src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Charaters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base62",
 203   US"base62d",
 204   US"base64",
 205   US"base64d",
 206   US"domain",
 207   US"escape",
 208   US"eval",
 209   US"eval10",
 210   US"expand",
 211   US"h",
 212   US"hash",
 213   US"hex2b64",
 214   US"hexquote",
 215   US"ipv6denorm",
 216   US"ipv6norm",
 217   US"l",
 218   US"lc",
 219   US"length",
 220   US"listcount",
 221   US"listnamed",
 222   US"mask",
 223   US"md5",
 224   US"nh",
 225   US"nhash",
 226   US"quote",
 227   US"randint",
 228   US"rfc2047",
 229   US"rfc2047d",
 230   US"rxquote",
 231   US"s",
 232   US"sha1",
 233   US"sha256",
 234   US"stat",
 235   US"str2b64",
 236   US"strlen",
 237   US"substr",
 238   US"uc",
 239   US"utf8clean" };
 240
 241 enum {
 242   EOP_ADDRESS =  nelem(op_table_underscore),
 243   EOP_ADDRESSES,
 244   EOP_BASE62,
 245   EOP_BASE62D,
 246   EOP_BASE64,
 247   EOP_BASE64D,
 248   EOP_DOMAIN,
 249   EOP_ESCAPE,
 250   EOP_EVAL,
 251   EOP_EVAL10,
 252   EOP_EXPAND,
 253   EOP_H,
 254   EOP_HASH,
 255   EOP_HEX2B64,
 256   EOP_HEXQUOTE,
 257   EOP_IPV6DENORM,
 258   EOP_IPV6NORM,
 259   EOP_L,
 260   EOP_LC,
 261   EOP_LENGTH,
 262   EOP_LISTCOUNT,
 263   EOP_LISTNAMED,
 264   EOP_MASK,
 265   EOP_MD5,
 266   EOP_NH,
 267   EOP_NHASH,
 268   EOP_QUOTE,
 269   EOP_RANDINT,
 270   EOP_RFC2047,
 271   EOP_RFC2047D,
 272   EOP_RXQUOTE,
 273   EOP_S,
 274   EOP_SHA1,
 275   EOP_SHA256,
 276   EOP_STAT,
 277   EOP_STR2B64,
 278   EOP_STRLEN,
 279   EOP_SUBSTR,
 280   EOP_UC,
 281   EOP_UTF8CLEAN };
 282
 283
 284 /* Table of condition names, and corresponding switch numbers. The names must
 285 be in alphabetical order. */
 286
 287 static uschar *cond_table[] = {
 288   US"<",
 289   US"<=",
 290   US"=",
 291   US"==",     /* Backward compatibility */
 292   US">",
 293   US">=",
 294   US"acl",
 295   US"and",
 296   US"bool",
 297   US"bool_lax",
 298   US"crypteq",
 299   US"def",
 300   US"eq",
 301   US"eqi",
 302   US"exists",
 303   US"first_delivery",
 304   US"forall",
 305   US"forany",
 306   US"ge",
 307   US"gei",
 308   US"gt",
 309   US"gti",
 310   US"inlist",
 311   US"inlisti",
 312   US"isip",
 313   US"isip4",
 314   US"isip6",
 315   US"ldapauth",
 316   US"le",
 317   US"lei",
 318   US"lt",
 319   US"lti",
 320   US"match",
 321   US"match_address",
 322   US"match_domain",
 323   US"match_ip",
 324   US"match_local_part",
 325   US"or",
 326   US"pam",
 327   US"pwcheck",
 328   US"queue_running",
 329   US"radius",
 330   US"saslauthd"
 331 };
 332
 333 enum {
 334   ECOND_NUM_L,
 335   ECOND_NUM_LE,
 336   ECOND_NUM_E,
 337   ECOND_NUM_EE,
 338   ECOND_NUM_G,
 339   ECOND_NUM_GE,
 340   ECOND_ACL,
 341   ECOND_AND,
 342   ECOND_BOOL,
 343   ECOND_BOOL_LAX,
 344   ECOND_CRYPTEQ,
 345   ECOND_DEF,
 346   ECOND_STR_EQ,
 347   ECOND_STR_EQI,
 348   ECOND_EXISTS,
 349   ECOND_FIRST_DELIVERY,
 350   ECOND_FORALL,
 351   ECOND_FORANY,
 352   ECOND_STR_GE,
 353   ECOND_STR_GEI,
 354   ECOND_STR_GT,
 355   ECOND_STR_GTI,
 356   ECOND_INLIST,
 357   ECOND_INLISTI,
 358   ECOND_ISIP,
 359   ECOND_ISIP4,
 360   ECOND_ISIP6,
 361   ECOND_LDAPAUTH,
 362   ECOND_STR_LE,
 363   ECOND_STR_LEI,
 364   ECOND_STR_LT,
 365   ECOND_STR_LTI,
 366   ECOND_MATCH,
 367   ECOND_MATCH_ADDRESS,
 368   ECOND_MATCH_DOMAIN,
 369   ECOND_MATCH_IP,
 370   ECOND_MATCH_LOCAL_PART,
 371   ECOND_OR,
 372   ECOND_PAM,
 373   ECOND_PWCHECK,
 374   ECOND_QUEUE_RUNNING,
 375   ECOND_RADIUS,
 376   ECOND_SASLAUTHD
 377 };
 378
 379
 380 /* Types of table entry */
 381
 382 enum vtypes {
 383   vtype_int,            /* value is address of int */
 384   vtype_filter_int,     /* ditto, but recognized only when filtering */
 385   vtype_ino,            /* value is address of ino_t (not always an int) */
 386   vtype_uid,            /* value is address of uid_t (not always an int) */
 387   vtype_gid,            /* value is address of gid_t (not always an int) */
 388   vtype_bool,           /* value is address of bool */
 389   vtype_stringptr,      /* value is address of pointer to string */
 390   vtype_msgbody,        /* as stringptr, but read when first required */
 391   vtype_msgbody_end,    /* ditto, the end of the message */
 392   vtype_msgheaders,     /* the message's headers, processed */
 393   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 394   vtype_localpart,      /* extract local part from string */
 395   vtype_domain,         /* extract domain from string */
 396   vtype_string_func,    /* value is string returned by given function */
 397   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 398   vtype_tode,           /* value not used; generate tod in epoch format */
 399   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 400   vtype_todf,           /* value not used; generate full tod */
 401   vtype_todl,           /* value not used; generate log tod */
 402   vtype_todlf,          /* value not used; generate log file datestamp tod */
 403   vtype_todzone,        /* value not used; generate time zone only */
 404   vtype_todzulu,        /* value not used; generate zulu tod */
 405   vtype_reply,          /* value not used; get reply from headers */
 406   vtype_pid,            /* value not used; result is pid */
 407   vtype_host_lookup,    /* value not used; get host name */
 408   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 409   vtype_pspace,         /* partition space; value is T/F for spool/log */
 410   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 411   vtype_cert            /* SSL certificate */
 412   #ifndef DISABLE_DKIM
 413   ,vtype_dkim           /* Lookup of value in DKIM signature */
 414   #endif
 415 };
 416
 417 /* Type for main variable table */
 418
 419 typedef struct {
 420   const char *name;
 421   enum vtypes type;
 422   void       *value;
 423 } var_entry;
 424
 425 /* Type for entries pointing to address/length pairs. Not currently
 426 in use. */
 427
 428 typedef struct {
 429   uschar **address;
 430   int  *length;
 431 } alblock;
 432
 433 static uschar * fn_recipients(void);
 434
 435 /* This table must be kept in alphabetical order. */
 436
 437 static var_entry var_table[] = {
 438   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 439      they will be confused with user-creatable ACL variables. */
 440   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 441   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 442   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 443   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 444   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 445   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 446   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 447   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 448   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 449   { "acl_narg",            vtype_int,         &acl_narg },
 450   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 451   { "address_data",        vtype_stringptr,   &deliver_address_data },
 452   { "address_file",        vtype_stringptr,   &address_file },
 453   { "address_pipe",        vtype_stringptr,   &address_pipe },
 454   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 455   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 456   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 457   { "authentication_failed",vtype_int,        &authentication_failed },
 458 #ifdef WITH_CONTENT_SCAN
 459   { "av_failed",           vtype_int,         &av_failed },
 460 #endif
 461 #ifdef EXPERIMENTAL_BRIGHTMAIL
 462   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 463   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 464   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 465   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 466 #endif
 467   { "body_linecount",      vtype_int,         &body_linecount },
 468   { "body_zerocount",      vtype_int,         &body_zerocount },
 469   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 470   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 471   { "caller_gid",          vtype_gid,         &real_gid },
 472   { "caller_uid",          vtype_uid,         &real_uid },
 473   { "callout_address",     vtype_stringptr,   &callout_address },
 474   { "compile_date",        vtype_stringptr,   &version_date },
 475   { "compile_number",      vtype_stringptr,   &version_cnumber },
 476   { "config_dir",          vtype_stringptr,   &config_main_directory },
 477   { "config_file",         vtype_stringptr,   &config_main_filename },
 478   { "csa_status",          vtype_stringptr,   &csa_status },
 479 #ifdef EXPERIMENTAL_DCC
 480   { "dcc_header",          vtype_stringptr,   &dcc_header },
 481   { "dcc_result",          vtype_stringptr,   &dcc_result },
 482 #endif
 483 #ifndef DISABLE_DKIM
 484   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 485   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 486   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 487   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 488   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 489   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 490   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 491   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 492   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 493   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 494   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 495   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 496   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 497   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 498   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 499   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 500   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 501   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 502   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 503   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 504   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 505 #endif
 506 #ifdef EXPERIMENTAL_DMARC
 507   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 508   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 509   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 510   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 511   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 512 #endif
 513   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 514   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 515   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 516   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 517   { "domain",              vtype_stringptr,   &deliver_domain },
 518   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 519 #ifndef DISABLE_EVENT
 520   { "event_data",          vtype_stringptr,   &event_data },
 521
 522   /*XXX want to use generic vars for as many of these as possible*/
 523   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 524
 525   { "event_name",          vtype_stringptr,   &event_name },
 526 #endif
 527   { "exim_gid",            vtype_gid,         &exim_gid },
 528   { "exim_path",           vtype_stringptr,   &exim_path },
 529   { "exim_uid",            vtype_uid,         &exim_uid },
 530   { "exim_version",        vtype_stringptr,   &version_string },
 531   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 532   { "home",                vtype_stringptr,   &deliver_home },
 533   { "host",                vtype_stringptr,   &deliver_host },
 534   { "host_address",        vtype_stringptr,   &deliver_host_address },
 535   { "host_data",           vtype_stringptr,   &host_data },
 536   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 537   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 538   { "host_port",           vtype_int,         &deliver_host_port },
 539   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 540   { "inode",               vtype_ino,         &deliver_inode },
 541   { "interface_address",   vtype_stringptr,   &interface_address },
 542   { "interface_port",      vtype_int,         &interface_port },
 543   { "item",                vtype_stringptr,   &iterate_item },
 544   #ifdef LOOKUP_LDAP
 545   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 546   #endif
 547   { "load_average",        vtype_load_avg,    NULL },
 548   { "local_part",          vtype_stringptr,   &deliver_localpart },
 549   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 550   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 551   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 552   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 553   { "local_user_gid",      vtype_gid,         &local_user_gid },
 554   { "local_user_uid",      vtype_uid,         &local_user_uid },
 555   { "localhost_number",    vtype_int,         &host_number },
 556   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 557   { "log_space",           vtype_pspace,      (void *)FALSE },
 558   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 559   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 560 #ifdef WITH_CONTENT_SCAN
 561   { "malware_name",        vtype_stringptr,   &malware_name },
 562 #endif
 563   { "max_received_linelength", vtype_int,     &max_received_linelength },
 564   { "message_age",         vtype_int,         &message_age },
 565   { "message_body",        vtype_msgbody,     &message_body },
 566   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 567   { "message_body_size",   vtype_int,         &message_body_size },
 568   { "message_exim_id",     vtype_stringptr,   &message_id },
 569   { "message_headers",     vtype_msgheaders,  NULL },
 570   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 571   { "message_id",          vtype_stringptr,   &message_id },
 572   { "message_linecount",   vtype_int,         &message_linecount },
 573   { "message_size",        vtype_int,         &message_size },
 574 #ifdef SUPPORT_I18N
 575   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 576 #endif
 577 #ifdef WITH_CONTENT_SCAN
 578   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 579   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 580   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 581   { "mime_charset",        vtype_stringptr,   &mime_charset },
 582   { "mime_content_description", vtype_stringptr, &mime_content_description },
 583   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 584   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 585   { "mime_content_size",   vtype_int,         &mime_content_size },
 586   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 587   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 588   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 589   { "mime_filename",       vtype_stringptr,   &mime_filename },
 590   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 591   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 592   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 593   { "mime_part_count",     vtype_int,         &mime_part_count },
 594 #endif
 595   { "n0",                  vtype_filter_int,  &filter_n[0] },
 596   { "n1",                  vtype_filter_int,  &filter_n[1] },
 597   { "n2",                  vtype_filter_int,  &filter_n[2] },
 598   { "n3",                  vtype_filter_int,  &filter_n[3] },
 599   { "n4",                  vtype_filter_int,  &filter_n[4] },
 600   { "n5",                  vtype_filter_int,  &filter_n[5] },
 601   { "n6",                  vtype_filter_int,  &filter_n[6] },
 602   { "n7",                  vtype_filter_int,  &filter_n[7] },
 603   { "n8",                  vtype_filter_int,  &filter_n[8] },
 604   { "n9",                  vtype_filter_int,  &filter_n[9] },
 605   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 606   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 607   { "originator_gid",      vtype_gid,         &originator_gid },
 608   { "originator_uid",      vtype_uid,         &originator_uid },
 609   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 610   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 611   { "pid",                 vtype_pid,         NULL },
 612 #ifndef DISABLE_PRDR
 613   { "prdr_requested",      vtype_bool,        &prdr_requested },
 614 #endif
 615   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 616 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 617   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 618   { "proxy_external_port", vtype_int,         &proxy_external_port },
 619   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 620   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 621   { "proxy_session",       vtype_bool,        &proxy_session },
 622 #endif
 623   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 624   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 625   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 626   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 627   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 628   { "queue_name",          vtype_stringptr,   &queue_name },
 629   { "rcpt_count",          vtype_int,         &rcpt_count },
 630   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 631   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 632   { "received_count",      vtype_int,         &received_count },
 633   { "received_for",        vtype_stringptr,   &received_for },
 634   { "received_ip_address", vtype_stringptr,   &interface_address },
 635   { "received_port",       vtype_int,         &interface_port },
 636   { "received_protocol",   vtype_stringptr,   &received_protocol },
 637   { "received_time",       vtype_int,         &received_time },
 638   { "recipient_data",      vtype_stringptr,   &recipient_data },
 639   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 640   { "recipients",          vtype_string_func, &fn_recipients },
 641   { "recipients_count",    vtype_int,         &recipients_count },
 642 #ifdef WITH_CONTENT_SCAN
 643   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 644 #endif
 645   { "reply_address",       vtype_reply,       NULL },
 646   { "return_path",         vtype_stringptr,   &return_path },
 647   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 648   { "router_name",         vtype_stringptr,   &router_name },
 649   { "runrc",               vtype_int,         &runrc },
 650   { "self_hostname",       vtype_stringptr,   &self_hostname },
 651   { "sender_address",      vtype_stringptr,   &sender_address },
 652   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 653   { "sender_address_domain", vtype_domain,    &sender_address },
 654   { "sender_address_local_part", vtype_localpart, &sender_address },
 655   { "sender_data",         vtype_stringptr,   &sender_data },
 656   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 657   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 658   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 659   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 660   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 661   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 662   { "sender_host_name",    vtype_host_lookup, NULL },
 663   { "sender_host_port",    vtype_int,         &sender_host_port },
 664   { "sender_ident",        vtype_stringptr,   &sender_ident },
 665   { "sender_rate",         vtype_stringptr,   &sender_rate },
 666   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 667   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 668   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 669   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 670   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 671   { "sending_port",        vtype_int,         &sending_port },
 672   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 673   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 674   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 675   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 676   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 677   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 678   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 679   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 680   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 681   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 682   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 683   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 684   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 685   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 686   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 687 #ifdef WITH_CONTENT_SCAN
 688   { "spam_action",         vtype_stringptr,   &spam_action },
 689   { "spam_bar",            vtype_stringptr,   &spam_bar },
 690   { "spam_report",         vtype_stringptr,   &spam_report },
 691   { "spam_score",          vtype_stringptr,   &spam_score },
 692   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 693 #endif
 694 #ifdef EXPERIMENTAL_SPF
 695   { "spf_guess",           vtype_stringptr,   &spf_guess },
 696   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 697   { "spf_received",        vtype_stringptr,   &spf_received },
 698   { "spf_result",          vtype_stringptr,   &spf_result },
 699   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 700 #endif
 701   { "spool_directory",     vtype_stringptr,   &spool_directory },
 702   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 703   { "spool_space",         vtype_pspace,      (void *)TRUE },
 704 #ifdef EXPERIMENTAL_SRS
 705   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 706   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 707   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 708   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 709   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 710   { "srs_status",          vtype_stringptr,   &srs_status },
 711 #endif
 712   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 713
 714   /* The non-(in,out) variables are now deprecated */
 715   { "tls_bits",            vtype_int,         &tls_in.bits },
 716   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 717   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 718
 719   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 720   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 721   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 722   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 723   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 724   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 725   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 726 #if defined(SUPPORT_TLS)
 727   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 728 #endif
 729   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 730   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 731   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 732 #ifdef EXPERIMENTAL_DANE
 733   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 734 #endif
 735   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 736   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 737   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 738   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 739 #if defined(SUPPORT_TLS)
 740   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 741 #endif
 742 #ifdef EXPERIMENTAL_DANE
 743   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 744 #endif
 745
 746   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 747 #if defined(SUPPORT_TLS)
 748   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 749 #endif
 750
 751   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 752   { "tod_epoch",           vtype_tode,        NULL },
 753   { "tod_epoch_l",         vtype_todel,       NULL },
 754   { "tod_full",            vtype_todf,        NULL },
 755   { "tod_log",             vtype_todl,        NULL },
 756   { "tod_logfile",         vtype_todlf,       NULL },
 757   { "tod_zone",            vtype_todzone,     NULL },
 758   { "tod_zulu",            vtype_todzulu,     NULL },
 759   { "transport_name",      vtype_stringptr,   &transport_name },
 760   { "value",               vtype_stringptr,   &lookup_value },
 761   { "verify_mode",         vtype_stringptr,   &verify_mode },
 762   { "version_number",      vtype_stringptr,   &version_string },
 763   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 764   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 765   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 766   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 767   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 768   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 769 };
 770
 771 static int var_table_size = nelem(var_table);
 772 static uschar var_buffer[256];
 773 static BOOL malformed_header;
 774
 775 /* For textual hashes */
 776
 777 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 778                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 779                                "0123456789";
 780
 781 enum { HMAC_MD5, HMAC_SHA1 };
 782
 783 /* For numeric hashes */
 784
 785 static unsigned int prime[] = {
 786   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 787  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 788  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 789
 790 /* For printing modes in symbolic form */
 791
 792 static uschar *mtable_normal[] =
 793   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 794
 795 static uschar *mtable_setid[] =
 796   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 797
 798 static uschar *mtable_sticky[] =
 799   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 800
 801
 802
 803 /*************************************************
 804 *           Tables for UTF-8 support             *
 805 *************************************************/
 806
 807 /* Table of the number of extra characters, indexed by the first character
 808 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 809 0x3d. */
 810
 811 static uschar utf8_table1[] = {
 812   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 813   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 814   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 815   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 816
 817 /* These are the masks for the data bits in the first byte of a character,
 818 indexed by the number of additional bytes. */
 819
 820 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 821
 822 /* Get the next UTF-8 character, advancing the pointer. */
 823
 824 #define GETUTF8INC(c, ptr) \
 825   c = *ptr++; \
 826   if ((c & 0xc0) == 0xc0) \
 827     { \
 828     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 829     int s = 6*a; \
 830     c = (c & utf8_table2[a]) << s; \
 831     while (a-- > 0) \
 832       { \
 833       s -= 6; \
 834       c |= (*ptr++ & 0x3f) << s; \
 835       } \
 836     }
 837
 838
 839 /*************************************************
 840 *           Binary chop search on a table        *
 841 *************************************************/
 842
 843 /* This is used for matching expansion items and operators.
 844
 845 Arguments:
 846   name        the name that is being sought
 847   table       the table to search
 848   table_size  the number of items in the table
 849
 850 Returns:      the offset in the table, or -1
 851 */
 852
 853 static int
 854 chop_match(uschar *name, uschar **table, int table_size)
 855 {
 856 uschar **bot = table;
 857 uschar **top = table + table_size;
 858
 859 while (top > bot)
 860   {
 861   uschar **mid = bot + (top - bot)/2;
 862   int c = Ustrcmp(name, *mid);
 863   if (c == 0) return mid - table;
 864   if (c > 0) bot = mid + 1; else top = mid;
 865   }
 866
 867 return -1;
 868 }
 869
 870
 871
 872 /*************************************************
 873 *          Check a condition string              *
 874 *************************************************/
 875
 876 /* This function is called to expand a string, and test the result for a "true"
 877 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 878 forced fail or lookup defer.
 879
 880 We used to release all store used, but this is not not safe due
 881 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 882 is reasonably careful to release what it can.
 883
 884 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 885
 886 Arguments:
 887   condition     the condition string
 888   m1            text to be incorporated in panic error
 889   m2            ditto
 890
 891 Returns:        TRUE if condition is met, FALSE if not
 892 */
 893
 894 BOOL
 895 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 896 {
 897 int rc;
 898 uschar *ss = expand_string(condition);
 899 if (ss == NULL)
 900   {
 901   if (!expand_string_forcedfail && !search_find_defer)
 902     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 903       "for %s %s: %s", condition, m1, m2, expand_string_message);
 904   return FALSE;
 905   }
 906 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 907   strcmpic(ss, US"false") != 0;
 908 return rc;
 909 }
 910
 911
 912
 913
 914 /*************************************************
 915 *        Pseudo-random number generation         *
 916 *************************************************/
 917
 918 /* Pseudo-random number generation.  The result is not "expected" to be
 919 cryptographically strong but not so weak that someone will shoot themselves
 920 in the foot using it as a nonce in some email header scheme or whatever
 921 weirdness they'll twist this into.  The result should ideally handle fork().
 922
 923 However, if we're stuck unable to provide this, then we'll fall back to
 924 appallingly bad randomness.
 925
 926 If SUPPORT_TLS is defined then this will not be used except as an emergency
 927 fallback.
 928
 929 Arguments:
 930   max       range maximum
 931 Returns     a random number in range [0, max-1]
 932 */
 933
 934 #ifdef SUPPORT_TLS
 935 # define vaguely_random_number vaguely_random_number_fallback
 936 #endif
 937 int
 938 vaguely_random_number(int max)
 939 {
 940 #ifdef SUPPORT_TLS
 941 # undef vaguely_random_number
 942 #endif
 943   static pid_t pid = 0;
 944   pid_t p2;
 945 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 946   struct timeval tv;
 947 #endif
 948
 949   p2 = getpid();
 950   if (p2 != pid)
 951     {
 952     if (pid != 0)
 953       {
 954
 955 #ifdef HAVE_ARC4RANDOM
 956       /* cryptographically strong randomness, common on *BSD platforms, not
 957       so much elsewhere.  Alas. */
 958 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 959       arc4random_stir();
 960 #endif
 961 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 962 #ifdef HAVE_SRANDOMDEV
 963       /* uses random(4) for seeding */
 964       srandomdev();
 965 #else
 966       gettimeofday(&tv, NULL);
 967       srandom(tv.tv_sec | tv.tv_usec | getpid());
 968 #endif
 969 #else
 970       /* Poor randomness and no seeding here */
 971 #endif
 972
 973       }
 974     pid = p2;
 975     }
 976
 977 #ifdef HAVE_ARC4RANDOM
 978   return arc4random() % max;
 979 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 980   return random() % max;
 981 #else
 982   /* This one returns a 16-bit number, definitely not crypto-strong */
 983   return random_number(max);
 984 #endif
 985 }
 986
 987
 988
 989
 990 /*************************************************
 991 *             Pick out a name from a string      *
 992 *************************************************/
 993
 994 /* If the name is too long, it is silently truncated.
 995
 996 Arguments:
 997   name      points to a buffer into which to put the name
 998   max       is the length of the buffer
 999   s         points to the first alphabetic character of the name
1000   extras    chars other than alphanumerics to permit
1001
1002 Returns:    pointer to the first character after the name
1003
1004 Note: The test for *s != 0 in the while loop is necessary because
1005 Ustrchr() yields non-NULL if the character is zero (which is not something
1006 I expected). */
1007
1008 static const uschar *
1009 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1010 {
1011 int ptr = 0;
1012 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1013   {
1014   if (ptr < max-1) name[ptr++] = *s;
1015   s++;
1016   }
1017 name[ptr] = 0;
1018 return s;
1019 }
1020
1021
1022
1023 /*************************************************
1024 *     Pick out the rest of a header name         *
1025 *************************************************/
1026
1027 /* A variable name starting $header_ (or just $h_ for those who like
1028 abbreviations) might not be the complete header name because headers can
1029 contain any printing characters in their names, except ':'. This function is
1030 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1031 on the end, if the name was terminated by white space.
1032
1033 Arguments:
1034   name      points to a buffer in which the name read so far exists
1035   max       is the length of the buffer
1036   s         points to the first character after the name so far, i.e. the
1037             first non-alphameric character after $header_xxxxx
1038
1039 Returns:    a pointer to the first character after the header name
1040 */
1041
1042 static const uschar *
1043 read_header_name(uschar *name, int max, const uschar *s)
1044 {
1045 int prelen = Ustrchr(name, '_') - name + 1;
1046 int ptr = Ustrlen(name) - prelen;
1047 if (ptr > 0) memmove(name, name+prelen, ptr);
1048 while (mac_isgraph(*s) && *s != ':')
1049   {
1050   if (ptr < max-1) name[ptr++] = *s;
1051   s++;
1052   }
1053 if (*s == ':') s++;
1054 name[ptr++] = ':';
1055 name[ptr] = 0;
1056 return s;
1057 }
1058
1059
1060
1061 /*************************************************
1062 *           Pick out a number from a string      *
1063 *************************************************/
1064
1065 /* Arguments:
1066   n     points to an integer into which to put the number
1067   s     points to the first digit of the number
1068
1069 Returns:  a pointer to the character after the last digit
1070 */
1071 /*XXX consider expanding to int_eximarith_t.  But the test for
1072 "overbig numbers" in 0002 still needs to overflow it. */
1073
1074 static uschar *
1075 read_number(int *n, uschar *s)
1076 {
1077 *n = 0;
1078 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1079 return s;
1080 }
1081
1082 static const uschar *
1083 read_cnumber(int *n, const uschar *s)
1084 {
1085 *n = 0;
1086 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1087 return s;
1088 }
1089
1090
1091
1092 /*************************************************
1093 *        Extract keyed subfield from a string    *
1094 *************************************************/
1095
1096 /* The yield is in dynamic store; NULL means that the key was not found.
