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