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.
 788
 789 We used to release all store used, but this is not not safe due
 790 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 791 is reasonably careful to release what it can.
 792
 793 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 794
 795 Arguments:
 796   condition     the condition string
 797   m1            text to be incorporated in panic error
 798   m2            ditto
 799
 800 Returns:        TRUE if condition is met, FALSE if not
 801 */
 802
 803 BOOL
 804 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 805 {
 806 int rc;
 807 uschar *ss = expand_string(condition);
 808 if (ss == NULL)
 809   {
 810   if (!expand_string_forcedfail && !search_find_defer)
 811     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 812       "for %s %s: %s", condition, m1, m2, expand_string_message);
 813   return FALSE;
 814   }
 815 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 816   strcmpic(ss, US"false") != 0;
 817 return rc;
 818 }
 819
 820
 821
 822
 823 /*************************************************
 824 *        Pseudo-random number generation         *
 825 *************************************************/
 826
 827 /* Pseudo-random number generation.  The result is not "expected" to be
 828 cryptographically strong but not so weak that someone will shoot themselves
 829 in the foot using it as a nonce in some email header scheme or whatever
 830 weirdness they'll twist this into.  The result should ideally handle fork().
 831
 832 However, if we're stuck unable to provide this, then we'll fall back to
 833 appallingly bad randomness.
 834
 835 If SUPPORT_TLS is defined then this will not be used except as an emergency
 836 fallback.
 837
 838 Arguments:
 839   max       range maximum
 840 Returns     a random number in range [0, max-1]
 841 */
 842
 843 #ifdef SUPPORT_TLS
 844 # define vaguely_random_number vaguely_random_number_fallback
 845 #endif
 846 int
 847 vaguely_random_number(int max)
 848 {
 849 #ifdef SUPPORT_TLS
 850 # undef vaguely_random_number
 851 #endif
 852   static pid_t pid = 0;
 853   pid_t p2;
 854 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 855   struct timeval tv;
 856 #endif
 857
 858   p2 = getpid();
 859   if (p2 != pid)
 860     {
 861     if (pid != 0)
 862       {
 863
 864 #ifdef HAVE_ARC4RANDOM
 865       /* cryptographically strong randomness, common on *BSD platforms, not
 866       so much elsewhere.  Alas. */
 867       arc4random_stir();
 868 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 869 #ifdef HAVE_SRANDOMDEV
 870       /* uses random(4) for seeding */
 871       srandomdev();
 872 #else
 873       gettimeofday(&tv, NULL);
 874       srandom(tv.tv_sec | tv.tv_usec | getpid());
 875 #endif
 876 #else
 877       /* Poor randomness and no seeding here */
 878 #endif
 879
 880       }
 881     pid = p2;
 882     }
 883
 884 #ifdef HAVE_ARC4RANDOM
 885   return arc4random() % max;
 886 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 887   return random() % max;
 888 #else
 889   /* This one returns a 16-bit number, definitely not crypto-strong */
 890   return random_number(max);
 891 #endif
 892 }
 893
 894
 895
 896
 897 /*************************************************
 898 *             Pick out a name from a string      *
 899 *************************************************/
 900
 901 /* If the name is too long, it is silently truncated.
 902
 903 Arguments:
 904   name      points to a buffer into which to put the name
 905   max       is the length of the buffer
 906   s         points to the first alphabetic character of the name
 907   extras    chars other than alphanumerics to permit
 908
 909 Returns:    pointer to the first character after the name
 910
 911 Note: The test for *s != 0 in the while loop is necessary because
 912 Ustrchr() yields non-NULL if the character is zero (which is not something
 913 I expected). */
 914
 915 static uschar *
 916 read_name(uschar *name, int max, uschar *s, uschar *extras)
 917 {
 918 int ptr = 0;
 919 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
 920   {
 921   if (ptr < max-1) name[ptr++] = *s;
 922   s++;
 923   }
 924 name[ptr] = 0;
 925 return s;
 926 }
 927
 928
 929
 930 /*************************************************
 931 *     Pick out the rest of a header name         *
 932 *************************************************/
 933
 934 /* A variable name starting $header_ (or just $h_ for those who like
 935 abbreviations) might not be the complete header name because headers can
 936 contain any printing characters in their names, except ':'. This function is
 937 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
 938 on the end, if the name was terminated by white space.
 939
 940 Arguments:
 941   name      points to a buffer in which the name read so far exists
 942   max       is the length of the buffer
 943   s         points to the first character after the name so far, i.e. the
 944             first non-alphameric character after $header_xxxxx
 945
 946 Returns:    a pointer to the first character after the header name
 947 */
 948
 949 static uschar *
 950 read_header_name(uschar *name, int max, uschar *s)
 951 {
 952 int prelen = Ustrchr(name, '_') - name + 1;
 953 int ptr = Ustrlen(name) - prelen;
 954 if (ptr > 0) memmove(name, name+prelen, ptr);
 955 while (mac_isgraph(*s) && *s != ':')
 956   {
 957   if (ptr < max-1) name[ptr++] = *s;
 958   s++;
 959   }
 960 if (*s == ':') s++;
 961 name[ptr++] = ':';
 962 name[ptr] = 0;
 963 return s;
 964 }
 965
 966
 967
 968 /*************************************************
 969 *           Pick out a number from a string      *
 970 *************************************************/
 971
 972 /* Arguments:
 973   n     points to an integer into which to put the number
 974   s     points to the first digit of the number
 975
 976 Returns:  a pointer to the character after the last digit
 977 */
 978
 979 static uschar *
 980 read_number(int *n, uschar *s)
 981 {
 982 *n = 0;
 983 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
 984 return s;
 985 }
 986
 987
 988
 989 /*************************************************
 990 *        Extract keyed subfield from a string    *
 991 *************************************************/
 992
 993 /* The yield is in dynamic store; NULL means that the key was not found.
 994
 995 Arguments:
 996   key       points to the name of the key
 997   s         points to the string from which to extract the subfield
 998
 999 Returns:    NULL if the subfield was not found, or
1000             a pointer to the subfield's data
1001 */
1002
1003 static uschar *
1004 expand_getkeyed(uschar *key, uschar *s)
1005 {
1006 int length = Ustrlen(key);
1007 while (isspace(*s)) s++;
1008
1009 /* Loop to search for the key */
1010
1011 while (*s != 0)
1012   {
1013   int dkeylength;
1014   uschar *data;
1015   uschar *dkey = s;
1016
1017   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1018   dkeylength = s - dkey;
1019   while (isspace(*s)) s++;
1020   if (*s == '=') while (isspace((*(++s))));
1021
1022   data = string_dequote(&s);
1023   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1024     return data;
1025
1026   while (isspace(*s)) s++;
1027   }
1028
1029 return NULL;
1030 }
1031
1032
1033
1034
1035 /*************************************************
1036 *   Extract numbered subfield from string        *
1037 *************************************************/
1038
1039 /* Extracts a numbered field from a string that is divided by tokens - for
1040 example a line from /etc/passwd is divided by colon characters.  First field is
1041 numbered one.  Negative arguments count from the right. Zero returns the whole
1042 string. Returns NULL if there are insufficient tokens in the string
1043
1044 ***WARNING***
1045 Modifies final argument - this is a dynamically generated string, so that's OK.
1046
1047 Arguments:
1048   field       number of field to be extracted,
1049                 first field = 1, whole string = 0, last field = -1
1050   separators  characters that are used to break string into tokens
1051   s           points to the string from which to extract the subfield
1052
1053 Returns:      NULL if the field was not found,
1054               a pointer to the field's data inside s (modified to add 0)
1055 */
1056
1057 static uschar *
1058 expand_gettokened (int field, uschar *separators, uschar *s)
1059 {
1060 int sep = 1;
1061 int count;
1062 uschar *ss = s;
1063 uschar *fieldtext = NULL;
1064
1065 if (field == 0) return s;
1066
1067 /* Break the line up into fields in place; for field > 0 we stop when we have
1068 done the number of fields we want. For field < 0 we continue till the end of
1069 the string, counting the number of fields. */
1070
1071 count = (field > 0)? field : INT_MAX;
1072
1073 while (count-- > 0)
1074   {
1075   size_t len;
1076
1077   /* Previous field was the last one in the string. For a positive field
1078   number, this means there are not enough fields. For a negative field number,
1079   check that there are enough, and scan back to find the one that is wanted. */
1080
1081   if (sep == 0)
1082     {
1083     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1084     if ((-field) == (INT_MAX - count - 1)) return s;
1085     while (field++ < 0)
1086       {
1087       ss--;
1088       while (ss[-1] != 0) ss--;
1089       }
1090     fieldtext = ss;
1091     break;
1092     }
1093
1094   /* Previous field was not last in the string; save its start and put a
1095   zero at its end. */
1096
1097   fieldtext = ss;
1098   len = Ustrcspn(ss, separators);
1099   sep = ss[len];
1100   ss[len] = 0;
1101   ss += len + 1;
1102   }
1103
1104 return fieldtext;
1105 }
1106
1107
1108
1109 /*************************************************
1110 *        Extract a substring from a string       *
1111 *************************************************/
1112
1113 /* Perform the ${substr or ${length expansion operations.
1114
1115 Arguments:
1116   subject     the input string
1117   value1      the offset from the start of the input string to the start of
1118                 the output string; if negative, count from the right.
1119   value2      the length of the output string, or negative (-1) for unset
1120                 if value1 is positive, unset means "all after"
1121                 if value1 is negative, unset means "all before"
1122   len         set to the length of the returned string
1123
1124 Returns:      pointer to the output string, or NULL if there is an error
1125 */
1126
1127 static uschar *
1128 extract_substr(uschar *subject, int value1, int value2, int *len)
1129 {
1130 int sublen = Ustrlen(subject);
1131
1132 if (value1 < 0)    /* count from right */
1133   {
1134   value1 += sublen;
1135
1136   /* If the position is before the start, skip to the start, and adjust the
1137   length. If the length ends up negative, the substring is null because nothing
1138   can precede. This falls out naturally when the length is unset, meaning "all
1139   to the left". */
1140
1141   if (value1 < 0)
1142     {
1143     value2 += value1;
1144     if (value2 < 0) value2 = 0;
1145     value1 = 0;
1146     }
1147
1148   /* Otherwise an unset length => characters before value1 */
1149
1150   else if (value2 < 0)
1151     {
1152     value2 = value1;
1153     value1 = 0;
1154     }
1155   }
1156
1157 /* For a non-negative offset, if the starting position is past the end of the
1158 string, the result will be the null string. Otherwise, an unset length means
1159 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1160
1161 else
1162   {
1163   if (value1 > sublen)
1164     {
1165     value1 = sublen;
1166     value2 = 0;
1167     }
1168   else if (value2 < 0) value2 = sublen;
1169   }
1170
1171 /* Cut the length down to the maximum possible for the offset value, and get
1172 the required characters. */
1173
1174 if (value1 + value2 > sublen) value2 = sublen - value1;
1175 *len = value2;
1176 return subject + value1;
1177 }
1178
1179
1180
1181
1182 /*************************************************
1183 *            Old-style hash of a string          *
1184 *************************************************/
1185
1186 /* Perform the ${hash expansion operation.
1187
1188 Arguments:
1189   subject     the input string (an expanded substring)
1190   value1      the length of the output string; if greater or equal to the
1191                 length of the input string, the input string is returned
1192   value2      the number of hash characters to use, or 26 if negative
1193   len         set to the length of the returned string
1194
1195 Returns:      pointer to the output string, or NULL if there is an error
1196 */
1197
1198 static uschar *
1199 compute_hash(uschar *subject, int value1, int value2, int *len)
1200 {
1201 int sublen = Ustrlen(subject);
1202
1203 if (value2 < 0) value2 = 26;
1204 else if (value2 > Ustrlen(hashcodes))
1205   {
1206   expand_string_message =
1207     string_sprintf("hash count \"%d\" too big", value2);
1208   return NULL;
1209   }
1210
1211 /* Calculate the hash text. We know it is shorter than the original string, so
1212 can safely place it in subject[] (we know that subject is always itself an
1213 expanded substring). */
1214
1215 if (value1 < sublen)
1216   {
1217   int c;
1218   int i = 0;
1219   int j = value1;
1220   while ((c = (subject[j])) != 0)
1221     {
1222     int shift = (c + j++) & 7;
1223     subject[i] ^= (c << shift) | (c >> (8-shift));
1224     if (++i >= value1) i = 0;
1225     }
1226   for (i = 0; i < value1; i++)
1227     subject[i] = hashcodes[(subject[i]) % value2];
1228   }
1229 else value1 = sublen;
1230
1231 *len = value1;
1232 return subject;
1233 }
1234
1235
1236
1237
1238 /*************************************************
1239 *             Numeric hash of a string           *
1240 *************************************************/
1241
1242 /* Perform the ${nhash expansion operation. The first characters of the
1243 string are treated as most important, and get the highest prime numbers.
1244
1245 Arguments:
1246   subject     the input string
1247   value1      the maximum value of the first part of the result
1248   value2      the maximum value of the second part of the result,
1249                 or negative to produce only a one-part result
1250   len         set to the length of the returned string
1251
1252 Returns:  pointer to the output string, or NULL if there is an error.
1253 */
1254
1255 static uschar *
1256 compute_nhash (uschar *subject, int value1, int value2, int *len)
1257 {
1258 uschar *s = subject;
1259 int i = 0;
1260 unsigned long int total = 0; /* no overflow */
1261
1262 while (*s != 0)
1263   {
1264   if (i == 0) i = sizeof(prime)/sizeof(int) - 1;
1265   total += prime[i--] * (unsigned int)(*s++);
1266   }
1267
1268 /* If value2 is unset, just compute one number */
1269
1270 if (value2 < 0)
1271   {
1272   s = string_sprintf("%d", total % value1);
1273   }
1274
1275 /* Otherwise do a div/mod hash */
1276
1277 else
1278   {
1279   total = total % (value1 * value2);
1280   s = string_sprintf("%d/%d", total/value2, total % value2);
1281   }
1282
1283 *len = Ustrlen(s);
1284 return s;
1285 }
1286
1287
1288
1289
1290
1291 /*************************************************
1292 *     Find the value of a header or headers      *
1293 *************************************************/
1294
1295 /* Multiple instances of the same header get concatenated, and this function
1296 can also return a concatenation of all the header lines. When concatenating
1297 specific headers that contain lists of addresses, a comma is inserted between
1298 them. Otherwise we use a straight concatenation. Because some messages can have
1299 pathologically large number of lines, there is a limit on the length that is
1300 returned. Also, to avoid massive store use which would result from using
1301 string_cat() as it copies and extends strings, we do a preliminary pass to find
1302 out exactly how much store will be needed. On "normal" messages this will be
1303 pretty trivial.
1304
1305 Arguments:
1306   name          the name of the header, without the leading $header_ or $h_,
1307                 or NULL if a concatenation of all headers is required
1308   exists_only   TRUE if called from a def: test; don't need to build a string;
1309                 just return a string that is not "" and not "0" if the header
1310                 exists
1311   newsize       return the size of memory block that was obtained; may be NULL
1312                 if exists_only is TRUE
1313   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1314                 other than concatenating, will be done on the header. Also used
1315                 for $message_headers_raw.
1316   charset       name of charset to translate MIME words to; used only if
1317                 want_raw is false; if NULL, no translation is done (this is
1318                 used for $bh_ and $bheader_)
1319
1320 Returns:        NULL if the header does not exist, else a pointer to a new
1321                 store block
1322 */
1323
1324 static uschar *
1325 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1326   uschar *charset)
1327 {
1328 BOOL found = name == NULL;
1329 int comma = 0;
1330 int len = found? 0 : Ustrlen(name);
1331 int i;
1332 uschar *yield = NULL;
1333 uschar *ptr = NULL;
1334
1335 /* Loop for two passes - saves code repetition */
1336
1337 for (i = 0; i < 2; i++)
1338   {
1339   int size = 0;
1340   header_line *h;
1341
1342   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1343     {
1344     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1345       {
1346       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1347         {
1348         int ilen;
1349         uschar *t;
1350
1351         if (exists_only) return US"1";      /* don't need actual string */
1352         found = TRUE;
1353         t = h->text + len;                  /* text to insert */
1354         if (!want_raw)                      /* unless wanted raw, */
1355           while (isspace(*t)) t++;          /* remove leading white space */
1356         ilen = h->slen - (t - h->text);     /* length to insert */
1357
1358         /* Unless wanted raw, remove trailing whitespace, including the
1359         newline. */
1360
1361         if (!want_raw)
1362           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1363
1364         /* Set comma = 1 if handling a single header and it's one of those
1365         that contains an address list, except when asked for raw headers. Only
1366         need to do this once. */
1367
1368         if (!want_raw && name != NULL && comma == 0 &&
1369             Ustrchr("BCFRST", h->type) != NULL)
1370           comma = 1;
1371
1372         /* First pass - compute total store needed; second pass - compute
1373         total store used, including this header. */
1374
1375         size += ilen + comma + 1;  /* +1 for the newline */
1376
1377         /* Second pass - concatentate the data, up to a maximum. Note that
1378         the loop stops when size hits the limit. */
1379
1380         if (i != 0)
1381           {
1382           if (size > header_insert_maxlen)
1383             {
1384             ilen -= size - header_insert_maxlen - 1;
1385             comma = 0;
1386             }
1387           Ustrncpy(ptr, t, ilen);
1388           ptr += ilen;
1389
1390           /* For a non-raw header, put in the comma if needed, then add
1391           back the newline we removed above, provided there was some text in
1392           the header. */
1393
1394           if (!want_raw && ilen > 0)
1395             {
1396             if (comma != 0) *ptr++ = ',';
1397             *ptr++ = '\n';
1398             }
1399           }
1400         }
1401       }
1402     }
1403
1404   /* At end of first pass, return NULL if no header found. Then truncate size
1405   if necessary, and get the buffer to hold the data, returning the buffer size.
1406   */
1407
1408   if (i == 0)
1409     {
1410     if (!found) return NULL;
1411     if (size > header_insert_maxlen) size = header_insert_maxlen;
1412     *newsize = size + 1;
1413     ptr = yield = store_get(*newsize);
1414     }
1415   }
1416
1417 /* That's all we do for raw header expansion. */
1418
1419 if (want_raw)
1420   {
1421   *ptr = 0;
1422   }
1423
1424 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1425 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1426 function can return an error with decoded data if the charset translation
1427 fails. If decoding fails, it returns NULL. */
1428
1429 else
1430   {
1431   uschar *decoded, *error;
1432   if (ptr > yield && ptr[-1] == '\n') ptr--;
1433   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1434   *ptr = 0;
1435   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1436     newsize, &error);
1437   if (error != NULL)
1438     {
1439     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1440       "    input was: %s\n", error, yield);
1441     }
1442   if (decoded != NULL) yield = decoded;
1443   }
1444
1445 return yield;
1446 }
1447
1448
1449
1450
1451 /*************************************************
1452 *               Return list of recipients        *
1453 *************************************************/
1454 /* A recipients list is available only during system message filtering,
1455 during ACL processing after DATA, and while expanding pipe commands
1456 generated from a system filter, but not elsewhere. */
1457
1458 static uschar *
1459 fn_recipients(void)
1460 {
1461 if (!enable_dollar_recipients) return NULL; else
1462   {
1463   int size = 128;
1464   int ptr = 0;
1465   int i;
1466   uschar * s = store_get(size);
1467   for (i = 0; i < recipients_count; i++)
1468     {
1469     if (i != 0) s = string_cat(s, &size, &ptr, US", ", 2);
1470     s = string_cat(s, &size, &ptr, recipients_list[i].address,
1471       Ustrlen(recipients_list[i].address));
1472     }
1473   s[ptr] = 0;     /* string_cat() leaves room */
1474   return s;
1475   }
1476 }
1477
1478
1479 /*************************************************
1480 *               Find value of a variable         *
1481 *************************************************/
1482
1483 /* The table of variables is kept in alphabetic order, so we can search it
1484 using a binary chop. The "choplen" variable is nothing to do with the binary
1485 chop.
1486
1487 Arguments:
1488   name          the name of the variable being sought
1489   exists_only   TRUE if this is a def: test; passed on to find_header()
1490   skipping      TRUE => skip any processing evaluation; this is not the same as
1491                   exists_only because def: may test for values that are first
1492                   evaluated here
1493   newsize       pointer to an int which is initially zero; if the answer is in
1494                 a new memory buffer, *newsize is set to its size
1495
1496 Returns:        NULL if the variable does not exist, or
1497                 a pointer to the variable's contents, or
1498                 something non-NULL if exists_only is TRUE
1499 */
1500
1501 static uschar *
1502 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1503 {
1504 int first = 0;
1505 int last = var_table_size;
1506
1507 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1508 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1509 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1510 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1511 (this gave backwards compatibility at the changeover). There may be built-in
1512 variables whose names start acl_ but they should never start in this way. This
1513 slightly messy specification is a consequence of the history, needless to say.