1097
1098 Arguments:
1099   key       points to the name of the key
1100   s         points to the string from which to extract the subfield
1101
1102 Returns:    NULL if the subfield was not found, or
1103             a pointer to the subfield's data
1104 */
1105
1106 static uschar *
1107 expand_getkeyed(uschar *key, const uschar *s)
1108 {
1109 int length = Ustrlen(key);
1110 while (isspace(*s)) s++;
1111
1112 /* Loop to search for the key */
1113
1114 while (*s != 0)
1115   {
1116   int dkeylength;
1117   uschar *data;
1118   const uschar *dkey = s;
1119
1120   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1121   dkeylength = s - dkey;
1122   while (isspace(*s)) s++;
1123   if (*s == '=') while (isspace((*(++s))));
1124
1125   data = string_dequote(&s);
1126   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1127     return data;
1128
1129   while (isspace(*s)) s++;
1130   }
1131
1132 return NULL;
1133 }
1134
1135
1136
1137 static var_entry *
1138 find_var_ent(uschar * name)
1139 {
1140 int first = 0;
1141 int last = var_table_size;
1142
1143 while (last > first)
1144   {
1145   int middle = (first + last)/2;
1146   int c = Ustrcmp(name, var_table[middle].name);
1147
1148   if (c > 0) { first = middle + 1; continue; }
1149   if (c < 0) { last = middle; continue; }
1150   return &var_table[middle];
1151   }
1152 return NULL;
1153 }
1154
1155 /*************************************************
1156 *   Extract numbered subfield from string        *
1157 *************************************************/
1158
1159 /* Extracts a numbered field from a string that is divided by tokens - for
1160 example a line from /etc/passwd is divided by colon characters.  First field is
1161 numbered one.  Negative arguments count from the right. Zero returns the whole
1162 string. Returns NULL if there are insufficient tokens in the string
1163
1164 ***WARNING***
1165 Modifies final argument - this is a dynamically generated string, so that's OK.
1166
1167 Arguments:
1168   field       number of field to be extracted,
1169                 first field = 1, whole string = 0, last field = -1
1170   separators  characters that are used to break string into tokens
1171   s           points to the string from which to extract the subfield
1172
1173 Returns:      NULL if the field was not found,
1174               a pointer to the field's data inside s (modified to add 0)
1175 */
1176
1177 static uschar *
1178 expand_gettokened (int field, uschar *separators, uschar *s)
1179 {
1180 int sep = 1;
1181 int count;
1182 uschar *ss = s;
1183 uschar *fieldtext = NULL;
1184
1185 if (field == 0) return s;
1186
1187 /* Break the line up into fields in place; for field > 0 we stop when we have
1188 done the number of fields we want. For field < 0 we continue till the end of
1189 the string, counting the number of fields. */
1190
1191 count = (field > 0)? field : INT_MAX;
1192
1193 while (count-- > 0)
1194   {
1195   size_t len;
1196
1197   /* Previous field was the last one in the string. For a positive field
1198   number, this means there are not enough fields. For a negative field number,
1199   check that there are enough, and scan back to find the one that is wanted. */
1200
1201   if (sep == 0)
1202     {
1203     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1204     if ((-field) == (INT_MAX - count - 1)) return s;
1205     while (field++ < 0)
1206       {
1207       ss--;
1208       while (ss[-1] != 0) ss--;
1209       }
1210     fieldtext = ss;
1211     break;
1212     }
1213
1214   /* Previous field was not last in the string; save its start and put a
1215   zero at its end. */
1216
1217   fieldtext = ss;
1218   len = Ustrcspn(ss, separators);
1219   sep = ss[len];
1220   ss[len] = 0;
1221   ss += len + 1;
1222   }
1223
1224 return fieldtext;
1225 }
1226
1227
1228 static uschar *
1229 expand_getlistele(int field, const uschar * list)
1230 {
1231 const uschar * tlist= list;
1232 int sep= 0;
1233 uschar dummy;
1234
1235 if(field<0)
1236   {
1237   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1238   sep= 0;
1239   }
1240 if(field==0) return NULL;
1241 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1242 return string_nextinlist(&list, &sep, NULL, 0);
1243 }
1244
1245
1246 /* Certificate fields, by name.  Worry about by-OID later */
1247 /* Names are chosen to not have common prefixes */
1248
1249 #ifdef SUPPORT_TLS
1250 typedef struct
1251 {
1252 uschar * name;
1253 int      namelen;
1254 uschar * (*getfn)(void * cert, uschar * mod);
1255 } certfield;
1256 static certfield certfields[] =
1257 {                       /* linear search; no special order */
1258   { US"version",         7,  &tls_cert_version },
1259   { US"serial_number",   13, &tls_cert_serial_number },
1260   { US"subject",         7,  &tls_cert_subject },
1261   { US"notbefore",       9,  &tls_cert_not_before },
1262   { US"notafter",        8,  &tls_cert_not_after },
1263   { US"issuer",          6,  &tls_cert_issuer },
1264   { US"signature",       9,  &tls_cert_signature },
1265   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1266   { US"subj_altname",    12, &tls_cert_subject_altname },
1267   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1268   { US"crl_uri",         7,  &tls_cert_crl_uri },
1269 };
1270
1271 static uschar *
1272 expand_getcertele(uschar * field, uschar * certvar)
1273 {
1274 var_entry * vp;
1275 certfield * cp;
1276
1277 if (!(vp = find_var_ent(certvar)))
1278   {
1279   expand_string_message =
1280     string_sprintf("no variable named \"%s\"", certvar);
1281   return NULL;          /* Unknown variable name */
1282   }
1283 /* NB this stops us passing certs around in variable.  Might
1284 want to do that in future */
1285 if (vp->type != vtype_cert)
1286   {
1287   expand_string_message =
1288     string_sprintf("\"%s\" is not a certificate", certvar);
1289   return NULL;          /* Unknown variable name */
1290   }
1291 if (!*(void **)vp->value)
1292   return NULL;
1293
1294 if (*field >= '0' && *field <= '9')
1295   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1296
1297 for(cp = certfields;
1298     cp < certfields + nelem(certfields);
1299     cp++)
1300   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1301     {
1302     uschar * modifier = *(field += cp->namelen) == ','
1303       ? ++field : NULL;
1304     return (*cp->getfn)( *(void **)vp->value, modifier );
1305     }
1306
1307 expand_string_message =
1308   string_sprintf("bad field selector \"%s\" for certextract", field);
1309 return NULL;
1310 }
1311 #endif  /*SUPPORT_TLS*/
1312
1313 /*************************************************
1314 *        Extract a substring from a string       *
1315 *************************************************/
1316
1317 /* Perform the ${substr or ${length expansion operations.
1318
1319 Arguments:
1320   subject     the input string
1321   value1      the offset from the start of the input string to the start of
1322                 the output string; if negative, count from the right.
1323   value2      the length of the output string, or negative (-1) for unset
1324                 if value1 is positive, unset means "all after"
1325                 if value1 is negative, unset means "all before"
1326   len         set to the length of the returned string
1327
1328 Returns:      pointer to the output string, or NULL if there is an error
1329 */
1330
1331 static uschar *
1332 extract_substr(uschar *subject, int value1, int value2, int *len)
1333 {
1334 int sublen = Ustrlen(subject);
1335
1336 if (value1 < 0)    /* count from right */
1337   {
1338   value1 += sublen;
1339
1340   /* If the position is before the start, skip to the start, and adjust the
1341   length. If the length ends up negative, the substring is null because nothing
1342   can precede. This falls out naturally when the length is unset, meaning "all
1343   to the left". */
1344
1345   if (value1 < 0)
1346     {
1347     value2 += value1;
1348     if (value2 < 0) value2 = 0;
1349     value1 = 0;
1350     }
1351
1352   /* Otherwise an unset length => characters before value1 */
1353
1354   else if (value2 < 0)
1355     {
1356     value2 = value1;
1357     value1 = 0;
1358     }
1359   }
1360
1361 /* For a non-negative offset, if the starting position is past the end of the
1362 string, the result will be the null string. Otherwise, an unset length means
1363 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1364
1365 else
1366   {
1367   if (value1 > sublen)
1368     {
1369     value1 = sublen;
1370     value2 = 0;
1371     }
1372   else if (value2 < 0) value2 = sublen;
1373   }
1374
1375 /* Cut the length down to the maximum possible for the offset value, and get
1376 the required characters. */
1377
1378 if (value1 + value2 > sublen) value2 = sublen - value1;
1379 *len = value2;
1380 return subject + value1;
1381 }
1382
1383
1384
1385
1386 /*************************************************
1387 *            Old-style hash of a string          *
1388 *************************************************/
1389
1390 /* Perform the ${hash expansion operation.
1391
1392 Arguments:
1393   subject     the input string (an expanded substring)
1394   value1      the length of the output string; if greater or equal to the
1395                 length of the input string, the input string is returned
1396   value2      the number of hash characters to use, or 26 if negative
1397   len         set to the length of the returned string
1398
1399 Returns:      pointer to the output string, or NULL if there is an error
1400 */
1401
1402 static uschar *
1403 compute_hash(uschar *subject, int value1, int value2, int *len)
1404 {
1405 int sublen = Ustrlen(subject);
1406
1407 if (value2 < 0) value2 = 26;
1408 else if (value2 > Ustrlen(hashcodes))
1409   {
1410   expand_string_message =
1411     string_sprintf("hash count \"%d\" too big", value2);
1412   return NULL;
1413   }
1414
1415 /* Calculate the hash text. We know it is shorter than the original string, so
1416 can safely place it in subject[] (we know that subject is always itself an
1417 expanded substring). */
1418
1419 if (value1 < sublen)
1420   {
1421   int c;
1422   int i = 0;
1423   int j = value1;
1424   while ((c = (subject[j])) != 0)
1425     {
1426     int shift = (c + j++) & 7;
1427     subject[i] ^= (c << shift) | (c >> (8-shift));
1428     if (++i >= value1) i = 0;
1429     }
1430   for (i = 0; i < value1; i++)
1431     subject[i] = hashcodes[(subject[i]) % value2];
1432   }
1433 else value1 = sublen;
1434
1435 *len = value1;
1436 return subject;
1437 }
1438
1439
1440
1441
1442 /*************************************************
1443 *             Numeric hash of a string           *
1444 *************************************************/
1445
1446 /* Perform the ${nhash expansion operation. The first characters of the
1447 string are treated as most important, and get the highest prime numbers.
1448
1449 Arguments:
1450   subject     the input string
1451   value1      the maximum value of the first part of the result
1452   value2      the maximum value of the second part of the result,
1453                 or negative to produce only a one-part result
1454   len         set to the length of the returned string
1455
1456 Returns:  pointer to the output string, or NULL if there is an error.
1457 */
1458
1459 static uschar *
1460 compute_nhash (uschar *subject, int value1, int value2, int *len)
1461 {
1462 uschar *s = subject;
1463 int i = 0;
1464 unsigned long int total = 0; /* no overflow */
1465
1466 while (*s != 0)
1467   {
1468   if (i == 0) i = nelem(prime) - 1;
1469   total += prime[i--] * (unsigned int)(*s++);
1470   }
1471
1472 /* If value2 is unset, just compute one number */
1473
1474 if (value2 < 0)
1475   {
1476   s = string_sprintf("%d", total % value1);
1477   }
1478
1479 /* Otherwise do a div/mod hash */
1480
1481 else
1482   {
1483   total = total % (value1 * value2);
1484   s = string_sprintf("%d/%d", total/value2, total % value2);
1485   }
1486
1487 *len = Ustrlen(s);
1488 return s;
1489 }
1490
1491
1492
1493
1494
1495 /*************************************************
1496 *     Find the value of a header or headers      *
1497 *************************************************/
1498
1499 /* Multiple instances of the same header get concatenated, and this function
1500 can also return a concatenation of all the header lines. When concatenating
1501 specific headers that contain lists of addresses, a comma is inserted between
1502 them. Otherwise we use a straight concatenation. Because some messages can have
1503 pathologically large number of lines, there is a limit on the length that is
1504 returned. Also, to avoid massive store use which would result from using
1505 string_cat() as it copies and extends strings, we do a preliminary pass to find
1506 out exactly how much store will be needed. On "normal" messages this will be
1507 pretty trivial.
1508
1509 Arguments:
1510   name          the name of the header, without the leading $header_ or $h_,
1511                 or NULL if a concatenation of all headers is required
1512   exists_only   TRUE if called from a def: test; don't need to build a string;
1513                 just return a string that is not "" and not "0" if the header
1514                 exists
1515   newsize       return the size of memory block that was obtained; may be NULL
1516                 if exists_only is TRUE
1517   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1518                 other than concatenating, will be done on the header. Also used
1519                 for $message_headers_raw.
1520   charset       name of charset to translate MIME words to; used only if
1521                 want_raw is false; if NULL, no translation is done (this is
1522                 used for $bh_ and $bheader_)
1523
1524 Returns:        NULL if the header does not exist, else a pointer to a new
1525                 store block
1526 */
1527
1528 static uschar *
1529 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1530   uschar *charset)
1531 {
1532 BOOL found = name == NULL;
1533 int comma = 0;
1534 int len = found? 0 : Ustrlen(name);
1535 int i;
1536 uschar *yield = NULL;
1537 uschar *ptr = NULL;
1538
1539 /* Loop for two passes - saves code repetition */
1540
1541 for (i = 0; i < 2; i++)
1542   {
1543   int size = 0;
1544   header_line *h;
1545
1546   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1547     {
1548     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1549       {
1550       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1551         {
1552         int ilen;
1553         uschar *t;
1554
1555         if (exists_only) return US"1";      /* don't need actual string */
1556         found = TRUE;
1557         t = h->text + len;                  /* text to insert */
1558         if (!want_raw)                      /* unless wanted raw, */
1559           while (isspace(*t)) t++;          /* remove leading white space */
1560         ilen = h->slen - (t - h->text);     /* length to insert */
1561
1562         /* Unless wanted raw, remove trailing whitespace, including the
1563         newline. */
1564
1565         if (!want_raw)
1566           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1567
1568         /* Set comma = 1 if handling a single header and it's one of those
1569         that contains an address list, except when asked for raw headers. Only
1570         need to do this once. */
1571
1572         if (!want_raw && name != NULL && comma == 0 &&
1573             Ustrchr("BCFRST", h->type) != NULL)
1574           comma = 1;
1575
1576         /* First pass - compute total store needed; second pass - compute
1577         total store used, including this header. */
1578
1579         size += ilen + comma + 1;  /* +1 for the newline */
1580
1581         /* Second pass - concatentate the data, up to a maximum. Note that
1582         the loop stops when size hits the limit. */
1583
1584         if (i != 0)
1585           {
1586           if (size > header_insert_maxlen)
1587             {
1588             ilen -= size - header_insert_maxlen - 1;
1589             comma = 0;
1590             }
1591           Ustrncpy(ptr, t, ilen);
1592           ptr += ilen;
1593
1594           /* For a non-raw header, put in the comma if needed, then add
1595           back the newline we removed above, provided there was some text in
1596           the header. */
1597
1598           if (!want_raw && ilen > 0)
1599             {
1600             if (comma != 0) *ptr++ = ',';
1601             *ptr++ = '\n';
1602             }
1603           }
1604         }
1605       }
1606     }
1607
1608   /* At end of first pass, return NULL if no header found. Then truncate size
1609   if necessary, and get the buffer to hold the data, returning the buffer size.
1610   */
1611
1612   if (i == 0)
1613     {
1614     if (!found) return NULL;
1615     if (size > header_insert_maxlen) size = header_insert_maxlen;
1616     *newsize = size + 1;
1617     ptr = yield = store_get(*newsize);
1618     }
1619   }
1620
1621 /* That's all we do for raw header expansion. */
1622
1623 if (want_raw)
1624   {
1625   *ptr = 0;
1626   }
1627
1628 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1629 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1630 function can return an error with decoded data if the charset translation
1631 fails. If decoding fails, it returns NULL. */
1632
1633 else
1634   {
1635   uschar *decoded, *error;
1636   if (ptr > yield && ptr[-1] == '\n') ptr--;
1637   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1638   *ptr = 0;
1639   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1640     newsize, &error);
1641   if (error != NULL)
1642     {
1643     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1644       "    input was: %s\n", error, yield);
1645     }
1646   if (decoded != NULL) yield = decoded;
1647   }
1648
1649 return yield;
1650 }
1651
1652
1653
1654
1655 /*************************************************
1656 *               Return list of recipients        *
1657 *************************************************/
1658 /* A recipients list is available only during system message filtering,
1659 during ACL processing after DATA, and while expanding pipe commands
1660 generated from a system filter, but not elsewhere. */
1661
1662 static uschar *
1663 fn_recipients(void)
1664 {
1665 if (!enable_dollar_recipients) return NULL; else
1666   {
1667   int size = 128;
1668   int ptr = 0;
1669   int i;
1670   uschar * s = store_get(size);
1671   for (i = 0; i < recipients_count; i++)
1672     {
1673     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1674     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1675     }
1676   s[ptr] = 0;     /* string_cat() leaves room */
1677   return s;
1678   }
1679 }
1680
1681
1682 /*************************************************
1683 *               Find value of a variable         *
1684 *************************************************/
1685
1686 /* The table of variables is kept in alphabetic order, so we can search it
1687 using a binary chop. The "choplen" variable is nothing to do with the binary
1688 chop.
1689
1690 Arguments:
1691   name          the name of the variable being sought
1692   exists_only   TRUE if this is a def: test; passed on to find_header()
1693   skipping      TRUE => skip any processing evaluation; this is not the same as
1694                   exists_only because def: may test for values that are first
1695                   evaluated here
1696   newsize       pointer to an int which is initially zero; if the answer is in
1697                 a new memory buffer, *newsize is set to its size
1698
1699 Returns:        NULL if the variable does not exist, or
1700                 a pointer to the variable's contents, or
1701                 something non-NULL if exists_only is TRUE
1702 */
1703
1704 static uschar *
1705 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1706 {
1707 var_entry * vp;
1708 uschar *s, *domain;
1709 uschar **ss;
1710 void * val;
1711
1712 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1713 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1714 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1715 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1716 (this gave backwards compatibility at the changeover). There may be built-in
1717 variables whose names start acl_ but they should never start in this way. This
1718 slightly messy specification is a consequence of the history, needless to say.
1719
1720 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1721 set, in which case give an error. */
1722
1723 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1724      !isalpha(name[5]))
1725   {
1726   tree_node *node =
1727     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1728   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1729   }
1730
1731 /* Handle $auth<n> variables. */
1732
1733 if (Ustrncmp(name, "auth", 4) == 0)
1734   {
1735   uschar *endptr;
1736   int n = Ustrtoul(name + 4, &endptr, 10);
1737   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1738     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1739   }
1740 else if (Ustrncmp(name, "regex", 5) == 0)
1741   {
1742   uschar *endptr;
1743   int n = Ustrtoul(name + 5, &endptr, 10);
1744   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1745     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1746   }
1747
1748 /* For all other variables, search the table */
1749
1750 if (!(vp = find_var_ent(name)))
1751   return NULL;          /* Unknown variable name */
1752
1753 /* Found an existing variable. If in skipping state, the value isn't needed,
1754 and we want to avoid processing (such as looking up the host name). */
1755
1756 if (skipping)
1757   return US"";
1758
1759 val = vp->value;
1760 switch (vp->type)
1761   {
1762   case vtype_filter_int:
1763     if (!filter_running) return NULL;
1764     /* Fall through */
1765     /* VVVVVVVVVVVV */
1766   case vtype_int:
1767     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1768     return var_buffer;
1769
1770   case vtype_ino:
1771     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1772     return var_buffer;
1773
1774   case vtype_gid:
1775     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1776     return var_buffer;
1777
1778   case vtype_uid:
1779     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1780     return var_buffer;
1781
1782   case vtype_bool:
1783     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1784     return var_buffer;
1785
1786   case vtype_stringptr:                      /* Pointer to string */
1787     return (s = *((uschar **)(val))) ? s : US"";
1788
1789   case vtype_pid:
1790     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1791     return var_buffer;
1792
1793   case vtype_load_avg:
1794     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1795     return var_buffer;
1796
1797   case vtype_host_lookup:                    /* Lookup if not done so */
1798     if (sender_host_name == NULL && sender_host_address != NULL &&
1799         !host_lookup_failed && host_name_lookup() == OK)
1800       host_build_sender_fullhost();
1801     return (sender_host_name == NULL)? US"" : sender_host_name;
1802
1803   case vtype_localpart:                      /* Get local part from address */
1804     s = *((uschar **)(val));
1805     if (s == NULL) return US"";
1806     domain = Ustrrchr(s, '@');
1807     if (domain == NULL) return s;
1808     if (domain - s > sizeof(var_buffer) - 1)
1809       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1810           " in string expansion", sizeof(var_buffer));
1811     Ustrncpy(var_buffer, s, domain - s);
1812     var_buffer[domain - s] = 0;
1813     return var_buffer;
1814
1815   case vtype_domain:                         /* Get domain from address */
1816     s = *((uschar **)(val));
1817     if (s == NULL) return US"";
1818     domain = Ustrrchr(s, '@');
1819     return (domain == NULL)? US"" : domain + 1;
1820
1821   case vtype_msgheaders:
1822     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1823
1824   case vtype_msgheaders_raw:
1825     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1826
1827   case vtype_msgbody:                        /* Pointer to msgbody string */
1828   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1829     ss = (uschar **)(val);
1830     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1831       {
1832       uschar *body;
1833       off_t start_offset = SPOOL_DATA_START_OFFSET;
1834       int len = message_body_visible;
1835       if (len > message_size) len = message_size;
1836       *ss = body = store_malloc(len+1);
1837       body[0] = 0;
1838       if (vp->type == vtype_msgbody_end)
1839         {
1840         struct stat statbuf;
1841         if (fstat(deliver_datafile, &statbuf) == 0)
1842           {
1843           start_offset = statbuf.st_size - len;
1844           if (start_offset < SPOOL_DATA_START_OFFSET)
1845             start_offset = SPOOL_DATA_START_OFFSET;
1846           }
1847         }
1848       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1849         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1850           strerror(errno));
1851       len = read(deliver_datafile, body, len);
1852       if (len > 0)
1853         {
1854         body[len] = 0;
1855         if (message_body_newlines)   /* Separate loops for efficiency */
1856           while (len > 0)
1857             { if (body[--len] == 0) body[len] = ' '; }
1858         else
1859           while (len > 0)
1860             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1861         }
1862       }
1863     return (*ss == NULL)? US"" : *ss;
1864
1865   case vtype_todbsdin:                       /* BSD inbox time of day */
1866     return tod_stamp(tod_bsdin);
1867
1868   case vtype_tode:                           /* Unix epoch time of day */
1869     return tod_stamp(tod_epoch);
1870
1871   case vtype_todel:                          /* Unix epoch/usec time of day */
1872     return tod_stamp(tod_epoch_l);
1873
1874   case vtype_todf:                           /* Full time of day */
1875     return tod_stamp(tod_full);
1876
1877   case vtype_todl:                           /* Log format time of day */
1878     return tod_stamp(tod_log_bare);            /* (without timezone) */
1879
1880   case vtype_todzone:                        /* Time zone offset only */
1881     return tod_stamp(tod_zone);
1882
1883   case vtype_todzulu:                        /* Zulu time */
1884     return tod_stamp(tod_zulu);
1885
1886   case vtype_todlf:                          /* Log file datestamp tod */
1887     return tod_stamp(tod_log_datestamp_daily);
1888
1889   case vtype_reply:                          /* Get reply address */
1890     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1891       headers_charset);
1892     if (s != NULL) while (isspace(*s)) s++;
1893     if (s == NULL || *s == 0)
1894       {
1895       *newsize = 0;                            /* For the *s==0 case */
1896       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1897       }
1898     if (s != NULL)
1899       {
1900       uschar *t;
1901       while (isspace(*s)) s++;
1902       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1903       while (t > s && isspace(t[-1])) t--;
1904       *t = 0;
1905       }
1906     return (s == NULL)? US"" : s;
1907
1908   case vtype_string_func:
1909     {
1910     uschar * (*fn)() = val;
1911     return fn();
1912     }
1913
1914   case vtype_pspace:
1915     {
1916     int inodes;
1917     sprintf(CS var_buffer, "%d",
1918       receive_statvfs(val == (void *)TRUE, &inodes));
1919     }
1920   return var_buffer;
1921
1922   case vtype_pinodes:
1923     {
1924     int inodes;
1925     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1926     sprintf(CS var_buffer, "%d", inodes);
1927     }
1928   return var_buffer;
1929
1930   case vtype_cert:
1931     return *(void **)val ? US"<cert>" : US"";
1932
1933 #ifndef DISABLE_DKIM
1934   case vtype_dkim:
1935     return dkim_exim_expand_query((int)(long)val);
1936 #endif
1937
1938   }
1939
1940 return NULL;  /* Unknown variable. Silences static checkers. */
1941 }
1942
1943
1944
1945
1946 void
1947 modify_variable(uschar *name, void * value)
1948 {
1949 var_entry * vp;
1950 if ((vp = find_var_ent(name))) vp->value = value;
1951 return;          /* Unknown variable name, fail silently */
1952 }
1953
1954
1955
1956
1957
1958 /*************************************************
1959 *           Read and expand substrings           *
1960 *************************************************/
1961
1962 /* This function is called to read and expand argument substrings for various
1963 expansion items. Some have a minimum requirement that is less than the maximum;
1964 in these cases, the first non-present one is set to NULL.
1965
1966 Arguments:
1967   sub        points to vector of pointers to set
1968   n          maximum number of substrings
1969   m          minimum required
1970   sptr       points to current string pointer
1971   skipping   the skipping flag
1972   check_end  if TRUE, check for final '}'
1973   name       name of item, for error message
1974   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1975              the store.
1976
1977 Returns:     0 OK; string pointer updated
1978              1 curly bracketing error (too few arguments)
1979              2 too many arguments (only if check_end is set); message set
1980              3 other error (expansion failure)
1981 */
1982
1983 static int
1984 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1985   BOOL check_end, uschar *name, BOOL *resetok)
1986 {
1987 int i;
1988 const uschar *s = *sptr;
1989
1990 while (isspace(*s)) s++;
1991 for (i = 0; i < n; i++)
1992   {
1993   if (*s != '{')
1994     {
1995     if (i < m)
1996       {
1997       expand_string_message = string_sprintf("Not enough arguments for '%s' "
1998         "(min is %d)", name, m);
1999       return 1;
2000       }
2001     sub[i] = NULL;
2002     break;
2003     }
2004   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2005     return 3;
2006   if (*s++ != '}') return 1;
2007   while (isspace(*s)) s++;
2008   }
2009 if (check_end && *s++ != '}')
2010   {
2011   if (s[-1] == '{')
2012     {
2013     expand_string_message = string_sprintf("Too many arguments for '%s' "
2014       "(max is %d)", name, n);
2015     return 2;
2016     }
2017   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2018   return 1;
2019   }
2020
2021 *sptr = s;
2022 return 0;
2023 }
2024
2025
2026
2027
2028 /*************************************************
2029 *     Elaborate message for bad variable         *
2030 *************************************************/
2031
2032 /* For the "unknown variable" message, take a look at the variable's name, and
2033 give additional information about possible ACL variables. The extra information
2034 is added on to expand_string_message.
2035
2036 Argument:   the name of the variable
2037 Returns:    nothing
2038 */
2039
2040 static void
2041 check_variable_error_message(uschar *name)
2042 {
2043 if (Ustrncmp(name, "acl_", 4) == 0)
2044   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2045     (name[4] == 'c' || name[4] == 'm')?
2046       (isalpha(name[5])?
