src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 # ifndef SUPPORT_CRYPTEQ
  21 #  define SUPPORT_CRYPTEQ
  22 # endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 # include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 # ifdef CRYPT_H
  31 #  include <crypt.h>
  32 # endif
  33 # ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 # endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Characters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"authresults",
 107   US"certextract",
 108   US"dlfunc",
 109   US"env",
 110   US"extract",
 111   US"filter",
 112   US"hash",
 113   US"hmac",
 114   US"if",
 115 #ifdef SUPPORT_I18N
 116   US"imapfolder",
 117 #endif
 118   US"length",
 119   US"listextract",
 120   US"lookup",
 121   US"map",
 122   US"nhash",
 123   US"perl",
 124   US"prvs",
 125   US"prvscheck",
 126   US"readfile",
 127   US"readsocket",
 128   US"reduce",
 129   US"run",
 130   US"sg",
 131   US"sort",
 132   US"substr",
 133   US"tr" };
 134
 135 enum {
 136   EITEM_ACL,
 137   EITEM_AUTHRESULTS,
 138   EITEM_CERTEXTRACT,
 139   EITEM_DLFUNC,
 140   EITEM_ENV,
 141   EITEM_EXTRACT,
 142   EITEM_FILTER,
 143   EITEM_HASH,
 144   EITEM_HMAC,
 145   EITEM_IF,
 146 #ifdef SUPPORT_I18N
 147   EITEM_IMAPFOLDER,
 148 #endif
 149   EITEM_LENGTH,
 150   EITEM_LISTEXTRACT,
 151   EITEM_LOOKUP,
 152   EITEM_MAP,
 153   EITEM_NHASH,
 154   EITEM_PERL,
 155   EITEM_PRVS,
 156   EITEM_PRVSCHECK,
 157   EITEM_READFILE,
 158   EITEM_READSOCK,
 159   EITEM_REDUCE,
 160   EITEM_RUN,
 161   EITEM_SG,
 162   EITEM_SORT,
 163   EITEM_SUBSTR,
 164   EITEM_TR };
 165
 166 /* Tables of operator names, and corresponding switch numbers. The names must be
 167 in alphabetical order. There are two tables, because underscore is used in some
 168 cases to introduce arguments, whereas for other it is part of the name. This is
 169 an historical mis-design. */
 170
 171 static uschar *op_table_underscore[] = {
 172   US"from_utf8",
 173   US"local_part",
 174   US"quote_local_part",
 175   US"reverse_ip",
 176   US"time_eval",
 177   US"time_interval"
 178 #ifdef SUPPORT_I18N
 179  ,US"utf8_domain_from_alabel",
 180   US"utf8_domain_to_alabel",
 181   US"utf8_localpart_from_alabel",
 182   US"utf8_localpart_to_alabel"
 183 #endif
 184   };
 185
 186 enum {
 187   EOP_FROM_UTF8,
 188   EOP_LOCAL_PART,
 189   EOP_QUOTE_LOCAL_PART,
 190   EOP_REVERSE_IP,
 191   EOP_TIME_EVAL,
 192   EOP_TIME_INTERVAL
 193 #ifdef SUPPORT_I18N
 194  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 195   EOP_UTF8_DOMAIN_TO_ALABEL,
 196   EOP_UTF8_LOCALPART_FROM_ALABEL,
 197   EOP_UTF8_LOCALPART_TO_ALABEL
 198 #endif
 199   };
 200
 201 static uschar *op_table_main[] = {
 202   US"address",
 203   US"addresses",
 204   US"base32",
 205   US"base32d",
 206   US"base62",
 207   US"base62d",
 208   US"base64",
 209   US"base64d",
 210   US"domain",
 211   US"escape",
 212   US"escape8bit",
 213   US"eval",
 214   US"eval10",
 215   US"expand",
 216   US"h",
 217   US"hash",
 218   US"hex2b64",
 219   US"hexquote",
 220   US"ipv6denorm",
 221   US"ipv6norm",
 222   US"l",
 223   US"lc",
 224   US"length",
 225   US"listcount",
 226   US"listnamed",
 227   US"mask",
 228   US"md5",
 229   US"nh",
 230   US"nhash",
 231   US"quote",
 232   US"randint",
 233   US"rfc2047",
 234   US"rfc2047d",
 235   US"rxquote",
 236   US"s",
 237   US"sha1",
 238   US"sha256",
 239   US"sha3",
 240   US"stat",
 241   US"str2b64",
 242   US"strlen",
 243   US"substr",
 244   US"uc",
 245   US"utf8clean" };
 246
 247 enum {
 248   EOP_ADDRESS =  nelem(op_table_underscore),
 249   EOP_ADDRESSES,
 250   EOP_BASE32,
 251   EOP_BASE32D,
 252   EOP_BASE62,
 253   EOP_BASE62D,
 254   EOP_BASE64,
 255   EOP_BASE64D,
 256   EOP_DOMAIN,
 257   EOP_ESCAPE,
 258   EOP_ESCAPE8BIT,
 259   EOP_EVAL,
 260   EOP_EVAL10,
 261   EOP_EXPAND,
 262   EOP_H,
 263   EOP_HASH,
 264   EOP_HEX2B64,
 265   EOP_HEXQUOTE,
 266   EOP_IPV6DENORM,
 267   EOP_IPV6NORM,
 268   EOP_L,
 269   EOP_LC,
 270   EOP_LENGTH,
 271   EOP_LISTCOUNT,
 272   EOP_LISTNAMED,
 273   EOP_MASK,
 274   EOP_MD5,
 275   EOP_NH,
 276   EOP_NHASH,
 277   EOP_QUOTE,
 278   EOP_RANDINT,
 279   EOP_RFC2047,
 280   EOP_RFC2047D,
 281   EOP_RXQUOTE,
 282   EOP_S,
 283   EOP_SHA1,
 284   EOP_SHA256,
 285   EOP_SHA3,
 286   EOP_STAT,
 287   EOP_STR2B64,
 288   EOP_STRLEN,
 289   EOP_SUBSTR,
 290   EOP_UC,
 291   EOP_UTF8CLEAN };
 292
 293
 294 /* Table of condition names, and corresponding switch numbers. The names must
 295 be in alphabetical order. */
 296
 297 static uschar *cond_table[] = {
 298   US"<",
 299   US"<=",
 300   US"=",
 301   US"==",     /* Backward compatibility */
 302   US">",
 303   US">=",
 304   US"acl",
 305   US"and",
 306   US"bool",
 307   US"bool_lax",
 308   US"crypteq",
 309   US"def",
 310   US"eq",
 311   US"eqi",
 312   US"exists",
 313   US"first_delivery",
 314   US"forall",
 315   US"forany",
 316   US"ge",
 317   US"gei",
 318   US"gt",
 319   US"gti",
 320   US"inlist",
 321   US"inlisti",
 322   US"isip",
 323   US"isip4",
 324   US"isip6",
 325   US"ldapauth",
 326   US"le",
 327   US"lei",
 328   US"lt",
 329   US"lti",
 330   US"match",
 331   US"match_address",
 332   US"match_domain",
 333   US"match_ip",
 334   US"match_local_part",
 335   US"or",
 336   US"pam",
 337   US"pwcheck",
 338   US"queue_running",
 339   US"radius",
 340   US"saslauthd"
 341 };
 342
 343 enum {
 344   ECOND_NUM_L,
 345   ECOND_NUM_LE,
 346   ECOND_NUM_E,
 347   ECOND_NUM_EE,
 348   ECOND_NUM_G,
 349   ECOND_NUM_GE,
 350   ECOND_ACL,
 351   ECOND_AND,
 352   ECOND_BOOL,
 353   ECOND_BOOL_LAX,
 354   ECOND_CRYPTEQ,
 355   ECOND_DEF,
 356   ECOND_STR_EQ,
 357   ECOND_STR_EQI,
 358   ECOND_EXISTS,
 359   ECOND_FIRST_DELIVERY,
 360   ECOND_FORALL,
 361   ECOND_FORANY,
 362   ECOND_STR_GE,
 363   ECOND_STR_GEI,
 364   ECOND_STR_GT,
 365   ECOND_STR_GTI,
 366   ECOND_INLIST,
 367   ECOND_INLISTI,
 368   ECOND_ISIP,
 369   ECOND_ISIP4,
 370   ECOND_ISIP6,
 371   ECOND_LDAPAUTH,
 372   ECOND_STR_LE,
 373   ECOND_STR_LEI,
 374   ECOND_STR_LT,
 375   ECOND_STR_LTI,
 376   ECOND_MATCH,
 377   ECOND_MATCH_ADDRESS,
 378   ECOND_MATCH_DOMAIN,
 379   ECOND_MATCH_IP,
 380   ECOND_MATCH_LOCAL_PART,
 381   ECOND_OR,
 382   ECOND_PAM,
 383   ECOND_PWCHECK,
 384   ECOND_QUEUE_RUNNING,
 385   ECOND_RADIUS,
 386   ECOND_SASLAUTHD
 387 };
 388
 389
 390 /* Types of table entry */
 391
 392 enum vtypes {
 393   vtype_int,            /* value is address of int */
 394   vtype_filter_int,     /* ditto, but recognized only when filtering */
 395   vtype_ino,            /* value is address of ino_t (not always an int) */
 396   vtype_uid,            /* value is address of uid_t (not always an int) */
 397   vtype_gid,            /* value is address of gid_t (not always an int) */
 398   vtype_bool,           /* value is address of bool */
 399   vtype_stringptr,      /* value is address of pointer to string */
 400   vtype_msgbody,        /* as stringptr, but read when first required */
 401   vtype_msgbody_end,    /* ditto, the end of the message */
 402   vtype_msgheaders,     /* the message's headers, processed */
 403   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 404   vtype_localpart,      /* extract local part from string */
 405   vtype_domain,         /* extract domain from string */
 406   vtype_string_func,    /* value is string returned by given function */
 407   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 408   vtype_tode,           /* value not used; generate tod in epoch format */
 409   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 410   vtype_todf,           /* value not used; generate full tod */
 411   vtype_todl,           /* value not used; generate log tod */
 412   vtype_todlf,          /* value not used; generate log file datestamp tod */
 413   vtype_todzone,        /* value not used; generate time zone only */
 414   vtype_todzulu,        /* value not used; generate zulu tod */
 415   vtype_reply,          /* value not used; get reply from headers */
 416   vtype_pid,            /* value not used; result is pid */
 417   vtype_host_lookup,    /* value not used; get host name */
 418   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 419   vtype_pspace,         /* partition space; value is T/F for spool/log */
 420   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 421   vtype_cert            /* SSL certificate */
 422   #ifndef DISABLE_DKIM
 423   ,vtype_dkim           /* Lookup of value in DKIM signature */
 424   #endif
 425 };
 426
 427 /* Type for main variable table */
 428
 429 typedef struct {
 430   const char *name;
 431   enum vtypes type;
 432   void       *value;
 433 } var_entry;
 434
 435 /* Type for entries pointing to address/length pairs. Not currently
 436 in use. */
 437
 438 typedef struct {
 439   uschar **address;
 440   int  *length;
 441 } alblock;
 442
 443 static uschar * fn_recipients(void);
 444
 445 /* This table must be kept in alphabetical order. */
 446
 447 static var_entry var_table[] = {
 448   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 449      they will be confused with user-creatable ACL variables. */
 450   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 451   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 452   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 453   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 454   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 455   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 456   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 457   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 458   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 459   { "acl_narg",            vtype_int,         &acl_narg },
 460   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 461   { "address_data",        vtype_stringptr,   &deliver_address_data },
 462   { "address_file",        vtype_stringptr,   &address_file },
 463   { "address_pipe",        vtype_stringptr,   &address_pipe },
 464 #ifdef EXPERIMENTAL_ARC
 465   { "arc_state",           vtype_stringptr,   &arc_state },
 466   { "arc_state_reason",    vtype_stringptr,   &arc_state_reason },
 467 #endif
 468   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 469   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 470   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 471   { "authentication_failed",vtype_int,        &authentication_failed },
 472 #ifdef WITH_CONTENT_SCAN
 473   { "av_failed",           vtype_int,         &av_failed },
 474 #endif
 475 #ifdef EXPERIMENTAL_BRIGHTMAIL
 476   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 477   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 478   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 479   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 480 #endif
 481   { "body_linecount",      vtype_int,         &body_linecount },
 482   { "body_zerocount",      vtype_int,         &body_zerocount },
 483   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 484   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 485   { "caller_gid",          vtype_gid,         &real_gid },
 486   { "caller_uid",          vtype_uid,         &real_uid },
 487   { "callout_address",     vtype_stringptr,   &callout_address },
 488   { "compile_date",        vtype_stringptr,   &version_date },
 489   { "compile_number",      vtype_stringptr,   &version_cnumber },
 490   { "config_dir",          vtype_stringptr,   &config_main_directory },
 491   { "config_file",         vtype_stringptr,   &config_main_filename },
 492   { "csa_status",          vtype_stringptr,   &csa_status },
 493 #ifdef EXPERIMENTAL_DCC
 494   { "dcc_header",          vtype_stringptr,   &dcc_header },
 495   { "dcc_result",          vtype_stringptr,   &dcc_result },
 496 #endif
 497 #ifndef DISABLE_DKIM
 498   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 499   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 500   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 501   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 502   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 503   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 504   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 505   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 506   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 507   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 508   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 509   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 510   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 511   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 512   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 513   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 514   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 515   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 516   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 517   { "dkim_verify_reason",  vtype_stringptr,   &dkim_verify_reason },
 518   { "dkim_verify_status",  vtype_stringptr,   &dkim_verify_status },
 519 #endif
 520 #ifdef EXPERIMENTAL_DMARC
 521   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 522   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 523   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 524   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 525 #endif
 526   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 527   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 528   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 529   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 530   { "domain",              vtype_stringptr,   &deliver_domain },
 531   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 532 #ifndef DISABLE_EVENT
 533   { "event_data",          vtype_stringptr,   &event_data },
 534
 535   /*XXX want to use generic vars for as many of these as possible*/
 536   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 537
 538   { "event_name",          vtype_stringptr,   &event_name },
 539 #endif
 540   { "exim_gid",            vtype_gid,         &exim_gid },
 541   { "exim_path",           vtype_stringptr,   &exim_path },
 542   { "exim_uid",            vtype_uid,         &exim_uid },
 543   { "exim_version",        vtype_stringptr,   &version_string },
 544   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 545   { "home",                vtype_stringptr,   &deliver_home },
 546   { "host",                vtype_stringptr,   &deliver_host },
 547   { "host_address",        vtype_stringptr,   &deliver_host_address },
 548   { "host_data",           vtype_stringptr,   &host_data },
 549   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 550   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 551   { "host_port",           vtype_int,         &deliver_host_port },
 552   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 553   { "inode",               vtype_ino,         &deliver_inode },
 554   { "interface_address",   vtype_stringptr,   &interface_address },
 555   { "interface_port",      vtype_int,         &interface_port },
 556   { "item",                vtype_stringptr,   &iterate_item },
 557   #ifdef LOOKUP_LDAP
 558   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 559   #endif
 560   { "load_average",        vtype_load_avg,    NULL },
 561   { "local_part",          vtype_stringptr,   &deliver_localpart },
 562   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 563   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 564   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 565 #ifdef HAVE_LOCAL_SCAN
 566   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 567 #endif
 568   { "local_user_gid",      vtype_gid,         &local_user_gid },
 569   { "local_user_uid",      vtype_uid,         &local_user_uid },
 570   { "localhost_number",    vtype_int,         &host_number },
 571   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 572   { "log_space",           vtype_pspace,      (void *)FALSE },
 573   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 574   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 575 #ifdef WITH_CONTENT_SCAN
 576   { "malware_name",        vtype_stringptr,   &malware_name },
 577 #endif
 578   { "max_received_linelength", vtype_int,     &max_received_linelength },
 579   { "message_age",         vtype_int,         &message_age },
 580   { "message_body",        vtype_msgbody,     &message_body },
 581   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 582   { "message_body_size",   vtype_int,         &message_body_size },
 583   { "message_exim_id",     vtype_stringptr,   &message_id },
 584   { "message_headers",     vtype_msgheaders,  NULL },
 585   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 586   { "message_id",          vtype_stringptr,   &message_id },
 587   { "message_linecount",   vtype_int,         &message_linecount },
 588   { "message_size",        vtype_int,         &message_size },
 589 #ifdef SUPPORT_I18N
 590   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 591 #endif
 592 #ifdef WITH_CONTENT_SCAN
 593   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 594   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 595   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 596   { "mime_charset",        vtype_stringptr,   &mime_charset },
 597   { "mime_content_description", vtype_stringptr, &mime_content_description },
 598   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 599   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 600   { "mime_content_size",   vtype_int,         &mime_content_size },
 601   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 602   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 603   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 604   { "mime_filename",       vtype_stringptr,   &mime_filename },
 605   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 606   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 607   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 608   { "mime_part_count",     vtype_int,         &mime_part_count },
 609 #endif
 610   { "n0",                  vtype_filter_int,  &filter_n[0] },
 611   { "n1",                  vtype_filter_int,  &filter_n[1] },
 612   { "n2",                  vtype_filter_int,  &filter_n[2] },
 613   { "n3",                  vtype_filter_int,  &filter_n[3] },
 614   { "n4",                  vtype_filter_int,  &filter_n[4] },
 615   { "n5",                  vtype_filter_int,  &filter_n[5] },
 616   { "n6",                  vtype_filter_int,  &filter_n[6] },
 617   { "n7",                  vtype_filter_int,  &filter_n[7] },
 618   { "n8",                  vtype_filter_int,  &filter_n[8] },
 619   { "n9",                  vtype_filter_int,  &filter_n[9] },
 620   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 621   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 622   { "originator_gid",      vtype_gid,         &originator_gid },
 623   { "originator_uid",      vtype_uid,         &originator_uid },
 624   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 625   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 626   { "pid",                 vtype_pid,         NULL },
 627 #ifndef DISABLE_PRDR
 628   { "prdr_requested",      vtype_bool,        &prdr_requested },
 629 #endif
 630   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 631 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 632   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 633   { "proxy_external_port", vtype_int,         &proxy_external_port },
 634   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 635   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 636   { "proxy_session",       vtype_bool,        &proxy_session },
 637 #endif
 638   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 639   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 640   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 641   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 642   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 643   { "queue_name",          vtype_stringptr,   &queue_name },
 644   { "rcpt_count",          vtype_int,         &rcpt_count },
 645   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 646   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 647   { "received_count",      vtype_int,         &received_count },
 648   { "received_for",        vtype_stringptr,   &received_for },
 649   { "received_ip_address", vtype_stringptr,   &interface_address },
 650   { "received_port",       vtype_int,         &interface_port },
 651   { "received_protocol",   vtype_stringptr,   &received_protocol },
 652   { "received_time",       vtype_int,         &received_time.tv_sec },
 653   { "recipient_data",      vtype_stringptr,   &recipient_data },
 654   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 655   { "recipients",          vtype_string_func, &fn_recipients },
 656   { "recipients_count",    vtype_int,         &recipients_count },
 657 #ifdef WITH_CONTENT_SCAN
 658   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 659 #endif
 660   { "reply_address",       vtype_reply,       NULL },
 661   { "return_path",         vtype_stringptr,   &return_path },
 662   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 663   { "router_name",         vtype_stringptr,   &router_name },
 664   { "runrc",               vtype_int,         &runrc },
 665   { "self_hostname",       vtype_stringptr,   &self_hostname },
 666   { "sender_address",      vtype_stringptr,   &sender_address },
 667   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 668   { "sender_address_domain", vtype_domain,    &sender_address },
 669   { "sender_address_local_part", vtype_localpart, &sender_address },
 670   { "sender_data",         vtype_stringptr,   &sender_data },
 671   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 672   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 673   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 674   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 675   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 676   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 677   { "sender_host_name",    vtype_host_lookup, NULL },
 678   { "sender_host_port",    vtype_int,         &sender_host_port },
 679   { "sender_ident",        vtype_stringptr,   &sender_ident },
 680   { "sender_rate",         vtype_stringptr,   &sender_rate },
 681   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 682   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 683   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 684   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 685   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 686   { "sending_port",        vtype_int,         &sending_port },
 687   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 688   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 689   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 690   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 691   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 692   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 693   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 694   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 695   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 696   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 697   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 698   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 699   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 700   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 701   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 702   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 703 #ifdef WITH_CONTENT_SCAN
 704   { "spam_action",         vtype_stringptr,   &spam_action },
 705   { "spam_bar",            vtype_stringptr,   &spam_bar },
 706   { "spam_report",         vtype_stringptr,   &spam_report },
 707   { "spam_score",          vtype_stringptr,   &spam_score },
 708   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 709 #endif
 710 #ifdef SUPPORT_SPF
 711   { "spf_guess",           vtype_stringptr,   &spf_guess },
 712   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 713   { "spf_received",        vtype_stringptr,   &spf_received },
 714   { "spf_result",          vtype_stringptr,   &spf_result },
 715   { "spf_result_guessed",  vtype_bool,        &spf_result_guessed },
 716   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 717 #endif
 718   { "spool_directory",     vtype_stringptr,   &spool_directory },
 719   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 720   { "spool_space",         vtype_pspace,      (void *)TRUE },
 721 #ifdef EXPERIMENTAL_SRS
 722   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 723   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 724   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 725   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 726   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 727   { "srs_status",          vtype_stringptr,   &srs_status },
 728 #endif
 729   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 730
 731   /* The non-(in,out) variables are now deprecated */
 732   { "tls_bits",            vtype_int,         &tls_in.bits },
 733   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 734   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 735
 736   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 737   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 738   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 739   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 740   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 741   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 742   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 743 #if defined(SUPPORT_TLS)
 744   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 745 #endif
 746   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 747   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 748   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 749 #ifdef SUPPORT_DANE
 750   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 751 #endif
 752   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 753   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 754   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 755   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 756 #if defined(SUPPORT_TLS)
 757   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 758 #endif
 759 #ifdef SUPPORT_DANE
 760   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 761 #endif
 762
 763   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 764 #if defined(SUPPORT_TLS)
 765   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 766 #endif
 767
 768   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 769   { "tod_epoch",           vtype_tode,        NULL },
 770   { "tod_epoch_l",         vtype_todel,       NULL },
 771   { "tod_full",            vtype_todf,        NULL },
 772   { "tod_log",             vtype_todl,        NULL },
 773   { "tod_logfile",         vtype_todlf,       NULL },
 774   { "tod_zone",            vtype_todzone,     NULL },
 775   { "tod_zulu",            vtype_todzulu,     NULL },
 776   { "transport_name",      vtype_stringptr,   &transport_name },
 777   { "value",               vtype_stringptr,   &lookup_value },
 778   { "verify_mode",         vtype_stringptr,   &verify_mode },
 779   { "version_number",      vtype_stringptr,   &version_string },
 780   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 781   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 782   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 783   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 784   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 785   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 786 };
 787
 788 static int var_table_size = nelem(var_table);
 789 static uschar var_buffer[256];
 790 static BOOL malformed_header;
 791
 792 /* For textual hashes */
 793
 794 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 795                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 796                                "0123456789";
 797
 798 enum { HMAC_MD5, HMAC_SHA1 };
 799
 800 /* For numeric hashes */
 801
 802 static unsigned int prime[] = {
 803   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 804  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 805  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 806
 807 /* For printing modes in symbolic form */
 808
 809 static uschar *mtable_normal[] =
 810   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 811
 812 static uschar *mtable_setid[] =
 813   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 814
 815 static uschar *mtable_sticky[] =
 816   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 817
 818
 819
 820 /*************************************************
 821 *           Tables for UTF-8 support             *
 822 *************************************************/
 823
 824 /* Table of the number of extra characters, indexed by the first character
 825 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 826 0x3d. */
 827
 828 static uschar utf8_table1[] = {
 829   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 830   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 831   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 832   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 833
 834 /* These are the masks for the data bits in the first byte of a character,
 835 indexed by the number of additional bytes. */
 836
 837 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 838
 839 /* Get the next UTF-8 character, advancing the pointer. */
 840
 841 #define GETUTF8INC(c, ptr) \
 842   c = *ptr++; \
 843   if ((c & 0xc0) == 0xc0) \
 844     { \
 845     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 846     int s = 6*a; \
 847     c = (c & utf8_table2[a]) << s; \
 848     while (a-- > 0) \
 849       { \
 850       s -= 6; \
 851       c |= (*ptr++ & 0x3f) << s; \
 852       } \
 853     }
 854
 855
 856
 857 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 858
 859 /*************************************************
 860 *           Binary chop search on a table        *
 861 *************************************************/
 862
 863 /* This is used for matching expansion items and operators.
 864
 865 Arguments:
 866   name        the name that is being sought
 867   table       the table to search
 868   table_size  the number of items in the table
 869
 870 Returns:      the offset in the table, or -1
 871 */
 872
 873 static int
 874 chop_match(uschar *name, uschar **table, int table_size)
 875 {
 876 uschar **bot = table;
 877 uschar **top = table + table_size;
 878
 879 while (top > bot)
 880   {
 881   uschar **mid = bot + (top - bot)/2;
 882   int c = Ustrcmp(name, *mid);
 883   if (c == 0) return mid - table;
 884   if (c > 0) bot = mid + 1; else top = mid;
 885   }
 886
 887 return -1;
 888 }
 889
 890
 891
 892 /*************************************************
 893 *          Check a condition string              *
 894 *************************************************/
 895
 896 /* This function is called to expand a string, and test the result for a "true"
 897 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 898 forced fail or lookup defer.
 899
 900 We used to release all store used, but this is not not safe due
 901 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 902 is reasonably careful to release what it can.
 903
 904 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 905
 906 Arguments:
 907   condition     the condition string
 908   m1            text to be incorporated in panic error
 909   m2            ditto
 910
 911 Returns:        TRUE if condition is met, FALSE if not
 912 */
 913
 914 BOOL
 915 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 916 {
 917 int rc;
 918 uschar *ss = expand_string(condition);
 919 if (ss == NULL)
 920   {
 921   if (!expand_string_forcedfail && !search_find_defer)
 922     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 923       "for %s %s: %s", condition, m1, m2, expand_string_message);
 924   return FALSE;
 925   }
 926 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 927   strcmpic(ss, US"false") != 0;
 928 return rc;
 929 }
 930
 931
 932
 933
 934 /*************************************************
 935 *        Pseudo-random number generation         *
 936 *************************************************/
 937
 938 /* Pseudo-random number generation.  The result is not "expected" to be
 939 cryptographically strong but not so weak that someone will shoot themselves
 940 in the foot using it as a nonce in some email header scheme or whatever
 941 weirdness they'll twist this into.  The result should ideally handle fork().
 942
 943 However, if we're stuck unable to provide this, then we'll fall back to
 944 appallingly bad randomness.
 945
 946 If SUPPORT_TLS is defined then this will not be used except as an emergency
 947 fallback.
 948
 949 Arguments:
 950   max       range maximum
 951 Returns     a random number in range [0, max-1]
 952 */
 953
 954 #ifdef SUPPORT_TLS
 955 # define vaguely_random_number vaguely_random_number_fallback
 956 #endif
 957 int
 958 vaguely_random_number(int max)
 959 {
 960 #ifdef SUPPORT_TLS
 961 # undef vaguely_random_number
 962 #endif
 963   static pid_t pid = 0;
 964   pid_t p2;
 965 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 966   struct timeval tv;
 967 #endif
 968
 969   p2 = getpid();
 970   if (p2 != pid)
 971     {
 972     if (pid != 0)
 973       {
 974
 975 #ifdef HAVE_ARC4RANDOM
 976       /* cryptographically strong randomness, common on *BSD platforms, not
 977       so much elsewhere.  Alas. */
 978 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 979       arc4random_stir();
 980 #endif
 981 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 982 #ifdef HAVE_SRANDOMDEV
 983       /* uses random(4) for seeding */
 984       srandomdev();
 985 #else
 986       gettimeofday(&tv, NULL);
 987       srandom(tv.tv_sec | tv.tv_usec | getpid());
 988 #endif
 989 #else
 990       /* Poor randomness and no seeding here */
 991 #endif
 992
 993       }
 994     pid = p2;
 995     }
 996
 997 #ifdef HAVE_ARC4RANDOM
 998   return arc4random() % max;
 999 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
1000   return random() % max;
1001 #else
1002   /* This one returns a 16-bit number, definitely not crypto-strong */
1003   return random_number(max);
1004 #endif
1005 }
1006
1007
1008
1009
1010 /*************************************************
1011 *             Pick out a name from a string      *
1012 *************************************************/
1013
1014 /* If the name is too long, it is silently truncated.
1015
1016 Arguments:
1017   name      points to a buffer into which to put the name
1018   max       is the length of the buffer
1019   s         points to the first alphabetic character of the name
1020   extras    chars other than alphanumerics to permit
1021
1022 Returns:    pointer to the first character after the name
1023
1024 Note: The test for *s != 0 in the while loop is necessary because
1025 Ustrchr() yields non-NULL if the character is zero (which is not something
1026 I expected). */
1027
1028 static const uschar *
1029 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1030 {
1031 int ptr = 0;
1032 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1033   {
1034   if (ptr < max-1) name[ptr++] = *s;
1035   s++;
1036   }
1037 name[ptr] = 0;
1038 return s;
1039 }
1040
1041
1042
1043 /*************************************************
1044 *     Pick out the rest of a header name         *
1045 *************************************************/
1046
1047 /* A variable name starting $header_ (or just $h_ for those who like
1048 abbreviations) might not be the complete header name because headers can
1049 contain any printing characters in their names, except ':'. This function is
1050 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1051 on the end, if the name was terminated by white space.