1514
1515 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1516 set, in which case give an error. */
1517
1518 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1519      !isalpha(name[5]))
1520   {
1521   tree_node *node =
1522     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1523   return (node == NULL)? (strict_acl_vars? NULL : US"") : node->data.ptr;
1524   }
1525
1526 /* Handle $auth<n> variables. */
1527
1528 if (Ustrncmp(name, "auth", 4) == 0)
1529   {
1530   uschar *endptr;
1531   int n = Ustrtoul(name + 4, &endptr, 10);
1532   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1533     return (auth_vars[n-1] == NULL)? US"" : auth_vars[n-1];
1534   }
1535
1536 /* For all other variables, search the table */
1537
1538 while (last > first)
1539   {
1540   uschar *s, *domain;
1541   uschar **ss;
1542   int middle = (first + last)/2;
1543   int c = Ustrcmp(name, var_table[middle].name);
1544
1545   if (c > 0) { first = middle + 1; continue; }
1546   if (c < 0) { last = middle; continue; }
1547
1548   /* Found an existing variable. If in skipping state, the value isn't needed,
1549   and we want to avoid processing (such as looking up the host name). */
1550
1551   if (skipping) return US"";
1552
1553   switch (var_table[middle].type)
1554     {
1555     case vtype_filter_int:
1556     if (!filter_running) return NULL;
1557     /* Fall through */
1558     /* VVVVVVVVVVVV */
1559     case vtype_int:
1560     sprintf(CS var_buffer, "%d", *(int *)(var_table[middle].value)); /* Integer */
1561     return var_buffer;
1562
1563     case vtype_ino:
1564     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(var_table[middle].value))); /* Inode */
1565     return var_buffer;
1566
1567     case vtype_gid:
1568     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(var_table[middle].value))); /* gid */
1569     return var_buffer;
1570
1571     case vtype_uid:
1572     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(var_table[middle].value))); /* uid */
1573     return var_buffer;
1574
1575     case vtype_bool:
1576     sprintf(CS var_buffer, "%s", *(BOOL *)(var_table[middle].value) ? "yes" : "no"); /* bool */
1577     return var_buffer;
1578
1579     case vtype_stringptr:                      /* Pointer to string */
1580     s = *((uschar **)(var_table[middle].value));
1581     return (s == NULL)? US"" : s;
1582
1583     case vtype_pid:
1584     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1585     return var_buffer;
1586
1587     case vtype_load_avg:
1588     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1589     return var_buffer;
1590
1591     case vtype_host_lookup:                    /* Lookup if not done so */
1592     if (sender_host_name == NULL && sender_host_address != NULL &&
1593         !host_lookup_failed && host_name_lookup() == OK)
1594       host_build_sender_fullhost();
1595     return (sender_host_name == NULL)? US"" : sender_host_name;
1596
1597     case vtype_localpart:                      /* Get local part from address */
1598     s = *((uschar **)(var_table[middle].value));
1599     if (s == NULL) return US"";
1600     domain = Ustrrchr(s, '@');
1601     if (domain == NULL) return s;
1602     if (domain - s > sizeof(var_buffer) - 1)
1603       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1604           " in string expansion", sizeof(var_buffer));
1605     Ustrncpy(var_buffer, s, domain - s);
1606     var_buffer[domain - s] = 0;
1607     return var_buffer;
1608
1609     case vtype_domain:                         /* Get domain from address */
1610     s = *((uschar **)(var_table[middle].value));
1611     if (s == NULL) return US"";
1612     domain = Ustrrchr(s, '@');
1613     return (domain == NULL)? US"" : domain + 1;
1614
1615     case vtype_msgheaders:
1616     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1617
1618     case vtype_msgheaders_raw:
1619     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1620
1621     case vtype_msgbody:                        /* Pointer to msgbody string */
1622     case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1623     ss = (uschar **)(var_table[middle].value);
1624     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1625       {
1626       uschar *body;
1627       off_t start_offset = SPOOL_DATA_START_OFFSET;
1628       int len = message_body_visible;
1629       if (len > message_size) len = message_size;
1630       *ss = body = store_malloc(len+1);
1631       body[0] = 0;
1632       if (var_table[middle].type == vtype_msgbody_end)
1633         {
1634         struct stat statbuf;
1635         if (fstat(deliver_datafile, &statbuf) == 0)
1636           {
1637           start_offset = statbuf.st_size - len;
1638           if (start_offset < SPOOL_DATA_START_OFFSET)
1639             start_offset = SPOOL_DATA_START_OFFSET;
1640           }
1641         }
1642       lseek(deliver_datafile, start_offset, SEEK_SET);
1643       len = read(deliver_datafile, body, len);
1644       if (len > 0)
1645         {
1646         body[len] = 0;
1647         if (message_body_newlines)   /* Separate loops for efficiency */
1648           {
1649           while (len > 0)
1650             { if (body[--len] == 0) body[len] = ' '; }
1651           }
1652         else
1653           {
1654           while (len > 0)
1655             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1656           }
1657         }
1658       }
1659     return (*ss == NULL)? US"" : *ss;
1660
1661     case vtype_todbsdin:                       /* BSD inbox time of day */
1662     return tod_stamp(tod_bsdin);
1663
1664     case vtype_tode:                           /* Unix epoch time of day */
1665     return tod_stamp(tod_epoch);
1666
1667     case vtype_todel:                          /* Unix epoch/usec time of day */
1668     return tod_stamp(tod_epoch_l);
1669
1670     case vtype_todf:                           /* Full time of day */
1671     return tod_stamp(tod_full);
1672
1673     case vtype_todl:                           /* Log format time of day */
1674     return tod_stamp(tod_log_bare);            /* (without timezone) */
1675
1676     case vtype_todzone:                        /* Time zone offset only */
1677     return tod_stamp(tod_zone);
1678
1679     case vtype_todzulu:                        /* Zulu time */
1680     return tod_stamp(tod_zulu);
1681
1682     case vtype_todlf:                          /* Log file datestamp tod */
1683     return tod_stamp(tod_log_datestamp_daily);
1684
1685     case vtype_reply:                          /* Get reply address */
1686     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1687       headers_charset);
1688     if (s != NULL) while (isspace(*s)) s++;
1689     if (s == NULL || *s == 0)
1690       {
1691       *newsize = 0;                            /* For the *s==0 case */
1692       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1693       }
1694     if (s != NULL)
1695       {
1696       uschar *t;
1697       while (isspace(*s)) s++;
1698       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1699       while (t > s && isspace(t[-1])) t--;
1700       *t = 0;
1701       }
1702     return (s == NULL)? US"" : s;
1703
1704     case vtype_string_func:
1705       {
1706       uschar * (*fn)() = var_table[middle].value;
1707       return fn();
1708       }
1709
1710     case vtype_pspace:
1711       {
1712       int inodes;
1713       sprintf(CS var_buffer, "%d",
1714         receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes));
1715       }
1716     return var_buffer;
1717
1718     case vtype_pinodes:
1719       {
1720       int inodes;
1721       (void) receive_statvfs(var_table[middle].value == (void *)TRUE, &inodes);
1722       sprintf(CS var_buffer, "%d", inodes);
1723       }
1724     return var_buffer;
1725
1726     #ifndef DISABLE_DKIM
1727     case vtype_dkim:
1728     return dkim_exim_expand_query((int)(long)var_table[middle].value);
1729     #endif
1730
1731     }
1732   }
1733
1734 return NULL;          /* Unknown variable name */
1735 }
1736
1737
1738
1739
1740 void
1741 modify_variable(uschar *name, void * value)
1742 {
1743 int first = 0;
1744 int last = var_table_size;
1745
1746 while (last > first)
1747   {
1748   int middle = (first + last)/2;
1749   int c = Ustrcmp(name, var_table[middle].name);
1750
1751   if (c > 0) { first = middle + 1; continue; }
1752   if (c < 0) { last = middle; continue; }
1753
1754   /* Found an existing variable; change the item it refers to */
1755   var_table[middle].value = value;
1756   return;
1757   }
1758 return;          /* Unknown variable name, fail silently */
1759 }
1760
1761
1762
1763
1764
1765 /*************************************************
1766 *           Read and expand substrings           *
1767 *************************************************/
1768
1769 /* This function is called to read and expand argument substrings for various
1770 expansion items. Some have a minimum requirement that is less than the maximum;
1771 in these cases, the first non-present one is set to NULL.
1772
1773 Arguments:
1774   sub        points to vector of pointers to set
1775   n          maximum number of substrings
1776   m          minimum required
1777   sptr       points to current string pointer
1778   skipping   the skipping flag
1779   check_end  if TRUE, check for final '}'
1780   name       name of item, for error message
1781
1782 Returns:     0 OK; string pointer updated
1783              1 curly bracketing error (too few arguments)
1784              2 too many arguments (only if check_end is set); message set
1785              3 other error (expansion failure)
1786 */
1787
1788 static int
1789 read_subs(uschar **sub, int n, int m, uschar **sptr, BOOL skipping,
1790   BOOL check_end, uschar *name)
1791 {
1792 int i;
1793 uschar *s = *sptr;
1794
1795 while (isspace(*s)) s++;
1796 for (i = 0; i < n; i++)
1797   {
1798   if (*s != '{')
1799     {
1800     if (i < m) return 1;
1801     sub[i] = NULL;
1802     break;
1803     }
1804   sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
1805   if (sub[i] == NULL) return 3;
1806   if (*s++ != '}') return 1;
1807   while (isspace(*s)) s++;
1808   }
1809 if (check_end && *s++ != '}')
1810   {
1811   if (s[-1] == '{')
1812     {
1813     expand_string_message = string_sprintf("Too many arguments for \"%s\" "
1814       "(max is %d)", name, n);
1815     return 2;
1816     }
1817   return 1;
1818   }
1819
1820 *sptr = s;
1821 return 0;
1822 }
1823
1824
1825
1826
1827 /*************************************************
1828 *     Elaborate message for bad variable         *
1829 *************************************************/
1830
1831 /* For the "unknown variable" message, take a look at the variable's name, and
1832 give additional information about possible ACL variables. The extra information
1833 is added on to expand_string_message.
1834
1835 Argument:   the name of the variable
1836 Returns:    nothing
1837 */
1838
1839 static void
1840 check_variable_error_message(uschar *name)
1841 {
1842 if (Ustrncmp(name, "acl_", 4) == 0)
1843   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
1844     (name[4] == 'c' || name[4] == 'm')?
1845       (isalpha(name[5])?
1846         US"6th character of a user-defined ACL variable must be a digit or underscore" :
1847         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
1848       ) :
1849       US"user-defined ACL variables must start acl_c or acl_m");
1850 }
1851
1852
1853
1854 /*
1855 Load args from sub array to globals, and call acl_check().
1856 Sub array will be corrupted on return.
1857
1858 Returns:       OK         access is granted by an ACCEPT verb
1859                DISCARD    access is granted by a DISCARD verb
1860                FAIL       access is denied
1861                FAIL_DROP  access is denied; drop the connection
1862                DEFER      can't tell at the moment
1863                ERROR      disaster
1864 */
1865 static int
1866 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
1867 {
1868 int i;
1869 uschar *tmp;
1870 int sav_narg = acl_narg;
1871 int ret;
1872 extern int acl_where;
1873
1874 if(--nsub > sizeof(acl_arg)/sizeof(*acl_arg)) nsub = sizeof(acl_arg)/sizeof(*acl_arg);
1875 for (i = 0; i < nsub && sub[i+1]; i++)
1876   {
1877   tmp = acl_arg[i];
1878   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
1879   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
1880   }
1881 acl_narg = i;
1882 while (i < nsub)
1883   {
1884   sub[i+1] = acl_arg[i];
1885   acl_arg[i++] = NULL;
1886   }
1887
1888 DEBUG(D_expand)
1889   debug_printf("expanding: acl: %s  arg: %s%s\n",
1890     sub[0],
1891     acl_narg>0 ? sub[1]   : US"<none>",
1892     acl_narg>1 ? " +more" : "");
1893
1894 ret = acl_eval(acl_where, NULL, sub[0], user_msgp, &tmp);
1895
1896 for (i = 0; i < nsub; i++)
1897   acl_arg[i] = sub[i+1];        /* restore old args */
1898 acl_narg = sav_narg;
1899
1900 return ret;
1901 }
1902
1903
1904
1905
1906 /*************************************************
1907 *        Read and evaluate a condition           *
1908 *************************************************/
1909
1910 /*
1911 Arguments:
1912   s        points to the start of the condition text
1913   yield    points to a BOOL to hold the result of the condition test;
1914            if NULL, we are just reading through a condition that is
1915            part of an "or" combination to check syntax, or in a state
1916            where the answer isn't required
1917
1918 Returns:   a pointer to the first character after the condition, or
1919            NULL after an error
1920 */
1921
1922 static uschar *
1923 eval_condition(uschar *s, BOOL *yield)
1924 {
1925 BOOL testfor = TRUE;
1926 BOOL tempcond, combined_cond;
1927 BOOL *subcondptr;
1928 BOOL sub2_honour_dollar = TRUE;
1929 int i, rc, cond_type, roffset;
1930 int_eximarith_t num[2];
1931 struct stat statbuf;
1932 uschar name[256];
1933 uschar *sub[10];
1934
1935 const pcre *re;
1936 const uschar *rerror;
1937
1938 for (;;)
1939   {
1940   while (isspace(*s)) s++;
1941   if (*s == '!') { testfor = !testfor; s++; } else break;
1942   }
1943
1944 /* Numeric comparisons are symbolic */
1945
1946 if (*s == '=' || *s == '>' || *s == '<')
1947   {
1948   int p = 0;
1949   name[p++] = *s++;
1950   if (*s == '=')
1951     {
1952     name[p++] = '=';
1953     s++;
1954     }
1955   name[p] = 0;
1956   }
1957
1958 /* All other conditions are named */
1959
1960 else s = read_name(name, 256, s, US"_");
1961
1962 /* If we haven't read a name, it means some non-alpha character is first. */
1963
1964 if (name[0] == 0)
1965   {
1966   expand_string_message = string_sprintf("condition name expected, "
1967     "but found \"%.16s\"", s);
1968   return NULL;
1969   }
1970
1971 /* Find which condition we are dealing with, and switch on it */
1972
1973 cond_type = chop_match(name, cond_table, sizeof(cond_table)/sizeof(uschar *));
1974 switch(cond_type)
1975   {
1976   /* def: tests for a non-empty variable, or for the existence of a header. If
1977   yield == NULL we are in a skipping state, and don't care about the answer. */
1978
1979   case ECOND_DEF:
1980   if (*s != ':')
1981     {
1982     expand_string_message = US"\":\" expected after \"def\"";
1983     return NULL;
1984     }
1985
1986   s = read_name(name, 256, s+1, US"_");
1987
1988   /* Test for a header's existence. If the name contains a closing brace
1989   character, this may be a user error where the terminating colon has been
1990   omitted. Set a flag to adjust a subsequent error message in this case. */
1991
1992   if (Ustrncmp(name, "h_", 2) == 0 ||
1993       Ustrncmp(name, "rh_", 3) == 0 ||
1994       Ustrncmp(name, "bh_", 3) == 0 ||
1995       Ustrncmp(name, "header_", 7) == 0 ||
1996       Ustrncmp(name, "rheader_", 8) == 0 ||
1997       Ustrncmp(name, "bheader_", 8) == 0)
1998     {
1999     s = read_header_name(name, 256, s);
2000     /* {-for-text-editors */
2001     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2002     if (yield != NULL) *yield =
2003       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2004     }
2005
2006   /* Test for a variable's having a non-empty value. A non-existent variable
2007   causes an expansion failure. */
2008
2009   else
2010     {
2011     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2012     if (value == NULL)
2013       {
2014       expand_string_message = (name[0] == 0)?
2015         string_sprintf("variable name omitted after \"def:\"") :
2016         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2017       check_variable_error_message(name);
2018       return NULL;
2019       }
2020     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2021     }
2022
2023   return s;
2024
2025
2026   /* first_delivery tests for first delivery attempt */
2027
2028   case ECOND_FIRST_DELIVERY:
2029   if (yield != NULL) *yield = deliver_firsttime == testfor;
2030   return s;
2031
2032
2033   /* queue_running tests for any process started by a queue runner */
2034
2035   case ECOND_QUEUE_RUNNING:
2036   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2037   return s;
2038
2039
2040   /* exists:  tests for file existence
2041        isip:  tests for any IP address
2042       isip4:  tests for an IPv4 address
2043       isip6:  tests for an IPv6 address
2044         pam:  does PAM authentication
2045      radius:  does RADIUS authentication
2046    ldapauth:  does LDAP authentication
2047     pwcheck:  does Cyrus SASL pwcheck authentication
2048   */
2049
2050   case ECOND_EXISTS:
2051   case ECOND_ISIP:
2052   case ECOND_ISIP4:
2053   case ECOND_ISIP6:
2054   case ECOND_PAM:
2055   case ECOND_RADIUS:
2056   case ECOND_LDAPAUTH:
2057   case ECOND_PWCHECK:
2058
2059   while (isspace(*s)) s++;
2060   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2061
2062   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE);
2063   if (sub[0] == NULL) return NULL;
2064   /* {-for-text-editors */
2065   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2066
2067   if (yield == NULL) return s;   /* No need to run the test if skipping */
2068
2069   switch(cond_type)
2070     {
2071     case ECOND_EXISTS:
2072     if ((expand_forbid & RDO_EXISTS) != 0)
2073       {
2074       expand_string_message = US"File existence tests are not permitted";
2075       return NULL;
2076       }
2077     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2078     break;
2079
2080     case ECOND_ISIP:
2081     case ECOND_ISIP4:
2082     case ECOND_ISIP6:
2083     rc = string_is_ip_address(sub[0], NULL);
2084     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2085              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2086     break;
2087
2088     /* Various authentication tests - all optionally compiled */
2089
2090     case ECOND_PAM:
2091     #ifdef SUPPORT_PAM
2092     rc = auth_call_pam(sub[0], &expand_string_message);
2093     goto END_AUTH;
2094     #else
2095     goto COND_FAILED_NOT_COMPILED;
2096     #endif  /* SUPPORT_PAM */
2097
2098     case ECOND_RADIUS:
2099     #ifdef RADIUS_CONFIG_FILE
2100     rc = auth_call_radius(sub[0], &expand_string_message);
2101     goto END_AUTH;
2102     #else
2103     goto COND_FAILED_NOT_COMPILED;
2104     #endif  /* RADIUS_CONFIG_FILE */
2105
2106     case ECOND_LDAPAUTH:
2107     #ifdef LOOKUP_LDAP
2108       {
2109       /* Just to keep the interface the same */
2110       BOOL do_cache;
2111       int old_pool = store_pool;
2112       store_pool = POOL_SEARCH;
2113       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2114         &expand_string_message, &do_cache);
2115       store_pool = old_pool;
2116       }
2117     goto END_AUTH;
2118     #else
2119     goto COND_FAILED_NOT_COMPILED;
2120     #endif  /* LOOKUP_LDAP */
2121
2122     case ECOND_PWCHECK:
2123     #ifdef CYRUS_PWCHECK_SOCKET
2124     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2125     goto END_AUTH;
2126     #else
2127     goto COND_FAILED_NOT_COMPILED;
2128     #endif  /* CYRUS_PWCHECK_SOCKET */
2129
2130     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2131         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2132     END_AUTH:
2133     if (rc == ERROR || rc == DEFER) return NULL;
2134     *yield = (rc == OK) == testfor;
2135     #endif
2136     }
2137   return s;
2138
2139
2140   /* call ACL (in a conditional context).  Accept true, deny false.
2141   Defer is a forced-fail.  Anything set by message= goes to $value.
2142   Up to ten parameters are used; we use the braces round the name+args
2143   like the saslauthd condition does, to permit a variable number of args.
2144   See also the expansion-item version EITEM_ACL and the traditional
2145   acl modifier ACLC_ACL.
2146   */
2147
2148   case ECOND_ACL:
2149     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2150     {
2151     uschar *user_msg;
2152     BOOL cond = FALSE;
2153     int size = 0;
2154     int ptr = 0;
2155
2156     while (isspace(*s)) s++;
2157     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2158
2159     switch(read_subs(sub, sizeof(sub)/sizeof(*sub), 1,
2160       &s, yield == NULL, TRUE, US"acl"))
2161       {
2162       case 1: expand_string_message = US"too few arguments or bracketing "
2163         "error for acl";
2164       case 2:
2165       case 3: return NULL;
2166       }
2167
2168     if (yield != NULL) switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
2169         {
2170         case OK:
2171           cond = TRUE;
2172         case FAIL:
2173           lookup_value = NULL;
2174           if (user_msg)
2175             {
2176             lookup_value = string_cat(NULL, &size, &ptr, user_msg, Ustrlen(user_msg));
2177             lookup_value[ptr] = '\0';
2178             }
2179           *yield = cond == testfor;
2180           break;
2181
2182         case DEFER:
2183           expand_string_forcedfail = TRUE;
2184         default:
2185           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2186           return NULL;
2187         }
2188     return s;
2189     }
2190
2191
2192   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2193
2194      ${if saslauthd {{username}{password}{service}{realm}}  {yes}[no}}
2195
2196   However, the last two are optional. That is why the whole set is enclosed
2197   in their own set of braces. */
2198
2199   case ECOND_SASLAUTHD:
2200   #ifndef CYRUS_SASLAUTHD_SOCKET
2201   goto COND_FAILED_NOT_COMPILED;
2202   #else
2203   while (isspace(*s)) s++;
2204   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2205   switch(read_subs(sub, 4, 2, &s, yield == NULL, TRUE, US"saslauthd"))
2206     {
2207     case 1: expand_string_message = US"too few arguments or bracketing "
2208       "error for saslauthd";
2209     case 2:
2210     case 3: return NULL;
2211     }
2212   if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2213   if (yield != NULL)
2214     {
2215     int rc;
2216     rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2217       &expand_string_message);
2218     if (rc == ERROR || rc == DEFER) return NULL;
2219     *yield = (rc == OK) == testfor;
2220     }
2221   return s;
2222   #endif /* CYRUS_SASLAUTHD_SOCKET */
2223
2224
2225   /* symbolic operators for numeric and string comparison, and a number of
2226   other operators, all requiring two arguments.
