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_string_func,    /* value is string returned by given function */
 371   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 372   vtype_tode,           /* value not used; generate tod in epoch format */
 373   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 374   vtype_todf,           /* value not used; generate full tod */
 375   vtype_todl,           /* value not used; generate log tod */
 376   vtype_todlf,          /* value not used; generate log file datestamp tod */
 377   vtype_todzone,        /* value not used; generate time zone only */
 378   vtype_todzulu,        /* value not used; generate zulu tod */
 379   vtype_reply,          /* value not used; get reply from headers */
 380   vtype_pid,            /* value not used; result is pid */
 381   vtype_host_lookup,    /* value not used; get host name */
 382   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 383   vtype_pspace,         /* partition space; value is T/F for spool/log */
 384   vtype_pinodes         /* partition inodes; value is T/F for spool/log */
 385   #ifndef DISABLE_DKIM
 386   ,vtype_dkim           /* Lookup of value in DKIM signature */
 387   #endif
 388   };
 389
 390 static uschar * fn_recipients(void);
 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   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 475   { "home",                vtype_stringptr,   &deliver_home },
 476   { "host",                vtype_stringptr,   &deliver_host },
 477   { "host_address",        vtype_stringptr,   &deliver_host_address },
 478   { "host_data",           vtype_stringptr,   &host_data },
 479   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 480   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 481   { "inode",               vtype_ino,         &deliver_inode },
 482   { "interface_address",   vtype_stringptr,   &interface_address },
 483   { "interface_port",      vtype_int,         &interface_port },
 484   { "item",                vtype_stringptr,   &iterate_item },
 485   #ifdef LOOKUP_LDAP
 486   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 487   #endif
 488   { "load_average",        vtype_load_avg,    NULL },
 489   { "local_part",          vtype_stringptr,   &deliver_localpart },
 490   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 491   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 492   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 493   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 494   { "local_user_gid",      vtype_gid,         &local_user_gid },
 495   { "local_user_uid",      vtype_uid,         &local_user_uid },
 496   { "localhost_number",    vtype_int,         &host_number },
 497   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 498   { "log_space",           vtype_pspace,      (void *)FALSE },
 499   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 500 #ifdef WITH_CONTENT_SCAN
 501   { "malware_name",        vtype_stringptr,   &malware_name },
 502 #endif
 503   { "max_received_linelength", vtype_int,     &max_received_linelength },
 504   { "message_age",         vtype_int,         &message_age },
 505   { "message_body",        vtype_msgbody,     &message_body },
 506   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 507   { "message_body_size",   vtype_int,         &message_body_size },
 508   { "message_exim_id",     vtype_stringptr,   &message_id },
 509   { "message_headers",     vtype_msgheaders,  NULL },
 510   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 511   { "message_id",          vtype_stringptr,   &message_id },
 512   { "message_linecount",   vtype_int,         &message_linecount },
 513   { "message_size",        vtype_int,         &message_size },
 514 #ifdef WITH_CONTENT_SCAN
 515   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 516   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 517   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 518   { "mime_charset",        vtype_stringptr,   &mime_charset },
 519   { "mime_content_description", vtype_stringptr, &mime_content_description },
 520   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 521   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 522   { "mime_content_size",   vtype_int,         &mime_content_size },
 523   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 524   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 525   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 526   { "mime_filename",       vtype_stringptr,   &mime_filename },
 527   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 528   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 529   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 530   { "mime_part_count",     vtype_int,         &mime_part_count },
 531 #endif
 532   { "n0",                  vtype_filter_int,  &filter_n[0] },
 533   { "n1",                  vtype_filter_int,  &filter_n[1] },
 534   { "n2",                  vtype_filter_int,  &filter_n[2] },
 535   { "n3",                  vtype_filter_int,  &filter_n[3] },
 536   { "n4",                  vtype_filter_int,  &filter_n[4] },
 537   { "n5",                  vtype_filter_int,  &filter_n[5] },
 538   { "n6",                  vtype_filter_int,  &filter_n[6] },
 539   { "n7",                  vtype_filter_int,  &filter_n[7] },
 540   { "n8",                  vtype_filter_int,  &filter_n[8] },
 541   { "n9",                  vtype_filter_int,  &filter_n[9] },
 542   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 543   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 544   { "originator_gid",      vtype_gid,         &originator_gid },
 545   { "originator_uid",      vtype_uid,         &originator_uid },
 546   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 547   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 548   { "pid",                 vtype_pid,         NULL },
 549   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 550   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 551   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 552   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 553   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 554   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 555   { "rcpt_count",          vtype_int,         &rcpt_count },
 556   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 557   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 558   { "received_count",      vtype_int,         &received_count },
 559   { "received_for",        vtype_stringptr,   &received_for },
 560   { "received_ip_address", vtype_stringptr,   &interface_address },
 561   { "received_port",       vtype_int,         &interface_port },
 562   { "received_protocol",   vtype_stringptr,   &received_protocol },
 563   { "received_time",       vtype_int,         &received_time },
 564   { "recipient_data",      vtype_stringptr,   &recipient_data },
 565   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 566   { "recipients",          vtype_string_func, &fn_recipients },
 567   { "recipients_count",    vtype_int,         &recipients_count },
 568 #ifdef WITH_CONTENT_SCAN
 569   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 570 #endif
 571   { "reply_address",       vtype_reply,       NULL },
 572   { "return_path",         vtype_stringptr,   &return_path },
 573   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 574   { "runrc",               vtype_int,         &runrc },
 575   { "self_hostname",       vtype_stringptr,   &self_hostname },
 576   { "sender_address",      vtype_stringptr,   &sender_address },
 577   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 578   { "sender_address_domain", vtype_domain,    &sender_address },
 579   { "sender_address_local_part", vtype_localpart, &sender_address },
 580   { "sender_data",         vtype_stringptr,   &sender_data },
 581   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 582   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 583   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 584   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 585   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 586   { "sender_host_name",    vtype_host_lookup, NULL },
 587   { "sender_host_port",    vtype_int,         &sender_host_port },
 588   { "sender_ident",        vtype_stringptr,   &sender_ident },
 589   { "sender_rate",         vtype_stringptr,   &sender_rate },
 590   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 591   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 592   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 593   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 594   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 595   { "sending_port",        vtype_int,         &sending_port },
 596   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 597   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 598   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 599   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 600   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 601   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 602   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 603   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 604   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 605   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 606   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 607   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 608   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 609   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 610   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 611 #ifdef WITH_CONTENT_SCAN
 612   { "spam_bar",            vtype_stringptr,   &spam_bar },
 613   { "spam_report",         vtype_stringptr,   &spam_report },
 614   { "spam_score",          vtype_stringptr,   &spam_score },
 615   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 616 #endif
 617 #ifdef EXPERIMENTAL_SPF
 618   { "spf_guess",           vtype_stringptr,   &spf_guess },
 619   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 620   { "spf_received",        vtype_stringptr,   &spf_received },
 621   { "spf_result",          vtype_stringptr,   &spf_result },
 622   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 623 #endif
 624   { "spool_directory",     vtype_stringptr,   &spool_directory },
 625   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 626   { "spool_space",         vtype_pspace,      (void *)TRUE },
 627 #ifdef EXPERIMENTAL_SRS
 628   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 629   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 630   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 631   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 632   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 633   { "srs_status",          vtype_stringptr,   &srs_status },
 634 #endif
 635   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 636
 637   /* The non-(in,out) variables are now deprecated */
 638   { "tls_bits",            vtype_int,         &tls_in.bits },
 639   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 640   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 641
 642   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 643   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 644   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 645   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 646 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 647   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 648 #endif
 649   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 650   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 651   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 652   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 653 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 654   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 655 #endif
 656
 657   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 658 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
 659   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 660 #endif
 661
 662   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 663   { "tod_epoch",           vtype_tode,        NULL },
 664   { "tod_epoch_l",         vtype_todel,       NULL },
 665   { "tod_full",            vtype_todf,        NULL },
 666   { "tod_log",             vtype_todl,        NULL },
 667   { "tod_logfile",         vtype_todlf,       NULL },
 668   { "tod_zone",            vtype_todzone,     NULL },
 669   { "tod_zulu",            vtype_todzulu,     NULL },
 670   { "value",               vtype_stringptr,   &lookup_value },
 671   { "version_number",      vtype_stringptr,   &version_string },
 672   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 673   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 674   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 675   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 676   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 677   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 678 };
 679
 680 static int var_table_size = sizeof(var_table)/sizeof(var_entry);
 681 static uschar var_buffer[256];
 682 static BOOL malformed_header;
 683
 684 /* For textual hashes */
 685
 686 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 687                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 688                                "0123456789";
 689
 690 enum { HMAC_MD5, HMAC_SHA1 };
 691
 692 /* For numeric hashes */
 693
 694 static unsigned int prime[] = {
 695   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 696  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 697  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 698
 699 /* For printing modes in symbolic form */
 700
 701 static uschar *mtable_normal[] =
 702   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 703
 704 static uschar *mtable_setid[] =
 705   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 706
 707 static uschar *mtable_sticky[] =
 708   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 709
 710
 711
 712 /*************************************************
 713 *           Tables for UTF-8 support             *
 714 *************************************************/
 715
 716 /* Table of the number of extra characters, indexed by the first character
 717 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 718 0x3d. */
 719
 720 static uschar utf8_table1[] = {
 721   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 722   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 723   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 724   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 725
 726 /* These are the masks for the data bits in the first byte of a character,
 727 indexed by the number of additional bytes. */
 728
 729 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 730
 731 /* Get the next UTF-8 character, advancing the pointer. */
 732
 733 #define GETUTF8INC(c, ptr) \
 734   c = *ptr++; \
 735   if ((c & 0xc0) == 0xc0) \
 736     { \
 737     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 738     int s = 6*a; \
 739     c = (c & utf8_table2[a]) << s; \
 740     while (a-- > 0) \
 741       { \
 742       s -= 6; \
 743       c |= (*ptr++ & 0x3f) << s; \
 744       } \
 745     }
 746
 747
 748 /*************************************************
 749 *           Binary chop search on a table        *
 750 *************************************************/
 751
 752 /* This is used for matching expansion items and operators.
 753
 754 Arguments:
 755   name        the name that is being sought
 756   table       the table to search
 757   table_size  the number of items in the table
 758
 759 Returns:      the offset in the table, or -1
 760 */
 761
 762 static int
 763 chop_match(uschar *name, uschar **table, int table_size)
 764 {
 765 uschar **bot = table;
 766 uschar **top = table + table_size;
 767
 768 while (top > bot)
 769   {
 770   uschar **mid = bot + (top - bot)/2;
 771   int c = Ustrcmp(name, *mid);
 772   if (c == 0) return mid - table;
 773   if (c > 0) bot = mid + 1; else top = mid;
 774   }
 775
 776 return -1;
 777 }
 778
 779
 780
 781 /*************************************************
 782 *          Check a condition string              *
 783 *************************************************/
 784
 785 /* This function is called to expand a string, and test the result for a "true"
 786 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 787 forced fail or lookup defer. All store used by the function can be released on
 788 exit.
 789
 790 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 791
 792 Arguments:
 793   condition     the condition string
 794   m1            text to be incorporated in panic error
 795   m2            ditto
 796
 797 Returns:        TRUE if condition is met, FALSE if not
 798 */
 799
 800 BOOL
 801 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 802 {
 803 int rc;
 804 void *reset_point = store_get(0);
 805 uschar *ss = expand_string(condition);
 806 if (ss == NULL)
 807   {
 808   if (!expand_string_forcedfail && !search_find_defer)
 809     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 810       "for %s %s: %s", condition, m1, m2, expand_string_message);
 811   return FALSE;
 812   }
 813 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 814   strcmpic(ss, US"false") != 0;
 815 store_reset(reset_point);
 816 return rc;
 817 }
 818
 819
 820
 821
 822 /*************************************************
 823 *        Pseudo-random number generation         *
 824 *************************************************/
 825
 826 /* Pseudo-random number generation.  The result is not "expected" to be
 827 cryptographically strong but not so weak that someone will shoot themselves
 828 in the foot using it as a nonce in some email header scheme or whatever
 829 weirdness they'll twist this into.  The result should ideally handle fork().
 830
 831 However, if we're stuck unable to provide this, then we'll fall back to
 832 appallingly bad randomness.
 833
 834 If SUPPORT_TLS is defined then this will not be used except as an emergency
 835 fallback.
 836
 837 Arguments:
 838   max       range maximum
 839 Returns     a random number in range [0, max-1]
 840 */
 841
 842 #ifdef SUPPORT_TLS
 843 # define vaguely_random_number vaguely_random_number_fallback
 844 #endif
 845 int
 846 vaguely_random_number(int max)
 847 {
 848 #ifdef SUPPORT_TLS
 849 # undef vaguely_random_number
 850 #endif
 851   static pid_t pid = 0;
 852   pid_t p2;
 853 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 854   struct timeval tv;
 855 #endif
 856
 857   p2 = getpid();
 858   if (p2 != pid)
 859     {
 860     if (pid != 0)
 861       {
 862
 863 #ifdef HAVE_ARC4RANDOM
 864       /* cryptographically strong randomness, common on *BSD platforms, not
 865       so much elsewhere.  Alas. */
 866       arc4random_stir();
 867 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 868 #ifdef HAVE_SRANDOMDEV
 869       /* uses random(4) for seeding */
 870       srandomdev();
 871 #else
 872       gettimeofday(&tv, NULL);
 873       srandom(tv.tv_sec | tv.tv_usec | getpid());
 874 #endif
 875 #else
 876       /* Poor randomness and no seeding here */
 877 #endif
 878
 879       }
 880     pid = p2;
 881     }
 882
 883 #ifdef HAVE_ARC4RANDOM
 884   return arc4random() % max;
 885 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 886   return random() % max;
 887 #else
 888   /* This one returns a 16-bit number, definitely not crypto-strong */
 889   return random_number(max);
 890 #endif
 891 }
 892
 893
 894
 895
 896 /*************************************************
 897 *             Pick out a name from a string      *
 898 *************************************************/
 899
 900 /* If the name is too long, it is silently truncated.
 901
 902 Arguments:
 903   name      points to a buffer into which to put the name
 904   max       is the length of the buffer
 905   s         points to the first alphabetic character of the name
 906   extras    chars other than alphanumerics to permit
 907
 908 Returns:    pointer to the first character after the name
 909
 910 Note: The test for *s != 0 in the while loop is necessary because
 911 Ustrchr() yields non-NULL if the character is zero (which is not something
 912 I expected). */
 913
 914 static uschar *
 915 read_name(uschar *name, int max, uschar *s, uschar *extras)
 916 {
 917 int ptr = 0;
 918 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 919   {
 920   if (ptr < max-1) name[ptr++] = *s;
 921   s++;
 922   }
 923 name[ptr] = 0;
 924 return s;
 925 }
 926
 927
 928
 929 /*************************************************
 930 *     Pick out the rest of a header name         *
 931 *************************************************/
 932
 933 /* A variable name starting $header_ (or just $h_ for those who like
 934 abbreviations) might not be the complete header name because headers can
 935 contain any printing characters in their names, except ':'. This function is
 936 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 937 on the end, if the name was terminated by white space.
 938
 939 Arguments:
 940   name      points to a buffer in which the name read so far exists
 941   max       is the length of the buffer
 942   s         points to the first character after the name so far, i.e. the
 943             first non-alphameric character after $header_xxxxx
 944
 945 Returns:    a pointer to the first character after the header name
 946 */
 947
 948 static uschar *
 949 read_header_name(uschar *name, int max, uschar *s)
 950 {
 951 int prelen = Ustrchr(name, '_') - name + 1;
 952 int ptr = Ustrlen(name) - prelen;
 953 if (ptr > 0) memmove(name, name+prelen, ptr);
 954 while (mac_isgraph(*s) && *s != ':')
 955   {
 956   if (ptr < max-1) name[ptr++] = *s;
 957   s++;
 958   }
 959 if (*s == ':') s++;
 960 name[ptr++] = ':';
 961 name[ptr] = 0;
 962 return s;
 963 }
 964
 965
 966
 967 /*************************************************
 968 *           Pick out a number from a string      *
 969 *************************************************/
 970
 971 /* Arguments:
 972   n     points to an integer into which to put the number
 973   s     points to the first digit of the number
 974
 975 Returns:  a pointer to the character after the last digit
 976 */
 977
 978 static uschar *
 979 read_number(int *n, uschar *s)
 980 {
 981 *n = 0;
 982 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
 983 return s;
 984 }
 985
 986
 987
 988 /*************************************************
 989 *        Extract keyed subfield from a string    *
 990 *************************************************/
 991
 992 /* The yield is in dynamic store; NULL means that the key was not found.
 993
 994 Arguments:
 995   key       points to the name of the key
 996   s         points to the string from which to extract the subfield
 997
 998 Returns:    NULL if the subfield was not found, or
 999             a pointer to the subfield's data
1000 */
1001
1002 static uschar *
1003 expand_getkeyed(uschar *key, uschar *s)
1004 {
1005 int length = Ustrlen(key);
1006 while (isspace(*s)) s++;
1007
1008 /* Loop to search for the key */
1009
1010 while (*s != 0)
1011   {
1012   int dkeylength;
1013   uschar *data;
1014   uschar *dkey = s;
1015
1016   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1017   dkeylength = s - dkey;
1018   while (isspace(*s)) s++;
1019   if (*s == '=') while (isspace((*(++s))));
1020
1021   data = string_dequote(&s);
1022   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1023     return data;
1024
1025   while (isspace(*s)) s++;
1026   }
1027
1028 return NULL;
1029 }
1030
1031
1032
1033
1034 /*************************************************
1035 *   Extract numbered subfield from string        *
1036 *************************************************/
1037
1038 /* Extracts a numbered field from a string that is divided by tokens - for
1039 example a line from /etc/passwd is divided by colon characters.  First field is
1040 numbered one.  Negative arguments count from the right. Zero returns the whole
1041 string. Returns NULL if there are insufficient tokens in the string
1042
1043 ***WARNING***
1044 Modifies final argument - this is a dynamically generated string, so that's OK.
1045
1046 Arguments:
1047   field       number of field to be extracted,
1048                 first field = 1, whole string = 0, last field = -1
1049   separators  characters that are used to break string into tokens
1050   s           points to the string from which to extract the subfield
1051
1052 Returns:      NULL if the field was not found,
1053               a pointer to the field's data inside s (modified to add 0)
1054 */
1055
1056 static uschar *
1057 expand_gettokened (int field, uschar *separators, uschar *s)
1058 {
1059 int sep = 1;
1060 int count;
1061 uschar *ss = s;
1062 uschar *fieldtext = NULL;
1063
1064 if (field == 0) return s;
1065
1066 /* Break the line up into fields in place; for field > 0 we stop when we have
1067 done the number of fields we want. For field < 0 we continue till the end of
1068 the string, counting the number of fields. */
1069
1070 count = (field > 0)? field : INT_MAX;
1071
1072 while (count-- > 0)
1073   {
1074   size_t len;
1075
1076   /* Previous field was the last one in the string. For a positive field
1077   number, this means there are not enough fields. For a negative field number,
1078   check that there are enough, and scan back to find the one that is wanted. */
1079
1080   if (sep == 0)
1081     {
1082     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1083     if ((-field) == (INT_MAX - count - 1)) return s;
1084     while (field++ < 0)
1085       {
1086       ss--;
1087       while (ss[-1] != 0) ss--;
1088       }
1089     fieldtext = ss;
1090     break;
1091     }
1092
1093   /* Previous field was not last in the string; save its start and put a
1094   zero at its end. */
1095
1096   fieldtext = ss;
1097   len = Ustrcspn(ss, separators);
1098   sep = ss[len];
1099   ss[len] = 0;
1100   ss += len + 1;
1101   }
1102
1103 return fieldtext;
1104 }
1105
1106
1107
1108 /*************************************************
1109 *        Extract a substring from a string       *
1110 *************************************************/
1111
1112 /* Perform the ${substr or ${length expansion operations.
1113
1114 Arguments:
1115   subject     the input string
1116   value1      the offset from the start of the input string to the start of
1117                 the output string; if negative, count from the right.
1118   value2      the length of the output string, or negative (-1) for unset
1119                 if value1 is positive, unset means "all after"
1120                 if value1 is negative, unset means "all before"
1121   len         set to the length of the returned string
1122
1123 Returns:      pointer to the output string, or NULL if there is an error
1124 */
1125
1126 static uschar *
1127 extract_substr(uschar *subject, int value1, int value2, int *len)
1128 {
1129 int sublen = Ustrlen(subject);
1130
1131 if (value1 < 0)    /* count from right */
1132   {
1133   value1 += sublen;
1134
1135   /* If the position is before the start, skip to the start, and adjust the
1136   length. If the length ends up negative, the substring is null because nothing
1137   can precede. This falls out naturally when the length is unset, meaning "all
1138   to the left". */
1139
1140   if (value1 < 0)
1141     {
1142     value2 += value1;
1143     if (value2 < 0) value2 = 0;
1144     value1 = 0;
1145     }
1146
1147   /* Otherwise an unset length => characters before value1 */
1148
1149   else if (value2 < 0)
1150     {
1151     value2 = value1;
1152     value1 = 0;
1153     }
1154   }
1155
1156 /* For a non-negative offset, if the starting position is past the end of the
1157 string, the result will be the null string. Otherwise, an unset length means
1158 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1159
1160 else
1161   {
1162   if (value1 > sublen)
1163     {
1164     value1 = sublen;
1165     value2 = 0;
1166     }
1167   else if (value2 < 0) value2 = sublen;
1168   }
1169
1170 /* Cut the length down to the maximum possible for the offset value, and get
1171 the required characters. */
1172
1173 if (value1 + value2 > sublen) value2 = sublen - value1;
1174 *len = value2;
1175 return subject + value1;
1176 }
1177
1178
1179
1180
1181 /*************************************************
1182 *            Old-style hash of a string          *
1183 *************************************************/
1184
1185 /* Perform the ${hash expansion operation.