1052
1053 Arguments:
1054   name      points to a buffer in which the name read so far exists
1055   max       is the length of the buffer
1056   s         points to the first character after the name so far, i.e. the
1057             first non-alphameric character after $header_xxxxx
1058
1059 Returns:    a pointer to the first character after the header name
1060 */
1061
1062 static const uschar *
1063 read_header_name(uschar *name, int max, const uschar *s)
1064 {
1065 int prelen = Ustrchr(name, '_') - name + 1;
1066 int ptr = Ustrlen(name) - prelen;
1067 if (ptr > 0) memmove(name, name+prelen, ptr);
1068 while (mac_isgraph(*s) && *s != ':')
1069   {
1070   if (ptr < max-1) name[ptr++] = *s;
1071   s++;
1072   }
1073 if (*s == ':') s++;
1074 name[ptr++] = ':';
1075 name[ptr] = 0;
1076 return s;
1077 }
1078
1079
1080
1081 /*************************************************
1082 *           Pick out a number from a string      *
1083 *************************************************/
1084
1085 /* Arguments:
1086   n     points to an integer into which to put the number
1087   s     points to the first digit of the number
1088
1089 Returns:  a pointer to the character after the last digit
1090 */
1091 /*XXX consider expanding to int_eximarith_t.  But the test for
1092 "overbig numbers" in 0002 still needs to overflow it. */
1093
1094 static uschar *
1095 read_number(int *n, uschar *s)
1096 {
1097 *n = 0;
1098 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1099 return s;
1100 }
1101
1102 static const uschar *
1103 read_cnumber(int *n, const uschar *s)
1104 {
1105 *n = 0;
1106 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1107 return s;
1108 }
1109
1110
1111
1112 /*************************************************
1113 *        Extract keyed subfield from a string    *
1114 *************************************************/
1115
1116 /* The yield is in dynamic store; NULL means that the key was not found.
1117
1118 Arguments:
1119   key       points to the name of the key
1120   s         points to the string from which to extract the subfield
1121
1122 Returns:    NULL if the subfield was not found, or
1123             a pointer to the subfield's data
1124 */
1125
1126 static uschar *
1127 expand_getkeyed(uschar *key, const uschar *s)
1128 {
1129 int length = Ustrlen(key);
1130 while (isspace(*s)) s++;
1131
1132 /* Loop to search for the key */
1133
1134 while (*s != 0)
1135   {
1136   int dkeylength;
1137   uschar *data;
1138   const uschar *dkey = s;
1139
1140   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1141   dkeylength = s - dkey;
1142   while (isspace(*s)) s++;
1143   if (*s == '=') while (isspace((*(++s))));
1144
1145   data = string_dequote(&s);
1146   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1147     return data;
1148
1149   while (isspace(*s)) s++;
1150   }
1151
1152 return NULL;
1153 }
1154
1155
1156
1157 static var_entry *
1158 find_var_ent(uschar * name)
1159 {
1160 int first = 0;
1161 int last = var_table_size;
1162
1163 while (last > first)
1164   {
1165   int middle = (first + last)/2;
1166   int c = Ustrcmp(name, var_table[middle].name);
1167
1168   if (c > 0) { first = middle + 1; continue; }
1169   if (c < 0) { last = middle; continue; }
1170   return &var_table[middle];
1171   }
1172 return NULL;
1173 }
1174
1175 /*************************************************
1176 *   Extract numbered subfield from string        *
1177 *************************************************/
1178
1179 /* Extracts a numbered field from a string that is divided by tokens - for
1180 example a line from /etc/passwd is divided by colon characters.  First field is
1181 numbered one.  Negative arguments count from the right. Zero returns the whole
1182 string. Returns NULL if there are insufficient tokens in the string
1183
1184 ***WARNING***
1185 Modifies final argument - this is a dynamically generated string, so that's OK.
1186
1187 Arguments:
1188   field       number of field to be extracted,
1189                 first field = 1, whole string = 0, last field = -1
1190   separators  characters that are used to break string into tokens
1191   s           points to the string from which to extract the subfield
1192
1193 Returns:      NULL if the field was not found,
1194               a pointer to the field's data inside s (modified to add 0)
1195 */
1196
1197 static uschar *
1198 expand_gettokened (int field, uschar *separators, uschar *s)
1199 {
1200 int sep = 1;
1201 int count;
1202 uschar *ss = s;
1203 uschar *fieldtext = NULL;
1204
1205 if (field == 0) return s;
1206
1207 /* Break the line up into fields in place; for field > 0 we stop when we have
1208 done the number of fields we want. For field < 0 we continue till the end of
1209 the string, counting the number of fields. */
1210
1211 count = (field > 0)? field : INT_MAX;
1212
1213 while (count-- > 0)
1214   {
1215   size_t len;
1216
1217   /* Previous field was the last one in the string. For a positive field
1218   number, this means there are not enough fields. For a negative field number,
1219   check that there are enough, and scan back to find the one that is wanted. */
1220
1221   if (sep == 0)
1222     {
1223     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1224     if ((-field) == (INT_MAX - count - 1)) return s;
1225     while (field++ < 0)
1226       {
1227       ss--;
1228       while (ss[-1] != 0) ss--;
1229       }
1230     fieldtext = ss;
1231     break;
1232     }
1233
1234   /* Previous field was not last in the string; save its start and put a
1235   zero at its end. */
1236
1237   fieldtext = ss;
1238   len = Ustrcspn(ss, separators);
1239   sep = ss[len];
1240   ss[len] = 0;
1241   ss += len + 1;
1242   }
1243
1244 return fieldtext;
1245 }
1246
1247
1248 static uschar *
1249 expand_getlistele(int field, const uschar * list)
1250 {
1251 const uschar * tlist= list;
1252 int sep= 0;
1253 uschar dummy;
1254
1255 if(field<0)
1256   {
1257   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1258   sep= 0;
1259   }
1260 if(field==0) return NULL;
1261 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1262 return string_nextinlist(&list, &sep, NULL, 0);
1263 }
1264
1265
1266 /* Certificate fields, by name.  Worry about by-OID later */
1267 /* Names are chosen to not have common prefixes */
1268
1269 #ifdef SUPPORT_TLS
1270 typedef struct
1271 {
1272 uschar * name;
1273 int      namelen;
1274 uschar * (*getfn)(void * cert, uschar * mod);
1275 } certfield;
1276 static certfield certfields[] =
1277 {                       /* linear search; no special order */
1278   { US"version",         7,  &tls_cert_version },
1279   { US"serial_number",   13, &tls_cert_serial_number },
1280   { US"subject",         7,  &tls_cert_subject },
1281   { US"notbefore",       9,  &tls_cert_not_before },
1282   { US"notafter",        8,  &tls_cert_not_after },
1283   { US"issuer",          6,  &tls_cert_issuer },
1284   { US"signature",       9,  &tls_cert_signature },
1285   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1286   { US"subj_altname",    12, &tls_cert_subject_altname },
1287   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1288   { US"crl_uri",         7,  &tls_cert_crl_uri },
1289 };
1290
1291 static uschar *
1292 expand_getcertele(uschar * field, uschar * certvar)
1293 {
1294 var_entry * vp;
1295 certfield * cp;
1296
1297 if (!(vp = find_var_ent(certvar)))
1298   {
1299   expand_string_message =
1300     string_sprintf("no variable named \"%s\"", certvar);
1301   return NULL;          /* Unknown variable name */
1302   }
1303 /* NB this stops us passing certs around in variable.  Might
1304 want to do that in future */
1305 if (vp->type != vtype_cert)
1306   {
1307   expand_string_message =
1308     string_sprintf("\"%s\" is not a certificate", certvar);
1309   return NULL;          /* Unknown variable name */
1310   }
1311 if (!*(void **)vp->value)
1312   return NULL;
1313
1314 if (*field >= '0' && *field <= '9')
1315   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1316
1317 for(cp = certfields;
1318     cp < certfields + nelem(certfields);
1319     cp++)
1320   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1321     {
1322     uschar * modifier = *(field += cp->namelen) == ','
1323       ? ++field : NULL;
1324     return (*cp->getfn)( *(void **)vp->value, modifier );
1325     }
1326
1327 expand_string_message =
1328   string_sprintf("bad field selector \"%s\" for certextract", field);
1329 return NULL;
1330 }
1331 #endif  /*SUPPORT_TLS*/
1332
1333 /*************************************************
1334 *        Extract a substring from a string       *
1335 *************************************************/
1336
1337 /* Perform the ${substr or ${length expansion operations.
1338
1339 Arguments:
1340   subject     the input string
1341   value1      the offset from the start of the input string to the start of
1342                 the output string; if negative, count from the right.
1343   value2      the length of the output string, or negative (-1) for unset
1344                 if value1 is positive, unset means "all after"
1345                 if value1 is negative, unset means "all before"
1346   len         set to the length of the returned string
1347
1348 Returns:      pointer to the output string, or NULL if there is an error
1349 */
1350
1351 static uschar *
1352 extract_substr(uschar *subject, int value1, int value2, int *len)
1353 {
1354 int sublen = Ustrlen(subject);
1355
1356 if (value1 < 0)    /* count from right */
1357   {
1358   value1 += sublen;
1359
1360   /* If the position is before the start, skip to the start, and adjust the
1361   length. If the length ends up negative, the substring is null because nothing
1362   can precede. This falls out naturally when the length is unset, meaning "all
1363   to the left". */
1364
1365   if (value1 < 0)
1366     {
1367     value2 += value1;
1368     if (value2 < 0) value2 = 0;
1369     value1 = 0;
1370     }
1371
1372   /* Otherwise an unset length => characters before value1 */
1373
1374   else if (value2 < 0)
1375     {
1376     value2 = value1;
1377     value1 = 0;
1378     }
1379   }
1380
1381 /* For a non-negative offset, if the starting position is past the end of the
1382 string, the result will be the null string. Otherwise, an unset length means
1383 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1384
1385 else
1386   {
1387   if (value1 > sublen)
1388     {
1389     value1 = sublen;
1390     value2 = 0;
1391     }
1392   else if (value2 < 0) value2 = sublen;
1393   }
1394
1395 /* Cut the length down to the maximum possible for the offset value, and get
1396 the required characters. */
1397
1398 if (value1 + value2 > sublen) value2 = sublen - value1;
1399 *len = value2;
1400 return subject + value1;
1401 }
1402
1403
1404
1405
1406 /*************************************************
1407 *            Old-style hash of a string          *
1408 *************************************************/
1409
1410 /* Perform the ${hash expansion operation.
1411
1412 Arguments:
1413   subject     the input string (an expanded substring)
1414   value1      the length of the output string; if greater or equal to the
1415                 length of the input string, the input string is returned
1416   value2      the number of hash characters to use, or 26 if negative
1417   len         set to the length of the returned string
1418
1419 Returns:      pointer to the output string, or NULL if there is an error
1420 */
1421
1422 static uschar *
1423 compute_hash(uschar *subject, int value1, int value2, int *len)
1424 {
1425 int sublen = Ustrlen(subject);
1426
1427 if (value2 < 0) value2 = 26;
1428 else if (value2 > Ustrlen(hashcodes))
1429   {
1430   expand_string_message =
1431     string_sprintf("hash count \"%d\" too big", value2);
1432   return NULL;
1433   }
1434
1435 /* Calculate the hash text. We know it is shorter than the original string, so
1436 can safely place it in subject[] (we know that subject is always itself an
1437 expanded substring). */
1438
1439 if (value1 < sublen)
1440   {
1441   int c;
1442   int i = 0;
1443   int j = value1;
1444   while ((c = (subject[j])) != 0)
1445     {
1446     int shift = (c + j++) & 7;
1447     subject[i] ^= (c << shift) | (c >> (8-shift));
1448     if (++i >= value1) i = 0;
1449     }
1450   for (i = 0; i < value1; i++)
1451     subject[i] = hashcodes[(subject[i]) % value2];
1452   }
1453 else value1 = sublen;
1454
1455 *len = value1;
1456 return subject;
1457 }
1458
1459
1460
1461
1462 /*************************************************
1463 *             Numeric hash of a string           *
1464 *************************************************/
1465
1466 /* Perform the ${nhash expansion operation. The first characters of the
1467 string are treated as most important, and get the highest prime numbers.
1468
1469 Arguments:
1470   subject     the input string
1471   value1      the maximum value of the first part of the result
1472   value2      the maximum value of the second part of the result,
1473                 or negative to produce only a one-part result
1474   len         set to the length of the returned string
1475
1476 Returns:  pointer to the output string, or NULL if there is an error.
1477 */
1478
1479 static uschar *
1480 compute_nhash (uschar *subject, int value1, int value2, int *len)
1481 {
1482 uschar *s = subject;
1483 int i = 0;
1484 unsigned long int total = 0; /* no overflow */
1485
1486 while (*s != 0)
1487   {
1488   if (i == 0) i = nelem(prime) - 1;
1489   total += prime[i--] * (unsigned int)(*s++);
1490   }
1491
1492 /* If value2 is unset, just compute one number */
1493
1494 if (value2 < 0)
1495   s = string_sprintf("%lu", total % value1);
1496
1497 /* Otherwise do a div/mod hash */
1498
1499 else
1500   {
1501   total = total % (value1 * value2);
1502   s = string_sprintf("%lu/%lu", total/value2, total % value2);
1503   }
1504
1505 *len = Ustrlen(s);
1506 return s;
1507 }
1508
1509
1510
1511
1512
1513 /*************************************************
1514 *     Find the value of a header or headers      *
1515 *************************************************/
1516
1517 /* Multiple instances of the same header get concatenated, and this function
1518 can also return a concatenation of all the header lines. When concatenating
1519 specific headers that contain lists of addresses, a comma is inserted between
1520 them. Otherwise we use a straight concatenation. Because some messages can have
1521 pathologically large number of lines, there is a limit on the length that is
1522 returned. Also, to avoid massive store use which would result from using
1523 string_cat() as it copies and extends strings, we do a preliminary pass to find
1524 out exactly how much store will be needed. On "normal" messages this will be
1525 pretty trivial.
1526
1527 Arguments:
1528   name          the name of the header, without the leading $header_ or $h_,
1529                 or NULL if a concatenation of all headers is required
1530   exists_only   TRUE if called from a def: test; don't need to build a string;
1531                 just return a string that is not "" and not "0" if the header
1532                 exists
1533   newsize       return the size of memory block that was obtained; may be NULL
1534                 if exists_only is TRUE
1535   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1536                 other than concatenating, will be done on the header. Also used
1537                 for $message_headers_raw.
1538   charset       name of charset to translate MIME words to; used only if
1539                 want_raw is false; if NULL, no translation is done (this is
1540                 used for $bh_ and $bheader_)
1541
1542 Returns:        NULL if the header does not exist, else a pointer to a new
1543                 store block
1544 */
1545
1546 static uschar *
1547 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1548   uschar *charset)
1549 {
1550 BOOL found = name == NULL;
1551 int comma = 0;
1552 int len = found? 0 : Ustrlen(name);
1553 int i;
1554 uschar *yield = NULL;
1555 uschar *ptr = NULL;
1556
1557 /* Loop for two passes - saves code repetition */
1558
1559 for (i = 0; i < 2; i++)
1560   {
1561   int size = 0;
1562   header_line *h;
1563
1564   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1565     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1566       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1567         {
1568         int ilen;
1569         uschar *t;
1570
1571         if (exists_only) return US"1";      /* don't need actual string */
1572         found = TRUE;
1573         t = h->text + len;                  /* text to insert */
1574         if (!want_raw)                      /* unless wanted raw, */
1575           while (isspace(*t)) t++;          /* remove leading white space */
1576         ilen = h->slen - (t - h->text);     /* length to insert */
1577
1578         /* Unless wanted raw, remove trailing whitespace, including the
1579         newline. */
1580
1581         if (!want_raw)
1582           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1583
1584         /* Set comma = 1 if handling a single header and it's one of those
1585         that contains an address list, except when asked for raw headers. Only
1586         need to do this once. */
1587
1588         if (!want_raw && name && comma == 0 &&
1589             Ustrchr("BCFRST", h->type) != NULL)
1590           comma = 1;
1591
1592         /* First pass - compute total store needed; second pass - compute
1593         total store used, including this header. */
1594
1595         size += ilen + comma + 1;  /* +1 for the newline */
1596
1597         /* Second pass - concatenate the data, up to a maximum. Note that
1598         the loop stops when size hits the limit. */
1599
1600         if (i != 0)
1601           {
1602           if (size > header_insert_maxlen)
1603             {
1604             ilen -= size - header_insert_maxlen - 1;
1605             comma = 0;
1606             }
1607           Ustrncpy(ptr, t, ilen);
1608           ptr += ilen;
1609
1610           /* For a non-raw header, put in the comma if needed, then add
1611           back the newline we removed above, provided there was some text in
1612           the header. */
1613
1614           if (!want_raw && ilen > 0)
1615             {
1616             if (comma != 0) *ptr++ = ',';
1617             *ptr++ = '\n';
1618             }
1619           }
1620         }
1621
1622   /* At end of first pass, return NULL if no header found. Then truncate size
1623   if necessary, and get the buffer to hold the data, returning the buffer size.
1624   */
1625
1626   if (i == 0)
1627     {
1628     if (!found) return NULL;
1629     if (size > header_insert_maxlen) size = header_insert_maxlen;
1630     *newsize = size + 1;
1631     ptr = yield = store_get(*newsize);
1632     }
1633   }
1634
1635 /* That's all we do for raw header expansion. */
1636
1637 if (want_raw)
1638   *ptr = 0;
1639
1640 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1641 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1642 function can return an error with decoded data if the charset translation
1643 fails. If decoding fails, it returns NULL. */
1644
1645 else
1646   {
1647   uschar *decoded, *error;
1648   if (ptr > yield && ptr[-1] == '\n') ptr--;
1649   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1650   *ptr = 0;
1651   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1652     newsize, &error);
1653   if (error != NULL)
1654     {
1655     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1656       "    input was: %s\n", error, yield);
1657     }
1658   if (decoded != NULL) yield = decoded;
1659   }
1660
1661 return yield;
1662 }
1663
1664
1665
1666
1667 /* Append a "local" element to an Autherntication-Results: header
1668 if this was a non-smtp message.
1669 */
1670
1671 static gstring *
1672 authres_local(gstring * g, const uschar * sysname)
1673 {
1674 if (!authentication_local)
1675   return g;
1676 g = string_append(g, 3, US";\n\tlocal=pass (non-smtp, ", sysname, US")");
1677 if (authenticated_id) g = string_append(g, 2, " u=", authenticated_id);
1678 return g;
1679 }
1680
1681
1682 /* Append an "iprev" element to an Autherntication-Results: header
1683 if we have attempted to get the calling host's name.
1684 */
1685
1686 static gstring *
1687 authres_iprev(gstring * g)
1688 {
1689 if (sender_host_name)
1690   return string_append(g, 3, US";\n\tiprev=pass (", sender_host_name, US")");
1691 if (host_lookup_deferred)
1692   return string_catn(g, US";\n\tiprev=temperror", 19);
1693 if (host_lookup_failed)
1694   return string_catn(g, US";\n\tiprev=fail", 13);
1695 return g;
1696 }
1697
1698
1699
1700 /*************************************************
1701 *               Return list of recipients        *
1702 *************************************************/
1703 /* A recipients list is available only during system message filtering,
1704 during ACL processing after DATA, and while expanding pipe commands
1705 generated from a system filter, but not elsewhere. */
1706
1707 static uschar *
1708 fn_recipients(void)
1709 {
1710 gstring * g = NULL;
1711 int i;
1712
1713 if (!enable_dollar_recipients) return NULL;
1714
1715 for (i = 0; i < recipients_count; i++)
1716   {
1717   /*XXX variant of list_appendele? */
1718   if (i != 0) g = string_catn(g, US", ", 2);
1719   g = string_cat(g, recipients_list[i].address);
1720   }
1721 return string_from_gstring(g);
1722 }
1723
1724
1725 /*************************************************
1726 *               Find value of a variable         *
1727 *************************************************/
1728
1729 /* The table of variables is kept in alphabetic order, so we can search it
1730 using a binary chop. The "choplen" variable is nothing to do with the binary
1731 chop.
1732
1733 Arguments:
1734   name          the name of the variable being sought
1735   exists_only   TRUE if this is a def: test; passed on to find_header()
1736   skipping      TRUE => skip any processing evaluation; this is not the same as
1737                   exists_only because def: may test for values that are first
1738                   evaluated here
1739   newsize       pointer to an int which is initially zero; if the answer is in
1740                 a new memory buffer, *newsize is set to its size
1741
1742 Returns:        NULL if the variable does not exist, or
1743                 a pointer to the variable's contents, or
1744                 something non-NULL if exists_only is TRUE
1745 */
1746
1747 static uschar *
1748 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1749 {
1750 var_entry * vp;
1751 uschar *s, *domain;
1752 uschar **ss;
1753 void * val;
1754
1755 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1756 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1757 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1758 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1759 (this gave backwards compatibility at the changeover). There may be built-in
1760 variables whose names start acl_ but they should never start in this way. This
1761 slightly messy specification is a consequence of the history, needless to say.
1762
1763 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1764 set, in which case give an error. */
1765
1766 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1767      !isalpha(name[5]))
1768   {
1769   tree_node *node =
1770     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1771   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1772   }
1773
1774 /* Handle $auth<n> variables. */
1775
1776 if (Ustrncmp(name, "auth", 4) == 0)
1777   {
1778   uschar *endptr;
1779   int n = Ustrtoul(name + 4, &endptr, 10);
1780   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1781     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1782   }
1783 else if (Ustrncmp(name, "regex", 5) == 0)
1784   {
1785   uschar *endptr;
1786   int n = Ustrtoul(name + 5, &endptr, 10);
1787   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1788     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1789   }
1790
1791 /* For all other variables, search the table */
1792
1793 if (!(vp = find_var_ent(name)))
1794   return NULL;          /* Unknown variable name */
1795
1796 /* Found an existing variable. If in skipping state, the value isn't needed,
1797 and we want to avoid processing (such as looking up the host name). */
1798
1799 if (skipping)
1800   return US"";
1801
1802 val = vp->value;
1803 switch (vp->type)
1804   {
1805   case vtype_filter_int:
1806     if (!filter_running) return NULL;
1807     /* Fall through */
1808     /* VVVVVVVVVVVV */
1809   case vtype_int:
1810     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1811     return var_buffer;
1812
1813   case vtype_ino:
1814     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1815     return var_buffer;
1816
1817   case vtype_gid:
1818     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1819     return var_buffer;
1820
1821   case vtype_uid:
1822     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1823     return var_buffer;
1824
1825   case vtype_bool:
1826     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1827     return var_buffer;
1828
1829   case vtype_stringptr:                      /* Pointer to string */
1830     return (s = *((uschar **)(val))) ? s : US"";
1831
1832   case vtype_pid:
1833     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1834     return var_buffer;
1835
1836   case vtype_load_avg:
1837     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1838     return var_buffer;
1839
1840   case vtype_host_lookup:                    /* Lookup if not done so */
1841     if (  !sender_host_name && sender_host_address
1842        && !host_lookup_failed && host_name_lookup() == OK)
1843       host_build_sender_fullhost();
1844     return sender_host_name ? sender_host_name : US"";
1845
1846   case vtype_localpart:                      /* Get local part from address */
1847     s = *((uschar **)(val));
1848     if (s == NULL) return US"";
1849     domain = Ustrrchr(s, '@');
1850     if (domain == NULL) return s;
1851     if (domain - s > sizeof(var_buffer) - 1)
1852       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1853           " in string expansion", sizeof(var_buffer));
1854     Ustrncpy(var_buffer, s, domain - s);
1855     var_buffer[domain - s] = 0;
1856     return var_buffer;
1857
1858   case vtype_domain:                         /* Get domain from address */
1859     s = *((uschar **)(val));
1860     if (s == NULL) return US"";
1861     domain = Ustrrchr(s, '@');
1862     return (domain == NULL)? US"" : domain + 1;
1863
1864   case vtype_msgheaders:
1865     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1866
1867   case vtype_msgheaders_raw:
1868     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1869
1870   case vtype_msgbody:                        /* Pointer to msgbody string */
1871   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1872     ss = (uschar **)(val);
1873     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1874       {
1875       uschar *body;
1876       off_t start_offset = SPOOL_DATA_START_OFFSET;
1877       int len = message_body_visible;
1878       if (len > message_size) len = message_size;
1879       *ss = body = store_malloc(len+1);
1880       body[0] = 0;
1881       if (vp->type == vtype_msgbody_end)
1882         {
1883         struct stat statbuf;
1884         if (fstat(deliver_datafile, &statbuf) == 0)
1885           {
1886           start_offset = statbuf.st_size - len;
1887           if (start_offset < SPOOL_DATA_START_OFFSET)
1888             start_offset = SPOOL_DATA_START_OFFSET;
1889           }
1890         }
1891       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1892         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1893           strerror(errno));
1894       len = read(deliver_datafile, body, len);
1895       if (len > 0)
1896         {
1897         body[len] = 0;
1898         if (message_body_newlines)   /* Separate loops for efficiency */
1899           while (len > 0)
1900             { if (body[--len] == 0) body[len] = ' '; }
1901         else
1902           while (len > 0)
1903             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1904         }
1905       }
1906     return *ss ? *ss : US"";
1907
1908   case vtype_todbsdin:                       /* BSD inbox time of day */
1909     return tod_stamp(tod_bsdin);
1910
1911   case vtype_tode:                           /* Unix epoch time of day */
1912     return tod_stamp(tod_epoch);
1913
1914   case vtype_todel:                          /* Unix epoch/usec time of day */
1915     return tod_stamp(tod_epoch_l);
1916
1917   case vtype_todf:                           /* Full time of day */
1918     return tod_stamp(tod_full);
1919
1920   case vtype_todl:                           /* Log format time of day */
1921     return tod_stamp(tod_log_bare);            /* (without timezone) */
1922
1923   case vtype_todzone:                        /* Time zone offset only */
1924     return tod_stamp(tod_zone);
1925
1926   case vtype_todzulu:                        /* Zulu time */
1927     return tod_stamp(tod_zulu);
1928
1929   case vtype_todlf:                          /* Log file datestamp tod */
1930     return tod_stamp(tod_log_datestamp_daily);
1931
1932   case vtype_reply:                          /* Get reply address */
1933     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1934       headers_charset);
1935     if (s != NULL) while (isspace(*s)) s++;
1936     if (s == NULL || *s == 0)
1937       {
1938       *newsize = 0;                            /* For the *s==0 case */
1939       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1940       }
1941     if (s != NULL)
1942       {
1943       uschar *t;
1944       while (isspace(*s)) s++;
1945       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1946       while (t > s && isspace(t[-1])) t--;
1947       *t = 0;
1948       }
1949     return (s == NULL)? US"" : s;
1950
1951   case vtype_string_func:
1952     {
1953     uschar * (*fn)() = val;
1954     return fn();
1955     }
1956
1957   case vtype_pspace:
1958     {
1959     int inodes;
1960     sprintf(CS var_buffer, "%d",
1961       receive_statvfs(val == (void *)TRUE, &inodes));
1962     }
1963   return var_buffer;
1964
1965   case vtype_pinodes:
1966     {
1967     int inodes;
1968     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1969     sprintf(CS var_buffer, "%d", inodes);
1970     }
1971   return var_buffer;
1972
1973   case vtype_cert:
1974     return *(void **)val ? US"<cert>" : US"";
1975
1976 #ifndef DISABLE_DKIM
1977   case vtype_dkim:
1978     return dkim_exim_expand_query((int)(long)val);
1979 #endif
1980
1981   }
1982
1983 return NULL;  /* Unknown variable. Silences static checkers. */
1984 }
1985
1986
1987
1988
1989 void
1990 modify_variable(uschar *name, void * value)
1991 {
1992 var_entry * vp;
1993 if ((vp = find_var_ent(name))) vp->value = value;
1994 return;          /* Unknown variable name, fail silently */
1995 }
1996
1997
1998
1999
2000
2001
2002 /*************************************************
2003 *           Read and expand substrings           *
2004 *************************************************/
2005
2006 /* This function is called to read and expand argument substrings for various
2007 expansion items. Some have a minimum requirement that is less than the maximum;
2008 in these cases, the first non-present one is set to NULL.
2009
2010 Arguments:
2011   sub        points to vector of pointers to set
2012   n          maximum number of substrings
2013   m          minimum required
2014   sptr       points to current string pointer
2015   skipping   the skipping flag
2016   check_end  if TRUE, check for final '}'
2017   name       name of item, for error message
2018   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
2019              the store.