2227
2228   crypteq:           encrypts plaintext and compares against an encrypted text,
2229                        using crypt(), crypt16(), MD5 or SHA-1
2230   inlist/inlisti:    checks if first argument is in the list of the second
2231   match:             does a regular expression match and sets up the numerical
2232                        variables if it succeeds
2233   match_address:     matches in an address list
2234   match_domain:      matches in a domain list
2235   match_ip:          matches a host list that is restricted to IP addresses
2236   match_local_part:  matches in a local part list
2237   */
2238
2239   case ECOND_MATCH_ADDRESS:
2240   case ECOND_MATCH_DOMAIN:
2241   case ECOND_MATCH_IP:
2242   case ECOND_MATCH_LOCAL_PART:
2243 #ifndef EXPAND_LISTMATCH_RHS
2244     sub2_honour_dollar = FALSE;
2245 #endif
2246     /* FALLTHROUGH */
2247
2248   case ECOND_CRYPTEQ:
2249   case ECOND_INLIST:
2250   case ECOND_INLISTI:
2251   case ECOND_MATCH:
2252
2253   case ECOND_NUM_L:     /* Numerical comparisons */
2254   case ECOND_NUM_LE:
2255   case ECOND_NUM_E:
2256   case ECOND_NUM_EE:
2257   case ECOND_NUM_G:
2258   case ECOND_NUM_GE:
2259
2260   case ECOND_STR_LT:    /* String comparisons */
2261   case ECOND_STR_LTI:
2262   case ECOND_STR_LE:
2263   case ECOND_STR_LEI:
2264   case ECOND_STR_EQ:
2265   case ECOND_STR_EQI:
2266   case ECOND_STR_GT:
2267   case ECOND_STR_GTI:
2268   case ECOND_STR_GE:
2269   case ECOND_STR_GEI:
2270
2271   for (i = 0; i < 2; i++)
2272     {
2273     /* Sometimes, we don't expand substrings; too many insecure configurations
2274     created using match_address{}{} and friends, where the second param
2275     includes information from untrustworthy sources. */
2276     BOOL honour_dollar = TRUE;
2277     if ((i > 0) && !sub2_honour_dollar)
2278       honour_dollar = FALSE;
2279
2280     while (isspace(*s)) s++;
2281     if (*s != '{')
2282       {
2283       if (i == 0) goto COND_FAILED_CURLY_START;
2284       expand_string_message = string_sprintf("missing 2nd string in {} "
2285         "after \"%s\"", name);
2286       return NULL;
2287       }
2288     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2289         honour_dollar);
2290     if (sub[i] == NULL) return NULL;
2291     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2292
2293     /* Convert to numerical if required; we know that the names of all the
2294     conditions that compare numbers do not start with a letter. This just saves
2295     checking for them individually. */
2296
2297     if (!isalpha(name[0]) && yield != NULL)
2298       {
2299       if (sub[i][0] == 0)
2300         {
2301         num[i] = 0;
2302         DEBUG(D_expand)
2303           debug_printf("empty string cast to zero for numerical comparison\n");
2304         }
2305       else
2306         {
2307         num[i] = expand_string_integer(sub[i], FALSE);
2308         if (expand_string_message != NULL) return NULL;
2309         }
2310       }
2311     }
2312
2313   /* Result not required */
2314
2315   if (yield == NULL) return s;
2316
2317   /* Do an appropriate comparison */
2318
2319   switch(cond_type)
2320     {
2321     case ECOND_NUM_E:
2322     case ECOND_NUM_EE:
2323     tempcond = (num[0] == num[1]);
2324     break;
2325
2326     case ECOND_NUM_G:
2327     tempcond = (num[0] > num[1]);
2328     break;
2329
2330     case ECOND_NUM_GE:
2331     tempcond = (num[0] >= num[1]);
2332     break;
2333
2334     case ECOND_NUM_L:
2335     tempcond = (num[0] < num[1]);
2336     break;
2337
2338     case ECOND_NUM_LE:
2339     tempcond = (num[0] <= num[1]);
2340     break;
2341
2342     case ECOND_STR_LT:
2343     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2344     break;
2345
2346     case ECOND_STR_LTI:
2347     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2348     break;
2349
2350     case ECOND_STR_LE:
2351     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2352     break;
2353
2354     case ECOND_STR_LEI:
2355     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2356     break;
2357
2358     case ECOND_STR_EQ:
2359     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2360     break;
2361
2362     case ECOND_STR_EQI:
2363     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2364     break;
2365
2366     case ECOND_STR_GT:
2367     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2368     break;
2369
2370     case ECOND_STR_GTI:
2371     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2372     break;
2373
2374     case ECOND_STR_GE:
2375     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2376     break;
2377
2378     case ECOND_STR_GEI:
2379     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2380     break;
2381
2382     case ECOND_MATCH:   /* Regular expression match */
2383     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2384       NULL);
2385     if (re == NULL)
2386       {
2387       expand_string_message = string_sprintf("regular expression error in "
2388         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2389       return NULL;
2390       }
2391     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2392     break;
2393
2394     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2395     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2396     goto MATCHED_SOMETHING;
2397
2398     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2399     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2400       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2401     goto MATCHED_SOMETHING;
2402
2403     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2404     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2405       {
2406       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2407         sub[0]);
2408       return NULL;
2409       }
2410     else
2411       {
2412       unsigned int *nullcache = NULL;
2413       check_host_block cb;
2414
2415       cb.host_name = US"";
2416       cb.host_address = sub[0];
2417
2418       /* If the host address starts off ::ffff: it is an IPv6 address in
2419       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2420       addresses. */
2421
2422       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2423         cb.host_address + 7 : cb.host_address;
2424
2425       rc = match_check_list(
2426              &sub[1],                   /* the list */
2427              0,                         /* separator character */
2428              &hostlist_anchor,          /* anchor pointer */
2429              &nullcache,                /* cache pointer */
2430              check_host,                /* function for testing */
2431              &cb,                       /* argument for function */
2432              MCL_HOST,                  /* type of check */
2433              sub[0],                    /* text for debugging */
2434              NULL);                     /* where to pass back data */
2435       }
2436     goto MATCHED_SOMETHING;
2437
2438     case ECOND_MATCH_LOCAL_PART:
2439     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2440       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2441     /* Fall through */
2442     /* VVVVVVVVVVVV */
2443     MATCHED_SOMETHING:
2444     switch(rc)
2445       {
2446       case OK:
2447       tempcond = TRUE;
2448       break;
2449
2450       case FAIL:
2451       tempcond = FALSE;
2452       break;
2453
2454       case DEFER:
2455       expand_string_message = string_sprintf("unable to complete match "
2456         "against \"%s\": %s", sub[1], search_error_message);
2457       return NULL;
2458       }
2459
2460     break;
2461
2462     /* Various "encrypted" comparisons. If the second string starts with
2463     "{" then an encryption type is given. Default to crypt() or crypt16()
2464     (build-time choice). */
2465     /* }-for-text-editors */
2466
2467     case ECOND_CRYPTEQ:
2468     #ifndef SUPPORT_CRYPTEQ
2469     goto COND_FAILED_NOT_COMPILED;
2470     #else
2471     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2472       {
2473       int sublen = Ustrlen(sub[1]+5);
2474       md5 base;
2475       uschar digest[16];
2476
2477       md5_start(&base);
2478       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2479
2480       /* If the length that we are comparing against is 24, the MD5 digest
2481       is expressed as a base64 string. This is the way LDAP does it. However,
2482       some other software uses a straightforward hex representation. We assume
2483       this if the length is 32. Other lengths fail. */
2484
2485       if (sublen == 24)
2486         {
2487         uschar *coded = auth_b64encode((uschar *)digest, 16);
2488         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2489           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2490         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2491         }
2492       else if (sublen == 32)
2493         {
2494         int i;
2495         uschar coded[36];
2496         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2497         coded[32] = 0;
2498         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2499           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2500         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2501         }
2502       else
2503         {
2504         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2505           "fail\n  crypted=%s\n", sub[1]+5);
2506         tempcond = FALSE;
2507         }
2508       }
2509
2510     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2511       {
2512       int sublen = Ustrlen(sub[1]+6);
2513       sha1 base;
2514       uschar digest[20];
2515
2516       sha1_start(&base);
2517       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2518
2519       /* If the length that we are comparing against is 28, assume the SHA1
2520       digest is expressed as a base64 string. If the length is 40, assume a
2521       straightforward hex representation. Other lengths fail. */
2522
2523       if (sublen == 28)
2524         {
2525         uschar *coded = auth_b64encode((uschar *)digest, 20);
2526         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2527           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2528         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2529         }
2530       else if (sublen == 40)
2531         {
2532         int i;
2533         uschar coded[44];
2534         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2535         coded[40] = 0;
2536         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2537           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2538         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2539         }
2540       else
2541         {
2542         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2543           "fail\n  crypted=%s\n", sub[1]+6);
2544         tempcond = FALSE;
2545         }
2546       }
2547
2548     else   /* {crypt} or {crypt16} and non-{ at start */
2549            /* }-for-text-editors */
2550       {
2551       int which = 0;
2552       uschar *coded;
2553
2554       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2555         {
2556         sub[1] += 7;
2557         which = 1;
2558         }
2559       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2560         {
2561         sub[1] += 9;
2562         which = 2;
2563         }
2564       else if (sub[1][0] == '{')                /* }-for-text-editors */
2565         {
2566         expand_string_message = string_sprintf("unknown encryption mechanism "
2567           "in \"%s\"", sub[1]);
2568         return NULL;
2569         }
2570
2571       switch(which)
2572         {
2573         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2574         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2575         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2576         }
2577
2578       #define STR(s) # s
2579       #define XSTR(s) STR(s)
2580       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2581         "  subject=%s\n  crypted=%s\n",
2582         (which == 0)? XSTR(DEFAULT_CRYPT) : (which == 1)? "crypt" : "crypt16",
2583         coded, sub[1]);
2584       #undef STR
2585       #undef XSTR
2586
2587       /* If the encrypted string contains fewer than two characters (for the
2588       salt), force failure. Otherwise we get false positives: with an empty
2589       string the yield of crypt() is an empty string! */
2590
2591       tempcond = (Ustrlen(sub[1]) < 2)? FALSE :
2592         (Ustrcmp(coded, sub[1]) == 0);
2593       }
2594     break;
2595     #endif  /* SUPPORT_CRYPTEQ */
2596
2597     case ECOND_INLIST:
2598     case ECOND_INLISTI:
2599       {
2600       int sep = 0;
2601       uschar *save_iterate_item = iterate_item;
2602       int (*compare)(const uschar *, const uschar *);
2603
2604       tempcond = FALSE;
2605       if (cond_type == ECOND_INLISTI)
2606         compare = strcmpic;
2607       else
2608         compare = (int (*)(const uschar *, const uschar *)) strcmp;
2609
2610       while ((iterate_item = string_nextinlist(&sub[1], &sep, NULL, 0)) != NULL)
2611         if (compare(sub[0], iterate_item) == 0)
2612           {
2613           tempcond = TRUE;
2614           break;
2615           }
2616       iterate_item = save_iterate_item;
2617       }
2618
2619     }   /* Switch for comparison conditions */
2620
2621   *yield = tempcond == testfor;
2622   return s;    /* End of comparison conditions */
2623
2624
2625   /* and/or: computes logical and/or of several conditions */
2626
2627   case ECOND_AND:
2628   case ECOND_OR:
2629   subcondptr = (yield == NULL)? NULL : &tempcond;
2630   combined_cond = (cond_type == ECOND_AND);
2631
2632   while (isspace(*s)) s++;
2633   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2634
2635   for (;;)
2636     {
2637     while (isspace(*s)) s++;
2638     /* {-for-text-editors */
2639     if (*s == '}') break;
2640     if (*s != '{')                                      /* }-for-text-editors */
2641       {
2642       expand_string_message = string_sprintf("each subcondition "
2643         "inside an \"%s{...}\" condition must be in its own {}", name);
2644       return NULL;
2645       }
2646
2647     s = eval_condition(s+1, subcondptr);
2648     if (s == NULL)
2649       {
2650       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2651         expand_string_message, name);
2652       return NULL;
2653       }
2654     while (isspace(*s)) s++;
2655
2656     /* {-for-text-editors */
2657     if (*s++ != '}')
2658       {
2659       /* {-for-text-editors */
2660       expand_string_message = string_sprintf("missing } at end of condition "
2661         "inside \"%s\" group", name);
2662       return NULL;
2663       }
2664
2665     if (yield != NULL)
2666       {
2667       if (cond_type == ECOND_AND)
2668         {
2669         combined_cond &= tempcond;
2670         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2671         }                                       /* evaluate any more */
2672       else
2673         {
2674         combined_cond |= tempcond;
2675         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2676         }                                       /* evaluate any more */
2677       }
2678     }
2679
2680   if (yield != NULL) *yield = (combined_cond == testfor);
2681   return ++s;
2682
2683
2684   /* forall/forany: iterates a condition with different values */
2685
2686   case ECOND_FORALL:
2687   case ECOND_FORANY:
2688     {
2689     int sep = 0;
2690     uschar *save_iterate_item = iterate_item;
2691
2692     while (isspace(*s)) s++;
2693     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2694     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE);
2695     if (sub[0] == NULL) return NULL;
2696     /* {-for-text-editors */
2697     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2698
2699     while (isspace(*s)) s++;
2700     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2701
2702     sub[1] = s;
2703
2704     /* Call eval_condition once, with result discarded (as if scanning a
2705     "false" part). This allows us to find the end of the condition, because if
2706     the list it empty, we won't actually evaluate the condition for real. */
2707
2708     s = eval_condition(sub[1], NULL);
2709     if (s == NULL)
2710       {
2711       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2712         expand_string_message, name);
2713       return NULL;
2714       }
2715     while (isspace(*s)) s++;
2716
2717     /* {-for-text-editors */
2718     if (*s++ != '}')
2719       {
2720       /* {-for-text-editors */
2721       expand_string_message = string_sprintf("missing } at end of condition "
2722         "inside \"%s\"", name);
2723       return NULL;
2724       }
2725
2726     if (yield != NULL) *yield = !testfor;
2727     while ((iterate_item = string_nextinlist(&sub[0], &sep, NULL, 0)) != NULL)
2728       {
2729       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2730       if (eval_condition(sub[1], &tempcond) == NULL)
2731         {
2732         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2733           expand_string_message, name);
2734         iterate_item = save_iterate_item;
2735         return NULL;
2736         }
2737       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2738         tempcond? "true":"false");
2739
2740       if (yield != NULL) *yield = (tempcond == testfor);
2741       if (tempcond == (cond_type == ECOND_FORANY)) break;
2742       }
2743
2744     iterate_item = save_iterate_item;
2745     return s;
2746     }
2747
2748
2749   /* The bool{} expansion condition maps a string to boolean.
2750   The values supported should match those supported by the ACL condition
2751   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2752   of true/false.  Note that Router "condition" rules have a different
2753   interpretation, where general data can be used and only a few values
2754   map to FALSE.
2755   Note that readconf.c boolean matching, for boolean configuration options,
2756   only matches true/yes/false/no.
2757   The bool_lax{} condition matches the Router logic, which is much more
2758   liberal. */
2759   case ECOND_BOOL:
2760   case ECOND_BOOL_LAX:
2761     {
2762     uschar *sub_arg[1];
2763     uschar *t, *t2;
2764     uschar *ourname;
2765     size_t len;
2766     BOOL boolvalue = FALSE;
2767     while (isspace(*s)) s++;
2768     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2769     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2770     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname))
2771       {
2772       case 1: expand_string_message = string_sprintf(
2773                   "too few arguments or bracketing error for %s",
2774                   ourname);
2775       /*FALLTHROUGH*/
2776       case 2:
2777       case 3: return NULL;
2778       }
2779     t = sub_arg[0];
2780     while (isspace(*t)) t++;
2781     len = Ustrlen(t);
2782     if (len)
2783       {
2784       /* trailing whitespace: seems like a good idea to ignore it too */
2785       t2 = t + len - 1;
2786       while (isspace(*t2)) t2--;
2787       if (t2 != (t + len))
2788         {
2789         *++t2 = '\0';
2790         len = t2 - t;
2791         }
2792       }
2793     DEBUG(D_expand)
2794       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
2795     /* logic for the lax case from expand_check_condition(), which also does
2796     expands, and the logic is both short and stable enough that there should
2797     be no maintenance burden from replicating it. */
2798     if (len == 0)
2799       boolvalue = FALSE;
2800     else if (Ustrspn(t, "0123456789") == len)
2801       {
2802       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
2803       /* expand_check_condition only does a literal string "0" check */
2804       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
2805         boolvalue = TRUE;
2806       }
2807     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
2808       boolvalue = TRUE;
2809     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
2810       boolvalue = FALSE;
2811     else if (cond_type == ECOND_BOOL_LAX)
2812       boolvalue = TRUE;
2813     else
2814       {
2815       expand_string_message = string_sprintf("unrecognised boolean "
2816        "value \"%s\"", t);
2817       return NULL;
2818       }
2819     if (yield != NULL) *yield = (boolvalue == testfor);
2820     return s;
2821     }
2822
2823   /* Unknown condition */
2824
2825   default:
2826   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
2827   return NULL;
2828   }   /* End switch on condition type */
2829
2830 /* Missing braces at start and end of data */
2831
2832 COND_FAILED_CURLY_START:
2833 expand_string_message = string_sprintf("missing { after \"%s\"", name);
2834 return NULL;
2835
2836 COND_FAILED_CURLY_END:
2837 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
2838   name);
2839 return NULL;
2840
2841 /* A condition requires code that is not compiled */
2842
2843 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
2844     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
2845     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
2846 COND_FAILED_NOT_COMPILED:
2847 expand_string_message = string_sprintf("support for \"%s\" not compiled",
2848   name);
2849 return NULL;
2850 #endif
2851 }
2852
2853
2854
2855
2856 /*************************************************
2857 *          Save numerical variables              *
2858 *************************************************/
2859
2860 /* This function is called from items such as "if" that want to preserve and
2861 restore the numbered variables.
2862
2863 Arguments:
2864   save_expand_string    points to an array of pointers to set
2865   save_expand_nlength   points to an array of ints for the lengths
2866
2867 Returns:                the value of expand max to save
2868 */
2869
2870 static int
2871 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
2872 {
2873 int i;
2874 for (i = 0; i <= expand_nmax; i++)
2875   {
2876   save_expand_nstring[i] = expand_nstring[i];
2877   save_expand_nlength[i] = expand_nlength[i];
2878   }
2879 return expand_nmax;
2880 }
2881
2882
2883
2884 /*************************************************
2885 *           Restore numerical variables          *
2886 *************************************************/
2887
2888 /* This function restored saved values of numerical strings.
2889
2890 Arguments:
2891   save_expand_nmax      the number of strings to restore
2892   save_expand_string    points to an array of pointers
2893   save_expand_nlength   points to an array of ints
2894
2895 Returns:                nothing
2896 */
2897
2898 static void
2899 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
2900   int *save_expand_nlength)
2901 {
2902 int i;
2903 expand_nmax = save_expand_nmax;
2904 for (i = 0; i <= expand_nmax; i++)
2905   {
2906   expand_nstring[i] = save_expand_nstring[i];
2907   expand_nlength[i] = save_expand_nlength[i];
2908   }
2909 }
2910
2911
2912
2913
2914
2915 /*************************************************
2916 *            Handle yes/no substrings            *
2917 *************************************************/
2918
2919 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
2920 alternative substrings that depend on whether or not the condition was true,
2921 or the lookup or extraction succeeded. The substrings always have to be
2922 expanded, to check their syntax, but "skipping" is set when the result is not
2923 needed - this avoids unnecessary nested lookups.
2924
2925 Arguments:
2926   skipping       TRUE if we were skipping when this item was reached
2927   yes            TRUE if the first string is to be used, else use the second
2928   save_lookup    a value to put back into lookup_value before the 2nd expansion
2929   sptr           points to the input string pointer
2930   yieldptr       points to the output string pointer
2931   sizeptr        points to the output string size
2932   ptrptr         points to the output string pointer
2933   type           "lookup" or "if" or "extract" or "run", for error message
2934
2935 Returns:         0 OK; lookup_value has been reset to save_lookup
2936                  1 expansion failed
2937                  2 expansion failed because of bracketing error
2938 */
2939
2940 static int
2941 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, uschar **sptr,
2942   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type)
2943 {
2944 int rc = 0;
2945 uschar *s = *sptr;    /* Local value */
2946 uschar *sub1, *sub2;
2947
2948 /* If there are no following strings, we substitute the contents of $value for
2949 lookups and for extractions in the success case. For the ${if item, the string
2950 "true" is substituted. In the fail case, nothing is substituted for all three
2951 items. */
2952
2953 while (isspace(*s)) s++;
2954 if (*s == '}')
2955   {
2956   if (type[0] == 'i')
2957     {
2958     if (yes) *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, US"true", 4);
2959     }
2960   else
2961     {
2962     if (yes && lookup_value != NULL)
2963       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value,
2964         Ustrlen(lookup_value));
2965     lookup_value = save_lookup;
2966     }
2967   s++;
2968   goto RETURN;
2969   }
2970
2971 /* The first following string must be braced. */
2972
2973 if (*s++ != '{') goto FAILED_CURLY;
2974
2975 /* Expand the first substring. Forced failures are noticed only if we actually
2976 want this string. Set skipping in the call in the fail case (this will always
2977 be the case if we were already skipping). */
2978
2979 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE);
2980 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
2981 expand_string_forcedfail = FALSE;
2982 if (*s++ != '}') goto FAILED_CURLY;
2983
2984 /* If we want the first string, add it to the output */
2985
2986 if (yes)
2987   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1, Ustrlen(sub1));
2988
2989 /* If this is called from a lookup or an extract, we want to restore $value to
2990 what it was at the start of the item, so that it has this value during the
2991 second string expansion. For the call from "if" or "run" to this function,
2992 save_lookup is set to lookup_value, so that this statement does nothing. */
2993
2994 lookup_value = save_lookup;
2995
2996 /* There now follows either another substring, or "fail", or nothing. This
2997 time, forced failures are noticed only if we want the second string. We must
2998 set skipping in the nested call if we don't want this string, or if we were
2999 already skipping. */
3000
3001 while (isspace(*s)) s++;
3002 if (*s == '{')
3003   {
3004   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE);
3005   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3006   expand_string_forcedfail = FALSE;
3007   if (*s++ != '}') goto FAILED_CURLY;
3008
3009   /* If we want the second string, add it to the output */
3010
3011   if (!yes)
3012     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2, Ustrlen(sub2));
3013   }
3014
3015 /* If there is no second string, but the word "fail" is present when the use of
3016 the second string is wanted, set a flag indicating it was a forced failure
3017 rather than a syntactic error. Swallow the terminating } in case this is nested
3018 inside another lookup or if or extract. */
3019
3020 else if (*s != '}')
3021   {
3022   uschar name[256];
3023   s = read_name(name, sizeof(name), s, US"_");
3024   if (Ustrcmp(name, "fail") == 0)
3025     {
3026     if (!yes && !skipping)
3027       {
3028       while (isspace(*s)) s++;
3029       if (*s++ != '}') goto FAILED_CURLY;
3030       expand_string_message =
3031         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3032       expand_string_forcedfail = TRUE;
3033       goto FAILED;
3034       }
3035     }
3036   else
3037     {
3038     expand_string_message =
3039       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3040     goto FAILED;
3041     }
3042   }
3043
3044 /* All we have to do now is to check on the final closing brace. */
3045
3046 while (isspace(*s)) s++;
3047 if (*s++ == '}') goto RETURN;
3048
3049 /* Get here if there is a bracketing failure */
3050
3051 FAILED_CURLY:
3052 rc++;
3053
3054 /* Get here for other failures */
3055
3056 FAILED:
3057 rc++;
3058
3059 /* Update the input pointer value before returning */
3060
3061 RETURN:
3062 *sptr = s;
3063 return rc;
3064 }
3065
3066
3067
3068
3069 /*************************************************
3070 *    Handle MD5 or SHA-1 computation for HMAC    *
3071 *************************************************/
3072
3073 /* These are some wrapping functions that enable the HMAC code to be a bit
3074 cleaner. A good compiler will spot the tail recursion.