1186
1187 Arguments:
1188   subject     the input string (an expanded substring)
1189   value1      the length of the output string; if greater or equal to the
1190                 length of the input string, the input string is returned
1191   value2      the number of hash characters to use, or 26 if negative
1192   len         set to the length of the returned string
1193
1194 Returns:      pointer to the output string, or NULL if there is an error
1195 */
1196
1197 static uschar *
1198 compute_hash(uschar *subject, int value1, int value2, int *len)
1199 {
1200 int sublen = Ustrlen(subject);
1201
1202 if (value2 < 0) value2 = 26;
1203 else if (value2 > Ustrlen(hashcodes))
1204   {
1205   expand_string_message =
1206     string_sprintf("hash count \"%d\" too big", value2);
1207   return NULL;
1208   }
1209
1210 /* Calculate the hash text. We know it is shorter than the original string, so
1211 can safely place it in subject[] (we know that subject is always itself an
1212 expanded substring). */
1213
1214 if (value1 < sublen)
1215   {
1216   int c;
1217   int i = 0;
1218   int j = value1;
1219   while ((c = (subject[j])) != 0)
1220     {
1221     int shift = (c + j++) & 7;
1222     subject[i] ^= (c << shift) | (c >> (8-shift));
1223     if (++i >= value1) i = 0;
1224     }
1225   for (i = 0; i < value1; i++)
1226     subject[i] = hashcodes[(subject[i]) % value2];
1227   }
1228 else value1 = sublen;
1229
1230 *len = value1;
1231 return subject;
1232 }
1233
1234
1235
1236
1237 /*************************************************
1238 *             Numeric hash of a string           *
1239 *************************************************/
1240
1241 /* Perform the ${nhash expansion operation. The first characters of the
1242 string are treated as most important, and get the highest prime numbers.
1243
1244 Arguments:
1245   subject     the input string
1246   value1      the maximum value of the first part of the result
1247   value2      the maximum value of the second part of the result,
1248                 or negative to produce only a one-part result
1249   len         set to the length of the returned string
1250
1251 Returns:  pointer to the output string, or NULL if there is an error.
1252 */
1253
1254 static uschar *
1255 compute_nhash (uschar *subject, int value1, int value2, int *len)
1256 {
1257 uschar *s = subject;
1258 int i = 0;
1259 unsigned long int total = 0; /* no overflow */
1260
1261 while (*s != 0)
1262   {
1263   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1264   total += prime[i--] * (unsigned int)(*s++);
1265   }
1266
1267 /* If value2 is unset, just compute one number */
1268
1269 if (value2 < 0)
1270   {
1271   s = string_sprintf("%d", total % value1);
1272   }
1273
1274 /* Otherwise do a div/mod hash */
1275
1276 else
1277   {
1278   total = total % (value1 * value2);
1279   s = string_sprintf("%d/%d", total/value2, total % value2);
1280   }
1281
1282 *len = Ustrlen(s);
1283 return s;
1284 }
1285
1286
1287
1288
1289
1290 /*************************************************
1291 *     Find the value of a header or headers      *
1292 *************************************************/
1293
1294 /* Multiple instances of the same header get concatenated, and this function
1295 can also return a concatenation of all the header lines. When concatenating
1296 specific headers that contain lists of addresses, a comma is inserted between
1297 them. Otherwise we use a straight concatenation. Because some messages can have
1298 pathologically large number of lines, there is a limit on the length that is
1299 returned. Also, to avoid massive store use which would result from using
1300 string_cat() as it copies and extends strings, we do a preliminary pass to find
1301 out exactly how much store will be needed. On "normal" messages this will be
1302 pretty trivial.
1303
1304 Arguments:
1305   name          the name of the header, without the leading $header_ or $h_,
1306                 or NULL if a concatenation of all headers is required
1307   exists_only   TRUE if called from a def: test; don't need to build a string;
1308                 just return a string that is not "" and not "0" if the header
1309                 exists
1310   newsize       return the size of memory block that was obtained; may be NULL
1311                 if exists_only is TRUE
1312   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1313                 other than concatenating, will be done on the header. Also used
1314                 for $message_headers_raw.
1315   charset       name of charset to translate MIME words to; used only if
1316                 want_raw is false; if NULL, no translation is done (this is
1317                 used for $bh_ and $bheader_)
1318
1319 Returns:        NULL if the header does not exist, else a pointer to a new
1320                 store block
1321 */
1322
1323 static uschar *
1324 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1325   uschar *charset)
1326 {
1327 BOOL found = name == NULL;
1328 int comma = 0;
1329 int len = found? 0 : Ustrlen(name);
1330 int i;
1331 uschar *yield = NULL;
1332 uschar *ptr = NULL;
1333
1334 /* Loop for two passes - saves code repetition */
1335
1336 for (i = 0; i < 2; i++)
1337   {
1338   int size = 0;
1339   header_line *h;
1340
1341   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1342     {
1343     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1344       {
1345       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1346         {
1347         int ilen;
1348         uschar *t;
1349
1350         if (exists_only) return US"1";      /* don't need actual string */
1351         found = TRUE;
1352         t = h->text + len;                  /* text to insert */
1353         if (!want_raw)                      /* unless wanted raw, */
1354           while (isspace(*t)) t++;          /* remove leading white space */
1355         ilen = h->slen - (t - h->text);     /* length to insert */
1356
1357         /* Unless wanted raw, remove trailing whitespace, including the
1358         newline. */
1359
1360         if (!want_raw)
1361           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1362
1363         /* Set comma = 1 if handling a single header and it's one of those
1364         that contains an address list, except when asked for raw headers. Only
1365         need to do this once. */
1366
1367         if (!want_raw && name != NULL && comma == 0 &&
1368             Ustrchr("BCFRST", h->type) != NULL)
1369           comma = 1;
1370
1371         /* First pass - compute total store needed; second pass - compute
1372         total store used, including this header. */
1373
1374         size += ilen + comma + 1;  /* +1 for the newline */
1375
1376         /* Second pass - concatentate the data, up to a maximum. Note that
1377         the loop stops when size hits the limit. */
1378
1379         if (i != 0)
1380           {
1381           if (size > header_insert_maxlen)
1382             {
1383             ilen -= size - header_insert_maxlen - 1;
1384             comma = 0;
1385             }
1386           Ustrncpy(ptr, t, ilen);
1387           ptr += ilen;
1388
1389           /* For a non-raw header, put in the comma if needed, then add
1390           back the newline we removed above, provided there was some text in
1391           the header. */
1392
1393           if (!want_raw && ilen > 0)
1394             {
1395             if (comma != 0) *ptr++ = ',';
1396             *ptr++ = '\n';
1397             }
1398           }
1399         }
1400       }
1401     }
1402
1403   /* At end of first pass, return NULL if no header found. Then truncate size
1404   if necessary, and get the buffer to hold the data, returning the buffer size.
1405   */
1406
1407   if (i == 0)
1408     {
1409     if (!found) return NULL;
1410     if (size > header_insert_maxlen) size = header_insert_maxlen;
1411     *newsize = size + 1;
1412     ptr = yield = store_get(*newsize);
1413     }
1414   }
1415
1416 /* That's all we do for raw header expansion. */
1417
1418 if (want_raw)
1419   {
1420   *ptr = 0;
1421   }
1422
1423 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1424 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1425 function can return an error with decoded data if the charset translation
1426 fails. If decoding fails, it returns NULL. */
1427
1428 else
1429   {
1430   uschar *decoded, *error;
1431   if (ptr > yield && ptr[-1] == '\n') ptr--;
1432   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1433   *ptr = 0;
1434   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1435     newsize, &error);
1436   if (error != NULL)
1437     {
1438     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1439       "    input was: %s\n", error, yield);
1440     }
1441   if (decoded != NULL) yield = decoded;
1442   }
1443
1444 return yield;
1445 }
1446
1447
1448
1449
1450 /*************************************************
1451 *               Return list of recipients        *
1452 *************************************************/
1453 /* A recipients list is available only during system message filtering,
1454 during ACL processing after DATA, and while expanding pipe commands
1455 generated from a system filter, but not elsewhere. */
1456
1457 static uschar *
1458 fn_recipients(void)
1459 {
1460 if (!enable_dollar_recipients) return NULL; else
1461   {
1462   int size = 128;
1463   int ptr = 0;
1464   int i;
1465   uschar * s = store_get(size);
1466   for (i = 0; i < recipients_count; i++)
1467     {
1468     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1469     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1470       Ustrlen(recipients_list[i].address));
1471     }
1472   s[ptr] = 0;     /* string_cat() leaves room */
1473   return s;
1474   }
1475 }
1476
1477
1478 /*************************************************
1479 *               Find value of a variable         *
1480 *************************************************/
1481
1482 /* The table of variables is kept in alphabetic order, so we can search it
1483 using a binary chop. The "choplen" variable is nothing to do with the binary
1484 chop.
1485
1486 Arguments:
1487   name          the name of the variable being sought
1488   exists_only   TRUE if this is a def: test; passed on to find_header()
1489   skipping      TRUE => skip any processing evaluation; this is not the same as
1490                   exists_only because def: may test for values that are first
1491                   evaluated here
1492   newsize       pointer to an int which is initially zero; if the answer is in
1493                 a new memory buffer, *newsize is set to its size
1494
1495 Returns:        NULL if the variable does not exist, or
1496                 a pointer to the variable's contents, or
1497                 something non-NULL if exists_only is TRUE
1498 */
1499
1500 static uschar *
1501 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1502 {
1503 int first = 0;
1504 int last = var_table_size;
1505
1506 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1507 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1508 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1509 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1510 (this gave backwards compatibility at the changeover). There may be built-in
1511 variables whose names start acl_ but they should never start in this way. This
1512 slightly messy specification is a consequence of the history, needless to say.
1513
1514 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1515 set, in which case give an error. */
1516
1517 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1518      !isalpha(name[5]))
1519   {
1520   tree_node *node =
1521     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1522   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1523   }
1524
1525 /* Handle $auth<n> variables. */
1526
1527 if (Ustrncmp(name, "auth", 4) == 0)
1528   {
1529   uschar *endptr;
1530   int n = Ustrtoul(name + 4, &endptr, 10);
1531   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1532     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1533   }
1534
1535 /* For all other variables, search the table */
1536
1537 while (last > first)
1538   {
1539   uschar *s, *domain;
1540   uschar **ss;
1541   int middle = (first + last)/2;
1542   int c = Ustrcmp(name, var_table[middle].name);
1543
1544   if (c > 0) { first = middle + 1; continue; }
1545   if (c < 0) { last = middle; continue; }
1546
1547   /* Found an existing variable. If in skipping state, the value isn't needed,
1548   and we want to avoid processing (such as looking up the host name). */
1549
1550   if (skipping) return US"";
1551
1552   switch (var_table[middle].type)
1553     {
1554     case vtype_filter_int:
1555     if (!filter_running) return NULL;
1556     /* Fall through */
1557     /* VVVVVVVVVVVV */
1558     case vtype_int:
1559     sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1560     return var_buffer;
1561
1562     case vtype_ino:
1563     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1564     return var_buffer;
1565
1566     case vtype_gid:
1567     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1568     return var_buffer;
1569
1570     case vtype_uid:
1571     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1572     return var_buffer;
1573
1574     case vtype_bool:
1575     sprintf(CS var_buffer, "%s", *(BOOL *)(var_table[middle].value) ? "yes" : "no"); /* bool */
1576     return var_buffer;
1577
1578     case vtype_stringptr:                      /* Pointer to string */
1579     s = *((uschar **)(var_table[middle].value));
1580     return (s == NULL)? US"" : s;
1581
1582     case vtype_pid:
1583     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1584     return var_buffer;
1585
1586     case vtype_load_avg:
1587     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1588     return var_buffer;
1589
1590     case vtype_host_lookup:                    /* Lookup if not done so */
1591     if (sender_host_name == NULL && sender_host_address != NULL &&
1592         !host_lookup_failed && host_name_lookup() == OK)
1593       host_build_sender_fullhost();
1594     return (sender_host_name == NULL)? US"" : sender_host_name;
1595
1596     case vtype_localpart:                      /* Get local part from address */
1597     s = *((uschar **)(var_table[middle].value));
1598     if (s == NULL) return US"";
1599     domain = Ustrrchr(s, '@');
1600     if (domain == NULL) return s;
1601     if (domain - s > sizeof(var_buffer) - 1)
1602       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1603           " in string expansion", sizeof(var_buffer));
1604     Ustrncpy(var_buffer, s, domain - s);
1605     var_buffer[domain - s] = 0;
1606     return var_buffer;
1607
1608     case vtype_domain:                         /* Get domain from address */
1609     s = *((uschar **)(var_table[middle].value));
1610     if (s == NULL) return US"";
1611     domain = Ustrrchr(s, '@');
1612     return (domain == NULL)? US"" : domain + 1;
1613
1614     case vtype_msgheaders:
1615     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1616
1617     case vtype_msgheaders_raw:
1618     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1619
1620     case vtype_msgbody:                        /* Pointer to msgbody string */
1621     case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1622     ss = (uschar **)(var_table[middle].value);
1623     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1624       {
1625       uschar *body;
1626       off_t start_offset = SPOOL_DATA_START_OFFSET;
1627       int len = message_body_visible;
1628       if (len > message_size) len = message_size;
1629       *ss = body = store_malloc(len+1);
1630       body[0] = 0;
1631       if (var_table[middle].type == vtype_msgbody_end)
1632         {
1633         struct stat statbuf;
1634         if (fstat(deliver_datafile, &statbuf) == 0)
1635           {
1636           start_offset = statbuf.st_size - len;
1637           if (start_offset < SPOOL_DATA_START_OFFSET)
1638             start_offset = SPOOL_DATA_START_OFFSET;
1639           }
1640         }
1641       lseek(deliver_datafile, start_offset, SEEK_SET);
1642       len = read(deliver_datafile, body, len);
1643       if (len > 0)
1644         {
1645         body[len] = 0;
1646         if (message_body_newlines)   /* Separate loops for efficiency */
1647           {
1648           while (len > 0)
1649             { if (body[--len] == 0) body[len] = ' '; }
1650           }
1651         else
1652           {
1653           while (len > 0)
1654             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1655           }
1656         }
1657       }
1658     return (*ss == NULL)? US"" : *ss;
1659
1660     case vtype_todbsdin:                       /* BSD inbox time of day */
1661     return tod_stamp(tod_bsdin);
1662
1663     case vtype_tode:                           /* Unix epoch time of day */
1664     return tod_stamp(tod_epoch);
1665
1666     case vtype_todel:                          /* Unix epoch/usec time of day */
1667     return tod_stamp(tod_epoch_l);
1668
1669     case vtype_todf:                           /* Full time of day */
1670     return tod_stamp(tod_full);
1671
1672     case vtype_todl:                           /* Log format time of day */
1673     return tod_stamp(tod_log_bare);            /* (without timezone) */
1674
1675     case vtype_todzone:                        /* Time zone offset only */
1676     return tod_stamp(tod_zone);
1677
1678     case vtype_todzulu:                        /* Zulu time */
1679     return tod_stamp(tod_zulu);
1680
1681     case vtype_todlf:                          /* Log file datestamp tod */
1682     return tod_stamp(tod_log_datestamp_daily);
1683
1684     case vtype_reply:                          /* Get reply address */
1685     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1686       headers_charset);
1687     if (s != NULL) while (isspace(*s)) s++;
1688     if (s == NULL || *s == 0)
1689       {
1690       *newsize = 0;                            /* For the *s==0 case */
1691       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1692       }
1693     if (s != NULL)
1694       {
1695       uschar *t;
1696       while (isspace(*s)) s++;
1697       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1698       while (t > s && isspace(t[-1])) t--;
1699       *t = 0;
1700       }
1701     return (s == NULL)? US"" : s;
1702
1703     case vtype_string_func:
1704       {
1705       uschar * (*fn)() = var_table[middle].value;
1706       return fn();
1707       }
1708
1709     case vtype_pspace:
1710       {
1711       int inodes;
1712       sprintf(CS var_buffer, "%d",
1713         receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes));
1714       }
1715     return var_buffer;
1716
1717     case vtype_pinodes:
1718       {
1719       int inodes;
1720       (void) receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes);
1721       sprintf(CS var_buffer, "%d", inodes);
1722       }
1723     return var_buffer;
1724
1725     #ifndef DISABLE_DKIM
1726     case vtype_dkim:
1727     return dkim_exim_expand_query((int)(long)var_table[middle].value);
1728     #endif
1729
1730     }
1731   }
1732
1733 return NULL;          /* Unknown variable name */
1734 }
1735
1736
1737
1738
1739 void
1740 modify_variable(uschar *name, void * value)
1741 {
1742 int first = 0;
1743 int last = var_table_size;
1744
1745 while (last > first)
1746   {
1747   int middle = (first + last)/2;
1748   int c = Ustrcmp(name, var_table[middle].name);
1749
1750   if (c > 0) { first = middle + 1; continue; }
1751   if (c < 0) { last = middle; continue; }
1752
1753   /* Found an existing variable; change the item it refers to */
1754   var_table[middle].value = value;
1755   return;
1756   }
1757 return;          /* Unknown variable name, fail silently */
1758 }
1759
1760
1761
1762
1763
1764 /*************************************************
1765 *           Read and expand substrings           *
1766 *************************************************/
1767
1768 /* This function is called to read and expand argument substrings for various
1769 expansion items. Some have a minimum requirement that is less than the maximum;
1770 in these cases, the first non-present one is set to NULL.
1771
1772 Arguments:
1773   sub        points to vector of pointers to set
1774   n          maximum number of substrings
1775   m          minimum required
1776   sptr       points to current string pointer
1777   skipping   the skipping flag
1778   check_end  if TRUE, check for final '}'
1779   name       name of item, for error message
1780
1781 Returns:     0 OK; string pointer updated
1782              1 curly bracketing error (too few arguments)
1783              2 too many arguments (only if check_end is set); message set
1784              3 other error (expansion failure)
1785 */
1786
1787 static int
1788 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1789   BOOL check_end, uschar *name)
1790 {
1791 int i;
1792 uschar *s = *sptr;
1793
1794 while (isspace(*s)) s++;
1795 for (i = 0; i < n; i++)
1796   {
1797   if (*s != '{')
1798     {
1799     if (i < m) return 1;
1800     sub[i] = NULL;
1801     break;
1802     }
1803   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
1804   if (sub[i] == NULL) return 3;
1805   if (*s++ != '}') return 1;
1806   while (isspace(*s)) s++;
1807   }
1808 if (check_end && *s++ != '}')
1809   {
1810   if (s[-1] == '{')
1811     {
1812     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1813       "(max is %d)", name, n);
1814     return 2;
1815     }
1816   return 1;
1817   }
1818
1819 *sptr = s;
1820 return 0;
1821 }
1822
1823
1824
1825
1826 /*************************************************
1827 *     Elaborate message for bad variable         *
1828 *************************************************/
1829
1830 /* For the "unknown variable" message, take a look at the variable's name, and
1831 give additional information about possible ACL variables. The extra information
1832 is added on to expand_string_message.
1833
1834 Argument:   the name of the variable
1835 Returns:    nothing
1836 */
1837
1838 static void
1839 check_variable_error_message(uschar *name)
1840 {
1841 if (Ustrncmp(name, "acl_", 4) == 0)
1842   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1843     (name[4] == 'c' || name[4] == 'm')?
1844       (isalpha(name[5])?
1845         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1846         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1847       ) :
1848       US"user-defined ACL variables must start acl_c or acl_m");
1849 }
1850
1851
1852
1853 /*
1854 Load args from sub array to globals, and call acl_check().
1855
1856 Returns:       OK         access is granted by an ACCEPT verb
1857                DISCARD    access is granted by a DISCARD verb
1858                FAIL       access is denied
1859                FAIL_DROP  access is denied; drop the connection
1860                DEFER      can't tell at the moment
1861                ERROR      disaster
1862 */
1863 static int
1864 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
1865 {
1866 int i;
1867 uschar *dummy_log_msg;
1868
1869 for (i = 1; i < nsub && sub[i]; i++)
1870   acl_arg[i-1] = sub[i];
1871 acl_narg = i-1;
1872 while (i < nsub)
1873   acl_arg[i++ - 1] = NULL;
1874
1875 DEBUG(D_expand)
1876   debug_printf("expanding: acl: %s  arg: %s%s\n",
1877     sub[0],
1878     acl_narg>0 ? sub[1]   : US"<none>",
1879     acl_narg>1 ? " +more" : "");
1880
1881 return acl_check(ACL_WHERE_EXPANSION, NULL, sub[0], user_msgp, &dummy_log_msg);
1882 }
1883
1884
1885
1886
1887 /*************************************************
1888 *        Read and evaluate a condition           *
1889 *************************************************/
1890
1891 /*
1892 Arguments:
1893   s        points to the start of the condition text
1894   yield    points to a BOOL to hold the result of the condition test;
1895            if NULL, we are just reading through a condition that is
1896            part of an "or" combination to check syntax, or in a state
1897            where the answer isn't required
1898
1899 Returns:   a pointer to the first character after the condition, or
1900            NULL after an error
1901 */
1902
1903 static uschar *
1904 eval_condition(uschar *s, BOOL *yield)
1905 {
1906 BOOL testfor = TRUE;
1907 BOOL tempcond, combined_cond;
1908 BOOL *subcondptr;
1909 BOOL sub2_honour_dollar = TRUE;
1910 int i, rc, cond_type, roffset;
1911 int_eximarith_t num[2];
1912 struct stat statbuf;
1913 uschar name[256];
1914 uschar *sub[10];
1915
1916 const pcre *re;
1917 const uschar *rerror;
1918
1919 for (;;)
1920   {
1921   while (isspace(*s)) s++;
1922   if (*s == '!') { testfor = !testfor; s++; } else break;
1923   }
1924
1925 /* Numeric comparisons are symbolic */
1926
1927 if (*s == '=' || *s == '>' || *s == '<')
1928   {
1929   int p = 0;
1930   name[p++] = *s++;
1931   if (*s == '=')
1932     {
1933     name[p++] = '=';
1934     s++;
1935     }
1936   name[p] = 0;
1937   }
1938
1939 /* All other conditions are named */
1940
1941 else s = read_name(name, 256, s, US"_");
1942
1943 /* If we haven't read a name, it means some non-alpha character is first. */
1944
1945 if (name[0] == 0)
1946   {
1947   expand_string_message = string_sprintf("condition name expected, "
1948     "but found \"%.16s\"", s);
1949   return NULL;
1950   }
1951
1952 /* Find which condition we are dealing with, and switch on it */
1953
1954 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1955 switch(cond_type)
1956   {
1957   /* def: tests for a non-empty variable, or for the existence of a header. If
1958   yield == NULL we are in a skipping state, and don't care about the answer. */
1959
1960   case ECOND_DEF:
1961   if (*s != ':')
1962     {
1963     expand_string_message = US"\":\" expected after \"def\"";
1964     return NULL;
1965     }
1966
1967   s = read_name(name, 256, s+1, US"_");
1968
1969   /* Test for a header's existence. If the name contains a closing brace
1970   character, this may be a user error where the terminating colon has been
1971   omitted. Set a flag to adjust a subsequent error message in this case. */
1972
1973   if (Ustrncmp(name, "h_", 2) == 0 ||
1974       Ustrncmp(name, "rh_", 3) == 0 ||
1975       Ustrncmp(name, "bh_", 3) == 0 ||
1976       Ustrncmp(name, "header_", 7) == 0 ||
1977       Ustrncmp(name, "rheader_", 8) == 0 ||
1978       Ustrncmp(name, "bheader_", 8) == 0)
1979     {
1980     s = read_header_name(name, 256, s);
1981     /* {-for-text-editors */
1982     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
1983     if (yield != NULL) *yield =
1984       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
1985     }
1986
1987   /* Test for a variable's having a non-empty value. A non-existent variable
1988   causes an expansion failure. */
1989
1990   else
1991     {
1992     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
1993     if (value == NULL)
1994       {
1995       expand_string_message = (name[0] == 0)?
