src/src/expand.c

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