           }
6672
6673         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6674
6675         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6676           {
6677           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6678             sub);
6679           goto EXPAND_FAILED;
6680           }
6681
6682         /* Convert the address to binary integer(s) and apply the mask */
6683
6684         sub[maskoffset] = 0;
6685         count = host_aton(sub, binary);
6686         host_mask(count, binary, mask);
6687
6688         /* Convert to masked textual format and add to output. */
6689
6690         yield = string_catn(yield, &size, &ptr, buffer,
6691           host_nmtoa(count, binary, mask, buffer, '.'));
6692         continue;
6693         }
6694
6695       case EOP_IPV6NORM:
6696       case EOP_IPV6DENORM:
6697         {
6698         int type = string_is_ip_address(sub, NULL);
6699         int binary[4];
6700         uschar buffer[44];
6701
6702         switch (type)
6703           {
6704           case 6:
6705             (void) host_aton(sub, binary);
6706             break;
6707
6708           case 4:       /* convert to IPv4-mapped IPv6 */
6709             binary[0] = binary[1] = 0;
6710             binary[2] = 0x0000ffff;
6711             (void) host_aton(sub, binary+3);
6712             break;
6713
6714           case 0:
6715             expand_string_message =
6716               string_sprintf("\"%s\" is not an IP address", sub);
6717             goto EXPAND_FAILED;
6718           }
6719
6720         yield = string_catn(yield, &size, &ptr, buffer,
6721                   c == EOP_IPV6NORM
6722                     ? ipv6_nmtoa(binary, buffer)
6723                     : host_nmtoa(4, binary, -1, buffer, ':')
6724                   );
6725         continue;
6726         }
6727
6728       case EOP_ADDRESS:
6729       case EOP_LOCAL_PART:
6730       case EOP_DOMAIN:
6731         {
6732         uschar *error;
6733         int start, end, domain;
6734         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6735           FALSE);
6736         if (t != NULL)
6737           {
6738           if (c != EOP_DOMAIN)
6739             {
6740             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6741             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6742             }
6743           else if (domain != 0)
6744             {
6745             domain += start;
6746             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6747             }
6748           }
6749         continue;
6750         }
6751
6752       case EOP_ADDRESSES:
6753         {
6754         uschar outsep[2] = { ':', '\0' };
6755         uschar *address, *error;
6756         int save_ptr = ptr;
6757         int start, end, domain;  /* Not really used */
6758
6759         while (isspace(*sub)) sub++;
6760         if (*sub == '>') { *outsep = *++sub; ++sub; }
6761         parse_allow_group = TRUE;
6762
6763         for (;;)
6764           {
6765           uschar *p = parse_find_address_end(sub, FALSE);
6766           uschar saveend = *p;
6767           *p = '\0';
6768           address = parse_extract_address(sub, &error, &start, &end, &domain,
6769             FALSE);
6770           *p = saveend;
6771
6772           /* Add the address to the output list that we are building. This is
6773           done in chunks by searching for the separator character. At the
6774           start, unless we are dealing with the first address of the output
6775           list, add in a space if the new address begins with the separator
6776           character, or is an empty string. */
6777
6778           if (address != NULL)
6779             {
6780             if (ptr != save_ptr && address[0] == *outsep)
6781               yield = string_catn(yield, &size, &ptr, US" ", 1);
6782
6783             for (;;)
6784               {
6785               size_t seglen = Ustrcspn(address, outsep);
6786               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6787
6788               /* If we got to the end of the string we output one character
6789               too many. */
6790
6791               if (address[seglen] == '\0') { ptr--; break; }
6792               yield = string_catn(yield, &size, &ptr, outsep, 1);
6793               address += seglen + 1;
6794               }
6795
6796             /* Output a separator after the string: we will remove the
6797             redundant final one at the end. */
6798
6799             yield = string_catn(yield, &size, &ptr, outsep, 1);
6800             }
6801
6802           if (saveend == '\0') break;
6803           sub = p + 1;
6804           }
6805
6806         /* If we have generated anything, remove the redundant final
6807         separator. */
6808
6809         if (ptr != save_ptr) ptr--;
6810         parse_allow_group = FALSE;
6811         continue;
6812         }
6813
6814
6815       /* quote puts a string in quotes if it is empty or contains anything
6816       other than alphamerics, underscore, dot, or hyphen.
6817
6818       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6819       be quoted in order to be a valid local part.