2047         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2048         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2049       ) :
2050       US"user-defined ACL variables must start acl_c or acl_m");
2051 }
2052
2053
2054
2055 /*
2056 Load args from sub array to globals, and call acl_check().
2057 Sub array will be corrupted on return.
2058
2059 Returns:       OK         access is granted by an ACCEPT verb
2060                DISCARD    access is (apparently) granted by a DISCARD verb
2061                FAIL       access is denied
2062                FAIL_DROP  access is denied; drop the connection
2063                DEFER      can't tell at the moment
2064                ERROR      disaster
2065 */
2066 static int
2067 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2068 {
2069 int i;
2070 int sav_narg = acl_narg;
2071 int ret;
2072 uschar * dummy_logmsg;
2073 extern int acl_where;
2074
2075 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2076 for (i = 0; i < nsub && sub[i+1]; i++)
2077   {
2078   uschar * tmp = acl_arg[i];
2079   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2080   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2081   }
2082 acl_narg = i;
2083 while (i < nsub)
2084   {
2085   sub[i+1] = acl_arg[i];
2086   acl_arg[i++] = NULL;
2087   }
2088
2089 DEBUG(D_expand)
2090   debug_printf("expanding: acl: %s  arg: %s%s\n",
2091     sub[0],
2092     acl_narg>0 ? acl_arg[0] : US"<none>",
2093     acl_narg>1 ? " +more"   : "");
2094
2095 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2096
2097 for (i = 0; i < nsub; i++)
2098   acl_arg[i] = sub[i+1];        /* restore old args */
2099 acl_narg = sav_narg;
2100
2101 return ret;
2102 }
2103
2104
2105
2106
2107 /*************************************************
2108 *        Read and evaluate a condition           *
2109 *************************************************/
2110
2111 /*
2112 Arguments:
2113   s        points to the start of the condition text
2114   resetok  points to a BOOL which is written false if it is unsafe to
2115            free memory. Certain condition types (acl) may have side-effect
2116            allocation which must be preserved.
2117   yield    points to a BOOL to hold the result of the condition test;
2118            if NULL, we are just reading through a condition that is
2119            part of an "or" combination to check syntax, or in a state
2120            where the answer isn't required
2121
2122 Returns:   a pointer to the first character after the condition, or
2123            NULL after an error
2124 */
2125
2126 static const uschar *
2127 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2128 {
2129 BOOL testfor = TRUE;
2130 BOOL tempcond, combined_cond;
2131 BOOL *subcondptr;
2132 BOOL sub2_honour_dollar = TRUE;
2133 int i, rc, cond_type, roffset;
2134 int_eximarith_t num[2];
2135 struct stat statbuf;
2136 uschar name[256];
2137 const uschar *sub[10];
2138
2139 const pcre *re;
2140 const uschar *rerror;
2141
2142 for (;;)
2143   {
2144   while (isspace(*s)) s++;
2145   if (*s == '!') { testfor = !testfor; s++; } else break;
2146   }
2147
2148 /* Numeric comparisons are symbolic */
2149
2150 if (*s == '=' || *s == '>' || *s == '<')
2151   {
2152   int p = 0;
2153   name[p++] = *s++;
2154   if (*s == '=')
2155     {
2156     name[p++] = '=';
2157     s++;
2158     }
2159   name[p] = 0;
2160   }
2161
2162 /* All other conditions are named */
2163
2164 else s = read_name(name, 256, s, US"_");
2165
2166 /* If we haven't read a name, it means some non-alpha character is first. */
2167
2168 if (name[0] == 0)
2169   {
2170   expand_string_message = string_sprintf("condition name expected, "
2171     "but found \"%.16s\"", s);
2172   return NULL;
2173   }
2174
2175 /* Find which condition we are dealing with, and switch on it */
2176
2177 cond_type = chop_match(name, cond_table, nelem(cond_table));
2178 switch(cond_type)
2179   {
2180   /* def: tests for a non-empty variable, or for the existence of a header. If
2181   yield == NULL we are in a skipping state, and don't care about the answer. */
2182
2183   case ECOND_DEF:
2184   if (*s != ':')
2185     {
2186     expand_string_message = US"\":\" expected after \"def\"";
2187     return NULL;
2188     }
2189
2190   s = read_name(name, 256, s+1, US"_");
2191
2192   /* Test for a header's existence. If the name contains a closing brace
2193   character, this may be a user error where the terminating colon has been
2194   omitted. Set a flag to adjust a subsequent error message in this case. */
2195
2196   if (Ustrncmp(name, "h_", 2) == 0 ||
2197       Ustrncmp(name, "rh_", 3) == 0 ||
2198       Ustrncmp(name, "bh_", 3) == 0 ||
2199       Ustrncmp(name, "header_", 7) == 0 ||
2200       Ustrncmp(name, "rheader_", 8) == 0 ||
2201       Ustrncmp(name, "bheader_", 8) == 0)
2202     {
2203     s = read_header_name(name, 256, s);
2204     /* {-for-text-editors */
2205     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2206     if (yield != NULL) *yield =
2207       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2208     }
2209
2210   /* Test for a variable's having a non-empty value. A non-existent variable
2211   causes an expansion failure. */
2212
2213   else
2214     {
2215     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2216     if (value == NULL)
2217       {
2218       expand_string_message = (name[0] == 0)?
2219         string_sprintf("variable name omitted after \"def:\"") :
2220         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2221       check_variable_error_message(name);
2222       return NULL;
2223       }
2224     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2225     }
2226
2227   return s;
2228
2229
2230   /* first_delivery tests for first delivery attempt */
2231
2232   case ECOND_FIRST_DELIVERY:
2233   if (yield != NULL) *yield = deliver_firsttime == testfor;
2234   return s;
2235
2236
2237   /* queue_running tests for any process started by a queue runner */
2238
2239   case ECOND_QUEUE_RUNNING:
2240   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2241   return s;
2242
2243
2244   /* exists:  tests for file existence
2245        isip:  tests for any IP address
2246       isip4:  tests for an IPv4 address
2247       isip6:  tests for an IPv6 address
2248         pam:  does PAM authentication
2249      radius:  does RADIUS authentication
2250    ldapauth:  does LDAP authentication
2251     pwcheck:  does Cyrus SASL pwcheck authentication
2252   */
2253
2254   case ECOND_EXISTS:
2255   case ECOND_ISIP:
2256   case ECOND_ISIP4:
2257   case ECOND_ISIP6:
2258   case ECOND_PAM:
2259   case ECOND_RADIUS:
2260   case ECOND_LDAPAUTH:
2261   case ECOND_PWCHECK:
2262
2263   while (isspace(*s)) s++;
2264   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2265
2266   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2267   if (sub[0] == NULL) return NULL;
2268   /* {-for-text-editors */
2269   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2270
2271   if (yield == NULL) return s;   /* No need to run the test if skipping */
2272
2273   switch(cond_type)
2274     {
2275     case ECOND_EXISTS:
2276     if ((expand_forbid & RDO_EXISTS) != 0)
2277       {
2278       expand_string_message = US"File existence tests are not permitted";
2279       return NULL;
2280       }
2281     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2282     break;
2283
2284     case ECOND_ISIP:
2285     case ECOND_ISIP4:
2286     case ECOND_ISIP6:
2287     rc = string_is_ip_address(sub[0], NULL);
2288     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2289              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2290     break;
2291
2292     /* Various authentication tests - all optionally compiled */
2293
2294     case ECOND_PAM:
2295     #ifdef SUPPORT_PAM
2296     rc = auth_call_pam(sub[0], &expand_string_message);
2297     goto END_AUTH;
2298     #else
2299     goto COND_FAILED_NOT_COMPILED;
2300     #endif  /* SUPPORT_PAM */
2301
2302     case ECOND_RADIUS:
2303     #ifdef RADIUS_CONFIG_FILE
2304     rc = auth_call_radius(sub[0], &expand_string_message);
2305     goto END_AUTH;
2306     #else
2307     goto COND_FAILED_NOT_COMPILED;
2308     #endif  /* RADIUS_CONFIG_FILE */
2309
2310     case ECOND_LDAPAUTH:
2311     #ifdef LOOKUP_LDAP
2312       {
2313       /* Just to keep the interface the same */
2314       BOOL do_cache;
2315       int old_pool = store_pool;
2316       store_pool = POOL_SEARCH;
2317       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2318         &expand_string_message, &do_cache);
2319       store_pool = old_pool;
2320       }
2321     goto END_AUTH;
2322     #else
2323     goto COND_FAILED_NOT_COMPILED;
2324     #endif  /* LOOKUP_LDAP */
2325
2326     case ECOND_PWCHECK:
2327     #ifdef CYRUS_PWCHECK_SOCKET
2328     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2329     goto END_AUTH;
2330     #else
2331     goto COND_FAILED_NOT_COMPILED;
2332     #endif  /* CYRUS_PWCHECK_SOCKET */
2333
2334     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2335         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2336     END_AUTH:
2337     if (rc == ERROR || rc == DEFER) return NULL;
2338     *yield = (rc == OK) == testfor;
2339     #endif
2340     }
2341   return s;
2342
2343
2344   /* call ACL (in a conditional context).  Accept true, deny false.
2345   Defer is a forced-fail.  Anything set by message= goes to $value.
2346   Up to ten parameters are used; we use the braces round the name+args
2347   like the saslauthd condition does, to permit a variable number of args.
2348   See also the expansion-item version EITEM_ACL and the traditional
2349   acl modifier ACLC_ACL.
2350   Since the ACL may allocate new global variables, tell our caller to not
2351   reclaim memory.
2352   */
2353
2354   case ECOND_ACL:
2355     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2356     {
2357     uschar *sub[10];
2358     uschar *user_msg;
2359     BOOL cond = FALSE;
2360     int size = 0;
2361     int ptr = 0;
2362
2363     while (isspace(*s)) s++;
2364     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2365
2366     switch(read_subs(sub, nelem(sub), 1,
2367       &s, yield == NULL, TRUE, US"acl", resetok))
2368       {
2369       case 1: expand_string_message = US"too few arguments or bracketing "
2370         "error for acl";
2371       case 2:
2372       case 3: return NULL;
2373       }
2374
2375     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2376     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2377         {
2378         case OK:
2379           cond = TRUE;
2380         case FAIL:
2381           lookup_value = NULL;
2382           if (user_msg)
2383             {
2384             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2385             lookup_value[ptr] = '\0';
2386             }
2387           *yield = cond == testfor;
2388           break;
2389
2390         case DEFER:
2391           expand_string_forcedfail = TRUE;
2392           /*FALLTHROUGH*/
2393         default:
2394           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2395           return NULL;
2396         }
2397     return s;
2398     }
2399
2400
2401   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2402
2403      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2404
2405   However, the last two are optional. That is why the whole set is enclosed
2406   in their own set of braces. */
2407
2408   case ECOND_SASLAUTHD:
2409 #ifndef CYRUS_SASLAUTHD_SOCKET
2410     goto COND_FAILED_NOT_COMPILED;
2411 #else
2412     {
2413     uschar *sub[4];
2414     while (isspace(*s)) s++;
2415     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2416     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2417                     resetok))
2418       {
2419       case 1: expand_string_message = US"too few arguments or bracketing "
2420         "error for saslauthd";
2421       case 2:
2422       case 3: return NULL;
2423       }
2424     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2425     if (yield != NULL)
2426       {
2427       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2428         &expand_string_message);
2429       if (rc == ERROR || rc == DEFER) return NULL;
2430       *yield = (rc == OK) == testfor;
2431       }
2432     return s;
2433     }
2434 #endif /* CYRUS_SASLAUTHD_SOCKET */
2435
2436
2437   /* symbolic operators for numeric and string comparison, and a number of
2438   other operators, all requiring two arguments.
2439
2440   crypteq:           encrypts plaintext and compares against an encrypted text,
2441                        using crypt(), crypt16(), MD5 or SHA-1
2442   inlist/inlisti:    checks if first argument is in the list of the second
2443   match:             does a regular expression match and sets up the numerical
2444                        variables if it succeeds
2445   match_address:     matches in an address list
2446   match_domain:      matches in a domain list
2447   match_ip:          matches a host list that is restricted to IP addresses
2448   match_local_part:  matches in a local part list
2449   */
2450
2451   case ECOND_MATCH_ADDRESS:
2452   case ECOND_MATCH_DOMAIN:
2453   case ECOND_MATCH_IP:
2454   case ECOND_MATCH_LOCAL_PART:
2455 #ifndef EXPAND_LISTMATCH_RHS
2456     sub2_honour_dollar = FALSE;
2457 #endif
2458     /* FALLTHROUGH */
2459
2460   case ECOND_CRYPTEQ:
2461   case ECOND_INLIST:
2462   case ECOND_INLISTI:
2463   case ECOND_MATCH:
2464
2465   case ECOND_NUM_L:     /* Numerical comparisons */
2466   case ECOND_NUM_LE:
2467   case ECOND_NUM_E:
2468   case ECOND_NUM_EE:
2469   case ECOND_NUM_G:
2470   case ECOND_NUM_GE:
2471
2472   case ECOND_STR_LT:    /* String comparisons */
2473   case ECOND_STR_LTI:
2474   case ECOND_STR_LE:
2475   case ECOND_STR_LEI:
2476   case ECOND_STR_EQ:
2477   case ECOND_STR_EQI:
2478   case ECOND_STR_GT:
2479   case ECOND_STR_GTI:
2480   case ECOND_STR_GE:
2481   case ECOND_STR_GEI:
2482
2483   for (i = 0; i < 2; i++)
2484     {
2485     /* Sometimes, we don't expand substrings; too many insecure configurations
2486     created using match_address{}{} and friends, where the second param
2487     includes information from untrustworthy sources. */
2488     BOOL honour_dollar = TRUE;
2489     if ((i > 0) && !sub2_honour_dollar)
2490       honour_dollar = FALSE;
2491
2492     while (isspace(*s)) s++;
2493     if (*s != '{')
2494       {
2495       if (i == 0) goto COND_FAILED_CURLY_START;
2496       expand_string_message = string_sprintf("missing 2nd string in {} "
2497         "after \"%s\"", name);
2498       return NULL;
2499       }
2500     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2501         honour_dollar, resetok);
2502     if (sub[i] == NULL) return NULL;
2503     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2504
2505     /* Convert to numerical if required; we know that the names of all the
2506     conditions that compare numbers do not start with a letter. This just saves
2507     checking for them individually. */
2508
2509     if (!isalpha(name[0]) && yield != NULL)
2510       {
2511       if (sub[i][0] == 0)
2512         {
2513         num[i] = 0;
2514         DEBUG(D_expand)
2515           debug_printf("empty string cast to zero for numerical comparison\n");
2516         }
2517       else
2518         {
2519         num[i] = expanded_string_integer(sub[i], FALSE);
2520         if (expand_string_message != NULL) return NULL;
2521         }
2522       }
2523     }
2524
2525   /* Result not required */
2526
2527   if (yield == NULL) return s;
2528
2529   /* Do an appropriate comparison */
2530
2531   switch(cond_type)
2532     {
2533     case ECOND_NUM_E:
2534     case ECOND_NUM_EE:
2535     tempcond = (num[0] == num[1]);
2536     break;
2537
2538     case ECOND_NUM_G:
2539     tempcond = (num[0] > num[1]);
2540     break;
2541
2542     case ECOND_NUM_GE:
2543     tempcond = (num[0] >= num[1]);
2544     break;
2545
2546     case ECOND_NUM_L:
2547     tempcond = (num[0] < num[1]);
2548     break;
2549
2550     case ECOND_NUM_LE:
2551     tempcond = (num[0] <= num[1]);
2552     break;
2553
2554     case ECOND_STR_LT:
2555     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2556     break;
2557
2558     case ECOND_STR_LTI:
2559     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2560     break;
2561
2562     case ECOND_STR_LE:
2563     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2564     break;
2565
2566     case ECOND_STR_LEI:
2567     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2568     break;
2569
2570     case ECOND_STR_EQ:
2571     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2572     break;
2573
2574     case ECOND_STR_EQI:
2575     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2576     break;
2577
2578     case ECOND_STR_GT:
2579     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2580     break;
2581
2582     case ECOND_STR_GTI:
2583     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2584     break;
2585
2586     case ECOND_STR_GE:
2587     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2588     break;
2589
2590     case ECOND_STR_GEI:
2591     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2592     break;
2593
2594     case ECOND_MATCH:   /* Regular expression match */
2595     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2596       NULL);
2597     if (re == NULL)
2598       {
2599       expand_string_message = string_sprintf("regular expression error in "
2600         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2601       return NULL;
2602       }
2603     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2604     break;
2605
2606     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2607     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2608     goto MATCHED_SOMETHING;
2609
2610     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2611     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2612       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2613     goto MATCHED_SOMETHING;
2614
2615     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2616     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2617       {
2618       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2619         sub[0]);
2620       return NULL;
2621       }
2622     else
2623       {
2624       unsigned int *nullcache = NULL;
2625       check_host_block cb;
2626
2627       cb.host_name = US"";
2628       cb.host_address = sub[0];
2629
2630       /* If the host address starts off ::ffff: it is an IPv6 address in
2631       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2632       addresses. */
2633
2634       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2635         cb.host_address + 7 : cb.host_address;
2636
2637       rc = match_check_list(
2638              &sub[1],                   /* the list */
2639              0,                         /* separator character */
2640              &hostlist_anchor,          /* anchor pointer */
2641              &nullcache,                /* cache pointer */
2642              check_host,                /* function for testing */
2643              &cb,                       /* argument for function */
2644              MCL_HOST,                  /* type of check */
2645              sub[0],                    /* text for debugging */
2646              NULL);                     /* where to pass back data */
2647       }
2648     goto MATCHED_SOMETHING;
2649
2650     case ECOND_MATCH_LOCAL_PART:
2651     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2652       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2653     /* Fall through */
2654     /* VVVVVVVVVVVV */
2655     MATCHED_SOMETHING:
2656     switch(rc)
2657       {
2658       case OK:
2659       tempcond = TRUE;
2660       break;
2661
2662       case FAIL:
2663       tempcond = FALSE;
2664       break;
2665
2666       case DEFER:
2667       expand_string_message = string_sprintf("unable to complete match "
2668         "against \"%s\": %s", sub[1], search_error_message);
2669       return NULL;
2670       }
2671
2672     break;
2673
2674     /* Various "encrypted" comparisons. If the second string starts with
2675     "{" then an encryption type is given. Default to crypt() or crypt16()
2676     (build-time choice). */
2677     /* }-for-text-editors */
2678
2679     case ECOND_CRYPTEQ:
2680     #ifndef SUPPORT_CRYPTEQ
2681     goto COND_FAILED_NOT_COMPILED;
2682     #else
2683     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2684       {
2685       int sublen = Ustrlen(sub[1]+5);
2686       md5 base;
2687       uschar digest[16];
2688
2689       md5_start(&base);
2690       md5_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2691
2692       /* If the length that we are comparing against is 24, the MD5 digest
2693       is expressed as a base64 string. This is the way LDAP does it. However,
2694       some other software uses a straightforward hex representation. We assume
2695       this if the length is 32. Other lengths fail. */
2696
2697       if (sublen == 24)
2698         {
2699         uschar *coded = b64encode((uschar *)digest, 16);
2700         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2701           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2702         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2703         }
2704       else if (sublen == 32)
2705         {
2706         int i;
2707         uschar coded[36];
2708         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2709         coded[32] = 0;
2710         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2711           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2712         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2713         }
2714       else
2715         {
2716         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2717           "fail\n  crypted=%s\n", sub[1]+5);
2718         tempcond = FALSE;
2719         }
2720       }
2721
2722     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2723       {
2724       int sublen = Ustrlen(sub[1]+6);
2725       sha1 base;
2726       uschar digest[20];
2727
2728       sha1_start(&base);
2729       sha1_end(&base, (uschar *)sub[0], Ustrlen(sub[0]), digest);
2730
2731       /* If the length that we are comparing against is 28, assume the SHA1
2732       digest is expressed as a base64 string. If the length is 40, assume a
2733       straightforward hex representation. Other lengths fail. */
2734
2735       if (sublen == 28)
2736         {
2737         uschar *coded = b64encode((uschar *)digest, 20);
2738         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2739           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2740         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2741         }
2742       else if (sublen == 40)
2743         {
2744         int i;
2745         uschar coded[44];
2746         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2747         coded[40] = 0;
2748         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2749           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2750         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2751         }
2752       else
2753         {
2754         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2755           "fail\n  crypted=%s\n", sub[1]+6);
2756         tempcond = FALSE;
2757         }
2758       }
2759
2760     else   /* {crypt} or {crypt16} and non-{ at start */
2761            /* }-for-text-editors */
2762       {
2763       int which = 0;
2764       uschar *coded;
2765
2766       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2767         {
2768         sub[1] += 7;
2769         which = 1;
2770         }
2771       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2772         {
2773         sub[1] += 9;
2774         which = 2;
2775         }
2776       else if (sub[1][0] == '{')                /* }-for-text-editors */
2777         {
2778         expand_string_message = string_sprintf("unknown encryption mechanism "
2779           "in \"%s\"", sub[1]);
2780         return NULL;
2781         }
2782
2783       switch(which)
2784         {
2785         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2786         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2787         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2788         }
2789
2790       #define STR(s) # s
2791       #define XSTR(s) STR(s)
2792       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2793         "  subject=%s\n  crypted=%s\n",
2794         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2795         coded, sub[1]);
2796       #undef STR
2797       #undef XSTR
2798
2799       /* If the encrypted string contains fewer than two characters (for the
2800       salt), force failure. Otherwise we get false positives: with an empty
2801       string the yield of crypt() is an empty string! */
2802
2803       if (coded)
2804         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2805       else if (errno == EINVAL)
2806         tempcond = FALSE;
2807       else
2808         {
2809         expand_string_message = string_sprintf("crypt error: %s\n",
2810           US strerror(errno));
2811         return NULL;
2812         }
2813       }
2814     break;
2815     #endif  /* SUPPORT_CRYPTEQ */
2816
2817     case ECOND_INLIST:
2818     case ECOND_INLISTI:
2819       {
2820       const uschar * list = sub[1];
2821       int sep = 0;
2822       uschar *save_iterate_item = iterate_item;
2823       int (*compare)(const uschar *, const uschar *);
2824
2825       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2826
2827       tempcond = FALSE;
2828       compare = cond_type == ECOND_INLISTI
2829         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2830
2831       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2832         if (compare(sub[0], iterate_item) == 0)
2833           {
2834           tempcond = TRUE;
2835           break;
2836           }
2837       iterate_item = save_iterate_item;
2838       }
2839
2840     }   /* Switch for comparison conditions */
2841
2842   *yield = tempcond == testfor;
2843   return s;    /* End of comparison conditions */
2844
2845
2846   /* and/or: computes logical and/or of several conditions */
2847
2848   case ECOND_AND:
2849   case ECOND_OR:
2850   subcondptr = (yield == NULL)? NULL : &tempcond;
2851   combined_cond = (cond_type == ECOND_AND);
2852
2853   while (isspace(*s)) s++;
2854   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2855
2856   for (;;)
2857     {
2858     while (isspace(*s)) s++;
2859     /* {-for-text-editors */
2860     if (*s == '}') break;
2861     if (*s != '{')                                      /* }-for-text-editors */
2862       {
2863       expand_string_message = string_sprintf("each subcondition "
2864         "inside an \"%s{...}\" condition must be in its own {}", name);
2865       return NULL;
2866       }
2867
2868     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2869       {
2870       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2871         expand_string_message, name);
2872       return NULL;
2873       }
2874     while (isspace(*s)) s++;
2875
2876     /* {-for-text-editors */
2877     if (*s++ != '}')
2878       {
2879       /* {-for-text-editors */
2880       expand_string_message = string_sprintf("missing } at end of condition "
2881         "inside \"%s\" group", name);
2882       return NULL;
2883       }
2884
2885     if (yield != NULL)
2886       {
2887       if (cond_type == ECOND_AND)
2888         {
2889         combined_cond &= tempcond;
2890         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2891         }                                       /* evaluate any more */
2892       else
2893         {
2894         combined_cond |= tempcond;
2895         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2896         }                                       /* evaluate any more */
2897       }
2898     }
2899
2900   if (yield != NULL) *yield = (combined_cond == testfor);
2901   return ++s;
2902
2903
2904   /* forall/forany: iterates a condition with different values */
2905
2906   case ECOND_FORALL:
2907   case ECOND_FORANY:
2908     {
2909     const uschar * list;
2910     int sep = 0;
2911     uschar *save_iterate_item = iterate_item;
2912
2913     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2914
2915     while (isspace(*s)) s++;
2916     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2917     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2918     if (sub[0] == NULL) return NULL;
2919     /* {-for-text-editors */
2920     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2921
2922     while (isspace(*s)) s++;
2923     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2924
2925     sub[1] = s;
2926
2927     /* Call eval_condition once, with result discarded (as if scanning a
2928     "false" part). This allows us to find the end of the condition, because if
2929     the list it empty, we won't actually evaluate the condition for real. */
2930
2931     if (!(s = eval_condition(sub[1], resetok, NULL)))
2932       {
2933       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2934         expand_string_message, name);
2935       return NULL;
2936       }
2937     while (isspace(*s)) s++;
2938
2939     /* {-for-text-editors */
2940     if (*s++ != '}')
2941       {
2942       /* {-for-text-editors */
2943       expand_string_message = string_sprintf("missing } at end of condition "
2944         "inside \"%s\"", name);
2945       return NULL;
2946       }
2947
2948     if (yield != NULL) *yield = !testfor;
2949     list = sub[0];
2950     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2951       {
2952       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2953       if (!eval_condition(sub[1], resetok, &tempcond))
2954         {
2955         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2956           expand_string_message, name);
2957         iterate_item = save_iterate_item;
2958         return NULL;
2959         }
2960       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2961         tempcond? "true":"false");
2962
2963       if (yield != NULL) *yield = (tempcond == testfor);
2964       if (tempcond == (cond_type == ECOND_FORANY)) break;
2965       }
2966
2967     iterate_item = save_iterate_item;
2968     return s;
2969     }
2970
2971
2972   /* The bool{} expansion condition maps a string to boolean.
2973   The values supported should match those supported by the ACL condition
2974   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2975   of true/false.  Note that Router "condition" rules have a different
2976   interpretation, where general data can be used and only a few values
2977   map to FALSE.
2978   Note that readconf.c boolean matching, for boolean configuration options,
2979   only matches true/yes/false/no.