3075
3076 Arguments:
3077   type         HMAC_MD5 or HMAC_SHA1
3078   remaining    are as for the cryptographic hash functions
3079
3080 Returns:       nothing
3081 */
3082
3083 static void
3084 chash_start(int type, void *base)
3085 {
3086 if (type == HMAC_MD5)
3087   md5_start((md5 *)base);
3088 else
3089   sha1_start((sha1 *)base);
3090 }
3091
3092 static void
3093 chash_mid(int type, void *base, uschar *string)
3094 {
3095 if (type == HMAC_MD5)
3096   md5_mid((md5 *)base, string);
3097 else
3098   sha1_mid((sha1 *)base, string);
3099 }
3100
3101 static void
3102 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3103 {
3104 if (type == HMAC_MD5)
3105   md5_end((md5 *)base, string, length, digest);
3106 else
3107   sha1_end((sha1 *)base, string, length, digest);
3108 }
3109
3110
3111
3112
3113
3114 /********************************************************
3115 * prvs: Get last three digits of days since Jan 1, 1970 *
3116 ********************************************************/
3117
3118 /* This is needed to implement the "prvs" BATV reverse
3119    path signing scheme
3120
3121 Argument: integer "days" offset to add or substract to
3122           or from the current number of days.
3123
3124 Returns:  pointer to string containing the last three
3125           digits of the number of days since Jan 1, 1970,
3126           modified by the offset argument, NULL if there
3127           was an error in the conversion.
3128
3129 */
3130
3131 static uschar *
3132 prvs_daystamp(int day_offset)
3133 {
3134 uschar *days = store_get(32);                /* Need at least 24 for cases */
3135 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3136   (time(NULL) + day_offset*86400)/86400);
3137 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3138 }
3139
3140
3141
3142 /********************************************************
3143 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3144 ********************************************************/
3145
3146 /* This is needed to implement the "prvs" BATV reverse
3147    path signing scheme
3148
3149 Arguments:
3150   address RFC2821 Address to use
3151       key The key to use (must be less than 64 characters
3152           in size)
3153   key_num Single-digit key number to use. Defaults to
3154           '0' when NULL.
3155
3156 Returns:  pointer to string containing the first three
3157           bytes of the final hash in hex format, NULL if
3158           there was an error in the process.
3159 */
3160
3161 static uschar *
3162 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3163 {
3164 uschar *hash_source, *p;
3165 int size = 0,offset = 0,i;
3166 sha1 sha1_base;
3167 void *use_base = &sha1_base;
3168 uschar innerhash[20];
3169 uschar finalhash[20];
3170 uschar innerkey[64];
3171 uschar outerkey[64];
3172 uschar *finalhash_hex = store_get(40);
3173
3174 if (key_num == NULL)
3175   key_num = US"0";
3176
3177 if (Ustrlen(key) > 64)
3178   return NULL;
3179
3180 hash_source = string_cat(NULL,&size,&offset,key_num,1);
3181 string_cat(hash_source,&size,&offset,daystamp,3);
3182 string_cat(hash_source,&size,&offset,address,Ustrlen(address));
3183 hash_source[offset] = '\0';
3184
3185 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3186
3187 memset(innerkey, 0x36, 64);
3188 memset(outerkey, 0x5c, 64);
3189
3190 for (i = 0; i < Ustrlen(key); i++)
3191   {
3192   innerkey[i] ^= key[i];
3193   outerkey[i] ^= key[i];
3194   }
3195
3196 chash_start(HMAC_SHA1, use_base);
3197 chash_mid(HMAC_SHA1, use_base, innerkey);
3198 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3199
3200 chash_start(HMAC_SHA1, use_base);
3201 chash_mid(HMAC_SHA1, use_base, outerkey);
3202 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3203
3204 p = finalhash_hex;
3205 for (i = 0; i < 3; i++)
3206   {
3207   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3208   *p++ = hex_digits[finalhash[i] & 0x0f];
3209   }
3210 *p = '\0';
3211
3212 return finalhash_hex;
3213 }
3214
3215
3216
3217
3218 /*************************************************
3219 *        Join a file onto the output string      *
3220 *************************************************/
3221
3222 /* This is used for readfile and after a run expansion. It joins the contents
3223 of a file onto the output string, globally replacing newlines with a given
3224 string (optionally). The file is closed at the end.
3225
3226 Arguments:
3227   f            the FILE
3228   yield        pointer to the expandable string
3229   sizep        pointer to the current size
3230   ptrp         pointer to the current position
3231   eol          newline replacement string, or NULL
3232
3233 Returns:       new value of string pointer
3234 */
3235
3236 static uschar *
3237 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3238 {
3239 int eollen;
3240 uschar buffer[1024];
3241
3242 eollen = (eol == NULL)? 0 : Ustrlen(eol);
3243
3244 while (Ufgets(buffer, sizeof(buffer), f) != NULL)
3245   {
3246   int len = Ustrlen(buffer);
3247   if (eol != NULL && buffer[len-1] == '\n') len--;
3248   yield = string_cat(yield, sizep, ptrp, buffer, len);
3249   if (buffer[len] != 0)
3250     yield = string_cat(yield, sizep, ptrp, eol, eollen);
3251   }
3252
3253 if (yield != NULL) yield[*ptrp] = 0;
3254
3255 return yield;
3256 }
3257
3258
3259
3260
3261 /*************************************************
3262 *          Evaluate numeric expression           *
3263 *************************************************/
3264
3265 /* This is a set of mutually recursive functions that evaluate an arithmetic
3266 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3267 these functions that is called from elsewhere is eval_expr, whose interface is:
3268
3269 Arguments:
3270   sptr        pointer to the pointer to the string - gets updated
3271   decimal     TRUE if numbers are to be assumed decimal
3272   error       pointer to where to put an error message - must be NULL on input
3273   endket      TRUE if ')' must terminate - FALSE for external call
3274
3275 Returns:      on success: the value of the expression, with *error still NULL
3276               on failure: an undefined value, with *error = a message
3277 */
3278
3279 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3280
3281
3282 static int_eximarith_t
3283 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3284 {
3285 uschar *s = *sptr;
3286 int_eximarith_t x = eval_op_or(&s, decimal, error);
3287 if (*error == NULL)
3288   {
3289   if (endket)
3290     {
3291     if (*s != ')')
3292       *error = US"expecting closing parenthesis";
3293     else
3294       while (isspace(*(++s)));
3295     }
3296   else if (*s != 0) *error = US"expecting operator";
3297   }
3298 *sptr = s;
3299 return x;
3300 }
3301
3302
3303 static int_eximarith_t
3304 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3305 {
3306 register int c;
3307 int_eximarith_t n;
3308 uschar *s = *sptr;
3309 while (isspace(*s)) s++;
3310 c = *s;
3311 if (isdigit(c))
3312   {
3313   int count;
3314   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3315   s += count;
3316   switch (tolower(*s))
3317     {
3318     default: break;
3319     case 'k': n *= 1024; s++; break;
3320     case 'm': n *= 1024*1024; s++; break;
3321     case 'g': n *= 1024*1024*1024; s++; break;
3322     }
3323   while (isspace (*s)) s++;
3324   }
3325 else if (c == '(')
3326   {
3327   s++;
3328   n = eval_expr(&s, decimal, error, 1);
3329   }
3330 else
3331   {
3332   *error = US"expecting number or opening parenthesis";
3333   n = 0;
3334   }
3335 *sptr = s;
3336 return n;
3337 }
3338
3339
3340 static int_eximarith_t
3341 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3342 {
3343 uschar *s = *sptr;
3344 int_eximarith_t x;
3345 while (isspace(*s)) s++;
3346 if (*s == '+' || *s == '-' || *s == '~')
3347   {
3348   int op = *s++;
3349   x = eval_op_unary(&s, decimal, error);
3350   if (op == '-') x = -x;
3351     else if (op == '~') x = ~x;
3352   }
3353 else
3354   {
3355   x = eval_number(&s, decimal, error);
3356   }
3357 *sptr = s;
3358 return x;
3359 }
3360
3361
3362 static int_eximarith_t
3363 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3364 {
3365 uschar *s = *sptr;
3366 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3367 if (*error == NULL)
3368   {
3369   while (*s == '*' || *s == '/' || *s == '%')
3370     {
3371     int op = *s++;
3372     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3373     if (*error != NULL) break;
3374     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3375      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3376      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3377      * -N*M is INT_MIN will yielf INT_MIN.
3378      * Since we don't support floating point, this is somewhat simpler.
3379      * Ideally, we'd return an error, but since we overflow for all other
3380      * arithmetic, consistency suggests otherwise, but what's the correct value
3381      * to use?  There is none.
3382      * The C standard guarantees overflow for unsigned arithmetic but signed
3383      * overflow invokes undefined behaviour; in practice, this is overflow
3384      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3385      * that long/longlong larger than int are available, or we could just work
3386      * with larger types.  We should consider whether to guarantee 32bit eval
3387      * and 64-bit working variables, with errors returned.  For now ...
3388      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3389      * can just let the other invalid results occur otherwise, as they have
3390      * until now.  For this one case, we can coerce.
3391      */
3392     if (y == -1 && x == LLONG_MIN && op != '*')
3393       {
3394       DEBUG(D_expand)
3395         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3396             LLONG_MIN, op, LLONG_MAX);
3397       x = LLONG_MAX;
3398       continue;
3399       }
3400     if (op == '*')
3401       x *= y;
3402     else
3403       {
3404       if (y == 0)
3405         {
3406         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3407         x = 0;
3408         break;
3409         }
3410       if (op == '/')
3411         x /= y;
3412       else
3413         x %= y;
3414       }
3415     }
3416   }
3417 *sptr = s;
3418 return x;
3419 }
3420
3421
3422 static int_eximarith_t
3423 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3424 {
3425 uschar *s = *sptr;
3426 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3427 if (*error == NULL)
3428   {
3429   while (*s == '+' || *s == '-')
3430     {
3431     int op = *s++;
3432     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3433     if (*error != NULL) break;
3434     if (op == '+') x += y; else x -= y;
3435     }
3436   }
3437 *sptr = s;
3438 return x;
3439 }
3440
3441
3442 static int_eximarith_t
3443 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3444 {
3445 uschar *s = *sptr;
3446 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3447 if (*error == NULL)
3448   {
3449   while ((*s == '<' || *s == '>') && s[1] == s[0])
3450     {
3451     int_eximarith_t y;
3452     int op = *s++;
3453     s++;
3454     y = eval_op_sum(&s, decimal, error);
3455     if (*error != NULL) break;
3456     if (op == '<') x <<= y; else x >>= y;
3457     }
3458   }
3459 *sptr = s;
3460 return x;
3461 }
3462
3463
3464 static int_eximarith_t
3465 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3466 {
3467 uschar *s = *sptr;
3468 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3469 if (*error == NULL)
3470   {
3471   while (*s == '&')
3472     {
3473     int_eximarith_t y;
3474     s++;
3475     y = eval_op_shift(&s, decimal, error);
3476     if (*error != NULL) break;
3477     x &= y;
3478     }
3479   }
3480 *sptr = s;
3481 return x;
3482 }
3483
3484
3485 static int_eximarith_t
3486 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3487 {
3488 uschar *s = *sptr;
3489 int_eximarith_t x = eval_op_and(&s, decimal, error);
3490 if (*error == NULL)
3491   {
3492   while (*s == '^')
3493     {
3494     int_eximarith_t y;
3495     s++;
3496     y = eval_op_and(&s, decimal, error);
3497     if (*error != NULL) break;
3498     x ^= y;
3499     }
3500   }
3501 *sptr = s;
3502 return x;
3503 }
3504
3505
3506 static int_eximarith_t
3507 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3508 {
3509 uschar *s = *sptr;
3510 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3511 if (*error == NULL)
3512   {
3513   while (*s == '|')
3514     {
3515     int_eximarith_t y;
3516     s++;
3517     y = eval_op_xor(&s, decimal, error);
3518     if (*error != NULL) break;
3519     x |= y;
3520     }
3521   }
3522 *sptr = s;
3523 return x;
3524 }
3525
3526
3527
3528 /*************************************************
3529 *                 Expand string                  *
3530 *************************************************/
3531
3532 /* Returns either an unchanged string, or the expanded string in stacking pool
3533 store. Interpreted sequences are:
3534
3535    \...                    normal escaping rules
3536    $name                   substitutes the variable
3537    ${name}                 ditto
3538    ${op:string}            operates on the expanded string value
3539    ${item{arg1}{arg2}...}  expands the args and then does the business
3540                              some literal args are not enclosed in {}
3541
3542 There are now far too many operators and item types to make it worth listing
3543 them here in detail any more.
3544
3545 We use an internal routine recursively to handle embedded substrings. The
3546 external function follows. The yield is NULL if the expansion failed, and there
3547 are two cases: if something collapsed syntactically, or if "fail" was given
3548 as the action on a lookup failure. These can be distinguised by looking at the
3549 variable expand_string_forcedfail, which is TRUE in the latter case.
3550
3551 The skipping flag is set true when expanding a substring that isn't actually
3552 going to be used (after "if" or "lookup") and it prevents lookups from
3553 happening lower down.
3554
3555 Store usage: At start, a store block of the length of the input plus 64
3556 is obtained. This is expanded as necessary by string_cat(), which might have to
3557 get a new block, or might be able to expand the original. At the end of the
3558 function we can release any store above that portion of the yield block that
3559 was actually used. In many cases this will be optimal.
3560
3561 However: if the first item in the expansion is a variable name or header name,
3562 we reset the store before processing it; if the result is in fresh store, we
3563 use that without copying. This is helpful for expanding strings like
3564 $message_headers which can get very long.
3565
3566 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3567 since resetting the store at the end of the expansion will free store that was
3568 allocated by the plugin code as well as the slop after the expanded string. So
3569 we skip any resets if ${dlfunc has been used. The same applies for ${acl. This
3570 is an unfortunate consequence of string expansion becoming too powerful.
3571
3572 Arguments:
3573   string         the string to be expanded
3574   ket_ends       true if expansion is to stop at }
3575   left           if not NULL, a pointer to the first character after the
3576                  expansion is placed here (typically used with ket_ends)
3577   skipping       TRUE for recursive calls when the value isn't actually going
3578                  to be used (to allow for optimisation)
3579   honour_dollar  TRUE if $ is to be expanded,
3580                  FALSE if it's just another character
3581
3582 Returns:         NULL if expansion fails:
3583                    expand_string_forcedfail is set TRUE if failure was forced
3584                    expand_string_message contains a textual error message
3585                  a pointer to the expanded string on success
3586 */
3587
3588 static uschar *
3589 expand_string_internal(uschar *string, BOOL ket_ends, uschar **left,
3590   BOOL skipping, BOOL honour_dollar)
3591 {
3592 int ptr = 0;
3593 int size = Ustrlen(string)+ 64;
3594 int item_type;
3595 uschar *yield = store_get(size);
3596 uschar *s = string;
3597 uschar *save_expand_nstring[EXPAND_MAXN+1];
3598 int save_expand_nlength[EXPAND_MAXN+1];
3599 BOOL resetok = TRUE;
3600
3601 expand_string_forcedfail = FALSE;
3602 expand_string_message = US"";
3603
3604 while (*s != 0)
3605   {
3606   uschar *value;
3607   uschar name[256];
3608
3609   /* \ escapes the next character, which must exist, or else
3610   the expansion fails. There's a special escape, \N, which causes
3611   copying of the subject verbatim up to the next \N. Otherwise,
3612   the escapes are the standard set. */
3613
3614   if (*s == '\\')
3615     {
3616     if (s[1] == 0)
3617       {
3618       expand_string_message = US"\\ at end of string";
3619       goto EXPAND_FAILED;
3620       }
3621
3622     if (s[1] == 'N')
3623       {
3624       uschar *t = s + 2;
3625       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3626       yield = string_cat(yield, &size, &ptr, t, s - t);
3627       if (*s != 0) s += 2;
3628       }
3629
3630     else
3631       {
3632       uschar ch[1];
3633       ch[0] = string_interpret_escape(&s);
3634       s++;
3635       yield = string_cat(yield, &size, &ptr, ch, 1);
3636       }
3637
3638     continue;
3639     }
3640
3641   /* Anything other than $ is just copied verbatim, unless we are
3642   looking for a terminating } character. */
3643
3644   if (ket_ends && *s == '}') break;
3645
3646   if (*s != '$' || !honour_dollar)
3647     {
3648     yield = string_cat(yield, &size, &ptr, s++, 1);
3649     continue;
3650     }
3651
3652   /* No { after the $ - must be a plain name or a number for string
3653   match variable. There has to be a fudge for variables that are the
3654   names of header fields preceded by "$header_" because header field
3655   names can contain any printing characters except space and colon.
3656   For those that don't like typing this much, "$h_" is a synonym for
3657   "$header_". A non-existent header yields a NULL value; nothing is
3658   inserted. */
3659
3660   if (isalpha((*(++s))))
3661     {
3662     int len;
3663     int newsize = 0;
3664
3665     s = read_name(name, sizeof(name), s, US"_");
3666
3667     /* If this is the first thing to be expanded, release the pre-allocated
3668     buffer. */
3669
3670     if (ptr == 0 && yield != NULL)
3671       {
3672       if (resetok) store_reset(yield);
3673       yield = NULL;
3674       size = 0;
3675       }
3676
3677     /* Header */
3678
3679     if (Ustrncmp(name, "h_", 2) == 0 ||
3680         Ustrncmp(name, "rh_", 3) == 0 ||
3681         Ustrncmp(name, "bh_", 3) == 0 ||
3682         Ustrncmp(name, "header_", 7) == 0 ||
3683         Ustrncmp(name, "rheader_", 8) == 0 ||
3684         Ustrncmp(name, "bheader_", 8) == 0)
3685       {
3686       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3687       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3688       s = read_header_name(name, sizeof(name), s);
3689       value = find_header(name, FALSE, &newsize, want_raw, charset);
3690
3691       /* If we didn't find the header, and the header contains a closing brace
3692       character, this may be a user error where the terminating colon
3693       has been omitted. Set a flag to adjust the error message in this case.
3694       But there is no error here - nothing gets inserted. */
3695
3696       if (value == NULL)
3697         {
3698         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3699         continue;
3700         }
3701       }
3702
3703     /* Variable */
3704
3705     else
3706       {
3707       value = find_variable(name, FALSE, skipping, &newsize);
3708       if (value == NULL)
3709         {
3710         expand_string_message =
3711           string_sprintf("unknown variable name \"%s\"", name);
3712           check_variable_error_message(name);
3713         goto EXPAND_FAILED;
3714         }
3715       }
3716
3717     /* If the data is known to be in a new buffer, newsize will be set to the
3718     size of that buffer. If this is the first thing in an expansion string,
3719     yield will be NULL; just point it at the new store instead of copying. Many
3720     expansion strings contain just one reference, so this is a useful
3721     optimization, especially for humungous headers. */
3722
3723     len = Ustrlen(value);
3724     if (yield == NULL && newsize != 0)
3725       {
3726       yield = value;
3727       size = newsize;
3728       ptr = len;
3729       }
3730     else yield = string_cat(yield, &size, &ptr, value, len);
3731
3732     continue;
3733     }
3734
3735   if (isdigit(*s))
3736     {
3737     int n;
3738     s = read_number(&n, s);
3739     if (n >= 0 && n <= expand_nmax)
3740       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3741         expand_nlength[n]);
3742     continue;
3743     }
3744
3745   /* Otherwise, if there's no '{' after $ it's an error. */
3746
3747   if (*s != '{')
3748     {
3749     expand_string_message = US"$ not followed by letter, digit, or {";
3750     goto EXPAND_FAILED;
3751     }
3752
3753   /* After { there can be various things, but they all start with
3754   an initial word, except for a number for a string match variable. */
3755
3756   if (isdigit((*(++s))))
3757     {
3758     int n;
3759     s = read_number(&n, s);
3760     if (*s++ != '}')
3761       {
3762       expand_string_message = US"} expected after number";
3763       goto EXPAND_FAILED;
3764       }
3765     if (n >= 0 && n <= expand_nmax)
3766       yield = string_cat(yield, &size, &ptr, expand_nstring[n],
3767         expand_nlength[n]);
3768     continue;
3769     }
3770
3771   if (!isalpha(*s))
3772     {
3773     expand_string_message = US"letter or digit expected after ${";
3774     goto EXPAND_FAILED;
3775     }
3776
3777   /* Allow "-" in names to cater for substrings with negative
3778   arguments. Since we are checking for known names after { this is
3779   OK. */
3780
3781   s = read_name(name, sizeof(name), s, US"_-");
3782   item_type = chop_match(name, item_table, sizeof(item_table)/sizeof(uschar *));
3783
3784   switch(item_type)
3785     {
3786     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
3787     If the ACL returns accept or reject we return content set by "message ="
3788     There is currently no limit on recursion; this would have us call
3789     acl_check_internal() directly and get a current level from somewhere.
