src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2012 */
   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(uschar *, BOOL, uschar **, BOOL, BOOL);
  17
  18 #ifdef STAND_ALONE
  19 #ifndef SUPPORT_CRYPTEQ
  20 #define SUPPORT_CRYPTEQ
  21 #endif
  22 #endif
  23
  24 #ifdef LOOKUP_LDAP
  25 #include "lookups/ldap.h"
  26 #endif
  27
  28 #ifdef SUPPORT_CRYPTEQ
  29 #ifdef CRYPT_H
  30 #include <crypt.h>
  31 #endif
  32 #ifndef HAVE_CRYPT16
  33 extern char* crypt16(char*, char*);
  34 #endif
  35 #endif
  36
  37 /* The handling of crypt16() is a mess. I will record below the analysis of the
  38 mess that was sent to me. We decided, however, to make changing this very low
  39 priority, because in practice people are moving away from the crypt()
  40 algorithms nowadays, so it doesn't seem worth it.
  41
  42 <quote>
  43 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  44 the first 8 characters of the password using a 20-round version of crypt
  45 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  46 or an empty block if the password is less than 9 characters, using a
  47 20-round version of crypt and the same salt as was used for the first
  48 block.  Charaters after the first 16 are ignored.  It always generates
  49 a 16-byte hash, which is expressed together with the salt as a string
  50 of 24 base 64 digits.  Here are some links to peruse:
  51
  52         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  53         http://seclists.org/bugtraq/1999/Mar/0076.html
  54
  55 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  56 and OSF/1.  This is the same as the standard crypt if given a password
  57 of 8 characters or less.  If given more, it first does the same as crypt
  58 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  59 using as salt the first two base 64 digits from the first hash block.
  60 If the password is more than 16 characters then it crypts the 17th to 24th
  61 characters using as salt the first two base 64 digits from the second hash
  62 block.  And so on: I've seen references to it cutting off the password at
  63 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  64
  65         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  66         http://seclists.org/bugtraq/1999/Mar/0109.html
  67         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  68              TET1_html/sec.c222.html#no_id_208
  69
  70 Exim has something it calls "crypt16".  It will either use a native
  71 crypt16 or its own implementation.  A native crypt16 will presumably
  72 be the one that I called "crypt16" above.  The internal "crypt16"
  73 function, however, is a two-block-maximum implementation of what I called
  74 "bigcrypt".  The documentation matches the internal code.
  75
  76 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  77 that crypt16 and bigcrypt were different things.
  78
  79 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  80 to whatever it is using under that name.  This unfortunately sets a
  81 precedent for using "{crypt16}" to identify two incompatible algorithms
  82 whose output can't be distinguished.  With "{crypt16}" thus rendered
  83 ambiguous, I suggest you deprecate it and invent two new identifiers
  84 for the two algorithms.
  85
  86 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  87 of the password separately means they can be cracked separately, so
  88 the double-length hash only doubles the cracking effort instead of
  89 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  90 bcrypt ({CRYPT}$2a$).
  91 </quote>
  92 */
  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"dlfunc",
 107   US"extract",
 108   US"filter",
 109   US"hash",
 110   US"hmac",
 111   US"if",
 112   US"length",
 113   US"lookup",
 114   US"map",
 115   US"nhash",
 116   US"perl",
 117   US"prvs",
 118   US"prvscheck",
 119   US"readfile",
 120   US"readsocket",
 121   US"reduce",
 122   US"run",
 123   US"sg",
 124   US"substr",
 125   US"tr" };
 126
 127 enum {
 128   EITEM_ACL,
 129   EITEM_DLFUNC,
 130   EITEM_EXTRACT,
 131   EITEM_FILTER,
 132   EITEM_HASH,
 133   EITEM_HMAC,
 134   EITEM_IF,
 135   EITEM_LENGTH,
 136   EITEM_LOOKUP,
 137   EITEM_MAP,
 138   EITEM_NHASH,
 139   EITEM_PERL,
 140   EITEM_PRVS,
 141   EITEM_PRVSCHECK,
 142   EITEM_READFILE,
 143   EITEM_READSOCK,
 144   EITEM_REDUCE,
 145   EITEM_RUN,
 146   EITEM_SG,
 147   EITEM_SUBSTR,
 148   EITEM_TR };
 149
 150 /* Tables of operator names, and corresponding switch numbers. The names must be
 151 in alphabetical order. There are two tables, because underscore is used in some
 152 cases to introduce arguments, whereas for other it is part of the name. This is
 153 an historical mis-design. */
 154
 155 static uschar *op_table_underscore[] = {
 156   US"from_utf8",
 157   US"local_part",
 158   US"quote_local_part",
 159   US"reverse_ip",
 160   US"time_eval",
 161   US"time_interval"};
 162
 163 enum {
 164   EOP_FROM_UTF8,
 165   EOP_LOCAL_PART,
 166   EOP_QUOTE_LOCAL_PART,
 167   EOP_REVERSE_IP,
 168   EOP_TIME_EVAL,
 169   EOP_TIME_INTERVAL };
 170
 171 static uschar *op_table_main[] = {
 172   US"address",
 173   US"addresses",
 174   US"base62",
 175   US"base62d",
 176   US"domain",
 177   US"escape",
 178   US"eval",
 179   US"eval10",
 180   US"expand",
 181   US"h",
 182   US"hash",
 183   US"hex2b64",
 184   US"l",
 185   US"lc",
 186   US"length",
 187   US"listcount",
 188   US"listnamed",
 189   US"mask",
 190   US"md5",
 191   US"nh",
 192   US"nhash",
 193   US"quote",
 194   US"randint",
 195   US"rfc2047",
 196   US"rfc2047d",
 197   US"rxquote",
 198   US"s",
 199   US"sha1",
 200   US"stat",
 201   US"str2b64",
 202   US"strlen",
 203   US"substr",
 204   US"uc" };
 205
 206 enum {
 207   EOP_ADDRESS =  sizeof(op_table_underscore)/sizeof(uschar *),
 208   EOP_ADDRESSES,
 209   EOP_BASE62,
 210   EOP_BASE62D,
 211   EOP_DOMAIN,
 212   EOP_ESCAPE,
 213   EOP_EVAL,
 214   EOP_EVAL10,
 215   EOP_EXPAND,
 216   EOP_H,
 217   EOP_HASH,
 218   EOP_HEX2B64,
 219   EOP_L,
 220   EOP_LC,
 221   EOP_LENGTH,
 222   EOP_LISTCOUNT,
 223   EOP_LISTNAMED,
 224   EOP_MASK,
 225   EOP_MD5,
 226   EOP_NH,
 227   EOP_NHASH,
 228   EOP_QUOTE,
 229   EOP_RANDINT,
 230   EOP_RFC2047,
 231   EOP_RFC2047D,
 232   EOP_RXQUOTE,
 233   EOP_S,
 234   EOP_SHA1,
 235   EOP_STAT,
 236   EOP_STR2B64,
 237   EOP_STRLEN,
 238   EOP_SUBSTR,
 239   EOP_UC };
 240
 241
 242 /* Table of condition names, and corresponding switch numbers. The names must
 243 be in alphabetical order. */
 244
 245 static uschar *cond_table[] = {
 246   US"<",
 247   US"<=",
 248   US"=",
 249   US"==",     /* Backward compatibility */
 250   US">",
 251   US">=",
 252   US"acl",
 253   US"and",
 254   US"bool",
 255   US"bool_lax",
 256   US"crypteq",
 257   US"def",
 258   US"eq",
 259   US"eqi",
 260   US"exists",
 261   US"first_delivery",
 262   US"forall",
 263   US"forany",
 264   US"ge",
 265   US"gei",
 266   US"gt",
 267   US"gti",
 268   US"inlist",
 269   US"inlisti",
 270   US"isip",
 271   US"isip4",
 272   US"isip6",
 273   US"ldapauth",
 274   US"le",
 275   US"lei",
 276   US"lt",
 277   US"lti",
 278   US"match",
 279   US"match_address",
 280   US"match_domain",
 281   US"match_ip",
 282   US"match_local_part",
 283   US"or",
 284   US"pam",
 285   US"pwcheck",
 286   US"queue_running",
 287   US"radius",
 288   US"saslauthd"
 289 };
 290
 291 enum {
 292   ECOND_NUM_L,
 293   ECOND_NUM_LE,
 294   ECOND_NUM_E,
 295   ECOND_NUM_EE,
 296   ECOND_NUM_G,
 297   ECOND_NUM_GE,
 298   ECOND_ACL,
 299   ECOND_AND,
 300   ECOND_BOOL,
 301   ECOND_BOOL_LAX,
 302   ECOND_CRYPTEQ,
 303   ECOND_DEF,
 304   ECOND_STR_EQ,
 305   ECOND_STR_EQI,
 306   ECOND_EXISTS,
 307   ECOND_FIRST_DELIVERY,
 308   ECOND_FORALL,
 309   ECOND_FORANY,
 310   ECOND_STR_GE,
 311   ECOND_STR_GEI,
 312   ECOND_STR_GT,
 313   ECOND_STR_GTI,
 314   ECOND_INLIST,
 315   ECOND_INLISTI,
 316   ECOND_ISIP,
 317   ECOND_ISIP4,
 318   ECOND_ISIP6,
 319   ECOND_LDAPAUTH,
 320   ECOND_STR_LE,
 321   ECOND_STR_LEI,
 322   ECOND_STR_LT,
 323   ECOND_STR_LTI,
 324   ECOND_MATCH,
 325   ECOND_MATCH_ADDRESS,
 326   ECOND_MATCH_DOMAIN,
 327   ECOND_MATCH_IP,
 328   ECOND_MATCH_LOCAL_PART,
 329   ECOND_OR,
 330   ECOND_PAM,
 331   ECOND_PWCHECK,
 332   ECOND_QUEUE_RUNNING,
 333   ECOND_RADIUS,
 334   ECOND_SASLAUTHD
 335 };
 336
 337
 338 /* Type for main variable table */
 339
 340 typedef struct {
 341   const char *name;
 342   int         type;
 343   void       *value;
 344 } var_entry;
 345
 346 /* Type for entries pointing to address/length pairs. Not currently
 347 in use. */
 348
 349 typedef struct {
 350   uschar **address;
 351   int  *length;
 352 } alblock;
 353
 354 /* Types of table entry */
 355
 356 enum {
 357   vtype_int,            /* value is address of int */
 358   vtype_filter_int,     /* ditto, but recognized only when filtering */
 359   vtype_ino,            /* value is address of ino_t (not always an int) */
 360   vtype_uid,            /* value is address of uid_t (not always an int) */
 361   vtype_gid,            /* value is address of gid_t (not always an int) */
 362   vtype_bool,           /* value is address of bool */
 363   vtype_stringptr,      /* value is address of pointer to string */
 364   vtype_msgbody,        /* as stringptr, but read when first required */
 365   vtype_msgbody_end,    /* ditto, the end of the message */
 366   vtype_msgheaders,     /* the message's headers, processed */
 367   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 368   vtype_localpart,      /* extract local part from string */
 369   vtype_domain,         /* extract domain from string */
 370   vtype_recipients,     /* extract recipients from recipients list */
 371                         /* (available only in system filters, ACLs, and */
 372                         /* local_scan()) */
 373   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 374   vtype_tode,           /* value not used; generate tod in epoch format */
 375   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 376   vtype_todf,           /* value not used; generate full tod */
 377   vtype_todl,           /* value not used; generate log tod */
 378   vtype_todlf,          /* value not used; generate log file datestamp tod */
 379   vtype_todzone,        /* value not used; generate time zone only */
 380   vtype_todzulu,        /* value not used; generate zulu tod */
 381   vtype_reply,          /* value not used; get reply from headers */
 382   vtype_pid,            /* value not used; result is pid */
 383   vtype_host_lookup,    /* value not used; get host name */
 384   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 385   vtype_pspace,         /* partition space; value is T/F for spool/log */
 386   vtype_pinodes         /* partition inodes; value is T/F for spool/log */
 387   #ifndef DISABLE_DKIM
 388   ,vtype_dkim           /* Lookup of value in DKIM signature */
 389   #endif
 390   };
 391
 392 /* This table must be kept in alphabetical order. */
 393
 394 static var_entry var_table[] = {
 395   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 396      they will be confused with user-creatable ACL variables. */
 397   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 398   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 399   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 400   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 401   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 402   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 403   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 404   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 405   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 406   { "acl_narg",            vtype_int,         &acl_narg },
 407   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 408   { "address_data",        vtype_stringptr,   &deliver_address_data },
 409   { "address_file",        vtype_stringptr,   &address_file },
 410   { "address_pipe",        vtype_stringptr,   &address_pipe },
 411   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 412   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 413   { "authentication_failed",vtype_int,        &authentication_failed },
 414 #ifdef WITH_CONTENT_SCAN
 415   { "av_failed",           vtype_int,         &av_failed },
 416 #endif
 417 #ifdef EXPERIMENTAL_BRIGHTMAIL
 418   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 419   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 420   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 421   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 422 #endif
 423   { "body_linecount",      vtype_int,         &body_linecount },
 424   { "body_zerocount",      vtype_int,         &body_zerocount },
 425   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 426   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 427   { "caller_gid",          vtype_gid,         &real_gid },
 428   { "caller_uid",          vtype_uid,         &real_uid },
 429   { "compile_date",        vtype_stringptr,   &version_date },
 430   { "compile_number",      vtype_stringptr,   &version_cnumber },
 431   { "csa_status",          vtype_stringptr,   &csa_status },
 432 #ifdef EXPERIMENTAL_DCC
 433   { "dcc_header",          vtype_stringptr,   &dcc_header },
 434   { "dcc_result",          vtype_stringptr,   &dcc_result },
 435 #endif
 436 #ifdef WITH_OLD_DEMIME
 437   { "demime_errorlevel",   vtype_int,         &demime_errorlevel },
 438   { "demime_reason",       vtype_stringptr,   &demime_reason },
 439 #endif
 440 #ifndef DISABLE_DKIM
 441   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 442   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 443   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 444   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 445   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 446   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 447   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 448   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 449   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 450   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 451   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 452   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 453   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 454   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 455   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 456   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 457   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 458   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 459   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 460   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 461 #endif
 462   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 463   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 464   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 465   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 466   { "domain",              vtype_stringptr,   &deliver_domain },
 467   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 468   { "exim_gid",            vtype_gid,         &exim_gid },
 469   { "exim_path",           vtype_stringptr,   &exim_path },
 470   { "exim_uid",            vtype_uid,         &exim_uid },
 471 #ifdef WITH_OLD_DEMIME
 472   { "found_extension",     vtype_stringptr,   &found_extension },
 473 #endif
 474   { "home",                vtype_stringptr,   &deliver_home },
 475   { "host",                vtype_stringptr,   &deliver_host },
 476   { "host_address",        vtype_stringptr,   &deliver_host_address },
 477   { "host_data",           vtype_stringptr,   &host_data },
 478   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 479   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 480   { "inode",               vtype_ino,         &deliver_inode },
 481   { "interface_address",   vtype_stringptr,   &interface_address },
 482   { "interface_port",      vtype_int,         &interface_port },
 483   { "item",                vtype_stringptr,   &iterate_item },
 484   #ifdef LOOKUP_LDAP
 485   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 486   #endif
 487   { "load_average",        vtype_load_avg,    NULL },
 488   { "local_part",          vtype_stringptr,   &deliver_localpart },
 489   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 490   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 491   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 492   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 493   { "local_user_gid",      vtype_gid,         &local_user_gid },
 494   { "local_user_uid",      vtype_uid,         &local_user_uid },
 495   { "localhost_number",    vtype_int,         &host_number },
 496   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 497   { "log_space",           vtype_pspace,      (void *)FALSE },
 498   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 499 #ifdef WITH_CONTENT_SCAN
 500   { "malware_name",        vtype_stringptr,   &malware_name },
 501 #endif
 502   { "max_received_linelength", vtype_int,     &max_received_linelength },
 503   { "message_age",         vtype_int,         &message_age },
 504   { "message_body",        vtype_msgbody,     &message_body },
 505   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 506   { "message_body_size",   vtype_int,         &message_body_size },
 507   { "message_exim_id",     vtype_stringptr,   &message_id },
 508   { "message_headers",     vtype_msgheaders,  NULL },
 509   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 510   { "message_id",          vtype_stringptr,   &message_id },
 511   { "message_linecount",   vtype_int,         &message_linecount },
 512   { "message_size",        vtype_int,         &message_size },
 513 #ifdef WITH_CONTENT_SCAN
 514   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 515   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 516   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 517   { "mime_charset",        vtype_stringptr,   &mime_charset },
 518   { "mime_content_description", vtype_stringptr, &mime_content_description },
 519   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 520   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 521   { "mime_content_size",   vtype_int,         &mime_content_size },
 522   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 523   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 524   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 525   { "mime_filename",       vtype_stringptr,   &mime_filename },
 526   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 527   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 528   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 529   { "mime_part_count",     vtype_int,         &mime_part_count },
 530 #endif
 531   { "n0",                  vtype_filter_int,  &filter_n[0] },
 532   { "n1",                  vtype_filter_int,  &filter_n[1] },
 533   { "n2",                  vtype_filter_int,  &filter_n[2] },
 534   { "n3",                  vtype_filter_int,  &filter_n[3] },
 535   { "n4",                  vtype_filter_int,  &filter_n[4] },
 536   { "n5",                  vtype_filter_int,  &filter_n[5] },
 537   { "n6",                  vtype_filter_int,  &filter_n[6] },
 538   { "n7",                  vtype_filter_int,  &filter_n[7] },
 539   { "n8",                  vtype_filter_int,  &filter_n[8] },
 540   { "n9",                  vtype_filter_int,  &filter_n[9] },
 541   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 542   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 543   { "originator_gid",      vtype_gid,         &originator_gid },
 544   { "originator_uid",      vtype_uid,         &originator_uid },
 545   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 546   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 547   { "pid",                 vtype_pid,         NULL },
 548   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 549   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 550   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 551   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 552   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 553   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 554   { "rcpt_count",          vtype_int,         &rcpt_count },
 555   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 556   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 557   { "received_count",      vtype_int,         &received_count },
 558   { "received_for",        vtype_stringptr,   &received_for },
 559   { "received_ip_address", vtype_stringptr,   &interface_address },
 560   { "received_port",       vtype_int,         &interface_port },
 561   { "received_protocol",   vtype_stringptr,   &received_protocol },
 562   { "received_time",       vtype_int,         &received_time },
 563   { "recipient_data",      vtype_stringptr,   &recipient_data },
 564   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 565   { "recipients",          vtype_recipients,  NULL },
 566   { "recipients_count",    vtype_int,         &recipients_count },
 567 #ifdef WITH_CONTENT_SCAN
 568   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 569 #endif
 570   { "reply_address",       vtype_reply,       NULL },
 571   { "return_path",         vtype_stringptr,   &return_path },
 572   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 573   { "runrc",               vtype_int,         &runrc },
 574   { "self_hostname",       vtype_stringptr,   &self_hostname },
 575   { "sender_address",      vtype_stringptr,   &sender_address },
 576   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 577   { "sender_address_domain", vtype_domain,    &sender_address },
 578   { "sender_address_local_part", vtype_localpart, &sender_address },
 579   { "sender_data",         vtype_stringptr,   &sender_data },
 580   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 581   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 582   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 583   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 584   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 585   { "sender_host_name",    vtype_host_lookup, NULL },
 586   { "sender_host_port",    vtype_int,         &sender_host_port },
 587   { "sender_ident",        vtype_stringptr,   &sender_ident },
 588   { "sender_rate",         vtype_stringptr,   &sender_rate },
 589   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 590   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 591   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 592   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 593   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 594   { "sending_port",        vtype_int,         &sending_port },
 595   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 596   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 597   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 598   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 599   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 600   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 601   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 602   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 603   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 604   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 605   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 606   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 607   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 608   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 609   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 610 #ifdef WITH_CONTENT_SCAN
 611   { "spam_bar",            vtype_stringptr,   &spam_bar },
 612   { "spam_report",         vtype_stringptr,   &spam_report },
 613   { "spam_score",          vtype_stringptr,   &spam_score },
 614   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 615 #endif
 616 #ifdef EXPERIMENTAL_SPF
 617   { "spf_guess",           vtype_stringptr,   &spf_guess },
 618   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 619   { "spf_received",        vtype_stringptr,   &spf_received },
 620   { "spf_result",          vtype_stringptr,   &spf_result },
 621   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 622 #endif
 623   { "spool_directory",     vtype_stringptr,   &spool_directory },
 624   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 625   { "spool_space",         vtype_pspace,      (void *)TRUE },
 626 #ifdef EXPERIMENTAL_SRS
 627   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 628   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 629   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 630   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 631   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 632   { "srs_status",          vtype_stringptr,   &srs_status },
 633 #endif
 634   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 635
 636   /* The non-(in,out) variables are now deprecated */
 637   { "tls_bits",            vtype_int,         &tls_in.bits },
 638   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 639   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 640
 641   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 642   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 643   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 644   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 645 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 646   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 647 #endif
 648   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 649   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 650   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 651   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 652 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 653   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 654 #endif
 655
 656   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 657 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 658   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 659 #endif
 660
 661   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 662   { "tod_epoch",           vtype_tode,        NULL },
 663   { "tod_epoch_l",         vtype_todel,       NULL },
 664   { "tod_full",            vtype_todf,        NULL },
 665   { "tod_log",             vtype_todl,        NULL },
 666   { "tod_logfile",         vtype_todlf,       NULL },
 667   { "tod_zone",            vtype_todzone,     NULL },
 668   { "tod_zulu",            vtype_todzulu,     NULL },
 669   { "value",               vtype_stringptr,   &lookup_value },
 670   { "version_number",      vtype_stringptr,   &version_string },
 671   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 672   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 673   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 674   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 675   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 676   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 677 };
 678
 679 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
 680 static uschar var_buffer[256];
 681 static BOOL malformed_header;
 682
 683 /* For textual hashes */
 684
 685 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 686                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 687                                "0123456789";
 688
 689 enum { HMAC_MD5, HMAC_SHA1 };
 690
 691 /* For numeric hashes */
 692
 693 static unsigned int prime[] = {
 694   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 695  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 696  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 697
 698 /* For printing modes in symbolic form */
 699
 700 static uschar *mtable_normal[] =
 701   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 702
 703 static uschar *mtable_setid[] =
 704   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 705
 706 static uschar *mtable_sticky[] =
 707   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 708
 709
 710
 711 /*************************************************
 712 *           Tables for UTF-8 support             *
 713 *************************************************/
 714
 715 /* Table of the number of extra characters, indexed by the first character
 716 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 717 0x3d. */
 718
 719 static uschar utf8_table1[] = {
 720   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 721   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 722   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 723   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 724
 725 /* These are the masks for the data bits in the first byte of a character,
 726 indexed by the number of additional bytes. */
 727
 728 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 729
 730 /* Get the next UTF-8 character, advancing the pointer. */
 731
 732 #define GETUTF8INC(c, ptr) \
 733   c = *ptr++; \
 734   if ((c & 0xc0) == 0xc0) \
 735     { \
 736     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 737     int s = 6*a; \
 738     c = (c & utf8_table2[a]) << s; \
 739     while (a-- > 0) \
 740       { \
 741       s -= 6; \
 742       c |= (*ptr++ & 0x3f) << s; \
 743       } \
 744     }
 745
 746
 747 /*************************************************
 748 *           Binary chop search on a table        *
 749 *************************************************/
 750
 751 /* This is used for matching expansion items and operators.
 752
 753 Arguments:
 754   name        the name that is being sought
 755   table       the table to search
 756   table_size  the number of items in the table
 757
 758 Returns:      the offset in the table, or -1
 759 */
 760
 761 static int
 762 chop_match(uschar *name, uschar **table, int table_size)
 763 {
 764 uschar **bot = table;
 765 uschar **top = table + table_size;
 766
 767 while (top > bot)
 768   {
 769   uschar **mid = bot + (top - bot)/2;
 770   int c = Ustrcmp(name, *mid);
 771   if (c == 0) return mid - table;
 772   if (c > 0) bot = mid + 1; else top = mid;
 773   }
 774
 775 return -1;
 776 }
 777
 778
 779
 780 /*************************************************
 781 *          Check a condition string              *
 782 *************************************************/
 783
 784 /* This function is called to expand a string, and test the result for a "true"
 785 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 786 forced fail or lookup defer. All store used by the function can be released on
 787 exit.