2980   The bool_lax{} condition matches the Router logic, which is much more
2981   liberal. */
2982   case ECOND_BOOL:
2983   case ECOND_BOOL_LAX:
2984     {
2985     uschar *sub_arg[1];
2986     uschar *t, *t2;
2987     uschar *ourname;
2988     size_t len;
2989     BOOL boolvalue = FALSE;
2990     while (isspace(*s)) s++;
2991     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2992     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2993     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2994       {
2995       case 1: expand_string_message = string_sprintf(
2996                   "too few arguments or bracketing error for %s",
2997                   ourname);
2998       /*FALLTHROUGH*/
2999       case 2:
3000       case 3: return NULL;
3001       }
3002     t = sub_arg[0];
3003     while (isspace(*t)) t++;
3004     len = Ustrlen(t);
3005     if (len)
3006       {
3007       /* trailing whitespace: seems like a good idea to ignore it too */
3008       t2 = t + len - 1;
3009       while (isspace(*t2)) t2--;
3010       if (t2 != (t + len))
3011         {
3012         *++t2 = '\0';
3013         len = t2 - t;
3014         }
3015       }
3016     DEBUG(D_expand)
3017       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3018     /* logic for the lax case from expand_check_condition(), which also does
3019     expands, and the logic is both short and stable enough that there should
3020     be no maintenance burden from replicating it. */
3021     if (len == 0)
3022       boolvalue = FALSE;
3023     else if (*t == '-'
3024              ? Ustrspn(t+1, "0123456789") == len-1
3025              : Ustrspn(t,   "0123456789") == len)
3026       {
3027       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3028       /* expand_check_condition only does a literal string "0" check */
3029       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3030         boolvalue = TRUE;
3031       }
3032     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3033       boolvalue = TRUE;
3034     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3035       boolvalue = FALSE;
3036     else if (cond_type == ECOND_BOOL_LAX)
3037       boolvalue = TRUE;
3038     else
3039       {
3040       expand_string_message = string_sprintf("unrecognised boolean "
3041        "value \"%s\"", t);
3042       return NULL;
3043       }
3044     if (yield != NULL) *yield = (boolvalue == testfor);
3045     return s;
3046     }
3047
3048   /* Unknown condition */
3049
3050   default:
3051   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3052   return NULL;
3053   }   /* End switch on condition type */
3054
3055 /* Missing braces at start and end of data */
3056
3057 COND_FAILED_CURLY_START:
3058 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3059 return NULL;
3060
3061 COND_FAILED_CURLY_END:
3062 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3063   name);
3064 return NULL;
3065
3066 /* A condition requires code that is not compiled */
3067
3068 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3069     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3070     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3071 COND_FAILED_NOT_COMPILED:
3072 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3073   name);
3074 return NULL;
3075 #endif
3076 }
3077
3078
3079
3080
3081 /*************************************************
3082 *          Save numerical variables              *
3083 *************************************************/
3084
3085 /* This function is called from items such as "if" that want to preserve and
3086 restore the numbered variables.
3087
3088 Arguments:
3089   save_expand_string    points to an array of pointers to set
3090   save_expand_nlength   points to an array of ints for the lengths
3091
3092 Returns:                the value of expand max to save
3093 */
3094
3095 static int
3096 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3097 {
3098 int i;
3099 for (i = 0; i <= expand_nmax; i++)
3100   {
3101   save_expand_nstring[i] = expand_nstring[i];
3102   save_expand_nlength[i] = expand_nlength[i];
3103   }
3104 return expand_nmax;
3105 }
3106
3107
3108
3109 /*************************************************
3110 *           Restore numerical variables          *
3111 *************************************************/
3112
3113 /* This function restored saved values of numerical strings.
3114
3115 Arguments:
3116   save_expand_nmax      the number of strings to restore
3117   save_expand_string    points to an array of pointers
3118   save_expand_nlength   points to an array of ints
3119
3120 Returns:                nothing
3121 */
3122
3123 static void
3124 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3125   int *save_expand_nlength)
3126 {
3127 int i;
3128 expand_nmax = save_expand_nmax;
3129 for (i = 0; i <= expand_nmax; i++)
3130   {
3131   expand_nstring[i] = save_expand_nstring[i];
3132   expand_nlength[i] = save_expand_nlength[i];
3133   }
3134 }
3135
3136
3137
3138
3139
3140 /*************************************************
3141 *            Handle yes/no substrings            *
3142 *************************************************/
3143
3144 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3145 alternative substrings that depend on whether or not the condition was true,
3146 or the lookup or extraction succeeded. The substrings always have to be
3147 expanded, to check their syntax, but "skipping" is set when the result is not
3148 needed - this avoids unnecessary nested lookups.
3149
3150 Arguments:
3151   skipping       TRUE if we were skipping when this item was reached
3152   yes            TRUE if the first string is to be used, else use the second
3153   save_lookup    a value to put back into lookup_value before the 2nd expansion
3154   sptr           points to the input string pointer
3155   yieldptr       points to the output string pointer
3156   sizeptr        points to the output string size
3157   ptrptr         points to the output string pointer
3158   type           "lookup", "if", "extract", "run", "env", "listextract" or
3159                  "certextract" for error message
3160   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3161                 the store.
3162
3163 Returns:         0 OK; lookup_value has been reset to save_lookup
3164                  1 expansion failed
3165                  2 expansion failed because of bracketing error
3166 */
3167
3168 static int
3169 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3170   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3171 {
3172 int rc = 0;
3173 const uschar *s = *sptr;    /* Local value */
3174 uschar *sub1, *sub2;
3175 const uschar * errwhere;
3176
3177 /* If there are no following strings, we substitute the contents of $value for
3178 lookups and for extractions in the success case. For the ${if item, the string
3179 "true" is substituted. In the fail case, nothing is substituted for all three
3180 items. */
3181
3182 while (isspace(*s)) s++;
3183 if (*s == '}')
3184   {
3185   if (type[0] == 'i')
3186     {
3187     if (yes) *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3188     }
3189   else
3190     {
3191     if (yes && lookup_value)
3192       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3193     lookup_value = save_lookup;
3194     }
3195   s++;
3196   goto RETURN;
3197   }
3198
3199 /* The first following string must be braced. */
3200
3201 if (*s++ != '{')
3202   {
3203   errwhere = US"'yes' part did not start with '{'";
3204   goto FAILED_CURLY;
3205   }
3206
3207 /* Expand the first substring. Forced failures are noticed only if we actually
3208 want this string. Set skipping in the call in the fail case (this will always
3209 be the case if we were already skipping). */
3210
3211 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3212 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3213 expand_string_forcedfail = FALSE;
3214 if (*s++ != '}')
3215   {
3216   errwhere = US"'yes' part did not end with '}'";
3217   goto FAILED_CURLY;
3218   }
3219
3220 /* If we want the first string, add it to the output */
3221
3222 if (yes)
3223   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3224
3225 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3226 $value to what it was at the start of the item, so that it has this value
3227 during the second string expansion. For the call from "if" or "run" to this
3228 function, save_lookup is set to lookup_value, so that this statement does
3229 nothing. */
3230
3231 lookup_value = save_lookup;
3232
3233 /* There now follows either another substring, or "fail", or nothing. This
3234 time, forced failures are noticed only if we want the second string. We must
3235 set skipping in the nested call if we don't want this string, or if we were
3236 already skipping. */
3237
3238 while (isspace(*s)) s++;
3239 if (*s == '{')
3240   {
3241   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3242   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3243   expand_string_forcedfail = FALSE;
3244   if (*s++ != '}')
3245     {
3246     errwhere = US"'no' part did not start with '{'";
3247     goto FAILED_CURLY;
3248     }
3249
3250   /* If we want the second string, add it to the output */
3251
3252   if (!yes)
3253     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3254   }
3255
3256 /* If there is no second string, but the word "fail" is present when the use of
3257 the second string is wanted, set a flag indicating it was a forced failure
3258 rather than a syntactic error. Swallow the terminating } in case this is nested
3259 inside another lookup or if or extract. */
3260
3261 else if (*s != '}')
3262   {
3263   uschar name[256];
3264   /* deconst cast ok here as source is s anyway */
3265   s = US read_name(name, sizeof(name), s, US"_");
3266   if (Ustrcmp(name, "fail") == 0)
3267     {
3268     if (!yes && !skipping)
3269       {
3270       while (isspace(*s)) s++;
3271       if (*s++ != '}')
3272         {
3273         errwhere = US"did not close with '}' after forcedfail";
3274         goto FAILED_CURLY;
3275         }
3276       expand_string_message =
3277         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3278       expand_string_forcedfail = TRUE;
3279       goto FAILED;
3280       }
3281     }
3282   else
3283     {
3284     expand_string_message =
3285       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3286     goto FAILED;
3287     }
3288   }
3289
3290 /* All we have to do now is to check on the final closing brace. */
3291
3292 while (isspace(*s)) s++;
3293 if (*s++ != '}')
3294   {
3295   errwhere = US"did not close with '}'";
3296   goto FAILED_CURLY;
3297   }
3298
3299
3300 RETURN:
3301 /* Update the input pointer value before returning */
3302 *sptr = s;
3303 return rc;
3304
3305 FAILED_CURLY:
3306   /* Get here if there is a bracketing failure */
3307   expand_string_message = string_sprintf(
3308     "curly-bracket problem in conditional yes/no parsing: %s\n"
3309     " remaining string is '%s'", errwhere, --s);
3310   rc = 2;
3311   goto RETURN;
3312
3313 FAILED:
3314   /* Get here for other failures */
3315   rc = 1;
3316   goto RETURN;
3317 }
3318
3319
3320
3321
3322 /*************************************************
3323 *    Handle MD5 or SHA-1 computation for HMAC    *
3324 *************************************************/
3325
3326 /* These are some wrapping functions that enable the HMAC code to be a bit
3327 cleaner. A good compiler will spot the tail recursion.
3328
3329 Arguments:
3330   type         HMAC_MD5 or HMAC_SHA1
3331   remaining    are as for the cryptographic hash functions
3332
3333 Returns:       nothing
3334 */
3335
3336 static void
3337 chash_start(int type, void *base)
3338 {
3339 if (type == HMAC_MD5)
3340   md5_start((md5 *)base);
3341 else
3342   sha1_start((sha1 *)base);
3343 }
3344
3345 static void
3346 chash_mid(int type, void *base, uschar *string)
3347 {
3348 if (type == HMAC_MD5)
3349   md5_mid((md5 *)base, string);
3350 else
3351   sha1_mid((sha1 *)base, string);
3352 }
3353
3354 static void
3355 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3356 {
3357 if (type == HMAC_MD5)
3358   md5_end((md5 *)base, string, length, digest);
3359 else
3360   sha1_end((sha1 *)base, string, length, digest);
3361 }
3362
3363
3364
3365
3366
3367 /********************************************************
3368 * prvs: Get last three digits of days since Jan 1, 1970 *
3369 ********************************************************/
3370
3371 /* This is needed to implement the "prvs" BATV reverse
3372    path signing scheme
3373
3374 Argument: integer "days" offset to add or substract to
3375           or from the current number of days.
3376
3377 Returns:  pointer to string containing the last three
3378           digits of the number of days since Jan 1, 1970,
3379           modified by the offset argument, NULL if there
3380           was an error in the conversion.
3381
3382 */
3383
3384 static uschar *
3385 prvs_daystamp(int day_offset)
3386 {
3387 uschar *days = store_get(32);                /* Need at least 24 for cases */
3388 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3389   (time(NULL) + day_offset*86400)/86400);
3390 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3391 }
3392
3393
3394
3395 /********************************************************
3396 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3397 ********************************************************/
3398
3399 /* This is needed to implement the "prvs" BATV reverse
3400    path signing scheme
3401
3402 Arguments:
3403   address RFC2821 Address to use
3404       key The key to use (must be less than 64 characters
3405           in size)
3406   key_num Single-digit key number to use. Defaults to
3407           '0' when NULL.
3408
3409 Returns:  pointer to string containing the first three
3410           bytes of the final hash in hex format, NULL if
3411           there was an error in the process.
3412 */
3413
3414 static uschar *
3415 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3416 {
3417 uschar *hash_source, *p;
3418 int size = 0,offset = 0,i;
3419 sha1 sha1_base;
3420 void *use_base = &sha1_base;
3421 uschar innerhash[20];
3422 uschar finalhash[20];
3423 uschar innerkey[64];
3424 uschar outerkey[64];
3425 uschar *finalhash_hex = store_get(40);
3426
3427 if (key_num == NULL)
3428   key_num = US"0";
3429
3430 if (Ustrlen(key) > 64)
3431   return NULL;
3432
3433 hash_source = string_catn(NULL, &size, &offset, key_num, 1);
3434 hash_source = string_catn(hash_source, &size, &offset, daystamp, 3);
3435 hash_source = string_cat(hash_source, &size, &offset, address);
3436 hash_source[offset] = '\0';
3437
3438 DEBUG(D_expand) debug_printf("prvs: hash source is '%s'\n", hash_source);
3439
3440 memset(innerkey, 0x36, 64);
3441 memset(outerkey, 0x5c, 64);
3442
3443 for (i = 0; i < Ustrlen(key); i++)
3444   {
3445   innerkey[i] ^= key[i];
3446   outerkey[i] ^= key[i];
3447   }
3448
3449 chash_start(HMAC_SHA1, use_base);
3450 chash_mid(HMAC_SHA1, use_base, innerkey);
3451 chash_end(HMAC_SHA1, use_base, hash_source, offset, innerhash);
3452
3453 chash_start(HMAC_SHA1, use_base);
3454 chash_mid(HMAC_SHA1, use_base, outerkey);
3455 chash_end(HMAC_SHA1, use_base, innerhash, 20, finalhash);
3456
3457 p = finalhash_hex;
3458 for (i = 0; i < 3; i++)
3459   {
3460   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3461   *p++ = hex_digits[finalhash[i] & 0x0f];
3462   }
3463 *p = '\0';
3464
3465 return finalhash_hex;
3466 }
3467
3468
3469
3470
3471 /*************************************************
3472 *        Join a file onto the output string      *
3473 *************************************************/
3474
3475 /* This is used for readfile/readsock and after a run expansion.
3476 It joins the contents of a file onto the output string, globally replacing
3477 newlines with a given string (optionally).
3478
3479 Arguments:
3480   f            the FILE
3481   yield        pointer to the expandable string
3482   sizep        pointer to the current size
3483   ptrp         pointer to the current position
3484   eol          newline replacement string, or NULL
3485
3486 Returns:       new value of string pointer
3487 */
3488
3489 static uschar *
3490 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3491 {
3492 int eollen = eol ? Ustrlen(eol) : 0;
3493 uschar buffer[1024];
3494
3495 while (Ufgets(buffer, sizeof(buffer), f))
3496   {
3497   int len = Ustrlen(buffer);
3498   if (eol && buffer[len-1] == '\n') len--;
3499   yield = string_catn(yield, sizep, ptrp, buffer, len);
3500   if (buffer[len] != 0)
3501     yield = string_catn(yield, sizep, ptrp, eol, eollen);
3502   }
3503
3504 if (yield) yield[*ptrp] = 0;
3505
3506 return yield;
3507 }
3508
3509
3510
3511
3512 /*************************************************
3513 *          Evaluate numeric expression           *
3514 *************************************************/
3515
3516 /* This is a set of mutually recursive functions that evaluate an arithmetic
3517 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3518 these functions that is called from elsewhere is eval_expr, whose interface is:
3519
3520 Arguments:
3521   sptr        pointer to the pointer to the string - gets updated
3522   decimal     TRUE if numbers are to be assumed decimal
3523   error       pointer to where to put an error message - must be NULL on input
3524   endket      TRUE if ')' must terminate - FALSE for external call
3525
3526 Returns:      on success: the value of the expression, with *error still NULL
3527               on failure: an undefined value, with *error = a message
3528 */
3529
3530 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3531
3532
3533 static int_eximarith_t
3534 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3535 {
3536 uschar *s = *sptr;
3537 int_eximarith_t x = eval_op_or(&s, decimal, error);
3538 if (*error == NULL)
3539   {
3540   if (endket)
3541     {
3542     if (*s != ')')
3543       *error = US"expecting closing parenthesis";
3544     else
3545       while (isspace(*(++s)));
3546     }
3547   else if (*s != 0) *error = US"expecting operator";
3548   }
3549 *sptr = s;
3550 return x;
3551 }
3552
3553
3554 static int_eximarith_t
3555 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3556 {
3557 register int c;
3558 int_eximarith_t n;
3559 uschar *s = *sptr;
3560 while (isspace(*s)) s++;
3561 c = *s;
3562 if (isdigit(c))
3563   {
3564   int count;
3565   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3566   s += count;
3567   switch (tolower(*s))
3568     {
3569     default: break;
3570     case 'k': n *= 1024; s++; break;
3571     case 'm': n *= 1024*1024; s++; break;
3572     case 'g': n *= 1024*1024*1024; s++; break;
3573     }
3574   while (isspace (*s)) s++;
3575   }
3576 else if (c == '(')
3577   {
3578   s++;
3579   n = eval_expr(&s, decimal, error, 1);
3580   }
3581 else
3582   {
3583   *error = US"expecting number or opening parenthesis";
3584   n = 0;
3585   }
3586 *sptr = s;
3587 return n;
3588 }
3589
3590
3591 static int_eximarith_t
3592 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3593 {
3594 uschar *s = *sptr;
3595 int_eximarith_t x;
3596 while (isspace(*s)) s++;
3597 if (*s == '+' || *s == '-' || *s == '~')
3598   {
3599   int op = *s++;
3600   x = eval_op_unary(&s, decimal, error);
3601   if (op == '-') x = -x;
3602     else if (op == '~') x = ~x;
3603   }
3604 else
3605   {
3606   x = eval_number(&s, decimal, error);
3607   }
3608 *sptr = s;
3609 return x;
3610 }
3611
3612
3613 static int_eximarith_t
3614 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3615 {
3616 uschar *s = *sptr;
3617 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3618 if (*error == NULL)
3619   {
3620   while (*s == '*' || *s == '/' || *s == '%')
3621     {
3622     int op = *s++;
3623     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3624     if (*error != NULL) break;
3625     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3626      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3627      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3628      * -N*M is INT_MIN will yielf INT_MIN.
3629      * Since we don't support floating point, this is somewhat simpler.
3630      * Ideally, we'd return an error, but since we overflow for all other
3631      * arithmetic, consistency suggests otherwise, but what's the correct value
3632      * to use?  There is none.
3633      * The C standard guarantees overflow for unsigned arithmetic but signed
3634      * overflow invokes undefined behaviour; in practice, this is overflow
3635      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3636      * that long/longlong larger than int are available, or we could just work
3637      * with larger types.  We should consider whether to guarantee 32bit eval
3638      * and 64-bit working variables, with errors returned.  For now ...
3639      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3640      * can just let the other invalid results occur otherwise, as they have
3641      * until now.  For this one case, we can coerce.
3642      */
3643     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3644       {
3645       DEBUG(D_expand)
3646         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3647             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3648       x = EXIM_ARITH_MAX;
3649       continue;
3650       }
3651     if (op == '*')
3652       x *= y;
3653     else
3654       {
3655       if (y == 0)
3656         {
3657         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3658         x = 0;
3659         break;
3660         }
3661       if (op == '/')
3662         x /= y;
3663       else
3664         x %= y;
3665       }
3666     }
3667   }
3668 *sptr = s;
3669 return x;
3670 }
3671
3672
3673 static int_eximarith_t
3674 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3675 {
3676 uschar *s = *sptr;
3677 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3678 if (!*error)
3679   {
3680   while (*s == '+' || *s == '-')
3681     {
3682     int op = *s++;
3683     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3684     if (*error) break;
3685     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3686        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3687       {                 /* over-conservative check */
3688       *error = op == '+'
3689         ? US"overflow in sum" : US"overflow in difference";
3690       break;
3691       }
3692     if (op == '+') x += y; else x -= y;
3693     }
3694   }
3695 *sptr = s;
3696 return x;
3697 }
3698
3699
3700 static int_eximarith_t
3701 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3702 {
3703 uschar *s = *sptr;
3704 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3705 if (*error == NULL)
3706   {
3707   while ((*s == '<' || *s == '>') && s[1] == s[0])
3708     {
3709     int_eximarith_t y;
3710     int op = *s++;
3711     s++;
3712     y = eval_op_sum(&s, decimal, error);
3713     if (*error != NULL) break;
3714     if (op == '<') x <<= y; else x >>= y;
3715     }
3716   }
3717 *sptr = s;
3718 return x;
3719 }
3720
3721
3722 static int_eximarith_t
3723 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3724 {
3725 uschar *s = *sptr;
3726 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3727 if (*error == NULL)
3728   {
3729   while (*s == '&')
3730     {
3731     int_eximarith_t y;
3732     s++;
3733     y = eval_op_shift(&s, decimal, error);
3734     if (*error != NULL) break;
3735     x &= y;
3736     }
3737   }
3738 *sptr = s;
3739 return x;
3740 }
3741
3742
3743 static int_eximarith_t
3744 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3745 {
3746 uschar *s = *sptr;
3747 int_eximarith_t x = eval_op_and(&s, decimal, error);
3748 if (*error == NULL)
3749   {
3750   while (*s == '^')
3751     {
3752     int_eximarith_t y;
3753     s++;
3754     y = eval_op_and(&s, decimal, error);
3755     if (*error != NULL) break;
3756     x ^= y;
3757     }
3758   }
3759 *sptr = s;
3760 return x;
3761 }
3762
3763
3764 static int_eximarith_t
3765 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3766 {
3767 uschar *s = *sptr;
3768 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3769 if (*error == NULL)
3770   {
3771   while (*s == '|')
3772     {
3773     int_eximarith_t y;
3774     s++;
3775     y = eval_op_xor(&s, decimal, error);
3776     if (*error != NULL) break;
3777     x |= y;
3778     }
3779   }
3780 *sptr = s;
3781 return x;
3782 }
3783
3784
3785
3786 /*************************************************
3787 *                 Expand string                  *
3788 *************************************************/
3789
3790 /* Returns either an unchanged string, or the expanded string in stacking pool
3791 store. Interpreted sequences are:
3792
3793    \...                    normal escaping rules
3794    $name                   substitutes the variable
3795    ${name}                 ditto
3796    ${op:string}            operates on the expanded string value
3797    ${item{arg1}{arg2}...}  expands the args and then does the business
3798                              some literal args are not enclosed in {}
3799
3800 There are now far too many operators and item types to make it worth listing
3801 them here in detail any more.
3802
3803 We use an internal routine recursively to handle embedded substrings. The
3804 external function follows. The yield is NULL if the expansion failed, and there
3805 are two cases: if something collapsed syntactically, or if "fail" was given
3806 as the action on a lookup failure. These can be distinguised by looking at the
3807 variable expand_string_forcedfail, which is TRUE in the latter case.
3808
3809 The skipping flag is set true when expanding a substring that isn't actually
3810 going to be used (after "if" or "lookup") and it prevents lookups from
3811 happening lower down.
3812
3813 Store usage: At start, a store block of the length of the input plus 64
3814 is obtained. This is expanded as necessary by string_cat(), which might have to
3815 get a new block, or might be able to expand the original. At the end of the
3816 function we can release any store above that portion of the yield block that
3817 was actually used. In many cases this will be optimal.
3818
3819 However: if the first item in the expansion is a variable name or header name,
3820 we reset the store before processing it; if the result is in fresh store, we
3821 use that without copying. This is helpful for expanding strings like
3822 $message_headers which can get very long.
3823
3824 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3825 since resetting the store at the end of the expansion will free store that was
3826 allocated by the plugin code as well as the slop after the expanded string. So
3827 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3828 and, given the acl condition, ${if }. This is an unfortunate consequence of
3829 string expansion becoming too powerful.
3830
3831 Arguments:
3832   string         the string to be expanded
3833   ket_ends       true if expansion is to stop at }
3834   left           if not NULL, a pointer to the first character after the
3835                  expansion is placed here (typically used with ket_ends)
3836   skipping       TRUE for recursive calls when the value isn't actually going
3837                  to be used (to allow for optimisation)
3838   honour_dollar  TRUE if $ is to be expanded,
3839                  FALSE if it's just another character
3840   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3841                  the store.
3842
3843 Returns:         NULL if expansion fails:
3844                    expand_string_forcedfail is set TRUE if failure was forced
3845                    expand_string_message contains a textual error message
3846                  a pointer to the expanded string on success
3847 */
3848
3849 static uschar *
3850 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3851   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3852 {
3853 int ptr = 0;
3854 int size = Ustrlen(string)+ 64;
3855 uschar *yield = store_get(size);
3856 int item_type;
3857 const uschar *s = string;
3858 uschar *save_expand_nstring[EXPAND_MAXN+1];
3859 int save_expand_nlength[EXPAND_MAXN+1];
3860 BOOL resetok = TRUE;
3861
3862 DEBUG(D_expand)
3863   debug_printf("%s: %s\n", skipping ? "   scanning" : "considering", string);
3864
3865 expand_string_forcedfail = FALSE;
3866 expand_string_message = US"";
3867
3868 while (*s != 0)
3869   {
3870   uschar *value;
3871   uschar name[256];
3872
3873   /* \ escapes the next character, which must exist, or else
3874   the expansion fails. There's a special escape, \N, which causes
3875   copying of the subject verbatim up to the next \N. Otherwise,
3876   the escapes are the standard set. */
3877
3878   if (*s == '\\')
3879     {
3880     if (s[1] == 0)
3881       {
3882       expand_string_message = US"\\ at end of string";
3883       goto EXPAND_FAILED;
3884       }
3885
3886     if (s[1] == 'N')
3887       {
3888       const uschar * t = s + 2;
3889       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3890       yield = string_catn(yield, &size, &ptr, t, s - t);
3891       if (*s != 0) s += 2;
3892       }
3893
3894     else
3895       {
3896       uschar ch[1];
3897       ch[0] = string_interpret_escape(&s);
3898       s++;
3899       yield = string_catn(yield, &size, &ptr, ch, 1);
3900       }
3901
3902     continue;
3903     }
3904
3905   /*{*/
3906   /* Anything other than $ is just copied verbatim, unless we are
3907   looking for a terminating } character. */
3908
3909   /*{*/
3910   if (ket_ends && *s == '}') break;
3911
3912   if (*s != '$' || !honour_dollar)
3913     {
3914     yield = string_catn(yield, &size, &ptr, s++, 1);
3915     continue;
3916     }
3917
3918   /* No { after the $ - must be a plain name or a number for string
3919   match variable. There has to be a fudge for variables that are the
3920   names of header fields preceded by "$header_" because header field
3921   names can contain any printing characters except space and colon.
3922   For those that don't like typing this much, "$h_" is a synonym for
3923   "$header_". A non-existent header yields a NULL value; nothing is
3924   inserted. */  /*}*/
3925
3926   if (isalpha((*(++s))))
3927     {
3928     int len;
3929     int newsize = 0;
3930
3931     s = read_name(name, sizeof(name), s, US"_");
3932
3933     /* If this is the first thing to be expanded, release the pre-allocated
3934     buffer. */
3935
3936     if (ptr == 0 && yield != NULL)
3937       {
3938       if (resetok) store_reset(yield);
3939       yield = NULL;
3940       size = 0;
3941       }
3942
3943     /* Header */
3944
3945     if (Ustrncmp(name, "h_", 2) == 0 ||
3946         Ustrncmp(name, "rh_", 3) == 0 ||
3947         Ustrncmp(name, "bh_", 3) == 0 ||
3948         Ustrncmp(name, "header_", 7) == 0 ||
3949         Ustrncmp(name, "rheader_", 8) == 0 ||
3950         Ustrncmp(name, "bheader_", 8) == 0)
3951       {
3952       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3953       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3954       s = read_header_name(name, sizeof(name), s);
3955       value = find_header(name, FALSE, &newsize, want_raw, charset);
3956
3957       /* If we didn't find the header, and the header contains a closing brace
3958       character, this may be a user error where the terminating colon
3959       has been omitted. Set a flag to adjust the error message in this case.