3790     See also the acl expansion condition ECOND_ACL and the traditional
3791     acl modifier ACLC_ACL.
3792     Assume that the function has side-effects on the store that must be preserved.
3793     */
3794
3795     case EITEM_ACL:
3796       /* ${acl {name} {arg1}{arg2}...} */
3797       {
3798       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
3799       uschar *user_msg;
3800
3801       switch(read_subs(sub, 10, 1, &s, skipping, TRUE, US"acl"))
3802         {
3803         case 1: goto EXPAND_FAILED_CURLY;
3804         case 2:
3805         case 3: goto EXPAND_FAILED;
3806         }
3807       if (skipping) continue;
3808
3809       resetok = FALSE;
3810       switch(eval_acl(sub, sizeof(sub)/sizeof(*sub), &user_msg))
3811         {
3812         case OK:
3813         case FAIL:
3814           if (user_msg)
3815             yield = string_cat(yield, &size, &ptr, user_msg, Ustrlen(user_msg));
3816           continue;
3817
3818         case DEFER:
3819           expand_string_forcedfail = TRUE;
3820         default:
3821           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
3822           goto EXPAND_FAILED;
3823         }
3824       }
3825
3826     /* Handle conditionals - preserve the values of the numerical expansion
3827     variables in case they get changed by a regular expression match in the
3828     condition. If not, they retain their external settings. At the end
3829     of this "if" section, they get restored to their previous values. */
3830
3831     case EITEM_IF:
3832       {
3833       BOOL cond = FALSE;
3834       uschar *next_s;
3835       int save_expand_nmax =
3836         save_expand_strings(save_expand_nstring, save_expand_nlength);
3837
3838       while (isspace(*s)) s++;
3839       next_s = eval_condition(s, skipping? NULL : &cond);
3840       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
3841
3842       DEBUG(D_expand)
3843         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
3844           cond? "true" : "false");
3845
3846       s = next_s;
3847
3848       /* The handling of "yes" and "no" result strings is now in a separate
3849       function that is also used by ${lookup} and ${extract} and ${run}. */
3850
3851       switch(process_yesno(
3852                skipping,                     /* were previously skipping */
3853                cond,                         /* success/failure indicator */
3854                lookup_value,                 /* value to reset for string2 */
3855                &s,                           /* input pointer */
3856                &yield,                       /* output pointer */
3857                &size,                        /* output size */
3858                &ptr,                         /* output current point */
3859                US"if"))                      /* condition type */
3860         {
3861         case 1: goto EXPAND_FAILED;          /* when all is well, the */
3862         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
3863         }
3864
3865       /* Restore external setting of expansion variables for continuation
3866       at this level. */
3867
3868       restore_expand_strings(save_expand_nmax, save_expand_nstring,
3869         save_expand_nlength);
3870       continue;
3871       }
3872
3873     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
3874     expanding an internal string that isn't actually going to be used. All we
3875     need to do is check the syntax, so don't do a lookup at all. Preserve the
3876     values of the numerical expansion variables in case they get changed by a
3877     partial lookup. If not, they retain their external settings. At the end
3878     of this "lookup" section, they get restored to their previous values. */
3879
3880     case EITEM_LOOKUP:
3881       {
3882       int stype, partial, affixlen, starflags;
3883       int expand_setup = 0;
3884       int nameptr = 0;
3885       uschar *key, *filename, *affix;
3886       uschar *save_lookup_value = lookup_value;
3887       int save_expand_nmax =
3888         save_expand_strings(save_expand_nstring, save_expand_nlength);
3889
3890       if ((expand_forbid & RDO_LOOKUP) != 0)
3891         {
3892         expand_string_message = US"lookup expansions are not permitted";
3893         goto EXPAND_FAILED;
3894         }
3895
3896       /* Get the key we are to look up for single-key+file style lookups.
3897       Otherwise set the key NULL pro-tem. */
3898
3899       while (isspace(*s)) s++;
3900       if (*s == '{')
3901         {
3902         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3903         if (key == NULL) goto EXPAND_FAILED;
3904         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3905         while (isspace(*s)) s++;
3906         }
3907       else key = NULL;
3908
3909       /* Find out the type of database */
3910
3911       if (!isalpha(*s))
3912         {
3913         expand_string_message = US"missing lookup type";
3914         goto EXPAND_FAILED;
3915         }
3916
3917       /* The type is a string that may contain special characters of various
3918       kinds. Allow everything except space or { to appear; the actual content
3919       is checked by search_findtype_partial. */
3920
3921       while (*s != 0 && *s != '{' && !isspace(*s))
3922         {
3923         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
3924         s++;
3925         }
3926       name[nameptr] = 0;
3927       while (isspace(*s)) s++;
3928
3929       /* Now check for the individual search type and any partial or default
3930       options. Only those types that are actually in the binary are valid. */
3931
3932       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
3933         &starflags);
3934       if (stype < 0)
3935         {
3936         expand_string_message = search_error_message;
3937         goto EXPAND_FAILED;
3938         }
3939
3940       /* Check that a key was provided for those lookup types that need it,
3941       and was not supplied for those that use the query style. */
3942
3943       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
3944         {
3945         if (key == NULL)
3946           {
3947           expand_string_message = string_sprintf("missing {key} for single-"
3948             "key \"%s\" lookup", name);
3949           goto EXPAND_FAILED;
3950           }
3951         }
3952       else
3953         {
3954         if (key != NULL)
3955           {
3956           expand_string_message = string_sprintf("a single key was given for "
3957             "lookup type \"%s\", which is not a single-key lookup type", name);
3958           goto EXPAND_FAILED;
3959           }
3960         }
3961
3962       /* Get the next string in brackets and expand it. It is the file name for
3963       single-key+file lookups, and the whole query otherwise. In the case of
3964       queries that also require a file name (e.g. sqlite), the file name comes
3965       first. */
3966
3967       if (*s != '{') goto EXPAND_FAILED_CURLY;
3968       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
3969       if (filename == NULL) goto EXPAND_FAILED;
3970       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
3971       while (isspace(*s)) s++;
3972
3973       /* If this isn't a single-key+file lookup, re-arrange the variables
3974       to be appropriate for the search_ functions. For query-style lookups,
3975       there is just a "key", and no file name. For the special query-style +
3976       file types, the query (i.e. "key") starts with a file name. */
3977
3978       if (key == NULL)
3979         {
3980         while (isspace(*filename)) filename++;
3981         key = filename;
3982
3983         if (mac_islookup(stype, lookup_querystyle))
3984           {
3985           filename = NULL;
3986           }
3987         else
3988           {
3989           if (*filename != '/')
3990             {
3991             expand_string_message = string_sprintf(
3992               "absolute file name expected for \"%s\" lookup", name);
3993             goto EXPAND_FAILED;
3994             }
3995           while (*key != 0 && !isspace(*key)) key++;
3996           if (*key != 0) *key++ = 0;
3997           }
3998         }
3999
4000       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4001       the entry was not found. Note that there is no search_close() function.
4002       Files are left open in case of re-use. At suitable places in higher logic,
4003       search_tidyup() is called to tidy all open files. This can save opening
4004       the same file several times. However, files may also get closed when
4005       others are opened, if too many are open at once. The rule is that a
4006       handle should not be used after a second search_open().
4007
4008       Request that a partial search sets up $1 and maybe $2 by passing
4009       expand_setup containing zero. If its value changes, reset expand_nmax,
4010       since new variables will have been set. Note that at the end of this
4011       "lookup" section, the old numeric variables are restored. */
4012
4013       if (skipping)
4014         lookup_value = NULL;
4015       else
4016         {
4017         void *handle = search_open(filename, stype, 0, NULL, NULL);
4018         if (handle == NULL)
4019           {
4020           expand_string_message = search_error_message;
4021           goto EXPAND_FAILED;
4022           }
4023         lookup_value = search_find(handle, filename, key, partial, affix,
4024           affixlen, starflags, &expand_setup);
4025         if (search_find_defer)
4026           {
4027           expand_string_message =
4028             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4029               string_printing2(key, FALSE), search_error_message);
4030           goto EXPAND_FAILED;
4031           }
4032         if (expand_setup > 0) expand_nmax = expand_setup;
4033         }
4034
4035       /* The handling of "yes" and "no" result strings is now in a separate
4036       function that is also used by ${if} and ${extract}. */
4037
4038       switch(process_yesno(
4039                skipping,                     /* were previously skipping */
4040                lookup_value != NULL,         /* success/failure indicator */
4041                save_lookup_value,            /* value to reset for string2 */
4042                &s,                           /* input pointer */
4043                &yield,                       /* output pointer */
4044                &size,                        /* output size */
4045                &ptr,                         /* output current point */
4046                US"lookup"))                  /* condition type */
4047         {
4048         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4049         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4050         }
4051
4052       /* Restore external setting of expansion variables for carrying on
4053       at this level, and continue. */
4054
4055       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4056         save_expand_nlength);
4057       continue;
4058       }
4059
4060     /* If Perl support is configured, handle calling embedded perl subroutines,
4061     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4062     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4063     arguments (defined below). */
4064
4065     #define EXIM_PERL_MAX_ARGS 8
4066
4067     case EITEM_PERL:
4068     #ifndef EXIM_PERL
4069     expand_string_message = US"\"${perl\" encountered, but this facility "
4070       "is not included in this binary";
4071     goto EXPAND_FAILED;
4072
4073     #else   /* EXIM_PERL */
4074       {
4075       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4076       uschar *new_yield;
4077
4078       if ((expand_forbid & RDO_PERL) != 0)
4079         {
4080         expand_string_message = US"Perl calls are not permitted";
4081         goto EXPAND_FAILED;
4082         }
4083
4084       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4085            US"perl"))
4086         {
4087         case 1: goto EXPAND_FAILED_CURLY;
4088         case 2:
4089         case 3: goto EXPAND_FAILED;
4090         }
4091
4092       /* If skipping, we don't actually do anything */
4093
4094       if (skipping) continue;
4095
4096       /* Start the interpreter if necessary */
4097
4098       if (!opt_perl_started)
4099         {
4100         uschar *initerror;
4101         if (opt_perl_startup == NULL)
4102           {
4103           expand_string_message = US"A setting of perl_startup is needed when "
4104             "using the Perl interpreter";
4105           goto EXPAND_FAILED;
4106           }
4107         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4108         initerror = init_perl(opt_perl_startup);
4109         if (initerror != NULL)
4110           {
4111           expand_string_message =
4112             string_sprintf("error in perl_startup code: %s\n", initerror);
4113           goto EXPAND_FAILED;
4114           }
4115         opt_perl_started = TRUE;
4116         }
4117
4118       /* Call the function */
4119
4120       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4121       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4122         sub_arg[0], sub_arg + 1);
4123
4124       /* NULL yield indicates failure; if the message pointer has been set to
4125       NULL, the yield was undef, indicating a forced failure. Otherwise the
4126       message will indicate some kind of Perl error. */
4127
4128       if (new_yield == NULL)
4129         {
4130         if (expand_string_message == NULL)
4131           {
4132           expand_string_message =
4133             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4134               "failure", sub_arg[0]);
4135           expand_string_forcedfail = TRUE;
4136           }
4137         goto EXPAND_FAILED;
4138         }
4139
4140       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4141       set during a callback from Perl. */
4142
4143       expand_string_forcedfail = FALSE;
4144       yield = new_yield;
4145       continue;
4146       }
4147     #endif /* EXIM_PERL */
4148
4149     /* Transform email address to "prvs" scheme to use
4150        as BATV-signed return path */
4151
4152     case EITEM_PRVS:
4153       {
4154       uschar *sub_arg[3];
4155       uschar *p,*domain;
4156
4157       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs"))
4158         {
4159         case 1: goto EXPAND_FAILED_CURLY;
4160         case 2:
4161         case 3: goto EXPAND_FAILED;
4162         }
4163
4164       /* If skipping, we don't actually do anything */
4165       if (skipping) continue;
4166
4167       /* sub_arg[0] is the address */
4168       domain = Ustrrchr(sub_arg[0],'@');
4169       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4170         {
4171         expand_string_message = US"prvs first argument must be a qualified email address";
4172         goto EXPAND_FAILED;
4173         }
4174
4175       /* Calculate the hash. The second argument must be a single-digit
4176       key number, or unset. */
4177
4178       if (sub_arg[2] != NULL &&
4179           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4180         {
4181         expand_string_message = US"prvs second argument must be a single digit";
4182         goto EXPAND_FAILED;
4183         }
4184
4185       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4186       if (p == NULL)
4187         {
4188         expand_string_message = US"prvs hmac-sha1 conversion failed";
4189         goto EXPAND_FAILED;
4190         }
4191
4192       /* Now separate the domain from the local part */
4193       *domain++ = '\0';
4194
4195       yield = string_cat(yield,&size,&ptr,US"prvs=",5);
4196       string_cat(yield,&size,&ptr,(sub_arg[2] != NULL) ? sub_arg[2] : US"0", 1);
4197       string_cat(yield,&size,&ptr,prvs_daystamp(7),3);
4198       string_cat(yield,&size,&ptr,p,6);
4199       string_cat(yield,&size,&ptr,US"=",1);
4200       string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4201       string_cat(yield,&size,&ptr,US"@",1);
4202       string_cat(yield,&size,&ptr,domain,Ustrlen(domain));
4203
4204       continue;
4205       }
4206
4207     /* Check a prvs-encoded address for validity */
4208
4209     case EITEM_PRVSCHECK:
4210       {
4211       uschar *sub_arg[3];
4212       int mysize = 0, myptr = 0;
4213       const pcre *re;
4214       uschar *p;
4215
4216       /* TF: Ugliness: We want to expand parameter 1 first, then set
4217          up expansion variables that are used in the expansion of
4218          parameter 2. So we clone the string for the first
4219          expansion, where we only expand parameter 1.
4220
4221          PH: Actually, that isn't necessary. The read_subs() function is
4222          designed to work this way for the ${if and ${lookup expansions. I've
4223          tidied the code.
4224       */
4225
4226       /* Reset expansion variables */
4227       prvscheck_result = NULL;
4228       prvscheck_address = NULL;
4229       prvscheck_keynum = NULL;
4230
4231       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4232         {
4233         case 1: goto EXPAND_FAILED_CURLY;
4234         case 2:
4235         case 3: goto EXPAND_FAILED;
4236         }
4237
4238       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4239                               TRUE,FALSE);
4240
4241       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4242         {
4243         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4244         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4245         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4246         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4247         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4248
4249         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4250         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4251         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4252         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4253         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4254
4255         /* Set up expansion variables */
4256         prvscheck_address = string_cat(NULL, &mysize, &myptr, local_part, Ustrlen(local_part));
4257         string_cat(prvscheck_address,&mysize,&myptr,US"@",1);
4258         string_cat(prvscheck_address,&mysize,&myptr,domain,Ustrlen(domain));
4259         prvscheck_address[myptr] = '\0';
4260         prvscheck_keynum = string_copy(key_num);
4261
4262         /* Now expand the second argument */
4263         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs"))
4264           {
4265           case 1: goto EXPAND_FAILED_CURLY;
4266           case 2:
4267           case 3: goto EXPAND_FAILED;
4268           }
4269
4270         /* Now we have the key and can check the address. */
4271
4272         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4273           daystamp);
4274
4275         if (p == NULL)
4276           {
4277           expand_string_message = US"hmac-sha1 conversion failed";
4278           goto EXPAND_FAILED;
4279           }
4280
4281         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4282         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4283
4284         if (Ustrcmp(p,hash) == 0)
4285           {
4286           /* Success, valid BATV address. Now check the expiry date. */
4287           uschar *now = prvs_daystamp(0);
4288           unsigned int inow = 0,iexpire = 1;
4289
4290           (void)sscanf(CS now,"%u",&inow);
4291           (void)sscanf(CS daystamp,"%u",&iexpire);
4292
4293           /* When "iexpire" is < 7, a "flip" has occured.
4294              Adjust "inow" accordingly. */
4295           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4296
4297           if (iexpire >= inow)
4298             {
4299             prvscheck_result = US"1";
4300             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4301             }
4302             else
4303             {
4304             prvscheck_result = NULL;
4305             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4306             }
4307           }
4308         else
4309           {
4310           prvscheck_result = NULL;
4311           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4312           }
4313
4314         /* Now expand the final argument. We leave this till now so that
4315         it can include $prvscheck_result. */
4316
4317         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs"))
4318           {
4319           case 1: goto EXPAND_FAILED_CURLY;
4320           case 2:
4321           case 3: goto EXPAND_FAILED;
4322           }
4323
4324         if (sub_arg[0] == NULL || *sub_arg[0] == '\0')
4325           yield = string_cat(yield,&size,&ptr,prvscheck_address,Ustrlen(prvscheck_address));
4326         else
4327           yield = string_cat(yield,&size,&ptr,sub_arg[0],Ustrlen(sub_arg[0]));
4328
4329         /* Reset the "internal" variables afterwards, because they are in
4330         dynamic store that will be reclaimed if the expansion succeeded. */
4331
4332         prvscheck_address = NULL;
4333         prvscheck_keynum = NULL;
4334         }
4335       else
4336         {
4337         /* Does not look like a prvs encoded address, return the empty string.