2020
2021 Returns:     0 OK; string pointer updated
2022              1 curly bracketing error (too few arguments)
2023              2 too many arguments (only if check_end is set); message set
2024              3 other error (expansion failure)
2025 */
2026
2027 static int
2028 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
2029   BOOL check_end, uschar *name, BOOL *resetok)
2030 {
2031 int i;
2032 const uschar *s = *sptr;
2033
2034 while (isspace(*s)) s++;
2035 for (i = 0; i < n; i++)
2036   {
2037   if (*s != '{')
2038     {
2039     if (i < m)
2040       {
2041       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2042         "(min is %d)", name, m);
2043       return 1;
2044       }
2045     sub[i] = NULL;
2046     break;
2047     }
2048   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2049     return 3;
2050   if (*s++ != '}') return 1;
2051   while (isspace(*s)) s++;
2052   }
2053 if (check_end && *s++ != '}')
2054   {
2055   if (s[-1] == '{')
2056     {
2057     expand_string_message = string_sprintf("Too many arguments for '%s' "
2058       "(max is %d)", name, n);
2059     return 2;
2060     }
2061   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2062   return 1;
2063   }
2064
2065 *sptr = s;
2066 return 0;
2067 }
2068
2069
2070
2071
2072 /*************************************************
2073 *     Elaborate message for bad variable         *
2074 *************************************************/
2075
2076 /* For the "unknown variable" message, take a look at the variable's name, and
2077 give additional information about possible ACL variables. The extra information
2078 is added on to expand_string_message.
2079
2080 Argument:   the name of the variable
2081 Returns:    nothing
2082 */
2083
2084 static void
2085 check_variable_error_message(uschar *name)
2086 {
2087 if (Ustrncmp(name, "acl_", 4) == 0)
2088   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2089     (name[4] == 'c' || name[4] == 'm')?
2090       (isalpha(name[5])?
2091         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2092         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2093       ) :
2094       US"user-defined ACL variables must start acl_c or acl_m");
2095 }
2096
2097
2098
2099 /*
2100 Load args from sub array to globals, and call acl_check().
2101 Sub array will be corrupted on return.
2102
2103 Returns:       OK         access is granted by an ACCEPT verb
2104                DISCARD    access is (apparently) granted by a DISCARD verb
2105                FAIL       access is denied
2106                FAIL_DROP  access is denied; drop the connection
2107                DEFER      can't tell at the moment
2108                ERROR      disaster
2109 */
2110 static int
2111 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2112 {
2113 int i;
2114 int sav_narg = acl_narg;
2115 int ret;
2116 uschar * dummy_logmsg;
2117 extern int acl_where;
2118
2119 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2120 for (i = 0; i < nsub && sub[i+1]; i++)
2121   {
2122   uschar * tmp = acl_arg[i];
2123   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2124   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2125   }
2126 acl_narg = i;
2127 while (i < nsub)
2128   {
2129   sub[i+1] = acl_arg[i];
2130   acl_arg[i++] = NULL;
2131   }
2132
2133 DEBUG(D_expand)
2134   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2135     sub[0],
2136     acl_narg>0 ? acl_arg[0] : US"<none>",
2137     acl_narg>1 ? " +more"   : "");
2138
2139 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2140
2141 for (i = 0; i < nsub; i++)
2142   acl_arg[i] = sub[i+1];        /* restore old args */
2143 acl_narg = sav_narg;
2144
2145 return ret;
2146 }
2147
2148
2149
2150
2151 /*************************************************
2152 *        Read and evaluate a condition           *
2153 *************************************************/
2154
2155 /*
2156 Arguments:
2157   s        points to the start of the condition text
2158   resetok  points to a BOOL which is written false if it is unsafe to
2159            free memory. Certain condition types (acl) may have side-effect
2160            allocation which must be preserved.
2161   yield    points to a BOOL to hold the result of the condition test;
2162            if NULL, we are just reading through a condition that is
2163            part of an "or" combination to check syntax, or in a state
2164            where the answer isn't required
2165
2166 Returns:   a pointer to the first character after the condition, or
2167            NULL after an error
2168 */
2169
2170 static const uschar *
2171 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2172 {
2173 BOOL testfor = TRUE;
2174 BOOL tempcond, combined_cond;
2175 BOOL *subcondptr;
2176 BOOL sub2_honour_dollar = TRUE;
2177 int i, rc, cond_type, roffset;
2178 int_eximarith_t num[2];
2179 struct stat statbuf;
2180 uschar name[256];
2181 const uschar *sub[10];
2182
2183 const pcre *re;
2184 const uschar *rerror;
2185
2186 for (;;)
2187   {
2188   while (isspace(*s)) s++;
2189   if (*s == '!') { testfor = !testfor; s++; } else break;
2190   }
2191
2192 /* Numeric comparisons are symbolic */
2193
2194 if (*s == '=' || *s == '>' || *s == '<')
2195   {
2196   int p = 0;
2197   name[p++] = *s++;
2198   if (*s == '=')
2199     {
2200     name[p++] = '=';
2201     s++;
2202     }
2203   name[p] = 0;
2204   }
2205
2206 /* All other conditions are named */
2207
2208 else s = read_name(name, 256, s, US"_");
2209
2210 /* If we haven't read a name, it means some non-alpha character is first. */
2211
2212 if (name[0] == 0)
2213   {
2214   expand_string_message = string_sprintf("condition name expected, "
2215     "but found \"%.16s\"", s);
2216   return NULL;
2217   }
2218
2219 /* Find which condition we are dealing with, and switch on it */
2220
2221 cond_type = chop_match(name, cond_table, nelem(cond_table));
2222 switch(cond_type)
2223   {
2224   /* def: tests for a non-empty variable, or for the existence of a header. If
2225   yield == NULL we are in a skipping state, and don't care about the answer. */
2226
2227   case ECOND_DEF:
2228   if (*s != ':')
2229     {
2230     expand_string_message = US"\":\" expected after \"def\"";
2231     return NULL;
2232     }
2233
2234   s = read_name(name, 256, s+1, US"_");
2235
2236   /* Test for a header's existence. If the name contains a closing brace
2237   character, this may be a user error where the terminating colon has been
2238   omitted. Set a flag to adjust a subsequent error message in this case. */
2239
2240   if (Ustrncmp(name, "h_", 2) == 0 ||
2241       Ustrncmp(name, "rh_", 3) == 0 ||
2242       Ustrncmp(name, "bh_", 3) == 0 ||
2243       Ustrncmp(name, "header_", 7) == 0 ||
2244       Ustrncmp(name, "rheader_", 8) == 0 ||
2245       Ustrncmp(name, "bheader_", 8) == 0)
2246     {
2247     s = read_header_name(name, 256, s);
2248     /* {-for-text-editors */
2249     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2250     if (yield != NULL) *yield =
2251       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2252     }
2253
2254   /* Test for a variable's having a non-empty value. A non-existent variable
2255   causes an expansion failure. */
2256
2257   else
2258     {
2259     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2260     if (value == NULL)
2261       {
2262       expand_string_message = (name[0] == 0)?
2263         string_sprintf("variable name omitted after \"def:\"") :
2264         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2265       check_variable_error_message(name);
2266       return NULL;
2267       }
2268     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2269     }
2270
2271   return s;
2272
2273
2274   /* first_delivery tests for first delivery attempt */
2275
2276   case ECOND_FIRST_DELIVERY:
2277   if (yield != NULL) *yield = deliver_firsttime == testfor;
2278   return s;
2279
2280
2281   /* queue_running tests for any process started by a queue runner */
2282
2283   case ECOND_QUEUE_RUNNING:
2284   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2285   return s;
2286
2287
2288   /* exists:  tests for file existence
2289        isip:  tests for any IP address
2290       isip4:  tests for an IPv4 address
2291       isip6:  tests for an IPv6 address
2292         pam:  does PAM authentication
2293      radius:  does RADIUS authentication
2294    ldapauth:  does LDAP authentication
2295     pwcheck:  does Cyrus SASL pwcheck authentication
2296   */
2297
2298   case ECOND_EXISTS:
2299   case ECOND_ISIP:
2300   case ECOND_ISIP4:
2301   case ECOND_ISIP6:
2302   case ECOND_PAM:
2303   case ECOND_RADIUS:
2304   case ECOND_LDAPAUTH:
2305   case ECOND_PWCHECK:
2306
2307   while (isspace(*s)) s++;
2308   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2309
2310   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2311   if (sub[0] == NULL) return NULL;
2312   /* {-for-text-editors */
2313   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2314
2315   if (yield == NULL) return s;   /* No need to run the test if skipping */
2316
2317   switch(cond_type)
2318     {
2319     case ECOND_EXISTS:
2320     if ((expand_forbid & RDO_EXISTS) != 0)
2321       {
2322       expand_string_message = US"File existence tests are not permitted";
2323       return NULL;
2324       }
2325     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2326     break;
2327
2328     case ECOND_ISIP:
2329     case ECOND_ISIP4:
2330     case ECOND_ISIP6:
2331     rc = string_is_ip_address(sub[0], NULL);
2332     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2333              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2334     break;
2335
2336     /* Various authentication tests - all optionally compiled */
2337
2338     case ECOND_PAM:
2339     #ifdef SUPPORT_PAM
2340     rc = auth_call_pam(sub[0], &expand_string_message);
2341     goto END_AUTH;
2342     #else
2343     goto COND_FAILED_NOT_COMPILED;
2344     #endif  /* SUPPORT_PAM */
2345
2346     case ECOND_RADIUS:
2347     #ifdef RADIUS_CONFIG_FILE
2348     rc = auth_call_radius(sub[0], &expand_string_message);
2349     goto END_AUTH;
2350     #else
2351     goto COND_FAILED_NOT_COMPILED;
2352     #endif  /* RADIUS_CONFIG_FILE */
2353
2354     case ECOND_LDAPAUTH:
2355     #ifdef LOOKUP_LDAP
2356       {
2357       /* Just to keep the interface the same */
2358       BOOL do_cache;
2359       int old_pool = store_pool;
2360       store_pool = POOL_SEARCH;
2361       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2362         &expand_string_message, &do_cache);
2363       store_pool = old_pool;
2364       }
2365     goto END_AUTH;
2366     #else
2367     goto COND_FAILED_NOT_COMPILED;
2368     #endif  /* LOOKUP_LDAP */
2369
2370     case ECOND_PWCHECK:
2371     #ifdef CYRUS_PWCHECK_SOCKET
2372     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2373     goto END_AUTH;
2374     #else
2375     goto COND_FAILED_NOT_COMPILED;
2376     #endif  /* CYRUS_PWCHECK_SOCKET */
2377
2378     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2379         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2380     END_AUTH:
2381     if (rc == ERROR || rc == DEFER) return NULL;
2382     *yield = (rc == OK) == testfor;
2383     #endif
2384     }
2385   return s;
2386
2387
2388   /* call ACL (in a conditional context).  Accept true, deny false.
2389   Defer is a forced-fail.  Anything set by message= goes to $value.
2390   Up to ten parameters are used; we use the braces round the name+args
2391   like the saslauthd condition does, to permit a variable number of args.
2392   See also the expansion-item version EITEM_ACL and the traditional
2393   acl modifier ACLC_ACL.
2394   Since the ACL may allocate new global variables, tell our caller to not
2395   reclaim memory.
2396   */
2397
2398   case ECOND_ACL:
2399     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2400     {
2401     uschar *sub[10];
2402     uschar *user_msg;
2403     BOOL cond = FALSE;
2404
2405     while (isspace(*s)) s++;
2406     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2407
2408     switch(read_subs(sub, nelem(sub), 1,
2409       &s, yield == NULL, TRUE, US"acl", resetok))
2410       {
2411       case 1: expand_string_message = US"too few arguments or bracketing "
2412         "error for acl";
2413       case 2:
2414       case 3: return NULL;
2415       }
2416
2417     if (yield != NULL)
2418       {
2419       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2420       switch(eval_acl(sub, nelem(sub), &user_msg))
2421         {
2422         case OK:
2423           cond = TRUE;
2424         case FAIL:
2425           lookup_value = NULL;
2426           if (user_msg)
2427             lookup_value = string_copy(user_msg);
2428           *yield = cond == testfor;
2429           break;
2430
2431         case DEFER:
2432           expand_string_forcedfail = TRUE;
2433           /*FALLTHROUGH*/
2434         default:
2435           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2436           return NULL;
2437         }
2438       }
2439     return s;
2440     }
2441
2442
2443   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2444
2445      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2446
2447   However, the last two are optional. That is why the whole set is enclosed
2448   in their own set of braces. */
2449
2450   case ECOND_SASLAUTHD:
2451 #ifndef CYRUS_SASLAUTHD_SOCKET
2452     goto COND_FAILED_NOT_COMPILED;
2453 #else
2454     {
2455     uschar *sub[4];
2456     while (isspace(*s)) s++;
2457     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2458     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2459                     resetok))
2460       {
2461       case 1: expand_string_message = US"too few arguments or bracketing "
2462         "error for saslauthd";
2463       case 2:
2464       case 3: return NULL;
2465       }
2466     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2467     if (yield != NULL)
2468       {
2469       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2470         &expand_string_message);
2471       if (rc == ERROR || rc == DEFER) return NULL;
2472       *yield = (rc == OK) == testfor;
2473       }
2474     return s;
2475     }
2476 #endif /* CYRUS_SASLAUTHD_SOCKET */
2477
2478
2479   /* symbolic operators for numeric and string comparison, and a number of
2480   other operators, all requiring two arguments.
2481
2482   crypteq:           encrypts plaintext and compares against an encrypted text,
2483                        using crypt(), crypt16(), MD5 or SHA-1
2484   inlist/inlisti:    checks if first argument is in the list of the second
2485   match:             does a regular expression match and sets up the numerical
2486                        variables if it succeeds
2487   match_address:     matches in an address list
2488   match_domain:      matches in a domain list
2489   match_ip:          matches a host list that is restricted to IP addresses
2490   match_local_part:  matches in a local part list
2491   */
2492
2493   case ECOND_MATCH_ADDRESS:
2494   case ECOND_MATCH_DOMAIN:
2495   case ECOND_MATCH_IP:
2496   case ECOND_MATCH_LOCAL_PART:
2497 #ifndef EXPAND_LISTMATCH_RHS
2498     sub2_honour_dollar = FALSE;
2499 #endif
2500     /* FALLTHROUGH */
2501
2502   case ECOND_CRYPTEQ:
2503   case ECOND_INLIST:
2504   case ECOND_INLISTI:
2505   case ECOND_MATCH:
2506
2507   case ECOND_NUM_L:     /* Numerical comparisons */
2508   case ECOND_NUM_LE:
2509   case ECOND_NUM_E:
2510   case ECOND_NUM_EE:
2511   case ECOND_NUM_G:
2512   case ECOND_NUM_GE:
2513
2514   case ECOND_STR_LT:    /* String comparisons */
2515   case ECOND_STR_LTI:
2516   case ECOND_STR_LE:
2517   case ECOND_STR_LEI:
2518   case ECOND_STR_EQ:
2519   case ECOND_STR_EQI:
2520   case ECOND_STR_GT:
2521   case ECOND_STR_GTI:
2522   case ECOND_STR_GE:
2523   case ECOND_STR_GEI:
2524
2525   for (i = 0; i < 2; i++)
2526     {
2527     /* Sometimes, we don't expand substrings; too many insecure configurations
2528     created using match_address{}{} and friends, where the second param
2529     includes information from untrustworthy sources. */
2530     BOOL honour_dollar = TRUE;
2531     if ((i > 0) && !sub2_honour_dollar)
2532       honour_dollar = FALSE;
2533
2534     while (isspace(*s)) s++;
2535     if (*s != '{')
2536       {
2537       if (i == 0) goto COND_FAILED_CURLY_START;
2538       expand_string_message = string_sprintf("missing 2nd string in {} "
2539         "after \"%s\"", name);
2540       return NULL;
2541       }
2542     if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2543         honour_dollar, resetok)))
2544       return NULL;
2545     DEBUG(D_expand) if (i == 1 && !sub2_honour_dollar && Ustrchr(sub[1], '$'))
2546       debug_printf_indent("WARNING: the second arg is NOT expanded,"
2547                         " for security reasons\n");
2548     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2549
2550     /* Convert to numerical if required; we know that the names of all the
2551     conditions that compare numbers do not start with a letter. This just saves
2552     checking for them individually. */
2553
2554     if (!isalpha(name[0]) && yield != NULL)
2555       if (sub[i][0] == 0)
2556         {
2557         num[i] = 0;
2558         DEBUG(D_expand)
2559           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2560         }
2561       else
2562         {
2563         num[i] = expanded_string_integer(sub[i], FALSE);
2564         if (expand_string_message != NULL) return NULL;
2565         }
2566     }
2567
2568   /* Result not required */
2569
2570   if (yield == NULL) return s;
2571
2572   /* Do an appropriate comparison */
2573
2574   switch(cond_type)
2575     {
2576     case ECOND_NUM_E:
2577     case ECOND_NUM_EE:
2578     tempcond = (num[0] == num[1]);
2579     break;
2580
2581     case ECOND_NUM_G:
2582     tempcond = (num[0] > num[1]);
2583     break;
2584
2585     case ECOND_NUM_GE:
2586     tempcond = (num[0] >= num[1]);
2587     break;
2588
2589     case ECOND_NUM_L:
2590     tempcond = (num[0] < num[1]);
2591     break;
2592
2593     case ECOND_NUM_LE:
2594     tempcond = (num[0] <= num[1]);
2595     break;
2596
2597     case ECOND_STR_LT:
2598     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2599     break;
2600
2601     case ECOND_STR_LTI:
2602     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2603     break;
2604
2605     case ECOND_STR_LE:
2606     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2607     break;
2608
2609     case ECOND_STR_LEI:
2610     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2611     break;
2612
2613     case ECOND_STR_EQ:
2614     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2615     break;
2616
2617     case ECOND_STR_EQI:
2618     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2619     break;
2620
2621     case ECOND_STR_GT:
2622     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2623     break;
2624
2625     case ECOND_STR_GTI:
2626     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2627     break;
2628
2629     case ECOND_STR_GE:
2630     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2631     break;
2632
2633     case ECOND_STR_GEI:
2634     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2635     break;
2636
2637     case ECOND_MATCH:   /* Regular expression match */
2638     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2639       NULL);
2640     if (re == NULL)
2641       {
2642       expand_string_message = string_sprintf("regular expression error in "
2643         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2644       return NULL;
2645       }
2646     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2647     break;
2648
2649     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2650     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2651     goto MATCHED_SOMETHING;
2652
2653     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2654     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2655       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2656     goto MATCHED_SOMETHING;
2657
2658     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2659     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2660       {
2661       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2662         sub[0]);
2663       return NULL;
2664       }
2665     else
2666       {
2667       unsigned int *nullcache = NULL;
2668       check_host_block cb;
2669
2670       cb.host_name = US"";
2671       cb.host_address = sub[0];
2672
2673       /* If the host address starts off ::ffff: it is an IPv6 address in
2674       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2675       addresses. */
2676
2677       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2678         cb.host_address + 7 : cb.host_address;
2679
2680       rc = match_check_list(
2681              &sub[1],                   /* the list */
2682              0,                         /* separator character */
2683              &hostlist_anchor,          /* anchor pointer */
2684              &nullcache,                /* cache pointer */
2685              check_host,                /* function for testing */
2686              &cb,                       /* argument for function */
2687              MCL_HOST,                  /* type of check */
2688              sub[0],                    /* text for debugging */
2689              NULL);                     /* where to pass back data */
2690       }
2691     goto MATCHED_SOMETHING;
2692
2693     case ECOND_MATCH_LOCAL_PART:
2694     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2695       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2696     /* Fall through */
2697     /* VVVVVVVVVVVV */
2698     MATCHED_SOMETHING:
2699     switch(rc)
2700       {
2701       case OK:
2702       tempcond = TRUE;
2703       break;
2704
2705       case FAIL:
2706       tempcond = FALSE;
2707       break;
2708
2709       case DEFER:
2710       expand_string_message = string_sprintf("unable to complete match "
2711         "against \"%s\": %s", sub[1], search_error_message);
2712       return NULL;
2713       }
2714
2715     break;
2716
2717     /* Various "encrypted" comparisons. If the second string starts with
2718     "{" then an encryption type is given. Default to crypt() or crypt16()
2719     (build-time choice). */
2720     /* }-for-text-editors */
2721
2722     case ECOND_CRYPTEQ:
2723     #ifndef SUPPORT_CRYPTEQ
2724     goto COND_FAILED_NOT_COMPILED;
2725     #else
2726     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2727       {
2728       int sublen = Ustrlen(sub[1]+5);
2729       md5 base;
2730       uschar digest[16];
2731
2732       md5_start(&base);
2733       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2734
2735       /* If the length that we are comparing against is 24, the MD5 digest
2736       is expressed as a base64 string. This is the way LDAP does it. However,
2737       some other software uses a straightforward hex representation. We assume
2738       this if the length is 32. Other lengths fail. */
2739
2740       if (sublen == 24)
2741         {
2742         uschar *coded = b64encode(digest, 16);
2743         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2744           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2745         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2746         }
2747       else if (sublen == 32)
2748         {
2749         int i;
2750         uschar coded[36];
2751         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2752         coded[32] = 0;
2753         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2754           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2755         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2756         }
2757       else
2758         {
2759         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2760           "fail\n  crypted=%s\n", sub[1]+5);
2761         tempcond = FALSE;
2762         }
2763       }
2764
2765     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2766       {
2767       int sublen = Ustrlen(sub[1]+6);
2768       hctx h;
2769       uschar digest[20];
2770
2771       sha1_start(&h);
2772       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2773
2774       /* If the length that we are comparing against is 28, assume the SHA1
2775       digest is expressed as a base64 string. If the length is 40, assume a
2776       straightforward hex representation. Other lengths fail. */
2777
2778       if (sublen == 28)
2779         {
2780         uschar *coded = b64encode(digest, 20);
2781         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2782           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2783         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2784         }
2785       else if (sublen == 40)
2786         {
2787         int i;
2788         uschar coded[44];
2789         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2790         coded[40] = 0;
2791         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2792           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2793         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2794         }
2795       else
2796         {
2797         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2798           "fail\n  crypted=%s\n", sub[1]+6);
2799         tempcond = FALSE;
2800         }
2801       }
2802
2803     else   /* {crypt} or {crypt16} and non-{ at start */
2804            /* }-for-text-editors */
2805       {
2806       int which = 0;
2807       uschar *coded;
2808
2809       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2810         {
2811         sub[1] += 7;
2812         which = 1;
2813         }
2814       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2815         {
2816         sub[1] += 9;
2817         which = 2;
2818         }
2819       else if (sub[1][0] == '{')                /* }-for-text-editors */
2820         {
2821         expand_string_message = string_sprintf("unknown encryption mechanism "
2822           "in \"%s\"", sub[1]);
2823         return NULL;
2824         }
2825
2826       switch(which)
2827         {
2828         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2829         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2830         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2831         }
2832
2833       #define STR(s) # s
2834       #define XSTR(s) STR(s)
2835       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2836         "  subject=%s\n  crypted=%s\n",
2837         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2838         coded, sub[1]);
2839       #undef STR
2840       #undef XSTR
2841
2842       /* If the encrypted string contains fewer than two characters (for the
2843       salt), force failure. Otherwise we get false positives: with an empty
2844       string the yield of crypt() is an empty string! */
2845
2846       if (coded)
2847         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2848       else if (errno == EINVAL)
2849         tempcond = FALSE;
2850       else
2851         {
2852         expand_string_message = string_sprintf("crypt error: %s\n",
2853           US strerror(errno));
2854         return NULL;
2855         }
2856       }
2857     break;
2858     #endif  /* SUPPORT_CRYPTEQ */
2859
2860     case ECOND_INLIST:
2861     case ECOND_INLISTI:
2862       {
2863       const uschar * list = sub[1];
2864       int sep = 0;
2865       uschar *save_iterate_item = iterate_item;
2866       int (*compare)(const uschar *, const uschar *);
2867
2868       DEBUG(D_expand) debug_printf_indent("condition: %s  item: %s\n", name, sub[0]);
2869
2870       tempcond = FALSE;
2871       compare = cond_type == ECOND_INLISTI
2872         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2873
2874       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2875         {
2876         DEBUG(D_expand) debug_printf_indent(" compare %s\n", iterate_item);
2877         if (compare(sub[0], iterate_item) == 0)
2878           {
2879           tempcond = TRUE;
2880           break;
2881           }
2882         }
2883       iterate_item = save_iterate_item;
2884       }
2885
2886     }   /* Switch for comparison conditions */
2887
2888   *yield = tempcond == testfor;
2889   return s;    /* End of comparison conditions */
2890
2891
2892   /* and/or: computes logical and/or of several conditions */
2893
2894   case ECOND_AND:
2895   case ECOND_OR:
2896   subcondptr = (yield == NULL)? NULL : &tempcond;
2897   combined_cond = (cond_type == ECOND_AND);
2898
2899   while (isspace(*s)) s++;
2900   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2901
2902   for (;;)
2903     {
2904     while (isspace(*s)) s++;
2905     /* {-for-text-editors */
2906     if (*s == '}') break;
2907     if (*s != '{')                                      /* }-for-text-editors */
2908       {
2909       expand_string_message = string_sprintf("each subcondition "
2910         "inside an \"%s{...}\" condition must be in its own {}", name);
2911       return NULL;
2912       }
2913
2914     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2915       {
2916       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2917         expand_string_message, name);
2918       return NULL;
2919       }
2920     while (isspace(*s)) s++;
2921
2922     /* {-for-text-editors */
2923     if (*s++ != '}')
2924       {
2925       /* {-for-text-editors */
2926       expand_string_message = string_sprintf("missing } at end of condition "
2927         "inside \"%s\" group", name);
2928       return NULL;
2929       }
2930
2931     if (yield != NULL)
2932       {
2933       if (cond_type == ECOND_AND)
2934         {
2935         combined_cond &= tempcond;
2936         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2937         }                                       /* evaluate any more */
2938       else
2939         {
2940         combined_cond |= tempcond;
2941         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2942         }                                       /* evaluate any more */
2943       }
2944     }
2945
2946   if (yield != NULL) *yield = (combined_cond == testfor);
2947   return ++s;
2948
2949
2950   /* forall/forany: iterates a condition with different values */
2951
2952   case ECOND_FORALL:
2953   case ECOND_FORANY:
2954     {
2955     const uschar * list;
2956     int sep = 0;
2957     uschar *save_iterate_item = iterate_item;
2958
2959     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2960
2961     while (isspace(*s)) s++;
2962     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2963     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2964     if (sub[0] == NULL) return NULL;
2965     /* {-for-text-editors */
2966     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2967
2968     while (isspace(*s)) s++;
2969     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2970
2971     sub[1] = s;
2972
2973     /* Call eval_condition once, with result discarded (as if scanning a
2974     "false" part). This allows us to find the end of the condition, because if
2975     the list it empty, we won't actually evaluate the condition for real. */
2976
2977     if (!(s = eval_condition(sub[1], resetok, NULL)))
2978       {
2979       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2980         expand_string_message, name);
2981       return NULL;
2982       }
2983     while (isspace(*s)) s++;
2984
2985     /* {-for-text-editors */
2986     if (*s++ != '}')
2987       {
2988       /* {-for-text-editors */
2989       expand_string_message = string_sprintf("missing } at end of condition "
2990         "inside \"%s\"", name);
2991       return NULL;
2992       }
2993
2994     if (yield != NULL) *yield = !testfor;
2995     list = sub[0];
2996     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2997       {
2998       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2999       if (!eval_condition(sub[1], resetok, &tempcond))
3000         {
3001         expand_string_message = string_sprintf("%s inside \"%s\" condition",
3002           expand_string_message, name);
3003         iterate_item = save_iterate_item;
3004         return NULL;
3005         }
3006       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
3007         tempcond? "true":"false");
3008
3009       if (yield != NULL) *yield = (tempcond == testfor);
3010       if (tempcond == (cond_type == ECOND_FORANY)) break;
3011       }
3012
3013     iterate_item = save_iterate_item;
3014     return s;
3015     }
3016
3017
3018   /* The bool{} expansion condition maps a string to boolean.
3019   The values supported should match those supported by the ACL condition
3020   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
3021   of true/false.  Note that Router "condition" rules have a different
3022   interpretation, where general data can be used and only a few values
3023   map to FALSE.
3024   Note that readconf.c boolean matching, for boolean configuration options,
3025   only matches true/yes/false/no.