3960       But there is no error here - nothing gets inserted. */
3961
3962       if (value == NULL)
3963         {
3964         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3965         continue;
3966         }
3967       }
3968
3969     /* Variable */
3970
3971     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3972       {
3973       expand_string_message =
3974         string_sprintf("unknown variable name \"%s\"", name);
3975         check_variable_error_message(name);
3976       goto EXPAND_FAILED;
3977       }
3978
3979     /* If the data is known to be in a new buffer, newsize will be set to the
3980     size of that buffer. If this is the first thing in an expansion string,
3981     yield will be NULL; just point it at the new store instead of copying. Many
3982     expansion strings contain just one reference, so this is a useful
3983     optimization, especially for humungous headers. */
3984
3985     len = Ustrlen(value);
3986     if (yield == NULL && newsize != 0)
3987       {
3988       yield = value;
3989       size = newsize;
3990       ptr = len;
3991       }
3992     else yield = string_catn(yield, &size, &ptr, value, len);
3993
3994     continue;
3995     }
3996
3997   if (isdigit(*s))
3998     {
3999     int n;
4000     s = read_cnumber(&n, s);
4001     if (n >= 0 && n <= expand_nmax)
4002       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4003         expand_nlength[n]);
4004     continue;
4005     }
4006
4007   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4008
4009   if (*s != '{')                                                        /*}*/
4010     {
4011     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4012     goto EXPAND_FAILED;
4013     }
4014
4015   /* After { there can be various things, but they all start with
4016   an initial word, except for a number for a string match variable. */
4017
4018   if (isdigit((*(++s))))
4019     {
4020     int n;
4021     s = read_cnumber(&n, s);            /*{*/
4022     if (*s++ != '}')
4023       {                                 /*{*/
4024       expand_string_message = US"} expected after number";
4025       goto EXPAND_FAILED;
4026       }
4027     if (n >= 0 && n <= expand_nmax)
4028       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4029         expand_nlength[n]);
4030     continue;
4031     }
4032
4033   if (!isalpha(*s))
4034     {
4035     expand_string_message = US"letter or digit expected after ${";      /*}*/
4036     goto EXPAND_FAILED;
4037     }
4038
4039   /* Allow "-" in names to cater for substrings with negative
4040   arguments. Since we are checking for known names after { this is
4041   OK. */
4042
4043   s = read_name(name, sizeof(name), s, US"_-");
4044   item_type = chop_match(name, item_table, nelem(item_table));
4045
4046   switch(item_type)
4047     {
4048     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4049     If the ACL returns accept or reject we return content set by "message ="
4050     There is currently no limit on recursion; this would have us call
4051     acl_check_internal() directly and get a current level from somewhere.
4052     See also the acl expansion condition ECOND_ACL and the traditional
4053     acl modifier ACLC_ACL.
4054     Assume that the function has side-effects on the store that must be preserved.
4055     */
4056
4057     case EITEM_ACL:
4058       /* ${acl {name} {arg1}{arg2}...} */
4059       {
4060       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4061       uschar *user_msg;
4062
4063       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4064                       &resetok))
4065         {
4066         case 1: goto EXPAND_FAILED_CURLY;
4067         case 2:
4068         case 3: goto EXPAND_FAILED;
4069         }
4070       if (skipping) continue;
4071
4072       resetok = FALSE;
4073       switch(eval_acl(sub, nelem(sub), &user_msg))
4074         {
4075         case OK:
4076         case FAIL:
4077           DEBUG(D_expand)
4078             debug_printf("acl expansion yield: %s\n", user_msg);
4079           if (user_msg)
4080             yield = string_cat(yield, &size, &ptr, user_msg);
4081           continue;
4082
4083         case DEFER:
4084           expand_string_forcedfail = TRUE;
4085           /*FALLTHROUGH*/
4086         default:
4087           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4088           goto EXPAND_FAILED;
4089         }
4090       }
4091
4092     /* Handle conditionals - preserve the values of the numerical expansion
4093     variables in case they get changed by a regular expression match in the
4094     condition. If not, they retain their external settings. At the end
4095     of this "if" section, they get restored to their previous values. */
4096
4097     case EITEM_IF:
4098       {
4099       BOOL cond = FALSE;
4100       const uschar *next_s;
4101       int save_expand_nmax =
4102         save_expand_strings(save_expand_nstring, save_expand_nlength);
4103
4104       while (isspace(*s)) s++;
4105       next_s = eval_condition(s, &resetok, skipping? NULL : &cond);
4106       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4107
4108       DEBUG(D_expand)
4109         debug_printf("condition: %.*s\n   result: %s\n", (int)(next_s - s), s,
4110           cond? "true" : "false");
4111
4112       s = next_s;
4113
4114       /* The handling of "yes" and "no" result strings is now in a separate
4115       function that is also used by ${lookup} and ${extract} and ${run}. */
4116
4117       switch(process_yesno(
4118                skipping,                     /* were previously skipping */
4119                cond,                         /* success/failure indicator */
4120                lookup_value,                 /* value to reset for string2 */
4121                &s,                           /* input pointer */
4122                &yield,                       /* output pointer */
4123                &size,                        /* output size */
4124                &ptr,                         /* output current point */
4125                US"if",                       /* condition type */
4126                &resetok))
4127         {
4128         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4129         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4130         }
4131
4132       /* Restore external setting of expansion variables for continuation
4133       at this level. */
4134
4135       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4136         save_expand_nlength);
4137       continue;
4138       }
4139
4140 #ifdef SUPPORT_I18N
4141     case EITEM_IMAPFOLDER:
4142       {                         /* ${imapfolder {name}{sep]{specials}} */
4143       uschar *sub_arg[3];
4144       uschar *encoded;
4145
4146       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4147                       &resetok))
4148         {
4149         case 1: goto EXPAND_FAILED_CURLY;
4150         case 2:
4151         case 3: goto EXPAND_FAILED;
4152         }
4153
4154       if (sub_arg[1] == NULL)           /* One argument */
4155         {
4156         sub_arg[1] = US"/";             /* default separator */
4157         sub_arg[2] = NULL;
4158         }
4159       else if (Ustrlen(sub_arg[1]) != 1)
4160         {
4161         expand_string_message =
4162           string_sprintf(
4163                 "IMAP folder separator must be one character, found \"%s\"",
4164                 sub_arg[1]);
4165         goto EXPAND_FAILED;
4166         }
4167
4168       if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4169                           sub_arg[1][0], sub_arg[2], &expand_string_message)))
4170         goto EXPAND_FAILED;
4171       if (!skipping)
4172         yield = string_cat(yield, &size, &ptr, encoded);
4173       continue;
4174       }
4175 #endif
4176
4177     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4178     expanding an internal string that isn't actually going to be used. All we
4179     need to do is check the syntax, so don't do a lookup at all. Preserve the
4180     values of the numerical expansion variables in case they get changed by a
4181     partial lookup. If not, they retain their external settings. At the end
4182     of this "lookup" section, they get restored to their previous values. */
4183
4184     case EITEM_LOOKUP:
4185       {
4186       int stype, partial, affixlen, starflags;
4187       int expand_setup = 0;
4188       int nameptr = 0;
4189       uschar *key, *filename;
4190       const uschar *affix;
4191       uschar *save_lookup_value = lookup_value;
4192       int save_expand_nmax =
4193         save_expand_strings(save_expand_nstring, save_expand_nlength);
4194
4195       if ((expand_forbid & RDO_LOOKUP) != 0)
4196         {
4197         expand_string_message = US"lookup expansions are not permitted";
4198         goto EXPAND_FAILED;
4199         }
4200
4201       /* Get the key we are to look up for single-key+file style lookups.
4202       Otherwise set the key NULL pro-tem. */
4203
4204       while (isspace(*s)) s++;
4205       if (*s == '{')                                    /*}*/
4206         {
4207         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4208         if (!key) goto EXPAND_FAILED;                   /*{{*/
4209         if (*s++ != '}')
4210           {
4211           expand_string_message = US"missing '}' after lookup key";
4212           goto EXPAND_FAILED_CURLY;
4213           }
4214         while (isspace(*s)) s++;
4215         }
4216       else key = NULL;
4217
4218       /* Find out the type of database */
4219
4220       if (!isalpha(*s))
4221         {
4222         expand_string_message = US"missing lookup type";
4223         goto EXPAND_FAILED;
4224         }
4225
4226       /* The type is a string that may contain special characters of various
4227       kinds. Allow everything except space or { to appear; the actual content
4228       is checked by search_findtype_partial. */         /*}*/
4229
4230       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4231         {
4232         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4233         s++;
4234         }
4235       name[nameptr] = 0;
4236       while (isspace(*s)) s++;
4237
4238       /* Now check for the individual search type and any partial or default
4239       options. Only those types that are actually in the binary are valid. */
4240
4241       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4242         &starflags);
4243       if (stype < 0)
4244         {
4245         expand_string_message = search_error_message;
4246         goto EXPAND_FAILED;
4247         }
4248
4249       /* Check that a key was provided for those lookup types that need it,
4250       and was not supplied for those that use the query style. */
4251
4252       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4253         {
4254         if (key == NULL)
4255           {
4256           expand_string_message = string_sprintf("missing {key} for single-"
4257             "key \"%s\" lookup", name);
4258           goto EXPAND_FAILED;
4259           }
4260         }
4261       else
4262         {
4263         if (key != NULL)
4264           {
4265           expand_string_message = string_sprintf("a single key was given for "
4266             "lookup type \"%s\", which is not a single-key lookup type", name);
4267           goto EXPAND_FAILED;
4268           }
4269         }
4270
4271       /* Get the next string in brackets and expand it. It is the file name for
4272       single-key+file lookups, and the whole query otherwise. In the case of
4273       queries that also require a file name (e.g. sqlite), the file name comes
4274       first. */
4275
4276       if (*s != '{')
4277         {
4278         expand_string_message = US"missing '{' for lookup file-or-query arg";
4279         goto EXPAND_FAILED_CURLY;
4280         }
4281       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4282       if (filename == NULL) goto EXPAND_FAILED;
4283       if (*s++ != '}')
4284         {
4285         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4286         goto EXPAND_FAILED_CURLY;
4287         }
4288       while (isspace(*s)) s++;
4289
4290       /* If this isn't a single-key+file lookup, re-arrange the variables
4291       to be appropriate for the search_ functions. For query-style lookups,
4292       there is just a "key", and no file name. For the special query-style +
4293       file types, the query (i.e. "key") starts with a file name. */
4294
4295       if (!key)
4296         {
4297         while (isspace(*filename)) filename++;
4298         key = filename;
4299
4300         if (mac_islookup(stype, lookup_querystyle))
4301           filename = NULL;
4302         else
4303           {
4304           if (*filename != '/')
4305             {
4306             expand_string_message = string_sprintf(
4307               "absolute file name expected for \"%s\" lookup", name);
4308             goto EXPAND_FAILED;
4309             }
4310           while (*key != 0 && !isspace(*key)) key++;
4311           if (*key != 0) *key++ = 0;
4312           }
4313         }
4314
4315       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4316       the entry was not found. Note that there is no search_close() function.
4317       Files are left open in case of re-use. At suitable places in higher logic,
4318       search_tidyup() is called to tidy all open files. This can save opening
4319       the same file several times. However, files may also get closed when
4320       others are opened, if too many are open at once. The rule is that a
4321       handle should not be used after a second search_open().
4322
4323       Request that a partial search sets up $1 and maybe $2 by passing
4324       expand_setup containing zero. If its value changes, reset expand_nmax,
4325       since new variables will have been set. Note that at the end of this
4326       "lookup" section, the old numeric variables are restored. */
4327
4328       if (skipping)
4329         lookup_value = NULL;
4330       else
4331         {
4332         void *handle = search_open(filename, stype, 0, NULL, NULL);
4333         if (handle == NULL)
4334           {
4335           expand_string_message = search_error_message;
4336           goto EXPAND_FAILED;
4337           }
4338         lookup_value = search_find(handle, filename, key, partial, affix,
4339           affixlen, starflags, &expand_setup);
4340         if (search_find_defer)
4341           {
4342           expand_string_message =
4343             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4344               string_printing2(key, FALSE), search_error_message);
4345           goto EXPAND_FAILED;
4346           }
4347         if (expand_setup > 0) expand_nmax = expand_setup;
4348         }
4349
4350       /* The handling of "yes" and "no" result strings is now in a separate
4351       function that is also used by ${if} and ${extract}. */
4352
4353       switch(process_yesno(
4354                skipping,                     /* were previously skipping */
4355                lookup_value != NULL,         /* success/failure indicator */
4356                save_lookup_value,            /* value to reset for string2 */
4357                &s,                           /* input pointer */
4358                &yield,                       /* output pointer */
4359                &size,                        /* output size */
4360                &ptr,                         /* output current point */
4361                US"lookup",                   /* condition type */
4362                &resetok))
4363         {
4364         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4365         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4366         }
4367
4368       /* Restore external setting of expansion variables for carrying on
4369       at this level, and continue. */
4370
4371       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4372         save_expand_nlength);
4373       continue;
4374       }
4375
4376     /* If Perl support is configured, handle calling embedded perl subroutines,
4377     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4378     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4379     arguments (defined below). */
4380
4381     #define EXIM_PERL_MAX_ARGS 8
4382
4383     case EITEM_PERL:
4384     #ifndef EXIM_PERL
4385     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4386       "is not included in this binary";
4387     goto EXPAND_FAILED;
4388
4389     #else   /* EXIM_PERL */
4390       {
4391       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4392       uschar *new_yield;
4393
4394       if ((expand_forbid & RDO_PERL) != 0)
4395         {
4396         expand_string_message = US"Perl calls are not permitted";
4397         goto EXPAND_FAILED;
4398         }
4399
4400       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4401            US"perl", &resetok))
4402         {
4403         case 1: goto EXPAND_FAILED_CURLY;
4404         case 2:
4405         case 3: goto EXPAND_FAILED;
4406         }
4407
4408       /* If skipping, we don't actually do anything */
4409
4410       if (skipping) continue;
4411
4412       /* Start the interpreter if necessary */
4413
4414       if (!opt_perl_started)
4415         {
4416         uschar *initerror;
4417         if (opt_perl_startup == NULL)
4418           {
4419           expand_string_message = US"A setting of perl_startup is needed when "
4420             "using the Perl interpreter";
4421           goto EXPAND_FAILED;
4422           }
4423         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4424         initerror = init_perl(opt_perl_startup);
4425         if (initerror != NULL)
4426           {
4427           expand_string_message =
4428             string_sprintf("error in perl_startup code: %s\n", initerror);
4429           goto EXPAND_FAILED;
4430           }
4431         opt_perl_started = TRUE;
4432         }
4433
4434       /* Call the function */
4435
4436       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4437       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4438         sub_arg[0], sub_arg + 1);
4439
4440       /* NULL yield indicates failure; if the message pointer has been set to
4441       NULL, the yield was undef, indicating a forced failure. Otherwise the
4442       message will indicate some kind of Perl error. */
4443
4444       if (new_yield == NULL)
4445         {
4446         if (expand_string_message == NULL)
4447           {
4448           expand_string_message =
4449             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4450               "failure", sub_arg[0]);
4451           expand_string_forcedfail = TRUE;
4452           }
4453         goto EXPAND_FAILED;
4454         }
4455
4456       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4457       set during a callback from Perl. */
4458
4459       expand_string_forcedfail = FALSE;
4460       yield = new_yield;
4461       continue;
4462       }
4463     #endif /* EXIM_PERL */
4464
4465     /* Transform email address to "prvs" scheme to use
4466        as BATV-signed return path */
4467
4468     case EITEM_PRVS:
4469       {
4470       uschar *sub_arg[3];
4471       uschar *p,*domain;
4472
4473       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4474         {
4475         case 1: goto EXPAND_FAILED_CURLY;
4476         case 2:
4477         case 3: goto EXPAND_FAILED;
4478         }
4479
4480       /* If skipping, we don't actually do anything */
4481       if (skipping) continue;
4482
4483       /* sub_arg[0] is the address */
4484       domain = Ustrrchr(sub_arg[0],'@');
4485       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4486         {
4487         expand_string_message = US"prvs first argument must be a qualified email address";
4488         goto EXPAND_FAILED;
4489         }
4490
4491       /* Calculate the hash. The second argument must be a single-digit
4492       key number, or unset. */
4493
4494       if (sub_arg[2] != NULL &&
4495           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4496         {
4497         expand_string_message = US"prvs second argument must be a single digit";
4498         goto EXPAND_FAILED;
4499         }
4500
4501       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4502       if (p == NULL)
4503         {
4504         expand_string_message = US"prvs hmac-sha1 conversion failed";
4505         goto EXPAND_FAILED;
4506         }
4507
4508       /* Now separate the domain from the local part */
4509       *domain++ = '\0';
4510
4511       yield = string_catn(yield, &size, &ptr, US"prvs=", 5);
4512       yield = string_catn(yield, &size, &ptr, sub_arg[2] ? sub_arg[2] : US"0", 1);
4513       yield = string_catn(yield, &size, &ptr, prvs_daystamp(7), 3);
4514       yield = string_catn(yield, &size, &ptr, p, 6);
4515       yield = string_catn(yield, &size, &ptr, US"=", 1);
4516       yield = string_cat (yield, &size, &ptr, sub_arg[0]);
4517       yield = string_catn(yield, &size, &ptr, US"@", 1);
4518       yield = string_cat (yield, &size, &ptr, domain);
4519
4520       continue;
4521       }
4522
4523     /* Check a prvs-encoded address for validity */
4524
4525     case EITEM_PRVSCHECK:
4526       {
4527       uschar *sub_arg[3];
4528       int mysize = 0, myptr = 0;
4529       const pcre *re;
4530       uschar *p;
4531
4532       /* TF: Ugliness: We want to expand parameter 1 first, then set
4533          up expansion variables that are used in the expansion of
4534          parameter 2. So we clone the string for the first
4535          expansion, where we only expand parameter 1.
4536
4537          PH: Actually, that isn't necessary. The read_subs() function is
4538          designed to work this way for the ${if and ${lookup expansions. I've
4539          tidied the code.
4540       */
4541
4542       /* Reset expansion variables */
4543       prvscheck_result = NULL;
4544       prvscheck_address = NULL;
4545       prvscheck_keynum = NULL;
4546
4547       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4548         {
4549         case 1: goto EXPAND_FAILED_CURLY;
4550         case 2:
4551         case 3: goto EXPAND_FAILED;
4552         }
4553
4554       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4555                               TRUE,FALSE);
4556
4557       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4558         {
4559         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4560         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4561         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4562         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4563         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4564
4565         DEBUG(D_expand) debug_printf("prvscheck localpart: %s\n", local_part);
4566         DEBUG(D_expand) debug_printf("prvscheck key number: %s\n", key_num);
4567         DEBUG(D_expand) debug_printf("prvscheck daystamp: %s\n", daystamp);
4568         DEBUG(D_expand) debug_printf("prvscheck hash: %s\n", hash);
4569         DEBUG(D_expand) debug_printf("prvscheck domain: %s\n", domain);
4570
4571         /* Set up expansion variables */
4572         prvscheck_address = string_cat (NULL, &mysize, &myptr, local_part);
4573         prvscheck_address = string_catn(prvscheck_address, &mysize, &myptr, US"@", 1);
4574         prvscheck_address = string_cat (prvscheck_address, &mysize, &myptr, domain);
4575         prvscheck_address[myptr] = '\0';
4576         prvscheck_keynum = string_copy(key_num);
4577
4578         /* Now expand the second argument */
4579         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4580           {
4581           case 1: goto EXPAND_FAILED_CURLY;
4582           case 2:
4583           case 3: goto EXPAND_FAILED;
4584           }
4585
4586         /* Now we have the key and can check the address. */
4587
4588         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4589           daystamp);
4590
4591         if (p == NULL)
4592           {
4593           expand_string_message = US"hmac-sha1 conversion failed";
4594           goto EXPAND_FAILED;
4595           }
4596
4597         DEBUG(D_expand) debug_printf("prvscheck: received hash is %s\n", hash);
4598         DEBUG(D_expand) debug_printf("prvscheck:      own hash is %s\n", p);
4599
4600         if (Ustrcmp(p,hash) == 0)
4601           {
4602           /* Success, valid BATV address. Now check the expiry date. */
4603           uschar *now = prvs_daystamp(0);
4604           unsigned int inow = 0,iexpire = 1;
4605
4606           (void)sscanf(CS now,"%u",&inow);
4607           (void)sscanf(CS daystamp,"%u",&iexpire);
4608
4609           /* When "iexpire" is < 7, a "flip" has occured.
4610              Adjust "inow" accordingly. */
4611           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4612
4613           if (iexpire >= inow)
4614             {
4615             prvscheck_result = US"1";
4616             DEBUG(D_expand) debug_printf("prvscheck: success, $pvrs_result set to 1\n");
4617             }
4618             else
4619             {
4620             prvscheck_result = NULL;
4621             DEBUG(D_expand) debug_printf("prvscheck: signature expired, $pvrs_result unset\n");
4622             }
4623           }
4624         else
4625           {
4626           prvscheck_result = NULL;
4627           DEBUG(D_expand) debug_printf("prvscheck: hash failure, $pvrs_result unset\n");
4628           }
4629
4630         /* Now expand the final argument. We leave this till now so that
4631         it can include $prvscheck_result. */
4632
4633         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4634           {
4635           case 1: goto EXPAND_FAILED_CURLY;
4636           case 2:
4637           case 3: goto EXPAND_FAILED;
4638           }
4639
4640         yield = string_cat(yield, &size, &ptr,
4641           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4642
4643         /* Reset the "internal" variables afterwards, because they are in
4644         dynamic store that will be reclaimed if the expansion succeeded. */
4645
4646         prvscheck_address = NULL;
4647         prvscheck_keynum = NULL;
4648         }
4649       else
4650         {
4651         /* Does not look like a prvs encoded address, return the empty string.
4652            We need to make sure all subs are expanded first, so as to skip over
4653            the entire item. */
4654
4655         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4656           {
4657           case 1: goto EXPAND_FAILED_CURLY;
4658           case 2:
4659           case 3: goto EXPAND_FAILED;
4660           }
4661         }
4662
4663       continue;
4664       }
4665
4666     /* Handle "readfile" to insert an entire file */
4667
4668     case EITEM_READFILE:
4669       {
4670       FILE *f;
4671       uschar *sub_arg[2];
4672
4673       if ((expand_forbid & RDO_READFILE) != 0)
4674         {
4675         expand_string_message = US"file insertions are not permitted";
4676         goto EXPAND_FAILED;
4677         }
4678
4679       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4680         {
4681         case 1: goto EXPAND_FAILED_CURLY;
4682         case 2:
4683         case 3: goto EXPAND_FAILED;
4684         }
4685
4686       /* If skipping, we don't actually do anything */
4687
4688       if (skipping) continue;
4689
4690       /* Open the file and read it */
4691
4692       f = Ufopen(sub_arg[0], "rb");
4693       if (f == NULL)
4694         {
4695         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4696         goto EXPAND_FAILED;
4697         }
4698
4699       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4700       (void)fclose(f);
4701       continue;
4702       }
4703
4704     /* Handle "readsocket" to insert data from a Unix domain socket */
4705
4706     case EITEM_READSOCK:
4707       {
4708       int fd;
4709       int timeout = 5;
4710       int save_ptr = ptr;
4711       FILE *f;
4712       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4713       uschar *arg;
4714       uschar *sub_arg[4];
4715
4716       if ((expand_forbid & RDO_READSOCK) != 0)
4717         {
4718         expand_string_message = US"socket insertions are not permitted";
4719         goto EXPAND_FAILED;
4720         }
4721
4722       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4723       because there may be a string for expansion on failure. */
4724
4725       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4726         {
4727         case 1: goto EXPAND_FAILED_CURLY;
4728         case 2:                             /* Won't occur: no end check */
4729         case 3: goto EXPAND_FAILED;
4730         }
4731
4732       /* Sort out timeout, if given */
4733
4734       if (sub_arg[2] != NULL)
4735         {
4736         timeout = readconf_readtime(sub_arg[2], 0, FALSE);
4737         if (timeout < 0)
4738           {
4739           expand_string_message = string_sprintf("bad time value %s",
4740             sub_arg[2]);
4741           goto EXPAND_FAILED;
4742           }
4743         }
4744       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4745
4746       /* If skipping, we don't actually do anything. Otherwise, arrange to
4747       connect to either an IP or a Unix socket. */
4748
4749       if (!skipping)
4750         {
4751         /* Handle an IP (internet) domain */
4752
4753         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4754           {
4755           int port;
4756           uschar *server_name = sub_arg[0] + 5;
4757           uschar *port_name = Ustrrchr(server_name, ':');
4758
4759           /* Sort out the port */
4760
4761           if (port_name == NULL)
4762             {
4763             expand_string_message =
4764               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4765             goto EXPAND_FAILED;
4766             }
4767           *port_name++ = 0;           /* Terminate server name */
4768
4769           if (isdigit(*port_name))
4770             {
4771             uschar *end;
4772             port = Ustrtol(port_name, &end, 0);
4773             if (end != port_name + Ustrlen(port_name))
4774               {
4775               expand_string_message =
4776                 string_sprintf("invalid port number %s", port_name);
4777               goto EXPAND_FAILED;
4778               }
4779             }
4780           else
4781             {
4782             struct servent *service_info = getservbyname(CS port_name, "tcp");
4783             if (service_info == NULL)
4784               {
4785               expand_string_message = string_sprintf("unknown port \"%s\"",
4786                 port_name);
4787               goto EXPAND_FAILED;
4788               }
4789             port = ntohs(service_info->s_port);
4790             }
4791
4792           if ((fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4793                   timeout, NULL, &expand_string_message)) < 0)
4794               goto SOCK_FAIL;
4795           }
4796
4797         /* Handle a Unix domain socket */
4798
4799         else
4800           {
4801           int rc;
4802           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4803             {
4804             expand_string_message = string_sprintf("failed to create socket: %s",
4805               strerror(errno));
4806             goto SOCK_FAIL;
4807             }
4808
4809           sockun.sun_family = AF_UNIX;
4810           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4811             sub_arg[0]);
4812
4813           sigalrm_seen = FALSE;
4814           alarm(timeout);
4815           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4816           alarm(0);
4817           if (sigalrm_seen)
4818             {
4819             expand_string_message = US "socket connect timed out";
4820             goto SOCK_FAIL;
4821             }
4822           if (rc < 0)
4823             {
4824             expand_string_message = string_sprintf("failed to connect to socket "
4825               "%s: %s", sub_arg[0], strerror(errno));
4826             goto SOCK_FAIL;
4827             }
4828           }
4829
4830         DEBUG(D_expand) debug_printf("connected to socket %s\n", sub_arg[0]);
4831
4832         /* Allow sequencing of test actions */
4833         if (running_in_test_harness) millisleep(100);
4834
4835         /* Write the request string, if not empty */
4836
4837         if (sub_arg[1][0] != 0)
4838           {
4839           int len = Ustrlen(sub_arg[1]);
4840           DEBUG(D_expand) debug_printf("writing \"%s\" to socket\n",
4841             sub_arg[1]);
4842           if (write(fd, sub_arg[1], len) != len)
4843             {
4844             expand_string_message = string_sprintf("request write to socket "
4845               "failed: %s", strerror(errno));
4846             goto SOCK_FAIL;
4847             }
4848           }
4849
4850         /* Shut down the sending side of the socket. This helps some servers to
4851         recognise that it is their turn to do some work. Just in case some
4852         system doesn't have this function, make it conditional. */
4853
4854         #ifdef SHUT_WR
4855         shutdown(fd, SHUT_WR);
4856         #endif
4857
4858         if (running_in_test_harness) millisleep(100);
4859
4860         /* Now we need to read from the socket, under a timeout. The function
4861         that reads a file can be used. */
4862
4863         f = fdopen(fd, "rb");
4864         sigalrm_seen = FALSE;
4865         alarm(timeout);
4866         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4867         alarm(0);
4868         (void)fclose(f);
4869
4870         /* After a timeout, we restore the pointer in the result, that is,
4871         make sure we add nothing from the socket. */
4872
4873         if (sigalrm_seen)
4874           {
4875           ptr = save_ptr;
4876           expand_string_message = US "socket read timed out";
4877           goto SOCK_FAIL;
4878           }
4879         }
4880
4881       /* The whole thing has worked (or we were skipping). If there is a
4882       failure string following, we need to skip it. */
4883
4884       if (*s == '{')
4885         {
4886         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4887           goto EXPAND_FAILED;
4888         if (*s++ != '}')
4889           {
4890           expand_string_message = US"missing '}' closing failstring for readsocket";
4891           goto EXPAND_FAILED_CURLY;
4892           }
4893         while (isspace(*s)) s++;
4894         }
4895
4896     readsock_done:
4897       if (*s++ != '}')
4898         {
4899         expand_string_message = US"missing '}' closing readsocket";
4900         goto EXPAND_FAILED_CURLY;
4901         }
4902       continue;
4903
4904       /* Come here on failure to create socket, connect socket, write to the
4905       socket, or timeout on reading. If another substring follows, expand and
4906       use it. Otherwise, those conditions give expand errors. */
4907
4908       SOCK_FAIL:
4909       if (*s != '{') goto EXPAND_FAILED;
4910       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4911       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4912         goto EXPAND_FAILED;
4913       yield = string_cat(yield, &size, &ptr, arg);
4914       if (*s++ != '}')
4915         {
4916         expand_string_message = US"missing '}' closing failstring for readsocket";
4917         goto EXPAND_FAILED_CURLY;
4918         }
4919       while (isspace(*s)) s++;
4920       goto readsock_done;
4921       }
4922
4923     /* Handle "run" to execute a program. */
4924
4925     case EITEM_RUN:
4926       {
4927       FILE *f;
4928       uschar *arg;
4929       const uschar **argv;
4930       pid_t pid;
4931       int fd_in, fd_out;
4932       int lsize = 0, lptr = 0;
4933
4934       if ((expand_forbid & RDO_RUN) != 0)
4935         {
4936         expand_string_message = US"running a command is not permitted";
4937         goto EXPAND_FAILED;
4938         }
4939
4940       while (isspace(*s)) s++;
4941       if (*s != '{')
4942         {
4943         expand_string_message = US"missing '{' for command arg of run";
4944         goto EXPAND_FAILED_CURLY;
4945         }
4946       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4947       if (arg == NULL) goto EXPAND_FAILED;
4948       while (isspace(*s)) s++;
4949       if (*s++ != '}')
4950         {
4951         expand_string_message = US"missing '}' closing command arg of run";
4952         goto EXPAND_FAILED_CURLY;
4953         }
4954
4955       if (skipping)   /* Just pretend it worked when we're skipping */
4956         runrc = 0;
4957       else
4958         {
4959         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4960             arg,                                /* raw command */
4961             FALSE,                              /* don't expand the arguments */
4962             0,                                  /* not relevant when... */
4963             NULL,                               /* no transporting address */
4964             US"${run} expansion",               /* for error messages */
4965             &expand_string_message))            /* where to put error message */
4966           goto EXPAND_FAILED;
4967
4968         /* Create the child process, making it a group leader. */
4969
4970         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
4971           {
4972           expand_string_message =
4973             string_sprintf("couldn't create child process: %s", strerror(errno));
4974           goto EXPAND_FAILED;
4975           }
4976
4977         /* Nothing is written to the standard input. */
4978
4979         (void)close(fd_in);
4980
4981         /* Read the pipe to get the command's output into $value (which is kept
4982         in lookup_value). Read during execution, so that if the output exceeds
4983         the OS pipe buffer limit, we don't block forever. Remember to not release
4984         memory just allocated for $value. */
4985
4986         resetok = FALSE;
4987         f = fdopen(fd_out, "rb");
4988         sigalrm_seen = FALSE;
4989         alarm(60);
4990         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
4991         alarm(0);
4992         (void)fclose(f);
4993
4994         /* Wait for the process to finish, applying the timeout, and inspect its
4995         return code for serious disasters. Simple non-zero returns are passed on.