6820
6821       In both cases, newlines and carriage returns are converted into \n and \r
6822       respectively */
6823
6824       case EOP_QUOTE:
6825       case EOP_QUOTE_LOCAL_PART:
6826       if (arg == NULL)
6827         {
6828         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6829         uschar *t = sub - 1;
6830
6831         if (c == EOP_QUOTE)
6832           {
6833           while (!needs_quote && *(++t) != 0)
6834             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6835           }
6836         else  /* EOP_QUOTE_LOCAL_PART */
6837           {
6838           while (!needs_quote && *(++t) != 0)
6839             needs_quote = !isalnum(*t) &&
6840               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6841               (*t != '.' || t == sub || t[1] == 0);
6842           }
6843
6844         if (needs_quote)
6845           {
6846           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6847           t = sub - 1;
6848           while (*(++t) != 0)
6849             {
6850             if (*t == '\n')
6851               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6852             else if (*t == '\r')
6853               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6854             else
6855               {
6856               if (*t == '\\' || *t == '"')
6857                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6858               yield = string_catn(yield, &size, &ptr, t, 1);
6859               }
6860             }
6861           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6862           }
6863         else yield = string_cat(yield, &size, &ptr, sub);
6864         continue;
6865         }
6866
6867       /* quote_lookuptype does lookup-specific quoting */
6868
6869       else
6870         {
6871         int n;
6872         uschar *opt = Ustrchr(arg, '_');
6873
6874         if (opt != NULL) *opt++ = 0;
6875
6876         n = search_findtype(arg, Ustrlen(arg));
6877         if (n < 0)
6878           {
6879           expand_string_message = search_error_message;
6880           goto EXPAND_FAILED;
6881           }
6882
6883         if (lookup_list[n]->quote != NULL)
6884           sub = (lookup_list[n]->quote)(sub, opt);
6885         else if (opt != NULL) sub = NULL;
6886
6887         if (sub == NULL)
6888           {
6889           expand_string_message = string_sprintf(
6890             "\"%s\" unrecognized after \"${quote_%s\"",
6891             opt, arg);
6892           goto EXPAND_FAILED;
6893           }
6894
6895         yield = string_cat(yield, &size, &ptr, sub);
6896         continue;
6897         }
6898
6899       /* rx quote sticks in \ before any non-alphameric character so that
6900       the insertion works in a regular expression. */
6901
6902       case EOP_RXQUOTE:
6903         {
6904         uschar *t = sub - 1;
6905         while (*(++t) != 0)
6906           {
6907           if (!isalnum(*t))
6908             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6909           yield = string_catn(yield, &size, &ptr, t, 1);
6910           }
6911         continue;
6912         }
6913
6914       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6915       prescribed by the RFC, if there are characters that need to be encoded */
6916
6917       case EOP_RFC2047:
6918         {
6919         uschar buffer[2048];
6920         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6921           buffer, sizeof(buffer), FALSE);
6922         yield = string_cat(yield, &size, &ptr, string);
6923         continue;
6924         }
6925
6926       /* RFC 2047 decode */
6927
6928       case EOP_RFC2047D:
6929         {
6930         int len;
6931         uschar *error;
6932         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6933           headers_charset, '?', &len, &error);
6934         if (error != NULL)
6935           {
6936           expand_string_message = error;
6937           goto EXPAND_FAILED;
6938           }
6939         yield = string_catn(yield, &size, &ptr, decoded, len);
6940         continue;
6941         }
6942
6943       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6944       underscores */
6945
6946       case EOP_FROM_UTF8:
6947         {
6948         while (*sub != 0)
6949           {
6950           int c;
6951           uschar buff[4];
6952           GETUTF8INC(c, sub);
6953           if (c > 255) c = '_';
6954           buff[0] = c;
6955           yield = string_catn(yield, &size, &ptr, buff, 1);
6956           }
6957         continue;
6958         }
6959
6960           /* replace illegal UTF-8 sequences by replacement character  */
6961
6962       #define UTF8_REPLACEMENT_CHAR US"?"