3026   The bool_lax{} condition matches the Router logic, which is much more
3027   liberal. */
3028   case ECOND_BOOL:
3029   case ECOND_BOOL_LAX:
3030     {
3031     uschar *sub_arg[1];
3032     uschar *t, *t2;
3033     uschar *ourname;
3034     size_t len;
3035     BOOL boolvalue = FALSE;
3036     while (isspace(*s)) s++;
3037     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3038     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3039     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3040       {
3041       case 1: expand_string_message = string_sprintf(
3042                   "too few arguments or bracketing error for %s",
3043                   ourname);
3044       /*FALLTHROUGH*/
3045       case 2:
3046       case 3: return NULL;
3047       }
3048     t = sub_arg[0];
3049     while (isspace(*t)) t++;
3050     len = Ustrlen(t);
3051     if (len)
3052       {
3053       /* trailing whitespace: seems like a good idea to ignore it too */
3054       t2 = t + len - 1;
3055       while (isspace(*t2)) t2--;
3056       if (t2 != (t + len))
3057         {
3058         *++t2 = '\0';
3059         len = t2 - t;
3060         }
3061       }
3062     DEBUG(D_expand)
3063       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3064     /* logic for the lax case from expand_check_condition(), which also does
3065     expands, and the logic is both short and stable enough that there should
3066     be no maintenance burden from replicating it. */
3067     if (len == 0)
3068       boolvalue = FALSE;
3069     else if (*t == '-'
3070              ? Ustrspn(t+1, "0123456789") == len-1
3071              : Ustrspn(t,   "0123456789") == len)
3072       {
3073       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3074       /* expand_check_condition only does a literal string "0" check */
3075       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3076         boolvalue = TRUE;
3077       }
3078     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3079       boolvalue = TRUE;
3080     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3081       boolvalue = FALSE;
3082     else if (cond_type == ECOND_BOOL_LAX)
3083       boolvalue = TRUE;
3084     else
3085       {
3086       expand_string_message = string_sprintf("unrecognised boolean "
3087        "value \"%s\"", t);
3088       return NULL;
3089       }
3090     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3091         boolvalue? "true":"false");
3092     if (yield != NULL) *yield = (boolvalue == testfor);
3093     return s;
3094     }
3095
3096   /* Unknown condition */
3097
3098   default:
3099   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3100   return NULL;
3101   }   /* End switch on condition type */
3102
3103 /* Missing braces at start and end of data */
3104
3105 COND_FAILED_CURLY_START:
3106 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3107 return NULL;
3108
3109 COND_FAILED_CURLY_END:
3110 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3111   name);
3112 return NULL;
3113
3114 /* A condition requires code that is not compiled */
3115
3116 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3117     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3118     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3119 COND_FAILED_NOT_COMPILED:
3120 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3121   name);
3122 return NULL;
3123 #endif
3124 }
3125
3126
3127
3128
3129 /*************************************************
3130 *          Save numerical variables              *
3131 *************************************************/
3132
3133 /* This function is called from items such as "if" that want to preserve and
3134 restore the numbered variables.
3135
3136 Arguments:
3137   save_expand_string    points to an array of pointers to set
3138   save_expand_nlength   points to an array of ints for the lengths
3139
3140 Returns:                the value of expand max to save
3141 */
3142
3143 static int
3144 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3145 {
3146 int i;
3147 for (i = 0; i <= expand_nmax; i++)
3148   {
3149   save_expand_nstring[i] = expand_nstring[i];
3150   save_expand_nlength[i] = expand_nlength[i];
3151   }
3152 return expand_nmax;
3153 }
3154
3155
3156
3157 /*************************************************
3158 *           Restore numerical variables          *
3159 *************************************************/
3160
3161 /* This function restored saved values of numerical strings.
3162
3163 Arguments:
3164   save_expand_nmax      the number of strings to restore
3165   save_expand_string    points to an array of pointers
3166   save_expand_nlength   points to an array of ints
3167
3168 Returns:                nothing
3169 */
3170
3171 static void
3172 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3173   int *save_expand_nlength)
3174 {
3175 int i;
3176 expand_nmax = save_expand_nmax;
3177 for (i = 0; i <= expand_nmax; i++)
3178   {
3179   expand_nstring[i] = save_expand_nstring[i];
3180   expand_nlength[i] = save_expand_nlength[i];
3181   }
3182 }
3183
3184
3185
3186
3187
3188 /*************************************************
3189 *            Handle yes/no substrings            *
3190 *************************************************/
3191
3192 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3193 alternative substrings that depend on whether or not the condition was true,
3194 or the lookup or extraction succeeded. The substrings always have to be
3195 expanded, to check their syntax, but "skipping" is set when the result is not
3196 needed - this avoids unnecessary nested lookups.
3197
3198 Arguments:
3199   skipping       TRUE if we were skipping when this item was reached
3200   yes            TRUE if the first string is to be used, else use the second
3201   save_lookup    a value to put back into lookup_value before the 2nd expansion
3202   sptr           points to the input string pointer
3203   yieldptr       points to the output growable-string pointer
3204   type           "lookup", "if", "extract", "run", "env", "listextract" or
3205                  "certextract" for error message
3206   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3207                 the store.
3208
3209 Returns:         0 OK; lookup_value has been reset to save_lookup
3210                  1 expansion failed
3211                  2 expansion failed because of bracketing error
3212 */
3213
3214 static int
3215 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3216   gstring ** yieldptr, uschar *type, BOOL *resetok)
3217 {
3218 int rc = 0;
3219 const uschar *s = *sptr;    /* Local value */
3220 uschar *sub1, *sub2;
3221 const uschar * errwhere;
3222
3223 /* If there are no following strings, we substitute the contents of $value for
3224 lookups and for extractions in the success case. For the ${if item, the string
3225 "true" is substituted. In the fail case, nothing is substituted for all three
3226 items. */
3227
3228 while (isspace(*s)) s++;
3229 if (*s == '}')
3230   {
3231   if (type[0] == 'i')
3232     {
3233     if (yes && !skipping)
3234       *yieldptr = string_catn(*yieldptr, US"true", 4);
3235     }
3236   else
3237     {
3238     if (yes && lookup_value && !skipping)
3239       *yieldptr = string_cat(*yieldptr, lookup_value);
3240     lookup_value = save_lookup;
3241     }
3242   s++;
3243   goto RETURN;
3244   }
3245
3246 /* The first following string must be braced. */
3247
3248 if (*s++ != '{')
3249   {
3250   errwhere = US"'yes' part did not start with '{'";
3251   goto FAILED_CURLY;
3252   }
3253
3254 /* Expand the first substring. Forced failures are noticed only if we actually
3255 want this string. Set skipping in the call in the fail case (this will always
3256 be the case if we were already skipping). */
3257
3258 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3259 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3260 expand_string_forcedfail = FALSE;
3261 if (*s++ != '}')
3262   {
3263   errwhere = US"'yes' part did not end with '}'";
3264   goto FAILED_CURLY;
3265   }
3266
3267 /* If we want the first string, add it to the output */
3268
3269 if (yes)
3270   *yieldptr = string_cat(*yieldptr, sub1);
3271
3272 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3273 $value to what it was at the start of the item, so that it has this value
3274 during the second string expansion. For the call from "if" or "run" to this
3275 function, save_lookup is set to lookup_value, so that this statement does
3276 nothing. */
3277
3278 lookup_value = save_lookup;
3279
3280 /* There now follows either another substring, or "fail", or nothing. This
3281 time, forced failures are noticed only if we want the second string. We must
3282 set skipping in the nested call if we don't want this string, or if we were
3283 already skipping. */
3284
3285 while (isspace(*s)) s++;
3286 if (*s == '{')
3287   {
3288   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3289   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3290   expand_string_forcedfail = FALSE;
3291   if (*s++ != '}')
3292     {
3293     errwhere = US"'no' part did not start with '{'";
3294     goto FAILED_CURLY;
3295     }
3296
3297   /* If we want the second string, add it to the output */
3298
3299   if (!yes)
3300     *yieldptr = string_cat(*yieldptr, sub2);
3301   }
3302
3303 /* If there is no second string, but the word "fail" is present when the use of
3304 the second string is wanted, set a flag indicating it was a forced failure
3305 rather than a syntactic error. Swallow the terminating } in case this is nested
3306 inside another lookup or if or extract. */
3307
3308 else if (*s != '}')
3309   {
3310   uschar name[256];
3311   /* deconst cast ok here as source is s anyway */
3312   s = US read_name(name, sizeof(name), s, US"_");
3313   if (Ustrcmp(name, "fail") == 0)
3314     {
3315     if (!yes && !skipping)
3316       {
3317       while (isspace(*s)) s++;
3318       if (*s++ != '}')
3319         {
3320         errwhere = US"did not close with '}' after forcedfail";
3321         goto FAILED_CURLY;
3322         }
3323       expand_string_message =
3324         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3325       expand_string_forcedfail = TRUE;
3326       goto FAILED;
3327       }
3328     }
3329   else
3330     {
3331     expand_string_message =
3332       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3333     goto FAILED;
3334     }
3335   }
3336
3337 /* All we have to do now is to check on the final closing brace. */
3338
3339 while (isspace(*s)) s++;
3340 if (*s++ != '}')
3341   {
3342   errwhere = US"did not close with '}'";
3343   goto FAILED_CURLY;
3344   }
3345
3346
3347 RETURN:
3348 /* Update the input pointer value before returning */
3349 *sptr = s;
3350 return rc;
3351
3352 FAILED_CURLY:
3353   /* Get here if there is a bracketing failure */
3354   expand_string_message = string_sprintf(
3355     "curly-bracket problem in conditional yes/no parsing: %s\n"
3356     " remaining string is '%s'", errwhere, --s);
3357   rc = 2;
3358   goto RETURN;
3359
3360 FAILED:
3361   /* Get here for other failures */
3362   rc = 1;
3363   goto RETURN;
3364 }
3365
3366
3367
3368
3369 /*************************************************
3370 *    Handle MD5 or SHA-1 computation for HMAC    *
3371 *************************************************/
3372
3373 /* These are some wrapping functions that enable the HMAC code to be a bit
3374 cleaner. A good compiler will spot the tail recursion.
3375
3376 Arguments:
3377   type         HMAC_MD5 or HMAC_SHA1
3378   remaining    are as for the cryptographic hash functions
3379
3380 Returns:       nothing
3381 */
3382
3383 static void
3384 chash_start(int type, void *base)
3385 {
3386 if (type == HMAC_MD5)
3387   md5_start((md5 *)base);
3388 else
3389   sha1_start((hctx *)base);
3390 }
3391
3392 static void
3393 chash_mid(int type, void *base, uschar *string)
3394 {
3395 if (type == HMAC_MD5)
3396   md5_mid((md5 *)base, string);
3397 else
3398   sha1_mid((hctx *)base, string);
3399 }
3400
3401 static void
3402 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3403 {
3404 if (type == HMAC_MD5)
3405   md5_end((md5 *)base, string, length, digest);
3406 else
3407   sha1_end((hctx *)base, string, length, digest);
3408 }
3409
3410
3411
3412
3413
3414 /********************************************************
3415 * prvs: Get last three digits of days since Jan 1, 1970 *
3416 ********************************************************/
3417
3418 /* This is needed to implement the "prvs" BATV reverse
3419    path signing scheme
3420
3421 Argument: integer "days" offset to add or substract to
3422           or from the current number of days.
3423
3424 Returns:  pointer to string containing the last three
3425           digits of the number of days since Jan 1, 1970,
3426           modified by the offset argument, NULL if there
3427           was an error in the conversion.
3428
3429 */
3430
3431 static uschar *
3432 prvs_daystamp(int day_offset)
3433 {
3434 uschar *days = store_get(32);                /* Need at least 24 for cases */
3435 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3436   (time(NULL) + day_offset*86400)/86400);
3437 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3438 }
3439
3440
3441
3442 /********************************************************
3443 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3444 ********************************************************/
3445
3446 /* This is needed to implement the "prvs" BATV reverse
3447    path signing scheme
3448
3449 Arguments:
3450   address RFC2821 Address to use
3451       key The key to use (must be less than 64 characters
3452           in size)
3453   key_num Single-digit key number to use. Defaults to
3454           '0' when NULL.
3455
3456 Returns:  pointer to string containing the first three
3457           bytes of the final hash in hex format, NULL if
3458           there was an error in the process.
3459 */
3460
3461 static uschar *
3462 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3463 {
3464 gstring * hash_source;
3465 uschar * p;
3466 int i;
3467 hctx h;
3468 uschar innerhash[20];
3469 uschar finalhash[20];
3470 uschar innerkey[64];
3471 uschar outerkey[64];
3472 uschar *finalhash_hex = store_get(40);
3473
3474 if (key_num == NULL)
3475   key_num = US"0";
3476
3477 if (Ustrlen(key) > 64)
3478   return NULL;
3479
3480 hash_source = string_catn(NULL, key_num, 1);
3481 hash_source = string_catn(hash_source, daystamp, 3);
3482 hash_source = string_cat(hash_source, address);
3483 (void) string_from_gstring(hash_source);
3484
3485 DEBUG(D_expand)
3486   debug_printf_indent("prvs: hash source is '%s'\n", hash_source->s);
3487
3488 memset(innerkey, 0x36, 64);
3489 memset(outerkey, 0x5c, 64);
3490
3491 for (i = 0; i < Ustrlen(key); i++)
3492   {
3493   innerkey[i] ^= key[i];
3494   outerkey[i] ^= key[i];
3495   }
3496
3497 chash_start(HMAC_SHA1, &h);
3498 chash_mid(HMAC_SHA1, &h, innerkey);
3499 chash_end(HMAC_SHA1, &h, hash_source->s, hash_source->ptr, innerhash);
3500
3501 chash_start(HMAC_SHA1, &h);
3502 chash_mid(HMAC_SHA1, &h, outerkey);
3503 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3504
3505 p = finalhash_hex;
3506 for (i = 0; i < 3; i++)
3507   {
3508   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3509   *p++ = hex_digits[finalhash[i] & 0x0f];
3510   }
3511 *p = '\0';
3512
3513 return finalhash_hex;
3514 }
3515
3516
3517
3518
3519 /*************************************************
3520 *        Join a file onto the output string      *
3521 *************************************************/
3522
3523 /* This is used for readfile/readsock and after a run expansion.
3524 It joins the contents of a file onto the output string, globally replacing
3525 newlines with a given string (optionally).
3526
3527 Arguments:
3528   f            the FILE
3529   yield        pointer to the expandable string struct
3530   eol          newline replacement string, or NULL
3531
3532 Returns:       new pointer for expandable string, terminated if non-null
3533 */
3534
3535 static gstring *
3536 cat_file(FILE *f, gstring *yield, uschar *eol)
3537 {
3538 uschar buffer[1024];
3539
3540 while (Ufgets(buffer, sizeof(buffer), f))
3541   {
3542   int len = Ustrlen(buffer);
3543   if (eol && buffer[len-1] == '\n') len--;
3544   yield = string_catn(yield, buffer, len);
3545   if (eol && buffer[len])
3546     yield = string_cat(yield, eol);
3547   }
3548
3549 (void) string_from_gstring(yield);
3550 return yield;
3551 }
3552
3553
3554
3555
3556 /*************************************************
3557 *          Evaluate numeric expression           *
3558 *************************************************/
3559
3560 /* This is a set of mutually recursive functions that evaluate an arithmetic
3561 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3562 these functions that is called from elsewhere is eval_expr, whose interface is:
3563
3564 Arguments:
3565   sptr        pointer to the pointer to the string - gets updated
3566   decimal     TRUE if numbers are to be assumed decimal
3567   error       pointer to where to put an error message - must be NULL on input
3568   endket      TRUE if ')' must terminate - FALSE for external call
3569
3570 Returns:      on success: the value of the expression, with *error still NULL
3571               on failure: an undefined value, with *error = a message
3572 */
3573
3574 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3575
3576
3577 static int_eximarith_t
3578 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3579 {
3580 uschar *s = *sptr;
3581 int_eximarith_t x = eval_op_or(&s, decimal, error);
3582 if (*error == NULL)
3583   {
3584   if (endket)
3585     {
3586     if (*s != ')')
3587       *error = US"expecting closing parenthesis";
3588     else
3589       while (isspace(*(++s)));
3590     }
3591   else if (*s != 0) *error = US"expecting operator";
3592   }
3593 *sptr = s;
3594 return x;
3595 }
3596
3597
3598 static int_eximarith_t
3599 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3600 {
3601 register int c;
3602 int_eximarith_t n;
3603 uschar *s = *sptr;
3604 while (isspace(*s)) s++;
3605 c = *s;
3606 if (isdigit(c))
3607   {
3608   int count;
3609   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3610   s += count;
3611   switch (tolower(*s))
3612     {
3613     default: break;
3614     case 'k': n *= 1024; s++; break;
3615     case 'm': n *= 1024*1024; s++; break;
3616     case 'g': n *= 1024*1024*1024; s++; break;
3617     }
3618   while (isspace (*s)) s++;
3619   }
3620 else if (c == '(')
3621   {
3622   s++;
3623   n = eval_expr(&s, decimal, error, 1);
3624   }
3625 else
3626   {
3627   *error = US"expecting number or opening parenthesis";
3628   n = 0;
3629   }
3630 *sptr = s;
3631 return n;
3632 }
3633
3634
3635 static int_eximarith_t
3636 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3637 {
3638 uschar *s = *sptr;
3639 int_eximarith_t x;
3640 while (isspace(*s)) s++;
3641 if (*s == '+' || *s == '-' || *s == '~')
3642   {
3643   int op = *s++;
3644   x = eval_op_unary(&s, decimal, error);
3645   if (op == '-') x = -x;
3646     else if (op == '~') x = ~x;
3647   }
3648 else
3649   {
3650   x = eval_number(&s, decimal, error);
3651   }
3652 *sptr = s;
3653 return x;
3654 }
3655
3656
3657 static int_eximarith_t
3658 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3659 {
3660 uschar *s = *sptr;
3661 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3662 if (*error == NULL)
3663   {
3664   while (*s == '*' || *s == '/' || *s == '%')
3665     {
3666     int op = *s++;
3667     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3668     if (*error != NULL) break;
3669     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3670      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3671      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3672      * -N*M is INT_MIN will yield INT_MIN.
3673      * Since we don't support floating point, this is somewhat simpler.
3674      * Ideally, we'd return an error, but since we overflow for all other
3675      * arithmetic, consistency suggests otherwise, but what's the correct value
3676      * to use?  There is none.
3677      * The C standard guarantees overflow for unsigned arithmetic but signed
3678      * overflow invokes undefined behaviour; in practice, this is overflow
3679      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3680      * that long/longlong larger than int are available, or we could just work
3681      * with larger types.  We should consider whether to guarantee 32bit eval
3682      * and 64-bit working variables, with errors returned.  For now ...
3683      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3684      * can just let the other invalid results occur otherwise, as they have
3685      * until now.  For this one case, we can coerce.
3686      */
3687     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3688       {
3689       DEBUG(D_expand)
3690         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3691             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3692       x = EXIM_ARITH_MAX;
3693       continue;
3694       }
3695     if (op == '*')
3696       x *= y;
3697     else
3698       {
3699       if (y == 0)
3700         {
3701         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3702         x = 0;
3703         break;
3704         }
3705       if (op == '/')
3706         x /= y;
3707       else
3708         x %= y;
3709       }
3710     }
3711   }
3712 *sptr = s;
3713 return x;
3714 }
3715
3716
3717 static int_eximarith_t
3718 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3719 {
3720 uschar *s = *sptr;
3721 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3722 if (!*error)
3723   {
3724   while (*s == '+' || *s == '-')
3725     {
3726     int op = *s++;
3727     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3728     if (*error) break;
3729     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3730        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3731       {                 /* over-conservative check */
3732       *error = op == '+'
3733         ? US"overflow in sum" : US"overflow in difference";
3734       break;
3735       }
3736     if (op == '+') x += y; else x -= y;
3737     }
3738   }
3739 *sptr = s;
3740 return x;
3741 }
3742
3743
3744 static int_eximarith_t
3745 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3746 {
3747 uschar *s = *sptr;
3748 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3749 if (*error == NULL)
3750   {
3751   while ((*s == '<' || *s == '>') && s[1] == s[0])
3752     {
3753     int_eximarith_t y;
3754     int op = *s++;
3755     s++;
3756     y = eval_op_sum(&s, decimal, error);
3757     if (*error != NULL) break;
3758     if (op == '<') x <<= y; else x >>= y;
3759     }
3760   }
3761 *sptr = s;
3762 return x;
3763 }
3764
3765
3766 static int_eximarith_t
3767 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3768 {
3769 uschar *s = *sptr;
3770 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3771 if (*error == NULL)
3772   {
3773   while (*s == '&')
3774     {
3775     int_eximarith_t y;
3776     s++;
3777     y = eval_op_shift(&s, decimal, error);
3778     if (*error != NULL) break;
3779     x &= y;
3780     }
3781   }
3782 *sptr = s;
3783 return x;
3784 }
3785
3786
3787 static int_eximarith_t
3788 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3789 {
3790 uschar *s = *sptr;
3791 int_eximarith_t x = eval_op_and(&s, decimal, error);
3792 if (*error == NULL)
3793   {
3794   while (*s == '^')
3795     {
3796     int_eximarith_t y;
3797     s++;
3798     y = eval_op_and(&s, decimal, error);
3799     if (*error != NULL) break;
3800     x ^= y;
3801     }
3802   }
3803 *sptr = s;
3804 return x;
3805 }
3806
3807
3808 static int_eximarith_t
3809 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3810 {
3811 uschar *s = *sptr;
3812 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3813 if (*error == NULL)
3814   {
3815   while (*s == '|')
3816     {
3817     int_eximarith_t y;
3818     s++;
3819     y = eval_op_xor(&s, decimal, error);
3820     if (*error != NULL) break;
3821     x |= y;
3822     }
3823   }
3824 *sptr = s;
3825 return x;
3826 }
3827
3828
3829
3830 /*************************************************
3831 *                 Expand string                  *
3832 *************************************************/
3833
3834 /* Returns either an unchanged string, or the expanded string in stacking pool
3835 store. Interpreted sequences are:
3836
3837    \...                    normal escaping rules
3838    $name                   substitutes the variable
3839    ${name}                 ditto
3840    ${op:string}            operates on the expanded string value
3841    ${item{arg1}{arg2}...}  expands the args and then does the business
3842                              some literal args are not enclosed in {}
3843
3844 There are now far too many operators and item types to make it worth listing
3845 them here in detail any more.
3846
3847 We use an internal routine recursively to handle embedded substrings. The
3848 external function follows. The yield is NULL if the expansion failed, and there
3849 are two cases: if something collapsed syntactically, or if "fail" was given
3850 as the action on a lookup failure. These can be distinguished by looking at the
3851 variable expand_string_forcedfail, which is TRUE in the latter case.
3852
3853 The skipping flag is set true when expanding a substring that isn't actually
3854 going to be used (after "if" or "lookup") and it prevents lookups from
3855 happening lower down.
3856
3857 Store usage: At start, a store block of the length of the input plus 64
3858 is obtained. This is expanded as necessary by string_cat(), which might have to
3859 get a new block, or might be able to expand the original. At the end of the
3860 function we can release any store above that portion of the yield block that
3861 was actually used. In many cases this will be optimal.
3862
3863 However: if the first item in the expansion is a variable name or header name,
3864 we reset the store before processing it; if the result is in fresh store, we
3865 use that without copying. This is helpful for expanding strings like
3866 $message_headers which can get very long.
3867
3868 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3869 since resetting the store at the end of the expansion will free store that was
3870 allocated by the plugin code as well as the slop after the expanded string. So
3871 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3872 and, given the acl condition, ${if }. This is an unfortunate consequence of
3873 string expansion becoming too powerful.
3874
3875 Arguments:
3876   string         the string to be expanded
3877   ket_ends       true if expansion is to stop at }
3878   left           if not NULL, a pointer to the first character after the
3879                  expansion is placed here (typically used with ket_ends)
3880   skipping       TRUE for recursive calls when the value isn't actually going
3881                  to be used (to allow for optimisation)
3882   honour_dollar  TRUE if $ is to be expanded,
3883                  FALSE if it's just another character
3884   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3885                  the store.
3886
3887 Returns:         NULL if expansion fails:
3888                    expand_string_forcedfail is set TRUE if failure was forced
3889                    expand_string_message contains a textual error message
3890                  a pointer to the expanded string on success
3891 */
3892
3893 static uschar *
3894 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3895   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3896 {
3897 gstring * yield = string_get(Ustrlen(string) + 64);
3898 int item_type;
3899 const uschar *s = string;
3900 uschar *save_expand_nstring[EXPAND_MAXN+1];
3901 int save_expand_nlength[EXPAND_MAXN+1];
3902 BOOL resetok = TRUE;
3903
3904 expand_level++;
3905 DEBUG(D_expand)
3906   debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
3907     skipping
3908     ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
3909     : "considering",
3910     string);
3911
3912 expand_string_forcedfail = FALSE;
3913 expand_string_message = US"";
3914
3915 while (*s != 0)
3916   {
3917   uschar *value;
3918   uschar name[256];
3919
3920   /* \ escapes the next character, which must exist, or else
3921   the expansion fails. There's a special escape, \N, which causes
3922   copying of the subject verbatim up to the next \N. Otherwise,
3923   the escapes are the standard set. */
3924
3925   if (*s == '\\')
3926     {
3927     if (s[1] == 0)
3928       {
3929       expand_string_message = US"\\ at end of string";
3930       goto EXPAND_FAILED;
3931       }
3932
3933     if (s[1] == 'N')
3934       {
3935       const uschar * t = s + 2;
3936       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3937       yield = string_catn(yield, t, s - t);
3938       if (*s != 0) s += 2;
3939       }
3940
3941     else
3942       {
3943       uschar ch[1];
3944       ch[0] = string_interpret_escape(&s);
3945       s++;
3946       yield = string_catn(yield, ch, 1);
3947       }
3948
3949     continue;
3950     }
3951
3952   /*{*/
3953   /* Anything other than $ is just copied verbatim, unless we are
3954   looking for a terminating } character. */
3955
3956   /*{*/
3957   if (ket_ends && *s == '}') break;
3958
3959   if (*s != '$' || !honour_dollar)
3960     {
3961     yield = string_catn(yield, s++, 1);
3962     continue;
3963     }
3964
3965   /* No { after the $ - must be a plain name or a number for string
3966   match variable. There has to be a fudge for variables that are the
3967   names of header fields preceded by "$header_" because header field
3968   names can contain any printing characters except space and colon.
3969   For those that don't like typing this much, "$h_" is a synonym for
3970   "$header_". A non-existent header yields a NULL value; nothing is
3971   inserted. */  /*}*/
3972
3973   if (isalpha((*(++s))))
3974     {
3975     int len;
3976     int newsize = 0;
3977     gstring * g = NULL;
3978
3979     s = read_name(name, sizeof(name), s, US"_");
3980
3981     /* If this is the first thing to be expanded, release the pre-allocated
3982     buffer. */
3983
3984     if (!yield)
3985       g = store_get(sizeof(gstring));
3986     else if (yield->ptr == 0)
3987       {
3988       if (resetok) store_reset(yield);
3989       yield = NULL;
3990       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
3991       }
3992
3993     /* Header */
3994
3995     if (Ustrncmp(name, "h_", 2) == 0 ||
3996         Ustrncmp(name, "rh_", 3) == 0 ||
3997         Ustrncmp(name, "bh_", 3) == 0 ||
3998         Ustrncmp(name, "header_", 7) == 0 ||
3999         Ustrncmp(name, "rheader_", 8) == 0 ||
4000         Ustrncmp(name, "bheader_", 8) == 0)
4001       {
4002       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
4003       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
4004       s = read_header_name(name, sizeof(name), s);
4005       value = find_header(name, FALSE, &newsize, want_raw, charset);
4006
4007       /* If we didn't find the header, and the header contains a closing brace
4008       character, this may be a user error where the terminating colon
4009       has been omitted. Set a flag to adjust the error message in this case.
4010       But there is no error here - nothing gets inserted. */
4011
4012       if (!value)
4013         {
4014         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
4015         continue;
4016         }
4017       }
4018
4019     /* Variable */
4020
4021     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
4022       {
4023       expand_string_message =
4024         string_sprintf("unknown variable name \"%s\"", name);
4025         check_variable_error_message(name);
4026       goto EXPAND_FAILED;
4027       }
4028
4029     /* If the data is known to be in a new buffer, newsize will be set to the
4030     size of that buffer. If this is the first thing in an expansion string,
4031     yield will be NULL; just point it at the new store instead of copying. Many
4032     expansion strings contain just one reference, so this is a useful
4033     optimization, especially for humungous headers.  We need to use a gstring
4034     structure that is not allocated after that new-buffer, else a later store
4035     reset in the middle of the buffer will make it inaccessible. */
4036
4037     len = Ustrlen(value);
4038     if (!yield && newsize != 0)
4039       {
4040       yield = g;
4041       yield->size = newsize;
4042       yield->ptr = len;
4043       yield->s = value;
4044       }
4045     else
4046       yield = string_catn(yield, value, len);
4047
4048     continue;
4049     }
4050
4051   if (isdigit(*s))
4052     {
4053     int n;
4054     s = read_cnumber(&n, s);
4055     if (n >= 0 && n <= expand_nmax)
4056       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4057     continue;
4058     }
4059
4060   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4061
4062   if (*s != '{')                                                        /*}*/
4063     {
4064     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4065     goto EXPAND_FAILED;
4066     }
4067
4068   /* After { there can be various things, but they all start with
4069   an initial word, except for a number for a string match variable. */
4070
4071   if (isdigit((*(++s))))
4072     {
4073     int n;
4074     s = read_cnumber(&n, s);            /*{*/
4075     if (*s++ != '}')
4076       {                                 /*{*/
4077       expand_string_message = US"} expected after number";
4078       goto EXPAND_FAILED;
4079       }
4080     if (n >= 0 && n <= expand_nmax)
4081       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4082     continue;
4083     }
4084
4085   if (!isalpha(*s))
4086     {
4087     expand_string_message = US"letter or digit expected after ${";      /*}*/
4088     goto EXPAND_FAILED;
4089     }
4090
4091   /* Allow "-" in names to cater for substrings with negative
4092   arguments. Since we are checking for known names after { this is
4093   OK. */
4094
4095   s = read_name(name, sizeof(name), s, US"_-");
4096   item_type = chop_match(name, item_table, nelem(item_table));
4097
4098   switch(item_type)
4099     {
4100     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4101     If the ACL returns accept or reject we return content set by "message ="
4102     There is currently no limit on recursion; this would have us call
4103     acl_check_internal() directly and get a current level from somewhere.