4338            We need to make sure all subs are expanded first, so as to skip over
4339            the entire item. */
4340
4341         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs"))
4342           {
4343           case 1: goto EXPAND_FAILED_CURLY;
4344           case 2:
4345           case 3: goto EXPAND_FAILED;
4346           }
4347         }
4348
4349       continue;
4350       }
4351
4352     /* Handle "readfile" to insert an entire file */
4353
4354     case EITEM_READFILE:
4355       {
4356       FILE *f;
4357       uschar *sub_arg[2];
4358
4359       if ((expand_forbid & RDO_READFILE) != 0)
4360         {
4361         expand_string_message = US"file insertions are not permitted";
4362         goto EXPAND_FAILED;
4363         }
4364
4365       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile"))
4366         {
4367         case 1: goto EXPAND_FAILED_CURLY;
4368         case 2:
4369         case 3: goto EXPAND_FAILED;
4370         }
4371
4372       /* If skipping, we don't actually do anything */
4373
4374       if (skipping) continue;
4375
4376       /* Open the file and read it */
4377
4378       f = Ufopen(sub_arg[0], "rb");
4379       if (f == NULL)
4380         {
4381         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4382         goto EXPAND_FAILED;
4383         }
4384
4385       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4386       (void)fclose(f);
4387       continue;
4388       }
4389
4390     /* Handle "readsocket" to insert data from a Unix domain socket */
4391
4392     case EITEM_READSOCK:
4393       {
4394       int fd;
4395       int timeout = 5;
4396       int save_ptr = ptr;
4397       FILE *f;
4398       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4399       uschar *arg;
4400       uschar *sub_arg[4];
4401
4402       if ((expand_forbid & RDO_READSOCK) != 0)
4403         {
4404         expand_string_message = US"socket insertions are not permitted";
4405         goto EXPAND_FAILED;
4406         }
4407
4408       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4409       because there may be a string for expansion on failure. */
4410
4411       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket"))
4412         {
4413         case 1: goto EXPAND_FAILED_CURLY;
4414         case 2:                             /* Won't occur: no end check */
4415         case 3: goto EXPAND_FAILED;
4416         }
4417
4418       /* Sort out timeout, if given */
4419
4420       if (sub_arg[2] != NULL)
4421         {
4422         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4423         if (timeout < 0)
4424           {
4425           expand_string_message = string_sprintf("bad time value %s",
4426             sub_arg[2]);
4427           goto EXPAND_FAILED;
4428           }
4429         }
4430       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4431
4432       /* If skipping, we don't actually do anything. Otherwise, arrange to
4433       connect to either an IP or a Unix socket. */
4434
4435       if (!skipping)
4436         {
4437         /* Handle an IP (internet) domain */
4438
4439         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4440           {
4441           BOOL connected = FALSE;
4442           int namelen, port;
4443           host_item shost;
4444           host_item *h;
4445           uschar *server_name = sub_arg[0] + 5;
4446           uschar *port_name = Ustrrchr(server_name, ':');
4447
4448           /* Sort out the port */
4449
4450           if (port_name == NULL)
4451             {
4452             expand_string_message =
4453               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4454             goto EXPAND_FAILED;
4455             }
4456           *port_name++ = 0;           /* Terminate server name */
4457
4458           if (isdigit(*port_name))
4459             {
4460             uschar *end;
4461             port = Ustrtol(port_name, &end, 0);
4462             if (end != port_name + Ustrlen(port_name))
4463               {
4464               expand_string_message =
4465                 string_sprintf("invalid port number %s", port_name);
4466               goto EXPAND_FAILED;
4467               }
4468             }
4469           else
4470             {
4471             struct servent *service_info = getservbyname(CS port_name, "tcp");
4472             if (service_info == NULL)
4473               {
4474               expand_string_message = string_sprintf("unknown port \"%s\"",
4475                 port_name);
4476               goto EXPAND_FAILED;
4477               }
4478             port = ntohs(service_info->s_port);
4479             }
4480
4481           /* Sort out the server. */
4482
4483           shost.next = NULL;
4484           shost.address = NULL;
4485           shost.port = port;
4486           shost.mx = -1;
4487
4488           namelen = Ustrlen(server_name);
4489
4490           /* Anything enclosed in [] must be an IP address. */
4491
4492           if (server_name[0] == '[' &&
4493               server_name[namelen - 1] == ']')
4494             {
4495             server_name[namelen - 1] = 0;
4496             server_name++;
4497             if (string_is_ip_address(server_name, NULL) == 0)
4498               {
4499               expand_string_message =
4500                 string_sprintf("malformed IP address \"%s\"", server_name);
4501               goto EXPAND_FAILED;
4502               }
4503             shost.name = shost.address = server_name;
4504             }
4505
4506           /* Otherwise check for an unadorned IP address */
4507
4508           else if (string_is_ip_address(server_name, NULL) != 0)
4509             shost.name = shost.address = server_name;
4510
4511           /* Otherwise lookup IP address(es) from the name */
4512
4513           else
4514             {
4515             shost.name = server_name;
4516             if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE, NULL,
4517                 FALSE) != HOST_FOUND)
4518               {
4519               expand_string_message =
4520                 string_sprintf("no IP address found for host %s", shost.name);
4521               goto EXPAND_FAILED;
4522               }
4523             }
4524
4525           /* Try to connect to the server - test each IP till one works */
4526
4527           for (h = &shost; h != NULL; h = h->next)
4528             {
4529             int af = (Ustrchr(h->address, ':') != 0)? AF_INET6 : AF_INET;
4530             if ((fd = ip_socket(SOCK_STREAM, af)) == -1)
4531               {
4532               expand_string_message = string_sprintf("failed to create socket: "
4533                 "%s", strerror(errno));
4534               goto SOCK_FAIL;
4535               }
4536
4537             if (ip_connect(fd, af, h->address, port, timeout) == 0)
4538               {
4539               connected = TRUE;
4540               break;
4541               }
4542             }
4543
4544           if (!connected)
4545             {
4546             expand_string_message = string_sprintf("failed to connect to "
4547               "socket %s: couldn't connect to any host", sub_arg[0],
4548               strerror(errno));
4549             goto SOCK_FAIL;
4550             }
4551           }
4552
4553         /* Handle a Unix domain socket */
4554
4555         else
4556           {
4557           int rc;
4558           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4559             {
4560             expand_string_message = string_sprintf("failed to create socket: %s",
4561               strerror(errno));
4562             goto SOCK_FAIL;
4563             }
4564
4565           sockun.sun_family = AF_UNIX;
4566           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4567             sub_arg[0]);
4568
4569           sigalrm_seen = FALSE;
4570           alarm(timeout);
4571           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4572           alarm(0);
4573           if (sigalrm_seen)
4574             {
4575             expand_string_message = US "socket connect timed out";
4576             goto SOCK_FAIL;
4577             }
4578           if (rc < 0)
4579             {
4580             expand_string_message = string_sprintf("failed to connect to socket "
4581               "%s: %s", sub_arg[0], strerror(errno));
4582             goto SOCK_FAIL;
4583             }
4584           }
4585
4586         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4587
4588         /* Write the request string, if not empty */
4589
4590         if (sub_arg[1][0] != 0)
4591           {
4592           int len = Ustrlen(sub_arg[1]);
4593           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4594             sub_arg[1]);
4595           if (write(fd, sub_arg[1], len) != len)
4596             {
4597             expand_string_message = string_sprintf("request write to socket "
4598               "failed: %s", strerror(errno));
4599             goto SOCK_FAIL;
4600             }
4601           }
4602
4603         /* Shut down the sending side of the socket. This helps some servers to
4604         recognise that it is their turn to do some work. Just in case some
4605         system doesn't have this function, make it conditional. */
4606
4607         #ifdef SHUT_WR
4608         shutdown(fd, SHUT_WR);
4609         #endif
4610
4611         /* Now we need to read from the socket, under a timeout. The function
4612         that reads a file can be used. */
4613
4614         f = fdopen(fd, "rb");
4615         sigalrm_seen = FALSE;
4616         alarm(timeout);
4617         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4618         alarm(0);
4619         (void)fclose(f);
4620
4621         /* After a timeout, we restore the pointer in the result, that is,
4622         make sure we add nothing from the socket. */
4623
4624         if (sigalrm_seen)
4625           {
4626           ptr = save_ptr;
4627           expand_string_message = US "socket read timed out";
4628           goto SOCK_FAIL;
4629           }
4630         }
4631
4632       /* The whole thing has worked (or we were skipping). If there is a
4633       failure string following, we need to skip it. */
4634
4635       if (*s == '{')
4636         {
4637         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE) == NULL)
4638           goto EXPAND_FAILED;
4639         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4640         while (isspace(*s)) s++;
4641         }
4642       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4643       continue;
4644
4645       /* Come here on failure to create socket, connect socket, write to the
4646       socket, or timeout on reading. If another substring follows, expand and
4647       use it. Otherwise, those conditions give expand errors. */
4648
4649       SOCK_FAIL:
4650       if (*s != '{') goto EXPAND_FAILED;
4651       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4652       arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE);
4653       if (arg == NULL) goto EXPAND_FAILED;
4654       yield = string_cat(yield, &size, &ptr, arg, Ustrlen(arg));
4655       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4656       while (isspace(*s)) s++;
4657       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4658       continue;
4659       }
4660
4661     /* Handle "run" to execute a program. */
4662
4663     case EITEM_RUN:
4664       {
4665       FILE *f;
4666       uschar *arg;
4667       uschar **argv;
4668       pid_t pid;
4669       int fd_in, fd_out;
4670       int lsize = 0;
4671       int lptr = 0;
4672
4673       if ((expand_forbid & RDO_RUN) != 0)
4674         {
4675         expand_string_message = US"running a command is not permitted";
4676         goto EXPAND_FAILED;
4677         }
4678
4679       while (isspace(*s)) s++;
4680       if (*s != '{') goto EXPAND_FAILED_CURLY;
4681       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
4682       if (arg == NULL) goto EXPAND_FAILED;
4683       while (isspace(*s)) s++;
4684       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
4685
4686       if (skipping)   /* Just pretend it worked when we're skipping */
4687         {
4688         runrc = 0;
4689         }
4690       else
4691         {
4692         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4693             arg,                                /* raw command */
4694             FALSE,                              /* don't expand the arguments */
4695             0,                                  /* not relevant when... */
4696             NULL,                               /* no transporting address */
4697             US"${run} expansion",               /* for error messages */
4698             &expand_string_message))            /* where to put error message */
4699           {
4700           goto EXPAND_FAILED;
4701           }
4702
4703         /* Create the child process, making it a group leader. */
4704
4705         pid = child_open(argv, NULL, 0077, &fd_in, &fd_out, TRUE);
4706
4707         if (pid < 0)
4708           {
4709           expand_string_message =
4710             string_sprintf("couldn't create child process: %s", strerror(errno));
4711           goto EXPAND_FAILED;
4712           }
4713
4714         /* Nothing is written to the standard input. */
4715
4716         (void)close(fd_in);
4717
4718         /* Read the pipe to get the command's output into $value (which is kept
4719         in lookup_value). Read during execution, so that if the output exceeds
4720         the OS pipe buffer limit, we don't block forever. */
4721
4722         f = fdopen(fd_out, "rb");
4723         sigalrm_seen = FALSE;
4724         alarm(60);
4725         lookup_value = cat_file(f, lookup_value, &lsize, &lptr, NULL);
4726         alarm(0);
4727         (void)fclose(f);
4728
4729         /* Wait for the process to finish, applying the timeout, and inspect its
4730         return code for serious disasters. Simple non-zero returns are passed on.
4731         */
4732
4733         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4734           {
4735           if (sigalrm_seen == TRUE || runrc == -256)
4736             {
4737             expand_string_message = string_sprintf("command timed out");
4738             killpg(pid, SIGKILL);       /* Kill the whole process group */
4739             }
4740
4741           else if (runrc == -257)
4742             expand_string_message = string_sprintf("wait() failed: %s",
4743               strerror(errno));
4744
4745           else
4746             expand_string_message = string_sprintf("command killed by signal %d",
4747               -runrc);
4748
4749           goto EXPAND_FAILED;
4750           }
4751         }
4752
4753       /* Process the yes/no strings; $value may be useful in both cases */
4754
4755       switch(process_yesno(
4756                skipping,                     /* were previously skipping */
4757                runrc == 0,                   /* success/failure indicator */
4758                lookup_value,                 /* value to reset for string2 */
4759                &s,                           /* input pointer */
4760                &yield,                       /* output pointer */
4761                &size,                        /* output size */
4762                &ptr,                         /* output current point */
4763                US"run"))                     /* condition type */
4764         {
4765         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4766         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4767         }
4768
4769       continue;
4770       }
4771
4772     /* Handle character translation for "tr" */
4773
4774     case EITEM_TR:
4775       {
4776       int oldptr = ptr;
4777       int o2m;
4778       uschar *sub[3];
4779
4780       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr"))
4781         {
4782         case 1: goto EXPAND_FAILED_CURLY;
4783         case 2:
4784         case 3: goto EXPAND_FAILED;
4785         }
4786
4787       yield = string_cat(yield, &size, &ptr, sub[0], Ustrlen(sub[0]));
4788       o2m = Ustrlen(sub[2]) - 1;
4789
4790       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
4791         {
4792         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
4793         if (m != NULL)
4794           {
4795           int o = m - sub[1];
4796           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
4797           }
4798         }
4799
4800       continue;
4801       }
4802
4803     /* Handle "hash", "length", "nhash", and "substr" when they are given with
4804     expanded arguments. */
4805
4806     case EITEM_HASH:
4807     case EITEM_LENGTH:
4808     case EITEM_NHASH:
4809     case EITEM_SUBSTR:
4810       {
4811       int i;
4812       int len;
4813       uschar *ret;
4814       int val[2] = { 0, -1 };
4815       uschar *sub[3];
4816
4817       /* "length" takes only 2 arguments whereas the others take 2 or 3.
4818       Ensure that sub[2] is set in the ${length case. */
4819
4820       sub[2] = NULL;
4821       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
4822              TRUE, name))
4823         {
4824         case 1: goto EXPAND_FAILED_CURLY;
4825         case 2:
4826         case 3: goto EXPAND_FAILED;
4827         }
4828
4829       /* Juggle the arguments if there are only two of them: always move the
4830       string to the last position and make ${length{n}{str}} equivalent to
4831       ${substr{0}{n}{str}}. See the defaults for val[] above. */
4832
4833       if (sub[2] == NULL)
4834         {
4835         sub[2] = sub[1];
4836         sub[1] = NULL;
4837         if (item_type == EITEM_LENGTH)
4838           {
4839           sub[1] = sub[0];
4840           sub[0] = NULL;
4841           }
4842         }
4843
4844       for (i = 0; i < 2; i++)
4845         {
4846         if (sub[i] == NULL) continue;
4847         val[i] = (int)Ustrtol(sub[i], &ret, 10);
4848         if (*ret != 0 || (i != 0 && val[i] < 0))
4849           {
4850           expand_string_message = string_sprintf("\"%s\" is not a%s number "
4851             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
4852           goto EXPAND_FAILED;
4853           }
4854         }
4855
4856       ret =
4857         (item_type == EITEM_HASH)?
4858           compute_hash(sub[2], val[0], val[1], &len) :
4859         (item_type == EITEM_NHASH)?
4860           compute_nhash(sub[2], val[0], val[1], &len) :
4861           extract_substr(sub[2], val[0], val[1], &len);
4862
4863       if (ret == NULL) goto EXPAND_FAILED;
4864       yield = string_cat(yield, &size, &ptr, ret, len);
4865       continue;
4866       }
4867
4868     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
4869     This code originally contributed by Steve Haslam. It currently supports
4870     the use of MD5 and SHA-1 hashes.
4871
4872     We need some workspace that is large enough to handle all the supported
4873     hash types. Use macros to set the sizes rather than be too elaborate. */
4874
4875     #define MAX_HASHLEN      20
4876     #define MAX_HASHBLOCKLEN 64
4877
4878     case EITEM_HMAC:
4879       {
4880       uschar *sub[3];
4881       md5 md5_base;
4882       sha1 sha1_base;
4883       void *use_base;
4884       int type, i;
4885       int hashlen;      /* Number of octets for the hash algorithm's output */
4886       int hashblocklen; /* Number of octets the hash algorithm processes */
4887       uschar *keyptr, *p;
4888       unsigned int keylen;
4889
4890       uschar keyhash[MAX_HASHLEN];
4891       uschar innerhash[MAX_HASHLEN];
4892       uschar finalhash[MAX_HASHLEN];
4893       uschar finalhash_hex[2*MAX_HASHLEN];
4894       uschar innerkey[MAX_HASHBLOCKLEN];
4895       uschar outerkey[MAX_HASHBLOCKLEN];
4896
4897       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name))
4898         {
4899         case 1: goto EXPAND_FAILED_CURLY;
4900         case 2:
4901         case 3: goto EXPAND_FAILED;
4902         }
4903
4904       if (Ustrcmp(sub[0], "md5") == 0)
4905         {
4906         type = HMAC_MD5;
4907         use_base = &md5_base;
4908         hashlen = 16;
4909         hashblocklen = 64;
4910         }
4911       else if (Ustrcmp(sub[0], "sha1") == 0)
4912         {
4913         type = HMAC_SHA1;
4914         use_base = &sha1_base;
4915         hashlen = 20;
4916         hashblocklen = 64;
4917         }
4918       else
4919         {
4920         expand_string_message =
4921           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
4922         goto EXPAND_FAILED;
4923         }
4924
4925       keyptr = sub[1];
4926       keylen = Ustrlen(keyptr);
4927
4928       /* If the key is longer than the hash block length, then hash the key
4929       first */
4930
4931       if (keylen > hashblocklen)
4932         {
4933         chash_start(type, use_base);
4934         chash_end(type, use_base, keyptr, keylen, keyhash);
4935         keyptr = keyhash;
4936         keylen = hashlen;
4937         }
4938
4939       /* Now make the inner and outer key values */
4940
4941       memset(innerkey, 0x36, hashblocklen);
4942       memset(outerkey, 0x5c, hashblocklen);
4943
4944       for (i = 0; i < keylen; i++)
4945         {
4946         innerkey[i] ^= keyptr[i];
4947         outerkey[i] ^= keyptr[i];
4948         }
4949
4950       /* Now do the hashes */
4951
4952       chash_start(type, use_base);
4953       chash_mid(type, use_base, innerkey);
4954       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
4955
4956       chash_start(type, use_base);
4957       chash_mid(type, use_base, outerkey);
4958       chash_end(type, use_base, innerhash, hashlen, finalhash);
4959
4960       /* Encode the final hash as a hex string */
4961
4962       p = finalhash_hex;
4963       for (i = 0; i < hashlen; i++)
4964         {
4965         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
4966         *p++ = hex_digits[finalhash[i] & 0x0f];
4967         }
4968
4969       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
4970         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
4971
4972       yield = string_cat(yield, &size, &ptr, finalhash_hex, hashlen*2);
4973       }
4974
4975     continue;
4976
4977     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
4978     We have to save the numerical variables and restore them afterwards. */
4979
4980     case EITEM_SG:
4981       {
4982       const pcre *re;
4983       int moffset, moffsetextra, slen;
4984       int roffset;
4985       int emptyopt;
4986       const uschar *rerror;
4987       uschar *subject;
4988       uschar *sub[3];
4989       int save_expand_nmax =
4990         save_expand_strings(save_expand_nstring, save_expand_nlength);
4991
4992       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg"))
4993         {
4994         case 1: goto EXPAND_FAILED_CURLY;
4995         case 2:
4996         case 3: goto EXPAND_FAILED;
4997         }
4998
4999       /* Compile the regular expression */
5000
5001       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5002         NULL);
5003
5004       if (re == NULL)
5005         {
5006         expand_string_message = string_sprintf("regular expression error in "
5007           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5008         goto EXPAND_FAILED;
5009         }
5010
5011       /* Now run a loop to do the substitutions as often as necessary. It ends
5012       when there are no more matches. Take care over matches of the null string;
5013       do the same thing as Perl does. */
5014
5015       subject = sub[0];
5016       slen = Ustrlen(sub[0]);
5017       moffset = moffsetextra = 0;
5018       emptyopt = 0;
5019
5020       for (;;)
5021         {
5022         int ovector[3*(EXPAND_MAXN+1)];
5023         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5024           PCRE_EOPT | emptyopt, ovector, sizeof(ovector)/sizeof(int));
5025         int nn;
5026         uschar *insert;
5027
5028         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5029         is not necessarily the end. We want to repeat the match from one
5030         character further along, but leaving the basic offset the same (for
5031         copying below). We can't be at the end of the string - that was checked
5032         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5033         finished; copy the remaining string and end the loop. */
5034
5035         if (n < 0)
5036           {
5037           if (emptyopt != 0)
5038             {
5039             moffsetextra = 1;
5040             emptyopt = 0;
5041             continue;
5042             }
5043           yield = string_cat(yield, &size, &ptr, subject+moffset, slen-moffset);
5044           break;
5045           }
5046
5047         /* Match - set up for expanding the replacement. */
5048
5049         if (n == 0) n = EXPAND_MAXN + 1;
5050         expand_nmax = 0;
5051         for (nn = 0; nn < n*2; nn += 2)
5052           {
5053           expand_nstring[expand_nmax] = subject + ovector[nn];
5054           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5055           }
5056         expand_nmax--;
5057
5058         /* Copy the characters before the match, plus the expanded insertion. */
5059
5060         yield = string_cat(yield, &size, &ptr, subject + moffset,
5061           ovector[0] - moffset);
5062         insert = expand_string(sub[2]);
5063         if (insert == NULL) goto EXPAND_FAILED;
5064         yield = string_cat(yield, &size, &ptr, insert, Ustrlen(insert));
5065
5066         moffset = ovector[1];
5067         moffsetextra = 0;
5068         emptyopt = 0;
5069
5070         /* If we have matched an empty string, first check to see if we are at
5071         the end of the subject. If so, the loop is over. Otherwise, mimic
5072         what Perl's /g options does. This turns out to be rather cunning. First
5073         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5074         string at the same point. If this fails (picked up above) we advance to
5075         the next character. */
5076
5077         if (ovector[0] == ovector[1])
5078           {
5079           if (ovector[0] == slen) break;
5080           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5081           }
5082         }
5083
5084       /* All done - restore numerical variables. */
5085
5086       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5087         save_expand_nlength);
5088       continue;
5089       }
5090
5091     /* Handle keyed and numbered substring extraction. If the first argument
5092     consists entirely of digits, then a numerical extraction is assumed. */
5093
5094     case EITEM_EXTRACT:
5095       {
5096       int i;
5097       int j = 2;
5098       int field_number = 1;
5099       BOOL field_number_set = FALSE;
5100       uschar *save_lookup_value = lookup_value;
5101       uschar *sub[3];
5102       int save_expand_nmax =
5103         save_expand_strings(save_expand_nstring, save_expand_nlength);
5104
5105       /* Read the arguments */
5106
5107       for (i = 0; i < j; i++)
5108         {
5109         while (isspace(*s)) s++;
5110         if (*s == '{')
5111           {
5112           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5113           if (sub[i] == NULL) goto EXPAND_FAILED;
5114           if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5115
5116           /* After removal of leading and trailing white space, the first
5117           argument must not be empty; if it consists entirely of digits
5118           (optionally preceded by a minus sign), this is a numerical
5119           extraction, and we expect 3 arguments. */
5120
5121           if (i == 0)
5122             {
5123             int len;
5124             int x = 0;
5125             uschar *p = sub[0];
5126
5127             while (isspace(*p)) p++;
5128             sub[0] = p;
5129
5130             len = Ustrlen(p);
5131             while (len > 0 && isspace(p[len-1])) len--;
5132             p[len] = 0;
5133
5134             if (*p == 0 && !skipping)
5135               {
5136               expand_string_message = US"first argument of \"extract\" must "
5137                 "not be empty";
5138               goto EXPAND_FAILED;
5139               }
5140
5141             if (*p == '-')
5142               {
5143               field_number = -1;
5144               p++;
5145               }
5146             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5147             if (*p == 0)
5148               {
5149               field_number *= x;
5150               j = 3;               /* Need 3 args */
5151               field_number_set = TRUE;
5152               }
5153             }
5154           }
5155         else goto EXPAND_FAILED_CURLY;
5156         }
5157
5158       /* Extract either the numbered or the keyed substring into $value. If
5159       skipping, just pretend the extraction failed. */
5160
5161       lookup_value = skipping? NULL : field_number_set?