6963
6964       case EOP_UTF8CLEAN:
6965         {
6966         int seq_len = 0, index = 0;
6967         int bytes_left = 0;
6968         long codepoint = -1;
6969         uschar seq_buff[4];                     /* accumulate utf-8 here */
6970
6971         while (*sub != 0)
6972           {
6973           int complete = 0;
6974           uschar c = *sub++;
6975
6976           if (bytes_left)
6977             {
6978             if ((c & 0xc0) != 0x80)
6979                     /* wrong continuation byte; invalidate all bytes */
6980               complete = 1; /* error */
6981             else
6982               {
6983               codepoint = (codepoint << 6) | (c & 0x3f);
6984               seq_buff[index++] = c;
6985               if (--bytes_left == 0)            /* codepoint complete */
6986                 if(codepoint > 0x10FFFF)        /* is it too large? */
6987                   complete = -1;        /* error (RFC3629 limit) */
6988                 else
6989                   {             /* finished; output utf-8 sequence */
6990                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
6991                   index = 0;
6992                   }
6993               }
6994             }
6995           else  /* no bytes left: new sequence */
6996             {
6997             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6998               {
6999               yield = string_catn(yield, &size, &ptr, &c, 1);
7000               continue;
7001               }
7002             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7003               {
7004               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7005                 complete = -1;
7006               else
7007                 {
7008                   bytes_left = 1;
7009                   codepoint = c & 0x1f;
7010                 }
7011               }
7012             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7013               {
7014               bytes_left = 2;
7015               codepoint = c & 0x0f;
7016               }
7017             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7018               {
7019               bytes_left = 3;
7020               codepoint = c & 0x07;
7021               }
7022             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7023               complete = -1;
7024
7025             seq_buff[index++] = c;
7026             seq_len = bytes_left + 1;
7027             }           /* if(bytes_left) */
7028
7029           if (complete != 0)
7030             {
7031             bytes_left = index = 0;
7032             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
7033             }
7034           if ((complete == 1) && ((c & 0x80) == 0))
7035                         /* ASCII character follows incomplete sequence */
7036               yield = string_catn(yield, &size, &ptr, &c, 1);
7037           }
7038         continue;
7039         }
7040
7041 #ifdef SUPPORT_I18N
7042       case EOP_UTF8_DOMAIN_TO_ALABEL:
7043         {
7044         uschar * error = NULL;
7045         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7046         if (error)
7047           {
7048           expand_string_message = string_sprintf(
7049             "error converting utf8 (%s) to alabel: %s",
7050             string_printing(sub), error);
7051           goto EXPAND_FAILED;
7052           }
7053         yield = string_cat(yield, &size, &ptr, s);
7054         continue;
7055         }
7056
7057       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7058         {
7059         uschar * error = NULL;
7060         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7061         if (error)
7062           {
7063           expand_string_message = string_sprintf(
7064             "error converting alabel (%s) to utf8: %s",
7065             string_printing(sub), error);
7066           goto EXPAND_FAILED;
7067           }
7068         yield = string_cat(yield, &size, &ptr, s);
7069         continue;
7070         }
7071
7072       case EOP_UTF8_LOCALPART_TO_ALABEL:
7073         {
7074         uschar * error = NULL;
7075         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7076         if (error)
7077           {
7078           expand_string_message = string_sprintf(
7079             "error converting utf8 (%s) to alabel: %s",
7080             string_printing(sub), error);
7081           goto EXPAND_FAILED;
7082           }
7083         yield = string_cat(yield, &size, &ptr, s);
7084         DEBUG(D_expand) debug_printf("yield: '%s'\n", yield);
7085         continue;
7086         }
7087
7088       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7089         {
7090         uschar * error = NULL;
7091         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7092         if (error)
7093           {
7094           expand_string_message = string_sprintf(
7095             "error converting alabel (%s) to utf8: %s",
7096             string_printing(sub), error);
7097           goto EXPAND_FAILED;
7098           }
7099         yield = string_cat(yield, &size, &ptr, s);
7100         continue;
7101         }
7102 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7103
7104       /* escape turns all non-printing characters into escape sequences. */
7105
7106       case EOP_ESCAPE:
7107         {
7108         const uschar *t = string_printing(sub);
7109         yield = string_cat(yield, &size, &ptr, t);
7110         continue;
7111         }
7112
7113       /* Handle numeric expression evaluation */
7114
7115       case EOP_EVAL:
7116       case EOP_EVAL10:
7117         {