 788
 789 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 790
 791 Arguments:
 792   condition     the condition string
 793   m1            text to be incorporated in panic error
 794   m2            ditto
 795
 796 Returns:        TRUE if condition is met, FALSE if not
 797 */
 798
 799 BOOL
 800 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 801 {
 802 int rc;
 803 void *reset_point = store_get(0);
 804 uschar *ss = expand_string(condition);
 805 if (ss == NULL)
 806   {
 807   if (!expand_string_forcedfail && !search_find_defer)
 808     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 809       "for %s %s: %s", condition, m1, m2, expand_string_message);
 810   return FALSE;
 811   }
 812 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 813   strcmpic(ss, US"false") != 0;
 814 store_reset(reset_point);
 815 return rc;
 816 }
 817
 818
 819
 820
 821 /*************************************************
 822 *        Pseudo-random number generation         *
 823 *************************************************/
 824
 825 /* Pseudo-random number generation.  The result is not "expected" to be
 826 cryptographically strong but not so weak that someone will shoot themselves
 827 in the foot using it as a nonce in some email header scheme or whatever
 828 weirdness they'll twist this into.  The result should ideally handle fork().
 829
 830 However, if we're stuck unable to provide this, then we'll fall back to
 831 appallingly bad randomness.
 832
 833 If SUPPORT_TLS is defined then this will not be used except as an emergency
 834 fallback.
 835
 836 Arguments:
 837   max       range maximum
 838 Returns     a random number in range [0, max-1]
 839 */
 840
 841 #ifdef SUPPORT_TLS
 842 # define vaguely_random_number vaguely_random_number_fallback
 843 #endif
 844 int
 845 vaguely_random_number(int max)
 846 {
 847 #ifdef SUPPORT_TLS
 848 # undef vaguely_random_number
 849 #endif
 850   static pid_t pid = 0;
 851   pid_t p2;
 852 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 853   struct timeval tv;
 854 #endif
 855
 856   p2 = getpid();
 857   if (p2 != pid)
 858     {
 859     if (pid != 0)
 860       {
 861
 862 #ifdef HAVE_ARC4RANDOM
 863       /* cryptographically strong randomness, common on *BSD platforms, not
 864       so much elsewhere.  Alas. */
 865       arc4random_stir();
 866 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 867 #ifdef HAVE_SRANDOMDEV
 868       /* uses random(4) for seeding */
 869       srandomdev();
 870 #else
 871       gettimeofday(&tv, NULL);
 872       srandom(tv.tv_sec | tv.tv_usec | getpid());
 873 #endif
 874 #else
 875       /* Poor randomness and no seeding here */
 876 #endif
 877
 878       }
 879     pid = p2;
 880     }
 881
 882 #ifdef HAVE_ARC4RANDOM
 883   return arc4random() % max;
 884 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 885   return random() % max;
 886 #else
 887   /* This one returns a 16-bit number, definitely not crypto-strong */
 888   return random_number(max);
 889 #endif
 890 }
 891
 892
 893
 894
 895 /*************************************************
 896 *             Pick out a name from a string      *
 897 *************************************************/
 898
 899 /* If the name is too long, it is silently truncated.
 900
 901 Arguments:
 902   name      points to a buffer into which to put the name
 903   max       is the length of the buffer
 904   s         points to the first alphabetic character of the name
 905   extras    chars other than alphanumerics to permit
 906
 907 Returns:    pointer to the first character after the name
 908
 909 Note: The test for *s != 0 in the while loop is necessary because
 910 Ustrchr() yields non-NULL if the character is zero (which is not something
 911 I expected). */
 912
 913 static uschar *
 914 read_name(uschar *name, int max, uschar *s, uschar *extras)
 915 {
 916 int ptr = 0;
 917 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 918   {
 919   if (ptr < max-1) name[ptr++] = *s;
 920   s++;
 921   }
 922 name[ptr] = 0;
 923 return s;
 924 }
 925
 926
 927
 928 /*************************************************
 929 *     Pick out the rest of a header name         *
 930 *************************************************/
 931
 932 /* A variable name starting $header_ (or just $h_ for those who like
 933 abbreviations) might not be the complete header name because headers can
 934 contain any printing characters in their names, except ':'. This function is
 935 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 936 on the end, if the name was terminated by white space.
 937
 938 Arguments:
 939   name      points to a buffer in which the name read so far exists
 940   max       is the length of the buffer
 941   s         points to the first character after the name so far, i.e. the
 942             first non-alphameric character after $header_xxxxx
 943
 944 Returns:    a pointer to the first character after the header name
 945 */
 946
 947 static uschar *
 948 read_header_name(uschar *name, int max, uschar *s)
 949 {
 950 int prelen = Ustrchr(name, '_') - name + 1;
 951 int ptr = Ustrlen(name) - prelen;
 952 if (ptr > 0) memmove(name, name+prelen, ptr);
 953 while (mac_isgraph(*s) && *s != ':')
 954   {
 955   if (ptr < max-1) name[ptr++] = *s;
 956   s++;
 957   }
 958 if (*s == ':') s++;
 959 name[ptr++] = ':';
 960 name[ptr] = 0;
 961 return s;
 962 }
 963
 964
 965
 966 /*************************************************
 967 *           Pick out a number from a string      *
 968 *************************************************/
 969
 970 /* Arguments:
 971   n     points to an integer into which to put the number
 972   s     points to the first digit of the number
 973
 974 Returns:  a pointer to the character after the last digit
 975 */
 976
 977 static uschar *
 978 read_number(int *n, uschar *s)
 979 {
 980 *n = 0;
 981 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
 982 return s;
 983 }
 984
 985
 986
 987 /*************************************************
 988 *        Extract keyed subfield from a string    *
 989 *************************************************/
 990
 991 /* The yield is in dynamic store; NULL means that the key was not found.
 992
 993 Arguments:
 994   key       points to the name of the key
 995   s         points to the string from which to extract the subfield
 996
 997 Returns:    NULL if the subfield was not found, or
 998             a pointer to the subfield's data
 999 */
1000
1001 static uschar *
1002 expand_getkeyed(uschar *key, uschar *s)
1003 {
1004 int length = Ustrlen(key);
1005 while (isspace(*s)) s++;
1006
1007 /* Loop to search for the key */
1008
1009 while (*s != 0)
1010   {
1011   int dkeylength;
1012   uschar *data;
1013   uschar *dkey = s;
1014
1015   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1016   dkeylength = s - dkey;
1017   while (isspace(*s)) s++;
1018   if (*s == '=') while (isspace((*(++s))));
1019
1020   data = string_dequote(&s);
1021   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1022     return data;
1023
1024   while (isspace(*s)) s++;
1025   }
1026
1027 return NULL;
1028 }
1029
1030
1031
1032
1033 /*************************************************
1034 *   Extract numbered subfield from string        *
1035 *************************************************/
1036
1037 /* Extracts a numbered field from a string that is divided by tokens - for
1038 example a line from /etc/passwd is divided by colon characters.  First field is
1039 numbered one.  Negative arguments count from the right. Zero returns the whole
1040 string. Returns NULL if there are insufficient tokens in the string
1041
1042 ***WARNING***
1043 Modifies final argument - this is a dynamically generated string, so that's OK.
1044
1045 Arguments:
1046   field       number of field to be extracted,
1047                 first field = 1, whole string = 0, last field = -1
1048   separators  characters that are used to break string into tokens
1049   s           points to the string from which to extract the subfield
1050
1051 Returns:      NULL if the field was not found,
1052               a pointer to the field's data inside s (modified to add 0)
1053 */
1054
1055 static uschar *
1056 expand_gettokened (int field, uschar *separators, uschar *s)
1057 {
1058 int sep = 1;
1059 int count;
1060 uschar *ss = s;
1061 uschar *fieldtext = NULL;
1062
1063 if (field == 0) return s;
1064
1065 /* Break the line up into fields in place; for field > 0 we stop when we have
1066 done the number of fields we want. For field < 0 we continue till the end of
1067 the string, counting the number of fields. */
1068
1069 count = (field > 0)? field : INT_MAX;
1070
1071 while (count-- > 0)
1072   {
1073   size_t len;
1074
1075   /* Previous field was the last one in the string. For a positive field
1076   number, this means there are not enough fields. For a negative field number,
1077   check that there are enough, and scan back to find the one that is wanted. */
1078
1079   if (sep == 0)
1080     {
1081     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1082     if ((-field) == (INT_MAX - count - 1)) return s;
1083     while (field++ < 0)
1084       {
1085       ss--;
1086       while (ss[-1] != 0) ss--;
1087       }
1088     fieldtext = ss;
1089     break;
1090     }
1091
1092   /* Previous field was not last in the string; save its start and put a
1093   zero at its end. */
1094
1095   fieldtext = ss;
1096   len = Ustrcspn(ss, separators);
1097   sep = ss[len];
1098   ss[len] = 0;
1099   ss += len + 1;
1100   }
1101
1102 return fieldtext;
1103 }
1104
1105
1106
1107 /*************************************************
1108 *        Extract a substring from a string       *
1109 *************************************************/
1110
1111 /* Perform the ${substr or ${length expansion operations.
1112
1113 Arguments:
1114   subject     the input string
1115   value1      the offset from the start of the input string to the start of
1116                 the output string; if negative, count from the right.
1117   value2      the length of the output string, or negative (-1) for unset
1118                 if value1 is positive, unset means "all after"
1119                 if value1 is negative, unset means "all before"
1120   len         set to the length of the returned string
1121
1122 Returns:      pointer to the output string, or NULL if there is an error
1123 */
1124
1125 static uschar *
1126 extract_substr(uschar *subject, int value1, int value2, int *len)
1127 {
1128 int sublen = Ustrlen(subject);
1129
1130 if (value1 < 0)    /* count from right */
1131   {
1132   value1 += sublen;
1133
1134   /* If the position is before the start, skip to the start, and adjust the
1135   length. If the length ends up negative, the substring is null because nothing
1136   can precede. This falls out naturally when the length is unset, meaning "all
1137   to the left". */
1138
1139   if (value1 < 0)
1140     {
1141     value2 += value1;
1142     if (value2 < 0) value2 = 0;
1143     value1 = 0;
1144     }
1145
1146   /* Otherwise an unset length => characters before value1 */
1147
1148   else if (value2 < 0)
1149     {
1150     value2 = value1;
1151     value1 = 0;
1152     }
1153   }
1154
1155 /* For a non-negative offset, if the starting position is past the end of the
1156 string, the result will be the null string. Otherwise, an unset length means
1157 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1158
1159 else
1160   {
1161   if (value1 > sublen)
1162     {
1163     value1 = sublen;
1164     value2 = 0;
1165     }
1166   else if (value2 < 0) value2 = sublen;
1167   }
1168
1169 /* Cut the length down to the maximum possible for the offset value, and get
1170 the required characters. */
1171
1172 if (value1 + value2 > sublen) value2 = sublen - value1;
1173 *len = value2;
1174 return subject + value1;
1175 }
1176
1177
1178
1179
1180 /*************************************************
1181 *            Old-style hash of a string          *
1182 *************************************************/
1183
1184 /* Perform the ${hash expansion operation.
1185
1186 Arguments:
1187   subject     the input string (an expanded substring)
1188   value1      the length of the output string; if greater or equal to the
1189                 length of the input string, the input string is returned
1190   value2      the number of hash characters to use, or 26 if negative
1191   len         set to the length of the returned string
1192
1193 Returns:      pointer to the output string, or NULL if there is an error
1194 */
1195
1196 static uschar *
1197 compute_hash(uschar *subject, int value1, int value2, int *len)
1198 {
1199 int sublen = Ustrlen(subject);
1200
1201 if (value2 < 0) value2 = 26;
1202 else if (value2 > Ustrlen(hashcodes))
1203   {
1204   expand_string_message =
1205     string_sprintf("hash count \"%d\" too big", value2);
1206   return NULL;
1207   }
1208
1209 /* Calculate the hash text. We know it is shorter than the original string, so
1210 can safely place it in subject[] (we know that subject is always itself an
1211 expanded substring). */
1212
1213 if (value1 < sublen)
1214   {
1215   int c;
1216   int i = 0;
1217   int j = value1;
1218   while ((c = (subject[j])) != 0)
1219     {
1220     int shift = (c + j++) & 7;
1221     subject[i] ^= (c << shift) | (c >> (8-shift));
1222     if (++i >= value1) i = 0;
1223     }
1224   for (i = 0; i < value1; i++)
1225     subject[i] = hashcodes[(subject[i]) % value2];
1226   }
1227 else value1 = sublen;
1228
1229 *len = value1;
1230 return subject;
1231 }
1232
1233
1234
1235
1236 /*************************************************
1237 *             Numeric hash of a string           *
1238 *************************************************/
1239
1240 /* Perform the ${nhash expansion operation. The first characters of the
1241 string are treated as most important, and get the highest prime numbers.
1242
1243 Arguments:
1244   subject     the input string
1245   value1      the maximum value of the first part of the result
1246   value2      the maximum value of the second part of the result,
1247                 or negative to produce only a one-part result
1248   len         set to the length of the returned string
1249
1250 Returns:  pointer to the output string, or NULL if there is an error.
1251 */
1252
1253 static uschar *
1254 compute_nhash (uschar *subject, int value1, int value2, int *len)
1255 {
1256 uschar *s = subject;
1257 int i = 0;
1258 unsigned long int total = 0; /* no overflow */
1259
1260 while (*s != 0)
1261   {
1262   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1263   total += prime[i--] * (unsigned int)(*s++);
1264   }
1265
1266 /* If value2 is unset, just compute one number */
1267
1268 if (value2 < 0)
1269   {
1270   s = string_sprintf("%d", total % value1);
1271   }
1272
1273 /* Otherwise do a div/mod hash */
1274
1275 else
1276   {
1277   total = total % (value1 * value2);
1278   s = string_sprintf("%d/%d", total/value2, total % value2);
1279   }
1280
1281 *len = Ustrlen(s);
1282 return s;
1283 }
1284
1285
1286
1287
1288
1289 /*************************************************
1290 *     Find the value of a header or headers      *
1291 *************************************************/
1292
1293 /* Multiple instances of the same header get concatenated, and this function
1294 can also return a concatenation of all the header lines. When concatenating
1295 specific headers that contain lists of addresses, a comma is inserted between
1296 them. Otherwise we use a straight concatenation. Because some messages can have
1297 pathologically large number of lines, there is a limit on the length that is
1298 returned. Also, to avoid massive store use which would result from using
1299 string_cat() as it copies and extends strings, we do a preliminary pass to find
1300 out exactly how much store will be needed. On "normal" messages this will be
1301 pretty trivial.
1302
1303 Arguments:
1304   name          the name of the header, without the leading $header_ or $h_,
1305                 or NULL if a concatenation of all headers is required
1306   exists_only   TRUE if called from a def: test; don't need to build a string;
1307                 just return a string that is not "" and not "0" if the header
1308                 exists
1309   newsize       return the size of memory block that was obtained; may be NULL
1310                 if exists_only is TRUE
1311   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1312                 other than concatenating, will be done on the header. Also used
1313                 for $message_headers_raw.
1314   charset       name of charset to translate MIME words to; used only if
1315                 want_raw is false; if NULL, no translation is done (this is
1316                 used for $bh_ and $bheader_)
1317
1318 Returns:        NULL if the header does not exist, else a pointer to a new
1319                 store block
1320 */
1321
1322 static uschar *
1323 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1324   uschar *charset)
1325 {
1326 BOOL found = name == NULL;
1327 int comma = 0;
1328 int len = found? 0 : Ustrlen(name);
1329 int i;
1330 uschar *yield = NULL;
1331 uschar *ptr = NULL;
1332
1333 /* Loop for two passes - saves code repetition */
1334
1335 for (i = 0; i < 2; i++)
1336   {
1337   int size = 0;
1338   header_line *h;
1339
1340   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1341     {
1342     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1343       {
1344       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1345         {
1346         int ilen;
1347         uschar *t;
1348
1349         if (exists_only) return US"1";      /* don't need actual string */
1350         found = TRUE;
1351         t = h->text + len;                  /* text to insert */
1352         if (!want_raw)                      /* unless wanted raw, */
1353           while (isspace(*t)) t++;          /* remove leading white space */
1354         ilen = h->slen - (t - h->text);     /* length to insert */
1355
1356         /* Unless wanted raw, remove trailing whitespace, including the
1357         newline. */
1358
1359         if (!want_raw)
1360           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1361
1362         /* Set comma = 1 if handling a single header and it's one of those
1363         that contains an address list, except when asked for raw headers. Only
1364         need to do this once. */
1365
1366         if (!want_raw && name != NULL && comma == 0 &&
1367             Ustrchr("BCFRST", h->type) != NULL)
1368           comma = 1;
1369
1370         /* First pass - compute total store needed; second pass - compute
1371         total store used, including this header. */
1372
1373         size += ilen + comma + 1;  /* +1 for the newline */
1374
1375         /* Second pass - concatentate the data, up to a maximum. Note that
1376         the loop stops when size hits the limit. */
1377
1378         if (i != 0)
1379           {
1380           if (size > header_insert_maxlen)
1381             {
1382             ilen -= size - header_insert_maxlen - 1;
1383             comma = 0;
1384             }
1385           Ustrncpy(ptr, t, ilen);
1386           ptr += ilen;
1387
1388           /* For a non-raw header, put in the comma if needed, then add
1389           back the newline we removed above, provided there was some text in
1390           the header. */
1391
1392           if (!want_raw && ilen > 0)
1393             {
1394             if (comma != 0) *ptr++ = ',';
1395             *ptr++ = '\n';
1396             }
1397           }
1398         }
1399       }
1400     }
1401
1402   /* At end of first pass, return NULL if no header found. Then truncate size
1403   if necessary, and get the buffer to hold the data, returning the buffer size.
1404   */
1405
1406   if (i == 0)
1407     {
1408     if (!found) return NULL;
1409     if (size > header_insert_maxlen) size = header_insert_maxlen;
1410     *newsize = size + 1;
1411     ptr = yield = store_get(*newsize);
1412     }
1413   }
1414
1415 /* That's all we do for raw header expansion. */
1416
1417 if (want_raw)
1418   {
1419   *ptr = 0;
1420   }
1421
1422 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1423 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1424 function can return an error with decoded data if the charset translation
1425 fails. If decoding fails, it returns NULL. */
1426
1427 else
1428   {
1429   uschar *decoded, *error;
1430   if (ptr > yield && ptr[-1] == '\n') ptr--;
1431   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1432   *ptr = 0;
1433   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1434     newsize, &error);
1435   if (error != NULL)
1436     {
1437     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1438       "    input was: %s\n", error, yield);
1439     }
1440   if (decoded != NULL) yield = decoded;
1441   }
1442
1443 return yield;
1444 }
1445
1446
1447
1448
1449 /*************************************************
1450 *               Find value of a variable         *
1451 *************************************************/
1452
1453 /* The table of variables is kept in alphabetic order, so we can search it
1454 using a binary chop. The "choplen" variable is nothing to do with the binary
1455 chop.
1456
1457 Arguments:
1458   name          the name of the variable being sought
1459   exists_only   TRUE if this is a def: test; passed on to find_header()
1460   skipping      TRUE => skip any processing evaluation; this is not the same as
1461                   exists_only because def: may test for values that are first
1462                   evaluated here
1463   newsize       pointer to an int which is initially zero; if the answer is in
1464                 a new memory buffer, *newsize is set to its size
1465
1466 Returns:        NULL if the variable does not exist, or
1467                 a pointer to the variable's contents, or
1468                 something non-NULL if exists_only is TRUE
1469 */
1470
1471 static uschar *
1472 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1473 {
1474 int first = 0;
1475 int last = var_table_size;
1476
1477 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1478 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1479 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1480 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1481 (this gave backwards compatibility at the changeover). There may be built-in
1482 variables whose names start acl_ but they should never start in this way. This
1483 slightly messy specification is a consequence of the history, needless to say.