4104     See also the acl expansion condition ECOND_ACL and the traditional
4105     acl modifier ACLC_ACL.
4106     Assume that the function has side-effects on the store that must be preserved.
4107     */
4108
4109     case EITEM_ACL:
4110       /* ${acl {name} {arg1}{arg2}...} */
4111       {
4112       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4113       uschar *user_msg;
4114
4115       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4116                       &resetok))
4117         {
4118         case 1: goto EXPAND_FAILED_CURLY;
4119         case 2:
4120         case 3: goto EXPAND_FAILED;
4121         }
4122       if (skipping) continue;
4123
4124       resetok = FALSE;
4125       switch(eval_acl(sub, nelem(sub), &user_msg))
4126         {
4127         case OK:
4128         case FAIL:
4129           DEBUG(D_expand)
4130             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4131           if (user_msg)
4132             yield = string_cat(yield, user_msg);
4133           continue;
4134
4135         case DEFER:
4136           expand_string_forcedfail = TRUE;
4137           /*FALLTHROUGH*/
4138         default:
4139           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4140           goto EXPAND_FAILED;
4141         }
4142       }
4143
4144     case EITEM_AUTHRESULTS:
4145       /* ${authresults {mysystemname}} */
4146       {
4147       uschar *sub_arg[1];
4148
4149       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4150                       &resetok))
4151         {
4152         case 1: goto EXPAND_FAILED_CURLY;
4153         case 2:
4154         case 3: goto EXPAND_FAILED;
4155         }
4156
4157       yield = string_append(yield, 3,
4158                         US"Authentication-Results: ", sub_arg[0], US"; none");
4159       yield->ptr -= 6;
4160
4161       yield = authres_local(yield, sub_arg[0]);
4162       yield = authres_iprev(yield);
4163       yield = authres_smtpauth(yield);
4164 #ifdef SUPPORT_SPF
4165       yield = authres_spf(yield);
4166 #endif
4167 #ifndef DISABLE_DKIM
4168       yield = authres_dkim(yield);
4169 #endif
4170 #ifdef EXPERIMENTAL_DMARC
4171       yield = authres_dmarc(yield);
4172 #endif
4173 #ifdef EXPERIMENTAL_ARC
4174       yield = authres_arc(yield);
4175 #endif
4176       continue;
4177       }
4178
4179     /* Handle conditionals - preserve the values of the numerical expansion
4180     variables in case they get changed by a regular expression match in the
4181     condition. If not, they retain their external settings. At the end
4182     of this "if" section, they get restored to their previous values. */
4183
4184     case EITEM_IF:
4185       {
4186       BOOL cond = FALSE;
4187       const uschar *next_s;
4188       int save_expand_nmax =
4189         save_expand_strings(save_expand_nstring, save_expand_nlength);
4190
4191       while (isspace(*s)) s++;
4192       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4193       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4194
4195       DEBUG(D_expand)
4196         {
4197         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4198           "condition: %.*s\n",
4199           (int)(next_s - s), s);
4200         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4201           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4202           "result: %s\n",
4203           cond ? "true" : "false");
4204         }
4205
4206       s = next_s;
4207
4208       /* The handling of "yes" and "no" result strings is now in a separate
4209       function that is also used by ${lookup} and ${extract} and ${run}. */
4210
4211       switch(process_yesno(
4212                skipping,                     /* were previously skipping */
4213                cond,                         /* success/failure indicator */
4214                lookup_value,                 /* value to reset for string2 */
4215                &s,                           /* input pointer */
4216                &yield,                       /* output pointer */
4217                US"if",                       /* condition type */
4218                &resetok))
4219         {
4220         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4221         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4222         }
4223
4224       /* Restore external setting of expansion variables for continuation
4225       at this level. */
4226
4227       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4228         save_expand_nlength);
4229       continue;
4230       }
4231
4232 #ifdef SUPPORT_I18N
4233     case EITEM_IMAPFOLDER:
4234       {                         /* ${imapfolder {name}{sep]{specials}} */
4235       uschar *sub_arg[3];
4236       uschar *encoded;
4237
4238       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4239                       &resetok))
4240         {
4241         case 1: goto EXPAND_FAILED_CURLY;
4242         case 2:
4243         case 3: goto EXPAND_FAILED;
4244         }
4245
4246       if (sub_arg[1] == NULL)           /* One argument */
4247         {
4248         sub_arg[1] = US"/";             /* default separator */
4249         sub_arg[2] = NULL;
4250         }
4251       else if (Ustrlen(sub_arg[1]) != 1)
4252         {
4253         expand_string_message =
4254           string_sprintf(
4255                 "IMAP folder separator must be one character, found \"%s\"",
4256                 sub_arg[1]);
4257         goto EXPAND_FAILED;
4258         }
4259
4260       if (!skipping)
4261         {
4262         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4263                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4264           goto EXPAND_FAILED;
4265         yield = string_cat(yield, encoded);
4266         }
4267       continue;
4268       }
4269 #endif
4270
4271     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4272     expanding an internal string that isn't actually going to be used. All we
4273     need to do is check the syntax, so don't do a lookup at all. Preserve the
4274     values of the numerical expansion variables in case they get changed by a
4275     partial lookup. If not, they retain their external settings. At the end
4276     of this "lookup" section, they get restored to their previous values. */
4277
4278     case EITEM_LOOKUP:
4279       {
4280       int stype, partial, affixlen, starflags;
4281       int expand_setup = 0;
4282       int nameptr = 0;
4283       uschar *key, *filename;
4284       const uschar *affix;
4285       uschar *save_lookup_value = lookup_value;
4286       int save_expand_nmax =
4287         save_expand_strings(save_expand_nstring, save_expand_nlength);
4288
4289       if ((expand_forbid & RDO_LOOKUP) != 0)
4290         {
4291         expand_string_message = US"lookup expansions are not permitted";
4292         goto EXPAND_FAILED;
4293         }
4294
4295       /* Get the key we are to look up for single-key+file style lookups.
4296       Otherwise set the key NULL pro-tem. */
4297
4298       while (isspace(*s)) s++;
4299       if (*s == '{')                                    /*}*/
4300         {
4301         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4302         if (!key) goto EXPAND_FAILED;                   /*{{*/
4303         if (*s++ != '}')
4304           {
4305           expand_string_message = US"missing '}' after lookup key";
4306           goto EXPAND_FAILED_CURLY;
4307           }
4308         while (isspace(*s)) s++;
4309         }
4310       else key = NULL;
4311
4312       /* Find out the type of database */
4313
4314       if (!isalpha(*s))
4315         {
4316         expand_string_message = US"missing lookup type";
4317         goto EXPAND_FAILED;
4318         }
4319
4320       /* The type is a string that may contain special characters of various
4321       kinds. Allow everything except space or { to appear; the actual content
4322       is checked by search_findtype_partial. */         /*}*/
4323
4324       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4325         {
4326         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4327         s++;
4328         }
4329       name[nameptr] = 0;
4330       while (isspace(*s)) s++;
4331
4332       /* Now check for the individual search type and any partial or default
4333       options. Only those types that are actually in the binary are valid. */
4334
4335       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4336         &starflags);
4337       if (stype < 0)
4338         {
4339         expand_string_message = search_error_message;
4340         goto EXPAND_FAILED;
4341         }
4342
4343       /* Check that a key was provided for those lookup types that need it,
4344       and was not supplied for those that use the query style. */
4345
4346       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4347         {
4348         if (key == NULL)
4349           {
4350           expand_string_message = string_sprintf("missing {key} for single-"
4351             "key \"%s\" lookup", name);
4352           goto EXPAND_FAILED;
4353           }
4354         }
4355       else
4356         {
4357         if (key != NULL)
4358           {
4359           expand_string_message = string_sprintf("a single key was given for "
4360             "lookup type \"%s\", which is not a single-key lookup type", name);
4361           goto EXPAND_FAILED;
4362           }
4363         }
4364
4365       /* Get the next string in brackets and expand it. It is the file name for
4366       single-key+file lookups, and the whole query otherwise. In the case of
4367       queries that also require a file name (e.g. sqlite), the file name comes
4368       first. */
4369
4370       if (*s != '{')
4371         {
4372         expand_string_message = US"missing '{' for lookup file-or-query arg";
4373         goto EXPAND_FAILED_CURLY;
4374         }
4375       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4376       if (filename == NULL) goto EXPAND_FAILED;
4377       if (*s++ != '}')
4378         {
4379         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4380         goto EXPAND_FAILED_CURLY;
4381         }
4382       while (isspace(*s)) s++;
4383
4384       /* If this isn't a single-key+file lookup, re-arrange the variables
4385       to be appropriate for the search_ functions. For query-style lookups,
4386       there is just a "key", and no file name. For the special query-style +
4387       file types, the query (i.e. "key") starts with a file name. */
4388
4389       if (!key)
4390         {
4391         while (isspace(*filename)) filename++;
4392         key = filename;
4393
4394         if (mac_islookup(stype, lookup_querystyle))
4395           filename = NULL;
4396         else
4397           {
4398           if (*filename != '/')
4399             {
4400             expand_string_message = string_sprintf(
4401               "absolute file name expected for \"%s\" lookup", name);
4402             goto EXPAND_FAILED;
4403             }
4404           while (*key != 0 && !isspace(*key)) key++;
4405           if (*key != 0) *key++ = 0;
4406           }
4407         }
4408
4409       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4410       the entry was not found. Note that there is no search_close() function.
4411       Files are left open in case of re-use. At suitable places in higher logic,
4412       search_tidyup() is called to tidy all open files. This can save opening
4413       the same file several times. However, files may also get closed when
4414       others are opened, if too many are open at once. The rule is that a
4415       handle should not be used after a second search_open().
4416
4417       Request that a partial search sets up $1 and maybe $2 by passing
4418       expand_setup containing zero. If its value changes, reset expand_nmax,
4419       since new variables will have been set. Note that at the end of this
4420       "lookup" section, the old numeric variables are restored. */
4421
4422       if (skipping)
4423         lookup_value = NULL;
4424       else
4425         {
4426         void *handle = search_open(filename, stype, 0, NULL, NULL);
4427         if (handle == NULL)
4428           {
4429           expand_string_message = search_error_message;
4430           goto EXPAND_FAILED;
4431           }
4432         lookup_value = search_find(handle, filename, key, partial, affix,
4433           affixlen, starflags, &expand_setup);
4434         if (search_find_defer)
4435           {
4436           expand_string_message =
4437             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4438               string_printing2(key, FALSE), search_error_message);
4439           goto EXPAND_FAILED;
4440           }
4441         if (expand_setup > 0) expand_nmax = expand_setup;
4442         }
4443
4444       /* The handling of "yes" and "no" result strings is now in a separate
4445       function that is also used by ${if} and ${extract}. */
4446
4447       switch(process_yesno(
4448                skipping,                     /* were previously skipping */
4449                lookup_value != NULL,         /* success/failure indicator */
4450                save_lookup_value,            /* value to reset for string2 */
4451                &s,                           /* input pointer */
4452                &yield,                       /* output pointer */
4453                US"lookup",                   /* condition type */
4454                &resetok))
4455         {
4456         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4457         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4458         }
4459
4460       /* Restore external setting of expansion variables for carrying on
4461       at this level, and continue. */
4462
4463       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4464         save_expand_nlength);
4465       continue;
4466       }
4467
4468     /* If Perl support is configured, handle calling embedded perl subroutines,
4469     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4470     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4471     arguments (defined below). */
4472
4473     #define EXIM_PERL_MAX_ARGS 8
4474
4475     case EITEM_PERL:
4476     #ifndef EXIM_PERL
4477     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4478       "is not included in this binary";
4479     goto EXPAND_FAILED;
4480
4481     #else   /* EXIM_PERL */
4482       {
4483       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4484       gstring *new_yield;
4485
4486       if ((expand_forbid & RDO_PERL) != 0)
4487         {
4488         expand_string_message = US"Perl calls are not permitted";
4489         goto EXPAND_FAILED;
4490         }
4491
4492       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4493            US"perl", &resetok))
4494         {
4495         case 1: goto EXPAND_FAILED_CURLY;
4496         case 2:
4497         case 3: goto EXPAND_FAILED;
4498         }
4499
4500       /* If skipping, we don't actually do anything */
4501
4502       if (skipping) continue;
4503
4504       /* Start the interpreter if necessary */
4505
4506       if (!opt_perl_started)
4507         {
4508         uschar *initerror;
4509         if (opt_perl_startup == NULL)
4510           {
4511           expand_string_message = US"A setting of perl_startup is needed when "
4512             "using the Perl interpreter";
4513           goto EXPAND_FAILED;
4514           }
4515         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4516         initerror = init_perl(opt_perl_startup);
4517         if (initerror != NULL)
4518           {
4519           expand_string_message =
4520             string_sprintf("error in perl_startup code: %s\n", initerror);
4521           goto EXPAND_FAILED;
4522           }
4523         opt_perl_started = TRUE;
4524         }
4525
4526       /* Call the function */
4527
4528       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4529       new_yield = call_perl_cat(yield, &expand_string_message,
4530         sub_arg[0], sub_arg + 1);
4531
4532       /* NULL yield indicates failure; if the message pointer has been set to
4533       NULL, the yield was undef, indicating a forced failure. Otherwise the
4534       message will indicate some kind of Perl error. */
4535
4536       if (new_yield == NULL)
4537         {
4538         if (expand_string_message == NULL)
4539           {
4540           expand_string_message =
4541             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4542               "failure", sub_arg[0]);
4543           expand_string_forcedfail = TRUE;
4544           }
4545         goto EXPAND_FAILED;
4546         }
4547
4548       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4549       set during a callback from Perl. */
4550
4551       expand_string_forcedfail = FALSE;
4552       yield = new_yield;
4553       continue;
4554       }
4555     #endif /* EXIM_PERL */
4556
4557     /* Transform email address to "prvs" scheme to use
4558        as BATV-signed return path */
4559
4560     case EITEM_PRVS:
4561       {
4562       uschar *sub_arg[3];
4563       uschar *p,*domain;
4564
4565       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4566         {
4567         case 1: goto EXPAND_FAILED_CURLY;
4568         case 2:
4569         case 3: goto EXPAND_FAILED;
4570         }
4571
4572       /* If skipping, we don't actually do anything */
4573       if (skipping) continue;
4574
4575       /* sub_arg[0] is the address */
4576       if (  !(domain = Ustrrchr(sub_arg[0],'@'))
4577          || domain == sub_arg[0] || Ustrlen(domain) == 1)
4578         {
4579         expand_string_message = US"prvs first argument must be a qualified email address";
4580         goto EXPAND_FAILED;
4581         }
4582
4583       /* Calculate the hash. The third argument must be a single-digit
4584       key number, or unset. */
4585
4586       if (  sub_arg[2]
4587          && (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4588         {
4589         expand_string_message = US"prvs third argument must be a single digit";
4590         goto EXPAND_FAILED;
4591         }
4592
4593       p = prvs_hmac_sha1(sub_arg[0], sub_arg[1], sub_arg[2], prvs_daystamp(7));
4594       if (!p)
4595         {
4596         expand_string_message = US"prvs hmac-sha1 conversion failed";
4597         goto EXPAND_FAILED;
4598         }
4599
4600       /* Now separate the domain from the local part */
4601       *domain++ = '\0';
4602
4603       yield = string_catn(yield, US"prvs=", 5);
4604       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
4605       yield = string_catn(yield, prvs_daystamp(7), 3);
4606       yield = string_catn(yield, p, 6);
4607       yield = string_catn(yield, US"=", 1);
4608       yield = string_cat (yield, sub_arg[0]);
4609       yield = string_catn(yield, US"@", 1);
4610       yield = string_cat (yield, domain);
4611
4612       continue;
4613       }
4614
4615     /* Check a prvs-encoded address for validity */
4616
4617     case EITEM_PRVSCHECK:
4618       {
4619       uschar *sub_arg[3];
4620       gstring * g;
4621       const pcre *re;
4622       uschar *p;
4623
4624       /* TF: Ugliness: We want to expand parameter 1 first, then set
4625          up expansion variables that are used in the expansion of
4626          parameter 2. So we clone the string for the first
4627          expansion, where we only expand parameter 1.
4628
4629          PH: Actually, that isn't necessary. The read_subs() function is
4630          designed to work this way for the ${if and ${lookup expansions. I've
4631          tidied the code.
4632       */
4633
4634       /* Reset expansion variables */
4635       prvscheck_result = NULL;
4636       prvscheck_address = NULL;
4637       prvscheck_keynum = NULL;
4638
4639       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4640         {
4641         case 1: goto EXPAND_FAILED_CURLY;
4642         case 2:
4643         case 3: goto EXPAND_FAILED;
4644         }
4645
4646       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4647                               TRUE,FALSE);
4648
4649       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4650         {
4651         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4652         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4653         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4654         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4655         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4656
4657         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4658         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4659         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4660         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4661         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4662
4663         /* Set up expansion variables */
4664         g = string_cat (NULL, local_part);
4665         g = string_catn(g, US"@", 1);
4666         g = string_cat (g, domain);
4667         prvscheck_address = string_from_gstring(g);
4668         prvscheck_keynum = string_copy(key_num);
4669
4670         /* Now expand the second argument */
4671         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4672           {
4673           case 1: goto EXPAND_FAILED_CURLY;
4674           case 2:
4675           case 3: goto EXPAND_FAILED;
4676           }
4677
4678         /* Now we have the key and can check the address. */
4679
4680         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4681           daystamp);
4682
4683         if (!p)
4684           {
4685           expand_string_message = US"hmac-sha1 conversion failed";
4686           goto EXPAND_FAILED;
4687           }
4688
4689         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4690         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4691
4692         if (Ustrcmp(p,hash) == 0)
4693           {
4694           /* Success, valid BATV address. Now check the expiry date. */
4695           uschar *now = prvs_daystamp(0);
4696           unsigned int inow = 0,iexpire = 1;
4697
4698           (void)sscanf(CS now,"%u",&inow);
4699           (void)sscanf(CS daystamp,"%u",&iexpire);
4700
4701           /* When "iexpire" is < 7, a "flip" has occured.
4702              Adjust "inow" accordingly. */
4703           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4704
4705           if (iexpire >= inow)
4706             {
4707             prvscheck_result = US"1";
4708             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4709             }
4710           else
4711             {
4712             prvscheck_result = NULL;
4713             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4714             }
4715           }
4716         else
4717           {
4718           prvscheck_result = NULL;
4719           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4720           }
4721
4722         /* Now expand the final argument. We leave this till now so that
4723         it can include $prvscheck_result. */
4724
4725         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4726           {
4727           case 1: goto EXPAND_FAILED_CURLY;
4728           case 2:
4729           case 3: goto EXPAND_FAILED;
4730           }
4731
4732         yield = string_cat(yield,
4733           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4734
4735         /* Reset the "internal" variables afterwards, because they are in
4736         dynamic store that will be reclaimed if the expansion succeeded. */
4737
4738         prvscheck_address = NULL;
4739         prvscheck_keynum = NULL;
4740         }
4741       else
4742         /* Does not look like a prvs encoded address, return the empty string.
4743            We need to make sure all subs are expanded first, so as to skip over
4744            the entire item. */
4745
4746         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4747           {
4748           case 1: goto EXPAND_FAILED_CURLY;
4749           case 2:
4750           case 3: goto EXPAND_FAILED;
4751           }
4752
4753       continue;
4754       }
4755
4756     /* Handle "readfile" to insert an entire file */
4757
4758     case EITEM_READFILE:
4759       {
4760       FILE *f;
4761       uschar *sub_arg[2];
4762
4763       if ((expand_forbid & RDO_READFILE) != 0)
4764         {
4765         expand_string_message = US"file insertions are not permitted";
4766         goto EXPAND_FAILED;
4767         }
4768
4769       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4770         {
4771         case 1: goto EXPAND_FAILED_CURLY;
4772         case 2:
4773         case 3: goto EXPAND_FAILED;
4774         }
4775
4776       /* If skipping, we don't actually do anything */
4777
4778       if (skipping) continue;
4779
4780       /* Open the file and read it */
4781
4782       if (!(f = Ufopen(sub_arg[0], "rb")))
4783         {
4784         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4785         goto EXPAND_FAILED;
4786         }
4787
4788       yield = cat_file(f, yield, sub_arg[1]);
4789       (void)fclose(f);
4790       continue;
4791       }
4792
4793     /* Handle "readsocket" to insert data from a socket, either
4794     Inet or Unix domain */
4795
4796     case EITEM_READSOCK:
4797       {
4798       int fd;
4799       int timeout = 5;
4800       int save_ptr = yield->ptr;
4801       FILE *f;
4802       uschar *arg;
4803       uschar *sub_arg[4];
4804       BOOL do_shutdown = TRUE;
4805       blob reqstr;
4806
4807       if (expand_forbid & RDO_READSOCK)
4808         {
4809         expand_string_message = US"socket insertions are not permitted";
4810         goto EXPAND_FAILED;
4811         }
4812
4813       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4814       because there may be a string for expansion on failure. */
4815
4816       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4817         {
4818         case 1: goto EXPAND_FAILED_CURLY;
4819         case 2:                             /* Won't occur: no end check */
4820         case 3: goto EXPAND_FAILED;
4821         }
4822
4823       /* Grab the request string, if any */
4824
4825       reqstr.data = sub_arg[1];
4826       reqstr.len = Ustrlen(sub_arg[1]);
4827
4828       /* Sort out timeout, if given.  The second arg is a list with the first element
4829       being a time value.  Any more are options of form "name=value".  Currently the
4830       only option recognised is "shutdown". */
4831
4832       if (sub_arg[2])
4833         {
4834         const uschar * list = sub_arg[2];
4835         uschar * item;
4836         int sep = 0;
4837
4838         item = string_nextinlist(&list, &sep, NULL, 0);
4839         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4840           {
4841           expand_string_message = string_sprintf("bad time value %s", item);
4842           goto EXPAND_FAILED;
4843           }
4844
4845         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4846           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4847             if (Ustrcmp(item + 9, US"no") == 0)
4848               do_shutdown = FALSE;
4849         }
4850       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4851
4852       /* If skipping, we don't actually do anything. Otherwise, arrange to
4853       connect to either an IP or a Unix socket. */
4854
4855       if (!skipping)
4856         {
4857         /* Handle an IP (internet) domain */
4858
4859         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4860           {
4861           int port;
4862           uschar * server_name = sub_arg[0] + 5;
4863           uschar * port_name = Ustrrchr(server_name, ':');
4864
4865           /* Sort out the port */
4866
4867           if (!port_name)
4868             {
4869             expand_string_message =
4870               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4871             goto EXPAND_FAILED;
4872             }
4873           *port_name++ = 0;           /* Terminate server name */
4874
4875           if (isdigit(*port_name))
4876             {
4877             uschar *end;
4878             port = Ustrtol(port_name, &end, 0);
4879             if (end != port_name + Ustrlen(port_name))
4880               {
4881               expand_string_message =
4882                 string_sprintf("invalid port number %s", port_name);
4883               goto EXPAND_FAILED;
4884               }
4885             }
4886           else
4887             {
4888             struct servent *service_info = getservbyname(CS port_name, "tcp");
4889             if (!service_info)
4890               {
4891               expand_string_message = string_sprintf("unknown port \"%s\"",
4892                 port_name);
4893               goto EXPAND_FAILED;
4894               }
4895             port = ntohs(service_info->s_port);
4896             }
4897
4898           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4899                   timeout, NULL, &expand_string_message, &reqstr);
4900           callout_address = NULL;
4901           if (fd < 0)
4902               goto SOCK_FAIL;
4903           reqstr.len = 0;
4904           }
4905
4906         /* Handle a Unix domain socket */
4907
4908         else
4909           {
4910           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4911           int rc;
4912
4913           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4914             {
4915             expand_string_message = string_sprintf("failed to create socket: %s",
4916               strerror(errno));
4917             goto SOCK_FAIL;
4918             }
4919
4920           sockun.sun_family = AF_UNIX;
4921           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4922             sub_arg[0]);
4923
4924           sigalrm_seen = FALSE;
4925           alarm(timeout);
4926           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4927           alarm(0);
4928           if (sigalrm_seen)
4929             {
4930             expand_string_message = US "socket connect timed out";
4931             goto SOCK_FAIL;
4932             }
4933           if (rc < 0)
4934             {
4935             expand_string_message = string_sprintf("failed to connect to socket "
4936               "%s: %s", sub_arg[0], strerror(errno));
4937             goto SOCK_FAIL;
4938             }
4939           }
4940
4941         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4942
4943         /* Allow sequencing of test actions */
4944         if (running_in_test_harness) millisleep(100);
4945
4946         /* Write the request string, if not empty or already done */
4947
4948         if (reqstr.len)
4949           {
4950           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4951             reqstr.data);
4952           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4953             {
4954             expand_string_message = string_sprintf("request write to socket "
4955               "failed: %s", strerror(errno));
4956             goto SOCK_FAIL;
4957             }
4958           }
4959
4960         /* Shut down the sending side of the socket. This helps some servers to
4961         recognise that it is their turn to do some work. Just in case some
4962         system doesn't have this function, make it conditional. */
4963
4964 #ifdef SHUT_WR
4965         if (do_shutdown) shutdown(fd, SHUT_WR);
4966 #endif
4967
4968         if (running_in_test_harness) millisleep(100);
4969
4970         /* Now we need to read from the socket, under a timeout. The function
4971         that reads a file can be used. */
4972
4973         f = fdopen(fd, "rb");
4974         sigalrm_seen = FALSE;
4975         alarm(timeout);
4976         yield = cat_file(f, yield, sub_arg[3]);
4977         alarm(0);
4978         (void)fclose(f);
4979
4980         /* After a timeout, we restore the pointer in the result, that is,
4981         make sure we add nothing from the socket. */
4982
4983         if (sigalrm_seen)
4984           {
4985           yield->ptr = save_ptr;
4986           expand_string_message = US "socket read timed out";
4987           goto SOCK_FAIL;
4988           }
4989         }
4990
4991       /* The whole thing has worked (or we were skipping). If there is a
4992       failure string following, we need to skip it. */
4993
4994       if (*s == '{')
4995         {
4996         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4997           goto EXPAND_FAILED;
4998         if (*s++ != '}')
4999           {
5000           expand_string_message = US"missing '}' closing failstring for readsocket";
5001           goto EXPAND_FAILED_CURLY;
5002           }
5003         while (isspace(*s)) s++;
5004         }
5005
5006     READSOCK_DONE:
5007       if (*s++ != '}')
5008         {
5009         expand_string_message = US"missing '}' closing readsocket";
5010         goto EXPAND_FAILED_CURLY;
5011         }
5012       continue;
5013
5014       /* Come here on failure to create socket, connect socket, write to the
5015       socket, or timeout on reading. If another substring follows, expand and
5016       use it. Otherwise, those conditions give expand errors. */
5017
5018     SOCK_FAIL:
5019       if (*s != '{') goto EXPAND_FAILED;
5020       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
5021       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
5022         goto EXPAND_FAILED;
5023       yield = string_cat(yield, arg);
5024       if (*s++ != '}')
5025         {
5026         expand_string_message = US"missing '}' closing failstring for readsocket";
5027         goto EXPAND_FAILED_CURLY;
5028         }
5029       while (isspace(*s)) s++;
5030       goto READSOCK_DONE;
5031       }
5032
5033     /* Handle "run" to execute a program. */
5034
5035     case EITEM_RUN:
5036       {
5037       FILE *f;
5038       uschar *arg;
5039       const uschar **argv;
5040       pid_t pid;
5041       int fd_in, fd_out;
5042
5043       if ((expand_forbid & RDO_RUN) != 0)
5044         {
5045         expand_string_message = US"running a command is not permitted";
5046         goto EXPAND_FAILED;
5047         }
5048
5049       while (isspace(*s)) s++;
5050       if (*s != '{')
5051         {
5052         expand_string_message = US"missing '{' for command arg of run";
5053         goto EXPAND_FAILED_CURLY;
5054         }
5055       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5056       if (arg == NULL) goto EXPAND_FAILED;
5057       while (isspace(*s)) s++;
5058       if (*s++ != '}')
5059         {
5060         expand_string_message = US"missing '}' closing command arg of run";
5061         goto EXPAND_FAILED_CURLY;
5062         }
5063
5064       if (skipping)   /* Just pretend it worked when we're skipping */
5065         {
5066         runrc = 0;
5067         lookup_value = NULL;
5068         }
5069       else
5070         {
5071         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5072             arg,                                /* raw command */
5073             FALSE,                              /* don't expand the arguments */
5074             0,                                  /* not relevant when... */
5075             NULL,                               /* no transporting address */
5076             US"${run} expansion",               /* for error messages */
5077             &expand_string_message))            /* where to put error message */
5078           goto EXPAND_FAILED;
5079
5080         /* Create the child process, making it a group leader. */
5081
5082         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5083           {
5084           expand_string_message =
5085             string_sprintf("couldn't create child process: %s", strerror(errno));
5086           goto EXPAND_FAILED;
5087           }
5088
5089         /* Nothing is written to the standard input. */
5090
5091         (void)close(fd_in);
5092
5093         /* Read the pipe to get the command's output into $value (which is kept
5094         in lookup_value). Read during execution, so that if the output exceeds
5095         the OS pipe buffer limit, we don't block forever. Remember to not release
5096         memory just allocated for $value. */
5097
5098         resetok = FALSE;
5099         f = fdopen(fd_out, "rb");
5100         sigalrm_seen = FALSE;
5101         alarm(60);
5102         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5103         alarm(0);
5104         (void)fclose(f);
5105
5106         /* Wait for the process to finish, applying the timeout, and inspect its
5107         return code for serious disasters. Simple non-zero returns are passed on.