4996         */
4997
4998         if (sigalrm_seen == TRUE || (runrc = child_close(pid, 30)) < 0)
4999           {
5000           if (sigalrm_seen == TRUE || runrc == -256)
5001             {
5002             expand_string_message = string_sprintf("command timed out");
5003             killpg(pid, SIGKILL);       /* Kill the whole process group */
5004             }
5005
5006           else if (runrc == -257)
5007             expand_string_message = string_sprintf("wait() failed: %s",
5008               strerror(errno));
5009
5010           else
5011             expand_string_message = string_sprintf("command killed by signal %d",
5012               -runrc);
5013
5014           goto EXPAND_FAILED;
5015           }
5016         }
5017
5018       /* Process the yes/no strings; $value may be useful in both cases */
5019
5020       switch(process_yesno(
5021                skipping,                     /* were previously skipping */
5022                runrc == 0,                   /* success/failure indicator */
5023                lookup_value,                 /* value to reset for string2 */
5024                &s,                           /* input pointer */
5025                &yield,                       /* output pointer */
5026                &size,                        /* output size */
5027                &ptr,                         /* output current point */
5028                US"run",                      /* condition type */
5029                &resetok))
5030         {
5031         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5032         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5033         }
5034
5035       continue;
5036       }
5037
5038     /* Handle character translation for "tr" */
5039
5040     case EITEM_TR:
5041       {
5042       int oldptr = ptr;
5043       int o2m;
5044       uschar *sub[3];
5045
5046       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5047         {
5048         case 1: goto EXPAND_FAILED_CURLY;
5049         case 2:
5050         case 3: goto EXPAND_FAILED;
5051         }
5052
5053       yield = string_cat(yield, &size, &ptr, sub[0]);
5054       o2m = Ustrlen(sub[2]) - 1;
5055
5056       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
5057         {
5058         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
5059         if (m != NULL)
5060           {
5061           int o = m - sub[1];
5062           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5063           }
5064         }
5065
5066       continue;
5067       }
5068
5069     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5070     expanded arguments. */
5071
5072     case EITEM_HASH:
5073     case EITEM_LENGTH:
5074     case EITEM_NHASH:
5075     case EITEM_SUBSTR:
5076       {
5077       int i;
5078       int len;
5079       uschar *ret;
5080       int val[2] = { 0, -1 };
5081       uschar *sub[3];
5082
5083       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5084       Ensure that sub[2] is set in the ${length } case. */
5085
5086       sub[2] = NULL;
5087       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5088              TRUE, name, &resetok))
5089         {
5090         case 1: goto EXPAND_FAILED_CURLY;
5091         case 2:
5092         case 3: goto EXPAND_FAILED;
5093         }
5094
5095       /* Juggle the arguments if there are only two of them: always move the
5096       string to the last position and make ${length{n}{str}} equivalent to
5097       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5098
5099       if (sub[2] == NULL)
5100         {
5101         sub[2] = sub[1];
5102         sub[1] = NULL;
5103         if (item_type == EITEM_LENGTH)
5104           {
5105           sub[1] = sub[0];
5106           sub[0] = NULL;
5107           }
5108         }
5109
5110       for (i = 0; i < 2; i++)
5111         {
5112         if (sub[i] == NULL) continue;
5113         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5114         if (*ret != 0 || (i != 0 && val[i] < 0))
5115           {
5116           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5117             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5118           goto EXPAND_FAILED;
5119           }
5120         }
5121
5122       ret =
5123         (item_type == EITEM_HASH)?
5124           compute_hash(sub[2], val[0], val[1], &len) :
5125         (item_type == EITEM_NHASH)?
5126           compute_nhash(sub[2], val[0], val[1], &len) :
5127           extract_substr(sub[2], val[0], val[1], &len);
5128
5129       if (ret == NULL) goto EXPAND_FAILED;
5130       yield = string_catn(yield, &size, &ptr, ret, len);
5131       continue;
5132       }
5133
5134     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5135     This code originally contributed by Steve Haslam. It currently supports
5136     the use of MD5 and SHA-1 hashes.
5137
5138     We need some workspace that is large enough to handle all the supported
5139     hash types. Use macros to set the sizes rather than be too elaborate. */
5140
5141     #define MAX_HASHLEN      20
5142     #define MAX_HASHBLOCKLEN 64
5143
5144     case EITEM_HMAC:
5145       {
5146       uschar *sub[3];
5147       md5 md5_base;
5148       sha1 sha1_base;
5149       void *use_base;
5150       int type, i;
5151       int hashlen;      /* Number of octets for the hash algorithm's output */
5152       int hashblocklen; /* Number of octets the hash algorithm processes */
5153       uschar *keyptr, *p;
5154       unsigned int keylen;
5155
5156       uschar keyhash[MAX_HASHLEN];
5157       uschar innerhash[MAX_HASHLEN];
5158       uschar finalhash[MAX_HASHLEN];
5159       uschar finalhash_hex[2*MAX_HASHLEN];
5160       uschar innerkey[MAX_HASHBLOCKLEN];
5161       uschar outerkey[MAX_HASHBLOCKLEN];
5162
5163       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5164         {
5165         case 1: goto EXPAND_FAILED_CURLY;
5166         case 2:
5167         case 3: goto EXPAND_FAILED;
5168         }
5169
5170       if (Ustrcmp(sub[0], "md5") == 0)
5171         {
5172         type = HMAC_MD5;
5173         use_base = &md5_base;
5174         hashlen = 16;
5175         hashblocklen = 64;
5176         }
5177       else if (Ustrcmp(sub[0], "sha1") == 0)
5178         {
5179         type = HMAC_SHA1;
5180         use_base = &sha1_base;
5181         hashlen = 20;
5182         hashblocklen = 64;
5183         }
5184       else
5185         {
5186         expand_string_message =
5187           string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5188         goto EXPAND_FAILED;
5189         }
5190
5191       keyptr = sub[1];
5192       keylen = Ustrlen(keyptr);
5193
5194       /* If the key is longer than the hash block length, then hash the key
5195       first */
5196
5197       if (keylen > hashblocklen)
5198         {
5199         chash_start(type, use_base);
5200         chash_end(type, use_base, keyptr, keylen, keyhash);
5201         keyptr = keyhash;
5202         keylen = hashlen;
5203         }
5204
5205       /* Now make the inner and outer key values */
5206
5207       memset(innerkey, 0x36, hashblocklen);
5208       memset(outerkey, 0x5c, hashblocklen);
5209
5210       for (i = 0; i < keylen; i++)
5211         {
5212         innerkey[i] ^= keyptr[i];
5213         outerkey[i] ^= keyptr[i];
5214         }
5215
5216       /* Now do the hashes */
5217
5218       chash_start(type, use_base);
5219       chash_mid(type, use_base, innerkey);
5220       chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5221
5222       chash_start(type, use_base);
5223       chash_mid(type, use_base, outerkey);
5224       chash_end(type, use_base, innerhash, hashlen, finalhash);
5225
5226       /* Encode the final hash as a hex string */
5227
5228       p = finalhash_hex;
5229       for (i = 0; i < hashlen; i++)
5230         {
5231         *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5232         *p++ = hex_digits[finalhash[i] & 0x0f];
5233         }
5234
5235       DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%.*s)=%.*s\n", sub[0],
5236         (int)keylen, keyptr, Ustrlen(sub[2]), sub[2], hashlen*2, finalhash_hex);
5237
5238       yield = string_catn(yield, &size, &ptr, finalhash_hex, hashlen*2);
5239       }
5240
5241     continue;
5242
5243     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5244     We have to save the numerical variables and restore them afterwards. */
5245
5246     case EITEM_SG:
5247       {
5248       const pcre *re;
5249       int moffset, moffsetextra, slen;
5250       int roffset;
5251       int emptyopt;
5252       const uschar *rerror;
5253       uschar *subject;
5254       uschar *sub[3];
5255       int save_expand_nmax =
5256         save_expand_strings(save_expand_nstring, save_expand_nlength);
5257
5258       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5259         {
5260         case 1: goto EXPAND_FAILED_CURLY;
5261         case 2:
5262         case 3: goto EXPAND_FAILED;
5263         }
5264
5265       /* Compile the regular expression */
5266
5267       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5268         NULL);
5269
5270       if (re == NULL)
5271         {
5272         expand_string_message = string_sprintf("regular expression error in "
5273           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5274         goto EXPAND_FAILED;
5275         }
5276
5277       /* Now run a loop to do the substitutions as often as necessary. It ends
5278       when there are no more matches. Take care over matches of the null string;
5279       do the same thing as Perl does. */
5280
5281       subject = sub[0];
5282       slen = Ustrlen(sub[0]);
5283       moffset = moffsetextra = 0;
5284       emptyopt = 0;
5285
5286       for (;;)
5287         {
5288         int ovector[3*(EXPAND_MAXN+1)];
5289         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5290           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5291         int nn;
5292         uschar *insert;
5293
5294         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5295         is not necessarily the end. We want to repeat the match from one
5296         character further along, but leaving the basic offset the same (for
5297         copying below). We can't be at the end of the string - that was checked
5298         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5299         finished; copy the remaining string and end the loop. */
5300
5301         if (n < 0)
5302           {
5303           if (emptyopt != 0)
5304             {
5305             moffsetextra = 1;
5306             emptyopt = 0;
5307             continue;
5308             }
5309           yield = string_catn(yield, &size, &ptr, subject+moffset, slen-moffset);
5310           break;
5311           }
5312
5313         /* Match - set up for expanding the replacement. */
5314
5315         if (n == 0) n = EXPAND_MAXN + 1;
5316         expand_nmax = 0;
5317         for (nn = 0; nn < n*2; nn += 2)
5318           {
5319           expand_nstring[expand_nmax] = subject + ovector[nn];
5320           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5321           }
5322         expand_nmax--;
5323
5324         /* Copy the characters before the match, plus the expanded insertion. */
5325
5326         yield = string_catn(yield, &size, &ptr, subject + moffset,
5327           ovector[0] - moffset);
5328         insert = expand_string(sub[2]);
5329         if (insert == NULL) goto EXPAND_FAILED;
5330         yield = string_cat(yield, &size, &ptr, insert);
5331
5332         moffset = ovector[1];
5333         moffsetextra = 0;
5334         emptyopt = 0;
5335
5336         /* If we have matched an empty string, first check to see if we are at
5337         the end of the subject. If so, the loop is over. Otherwise, mimic
5338         what Perl's /g options does. This turns out to be rather cunning. First
5339         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5340         string at the same point. If this fails (picked up above) we advance to
5341         the next character. */
5342
5343         if (ovector[0] == ovector[1])
5344           {
5345           if (ovector[0] == slen) break;
5346           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5347           }
5348         }
5349
5350       /* All done - restore numerical variables. */
5351
5352       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5353         save_expand_nlength);
5354       continue;
5355       }
5356
5357     /* Handle keyed and numbered substring extraction. If the first argument
5358     consists entirely of digits, then a numerical extraction is assumed. */
5359
5360     case EITEM_EXTRACT:
5361       {
5362       int i;
5363       int j;
5364       int field_number = 1;
5365       BOOL field_number_set = FALSE;
5366       uschar *save_lookup_value = lookup_value;
5367       uschar *sub[3];
5368       int save_expand_nmax =
5369         save_expand_strings(save_expand_nstring, save_expand_nlength);
5370
5371       /* While skipping we cannot rely on the data for expansions being
5372       available (eg. $item) hence cannot decide on numeric vs. keyed.
5373       Read a maximum of 5 arguments (inclding the yes/no) */
5374
5375       if (skipping)
5376         {
5377         while (isspace(*s)) s++;
5378         for (j = 5; j > 0 && *s == '{'; j--)
5379           {
5380           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5381             goto EXPAND_FAILED;                                 /*{*/
5382           if (*s++ != '}')
5383             {
5384             expand_string_message = US"missing '{' for arg of extract";
5385             goto EXPAND_FAILED_CURLY;
5386             }
5387           while (isspace(*s)) s++;
5388           }
5389         if (  Ustrncmp(s, "fail", 4) == 0
5390            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5391            )
5392           {
5393           s += 4;
5394           while (isspace(*s)) s++;
5395           }
5396         if (*s != '}')
5397           {
5398           expand_string_message = US"missing '}' closing extract";
5399           goto EXPAND_FAILED_CURLY;
5400           }
5401         }
5402
5403       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5404         {
5405         while (isspace(*s)) s++;
5406         if (*s == '{')                                          /*}*/
5407           {
5408           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5409           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5410           if (*s++ != '}')
5411             {
5412             expand_string_message = string_sprintf(
5413               "missing '}' closing arg %d of extract", i+1);
5414             goto EXPAND_FAILED_CURLY;
5415             }
5416
5417           /* After removal of leading and trailing white space, the first
5418           argument must not be empty; if it consists entirely of digits
5419           (optionally preceded by a minus sign), this is a numerical
5420           extraction, and we expect 3 arguments. */
5421
5422           if (i == 0)
5423             {
5424             int len;
5425             int x = 0;
5426             uschar *p = sub[0];
5427
5428             while (isspace(*p)) p++;
5429             sub[0] = p;
5430
5431             len = Ustrlen(p);
5432             while (len > 0 && isspace(p[len-1])) len--;
5433             p[len] = 0;
5434
5435             if (*p == 0)
5436               {
5437               expand_string_message = US"first argument of \"extract\" must "
5438                 "not be empty";
5439               goto EXPAND_FAILED;
5440               }
5441
5442             if (*p == '-')
5443               {
5444               field_number = -1;
5445               p++;
5446               }
5447             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5448             if (*p == 0)
5449               {
5450               field_number *= x;
5451               j = 3;               /* Need 3 args */
5452               field_number_set = TRUE;
5453               }
5454             }
5455           }
5456         else
5457           {
5458           expand_string_message = string_sprintf(
5459             "missing '{' for arg %d of extract", i+1);
5460           goto EXPAND_FAILED_CURLY;
5461           }
5462         }
5463
5464       /* Extract either the numbered or the keyed substring into $value. If
5465       skipping, just pretend the extraction failed. */
5466
5467       lookup_value = skipping? NULL : field_number_set?
5468         expand_gettokened(field_number, sub[1], sub[2]) :
5469         expand_getkeyed(sub[0], sub[1]);
5470
5471       /* If no string follows, $value gets substituted; otherwise there can
5472       be yes/no strings, as for lookup or if. */
5473
5474       switch(process_yesno(
5475                skipping,                     /* were previously skipping */
5476                lookup_value != NULL,         /* success/failure indicator */
5477                save_lookup_value,            /* value to reset for string2 */
5478                &s,                           /* input pointer */
5479                &yield,                       /* output pointer */
5480                &size,                        /* output size */
5481                &ptr,                         /* output current point */
5482                US"extract",                  /* condition type */
5483                &resetok))
5484         {
5485         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5486         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5487         }
5488
5489       /* All done - restore numerical variables. */
5490
5491       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5492         save_expand_nlength);
5493
5494       continue;
5495       }
5496
5497     /* return the Nth item from a list */
5498
5499     case EITEM_LISTEXTRACT:
5500       {
5501       int i;
5502       int field_number = 1;
5503       uschar *save_lookup_value = lookup_value;
5504       uschar *sub[2];
5505       int save_expand_nmax =
5506         save_expand_strings(save_expand_nstring, save_expand_nlength);
5507
5508       /* Read the field & list arguments */
5509
5510       for (i = 0; i < 2; i++)
5511         {
5512         while (isspace(*s)) s++;
5513         if (*s != '{')                                  /*}*/
5514           {
5515           expand_string_message = string_sprintf(
5516             "missing '{' for arg %d of listextract", i+1);
5517           goto EXPAND_FAILED_CURLY;
5518           }
5519
5520         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5521         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5522         if (*s++ != '}')
5523           {
5524           expand_string_message = string_sprintf(
5525             "missing '}' closing arg %d of listextract", i+1);
5526           goto EXPAND_FAILED_CURLY;
5527           }
5528
5529         /* After removal of leading and trailing white space, the first
5530         argument must be numeric and nonempty. */
5531
5532         if (i == 0)
5533           {
5534           int len;
5535           int x = 0;
5536           uschar *p = sub[0];
5537
5538           while (isspace(*p)) p++;
5539           sub[0] = p;
5540
5541           len = Ustrlen(p);
5542           while (len > 0 && isspace(p[len-1])) len--;
5543           p[len] = 0;
5544
5545           if (!*p && !skipping)
5546             {
5547             expand_string_message = US"first argument of \"listextract\" must "
5548               "not be empty";
5549             goto EXPAND_FAILED;
5550             }
5551
5552           if (*p == '-')
5553             {
5554             field_number = -1;
5555             p++;
5556             }
5557           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5558           if (*p)
5559             {
5560             expand_string_message = US"first argument of \"listextract\" must "
5561               "be numeric";
5562             goto EXPAND_FAILED;
5563             }
5564           field_number *= x;
5565           }
5566         }
5567
5568       /* Extract the numbered element into $value. If
5569       skipping, just pretend the extraction failed. */
5570
5571       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5572
5573       /* If no string follows, $value gets substituted; otherwise there can
5574       be yes/no strings, as for lookup or if. */
5575
5576       switch(process_yesno(
5577                skipping,                     /* were previously skipping */
5578                lookup_value != NULL,         /* success/failure indicator */
5579                save_lookup_value,            /* value to reset for string2 */
5580                &s,                           /* input pointer */
5581                &yield,                       /* output pointer */
5582                &size,                        /* output size */
5583                &ptr,                         /* output current point */
5584                US"listextract",              /* condition type */
5585                &resetok))
5586         {
5587         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5588         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5589         }
5590
5591       /* All done - restore numerical variables. */
5592
5593       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5594         save_expand_nlength);
5595
5596       continue;
5597       }
5598
5599 #ifdef SUPPORT_TLS
5600     case EITEM_CERTEXTRACT:
5601       {
5602       uschar *save_lookup_value = lookup_value;
5603       uschar *sub[2];
5604       int save_expand_nmax =
5605         save_expand_strings(save_expand_nstring, save_expand_nlength);
5606
5607       /* Read the field argument */
5608       while (isspace(*s)) s++;
5609       if (*s != '{')                                    /*}*/
5610         {
5611         expand_string_message = US"missing '{' for field arg of certextract";
5612         goto EXPAND_FAILED_CURLY;
5613         }
5614       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5615       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5616       if (*s++ != '}')
5617         {
5618         expand_string_message = US"missing '}' closing field arg of certextract";
5619         goto EXPAND_FAILED_CURLY;
5620         }
5621       /* strip spaces fore & aft */
5622       {
5623       int len;
5624       uschar *p = sub[0];
5625
5626       while (isspace(*p)) p++;
5627       sub[0] = p;
5628
5629       len = Ustrlen(p);
5630       while (len > 0 && isspace(p[len-1])) len--;
5631       p[len] = 0;
5632       }
5633
5634       /* inspect the cert argument */
5635       while (isspace(*s)) s++;
5636       if (*s != '{')                                    /*}*/
5637         {
5638         expand_string_message = US"missing '{' for cert variable arg of certextract";
5639         goto EXPAND_FAILED_CURLY;
5640         }
5641       if (*++s != '$')
5642         {
5643         expand_string_message = US"second argument of \"certextract\" must "
5644           "be a certificate variable";
5645         goto EXPAND_FAILED;
5646         }
5647       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5648       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5649       if (*s++ != '}')
5650         {
5651         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5652         goto EXPAND_FAILED_CURLY;
5653         }
5654
5655       if (skipping)
5656         lookup_value = NULL;
5657       else
5658         {
5659         lookup_value = expand_getcertele(sub[0], sub[1]);
5660         if (*expand_string_message) goto EXPAND_FAILED;
5661         }
5662       switch(process_yesno(
5663                skipping,                     /* were previously skipping */
5664                lookup_value != NULL,         /* success/failure indicator */
5665                save_lookup_value,            /* value to reset for string2 */
5666                &s,                           /* input pointer */
5667                &yield,                       /* output pointer */
5668                &size,                        /* output size */
5669                &ptr,                         /* output current point */
5670                US"certextract",              /* condition type */
5671                &resetok))
5672         {
5673         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5674         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5675         }
5676
5677       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5678         save_expand_nlength);
5679       continue;
5680       }
5681 #endif  /*SUPPORT_TLS*/
5682
5683     /* Handle list operations */
5684
5685     case EITEM_FILTER:
5686     case EITEM_MAP:
5687     case EITEM_REDUCE:
5688       {
5689       int sep = 0;
5690       int save_ptr = ptr;
5691       uschar outsep[2] = { '\0', '\0' };
5692       const uschar *list, *expr, *temp;
5693       uschar *save_iterate_item = iterate_item;
5694       uschar *save_lookup_value = lookup_value;
5695
5696       while (isspace(*s)) s++;
5697       if (*s++ != '{')
5698         {
5699         expand_string_message =
5700           string_sprintf("missing '{' for first arg of %s", name);
5701         goto EXPAND_FAILED_CURLY;
5702         }
5703
5704       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5705       if (list == NULL) goto EXPAND_FAILED;
5706       if (*s++ != '}')
5707         {
5708         expand_string_message =
5709           string_sprintf("missing '}' closing first arg of %s", name);
5710         goto EXPAND_FAILED_CURLY;
5711         }
5712
5713       if (item_type == EITEM_REDUCE)
5714         {
5715         uschar * t;
5716         while (isspace(*s)) s++;
5717         if (*s++ != '{')
5718           {
5719           expand_string_message = US"missing '{' for second arg of reduce";
5720           goto EXPAND_FAILED_CURLY;
5721           }
5722         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5723         if (!t) goto EXPAND_FAILED;
5724         lookup_value = t;
5725         if (*s++ != '}')
5726           {
5727           expand_string_message = US"missing '}' closing second arg of reduce";
5728           goto EXPAND_FAILED_CURLY;
5729           }
5730         }
5731
5732       while (isspace(*s)) s++;
5733       if (*s++ != '{')
5734         {
5735         expand_string_message =
5736           string_sprintf("missing '{' for last arg of %s", name);
5737         goto EXPAND_FAILED_CURLY;
5738         }
5739
5740       expr = s;
5741
5742       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5743       if scanning a "false" part). This allows us to find the end of the
5744       condition, because if the list is empty, we won't actually evaluate the
5745       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5746       the normal internal expansion function. */
5747
5748       if (item_type == EITEM_FILTER)
5749         {
5750         temp = eval_condition(expr, &resetok, NULL);
5751         if (temp != NULL) s = temp;
5752         }
5753       else
5754         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5755
5756       if (temp == NULL)
5757         {
5758         expand_string_message = string_sprintf("%s inside \"%s\" item",
5759           expand_string_message, name);
5760         goto EXPAND_FAILED;
5761         }
5762
5763       while (isspace(*s)) s++;
5764       if (*s++ != '}')
5765         {                                               /*{*/
5766         expand_string_message = string_sprintf("missing } at end of condition "
5767           "or expression inside \"%s\"", name);
5768         goto EXPAND_FAILED;
5769         }
5770
5771       while (isspace(*s)) s++;                          /*{*/
5772       if (*s++ != '}')
5773         {                                               /*{*/
5774         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5775           name);
5776         goto EXPAND_FAILED;
5777         }
5778
5779       /* If we are skipping, we can now just move on to the next item. When
5780       processing for real, we perform the iteration. */
5781
5782       if (skipping) continue;
5783       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
5784         {
5785         *outsep = (uschar)sep;      /* Separator as a string */
5786
5787         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
5788
5789         if (item_type == EITEM_FILTER)
5790           {
5791           BOOL condresult;
5792           if (eval_condition(expr, &resetok, &condresult) == NULL)
5793             {
5794             iterate_item = save_iterate_item;
5795             lookup_value = save_lookup_value;
5796             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5797               expand_string_message, name);
5798             goto EXPAND_FAILED;
5799             }
5800           DEBUG(D_expand) debug_printf("%s: condition is %s\n", name,
5801             condresult? "true":"false");
5802           if (condresult)
5803             temp = iterate_item;    /* TRUE => include this item */
5804           else
5805             continue;               /* FALSE => skip this item */
5806           }
5807
5808         /* EITEM_MAP and EITEM_REDUCE */
5809
5810         else
5811           {
5812           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5813           temp = t;
5814           if (temp == NULL)
5815             {
5816             iterate_item = save_iterate_item;
5817             expand_string_message = string_sprintf("%s inside \"%s\" item",
5818               expand_string_message, name);
5819             goto EXPAND_FAILED;
5820             }
5821           if (item_type == EITEM_REDUCE)
5822             {
5823             lookup_value = t;         /* Update the value of $value */
5824             continue;                 /* and continue the iteration */
5825             }
5826           }
5827
5828         /* We reach here for FILTER if the condition is true, always for MAP,
5829         and never for REDUCE. The value in "temp" is to be added to the output
5830         list that is being created, ensuring that any occurrences of the
5831         separator character are doubled. Unless we are dealing with the first
5832         item of the output list, add in a space if the new item begins with the
5833         separator character, or is an empty string. */
5834
5835         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5836           yield = string_catn(yield, &size, &ptr, US" ", 1);
5837
5838         /* Add the string in "temp" to the output list that we are building,
5839         This is done in chunks by searching for the separator character. */
5840
5841         for (;;)
5842           {
5843           size_t seglen = Ustrcspn(temp, outsep);
5844
5845           yield = string_catn(yield, &size, &ptr, temp, seglen + 1);
5846
5847           /* If we got to the end of the string we output one character
5848           too many; backup and end the loop. Otherwise arrange to double the