7118         uschar *save_sub = sub;
7119         uschar *error = NULL;
7120         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7121         if (error != NULL)
7122           {
7123           expand_string_message = string_sprintf("error in expression "
7124             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7125               save_sub);
7126           goto EXPAND_FAILED;
7127           }
7128         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7129         yield = string_cat(yield, &size, &ptr, var_buffer);
7130         continue;
7131         }
7132
7133       /* Handle time period formating */
7134
7135       case EOP_TIME_EVAL:
7136         {
7137         int n = readconf_readtime(sub, 0, FALSE);
7138         if (n < 0)
7139           {
7140           expand_string_message = string_sprintf("string \"%s\" is not an "
7141             "Exim time interval in \"%s\" operator", sub, name);
7142           goto EXPAND_FAILED;
7143           }
7144         sprintf(CS var_buffer, "%d", n);
7145         yield = string_cat(yield, &size, &ptr, var_buffer);
7146         continue;
7147         }
7148
7149       case EOP_TIME_INTERVAL:
7150         {
7151         int n;
7152         uschar *t = read_number(&n, sub);
7153         if (*t != 0) /* Not A Number*/
7154           {
7155           expand_string_message = string_sprintf("string \"%s\" is not a "
7156             "positive number in \"%s\" operator", sub, name);
7157           goto EXPAND_FAILED;
7158           }
7159         t = readconf_printtime(n);
7160         yield = string_cat(yield, &size, &ptr, t);
7161         continue;
7162         }
7163
7164       /* Convert string to base64 encoding */
7165
7166       case EOP_STR2B64:
7167       case EOP_BASE64:
7168         {
7169 #ifdef SUPPORT_TLS
7170         uschar * s = vp && *(void **)vp->value
7171           ? tls_cert_der_b64(*(void **)vp->value)
7172           : b64encode(sub, Ustrlen(sub));
7173 #else
7174         uschar * s = b64encode(sub, Ustrlen(sub));
7175 #endif
7176         yield = string_cat(yield, &size, &ptr, s);
7177         continue;
7178         }
7179
7180       case EOP_BASE64D:
7181         {
7182         uschar * s;
7183         int len = b64decode(sub, &s);
7184         if (len < 0)
7185           {
7186           expand_string_message = string_sprintf("string \"%s\" is not "
7187             "well-formed for \"%s\" operator", sub, name);
7188           goto EXPAND_FAILED;
7189           }
7190         yield = string_cat(yield, &size, &ptr, s);
7191         continue;
7192         }
7193
7194       /* strlen returns the length of the string */
7195
7196       case EOP_STRLEN:
7197         {
7198         uschar buff[24];
7199         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7200         yield = string_cat(yield, &size, &ptr, buff);
7201         continue;
7202         }
7203
7204       /* length_n or l_n takes just the first n characters or the whole string,
7205       whichever is the shorter;
7206
7207       substr_m_n, and s_m_n take n characters from offset m; negative m take
7208       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7209       takes the rest, either to the right or to the left.
7210
7211       hash_n or h_n makes a hash of length n from the string, yielding n
7212       characters from the set a-z; hash_n_m makes a hash of length n, but
7213       uses m characters from the set a-zA-Z0-9.
7214
7215       nhash_n returns a single number between 0 and n-1 (in text form), while
7216       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7217       between 0 and n-1 and the second between 0 and m-1. */
7218
7219       case EOP_LENGTH:
7220       case EOP_L:
7221       case EOP_SUBSTR:
7222       case EOP_S:
7223       case EOP_HASH:
7224       case EOP_H:
7225       case EOP_NHASH:
7226       case EOP_NH:
7227         {
7228         int sign = 1;
7229         int value1 = 0;
7230         int value2 = -1;
7231         int *pn;
7232         int len;
7233         uschar *ret;
7234
7235         if (arg == NULL)
7236           {
7237           expand_string_message = string_sprintf("missing values after %s",
7238             name);
7239           goto EXPAND_FAILED;
7240           }
7241
7242         /* "length" has only one argument, effectively being synonymous with
7243         substr_0_n. */
7244
7245         if (c == EOP_LENGTH || c == EOP_L)
7246           {
7247           pn = &value2;
7248           value2 = 0;
7249           }
7250
7251         /* The others have one or two arguments; for "substr" the first may be
7252         negative. The second being negative means "not supplied". */
7253
7254         else
7255           {
7256           pn = &value1;
7257           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7258           }
7259
7260         /* Read up to two numbers, separated by underscores */
7261
7262         ret = arg;
7263         while (*arg != 0)
7264           {
7265           if (arg != ret && *arg == '_' && pn == &value1)
7266             {
7267             pn = &value2;
7268             value2 = 0;
7269             if (arg[1] != 0) arg++;
7270             }
7271           else if (!isdigit(*arg))
7272             {
7273             expand_string_message =
7274               string_sprintf("non-digit after underscore in \"%s\"", name);
7275             goto EXPAND_FAILED;
7276             }
7277           else *pn = (*pn)*10 + *arg++ - '0';
7278           }
7279         value1 *= sign;
7280
7281         /* Perform the required operation */
7282
7283         ret =
7284           (c == EOP_HASH || c == EOP_H)?