1484
1485 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1486 set, in which case give an error. */
1487
1488 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1489      !isalpha(name[5]))
1490   {
1491   tree_node *node =
1492     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1493   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1494   }
1495
1496 /* Handle $auth<n> variables. */
1497
1498 if (Ustrncmp(name, "auth", 4) == 0)
1499   {
1500   uschar *endptr;
1501   int n = Ustrtoul(name + 4, &endptr, 10);
1502   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1503     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1504   }
1505
1506 /* For all other variables, search the table */
1507
1508 while (last > first)
1509   {
1510   uschar *s, *domain;
1511   uschar **ss;
1512   int middle = (first + last)/2;
1513   int c = Ustrcmp(name, var_table[middle].name);
1514
1515   if (c > 0) { first = middle + 1; continue; }
1516   if (c < 0) { last = middle; continue; }
1517
1518   /* Found an existing variable. If in skipping state, the value isn't needed,
1519   and we want to avoid processing (such as looking up the host name). */
1520
1521   if (skipping) return US"";
1522
1523   switch (var_table[middle].type)
1524     {
1525     case vtype_filter_int:
1526     if (!filter_running) return NULL;
1527     /* Fall through */
1528     /* VVVVVVVVVVVV */
1529     case vtype_int:
1530     sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1531     return var_buffer;
1532
1533     case vtype_ino:
1534     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1535     return var_buffer;
1536
1537     case vtype_gid:
1538     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1539     return var_buffer;
1540
1541     case vtype_uid:
1542     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1543     return var_buffer;
1544
1545     case vtype_bool:
1546     sprintf(CS var_buffer, "%s", *(BOOL *)(var_table[middle].value) ? "yes" : "no"); /* bool */
1547     return var_buffer;
1548
1549     case vtype_stringptr:                      /* Pointer to string */
1550     s = *((uschar **)(var_table[middle].value));
1551     return (s == NULL)? US"" : s;
1552
1553     case vtype_pid:
1554     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1555     return var_buffer;
1556
1557     case vtype_load_avg:
1558     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1559     return var_buffer;
1560
1561     case vtype_host_lookup:                    /* Lookup if not done so */
1562     if (sender_host_name == NULL && sender_host_address != NULL &&
1563         !host_lookup_failed && host_name_lookup() == OK)
1564       host_build_sender_fullhost();
1565     return (sender_host_name == NULL)? US"" : sender_host_name;
1566
1567     case vtype_localpart:                      /* Get local part from address */
1568     s = *((uschar **)(var_table[middle].value));
1569     if (s == NULL) return US"";
1570     domain = Ustrrchr(s, '@');
1571     if (domain == NULL) return s;
1572     if (domain - s > sizeof(var_buffer) - 1)
1573       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1574           " in string expansion", sizeof(var_buffer));
1575     Ustrncpy(var_buffer, s, domain - s);
1576     var_buffer[domain - s] = 0;
1577     return var_buffer;
1578
1579     case vtype_domain:                         /* Get domain from address */
1580     s = *((uschar **)(var_table[middle].value));
1581     if (s == NULL) return US"";
1582     domain = Ustrrchr(s, '@');
1583     return (domain == NULL)? US"" : domain + 1;
1584
1585     case vtype_msgheaders:
1586     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1587
1588     case vtype_msgheaders_raw:
1589     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1590
1591     case vtype_msgbody:                        /* Pointer to msgbody string */
1592     case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1593     ss = (uschar **)(var_table[middle].value);
1594     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1595       {
1596       uschar *body;
1597       off_t start_offset = SPOOL_DATA_START_OFFSET;
1598       int len = message_body_visible;
1599       if (len > message_size) len = message_size;
1600       *ss = body = store_malloc(len+1);
1601       body[0] = 0;
1602       if (var_table[middle].type == vtype_msgbody_end)
1603         {
1604         struct stat statbuf;
1605         if (fstat(deliver_datafile, &statbuf) == 0)
1606           {
1607           start_offset = statbuf.st_size - len;
1608           if (start_offset < SPOOL_DATA_START_OFFSET)
1609             start_offset = SPOOL_DATA_START_OFFSET;
1610           }
1611         }
1612       lseek(deliver_datafile, start_offset, SEEK_SET);
1613       len = read(deliver_datafile, body, len);
1614       if (len > 0)
1615         {
1616         body[len] = 0;
1617         if (message_body_newlines)   /* Separate loops for efficiency */
1618           {
1619           while (len > 0)
1620             { if (body[--len] == 0) body[len] = ' '; }
1621           }
1622         else
1623           {
1624           while (len > 0)
1625             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1626           }
1627         }
1628       }
1629     return (*ss == NULL)? US"" : *ss;
1630
1631     case vtype_todbsdin:                       /* BSD inbox time of day */
1632     return tod_stamp(tod_bsdin);
1633
1634     case vtype_tode:                           /* Unix epoch time of day */
1635     return tod_stamp(tod_epoch);
1636
1637     case vtype_todel:                          /* Unix epoch/usec time of day */
1638     return tod_stamp(tod_epoch_l);
1639
1640     case vtype_todf:                           /* Full time of day */
1641     return tod_stamp(tod_full);
1642
1643     case vtype_todl:                           /* Log format time of day */
1644     return tod_stamp(tod_log_bare);            /* (without timezone) */
1645
1646     case vtype_todzone:                        /* Time zone offset only */
1647     return tod_stamp(tod_zone);
1648
1649     case vtype_todzulu:                        /* Zulu time */
1650     return tod_stamp(tod_zulu);
1651
1652     case vtype_todlf:                          /* Log file datestamp tod */
1653     return tod_stamp(tod_log_datestamp_daily);
1654
1655     case vtype_reply:                          /* Get reply address */
1656     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1657       headers_charset);
1658     if (s != NULL) while (isspace(*s)) s++;
1659     if (s == NULL || *s == 0)
1660       {
1661       *newsize = 0;                            /* For the *s==0 case */
1662       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1663       }
1664     if (s != NULL)
1665       {
1666       uschar *t;
1667       while (isspace(*s)) s++;
1668       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1669       while (t > s && isspace(t[-1])) t--;
1670       *t = 0;
1671       }
1672     return (s == NULL)? US"" : s;
1673
1674     /* A recipients list is available only during system message filtering,
1675     during ACL processing after DATA, and while expanding pipe commands
1676     generated from a system filter, but not elsewhere. */
1677
1678     case vtype_recipients:
1679     if (!enable_dollar_recipients) return NULL; else
1680       {
1681       int size = 128;
1682       int ptr = 0;
1683       int i;
1684       s = store_get(size);
1685       for (i = 0; i < recipients_count; i++)
1686         {
1687         if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1688         s = string_cat(s, &size, &ptr, recipients_list[i].address,
1689           Ustrlen(recipients_list[i].address));
1690         }
1691       s[ptr] = 0;     /* string_cat() leaves room */
1692       }
1693     return s;
1694
1695     case vtype_pspace:
1696       {
1697       int inodes;
1698       sprintf(CS var_buffer, "%d",
1699         receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes));
1700       }
1701     return var_buffer;
1702
1703     case vtype_pinodes:
1704       {
1705       int inodes;
1706       (void) receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes);
1707       sprintf(CS var_buffer, "%d", inodes);
1708       }
1709     return var_buffer;
1710
1711     #ifndef DISABLE_DKIM
1712     case vtype_dkim:
1713     return dkim_exim_expand_query((int)(long)var_table[middle].value);
1714     #endif
1715
1716     }
1717   }
1718
1719 return NULL;          /* Unknown variable name */
1720 }
1721
1722
1723
1724
1725 void
1726 modify_variable(uschar *name, void * value)
1727 {
1728 int first = 0;
1729 int last = var_table_size;
1730
1731 while (last > first)
1732   {
1733   int middle = (first + last)/2;
1734   int c = Ustrcmp(name, var_table[middle].name);
1735
1736   if (c > 0) { first = middle + 1; continue; }
1737   if (c < 0) { last = middle; continue; }
1738
1739   /* Found an existing variable; change the item it refers to */
1740   var_table[middle].value = value;
1741   return;
1742   }
1743 return;          /* Unknown variable name, fail silently */
1744 }
1745
1746
1747
1748
1749
1750 /*************************************************
1751 *           Read and expand substrings           *
1752 *************************************************/
1753
1754 /* This function is called to read and expand argument substrings for various
1755 expansion items. Some have a minimum requirement that is less than the maximum;
1756 in these cases, the first non-present one is set to NULL.
1757
1758 Arguments:
1759   sub        points to vector of pointers to set
1760   n          maximum number of substrings
1761   m          minimum required
1762   sptr       points to current string pointer
1763   skipping   the skipping flag
1764   check_end  if TRUE, check for final '}'
1765   name       name of item, for error message
1766
1767 Returns:     0 OK; string pointer updated
1768              1 curly bracketing error (too few arguments)
1769              2 too many arguments (only if check_end is set); message set
1770              3 other error (expansion failure)
1771 */
1772
1773 static int
1774 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1775   BOOL check_end, uschar *name)
1776 {
1777 int i;
1778 uschar *s = *sptr;
1779
1780 while (isspace(*s)) s++;
1781 for (i = 0; i < n; i++)
1782   {
1783   if (*s != '{')
1784     {
1785     if (i < m) return 1;
1786     sub[i] = NULL;
1787     break;
1788     }
1789   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
1790   if (sub[i] == NULL) return 3;
1791   if (*s++ != '}') return 1;
1792   while (isspace(*s)) s++;
1793   }
1794 if (check_end && *s++ != '}')
1795   {
1796   if (s[-1] == '{')
1797     {
1798     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1799       "(max is %d)", name, n);
1800     return 2;
1801     }
1802   return 1;
1803   }
1804
1805 *sptr = s;
1806 return 0;
1807 }
1808
1809
1810
1811
1812 /*************************************************
1813 *     Elaborate message for bad variable         *
1814 *************************************************/
1815
1816 /* For the "unknown variable" message, take a look at the variable's name, and
1817 give additional information about possible ACL variables. The extra information
1818 is added on to expand_string_message.
1819
1820 Argument:   the name of the variable
1821 Returns:    nothing
1822 */
1823
1824 static void
1825 check_variable_error_message(uschar *name)
1826 {
1827 if (Ustrncmp(name, "acl_", 4) == 0)
1828   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1829     (name[4] == 'c' || name[4] == 'm')?
1830       (isalpha(name[5])?
1831         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1832         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1833       ) :
1834       US"user-defined ACL variables must start acl_c or acl_m");
1835 }
1836
1837
1838
1839 /*
1840 Load args from sub array to globals, and call acl_check().
1841
1842 Returns:       OK         access is granted by an ACCEPT verb
1843                DISCARD    access is granted by a DISCARD verb
1844                FAIL       access is denied
1845                FAIL_DROP  access is denied; drop the connection
1846                DEFER      can't tell at the moment
1847                ERROR      disaster
1848 */
1849 static int
1850 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
1851 {
1852 int i;
1853 uschar *dummy_log_msg;
1854
1855 for (i = 1; i < nsub && sub[i]; i++)
1856   acl_arg[i-1] = sub[i];
1857 acl_narg = i-1;
1858 while (i < nsub)
1859   acl_arg[i++ - 1] = NULL;
1860
1861 DEBUG(D_expand)
1862   debug_printf("expanding: acl: %s  arg: %s%s\n",
1863     sub[0],
1864     acl_narg>0 ? sub[1]   : US"<none>",
1865     acl_narg>1 ? " +more" : "");
1866
1867 return acl_check(ACL_WHERE_EXPANSION, NULL, sub[0], user_msgp, &dummy_log_msg);
1868 }
1869
1870
1871
1872
1873 /*************************************************
1874 *        Read and evaluate a condition           *
1875 *************************************************/
1876
1877 /*
1878 Arguments:
1879   s        points to the start of the condition text
1880   yield    points to a BOOL to hold the result of the condition test;
1881            if NULL, we are just reading through a condition that is
1882            part of an "or" combination to check syntax, or in a state
1883            where the answer isn't required
1884
1885 Returns:   a pointer to the first character after the condition, or
1886            NULL after an error
1887 */
1888
1889 static uschar *
1890 eval_condition(uschar *s, BOOL *yield)
1891 {
1892 BOOL testfor = TRUE;
1893 BOOL tempcond, combined_cond;
1894 BOOL *subcondptr;
1895 BOOL sub2_honour_dollar = TRUE;
1896 int i, rc, cond_type, roffset;
1897 int_eximarith_t num[2];
1898 struct stat statbuf;
1899 uschar name[256];
1900 uschar *sub[10];
1901
1902 const pcre *re;
1903 const uschar *rerror;
1904
1905 for (;;)
1906   {
1907   while (isspace(*s)) s++;
1908   if (*s == '!') { testfor = !testfor; s++; } else break;
1909   }
1910
1911 /* Numeric comparisons are symbolic */
1912
1913 if (*s == '=' || *s == '>' || *s == '<')
1914   {
1915   int p = 0;
1916   name[p++] = *s++;
1917   if (*s == '=')
1918     {
1919     name[p++] = '=';
1920     s++;
1921     }
1922   name[p] = 0;
1923   }
1924
1925 /* All other conditions are named */
1926
1927 else s = read_name(name, 256, s, US"_");
1928
1929 /* If we haven't read a name, it means some non-alpha character is first. */
1930
1931 if (name[0] == 0)
1932   {
1933   expand_string_message = string_sprintf("condition name expected, "
1934     "but found \"%.16s\"", s);
1935   return NULL;
1936   }
1937
1938 /* Find which condition we are dealing with, and switch on it */
1939
1940 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1941 switch(cond_type)
1942   {
1943   /* def: tests for a non-empty variable, or for the existence of a header. If
1944   yield == NULL we are in a skipping state, and don't care about the answer. */
1945
1946   case ECOND_DEF:
1947   if (*s != ':')
1948     {
1949     expand_string_message = US"\":\" expected after \"def\"";
1950     return NULL;
1951     }
1952
1953   s = read_name(name, 256, s+1, US"_");
1954
1955   /* Test for a header's existence. If the name contains a closing brace
1956   character, this may be a user error where the terminating colon has been
1957   omitted. Set a flag to adjust a subsequent error message in this case. */
1958
1959   if (Ustrncmp(name, "h_", 2) == 0 ||
1960       Ustrncmp(name, "rh_", 3) == 0 ||
1961       Ustrncmp(name, "bh_", 3) == 0 ||
1962       Ustrncmp(name, "header_", 7) == 0 ||
1963       Ustrncmp(name, "rheader_", 8) == 0 ||
1964       Ustrncmp(name, "bheader_", 8) == 0)
1965     {
1966     s = read_header_name(name, 256, s);
1967     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
1968     if (yield != NULL) *yield =
1969       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1970     }
1971
1972   /* Test for a variable's having a non-empty value. A non-existent variable
1973   causes an expansion failure. */
1974
1975   else
1976     {
1977     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1978     if (value == NULL)
1979       {
1980       expand_string_message = (name[0] == 0)?
1981         string_sprintf("variable name omitted after \"def:\"") :
1982         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1983       check_variable_error_message(name);
1984       return NULL;
1985       }
1986     if (yield != NULL) *yield = (value[0] != 0) == testfor;
1987     }
1988
1989   return s;
1990
1991
1992   /* first_delivery tests for first delivery attempt */
1993
1994   case ECOND_FIRST_DELIVERY:
1995   if (yield != NULL) *yield = deliver_firsttime == testfor;
1996   return s;
1997
1998
1999   /* queue_running tests for any process started by a queue runner */
2000
2001   case ECOND_QUEUE_RUNNING:
2002   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2003   return s;
2004
2005
2006   /* exists:  tests for file existence
2007        isip:  tests for any IP address
2008       isip4:  tests for an IPv4 address
2009       isip6:  tests for an IPv6 address
2010         pam:  does PAM authentication
2011      radius:  does RADIUS authentication
2012    ldapauth:  does LDAP authentication
2013     pwcheck:  does Cyrus SASL pwcheck authentication
2014   */
2015
2016   case ECOND_EXISTS:
2017   case ECOND_ISIP:
2018   case ECOND_ISIP4:
2019   case ECOND_ISIP6:
2020   case ECOND_PAM:
2021   case ECOND_RADIUS:
2022   case ECOND_LDAPAUTH:
2023   case ECOND_PWCHECK:
2024
2025   while (isspace(*s)) s++;
2026   if (*s != '{') goto COND_FAILED_CURLY_START;
2027
2028   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE);
2029   if (sub[0] == NULL) return NULL;
2030   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2031
2032   if (yield == NULL) return s;   /* No need to run the test if skipping */
2033
2034   switch(cond_type)
2035     {
2036     case ECOND_EXISTS:
2037     if ((expand_forbid & RDO_EXISTS) != 0)
2038       {
2039       expand_string_message = US"File existence tests are not permitted";
2040       return NULL;
2041       }
2042     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2043     break;
2044
2045     case ECOND_ISIP:
2046     case ECOND_ISIP4:
2047     case ECOND_ISIP6:
2048     rc = string_is_ip_address(sub[0], NULL);
2049     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2050              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2051     break;
2052
2053     /* Various authentication tests - all optionally compiled */
2054
2055     case ECOND_PAM:
2056     #ifdef SUPPORT_PAM
2057     rc = auth_call_pam(sub[0], &expand_string_message);
2058     goto END_AUTH;
2059     #else
2060     goto COND_FAILED_NOT_COMPILED;
2061     #endif  /* SUPPORT_PAM */
2062
2063     case ECOND_RADIUS:
2064     #ifdef RADIUS_CONFIG_FILE
2065     rc = auth_call_radius(sub[0], &expand_string_message);
2066     goto END_AUTH;
2067     #else
2068     goto COND_FAILED_NOT_COMPILED;
2069     #endif  /* RADIUS_CONFIG_FILE */
2070
2071     case ECOND_LDAPAUTH:
2072     #ifdef LOOKUP_LDAP
2073       {
2074       /* Just to keep the interface the same */
2075       BOOL do_cache;
2076       int old_pool = store_pool;
2077       store_pool = POOL_SEARCH;
2078       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2079         &expand_string_message, &do_cache);
2080       store_pool = old_pool;
2081       }
2082     goto END_AUTH;
2083     #else
2084     goto COND_FAILED_NOT_COMPILED;
2085     #endif  /* LOOKUP_LDAP */
2086
2087     case ECOND_PWCHECK:
2088     #ifdef CYRUS_PWCHECK_SOCKET
2089     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2090     goto END_AUTH;
2091     #else
2092     goto COND_FAILED_NOT_COMPILED;
2093     #endif  /* CYRUS_PWCHECK_SOCKET */
2094
2095     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2096         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2097     END_AUTH:
2098     if (rc == ERROR || rc == DEFER) return NULL;
2099     *yield = (rc == OK) == testfor;
2100     #endif
2101     }
2102   return s;
2103
2104
2105   /* call ACL (in a conditional context).  Accept true, deny false.
2106   Defer is a forced-fail.  Anything set by message= goes to $value.
2107   Up to ten parameters are used; we use the braces round the name+args
2108   like the saslauthd condition does, to permit a variable number of args.
2109   See also the expansion-item version EITEM_ACL and the traditional
2110   acl modifier ACLC_ACL.
2111   */
2112
2113   case ECOND_ACL:
2114     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2115     {
2116     uschar *nameargs;
2117     uschar *user_msg;
2118     BOOL cond = FALSE;
2119     int size = 0;
2120     int ptr = 0;
2121
2122     while (isspace(*s)) s++;
2123     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2124
2125     switch(read_subs(sub, sizeof(sub)/sizeof(*sub), 1,
2126       &s, yield == NULL, TRUE, US"acl"))
2127       {
2128       case 1: expand_string_message = US"too few arguments or bracketing "
2129         "error for acl";
2130       case 2:
2131       case 3: return NULL;
2132       }
2133
2134     if (yield != NULL) switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
2135         {
2136         case OK:
2137           cond = TRUE;
2138         case FAIL:
2139           lookup_value = NULL;
2140           if (user_msg)
2141             {
2142             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2143             lookup_value[ptr] = '\0';
2144             }
2145           *yield = cond;
2146           break;
2147
2148         case DEFER:
2149           expand_string_forcedfail = TRUE;
2150         default:
2151           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2152           return NULL;
2153         }
2154     return s;
2155     }
2156
2157
2158   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2159
2160      ${if saslauthd {{username}{password}{service}{realm}}  {yes}[no}}
2161
2162   However, the last two are optional. That is why the whole set is enclosed
2163   in their own set of braces. */
2164
2165   case ECOND_SASLAUTHD:
2166   #ifndef CYRUS_SASLAUTHD_SOCKET
2167   goto COND_FAILED_NOT_COMPILED;
2168   #else
2169   while (isspace(*s)) s++;
2170   if (*s++ != '{') goto COND_FAILED_CURLY_START;
2171   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
2172     {
2173     case 1: expand_string_message = US"too few arguments or bracketing "
2174       "error for saslauthd";
2175     case 2:
2176     case 3: return NULL;
2177     }
2178   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2179   if (yield != NULL)
2180     {
2181     int rc;
2182     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2183       &expand_string_message);
2184     if (rc == ERROR || rc == DEFER) return NULL;
2185     *yield = (rc == OK) == testfor;
2186     }
2187   return s;
2188   #endif /* CYRUS_SASLAUTHD_SOCKET */
2189
2190
2191   /* symbolic operators for numeric and string comparison, and a number of
2192   other operators, all requiring two arguments.