5849           separator. */
5850
5851           if (temp[seglen] == '\0') { ptr--; break; }
5852           yield = string_catn(yield, &size, &ptr, outsep, 1);
5853           temp += seglen + 1;
5854           }
5855
5856         /* Output a separator after the string: we will remove the redundant
5857         final one at the end. */
5858
5859         yield = string_catn(yield, &size, &ptr, outsep, 1);
5860         }   /* End of iteration over the list loop */
5861
5862       /* REDUCE has generated no output above: output the final value of
5863       $value. */
5864
5865       if (item_type == EITEM_REDUCE)
5866         {
5867         yield = string_cat(yield, &size, &ptr, lookup_value);
5868         lookup_value = save_lookup_value;  /* Restore $value */
5869         }
5870
5871       /* FILTER and MAP generate lists: if they have generated anything, remove
5872       the redundant final separator. Even though an empty item at the end of a
5873       list does not count, this is tidier. */
5874
5875       else if (ptr != save_ptr) ptr--;
5876
5877       /* Restore preserved $item */
5878
5879       iterate_item = save_iterate_item;
5880       continue;
5881       }
5882
5883     case EITEM_SORT:
5884       {
5885       int sep = 0;
5886       const uschar *srclist, *cmp, *xtract;
5887       uschar *srcitem;
5888       const uschar *dstlist = NULL, *dstkeylist = NULL;
5889       uschar * tmp;
5890       uschar *save_iterate_item = iterate_item;
5891
5892       while (isspace(*s)) s++;
5893       if (*s++ != '{')
5894         {
5895         expand_string_message = US"missing '{' for list arg of sort";
5896         goto EXPAND_FAILED_CURLY;
5897         }
5898
5899       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5900       if (!srclist) goto EXPAND_FAILED;
5901       if (*s++ != '}')
5902         {
5903         expand_string_message = US"missing '}' closing list arg of sort";
5904         goto EXPAND_FAILED_CURLY;
5905         }
5906
5907       while (isspace(*s)) s++;
5908       if (*s++ != '{')
5909         {
5910         expand_string_message = US"missing '{' for comparator arg of sort";
5911         goto EXPAND_FAILED_CURLY;
5912         }
5913
5914       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5915       if (!cmp) goto EXPAND_FAILED;
5916       if (*s++ != '}')
5917         {
5918         expand_string_message = US"missing '}' closing comparator arg of sort";
5919         goto EXPAND_FAILED_CURLY;
5920         }
5921
5922       while (isspace(*s)) s++;
5923       if (*s++ != '{')
5924         {
5925         expand_string_message = US"missing '{' for extractor arg of sort";
5926         goto EXPAND_FAILED_CURLY;
5927         }
5928
5929       xtract = s;
5930       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5931       if (!tmp) goto EXPAND_FAILED;
5932       xtract = string_copyn(xtract, s - xtract);
5933
5934       if (*s++ != '}')
5935         {
5936         expand_string_message = US"missing '}' closing extractor arg of sort";
5937         goto EXPAND_FAILED_CURLY;
5938         }
5939                                                         /*{*/
5940       if (*s++ != '}')
5941         {                                               /*{*/
5942         expand_string_message = US"missing } at end of \"sort\"";
5943         goto EXPAND_FAILED;
5944         }
5945
5946       if (skipping) continue;
5947
5948       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5949         {
5950         uschar * dstitem;
5951         uschar * newlist = NULL;
5952         uschar * newkeylist = NULL;
5953         uschar * srcfield;
5954
5955         DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, srcitem);
5956
5957         /* extract field for comparisons */
5958         iterate_item = srcitem;
5959         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5960                                           TRUE, &resetok))
5961            || !*srcfield)
5962           {
5963           expand_string_message = string_sprintf(
5964               "field-extract in sort: \"%s\"", xtract);
5965           goto EXPAND_FAILED;
5966           }
5967
5968         /* Insertion sort */
5969
5970         /* copy output list until new-item < list-item */
5971         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5972           {
5973           uschar * dstfield;
5974           uschar * expr;
5975           BOOL before;
5976
5977           /* field for comparison */
5978           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
5979             goto sort_mismatch;
5980
5981           /* build and run condition string */
5982           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
5983
5984           DEBUG(D_expand) debug_printf("%s: cond = \"%s\"\n", name, expr);
5985           if (!eval_condition(expr, &resetok, &before))
5986             {
5987             expand_string_message = string_sprintf("comparison in sort: %s",
5988                 expr);
5989             goto EXPAND_FAILED;
5990             }
5991
5992           if (before)
5993             {
5994             /* New-item sorts before this dst-item.  Append new-item,
5995             then dst-item, then remainder of dst list. */
5996
5997             newlist = string_append_listele(newlist, sep, srcitem);
5998             newkeylist = string_append_listele(newkeylist, sep, srcfield);
5999             srcitem = NULL;
6000
6001             newlist = string_append_listele(newlist, sep, dstitem);
6002             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6003
6004             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6005               {
6006               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6007                 goto sort_mismatch;
6008               newlist = string_append_listele(newlist, sep, dstitem);
6009               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6010               }
6011
6012             break;
6013             }
6014
6015           newlist = string_append_listele(newlist, sep, dstitem);
6016           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6017           }
6018
6019         /* If we ran out of dstlist without consuming srcitem, append it */
6020         if (srcitem)
6021           {
6022           newlist = string_append_listele(newlist, sep, srcitem);
6023           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6024           }
6025
6026         dstlist = newlist;
6027         dstkeylist = newkeylist;
6028
6029         DEBUG(D_expand) debug_printf("%s: dstlist = \"%s\"\n", name, dstlist);
6030         DEBUG(D_expand) debug_printf("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6031         }
6032
6033       if (dstlist)
6034         yield = string_cat(yield, &size, &ptr, dstlist);
6035
6036       /* Restore preserved $item */
6037       iterate_item = save_iterate_item;
6038       continue;
6039
6040       sort_mismatch:
6041         expand_string_message = US"Internal error in sort (list mismatch)";
6042         goto EXPAND_FAILED;
6043       }
6044
6045
6046     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6047     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6048     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6049     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6050
6051     #define EXPAND_DLFUNC_MAX_ARGS 8
6052
6053     case EITEM_DLFUNC:
6054 #ifndef EXPAND_DLFUNC
6055       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6056         "is not included in this binary";
6057       goto EXPAND_FAILED;
6058
6059 #else   /* EXPAND_DLFUNC */
6060       {
6061       tree_node *t;
6062       exim_dlfunc_t *func;
6063       uschar *result;
6064       int status, argc;
6065       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6066
6067       if ((expand_forbid & RDO_DLFUNC) != 0)
6068         {
6069         expand_string_message =
6070           US"dynamically-loaded functions are not permitted";
6071         goto EXPAND_FAILED;
6072         }
6073
6074       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6075            TRUE, US"dlfunc", &resetok))
6076         {
6077         case 1: goto EXPAND_FAILED_CURLY;
6078         case 2:
6079         case 3: goto EXPAND_FAILED;
6080         }
6081
6082       /* If skipping, we don't actually do anything */
6083
6084       if (skipping) continue;
6085
6086       /* Look up the dynamically loaded object handle in the tree. If it isn't
6087       found, dlopen() the file and put the handle in the tree for next time. */
6088
6089       t = tree_search(dlobj_anchor, argv[0]);
6090       if (t == NULL)
6091         {
6092         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6093         if (handle == NULL)
6094           {
6095           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6096             argv[0], dlerror());
6097           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6098           goto EXPAND_FAILED;
6099           }
6100         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6101         Ustrcpy(t->name, argv[0]);
6102         t->data.ptr = handle;
6103         (void)tree_insertnode(&dlobj_anchor, t);
6104         }
6105
6106       /* Having obtained the dynamically loaded object handle, look up the
6107       function pointer. */
6108
6109       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6110       if (func == NULL)
6111         {
6112         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6113           "%s", argv[1], argv[0], dlerror());
6114         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6115         goto EXPAND_FAILED;
6116         }
6117
6118       /* Call the function and work out what to do with the result. If it
6119       returns OK, we have a replacement string; if it returns DEFER then
6120       expansion has failed in a non-forced manner; if it returns FAIL then
6121       failure was forced; if it returns ERROR or any other value there's a
6122       problem, so panic slightly. In any case, assume that the function has
6123       side-effects on the store that must be preserved. */
6124
6125       resetok = FALSE;
6126       result = NULL;
6127       for (argc = 0; argv[argc] != NULL; argc++);
6128       status = func(&result, argc - 2, &argv[2]);
6129       if(status == OK)
6130         {
6131         if (result == NULL) result = US"";
6132         yield = string_cat(yield, &size, &ptr, result);
6133         continue;
6134         }
6135       else
6136         {
6137         expand_string_message = result == NULL ? US"(no message)" : result;
6138         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6139           else if(status != FAIL)
6140             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6141               argv[0], argv[1], status, expand_string_message);
6142         goto EXPAND_FAILED;
6143         }
6144       }
6145 #endif /* EXPAND_DLFUNC */
6146
6147     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6148       {
6149       uschar * key;
6150       uschar *save_lookup_value = lookup_value;
6151
6152       while (isspace(*s)) s++;
6153       if (*s != '{')                                    /*}*/
6154         goto EXPAND_FAILED;
6155
6156       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6157       if (!key) goto EXPAND_FAILED;                     /*{*/
6158       if (*s++ != '}')
6159         {
6160         expand_string_message = US"missing '{' for name arg of env";
6161         goto EXPAND_FAILED_CURLY;
6162         }
6163
6164       lookup_value = US getenv(CS key);
6165
6166       switch(process_yesno(
6167                skipping,                     /* were previously skipping */
6168                lookup_value != NULL,         /* success/failure indicator */
6169                save_lookup_value,            /* value to reset for string2 */
6170                &s,                           /* input pointer */
6171                &yield,                       /* output pointer */
6172                &size,                        /* output size */
6173                &ptr,                         /* output current point */
6174                US"env",                      /* condition type */
6175                &resetok))
6176         {
6177         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6178         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6179         }
6180       continue;
6181       }
6182     }   /* EITEM_* switch */
6183
6184   /* Control reaches here if the name is not recognized as one of the more
6185   complicated expansion items. Check for the "operator" syntax (name terminated
6186   by a colon). Some of the operators have arguments, separated by _ from the
6187   name. */
6188
6189   if (*s == ':')
6190     {
6191     int c;
6192     uschar *arg = NULL;
6193     uschar *sub;
6194     var_entry *vp = NULL;
6195
6196     /* Owing to an historical mis-design, an underscore may be part of the
6197     operator name, or it may introduce arguments.  We therefore first scan the
6198     table of names that contain underscores. If there is no match, we cut off
6199     the arguments and then scan the main table. */
6200
6201     if ((c = chop_match(name, op_table_underscore,
6202                         nelem(op_table_underscore))) < 0)
6203       {
6204       arg = Ustrchr(name, '_');
6205       if (arg != NULL) *arg = 0;
6206       c = chop_match(name, op_table_main, nelem(op_table_main));
6207       if (c >= 0) c += nelem(op_table_underscore);
6208       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6209       }
6210
6211     /* Deal specially with operators that might take a certificate variable
6212     as we do not want to do the usual expansion. For most, expand the string.*/
6213     switch(c)
6214       {
6215 #ifdef SUPPORT_TLS
6216       case EOP_MD5:
6217       case EOP_SHA1:
6218       case EOP_SHA256:
6219       case EOP_BASE64:
6220         if (s[1] == '$')
6221           {
6222           const uschar * s1 = s;
6223           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6224                   FALSE, &resetok);
6225           if (!sub)       goto EXPAND_FAILED;           /*{*/
6226           if (*s1 != '}')
6227             {
6228             expand_string_message =
6229               string_sprintf("missing '}' closing cert arg of %s", name);
6230             goto EXPAND_FAILED_CURLY;
6231             }
6232           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6233             {
6234             s = s1+1;
6235             break;
6236             }
6237           vp = NULL;
6238           }
6239         /*FALLTHROUGH*/
6240 #endif
6241       default:
6242         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6243         if (!sub) goto EXPAND_FAILED;
6244         s++;
6245         break;
6246       }
6247
6248     /* If we are skipping, we don't need to perform the operation at all.
6249     This matters for operations like "mask", because the data may not be
6250     in the correct format when skipping. For example, the expression may test
6251     for the existence of $sender_host_address before trying to mask it. For
6252     other operations, doing them may not fail, but it is a waste of time. */
6253
6254     if (skipping && c >= 0) continue;
6255
6256     /* Otherwise, switch on the operator type */
6257
6258     switch(c)
6259       {
6260       case EOP_BASE62:
6261         {
6262         uschar *t;
6263         unsigned long int n = Ustrtoul(sub, &t, 10);
6264         if (*t != 0)
6265           {
6266           expand_string_message = string_sprintf("argument for base62 "
6267             "operator is \"%s\", which is not a decimal number", sub);
6268           goto EXPAND_FAILED;
6269           }
6270         t = string_base62(n);
6271         yield = string_cat(yield, &size, &ptr, t);
6272         continue;
6273         }
6274
6275       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6276
6277       case EOP_BASE62D:
6278         {
6279         uschar buf[16];
6280         uschar *tt = sub;
6281         unsigned long int n = 0;
6282         while (*tt != 0)
6283           {
6284           uschar *t = Ustrchr(base62_chars, *tt++);
6285           if (t == NULL)
6286             {
6287             expand_string_message = string_sprintf("argument for base62d "
6288               "operator is \"%s\", which is not a base %d number", sub,
6289               BASE_62);
6290             goto EXPAND_FAILED;
6291             }
6292           n = n * BASE_62 + (t - base62_chars);
6293           }
6294         (void)sprintf(CS buf, "%ld", n);
6295         yield = string_cat(yield, &size, &ptr, buf);
6296         continue;
6297         }
6298
6299       case EOP_EXPAND:
6300         {
6301         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6302         if (expanded == NULL)
6303           {
6304           expand_string_message =
6305             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6306               expand_string_message);
6307           goto EXPAND_FAILED;
6308           }
6309         yield = string_cat(yield, &size, &ptr, expanded);
6310         continue;
6311         }
6312
6313       case EOP_LC:
6314         {
6315         int count = 0;
6316         uschar *t = sub - 1;
6317         while (*(++t) != 0) { *t = tolower(*t); count++; }
6318         yield = string_catn(yield, &size, &ptr, sub, count);
6319         continue;
6320         }
6321
6322       case EOP_UC:
6323         {
6324         int count = 0;
6325         uschar *t = sub - 1;
6326         while (*(++t) != 0) { *t = toupper(*t); count++; }
6327         yield = string_catn(yield, &size, &ptr, sub, count);
6328         continue;
6329         }
6330
6331       case EOP_MD5:
6332 #ifdef SUPPORT_TLS
6333         if (vp && *(void **)vp->value)
6334           {
6335           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6336           yield = string_cat(yield, &size, &ptr, cp);
6337           }
6338         else
6339 #endif
6340           {
6341           md5 base;
6342           uschar digest[16];
6343           int j;
6344           char st[33];
6345           md5_start(&base);
6346           md5_end(&base, sub, Ustrlen(sub), digest);
6347           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6348           yield = string_cat(yield, &size, &ptr, US st);
6349           }
6350         continue;
6351
6352       case EOP_SHA1:
6353 #ifdef SUPPORT_TLS
6354         if (vp && *(void **)vp->value)
6355           {
6356           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6357           yield = string_cat(yield, &size, &ptr, cp);
6358           }
6359         else
6360 #endif
6361           {
6362           sha1 base;
6363           uschar digest[20];
6364           int j;
6365           char st[41];
6366           sha1_start(&base);
6367           sha1_end(&base, sub, Ustrlen(sub), digest);
6368           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6369           yield = string_cat(yield, &size, &ptr, US st);
6370           }
6371         continue;
6372
6373       case EOP_SHA256:
6374 #ifdef SUPPORT_TLS
6375         if (vp && *(void **)vp->value)
6376           {
6377           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6378           yield = string_cat(yield, &size, &ptr, cp);
6379           }
6380         else
6381 #endif
6382           expand_string_message = US"sha256 only supported for certificates";
6383         continue;
6384
6385       /* Convert hex encoding to base64 encoding */
6386
6387       case EOP_HEX2B64:
6388         {
6389         int c = 0;
6390         int b = -1;
6391         uschar *in = sub;
6392         uschar *out = sub;
6393         uschar *enc;
6394
6395         for (enc = sub; *enc != 0; enc++)
6396           {
6397           if (!isxdigit(*enc))
6398             {
6399             expand_string_message = string_sprintf("\"%s\" is not a hex "
6400               "string", sub);
6401             goto EXPAND_FAILED;
6402             }
6403           c++;
6404           }
6405
6406         if ((c & 1) != 0)
6407           {
6408           expand_string_message = string_sprintf("\"%s\" contains an odd "
6409             "number of characters", sub);
6410           goto EXPAND_FAILED;
6411           }
6412
6413         while ((c = *in++) != 0)
6414           {
6415           if (isdigit(c)) c -= '0';
6416           else c = toupper(c) - 'A' + 10;
6417           if (b == -1)
6418             {
6419             b = c << 4;
6420             }
6421           else
6422             {
6423             *out++ = b | c;
6424             b = -1;
6425             }
6426           }
6427
6428         enc = b64encode(sub, out - sub);
6429         yield = string_cat(yield, &size, &ptr, enc);
6430         continue;
6431         }
6432
6433       /* Convert octets outside 0x21..0x7E to \xXX form */
6434
6435       case EOP_HEXQUOTE:
6436         {
6437         uschar *t = sub - 1;
6438         while (*(++t) != 0)
6439           {
6440           if (*t < 0x21 || 0x7E < *t)
6441             yield = string_catn(yield, &size, &ptr,
6442               string_sprintf("\\x%02x", *t), 4);
6443           else
6444             yield = string_catn(yield, &size, &ptr, t, 1);
6445           }
6446         continue;
6447         }
6448
6449       /* count the number of list elements */
6450
6451       case EOP_LISTCOUNT:
6452         {
6453         int cnt = 0;
6454         int sep = 0;
6455         uschar * cp;
6456         uschar buffer[256];
6457
6458         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6459         cp = string_sprintf("%d", cnt);
6460         yield = string_cat(yield, &size, &ptr, cp);
6461         continue;
6462         }
6463
6464       /* expand a named list given the name */
6465       /* handles nested named lists; requotes as colon-sep list */
6466
6467       case EOP_LISTNAMED:
6468         {
6469         tree_node *t = NULL;
6470         const uschar * list;
6471         int sep = 0;
6472         uschar * item;
6473         uschar * suffix = US"";
6474         BOOL needsep = FALSE;
6475         uschar buffer[256];
6476
6477         if (*sub == '+') sub++;
6478         if (arg == NULL)        /* no-argument version */
6479           {
6480           if (!(t = tree_search(addresslist_anchor, sub)) &&
6481               !(t = tree_search(domainlist_anchor,  sub)) &&
6482               !(t = tree_search(hostlist_anchor,    sub)))
6483             t = tree_search(localpartlist_anchor, sub);
6484           }
6485         else switch(*arg)       /* specific list-type version */
6486           {
6487           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6488           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6489           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6490           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6491           default:
6492             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6493             goto EXPAND_FAILED;
6494           }
6495
6496         if(!t)
6497           {
6498           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6499             sub, !arg?""
6500               : *arg=='a'?"address "
6501               : *arg=='d'?"domain "
6502               : *arg=='h'?"host "
6503               : *arg=='l'?"localpart "
6504               : 0);
6505           goto EXPAND_FAILED;
6506           }
6507
6508         list = ((namedlist_block *)(t->data.ptr))->string;
6509
6510         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6511           {
6512           uschar * buf = US" : ";
6513           if (needsep)
6514             yield = string_catn(yield, &size, &ptr, buf, 3);
6515           else
6516             needsep = TRUE;
6517
6518           if (*item == '+')     /* list item is itself a named list */
6519             {
6520             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6521             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6522             }
6523           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6524             {
6525             char * cp;
6526             char tok[3];
6527             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6528             while ((cp= strpbrk((const char *)item, tok)))
6529               {
6530               yield = string_catn(yield, &size, &ptr, item, cp-(char *)item);
6531               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6532                 {
6533                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6534                 item = (uschar *)cp;
6535                 }
6536               else              /* sep in item; should already be doubled; emit once */
6537                 {
6538                 yield = string_catn(yield, &size, &ptr, (uschar *)tok, 1);
6539                 if (*cp == sep) cp++;
6540                 item = (uschar *)cp;
6541                 }
6542               }
6543             }
6544           yield = string_cat(yield, &size, &ptr, item);
6545           }
6546         continue;
6547         }
6548
6549       /* mask applies a mask to an IP address; for example the result of
6550       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6551
6552       case EOP_MASK:
6553         {
6554         int count;
6555         uschar *endptr;
6556         int binary[4];
6557         int mask, maskoffset;
6558         int type = string_is_ip_address(sub, &maskoffset);
6559         uschar buffer[64];
6560
6561         if (type == 0)
6562           {
6563           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6564            sub);
6565           goto EXPAND_FAILED;
6566           }
6567
6568         if (maskoffset == 0)
6569           {
6570           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6571             sub);
6572           goto EXPAND_FAILED;
6573           }
6574
6575         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6576
6577         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6578           {
6579           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6580             sub);
6581           goto EXPAND_FAILED;
6582           }
6583
6584         /* Convert the address to binary integer(s) and apply the mask */
6585
6586         sub[maskoffset] = 0;
6587         count = host_aton(sub, binary);
6588         host_mask(count, binary, mask);
6589
6590         /* Convert to masked textual format and add to output. */
6591
6592         yield = string_catn(yield, &size, &ptr, buffer,
6593           host_nmtoa(count, binary, mask, buffer, '.'));
6594         continue;
6595         }
6596
6597       case EOP_IPV6NORM:
6598       case EOP_IPV6DENORM:
6599         {
6600         int type = string_is_ip_address(sub, NULL);
6601         int binary[4];
6602         uschar buffer[44];
6603
6604         switch (type)
6605           {
6606           case 6:
6607             (void) host_aton(sub, binary);
6608             break;
6609
6610           case 4:       /* convert to IPv4-mapped IPv6 */
6611             binary[0] = binary[1] = 0;
6612             binary[2] = 0x0000ffff;
6613             (void) host_aton(sub, binary+3);
6614             break;
6615
6616           case 0:
6617             expand_string_message =
6618               string_sprintf("\"%s\" is not an IP address", sub);
6619             goto EXPAND_FAILED;
6620           }
6621
6622         yield = string_catn(yield, &size, &ptr, buffer,
6623                   c == EOP_IPV6NORM
6624                     ? ipv6_nmtoa(binary, buffer)
6625                     : host_nmtoa(4, binary, -1, buffer, ':')
6626                   );
6627         continue;
6628         }
6629
6630       case EOP_ADDRESS:
6631       case EOP_LOCAL_PART:
6632       case EOP_DOMAIN:
6633         {
6634         uschar *error;
6635         int start, end, domain;
6636         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6637           FALSE);
6638         if (t != NULL)
6639           {
6640           if (c != EOP_DOMAIN)
6641             {
6642             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6643             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6644             }
6645           else if (domain != 0)
6646             {
6647             domain += start;
6648             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6649             }
6650           }
6651         continue;
6652         }
6653
6654       case EOP_ADDRESSES:
6655         {
6656         uschar outsep[2] = { ':', '\0' };
6657         uschar *address, *error;
6658         int save_ptr = ptr;
6659         int start, end, domain;  /* Not really used */
6660
6661         while (isspace(*sub)) sub++;
6662         if (*sub == '>') { *outsep = *++sub; ++sub; }
6663         parse_allow_group = TRUE;
6664
6665         for (;;)
6666           {
6667           uschar *p = parse_find_address_end(sub, FALSE);
6668           uschar saveend = *p;
6669           *p = '\0';
6670           address = parse_extract_address(sub, &error, &start, &end, &domain,
6671             FALSE);
6672           *p = saveend;
6673
6674           /* Add the address to the output list that we are building. This is
6675           done in chunks by searching for the separator character. At the
6676           start, unless we are dealing with the first address of the output
6677           list, add in a space if the new address begins with the separator
6678           character, or is an empty string. */
6679
6680           if (address != NULL)
6681             {
6682             if (ptr != save_ptr && address[0] == *outsep)
6683               yield = string_catn(yield, &size, &ptr, US" ", 1);
6684
6685             for (;;)
6686               {
6687               size_t seglen = Ustrcspn(address, outsep);
6688               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6689
6690               /* If we got to the end of the string we output one character
6691               too many. */
6692
6693               if (address[seglen] == '\0') { ptr--; break; }
6694               yield = string_catn(yield, &size, &ptr, outsep, 1);
6695               address += seglen + 1;
6696               }
6697
6698             /* Output a separator after the string: we will remove the
6699             redundant final one at the end. */
6700
6701             yield = string_catn(yield, &size, &ptr, outsep, 1);
6702             }
6703
6704           if (saveend == '\0') break;
6705           sub = p + 1;
6706           }
6707
6708         /* If we have generated anything, remove the redundant final
6709         separator. */
6710
6711         if (ptr != save_ptr) ptr--;
6712         parse_allow_group = FALSE;
6713         continue;
6714         }
6715
6716
6717       /* quote puts a string in quotes if it is empty or contains anything
6718       other than alphamerics, underscore, dot, or hyphen.
6719
6720       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6721       be quoted in order to be a valid local part.