7285              compute_hash(sub, value1, value2, &len) :
7286           (c == EOP_NHASH || c == EOP_NH)?
7287              compute_nhash(sub, value1, value2, &len) :
7288              extract_substr(sub, value1, value2, &len);
7289
7290         if (ret == NULL) goto EXPAND_FAILED;
7291         yield = string_catn(yield, &size, &ptr, ret, len);
7292         continue;
7293         }
7294
7295       /* Stat a path */
7296
7297       case EOP_STAT:
7298         {
7299         uschar *s;
7300         uschar smode[12];
7301         uschar **modetable[3];
7302         int i;
7303         mode_t mode;
7304         struct stat st;
7305
7306         if ((expand_forbid & RDO_EXISTS) != 0)
7307           {
7308           expand_string_message = US"Use of the stat() expansion is not permitted";
7309           goto EXPAND_FAILED;
7310           }
7311
7312         if (stat(CS sub, &st) < 0)
7313           {
7314           expand_string_message = string_sprintf("stat(%s) failed: %s",
7315             sub, strerror(errno));
7316           goto EXPAND_FAILED;
7317           }
7318         mode = st.st_mode;
7319         switch (mode & S_IFMT)
7320           {
7321           case S_IFIFO: smode[0] = 'p'; break;
7322           case S_IFCHR: smode[0] = 'c'; break;
7323           case S_IFDIR: smode[0] = 'd'; break;
7324           case S_IFBLK: smode[0] = 'b'; break;
7325           case S_IFREG: smode[0] = '-'; break;
7326           default: smode[0] = '?'; break;
7327           }
7328
7329         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7330         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7331         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7332
7333         for (i = 0; i < 3; i++)
7334           {
7335           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7336           mode >>= 3;
7337           }
7338
7339         smode[10] = 0;
7340         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7341           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7342           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7343           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7344           (long)st.st_gid, st.st_size, (long)st.st_atime,
7345           (long)st.st_mtime, (long)st.st_ctime);
7346         yield = string_cat(yield, &size, &ptr, s);
7347         continue;
7348         }
7349
7350       /* vaguely random number less than N */
7351
7352       case EOP_RANDINT:
7353         {
7354         int_eximarith_t max;
7355         uschar *s;
7356
7357         max = expanded_string_integer(sub, TRUE);
7358         if (expand_string_message != NULL)
7359           goto EXPAND_FAILED;
7360         s = string_sprintf("%d", vaguely_random_number((int)max));
7361         yield = string_cat(yield, &size, &ptr, s);
7362         continue;
7363         }
7364
7365       /* Reverse IP, including IPv6 to dotted-nibble */
7366
7367       case EOP_REVERSE_IP:
7368         {
7369         int family, maskptr;
7370         uschar reversed[128];
7371
7372         family = string_is_ip_address(sub, &maskptr);
7373         if (family == 0)
7374           {
7375           expand_string_message = string_sprintf(
7376               "reverse_ip() not given an IP address [%s]", sub);
7377           goto EXPAND_FAILED;
7378           }
7379         invert_address(reversed, sub);
7380         yield = string_cat(yield, &size, &ptr, reversed);
7381         continue;
7382         }
7383
7384       /* Unknown operator */
7385
7386       default:
7387       expand_string_message =
7388         string_sprintf("unknown expansion operator \"%s\"", name);
7389       goto EXPAND_FAILED;
7390       }
7391     }
7392
7393   /* Handle a plain name. If this is the first thing in the expansion, release
7394   the pre-allocated buffer. If the result data is known to be in a new buffer,
7395   newsize will be set to the size of that buffer, and we can just point at that
7396   store instead of copying. Many expansion strings contain just one reference,
7397   so this is a useful optimization, especially for humungous headers
7398   ($message_headers). */
7399                                                 /*{*/
7400   if (*s++ == '}')
7401     {
7402     int len;
7403     int newsize = 0;
7404     if (ptr == 0)
7405       {
7406       if (resetok) store_reset(yield);
7407       yield = NULL;
7408       size = 0;
7409       }
7410     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7411       {
7412       expand_string_message =
7413         string_sprintf("unknown variable in \"${%s}\"", name);
7414       check_variable_error_message(name);
7415       goto EXPAND_FAILED;
7416       }
7417     len = Ustrlen(value);
7418     if (!yield && newsize)
7419       {
7420       yield = value;
7421       size = newsize;
7422       ptr = len;
7423       }
7424     else
7425       yield = string_catn(yield, &size, &ptr, value, len);
7426     continue;
7427     }
7428
7429   /* Else there's something wrong */
7430
7431   expand_string_message =
7432     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7433     "in a variable reference)", name);
7434   goto EXPAND_FAILED;
7435   }
7436
7437 /* If we hit the end of the string when ket_ends is set, there is a missing
7438 terminating brace. */
7439
7440 if (ket_ends && *s == 0)
7441   {
7442   expand_string_message = malformed_header?