5108         */
5109
5110         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5111           {
5112           if (sigalrm_seen || runrc == -256)
5113             {
5114             expand_string_message = string_sprintf("command timed out");
5115             killpg(pid, SIGKILL);       /* Kill the whole process group */
5116             }
5117
5118           else if (runrc == -257)
5119             expand_string_message = string_sprintf("wait() failed: %s",
5120               strerror(errno));
5121
5122           else
5123             expand_string_message = string_sprintf("command killed by signal %d",
5124               -runrc);
5125
5126           goto EXPAND_FAILED;
5127           }
5128         }
5129
5130       /* Process the yes/no strings; $value may be useful in both cases */
5131
5132       switch(process_yesno(
5133                skipping,                     /* were previously skipping */
5134                runrc == 0,                   /* success/failure indicator */
5135                lookup_value,                 /* value to reset for string2 */
5136                &s,                           /* input pointer */
5137                &yield,                       /* output pointer */
5138                US"run",                      /* condition type */
5139                &resetok))
5140         {
5141         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5142         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5143         }
5144
5145       continue;
5146       }
5147
5148     /* Handle character translation for "tr" */
5149
5150     case EITEM_TR:
5151       {
5152       int oldptr = yield->ptr;
5153       int o2m;
5154       uschar *sub[3];
5155
5156       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5157         {
5158         case 1: goto EXPAND_FAILED_CURLY;
5159         case 2:
5160         case 3: goto EXPAND_FAILED;
5161         }
5162
5163       yield = string_cat(yield, sub[0]);
5164       o2m = Ustrlen(sub[2]) - 1;
5165
5166       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5167         {
5168         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5169         if (m != NULL)
5170           {
5171           int o = m - sub[1];
5172           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5173           }
5174         }
5175
5176       continue;
5177       }
5178
5179     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5180     expanded arguments. */
5181
5182     case EITEM_HASH:
5183     case EITEM_LENGTH:
5184     case EITEM_NHASH:
5185     case EITEM_SUBSTR:
5186       {
5187       int i;
5188       int len;
5189       uschar *ret;
5190       int val[2] = { 0, -1 };
5191       uschar *sub[3];
5192
5193       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5194       Ensure that sub[2] is set in the ${length } case. */
5195
5196       sub[2] = NULL;
5197       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5198              TRUE, name, &resetok))
5199         {
5200         case 1: goto EXPAND_FAILED_CURLY;
5201         case 2:
5202         case 3: goto EXPAND_FAILED;
5203         }
5204
5205       /* Juggle the arguments if there are only two of them: always move the
5206       string to the last position and make ${length{n}{str}} equivalent to
5207       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5208
5209       if (sub[2] == NULL)
5210         {
5211         sub[2] = sub[1];
5212         sub[1] = NULL;
5213         if (item_type == EITEM_LENGTH)
5214           {
5215           sub[1] = sub[0];
5216           sub[0] = NULL;
5217           }
5218         }
5219
5220       for (i = 0; i < 2; i++)
5221         {
5222         if (sub[i] == NULL) continue;
5223         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5224         if (*ret != 0 || (i != 0 && val[i] < 0))
5225           {
5226           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5227             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5228           goto EXPAND_FAILED;
5229           }
5230         }
5231
5232       ret =
5233         (item_type == EITEM_HASH)?
5234           compute_hash(sub[2], val[0], val[1], &len) :
5235         (item_type == EITEM_NHASH)?
5236           compute_nhash(sub[2], val[0], val[1], &len) :
5237           extract_substr(sub[2], val[0], val[1], &len);
5238
5239       if (ret == NULL) goto EXPAND_FAILED;
5240       yield = string_catn(yield, ret, len);
5241       continue;
5242       }
5243
5244     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5245     This code originally contributed by Steve Haslam. It currently supports
5246     the use of MD5 and SHA-1 hashes.
5247
5248     We need some workspace that is large enough to handle all the supported
5249     hash types. Use macros to set the sizes rather than be too elaborate. */
5250
5251     #define MAX_HASHLEN      20
5252     #define MAX_HASHBLOCKLEN 64
5253
5254     case EITEM_HMAC:
5255       {
5256       uschar *sub[3];
5257       md5 md5_base;
5258       hctx sha1_ctx;
5259       void *use_base;
5260       int type, i;
5261       int hashlen;      /* Number of octets for the hash algorithm's output */
5262       int hashblocklen; /* Number of octets the hash algorithm processes */
5263       uschar *keyptr, *p;
5264       unsigned int keylen;
5265
5266       uschar keyhash[MAX_HASHLEN];
5267       uschar innerhash[MAX_HASHLEN];
5268       uschar finalhash[MAX_HASHLEN];
5269       uschar finalhash_hex[2*MAX_HASHLEN];
5270       uschar innerkey[MAX_HASHBLOCKLEN];
5271       uschar outerkey[MAX_HASHBLOCKLEN];
5272
5273       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5274         {
5275         case 1: goto EXPAND_FAILED_CURLY;
5276         case 2:
5277         case 3: goto EXPAND_FAILED;
5278         }
5279
5280       if (!skipping)
5281         {
5282         if (Ustrcmp(sub[0], "md5") == 0)
5283           {
5284           type = HMAC_MD5;
5285           use_base = &md5_base;
5286           hashlen = 16;
5287           hashblocklen = 64;
5288           }
5289         else if (Ustrcmp(sub[0], "sha1") == 0)
5290           {
5291           type = HMAC_SHA1;
5292           use_base = &sha1_ctx;
5293           hashlen = 20;
5294           hashblocklen = 64;
5295           }
5296         else
5297           {
5298           expand_string_message =
5299             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5300           goto EXPAND_FAILED;
5301           }
5302
5303         keyptr = sub[1];
5304         keylen = Ustrlen(keyptr);
5305
5306         /* If the key is longer than the hash block length, then hash the key
5307         first */
5308
5309         if (keylen > hashblocklen)
5310           {
5311           chash_start(type, use_base);
5312           chash_end(type, use_base, keyptr, keylen, keyhash);
5313           keyptr = keyhash;
5314           keylen = hashlen;
5315           }
5316
5317         /* Now make the inner and outer key values */
5318
5319         memset(innerkey, 0x36, hashblocklen);
5320         memset(outerkey, 0x5c, hashblocklen);
5321
5322         for (i = 0; i < keylen; i++)
5323           {
5324           innerkey[i] ^= keyptr[i];
5325           outerkey[i] ^= keyptr[i];
5326           }
5327
5328         /* Now do the hashes */
5329
5330         chash_start(type, use_base);
5331         chash_mid(type, use_base, innerkey);
5332         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5333
5334         chash_start(type, use_base);
5335         chash_mid(type, use_base, outerkey);
5336         chash_end(type, use_base, innerhash, hashlen, finalhash);
5337
5338         /* Encode the final hash as a hex string */
5339
5340         p = finalhash_hex;
5341         for (i = 0; i < hashlen; i++)
5342           {
5343           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5344           *p++ = hex_digits[finalhash[i] & 0x0f];
5345           }
5346
5347         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5348           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5349
5350         yield = string_catn(yield, finalhash_hex, hashlen*2);
5351         }
5352       continue;
5353       }
5354
5355     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5356     We have to save the numerical variables and restore them afterwards. */
5357
5358     case EITEM_SG:
5359       {
5360       const pcre *re;
5361       int moffset, moffsetextra, slen;
5362       int roffset;
5363       int emptyopt;
5364       const uschar *rerror;
5365       uschar *subject;
5366       uschar *sub[3];
5367       int save_expand_nmax =
5368         save_expand_strings(save_expand_nstring, save_expand_nlength);
5369
5370       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5371         {
5372         case 1: goto EXPAND_FAILED_CURLY;
5373         case 2:
5374         case 3: goto EXPAND_FAILED;
5375         }
5376
5377       /* Compile the regular expression */
5378
5379       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5380         NULL);
5381
5382       if (re == NULL)
5383         {
5384         expand_string_message = string_sprintf("regular expression error in "
5385           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5386         goto EXPAND_FAILED;
5387         }
5388
5389       /* Now run a loop to do the substitutions as often as necessary. It ends
5390       when there are no more matches. Take care over matches of the null string;
5391       do the same thing as Perl does. */
5392
5393       subject = sub[0];
5394       slen = Ustrlen(sub[0]);
5395       moffset = moffsetextra = 0;
5396       emptyopt = 0;
5397
5398       for (;;)
5399         {
5400         int ovector[3*(EXPAND_MAXN+1)];
5401         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5402           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5403         int nn;
5404         uschar *insert;
5405
5406         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5407         is not necessarily the end. We want to repeat the match from one
5408         character further along, but leaving the basic offset the same (for
5409         copying below). We can't be at the end of the string - that was checked
5410         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5411         finished; copy the remaining string and end the loop. */
5412
5413         if (n < 0)
5414           {
5415           if (emptyopt != 0)
5416             {
5417             moffsetextra = 1;
5418             emptyopt = 0;
5419             continue;
5420             }
5421           yield = string_catn(yield, subject+moffset, slen-moffset);
5422           break;
5423           }
5424
5425         /* Match - set up for expanding the replacement. */
5426
5427         if (n == 0) n = EXPAND_MAXN + 1;
5428         expand_nmax = 0;
5429         for (nn = 0; nn < n*2; nn += 2)
5430           {
5431           expand_nstring[expand_nmax] = subject + ovector[nn];
5432           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5433           }
5434         expand_nmax--;
5435
5436         /* Copy the characters before the match, plus the expanded insertion. */
5437
5438         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5439         insert = expand_string(sub[2]);
5440         if (insert == NULL) goto EXPAND_FAILED;
5441         yield = string_cat(yield, insert);
5442
5443         moffset = ovector[1];
5444         moffsetextra = 0;
5445         emptyopt = 0;
5446
5447         /* If we have matched an empty string, first check to see if we are at
5448         the end of the subject. If so, the loop is over. Otherwise, mimic
5449         what Perl's /g options does. This turns out to be rather cunning. First
5450         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5451         string at the same point. If this fails (picked up above) we advance to
5452         the next character. */
5453
5454         if (ovector[0] == ovector[1])
5455           {
5456           if (ovector[0] == slen) break;
5457           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5458           }
5459         }
5460
5461       /* All done - restore numerical variables. */
5462
5463       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5464         save_expand_nlength);
5465       continue;
5466       }
5467
5468     /* Handle keyed and numbered substring extraction. If the first argument
5469     consists entirely of digits, then a numerical extraction is assumed. */
5470
5471     case EITEM_EXTRACT:
5472       {
5473       int i;
5474       int j;
5475       int field_number = 1;
5476       BOOL field_number_set = FALSE;
5477       uschar *save_lookup_value = lookup_value;
5478       uschar *sub[3];
5479       int save_expand_nmax =
5480         save_expand_strings(save_expand_nstring, save_expand_nlength);
5481
5482       /* While skipping we cannot rely on the data for expansions being
5483       available (eg. $item) hence cannot decide on numeric vs. keyed.
5484       Read a maximum of 5 arguments (including the yes/no) */
5485
5486       if (skipping)
5487         {
5488         while (isspace(*s)) s++;
5489         for (j = 5; j > 0 && *s == '{'; j--)
5490           {
5491           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5492             goto EXPAND_FAILED;                                 /*{*/
5493           if (*s++ != '}')
5494             {
5495             expand_string_message = US"missing '{' for arg of extract";
5496             goto EXPAND_FAILED_CURLY;
5497             }
5498           while (isspace(*s)) s++;
5499           }
5500         if (  Ustrncmp(s, "fail", 4) == 0
5501            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5502            )
5503           {
5504           s += 4;
5505           while (isspace(*s)) s++;
5506           }
5507         if (*s != '}')
5508           {
5509           expand_string_message = US"missing '}' closing extract";
5510           goto EXPAND_FAILED_CURLY;
5511           }
5512         }
5513
5514       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5515         {
5516         while (isspace(*s)) s++;
5517         if (*s == '{')                                          /*}*/
5518           {
5519           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5520           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5521           if (*s++ != '}')
5522             {
5523             expand_string_message = string_sprintf(
5524               "missing '}' closing arg %d of extract", i+1);
5525             goto EXPAND_FAILED_CURLY;
5526             }
5527
5528           /* After removal of leading and trailing white space, the first
5529           argument must not be empty; if it consists entirely of digits
5530           (optionally preceded by a minus sign), this is a numerical
5531           extraction, and we expect 3 arguments. */
5532
5533           if (i == 0)
5534             {
5535             int len;
5536             int x = 0;
5537             uschar *p = sub[0];
5538
5539             while (isspace(*p)) p++;
5540             sub[0] = p;
5541
5542             len = Ustrlen(p);
5543             while (len > 0 && isspace(p[len-1])) len--;
5544             p[len] = 0;
5545
5546             if (*p == 0)
5547               {
5548               expand_string_message = US"first argument of \"extract\" must "
5549                 "not be empty";
5550               goto EXPAND_FAILED;
5551               }
5552
5553             if (*p == '-')
5554               {
5555               field_number = -1;
5556               p++;
5557               }
5558             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5559             if (*p == 0)
5560               {
5561               field_number *= x;
5562               j = 3;               /* Need 3 args */
5563               field_number_set = TRUE;
5564               }
5565             }
5566           }
5567         else
5568           {
5569           expand_string_message = string_sprintf(
5570             "missing '{' for arg %d of extract", i+1);
5571           goto EXPAND_FAILED_CURLY;
5572           }
5573         }
5574
5575       /* Extract either the numbered or the keyed substring into $value. If
5576       skipping, just pretend the extraction failed. */
5577
5578       lookup_value = skipping? NULL : field_number_set?
5579         expand_gettokened(field_number, sub[1], sub[2]) :
5580         expand_getkeyed(sub[0], sub[1]);
5581
5582       /* If no string follows, $value gets substituted; otherwise there can
5583       be yes/no strings, as for lookup or if. */
5584
5585       switch(process_yesno(
5586                skipping,                     /* were previously skipping */
5587                lookup_value != NULL,         /* success/failure indicator */
5588                save_lookup_value,            /* value to reset for string2 */
5589                &s,                           /* input pointer */
5590                &yield,                       /* output pointer */
5591                US"extract",                  /* condition type */
5592                &resetok))
5593         {
5594         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5595         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5596         }
5597
5598       /* All done - restore numerical variables. */
5599
5600       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5601         save_expand_nlength);
5602
5603       continue;
5604       }
5605
5606     /* return the Nth item from a list */
5607
5608     case EITEM_LISTEXTRACT:
5609       {
5610       int i;
5611       int field_number = 1;
5612       uschar *save_lookup_value = lookup_value;
5613       uschar *sub[2];
5614       int save_expand_nmax =
5615         save_expand_strings(save_expand_nstring, save_expand_nlength);
5616
5617       /* Read the field & list arguments */
5618
5619       for (i = 0; i < 2; i++)
5620         {
5621         while (isspace(*s)) s++;
5622         if (*s != '{')                                  /*}*/
5623           {
5624           expand_string_message = string_sprintf(
5625             "missing '{' for arg %d of listextract", i+1);
5626           goto EXPAND_FAILED_CURLY;
5627           }
5628
5629         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5630         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5631         if (*s++ != '}')
5632           {
5633           expand_string_message = string_sprintf(
5634             "missing '}' closing arg %d of listextract", i+1);
5635           goto EXPAND_FAILED_CURLY;
5636           }
5637
5638         /* After removal of leading and trailing white space, the first
5639         argument must be numeric and nonempty. */
5640
5641         if (i == 0)
5642           {
5643           int len;
5644           int x = 0;
5645           uschar *p = sub[0];
5646
5647           while (isspace(*p)) p++;
5648           sub[0] = p;
5649
5650           len = Ustrlen(p);
5651           while (len > 0 && isspace(p[len-1])) len--;
5652           p[len] = 0;
5653
5654           if (!*p && !skipping)
5655             {
5656             expand_string_message = US"first argument of \"listextract\" must "
5657               "not be empty";
5658             goto EXPAND_FAILED;
5659             }
5660
5661           if (*p == '-')
5662             {
5663             field_number = -1;
5664             p++;
5665             }
5666           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5667           if (*p)
5668             {
5669             expand_string_message = US"first argument of \"listextract\" must "
5670               "be numeric";
5671             goto EXPAND_FAILED;
5672             }
5673           field_number *= x;
5674           }
5675         }
5676
5677       /* Extract the numbered element into $value. If
5678       skipping, just pretend the extraction failed. */
5679
5680       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5681
5682       /* If no string follows, $value gets substituted; otherwise there can
5683       be yes/no strings, as for lookup or if. */
5684
5685       switch(process_yesno(
5686                skipping,                     /* were previously skipping */
5687                lookup_value != NULL,         /* success/failure indicator */
5688                save_lookup_value,            /* value to reset for string2 */
5689                &s,                           /* input pointer */
5690                &yield,                       /* output pointer */
5691                US"listextract",              /* condition type */
5692                &resetok))
5693         {
5694         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5695         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5696         }
5697
5698       /* All done - restore numerical variables. */
5699
5700       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5701         save_expand_nlength);
5702
5703       continue;
5704       }
5705
5706 #ifdef SUPPORT_TLS
5707     case EITEM_CERTEXTRACT:
5708       {
5709       uschar *save_lookup_value = lookup_value;
5710       uschar *sub[2];
5711       int save_expand_nmax =
5712         save_expand_strings(save_expand_nstring, save_expand_nlength);
5713
5714       /* Read the field argument */
5715       while (isspace(*s)) s++;
5716       if (*s != '{')                                    /*}*/
5717         {
5718         expand_string_message = US"missing '{' for field arg of certextract";
5719         goto EXPAND_FAILED_CURLY;
5720         }
5721       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5722       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5723       if (*s++ != '}')
5724         {
5725         expand_string_message = US"missing '}' closing field arg of certextract";
5726         goto EXPAND_FAILED_CURLY;
5727         }
5728       /* strip spaces fore & aft */
5729       {
5730       int len;
5731       uschar *p = sub[0];
5732
5733       while (isspace(*p)) p++;
5734       sub[0] = p;
5735
5736       len = Ustrlen(p);
5737       while (len > 0 && isspace(p[len-1])) len--;
5738       p[len] = 0;
5739       }
5740
5741       /* inspect the cert argument */
5742       while (isspace(*s)) s++;
5743       if (*s != '{')                                    /*}*/
5744         {
5745         expand_string_message = US"missing '{' for cert variable arg of certextract";
5746         goto EXPAND_FAILED_CURLY;
5747         }
5748       if (*++s != '$')
5749         {
5750         expand_string_message = US"second argument of \"certextract\" must "
5751           "be a certificate variable";
5752         goto EXPAND_FAILED;
5753         }
5754       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5755       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5756       if (*s++ != '}')
5757         {
5758         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5759         goto EXPAND_FAILED_CURLY;
5760         }
5761
5762       if (skipping)
5763         lookup_value = NULL;
5764       else
5765         {
5766         lookup_value = expand_getcertele(sub[0], sub[1]);
5767         if (*expand_string_message) goto EXPAND_FAILED;
5768         }
5769       switch(process_yesno(
5770                skipping,                     /* were previously skipping */
5771                lookup_value != NULL,         /* success/failure indicator */
5772                save_lookup_value,            /* value to reset for string2 */
5773                &s,                           /* input pointer */
5774                &yield,                       /* output pointer */
5775                US"certextract",              /* condition type */
5776                &resetok))
5777         {
5778         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5779         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5780         }
5781
5782       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5783         save_expand_nlength);
5784       continue;
5785       }
5786 #endif  /*SUPPORT_TLS*/
5787
5788     /* Handle list operations */
5789
5790     case EITEM_FILTER:
5791     case EITEM_MAP:
5792     case EITEM_REDUCE:
5793       {
5794       int sep = 0;
5795       int save_ptr = yield->ptr;
5796       uschar outsep[2] = { '\0', '\0' };
5797       const uschar *list, *expr, *temp;
5798       uschar *save_iterate_item = iterate_item;
5799       uschar *save_lookup_value = lookup_value;
5800
5801       while (isspace(*s)) s++;
5802       if (*s++ != '{')
5803         {
5804         expand_string_message =
5805           string_sprintf("missing '{' for first arg of %s", name);
5806         goto EXPAND_FAILED_CURLY;
5807         }
5808
5809       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5810       if (list == NULL) goto EXPAND_FAILED;
5811       if (*s++ != '}')
5812         {
5813         expand_string_message =
5814           string_sprintf("missing '}' closing first arg of %s", name);
5815         goto EXPAND_FAILED_CURLY;
5816         }
5817
5818       if (item_type == EITEM_REDUCE)
5819         {
5820         uschar * t;
5821         while (isspace(*s)) s++;
5822         if (*s++ != '{')
5823           {
5824           expand_string_message = US"missing '{' for second arg of reduce";
5825           goto EXPAND_FAILED_CURLY;
5826           }
5827         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5828         if (!t) goto EXPAND_FAILED;
5829         lookup_value = t;
5830         if (*s++ != '}')
5831           {
5832           expand_string_message = US"missing '}' closing second arg of reduce";
5833           goto EXPAND_FAILED_CURLY;
5834           }
5835         }
5836
5837       while (isspace(*s)) s++;
5838       if (*s++ != '{')
5839         {
5840         expand_string_message =
5841           string_sprintf("missing '{' for last arg of %s", name);
5842         goto EXPAND_FAILED_CURLY;
5843         }
5844
5845       expr = s;
5846
5847       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5848       if scanning a "false" part). This allows us to find the end of the
5849       condition, because if the list is empty, we won't actually evaluate the
5850       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5851       the normal internal expansion function. */
5852
5853       if (item_type == EITEM_FILTER)
5854         {
5855         temp = eval_condition(expr, &resetok, NULL);
5856         if (temp != NULL) s = temp;
5857         }
5858       else
5859         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5860
5861       if (temp == NULL)
5862         {
5863         expand_string_message = string_sprintf("%s inside \"%s\" item",
5864           expand_string_message, name);
5865         goto EXPAND_FAILED;
5866         }
5867
5868       while (isspace(*s)) s++;
5869       if (*s++ != '}')
5870         {                                               /*{*/
5871         expand_string_message = string_sprintf("missing } at end of condition "
5872           "or expression inside \"%s\"; could be an unquoted } in the content",
5873           name);
5874         goto EXPAND_FAILED;
5875         }
5876
5877       while (isspace(*s)) s++;                          /*{*/
5878       if (*s++ != '}')
5879         {                                               /*{*/
5880         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5881           name);
5882         goto EXPAND_FAILED;
5883         }
5884
5885       /* If we are skipping, we can now just move on to the next item. When
5886       processing for real, we perform the iteration. */
5887
5888       if (skipping) continue;
5889       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5890         {
5891         *outsep = (uschar)sep;      /* Separator as a string */
5892
5893         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5894                           name, iterate_item, lookup_value);
5895
5896         if (item_type == EITEM_FILTER)
5897           {
5898           BOOL condresult;
5899           if (eval_condition(expr, &resetok, &condresult) == NULL)
5900             {
5901             iterate_item = save_iterate_item;
5902             lookup_value = save_lookup_value;
5903             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5904               expand_string_message, name);
5905             goto EXPAND_FAILED;
5906             }
5907           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5908             condresult? "true":"false");
5909           if (condresult)
5910             temp = iterate_item;    /* TRUE => include this item */
5911           else
5912             continue;               /* FALSE => skip this item */
5913           }
5914
5915         /* EITEM_MAP and EITEM_REDUCE */
5916
5917         else
5918           {
5919           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5920           temp = t;
5921           if (temp == NULL)
5922             {
5923             iterate_item = save_iterate_item;
5924             expand_string_message = string_sprintf("%s inside \"%s\" item",
5925               expand_string_message, name);
5926             goto EXPAND_FAILED;
5927             }
5928           if (item_type == EITEM_REDUCE)
5929             {
5930             lookup_value = t;         /* Update the value of $value */
5931             continue;                 /* and continue the iteration */
5932             }
5933           }
5934
5935         /* We reach here for FILTER if the condition is true, always for MAP,
5936         and never for REDUCE. The value in "temp" is to be added to the output
5937         list that is being created, ensuring that any occurrences of the
5938         separator character are doubled. Unless we are dealing with the first
5939         item of the output list, add in a space if the new item begins with the
5940         separator character, or is an empty string. */
5941
5942         if (yield->ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5943           yield = string_catn(yield, US" ", 1);
5944
5945         /* Add the string in "temp" to the output list that we are building,
5946         This is done in chunks by searching for the separator character. */
5947
5948         for (;;)
5949           {
5950           size_t seglen = Ustrcspn(temp, outsep);
5951
5952           yield = string_catn(yield, temp, seglen + 1);
5953
5954           /* If we got to the end of the string we output one character
5955           too many; backup and end the loop. Otherwise arrange to double the
5956           separator. */
5957
5958           if (temp[seglen] == '\0') { yield->ptr--; break; }
5959           yield = string_catn(yield, outsep, 1);
5960           temp += seglen + 1;
5961           }
5962
5963         /* Output a separator after the string: we will remove the redundant
5964         final one at the end. */
5965
5966         yield = string_catn(yield, outsep, 1);
5967         }   /* End of iteration over the list loop */
5968
5969       /* REDUCE has generated no output above: output the final value of
5970       $value. */
5971
5972       if (item_type == EITEM_REDUCE)
5973         {
5974         yield = string_cat(yield, lookup_value);
5975         lookup_value = save_lookup_value;  /* Restore $value */
5976         }
5977
5978       /* FILTER and MAP generate lists: if they have generated anything, remove
5979       the redundant final separator. Even though an empty item at the end of a
5980       list does not count, this is tidier. */
5981
5982       else if (yield->ptr != save_ptr) yield->ptr--;
5983
5984       /* Restore preserved $item */
5985
5986       iterate_item = save_iterate_item;
5987       continue;
5988       }
5989
5990     case EITEM_SORT:
5991       {
5992       int sep = 0;
5993       const uschar *srclist, *cmp, *xtract;
5994       uschar *srcitem;
5995       const uschar *dstlist = NULL, *dstkeylist = NULL;
5996       uschar * tmp;
5997       uschar *save_iterate_item = iterate_item;
5998
5999       while (isspace(*s)) s++;
6000       if (*s++ != '{')
6001         {
6002         expand_string_message = US"missing '{' for list arg of sort";
6003         goto EXPAND_FAILED_CURLY;
6004         }
6005
6006       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
6007       if (!srclist) goto EXPAND_FAILED;
6008       if (*s++ != '}')
6009         {
6010         expand_string_message = US"missing '}' closing list arg of sort";
6011         goto EXPAND_FAILED_CURLY;
6012         }
6013
6014       while (isspace(*s)) s++;
6015       if (*s++ != '{')
6016         {
6017         expand_string_message = US"missing '{' for comparator arg of sort";
6018         goto EXPAND_FAILED_CURLY;
6019         }
6020
6021       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
6022       if (!cmp) goto EXPAND_FAILED;
6023       if (*s++ != '}')
6024         {
6025         expand_string_message = US"missing '}' closing comparator arg of sort";
6026         goto EXPAND_FAILED_CURLY;
6027         }
6028
6029       while (isspace(*s)) s++;
6030       if (*s++ != '{')
6031         {
6032         expand_string_message = US"missing '{' for extractor arg of sort";
6033         goto EXPAND_FAILED_CURLY;
6034         }
6035
6036       xtract = s;
6037       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
6038       if (!tmp) goto EXPAND_FAILED;
6039       xtract = string_copyn(xtract, s - xtract);
6040
6041       if (*s++ != '}')
6042         {
6043         expand_string_message = US"missing '}' closing extractor arg of sort";
6044         goto EXPAND_FAILED_CURLY;
6045         }
6046                                                         /*{*/
6047       if (*s++ != '}')
6048         {                                               /*{*/
6049         expand_string_message = US"missing } at end of \"sort\"";
6050         goto EXPAND_FAILED;
6051         }
6052
6053       if (skipping) continue;
6054
6055       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
6056         {
6057         uschar * dstitem;
6058         gstring * newlist = NULL;
6059         gstring * newkeylist = NULL;
6060         uschar * srcfield;
6061
6062         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6063
6064         /* extract field for comparisons */
6065         iterate_item = srcitem;
6066         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6067                                           TRUE, &resetok))
6068            || !*srcfield)
6069           {
6070           expand_string_message = string_sprintf(
6071               "field-extract in sort: \"%s\"", xtract);
6072           goto EXPAND_FAILED;
6073           }
6074
6075         /* Insertion sort */
6076
6077         /* copy output list until new-item < list-item */
6078         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6079           {
6080           uschar * dstfield;
6081           uschar * expr;
6082           BOOL before;
6083
6084           /* field for comparison */
6085           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6086             goto sort_mismatch;
6087
6088           /* build and run condition string */
6089           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6090
6091           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6092           if (!eval_condition(expr, &resetok, &before))
6093             {
6094             expand_string_message = string_sprintf("comparison in sort: %s",
6095                 expr);
6096             goto EXPAND_FAILED;
6097             }
6098
6099           if (before)
6100             {
6101             /* New-item sorts before this dst-item.  Append new-item,
6102             then dst-item, then remainder of dst list. */
6103
6104             newlist = string_append_listele(newlist, sep, srcitem);
6105             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6106             srcitem = NULL;
6107
6108             newlist = string_append_listele(newlist, sep, dstitem);
6109             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6110
6111             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6112               {
6113               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6114                 goto sort_mismatch;
6115               newlist = string_append_listele(newlist, sep, dstitem);
6116               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6117               }
6118
6119             break;
6120             }
6121
6122           newlist = string_append_listele(newlist, sep, dstitem);
6123           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6124           }
6125
6126         /* If we ran out of dstlist without consuming srcitem, append it */
6127         if (srcitem)
6128           {
6129           newlist = string_append_listele(newlist, sep, srcitem);
6130           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6131           }
6132
6133         dstlist = newlist->s;
6134         dstkeylist = newkeylist->s;
6135
6136         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6137         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6138         }
6139
6140       if (dstlist)
6141         yield = string_cat(yield, dstlist);
6142
6143       /* Restore preserved $item */
6144       iterate_item = save_iterate_item;
6145       continue;
6146
6147       sort_mismatch:
6148         expand_string_message = US"Internal error in sort (list mismatch)";
6149         goto EXPAND_FAILED;
6150       }
6151
6152
6153     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6154     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6155     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6156     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6157
6158     #define EXPAND_DLFUNC_MAX_ARGS 8
6159
6160     case EITEM_DLFUNC:
6161 #ifndef EXPAND_DLFUNC
6162       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6163         "is not included in this binary";
6164       goto EXPAND_FAILED;
6165
6166 #else   /* EXPAND_DLFUNC */
6167       {
6168       tree_node *t;
6169       exim_dlfunc_t *func;
6170       uschar *result;
6171       int status, argc;
6172       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6173
6174       if ((expand_forbid & RDO_DLFUNC) != 0)
6175         {
6176         expand_string_message =
6177           US"dynamically-loaded functions are not permitted";
6178         goto EXPAND_FAILED;
6179         }
6180
6181       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6182            TRUE, US"dlfunc", &resetok))
6183         {
6184         case 1: goto EXPAND_FAILED_CURLY;
6185         case 2:
6186         case 3: goto EXPAND_FAILED;
6187         }
6188
6189       /* If skipping, we don't actually do anything */
6190
6191       if (skipping) continue;
6192
6193       /* Look up the dynamically loaded object handle in the tree. If it isn't
6194       found, dlopen() the file and put the handle in the tree for next time. */
6195
6196       t = tree_search(dlobj_anchor, argv[0]);
6197       if (t == NULL)
6198         {
6199         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6200         if (handle == NULL)
6201           {
6202           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6203             argv[0], dlerror());
6204           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6205           goto EXPAND_FAILED;
6206           }
6207         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6208         Ustrcpy(t->name, argv[0]);
6209         t->data.ptr = handle;
6210         (void)tree_insertnode(&dlobj_anchor, t);
6211         }
6212
6213       /* Having obtained the dynamically loaded object handle, look up the
6214       function pointer. */
6215
6216       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6217       if (func == NULL)
6218         {
6219         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6220           "%s", argv[1], argv[0], dlerror());
6221         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6222         goto EXPAND_FAILED;
6223         }
6224
6225       /* Call the function and work out what to do with the result. If it
6226       returns OK, we have a replacement string; if it returns DEFER then
6227       expansion has failed in a non-forced manner; if it returns FAIL then
6228       failure was forced; if it returns ERROR or any other value there's a
6229       problem, so panic slightly. In any case, assume that the function has
6230       side-effects on the store that must be preserved. */
6231
6232       resetok = FALSE;
6233       result = NULL;
6234       for (argc = 0; argv[argc] != NULL; argc++);
6235       status = func(&result, argc - 2, &argv[2]);
6236       if(status == OK)
6237         {
6238         if (result == NULL) result = US"";
6239         yield = string_cat(yield, result);
6240         continue;
6241         }
6242       else
6243         {
6244         expand_string_message = result == NULL ? US"(no message)" : result;
6245         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6246           else if(status != FAIL)
6247             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6248               argv[0], argv[1], status, expand_string_message);
6249         goto EXPAND_FAILED;
6250         }
6251       }
6252 #endif /* EXPAND_DLFUNC */
6253
6254     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6255       {
6256       uschar * key;
6257       uschar *save_lookup_value = lookup_value;
6258
6259       while (isspace(*s)) s++;
6260       if (*s != '{')                                    /*}*/
6261         goto EXPAND_FAILED;
6262
6263       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6264       if (!key) goto EXPAND_FAILED;                     /*{*/
6265       if (*s++ != '}')
6266         {
6267         expand_string_message = US"missing '{' for name arg of env";
6268         goto EXPAND_FAILED_CURLY;
6269         }
6270
6271       lookup_value = US getenv(CS key);
6272
6273       switch(process_yesno(
6274                skipping,                     /* were previously skipping */
6275                lookup_value != NULL,         /* success/failure indicator */
6276                save_lookup_value,            /* value to reset for string2 */
6277                &s,                           /* input pointer */
6278                &yield,                       /* output pointer */
6279                US"env",                      /* condition type */
6280                &resetok))
6281         {
6282         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6283         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6284         }
6285       continue;
6286       }
6287     }   /* EITEM_* switch */
6288
6289   /* Control reaches here if the name is not recognized as one of the more
6290   complicated expansion items. Check for the "operator" syntax (name terminated
6291   by a colon). Some of the operators have arguments, separated by _ from the
6292   name. */
6293
6294   if (*s == ':')
6295     {
6296     int c;
6297     uschar *arg = NULL;
6298     uschar *sub;
6299     var_entry *vp = NULL;
6300
6301     /* Owing to an historical mis-design, an underscore may be part of the
6302     operator name, or it may introduce arguments.  We therefore first scan the
6303     table of names that contain underscores. If there is no match, we cut off
6304     the arguments and then scan the main table. */
6305
6306     if ((c = chop_match(name, op_table_underscore,
6307                         nelem(op_table_underscore))) < 0)
6308       {
6309       arg = Ustrchr(name, '_');
6310       if (arg != NULL) *arg = 0;
6311       c = chop_match(name, op_table_main, nelem(op_table_main));
6312       if (c >= 0) c += nelem(op_table_underscore);
6313       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6314       }
6315
6316     /* Deal specially with operators that might take a certificate variable
6317     as we do not want to do the usual expansion. For most, expand the string.*/
6318     switch(c)
6319       {
6320 #ifdef SUPPORT_TLS
6321       case EOP_MD5:
6322       case EOP_SHA1:
6323       case EOP_SHA256:
6324       case EOP_BASE64:
6325         if (s[1] == '$')
6326           {
6327           const uschar * s1 = s;
6328           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6329                   FALSE, &resetok);
6330           if (!sub)       goto EXPAND_FAILED;           /*{*/
6331           if (*s1 != '}')
6332             {
6333             expand_string_message =
6334               string_sprintf("missing '}' closing cert arg of %s", name);
6335             goto EXPAND_FAILED_CURLY;
6336             }
6337           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6338             {
6339             s = s1+1;
6340             break;
6341             }
6342           vp = NULL;
6343           }
6344         /*FALLTHROUGH*/
6345 #endif
6346       default:
6347         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6348         if (!sub) goto EXPAND_FAILED;
6349         s++;
6350         break;
6351       }
6352
6353     /* If we are skipping, we don't need to perform the operation at all.