2193
2194   crypteq:           encrypts plaintext and compares against an encrypted text,
2195                        using crypt(), crypt16(), MD5 or SHA-1
2196   inlist/inlisti:    checks if first argument is in the list of the second
2197   match:             does a regular expression match and sets up the numerical
2198                        variables if it succeeds
2199   match_address:     matches in an address list
2200   match_domain:      matches in a domain list
2201   match_ip:          matches a host list that is restricted to IP addresses
2202   match_local_part:  matches in a local part list
2203   */
2204
2205   case ECOND_MATCH_ADDRESS:
2206   case ECOND_MATCH_DOMAIN:
2207   case ECOND_MATCH_IP:
2208   case ECOND_MATCH_LOCAL_PART:
2209 #ifndef EXPAND_LISTMATCH_RHS
2210     sub2_honour_dollar = FALSE;
2211 #endif
2212     /* FALLTHROUGH */
2213
2214   case ECOND_CRYPTEQ:
2215   case ECOND_INLIST:
2216   case ECOND_INLISTI:
2217   case ECOND_MATCH:
2218
2219   case ECOND_NUM_L:     /* Numerical comparisons */
2220   case ECOND_NUM_LE:
2221   case ECOND_NUM_E:
2222   case ECOND_NUM_EE:
2223   case ECOND_NUM_G:
2224   case ECOND_NUM_GE:
2225
2226   case ECOND_STR_LT:    /* String comparisons */
2227   case ECOND_STR_LTI:
2228   case ECOND_STR_LE:
2229   case ECOND_STR_LEI:
2230   case ECOND_STR_EQ:
2231   case ECOND_STR_EQI:
2232   case ECOND_STR_GT:
2233   case ECOND_STR_GTI:
2234   case ECOND_STR_GE:
2235   case ECOND_STR_GEI:
2236
2237   for (i = 0; i < 2; i++)
2238     {
2239     /* Sometimes, we don't expand substrings; too many insecure configurations
2240     created using match_address{}{} and friends, where the second param
2241     includes information from untrustworthy sources. */
2242     BOOL honour_dollar = TRUE;
2243     if ((i > 0) && !sub2_honour_dollar)
2244       honour_dollar = FALSE;
2245
2246     while (isspace(*s)) s++;
2247     if (*s != '{')
2248       {
2249       if (i == 0) goto COND_FAILED_CURLY_START;
2250       expand_string_message = string_sprintf("missing 2nd string in {} "
2251         "after \"%s\"", name);
2252       return NULL;
2253       }
2254     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2255         honour_dollar);
2256     if (sub[i] == NULL) return NULL;
2257     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2258
2259     /* Convert to numerical if required; we know that the names of all the
2260     conditions that compare numbers do not start with a letter. This just saves
2261     checking for them individually. */
2262
2263     if (!isalpha(name[0]) && yield != NULL)
2264       {
2265       if (sub[i][0] == 0)
2266         {
2267         num[i] = 0;
2268         DEBUG(D_expand)
2269           debug_printf("empty string cast to zero for numerical comparison\n");
2270         }
2271       else
2272         {
2273         num[i] = expand_string_integer(sub[i], FALSE);
2274         if (expand_string_message != NULL) return NULL;
2275         }
2276       }
2277     }
2278
2279   /* Result not required */
2280
2281   if (yield == NULL) return s;
2282
2283   /* Do an appropriate comparison */
2284
2285   switch(cond_type)
2286     {
2287     case ECOND_NUM_E:
2288     case ECOND_NUM_EE:
2289     *yield = (num[0] == num[1]) == testfor;
2290     break;
2291
2292     case ECOND_NUM_G:
2293     *yield = (num[0] > num[1]) == testfor;
2294     break;
2295
2296     case ECOND_NUM_GE:
2297     *yield = (num[0] >= num[1]) == testfor;
2298     break;
2299
2300     case ECOND_NUM_L:
2301     *yield = (num[0] < num[1]) == testfor;
2302     break;
2303
2304     case ECOND_NUM_LE:
2305     *yield = (num[0] <= num[1]) == testfor;
2306     break;
2307
2308     case ECOND_STR_LT:
2309     *yield = (Ustrcmp(sub[0], sub[1]) < 0) == testfor;
2310     break;
2311
2312     case ECOND_STR_LTI:
2313     *yield = (strcmpic(sub[0], sub[1]) < 0) == testfor;
2314     break;
2315
2316     case ECOND_STR_LE:
2317     *yield = (Ustrcmp(sub[0], sub[1]) <= 0) == testfor;
2318     break;
2319
2320     case ECOND_STR_LEI:
2321     *yield = (strcmpic(sub[0], sub[1]) <= 0) == testfor;
2322     break;
2323
2324     case ECOND_STR_EQ:
2325     *yield = (Ustrcmp(sub[0], sub[1]) == 0) == testfor;
2326     break;
2327
2328     case ECOND_STR_EQI:
2329     *yield = (strcmpic(sub[0], sub[1]) == 0) == testfor;
2330     break;
2331
2332     case ECOND_STR_GT:
2333     *yield = (Ustrcmp(sub[0], sub[1]) > 0) == testfor;
2334     break;
2335
2336     case ECOND_STR_GTI:
2337     *yield = (strcmpic(sub[0], sub[1]) > 0) == testfor;
2338     break;
2339
2340     case ECOND_STR_GE:
2341     *yield = (Ustrcmp(sub[0], sub[1]) >= 0) == testfor;
2342     break;
2343
2344     case ECOND_STR_GEI:
2345     *yield = (strcmpic(sub[0], sub[1]) >= 0) == testfor;
2346     break;
2347
2348     case ECOND_MATCH:   /* Regular expression match */
2349     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2350       NULL);
2351     if (re == NULL)
2352       {
2353       expand_string_message = string_sprintf("regular expression error in "
2354         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2355       return NULL;
2356       }
2357     *yield = regex_match_and_setup(re, sub[0], 0, -1) == testfor;
2358     break;
2359
2360     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2361     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2362     goto MATCHED_SOMETHING;
2363
2364     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2365     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2366       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2367     goto MATCHED_SOMETHING;
2368
2369     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2370     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2371       {
2372       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2373         sub[0]);
2374       return NULL;
2375       }
2376     else
2377       {
2378       unsigned int *nullcache = NULL;
2379       check_host_block cb;
2380
2381       cb.host_name = US"";
2382       cb.host_address = sub[0];
2383
2384       /* If the host address starts off ::ffff: it is an IPv6 address in
2385       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2386       addresses. */
2387
2388       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2389         cb.host_address + 7 : cb.host_address;
2390
2391       rc = match_check_list(
2392              &sub[1],                   /* the list */
2393              0,                         /* separator character */
2394              &hostlist_anchor,          /* anchor pointer */
2395              &nullcache,                /* cache pointer */
2396              check_host,                /* function for testing */
2397              &cb,                       /* argument for function */
2398              MCL_HOST,                  /* type of check */
2399              sub[0],                    /* text for debugging */
2400              NULL);                     /* where to pass back data */
2401       }
2402     goto MATCHED_SOMETHING;
2403
2404     case ECOND_MATCH_LOCAL_PART:
2405     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2406       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2407     /* Fall through */
2408     /* VVVVVVVVVVVV */
2409     MATCHED_SOMETHING:
2410     switch(rc)
2411       {
2412       case OK:
2413       *yield = testfor;
2414       break;
2415
2416       case FAIL:
2417       *yield = !testfor;
2418       break;
2419
2420       case DEFER:
2421       expand_string_message = string_sprintf("unable to complete match "
2422         "against \"%s\": %s", sub[1], search_error_message);
2423       return NULL;
2424       }
2425
2426     break;
2427
2428     /* Various "encrypted" comparisons. If the second string starts with
2429     "{" then an encryption type is given. Default to crypt() or crypt16()
2430     (build-time choice). */
2431
2432     case ECOND_CRYPTEQ:
2433     #ifndef SUPPORT_CRYPTEQ
2434     goto COND_FAILED_NOT_COMPILED;
2435     #else
2436     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2437       {
2438       int sublen = Ustrlen(sub[1]+5);
2439       md5 base;
2440       uschar digest[16];
2441
2442       md5_start(&base);
2443       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2444
2445       /* If the length that we are comparing against is 24, the MD5 digest
2446       is expressed as a base64 string. This is the way LDAP does it. However,
2447       some other software uses a straightforward hex representation. We assume
2448       this if the length is 32. Other lengths fail. */
2449
2450       if (sublen == 24)
2451         {
2452         uschar *coded = auth_b64encode((uschar *)digest, 16);
2453         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2454           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2455         *yield = (Ustrcmp(coded, sub[1]+5) == 0) == testfor;
2456         }
2457       else if (sublen == 32)
2458         {
2459         int i;
2460         uschar coded[36];
2461         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2462         coded[32] = 0;
2463         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2464           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2465         *yield = (strcmpic(coded, sub[1]+5) == 0) == testfor;
2466         }
2467       else
2468         {
2469         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2470           "fail\n  crypted=%s\n", sub[1]+5);
2471         *yield = !testfor;
2472         }
2473       }
2474
2475     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2476       {
2477       int sublen = Ustrlen(sub[1]+6);
2478       sha1 base;
2479       uschar digest[20];
2480
2481       sha1_start(&base);
2482       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2483
2484       /* If the length that we are comparing against is 28, assume the SHA1
2485       digest is expressed as a base64 string. If the length is 40, assume a
2486       straightforward hex representation. Other lengths fail. */
2487
2488       if (sublen == 28)
2489         {
2490         uschar *coded = auth_b64encode((uschar *)digest, 20);
2491         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2492           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2493         *yield = (Ustrcmp(coded, sub[1]+6) == 0) == testfor;
2494         }
2495       else if (sublen == 40)
2496         {
2497         int i;
2498         uschar coded[44];
2499         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2500         coded[40] = 0;
2501         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2502           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2503         *yield = (strcmpic(coded, sub[1]+6) == 0) == testfor;
2504         }
2505       else
2506         {
2507         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2508           "fail\n  crypted=%s\n", sub[1]+6);
2509         *yield = !testfor;
2510         }
2511       }
2512
2513     else   /* {crypt} or {crypt16} and non-{ at start */
2514            /* }-for-text-editors */
2515       {
2516       int which = 0;
2517       uschar *coded;
2518
2519       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2520         {
2521         sub[1] += 7;
2522         which = 1;
2523         }
2524       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2525         {
2526         sub[1] += 9;
2527         which = 2;
2528         }
2529       else if (sub[1][0] == '{')
2530         {
2531         expand_string_message = string_sprintf("unknown encryption mechanism "
2532           "in \"%s\"", sub[1]);
2533         return NULL;
2534         }
2535
2536       switch(which)
2537         {
2538         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2539         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2540         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2541         }
2542
2543       #define STR(s) # s
2544       #define XSTR(s) STR(s)
2545       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2546         "  subject=%s\n  crypted=%s\n",
2547         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2548         coded, sub[1]);
2549       #undef STR
2550       #undef XSTR
2551
2552       /* If the encrypted string contains fewer than two characters (for the
2553       salt), force failure. Otherwise we get false positives: with an empty
2554       string the yield of crypt() is an empty string! */
2555
2556       *yield = (Ustrlen(sub[1]) < 2)? !testfor :
2557         (Ustrcmp(coded, sub[1]) == 0) == testfor;
2558       }
2559     break;
2560     #endif  /* SUPPORT_CRYPTEQ */
2561
2562     case ECOND_INLIST:
2563     case ECOND_INLISTI:
2564       {
2565       int sep = 0;
2566       BOOL found = FALSE;
2567       uschar *save_iterate_item = iterate_item;
2568       int (*compare)(const uschar *, const uschar *);
2569
2570       if (cond_type == ECOND_INLISTI)
2571         compare = strcmpic;
2572       else
2573         compare = (int (*)(const uschar *, const uschar *)) strcmp;
2574
2575       while ((iterate_item = string_nextinlist(&sub[1], &sep, NULL, 0)) != NULL)
2576         if (compare(sub[0], iterate_item) == 0)
2577           {
2578           found = TRUE;
2579           break;
2580           }
2581       iterate_item = save_iterate_item;
2582       *yield = found;
2583       }
2584
2585     }   /* Switch for comparison conditions */
2586
2587   return s;    /* End of comparison conditions */
2588
2589
2590   /* and/or: computes logical and/or of several conditions */
2591
2592   case ECOND_AND:
2593   case ECOND_OR:
2594   subcondptr = (yield == NULL)? NULL : &tempcond;
2595   combined_cond = (cond_type == ECOND_AND);
2596
2597   while (isspace(*s)) s++;
2598   if (*s++ != '{') goto COND_FAILED_CURLY_START;
2599
2600   for (;;)
2601     {
2602     while (isspace(*s)) s++;
2603     if (*s == '}') break;
2604     if (*s != '{')
2605       {
2606       expand_string_message = string_sprintf("each subcondition "
2607         "inside an \"%s{...}\" condition must be in its own {}", name);
2608       return NULL;
2609       }
2610
2611     s = eval_condition(s+1, subcondptr);
2612     if (s == NULL)
2613       {
2614       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2615         expand_string_message, name);
2616       return NULL;
2617       }
2618     while (isspace(*s)) s++;
2619
2620     if (*s++ != '}')
2621       {
2622       expand_string_message = string_sprintf("missing } at end of condition "
2623         "inside \"%s\" group", name);
2624       return NULL;
2625       }
2626
2627     if (yield != NULL)
2628       {
2629       if (cond_type == ECOND_AND)
2630         {
2631         combined_cond &= tempcond;
2632         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2633         }                                       /* evaluate any more */
2634       else
2635         {
2636         combined_cond |= tempcond;
2637         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2638         }                                       /* evaluate any more */
2639       }
2640     }
2641
2642   if (yield != NULL) *yield = (combined_cond == testfor);
2643   return ++s;
2644
2645
2646   /* forall/forany: iterates a condition with different values */
2647
2648   case ECOND_FORALL:
2649   case ECOND_FORANY:
2650     {
2651     int sep = 0;
2652     uschar *save_iterate_item = iterate_item;
2653
2654     while (isspace(*s)) s++;
2655     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2656     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE);
2657     if (sub[0] == NULL) return NULL;
2658     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2659
2660     while (isspace(*s)) s++;
2661     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2662
2663     sub[1] = s;
2664
2665     /* Call eval_condition once, with result discarded (as if scanning a
2666     "false" part). This allows us to find the end of the condition, because if
2667     the list it empty, we won't actually evaluate the condition for real. */
2668
2669     s = eval_condition(sub[1], NULL);
2670     if (s == NULL)
2671       {
2672       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2673         expand_string_message, name);
2674       return NULL;
2675       }
2676     while (isspace(*s)) s++;
2677
2678     if (*s++ != '}')
2679       {
2680       expand_string_message = string_sprintf("missing } at end of condition "
2681         "inside \"%s\"", name);
2682       return NULL;
2683       }
2684
2685     if (yield != NULL) *yield = !testfor;
2686     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2687       {
2688       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2689       if (eval_condition(sub[1], &tempcond) == NULL)
2690         {
2691         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2692           expand_string_message, name);
2693         iterate_item = save_iterate_item;
2694         return NULL;
2695         }
2696       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2697         tempcond? "true":"false");
2698
2699       if (yield != NULL) *yield = (tempcond == testfor);
2700       if (tempcond == (cond_type == ECOND_FORANY)) break;
2701       }
2702
2703     iterate_item = save_iterate_item;
2704     return s;
2705     }
2706
2707
2708   /* The bool{} expansion condition maps a string to boolean.
2709   The values supported should match those supported by the ACL condition
2710   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2711   of true/false.  Note that Router "condition" rules have a different
2712   interpretation, where general data can be used and only a few values
2713   map to FALSE.
2714   Note that readconf.c boolean matching, for boolean configuration options,
2715   only matches true/yes/false/no.
2716   The bool_lax{} condition matches the Router logic, which is much more
2717   liberal. */
2718   case ECOND_BOOL:
2719   case ECOND_BOOL_LAX:
2720     {
2721     uschar *sub_arg[1];
2722     uschar *t, *t2;
2723     uschar *ourname;
2724     size_t len;
2725     BOOL boolvalue = FALSE;
2726     while (isspace(*s)) s++;
2727     if (*s != '{') goto COND_FAILED_CURLY_START;
2728     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2729     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname))
2730       {
2731       case 1: expand_string_message = string_sprintf(
2732                   "too few arguments or bracketing error for %s",
2733                   ourname);
2734       /*FALLTHROUGH*/
2735       case 2:
2736       case 3: return NULL;
2737       }
2738     t = sub_arg[0];
2739     while (isspace(*t)) t++;
2740     len = Ustrlen(t);
2741     if (len)
2742       {
2743       /* trailing whitespace: seems like a good idea to ignore it too */
2744       t2 = t + len - 1;
2745       while (isspace(*t2)) t2--;
2746       if (t2 != (t + len))
2747         {
2748         *++t2 = '\0';
2749         len = t2 - t;
2750         }
2751       }
2752     DEBUG(D_expand)
2753       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
2754     /* logic for the lax case from expand_check_condition(), which also does
2755     expands, and the logic is both short and stable enough that there should
2756     be no maintenance burden from replicating it. */
2757     if (len == 0)
2758       boolvalue = FALSE;
2759     else if (Ustrspn(t, "0123456789") == len)
2760       {
2761       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
2762       /* expand_check_condition only does a literal string "0" check */
2763       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
2764         boolvalue = TRUE;
2765       }
2766     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
2767       boolvalue = TRUE;
2768     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
2769       boolvalue = FALSE;
2770     else if (cond_type == ECOND_BOOL_LAX)
2771       boolvalue = TRUE;
2772     else
2773       {
2774       expand_string_message = string_sprintf("unrecognised boolean "
2775        "value \"%s\"", t);
2776       return NULL;
2777       }
2778     if (yield != NULL) *yield = (boolvalue == testfor);
2779     return s;
2780     }
2781
2782   /* Unknown condition */
2783
2784   default:
2785   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2786   return NULL;
2787   }   /* End switch on condition type */
2788
2789 /* Missing braces at start and end of data */
2790
2791 COND_FAILED_CURLY_START:
2792 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2793 return NULL;
2794
2795 COND_FAILED_CURLY_END:
2796 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2797   name);
2798 return NULL;
2799
2800 /* A condition requires code that is not compiled */
2801
2802 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2803     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2804     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2805 COND_FAILED_NOT_COMPILED:
2806 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2807   name);
2808 return NULL;
2809 #endif
2810 }
2811
2812
2813
2814
2815 /*************************************************
2816 *          Save numerical variables              *
2817 *************************************************/
2818
2819 /* This function is called from items such as "if" that want to preserve and
2820 restore the numbered variables.
2821
2822 Arguments:
2823   save_expand_string    points to an array of pointers to set
2824   save_expand_nlength   points to an array of ints for the lengths
2825
2826 Returns:                the value of expand max to save
2827 */
2828
2829 static int
2830 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2831 {
2832 int i;
2833 for (i = 0; i <= expand_nmax; i++)
2834   {
2835   save_expand_nstring[i] = expand_nstring[i];
2836   save_expand_nlength[i] = expand_nlength[i];
2837   }
2838 return expand_nmax;
2839 }
2840
2841
2842
2843 /*************************************************
2844 *           Restore numerical variables          *
2845 *************************************************/
2846
2847 /* This function restored saved values of numerical strings.
2848
2849 Arguments:
2850   save_expand_nmax      the number of strings to restore
2851   save_expand_string    points to an array of pointers
2852   save_expand_nlength   points to an array of ints
2853
2854 Returns:                nothing
2855 */
2856
2857 static void
2858 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2859   int *save_expand_nlength)
2860 {
2861 int i;
2862 expand_nmax = save_expand_nmax;
2863 for (i = 0; i <= expand_nmax; i++)
2864   {
2865   expand_nstring[i] = save_expand_nstring[i];
2866   expand_nlength[i] = save_expand_nlength[i];
2867   }
2868 }
2869
2870
2871
2872
2873
2874 /*************************************************
2875 *            Handle yes/no substrings            *
2876 *************************************************/
2877
2878 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2879 alternative substrings that depend on whether or not the condition was true,
2880 or the lookup or extraction succeeded. The substrings always have to be
2881 expanded, to check their syntax, but "skipping" is set when the result is not
2882 needed - this avoids unnecessary nested lookups.
2883
2884 Arguments:
2885   skipping       TRUE if we were skipping when this item was reached
2886   yes            TRUE if the first string is to be used, else use the second
2887   save_lookup    a value to put back into lookup_value before the 2nd expansion
2888   sptr           points to the input string pointer
2889   yieldptr       points to the output string pointer
2890   sizeptr        points to the output string size
2891   ptrptr         points to the output string pointer
2892   type           "lookup" or "if" or "extract" or "run", for error message
2893
2894 Returns:         0 OK; lookup_value has been reset to save_lookup
2895                  1 expansion failed
2896                  2 expansion failed because of bracketing error
2897 */
2898
2899 static int
2900 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2901   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2902 {
2903 int rc = 0;
2904 uschar *s = *sptr;    /* Local value */
2905 uschar *sub1, *sub2;
2906
2907 /* If there are no following strings, we substitute the contents of $value for
2908 lookups and for extractions in the success case. For the ${if item, the string
2909 "true" is substituted. In the fail case, nothing is substituted for all three
2910 items. */
2911
2912 while (isspace(*s)) s++;
2913 if (*s == '}')
2914   {
2915   if (type[0] == 'i')
2916     {
2917     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2918     }
2919   else
2920     {
2921     if (yes && lookup_value != NULL)
2922       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2923         Ustrlen(lookup_value));
2924     lookup_value = save_lookup;
2925     }
2926   s++;
2927   goto RETURN;
2928   }
2929
2930 /* The first following string must be braced. */
2931
2932 if (*s++ != '{') goto FAILED_CURLY;
2933
2934 /* Expand the first substring. Forced failures are noticed only if we actually
2935 want this string. Set skipping in the call in the fail case (this will always
2936 be the case if we were already skipping). */
2937
2938 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE);
2939 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2940 expand_string_forcedfail = FALSE;
2941 if (*s++ != '}') goto FAILED_CURLY;
2942
2943 /* If we want the first string, add it to the output */
2944
2945 if (yes)
2946   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2947
2948 /* If this is called from a lookup or an extract, we want to restore $value to
2949 what it was at the start of the item, so that it has this value during the
2950 second string expansion. For the call from "if" or "run" to this function,
2951 save_lookup is set to lookup_value, so that this statement does nothing. */
2952
2953 lookup_value = save_lookup;
2954
2955 /* There now follows either another substring, or "fail", or nothing. This
2956 time, forced failures are noticed only if we want the second string. We must
2957 set skipping in the nested call if we don't want this string, or if we were
2958 already skipping. */
2959
2960 while (isspace(*s)) s++;
2961 if (*s == '{')
2962   {
2963   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE);
2964   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2965   expand_string_forcedfail = FALSE;
2966   if (*s++ != '}') goto FAILED_CURLY;
2967
2968   /* If we want the second string, add it to the output */
2969
2970   if (!yes)
2971     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2972   }
2973
2974 /* If there is no second string, but the word "fail" is present when the use of
2975 the second string is wanted, set a flag indicating it was a forced failure
2976 rather than a syntactic error. Swallow the terminating } in case this is nested
2977 inside another lookup or if or extract. */
2978
2979 else if (*s != '}')
2980   {
2981   uschar name[256];
2982   s = read_name(name, sizeof(name), s, US"_");
2983   if (Ustrcmp(name, "fail") == 0)
2984     {
2985     if (!yes && !skipping)
2986       {
2987       while (isspace(*s)) s++;
2988       if (*s++ != '}') goto FAILED_CURLY;
2989       expand_string_message =
2990         string_sprintf("\"%s\" failed and \"fail\" requested", type);
2991       expand_string_forcedfail = TRUE;
2992       goto FAILED;
2993       }
2994     }
2995   else
2996     {
2997     expand_string_message =
2998       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
2999     goto FAILED;
3000     }
3001   }
3002
3003 /* All we have to do now is to check on the final closing brace. */
3004
3005 while (isspace(*s)) s++;
3006 if (*s++ == '}') goto RETURN;
3007
3008 /* Get here if there is a bracketing failure */
3009
3010 FAILED_CURLY:
3011 rc++;
3012
3013 /* Get here for other failures */
3014
3015 FAILED:
3016 rc++;
3017
3018 /* Update the input pointer value before returning */
3019
3020 RETURN:
3021 *sptr = s;
3022 return rc;
3023 }
3024
3025
3026
3027
3028 /*************************************************
3029 *    Handle MD5 or SHA-1 computation for HMAC    *
3030 *************************************************/
3031
3032 /* These are some wrapping functions that enable the HMAC code to be a bit
3033 cleaner. A good compiler will spot the tail recursion.
3034
3035 Arguments:
3036   type         HMAC_MD5 or HMAC_SHA1
3037   remaining    are as for the cryptographic hash functions
3038
3039 Returns:       nothing
3040 */
3041
3042 static void
3043 chash_start(int type, void *base)
3044 {
3045 if (type == HMAC_MD5)
3046   md5_start((md5 *)base);
3047 else
3048   sha1_start((sha1 *)base);
3049 }
3050
3051 static void
3052 chash_mid(int type, void *base, uschar *string)
3053 {
3054 if (type == HMAC_MD5)
3055   md5_mid((md5 *)base, string);
3056 else
3057   sha1_mid((sha1 *)base, string);
3058 }
3059
3060 static void
3061 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3062 {
3063 if (type == HMAC_MD5)
3064   md5_end((md5 *)base, string, length, digest);
3065 else
3066   sha1_end((sha1 *)base, string, length, digest);
3067 }
3068
3069
3070
3071
3072
3073 /********************************************************
3074 * prvs: Get last three digits of days since Jan 1, 1970 *
3075 ********************************************************/
3076
3077 /* This is needed to implement the "prvs" BATV reverse
3078    path signing scheme
3079
3080 Argument: integer "days" offset to add or substract to
3081           or from the current number of days.
3082
3083 Returns:  pointer to string containing the last three
3084           digits of the number of days since Jan 1, 1970,
3085           modified by the offset argument, NULL if there
3086           was an error in the conversion.
3087
3088 */
3089
3090 static uschar *
3091 prvs_daystamp(int day_offset)
3092 {
3093 uschar *days = store_get(32);                /* Need at least 24 for cases */
3094 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3095   (time(NULL) + day_offset*86400)/86400);
3096 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3097 }
3098
3099
3100
3101 /********************************************************
3102 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3103 ********************************************************/
3104
3105 /* This is needed to implement the "prvs" BATV reverse
3106    path signing scheme
3107
3108 Arguments:
3109   address RFC2821 Address to use
3110       key The key to use (must be less than 64 characters
3111           in size)
3112   key_num Single-digit key number to use. Defaults to
3113           '0' when NULL.
3114
3115 Returns:  pointer to string containing the first three
3116           bytes of the final hash in hex format, NULL if
3117           there was an error in the process.
3118 */
3119
3120 static uschar *
3121 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3122 {
3123 uschar *hash_source, *p;
3124 int size = 0,offset = 0,i;
3125 sha1 sha1_base;
3126 void *use_base = &sha1_base;
3127 uschar innerhash[20];
3128 uschar finalhash[20];
3129 uschar innerkey[64];
3130 uschar outerkey[64];
3131 uschar *finalhash_hex = store_get(40);
3132
3133 if (key_num == NULL)
3134   key_num = US"0";
3135
3136 if (Ustrlen(key) > 64)
3137   return NULL;
3138
3139 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3140 string_cat(hash_source,&size,&offset,daystamp,3);
3141 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3142 hash_source[offset] = '\0';
3143
3144 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3145
3146 memset(innerkey, 0x36, 64);
3147 memset(outerkey, 0x5c, 64);
3148
3149 for (i = 0; i < Ustrlen(key); i++)
3150   {
3151   innerkey[i] ^= key[i];
3152   outerkey[i] ^= key[i];
3153   }
3154
3155 chash_start(HMAC_SHA1, use_base);
3156 chash_mid(HMAC_SHA1, use_base, innerkey);
3157 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3158
3159 chash_start(HMAC_SHA1, use_base);
3160 chash_mid(HMAC_SHA1, use_base, outerkey);
3161 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3162
3163 p = finalhash_hex;
3164 for (i = 0; i < 3; i++)
3165   {
3166   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3167   *p++ = hex_digits[finalhash[i] & 0x0f];
3168   }
3169 *p = '\0';
3170
3171 return finalhash_hex;
3172 }
3173
3174
3175
3176
3177 /*************************************************
3178 *        Join a file onto the output string      *
3179 *************************************************/
3180
3181 /* This is used for readfile and after a run expansion. It joins the contents
3182 of a file onto the output string, globally replacing newlines with a given
3183 string (optionally). The file is closed at the end.
3184
3185 Arguments:
3186   f            the FILE
3187   yield        pointer to the expandable string
3188   sizep        pointer to the current size
3189   ptrp         pointer to the current position
3190   eol          newline replacement string, or NULL
3191
3192 Returns:       new value of string pointer
3193 */
3194
3195 static uschar *
3196 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3197 {
3198 int eollen;
3199 uschar buffer[1024];
3200
3201 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3202
3203 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3204   {
3205   int len = Ustrlen(buffer);
3206   if (eol != NULL && buffer[len-1] == '\n') len--;
3207   yield = string_cat(yield, sizep, ptrp, buffer, len);
3208   if (buffer[len] != 0)
3209     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3210   }
3211
3212 if (yield != NULL) yield[*ptrp] = 0;
3213
3214 return yield;
3215 }
3216
3217
3218
3219
3220 /*************************************************
3221 *          Evaluate numeric expression           *
3222 *************************************************/
3223
3224 /* This is a set of mutually recursive functions that evaluate an arithmetic
3225 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3226 these functions that is called from elsewhere is eval_expr, whose interface is:
3227
3228 Arguments:
3229   sptr        pointer to the pointer to the string - gets updated
3230   decimal     TRUE if numbers are to be assumed decimal
3231   error       pointer to where to put an error message - must be NULL on input
3232   endket      TRUE if ')' must terminate - FALSE for external call
3233
3234 Returns:      on success: the value of the expression, with *error still NULL
3235               on failure: an undefined value, with *error = a message
3236 */
3237
3238 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3239
3240
3241 static int_eximarith_t
3242 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3243 {
3244 uschar *s = *sptr;
3245 int_eximarith_t x = eval_op_or(&s, decimal, error);
3246 if (*error == NULL)
3247   {
3248   if (endket)
3249     {
3250     if (*s != ')')
3251       *error = US"expecting closing parenthesis";
3252     else
3253       while (isspace(*(++s)));
3254     }
3255   else if (*s != 0) *error = US"expecting operator";
3256   }
3257 *sptr = s;
3258 return x;
3259 }
3260
3261
3262 static int_eximarith_t
3263 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3264 {
3265 register int c;
3266 int_eximarith_t n;
3267 uschar *s = *sptr;
3268 while (isspace(*s)) s++;
3269 c = *s;
3270 if (isdigit(c))
3271   {
3272   int count;
3273   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3274   s += count;
3275   switch (tolower(*s))
3276     {
3277     default: break;
3278     case 'k': n *= 1024; s++; break;
3279     case 'm': n *= 1024*1024; s++; break;
3280     case 'g': n *= 1024*1024*1024; s++; break;
3281     }
3282   while (isspace (*s)) s++;
3283   }
3284 else if (c == '(')
3285   {
3286   s++;
3287   n = eval_expr(&s, decimal, error, 1);
3288   }
3289 else
3290   {
3291   *error = US"expecting number or opening parenthesis";
3292   n = 0;
3293   }
3294 *sptr = s;
3295 return n;
3296 }
3297
3298
3299 static int_eximarith_t
3300 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3301 {
3302 uschar *s = *sptr;
3303 int_eximarith_t x;
3304 while (isspace(*s)) s++;
3305 if (*s == '+' || *s == '-' || *s == '~')
3306   {
3307   int op = *s++;
3308   x = eval_op_unary(&s, decimal, error);
3309   if (op == '-') x = -x;
3310     else if (op == '~') x = ~x;
3311   }
3312 else
3313   {
3314   x = eval_number(&s, decimal, error);
3315   }
3316 *sptr = s;
3317 return x;
3318 }
3319
3320
3321 static int_eximarith_t
3322 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3323 {
3324 uschar *s = *sptr;
3325 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3326 if (*error == NULL)
3327   {
3328   while (*s == '*' || *s == '/' || *s == '%')
3329     {
3330     int op = *s++;
3331     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3332     if (*error != NULL) break;
3333     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3334      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3335      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3336      * -N*M is INT_MIN will yielf INT_MIN.