7443     US"missing } at end of string - could be header name not terminated by colon"
7444     :
7445     US"missing } at end of string";
7446   goto EXPAND_FAILED;
7447   }
7448
7449 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7450 added to the string. If so, set up an empty string. Add a terminating zero. If
7451 left != NULL, return a pointer to the terminator. */
7452
7453 if (yield == NULL) yield = store_get(1);
7454 yield[ptr] = 0;
7455 if (left != NULL) *left = s;
7456
7457 /* Any stacking store that was used above the final string is no longer needed.
7458 In many cases the final string will be the first one that was got and so there
7459 will be optimal store usage. */
7460
7461 if (resetok) store_reset(yield + ptr + 1);
7462 else if (resetok_p) *resetok_p = FALSE;
7463
7464 DEBUG(D_expand)
7465   {
7466   debug_printf("  expanding: %.*s\n     result: %s\n", (int)(s - string), string,
7467     yield);
7468   if (skipping) debug_printf("   skipping: result is not used\n");
7469   }
7470 return yield;
7471
7472 /* This is the failure exit: easiest to program with a goto. We still need
7473 to update the pointer to the terminator, for cases of nested calls with "fail".
7474 */
7475
7476 EXPAND_FAILED_CURLY:
7477 if (malformed_header)
7478   expand_string_message =
7479     US"missing or misplaced { or } - could be header name not terminated by colon";
7480
7481 else if (!expand_string_message || !*expand_string_message)
7482   expand_string_message = US"missing or misplaced { or }";
7483
7484 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7485 that is a bad idea, because expand_string_message is in dynamic store. */
7486
7487 EXPAND_FAILED:
7488 if (left != NULL) *left = s;
7489 DEBUG(D_expand)
7490   {
7491   debug_printf("failed to expand: %s\n", string);
7492   debug_printf("   error message: %s\n", expand_string_message);
7493   if (expand_string_forcedfail) debug_printf("failure was forced\n");
7494   }
7495 if (resetok_p) *resetok_p = resetok;
7496 return NULL;
7497 }
7498
7499
7500 /* This is the external function call. Do a quick check for any expansion
7501 metacharacters, and if there are none, just return the input string.
7502
7503 Argument: the string to be expanded
7504 Returns:  the expanded string, or NULL if expansion failed; if failure was
7505           due to a lookup deferring, search_find_defer will be TRUE
7506 */
7507
7508 uschar *
7509 expand_string(uschar *string)
7510 {
7511 search_find_defer = FALSE;
7512 malformed_header = FALSE;
7513 return (Ustrpbrk(string, "$\\") == NULL)? string :
7514   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7515 }
7516
7517
7518
7519 const uschar *
7520 expand_cstring(const uschar *string)
7521 {
7522 search_find_defer = FALSE;
7523 malformed_header = FALSE;
7524 return (Ustrpbrk(string, "$\\") == NULL)? string :
7525   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7526 }
7527
7528
7529
7530 /*************************************************
7531 *              Expand and copy                   *
7532 *************************************************/
7533
7534 /* Now and again we want to expand a string and be sure that the result is in a
7535 new bit of store. This function does that.
7536 Since we know it has been copied, the de-const cast is safe.
7537
7538 Argument: the string to be expanded
7539 Returns:  the expanded string, always in a new bit of store, or NULL
7540 */
7541
7542 uschar *
7543 expand_string_copy(const uschar *string)
7544 {
7545 const uschar *yield = expand_cstring(string);
7546 if (yield == string) yield = string_copy(string);
7547 return US yield;
7548 }
7549
7550
7551
7552 /*************************************************
7553 *        Expand and interpret as an integer      *
7554 *************************************************/
7555
7556 /* Expand a string, and convert the result into an integer.