1996         string_sprintf("variable name omitted after \"def:\"") :
1997         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
1998       check_variable_error_message(name);
1999       return NULL;
2000       }
2001     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2002     }
2003
2004   return s;
2005
2006
2007   /* first_delivery tests for first delivery attempt */
2008
2009   case ECOND_FIRST_DELIVERY:
2010   if (yield != NULL) *yield = deliver_firsttime == testfor;
2011   return s;
2012
2013
2014   /* queue_running tests for any process started by a queue runner */
2015
2016   case ECOND_QUEUE_RUNNING:
2017   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2018   return s;
2019
2020
2021   /* exists:  tests for file existence
2022        isip:  tests for any IP address
2023       isip4:  tests for an IPv4 address
2024       isip6:  tests for an IPv6 address
2025         pam:  does PAM authentication
2026      radius:  does RADIUS authentication
2027    ldapauth:  does LDAP authentication
2028     pwcheck:  does Cyrus SASL pwcheck authentication
2029   */
2030
2031   case ECOND_EXISTS:
2032   case ECOND_ISIP:
2033   case ECOND_ISIP4:
2034   case ECOND_ISIP6:
2035   case ECOND_PAM:
2036   case ECOND_RADIUS:
2037   case ECOND_LDAPAUTH:
2038   case ECOND_PWCHECK:
2039
2040   while (isspace(*s)) s++;
2041   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2042
2043   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE);
2044   if (sub[0] == NULL) return NULL;
2045   /* {-for-text-editors */
2046   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2047
2048   if (yield == NULL) return s;   /* No need to run the test if skipping */
2049
2050   switch(cond_type)
2051     {
2052     case ECOND_EXISTS:
2053     if ((expand_forbid & RDO_EXISTS) != 0)
2054       {
2055       expand_string_message = US"File existence tests are not permitted";
2056       return NULL;
2057       }
2058     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2059     break;
2060
2061     case ECOND_ISIP:
2062     case ECOND_ISIP4:
2063     case ECOND_ISIP6:
2064     rc = string_is_ip_address(sub[0], NULL);
2065     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2066              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2067     break;
2068
2069     /* Various authentication tests - all optionally compiled */
2070
2071     case ECOND_PAM:
2072     #ifdef SUPPORT_PAM
2073     rc = auth_call_pam(sub[0], &expand_string_message);
2074     goto END_AUTH;
2075     #else
2076     goto COND_FAILED_NOT_COMPILED;
2077     #endif  /* SUPPORT_PAM */
2078
2079     case ECOND_RADIUS:
2080     #ifdef RADIUS_CONFIG_FILE
2081     rc = auth_call_radius(sub[0], &expand_string_message);
2082     goto END_AUTH;
2083     #else
2084     goto COND_FAILED_NOT_COMPILED;
2085     #endif  /* RADIUS_CONFIG_FILE */
2086
2087     case ECOND_LDAPAUTH:
2088     #ifdef LOOKUP_LDAP
2089       {
2090       /* Just to keep the interface the same */
2091       BOOL do_cache;
2092       int old_pool = store_pool;
2093       store_pool = POOL_SEARCH;
2094       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2095         &expand_string_message, &do_cache);
2096       store_pool = old_pool;
2097       }
2098     goto END_AUTH;
2099     #else
2100     goto COND_FAILED_NOT_COMPILED;
2101     #endif  /* LOOKUP_LDAP */
2102
2103     case ECOND_PWCHECK:
2104     #ifdef CYRUS_PWCHECK_SOCKET
2105     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2106     goto END_AUTH;
2107     #else
2108     goto COND_FAILED_NOT_COMPILED;
2109     #endif  /* CYRUS_PWCHECK_SOCKET */
2110
2111     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2112         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2113     END_AUTH:
2114     if (rc == ERROR || rc == DEFER) return NULL;
2115     *yield = (rc == OK) == testfor;
2116     #endif
2117     }
2118   return s;
2119
2120
2121   /* call ACL (in a conditional context).  Accept true, deny false.
2122   Defer is a forced-fail.  Anything set by message= goes to $value.
2123   Up to ten parameters are used; we use the braces round the name+args
2124   like the saslauthd condition does, to permit a variable number of args.
2125   See also the expansion-item version EITEM_ACL and the traditional
2126   acl modifier ACLC_ACL.
2127   */
2128
2129   case ECOND_ACL:
2130     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2131     {
2132     uschar *nameargs;
2133     uschar *user_msg;
2134     BOOL cond = FALSE;
2135     int size = 0;
2136     int ptr = 0;
2137
2138     while (isspace(*s)) s++;
2139     if (*s++ != '{') goto COND_FAILED_CURLY_START;
2140
2141     switch(read_subs(sub, sizeof(sub)/sizeof(*sub), 1,
2142       &s, yield == NULL, TRUE, US"acl"))
2143       {
2144       case 1: expand_string_message = US"too few arguments or bracketing "
2145         "error for acl";
2146       case 2:
2147       case 3: return NULL;
2148       }
2149
2150     if (yield != NULL) switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
2151         {
2152         case OK:
2153           cond = TRUE;
2154         case FAIL:
2155           lookup_value = NULL;
2156           if (user_msg)
2157             {
2158             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2159             lookup_value[ptr] = '\0';
2160             }
2161           *yield = cond == testfor;
2162           break;
2163
2164         case DEFER:
2165           expand_string_forcedfail = TRUE;
2166         default:
2167           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2168           return NULL;
2169         }
2170     return s;
2171     }
2172
2173
2174   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2175
2176      ${if saslauthd {{username}{password}{service}{realm}}  {yes}[no}}
2177
2178   However, the last two are optional. That is why the whole set is enclosed
2179   in their own set of braces. */
2180
2181   case ECOND_SASLAUTHD:
2182   #ifndef CYRUS_SASLAUTHD_SOCKET
2183   goto COND_FAILED_NOT_COMPILED;
2184   #else
2185   while (isspace(*s)) s++;
2186   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2187   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
2188     {
2189     case 1: expand_string_message = US"too few arguments or bracketing "
2190       "error for saslauthd";
2191     case 2:
2192     case 3: return NULL;
2193     }
2194   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2195   if (yield != NULL)
2196     {
2197     int rc;
2198     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2199       &expand_string_message);
2200     if (rc == ERROR || rc == DEFER) return NULL;
2201     *yield = (rc == OK) == testfor;
2202     }
2203   return s;
2204   #endif /* CYRUS_SASLAUTHD_SOCKET */
2205
2206
2207   /* symbolic operators for numeric and string comparison, and a number of
2208   other operators, all requiring two arguments.
2209
2210   crypteq:           encrypts plaintext and compares against an encrypted text,
2211                        using crypt(), crypt16(), MD5 or SHA-1
2212   inlist/inlisti:    checks if first argument is in the list of the second
2213   match:             does a regular expression match and sets up the numerical
2214                        variables if it succeeds
2215   match_address:     matches in an address list
2216   match_domain:      matches in a domain list
2217   match_ip:          matches a host list that is restricted to IP addresses
2218   match_local_part:  matches in a local part list
2219   */
2220
2221   case ECOND_MATCH_ADDRESS:
2222   case ECOND_MATCH_DOMAIN:
2223   case ECOND_MATCH_IP:
2224   case ECOND_MATCH_LOCAL_PART:
2225 #ifndef EXPAND_LISTMATCH_RHS
2226     sub2_honour_dollar = FALSE;
2227 #endif
2228     /* FALLTHROUGH */
2229
2230   case ECOND_CRYPTEQ:
2231   case ECOND_INLIST:
2232   case ECOND_INLISTI:
2233   case ECOND_MATCH:
2234
2235   case ECOND_NUM_L:     /* Numerical comparisons */
2236   case ECOND_NUM_LE:
2237   case ECOND_NUM_E:
2238   case ECOND_NUM_EE:
2239   case ECOND_NUM_G:
2240   case ECOND_NUM_GE:
2241
2242   case ECOND_STR_LT:    /* String comparisons */
2243   case ECOND_STR_LTI:
2244   case ECOND_STR_LE:
2245   case ECOND_STR_LEI:
2246   case ECOND_STR_EQ:
2247   case ECOND_STR_EQI:
2248   case ECOND_STR_GT:
2249   case ECOND_STR_GTI:
2250   case ECOND_STR_GE:
2251   case ECOND_STR_GEI:
2252
2253   for (i = 0; i < 2; i++)
2254     {
2255     /* Sometimes, we don't expand substrings; too many insecure configurations
2256     created using match_address{}{} and friends, where the second param
2257     includes information from untrustworthy sources. */
2258     BOOL honour_dollar = TRUE;
2259     if ((i > 0) && !sub2_honour_dollar)
2260       honour_dollar = FALSE;
2261
2262     while (isspace(*s)) s++;
2263     if (*s != '{')
2264       {
2265       if (i == 0) goto COND_FAILED_CURLY_START;
2266       expand_string_message = string_sprintf("missing 2nd string in {} "
2267         "after \"%s\"", name);
2268       return NULL;
2269       }
2270     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2271         honour_dollar);
2272     if (sub[i] == NULL) return NULL;
2273     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2274
2275     /* Convert to numerical if required; we know that the names of all the
2276     conditions that compare numbers do not start with a letter. This just saves
2277     checking for them individually. */
2278
2279     if (!isalpha(name[0]) && yield != NULL)
2280       {
2281       if (sub[i][0] == 0)
2282         {
2283         num[i] = 0;
2284         DEBUG(D_expand)
2285           debug_printf("empty string cast to zero for numerical comparison\n");
2286         }
2287       else
2288         {
2289         num[i] = expand_string_integer(sub[i], FALSE);
2290         if (expand_string_message != NULL) return NULL;
2291         }
2292       }
2293     }
2294
2295   /* Result not required */
2296
2297   if (yield == NULL) return s;
2298
2299   /* Do an appropriate comparison */
2300
2301   switch(cond_type)
2302     {
2303     case ECOND_NUM_E:
2304     case ECOND_NUM_EE:
2305     tempcond = (num[0] == num[1]);
2306     break;
2307
2308     case ECOND_NUM_G:
2309     tempcond = (num[0] > num[1]);
2310     break;
2311
2312     case ECOND_NUM_GE:
2313     tempcond = (num[0] >= num[1]);
2314     break;
2315
2316     case ECOND_NUM_L:
2317     tempcond = (num[0] < num[1]);
2318     break;
2319
2320     case ECOND_NUM_LE:
2321     tempcond = (num[0] <= num[1]);
2322     break;
2323
2324     case ECOND_STR_LT:
2325     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2326     break;
2327
2328     case ECOND_STR_LTI:
2329     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2330     break;
2331
2332     case ECOND_STR_LE:
2333     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2334     break;
2335
2336     case ECOND_STR_LEI:
2337     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2338     break;
2339
2340     case ECOND_STR_EQ:
2341     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2342     break;
2343
2344     case ECOND_STR_EQI:
2345     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2346     break;
2347
2348     case ECOND_STR_GT:
2349     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2350     break;
2351
2352     case ECOND_STR_GTI:
2353     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2354     break;
2355
2356     case ECOND_STR_GE:
2357     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2358     break;
2359
2360     case ECOND_STR_GEI:
2361     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2362     break;
2363
2364     case ECOND_MATCH:   /* Regular expression match */
2365     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2366       NULL);
2367     if (re == NULL)
2368       {
2369       expand_string_message = string_sprintf("regular expression error in "
2370         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2371       return NULL;
2372       }
2373     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2374     break;
2375
2376     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2377     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2378     goto MATCHED_SOMETHING;
2379
2380     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2381     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2382       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2383     goto MATCHED_SOMETHING;
2384
2385     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2386     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2387       {
2388       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2389         sub[0]);
2390       return NULL;
2391       }
2392     else
2393       {
2394       unsigned int *nullcache = NULL;
2395       check_host_block cb;
2396
2397       cb.host_name = US"";
2398       cb.host_address = sub[0];
2399
2400       /* If the host address starts off ::ffff: it is an IPv6 address in
2401       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2402       addresses. */
2403
2404       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2405         cb.host_address + 7 : cb.host_address;
2406
2407       rc = match_check_list(
2408              &sub[1],                   /* the list */
2409              0,                         /* separator character */
2410              &hostlist_anchor,          /* anchor pointer */
2411              &nullcache,                /* cache pointer */
2412              check_host,                /* function for testing */
2413              &cb,                       /* argument for function */
2414              MCL_HOST,                  /* type of check */
2415              sub[0],                    /* text for debugging */
2416              NULL);                     /* where to pass back data */
2417       }
2418     goto MATCHED_SOMETHING;
2419
2420     case ECOND_MATCH_LOCAL_PART:
2421     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2422       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2423     /* Fall through */
2424     /* VVVVVVVVVVVV */
2425     MATCHED_SOMETHING:
2426     switch(rc)
2427       {
2428       case OK:
2429       tempcond = TRUE;
2430       break;
2431
2432       case FAIL:
2433       tempcond = FALSE;
2434       break;
2435
2436       case DEFER:
2437       expand_string_message = string_sprintf("unable to complete match "
2438         "against \"%s\": %s", sub[1], search_error_message);
2439       return NULL;
2440       }
2441
2442     break;
2443
2444     /* Various "encrypted" comparisons. If the second string starts with
2445     "{" then an encryption type is given. Default to crypt() or crypt16()
2446     (build-time choice). */
2447     /* }-for-text-editors */
2448
2449     case ECOND_CRYPTEQ:
2450     #ifndef SUPPORT_CRYPTEQ
2451     goto COND_FAILED_NOT_COMPILED;
2452     #else
2453     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2454       {
2455       int sublen = Ustrlen(sub[1]+5);
2456       md5 base;
2457       uschar digest[16];
2458
2459       md5_start(&base);
2460       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2461
2462       /* If the length that we are comparing against is 24, the MD5 digest
2463       is expressed as a base64 string. This is the way LDAP does it. However,
2464       some other software uses a straightforward hex representation. We assume
2465       this if the length is 32. Other lengths fail. */
2466
2467       if (sublen == 24)
2468         {
2469         uschar *coded = auth_b64encode((uschar *)digest, 16);
2470         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2471           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2472         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2473         }
2474       else if (sublen == 32)
2475         {
2476         int i;
2477         uschar coded[36];
2478         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2479         coded[32] = 0;
2480         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2481           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2482         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2483         }
2484       else
2485         {
2486         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2487           "fail\n  crypted=%s\n", sub[1]+5);
2488         tempcond = FALSE;
2489         }
2490       }
2491
2492     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2493       {
2494       int sublen = Ustrlen(sub[1]+6);
2495       sha1 base;
2496       uschar digest[20];
2497
2498       sha1_start(&base);
2499       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2500
2501       /* If the length that we are comparing against is 28, assume the SHA1
2502       digest is expressed as a base64 string. If the length is 40, assume a
2503       straightforward hex representation. Other lengths fail. */
2504
2505       if (sublen == 28)
2506         {
2507         uschar *coded = auth_b64encode((uschar *)digest, 20);
2508         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2509           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2510         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2511         }
2512       else if (sublen == 40)
2513         {
2514         int i;
2515         uschar coded[44];
2516         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2517         coded[40] = 0;
2518         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2519           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2520         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2521         }
2522       else
2523         {
2524         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2525           "fail\n  crypted=%s\n", sub[1]+6);
2526         tempcond = FALSE;
2527         }
2528       }
2529
2530     else   /* {crypt} or {crypt16} and non-{ at start */
2531            /* }-for-text-editors */
2532       {
2533       int which = 0;
2534       uschar *coded;
2535
2536       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2537         {
2538         sub[1] += 7;
2539         which = 1;
2540         }
2541       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2542         {
2543         sub[1] += 9;
2544         which = 2;
2545         }
2546       else if (sub[1][0] == '{')                /* }-for-text-editors */
2547         {
2548         expand_string_message = string_sprintf("unknown encryption mechanism "
2549           "in \"%s\"", sub[1]);
2550         return NULL;
2551         }
2552
2553       switch(which)
2554         {
2555         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2556         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2557         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2558         }
2559
2560       #define STR(s) # s
2561       #define XSTR(s) STR(s)
2562       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2563         "  subject=%s\n  crypted=%s\n",
2564         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2565         coded, sub[1]);
2566       #undef STR
2567       #undef XSTR
2568
2569       /* If the encrypted string contains fewer than two characters (for the
2570       salt), force failure. Otherwise we get false positives: with an empty
2571       string the yield of crypt() is an empty string! */
2572
2573       tempcond = (Ustrlen(sub[1]) < 2)? FALSE :
2574         (Ustrcmp(coded, sub[1]) == 0);
2575       }
2576     break;
2577     #endif  /* SUPPORT_CRYPTEQ */
2578
2579     case ECOND_INLIST:
2580     case ECOND_INLISTI:
2581       {
2582       int sep = 0;
2583       uschar *save_iterate_item = iterate_item;
2584       int (*compare)(const uschar *, const uschar *);
2585
2586       tempcond = FALSE;
2587       if (cond_type == ECOND_INLISTI)
2588         compare = strcmpic;
2589       else
2590         compare = (int (*)(const uschar *, const uschar *)) strcmp;
2591
2592       while ((iterate_item = string_nextinlist(&sub[1], &sep, NULL, 0)) != NULL)
2593         if (compare(sub[0], iterate_item) == 0)
2594           {
2595           tempcond = TRUE;
2596           break;
2597           }
2598       iterate_item = save_iterate_item;
2599       }
2600
2601     }   /* Switch for comparison conditions */
2602
2603   *yield = tempcond == testfor;
2604   return s;    /* End of comparison conditions */
2605
2606
2607   /* and/or: computes logical and/or of several conditions */
2608
2609   case ECOND_AND:
2610   case ECOND_OR:
2611   subcondptr = (yield == NULL)? NULL : &tempcond;
2612   combined_cond = (cond_type == ECOND_AND);
2613
2614   while (isspace(*s)) s++;
2615   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2616
2617   for (;;)
2618     {
2619     while (isspace(*s)) s++;
2620     /* {-for-text-editors */
2621     if (*s == '}') break;
2622     if (*s != '{')                                      /* }-for-text-editors */
2623       {
2624       expand_string_message = string_sprintf("each subcondition "
2625         "inside an \"%s{...}\" condition must be in its own {}", name);
2626       return NULL;
2627       }
2628
2629     s = eval_condition(s+1, subcondptr);
2630     if (s == NULL)
2631       {
2632       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2633         expand_string_message, name);
2634       return NULL;
2635       }
2636     while (isspace(*s)) s++;
2637
2638     /* {-for-text-editors */
2639     if (*s++ != '}')
2640       {
2641       /* {-for-text-editors */
2642       expand_string_message = string_sprintf("missing } at end of condition "
2643         "inside \"%s\" group", name);
2644       return NULL;
2645       }
2646
2647     if (yield != NULL)
2648       {
2649       if (cond_type == ECOND_AND)
2650         {
2651         combined_cond &= tempcond;
2652         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2653         }                                       /* evaluate any more */
2654       else
2655         {
2656         combined_cond |= tempcond;
2657         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2658         }                                       /* evaluate any more */
2659       }
2660     }
2661
2662   if (yield != NULL) *yield = (combined_cond == testfor);
2663   return ++s;
2664
2665
2666   /* forall/forany: iterates a condition with different values */
2667
2668   case ECOND_FORALL:
2669   case ECOND_FORANY:
2670     {
2671     int sep = 0;
2672     uschar *save_iterate_item = iterate_item;
2673
2674     while (isspace(*s)) s++;
2675     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2676     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE);
2677     if (sub[0] == NULL) return NULL;
2678     /* {-for-text-editors */
2679     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2680
2681     while (isspace(*s)) s++;
2682     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2683
2684     sub[1] = s;
2685
2686     /* Call eval_condition once, with result discarded (as if scanning a
2687     "false" part). This allows us to find the end of the condition, because if
2688     the list it empty, we won't actually evaluate the condition for real. */
2689
2690     s = eval_condition(sub[1], NULL);
2691     if (s == NULL)
2692       {
2693       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2694         expand_string_message, name);
2695       return NULL;
2696       }
2697     while (isspace(*s)) s++;
2698
2699     /* {-for-text-editors */
2700     if (*s++ != '}')
2701       {
2702       /* {-for-text-editors */
2703       expand_string_message = string_sprintf("missing } at end of condition "
2704         "inside \"%s\"", name);
2705       return NULL;
2706       }
2707
2708     if (yield != NULL) *yield = !testfor;
2709     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2710       {
2711       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2712       if (eval_condition(sub[1], &tempcond) == NULL)
2713         {
2714         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2715           expand_string_message, name);
2716         iterate_item = save_iterate_item;
2717         return NULL;
2718         }
2719       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2720         tempcond? "true":"false");
2721
2722       if (yield != NULL) *yield = (tempcond == testfor);
2723       if (tempcond == (cond_type == ECOND_FORANY)) break;
2724       }
2725
2726     iterate_item = save_iterate_item;
2727     return s;
2728     }
2729
2730
2731   /* The bool{} expansion condition maps a string to boolean.
2732   The values supported should match those supported by the ACL condition
2733   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2734   of true/false.  Note that Router "condition" rules have a different
2735   interpretation, where general data can be used and only a few values
2736   map to FALSE.