3337      * Since we don't support floating point, this is somewhat simpler.
3338      * Ideally, we'd return an error, but since we overflow for all other
3339      * arithmetic, consistency suggests otherwise, but what's the correct value
3340      * to use?  There is none.
3341      * The C standard guarantees overflow for unsigned arithmetic but signed
3342      * overflow invokes undefined behaviour; in practice, this is overflow
3343      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3344      * that long/longlong larger than int are available, or we could just work
3345      * with larger types.  We should consider whether to guarantee 32bit eval
3346      * and 64-bit working variables, with errors returned.  For now ...
3347      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3348      * can just let the other invalid results occur otherwise, as they have
3349      * until now.  For this one case, we can coerce.
3350      */
3351     if (y == -1 && x == LLONG_MIN && op != '*')
3352       {
3353       DEBUG(D_expand)
3354         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3355             LLONG_MIN, op, LLONG_MAX);
3356       x = LLONG_MAX;
3357       continue;
3358       }
3359     if (op == '*')
3360       x *= y;
3361     else
3362       {
3363       if (y == 0)
3364         {
3365         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3366         x = 0;
3367         break;
3368         }
3369       if (op == '/')
3370         x /= y;
3371       else
3372         x %= y;
3373       }
3374     }
3375   }
3376 *sptr = s;
3377 return x;
3378 }
3379
3380
3381 static int_eximarith_t
3382 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3383 {
3384 uschar *s = *sptr;
3385 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3386 if (*error == NULL)
3387   {
3388   while (*s == '+' || *s == '-')
3389     {
3390     int op = *s++;
3391     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3392     if (*error != NULL) break;
3393     if (op == '+') x += y; else x -= y;
3394     }
3395   }
3396 *sptr = s;
3397 return x;
3398 }
3399
3400
3401 static int_eximarith_t
3402 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3403 {
3404 uschar *s = *sptr;
3405 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3406 if (*error == NULL)
3407   {
3408   while ((*s == '<' || *s == '>') && s[1] == s[0])
3409     {
3410     int_eximarith_t y;
3411     int op = *s++;
3412     s++;
3413     y = eval_op_sum(&s, decimal, error);
3414     if (*error != NULL) break;
3415     if (op == '<') x <<= y; else x >>= y;
3416     }
3417   }
3418 *sptr = s;
3419 return x;
3420 }
3421
3422
3423 static int_eximarith_t
3424 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3425 {
3426 uschar *s = *sptr;
3427 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3428 if (*error == NULL)
3429   {
3430   while (*s == '&')
3431     {
3432     int_eximarith_t y;
3433     s++;
3434     y = eval_op_shift(&s, decimal, error);
3435     if (*error != NULL) break;
3436     x &= y;
3437     }
3438   }
3439 *sptr = s;
3440 return x;
3441 }
3442
3443
3444 static int_eximarith_t
3445 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3446 {
3447 uschar *s = *sptr;
3448 int_eximarith_t x = eval_op_and(&s, decimal, error);
3449 if (*error == NULL)
3450   {
3451   while (*s == '^')
3452     {
3453     int_eximarith_t y;
3454     s++;
3455     y = eval_op_and(&s, decimal, error);
3456     if (*error != NULL) break;
3457     x ^= y;
3458     }
3459   }
3460 *sptr = s;
3461 return x;
3462 }
3463
3464
3465 static int_eximarith_t
3466 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3467 {
3468 uschar *s = *sptr;
3469 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3470 if (*error == NULL)
3471   {
3472   while (*s == '|')
3473     {
3474     int_eximarith_t y;
3475     s++;
3476     y = eval_op_xor(&s, decimal, error);
3477     if (*error != NULL) break;
3478     x |= y;
3479     }
3480   }
3481 *sptr = s;
3482 return x;
3483 }
3484
3485
3486
3487 /*************************************************
3488 *                 Expand string                  *
3489 *************************************************/
3490
3491 /* Returns either an unchanged string, or the expanded string in stacking pool
3492 store. Interpreted sequences are:
3493
3494    \...                    normal escaping rules
3495    $name                   substitutes the variable
3496    ${name}                 ditto
3497    ${op:string}            operates on the expanded string value
3498    ${item{arg1}{arg2}...}  expands the args and then does the business
3499                              some literal args are not enclosed in {}
3500
3501 There are now far too many operators and item types to make it worth listing
3502 them here in detail any more.
3503
3504 We use an internal routine recursively to handle embedded substrings. The
3505 external function follows. The yield is NULL if the expansion failed, and there
3506 are two cases: if something collapsed syntactically, or if "fail" was given
3507 as the action on a lookup failure. These can be distinguised by looking at the
3508 variable expand_string_forcedfail, which is TRUE in the latter case.
3509
3510 The skipping flag is set true when expanding a substring that isn't actually
3511 going to be used (after "if" or "lookup") and it prevents lookups from
3512 happening lower down.
3513
3514 Store usage: At start, a store block of the length of the input plus 64
3515 is obtained. This is expanded as necessary by string_cat(), which might have to
3516 get a new block, or might be able to expand the original. At the end of the
3517 function we can release any store above that portion of the yield block that
3518 was actually used. In many cases this will be optimal.
3519
3520 However: if the first item in the expansion is a variable name or header name,
3521 we reset the store before processing it; if the result is in fresh store, we
3522 use that without copying. This is helpful for expanding strings like
3523 $message_headers which can get very long.
3524
3525 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3526 since resetting the store at the end of the expansion will free store that was
3527 allocated by the plugin code as well as the slop after the expanded string. So
3528 we skip any resets if ${dlfunc has been used. This is an unfortunate
3529 consequence of string expansion becoming too powerful.
3530
3531 Arguments:
3532   string         the string to be expanded
3533   ket_ends       true if expansion is to stop at }
3534   left           if not NULL, a pointer to the first character after the
3535                  expansion is placed here (typically used with ket_ends)
3536   skipping       TRUE for recursive calls when the value isn't actually going
3537                  to be used (to allow for optimisation)
3538   honour_dollar  TRUE if $ is to be expanded,
3539                  FALSE if it's just another character
3540
3541 Returns:         NULL if expansion fails:
3542                    expand_string_forcedfail is set TRUE if failure was forced
3543                    expand_string_message contains a textual error message
3544                  a pointer to the expanded string on success
3545 */
3546
3547 static uschar *
3548 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3549   BOOL skipping, BOOL honour_dollar)
3550 {
3551 int ptr = 0;
3552 int size = Ustrlen(string)+ 64;
3553 int item_type;
3554 uschar *yield = store_get(size);
3555 uschar *s = string;
3556 uschar *save_expand_nstring[EXPAND_MAXN+1];
3557 int save_expand_nlength[EXPAND_MAXN+1];
3558 BOOL resetok = TRUE;
3559
3560 expand_string_forcedfail = FALSE;
3561 expand_string_message = US"";
3562
3563 while (*s != 0)
3564   {
3565   uschar *value;
3566   uschar name[256];
3567
3568   /* \ escapes the next character, which must exist, or else
3569   the expansion fails. There's a special escape, \N, which causes
3570   copying of the subject verbatim up to the next \N. Otherwise,
3571   the escapes are the standard set. */
3572
3573   if (*s == '\\')
3574     {
3575     if (s[1] == 0)
3576       {
3577       expand_string_message = US"\\ at end of string";
3578       goto EXPAND_FAILED;
3579       }
3580
3581     if (s[1] == 'N')
3582       {
3583       uschar *t = s + 2;
3584       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3585       yield = string_cat(yield, &size, &ptr, t, s - t);
3586       if (*s != 0) s += 2;
3587       }
3588
3589     else
3590       {
3591       uschar ch[1];
3592       ch[0] = string_interpret_escape(&s);
3593       s++;
3594       yield = string_cat(yield, &size, &ptr, ch, 1);
3595       }
3596
3597     continue;
3598     }
3599
3600   /* Anything other than $ is just copied verbatim, unless we are
3601   looking for a terminating } character. */
3602
3603   if (ket_ends && *s == '}') break;
3604
3605   if (*s != '$' || !honour_dollar)
3606     {
3607     yield = string_cat(yield, &size, &ptr, s++, 1);
3608     continue;
3609     }
3610
3611   /* No { after the $ - must be a plain name or a number for string
3612   match variable. There has to be a fudge for variables that are the
3613   names of header fields preceded by "$header_" because header field
3614   names can contain any printing characters except space and colon.
3615   For those that don't like typing this much, "$h_" is a synonym for
3616   "$header_". A non-existent header yields a NULL value; nothing is
3617   inserted. */
3618
3619   if (isalpha((*(++s))))
3620     {
3621     int len;
3622     int newsize = 0;
3623
3624     s = read_name(name, sizeof(name), s, US"_");
3625
3626     /* If this is the first thing to be expanded, release the pre-allocated
3627     buffer. */
3628
3629     if (ptr == 0 && yield != NULL)
3630       {
3631       if (resetok) store_reset(yield);
3632       yield = NULL;
3633       size = 0;
3634       }
3635
3636     /* Header */
3637
3638     if (Ustrncmp(name, "h_", 2) == 0 ||
3639         Ustrncmp(name, "rh_", 3) == 0 ||
3640         Ustrncmp(name, "bh_", 3) == 0 ||
3641         Ustrncmp(name, "header_", 7) == 0 ||
3642         Ustrncmp(name, "rheader_", 8) == 0 ||
3643         Ustrncmp(name, "bheader_", 8) == 0)
3644       {
3645       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3646       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3647       s = read_header_name(name, sizeof(name), s);
3648       value = find_header(name, FALSE, &newsize, want_raw, charset);
3649
3650       /* If we didn't find the header, and the header contains a closing brace
3651       character, this may be a user error where the terminating colon
3652       has been omitted. Set a flag to adjust the error message in this case.
3653       But there is no error here - nothing gets inserted. */
3654
3655       if (value == NULL)
3656         {
3657         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3658         continue;
3659         }
3660       }
3661
3662     /* Variable */
3663
3664     else
3665       {
3666       value = find_variable(name, FALSE, skipping, &newsize);
3667       if (value == NULL)
3668         {
3669         expand_string_message =
3670           string_sprintf("unknown variable name \"%s\"", name);
3671           check_variable_error_message(name);
3672         goto EXPAND_FAILED;
3673         }
3674       }
3675
3676     /* If the data is known to be in a new buffer, newsize will be set to the
3677     size of that buffer. If this is the first thing in an expansion string,
3678     yield will be NULL; just point it at the new store instead of copying. Many
3679     expansion strings contain just one reference, so this is a useful
3680     optimization, especially for humungous headers. */
3681
3682     len = Ustrlen(value);
3683     if (yield == NULL && newsize != 0)
3684       {
3685       yield = value;
3686       size = newsize;
3687       ptr = len;
3688       }
3689     else yield = string_cat(yield, &size, &ptr, value, len);
3690
3691     continue;
3692     }
3693
3694   if (isdigit(*s))
3695     {
3696     int n;
3697     s = read_number(&n, s);
3698     if (n >= 0 && n <= expand_nmax)
3699       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3700         expand_nlength[n]);
3701     continue;
3702     }
3703
3704   /* Otherwise, if there's no '{' after $ it's an error. */
3705
3706   if (*s != '{')
3707     {
3708     expand_string_message = US"$ not followed by letter, digit, or {";
3709     goto EXPAND_FAILED;
3710     }
3711
3712   /* After { there can be various things, but they all start with
3713   an initial word, except for a number for a string match variable. */
3714
3715   if (isdigit((*(++s))))
3716     {
3717     int n;
3718     s = read_number(&n, s);
3719     if (*s++ != '}')
3720       {
3721       expand_string_message = US"} expected after number";
3722       goto EXPAND_FAILED;
3723       }
3724     if (n >= 0 && n <= expand_nmax)
3725       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3726         expand_nlength[n]);
3727     continue;
3728     }
3729
3730   if (!isalpha(*s))
3731     {
3732     expand_string_message = US"letter or digit expected after ${";
3733     goto EXPAND_FAILED;
3734     }
3735
3736   /* Allow "-" in names to cater for substrings with negative
3737   arguments. Since we are checking for known names after { this is
3738   OK. */
3739
3740   s = read_name(name, sizeof(name), s, US"_-");
3741   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3742
3743   switch(item_type)
3744     {
3745     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
3746     If the ACL returns accept or reject we return content set by "message ="
3747     There is currently no limit on recursion; this would have us call
3748     acl_check_internal() directly and get a current level from somewhere.
3749     See also the acl expansion condition ECOND_ACL and the traditional
3750     acl modifier ACLC_ACL.
3751     */
3752
3753     case EITEM_ACL:
3754       /* ${acl {name} {arg1}{arg2}...} */
3755       {
3756       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
3757       uschar *user_msg;
3758
3759       switch(read_subs(sub, 10, 1, &s, skipping, TRUE, US"acl"))
3760         {
3761         case 1: goto EXPAND_FAILED_CURLY;
3762         case 2:
3763         case 3: goto EXPAND_FAILED;
3764         }
3765       if (skipping) continue;
3766
3767       switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
3768         {
3769         case OK:
3770         case FAIL:
3771           if (user_msg)
3772             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
3773           continue;
3774
3775         case DEFER:
3776           expand_string_forcedfail = TRUE;
3777         default:
3778           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
3779           goto EXPAND_FAILED;
3780         }
3781       }
3782
3783     /* Handle conditionals - preserve the values of the numerical expansion
3784     variables in case they get changed by a regular expression match in the
3785     condition. If not, they retain their external settings. At the end
3786     of this "if" section, they get restored to their previous values. */
3787
3788     case EITEM_IF:
3789       {
3790       BOOL cond = FALSE;
3791       uschar *next_s;
3792       int save_expand_nmax =
3793         save_expand_strings(save_expand_nstring, save_expand_nlength);
3794
3795       while (isspace(*s)) s++;
3796       next_s = eval_condition(s, skipping? NULL : &cond);
3797       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3798
3799       DEBUG(D_expand)
3800         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3801           cond? "true" : "false");
3802
3803       s = next_s;
3804
3805       /* The handling of "yes" and "no" result strings is now in a separate
3806       function that is also used by ${lookup} and ${extract} and ${run}. */
3807
3808       switch(process_yesno(
3809                skipping,                     /* were previously skipping */
3810                cond,                         /* success/failure indicator */
3811                lookup_value,                 /* value to reset for string2 */
3812                &s,                           /* input pointer */
3813                &yield,                       /* output pointer */
3814                &size,                        /* output size */
3815                &ptr,                         /* output current point */
3816                US"if"))                      /* condition type */
3817         {
3818         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3819         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3820         }
3821
3822       /* Restore external setting of expansion variables for continuation
3823       at this level. */
3824
3825       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3826         save_expand_nlength);
3827       continue;
3828       }
3829
3830     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
3831     expanding an internal string that isn't actually going to be used. All we
3832     need to do is check the syntax, so don't do a lookup at all. Preserve the
3833     values of the numerical expansion variables in case they get changed by a
3834     partial lookup. If not, they retain their external settings. At the end
3835     of this "lookup" section, they get restored to their previous values. */
3836
3837     case EITEM_LOOKUP:
3838       {
3839       int stype, partial, affixlen, starflags;
3840       int expand_setup = 0;
3841       int nameptr = 0;
3842       uschar *key, *filename, *affix;
3843       uschar *save_lookup_value = lookup_value;
3844       int save_expand_nmax =
3845         save_expand_strings(save_expand_nstring, save_expand_nlength);
3846
3847       if ((expand_forbid & RDO_LOOKUP) != 0)
3848         {
3849         expand_string_message = US"lookup expansions are not permitted";
3850         goto EXPAND_FAILED;
3851         }
3852
3853       /* Get the key we are to look up for single-key+file style lookups.
3854       Otherwise set the key NULL pro-tem. */
3855
3856       while (isspace(*s)) s++;
3857       if (*s == '{')
3858         {
3859         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3860         if (key == NULL) goto EXPAND_FAILED;
3861         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3862         while (isspace(*s)) s++;
3863         }
3864       else key = NULL;
3865
3866       /* Find out the type of database */
3867
3868       if (!isalpha(*s))
3869         {
3870         expand_string_message = US"missing lookup type";
3871         goto EXPAND_FAILED;
3872         }
3873
3874       /* The type is a string that may contain special characters of various
3875       kinds. Allow everything except space or { to appear; the actual content
3876       is checked by search_findtype_partial. */
3877
3878       while (*s != 0 && *s != '{' && !isspace(*s))
3879         {
3880         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
3881         s++;
3882         }
3883       name[nameptr] = 0;
3884       while (isspace(*s)) s++;
3885
3886       /* Now check for the individual search type and any partial or default
3887       options. Only those types that are actually in the binary are valid. */
3888
3889       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
3890         &starflags);
3891       if (stype < 0)
3892         {
3893         expand_string_message = search_error_message;
3894         goto EXPAND_FAILED;
3895         }
3896
3897       /* Check that a key was provided for those lookup types that need it,
3898       and was not supplied for those that use the query style. */
3899
3900       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
3901         {
3902         if (key == NULL)
3903           {
3904           expand_string_message = string_sprintf("missing {key} for single-"
3905             "key \"%s\" lookup", name);
3906           goto EXPAND_FAILED;
3907           }
3908         }
3909       else
3910         {
3911         if (key != NULL)
3912           {
3913           expand_string_message = string_sprintf("a single key was given for "
3914             "lookup type \"%s\", which is not a single-key lookup type", name);
3915           goto EXPAND_FAILED;
3916           }
3917         }
3918
3919       /* Get the next string in brackets and expand it. It is the file name for
3920       single-key+file lookups, and the whole query otherwise. In the case of
3921       queries that also require a file name (e.g. sqlite), the file name comes
3922       first. */
3923
3924       if (*s != '{') goto EXPAND_FAILED_CURLY;
3925       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3926       if (filename == NULL) goto EXPAND_FAILED;
3927       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3928       while (isspace(*s)) s++;
3929
3930       /* If this isn't a single-key+file lookup, re-arrange the variables
3931       to be appropriate for the search_ functions. For query-style lookups,
3932       there is just a "key", and no file name. For the special query-style +
3933       file types, the query (i.e. "key") starts with a file name. */
3934
3935       if (key == NULL)
3936         {
3937         while (isspace(*filename)) filename++;
3938         key = filename;
3939
3940         if (mac_islookup(stype, lookup_querystyle))
3941           {
3942           filename = NULL;
3943           }
3944         else
3945           {
3946           if (*filename != '/')
3947             {
3948             expand_string_message = string_sprintf(
3949               "absolute file name expected for \"%s\" lookup", name);
3950             goto EXPAND_FAILED;
3951             }
3952           while (*key != 0 && !isspace(*key)) key++;
3953           if (*key != 0) *key++ = 0;
3954           }
3955         }
3956
3957       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
3958       the entry was not found. Note that there is no search_close() function.
3959       Files are left open in case of re-use. At suitable places in higher logic,
3960       search_tidyup() is called to tidy all open files. This can save opening
3961       the same file several times. However, files may also get closed when
3962       others are opened, if too many are open at once. The rule is that a
3963       handle should not be used after a second search_open().
3964
3965       Request that a partial search sets up $1 and maybe $2 by passing
3966       expand_setup containing zero. If its value changes, reset expand_nmax,
3967       since new variables will have been set. Note that at the end of this
3968       "lookup" section, the old numeric variables are restored. */
3969
3970       if (skipping)
3971         lookup_value = NULL;
3972       else
3973         {
3974         void *handle = search_open(filename, stype, 0, NULL, NULL);
3975         if (handle == NULL)
3976           {
3977           expand_string_message = search_error_message;
3978           goto EXPAND_FAILED;
3979           }
3980         lookup_value = search_find(handle, filename, key, partial, affix,
3981           affixlen, starflags, &expand_setup);
3982         if (search_find_defer)
3983           {
3984           expand_string_message =
3985             string_sprintf("lookup of \"%s\" gave DEFER: %s",
3986               string_printing2(key, FALSE), search_error_message);
3987           goto EXPAND_FAILED;
3988           }
3989         if (expand_setup > 0) expand_nmax = expand_setup;
3990         }
3991
3992       /* The handling of "yes" and "no" result strings is now in a separate
3993       function that is also used by ${if} and ${extract}. */
3994
3995       switch(process_yesno(
3996                skipping,                     /* were previously skipping */
3997                lookup_value != NULL,         /* success/failure indicator */
3998                save_lookup_value,            /* value to reset for string2 */
3999                &s,                           /* input pointer */
4000                &yield,                       /* output pointer */
4001                &size,                        /* output size */
4002                &ptr,                         /* output current point */
4003                US"lookup"))                  /* condition type */
4004         {
4005         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4006         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4007         }
4008
4009       /* Restore external setting of expansion variables for carrying on
4010       at this level, and continue. */
4011
4012       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4013         save_expand_nlength);
4014       continue;
4015       }
4016
4017     /* If Perl support is configured, handle calling embedded perl subroutines,
4018     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4019     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4020     arguments (defined below). */
4021
4022     #define EXIM_PERL_MAX_ARGS 8
4023
4024     case EITEM_PERL:
4025     #ifndef EXIM_PERL
4026     expand_string_message = US"\"${perl\" encountered, but this facility "
4027       "is not included in this binary";
4028     goto EXPAND_FAILED;
4029
4030     #else   /* EXIM_PERL */
4031       {
4032       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4033       uschar *new_yield;
4034
4035       if ((expand_forbid & RDO_PERL) != 0)
4036         {
4037         expand_string_message = US"Perl calls are not permitted";
4038         goto EXPAND_FAILED;
4039         }
4040
4041       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4042            US"perl"))
4043         {
4044         case 1: goto EXPAND_FAILED_CURLY;
4045         case 2:
4046         case 3: goto EXPAND_FAILED;
4047         }
4048
4049       /* If skipping, we don't actually do anything */
4050
4051       if (skipping) continue;
4052
4053       /* Start the interpreter if necessary */
4054
4055       if (!opt_perl_started)
4056         {
4057         uschar *initerror;
4058         if (opt_perl_startup == NULL)
4059           {
4060           expand_string_message = US"A setting of perl_startup is needed when "
4061             "using the Perl interpreter";
4062           goto EXPAND_FAILED;
4063           }
4064         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4065         initerror = init_perl(opt_perl_startup);
4066         if (initerror != NULL)
4067           {
4068           expand_string_message =
4069             string_sprintf("error in perl_startup code: %s\n", initerror);
4070           goto EXPAND_FAILED;
4071           }
4072         opt_perl_started = TRUE;
4073         }
4074
4075       /* Call the function */
4076
4077       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4078       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4079         sub_arg[0], sub_arg + 1);
4080
4081       /* NULL yield indicates failure; if the message pointer has been set to
4082       NULL, the yield was undef, indicating a forced failure. Otherwise the
4083       message will indicate some kind of Perl error. */
4084
4085       if (new_yield == NULL)
4086         {
4087         if (expand_string_message == NULL)
4088           {
4089           expand_string_message =
4090             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4091               "failure", sub_arg[0]);
4092           expand_string_forcedfail = TRUE;
4093           }
4094         goto EXPAND_FAILED;
4095         }
4096
4097       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4098       set during a callback from Perl. */
4099
4100       expand_string_forcedfail = FALSE;
4101       yield = new_yield;
4102       continue;
4103       }
4104     #endif /* EXIM_PERL */
4105
4106     /* Transform email address to "prvs" scheme to use
4107        as BATV-signed return path */
4108
4109     case EITEM_PRVS:
4110       {
4111       uschar *sub_arg[3];
4112       uschar *p,*domain;
4113
4114       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs"))
4115         {
4116         case 1: goto EXPAND_FAILED_CURLY;
4117         case 2:
4118         case 3: goto EXPAND_FAILED;
4119         }
4120
4121       /* If skipping, we don't actually do anything */
4122       if (skipping) continue;
4123
4124       /* sub_arg[0] is the address */
4125       domain = Ustrrchr(sub_arg[0],'@');
4126       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4127         {
4128         expand_string_message = US"prvs first argument must be a qualified email address";
4129         goto EXPAND_FAILED;
4130         }
4131
4132       /* Calculate the hash. The second argument must be a single-digit
4133       key number, or unset. */
4134
4135       if (sub_arg[2] != NULL &&
4136           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4137         {
4138         expand_string_message = US"prvs second argument must be a single digit";
4139         goto EXPAND_FAILED;
4140         }
4141
4142       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4143       if (p == NULL)
4144         {
4145         expand_string_message = US"prvs hmac-sha1 conversion failed";
4146         goto EXPAND_FAILED;
4147         }
4148
4149       /* Now separate the domain from the local part */
4150       *domain++ = '\0';
4151
4152       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4153       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4154       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4155       string_cat(yield,&size,&ptr,p,6);
4156       string_cat(yield,&size,&ptr,US"=",1);
4157       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4158       string_cat(yield,&size,&ptr,US"@",1);
4159       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4160
4161       continue;
4162       }
4163
4164     /* Check a prvs-encoded address for validity */
4165
4166     case EITEM_PRVSCHECK:
4167       {
4168       uschar *sub_arg[3];
4169       int mysize = 0, myptr = 0;
4170       const pcre *re;
4171       uschar *p;
4172
4173       /* TF: Ugliness: We want to expand parameter 1 first, then set
4174          up expansion variables that are used in the expansion of
4175          parameter 2. So we clone the string for the first
4176          expansion, where we only expand parameter 1.