6354     This matters for operations like "mask", because the data may not be
6355     in the correct format when skipping. For example, the expression may test
6356     for the existence of $sender_host_address before trying to mask it. For
6357     other operations, doing them may not fail, but it is a waste of time. */
6358
6359     if (skipping && c >= 0) continue;
6360
6361     /* Otherwise, switch on the operator type */
6362
6363     switch(c)
6364       {
6365       case EOP_BASE32:
6366         {
6367         uschar *t;
6368         unsigned long int n = Ustrtoul(sub, &t, 10);
6369         gstring * g = NULL;
6370
6371         if (*t != 0)
6372           {
6373           expand_string_message = string_sprintf("argument for base32 "
6374             "operator is \"%s\", which is not a decimal number", sub);
6375           goto EXPAND_FAILED;
6376           }
6377         for ( ; n; n >>= 5)
6378           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6379
6380         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6381         continue;
6382         }
6383
6384       case EOP_BASE32D:
6385         {
6386         uschar *tt = sub;
6387         unsigned long int n = 0;
6388         uschar * s;
6389         while (*tt)
6390           {
6391           uschar * t = Ustrchr(base32_chars, *tt++);
6392           if (t == NULL)
6393             {
6394             expand_string_message = string_sprintf("argument for base32d "
6395               "operator is \"%s\", which is not a base 32 number", sub);
6396             goto EXPAND_FAILED;
6397             }
6398           n = n * 32 + (t - base32_chars);
6399           }
6400         s = string_sprintf("%ld", n);
6401         yield = string_cat(yield, s);
6402         continue;
6403         }
6404
6405       case EOP_BASE62:
6406         {
6407         uschar *t;
6408         unsigned long int n = Ustrtoul(sub, &t, 10);
6409         if (*t != 0)
6410           {
6411           expand_string_message = string_sprintf("argument for base62 "
6412             "operator is \"%s\", which is not a decimal number", sub);
6413           goto EXPAND_FAILED;
6414           }
6415         t = string_base62(n);
6416         yield = string_cat(yield, t);
6417         continue;
6418         }
6419
6420       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6421
6422       case EOP_BASE62D:
6423         {
6424         uschar buf[16];
6425         uschar *tt = sub;
6426         unsigned long int n = 0;
6427         while (*tt != 0)
6428           {
6429           uschar *t = Ustrchr(base62_chars, *tt++);
6430           if (t == NULL)
6431             {
6432             expand_string_message = string_sprintf("argument for base62d "
6433               "operator is \"%s\", which is not a base %d number", sub,
6434               BASE_62);
6435             goto EXPAND_FAILED;
6436             }
6437           n = n * BASE_62 + (t - base62_chars);
6438           }
6439         (void)sprintf(CS buf, "%ld", n);
6440         yield = string_cat(yield, buf);
6441         continue;
6442         }
6443
6444       case EOP_EXPAND:
6445         {
6446         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6447         if (expanded == NULL)
6448           {
6449           expand_string_message =
6450             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6451               expand_string_message);
6452           goto EXPAND_FAILED;
6453           }
6454         yield = string_cat(yield, expanded);
6455         continue;
6456         }
6457
6458       case EOP_LC:
6459         {
6460         int count = 0;
6461         uschar *t = sub - 1;
6462         while (*(++t) != 0) { *t = tolower(*t); count++; }
6463         yield = string_catn(yield, sub, count);
6464         continue;
6465         }
6466
6467       case EOP_UC:
6468         {
6469         int count = 0;
6470         uschar *t = sub - 1;
6471         while (*(++t) != 0) { *t = toupper(*t); count++; }
6472         yield = string_catn(yield, sub, count);
6473         continue;
6474         }
6475
6476       case EOP_MD5:
6477 #ifdef SUPPORT_TLS
6478         if (vp && *(void **)vp->value)
6479           {
6480           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6481           yield = string_cat(yield, cp);
6482           }
6483         else
6484 #endif
6485           {
6486           md5 base;
6487           uschar digest[16];
6488           int j;
6489           char st[33];
6490           md5_start(&base);
6491           md5_end(&base, sub, Ustrlen(sub), digest);
6492           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6493           yield = string_cat(yield, US st);
6494           }
6495         continue;
6496
6497       case EOP_SHA1:
6498 #ifdef SUPPORT_TLS
6499         if (vp && *(void **)vp->value)
6500           {
6501           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6502           yield = string_cat(yield, cp);
6503           }
6504         else
6505 #endif
6506           {
6507           hctx h;
6508           uschar digest[20];
6509           int j;
6510           char st[41];
6511           sha1_start(&h);
6512           sha1_end(&h, sub, Ustrlen(sub), digest);
6513           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6514           yield = string_catn(yield, US st, 40);
6515           }
6516         continue;
6517
6518       case EOP_SHA256:
6519 #ifdef EXIM_HAVE_SHA2
6520         if (vp && *(void **)vp->value)
6521           {
6522           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6523           yield = string_cat(yield, cp);
6524           }
6525         else
6526           {
6527           hctx h;
6528           blob b;
6529           char st[3];
6530
6531           if (!exim_sha_init(&h, HASH_SHA2_256))
6532             {
6533             expand_string_message = US"unrecognised sha256 variant";
6534             goto EXPAND_FAILED;
6535             }
6536           exim_sha_update(&h, sub, Ustrlen(sub));
6537           exim_sha_finish(&h, &b);
6538           while (b.len-- > 0)
6539             {
6540             sprintf(st, "%02X", *b.data++);
6541             yield = string_catn(yield, US st, 2);
6542             }
6543           }
6544 #else
6545           expand_string_message = US"sha256 only supported with TLS";
6546 #endif
6547         continue;
6548
6549       case EOP_SHA3:
6550 #ifdef EXIM_HAVE_SHA3
6551         {
6552         hctx h;
6553         blob b;
6554         char st[3];
6555         hashmethod m = !arg ? HASH_SHA3_256
6556           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6557           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6558           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6559           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6560           : HASH_BADTYPE;
6561
6562         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6563           {
6564           expand_string_message = US"unrecognised sha3 variant";
6565           goto EXPAND_FAILED;
6566           }
6567
6568         exim_sha_update(&h, sub, Ustrlen(sub));
6569         exim_sha_finish(&h, &b);
6570         while (b.len-- > 0)
6571           {
6572           sprintf(st, "%02X", *b.data++);
6573           yield = string_catn(yield, US st, 2);
6574           }
6575         }
6576         continue;
6577 #else
6578         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 + or OpenSSL 1.1.1 +";
6579         goto EXPAND_FAILED;
6580 #endif
6581
6582       /* Convert hex encoding to base64 encoding */
6583
6584       case EOP_HEX2B64:
6585         {
6586         int c = 0;
6587         int b = -1;
6588         uschar *in = sub;
6589         uschar *out = sub;
6590         uschar *enc;
6591
6592         for (enc = sub; *enc != 0; enc++)
6593           {
6594           if (!isxdigit(*enc))
6595             {
6596             expand_string_message = string_sprintf("\"%s\" is not a hex "
6597               "string", sub);
6598             goto EXPAND_FAILED;
6599             }
6600           c++;
6601           }
6602
6603         if ((c & 1) != 0)
6604           {
6605           expand_string_message = string_sprintf("\"%s\" contains an odd "
6606             "number of characters", sub);
6607           goto EXPAND_FAILED;
6608           }
6609
6610         while ((c = *in++) != 0)
6611           {
6612           if (isdigit(c)) c -= '0';
6613           else c = toupper(c) - 'A' + 10;
6614           if (b == -1)
6615             {
6616             b = c << 4;
6617             }
6618           else
6619             {
6620             *out++ = b | c;
6621             b = -1;
6622             }
6623           }
6624
6625         enc = b64encode(sub, out - sub);
6626         yield = string_cat(yield, enc);
6627         continue;
6628         }
6629
6630       /* Convert octets outside 0x21..0x7E to \xXX form */
6631
6632       case EOP_HEXQUOTE:
6633         {
6634         uschar *t = sub - 1;
6635         while (*(++t) != 0)
6636           {
6637           if (*t < 0x21 || 0x7E < *t)
6638             yield = string_catn(yield, string_sprintf("\\x%02x", *t), 4);
6639           else
6640             yield = string_catn(yield, t, 1);
6641           }
6642         continue;
6643         }
6644
6645       /* count the number of list elements */
6646
6647       case EOP_LISTCOUNT:
6648         {
6649         int cnt = 0;
6650         int sep = 0;
6651         uschar * cp;
6652         uschar buffer[256];
6653
6654         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6655         cp = string_sprintf("%d", cnt);
6656         yield = string_cat(yield, cp);
6657         continue;
6658         }
6659
6660       /* expand a named list given the name */
6661       /* handles nested named lists; requotes as colon-sep list */
6662
6663       case EOP_LISTNAMED:
6664         {
6665         tree_node *t = NULL;
6666         const uschar * list;
6667         int sep = 0;
6668         uschar * item;
6669         uschar * suffix = US"";
6670         BOOL needsep = FALSE;
6671         uschar buffer[256];
6672
6673         if (*sub == '+') sub++;
6674         if (arg == NULL)        /* no-argument version */
6675           {
6676           if (!(t = tree_search(addresslist_anchor, sub)) &&
6677               !(t = tree_search(domainlist_anchor,  sub)) &&
6678               !(t = tree_search(hostlist_anchor,    sub)))
6679             t = tree_search(localpartlist_anchor, sub);
6680           }
6681         else switch(*arg)       /* specific list-type version */
6682           {
6683           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6684           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6685           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6686           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6687           default:
6688             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6689             goto EXPAND_FAILED;
6690           }
6691
6692         if(!t)
6693           {
6694           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6695             sub, !arg?""
6696               : *arg=='a'?"address "
6697               : *arg=='d'?"domain "
6698               : *arg=='h'?"host "
6699               : *arg=='l'?"localpart "
6700               : 0);
6701           goto EXPAND_FAILED;
6702           }
6703
6704         list = ((namedlist_block *)(t->data.ptr))->string;
6705
6706         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
6707           {
6708           uschar * buf = US" : ";
6709           if (needsep)
6710             yield = string_catn(yield, buf, 3);
6711           else
6712             needsep = TRUE;
6713
6714           if (*item == '+')     /* list item is itself a named list */
6715             {
6716             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6717             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6718             }
6719           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6720             {
6721             char * cp;
6722             char tok[3];
6723             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6724             while ((cp= strpbrk(CCS item, tok)))
6725               {
6726               yield = string_catn(yield, item, cp - CS item);
6727               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6728                 {
6729                 yield = string_catn(yield, US"::", 2);
6730                 item = US cp;
6731                 }
6732               else              /* sep in item; should already be doubled; emit once */
6733                 {
6734                 yield = string_catn(yield, US tok, 1);
6735                 if (*cp == sep) cp++;
6736                 item = US cp;
6737                 }
6738               }
6739             }
6740           yield = string_cat(yield, item);
6741           }
6742         continue;
6743         }
6744
6745       /* mask applies a mask to an IP address; for example the result of
6746       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6747
6748       case EOP_MASK:
6749         {
6750         int count;
6751         uschar *endptr;
6752         int binary[4];
6753         int mask, maskoffset;
6754         int type = string_is_ip_address(sub, &maskoffset);
6755         uschar buffer[64];
6756
6757         if (type == 0)
6758           {
6759           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6760            sub);
6761           goto EXPAND_FAILED;
6762           }
6763
6764         if (maskoffset == 0)
6765           {
6766           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6767             sub);
6768           goto EXPAND_FAILED;
6769           }
6770
6771         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6772
6773         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6774           {
6775           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6776             sub);
6777           goto EXPAND_FAILED;
6778           }
6779
6780         /* Convert the address to binary integer(s) and apply the mask */
6781
6782         sub[maskoffset] = 0;
6783         count = host_aton(sub, binary);
6784         host_mask(count, binary, mask);
6785
6786         /* Convert to masked textual format and add to output. */
6787
6788         yield = string_catn(yield, buffer,
6789           host_nmtoa(count, binary, mask, buffer, '.'));
6790         continue;
6791         }
6792
6793       case EOP_IPV6NORM:
6794       case EOP_IPV6DENORM:
6795         {
6796         int type = string_is_ip_address(sub, NULL);
6797         int binary[4];
6798         uschar buffer[44];
6799
6800         switch (type)
6801           {
6802           case 6:
6803             (void) host_aton(sub, binary);
6804             break;
6805
6806           case 4:       /* convert to IPv4-mapped IPv6 */
6807             binary[0] = binary[1] = 0;
6808             binary[2] = 0x0000ffff;
6809             (void) host_aton(sub, binary+3);
6810             break;
6811
6812           case 0:
6813             expand_string_message =
6814               string_sprintf("\"%s\" is not an IP address", sub);
6815             goto EXPAND_FAILED;
6816           }
6817
6818         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
6819                     ? ipv6_nmtoa(binary, buffer)
6820                     : host_nmtoa(4, binary, -1, buffer, ':')
6821                   );
6822         continue;
6823         }
6824
6825       case EOP_ADDRESS:
6826       case EOP_LOCAL_PART:
6827       case EOP_DOMAIN:
6828         {
6829         uschar * error;
6830         int start, end, domain;
6831         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6832           FALSE);
6833         if (t)
6834           if (c != EOP_DOMAIN)
6835             {
6836             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6837             yield = string_catn(yield, sub+start, end-start);
6838             }
6839           else if (domain != 0)
6840             {
6841             domain += start;
6842             yield = string_catn(yield, sub+domain, end-domain);
6843             }
6844         continue;
6845         }
6846
6847       case EOP_ADDRESSES:
6848         {
6849         uschar outsep[2] = { ':', '\0' };
6850         uschar *address, *error;
6851         int save_ptr = yield->ptr;
6852         int start, end, domain;  /* Not really used */
6853
6854         while (isspace(*sub)) sub++;
6855         if (*sub == '>')
6856           if (*outsep = *++sub) ++sub;
6857           else
6858             {
6859             expand_string_message = string_sprintf("output separator "
6860               "missing in expanding ${addresses:%s}", --sub);
6861             goto EXPAND_FAILED;
6862             }
6863         parse_allow_group = TRUE;
6864
6865         for (;;)
6866           {
6867           uschar *p = parse_find_address_end(sub, FALSE);
6868           uschar saveend = *p;
6869           *p = '\0';
6870           address = parse_extract_address(sub, &error, &start, &end, &domain,
6871             FALSE);
6872           *p = saveend;
6873
6874           /* Add the address to the output list that we are building. This is
6875           done in chunks by searching for the separator character. At the
6876           start, unless we are dealing with the first address of the output
6877           list, add in a space if the new address begins with the separator
6878           character, or is an empty string. */
6879
6880           if (address != NULL)
6881             {
6882             if (yield->ptr != save_ptr && address[0] == *outsep)
6883               yield = string_catn(yield, US" ", 1);
6884
6885             for (;;)
6886               {
6887               size_t seglen = Ustrcspn(address, outsep);
6888               yield = string_catn(yield, address, seglen + 1);
6889
6890               /* If we got to the end of the string we output one character
6891               too many. */
6892
6893               if (address[seglen] == '\0') { yield->ptr--; break; }
6894               yield = string_catn(yield, outsep, 1);
6895               address += seglen + 1;
6896               }
6897
6898             /* Output a separator after the string: we will remove the
6899             redundant final one at the end. */
6900
6901             yield = string_catn(yield, outsep, 1);
6902             }
6903
6904           if (saveend == '\0') break;
6905           sub = p + 1;
6906           }
6907
6908         /* If we have generated anything, remove the redundant final
6909         separator. */
6910
6911         if (yield->ptr != save_ptr) yield->ptr--;
6912         parse_allow_group = FALSE;
6913         continue;
6914         }
6915
6916
6917       /* quote puts a string in quotes if it is empty or contains anything
6918       other than alphamerics, underscore, dot, or hyphen.
6919
6920       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6921       be quoted in order to be a valid local part.
6922
6923       In both cases, newlines and carriage returns are converted into \n and \r
6924       respectively */
6925
6926       case EOP_QUOTE:
6927       case EOP_QUOTE_LOCAL_PART:
6928       if (arg == NULL)
6929         {
6930         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6931         uschar *t = sub - 1;
6932
6933         if (c == EOP_QUOTE)
6934           {
6935           while (!needs_quote && *(++t) != 0)
6936             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6937           }
6938         else  /* EOP_QUOTE_LOCAL_PART */
6939           {
6940           while (!needs_quote && *(++t) != 0)
6941             needs_quote = !isalnum(*t) &&
6942               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6943               (*t != '.' || t == sub || t[1] == 0);
6944           }
6945
6946         if (needs_quote)
6947           {
6948           yield = string_catn(yield, US"\"", 1);
6949           t = sub - 1;
6950           while (*(++t) != 0)
6951             {
6952             if (*t == '\n')
6953               yield = string_catn(yield, US"\\n", 2);
6954             else if (*t == '\r')
6955               yield = string_catn(yield, US"\\r", 2);
6956             else
6957               {
6958               if (*t == '\\' || *t == '"')
6959                 yield = string_catn(yield, US"\\", 1);
6960               yield = string_catn(yield, t, 1);
6961               }
6962             }
6963           yield = string_catn(yield, US"\"", 1);
6964           }
6965         else yield = string_cat(yield, sub);
6966         continue;
6967         }
6968
6969       /* quote_lookuptype does lookup-specific quoting */
6970
6971       else
6972         {
6973         int n;
6974         uschar *opt = Ustrchr(arg, '_');
6975
6976         if (opt != NULL) *opt++ = 0;
6977
6978         n = search_findtype(arg, Ustrlen(arg));
6979         if (n < 0)
6980           {
6981           expand_string_message = search_error_message;
6982           goto EXPAND_FAILED;
6983           }
6984
6985         if (lookup_list[n]->quote != NULL)
6986           sub = (lookup_list[n]->quote)(sub, opt);
6987         else if (opt != NULL) sub = NULL;
6988
6989         if (sub == NULL)
6990           {
6991           expand_string_message = string_sprintf(
6992             "\"%s\" unrecognized after \"${quote_%s\"",
6993             opt, arg);
6994           goto EXPAND_FAILED;
6995           }
6996
6997         yield = string_cat(yield, sub);
6998         continue;
6999         }
7000
7001       /* rx quote sticks in \ before any non-alphameric character so that
7002       the insertion works in a regular expression. */
7003
7004       case EOP_RXQUOTE:
7005         {
7006         uschar *t = sub - 1;
7007         while (*(++t) != 0)
7008           {
7009           if (!isalnum(*t))
7010             yield = string_catn(yield, US"\\", 1);
7011           yield = string_catn(yield, t, 1);
7012           }
7013         continue;
7014         }
7015
7016       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
7017       prescribed by the RFC, if there are characters that need to be encoded */
7018
7019       case EOP_RFC2047:
7020         {
7021         uschar buffer[2048];
7022         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
7023           buffer, sizeof(buffer), FALSE);
7024         yield = string_cat(yield, string);
7025         continue;
7026         }
7027
7028       /* RFC 2047 decode */
7029
7030       case EOP_RFC2047D:
7031         {
7032         int len;
7033         uschar *error;
7034         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
7035           headers_charset, '?', &len, &error);
7036         if (error != NULL)
7037           {
7038           expand_string_message = error;
7039           goto EXPAND_FAILED;
7040           }
7041         yield = string_catn(yield, decoded, len);
7042         continue;
7043         }
7044
7045       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
7046       underscores */
7047
7048       case EOP_FROM_UTF8:
7049         {
7050         while (*sub != 0)
7051           {
7052           int c;
7053           uschar buff[4];
7054           GETUTF8INC(c, sub);
7055           if (c > 255) c = '_';
7056           buff[0] = c;
7057           yield = string_catn(yield, buff, 1);
7058           }
7059         continue;
7060         }
7061
7062           /* replace illegal UTF-8 sequences by replacement character  */
7063
7064       #define UTF8_REPLACEMENT_CHAR US"?"