2737   Note that readconf.c boolean matching, for boolean configuration options,
2738   only matches true/yes/false/no.
2739   The bool_lax{} condition matches the Router logic, which is much more
2740   liberal. */
2741   case ECOND_BOOL:
2742   case ECOND_BOOL_LAX:
2743     {
2744     uschar *sub_arg[1];
2745     uschar *t, *t2;
2746     uschar *ourname;
2747     size_t len;
2748     BOOL boolvalue = FALSE;
2749     while (isspace(*s)) s++;
2750     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2751     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2752     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname))
2753       {
2754       case 1: expand_string_message = string_sprintf(
2755                   "too few arguments or bracketing error for %s",
2756                   ourname);
2757       /*FALLTHROUGH*/
2758       case 2:
2759       case 3: return NULL;
2760       }
2761     t = sub_arg[0];
2762     while (isspace(*t)) t++;
2763     len = Ustrlen(t);
2764     if (len)
2765       {
2766       /* trailing whitespace: seems like a good idea to ignore it too */
2767       t2 = t + len - 1;
2768       while (isspace(*t2)) t2--;
2769       if (t2 != (t + len))
2770         {
2771         *++t2 = '\0';
2772         len = t2 - t;
2773         }
2774       }
2775     DEBUG(D_expand)
2776       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
2777     /* logic for the lax case from expand_check_condition(), which also does
2778     expands, and the logic is both short and stable enough that there should
2779     be no maintenance burden from replicating it. */
2780     if (len == 0)
2781       boolvalue = FALSE;
2782     else if (Ustrspn(t, "0123456789") == len)
2783       {
2784       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
2785       /* expand_check_condition only does a literal string "0" check */
2786       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
2787         boolvalue = TRUE;
2788       }
2789     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
2790       boolvalue = TRUE;
2791     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
2792       boolvalue = FALSE;
2793     else if (cond_type == ECOND_BOOL_LAX)
2794       boolvalue = TRUE;
2795     else
2796       {
2797       expand_string_message = string_sprintf("unrecognised boolean "
2798        "value \"%s\"", t);
2799       return NULL;
2800       }
2801     if (yield != NULL) *yield = (boolvalue == testfor);
2802     return s;
2803     }
2804
2805   /* Unknown condition */
2806
2807   default:
2808   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2809   return NULL;
2810   }   /* End switch on condition type */
2811
2812 /* Missing braces at start and end of data */
2813
2814 COND_FAILED_CURLY_START:
2815 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2816 return NULL;
2817
2818 COND_FAILED_CURLY_END:
2819 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2820   name);
2821 return NULL;
2822
2823 /* A condition requires code that is not compiled */
2824
2825 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2826     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2827     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2828 COND_FAILED_NOT_COMPILED:
2829 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2830   name);
2831 return NULL;
2832 #endif
2833 }
2834
2835
2836
2837
2838 /*************************************************
2839 *          Save numerical variables              *
2840 *************************************************/
2841
2842 /* This function is called from items such as "if" that want to preserve and
2843 restore the numbered variables.
2844
2845 Arguments:
2846   save_expand_string    points to an array of pointers to set
2847   save_expand_nlength   points to an array of ints for the lengths
2848
2849 Returns:                the value of expand max to save
2850 */
2851
2852 static int
2853 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2854 {
2855 int i;
2856 for (i = 0; i <= expand_nmax; i++)
2857   {
2858   save_expand_nstring[i] = expand_nstring[i];
2859   save_expand_nlength[i] = expand_nlength[i];
2860   }
2861 return expand_nmax;
2862 }
2863
2864
2865
2866 /*************************************************
2867 *           Restore numerical variables          *
2868 *************************************************/
2869
2870 /* This function restored saved values of numerical strings.
2871
2872 Arguments:
2873   save_expand_nmax      the number of strings to restore
2874   save_expand_string    points to an array of pointers
2875   save_expand_nlength   points to an array of ints
2876
2877 Returns:                nothing
2878 */
2879
2880 static void
2881 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2882   int *save_expand_nlength)
2883 {
2884 int i;
2885 expand_nmax = save_expand_nmax;
2886 for (i = 0; i <= expand_nmax; i++)
2887   {
2888   expand_nstring[i] = save_expand_nstring[i];
2889   expand_nlength[i] = save_expand_nlength[i];
2890   }
2891 }
2892
2893
2894
2895
2896
2897 /*************************************************
2898 *            Handle yes/no substrings            *
2899 *************************************************/
2900
2901 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2902 alternative substrings that depend on whether or not the condition was true,
2903 or the lookup or extraction succeeded. The substrings always have to be
2904 expanded, to check their syntax, but "skipping" is set when the result is not
2905 needed - this avoids unnecessary nested lookups.
2906
2907 Arguments:
2908   skipping       TRUE if we were skipping when this item was reached
2909   yes            TRUE if the first string is to be used, else use the second
2910   save_lookup    a value to put back into lookup_value before the 2nd expansion
2911   sptr           points to the input string pointer
2912   yieldptr       points to the output string pointer
2913   sizeptr        points to the output string size
2914   ptrptr         points to the output string pointer
2915   type           "lookup" or "if" or "extract" or "run", for error message
2916
2917 Returns:         0 OK; lookup_value has been reset to save_lookup
2918                  1 expansion failed
2919                  2 expansion failed because of bracketing error
2920 */
2921
2922 static int
2923 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2924   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2925 {
2926 int rc = 0;
2927 uschar *s = *sptr;    /* Local value */
2928 uschar *sub1, *sub2;
2929
2930 /* If there are no following strings, we substitute the contents of $value for
2931 lookups and for extractions in the success case. For the ${if item, the string
2932 "true" is substituted. In the fail case, nothing is substituted for all three
2933 items. */
2934
2935 while (isspace(*s)) s++;
2936 if (*s == '}')
2937   {
2938   if (type[0] == 'i')
2939     {
2940     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2941     }
2942   else
2943     {
2944     if (yes && lookup_value != NULL)
2945       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2946         Ustrlen(lookup_value));
2947     lookup_value = save_lookup;
2948     }
2949   s++;
2950   goto RETURN;
2951   }
2952
2953 /* The first following string must be braced. */
2954
2955 if (*s++ != '{') goto FAILED_CURLY;
2956
2957 /* Expand the first substring. Forced failures are noticed only if we actually
2958 want this string. Set skipping in the call in the fail case (this will always
2959 be the case if we were already skipping). */
2960
2961 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE);
2962 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2963 expand_string_forcedfail = FALSE;
2964 if (*s++ != '}') goto FAILED_CURLY;
2965
2966 /* If we want the first string, add it to the output */
2967
2968 if (yes)
2969   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2970
2971 /* If this is called from a lookup or an extract, we want to restore $value to
2972 what it was at the start of the item, so that it has this value during the
2973 second string expansion. For the call from "if" or "run" to this function,
2974 save_lookup is set to lookup_value, so that this statement does nothing. */
2975
2976 lookup_value = save_lookup;
2977
2978 /* There now follows either another substring, or "fail", or nothing. This
2979 time, forced failures are noticed only if we want the second string. We must
2980 set skipping in the nested call if we don't want this string, or if we were
2981 already skipping. */
2982
2983 while (isspace(*s)) s++;
2984 if (*s == '{')
2985   {
2986   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE);
2987   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
2988   expand_string_forcedfail = FALSE;
2989   if (*s++ != '}') goto FAILED_CURLY;
2990
2991   /* If we want the second string, add it to the output */
2992
2993   if (!yes)
2994     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
2995   }
2996
2997 /* If there is no second string, but the word "fail" is present when the use of
2998 the second string is wanted, set a flag indicating it was a forced failure
2999 rather than a syntactic error. Swallow the terminating } in case this is nested
3000 inside another lookup or if or extract. */
3001
3002 else if (*s != '}')
3003   {
3004   uschar name[256];
3005   s = read_name(name, sizeof(name), s, US"_");
3006   if (Ustrcmp(name, "fail") == 0)
3007     {
3008     if (!yes && !skipping)
3009       {
3010       while (isspace(*s)) s++;
3011       if (*s++ != '}') goto FAILED_CURLY;
3012       expand_string_message =
3013         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3014       expand_string_forcedfail = TRUE;
3015       goto FAILED;
3016       }
3017     }
3018   else
3019     {
3020     expand_string_message =
3021       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3022     goto FAILED;
3023     }
3024   }
3025
3026 /* All we have to do now is to check on the final closing brace. */
3027
3028 while (isspace(*s)) s++;
3029 if (*s++ == '}') goto RETURN;
3030
3031 /* Get here if there is a bracketing failure */
3032
3033 FAILED_CURLY:
3034 rc++;
3035
3036 /* Get here for other failures */
3037
3038 FAILED:
3039 rc++;
3040
3041 /* Update the input pointer value before returning */
3042
3043 RETURN:
3044 *sptr = s;
3045 return rc;
3046 }
3047
3048
3049
3050
3051 /*************************************************
3052 *    Handle MD5 or SHA-1 computation for HMAC    *
3053 *************************************************/
3054
3055 /* These are some wrapping functions that enable the HMAC code to be a bit
3056 cleaner. A good compiler will spot the tail recursion.
3057
3058 Arguments:
3059   type         HMAC_MD5 or HMAC_SHA1
3060   remaining    are as for the cryptographic hash functions
3061
3062 Returns:       nothing
3063 */
3064
3065 static void
3066 chash_start(int type, void *base)
3067 {
3068 if (type == HMAC_MD5)
3069   md5_start((md5 *)base);
3070 else
3071   sha1_start((sha1 *)base);
3072 }
3073
3074 static void
3075 chash_mid(int type, void *base, uschar *string)
3076 {
3077 if (type == HMAC_MD5)
3078   md5_mid((md5 *)base, string);
3079 else
3080   sha1_mid((sha1 *)base, string);
3081 }
3082
3083 static void
3084 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3085 {
3086 if (type == HMAC_MD5)
3087   md5_end((md5 *)base, string, length, digest);
3088 else
3089   sha1_end((sha1 *)base, string, length, digest);
3090 }
3091
3092
3093
3094
3095
3096 /********************************************************
3097 * prvs: Get last three digits of days since Jan 1, 1970 *
3098 ********************************************************/
3099
3100 /* This is needed to implement the "prvs" BATV reverse
3101    path signing scheme
3102
3103 Argument: integer "days" offset to add or substract to
3104           or from the current number of days.
3105
3106 Returns:  pointer to string containing the last three
3107           digits of the number of days since Jan 1, 1970,
3108           modified by the offset argument, NULL if there
3109           was an error in the conversion.
3110
3111 */
3112
3113 static uschar *
3114 prvs_daystamp(int day_offset)
3115 {
3116 uschar *days = store_get(32);                /* Need at least 24 for cases */
3117 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3118   (time(NULL) + day_offset*86400)/86400);
3119 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3120 }
3121
3122
3123
3124 /********************************************************
3125 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3126 ********************************************************/
3127
3128 /* This is needed to implement the "prvs" BATV reverse
3129    path signing scheme
3130
3131 Arguments:
3132   address RFC2821 Address to use
3133       key The key to use (must be less than 64 characters
3134           in size)
3135   key_num Single-digit key number to use. Defaults to
3136           '0' when NULL.
3137
3138 Returns:  pointer to string containing the first three
3139           bytes of the final hash in hex format, NULL if
3140           there was an error in the process.
3141 */
3142
3143 static uschar *
3144 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3145 {
3146 uschar *hash_source, *p;
3147 int size = 0,offset = 0,i;
3148 sha1 sha1_base;
3149 void *use_base = &sha1_base;
3150 uschar innerhash[20];
3151 uschar finalhash[20];
3152 uschar innerkey[64];
3153 uschar outerkey[64];
3154 uschar *finalhash_hex = store_get(40);
3155
3156 if (key_num == NULL)
3157   key_num = US"0";
3158
3159 if (Ustrlen(key) > 64)
3160   return NULL;
3161
3162 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3163 string_cat(hash_source,&size,&offset,daystamp,3);
3164 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3165 hash_source[offset] = '\0';
3166
3167 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3168
3169 memset(innerkey, 0x36, 64);
3170 memset(outerkey, 0x5c, 64);
3171
3172 for (i = 0; i < Ustrlen(key); i++)
3173   {
3174   innerkey[i] ^= key[i];
3175   outerkey[i] ^= key[i];
3176   }
3177
3178 chash_start(HMAC_SHA1, use_base);
3179 chash_mid(HMAC_SHA1, use_base, innerkey);
3180 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3181
3182 chash_start(HMAC_SHA1, use_base);
3183 chash_mid(HMAC_SHA1, use_base, outerkey);
3184 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3185
3186 p = finalhash_hex;
3187 for (i = 0; i < 3; i++)
3188   {
3189   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3190   *p++ = hex_digits[finalhash[i] & 0x0f];
3191   }
3192 *p = '\0';
3193
3194 return finalhash_hex;
3195 }
3196
3197
3198
3199
3200 /*************************************************
3201 *        Join a file onto the output string      *
3202 *************************************************/
3203
3204 /* This is used for readfile and after a run expansion. It joins the contents
3205 of a file onto the output string, globally replacing newlines with a given
3206 string (optionally). The file is closed at the end.
3207
3208 Arguments:
3209   f            the FILE
3210   yield        pointer to the expandable string
3211   sizep        pointer to the current size
3212   ptrp         pointer to the current position
3213   eol          newline replacement string, or NULL
3214
3215 Returns:       new value of string pointer
3216 */
3217
3218 static uschar *
3219 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3220 {
3221 int eollen;
3222 uschar buffer[1024];
3223
3224 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3225
3226 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3227   {
3228   int len = Ustrlen(buffer);
3229   if (eol != NULL && buffer[len-1] == '\n') len--;
3230   yield = string_cat(yield, sizep, ptrp, buffer, len);
3231   if (buffer[len] != 0)
3232     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3233   }
3234
3235 if (yield != NULL) yield[*ptrp] = 0;
3236
3237 return yield;
3238 }
3239
3240
3241
3242
3243 /*************************************************
3244 *          Evaluate numeric expression           *
3245 *************************************************/
3246
3247 /* This is a set of mutually recursive functions that evaluate an arithmetic
3248 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3249 these functions that is called from elsewhere is eval_expr, whose interface is:
3250
3251 Arguments:
3252   sptr        pointer to the pointer to the string - gets updated
3253   decimal     TRUE if numbers are to be assumed decimal
3254   error       pointer to where to put an error message - must be NULL on input
3255   endket      TRUE if ')' must terminate - FALSE for external call
3256
3257 Returns:      on success: the value of the expression, with *error still NULL
3258               on failure: an undefined value, with *error = a message
3259 */
3260
3261 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3262
3263
3264 static int_eximarith_t
3265 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3266 {
3267 uschar *s = *sptr;
3268 int_eximarith_t x = eval_op_or(&s, decimal, error);
3269 if (*error == NULL)
3270   {
3271   if (endket)
3272     {
3273     if (*s != ')')
3274       *error = US"expecting closing parenthesis";
3275     else
3276       while (isspace(*(++s)));
3277     }
3278   else if (*s != 0) *error = US"expecting operator";
3279   }
3280 *sptr = s;
3281 return x;
3282 }
3283
3284
3285 static int_eximarith_t
3286 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3287 {
3288 register int c;
3289 int_eximarith_t n;
3290 uschar *s = *sptr;
3291 while (isspace(*s)) s++;
3292 c = *s;
3293 if (isdigit(c))
3294   {
3295   int count;
3296   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3297   s += count;
3298   switch (tolower(*s))
3299     {
3300     default: break;
3301     case 'k': n *= 1024; s++; break;
3302     case 'm': n *= 1024*1024; s++; break;
3303     case 'g': n *= 1024*1024*1024; s++; break;
3304     }
3305   while (isspace (*s)) s++;
3306   }
3307 else if (c == '(')
3308   {
3309   s++;
3310   n = eval_expr(&s, decimal, error, 1);
3311   }
3312 else
3313   {
3314   *error = US"expecting number or opening parenthesis";
3315   n = 0;
3316   }
3317 *sptr = s;
3318 return n;
3319 }
3320
3321
3322 static int_eximarith_t
3323 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3324 {
3325 uschar *s = *sptr;
3326 int_eximarith_t x;
3327 while (isspace(*s)) s++;
3328 if (*s == '+' || *s == '-' || *s == '~')
3329   {
3330   int op = *s++;
3331   x = eval_op_unary(&s, decimal, error);
3332   if (op == '-') x = -x;
3333     else if (op == '~') x = ~x;
3334   }
3335 else
3336   {
3337   x = eval_number(&s, decimal, error);
3338   }
3339 *sptr = s;
3340 return x;
3341 }
3342
3343
3344 static int_eximarith_t
3345 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3346 {
3347 uschar *s = *sptr;
3348 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3349 if (*error == NULL)
3350   {
3351   while (*s == '*' || *s == '/' || *s == '%')
3352     {
3353     int op = *s++;
3354     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3355     if (*error != NULL) break;
3356     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3357      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3358      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3359      * -N*M is INT_MIN will yielf INT_MIN.
3360      * Since we don't support floating point, this is somewhat simpler.
3361      * Ideally, we'd return an error, but since we overflow for all other
3362      * arithmetic, consistency suggests otherwise, but what's the correct value
3363      * to use?  There is none.
3364      * The C standard guarantees overflow for unsigned arithmetic but signed
3365      * overflow invokes undefined behaviour; in practice, this is overflow
3366      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3367      * that long/longlong larger than int are available, or we could just work
3368      * with larger types.  We should consider whether to guarantee 32bit eval
3369      * and 64-bit working variables, with errors returned.  For now ...
3370      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3371      * can just let the other invalid results occur otherwise, as they have
3372      * until now.  For this one case, we can coerce.
3373      */
3374     if (y == -1 && x == LLONG_MIN && op != '*')
3375       {
3376       DEBUG(D_expand)
3377         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3378             LLONG_MIN, op, LLONG_MAX);
3379       x = LLONG_MAX;
3380       continue;
3381       }
3382     if (op == '*')
3383       x *= y;
3384     else
3385       {
3386       if (y == 0)
3387         {
3388         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3389         x = 0;
3390         break;
3391         }
3392       if (op == '/')
3393         x /= y;
3394       else
3395         x %= y;
3396       }
3397     }
3398   }
3399 *sptr = s;
3400 return x;
3401 }
3402
3403
3404 static int_eximarith_t
3405 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3406 {
3407 uschar *s = *sptr;
3408 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3409 if (*error == NULL)
3410   {
3411   while (*s == '+' || *s == '-')
3412     {
3413     int op = *s++;
3414     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3415     if (*error != NULL) break;
3416     if (op == '+') x += y; else x -= y;
3417     }
3418   }
3419 *sptr = s;
3420 return x;
3421 }
3422
3423
3424 static int_eximarith_t
3425 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3426 {
3427 uschar *s = *sptr;
3428 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3429 if (*error == NULL)
3430   {
3431   while ((*s == '<' || *s == '>') && s[1] == s[0])
3432     {
3433     int_eximarith_t y;
3434     int op = *s++;
3435     s++;
3436     y = eval_op_sum(&s, decimal, error);
3437     if (*error != NULL) break;
3438     if (op == '<') x <<= y; else x >>= y;
3439     }
3440   }
3441 *sptr = s;
3442 return x;
3443 }
3444
3445
3446 static int_eximarith_t
3447 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3448 {
3449 uschar *s = *sptr;
3450 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3451 if (*error == NULL)
3452   {
3453   while (*s == '&')
3454     {
3455     int_eximarith_t y;
3456     s++;
3457     y = eval_op_shift(&s, decimal, error);
3458     if (*error != NULL) break;
3459     x &= y;
3460     }
3461   }
3462 *sptr = s;
3463 return x;
3464 }
3465
3466
3467 static int_eximarith_t
3468 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3469 {
3470 uschar *s = *sptr;
3471 int_eximarith_t x = eval_op_and(&s, decimal, error);
3472 if (*error == NULL)
3473   {
3474   while (*s == '^')
3475     {
3476     int_eximarith_t y;
3477     s++;
3478     y = eval_op_and(&s, decimal, error);
3479     if (*error != NULL) break;
3480     x ^= y;
3481     }
3482   }
3483 *sptr = s;
3484 return x;
3485 }
3486
3487
3488 static int_eximarith_t
3489 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3490 {
3491 uschar *s = *sptr;
3492 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3493 if (*error == NULL)
3494   {
3495   while (*s == '|')
3496     {
3497     int_eximarith_t y;
3498     s++;
3499     y = eval_op_xor(&s, decimal, error);
3500     if (*error != NULL) break;
3501     x |= y;
3502     }
3503   }
3504 *sptr = s;
3505 return x;
3506 }
3507
3508
3509
3510 /*************************************************
3511 *                 Expand string                  *
3512 *************************************************/
3513
3514 /* Returns either an unchanged string, or the expanded string in stacking pool
3515 store. Interpreted sequences are:
3516
3517    \...                    normal escaping rules
3518    $name                   substitutes the variable
3519    ${name}                 ditto
3520    ${op:string}            operates on the expanded string value
3521    ${item{arg1}{arg2}...}  expands the args and then does the business
3522                              some literal args are not enclosed in {}
3523
3524 There are now far too many operators and item types to make it worth listing
3525 them here in detail any more.
3526
3527 We use an internal routine recursively to handle embedded substrings. The
3528 external function follows. The yield is NULL if the expansion failed, and there
3529 are two cases: if something collapsed syntactically, or if "fail" was given
3530 as the action on a lookup failure. These can be distinguised by looking at the
3531 variable expand_string_forcedfail, which is TRUE in the latter case.
3532
3533 The skipping flag is set true when expanding a substring that isn't actually
3534 going to be used (after "if" or "lookup") and it prevents lookups from
3535 happening lower down.
3536
3537 Store usage: At start, a store block of the length of the input plus 64
3538 is obtained. This is expanded as necessary by string_cat(), which might have to
3539 get a new block, or might be able to expand the original. At the end of the
3540 function we can release any store above that portion of the yield block that
3541 was actually used. In many cases this will be optimal.
3542
3543 However: if the first item in the expansion is a variable name or header name,
3544 we reset the store before processing it; if the result is in fresh store, we
3545 use that without copying. This is helpful for expanding strings like
3546 $message_headers which can get very long.