4177
4178          PH: Actually, that isn't necessary. The read_subs() function is
4179          designed to work this way for the ${if and ${lookup expansions. I've
4180          tidied the code.
4181       */
4182
4183       /* Reset expansion variables */
4184       prvscheck_result = NULL;
4185       prvscheck_address = NULL;
4186       prvscheck_keynum = NULL;
4187
4188       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4189         {
4190         case 1: goto EXPAND_FAILED_CURLY;
4191         case 2:
4192         case 3: goto EXPAND_FAILED;
4193         }
4194
4195       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4196                               TRUE,FALSE);
4197
4198       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4199         {
4200         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4201         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4202         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4203         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4204         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4205
4206         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4207         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4208         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4209         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4210         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4211
4212         /* Set up expansion variables */
4213         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4214         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4215         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4216         prvscheck_address[myptr] = '\0';
4217         prvscheck_keynum = string_copy(key_num);
4218
4219         /* Now expand the second argument */
4220         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4221           {
4222           case 1: goto EXPAND_FAILED_CURLY;
4223           case 2:
4224           case 3: goto EXPAND_FAILED;
4225           }
4226
4227         /* Now we have the key and can check the address. */
4228
4229         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4230           daystamp);
4231
4232         if (p == NULL)
4233           {
4234           expand_string_message = US"hmac-sha1 conversion failed";
4235           goto EXPAND_FAILED;
4236           }
4237
4238         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4239         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4240
4241         if (Ustrcmp(p,hash) == 0)
4242           {
4243           /* Success, valid BATV address. Now check the expiry date. */
4244           uschar *now = prvs_daystamp(0);
4245           unsigned int inow = 0,iexpire = 1;
4246
4247           (void)sscanf(CS now,"%u",&inow);
4248           (void)sscanf(CS daystamp,"%u",&iexpire);
4249
4250           /* When "iexpire" is < 7, a "flip" has occured.
4251              Adjust "inow" accordingly. */
4252           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4253
4254           if (iexpire >= inow)
4255             {
4256             prvscheck_result = US"1";
4257             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4258             }
4259             else
4260             {
4261             prvscheck_result = NULL;
4262             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4263             }
4264           }
4265         else
4266           {
4267           prvscheck_result = NULL;
4268           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4269           }
4270
4271         /* Now expand the final argument. We leave this till now so that
4272         it can include $prvscheck_result. */
4273
4274         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs"))
4275           {
4276           case 1: goto EXPAND_FAILED_CURLY;
4277           case 2:
4278           case 3: goto EXPAND_FAILED;
4279           }
4280
4281         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4282           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4283         else
4284           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4285
4286         /* Reset the "internal" variables afterwards, because they are in
4287         dynamic store that will be reclaimed if the expansion succeeded. */
4288
4289         prvscheck_address = NULL;
4290         prvscheck_keynum = NULL;
4291         }
4292       else
4293         {
4294         /* Does not look like a prvs encoded address, return the empty string.
4295            We need to make sure all subs are expanded first, so as to skip over
4296            the entire item. */
4297
4298         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs"))
4299           {
4300           case 1: goto EXPAND_FAILED_CURLY;
4301           case 2:
4302           case 3: goto EXPAND_FAILED;
4303           }
4304         }
4305
4306       continue;
4307       }
4308
4309     /* Handle "readfile" to insert an entire file */
4310
4311     case EITEM_READFILE:
4312       {
4313       FILE *f;
4314       uschar *sub_arg[2];
4315
4316       if ((expand_forbid & RDO_READFILE) != 0)
4317         {
4318         expand_string_message = US"file insertions are not permitted";
4319         goto EXPAND_FAILED;
4320         }
4321
4322       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
4323         {
4324         case 1: goto EXPAND_FAILED_CURLY;
4325         case 2:
4326         case 3: goto EXPAND_FAILED;
4327         }
4328
4329       /* If skipping, we don't actually do anything */
4330
4331       if (skipping) continue;
4332
4333       /* Open the file and read it */
4334
4335       f = Ufopen(sub_arg[0], "rb");
4336       if (f == NULL)
4337         {
4338         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4339         goto EXPAND_FAILED;
4340         }
4341
4342       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4343       (void)fclose(f);
4344       continue;
4345       }
4346
4347     /* Handle "readsocket" to insert data from a Unix domain socket */
4348
4349     case EITEM_READSOCK:
4350       {
4351       int fd;
4352       int timeout = 5;
4353       int save_ptr = ptr;
4354       FILE *f;
4355       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4356       uschar *arg;
4357       uschar *sub_arg[4];
4358
4359       if ((expand_forbid & RDO_READSOCK) != 0)
4360         {
4361         expand_string_message = US"socket insertions are not permitted";
4362         goto EXPAND_FAILED;
4363         }
4364
4365       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4366       because there may be a string for expansion on failure. */
4367
4368       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
4369         {
4370         case 1: goto EXPAND_FAILED_CURLY;
4371         case 2:                             /* Won't occur: no end check */
4372         case 3: goto EXPAND_FAILED;
4373         }
4374
4375       /* Sort out timeout, if given */
4376
4377       if (sub_arg[2] != NULL)
4378         {
4379         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4380         if (timeout < 0)
4381           {
4382           expand_string_message = string_sprintf("bad time value %s",
4383             sub_arg[2]);
4384           goto EXPAND_FAILED;
4385           }
4386         }
4387       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4388
4389       /* If skipping, we don't actually do anything. Otherwise, arrange to
4390       connect to either an IP or a Unix socket. */
4391
4392       if (!skipping)
4393         {
4394         /* Handle an IP (internet) domain */
4395
4396         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4397           {
4398           BOOL connected = FALSE;
4399           int namelen, port;
4400           host_item shost;
4401           host_item *h;
4402           uschar *server_name = sub_arg[0] + 5;
4403           uschar *port_name = Ustrrchr(server_name, ':');
4404
4405           /* Sort out the port */
4406
4407           if (port_name == NULL)
4408             {
4409             expand_string_message =
4410               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4411             goto EXPAND_FAILED;
4412             }
4413           *port_name++ = 0;           /* Terminate server name */
4414
4415           if (isdigit(*port_name))
4416             {
4417             uschar *end;
4418             port = Ustrtol(port_name, &end, 0);
4419             if (end != port_name + Ustrlen(port_name))
4420               {
4421               expand_string_message =
4422                 string_sprintf("invalid port number %s", port_name);
4423               goto EXPAND_FAILED;
4424               }
4425             }
4426           else
4427             {
4428             struct servent *service_info = getservbyname(CS port_name, "tcp");
4429             if (service_info == NULL)
4430               {
4431               expand_string_message = string_sprintf("unknown port \"%s\"",
4432                 port_name);
4433               goto EXPAND_FAILED;
4434               }
4435             port = ntohs(service_info->s_port);
4436             }
4437
4438           /* Sort out the server. */
4439
4440           shost.next = NULL;
4441           shost.address = NULL;
4442           shost.port = port;
4443           shost.mx = -1;
4444
4445           namelen = Ustrlen(server_name);
4446
4447           /* Anything enclosed in [] must be an IP address. */
4448
4449           if (server_name[0] == '[' &&
4450               server_name[namelen - 1] == ']')
4451             {
4452             server_name[namelen - 1] = 0;
4453             server_name++;
4454             if (string_is_ip_address(server_name, NULL) == 0)
4455               {
4456               expand_string_message =
4457                 string_sprintf("malformed IP address \"%s\"", server_name);
4458               goto EXPAND_FAILED;
4459               }
4460             shost.name = shost.address = server_name;
4461             }
4462
4463           /* Otherwise check for an unadorned IP address */
4464
4465           else if (string_is_ip_address(server_name, NULL) != 0)
4466             shost.name = shost.address = server_name;
4467
4468           /* Otherwise lookup IP address(es) from the name */
4469
4470           else
4471             {
4472             shost.name = server_name;
4473             if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
4474                 FALSE) != HOST_FOUND)
4475               {
4476               expand_string_message =
4477                 string_sprintf("no IP address found for host %s", shost.name);
4478               goto EXPAND_FAILED;
4479               }
4480             }
4481
4482           /* Try to connect to the server - test each IP till one works */
4483
4484           for (h = &shost; h != NULL; h = h->next)
4485             {
4486             int af = (Ustrchr(h->address, ':') != 0)? AF_INET6 : AF_INET;
4487             if ((fd = ip_socket(SOCK_STREAM, af)) == -1)
4488               {
4489               expand_string_message = string_sprintf("failed to create socket: "
4490                 "%s", strerror(errno));
4491               goto SOCK_FAIL;
4492               }
4493
4494             if (ip_connect(fd, af, h->address, port, timeout) == 0)
4495               {
4496               connected = TRUE;
4497               break;
4498               }
4499             }
4500
4501           if (!connected)
4502             {
4503             expand_string_message = string_sprintf("failed to connect to "
4504               "socket %s: couldn't connect to any host", sub_arg[0],
4505               strerror(errno));
4506             goto SOCK_FAIL;
4507             }
4508           }
4509
4510         /* Handle a Unix domain socket */
4511
4512         else
4513           {
4514           int rc;
4515           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4516             {
4517             expand_string_message = string_sprintf("failed to create socket: %s",
4518               strerror(errno));
4519             goto SOCK_FAIL;
4520             }
4521
4522           sockun.sun_family = AF_UNIX;
4523           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4524             sub_arg[0]);
4525
4526           sigalrm_seen = FALSE;
4527           alarm(timeout);
4528           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4529           alarm(0);
4530           if (sigalrm_seen)
4531             {
4532             expand_string_message = US "socket connect timed out";
4533             goto SOCK_FAIL;
4534             }
4535           if (rc < 0)
4536             {
4537             expand_string_message = string_sprintf("failed to connect to socket "
4538               "%s: %s", sub_arg[0], strerror(errno));
4539             goto SOCK_FAIL;
4540             }
4541           }
4542
4543         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4544
4545         /* Write the request string, if not empty */
4546
4547         if (sub_arg[1][0] != 0)
4548           {
4549           int len = Ustrlen(sub_arg[1]);
4550           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4551             sub_arg[1]);
4552           if (write(fd, sub_arg[1], len) != len)
4553             {
4554             expand_string_message = string_sprintf("request write to socket "
4555               "failed: %s", strerror(errno));
4556             goto SOCK_FAIL;
4557             }
4558           }
4559
4560         /* Shut down the sending side of the socket. This helps some servers to
4561         recognise that it is their turn to do some work. Just in case some
4562         system doesn't have this function, make it conditional. */
4563
4564         #ifdef SHUT_WR
4565         shutdown(fd, SHUT_WR);
4566         #endif
4567
4568         /* Now we need to read from the socket, under a timeout. The function
4569         that reads a file can be used. */
4570
4571         f = fdopen(fd, "rb");
4572         sigalrm_seen = FALSE;
4573         alarm(timeout);
4574         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4575         alarm(0);
4576         (void)fclose(f);
4577
4578         /* After a timeout, we restore the pointer in the result, that is,
4579         make sure we add nothing from the socket. */
4580
4581         if (sigalrm_seen)
4582           {
4583           ptr = save_ptr;
4584           expand_string_message = US "socket read timed out";
4585           goto SOCK_FAIL;
4586           }
4587         }
4588
4589       /* The whole thing has worked (or we were skipping). If there is a
4590       failure string following, we need to skip it. */
4591
4592       if (*s == '{')
4593         {
4594         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE) == NULL)
4595           goto EXPAND_FAILED;
4596         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4597         while (isspace(*s)) s++;
4598         }
4599       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4600       continue;
4601
4602       /* Come here on failure to create socket, connect socket, write to the
4603       socket, or timeout on reading. If another substring follows, expand and
4604       use it. Otherwise, those conditions give expand errors. */
4605
4606       SOCK_FAIL:
4607       if (*s != '{') goto EXPAND_FAILED;
4608       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4609       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE);
4610       if (arg == NULL) goto EXPAND_FAILED;
4611       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4612       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4613       while (isspace(*s)) s++;
4614       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4615       continue;
4616       }
4617
4618     /* Handle "run" to execute a program. */
4619
4620     case EITEM_RUN:
4621       {
4622       FILE *f;
4623       uschar *arg;
4624       uschar **argv;
4625       pid_t pid;
4626       int fd_in, fd_out;
4627       int lsize = 0;
4628       int lptr = 0;
4629
4630       if ((expand_forbid & RDO_RUN) != 0)
4631         {
4632         expand_string_message = US"running a command is not permitted";
4633         goto EXPAND_FAILED;
4634         }
4635
4636       while (isspace(*s)) s++;
4637       if (*s != '{') goto EXPAND_FAILED_CURLY;
4638       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
4639       if (arg == NULL) goto EXPAND_FAILED;
4640       while (isspace(*s)) s++;
4641       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4642
4643       if (skipping)   /* Just pretend it worked when we're skipping */
4644         {
4645         runrc = 0;
4646         }
4647       else
4648         {
4649         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4650             arg,                                /* raw command */
4651             FALSE,                              /* don't expand the arguments */
4652             0,                                  /* not relevant when... */
4653             NULL,                               /* no transporting address */
4654             US"${run} expansion",               /* for error messages */
4655             &expand_string_message))            /* where to put error message */
4656           {
4657           goto EXPAND_FAILED;
4658           }
4659
4660         /* Create the child process, making it a group leader. */
4661
4662         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4663
4664         if (pid < 0)
4665           {
4666           expand_string_message =
4667             string_sprintf("couldn't create child process: %s", strerror(errno));
4668           goto EXPAND_FAILED;
4669           }
4670
4671         /* Nothing is written to the standard input. */
4672
4673         (void)close(fd_in);
4674
4675         /* Read the pipe to get the command's output into $value (which is kept
4676         in lookup_value). Read during execution, so that if the output exceeds
4677         the OS pipe buffer limit, we don't block forever. */
4678
4679         f = fdopen(fd_out, "rb");
4680         sigalrm_seen = FALSE;
4681         alarm(60);
4682         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4683         alarm(0);
4684         (void)fclose(f);
4685
4686         /* Wait for the process to finish, applying the timeout, and inspect its
4687         return code for serious disasters. Simple non-zero returns are passed on.
4688         */
4689
4690         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4691           {
4692           if (sigalrm_seen == TRUE || runrc == -256)
4693             {
4694             expand_string_message = string_sprintf("command timed out");
4695             killpg(pid, SIGKILL);       /* Kill the whole process group */
4696             }
4697
4698           else if (runrc == -257)
4699             expand_string_message = string_sprintf("wait() failed: %s",
4700               strerror(errno));
4701
4702           else
4703             expand_string_message = string_sprintf("command killed by signal %d",
4704               -runrc);
4705
4706           goto EXPAND_FAILED;
4707           }
4708         }
4709
4710       /* Process the yes/no strings; $value may be useful in both cases */
4711
4712       switch(process_yesno(
4713                skipping,                     /* were previously skipping */
4714                runrc == 0,                   /* success/failure indicator */
4715                lookup_value,                 /* value to reset for string2 */
4716                &s,                           /* input pointer */
4717                &yield,                       /* output pointer */
4718                &size,                        /* output size */
4719                &ptr,                         /* output current point */
4720                US"run"))                     /* condition type */
4721         {
4722         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4723         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4724         }
4725
4726       continue;
4727       }
4728
4729     /* Handle character translation for "tr" */
4730
4731     case EITEM_TR:
4732       {
4733       int oldptr = ptr;
4734       int o2m;
4735       uschar *sub[3];
4736
4737       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
4738         {
4739         case 1: goto EXPAND_FAILED_CURLY;
4740         case 2:
4741         case 3: goto EXPAND_FAILED;
4742         }
4743
4744       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4745       o2m = Ustrlen(sub[2]) - 1;
4746
4747       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4748         {
4749         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4750         if (m != NULL)
4751           {
4752           int o = m - sub[1];
4753           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4754           }
4755         }
4756
4757       continue;
4758       }
4759
4760     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4761     expanded arguments. */
4762
4763     case EITEM_HASH:
4764     case EITEM_LENGTH:
4765     case EITEM_NHASH:
4766     case EITEM_SUBSTR:
4767       {
4768       int i;
4769       int len;
4770       uschar *ret;
4771       int val[2] = { 0, -1 };
4772       uschar *sub[3];
4773
4774       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4775       Ensure that sub[2] is set in the ${length case. */
4776
4777       sub[2] = NULL;
4778       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4779              TRUE, name))
4780         {
4781         case 1: goto EXPAND_FAILED_CURLY;
4782         case 2:
4783         case 3: goto EXPAND_FAILED;
4784         }
4785
4786       /* Juggle the arguments if there are only two of them: always move the
4787       string to the last position and make ${length{n}{str}} equivalent to
4788       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4789
4790       if (sub[2] == NULL)
4791         {
4792         sub[2] = sub[1];
4793         sub[1] = NULL;
4794         if (item_type == EITEM_LENGTH)
4795           {
4796           sub[1] = sub[0];
4797           sub[0] = NULL;
4798           }
4799         }
4800
4801       for (i = 0; i < 2; i++)
4802         {
4803         if (sub[i] == NULL) continue;
4804         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4805         if (*ret != 0 || (i != 0 && val[i] < 0))
4806           {
4807           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4808             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4809           goto EXPAND_FAILED;
4810           }
4811         }
4812
4813       ret =
4814         (item_type == EITEM_HASH)?
4815           compute_hash(sub[2], val[0], val[1], &len) :
4816         (item_type == EITEM_NHASH)?
4817           compute_nhash(sub[2], val[0], val[1], &len) :
4818           extract_substr(sub[2], val[0], val[1], &len);
4819
4820       if (ret == NULL) goto EXPAND_FAILED;
4821       yield = string_cat(yield, &size, &ptr, ret, len);
4822       continue;
4823       }
4824
4825     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4826     This code originally contributed by Steve Haslam. It currently supports
4827     the use of MD5 and SHA-1 hashes.