7557
7558 Arguments:
7559   string  the string to be expanded
7560   isplus  TRUE if a non-negative number is expected
7561
7562 Returns:  the integer value, or
7563           -1 for an expansion error               ) in both cases, message in
7564           -2 for an integer interpretation error  ) expand_string_message
7565           expand_string_message is set NULL for an OK integer
7566 */
7567
7568 int_eximarith_t
7569 expand_string_integer(uschar *string, BOOL isplus)
7570 {
7571 return expanded_string_integer(expand_string(string), isplus);
7572 }
7573
7574
7575 /*************************************************
7576  *         Interpret string as an integer        *
7577  *************************************************/
7578
7579 /* Convert a string (that has already been expanded) into an integer.
7580
7581 This function is used inside the expansion code.
7582
7583 Arguments:
7584   s       the string to be expanded
7585   isplus  TRUE if a non-negative number is expected
7586
7587 Returns:  the integer value, or
7588           -1 if string is NULL (which implies an expansion error)
7589           -2 for an integer interpretation error
7590           expand_string_message is set NULL for an OK integer
7591 */
7592
7593 static int_eximarith_t
7594 expanded_string_integer(const uschar *s, BOOL isplus)
7595 {
7596 int_eximarith_t value;
7597 uschar *msg = US"invalid integer \"%s\"";
7598 uschar *endptr;
7599
7600 /* If expansion failed, expand_string_message will be set. */
7601
7602 if (s == NULL) return -1;
7603
7604 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7605 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7606 systems, so we set it zero ourselves. */
7607
7608 errno = 0;
7609 expand_string_message = NULL;               /* Indicates no error */
7610
7611 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7612 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7613 the behaviour explicitly.  Stripping leading whitespace is a harmless
7614 noop change since strtol skips it anyway (provided that there is a number
7615 to find at all). */
7616 if (isspace(*s))
7617   {
7618   while (isspace(*s)) ++s;
7619   if (*s == '\0')
7620     {
7621       DEBUG(D_expand)
7622        debug_printf("treating blank string as number 0\n");
7623       return 0;
7624     }
7625   }
7626
7627 value = strtoll(CS s, CSS &endptr, 10);
7628
7629 if (endptr == s)
7630   {
7631   msg = US"integer expected but \"%s\" found";
7632   }
7633 else if (value < 0 && isplus)
7634   {
7635   msg = US"non-negative integer expected but \"%s\" found";
7636   }
7637 else
7638   {
7639   switch (tolower(*endptr))
7640     {
7641     default:
7642       break;
7643     case 'k':
7644       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7645       else value *= 1024;
7646       endptr++;
7647       break;
7648     case 'm':
7649       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7650       else value *= 1024*1024;
7651       endptr++;
7652       break;
7653     case 'g':
7654       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7655       else value *= 1024*1024*1024;
7656       endptr++;
7657       break;
7658     }
7659   if (errno == ERANGE)
7660     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7661   else
7662     {
7663     while (isspace(*endptr)) endptr++;
7664     if (*endptr == 0) return value;
7665     }
7666   }
7667
7668 expand_string_message = string_sprintf(CS msg, s);
7669 return -2;
7670 }
7671
7672
7673 /* These values are usually fixed boolean values, but they are permitted to be
7674 expanded strings.