3547
3548 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3549 since resetting the store at the end of the expansion will free store that was
3550 allocated by the plugin code as well as the slop after the expanded string. So
3551 we skip any resets if ${dlfunc has been used. This is an unfortunate
3552 consequence of string expansion becoming too powerful.
3553
3554 Arguments:
3555   string         the string to be expanded
3556   ket_ends       true if expansion is to stop at }
3557   left           if not NULL, a pointer to the first character after the
3558                  expansion is placed here (typically used with ket_ends)
3559   skipping       TRUE for recursive calls when the value isn't actually going
3560                  to be used (to allow for optimisation)
3561   honour_dollar  TRUE if $ is to be expanded,
3562                  FALSE if it's just another character
3563
3564 Returns:         NULL if expansion fails:
3565                    expand_string_forcedfail is set TRUE if failure was forced
3566                    expand_string_message contains a textual error message
3567                  a pointer to the expanded string on success
3568 */
3569
3570 static uschar *
3571 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3572   BOOL skipping, BOOL honour_dollar)
3573 {
3574 int ptr = 0;
3575 int size = Ustrlen(string)+ 64;
3576 int item_type;
3577 uschar *yield = store_get(size);
3578 uschar *s = string;
3579 uschar *save_expand_nstring[EXPAND_MAXN+1];
3580 int save_expand_nlength[EXPAND_MAXN+1];
3581 BOOL resetok = TRUE;
3582
3583 expand_string_forcedfail = FALSE;
3584 expand_string_message = US"";
3585
3586 while (*s != 0)
3587   {
3588   uschar *value;
3589   uschar name[256];
3590
3591   /* \ escapes the next character, which must exist, or else
3592   the expansion fails. There's a special escape, \N, which causes
3593   copying of the subject verbatim up to the next \N. Otherwise,
3594   the escapes are the standard set. */
3595
3596   if (*s == '\\')
3597     {
3598     if (s[1] == 0)
3599       {
3600       expand_string_message = US"\\ at end of string";
3601       goto EXPAND_FAILED;
3602       }
3603
3604     if (s[1] == 'N')
3605       {
3606       uschar *t = s + 2;
3607       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3608       yield = string_cat(yield, &size, &ptr, t, s - t);
3609       if (*s != 0) s += 2;
3610       }
3611
3612     else
3613       {
3614       uschar ch[1];
3615       ch[0] = string_interpret_escape(&s);
3616       s++;
3617       yield = string_cat(yield, &size, &ptr, ch, 1);
3618       }
3619
3620     continue;
3621     }
3622
3623   /* Anything other than $ is just copied verbatim, unless we are
3624   looking for a terminating } character. */
3625
3626   if (ket_ends && *s == '}') break;
3627
3628   if (*s != '$' || !honour_dollar)
3629     {
3630     yield = string_cat(yield, &size, &ptr, s++, 1);
3631     continue;
3632     }
3633
3634   /* No { after the $ - must be a plain name or a number for string
3635   match variable. There has to be a fudge for variables that are the
3636   names of header fields preceded by "$header_" because header field
3637   names can contain any printing characters except space and colon.
3638   For those that don't like typing this much, "$h_" is a synonym for
3639   "$header_". A non-existent header yields a NULL value; nothing is
3640   inserted. */
3641
3642   if (isalpha((*(++s))))
3643     {
3644     int len;
3645     int newsize = 0;
3646
3647     s = read_name(name, sizeof(name), s, US"_");
3648
3649     /* If this is the first thing to be expanded, release the pre-allocated
3650     buffer. */
3651
3652     if (ptr == 0 && yield != NULL)
3653       {
3654       if (resetok) store_reset(yield);
3655       yield = NULL;
3656       size = 0;
3657       }
3658
3659     /* Header */
3660
3661     if (Ustrncmp(name, "h_", 2) == 0 ||
3662         Ustrncmp(name, "rh_", 3) == 0 ||
3663         Ustrncmp(name, "bh_", 3) == 0 ||
3664         Ustrncmp(name, "header_", 7) == 0 ||
3665         Ustrncmp(name, "rheader_", 8) == 0 ||
3666         Ustrncmp(name, "bheader_", 8) == 0)
3667       {
3668       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3669       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3670       s = read_header_name(name, sizeof(name), s);
3671       value = find_header(name, FALSE, &newsize, want_raw, charset);
3672
3673       /* If we didn't find the header, and the header contains a closing brace
3674       character, this may be a user error where the terminating colon
3675       has been omitted. Set a flag to adjust the error message in this case.
3676       But there is no error here - nothing gets inserted. */
3677
3678       if (value == NULL)
3679         {
3680         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3681         continue;
3682         }
3683       }
3684
3685     /* Variable */
3686
3687     else
3688       {
3689       value = find_variable(name, FALSE, skipping, &newsize);
3690       if (value == NULL)
3691         {
3692         expand_string_message =
3693           string_sprintf("unknown variable name \"%s\"", name);
3694           check_variable_error_message(name);
3695         goto EXPAND_FAILED;
3696         }
3697       }
3698
3699     /* If the data is known to be in a new buffer, newsize will be set to the
3700     size of that buffer. If this is the first thing in an expansion string,
3701     yield will be NULL; just point it at the new store instead of copying. Many
3702     expansion strings contain just one reference, so this is a useful
3703     optimization, especially for humungous headers. */
3704
3705     len = Ustrlen(value);
3706     if (yield == NULL && newsize != 0)
3707       {
3708       yield = value;
3709       size = newsize;
3710       ptr = len;
3711       }
3712     else yield = string_cat(yield, &size, &ptr, value, len);
3713
3714     continue;
3715     }
3716
3717   if (isdigit(*s))
3718     {
3719     int n;
3720     s = read_number(&n, s);
3721     if (n >= 0 && n <= expand_nmax)
3722       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3723         expand_nlength[n]);
3724     continue;
3725     }
3726
3727   /* Otherwise, if there's no '{' after $ it's an error. */
3728
3729   if (*s != '{')
3730     {
3731     expand_string_message = US"$ not followed by letter, digit, or {";
3732     goto EXPAND_FAILED;
3733     }
3734
3735   /* After { there can be various things, but they all start with
3736   an initial word, except for a number for a string match variable. */
3737
3738   if (isdigit((*(++s))))
3739     {
3740     int n;
3741     s = read_number(&n, s);
3742     if (*s++ != '}')
3743       {
3744       expand_string_message = US"} expected after number";
3745       goto EXPAND_FAILED;
3746       }
3747     if (n >= 0 && n <= expand_nmax)
3748       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3749         expand_nlength[n]);
3750     continue;
3751     }
3752
3753   if (!isalpha(*s))
3754     {
3755     expand_string_message = US"letter or digit expected after ${";
3756     goto EXPAND_FAILED;
3757     }
3758
3759   /* Allow "-" in names to cater for substrings with negative
3760   arguments. Since we are checking for known names after { this is
3761   OK. */
3762
3763   s = read_name(name, sizeof(name), s, US"_-");
3764   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3765
3766   switch(item_type)
3767     {
3768     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
3769     If the ACL returns accept or reject we return content set by "message ="
3770     There is currently no limit on recursion; this would have us call
3771     acl_check_internal() directly and get a current level from somewhere.
3772     See also the acl expansion condition ECOND_ACL and the traditional
3773     acl modifier ACLC_ACL.
3774     */
3775
3776     case EITEM_ACL:
3777       /* ${acl {name} {arg1}{arg2}...} */
3778       {
3779       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
3780       uschar *user_msg;
3781
3782       switch(read_subs(sub, 10, 1, &s, skipping, TRUE, US"acl"))
3783         {
3784         case 1: goto EXPAND_FAILED_CURLY;
3785         case 2:
3786         case 3: goto EXPAND_FAILED;
3787         }
3788       if (skipping) continue;
3789
3790       switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
3791         {
3792         case OK:
3793         case FAIL:
3794           if (user_msg)
3795             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
3796           continue;
3797
3798         case DEFER:
3799           expand_string_forcedfail = TRUE;
3800         default:
3801           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
3802           goto EXPAND_FAILED;
3803         }
3804       }
3805
3806     /* Handle conditionals - preserve the values of the numerical expansion
3807     variables in case they get changed by a regular expression match in the
3808     condition. If not, they retain their external settings. At the end
3809     of this "if" section, they get restored to their previous values. */
3810
3811     case EITEM_IF:
3812       {
3813       BOOL cond = FALSE;
3814       uschar *next_s;
3815       int save_expand_nmax =
3816         save_expand_strings(save_expand_nstring, save_expand_nlength);
3817
3818       while (isspace(*s)) s++;
3819       next_s = eval_condition(s, skipping? NULL : &cond);
3820       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3821
3822       DEBUG(D_expand)
3823         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3824           cond? "true" : "false");
3825
3826       s = next_s;
3827
3828       /* The handling of "yes" and "no" result strings is now in a separate
3829       function that is also used by ${lookup} and ${extract} and ${run}. */
3830
3831       switch(process_yesno(
3832                skipping,                     /* were previously skipping */
3833                cond,                         /* success/failure indicator */
3834                lookup_value,                 /* value to reset for string2 */
3835                &s,                           /* input pointer */
3836                &yield,                       /* output pointer */
3837                &size,                        /* output size */
3838                &ptr,                         /* output current point */
3839                US"if"))                      /* condition type */
3840         {
3841         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3842         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3843         }
3844
3845       /* Restore external setting of expansion variables for continuation
3846       at this level. */
3847
3848       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3849         save_expand_nlength);
3850       continue;
3851       }
3852
3853     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
3854     expanding an internal string that isn't actually going to be used. All we
3855     need to do is check the syntax, so don't do a lookup at all. Preserve the
3856     values of the numerical expansion variables in case they get changed by a
3857     partial lookup. If not, they retain their external settings. At the end
3858     of this "lookup" section, they get restored to their previous values. */
3859
3860     case EITEM_LOOKUP:
3861       {
3862       int stype, partial, affixlen, starflags;
3863       int expand_setup = 0;
3864       int nameptr = 0;
3865       uschar *key, *filename, *affix;
3866       uschar *save_lookup_value = lookup_value;
3867       int save_expand_nmax =
3868         save_expand_strings(save_expand_nstring, save_expand_nlength);
3869
3870       if ((expand_forbid & RDO_LOOKUP) != 0)
3871         {
3872         expand_string_message = US"lookup expansions are not permitted";
3873         goto EXPAND_FAILED;
3874         }
3875
3876       /* Get the key we are to look up for single-key+file style lookups.
3877       Otherwise set the key NULL pro-tem. */
3878
3879       while (isspace(*s)) s++;
3880       if (*s == '{')
3881         {
3882         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3883         if (key == NULL) goto EXPAND_FAILED;
3884         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3885         while (isspace(*s)) s++;
3886         }
3887       else key = NULL;
3888
3889       /* Find out the type of database */
3890
3891       if (!isalpha(*s))
3892         {
3893         expand_string_message = US"missing lookup type";
3894         goto EXPAND_FAILED;
3895         }
3896
3897       /* The type is a string that may contain special characters of various
3898       kinds. Allow everything except space or { to appear; the actual content
3899       is checked by search_findtype_partial. */
3900
3901       while (*s != 0 && *s != '{' && !isspace(*s))
3902         {
3903         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
3904         s++;
3905         }
3906       name[nameptr] = 0;
3907       while (isspace(*s)) s++;
3908
3909       /* Now check for the individual search type and any partial or default
3910       options. Only those types that are actually in the binary are valid. */
3911
3912       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
3913         &starflags);
3914       if (stype < 0)
3915         {
3916         expand_string_message = search_error_message;
3917         goto EXPAND_FAILED;
3918         }
3919
3920       /* Check that a key was provided for those lookup types that need it,
3921       and was not supplied for those that use the query style. */
3922
3923       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
3924         {
3925         if (key == NULL)
3926           {
3927           expand_string_message = string_sprintf("missing {key} for single-"
3928             "key \"%s\" lookup", name);
3929           goto EXPAND_FAILED;
3930           }
3931         }
3932       else
3933         {
3934         if (key != NULL)
3935           {
3936           expand_string_message = string_sprintf("a single key was given for "
3937             "lookup type \"%s\", which is not a single-key lookup type", name);
3938           goto EXPAND_FAILED;
3939           }
3940         }
3941
3942       /* Get the next string in brackets and expand it. It is the file name for
3943       single-key+file lookups, and the whole query otherwise. In the case of
3944       queries that also require a file name (e.g. sqlite), the file name comes
3945       first. */
3946
3947       if (*s != '{') goto EXPAND_FAILED_CURLY;
3948       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3949       if (filename == NULL) goto EXPAND_FAILED;
3950       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3951       while (isspace(*s)) s++;
3952
3953       /* If this isn't a single-key+file lookup, re-arrange the variables
3954       to be appropriate for the search_ functions. For query-style lookups,
3955       there is just a "key", and no file name. For the special query-style +
3956       file types, the query (i.e. "key") starts with a file name. */
3957
3958       if (key == NULL)
3959         {
3960         while (isspace(*filename)) filename++;
3961         key = filename;
3962
3963         if (mac_islookup(stype, lookup_querystyle))
3964           {
3965           filename = NULL;
3966           }
3967         else
3968           {
3969           if (*filename != '/')
3970             {
3971             expand_string_message = string_sprintf(
3972               "absolute file name expected for \"%s\" lookup", name);
3973             goto EXPAND_FAILED;
3974             }
3975           while (*key != 0 && !isspace(*key)) key++;
3976           if (*key != 0) *key++ = 0;
3977           }
3978         }
3979
3980       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
3981       the entry was not found. Note that there is no search_close() function.
3982       Files are left open in case of re-use. At suitable places in higher logic,
3983       search_tidyup() is called to tidy all open files. This can save opening
3984       the same file several times. However, files may also get closed when
3985       others are opened, if too many are open at once. The rule is that a
3986       handle should not be used after a second search_open().
3987
3988       Request that a partial search sets up $1 and maybe $2 by passing
3989       expand_setup containing zero. If its value changes, reset expand_nmax,
3990       since new variables will have been set. Note that at the end of this
3991       "lookup" section, the old numeric variables are restored. */
3992
3993       if (skipping)
3994         lookup_value = NULL;
3995       else
3996         {
3997         void *handle = search_open(filename, stype, 0, NULL, NULL);
3998         if (handle == NULL)
3999           {
4000           expand_string_message = search_error_message;
4001           goto EXPAND_FAILED;
4002           }
4003         lookup_value = search_find(handle, filename, key, partial, affix,
4004           affixlen, starflags, &expand_setup);
4005         if (search_find_defer)
4006           {
4007           expand_string_message =
4008             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4009               string_printing2(key, FALSE), search_error_message);
4010           goto EXPAND_FAILED;
4011           }
4012         if (expand_setup > 0) expand_nmax = expand_setup;
4013         }
4014
4015       /* The handling of "yes" and "no" result strings is now in a separate
4016       function that is also used by ${if} and ${extract}. */
4017
4018       switch(process_yesno(
4019                skipping,                     /* were previously skipping */
4020                lookup_value != NULL,         /* success/failure indicator */
4021                save_lookup_value,            /* value to reset for string2 */
4022                &s,                           /* input pointer */
4023                &yield,                       /* output pointer */
4024                &size,                        /* output size */
4025                &ptr,                         /* output current point */
4026                US"lookup"))                  /* condition type */
4027         {
4028         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4029         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4030         }
4031
4032       /* Restore external setting of expansion variables for carrying on
4033       at this level, and continue. */
4034
4035       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4036         save_expand_nlength);
4037       continue;
4038       }
4039
4040     /* If Perl support is configured, handle calling embedded perl subroutines,
4041     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4042     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4043     arguments (defined below). */
4044
4045     #define EXIM_PERL_MAX_ARGS 8
4046
4047     case EITEM_PERL:
4048     #ifndef EXIM_PERL
4049     expand_string_message = US"\"${perl\" encountered, but this facility "
4050       "is not included in this binary";
4051     goto EXPAND_FAILED;
4052
4053     #else   /* EXIM_PERL */
4054       {
4055       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4056       uschar *new_yield;
4057
4058       if ((expand_forbid & RDO_PERL) != 0)
4059         {
4060         expand_string_message = US"Perl calls are not permitted";
4061         goto EXPAND_FAILED;
4062         }
4063
4064       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4065            US"perl"))
4066         {
4067         case 1: goto EXPAND_FAILED_CURLY;
4068         case 2:
4069         case 3: goto EXPAND_FAILED;
4070         }
4071
4072       /* If skipping, we don't actually do anything */
4073
4074       if (skipping) continue;
4075
4076       /* Start the interpreter if necessary */
4077
4078       if (!opt_perl_started)
4079         {
4080         uschar *initerror;
4081         if (opt_perl_startup == NULL)
4082           {
4083           expand_string_message = US"A setting of perl_startup is needed when "
4084             "using the Perl interpreter";
4085           goto EXPAND_FAILED;
4086           }
4087         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4088         initerror = init_perl(opt_perl_startup);
4089         if (initerror != NULL)
4090           {
4091           expand_string_message =
4092             string_sprintf("error in perl_startup code: %s\n", initerror);
4093           goto EXPAND_FAILED;
4094           }
4095         opt_perl_started = TRUE;
4096         }
4097
4098       /* Call the function */
4099
4100       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4101       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4102         sub_arg[0], sub_arg + 1);
4103
4104       /* NULL yield indicates failure; if the message pointer has been set to
4105       NULL, the yield was undef, indicating a forced failure. Otherwise the
4106       message will indicate some kind of Perl error. */
4107
4108       if (new_yield == NULL)
4109         {
4110         if (expand_string_message == NULL)
4111           {
4112           expand_string_message =
4113             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4114               "failure", sub_arg[0]);
4115           expand_string_forcedfail = TRUE;
4116           }
4117         goto EXPAND_FAILED;
4118         }
4119
4120       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4121       set during a callback from Perl. */
4122
4123       expand_string_forcedfail = FALSE;
4124       yield = new_yield;
4125       continue;
4126       }
4127     #endif /* EXIM_PERL */
4128
4129     /* Transform email address to "prvs" scheme to use
4130        as BATV-signed return path */
4131
4132     case EITEM_PRVS:
4133       {
4134       uschar *sub_arg[3];
4135       uschar *p,*domain;
4136
4137       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs"))
4138         {
4139         case 1: goto EXPAND_FAILED_CURLY;
4140         case 2:
4141         case 3: goto EXPAND_FAILED;
4142         }
4143
4144       /* If skipping, we don't actually do anything */
4145       if (skipping) continue;
4146
4147       /* sub_arg[0] is the address */
4148       domain = Ustrrchr(sub_arg[0],'@');
4149       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4150         {
4151         expand_string_message = US"prvs first argument must be a qualified email address";
4152         goto EXPAND_FAILED;
4153         }
4154
4155       /* Calculate the hash. The second argument must be a single-digit
4156       key number, or unset. */
4157
4158       if (sub_arg[2] != NULL &&
4159           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4160         {
4161         expand_string_message = US"prvs second argument must be a single digit";
4162         goto EXPAND_FAILED;
4163         }
4164
4165       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4166       if (p == NULL)
4167         {
4168         expand_string_message = US"prvs hmac-sha1 conversion failed";
4169         goto EXPAND_FAILED;
4170         }
4171
4172       /* Now separate the domain from the local part */
4173       *domain++ = '\0';
4174
4175       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4176       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4177       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4178       string_cat(yield,&size,&ptr,p,6);
4179       string_cat(yield,&size,&ptr,US"=",1);
4180       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4181       string_cat(yield,&size,&ptr,US"@",1);
4182       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4183
4184       continue;
4185       }
4186
4187     /* Check a prvs-encoded address for validity */
4188
4189     case EITEM_PRVSCHECK:
4190       {
4191       uschar *sub_arg[3];
4192       int mysize = 0, myptr = 0;
4193       const pcre *re;
4194       uschar *p;
4195
4196       /* TF: Ugliness: We want to expand parameter 1 first, then set
4197          up expansion variables that are used in the expansion of
4198          parameter 2. So we clone the string for the first
4199          expansion, where we only expand parameter 1.
4200
4201          PH: Actually, that isn't necessary. The read_subs() function is
4202          designed to work this way for the ${if and ${lookup expansions. I've
4203          tidied the code.
4204       */
4205
4206       /* Reset expansion variables */
4207       prvscheck_result = NULL;
4208       prvscheck_address = NULL;
4209       prvscheck_keynum = NULL;
4210
4211       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4212         {
4213         case 1: goto EXPAND_FAILED_CURLY;
4214         case 2:
4215         case 3: goto EXPAND_FAILED;
4216         }
4217
4218       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4219                               TRUE,FALSE);
4220
4221       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4222         {
4223         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4224         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4225         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4226         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4227         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4228
4229         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4230         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4231         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4232         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4233         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4234
4235         /* Set up expansion variables */
4236         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4237         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4238         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4239         prvscheck_address[myptr] = '\0';
4240         prvscheck_keynum = string_copy(key_num);
4241
4242         /* Now expand the second argument */
4243         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4244           {
4245           case 1: goto EXPAND_FAILED_CURLY;
4246           case 2:
4247           case 3: goto EXPAND_FAILED;
4248           }
4249
4250         /* Now we have the key and can check the address. */
4251
4252         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4253           daystamp);
4254
4255         if (p == NULL)
4256           {
4257           expand_string_message = US"hmac-sha1 conversion failed";
4258           goto EXPAND_FAILED;
4259           }
4260
4261         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4262         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4263
4264         if (Ustrcmp(p,hash) == 0)
4265           {
4266           /* Success, valid BATV address. Now check the expiry date. */
4267           uschar *now = prvs_daystamp(0);
4268           unsigned int inow = 0,iexpire = 1;
4269
4270           (void)sscanf(CS now,"%u",&inow);
4271           (void)sscanf(CS daystamp,"%u",&iexpire);
4272
4273           /* When "iexpire" is < 7, a "flip" has occured.
4274              Adjust "inow" accordingly. */
4275           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4276
4277           if (iexpire >= inow)
4278             {
4279             prvscheck_result = US"1";
4280             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4281             }
4282             else
4283             {
4284             prvscheck_result = NULL;
4285             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4286             }
4287           }
4288         else
4289           {
4290           prvscheck_result = NULL;
4291           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4292           }
4293
4294         /* Now expand the final argument. We leave this till now so that
4295         it can include $prvscheck_result. */
4296
4297         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs"))
4298           {
4299           case 1: goto EXPAND_FAILED_CURLY;
4300           case 2:
4301           case 3: goto EXPAND_FAILED;
4302           }
4303
4304         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4305           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4306         else
4307           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4308
4309         /* Reset the "internal" variables afterwards, because they are in
4310         dynamic store that will be reclaimed if the expansion succeeded. */
4311
4312         prvscheck_address = NULL;
4313         prvscheck_keynum = NULL;
4314         }
4315       else
4316         {
4317         /* Does not look like a prvs encoded address, return the empty string.