4828
4829     We need some workspace that is large enough to handle all the supported
4830     hash types. Use macros to set the sizes rather than be too elaborate. */
4831
4832     #define MAX_HASHLEN      20
4833     #define MAX_HASHBLOCKLEN 64
4834
4835     case EITEM_HMAC:
4836       {
4837       uschar *sub[3];
4838       md5 md5_base;
4839       sha1 sha1_base;
4840       void *use_base;
4841       int type, i;
4842       int hashlen;      /* Number of octets for the hash algorithm's output */
4843       int hashblocklen; /* Number of octets the hash algorithm processes */
4844       uschar *keyptr, *p;
4845       unsigned int keylen;
4846
4847       uschar keyhash[MAX_HASHLEN];
4848       uschar innerhash[MAX_HASHLEN];
4849       uschar finalhash[MAX_HASHLEN];
4850       uschar finalhash_hex[2*MAX_HASHLEN];
4851       uschar innerkey[MAX_HASHBLOCKLEN];
4852       uschar outerkey[MAX_HASHBLOCKLEN];
4853
4854       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
4855         {
4856         case 1: goto EXPAND_FAILED_CURLY;
4857         case 2:
4858         case 3: goto EXPAND_FAILED;
4859         }
4860
4861       if (Ustrcmp(sub[0], "md5") == 0)
4862         {
4863         type = HMAC_MD5;
4864         use_base = &md5_base;
4865         hashlen = 16;
4866         hashblocklen = 64;
4867         }
4868       else if (Ustrcmp(sub[0], "sha1") == 0)
4869         {
4870         type = HMAC_SHA1;
4871         use_base = &sha1_base;
4872         hashlen = 20;
4873         hashblocklen = 64;
4874         }
4875       else
4876         {
4877         expand_string_message =
4878           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
4879         goto EXPAND_FAILED;
4880         }
4881
4882       keyptr = sub[1];
4883       keylen = Ustrlen(keyptr);
4884
4885       /* If the key is longer than the hash block length, then hash the key
4886       first */
4887
4888       if (keylen > hashblocklen)
4889         {
4890         chash_start(type, use_base);
4891         chash_end(type, use_base, keyptr, keylen, keyhash);
4892         keyptr = keyhash;
4893         keylen = hashlen;
4894         }
4895
4896       /* Now make the inner and outer key values */
4897
4898       memset(innerkey, 0x36, hashblocklen);
4899       memset(outerkey, 0x5c, hashblocklen);
4900
4901       for (i = 0; i < keylen; i++)
4902         {
4903         innerkey[i] ^= keyptr[i];
4904         outerkey[i] ^= keyptr[i];
4905         }
4906
4907       /* Now do the hashes */
4908
4909       chash_start(type, use_base);
4910       chash_mid(type, use_base, innerkey);
4911       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
4912
4913       chash_start(type, use_base);
4914       chash_mid(type, use_base, outerkey);
4915       chash_end(type, use_base, innerhash, hashlen, finalhash);
4916
4917       /* Encode the final hash as a hex string */
4918
4919       p = finalhash_hex;
4920       for (i = 0; i < hashlen; i++)
4921         {
4922         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
4923         *p++ = hex_digits[finalhash[i] & 0x0f];
4924         }
4925
4926       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
4927         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
4928
4929       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
4930       }
4931
4932     continue;
4933
4934     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
4935     We have to save the numerical variables and restore them afterwards. */
4936
4937     case EITEM_SG:
4938       {
4939       const pcre *re;
4940       int moffset, moffsetextra, slen;
4941       int roffset;
4942       int emptyopt;
4943       const uschar *rerror;
4944       uschar *subject;
4945       uschar *sub[3];
4946       int save_expand_nmax =
4947         save_expand_strings(save_expand_nstring, save_expand_nlength);
4948
4949       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
4950         {
4951         case 1: goto EXPAND_FAILED_CURLY;
4952         case 2:
4953         case 3: goto EXPAND_FAILED;
4954         }
4955
4956       /* Compile the regular expression */
4957
4958       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
4959         NULL);
4960
4961       if (re == NULL)
4962         {
4963         expand_string_message = string_sprintf("regular expression error in "
4964           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
4965         goto EXPAND_FAILED;
4966         }
4967
4968       /* Now run a loop to do the substitutions as often as necessary. It ends
4969       when there are no more matches. Take care over matches of the null string;
4970       do the same thing as Perl does. */
4971
4972       subject = sub[0];
4973       slen = Ustrlen(sub[0]);
4974       moffset = moffsetextra = 0;
4975       emptyopt = 0;
4976
4977       for (;;)
4978         {
4979         int ovector[3*(EXPAND_MAXN+1)];
4980         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
4981           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
4982         int nn;
4983         uschar *insert;
4984
4985         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
4986         is not necessarily the end. We want to repeat the match from one
4987         character further along, but leaving the basic offset the same (for
4988         copying below). We can't be at the end of the string - that was checked
4989         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
4990         finished; copy the remaining string and end the loop. */
4991
4992         if (n < 0)
4993           {
4994           if (emptyopt != 0)
4995             {
4996             moffsetextra = 1;
4997             emptyopt = 0;
4998             continue;
4999             }
5000           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5001           break;
5002           }
5003
5004         /* Match - set up for expanding the replacement. */
5005
5006         if (n == 0) n = EXPAND_MAXN + 1;
5007         expand_nmax = 0;
5008         for (nn = 0; nn < n*2; nn += 2)
5009           {
5010           expand_nstring[expand_nmax] = subject + ovector[nn];
5011           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5012           }
5013         expand_nmax--;
5014
5015         /* Copy the characters before the match, plus the expanded insertion. */
5016
5017         yield = string_cat(yield, &size, &ptr, subject + moffset,
5018           ovector[0] - moffset);
5019         insert = expand_string(sub[2]);
5020         if (insert == NULL) goto EXPAND_FAILED;
5021         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5022
5023         moffset = ovector[1];
5024         moffsetextra = 0;
5025         emptyopt = 0;
5026
5027         /* If we have matched an empty string, first check to see if we are at
5028         the end of the subject. If so, the loop is over. Otherwise, mimic
5029         what Perl's /g options does. This turns out to be rather cunning. First
5030         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5031         string at the same point. If this fails (picked up above) we advance to
5032         the next character. */
5033
5034         if (ovector[0] == ovector[1])
5035           {
5036           if (ovector[0] == slen) break;
5037           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5038           }
5039         }
5040
5041       /* All done - restore numerical variables. */
5042
5043       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5044         save_expand_nlength);
5045       continue;
5046       }
5047
5048     /* Handle keyed and numbered substring extraction. If the first argument
5049     consists entirely of digits, then a numerical extraction is assumed. */
5050
5051     case EITEM_EXTRACT:
5052       {
5053       int i;
5054       int j = 2;
5055       int field_number = 1;
5056       BOOL field_number_set = FALSE;
5057       uschar *save_lookup_value = lookup_value;
5058       uschar *sub[3];
5059       int save_expand_nmax =
5060         save_expand_strings(save_expand_nstring, save_expand_nlength);
5061
5062       /* Read the arguments */
5063
5064       for (i = 0; i < j; i++)
5065         {
5066         while (isspace(*s)) s++;
5067         if (*s == '{')
5068           {
5069           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5070           if (sub[i] == NULL) goto EXPAND_FAILED;
5071           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5072
5073           /* After removal of leading and trailing white space, the first
5074           argument must not be empty; if it consists entirely of digits
5075           (optionally preceded by a minus sign), this is a numerical
5076           extraction, and we expect 3 arguments. */
5077
5078           if (i == 0)
5079             {
5080             int len;
5081             int x = 0;
5082             uschar *p = sub[0];
5083
5084             while (isspace(*p)) p++;
5085             sub[0] = p;
5086
5087             len = Ustrlen(p);
5088             while (len > 0 && isspace(p[len-1])) len--;
5089             p[len] = 0;
5090
5091             if (*p == 0 && !skipping)
5092               {
5093               expand_string_message = US"first argument of \"extract\" must "
5094                 "not be empty";
5095               goto EXPAND_FAILED;
5096               }
5097
5098             if (*p == '-')
5099               {
5100               field_number = -1;
5101               p++;
5102               }
5103             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5104             if (*p == 0)
5105               {
5106               field_number *= x;
5107               j = 3;               /* Need 3 args */
5108               field_number_set = TRUE;
5109               }
5110             }
5111           }
5112         else goto EXPAND_FAILED_CURLY;
5113         }
5114
5115       /* Extract either the numbered or the keyed substring into $value. If
5116       skipping, just pretend the extraction failed. */
5117
5118       lookup_value = skipping? NULL : field_number_set?
5119         expand_gettokened(field_number, sub[1], sub[2]) :
5120         expand_getkeyed(sub[0], sub[1]);
5121
5122       /* If no string follows, $value gets substituted; otherwise there can
5123       be yes/no strings, as for lookup or if. */
5124
5125       switch(process_yesno(
5126                skipping,                     /* were previously skipping */
5127                lookup_value != NULL,         /* success/failure indicator */
5128                save_lookup_value,            /* value to reset for string2 */
5129                &s,                           /* input pointer */
5130                &yield,                       /* output pointer */
5131                &size,                        /* output size */
5132                &ptr,                         /* output current point */
5133                US"extract"))                 /* condition type */
5134         {
5135         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5136         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5137         }
5138
5139       /* All done - restore numerical variables. */
5140
5141       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5142         save_expand_nlength);
5143
5144       continue;
5145       }
5146
5147
5148     /* Handle list operations */
5149
5150     case EITEM_FILTER:
5151     case EITEM_MAP:
5152     case EITEM_REDUCE:
5153       {
5154       int sep = 0;
5155       int save_ptr = ptr;
5156       uschar outsep[2] = { '\0', '\0' };
5157       uschar *list, *expr, *temp;
5158       uschar *save_iterate_item = iterate_item;
5159       uschar *save_lookup_value = lookup_value;
5160
5161       while (isspace(*s)) s++;
5162       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5163
5164       list = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5165       if (list == NULL) goto EXPAND_FAILED;
5166       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5167
5168       if (item_type == EITEM_REDUCE)
5169         {
5170         while (isspace(*s)) s++;
5171         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5172         temp = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5173         if (temp == NULL) goto EXPAND_FAILED;
5174         lookup_value = temp;
5175         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5176         }
5177
5178       while (isspace(*s)) s++;
5179       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5180
5181       expr = s;
5182
5183       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5184       if scanning a "false" part). This allows us to find the end of the
5185       condition, because if the list is empty, we won't actually evaluate the
5186       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5187       the normal internal expansion function. */
5188
5189       if (item_type == EITEM_FILTER)
5190         {
5191         temp = eval_condition(expr, NULL);
5192         if (temp != NULL) s = temp;
5193         }
5194       else
5195         {
5196         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE);
5197         }
5198
5199       if (temp == NULL)
5200         {
5201         expand_string_message = string_sprintf("%s inside \"%s\" item",
5202           expand_string_message, name);
5203         goto EXPAND_FAILED;
5204         }
5205
5206       while (isspace(*s)) s++;
5207       if (*s++ != '}')
5208         {
5209         expand_string_message = string_sprintf("missing } at end of condition "
5210           "or expression inside \"%s\"", name);
5211         goto EXPAND_FAILED;
5212         }
5213
5214       while (isspace(*s)) s++;
5215       if (*s++ != '}')
5216         {
5217         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5218           name);
5219         goto EXPAND_FAILED;
5220         }
5221
5222       /* If we are skipping, we can now just move on to the next item. When
5223       processing for real, we perform the iteration. */
5224
5225       if (skipping) continue;
5226       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5227         {
5228         *outsep = (uschar)sep;      /* Separator as a string */
5229
5230         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5231
5232         if (item_type == EITEM_FILTER)
5233           {
5234           BOOL condresult;
5235           if (eval_condition(expr, &condresult) == NULL)
5236             {
5237             iterate_item = save_iterate_item;
5238             lookup_value = save_lookup_value;
5239             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5240               expand_string_message, name);
5241             goto EXPAND_FAILED;
5242             }
5243           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5244             condresult? "true":"false");
5245           if (condresult)
5246             temp = iterate_item;    /* TRUE => include this item */
5247           else
5248             continue;               /* FALSE => skip this item */
5249           }
5250
5251         /* EITEM_MAP and EITEM_REDUCE */
5252
5253         else
5254           {
5255           temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE);
5256           if (temp == NULL)
5257             {
5258             iterate_item = save_iterate_item;
5259             expand_string_message = string_sprintf("%s inside \"%s\" item",
5260               expand_string_message, name);
5261             goto EXPAND_FAILED;
5262             }
5263           if (item_type == EITEM_REDUCE)
5264             {
5265             lookup_value = temp;      /* Update the value of $value */
5266             continue;                 /* and continue the iteration */
5267             }
5268           }
5269
5270         /* We reach here for FILTER if the condition is true, always for MAP,
5271         and never for REDUCE. The value in "temp" is to be added to the output
5272         list that is being created, ensuring that any occurrences of the
5273         separator character are doubled. Unless we are dealing with the first
5274         item of the output list, add in a space if the new item begins with the
5275         separator character, or is an empty string. */
5276
5277         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5278           yield = string_cat(yield, &size, &ptr, US" ", 1);
5279
5280         /* Add the string in "temp" to the output list that we are building,
5281         This is done in chunks by searching for the separator character. */
5282
5283         for (;;)
5284           {
5285           size_t seglen = Ustrcspn(temp, outsep);
5286             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5287
5288           /* If we got to the end of the string we output one character
5289           too many; backup and end the loop. Otherwise arrange to double the
5290           separator. */
5291
5292           if (temp[seglen] == '\0') { ptr--; break; }
5293           yield = string_cat(yield, &size, &ptr, outsep, 1);
5294           temp += seglen + 1;
5295           }
5296
5297         /* Output a separator after the string: we will remove the redundant
5298         final one at the end. */
5299
5300         yield = string_cat(yield, &size, &ptr, outsep, 1);
5301         }   /* End of iteration over the list loop */
5302
5303       /* REDUCE has generated no output above: output the final value of
5304       $value. */
5305
5306       if (item_type == EITEM_REDUCE)
5307         {
5308         yield = string_cat(yield, &size, &ptr, lookup_value,
5309           Ustrlen(lookup_value));
5310         lookup_value = save_lookup_value;  /* Restore $value */
5311         }
5312
5313       /* FILTER and MAP generate lists: if they have generated anything, remove
5314       the redundant final separator. Even though an empty item at the end of a
5315       list does not count, this is tidier. */
5316
5317       else if (ptr != save_ptr) ptr--;
5318
5319       /* Restore preserved $item */
5320
5321       iterate_item = save_iterate_item;
5322       continue;
5323       }
5324
5325
5326     /* If ${dlfunc support is configured, handle calling dynamically-loaded
5327     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5328     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5329     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5330
5331     #define EXPAND_DLFUNC_MAX_ARGS 8
5332
5333     case EITEM_DLFUNC:
5334     #ifndef EXPAND_DLFUNC
5335     expand_string_message = US"\"${dlfunc\" encountered, but this facility "
5336       "is not included in this binary";
5337     goto EXPAND_FAILED;
5338
5339     #else   /* EXPAND_DLFUNC */
5340       {
5341       tree_node *t;
5342       exim_dlfunc_t *func;
5343       uschar *result;
5344       int status, argc;
5345       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5346
5347       if ((expand_forbid & RDO_DLFUNC) != 0)
5348         {
5349         expand_string_message =
5350           US"dynamically-loaded functions are not permitted";
5351         goto EXPAND_FAILED;
5352         }
5353
5354       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5355            TRUE, US"dlfunc"))
5356         {
5357         case 1: goto EXPAND_FAILED_CURLY;
5358         case 2:
5359         case 3: goto EXPAND_FAILED;
5360         }
5361
5362       /* If skipping, we don't actually do anything */
5363
5364       if (skipping) continue;
5365
5366       /* Look up the dynamically loaded object handle in the tree. If it isn't
5367       found, dlopen() the file and put the handle in the tree for next time. */
5368
5369       t = tree_search(dlobj_anchor, argv[0]);
5370       if (t == NULL)
5371         {
5372         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5373         if (handle == NULL)
5374           {
5375           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5376             argv[0], dlerror());
5377           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5378           goto EXPAND_FAILED;
5379           }
5380         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5381         Ustrcpy(t->name, argv[0]);
5382         t->data.ptr = handle;
5383         (void)tree_insertnode(&dlobj_anchor, t);
5384         }
5385
5386       /* Having obtained the dynamically loaded object handle, look up the
5387       function pointer. */
5388
5389       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5390       if (func == NULL)
5391         {
5392         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5393           "%s", argv[1], argv[0], dlerror());
5394         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5395         goto EXPAND_FAILED;
5396         }
5397
5398       /* Call the function and work out what to do with the result. If it
5399       returns OK, we have a replacement string; if it returns DEFER then
5400       expansion has failed in a non-forced manner; if it returns FAIL then
5401       failure was forced; if it returns ERROR or any other value there's a
5402       problem, so panic slightly. In any case, assume that the function has
5403       side-effects on the store that must be preserved. */
5404
5405       resetok = FALSE;
5406       result = NULL;
5407       for (argc = 0; argv[argc] != NULL; argc++);
5408       status = func(&result, argc - 2, &argv[2]);
5409       if(status == OK)
5410         {
5411         if (result == NULL) result = US"";
5412         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5413         continue;
5414         }
5415       else
5416         {
5417         expand_string_message = result == NULL ? US"(no message)" : result;
5418         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5419           else if(status != FAIL)
5420             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5421               argv[0], argv[1], status, expand_string_message);
5422         goto EXPAND_FAILED;
5423         }
5424       }
5425     #endif /* EXPAND_DLFUNC */
5426     }
5427
5428   /* Control reaches here if the name is not recognized as one of the more
5429   complicated expansion items. Check for the "operator" syntax (name terminated
5430   by a colon). Some of the operators have arguments, separated by _ from the
5431   name. */
5432
5433   if (*s == ':')
5434     {
5435     int c;
5436     uschar *arg = NULL;
5437     uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5438     if (sub == NULL) goto EXPAND_FAILED;
5439     s++;
5440
5441     /* Owing to an historical mis-design, an underscore may be part of the
5442     operator name, or it may introduce arguments.  We therefore first scan the
5443     table of names that contain underscores. If there is no match, we cut off
5444     the arguments and then scan the main table. */
5445
5446     c = chop_match(name, op_table_underscore,
5447       sizeof(op_table_underscore)/sizeof(uschar *));
5448
5449     if (c < 0)
5450       {
5451       arg = Ustrchr(name, '_');
5452       if (arg != NULL) *arg = 0;
5453       c = chop_match(name, op_table_main,
5454         sizeof(op_table_main)/sizeof(uschar *));
5455       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
5456       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
5457       }
5458
5459     /* If we are skipping, we don't need to perform the operation at all.
5460     This matters for operations like "mask", because the data may not be
5461     in the correct format when skipping. For example, the expression may test
5462     for the existence of $sender_host_address before trying to mask it. For
5463     other operations, doing them may not fail, but it is a waste of time. */
5464
5465     if (skipping && c >= 0) continue;
5466
5467     /* Otherwise, switch on the operator type */
5468
5469     switch(c)
5470       {
5471       case EOP_BASE62:
5472         {
5473         uschar *t;
5474         unsigned long int n = Ustrtoul(sub, &t, 10);
5475         if (*t != 0)
5476           {
5477           expand_string_message = string_sprintf("argument for base62 "
5478             "operator is \"%s\", which is not a decimal number", sub);
5479           goto EXPAND_FAILED;
5480           }
5481         t = string_base62(n);
5482         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5483         continue;
5484         }
5485
5486       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
5487
5488       case EOP_BASE62D:
5489         {
5490         uschar buf[16];
5491         uschar *tt = sub;
5492         unsigned long int n = 0;
5493         while (*tt != 0)
5494           {
5495           uschar *t = Ustrchr(base62_chars, *tt++);
5496           if (t == NULL)
5497             {
5498             expand_string_message = string_sprintf("argument for base62d "
5499               "operator is \"%s\", which is not a base %d number", sub,
5500               BASE_62);
5501             goto EXPAND_FAILED;
5502             }
5503           n = n * BASE_62 + (t - base62_chars);
5504           }
5505         (void)sprintf(CS buf, "%ld", n);
5506         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
5507         continue;
5508         }
5509
5510       case EOP_EXPAND:
5511         {
5512         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE);
5513         if (expanded == NULL)
5514           {
5515           expand_string_message =
5516             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
5517               expand_string_message);
5518           goto EXPAND_FAILED;
5519           }
5520         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
5521         continue;
5522         }
5523
5524       case EOP_LC:
5525         {
5526         int count = 0;
5527         uschar *t = sub - 1;
5528         while (*(++t) != 0) { *t = tolower(*t); count++; }
5529         yield = string_cat(yield, &size, &ptr, sub, count);
5530         continue;
5531         }
5532
5533       case EOP_UC:
5534         {
5535         int count = 0;
5536         uschar *t = sub - 1;
5537         while (*(++t) != 0) { *t = toupper(*t); count++; }
5538         yield = string_cat(yield, &size, &ptr, sub, count);
5539         continue;
5540         }
5541
5542       case EOP_MD5:
5543         {
5544         md5 base;
5545         uschar digest[16];
5546         int j;
5547         char st[33];
5548         md5_start(&base);
5549         md5_end(&base, sub, Ustrlen(sub), digest);
5550         for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
5551         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5552         continue;
5553         }
5554
5555       case EOP_SHA1:
5556         {
5557         sha1 base;
5558         uschar digest[20];
5559         int j;
5560         char st[41];
5561         sha1_start(&base);
5562         sha1_end(&base, sub, Ustrlen(sub), digest);
5563         for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
5564         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5565         continue;
5566         }
5567
5568       /* Convert hex encoding to base64 encoding */
5569
5570       case EOP_HEX2B64:
5571         {
5572         int c = 0;
5573         int b = -1;
5574         uschar *in = sub;
5575         uschar *out = sub;
5576         uschar *enc;
5577
5578         for (enc = sub; *enc != 0; enc++)
5579           {
5580           if (!isxdigit(*enc))
5581             {
5582             expand_string_message = string_sprintf("\"%s\" is not a hex "
5583               "string", sub);
5584             goto EXPAND_FAILED;
5585             }
5586           c++;
5587           }
5588
5589         if ((c & 1) != 0)
5590           {
5591           expand_string_message = string_sprintf("\"%s\" contains an odd "
5592             "number of characters", sub);
5593           goto EXPAND_FAILED;
5594           }
5595
5596         while ((c = *in++) != 0)
5597           {
5598           if (isdigit(c)) c -= '0';
5599           else c = toupper(c) - 'A' + 10;
5600           if (b == -1)
5601             {
5602             b = c << 4;
5603             }
5604           else
5605             {
5606             *out++ = b | c;
5607             b = -1;
5608             }
5609           }
5610
5611         enc = auth_b64encode(sub, out - sub);
5612         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
5613         continue;
5614         }
5615
5616       /* count the number of list elements */
5617
5618       case EOP_LISTCOUNT:
5619         {
5620         int cnt = 0;
5621         int sep = 0;
5622         uschar * cp;
5623         uschar buffer[256];
5624
5625         while (string_nextinlist(&sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
5626         cp = string_sprintf("%d", cnt);
5627         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5628         continue;
5629         }
5630
5631       /* expand a named list given the name */
5632       /* handles nested named lists; requotes as colon-sep list */
5633
5634       case EOP_LISTNAMED:
5635         {
5636         tree_node *t = NULL;
5637         uschar * list;
5638         int sep = 0;
5639         uschar * item;
5640         uschar * suffix = "";
5641         BOOL needsep = FALSE;
5642         uschar buffer[256];
5643
5644         if (*sub == '+') sub++;
5645         if (arg == NULL)        /* no-argument version */
5646           {
5647           if (!(t = tree_search(addresslist_anchor, sub)) &&
5648               !(t = tree_search(domainlist_anchor,  sub)) &&
5649               !(t = tree_search(hostlist_anchor,    sub)))
5650             t = tree_search(localpartlist_anchor, sub);
5651           }
5652         else switch(*arg)       /* specific list-type version */
5653           {
5654           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = "_a"; break;
5655           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = "_d"; break;
5656           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = "_h"; break;
5657           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = "_l"; break;
5658           default:
5659             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
5660             goto EXPAND_FAILED;
5661           }
5662
5663         if(!t)
5664           {
5665           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
5666             sub, !arg?""
5667               : *arg=='a'?"address "
5668               : *arg=='d'?"domain "
5669               : *arg=='h'?"host "
5670               : *arg=='l'?"localpart "
5671               : 0);
5672           goto EXPAND_FAILED;
5673           }
5674
5675         list = ((namedlist_block *)(t->data.ptr))->string;
5676
5677         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
5678           {
5679           uschar * buf = US" : ";
5680           if (needsep)
5681             yield = string_cat(yield, &size, &ptr, buf, 3);
5682           else
5683             needsep = TRUE;
5684
5685           if (*item == '+')     /* list item is itself a named list */
5686             {
5687             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
5688             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE);
5689             }
5690           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
5691             {
5692             char * cp;
5693             char tok[3];
5694             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
5695             while ((cp= strpbrk((const char *)item, tok)))
5696               {
5697               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
5698               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
5699                 {
5700                 yield = string_cat(yield, &size, &ptr, US"::", 2);
5701                 item = cp;
5702                 }
5703               else              /* sep in item; should already be doubled; emit once */
5704                 {
5705                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
5706                 if (*cp == sep) cp++;
5707                 item = cp;
5708                 }
5709               }
5710             }
5711           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
5712           }
5713         continue;
5714         }
5715
5716       /* mask applies a mask to an IP address; for example the result of
5717       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
5718
5719       case EOP_MASK:
5720         {
5721         int count;
5722         uschar *endptr;
5723         int binary[4];
5724         int mask, maskoffset;
5725         int type = string_is_ip_address(sub, &maskoffset);
5726         uschar buffer[64];
5727
5728         if (type == 0)
5729           {
5730           expand_string_message = string_sprintf("\"%s\" is not an IP address",
5731            sub);
5732           goto EXPAND_FAILED;
5733           }
5734
5735         if (maskoffset == 0)
5736           {
5737           expand_string_message = string_sprintf("missing mask value in \"%s\"",
5738             sub);
5739           goto EXPAND_FAILED;
5740           }
5741
5742         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
5743
5744         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
5745           {
5746           expand_string_message = string_sprintf("mask value too big in \"%s\"",
5747             sub);
5748           goto EXPAND_FAILED;
5749           }
5750
5751         /* Convert the address to binary integer(s) and apply the mask */
5752
5753         sub[maskoffset] = 0;
5754         count = host_aton(sub, binary);
5755         host_mask(count, binary, mask);
5756
5757         /* Convert to masked textual format and add to output. */
5758
5759         yield = string_cat(yield, &size, &ptr, buffer,
5760           host_nmtoa(count, binary, mask, buffer, '.'));
5761         continue;
5762         }
5763
5764       case EOP_ADDRESS:
5765       case EOP_LOCAL_PART:
5766       case EOP_DOMAIN:
5767         {
5768         uschar *error;
5769         int start, end, domain;
5770         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
5771           FALSE);
5772         if (t != NULL)
5773           {
5774           if (c != EOP_DOMAIN)
5775             {
5776             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
5777             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
5778             }
5779           else if (domain != 0)
5780             {
5781             domain += start;
5782             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
5783             }
5784           }
5785         continue;
5786         }
5787
5788       case EOP_ADDRESSES:
5789         {
5790         uschar outsep[2] = { ':', '\0' };
5791         uschar *address, *error;
5792         int save_ptr = ptr;
5793         int start, end, domain;  /* Not really used */
5794
5795         while (isspace(*sub)) sub++;
5796         if (*sub == '>') { *outsep = *++sub; ++sub; }
5797         parse_allow_group = TRUE;
5798
5799         for (;;)
5800           {
5801           uschar *p = parse_find_address_end(sub, FALSE);
5802           uschar saveend = *p;
5803           *p = '\0';
5804           address = parse_extract_address(sub, &error, &start, &end, &domain,
5805             FALSE);
5806           *p = saveend;
5807
5808           /* Add the address to the output list that we are building. This is
5809           done in chunks by searching for the separator character. At the
5810           start, unless we are dealing with the first address of the output
5811           list, add in a space if the new address begins with the separator
5812           character, or is an empty string. */
5813
5814           if (address != NULL)
5815             {
5816             if (ptr != save_ptr && address[0] == *outsep)
5817               yield = string_cat(yield, &size, &ptr, US" ", 1);
5818
5819             for (;;)
5820               {
5821               size_t seglen = Ustrcspn(address, outsep);
5822               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
5823
5824               /* If we got to the end of the string we output one character
5825               too many. */
5826
5827               if (address[seglen] == '\0') { ptr--; break; }
5828               yield = string_cat(yield, &size, &ptr, outsep, 1);
5829               address += seglen + 1;
5830               }
5831
5832             /* Output a separator after the string: we will remove the
5833             redundant final one at the end. */
5834
5835             yield = string_cat(yield, &size, &ptr, outsep, 1);
5836             }
5837
5838           if (saveend == '\0') break;
5839           sub = p + 1;
5840           }
5841
5842         /* If we have generated anything, remove the redundant final
5843         separator. */
5844
5845         if (ptr != save_ptr) ptr--;
5846         parse_allow_group = FALSE;
5847         continue;
5848         }
5849
5850
5851       /* quote puts a string in quotes if it is empty or contains anything
5852       other than alphamerics, underscore, dot, or hyphen.