7065
7066       case EOP_UTF8CLEAN:
7067         {
7068         int seq_len = 0, index = 0;
7069         int bytes_left = 0;
7070         long codepoint = -1;
7071         uschar seq_buff[4];                     /* accumulate utf-8 here */
7072
7073         while (*sub != 0)
7074           {
7075           int complete = 0;
7076           uschar c = *sub++;
7077
7078           if (bytes_left)
7079             {
7080             if ((c & 0xc0) != 0x80)
7081                     /* wrong continuation byte; invalidate all bytes */
7082               complete = 1; /* error */
7083             else
7084               {
7085               codepoint = (codepoint << 6) | (c & 0x3f);
7086               seq_buff[index++] = c;
7087               if (--bytes_left == 0)            /* codepoint complete */
7088                 if(codepoint > 0x10FFFF)        /* is it too large? */
7089                   complete = -1;        /* error (RFC3629 limit) */
7090                 else
7091                   {             /* finished; output utf-8 sequence */
7092                   yield = string_catn(yield, seq_buff, seq_len);
7093                   index = 0;
7094                   }
7095               }
7096             }
7097           else  /* no bytes left: new sequence */
7098             {
7099             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7100               {
7101               yield = string_catn(yield, &c, 1);
7102               continue;
7103               }
7104             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7105               {
7106               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7107                 complete = -1;
7108               else
7109                 {
7110                   bytes_left = 1;
7111                   codepoint = c & 0x1f;
7112                 }
7113               }
7114             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7115               {
7116               bytes_left = 2;
7117               codepoint = c & 0x0f;
7118               }
7119             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7120               {
7121               bytes_left = 3;
7122               codepoint = c & 0x07;
7123               }
7124             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7125               complete = -1;
7126
7127             seq_buff[index++] = c;
7128             seq_len = bytes_left + 1;
7129             }           /* if(bytes_left) */
7130
7131           if (complete != 0)
7132             {
7133             bytes_left = index = 0;
7134             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7135             }
7136           if ((complete == 1) && ((c & 0x80) == 0))
7137                         /* ASCII character follows incomplete sequence */
7138               yield = string_catn(yield, &c, 1);
7139           }
7140         continue;
7141         }
7142
7143 #ifdef SUPPORT_I18N
7144       case EOP_UTF8_DOMAIN_TO_ALABEL:
7145         {
7146         uschar * error = NULL;
7147         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7148         if (error)
7149           {
7150           expand_string_message = string_sprintf(
7151             "error converting utf8 (%s) to alabel: %s",
7152             string_printing(sub), error);
7153           goto EXPAND_FAILED;
7154           }
7155         yield = string_cat(yield, s);
7156         continue;
7157         }
7158
7159       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7160         {
7161         uschar * error = NULL;
7162         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7163         if (error)
7164           {
7165           expand_string_message = string_sprintf(
7166             "error converting alabel (%s) to utf8: %s",
7167             string_printing(sub), error);
7168           goto EXPAND_FAILED;
7169           }
7170         yield = string_cat(yield, s);
7171         continue;
7172         }
7173
7174       case EOP_UTF8_LOCALPART_TO_ALABEL:
7175         {
7176         uschar * error = NULL;
7177         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7178         if (error)
7179           {
7180           expand_string_message = string_sprintf(
7181             "error converting utf8 (%s) to alabel: %s",
7182             string_printing(sub), error);
7183           goto EXPAND_FAILED;
7184           }
7185         yield = string_cat(yield, s);
7186         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7187         continue;
7188         }
7189
7190       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7191         {
7192         uschar * error = NULL;
7193         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7194         if (error)
7195           {
7196           expand_string_message = string_sprintf(
7197             "error converting alabel (%s) to utf8: %s",
7198             string_printing(sub), error);
7199           goto EXPAND_FAILED;
7200           }
7201         yield = string_cat(yield, s);
7202         continue;
7203         }
7204 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7205
7206       /* escape turns all non-printing characters into escape sequences. */
7207
7208       case EOP_ESCAPE:
7209         {
7210         const uschar * t = string_printing(sub);
7211         yield = string_cat(yield, t);
7212         continue;
7213         }
7214
7215       case EOP_ESCAPE8BIT:
7216         {
7217         const uschar * s = sub;
7218         uschar c;
7219
7220         for (s = sub; (c = *s); s++)
7221           yield = c < 127 && c != '\\'
7222             ? string_catn(yield, s, 1)
7223             : string_catn(yield, string_sprintf("\\%03o", c), 4);
7224         continue;
7225         }
7226
7227       /* Handle numeric expression evaluation */
7228
7229       case EOP_EVAL:
7230       case EOP_EVAL10:
7231         {
7232         uschar *save_sub = sub;
7233         uschar *error = NULL;
7234         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7235         if (error != NULL)
7236           {
7237           expand_string_message = string_sprintf("error in expression "
7238             "evaluation: %s (after processing \"%.*s\")", error,
7239             (int)(sub-save_sub), save_sub);
7240           goto EXPAND_FAILED;
7241           }
7242         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7243         yield = string_cat(yield, var_buffer);
7244         continue;
7245         }
7246
7247       /* Handle time period formating */
7248
7249       case EOP_TIME_EVAL:
7250         {
7251         int n = readconf_readtime(sub, 0, FALSE);
7252         if (n < 0)
7253           {
7254           expand_string_message = string_sprintf("string \"%s\" is not an "
7255             "Exim time interval in \"%s\" operator", sub, name);
7256           goto EXPAND_FAILED;
7257           }
7258         sprintf(CS var_buffer, "%d", n);
7259         yield = string_cat(yield, var_buffer);
7260         continue;
7261         }
7262
7263       case EOP_TIME_INTERVAL:
7264         {
7265         int n;
7266         uschar *t = read_number(&n, sub);
7267         if (*t != 0) /* Not A Number*/
7268           {
7269           expand_string_message = string_sprintf("string \"%s\" is not a "
7270             "positive number in \"%s\" operator", sub, name);
7271           goto EXPAND_FAILED;
7272           }
7273         t = readconf_printtime(n);
7274         yield = string_cat(yield, t);
7275         continue;
7276         }
7277
7278       /* Convert string to base64 encoding */
7279
7280       case EOP_STR2B64:
7281       case EOP_BASE64:
7282         {
7283 #ifdef SUPPORT_TLS
7284         uschar * s = vp && *(void **)vp->value
7285           ? tls_cert_der_b64(*(void **)vp->value)
7286           : b64encode(sub, Ustrlen(sub));
7287 #else
7288         uschar * s = b64encode(sub, Ustrlen(sub));
7289 #endif
7290         yield = string_cat(yield, s);
7291         continue;
7292         }
7293
7294       case EOP_BASE64D:
7295         {
7296         uschar * s;
7297         int len = b64decode(sub, &s);
7298         if (len < 0)
7299           {
7300           expand_string_message = string_sprintf("string \"%s\" is not "
7301             "well-formed for \"%s\" operator", sub, name);
7302           goto EXPAND_FAILED;
7303           }
7304         yield = string_cat(yield, s);
7305         continue;
7306         }
7307
7308       /* strlen returns the length of the string */
7309
7310       case EOP_STRLEN:
7311         {
7312         uschar buff[24];
7313         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7314         yield = string_cat(yield, buff);
7315         continue;
7316         }
7317
7318       /* length_n or l_n takes just the first n characters or the whole string,
7319       whichever is the shorter;
7320
7321       substr_m_n, and s_m_n take n characters from offset m; negative m take
7322       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7323       takes the rest, either to the right or to the left.
7324
7325       hash_n or h_n makes a hash of length n from the string, yielding n
7326       characters from the set a-z; hash_n_m makes a hash of length n, but
7327       uses m characters from the set a-zA-Z0-9.
7328
7329       nhash_n returns a single number between 0 and n-1 (in text form), while
7330       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7331       between 0 and n-1 and the second between 0 and m-1. */
7332
7333       case EOP_LENGTH:
7334       case EOP_L:
7335       case EOP_SUBSTR:
7336       case EOP_S:
7337       case EOP_HASH:
7338       case EOP_H:
7339       case EOP_NHASH:
7340       case EOP_NH:
7341         {
7342         int sign = 1;
7343         int value1 = 0;
7344         int value2 = -1;
7345         int *pn;
7346         int len;
7347         uschar *ret;
7348
7349         if (arg == NULL)
7350           {
7351           expand_string_message = string_sprintf("missing values after %s",
7352             name);
7353           goto EXPAND_FAILED;
7354           }
7355
7356         /* "length" has only one argument, effectively being synonymous with
7357         substr_0_n. */
7358
7359         if (c == EOP_LENGTH || c == EOP_L)
7360           {
7361           pn = &value2;
7362           value2 = 0;
7363           }
7364
7365         /* The others have one or two arguments; for "substr" the first may be
7366         negative. The second being negative means "not supplied". */
7367
7368         else
7369           {
7370           pn = &value1;
7371           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7372           }
7373
7374         /* Read up to two numbers, separated by underscores */
7375
7376         ret = arg;
7377         while (*arg != 0)
7378           {
7379           if (arg != ret && *arg == '_' && pn == &value1)
7380             {
7381             pn = &value2;
7382             value2 = 0;
7383             if (arg[1] != 0) arg++;
7384             }
7385           else if (!isdigit(*arg))
7386             {
7387             expand_string_message =
7388               string_sprintf("non-digit after underscore in \"%s\"", name);
7389             goto EXPAND_FAILED;
7390             }
7391           else *pn = (*pn)*10 + *arg++ - '0';
7392           }
7393         value1 *= sign;
7394
7395         /* Perform the required operation */
7396
7397         ret =
7398           (c == EOP_HASH || c == EOP_H)?
7399              compute_hash(sub, value1, value2, &len) :
7400           (c == EOP_NHASH || c == EOP_NH)?
7401              compute_nhash(sub, value1, value2, &len) :
7402              extract_substr(sub, value1, value2, &len);
7403
7404         if (ret == NULL) goto EXPAND_FAILED;
7405         yield = string_catn(yield, ret, len);
7406         continue;
7407         }
7408
7409       /* Stat a path */
7410
7411       case EOP_STAT:
7412         {
7413         uschar *s;
7414         uschar smode[12];
7415         uschar **modetable[3];
7416         int i;
7417         mode_t mode;
7418         struct stat st;
7419
7420         if ((expand_forbid & RDO_EXISTS) != 0)
7421           {
7422           expand_string_message = US"Use of the stat() expansion is not permitted";
7423           goto EXPAND_FAILED;
7424           }
7425
7426         if (stat(CS sub, &st) < 0)
7427           {
7428           expand_string_message = string_sprintf("stat(%s) failed: %s",
7429             sub, strerror(errno));
7430           goto EXPAND_FAILED;
7431           }
7432         mode = st.st_mode;
7433         switch (mode & S_IFMT)
7434           {
7435           case S_IFIFO: smode[0] = 'p'; break;
7436           case S_IFCHR: smode[0] = 'c'; break;
7437           case S_IFDIR: smode[0] = 'd'; break;
7438           case S_IFBLK: smode[0] = 'b'; break;
7439           case S_IFREG: smode[0] = '-'; break;
7440           default: smode[0] = '?'; break;
7441           }
7442
7443         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7444         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7445         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7446
7447         for (i = 0; i < 3; i++)
7448           {
7449           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7450           mode >>= 3;
7451           }
7452
7453         smode[10] = 0;
7454         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7455           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7456           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7457           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7458           (long)st.st_gid, st.st_size, (long)st.st_atime,
7459           (long)st.st_mtime, (long)st.st_ctime);
7460         yield = string_cat(yield, s);
7461         continue;
7462         }
7463
7464       /* vaguely random number less than N */
7465
7466       case EOP_RANDINT:
7467         {
7468         int_eximarith_t max;
7469         uschar *s;
7470
7471         max = expanded_string_integer(sub, TRUE);
7472         if (expand_string_message != NULL)
7473           goto EXPAND_FAILED;
7474         s = string_sprintf("%d", vaguely_random_number((int)max));
7475         yield = string_cat(yield, s);
7476         continue;
7477         }
7478
7479       /* Reverse IP, including IPv6 to dotted-nibble */
7480
7481       case EOP_REVERSE_IP:
7482         {
7483         int family, maskptr;
7484         uschar reversed[128];
7485
7486         family = string_is_ip_address(sub, &maskptr);
7487         if (family == 0)
7488           {
7489           expand_string_message = string_sprintf(
7490               "reverse_ip() not given an IP address [%s]", sub);
7491           goto EXPAND_FAILED;
7492           }
7493         invert_address(reversed, sub);
7494         yield = string_cat(yield, reversed);
7495         continue;
7496         }
7497
7498       /* Unknown operator */
7499
7500       default:
7501       expand_string_message =
7502         string_sprintf("unknown expansion operator \"%s\"", name);
7503       goto EXPAND_FAILED;
7504       }
7505     }
7506
7507   /* Handle a plain name. If this is the first thing in the expansion, release
7508   the pre-allocated buffer. If the result data is known to be in a new buffer,
7509   newsize will be set to the size of that buffer, and we can just point at that
7510   store instead of copying. Many expansion strings contain just one reference,
7511   so this is a useful optimization, especially for humungous headers
7512   ($message_headers). */
7513                                                 /*{*/
7514   if (*s++ == '}')
7515     {
7516     int len;
7517     int newsize = 0;
7518     gstring * g = NULL;
7519
7520     if (!yield)
7521       g = store_get(sizeof(gstring));
7522     else if (yield->ptr == 0)
7523       {
7524       if (resetok) store_reset(yield);
7525       yield = NULL;
7526       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
7527       }
7528     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7529       {
7530       expand_string_message =
7531         string_sprintf("unknown variable in \"${%s}\"", name);
7532       check_variable_error_message(name);
7533       goto EXPAND_FAILED;
7534       }
7535     len = Ustrlen(value);
7536     if (!yield && newsize)
7537       {
7538       yield = g;
7539       yield->size = newsize;
7540       yield->ptr = len;
7541       yield->s = value;
7542       }
7543     else
7544       yield = string_catn(yield, value, len);
7545     continue;
7546     }
7547
7548   /* Else there's something wrong */
7549
7550   expand_string_message =
7551     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7552     "in a variable reference)", name);
7553   goto EXPAND_FAILED;
7554   }
7555
7556 /* If we hit the end of the string when ket_ends is set, there is a missing
7557 terminating brace. */
7558
7559 if (ket_ends && *s == 0)
7560   {
7561   expand_string_message = malformed_header
7562     ? US"missing } at end of string - could be header name not terminated by colon"
7563     : US"missing } at end of string";
7564   goto EXPAND_FAILED;
7565   }
7566
7567 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7568 added to the string. If so, set up an empty string. Add a terminating zero. If
7569 left != NULL, return a pointer to the terminator. */
7570
7571 if (!yield)
7572   yield = string_get(1);
7573 (void) string_from_gstring(yield);
7574 if (left) *left = s;
7575
7576 /* Any stacking store that was used above the final string is no longer needed.
7577 In many cases the final string will be the first one that was got and so there
7578 will be optimal store usage. */
7579
7580 if (resetok) store_reset(yield->s + (yield->size = yield->ptr + 1));
7581 else if (resetok_p) *resetok_p = FALSE;
7582
7583 DEBUG(D_expand)
7584   {
7585   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7586     "expanding: %.*s\n",
7587     (int)(s - string), string);
7588   debug_printf_indent("%s"
7589     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7590     "result: %s\n",
7591     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7592     yield->s);
7593   if (skipping)
7594     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7595       "skipping: result is not used\n");
7596   }
7597 expand_level--;
7598 return yield->s;
7599
7600 /* This is the failure exit: easiest to program with a goto. We still need
7601 to update the pointer to the terminator, for cases of nested calls with "fail".
7602 */
7603
7604 EXPAND_FAILED_CURLY:
7605 if (malformed_header)
7606   expand_string_message =
7607     US"missing or misplaced { or } - could be header name not terminated by colon";
7608
7609 else if (!expand_string_message || !*expand_string_message)
7610   expand_string_message = US"missing or misplaced { or }";
7611
7612 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7613 that is a bad idea, because expand_string_message is in dynamic store. */
7614
7615 EXPAND_FAILED:
7616 if (left) *left = s;
7617 DEBUG(D_expand)
7618   {
7619   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7620     string);
7621   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7622     "error message: %s\n",
7623     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7624     expand_string_message);
7625   if (expand_string_forcedfail)
7626     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7627   }
7628 if (resetok_p && !resetok) *resetok_p = FALSE;
7629 expand_level--;
7630 return NULL;
7631 }
7632
7633
7634 /* This is the external function call. Do a quick check for any expansion
7635 metacharacters, and if there are none, just return the input string.
7636
7637 Argument: the string to be expanded
7638 Returns:  the expanded string, or NULL if expansion failed; if failure was
7639           due to a lookup deferring, search_find_defer will be TRUE
7640 */
7641
7642 const uschar *
7643 expand_cstring(const uschar * string)
7644 {
7645 if (Ustrpbrk(string, "$\\") != NULL)
7646   {
7647   int old_pool = store_pool;
7648   uschar * s;
7649
7650   search_find_defer = FALSE;
7651   malformed_header = FALSE;
7652   store_pool = POOL_MAIN;
7653     s = expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7654   store_pool = old_pool;
7655   return s;
7656   }
7657 return string;
7658 }
7659
7660
7661 uschar *
7662 expand_string(uschar * string)
7663 {
7664 return US expand_cstring(CUS string);
7665 }
7666
7667
7668
7669
7670
7671 /*************************************************
7672 *              Expand and copy                   *
7673 *************************************************/
7674
7675 /* Now and again we want to expand a string and be sure that the result is in a
7676 new bit of store. This function does that.
7677 Since we know it has been copied, the de-const cast is safe.
7678
7679 Argument: the string to be expanded
7680 Returns:  the expanded string, always in a new bit of store, or NULL
7681 */
7682
7683 uschar *
7684 expand_string_copy(const uschar *string)
7685 {
7686 const uschar *yield = expand_cstring(string);
7687 if (yield == string) yield = string_copy(string);
7688 return US yield;
7689 }
7690
7691
7692
7693 /*************************************************
7694 *        Expand and interpret as an integer      *
7695 *************************************************/
7696
7697 /* Expand a string, and convert the result into an integer.
7698
7699 Arguments:
7700   string  the string to be expanded
7701   isplus  TRUE if a non-negative number is expected
7702
7703 Returns:  the integer value, or
7704           -1 for an expansion error               ) in both cases, message in
7705           -2 for an integer interpretation error  ) expand_string_message
7706           expand_string_message is set NULL for an OK integer
7707 */
7708
7709 int_eximarith_t
7710 expand_string_integer(uschar *string, BOOL isplus)
7711 {
7712 return expanded_string_integer(expand_string(string), isplus);
7713 }
7714
7715
7716 /*************************************************
7717  *         Interpret string as an integer        *
7718  *************************************************/
7719
7720 /* Convert a string (that has already been expanded) into an integer.
7721
7722 This function is used inside the expansion code.
7723
7724 Arguments:
7725   s       the string to be expanded
7726   isplus  TRUE if a non-negative number is expected
7727
7728 Returns:  the integer value, or
7729           -1 if string is NULL (which implies an expansion error)
7730           -2 for an integer interpretation error
7731           expand_string_message is set NULL for an OK integer
7732 */
7733
7734 static int_eximarith_t
7735 expanded_string_integer(const uschar *s, BOOL isplus)
7736 {
7737 int_eximarith_t value;
7738 uschar *msg = US"invalid integer \"%s\"";
7739 uschar *endptr;
7740
7741 /* If expansion failed, expand_string_message will be set. */
7742
7743 if (s == NULL) return -1;
7744
7745 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7746 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7747 systems, so we set it zero ourselves. */
7748
7749 errno = 0;
7750 expand_string_message = NULL;               /* Indicates no error */
7751
7752 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7753 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7754 the behaviour explicitly.  Stripping leading whitespace is a harmless
7755 noop change since strtol skips it anyway (provided that there is a number
7756 to find at all). */
7757 if (isspace(*s))
7758   {
7759   while (isspace(*s)) ++s;
7760   if (*s == '\0')
7761     {
7762       DEBUG(D_expand)
7763        debug_printf_indent("treating blank string as number 0\n");
7764       return 0;
7765     }
7766   }
7767
7768 value = strtoll(CS s, CSS &endptr, 10);
7769
7770 if (endptr == s)
7771   {
7772   msg = US"integer expected but \"%s\" found";
7773   }
7774 else if (value < 0 && isplus)
7775   {
7776   msg = US"non-negative integer expected but \"%s\" found";
7777   }
7778 else
7779   {
7780   switch (tolower(*endptr))
7781     {
7782     default:
7783       break;
7784     case 'k':
7785       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7786       else value *= 1024;
7787       endptr++;
7788       break;
7789     case 'm':
7790       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7791       else value *= 1024*1024;
7792       endptr++;
7793       break;
7794     case 'g':
7795       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7796       else value *= 1024*1024*1024;
7797       endptr++;
7798       break;
7799     }
7800   if (errno == ERANGE)
7801     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7802   else
7803     {
7804     while (isspace(*endptr)) endptr++;
7805     if (*endptr == 0) return value;
7806     }
7807   }
7808
7809 expand_string_message = string_sprintf(CS msg, s);
7810 return -2;
7811 }
7812
7813
7814 /* These values are usually fixed boolean values, but they are permitted to be
7815 expanded strings.
7816
7817 Arguments:
7818   addr       address being routed
7819   mtype      the module type
7820   mname      the module name
7821   dbg_opt    debug selectors
7822   oname      the option name
7823   bvalue     the router's boolean value
7824   svalue     the router's string value
7825   rvalue     where to put the returned value
7826
7827 Returns:     OK     value placed in rvalue
7828              DEFER  expansion failed
7829 */
7830
7831 int
7832 exp_bool(address_item *addr,
7833   uschar *mtype, uschar *mname, unsigned dbg_opt,
7834   uschar *oname, BOOL bvalue,
7835   uschar *svalue, BOOL *rvalue)
7836 {
7837 uschar *expanded;
7838 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7839
7840 expanded = expand_string(svalue);
7841 if (expanded == NULL)
7842   {
7843   if (expand_string_forcedfail)
7844     {
7845     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7846     *rvalue = bvalue;
7847     return OK;
7848     }
7849   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7850       oname, mname, mtype, expand_string_message);
7851   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7852   return DEFER;
7853   }
7854
7855 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7856   expanded);
7857
7858 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7859   *rvalue = TRUE;
7860 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7861   *rvalue = FALSE;
7862 else
7863   {
7864   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7865     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7866   return DEFER;
7867   }
7868
7869 return OK;
7870 }
7871
7872
7873
7874 /* Avoid potentially exposing a password in a string about to be logged */
7875
7876 uschar *
7877 expand_hide_passwords(uschar * s)
7878 {
7879 return (  (  Ustrstr(s, "failed to expand") != NULL
7880           || Ustrstr(s, "expansion of ")    != NULL
7881           )
7882        && (  Ustrstr(s, "mysql")   != NULL
7883           || Ustrstr(s, "pgsql")   != NULL
7884           || Ustrstr(s, "redis")   != NULL
7885           || Ustrstr(s, "sqlite")  != NULL
7886           || Ustrstr(s, "ldap:")   != NULL
7887           || Ustrstr(s, "ldaps:")  != NULL
7888           || Ustrstr(s, "ldapi:")  != NULL
7889           || Ustrstr(s, "ldapdn:") != NULL
7890           || Ustrstr(s, "ldapm:")  != NULL
7891        )  )
7892   ? US"Temporary internal error" : s;
7893 }
7894
7895
7896 /* Read given named file into big_buffer.  Use for keying material etc.
7897 The content will have an ascii NUL appended.
7898
7899 Arguments:
7900  filename       as it says
7901
7902 Return:  pointer to buffer, or NULL on error.
7903 */
7904
7905 uschar *
7906 expand_file_big_buffer(const uschar * filename)
7907 {
7908 int fd, off = 0, len;
7909
7910 if ((fd = open(CS filename, O_RDONLY)) < 0)
7911   {
7912   log_write(0, LOG_MAIN | LOG_PANIC, "unable to open file for reading: %s",
7913              filename);
7914   return NULL;
7915   }
7916
7917 do
7918   {
7919   if ((len = read(fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
7920     {
7921     (void) close(fd);
7922     log_write(0, LOG_MAIN|LOG_PANIC, "unable to read file: %s", filename);
7923     return NULL;
7924     }
7925   off += len;
7926   }
7927 while (len > 0);
7928
7929 (void) close(fd);
7930 big_buffer[off] = '\0';
7931 return big_buffer;
7932 }
7933
7934
7935
7936 /*************************************************
7937 * Error-checking for testsuite                   *
7938 *************************************************/
7939 typedef struct {
7940   uschar *      region_start;
7941   uschar *      region_end;
7942   const uschar *var_name;
7943   const uschar *var_data;
7944 } err_ctx;
7945
7946 static void
7947 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7948 {
7949 err_ctx * e = ctx;
7950 if (var_data >= e->region_start  &&  var_data < e->region_end)
7951   {
7952   e->var_name = CUS var_name;
7953   e->var_data = CUS var_data;
7954   }
7955 }
7956
7957 void
7958 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7959 {
7960 err_ctx e = { .region_start = ptr, .region_end = US ptr + len,
7961               .var_name = NULL, .var_data = NULL };
7962 int i;
7963 var_entry * v;
7964
7965 /* check acl_ variables */
7966 tree_walk(acl_var_c, assert_variable_notin, &e);
7967 tree_walk(acl_var_m, assert_variable_notin, &e);
7968
7969 /* check auth<n> variables */
7970 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7971   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7972
7973 /* check regex<n> variables */
7974 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7975   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7976
7977 /* check known-name variables */
7978 for (v = var_table; v < var_table + var_table_size; v++)
7979   if (v->type == vtype_stringptr)
7980     assert_variable_notin(US v->name, *(USS v->value), &e);
7981
7982 /* check dns and address trees */
7983 tree_walk(tree_dns_fails,     assert_variable_notin, &e);
7984 tree_walk(tree_duplicates,    assert_variable_notin, &e);
7985 tree_walk(tree_nonrecipients, assert_variable_notin, &e);
7986 tree_walk(tree_unusable,      assert_variable_notin, &e);
7987
7988 if (e.var_name)
7989   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7990     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7991     e.var_name, filename, linenumber, e.var_data);
7992 }
7993
7994
7995
7996 /*************************************************
7997 **************************************************
7998 *             Stand-alone test program           *
7999 **************************************************
8000 *************************************************/
8001
8002 #ifdef STAND_ALONE
8003
8004
8005 BOOL
8006 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
8007 {
8008 int ovector[3*(EXPAND_MAXN+1)];
8009 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
8010   ovector, nelem(ovector));
8011 BOOL yield = n >= 0;
8012 if (n == 0) n = EXPAND_MAXN + 1;
8013 if (yield)
8014   {
8015   int nn;
8016   expand_nmax = (setup < 0)? 0 : setup + 1;
8017   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
8018     {
8019     expand_nstring[expand_nmax] = subject + ovector[nn];
8020     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
8021     }
8022   expand_nmax--;
8023   }
8024 return yield;
8025 }
8026
8027
8028 int main(int argc, uschar **argv)
8029 {
8030 int i;
8031 uschar buffer[1024];
8032
8033 debug_selector = D_v;
8034 debug_file = stderr;
8035 debug_fd = fileno(debug_file);
8036 big_buffer = malloc(big_buffer_size);
8037
8038 for (i = 1; i < argc; i++)
8039   {
8040   if (argv[i][0] == '+')
8041     {
8042     debug_trace_memory = 2;
8043     argv[i]++;
8044     }
8045   if (isdigit(argv[i][0]))
8046     debug_selector = Ustrtol(argv[i], NULL, 0);
8047   else
8048     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
8049         Ustrlen(argv[i]))
8050       {
8051 #ifdef LOOKUP_LDAP
8052       eldap_default_servers = argv[i];
8053 #endif
8054 #ifdef LOOKUP_MYSQL
8055       mysql_servers = argv[i];
8056 #endif
8057 #ifdef LOOKUP_PGSQL
8058       pgsql_servers = argv[i];
8059 #endif
8060 #ifdef LOOKUP_REDIS
8061       redis_servers = argv[i];
8062 #endif
8063       }
8064 #ifdef EXIM_PERL
8065   else opt_perl_startup = argv[i];
8066 #endif
8067   }
8068
8069 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
8070
8071 expand_nstring[1] = US"string 1....";
8072 expand_nlength[1] = 8;
8073 expand_nmax = 1;
8074
8075 #ifdef EXIM_PERL
8076 if (opt_perl_startup != NULL)
8077   {
8078   uschar *errstr;
8079   printf("Starting Perl interpreter\n");
8080   errstr = init_perl(opt_perl_startup);
8081   if (errstr != NULL)
8082     {
8083     printf("** error in perl_startup code: %s\n", errstr);
8084     return EXIT_FAILURE;
8085     }
8086   }
8087 #endif /* EXIM_PERL */
8088
8089 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
8090   {
8091   void *reset_point = store_get(0);
8092   uschar *yield = expand_string(buffer);
8093   if (yield != NULL)
8094     {
8095     printf("%s\n", yield);
8096     store_reset(reset_point);
8097     }
8098   else
8099     {
8100     if (search_find_defer) printf("search_find deferred\n");
8101     printf("Failed: %s\n", expand_string_message);
8102     if (expand_string_forcedfail) printf("Forced failure\n");
8103     printf("\n");
8104     }
8105   }
8106
8107 search_tidyup();
8108
8109 return 0;
8110 }
8111
8112 #endif
8113
8114 /* vi: aw ai sw=2
8115 */
8116 /* End of expand.c */