7675
7676 Arguments:
7677   addr       address being routed
7678   mtype      the module type
7679   mname      the module name
7680   dbg_opt    debug selectors
7681   oname      the option name
7682   bvalue     the router's boolean value
7683   svalue     the router's string value
7684   rvalue     where to put the returned value
7685
7686 Returns:     OK     value placed in rvalue
7687              DEFER  expansion failed
7688 */
7689
7690 int
7691 exp_bool(address_item *addr,
7692   uschar *mtype, uschar *mname, unsigned dbg_opt,
7693   uschar *oname, BOOL bvalue,
7694   uschar *svalue, BOOL *rvalue)
7695 {
7696 uschar *expanded;
7697 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7698
7699 expanded = expand_string(svalue);
7700 if (expanded == NULL)
7701   {
7702   if (expand_string_forcedfail)
7703     {
7704     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7705     *rvalue = bvalue;
7706     return OK;
7707     }
7708   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7709       oname, mname, mtype, expand_string_message);
7710   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7711   return DEFER;
7712   }
7713
7714 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7715   expanded);
7716
7717 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7718   *rvalue = TRUE;
7719 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7720   *rvalue = FALSE;
7721 else
7722   {
7723   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7724     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7725   return DEFER;
7726   }
7727
7728 return OK;
7729 }
7730
7731
7732
7733 /* Avoid potentially exposing a password in a string about to be logged */
7734
7735 uschar *
7736 expand_hide_passwords(uschar * s)
7737 {
7738 return (  (  Ustrstr(s, "failed to expand") != NULL
7739           || Ustrstr(s, "expansion of ")    != NULL
7740           )
7741        && (  Ustrstr(s, "mysql")   != NULL
7742           || Ustrstr(s, "pgsql")   != NULL
7743           || Ustrstr(s, "redis")   != NULL
7744           || Ustrstr(s, "sqlite")  != NULL
7745           || Ustrstr(s, "ldap:")   != NULL
7746           || Ustrstr(s, "ldaps:")  != NULL
7747           || Ustrstr(s, "ldapi:")  != NULL
7748           || Ustrstr(s, "ldapdn:") != NULL
7749           || Ustrstr(s, "ldapm:")  != NULL
7750        )  )
7751   ? US"Temporary internal error" : s;
7752 }
7753
7754
7755
7756
7757 /*************************************************
7758 **************************************************
7759 *             Stand-alone test program           *
7760 **************************************************
7761 *************************************************/
7762
7763 #ifdef STAND_ALONE
7764
7765
7766 BOOL
7767 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7768 {
7769 int ovector[3*(EXPAND_MAXN+1)];
7770 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7771   ovector, nelem(ovector));
7772 BOOL yield = n >= 0;
7773 if (n == 0) n = EXPAND_MAXN + 1;
7774 if (yield)
7775   {
7776   int nn;
7777   expand_nmax = (setup < 0)? 0 : setup + 1;
7778   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7779     {
7780     expand_nstring[expand_nmax] = subject + ovector[nn];
7781     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7782     }
7783   expand_nmax--;
7784   }
7785 return yield;
7786 }
7787
7788
7789 int main(int argc, uschar **argv)
7790 {
7791 int i;
7792 uschar buffer[1024];
7793
7794 debug_selector = D_v;
7795 debug_file = stderr;
7796 debug_fd = fileno(debug_file);
7797 big_buffer = malloc(big_buffer_size);
7798
7799 for (i = 1; i < argc; i++)
7800   {
7801   if (argv[i][0] == '+')
7802     {
7803     debug_trace_memory = 2;
7804     argv[i]++;
7805     }
7806   if (isdigit(argv[i][0]))
7807     debug_selector = Ustrtol(argv[i], NULL, 0);
7808   else
7809     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7810         Ustrlen(argv[i]))
7811       {
7812 #ifdef LOOKUP_LDAP
7813       eldap_default_servers = argv[i];
7814 #endif
7815 #ifdef LOOKUP_MYSQL
7816       mysql_servers = argv[i];
7817 #endif
7818 #ifdef LOOKUP_PGSQL
7819       pgsql_servers = argv[i];
7820 #endif
7821 #ifdef LOOKUP_REDIS
7822       redis_servers = argv[i];
7823 #endif
7824       }
7825 #ifdef EXIM_PERL
7826   else opt_perl_startup = argv[i];
7827 #endif
7828   }
7829
7830 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7831
7832 expand_nstring[1] = US"string 1....";
7833 expand_nlength[1] = 8;
7834 expand_nmax = 1;
7835
7836 #ifdef EXIM_PERL
7837 if (opt_perl_startup != NULL)
7838   {
7839   uschar *errstr;
7840   printf("Starting Perl interpreter\n");
7841   errstr = init_perl(opt_perl_startup);
7842   if (errstr != NULL)
7843     {
7844     printf("** error in perl_startup code: %s\n", errstr);
7845     return EXIT_FAILURE;
7846     }
7847   }
7848 #endif /* EXIM_PERL */
7849
7850 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7851   {
7852   void *reset_point = store_get(0);
7853   uschar *yield = expand_string(buffer);
7854   if (yield != NULL)
7855     {
7856     printf("%s\n", yield);
7857     store_reset(reset_point);
7858     }
7859   else
7860     {
7861     if (search_find_defer) printf("search_find deferred\n");
7862     printf("Failed: %s\n", expand_string_message);
7863     if (expand_string_forcedfail) printf("Forced failure\n");
7864     printf("\n");
7865     }
7866   }
7867
7868 search_tidyup();
7869
7870 return 0;
7871 }
7872
7873 #endif
7874
7875 /* vi: aw ai sw=2
7876 */
7877 /* End of expand.c */