5853
5854       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
5855       be quoted in order to be a valid local part.
5856
5857       In both cases, newlines and carriage returns are converted into \n and \r
5858       respectively */
5859
5860       case EOP_QUOTE:
5861       case EOP_QUOTE_LOCAL_PART:
5862       if (arg == NULL)
5863         {
5864         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
5865         uschar *t = sub - 1;
5866
5867         if (c == EOP_QUOTE)
5868           {
5869           while (!needs_quote && *(++t) != 0)
5870             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
5871           }
5872         else  /* EOP_QUOTE_LOCAL_PART */
5873           {
5874           while (!needs_quote && *(++t) != 0)
5875             needs_quote = !isalnum(*t) &&
5876               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
5877               (*t != '.' || t == sub || t[1] == 0);
5878           }
5879
5880         if (needs_quote)
5881           {
5882           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5883           t = sub - 1;
5884           while (*(++t) != 0)
5885             {
5886             if (*t == '\n')
5887               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
5888             else if (*t == '\r')
5889               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
5890             else
5891               {
5892               if (*t == '\\' || *t == '"')
5893                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
5894               yield = string_cat(yield, &size, &ptr, t, 1);
5895               }
5896             }
5897           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5898           }
5899         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5900         continue;
5901         }
5902
5903       /* quote_lookuptype does lookup-specific quoting */
5904
5905       else
5906         {
5907         int n;
5908         uschar *opt = Ustrchr(arg, '_');
5909
5910         if (opt != NULL) *opt++ = 0;
5911
5912         n = search_findtype(arg, Ustrlen(arg));
5913         if (n < 0)
5914           {
5915           expand_string_message = search_error_message;
5916           goto EXPAND_FAILED;
5917           }
5918
5919         if (lookup_list[n]->quote != NULL)
5920           sub = (lookup_list[n]->quote)(sub, opt);
5921         else if (opt != NULL) sub = NULL;
5922
5923         if (sub == NULL)
5924           {
5925           expand_string_message = string_sprintf(
5926             "\"%s\" unrecognized after \"${quote_%s\"",
5927             opt, arg);
5928           goto EXPAND_FAILED;
5929           }
5930
5931         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5932         continue;
5933         }
5934
5935       /* rx quote sticks in \ before any non-alphameric character so that
5936       the insertion works in a regular expression. */
5937
5938       case EOP_RXQUOTE:
5939         {
5940         uschar *t = sub - 1;
5941         while (*(++t) != 0)
5942           {
5943           if (!isalnum(*t))
5944             yield = string_cat(yield, &size, &ptr, US"\\", 1);
5945           yield = string_cat(yield, &size, &ptr, t, 1);
5946           }
5947         continue;
5948         }
5949
5950       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
5951       prescribed by the RFC, if there are characters that need to be encoded */
5952
5953       case EOP_RFC2047:
5954         {
5955         uschar buffer[2048];
5956         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
5957           buffer, sizeof(buffer), FALSE);
5958         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
5959         continue;
5960         }
5961
5962       /* RFC 2047 decode */
5963
5964       case EOP_RFC2047D:
5965         {
5966         int len;
5967         uschar *error;
5968         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
5969           headers_charset, '?', &len, &error);
5970         if (error != NULL)
5971           {
5972           expand_string_message = error;
5973           goto EXPAND_FAILED;
5974           }
5975         yield = string_cat(yield, &size, &ptr, decoded, len);
5976         continue;
5977         }
5978
5979       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
5980       underscores */
5981
5982       case EOP_FROM_UTF8:
5983         {
5984         while (*sub != 0)
5985           {
5986           int c;
5987           uschar buff[4];
5988           GETUTF8INC(c, sub);
5989           if (c > 255) c = '_';
5990           buff[0] = c;
5991           yield = string_cat(yield, &size, &ptr, buff, 1);
5992           }
5993         continue;
5994         }
5995
5996       /* escape turns all non-printing characters into escape sequences. */
5997
5998       case EOP_ESCAPE:
5999         {
6000         uschar *t = string_printing(sub);
6001         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6002         continue;
6003         }
6004
6005       /* Handle numeric expression evaluation */
6006
6007       case EOP_EVAL:
6008       case EOP_EVAL10:
6009         {
6010         uschar *save_sub = sub;
6011         uschar *error = NULL;
6012         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6013         if (error != NULL)
6014           {
6015           expand_string_message = string_sprintf("error in expression "
6016             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6017               save_sub);
6018           goto EXPAND_FAILED;
6019           }
6020         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6021         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6022         continue;
6023         }
6024
6025       /* Handle time period formating */
6026
6027       case EOP_TIME_EVAL:
6028         {
6029         int n = readconf_readtime(sub, 0, FALSE);
6030         if (n < 0)
6031           {
6032           expand_string_message = string_sprintf("string \"%s\" is not an "
6033             "Exim time interval in \"%s\" operator", sub, name);
6034           goto EXPAND_FAILED;
6035           }
6036         sprintf(CS var_buffer, "%d", n);
6037         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6038         continue;
6039         }
6040
6041       case EOP_TIME_INTERVAL:
6042         {
6043         int n;
6044         uschar *t = read_number(&n, sub);
6045         if (*t != 0) /* Not A Number*/
6046           {
6047           expand_string_message = string_sprintf("string \"%s\" is not a "
6048             "positive number in \"%s\" operator", sub, name);
6049           goto EXPAND_FAILED;
6050           }
6051         t = readconf_printtime(n);
6052         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6053         continue;
6054         }
6055
6056       /* Convert string to base64 encoding */
6057
6058       case EOP_STR2B64:
6059         {
6060         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
6061         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
6062         continue;
6063         }
6064
6065       /* strlen returns the length of the string */
6066
6067       case EOP_STRLEN:
6068         {
6069         uschar buff[24];
6070         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6071         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6072         continue;
6073         }
6074
6075       /* length_n or l_n takes just the first n characters or the whole string,
6076       whichever is the shorter;
6077
6078       substr_m_n, and s_m_n take n characters from offset m; negative m take
6079       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6080       takes the rest, either to the right or to the left.
6081
6082       hash_n or h_n makes a hash of length n from the string, yielding n
6083       characters from the set a-z; hash_n_m makes a hash of length n, but
6084       uses m characters from the set a-zA-Z0-9.
6085
6086       nhash_n returns a single number between 0 and n-1 (in text form), while
6087       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6088       between 0 and n-1 and the second between 0 and m-1. */
6089
6090       case EOP_LENGTH:
6091       case EOP_L:
6092       case EOP_SUBSTR:
6093       case EOP_S:
6094       case EOP_HASH:
6095       case EOP_H:
6096       case EOP_NHASH:
6097       case EOP_NH:
6098         {
6099         int sign = 1;
6100         int value1 = 0;
6101         int value2 = -1;
6102         int *pn;
6103         int len;
6104         uschar *ret;
6105
6106         if (arg == NULL)
6107           {
6108           expand_string_message = string_sprintf("missing values after %s",
6109             name);
6110           goto EXPAND_FAILED;
6111           }
6112
6113         /* "length" has only one argument, effectively being synonymous with
6114         substr_0_n. */
6115
6116         if (c == EOP_LENGTH || c == EOP_L)
6117           {
6118           pn = &value2;
6119           value2 = 0;
6120           }
6121
6122         /* The others have one or two arguments; for "substr" the first may be
6123         negative. The second being negative means "not supplied". */
6124
6125         else
6126           {
6127           pn = &value1;
6128           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6129           }
6130
6131         /* Read up to two numbers, separated by underscores */
6132
6133         ret = arg;
6134         while (*arg != 0)
6135           {
6136           if (arg != ret && *arg == '_' && pn == &value1)
6137             {
6138             pn = &value2;
6139             value2 = 0;
6140             if (arg[1] != 0) arg++;
6141             }
6142           else if (!isdigit(*arg))
6143             {
6144             expand_string_message =
6145               string_sprintf("non-digit after underscore in \"%s\"", name);
6146             goto EXPAND_FAILED;
6147             }
6148           else *pn = (*pn)*10 + *arg++ - '0';
6149           }
6150         value1 *= sign;
6151
6152         /* Perform the required operation */
6153
6154         ret =
6155           (c == EOP_HASH || c == EOP_H)?
6156              compute_hash(sub, value1, value2, &len) :
6157           (c == EOP_NHASH || c == EOP_NH)?
6158              compute_nhash(sub, value1, value2, &len) :
6159              extract_substr(sub, value1, value2, &len);
6160
6161         if (ret == NULL) goto EXPAND_FAILED;
6162         yield = string_cat(yield, &size, &ptr, ret, len);
6163         continue;
6164         }
6165
6166       /* Stat a path */
6167
6168       case EOP_STAT:
6169         {
6170         uschar *s;
6171         uschar smode[12];
6172         uschar **modetable[3];
6173         int i;
6174         mode_t mode;
6175         struct stat st;
6176
6177         if ((expand_forbid & RDO_EXISTS) != 0)
6178           {
6179           expand_string_message = US"Use of the stat() expansion is not permitted";
6180           goto EXPAND_FAILED;
6181           }
6182
6183         if (stat(CS sub, &st) < 0)
6184           {
6185           expand_string_message = string_sprintf("stat(%s) failed: %s",
6186             sub, strerror(errno));
6187           goto EXPAND_FAILED;
6188           }
6189         mode = st.st_mode;
6190         switch (mode & S_IFMT)
6191           {
6192           case S_IFIFO: smode[0] = 'p'; break;
6193           case S_IFCHR: smode[0] = 'c'; break;
6194           case S_IFDIR: smode[0] = 'd'; break;
6195           case S_IFBLK: smode[0] = 'b'; break;
6196           case S_IFREG: smode[0] = '-'; break;
6197           default: smode[0] = '?'; break;
6198           }
6199
6200         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
6201         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
6202         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
6203
6204         for (i = 0; i < 3; i++)
6205           {
6206           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
6207           mode >>= 3;
6208           }
6209
6210         smode[10] = 0;
6211         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
6212           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
6213           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
6214           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
6215           (long)st.st_gid, st.st_size, (long)st.st_atime,
6216           (long)st.st_mtime, (long)st.st_ctime);
6217         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6218         continue;
6219         }
6220
6221       /* vaguely random number less than N */
6222
6223       case EOP_RANDINT:
6224         {
6225         int_eximarith_t max;
6226         uschar *s;
6227
6228         max = expand_string_integer(sub, TRUE);
6229         if (expand_string_message != NULL)
6230           goto EXPAND_FAILED;
6231         s = string_sprintf("%d", vaguely_random_number((int)max));
6232         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6233         continue;
6234         }
6235
6236       /* Reverse IP, including IPv6 to dotted-nibble */
6237
6238       case EOP_REVERSE_IP:
6239         {
6240         int family, maskptr;
6241         uschar reversed[128];
6242
6243         family = string_is_ip_address(sub, &maskptr);
6244         if (family == 0)
6245           {
6246           expand_string_message = string_sprintf(
6247               "reverse_ip() not given an IP address [%s]", sub);
6248           goto EXPAND_FAILED;
6249           }
6250         invert_address(reversed, sub);
6251         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
6252         continue;
6253         }
6254
6255       /* Unknown operator */
6256
6257       default:
6258       expand_string_message =
6259         string_sprintf("unknown expansion operator \"%s\"", name);
6260       goto EXPAND_FAILED;
6261       }
6262     }
6263
6264   /* Handle a plain name. If this is the first thing in the expansion, release
6265   the pre-allocated buffer. If the result data is known to be in a new buffer,
6266   newsize will be set to the size of that buffer, and we can just point at that
6267   store instead of copying. Many expansion strings contain just one reference,
6268   so this is a useful optimization, especially for humungous headers
6269   ($message_headers). */
6270
6271   if (*s++ == '}')
6272     {
6273     int len;
6274     int newsize = 0;
6275     if (ptr == 0)
6276       {
6277       if (resetok) store_reset(yield);
6278       yield = NULL;
6279       size = 0;
6280       }
6281     value = find_variable(name, FALSE, skipping, &newsize);
6282     if (value == NULL)
6283       {
6284       expand_string_message =
6285         string_sprintf("unknown variable in \"${%s}\"", name);
6286       check_variable_error_message(name);
6287       goto EXPAND_FAILED;
6288       }
6289     len = Ustrlen(value);
6290     if (yield == NULL && newsize != 0)
6291       {
6292       yield = value;
6293       size = newsize;
6294       ptr = len;
6295       }
6296     else yield = string_cat(yield, &size, &ptr, value, len);
6297     continue;
6298     }
6299
6300   /* Else there's something wrong */
6301
6302   expand_string_message =
6303     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
6304     "in a variable reference)", name);
6305   goto EXPAND_FAILED;
6306   }
6307
6308 /* If we hit the end of the string when ket_ends is set, there is a missing
6309 terminating brace. */
6310
6311 if (ket_ends && *s == 0)
6312   {
6313   expand_string_message = malformed_header?
6314     US"missing } at end of string - could be header name not terminated by colon"
6315     :
6316     US"missing } at end of string";
6317   goto EXPAND_FAILED;
6318   }
6319
6320 /* Expansion succeeded; yield may still be NULL here if nothing was actually
6321 added to the string. If so, set up an empty string. Add a terminating zero. If
6322 left != NULL, return a pointer to the terminator. */
6323
6324 if (yield == NULL) yield = store_get(1);
6325 yield[ptr] = 0;
6326 if (left != NULL) *left = s;
6327
6328 /* Any stacking store that was used above the final string is no longer needed.
6329 In many cases the final string will be the first one that was got and so there
6330 will be optimal store usage. */
6331
6332 if (resetok) store_reset(yield + ptr + 1);
6333 DEBUG(D_expand)
6334   {
6335   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
6336     yield);
6337   if (skipping) debug_printf("skipping: result is not used\n");
6338   }
6339 return yield;
6340
6341 /* This is the failure exit: easiest to program with a goto. We still need
6342 to update the pointer to the terminator, for cases of nested calls with "fail".
6343 */
6344
6345 EXPAND_FAILED_CURLY:
6346 expand_string_message = malformed_header?
6347   US"missing or misplaced { or } - could be header name not terminated by colon"
6348   :
6349   US"missing or misplaced { or }";
6350
6351 /* At one point, Exim reset the store to yield (if yield was not NULL), but
6352 that is a bad idea, because expand_string_message is in dynamic store. */
6353
6354 EXPAND_FAILED:
6355 if (left != NULL) *left = s;
6356 DEBUG(D_expand)
6357   {
6358   debug_printf("failed to expand: %s\n", string);
6359   debug_printf("   error message: %s\n", expand_string_message);
6360   if (expand_string_forcedfail) debug_printf("failure was forced\n");
6361   }
6362 return NULL;
6363 }
6364
6365
6366 /* This is the external function call. Do a quick check for any expansion
6367 metacharacters, and if there are none, just return the input string.
6368
6369 Argument: the string to be expanded
6370 Returns:  the expanded string, or NULL if expansion failed; if failure was
6371           due to a lookup deferring, search_find_defer will be TRUE
6372 */
6373
6374 uschar *
6375 expand_string(uschar *string)
6376 {
6377 search_find_defer = FALSE;
6378 malformed_header = FALSE;
6379 return (Ustrpbrk(string, "$\\") == NULL)? string :
6380   expand_string_internal(string, FALSE, NULL, FALSE, TRUE);
6381 }
6382
6383
6384
6385 /*************************************************
6386 *              Expand and copy                   *
6387 *************************************************/
6388
6389 /* Now and again we want to expand a string and be sure that the result is in a
6390 new bit of store. This function does that.
6391
6392 Argument: the string to be expanded
6393 Returns:  the expanded string, always in a new bit of store, or NULL
6394 */
6395
6396 uschar *
6397 expand_string_copy(uschar *string)
6398 {
6399 uschar *yield = expand_string(string);
6400 if (yield == string) yield = string_copy(string);
6401 return yield;
6402 }
6403
6404
6405
6406 /*************************************************
6407 *        Expand and interpret as an integer      *
6408 *************************************************/
6409
6410 /* Expand a string, and convert the result into an integer.
6411
6412 Arguments:
6413   string  the string to be expanded
6414   isplus  TRUE if a non-negative number is expected
6415
6416 Returns:  the integer value, or
6417           -1 for an expansion error               ) in both cases, message in
6418           -2 for an integer interpretation error  ) expand_string_message
6419           expand_string_message is set NULL for an OK integer
6420 */
6421
6422 int_eximarith_t
6423 expand_string_integer(uschar *string, BOOL isplus)
6424 {
6425 int_eximarith_t value;
6426 uschar *s = expand_string(string);
6427 uschar *msg = US"invalid integer \"%s\"";
6428 uschar *endptr;
6429
6430 /* If expansion failed, expand_string_message will be set. */
6431
6432 if (s == NULL) return -1;
6433
6434 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
6435 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
6436 systems, so we set it zero ourselves. */
6437
6438 errno = 0;
6439 expand_string_message = NULL;               /* Indicates no error */
6440
6441 /* Before Exim 4.64, strings consisting entirely of whitespace compared
6442 equal to 0.  Unfortunately, people actually relied upon that, so preserve
6443 the behaviour explicitly.  Stripping leading whitespace is a harmless
6444 noop change since strtol skips it anyway (provided that there is a number
6445 to find at all). */
6446 if (isspace(*s))
6447   {
6448   while (isspace(*s)) ++s;
6449   if (*s == '\0')
6450     {
6451       DEBUG(D_expand)
6452        debug_printf("treating blank string as number 0\n");
6453       return 0;
6454     }
6455   }
6456
6457 value = strtoll(CS s, CSS &endptr, 10);
6458
6459 if (endptr == s)
6460   {
6461   msg = US"integer expected but \"%s\" found";
6462   }
6463 else if (value < 0 && isplus)
6464   {
6465   msg = US"non-negative integer expected but \"%s\" found";
6466   }
6467 else
6468   {
6469   switch (tolower(*endptr))
6470     {
6471     default:
6472       break;
6473     case 'k':
6474       if (value > LLONG_MAX/1024 || value < LLONG_MIN/1024) errno = ERANGE;
6475       else value *= 1024;
6476       endptr++;
6477       break;
6478     case 'm':
6479       if (value > LLONG_MAX/(1024*1024) || value < LLONG_MIN/(1024*1024)) errno = ERANGE;
6480       else value *= 1024*1024;
6481       endptr++;
6482       break;
6483     case 'g':
6484       if (value > LLONG_MAX/(1024*1024*1024) || value < LLONG_MIN/(1024*1024*1024)) errno = ERANGE;
6485       else value *= 1024*1024*1024;
6486       endptr++;
6487       break;
6488     }
6489   if (errno == ERANGE)
6490     msg = US"absolute value of integer \"%s\" is too large (overflow)";
6491   else
6492     {
6493     while (isspace(*endptr)) endptr++;
6494     if (*endptr == 0) return (int)value;
6495     }
6496   }
6497
6498 expand_string_message = string_sprintf(CS msg, s);
6499 return -2;
6500 }
6501
6502
6503 /*************************************************
6504 **************************************************
6505 *             Stand-alone test program           *
6506 **************************************************
6507 *************************************************/
6508
6509 #ifdef STAND_ALONE
6510
6511
6512 BOOL
6513 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
6514 {
6515 int ovector[3*(EXPAND_MAXN+1)];
6516 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
6517   ovector, sizeof(ovector)/sizeof(int));
6518 BOOL yield = n >= 0;
6519 if (n == 0) n = EXPAND_MAXN + 1;
6520 if (yield)
6521   {
6522   int nn;
6523   expand_nmax = (setup < 0)? 0 : setup + 1;
6524   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
6525     {
6526     expand_nstring[expand_nmax] = subject + ovector[nn];
6527     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
6528     }
6529   expand_nmax--;
6530   }
6531 return yield;
6532 }
6533
6534
6535 int main(int argc, uschar **argv)
6536 {
6537 int i;
6538 uschar buffer[1024];
6539
6540 debug_selector = D_v;
6541 debug_file = stderr;
6542 debug_fd = fileno(debug_file);
6543 big_buffer = malloc(big_buffer_size);
6544
6545 for (i = 1; i < argc; i++)
6546   {
6547   if (argv[i][0] == '+')
6548     {
6549     debug_trace_memory = 2;
6550     argv[i]++;
6551     }
6552   if (isdigit(argv[i][0]))
6553     debug_selector = Ustrtol(argv[i], NULL, 0);
6554   else
6555     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
6556         Ustrlen(argv[i]))
6557       {
6558       #ifdef LOOKUP_LDAP
6559       eldap_default_servers = argv[i];
6560       #endif
6561       #ifdef LOOKUP_MYSQL
6562       mysql_servers = argv[i];
6563       #endif
6564       #ifdef LOOKUP_PGSQL
6565       pgsql_servers = argv[i];
6566       #endif
6567       }
6568   #ifdef EXIM_PERL
6569   else opt_perl_startup = argv[i];
6570   #endif
6571   }
6572
6573 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
6574
6575 expand_nstring[1] = US"string 1....";
6576 expand_nlength[1] = 8;
6577 expand_nmax = 1;
6578
6579 #ifdef EXIM_PERL
6580 if (opt_perl_startup != NULL)
6581   {
6582   uschar *errstr;
6583   printf("Starting Perl interpreter\n");
6584   errstr = init_perl(opt_perl_startup);
6585   if (errstr != NULL)
6586     {
6587     printf("** error in perl_startup code: %s\n", errstr);
6588     return EXIT_FAILURE;
6589     }
6590   }
6591 #endif /* EXIM_PERL */
6592
6593 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
6594   {
6595   void *reset_point = store_get(0);
6596   uschar *yield = expand_string(buffer);
6597   if (yield != NULL)
6598     {
6599     printf("%s\n", yield);
6600     store_reset(reset_point);
6601     }
6602   else
6603     {
6604     if (search_find_defer) printf("search_find deferred\n");
6605     printf("Failed: %s\n", expand_string_message);
6606     if (expand_string_forcedfail) printf("Forced failure\n");
6607     printf("\n");
6608     }
6609   }
6610
6611 search_tidyup();
6612
6613 return 0;
6614 }
6615
6616 #endif
6617
6618 /* End of expand.c */