5162         expand_gettokened(field_number, sub[1], sub[2]) :
5163         expand_getkeyed(sub[0], sub[1]);
5164
5165       /* If no string follows, $value gets substituted; otherwise there can
5166       be yes/no strings, as for lookup or if. */
5167
5168       switch(process_yesno(
5169                skipping,                     /* were previously skipping */
5170                lookup_value != NULL,         /* success/failure indicator */
5171                save_lookup_value,            /* value to reset for string2 */
5172                &s,                           /* input pointer */
5173                &yield,                       /* output pointer */
5174                &size,                        /* output size */
5175                &ptr,                         /* output current point */
5176                US"extract"))                 /* condition type */
5177         {
5178         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5179         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5180         }
5181
5182       /* All done - restore numerical variables. */
5183
5184       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5185         save_expand_nlength);
5186
5187       continue;
5188       }
5189
5190
5191     /* Handle list operations */
5192
5193     case EITEM_FILTER:
5194     case EITEM_MAP:
5195     case EITEM_REDUCE:
5196       {
5197       int sep = 0;
5198       int save_ptr = ptr;
5199       uschar outsep[2] = { '\0', '\0' };
5200       uschar *list, *expr, *temp;
5201       uschar *save_iterate_item = iterate_item;
5202       uschar *save_lookup_value = lookup_value;
5203
5204       while (isspace(*s)) s++;
5205       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5206
5207       list = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5208       if (list == NULL) goto EXPAND_FAILED;
5209       if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5210
5211       if (item_type == EITEM_REDUCE)
5212         {
5213         while (isspace(*s)) s++;
5214         if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5215         temp = expand_string_internal(s, TRUE, &s, skipping, TRUE);
5216         if (temp == NULL) goto EXPAND_FAILED;
5217         lookup_value = temp;
5218         if (*s++ != '}') goto EXPAND_FAILED_CURLY;
5219         }
5220
5221       while (isspace(*s)) s++;
5222       if (*s++ != '{') goto EXPAND_FAILED_CURLY;
5223
5224       expr = s;
5225
5226       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5227       if scanning a "false" part). This allows us to find the end of the
5228       condition, because if the list is empty, we won't actually evaluate the
5229       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5230       the normal internal expansion function. */
5231
5232       if (item_type == EITEM_FILTER)
5233         {
5234         temp = eval_condition(expr, NULL);
5235         if (temp != NULL) s = temp;
5236         }
5237       else
5238         {
5239         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE);
5240         }
5241
5242       if (temp == NULL)
5243         {
5244         expand_string_message = string_sprintf("%s inside \"%s\" item",
5245           expand_string_message, name);
5246         goto EXPAND_FAILED;
5247         }
5248
5249       while (isspace(*s)) s++;
5250       if (*s++ != '}')
5251         {
5252         expand_string_message = string_sprintf("missing } at end of condition "
5253           "or expression inside \"%s\"", name);
5254         goto EXPAND_FAILED;
5255         }
5256
5257       while (isspace(*s)) s++;
5258       if (*s++ != '}')
5259         {
5260         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5261           name);
5262         goto EXPAND_FAILED;
5263         }
5264
5265       /* If we are skipping, we can now just move on to the next item. When
5266       processing for real, we perform the iteration. */
5267
5268       if (skipping) continue;
5269       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5270         {
5271         *outsep = (uschar)sep;      /* Separator as a string */
5272
5273         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5274
5275         if (item_type == EITEM_FILTER)
5276           {
5277           BOOL condresult;
5278           if (eval_condition(expr, &condresult) == NULL)
5279             {
5280             iterate_item = save_iterate_item;
5281             lookup_value = save_lookup_value;
5282             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5283               expand_string_message, name);
5284             goto EXPAND_FAILED;
5285             }
5286           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5287             condresult? "true":"false");
5288           if (condresult)
5289             temp = iterate_item;    /* TRUE => include this item */
5290           else
5291             continue;               /* FALSE => skip this item */
5292           }
5293
5294         /* EITEM_MAP and EITEM_REDUCE */
5295
5296         else
5297           {
5298           temp = expand_string_internal(expr, TRUE, NULL, skipping, TRUE);
5299           if (temp == NULL)
5300             {
5301             iterate_item = save_iterate_item;
5302             expand_string_message = string_sprintf("%s inside \"%s\" item",
5303               expand_string_message, name);
5304             goto EXPAND_FAILED;
5305             }
5306           if (item_type == EITEM_REDUCE)
5307             {
5308             lookup_value = temp;      /* Update the value of $value */
5309             continue;                 /* and continue the iteration */
5310             }
5311           }
5312
5313         /* We reach here for FILTER if the condition is true, always for MAP,
5314         and never for REDUCE. The value in "temp" is to be added to the output
5315         list that is being created, ensuring that any occurrences of the
5316         separator character are doubled. Unless we are dealing with the first
5317         item of the output list, add in a space if the new item begins with the
5318         separator character, or is an empty string. */
5319
5320         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5321           yield = string_cat(yield, &size, &ptr, US" ", 1);
5322
5323         /* Add the string in "temp" to the output list that we are building,
5324         This is done in chunks by searching for the separator character. */
5325
5326         for (;;)
5327           {
5328           size_t seglen = Ustrcspn(temp, outsep);
5329             yield = string_cat(yield, &size, &ptr, temp, seglen + 1);
5330
5331           /* If we got to the end of the string we output one character
5332           too many; backup and end the loop. Otherwise arrange to double the
5333           separator. */
5334
5335           if (temp[seglen] == '\0') { ptr--; break; }
5336           yield = string_cat(yield, &size, &ptr, outsep, 1);
5337           temp += seglen + 1;
5338           }
5339
5340         /* Output a separator after the string: we will remove the redundant
5341         final one at the end. */
5342
5343         yield = string_cat(yield, &size, &ptr, outsep, 1);
5344         }   /* End of iteration over the list loop */
5345
5346       /* REDUCE has generated no output above: output the final value of
5347       $value. */
5348
5349       if (item_type == EITEM_REDUCE)
5350         {
5351         yield = string_cat(yield, &size, &ptr, lookup_value,
5352           Ustrlen(lookup_value));
5353         lookup_value = save_lookup_value;  /* Restore $value */
5354         }
5355
5356       /* FILTER and MAP generate lists: if they have generated anything, remove
5357       the redundant final separator. Even though an empty item at the end of a
5358       list does not count, this is tidier. */
5359
5360       else if (ptr != save_ptr) ptr--;
5361
5362       /* Restore preserved $item */
5363
5364       iterate_item = save_iterate_item;
5365       continue;
5366       }
5367
5368
5369     /* If ${dlfunc support is configured, handle calling dynamically-loaded
5370     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
5371     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
5372     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
5373
5374     #define EXPAND_DLFUNC_MAX_ARGS 8
5375
5376     case EITEM_DLFUNC:
5377     #ifndef EXPAND_DLFUNC
5378     expand_string_message = US"\"${dlfunc\" encountered, but this facility "
5379       "is not included in this binary";
5380     goto EXPAND_FAILED;
5381
5382     #else   /* EXPAND_DLFUNC */
5383       {
5384       tree_node *t;
5385       exim_dlfunc_t *func;
5386       uschar *result;
5387       int status, argc;
5388       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
5389
5390       if ((expand_forbid & RDO_DLFUNC) != 0)
5391         {
5392         expand_string_message =
5393           US"dynamically-loaded functions are not permitted";
5394         goto EXPAND_FAILED;
5395         }
5396
5397       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
5398            TRUE, US"dlfunc"))
5399         {
5400         case 1: goto EXPAND_FAILED_CURLY;
5401         case 2:
5402         case 3: goto EXPAND_FAILED;
5403         }
5404
5405       /* If skipping, we don't actually do anything */
5406
5407       if (skipping) continue;
5408
5409       /* Look up the dynamically loaded object handle in the tree. If it isn't
5410       found, dlopen() the file and put the handle in the tree for next time. */
5411
5412       t = tree_search(dlobj_anchor, argv[0]);
5413       if (t == NULL)
5414         {
5415         void *handle = dlopen(CS argv[0], RTLD_LAZY);
5416         if (handle == NULL)
5417           {
5418           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
5419             argv[0], dlerror());
5420           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5421           goto EXPAND_FAILED;
5422           }
5423         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
5424         Ustrcpy(t->name, argv[0]);
5425         t->data.ptr = handle;
5426         (void)tree_insertnode(&dlobj_anchor, t);
5427         }
5428
5429       /* Having obtained the dynamically loaded object handle, look up the
5430       function pointer. */
5431
5432       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
5433       if (func == NULL)
5434         {
5435         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
5436           "%s", argv[1], argv[0], dlerror());
5437         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
5438         goto EXPAND_FAILED;
5439         }
5440
5441       /* Call the function and work out what to do with the result. If it
5442       returns OK, we have a replacement string; if it returns DEFER then
5443       expansion has failed in a non-forced manner; if it returns FAIL then
5444       failure was forced; if it returns ERROR or any other value there's a
5445       problem, so panic slightly. In any case, assume that the function has
5446       side-effects on the store that must be preserved. */
5447
5448       resetok = FALSE;
5449       result = NULL;
5450       for (argc = 0; argv[argc] != NULL; argc++);
5451       status = func(&result, argc - 2, &argv[2]);
5452       if(status == OK)
5453         {
5454         if (result == NULL) result = US"";
5455         yield = string_cat(yield, &size, &ptr, result, Ustrlen(result));
5456         continue;
5457         }
5458       else
5459         {
5460         expand_string_message = result == NULL ? US"(no message)" : result;
5461         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
5462           else if(status != FAIL)
5463             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
5464               argv[0], argv[1], status, expand_string_message);
5465         goto EXPAND_FAILED;
5466         }
5467       }
5468     #endif /* EXPAND_DLFUNC */
5469     }
5470
5471   /* Control reaches here if the name is not recognized as one of the more
5472   complicated expansion items. Check for the "operator" syntax (name terminated
5473   by a colon). Some of the operators have arguments, separated by _ from the
5474   name. */
5475
5476   if (*s == ':')
5477     {
5478     int c;
5479     uschar *arg = NULL;
5480     uschar *sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE);
5481     if (sub == NULL) goto EXPAND_FAILED;
5482     s++;
5483
5484     /* Owing to an historical mis-design, an underscore may be part of the
5485     operator name, or it may introduce arguments.  We therefore first scan the
5486     table of names that contain underscores. If there is no match, we cut off
5487     the arguments and then scan the main table. */
5488
5489     c = chop_match(name, op_table_underscore,
5490       sizeof(op_table_underscore)/sizeof(uschar *));
5491
5492     if (c < 0)
5493       {
5494       arg = Ustrchr(name, '_');
5495       if (arg != NULL) *arg = 0;
5496       c = chop_match(name, op_table_main,
5497         sizeof(op_table_main)/sizeof(uschar *));
5498       if (c >= 0) c += sizeof(op_table_underscore)/sizeof(uschar *);
5499       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
5500       }
5501
5502     /* If we are skipping, we don't need to perform the operation at all.
5503     This matters for operations like "mask", because the data may not be
5504     in the correct format when skipping. For example, the expression may test
5505     for the existence of $sender_host_address before trying to mask it. For
5506     other operations, doing them may not fail, but it is a waste of time. */
5507
5508     if (skipping && c >= 0) continue;
5509
5510     /* Otherwise, switch on the operator type */
5511
5512     switch(c)
5513       {
5514       case EOP_BASE62:
5515         {
5516         uschar *t;
5517         unsigned long int n = Ustrtoul(sub, &t, 10);
5518         if (*t != 0)
5519           {
5520           expand_string_message = string_sprintf("argument for base62 "
5521             "operator is \"%s\", which is not a decimal number", sub);
5522           goto EXPAND_FAILED;
5523           }
5524         t = string_base62(n);
5525         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
5526         continue;
5527         }
5528
5529       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
5530
5531       case EOP_BASE62D:
5532         {
5533         uschar buf[16];
5534         uschar *tt = sub;
5535         unsigned long int n = 0;
5536         while (*tt != 0)
5537           {
5538           uschar *t = Ustrchr(base62_chars, *tt++);
5539           if (t == NULL)
5540             {
5541             expand_string_message = string_sprintf("argument for base62d "
5542               "operator is \"%s\", which is not a base %d number", sub,
5543               BASE_62);
5544             goto EXPAND_FAILED;
5545             }
5546           n = n * BASE_62 + (t - base62_chars);
5547           }
5548         (void)sprintf(CS buf, "%ld", n);
5549         yield = string_cat(yield, &size, &ptr, buf, Ustrlen(buf));
5550         continue;
5551         }
5552
5553       case EOP_EXPAND:
5554         {
5555         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE);
5556         if (expanded == NULL)
5557           {
5558           expand_string_message =
5559             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
5560               expand_string_message);
5561           goto EXPAND_FAILED;
5562           }
5563         yield = string_cat(yield, &size, &ptr, expanded, Ustrlen(expanded));
5564         continue;
5565         }
5566
5567       case EOP_LC:
5568         {
5569         int count = 0;
5570         uschar *t = sub - 1;
5571         while (*(++t) != 0) { *t = tolower(*t); count++; }
5572         yield = string_cat(yield, &size, &ptr, sub, count);
5573         continue;
5574         }
5575
5576       case EOP_UC:
5577         {
5578         int count = 0;
5579         uschar *t = sub - 1;
5580         while (*(++t) != 0) { *t = toupper(*t); count++; }
5581         yield = string_cat(yield, &size, &ptr, sub, count);
5582         continue;
5583         }
5584
5585       case EOP_MD5:
5586         {
5587         md5 base;
5588         uschar digest[16];
5589         int j;
5590         char st[33];
5591         md5_start(&base);
5592         md5_end(&base, sub, Ustrlen(sub), digest);
5593         for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
5594         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5595         continue;
5596         }
5597
5598       case EOP_SHA1:
5599         {
5600         sha1 base;
5601         uschar digest[20];
5602         int j;
5603         char st[41];
5604         sha1_start(&base);
5605         sha1_end(&base, sub, Ustrlen(sub), digest);
5606         for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
5607         yield = string_cat(yield, &size, &ptr, US st, (int)strlen(st));
5608         continue;
5609         }
5610
5611       /* Convert hex encoding to base64 encoding */
5612
5613       case EOP_HEX2B64:
5614         {
5615         int c = 0;
5616         int b = -1;
5617         uschar *in = sub;
5618         uschar *out = sub;
5619         uschar *enc;
5620
5621         for (enc = sub; *enc != 0; enc++)
5622           {
5623           if (!isxdigit(*enc))
5624             {
5625             expand_string_message = string_sprintf("\"%s\" is not a hex "
5626               "string", sub);
5627             goto EXPAND_FAILED;
5628             }
5629           c++;
5630           }
5631
5632         if ((c & 1) != 0)
5633           {
5634           expand_string_message = string_sprintf("\"%s\" contains an odd "
5635             "number of characters", sub);
5636           goto EXPAND_FAILED;
5637           }
5638
5639         while ((c = *in++) != 0)
5640           {
5641           if (isdigit(c)) c -= '0';
5642           else c = toupper(c) - 'A' + 10;
5643           if (b == -1)
5644             {
5645             b = c << 4;
5646             }
5647           else
5648             {
5649             *out++ = b | c;
5650             b = -1;
5651             }
5652           }
5653
5654         enc = auth_b64encode(sub, out - sub);
5655         yield = string_cat(yield, &size, &ptr, enc, Ustrlen(enc));
5656         continue;
5657         }
5658
5659       /* count the number of list elements */
5660
5661       case EOP_LISTCOUNT:
5662         {
5663         int cnt = 0;
5664         int sep = 0;
5665         uschar * cp;
5666         uschar buffer[256];
5667
5668         while (string_nextinlist(&sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
5669         cp = string_sprintf("%d", cnt);
5670         yield = string_cat(yield, &size, &ptr, cp, Ustrlen(cp));
5671         continue;
5672         }
5673
5674       /* expand a named list given the name */
5675       /* handles nested named lists; requotes as colon-sep list */
5676
5677       case EOP_LISTNAMED:
5678         {
5679         tree_node *t = NULL;
5680         uschar * list;
5681         int sep = 0;
5682         uschar * item;
5683         uschar * suffix = US"";
5684         BOOL needsep = FALSE;
5685         uschar buffer[256];
5686
5687         if (*sub == '+') sub++;
5688         if (arg == NULL)        /* no-argument version */
5689           {
5690           if (!(t = tree_search(addresslist_anchor, sub)) &&
5691               !(t = tree_search(domainlist_anchor,  sub)) &&
5692               !(t = tree_search(hostlist_anchor,    sub)))
5693             t = tree_search(localpartlist_anchor, sub);
5694           }
5695         else switch(*arg)       /* specific list-type version */
5696           {
5697           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
5698           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
5699           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
5700           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
5701           default:
5702             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
5703             goto EXPAND_FAILED;
5704           }
5705
5706         if(!t)
5707           {
5708           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
5709             sub, !arg?""
5710               : *arg=='a'?"address "
5711               : *arg=='d'?"domain "
5712               : *arg=='h'?"host "
5713               : *arg=='l'?"localpart "
5714               : 0);
5715           goto EXPAND_FAILED;
5716           }
5717
5718         list = ((namedlist_block *)(t->data.ptr))->string;
5719
5720         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
5721           {
5722           uschar * buf = US" : ";
5723           if (needsep)
5724             yield = string_cat(yield, &size, &ptr, buf, 3);
5725           else
5726             needsep = TRUE;
5727
5728           if (*item == '+')     /* list item is itself a named list */
5729             {
5730             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
5731             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE);
5732             }
5733           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
5734             {
5735             char * cp;
5736             char tok[3];
5737             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
5738             while ((cp= strpbrk((const char *)item, tok)))
5739               {
5740               yield = string_cat(yield, &size, &ptr, item, cp-(char *)item);
5741               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
5742                 {
5743                 yield = string_cat(yield, &size, &ptr, US"::", 2);
5744                 item = (uschar *)cp;
5745                 }
5746               else              /* sep in item; should already be doubled; emit once */
5747                 {
5748                 yield = string_cat(yield, &size, &ptr, (uschar *)tok, 1);
5749                 if (*cp == sep) cp++;
5750                 item = (uschar *)cp;
5751                 }
5752               }
5753             }
5754           yield = string_cat(yield, &size, &ptr, item, Ustrlen(item));
5755           }
5756         continue;
5757         }
5758
5759       /* mask applies a mask to an IP address; for example the result of
5760       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
5761
5762       case EOP_MASK:
5763         {
5764         int count;
5765         uschar *endptr;
5766         int binary[4];
5767         int mask, maskoffset;
5768         int type = string_is_ip_address(sub, &maskoffset);
5769         uschar buffer[64];
5770
5771         if (type == 0)
5772           {
5773           expand_string_message = string_sprintf("\"%s\" is not an IP address",
5774            sub);
5775           goto EXPAND_FAILED;
5776           }
5777
5778         if (maskoffset == 0)
5779           {
5780           expand_string_message = string_sprintf("missing mask value in \"%s\"",
5781             sub);
5782           goto EXPAND_FAILED;
5783           }
5784
5785         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
5786
5787         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
5788           {
5789           expand_string_message = string_sprintf("mask value too big in \"%s\"",
5790             sub);
5791           goto EXPAND_FAILED;
5792           }
5793
5794         /* Convert the address to binary integer(s) and apply the mask */
5795
5796         sub[maskoffset] = 0;
5797         count = host_aton(sub, binary);
5798         host_mask(count, binary, mask);
5799
5800         /* Convert to masked textual format and add to output. */
5801
5802         yield = string_cat(yield, &size, &ptr, buffer,
5803           host_nmtoa(count, binary, mask, buffer, '.'));
5804         continue;
5805         }
5806
5807       case EOP_ADDRESS:
5808       case EOP_LOCAL_PART:
5809       case EOP_DOMAIN:
5810         {
5811         uschar *error;
5812         int start, end, domain;
5813         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
5814           FALSE);
5815         if (t != NULL)
5816           {
5817           if (c != EOP_DOMAIN)
5818             {
5819             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
5820             yield = string_cat(yield, &size, &ptr, sub+start, end-start);
5821             }
5822           else if (domain != 0)
5823             {
5824             domain += start;
5825             yield = string_cat(yield, &size, &ptr, sub+domain, end-domain);
5826             }
5827           }
5828         continue;
5829         }
5830
5831       case EOP_ADDRESSES:
5832         {
5833         uschar outsep[2] = { ':', '\0' };
5834         uschar *address, *error;
5835         int save_ptr = ptr;
5836         int start, end, domain;  /* Not really used */
5837
5838         while (isspace(*sub)) sub++;
5839         if (*sub == '>') { *outsep = *++sub; ++sub; }
5840         parse_allow_group = TRUE;
5841
5842         for (;;)
5843           {
5844           uschar *p = parse_find_address_end(sub, FALSE);
5845           uschar saveend = *p;
5846           *p = '\0';
5847           address = parse_extract_address(sub, &error, &start, &end, &domain,
5848             FALSE);
5849           *p = saveend;
5850
5851           /* Add the address to the output list that we are building. This is
5852           done in chunks by searching for the separator character. At the
5853           start, unless we are dealing with the first address of the output
5854           list, add in a space if the new address begins with the separator
5855           character, or is an empty string. */
5856
5857           if (address != NULL)
5858             {
5859             if (ptr != save_ptr && address[0] == *outsep)
5860               yield = string_cat(yield, &size, &ptr, US" ", 1);
5861
5862             for (;;)
5863               {
5864               size_t seglen = Ustrcspn(address, outsep);
5865               yield = string_cat(yield, &size, &ptr, address, seglen + 1);
5866
5867               /* If we got to the end of the string we output one character
5868               too many. */
5869
5870               if (address[seglen] == '\0') { ptr--; break; }
5871               yield = string_cat(yield, &size, &ptr, outsep, 1);
5872               address += seglen + 1;
5873               }
5874
5875             /* Output a separator after the string: we will remove the
5876             redundant final one at the end. */
5877
5878             yield = string_cat(yield, &size, &ptr, outsep, 1);
5879             }
5880
5881           if (saveend == '\0') break;
5882           sub = p + 1;
5883           }
5884
5885         /* If we have generated anything, remove the redundant final
5886         separator. */
5887
5888         if (ptr != save_ptr) ptr--;
5889         parse_allow_group = FALSE;
5890         continue;
5891         }
5892
5893
5894       /* quote puts a string in quotes if it is empty or contains anything
5895       other than alphamerics, underscore, dot, or hyphen.
5896
5897       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
5898       be quoted in order to be a valid local part.