4318            We need to make sure all subs are expanded first, so as to skip over
4319            the entire item. */
4320
4321         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs"))
4322           {
4323           case 1: goto EXPAND_FAILED_CURLY;
4324           case 2:
4325           case 3: goto EXPAND_FAILED;
4326           }
4327         }
4328
4329       continue;
4330       }
4331
4332     /* Handle "readfile" to insert an entire file */
4333
4334     case EITEM_READFILE:
4335       {
4336       FILE *f;
4337       uschar *sub_arg[2];
4338
4339       if ((expand_forbid & RDO_READFILE) != 0)
4340         {
4341         expand_string_message = US"file insertions are not permitted";
4342         goto EXPAND_FAILED;
4343         }
4344
4345       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
4346         {
4347         case 1: goto EXPAND_FAILED_CURLY;
4348         case 2:
4349         case 3: goto EXPAND_FAILED;
4350         }
4351
4352       /* If skipping, we don't actually do anything */
4353
4354       if (skipping) continue;
4355
4356       /* Open the file and read it */
4357
4358       f = Ufopen(sub_arg[0], "rb");
4359       if (f == NULL)
4360         {
4361         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4362         goto EXPAND_FAILED;
4363         }
4364
4365       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4366       (void)fclose(f);
4367       continue;
4368       }
4369
4370     /* Handle "readsocket" to insert data from a Unix domain socket */
4371
4372     case EITEM_READSOCK:
4373       {
4374       int fd;
4375       int timeout = 5;
4376       int save_ptr = ptr;
4377       FILE *f;
4378       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4379       uschar *arg;
4380       uschar *sub_arg[4];
4381
4382       if ((expand_forbid & RDO_READSOCK) != 0)
4383         {
4384         expand_string_message = US"socket insertions are not permitted";
4385         goto EXPAND_FAILED;
4386         }
4387
4388       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4389       because there may be a string for expansion on failure. */
4390
4391       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
4392         {
4393         case 1: goto EXPAND_FAILED_CURLY;
4394         case 2:                             /* Won't occur: no end check */
4395         case 3: goto EXPAND_FAILED;
4396         }
4397
4398       /* Sort out timeout, if given */
4399
4400       if (sub_arg[2] != NULL)
4401         {
4402         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4403         if (timeout < 0)
4404           {
4405           expand_string_message = string_sprintf("bad time value %s",
4406             sub_arg[2]);
4407           goto EXPAND_FAILED;
4408           }
4409         }
4410       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4411
4412       /* If skipping, we don't actually do anything. Otherwise, arrange to
4413       connect to either an IP or a Unix socket. */
4414
4415       if (!skipping)
4416         {
4417         /* Handle an IP (internet) domain */
4418
4419         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4420           {
4421           BOOL connected = FALSE;
4422           int namelen, port;
4423           host_item shost;
4424           host_item *h;
4425           uschar *server_name = sub_arg[0] + 5;
4426           uschar *port_name = Ustrrchr(server_name, ':');
4427
4428           /* Sort out the port */
4429
4430           if (port_name == NULL)
4431             {
4432             expand_string_message =
4433               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4434             goto EXPAND_FAILED;
4435             }
4436           *port_name++ = 0;           /* Terminate server name */
4437
4438           if (isdigit(*port_name))
4439             {
4440             uschar *end;
4441             port = Ustrtol(port_name, &end, 0);
4442             if (end != port_name + Ustrlen(port_name))
4443               {
4444               expand_string_message =
4445                 string_sprintf("invalid port number %s", port_name);
4446               goto EXPAND_FAILED;
4447               }
4448             }
4449           else
4450             {
4451             struct servent *service_info = getservbyname(CS port_name, "tcp");
4452             if (service_info == NULL)
4453               {
4454               expand_string_message = string_sprintf("unknown port \"%s\"",
4455                 port_name);
4456               goto EXPAND_FAILED;
4457               }
4458             port = ntohs(service_info->s_port);
4459             }
4460
4461           /* Sort out the server. */
4462
4463           shost.next = NULL;
4464           shost.address = NULL;
4465           shost.port = port;
4466           shost.mx = -1;
4467
4468           namelen = Ustrlen(server_name);
4469
4470           /* Anything enclosed in [] must be an IP address. */
4471
4472           if (server_name[0] == '[' &&
4473               server_name[namelen - 1] == ']')
4474             {
4475             server_name[namelen - 1] = 0;
4476             server_name++;
4477             if (string_is_ip_address(server_name, NULL) == 0)
4478               {
4479               expand_string_message =
4480                 string_sprintf("malformed IP address \"%s\"", server_name);
4481               goto EXPAND_FAILED;
4482               }
4483             shost.name = shost.address = server_name;
4484             }
4485
4486           /* Otherwise check for an unadorned IP address */
4487
4488           else if (string_is_ip_address(server_name, NULL) != 0)
4489             shost.name = shost.address = server_name;
4490
4491           /* Otherwise lookup IP address(es) from the name */
4492
4493           else
4494             {
4495             shost.name = server_name;
4496             if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
4497                 FALSE) != HOST_FOUND)
4498               {
4499               expand_string_message =
4500                 string_sprintf("no IP address found for host %s", shost.name);
4501               goto EXPAND_FAILED;
4502               }
4503             }
4504
4505           /* Try to connect to the server - test each IP till one works */
4506
4507           for (h = &shost; h != NULL; h = h->next)
4508             {
4509             int af = (Ustrchr(h->address, ':') != 0)? AF_INET6 : AF_INET;
4510             if ((fd = ip_socket(SOCK_STREAM, af)) == -1)
4511               {
4512               expand_string_message = string_sprintf("failed to create socket: "
4513                 "%s", strerror(errno));
4514               goto SOCK_FAIL;
4515               }
4516
4517             if (ip_connect(fd, af, h->address, port, timeout) == 0)
4518               {
4519               connected = TRUE;
4520               break;
4521               }
4522             }
4523
4524           if (!connected)
4525             {
4526             expand_string_message = string_sprintf("failed to connect to "
4527               "socket %s: couldn't connect to any host", sub_arg[0],
4528               strerror(errno));
4529             goto SOCK_FAIL;
4530             }
4531           }
4532
4533         /* Handle a Unix domain socket */
4534
4535         else
4536           {
4537           int rc;
4538           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4539             {
4540             expand_string_message = string_sprintf("failed to create socket: %s",
4541               strerror(errno));
4542             goto SOCK_FAIL;
4543             }
4544
4545           sockun.sun_family = AF_UNIX;
4546           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4547             sub_arg[0]);
4548
4549           sigalrm_seen = FALSE;
4550           alarm(timeout);
4551           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4552           alarm(0);
4553           if (sigalrm_seen)
4554             {
4555             expand_string_message = US "socket connect timed out";
4556             goto SOCK_FAIL;
4557             }
4558           if (rc < 0)
4559             {
4560             expand_string_message = string_sprintf("failed to connect to socket "
4561               "%s: %s", sub_arg[0], strerror(errno));
4562             goto SOCK_FAIL;
4563             }
4564           }
4565
4566         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4567
4568         /* Write the request string, if not empty */
4569
4570         if (sub_arg[1][0] != 0)
4571           {
4572           int len = Ustrlen(sub_arg[1]);
4573           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4574             sub_arg[1]);
4575           if (write(fd, sub_arg[1], len) != len)
4576             {
4577             expand_string_message = string_sprintf("request write to socket "
4578               "failed: %s", strerror(errno));
4579             goto SOCK_FAIL;
4580             }
4581           }
4582
4583         /* Shut down the sending side of the socket. This helps some servers to
4584         recognise that it is their turn to do some work. Just in case some
4585         system doesn't have this function, make it conditional. */
4586
4587         #ifdef SHUT_WR
4588         shutdown(fd, SHUT_WR);
4589         #endif
4590
4591         /* Now we need to read from the socket, under a timeout. The function
4592         that reads a file can be used. */
4593
4594         f = fdopen(fd, "rb");
4595         sigalrm_seen = FALSE;
4596         alarm(timeout);
4597         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4598         alarm(0);
4599         (void)fclose(f);
4600
4601         /* After a timeout, we restore the pointer in the result, that is,
4602         make sure we add nothing from the socket. */
4603
4604         if (sigalrm_seen)
4605           {
4606           ptr = save_ptr;
4607           expand_string_message = US "socket read timed out";
4608           goto SOCK_FAIL;
4609           }
4610         }
4611
4612       /* The whole thing has worked (or we were skipping). If there is a
4613       failure string following, we need to skip it. */
4614
4615       if (*s == '{')
4616         {
4617         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE) == NULL)
4618           goto EXPAND_FAILED;
4619         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4620         while (isspace(*s)) s++;
4621         }
4622       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4623       continue;
4624
4625       /* Come here on failure to create socket, connect socket, write to the
4626       socket, or timeout on reading. If another substring follows, expand and
4627       use it. Otherwise, those conditions give expand errors. */
4628
4629       SOCK_FAIL:
4630       if (*s != '{') goto EXPAND_FAILED;
4631       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4632       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE);
4633       if (arg == NULL) goto EXPAND_FAILED;
4634       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4635       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4636       while (isspace(*s)) s++;
4637       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4638       continue;
4639       }
4640
4641     /* Handle "run" to execute a program. */
4642
4643     case EITEM_RUN:
4644       {
4645       FILE *f;
4646       uschar *arg;
4647       uschar **argv;
4648       pid_t pid;
4649       int fd_in, fd_out;
4650       int lsize = 0;
4651       int lptr = 0;
4652
4653       if ((expand_forbid & RDO_RUN) != 0)
4654         {
4655         expand_string_message = US"running a command is not permitted";
4656         goto EXPAND_FAILED;
4657         }
4658
4659       while (isspace(*s)) s++;
4660       if (*s != '{') goto EXPAND_FAILED_CURLY;
4661       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
4662       if (arg == NULL) goto EXPAND_FAILED;
4663       while (isspace(*s)) s++;
4664       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4665
4666       if (skipping)   /* Just pretend it worked when we're skipping */
4667         {
4668         runrc = 0;
4669         }
4670       else
4671         {
4672         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4673             arg,                                /* raw command */
4674             FALSE,                              /* don't expand the arguments */
4675             0,                                  /* not relevant when... */
4676             NULL,                               /* no transporting address */
4677             US"${run} expansion",               /* for error messages */
4678             &expand_string_message))            /* where to put error message */
4679           {
4680           goto EXPAND_FAILED;
4681           }
4682
4683         /* Create the child process, making it a group leader. */
4684
4685         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4686
4687         if (pid < 0)
4688           {
4689           expand_string_message =
4690             string_sprintf("couldn't create child process: %s", strerror(errno));
4691           goto EXPAND_FAILED;
4692           }
4693
4694         /* Nothing is written to the standard input. */
4695
4696         (void)close(fd_in);
4697
4698         /* Read the pipe to get the command's output into $value (which is kept
4699         in lookup_value). Read during execution, so that if the output exceeds
4700         the OS pipe buffer limit, we don't block forever. */
4701
4702         f = fdopen(fd_out, "rb");
4703         sigalrm_seen = FALSE;
4704         alarm(60);
4705         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4706         alarm(0);
4707         (void)fclose(f);
4708
4709         /* Wait for the process to finish, applying the timeout, and inspect its
4710         return code for serious disasters. Simple non-zero returns are passed on.
4711         */
4712
4713         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4714           {
4715           if (sigalrm_seen == TRUE || runrc == -256)
4716             {
4717             expand_string_message = string_sprintf("command timed out");
4718             killpg(pid, SIGKILL);       /* Kill the whole process group */
4719             }
4720
4721           else if (runrc == -257)
4722             expand_string_message = string_sprintf("wait() failed: %s",
4723               strerror(errno));
4724
4725           else
4726             expand_string_message = string_sprintf("command killed by signal %d",
4727               -runrc);
4728
4729           goto EXPAND_FAILED;
4730           }
4731         }
4732
4733       /* Process the yes/no strings; $value may be useful in both cases */
4734
4735       switch(process_yesno(
4736                skipping,                     /* were previously skipping */
4737                runrc == 0,                   /* success/failure indicator */
4738                lookup_value,                 /* value to reset for string2 */
4739                &s,                           /* input pointer */
4740                &yield,                       /* output pointer */
4741                &size,                        /* output size */
4742                &ptr,                         /* output current point */
4743                US"run"))                     /* condition type */
4744         {
4745         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4746         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4747         }
4748
4749       continue;
4750       }
4751
4752     /* Handle character translation for "tr" */
4753
4754     case EITEM_TR:
4755       {
4756       int oldptr = ptr;
4757       int o2m;
4758       uschar *sub[3];
4759
4760       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
4761         {
4762         case 1: goto EXPAND_FAILED_CURLY;
4763         case 2:
4764         case 3: goto EXPAND_FAILED;
4765         }
4766
4767       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4768       o2m = Ustrlen(sub[2]) - 1;
4769
4770       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4771         {
4772         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4773         if (m != NULL)
4774           {
4775           int o = m - sub[1];
4776           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4777           }
4778         }
4779
4780       continue;
4781       }
4782
4783     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4784     expanded arguments. */
4785
4786     case EITEM_HASH:
4787     case EITEM_LENGTH:
4788     case EITEM_NHASH:
4789     case EITEM_SUBSTR:
4790       {
4791       int i;
4792       int len;
4793       uschar *ret;
4794       int val[2] = { 0, -1 };
4795       uschar *sub[3];
4796
4797       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4798       Ensure that sub[2] is set in the ${length case. */
4799
4800       sub[2] = NULL;
4801       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4802              TRUE, name))
4803         {
4804         case 1: goto EXPAND_FAILED_CURLY;
4805         case 2:
4806         case 3: goto EXPAND_FAILED;
4807         }
4808
4809       /* Juggle the arguments if there are only two of them: always move the
4810       string to the last position and make ${length{n}{str}} equivalent to
4811       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4812
4813       if (sub[2] == NULL)
4814         {
4815         sub[2] = sub[1];
4816         sub[1] = NULL;
4817         if (item_type == EITEM_LENGTH)
4818           {
4819           sub[1] = sub[0];
4820           sub[0] = NULL;
4821           }
4822         }
4823
4824       for (i = 0; i < 2; i++)
4825         {
4826         if (sub[i] == NULL) continue;
4827         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4828         if (*ret != 0 || (i != 0 && val[i] < 0))
4829           {
4830           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4831             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4832           goto EXPAND_FAILED;
4833           }
4834         }
4835
4836       ret =
4837         (item_type == EITEM_HASH)?
4838           compute_hash(sub[2], val[0], val[1], &len) :
4839         (item_type == EITEM_NHASH)?
4840           compute_nhash(sub[2], val[0], val[1], &len) :
4841           extract_substr(sub[2], val[0], val[1], &len);
4842
4843       if (ret == NULL) goto EXPAND_FAILED;
4844       yield = string_cat(yield, &size, &ptr, ret, len);
4845       continue;
4846       }
4847
4848     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4849     This code originally contributed by Steve Haslam. It currently supports
4850     the use of MD5 and SHA-1 hashes.
4851
4852     We need some workspace that is large enough to handle all the supported
4853     hash types. Use macros to set the sizes rather than be too elaborate. */
4854
4855     #define MAX_HASHLEN      20
4856     #define MAX_HASHBLOCKLEN 64
4857
4858     case EITEM_HMAC:
4859       {
4860       uschar *sub[3];
4861       md5 md5_base;
4862       sha1 sha1_base;
4863       void *use_base;
4864       int type, i;
4865       int hashlen;      /* Number of octets for the hash algorithm's output */
4866       int hashblocklen; /* Number of octets the hash algorithm processes */
4867       uschar *keyptr, *p;
4868       unsigned int keylen;
4869
4870       uschar keyhash[MAX_HASHLEN];
4871       uschar innerhash[MAX_HASHLEN];
4872       uschar finalhash[MAX_HASHLEN];
4873       uschar finalhash_hex[2*MAX_HASHLEN];
4874       uschar innerkey[MAX_HASHBLOCKLEN];
4875       uschar outerkey[MAX_HASHBLOCKLEN];
4876
4877       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
4878         {
4879         case 1: goto EXPAND_FAILED_CURLY;
4880         case 2:
4881         case 3: goto EXPAND_FAILED;
4882         }
4883
4884       if (Ustrcmp(sub[0], "md5") == 0)
4885         {
4886         type = HMAC_MD5;
4887         use_base = &md5_base;
4888         hashlen = 16;
4889         hashblocklen = 64;
4890         }
4891       else if (Ustrcmp(sub[0], "sha1") == 0)
4892         {
4893         type = HMAC_SHA1;
4894         use_base = &sha1_base;
4895         hashlen = 20;
4896         hashblocklen = 64;
4897         }
4898       else
4899         {
4900         expand_string_message =
4901           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
4902         goto EXPAND_FAILED;
4903         }
4904
4905       keyptr = sub[1];
4906       keylen = Ustrlen(keyptr);
4907
4908       /* If the key is longer than the hash block length, then hash the key
4909       first */
4910
4911       if (keylen > hashblocklen)
4912         {
4913         chash_start(type, use_base);
4914         chash_end(type, use_base, keyptr, keylen, keyhash);
4915         keyptr = keyhash;
4916         keylen = hashlen;
4917         }
4918
4919       /* Now make the inner and outer key values */
4920
4921       memset(innerkey, 0x36, hashblocklen);
4922       memset(outerkey, 0x5c, hashblocklen);
4923
4924       for (i = 0; i < keylen; i++)
4925         {
4926         innerkey[i] ^= keyptr[i];
4927         outerkey[i] ^= keyptr[i];
4928         }
4929
4930       /* Now do the hashes */
4931
4932       chash_start(type, use_base);
4933       chash_mid(type, use_base, innerkey);
4934       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
4935
4936       chash_start(type, use_base);
4937       chash_mid(type, use_base, outerkey);
4938       chash_end(type, use_base, innerhash, hashlen, finalhash);
4939
4940       /* Encode the final hash as a hex string */
4941
4942       p = finalhash_hex;
4943       for (i = 0; i < hashlen; i++)
4944         {
4945         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
4946         *p++ = hex_digits[finalhash[i] & 0x0f];
4947         }
4948
4949       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
4950         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
4951
4952       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
4953       }
4954
4955     continue;
4956
4957     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
4958     We have to save the numerical variables and restore them afterwards. */
4959
4960     case EITEM_SG:
4961       {
4962       const pcre *re;
4963       int moffset, moffsetextra, slen;
4964       int roffset;
4965       int emptyopt;
4966       const uschar *rerror;
4967       uschar *subject;
4968       uschar *sub[3];
4969       int save_expand_nmax =
4970         save_expand_strings(save_expand_nstring, save_expand_nlength);
4971
4972       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
4973         {
4974         case 1: goto EXPAND_FAILED_CURLY;
4975         case 2:
4976         case 3: goto EXPAND_FAILED;
4977         }
4978
4979       /* Compile the regular expression */
4980
4981       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
4982         NULL);
4983
4984       if (re == NULL)
4985         {
4986         expand_string_message = string_sprintf("regular expression error in "
4987           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
4988         goto EXPAND_FAILED;
4989         }
4990
4991       /* Now run a loop to do the substitutions as often as necessary. It ends
4992       when there are no more matches. Take care over matches of the null string;
4993       do the same thing as Perl does. */
4994
4995       subject = sub[0];
4996       slen = Ustrlen(sub[0]);
4997       moffset = moffsetextra = 0;
4998       emptyopt = 0;
4999
5000       for (;;)
5001         {
5002         int ovector[3*(EXPAND_MAXN+1)];
5003         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5004           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
5005         int nn;
5006         uschar *insert;
5007
5008         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5009         is not necessarily the end. We want to repeat the match from one
5010         character further along, but leaving the basic offset the same (for
5011         copying below). We can't be at the end of the string - that was checked
5012         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5013         finished; copy the remaining string and end the loop. */
5014
5015         if (n < 0)
5016           {
5017           if (emptyopt != 0)
5018             {
5019             moffsetextra = 1;
5020             emptyopt = 0;
5021             continue;
5022             }
5023           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5024           break;
5025           }
5026
5027         /* Match - set up for expanding the replacement. */
5028
5029         if (n == 0) n = EXPAND_MAXN + 1;
5030         expand_nmax = 0;
5031         for (nn = 0; nn < n*2; nn += 2)
5032           {
5033           expand_nstring[expand_nmax] = subject + ovector[nn];
5034           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5035           }
5036         expand_nmax--;
5037
5038         /* Copy the characters before the match, plus the expanded insertion. */
5039
5040         yield = string_cat(yield, &size, &ptr, subject + moffset,
5041           ovector[0] - moffset);
5042         insert = expand_string(sub[2]);
5043         if (insert == NULL) goto EXPAND_FAILED;
5044         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5045
5046         moffset = ovector[1];
5047         moffsetextra = 0;
5048         emptyopt = 0;
5049
5050         /* If we have matched an empty string, first check to see if we are at
5051         the end of the subject. If so, the loop is over. Otherwise, mimic
5052         what Perl's /g options does. This turns out to be rather cunning. First
5053         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5054         string at the same point. If this fails (picked up above) we advance to
5055         the next character. */
5056
5057         if (ovector[0] == ovector[1])
5058           {
5059           if (ovector[0] == slen) break;
5060           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5061           }
5062         }
5063
5064       /* All done - restore numerical variables. */
5065
5066       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5067         save_expand_nlength);
5068       continue;
5069       }
5070
5071     /* Handle keyed and numbered substring extraction. If the first argument
5072     consists entirely of digits, then a numerical extraction is assumed. */
5073
5074     case EITEM_EXTRACT:
5075       {
5076       int i;
5077       int j = 2;
5078       int field_number = 1;
5079       BOOL field_number_set = FALSE;
5080       uschar *save_lookup_value = lookup_value;
5081       uschar *sub[3];
5082       int save_expand_nmax =
5083         save_expand_strings(save_expand_nstring, save_expand_nlength);
5084
5085       /* Read the arguments */
5086
5087       for (i = 0; i < j; i++)
5088         {
5089         while (isspace(*s)) s++;
5090         if (*s == '{')
5091           {
5092           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5093           if (sub[i] == NULL) goto EXPAND_FAILED;
5094           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5095
5096           /* After removal of leading and trailing white space, the first
5097           argument must not be empty; if it consists entirely of digits
5098           (optionally preceded by a minus sign), this is a numerical
5099           extraction, and we expect 3 arguments. */
5100
5101           if (i == 0)
5102             {
5103             int len;
5104             int x = 0;
5105             uschar *p = sub[0];
5106
5107             while (isspace(*p)) p++;
5108             sub[0] = p;
5109
5110             len = Ustrlen(p);
5111             while (len > 0 && isspace(p[len-1])) len--;
5112             p[len] = 0;
5113
5114             if (*p == 0 && !skipping)
5115               {
5116               expand_string_message = US"first argument of \"extract\" must "
5117                 "not be empty";
5118               goto EXPAND_FAILED;
5119               }
5120
5121             if (*p == '-')
5122               {
5123               field_number = -1;
5124               p++;
5125               }
5126             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5127             if (*p == 0)
5128               {
5129               field_number *= x;
5130               j = 3;               /* Need 3 args */
5131               field_number_set = TRUE;
5132               }
5133             }
5134           }
5135         else goto EXPAND_FAILED_CURLY;
5136         }
5137
5138       /* Extract either the numbered or the keyed substring into $value. If
5139       skipping, just pretend the extraction failed. */
5140
5141       lookup_value = skipping? NULL : field_number_set?
5142         expand_gettokened(field_number, sub[1], sub[2]) :
5143         expand_getkeyed(sub[0], sub[1]);
5144
5145       /* If no string follows, $value gets substituted; otherwise there can
5146       be yes/no strings, as for lookup or if. */
5147
5148       switch(process_yesno(
5149                skipping,                     /* were previously skipping */
5150                lookup_value != NULL,         /* success/failure indicator */
5151                save_lookup_value,            /* value to reset for string2 */
5152                &s,                           /* input pointer */
5153                &yield,                       /* output pointer */
5154                &size,                        /* output size */
5155                &ptr,                         /* output current point */
5156                US"extract"))                 /* condition type */
5157         {
5158         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5159         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5160         }
5161
5162       /* All done - restore numerical variables. */
5163
5164       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5165         save_expand_nlength);
5166
5167       continue;
5168       }
5169
5170
5171     /* Handle list operations */
5172
5173     case EITEM_FILTER:
5174     case EITEM_MAP:
5175     case EITEM_REDUCE:
5176       {
5177       int sep = 0;
5178       int save_ptr = ptr;
5179       uschar outsep[2] = { '\0', '\0' };
5180       uschar *list, *expr, *temp;
5181       uschar *save_iterate_item = iterate_item;
5182       uschar *save_lookup_value = lookup_value;
5183
5184       while (isspace(*s)) s++;
5185       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5186
5187       list = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5188       if (list == NULL) goto EXPAND_FAILED;
5189       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5190
5191       if (item_type == EITEM_REDUCE)
5192         {
5193         while (isspace(*s)) s++;
5194         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5195         temp = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5196         if (temp == NULL) goto EXPAND_FAILED;
5197         lookup_value = temp;
5198         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5199         }
5200
5201       while (isspace(*s)) s++;
5202       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5203
5204       expr = s;
5205
5206       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5207       if scanning a "false" part). This allows us to find the end of the
5208       condition, because if the list is empty, we won't actually evaluate the
5209       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5210       the normal internal expansion function. */
5211
5212       if (item_type == EITEM_FILTER)
5213         {
5214         temp = eval_condition(expr, NULL);
5215         if (temp != NULL) s = temp;
5216         }
5217       else
5218         {
5219         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE);
5220         }
5221
5222       if (temp == NULL)
5223         {
5224         expand_string_message = string_sprintf("%s inside \"%s\" item",
5225           expand_string_message, name);
5226         goto EXPAND_FAILED;
5227         }
5228
5229       while (isspace(*s)) s++;
5230       if (*s++ != '}')
5231         {
5232         expand_string_message = string_sprintf("missing } at end of condition "
5233           "or expression inside \"%s\"", name);
5234         goto EXPAND_FAILED;
5235         }
5236
5237       while (isspace(*s)) s++;
5238       if (*s++ != '}')
5239         {
5240         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5241           name);
5242         goto EXPAND_FAILED;
5243         }
5244
5245       /* If we are skipping, we can now just move on to the next item. When
5246       processing for real, we perform the iteration. */
5247
5248       if (skipping) continue;
5249       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5250         {
5251         *outsep = (uschar)sep;      /* Separator as a string */
5252
5253         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5254
5255         if (item_type == EITEM_FILTER)
5256           {
5257           BOOL condresult;
5258           if (eval_condition(expr, &condresult) == NULL)
5259             {
5260             iterate_item = save_iterate_item;
5261             lookup_value = save_lookup_value;
5262             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5263               expand_string_message, name);
5264             goto EXPAND_FAILED;
5265             }
5266           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5267             condresult? "true":"false");
5268           if (condresult)
5269             temp = iterate_item;    /* TRUE => include this item */
5270           else
5271             continue;               /* FALSE => skip this item */
5272           }
5273
5274         /* EITEM_MAP and EITEM_REDUCE */
5275
5276         else
5277           {
5278           temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE);
5279           if (temp == NULL)
5280             {
5281             iterate_item = save_iterate_item;
5282             expand_string_message = string_sprintf("%s inside \"%s\" item",
5283               expand_string_message, name);
5284             goto EXPAND_FAILED;
5285             }
5286           if (item_type == EITEM_REDUCE)
5287             {
5288             lookup_value = temp;      /* Update the value of $value */
5289             continue;                 /* and continue the iteration */
5290             }
5291           }
5292
5293         /* We reach here for FILTER if the condition is true, always for MAP,
5294         and never for REDUCE. The value in "temp" is to be added to the output
5295         list that is being created, ensuring that any occurrences of the
5296         separator character are doubled. Unless we are dealing with the first
5297         item of the output list, add in a space if the new item begins with the
5298         separator character, or is an empty string. */
5299
5300         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5301           yield = string_cat(yield, &size, &ptr, US" ", 1);
5302
5303         /* Add the string in "temp" to the output list that we are building,
5304         This is done in chunks by searching for the separator character. */
5305
5306         for (;;)
5307           {
5308           size_t seglen = Ustrcspn(temp, outsep);
5309             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5310
5311           /* If we got to the end of the string we output one character
5312           too many; backup and end the loop. Otherwise arrange to double the
5313           separator. */
5314
5315           if (temp[seglen] == '\0') { ptr--; break; }
5316           yield = string_cat(yield, &size, &ptr, outsep, 1);
5317           temp += seglen + 1;
5318           }
5319
5320         /* Output a separator after the string: we will remove the redundant
5321         final one at the end. */
5322
5323         yield = string_cat(yield, &size, &ptr, outsep, 1);
5324         }   /* End of iteration over the list loop */
5325
5326       /* REDUCE has generated no output above: output the final value of
5327       $value. */
5328
5329       if (item_type == EITEM_REDUCE)
5330         {
5331         yield = string_cat(yield, &size, &ptr, lookup_value,
5332           Ustrlen(lookup_value));
5333         lookup_value = save_lookup_value;  /* Restore $value */
5334         }
5335
5336       /* FILTER and MAP generate lists: if they have generated anything, remove
5337       the redundant final separator. Even though an empty item at the end of a
5338       list does not count, this is tidier. */
5339
5340       else if (ptr != save_ptr) ptr--;
5341
5342       /* Restore preserved $item */
5343
5344       iterate_item = save_iterate_item;
5345       continue;
5346       }
5347
5348
5349     /* If ${dlfunc support is configured, handle calling dynamically-loaded
5350     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5351     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5352     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5353
5354     #define EXPAND_DLFUNC_MAX_ARGS 8
5355
5356     case EITEM_DLFUNC:
5357     #ifndef EXPAND_DLFUNC
5358     expand_string_message = US"\"${dlfunc\" encountered, but this facility "
5359       "is not included in this binary";
5360     goto EXPAND_FAILED;
5361
5362     #else   /* EXPAND_DLFUNC */
5363       {
5364       tree_node *t;
5365       exim_dlfunc_t *func;
5366       uschar *result;
5367       int status, argc;
5368       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5369
5370       if ((expand_forbid & RDO_DLFUNC) != 0)
5371         {
5372         expand_string_message =
5373           US"dynamically-loaded functions are not permitted";
5374         goto EXPAND_FAILED;
5375         }
5376
5377       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5378            TRUE, US"dlfunc"))
5379         {
5380         case 1: goto EXPAND_FAILED_CURLY;
5381         case 2:
5382         case 3: goto EXPAND_FAILED;
5383         }
5384
5385       /* If skipping, we don't actually do anything */
5386
5387       if (skipping) continue;
5388
5389       /* Look up the dynamically loaded object handle in the tree. If it isn't
5390       found, dlopen() the file and put the handle in the tree for next time. */
5391
5392       t = tree_search(dlobj_anchor, argv[0]);
5393       if (t == NULL)
5394         {
5395         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5396         if (handle == NULL)
5397           {
5398           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5399             argv[0], dlerror());
5400           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5401           goto EXPAND_FAILED;
5402           }
5403         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5404         Ustrcpy(t->name, argv[0]);
5405         t->data.ptr = handle;
5406         (void)tree_insertnode(&dlobj_anchor, t);
5407         }
5408
5409       /* Having obtained the dynamically loaded object handle, look up the
5410       function pointer. */
5411
5412       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5413       if (func == NULL)
5414         {
5415         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5416           "%s", argv[1], argv[0], dlerror());
5417         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5418         goto EXPAND_FAILED;
5419         }
5420
5421       /* Call the function and work out what to do with the result. If it
5422       returns OK, we have a replacement string; if it returns DEFER then
5423       expansion has failed in a non-forced manner; if it returns FAIL then
5424       failure was forced; if it returns ERROR or any other value there's a
5425       problem, so panic slightly. In any case, assume that the function has
5426       side-effects on the store that must be preserved. */
5427
5428       resetok = FALSE;
5429       result = NULL;
5430       for (argc = 0; argv[argc] != NULL; argc++);
5431       status = func(&result, argc - 2, &argv[2]);
5432       if(status == OK)
5433         {
5434         if (result == NULL) result = US"";
5435         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5436         continue;
5437         }
5438       else
5439         {
5440         expand_string_message = result == NULL ? US"(no message)" : result;
5441         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5442           else if(status != FAIL)
5443             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5444               argv[0], argv[1], status, expand_string_message);
5445         goto EXPAND_FAILED;
5446         }
5447       }
5448     #endif /* EXPAND_DLFUNC */
5449     }
5450
5451   /* Control reaches here if the name is not recognized as one of the more
5452   complicated expansion items. Check for the "operator" syntax (name terminated
5453   by a colon). Some of the operators have arguments, separated by _ from the
5454   name. */
5455
5456   if (*s == ':')
5457     {
5458     int c;
5459     uschar *arg = NULL;
5460     uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5461     if (sub == NULL) goto EXPAND_FAILED;
5462     s++;
5463
5464     /* Owing to an historical mis-design, an underscore may be part of the
5465     operator name, or it may introduce arguments.  We therefore first scan the
5466     table of names that contain underscores. If there is no match, we cut off
5467     the arguments and then scan the main table. */
5468
5469     c = chop_match(name, op_table_underscore,
5470       sizeof(op_table_underscore)/sizeof(uschar *));
5471
5472     if (c < 0)
5473       {
5474       arg = Ustrchr(name, '_');
5475       if (arg != NULL) *arg = 0;
5476       c = chop_match(name, op_table_main,
5477         sizeof(op_table_main)/sizeof(uschar *));
5478       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
5479       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
5480       }
5481
5482     /* If we are skipping, we don't need to perform the operation at all.
5483     This matters for operations like "mask", because the data may not be
5484     in the correct format when skipping. For example, the expression may test
5485     for the existence of $sender_host_address before trying to mask it. For
5486     other operations, doing them may not fail, but it is a waste of time. */
5487
5488     if (skipping && c >= 0) continue;
5489
5490     /* Otherwise, switch on the operator type */
5491
5492     switch(c)
5493       {
5494       case EOP_BASE62:
5495         {
5496         uschar *t;
5497         unsigned long int n = Ustrtoul(sub, &t, 10);
5498         if (*t != 0)
5499           {
5500           expand_string_message = string_sprintf("argument for base62 "
5501             "operator is \"%s\", which is not a decimal number", sub);
5502           goto EXPAND_FAILED;
5503           }
5504         t = string_base62(n);
5505         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5506         continue;
5507         }
5508
5509       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
5510
5511       case EOP_BASE62D:
5512         {
5513         uschar buf[16];
5514         uschar *tt = sub;
5515         unsigned long int n = 0;
5516         while (*tt != 0)
5517           {
5518           uschar *t = Ustrchr(base62_chars, *tt++);
5519           if (t == NULL)
5520             {
5521             expand_string_message = string_sprintf("argument for base62d "
5522               "operator is \"%s\", which is not a base %d number", sub,
5523               BASE_62);
5524             goto EXPAND_FAILED;
5525             }
5526           n = n * BASE_62 + (t - base62_chars);
5527           }
5528         (void)sprintf(CS buf, "%ld", n);
5529         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
5530         continue;
5531         }
5532
5533       case EOP_EXPAND:
5534         {
5535         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE);
5536         if (expanded == NULL)
5537           {
5538           expand_string_message =
5539             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
5540               expand_string_message);
5541           goto EXPAND_FAILED;
5542           }
5543         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
5544         continue;
5545         }
5546
5547       case EOP_LC:
5548         {
5549         int count = 0;
5550         uschar *t = sub - 1;
5551         while (*(++t) != 0) { *t = tolower(*t); count++; }
5552         yield = string_cat(yield, &size, &ptr, sub, count);
5553         continue;
5554         }
5555
5556       case EOP_UC:
5557         {
5558         int count = 0;
5559         uschar *t = sub - 1;
5560         while (*(++t) != 0) { *t = toupper(*t); count++; }
5561         yield = string_cat(yield, &size, &ptr, sub, count);
5562         continue;
5563         }
5564
5565       case EOP_MD5:
5566         {
5567         md5 base;
5568         uschar digest[16];
5569         int j;
5570         char st[33];
5571         md5_start(&base);
5572         md5_end(&base, sub, Ustrlen(sub), digest);
5573         for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
5574         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5575         continue;
5576         }
5577
5578       case EOP_SHA1:
5579         {
5580         sha1 base;
5581         uschar digest[20];
5582         int j;
5583         char st[41];
5584         sha1_start(&base);
5585         sha1_end(&base, sub, Ustrlen(sub), digest);
5586         for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
5587         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5588         continue;
5589         }
5590
5591       /* Convert hex encoding to base64 encoding */
5592
5593       case EOP_HEX2B64:
5594         {
5595         int c = 0;
5596         int b = -1;
5597         uschar *in = sub;
5598         uschar *out = sub;
5599         uschar *enc;
5600
5601         for (enc = sub; *enc != 0; enc++)
5602           {
5603           if (!isxdigit(*enc))
5604             {
5605             expand_string_message = string_sprintf("\"%s\" is not a hex "
5606               "string", sub);
5607             goto EXPAND_FAILED;
5608             }
5609           c++;
5610           }
5611
5612         if ((c & 1) != 0)
5613           {
5614           expand_string_message = string_sprintf("\"%s\" contains an odd "
5615             "number of characters", sub);
5616           goto EXPAND_FAILED;
5617           }
5618
5619         while ((c = *in++) != 0)
5620           {
5621           if (isdigit(c)) c -= '0';
5622           else c = toupper(c) - 'A' + 10;
5623           if (b == -1)
5624             {
5625             b = c << 4;
5626             }
5627           else
5628             {
5629             *out++ = b | c;
5630             b = -1;
5631             }
5632           }
5633
5634         enc = auth_b64encode(sub, out - sub);
5635         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
5636         continue;
5637         }
5638
5639       /* count the number of list elements */
5640
5641       case EOP_LISTCOUNT:
5642         {
5643         int cnt = 0;
5644         int sep = 0;
5645         uschar * cp;
5646         uschar buffer[256];
5647
5648         while (string_nextinlist(&sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
5649         cp = string_sprintf("%d", cnt);
5650         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5651         continue;
5652         }
5653
5654       /* expand a named list given the name */
5655       /* handles nested named lists; requotes as colon-sep list */
5656
5657       case EOP_LISTNAMED:
5658         {
5659         tree_node *t = NULL;
5660         uschar * list;
5661         int sep = 0;
5662         uschar * item;
5663         uschar * suffix = "";
5664         BOOL needsep = FALSE;
5665         uschar buffer[256];
5666
5667         if (*sub == '+') sub++;
5668         if (arg == NULL)        /* no-argument version */
5669           {
5670           if (!(t = tree_search(addresslist_anchor, sub)) &&
5671               !(t = tree_search(domainlist_anchor,  sub)) &&
5672               !(t = tree_search(hostlist_anchor,    sub)))
5673             t = tree_search(localpartlist_anchor, sub);
5674           }
5675         else switch(*arg)       /* specific list-type version */
5676           {
5677           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = "_a"; break;
5678           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = "_d"; break;
5679           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = "_h"; break;
5680           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = "_l"; break;
5681           default:
5682             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
5683             goto EXPAND_FAILED;
5684           }
5685
5686         if(!t)
5687           {
5688           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
5689             sub, !arg?""
5690               : *arg=='a'?"address "
5691               : *arg=='d'?"domain "
5692               : *arg=='h'?"host "
5693               : *arg=='l'?"localpart "
5694               : 0);
5695           goto EXPAND_FAILED;
5696           }
5697
5698         list = ((namedlist_block *)(t->data.ptr))->string;
5699
5700         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
5701           {
5702           uschar * buf = US" : ";
5703           if (needsep)
5704             yield = string_cat(yield, &size, &ptr, buf, 3);
5705           else
5706             needsep = TRUE;
5707
5708           if (*item == '+')     /* list item is itself a named list */
5709             {
5710             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
5711             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE);
5712             }
5713           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
5714             {
5715             char * cp;
5716             char tok[3];
5717             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
5718             while ((cp= strpbrk((const char *)item, tok)))
5719               {
5720               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
5721               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
5722                 {
5723                 yield = string_cat(yield, &size, &ptr, US"::", 2);
5724                 item = cp;
5725                 }
5726               else              /* sep in item; should already be doubled; emit once */
5727                 {
5728                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
5729                 if (*cp == sep) cp++;
5730                 item = cp;
5731                 }
5732               }
5733             }
5734           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
5735           }
5736         continue;
5737         }
5738
5739       /* mask applies a mask to an IP address; for example the result of
5740       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
5741
5742       case EOP_MASK:
5743         {
5744         int count;
5745         uschar *endptr;
5746         int binary[4];
5747         int mask, maskoffset;
5748         int type = string_is_ip_address(sub, &maskoffset);
5749         uschar buffer[64];
5750
5751         if (type == 0)
5752           {
5753           expand_string_message = string_sprintf("\"%s\" is not an IP address",
5754            sub);
5755           goto EXPAND_FAILED;
5756           }
5757
5758         if (maskoffset == 0)
5759           {
5760           expand_string_message = string_sprintf("missing mask value in \"%s\"",
5761             sub);
5762           goto EXPAND_FAILED;
5763           }
5764
5765         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
5766
5767         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
5768           {
5769           expand_string_message = string_sprintf("mask value too big in \"%s\"",
5770             sub);
5771           goto EXPAND_FAILED;
5772           }
5773
5774         /* Convert the address to binary integer(s) and apply the mask */
5775
5776         sub[maskoffset] = 0;
5777         count = host_aton(sub, binary);
5778         host_mask(count, binary, mask);
5779
5780         /* Convert to masked textual format and add to output. */
5781
5782         yield = string_cat(yield, &size, &ptr, buffer,
5783           host_nmtoa(count, binary, mask, buffer, '.'));
5784         continue;
5785         }
5786
5787       case EOP_ADDRESS:
5788       case EOP_LOCAL_PART:
5789       case EOP_DOMAIN:
5790         {
5791         uschar *error;
5792         int start, end, domain;
5793         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
5794           FALSE);
5795         if (t != NULL)
5796           {
5797           if (c != EOP_DOMAIN)
5798             {
5799             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
5800             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
5801             }
5802           else if (domain != 0)
5803             {
5804             domain += start;
5805             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
5806             }
5807           }
5808         continue;
5809         }
5810
5811       case EOP_ADDRESSES:
5812         {
5813         uschar outsep[2] = { ':', '\0' };
5814         uschar *address, *error;
5815         int save_ptr = ptr;
5816         int start, end, domain;  /* Not really used */
5817
5818         while (isspace(*sub)) sub++;
5819         if (*sub == '>') { *outsep = *++sub; ++sub; }
5820         parse_allow_group = TRUE;
5821
5822         for (;;)
5823           {
5824           uschar *p = parse_find_address_end(sub, FALSE);
5825           uschar saveend = *p;
5826           *p = '\0';
5827           address = parse_extract_address(sub, &error, &start, &end, &domain,
5828             FALSE);
5829           *p = saveend;
5830
5831           /* Add the address to the output list that we are building. This is
5832           done in chunks by searching for the separator character. At the
5833           start, unless we are dealing with the first address of the output
5834           list, add in a space if the new address begins with the separator
5835           character, or is an empty string. */
5836
5837           if (address != NULL)
5838             {
5839             if (ptr != save_ptr && address[0] == *outsep)
5840               yield = string_cat(yield, &size, &ptr, US" ", 1);
5841
5842             for (;;)
5843               {
5844               size_t seglen = Ustrcspn(address, outsep);
5845               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
5846
5847               /* If we got to the end of the string we output one character
5848               too many. */
5849
5850               if (address[seglen] == '\0') { ptr--; break; }
5851               yield = string_cat(yield, &size, &ptr, outsep, 1);
5852               address += seglen + 1;
5853               }
5854
5855             /* Output a separator after the string: we will remove the
5856             redundant final one at the end. */
5857
5858             yield = string_cat(yield, &size, &ptr, outsep, 1);
5859             }
5860
5861           if (saveend == '\0') break;
5862           sub = p + 1;
5863           }
5864
5865         /* If we have generated anything, remove the redundant final
5866         separator. */
5867
5868         if (ptr != save_ptr) ptr--;
5869         parse_allow_group = FALSE;
5870         continue;
5871         }
5872
5873
5874       /* quote puts a string in quotes if it is empty or contains anything
5875       other than alphamerics, underscore, dot, or hyphen.