5899
5900       In both cases, newlines and carriage returns are converted into \n and \r
5901       respectively */
5902
5903       case EOP_QUOTE:
5904       case EOP_QUOTE_LOCAL_PART:
5905       if (arg == NULL)
5906         {
5907         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
5908         uschar *t = sub - 1;
5909
5910         if (c == EOP_QUOTE)
5911           {
5912           while (!needs_quote && *(++t) != 0)
5913             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
5914           }
5915         else  /* EOP_QUOTE_LOCAL_PART */
5916           {
5917           while (!needs_quote && *(++t) != 0)
5918             needs_quote = !isalnum(*t) &&
5919               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
5920               (*t != '.' || t == sub || t[1] == 0);
5921           }
5922
5923         if (needs_quote)
5924           {
5925           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5926           t = sub - 1;
5927           while (*(++t) != 0)
5928             {
5929             if (*t == '\n')
5930               yield = string_cat(yield, &size, &ptr, US"\\n", 2);
5931             else if (*t == '\r')
5932               yield = string_cat(yield, &size, &ptr, US"\\r", 2);
5933             else
5934               {
5935               if (*t == '\\' || *t == '"')
5936                 yield = string_cat(yield, &size, &ptr, US"\\", 1);
5937               yield = string_cat(yield, &size, &ptr, t, 1);
5938               }
5939             }
5940           yield = string_cat(yield, &size, &ptr, US"\"", 1);
5941           }
5942         else yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5943         continue;
5944         }
5945
5946       /* quote_lookuptype does lookup-specific quoting */
5947
5948       else
5949         {
5950         int n;
5951         uschar *opt = Ustrchr(arg, '_');
5952
5953         if (opt != NULL) *opt++ = 0;
5954
5955         n = search_findtype(arg, Ustrlen(arg));
5956         if (n < 0)
5957           {
5958           expand_string_message = search_error_message;
5959           goto EXPAND_FAILED;
5960           }
5961
5962         if (lookup_list[n]->quote != NULL)
5963           sub = (lookup_list[n]->quote)(sub, opt);
5964         else if (opt != NULL) sub = NULL;
5965
5966         if (sub == NULL)
5967           {
5968           expand_string_message = string_sprintf(
5969             "\"%s\" unrecognized after \"${quote_%s\"",
5970             opt, arg);
5971           goto EXPAND_FAILED;
5972           }
5973
5974         yield = string_cat(yield, &size, &ptr, sub, Ustrlen(sub));
5975         continue;
5976         }
5977
5978       /* rx quote sticks in \ before any non-alphameric character so that
5979       the insertion works in a regular expression. */
5980
5981       case EOP_RXQUOTE:
5982         {
5983         uschar *t = sub - 1;
5984         while (*(++t) != 0)
5985           {
5986           if (!isalnum(*t))
5987             yield = string_cat(yield, &size, &ptr, US"\\", 1);
5988           yield = string_cat(yield, &size, &ptr, t, 1);
5989           }
5990         continue;
5991         }
5992
5993       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
5994       prescribed by the RFC, if there are characters that need to be encoded */
5995
5996       case EOP_RFC2047:
5997         {
5998         uschar buffer[2048];
5999         uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6000           buffer, sizeof(buffer), FALSE);
6001         yield = string_cat(yield, &size, &ptr, string, Ustrlen(string));
6002         continue;
6003         }
6004
6005       /* RFC 2047 decode */
6006
6007       case EOP_RFC2047D:
6008         {
6009         int len;
6010         uschar *error;
6011         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6012           headers_charset, '?', &len, &error);
6013         if (error != NULL)
6014           {
6015           expand_string_message = error;
6016           goto EXPAND_FAILED;
6017           }
6018         yield = string_cat(yield, &size, &ptr, decoded, len);
6019         continue;
6020         }
6021
6022       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6023       underscores */
6024
6025       case EOP_FROM_UTF8:
6026         {
6027         while (*sub != 0)
6028           {
6029           int c;
6030           uschar buff[4];
6031           GETUTF8INC(c, sub);
6032           if (c > 255) c = '_';
6033           buff[0] = c;
6034           yield = string_cat(yield, &size, &ptr, buff, 1);
6035           }
6036         continue;
6037         }
6038
6039       /* escape turns all non-printing characters into escape sequences. */
6040
6041       case EOP_ESCAPE:
6042         {
6043         uschar *t = string_printing(sub);
6044         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6045         continue;
6046         }
6047
6048       /* Handle numeric expression evaluation */
6049
6050       case EOP_EVAL:
6051       case EOP_EVAL10:
6052         {
6053         uschar *save_sub = sub;
6054         uschar *error = NULL;
6055         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
6056         if (error != NULL)
6057           {
6058           expand_string_message = string_sprintf("error in expression "
6059             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
6060               save_sub);
6061           goto EXPAND_FAILED;
6062           }
6063         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
6064         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6065         continue;
6066         }
6067
6068       /* Handle time period formating */
6069
6070       case EOP_TIME_EVAL:
6071         {
6072         int n = readconf_readtime(sub, 0, FALSE);
6073         if (n < 0)
6074           {
6075           expand_string_message = string_sprintf("string \"%s\" is not an "
6076             "Exim time interval in \"%s\" operator", sub, name);
6077           goto EXPAND_FAILED;
6078           }
6079         sprintf(CS var_buffer, "%d", n);
6080         yield = string_cat(yield, &size, &ptr, var_buffer, Ustrlen(var_buffer));
6081         continue;
6082         }
6083
6084       case EOP_TIME_INTERVAL:
6085         {
6086         int n;
6087         uschar *t = read_number(&n, sub);
6088         if (*t != 0) /* Not A Number*/
6089           {
6090           expand_string_message = string_sprintf("string \"%s\" is not a "
6091             "positive number in \"%s\" operator", sub, name);
6092           goto EXPAND_FAILED;
6093           }
6094         t = readconf_printtime(n);
6095         yield = string_cat(yield, &size, &ptr, t, Ustrlen(t));
6096         continue;
6097         }
6098
6099       /* Convert string to base64 encoding */
6100
6101       case EOP_STR2B64:
6102         {
6103         uschar *encstr = auth_b64encode(sub, Ustrlen(sub));
6104         yield = string_cat(yield, &size, &ptr, encstr, Ustrlen(encstr));
6105         continue;
6106         }
6107
6108       /* strlen returns the length of the string */
6109
6110       case EOP_STRLEN:
6111         {
6112         uschar buff[24];
6113         (void)sprintf(CS buff, "%d", Ustrlen(sub));
6114         yield = string_cat(yield, &size, &ptr, buff, Ustrlen(buff));
6115         continue;
6116         }
6117
6118       /* length_n or l_n takes just the first n characters or the whole string,
6119       whichever is the shorter;
6120
6121       substr_m_n, and s_m_n take n characters from offset m; negative m take
6122       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
6123       takes the rest, either to the right or to the left.
6124
6125       hash_n or h_n makes a hash of length n from the string, yielding n
6126       characters from the set a-z; hash_n_m makes a hash of length n, but
6127       uses m characters from the set a-zA-Z0-9.
6128
6129       nhash_n returns a single number between 0 and n-1 (in text form), while
6130       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
6131       between 0 and n-1 and the second between 0 and m-1. */
6132
6133       case EOP_LENGTH:
6134       case EOP_L:
6135       case EOP_SUBSTR:
6136       case EOP_S:
6137       case EOP_HASH:
6138       case EOP_H:
6139       case EOP_NHASH:
6140       case EOP_NH:
6141         {
6142         int sign = 1;
6143         int value1 = 0;
6144         int value2 = -1;
6145         int *pn;
6146         int len;
6147         uschar *ret;
6148
6149         if (arg == NULL)
6150           {
6151           expand_string_message = string_sprintf("missing values after %s",
6152             name);
6153           goto EXPAND_FAILED;
6154           }
6155
6156         /* "length" has only one argument, effectively being synonymous with
6157         substr_0_n. */
6158
6159         if (c == EOP_LENGTH || c == EOP_L)
6160           {
6161           pn = &value2;
6162           value2 = 0;
6163           }
6164
6165         /* The others have one or two arguments; for "substr" the first may be
6166         negative. The second being negative means "not supplied". */
6167
6168         else
6169           {
6170           pn = &value1;
6171           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
6172           }
6173
6174         /* Read up to two numbers, separated by underscores */
6175
6176         ret = arg;
6177         while (*arg != 0)
6178           {
6179           if (arg != ret && *arg == '_' && pn == &value1)
6180             {
6181             pn = &value2;
6182             value2 = 0;
6183             if (arg[1] != 0) arg++;
6184             }
6185           else if (!isdigit(*arg))
6186             {
6187             expand_string_message =
6188               string_sprintf("non-digit after underscore in \"%s\"", name);
6189             goto EXPAND_FAILED;
6190             }
6191           else *pn = (*pn)*10 + *arg++ - '0';
6192           }
6193         value1 *= sign;
6194
6195         /* Perform the required operation */
6196
6197         ret =
6198           (c == EOP_HASH || c == EOP_H)?
6199              compute_hash(sub, value1, value2, &len) :
6200           (c == EOP_NHASH || c == EOP_NH)?
6201              compute_nhash(sub, value1, value2, &len) :
6202              extract_substr(sub, value1, value2, &len);
6203
6204         if (ret == NULL) goto EXPAND_FAILED;
6205         yield = string_cat(yield, &size, &ptr, ret, len);
6206         continue;
6207         }
6208
6209       /* Stat a path */
6210
6211       case EOP_STAT:
6212         {
6213         uschar *s;
6214         uschar smode[12];
6215         uschar **modetable[3];
6216         int i;
6217         mode_t mode;
6218         struct stat st;
6219
6220         if ((expand_forbid & RDO_EXISTS) != 0)
6221           {
6222           expand_string_message = US"Use of the stat() expansion is not permitted";
6223           goto EXPAND_FAILED;
6224           }
6225
6226         if (stat(CS sub, &st) < 0)
6227           {
6228           expand_string_message = string_sprintf("stat(%s) failed: %s",
6229             sub, strerror(errno));
6230           goto EXPAND_FAILED;
6231           }
6232         mode = st.st_mode;
6233         switch (mode & S_IFMT)
6234           {
6235           case S_IFIFO: smode[0] = 'p'; break;
6236           case S_IFCHR: smode[0] = 'c'; break;
6237           case S_IFDIR: smode[0] = 'd'; break;
6238           case S_IFBLK: smode[0] = 'b'; break;
6239           case S_IFREG: smode[0] = '-'; break;
6240           default: smode[0] = '?'; break;
6241           }
6242
6243         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
6244         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
6245         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
6246
6247         for (i = 0; i < 3; i++)
6248           {
6249           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
6250           mode >>= 3;
6251           }
6252
6253         smode[10] = 0;
6254         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
6255           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
6256           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
6257           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
6258           (long)st.st_gid, st.st_size, (long)st.st_atime,
6259           (long)st.st_mtime, (long)st.st_ctime);
6260         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6261         continue;
6262         }
6263
6264       /* vaguely random number less than N */
6265
6266       case EOP_RANDINT:
6267         {
6268         int_eximarith_t max;
6269         uschar *s;
6270
6271         max = expand_string_integer(sub, TRUE);
6272         if (expand_string_message != NULL)
6273           goto EXPAND_FAILED;
6274         s = string_sprintf("%d", vaguely_random_number((int)max));
6275         yield = string_cat(yield, &size, &ptr, s, Ustrlen(s));
6276         continue;
6277         }
6278
6279       /* Reverse IP, including IPv6 to dotted-nibble */
6280
6281       case EOP_REVERSE_IP:
6282         {
6283         int family, maskptr;
6284         uschar reversed[128];
6285
6286         family = string_is_ip_address(sub, &maskptr);
6287         if (family == 0)
6288           {
6289           expand_string_message = string_sprintf(
6290               "reverse_ip() not given an IP address [%s]", sub);
6291           goto EXPAND_FAILED;
6292           }
6293         invert_address(reversed, sub);
6294         yield = string_cat(yield, &size, &ptr, reversed, Ustrlen(reversed));
6295         continue;
6296         }
6297
6298       /* Unknown operator */
6299
6300       default:
6301       expand_string_message =
6302         string_sprintf("unknown expansion operator \"%s\"", name);
6303       goto EXPAND_FAILED;
6304       }
6305     }
6306
6307   /* Handle a plain name. If this is the first thing in the expansion, release
6308   the pre-allocated buffer. If the result data is known to be in a new buffer,
6309   newsize will be set to the size of that buffer, and we can just point at that
6310   store instead of copying. Many expansion strings contain just one reference,
6311   so this is a useful optimization, especially for humungous headers
6312   ($message_headers). */
6313
6314   if (*s++ == '}')
6315     {
6316     int len;
6317     int newsize = 0;
6318     if (ptr == 0)
6319       {
6320       if (resetok) store_reset(yield);
6321       yield = NULL;
6322       size = 0;
6323       }
6324     value = find_variable(name, FALSE, skipping, &newsize);
6325     if (value == NULL)
6326       {
6327       expand_string_message =
6328         string_sprintf("unknown variable in \"${%s}\"", name);
6329       check_variable_error_message(name);
6330       goto EXPAND_FAILED;
6331       }
6332     len = Ustrlen(value);
6333     if (yield == NULL && newsize != 0)
6334       {
6335       yield = value;
6336       size = newsize;
6337       ptr = len;
6338       }
6339     else yield = string_cat(yield, &size, &ptr, value, len);
6340     continue;
6341     }
6342
6343   /* Else there's something wrong */
6344
6345   expand_string_message =
6346     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
6347     "in a variable reference)", name);
6348   goto EXPAND_FAILED;
6349   }
6350
6351 /* If we hit the end of the string when ket_ends is set, there is a missing
6352 terminating brace. */
6353
6354 if (ket_ends && *s == 0)
6355   {
6356   expand_string_message = malformed_header?
6357     US"missing } at end of string - could be header name not terminated by colon"
6358     :
6359     US"missing } at end of string";
6360   goto EXPAND_FAILED;
6361   }
6362
6363 /* Expansion succeeded; yield may still be NULL here if nothing was actually
6364 added to the string. If so, set up an empty string. Add a terminating zero. If
6365 left != NULL, return a pointer to the terminator. */
6366
6367 if (yield == NULL) yield = store_get(1);
6368 yield[ptr] = 0;
6369 if (left != NULL) *left = s;
6370
6371 /* Any stacking store that was used above the final string is no longer needed.
6372 In many cases the final string will be the first one that was got and so there
6373 will be optimal store usage. */
6374
6375 if (resetok) store_reset(yield + ptr + 1);
6376 DEBUG(D_expand)
6377   {
6378   debug_printf("expanding: %.*s\n   result: %s\n", (int)(s - string), string,
6379     yield);
6380   if (skipping) debug_printf("skipping: result is not used\n");
6381   }
6382 return yield;
6383
6384 /* This is the failure exit: easiest to program with a goto. We still need
6385 to update the pointer to the terminator, for cases of nested calls with "fail".
6386 */
6387
6388 EXPAND_FAILED_CURLY:
6389 expand_string_message = malformed_header?
6390   US"missing or misplaced { or } - could be header name not terminated by colon"
6391   :
6392   US"missing or misplaced { or }";
6393
6394 /* At one point, Exim reset the store to yield (if yield was not NULL), but
6395 that is a bad idea, because expand_string_message is in dynamic store. */
6396
6397 EXPAND_FAILED:
6398 if (left != NULL) *left = s;
6399 DEBUG(D_expand)
6400   {
6401   debug_printf("failed to expand: %s\n", string);
6402   debug_printf("   error message: %s\n", expand_string_message);
6403   if (expand_string_forcedfail) debug_printf("failure was forced\n");
6404   }
6405 return NULL;
6406 }
6407
6408
6409 /* This is the external function call. Do a quick check for any expansion
6410 metacharacters, and if there are none, just return the input string.
6411
6412 Argument: the string to be expanded
6413 Returns:  the expanded string, or NULL if expansion failed; if failure was
6414           due to a lookup deferring, search_find_defer will be TRUE
6415 */
6416
6417 uschar *
6418 expand_string(uschar *string)
6419 {
6420 search_find_defer = FALSE;
6421 malformed_header = FALSE;
6422 return (Ustrpbrk(string, "$\\") == NULL)? string :
6423   expand_string_internal(string, FALSE, NULL, FALSE, TRUE);
6424 }
6425
6426
6427
6428 /*************************************************
6429 *              Expand and copy                   *
6430 *************************************************/
6431
6432 /* Now and again we want to expand a string and be sure that the result is in a
6433 new bit of store. This function does that.
6434
6435 Argument: the string to be expanded
6436 Returns:  the expanded string, always in a new bit of store, or NULL
6437 */
6438
6439 uschar *
6440 expand_string_copy(uschar *string)
6441 {
6442 uschar *yield = expand_string(string);
6443 if (yield == string) yield = string_copy(string);
6444 return yield;
6445 }
6446
6447
6448
6449 /*************************************************
6450 *        Expand and interpret as an integer      *
6451 *************************************************/
6452
6453 /* Expand a string, and convert the result into an integer.
6454
6455 Arguments:
6456   string  the string to be expanded
6457   isplus  TRUE if a non-negative number is expected
6458
6459 Returns:  the integer value, or
6460           -1 for an expansion error               ) in both cases, message in
6461           -2 for an integer interpretation error  ) expand_string_message
6462           expand_string_message is set NULL for an OK integer
6463 */
6464
6465 int_eximarith_t
6466 expand_string_integer(uschar *string, BOOL isplus)
6467 {
6468 int_eximarith_t value;
6469 uschar *s = expand_string(string);
6470 uschar *msg = US"invalid integer \"%s\"";
6471 uschar *endptr;
6472
6473 /* If expansion failed, expand_string_message will be set. */
6474
6475 if (s == NULL) return -1;
6476
6477 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
6478 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
6479 systems, so we set it zero ourselves. */
6480
6481 errno = 0;
6482 expand_string_message = NULL;               /* Indicates no error */
6483
6484 /* Before Exim 4.64, strings consisting entirely of whitespace compared
6485 equal to 0.  Unfortunately, people actually relied upon that, so preserve
6486 the behaviour explicitly.  Stripping leading whitespace is a harmless
6487 noop change since strtol skips it anyway (provided that there is a number
6488 to find at all). */
6489 if (isspace(*s))
6490   {
6491   while (isspace(*s)) ++s;
6492   if (*s == '\0')
6493     {
6494       DEBUG(D_expand)
6495        debug_printf("treating blank string as number 0\n");
6496       return 0;
6497     }
6498   }
6499
6500 value = strtoll(CS s, CSS &endptr, 10);
6501
6502 if (endptr == s)
6503   {
6504   msg = US"integer expected but \"%s\" found";
6505   }
6506 else if (value < 0 && isplus)
6507   {
6508   msg = US"non-negative integer expected but \"%s\" found";
6509   }
6510 else
6511   {
6512   switch (tolower(*endptr))
6513     {
6514     default:
6515       break;
6516     case 'k':
6517       if (value > LLONG_MAX/1024 || value < LLONG_MIN/1024) errno = ERANGE;
6518       else value *= 1024;
6519       endptr++;
6520       break;
6521     case 'm':
6522       if (value > LLONG_MAX/(1024*1024) || value < LLONG_MIN/(1024*1024)) errno = ERANGE;
6523       else value *= 1024*1024;
6524       endptr++;
6525       break;
6526     case 'g':
6527       if (value > LLONG_MAX/(1024*1024*1024) || value < LLONG_MIN/(1024*1024*1024)) errno = ERANGE;
6528       else value *= 1024*1024*1024;
6529       endptr++;
6530       break;
6531     }
6532   if (errno == ERANGE)
6533     msg = US"absolute value of integer \"%s\" is too large (overflow)";
6534   else
6535     {
6536     while (isspace(*endptr)) endptr++;
6537     if (*endptr == 0) return (int)value;
6538     }
6539   }
6540
6541 expand_string_message = string_sprintf(CS msg, s);
6542 return -2;
6543 }
6544
6545
6546 /*************************************************
6547 **************************************************
6548 *             Stand-alone test program           *
6549 **************************************************
6550 *************************************************/
6551
6552 #ifdef STAND_ALONE
6553
6554
6555 BOOL
6556 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
6557 {
6558 int ovector[3*(EXPAND_MAXN+1)];
6559 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
6560   ovector, sizeof(ovector)/sizeof(int));
6561 BOOL yield = n >= 0;
6562 if (n == 0) n = EXPAND_MAXN + 1;
6563 if (yield)
6564   {
6565   int nn;
6566   expand_nmax = (setup < 0)? 0 : setup + 1;
6567   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
6568     {
6569     expand_nstring[expand_nmax] = subject + ovector[nn];
6570     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
6571     }
6572   expand_nmax--;
6573   }
6574 return yield;
6575 }
6576
6577
6578 int main(int argc, uschar **argv)
6579 {
6580 int i;
6581 uschar buffer[1024];
6582
6583 debug_selector = D_v;
6584 debug_file = stderr;
6585 debug_fd = fileno(debug_file);
6586 big_buffer = malloc(big_buffer_size);
6587
6588 for (i = 1; i < argc; i++)
6589   {
6590   if (argv[i][0] == '+')
6591     {
6592     debug_trace_memory = 2;
6593     argv[i]++;
6594     }
6595   if (isdigit(argv[i][0]))
6596     debug_selector = Ustrtol(argv[i], NULL, 0);
6597   else
6598     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
6599         Ustrlen(argv[i]))
6600       {
6601       #ifdef LOOKUP_LDAP
6602       eldap_default_servers = argv[i];
6603       #endif
6604       #ifdef LOOKUP_MYSQL
6605       mysql_servers = argv[i];
6606       #endif
6607       #ifdef LOOKUP_PGSQL
6608       pgsql_servers = argv[i];
6609       #endif
6610       }
6611   #ifdef EXIM_PERL
6612   else opt_perl_startup = argv[i];
6613   #endif
6614   }
6615
6616 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
6617
6618 expand_nstring[1] = US"string 1....";
6619 expand_nlength[1] = 8;
6620 expand_nmax = 1;
6621
6622 #ifdef EXIM_PERL
6623 if (opt_perl_startup != NULL)
6624   {
6625   uschar *errstr;
6626   printf("Starting Perl interpreter\n");
6627   errstr = init_perl(opt_perl_startup);
6628   if (errstr != NULL)
6629     {
6630     printf("** error in perl_startup code: %s\n", errstr);
6631     return EXIT_FAILURE;
6632     }
6633   }
6634 #endif /* EXIM_PERL */
6635
6636 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
6637   {
6638   void *reset_point = store_get(0);
6639   uschar *yield = expand_string(buffer);
6640   if (yield != NULL)
6641     {
6642     printf("%s\n", yield);
6643     store_reset(reset_point);
6644     }
6645   else
6646     {
6647     if (search_find_defer) printf("search_find deferred\n");
6648     printf("Failed: %s\n", expand_string_message);
6649     if (expand_string_forcedfail) printf("Forced failure\n");
6650     printf("\n");
6651     }
6652   }
6653
6654 search_tidyup();
6655
6656 return 0;
6657 }
6658
6659 #endif
6660
6661 /* End of expand.c */