5876
5877       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
5878       be quoted in order to be a valid local part.
5879
5880       In both cases, newlines and carriage returns are converted into \n and \r
5881       respectively */
5882
5883       case EOP_QUOTE:
5884       case EOP_QUOTE_LOCAL_PART:
5885       if (arg == NULL)
5886         {
5887         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
5888         uschar *t = sub - 1;
5889
5890         if (c == EOP_QUOTE)
5891           {
5892           while (!needs_quote && *(++t) != 0)
5893             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
5894           }
5895         else  /* EOP_QUOTE_LOCAL_PART */
5896           {
5897           while (!needs_quote && *(++t) != 0)
5898             needs_quote = !isalnum(*t) &&
5899               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
5900               (*t != '.' || t == sub || t[1] == 0);
5901           }
5902
5903         if (needs_quote)
5904           {
5905           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5906           t = sub - 1;
5907           while (*(++t) != 0)
5908             {
5909             if (*t == '\n')
5910               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
5911             else if (*t == '\r')
5912               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
5913             else
5914               {
5915               if (*t == '\\' || *t == '"')
5916                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
5917               yield = string_cat(yield, &size, &ptr, t, 1);
5918               }
5919             }
5920           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5921           }
5922         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5923         continue;
5924         }
5925
5926       /* quote_lookuptype does lookup-specific quoting */
5927
5928       else
5929         {
5930         int n;
5931         uschar *opt = Ustrchr(arg, '_');
5932
5933         if (opt != NULL) *opt++ = 0;
5934
5935         n = search_findtype(arg, Ustrlen(arg));
5936         if (n < 0)
5937           {
5938           expand_string_message = search_error_message;
5939           goto EXPAND_FAILED;
5940           }
5941
5942         if (lookup_list[n]->quote != NULL)
5943           sub = (lookup_list[n]->quote)(sub, opt);
5944         else if (opt != NULL) sub = NULL;
5945
5946         if (sub == NULL)
5947           {
5948           expand_string_message = string_sprintf(
5949             "\"%s\" unrecognized after \"${quote_%s\"",
5950             opt, arg);
5951           goto EXPAND_FAILED;
5952           }
5953
5954         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5955         continue;
5956         }
5957
5958       /* rx quote sticks in \ before any non-alphameric character so that
5959       the insertion works in a regular expression. */
5960
5961       case EOP_RXQUOTE:
5962         {
5963         uschar *t = sub - 1;
5964         while (*(++t) != 0)
5965           {
5966           if (!isalnum(*t))
5967             yield = string_cat(yield, &size, &ptr, US"\\", 1);
5968           yield = string_cat(yield, &size, &ptr, t, 1);
5969           }
5970         continue;
5971         }
5972
5973       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
5974       prescribed by the RFC, if there are characters that need to be encoded */
5975
5976       case EOP_RFC2047:
5977         {
5978         uschar buffer[2048];
5979         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
5980           buffer, sizeof(buffer), FALSE);
5981         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
5982         continue;
5983         }
5984
5985       /* RFC 2047 decode */
5986
5987       case EOP_RFC2047D:
5988         {
5989         int len;
5990         uschar *error;
5991         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
5992           headers_charset, '?', &len, &error);
5993         if (error != NULL)
5994           {
5995           expand_string_message = error;
5996           goto EXPAND_FAILED;
5997           }
5998         yield = string_cat(yield, &size, &ptr, decoded, len);
5999         continue;
6000         }
6001
6002       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6003       underscores */
6004
6005       case EOP_FROM_UTF8:
6006         {
6007         while (*sub != 0)
6008           {
6009           int c;
6010           uschar buff[4];
6011           GETUTF8INC(c, sub);
6012           if (c > 255) c = '_';
6013           buff[0] = c;
6014           yield = string_cat(yield, &size, &ptr, buff, 1);
6015           }
6016         continue;
6017         }
6018
6019       /* escape turns all non-printing characters into escape sequences. */
6020
6021       case EOP_ESCAPE:
6022         {
6023         uschar *t = string_printing(sub);
6024         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6025         continue;
6026         }
6027
6028       /* Handle numeric expression evaluation */
6029
6030       case EOP_EVAL:
6031       case EOP_EVAL10:
6032         {
6033         uschar *save_sub = sub;
6034         uschar *error = NULL;
6035         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6036         if (error != NULL)
6037           {
6038           expand_string_message = string_sprintf("error in expression "
6039             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6040               save_sub);
6041           goto EXPAND_FAILED;
6042           }
6043         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6044         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6045         continue;
6046         }
6047
6048       /* Handle time period formating */
6049
6050       case EOP_TIME_EVAL:
6051         {
6052         int n = readconf_readtime(sub, 0, FALSE);
6053         if (n < 0)
6054           {
6055           expand_string_message = string_sprintf("string \"%s\" is not an "
6056             "Exim time interval in \"%s\" operator", sub, name);
6057           goto EXPAND_FAILED;
6058           }
6059         sprintf(CS var_buffer, "%d", n);
6060         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6061         continue;
6062         }
6063
6064       case EOP_TIME_INTERVAL:
6065         {
6066         int n;
6067         uschar *t = read_number(&n, sub);
6068         if (*t != 0) /* Not A Number*/
6069           {
6070           expand_string_message = string_sprintf("string \"%s\" is not a "
6071             "positive number in \"%s\" operator", sub, name);
6072           goto EXPAND_FAILED;
6073           }
6074         t = readconf_printtime(n);
6075         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6076         continue;
6077         }
6078
6079       /* Convert string to base64 encoding */
6080
6081       case EOP_STR2B64:
6082         {
6083         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
6084         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
6085         continue;
6086         }
6087
6088       /* strlen returns the length of the string */
6089
6090       case EOP_STRLEN:
6091         {
6092         uschar buff[24];
6093         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6094         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6095         continue;
6096         }
6097
6098       /* length_n or l_n takes just the first n characters or the whole string,
6099       whichever is the shorter;
6100
6101       substr_m_n, and s_m_n take n characters from offset m; negative m take
6102       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6103       takes the rest, either to the right or to the left.
6104
6105       hash_n or h_n makes a hash of length n from the string, yielding n
6106       characters from the set a-z; hash_n_m makes a hash of length n, but
6107       uses m characters from the set a-zA-Z0-9.
6108
6109       nhash_n returns a single number between 0 and n-1 (in text form), while
6110       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6111       between 0 and n-1 and the second between 0 and m-1. */
6112
6113       case EOP_LENGTH:
6114       case EOP_L:
6115       case EOP_SUBSTR:
6116       case EOP_S:
6117       case EOP_HASH:
6118       case EOP_H:
6119       case EOP_NHASH:
6120       case EOP_NH:
6121         {
6122         int sign = 1;
6123         int value1 = 0;
6124         int value2 = -1;
6125         int *pn;
6126         int len;
6127         uschar *ret;
6128
6129         if (arg == NULL)
6130           {
6131           expand_string_message = string_sprintf("missing values after %s",
6132             name);
6133           goto EXPAND_FAILED;
6134           }
6135
6136         /* "length" has only one argument, effectively being synonymous with
6137         substr_0_n. */
6138
6139         if (c == EOP_LENGTH || c == EOP_L)
6140           {
6141           pn = &value2;
6142           value2 = 0;
6143           }
6144
6145         /* The others have one or two arguments; for "substr" the first may be
6146         negative. The second being negative means "not supplied". */
6147
6148         else
6149           {
6150           pn = &value1;
6151           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6152           }
6153
6154         /* Read up to two numbers, separated by underscores */
6155
6156         ret = arg;
6157         while (*arg != 0)
6158           {
6159           if (arg != ret && *arg == '_' && pn == &value1)
6160             {
6161             pn = &value2;
6162             value2 = 0;
6163             if (arg[1] != 0) arg++;
6164             }
6165           else if (!isdigit(*arg))
6166             {
6167             expand_string_message =
6168               string_sprintf("non-digit after underscore in \"%s\"", name);
6169             goto EXPAND_FAILED;
6170             }
6171           else *pn = (*pn)*10 + *arg++ - '0';
6172           }
6173         value1 *= sign;
6174
6175         /* Perform the required operation */
6176
6177         ret =
6178           (c == EOP_HASH || c == EOP_H)?
6179              compute_hash(sub, value1, value2, &len) :
6180           (c == EOP_NHASH || c == EOP_NH)?
6181              compute_nhash(sub, value1, value2, &len) :
6182              extract_substr(sub, value1, value2, &len);
6183
6184         if (ret == NULL) goto EXPAND_FAILED;
6185         yield = string_cat(yield, &size, &ptr, ret, len);
6186         continue;
6187         }
6188
6189       /* Stat a path */
6190
6191       case EOP_STAT:
6192         {
6193         uschar *s;
6194         uschar smode[12];
6195         uschar **modetable[3];
6196         int i;
6197         mode_t mode;
6198         struct stat st;
6199
6200         if ((expand_forbid & RDO_EXISTS) != 0)
6201           {
6202           expand_string_message = US"Use of the stat() expansion is not permitted";
6203           goto EXPAND_FAILED;
6204           }
6205
6206         if (stat(CS sub, &st) < 0)
6207           {
6208           expand_string_message = string_sprintf("stat(%s) failed: %s",
6209             sub, strerror(errno));
6210           goto EXPAND_FAILED;
6211           }
6212         mode = st.st_mode;
6213         switch (mode & S_IFMT)
6214           {
6215           case S_IFIFO: smode[0] = 'p'; break;
6216           case S_IFCHR: smode[0] = 'c'; break;
6217           case S_IFDIR: smode[0] = 'd'; break;
6218           case S_IFBLK: smode[0] = 'b'; break;
6219           case S_IFREG: smode[0] = '-'; break;
6220           default: smode[0] = '?'; break;
6221           }
6222
6223         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
6224         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
6225         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
6226
6227         for (i = 0; i < 3; i++)
6228           {
6229           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
6230           mode >>= 3;
6231           }
6232
6233         smode[10] = 0;
6234         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
6235           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
6236           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
6237           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
6238           (long)st.st_gid, st.st_size, (long)st.st_atime,
6239           (long)st.st_mtime, (long)st.st_ctime);
6240         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6241         continue;
6242         }
6243
6244       /* vaguely random number less than N */
6245
6246       case EOP_RANDINT:
6247         {
6248         int_eximarith_t max;
6249         uschar *s;
6250
6251         max = expand_string_integer(sub, TRUE);
6252         if (expand_string_message != NULL)
6253           goto EXPAND_FAILED;
6254         s = string_sprintf("%d", vaguely_random_number((int)max));
6255         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6256         continue;
6257         }
6258
6259       /* Reverse IP, including IPv6 to dotted-nibble */
6260
6261       case EOP_REVERSE_IP:
6262         {
6263         int family, maskptr;
6264         uschar reversed[128];
6265
6266         family = string_is_ip_address(sub, &maskptr);
6267         if (family == 0)
6268           {
6269           expand_string_message = string_sprintf(
6270               "reverse_ip() not given an IP address [%s]", sub);
6271           goto EXPAND_FAILED;
6272           }
6273         invert_address(reversed, sub);
6274         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
6275         continue;
6276         }
6277
6278       /* Unknown operator */
6279
6280       default:
6281       expand_string_message =
6282         string_sprintf("unknown expansion operator \"%s\"", name);
6283       goto EXPAND_FAILED;
6284       }
6285     }
6286
6287   /* Handle a plain name. If this is the first thing in the expansion, release
6288   the pre-allocated buffer. If the result data is known to be in a new buffer,
6289   newsize will be set to the size of that buffer, and we can just point at that
6290   store instead of copying. Many expansion strings contain just one reference,
6291   so this is a useful optimization, especially for humungous headers
6292   ($message_headers). */
6293
6294   if (*s++ == '}')
6295     {
6296     int len;
6297     int newsize = 0;
6298     if (ptr == 0)
6299       {
6300       if (resetok) store_reset(yield);
6301       yield = NULL;
6302       size = 0;
6303       }
6304     value = find_variable(name, FALSE, skipping, &newsize);
6305     if (value == NULL)
6306       {
6307       expand_string_message =
6308         string_sprintf("unknown variable in \"${%s}\"", name);
6309       check_variable_error_message(name);
6310       goto EXPAND_FAILED;
6311       }
6312     len = Ustrlen(value);
6313     if (yield == NULL && newsize != 0)
6314       {
6315       yield = value;
6316       size = newsize;
6317       ptr = len;
6318       }
6319     else yield = string_cat(yield, &size, &ptr, value, len);
6320     continue;
6321     }
6322
6323   /* Else there's something wrong */
6324
6325   expand_string_message =
6326     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
6327     "in a variable reference)", name);
6328   goto EXPAND_FAILED;
6329   }
6330
6331 /* If we hit the end of the string when ket_ends is set, there is a missing
6332 terminating brace. */
6333
6334 if (ket_ends && *s == 0)
6335   {
6336   expand_string_message = malformed_header?
6337     US"missing } at end of string - could be header name not terminated by colon"
6338     :
6339     US"missing } at end of string";
6340   goto EXPAND_FAILED;
6341   }
6342
6343 /* Expansion succeeded; yield may still be NULL here if nothing was actually
6344 added to the string. If so, set up an empty string. Add a terminating zero. If
6345 left != NULL, return a pointer to the terminator. */
6346
6347 if (yield == NULL) yield = store_get(1);
6348 yield[ptr] = 0;
6349 if (left != NULL) *left = s;
6350
6351 /* Any stacking store that was used above the final string is no longer needed.
6352 In many cases the final string will be the first one that was got and so there
6353 will be optimal store usage. */
6354
6355 if (resetok) store_reset(yield + ptr + 1);
6356 DEBUG(D_expand)
6357   {
6358   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
6359     yield);
6360   if (skipping) debug_printf("skipping: result is not used\n");
6361   }
6362 return yield;
6363
6364 /* This is the failure exit: easiest to program with a goto. We still need
6365 to update the pointer to the terminator, for cases of nested calls with "fail".
6366 */
6367
6368 EXPAND_FAILED_CURLY:
6369 expand_string_message = malformed_header?
6370   US"missing or misplaced { or } - could be header name not terminated by colon"
6371   :
6372   US"missing or misplaced { or }";
6373
6374 /* At one point, Exim reset the store to yield (if yield was not NULL), but
6375 that is a bad idea, because expand_string_message is in dynamic store. */
6376
6377 EXPAND_FAILED:
6378 if (left != NULL) *left = s;
6379 DEBUG(D_expand)
6380   {
6381   debug_printf("failed to expand: %s\n", string);
6382   debug_printf("   error message: %s\n", expand_string_message);
6383   if (expand_string_forcedfail) debug_printf("failure was forced\n");
6384   }
6385 return NULL;
6386 }
6387
6388
6389 /* This is the external function call. Do a quick check for any expansion
6390 metacharacters, and if there are none, just return the input string.
6391
6392 Argument: the string to be expanded
6393 Returns:  the expanded string, or NULL if expansion failed; if failure was
6394           due to a lookup deferring, search_find_defer will be TRUE
6395 */
6396
6397 uschar *
6398 expand_string(uschar *string)
6399 {
6400 search_find_defer = FALSE;
6401 malformed_header = FALSE;
6402 return (Ustrpbrk(string, "$\\") == NULL)? string :
6403   expand_string_internal(string, FALSE, NULL, FALSE, TRUE);
6404 }
6405
6406
6407
6408 /*************************************************
6409 *              Expand and copy                   *
6410 *************************************************/
6411
6412 /* Now and again we want to expand a string and be sure that the result is in a
6413 new bit of store. This function does that.
6414
6415 Argument: the string to be expanded
6416 Returns:  the expanded string, always in a new bit of store, or NULL
6417 */
6418
6419 uschar *
6420 expand_string_copy(uschar *string)
6421 {
6422 uschar *yield = expand_string(string);
6423 if (yield == string) yield = string_copy(string);
6424 return yield;
6425 }
6426
6427
6428
6429 /*************************************************
6430 *        Expand and interpret as an integer      *
6431 *************************************************/
6432
6433 /* Expand a string, and convert the result into an integer.
6434
6435 Arguments:
6436   string  the string to be expanded
6437   isplus  TRUE if a non-negative number is expected
6438
6439 Returns:  the integer value, or
6440           -1 for an expansion error               ) in both cases, message in
6441           -2 for an integer interpretation error  ) expand_string_message
6442           expand_string_message is set NULL for an OK integer
6443 */
6444
6445 int_eximarith_t
6446 expand_string_integer(uschar *string, BOOL isplus)
6447 {
6448 int_eximarith_t value;
6449 uschar *s = expand_string(string);
6450 uschar *msg = US"invalid integer \"%s\"";
6451 uschar *endptr;
6452
6453 /* If expansion failed, expand_string_message will be set. */
6454
6455 if (s == NULL) return -1;
6456
6457 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
6458 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
6459 systems, so we set it zero ourselves. */
6460
6461 errno = 0;
6462 expand_string_message = NULL;               /* Indicates no error */
6463
6464 /* Before Exim 4.64, strings consisting entirely of whitespace compared
6465 equal to 0.  Unfortunately, people actually relied upon that, so preserve
6466 the behaviour explicitly.  Stripping leading whitespace is a harmless
6467 noop change since strtol skips it anyway (provided that there is a number
6468 to find at all). */
6469 if (isspace(*s))
6470   {
6471   while (isspace(*s)) ++s;
6472   if (*s == '\0')
6473     {
6474       DEBUG(D_expand)
6475        debug_printf("treating blank string as number 0\n");
6476       return 0;
6477     }
6478   }
6479
6480 value = strtoll(CS s, CSS &endptr, 10);
6481
6482 if (endptr == s)
6483   {
6484   msg = US"integer expected but \"%s\" found";
6485   }
6486 else if (value < 0 && isplus)
6487   {
6488   msg = US"non-negative integer expected but \"%s\" found";
6489   }
6490 else
6491   {
6492   switch (tolower(*endptr))
6493     {
6494     default:
6495       break;
6496     case 'k':
6497       if (value > LLONG_MAX/1024 || value < LLONG_MIN/1024) errno = ERANGE;
6498       else value *= 1024;
6499       endptr++;
6500       break;
6501     case 'm':
6502       if (value > LLONG_MAX/(1024*1024) || value < LLONG_MIN/(1024*1024)) errno = ERANGE;
6503       else value *= 1024*1024;
6504       endptr++;
6505       break;
6506     case 'g':
6507       if (value > LLONG_MAX/(1024*1024*1024) || value < LLONG_MIN/(1024*1024*1024)) errno = ERANGE;
6508       else value *= 1024*1024*1024;
6509       endptr++;
6510       break;
6511     }
6512   if (errno == ERANGE)
6513     msg = US"absolute value of integer \"%s\" is too large (overflow)";
6514   else
6515     {
6516     while (isspace(*endptr)) endptr++;
6517     if (*endptr == 0) return (int)value;
6518     }
6519   }
6520
6521 expand_string_message = string_sprintf(CS msg, s);
6522 return -2;
6523 }
6524
6525
6526 /*************************************************
6527 **************************************************
6528 *             Stand-alone test program           *
6529 **************************************************
6530 *************************************************/
6531
6532 #ifdef STAND_ALONE
6533
6534
6535 BOOL
6536 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
6537 {
6538 int ovector[3*(EXPAND_MAXN+1)];
6539 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
6540   ovector, sizeof(ovector)/sizeof(int));
6541 BOOL yield = n >= 0;
6542 if (n == 0) n = EXPAND_MAXN + 1;
6543 if (yield)
6544   {
6545   int nn;
6546   expand_nmax = (setup < 0)? 0 : setup + 1;
6547   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
6548     {
6549     expand_nstring[expand_nmax] = subject + ovector[nn];
6550     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
6551     }
6552   expand_nmax--;
6553   }
6554 return yield;
6555 }
6556
6557
6558 int main(int argc, uschar **argv)
6559 {
6560 int i;
6561 uschar buffer[1024];
6562
6563 debug_selector = D_v;
6564 debug_file = stderr;
6565 debug_fd = fileno(debug_file);
6566 big_buffer = malloc(big_buffer_size);
6567
6568 for (i = 1; i < argc; i++)
6569   {
6570   if (argv[i][0] == '+')
6571     {
6572     debug_trace_memory = 2;
6573     argv[i]++;
6574     }
6575   if (isdigit(argv[i][0]))
6576     debug_selector = Ustrtol(argv[i], NULL, 0);
6577   else
6578     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
6579         Ustrlen(argv[i]))
6580       {
6581       #ifdef LOOKUP_LDAP
6582       eldap_default_servers = argv[i];
6583       #endif
6584       #ifdef LOOKUP_MYSQL
6585       mysql_servers = argv[i];
6586       #endif
6587       #ifdef LOOKUP_PGSQL
6588       pgsql_servers = argv[i];
6589       #endif
6590       }
6591   #ifdef EXIM_PERL
6592   else opt_perl_startup = argv[i];
6593   #endif
6594   }
6595
6596 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
6597
6598 expand_nstring[1] = US"string 1....";
6599 expand_nlength[1] = 8;
6600 expand_nmax = 1;
6601
6602 #ifdef EXIM_PERL
6603 if (opt_perl_startup != NULL)
6604   {
6605   uschar *errstr;
6606   printf("Starting Perl interpreter\n");
6607   errstr = init_perl(opt_perl_startup);
6608   if (errstr != NULL)
6609     {
6610     printf("** error in perl_startup code: %s\n", errstr);
6611     return EXIT_FAILURE;
6612     }
6613   }
6614 #endif /* EXIM_PERL */
6615
6616 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
6617   {
6618   void *reset_point = store_get(0);
6619   uschar *yield = expand_string(buffer);
6620   if (yield != NULL)
6621     {
6622     printf("%s\n", yield);
6623     store_reset(reset_point);
6624     }
6625   else
6626     {
6627     if (search_find_defer) printf("search_find deferred\n");
6628     printf("Failed: %s\n", expand_string_message);
6629     if (expand_string_forcedfail) printf("Forced failure\n");
6630     printf("\n");
6631     }
6632   }
6633
6634 search_tidyup();
6635
6636 return 0;
6637 }
6638
6639 #endif
6640
6641 /* End of expand.c */