6722
6723       In both cases, newlines and carriage returns are converted into \n and \r
6724       respectively */
6725
6726       case EOP_QUOTE:
6727       case EOP_QUOTE_LOCAL_PART:
6728       if (arg == NULL)
6729         {
6730         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6731         uschar *t = sub - 1;
6732
6733         if (c == EOP_QUOTE)
6734           {
6735           while (!needs_quote && *(++t) != 0)
6736             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6737           }
6738         else  /* EOP_QUOTE_LOCAL_PART */
6739           {
6740           while (!needs_quote && *(++t) != 0)
6741             needs_quote = !isalnum(*t) &&
6742               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6743               (*t != '.' || t == sub || t[1] == 0);
6744           }
6745
6746         if (needs_quote)
6747           {
6748           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6749           t = sub - 1;
6750           while (*(++t) != 0)
6751             {
6752             if (*t == '\n')
6753               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6754             else if (*t == '\r')
6755               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6756             else
6757               {
6758               if (*t == '\\' || *t == '"')
6759                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6760               yield = string_catn(yield, &size, &ptr, t, 1);
6761               }
6762             }
6763           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6764           }
6765         else yield = string_cat(yield, &size, &ptr, sub);
6766         continue;
6767         }
6768
6769       /* quote_lookuptype does lookup-specific quoting */
6770
6771       else
6772         {
6773         int n;
6774         uschar *opt = Ustrchr(arg, '_');
6775
6776         if (opt != NULL) *opt++ = 0;
6777
6778         n = search_findtype(arg, Ustrlen(arg));
6779         if (n < 0)
6780           {
6781           expand_string_message = search_error_message;
6782           goto EXPAND_FAILED;
6783           }
6784
6785         if (lookup_list[n]->quote != NULL)
6786           sub = (lookup_list[n]->quote)(sub, opt);
6787         else if (opt != NULL) sub = NULL;
6788
6789         if (sub == NULL)
6790           {
6791           expand_string_message = string_sprintf(
6792             "\"%s\" unrecognized after \"${quote_%s\"",
6793             opt, arg);
6794           goto EXPAND_FAILED;
6795           }
6796
6797         yield = string_cat(yield, &size, &ptr, sub);
6798         continue;
6799         }
6800
6801       /* rx quote sticks in \ before any non-alphameric character so that
6802       the insertion works in a regular expression. */
6803
6804       case EOP_RXQUOTE:
6805         {
6806         uschar *t = sub - 1;
6807         while (*(++t) != 0)
6808           {
6809           if (!isalnum(*t))
6810             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6811           yield = string_catn(yield, &size, &ptr, t, 1);
6812           }
6813         continue;
6814         }
6815
6816       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6817       prescribed by the RFC, if there are characters that need to be encoded */
6818
6819       case EOP_RFC2047:
6820         {
6821         uschar buffer[2048];
6822         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6823           buffer, sizeof(buffer), FALSE);
6824         yield = string_cat(yield, &size, &ptr, string);
6825         continue;
6826         }
6827
6828       /* RFC 2047 decode */
6829
6830       case EOP_RFC2047D:
6831         {
6832         int len;
6833         uschar *error;
6834         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6835           headers_charset, '?', &len, &error);
6836         if (error != NULL)
6837           {
6838           expand_string_message = error;
6839           goto EXPAND_FAILED;
6840           }
6841         yield = string_catn(yield, &size, &ptr, decoded, len);
6842         continue;
6843         }
6844
6845       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6846       underscores */
6847
6848       case EOP_FROM_UTF8:
6849         {
6850         while (*sub != 0)
6851           {
6852           int c;
6853           uschar buff[4];
6854           GETUTF8INC(c, sub);
6855           if (c > 255) c = '_';
6856           buff[0] = c;
6857           yield = string_catn(yield, &size, &ptr, buff, 1);
6858           }
6859         continue;
6860         }
6861
6862           /* replace illegal UTF-8 sequences by replacement character  */
6863
6864       #define UTF8_REPLACEMENT_CHAR US"?"
6865
6866       case EOP_UTF8CLEAN:
6867         {
6868         int seq_len = 0, index = 0;
6869         int bytes_left = 0;
6870         long codepoint = -1;
6871         uschar seq_buff[4];                     /* accumulate utf-8 here */
6872
6873         while (*sub != 0)
6874           {
6875           int complete = 0;
6876           uschar c = *sub++;
6877
6878           if (bytes_left)
6879             {
6880             if ((c & 0xc0) != 0x80)
6881                     /* wrong continuation byte; invalidate all bytes */
6882               complete = 1; /* error */
6883             else
6884               {
6885               codepoint = (codepoint << 6) | (c & 0x3f);
6886               seq_buff[index++] = c;
6887               if (--bytes_left == 0)            /* codepoint complete */
6888                 if(codepoint > 0x10FFFF)        /* is it too large? */
6889                   complete = -1;        /* error (RFC3629 limit) */
6890                 else
6891                   {             /* finished; output utf-8 sequence */
6892                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
6893                   index = 0;
6894                   }
6895               }
6896             }
6897           else  /* no bytes left: new sequence */
6898             {
6899             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6900               {
6901               yield = string_catn(yield, &size, &ptr, &c, 1);
6902               continue;
6903               }
6904             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
6905               {
6906               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
6907                 complete = -1;
6908               else
6909                 {
6910                   bytes_left = 1;
6911                   codepoint = c & 0x1f;
6912                 }
6913               }
6914             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
6915               {
6916               bytes_left = 2;
6917               codepoint = c & 0x0f;
6918               }
6919             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
6920               {
6921               bytes_left = 3;
6922               codepoint = c & 0x07;
6923               }
6924             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
6925               complete = -1;
6926
6927             seq_buff[index++] = c;
6928             seq_len = bytes_left + 1;
6929             }           /* if(bytes_left) */
6930
6931           if (complete != 0)
6932             {
6933             bytes_left = index = 0;
6934             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
6935             }
6936           if ((complete == 1) && ((c & 0x80) == 0))
6937                         /* ASCII character follows incomplete sequence */
6938               yield = string_catn(yield, &size, &ptr, &c, 1);
6939           }
6940         continue;
6941         }
6942
6943 #ifdef SUPPORT_I18N
6944       case EOP_UTF8_DOMAIN_TO_ALABEL:
6945         {
6946         uschar * error = NULL;
6947         uschar * s = string_domain_utf8_to_alabel(sub, &error);
6948         if (error)
6949           {
6950           expand_string_message = string_sprintf(
6951             "error converting utf8 (%s) to alabel: %s",
6952             string_printing(sub), error);
6953           goto EXPAND_FAILED;
6954           }
6955         yield = string_cat(yield, &size, &ptr, s);
6956         continue;
6957         }
6958
6959       case EOP_UTF8_DOMAIN_FROM_ALABEL:
6960         {
6961         uschar * error = NULL;
6962         uschar * s = string_domain_alabel_to_utf8(sub, &error);
6963         if (error)
6964           {
6965           expand_string_message = string_sprintf(
6966             "error converting alabel (%s) to utf8: %s",
6967             string_printing(sub), error);
6968           goto EXPAND_FAILED;
6969           }
6970         yield = string_cat(yield, &size, &ptr, s);
6971         continue;
6972         }
6973
6974       case EOP_UTF8_LOCALPART_TO_ALABEL:
6975         {
6976         uschar * error = NULL;
6977         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
6978         if (error)
6979           {
6980           expand_string_message = string_sprintf(
6981             "error converting utf8 (%s) to alabel: %s",
6982             string_printing(sub), error);
6983           goto EXPAND_FAILED;
6984           }
6985         yield = string_cat(yield, &size, &ptr, s);
6986         DEBUG(D_expand) debug_printf("yield: '%s'\n", yield);
6987         continue;
6988         }
6989
6990       case EOP_UTF8_LOCALPART_FROM_ALABEL:
6991         {
6992         uschar * error = NULL;
6993         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
6994         if (error)
6995           {
6996           expand_string_message = string_sprintf(
6997             "error converting alabel (%s) to utf8: %s",
6998             string_printing(sub), error);
6999           goto EXPAND_FAILED;
7000           }
7001         yield = string_cat(yield, &size, &ptr, s);
7002         continue;
7003         }
7004 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7005
7006       /* escape turns all non-printing characters into escape sequences. */
7007
7008       case EOP_ESCAPE:
7009         {
7010         const uschar *t = string_printing(sub);
7011         yield = string_cat(yield, &size, &ptr, t);
7012         continue;
7013         }
7014
7015       /* Handle numeric expression evaluation */
7016
7017       case EOP_EVAL:
7018       case EOP_EVAL10:
7019         {
7020         uschar *save_sub = sub;
7021         uschar *error = NULL;
7022         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7023         if (error != NULL)
7024           {
7025           expand_string_message = string_sprintf("error in expression "
7026             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7027               save_sub);
7028           goto EXPAND_FAILED;
7029           }
7030         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7031         yield = string_cat(yield, &size, &ptr, var_buffer);
7032         continue;
7033         }
7034
7035       /* Handle time period formating */
7036
7037       case EOP_TIME_EVAL:
7038         {
7039         int n = readconf_readtime(sub, 0, FALSE);
7040         if (n < 0)
7041           {
7042           expand_string_message = string_sprintf("string \"%s\" is not an "
7043             "Exim time interval in \"%s\" operator", sub, name);
7044           goto EXPAND_FAILED;
7045           }
7046         sprintf(CS var_buffer, "%d", n);
7047         yield = string_cat(yield, &size, &ptr, var_buffer);
7048         continue;
7049         }
7050
7051       case EOP_TIME_INTERVAL:
7052         {
7053         int n;
7054         uschar *t = read_number(&n, sub);
7055         if (*t != 0) /* Not A Number*/
7056           {
7057           expand_string_message = string_sprintf("string \"%s\" is not a "
7058             "positive number in \"%s\" operator", sub, name);
7059           goto EXPAND_FAILED;
7060           }
7061         t = readconf_printtime(n);
7062         yield = string_cat(yield, &size, &ptr, t);
7063         continue;
7064         }
7065
7066       /* Convert string to base64 encoding */
7067
7068       case EOP_STR2B64:
7069       case EOP_BASE64:
7070         {
7071 #ifdef SUPPORT_TLS
7072         uschar * s = vp && *(void **)vp->value
7073           ? tls_cert_der_b64(*(void **)vp->value)
7074           : b64encode(sub, Ustrlen(sub));
7075 #else
7076         uschar * s = b64encode(sub, Ustrlen(sub));
7077 #endif
7078         yield = string_cat(yield, &size, &ptr, s);
7079         continue;
7080         }
7081
7082       case EOP_BASE64D:
7083         {
7084         uschar * s;
7085         int len = b64decode(sub, &s);
7086         if (len < 0)
7087           {
7088           expand_string_message = string_sprintf("string \"%s\" is not "
7089             "well-formed for \"%s\" operator", sub, name);
7090           goto EXPAND_FAILED;
7091           }
7092         yield = string_cat(yield, &size, &ptr, s);
7093         continue;
7094         }
7095
7096       /* strlen returns the length of the string */
7097
7098       case EOP_STRLEN:
7099         {
7100         uschar buff[24];
7101         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7102         yield = string_cat(yield, &size, &ptr, buff);
7103         continue;
7104         }
7105
7106       /* length_n or l_n takes just the first n characters or the whole string,
7107       whichever is the shorter;
7108
7109       substr_m_n, and s_m_n take n characters from offset m; negative m take
7110       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7111       takes the rest, either to the right or to the left.
7112
7113       hash_n or h_n makes a hash of length n from the string, yielding n
7114       characters from the set a-z; hash_n_m makes a hash of length n, but
7115       uses m characters from the set a-zA-Z0-9.
7116
7117       nhash_n returns a single number between 0 and n-1 (in text form), while
7118       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7119       between 0 and n-1 and the second between 0 and m-1. */
7120
7121       case EOP_LENGTH:
7122       case EOP_L:
7123       case EOP_SUBSTR:
7124       case EOP_S:
7125       case EOP_HASH:
7126       case EOP_H:
7127       case EOP_NHASH:
7128       case EOP_NH:
7129         {
7130         int sign = 1;
7131         int value1 = 0;
7132         int value2 = -1;
7133         int *pn;
7134         int len;
7135         uschar *ret;
7136
7137         if (arg == NULL)
7138           {
7139           expand_string_message = string_sprintf("missing values after %s",
7140             name);
7141           goto EXPAND_FAILED;
7142           }
7143
7144         /* "length" has only one argument, effectively being synonymous with
7145         substr_0_n. */
7146
7147         if (c == EOP_LENGTH || c == EOP_L)
7148           {
7149           pn = &value2;
7150           value2 = 0;
7151           }
7152
7153         /* The others have one or two arguments; for "substr" the first may be
7154         negative. The second being negative means "not supplied". */
7155
7156         else
7157           {
7158           pn = &value1;
7159           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7160           }
7161
7162         /* Read up to two numbers, separated by underscores */
7163
7164         ret = arg;
7165         while (*arg != 0)
7166           {
7167           if (arg != ret && *arg == '_' && pn == &value1)
7168             {
7169             pn = &value2;
7170             value2 = 0;
7171             if (arg[1] != 0) arg++;
7172             }
7173           else if (!isdigit(*arg))
7174             {
7175             expand_string_message =
7176               string_sprintf("non-digit after underscore in \"%s\"", name);
7177             goto EXPAND_FAILED;
7178             }
7179           else *pn = (*pn)*10 + *arg++ - '0';
7180           }
7181         value1 *= sign;
7182
7183         /* Perform the required operation */
7184
7185         ret =
7186           (c == EOP_HASH || c == EOP_H)?
7187              compute_hash(sub, value1, value2, &len) :
7188           (c == EOP_NHASH || c == EOP_NH)?
7189              compute_nhash(sub, value1, value2, &len) :
7190              extract_substr(sub, value1, value2, &len);
7191
7192         if (ret == NULL) goto EXPAND_FAILED;
7193         yield = string_catn(yield, &size, &ptr, ret, len);
7194         continue;
7195         }
7196
7197       /* Stat a path */
7198
7199       case EOP_STAT:
7200         {
7201         uschar *s;
7202         uschar smode[12];
7203         uschar **modetable[3];
7204         int i;
7205         mode_t mode;
7206         struct stat st;
7207
7208         if ((expand_forbid & RDO_EXISTS) != 0)
7209           {
7210           expand_string_message = US"Use of the stat() expansion is not permitted";
7211           goto EXPAND_FAILED;
7212           }
7213
7214         if (stat(CS sub, &st) < 0)
7215           {
7216           expand_string_message = string_sprintf("stat(%s) failed: %s",
7217             sub, strerror(errno));
7218           goto EXPAND_FAILED;
7219           }
7220         mode = st.st_mode;
7221         switch (mode & S_IFMT)
7222           {
7223           case S_IFIFO: smode[0] = 'p'; break;
7224           case S_IFCHR: smode[0] = 'c'; break;
7225           case S_IFDIR: smode[0] = 'd'; break;
7226           case S_IFBLK: smode[0] = 'b'; break;
7227           case S_IFREG: smode[0] = '-'; break;
7228           default: smode[0] = '?'; break;
7229           }
7230
7231         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7232         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7233         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7234
7235         for (i = 0; i < 3; i++)
7236           {
7237           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7238           mode >>= 3;
7239           }
7240
7241         smode[10] = 0;
7242         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7243           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7244           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7245           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7246           (long)st.st_gid, st.st_size, (long)st.st_atime,
7247           (long)st.st_mtime, (long)st.st_ctime);
7248         yield = string_cat(yield, &size, &ptr, s);
7249         continue;
7250         }
7251
7252       /* vaguely random number less than N */
7253
7254       case EOP_RANDINT:
7255         {
7256         int_eximarith_t max;
7257         uschar *s;
7258
7259         max = expanded_string_integer(sub, TRUE);
7260         if (expand_string_message != NULL)
7261           goto EXPAND_FAILED;
7262         s = string_sprintf("%d", vaguely_random_number((int)max));
7263         yield = string_cat(yield, &size, &ptr, s);
7264         continue;
7265         }
7266
7267       /* Reverse IP, including IPv6 to dotted-nibble */
7268
7269       case EOP_REVERSE_IP:
7270         {
7271         int family, maskptr;
7272         uschar reversed[128];
7273
7274         family = string_is_ip_address(sub, &maskptr);
7275         if (family == 0)
7276           {
7277           expand_string_message = string_sprintf(
7278               "reverse_ip() not given an IP address [%s]", sub);
7279           goto EXPAND_FAILED;
7280           }
7281         invert_address(reversed, sub);
7282         yield = string_cat(yield, &size, &ptr, reversed);
7283         continue;
7284         }
7285
7286       /* Unknown operator */
7287
7288       default:
7289       expand_string_message =
7290         string_sprintf("unknown expansion operator \"%s\"", name);
7291       goto EXPAND_FAILED;
7292       }
7293     }
7294
7295   /* Handle a plain name. If this is the first thing in the expansion, release
7296   the pre-allocated buffer. If the result data is known to be in a new buffer,
7297   newsize will be set to the size of that buffer, and we can just point at that
7298   store instead of copying. Many expansion strings contain just one reference,
7299   so this is a useful optimization, especially for humungous headers
7300   ($message_headers). */
7301                                                 /*{*/
7302   if (*s++ == '}')
7303     {
7304     int len;
7305     int newsize = 0;
7306     if (ptr == 0)
7307       {
7308       if (resetok) store_reset(yield);
7309       yield = NULL;
7310       size = 0;
7311       }
7312     value = find_variable(name, FALSE, skipping, &newsize);
7313     if (value == NULL)
7314       {
7315       expand_string_message =
7316         string_sprintf("unknown variable in \"${%s}\"", name);
7317       check_variable_error_message(name);
7318       goto EXPAND_FAILED;
7319       }
7320     len = Ustrlen(value);
7321     if (yield == NULL && newsize != 0)
7322       {
7323       yield = value;
7324       size = newsize;
7325       ptr = len;
7326       }
7327     else yield = string_catn(yield, &size, &ptr, value, len);
7328     continue;
7329     }
7330
7331   /* Else there's something wrong */
7332
7333   expand_string_message =
7334     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7335     "in a variable reference)", name);
7336   goto EXPAND_FAILED;
7337   }
7338
7339 /* If we hit the end of the string when ket_ends is set, there is a missing
7340 terminating brace. */
7341
7342 if (ket_ends && *s == 0)
7343   {
7344   expand_string_message = malformed_header?
7345     US"missing } at end of string - could be header name not terminated by colon"
7346     :
7347     US"missing } at end of string";
7348   goto EXPAND_FAILED;
7349   }
7350
7351 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7352 added to the string. If so, set up an empty string. Add a terminating zero. If
7353 left != NULL, return a pointer to the terminator. */
7354
7355 if (yield == NULL) yield = store_get(1);
7356 yield[ptr] = 0;
7357 if (left != NULL) *left = s;
7358
7359 /* Any stacking store that was used above the final string is no longer needed.
7360 In many cases the final string will be the first one that was got and so there
7361 will be optimal store usage. */
7362
7363 if (resetok) store_reset(yield + ptr + 1);
7364 else if (resetok_p) *resetok_p = FALSE;
7365
7366 DEBUG(D_expand)
7367   {
7368   debug_printf("  expanding: %.*s\n     result: %s\n", (int)(s - string), string,
7369     yield);
7370   if (skipping) debug_printf("   skipping: result is not used\n");
7371   }
7372 return yield;
7373
7374 /* This is the failure exit: easiest to program with a goto. We still need
7375 to update the pointer to the terminator, for cases of nested calls with "fail".
7376 */
7377
7378 EXPAND_FAILED_CURLY:
7379 if (malformed_header)
7380   expand_string_message =
7381     US"missing or misplaced { or } - could be header name not terminated by colon";
7382
7383 else if (!expand_string_message || !*expand_string_message)
7384   expand_string_message = US"missing or misplaced { or }";
7385
7386 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7387 that is a bad idea, because expand_string_message is in dynamic store. */
7388
7389 EXPAND_FAILED:
7390 if (left != NULL) *left = s;
7391 DEBUG(D_expand)
7392   {
7393   debug_printf("failed to expand: %s\n", string);
7394   debug_printf("   error message: %s\n", expand_string_message);
7395   if (expand_string_forcedfail) debug_printf("failure was forced\n");
7396   }
7397 if (resetok_p) *resetok_p = resetok;
7398 return NULL;
7399 }
7400
7401
7402 /* This is the external function call. Do a quick check for any expansion
7403 metacharacters, and if there are none, just return the input string.
7404
7405 Argument: the string to be expanded
7406 Returns:  the expanded string, or NULL if expansion failed; if failure was
7407           due to a lookup deferring, search_find_defer will be TRUE
7408 */
7409
7410 uschar *
7411 expand_string(uschar *string)
7412 {
7413 search_find_defer = FALSE;
7414 malformed_header = FALSE;
7415 return (Ustrpbrk(string, "$\\") == NULL)? string :
7416   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7417 }
7418
7419
7420
7421 const uschar *
7422 expand_cstring(const uschar *string)
7423 {
7424 search_find_defer = FALSE;
7425 malformed_header = FALSE;
7426 return (Ustrpbrk(string, "$\\") == NULL)? string :
7427   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7428 }
7429
7430
7431
7432 /*************************************************
7433 *              Expand and copy                   *
7434 *************************************************/
7435
7436 /* Now and again we want to expand a string and be sure that the result is in a
7437 new bit of store. This function does that.
7438 Since we know it has been copied, the de-const cast is safe.
7439
7440 Argument: the string to be expanded
7441 Returns:  the expanded string, always in a new bit of store, or NULL
7442 */
7443
7444 uschar *
7445 expand_string_copy(const uschar *string)
7446 {
7447 const uschar *yield = expand_cstring(string);
7448 if (yield == string) yield = string_copy(string);
7449 return US yield;
7450 }
7451
7452
7453
7454 /*************************************************
7455 *        Expand and interpret as an integer      *
7456 *************************************************/
7457
7458 /* Expand a string, and convert the result into an integer.
7459
7460 Arguments:
7461   string  the string to be expanded
7462   isplus  TRUE if a non-negative number is expected
7463
7464 Returns:  the integer value, or
7465           -1 for an expansion error               ) in both cases, message in
7466           -2 for an integer interpretation error  ) expand_string_message
7467           expand_string_message is set NULL for an OK integer
7468 */
7469
7470 int_eximarith_t
7471 expand_string_integer(uschar *string, BOOL isplus)
7472 {
7473 return expanded_string_integer(expand_string(string), isplus);
7474 }
7475
7476
7477 /*************************************************
7478  *         Interpret string as an integer        *
7479  *************************************************/
7480
7481 /* Convert a string (that has already been expanded) into an integer.
7482
7483 This function is used inside the expansion code.
7484
7485 Arguments:
7486   s       the string to be expanded
7487   isplus  TRUE if a non-negative number is expected
7488
7489 Returns:  the integer value, or
7490           -1 if string is NULL (which implies an expansion error)
7491           -2 for an integer interpretation error
7492           expand_string_message is set NULL for an OK integer
7493 */
7494
7495 static int_eximarith_t
7496 expanded_string_integer(const uschar *s, BOOL isplus)
7497 {
7498 int_eximarith_t value;
7499 uschar *msg = US"invalid integer \"%s\"";
7500 uschar *endptr;
7501
7502 /* If expansion failed, expand_string_message will be set. */
7503
7504 if (s == NULL) return -1;
7505
7506 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7507 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7508 systems, so we set it zero ourselves. */
7509
7510 errno = 0;
7511 expand_string_message = NULL;               /* Indicates no error */
7512
7513 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7514 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7515 the behaviour explicitly.  Stripping leading whitespace is a harmless
7516 noop change since strtol skips it anyway (provided that there is a number
7517 to find at all). */
7518 if (isspace(*s))
7519   {
7520   while (isspace(*s)) ++s;
7521   if (*s == '\0')
7522     {
7523       DEBUG(D_expand)
7524        debug_printf("treating blank string as number 0\n");
7525       return 0;
7526     }
7527   }
7528
7529 value = strtoll(CS s, CSS &endptr, 10);
7530
7531 if (endptr == s)
7532   {
7533   msg = US"integer expected but \"%s\" found";
7534   }
7535 else if (value < 0 && isplus)
7536   {
7537   msg = US"non-negative integer expected but \"%s\" found";
7538   }
7539 else
7540   {
7541   switch (tolower(*endptr))
7542     {
7543     default:
7544       break;
7545     case 'k':
7546       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7547       else value *= 1024;
7548       endptr++;
7549       break;
7550     case 'm':
7551       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7552       else value *= 1024*1024;
7553       endptr++;
7554       break;
7555     case 'g':
7556       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7557       else value *= 1024*1024*1024;
7558       endptr++;
7559       break;
7560     }
7561   if (errno == ERANGE)
7562     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7563   else
7564     {
7565     while (isspace(*endptr)) endptr++;
7566     if (*endptr == 0) return value;
7567     }
7568   }
7569
7570 expand_string_message = string_sprintf(CS msg, s);
7571 return -2;
7572 }
7573
7574
7575 /* These values are usually fixed boolean values, but they are permitted to be
7576 expanded strings.
7577
7578 Arguments:
7579   addr       address being routed
7580   mtype      the module type
7581   mname      the module name
7582   dbg_opt    debug selectors
7583   oname      the option name
7584   bvalue     the router's boolean value
7585   svalue     the router's string value
7586   rvalue     where to put the returned value
7587
7588 Returns:     OK     value placed in rvalue
7589              DEFER  expansion failed
7590 */
7591
7592 int
7593 exp_bool(address_item *addr,
7594   uschar *mtype, uschar *mname, unsigned dbg_opt,
7595   uschar *oname, BOOL bvalue,
7596   uschar *svalue, BOOL *rvalue)
7597 {
7598 uschar *expanded;
7599 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7600
7601 expanded = expand_string(svalue);
7602 if (expanded == NULL)
7603   {
7604   if (expand_string_forcedfail)
7605     {
7606     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7607     *rvalue = bvalue;
7608     return OK;
7609     }
7610   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7611       oname, mname, mtype, expand_string_message);
7612   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7613   return DEFER;
7614   }
7615
7616 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7617   expanded);
7618
7619 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7620   *rvalue = TRUE;
7621 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7622   *rvalue = FALSE;
7623 else
7624   {
7625   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7626     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7627   return DEFER;
7628   }
7629
7630 return OK;
7631 }
7632
7633
7634
7635 /* Avoid potentially exposing a password in a string about to be logged */
7636
7637 uschar *
7638 expand_hide_passwords(uschar * s)
7639 {
7640 return (  (  Ustrstr(s, "failed to expand") != NULL
7641           || Ustrstr(s, "expansion of ")    != NULL
7642           )
7643        && (  Ustrstr(s, "mysql")   != NULL
7644           || Ustrstr(s, "pgsql")   != NULL
7645           || Ustrstr(s, "redis")   != NULL
7646           || Ustrstr(s, "sqlite")  != NULL
7647           || Ustrstr(s, "ldap:")   != NULL
7648           || Ustrstr(s, "ldaps:")  != NULL
7649           || Ustrstr(s, "ldapi:")  != NULL
7650           || Ustrstr(s, "ldapdn:") != NULL
7651           || Ustrstr(s, "ldapm:")  != NULL
7652        )  )
7653   ? US"Temporary internal error" : s;
7654 }
7655
7656
7657
7658
7659 /*************************************************
7660 **************************************************
7661 *             Stand-alone test program           *
7662 **************************************************
7663 *************************************************/
7664
7665 #ifdef STAND_ALONE
7666
7667
7668 BOOL
7669 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7670 {
7671 int ovector[3*(EXPAND_MAXN+1)];
7672 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7673   ovector, nelem(ovector));
7674 BOOL yield = n >= 0;
7675 if (n == 0) n = EXPAND_MAXN + 1;
7676 if (yield)
7677   {
7678   int nn;
7679   expand_nmax = (setup < 0)? 0 : setup + 1;
7680   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7681     {
7682     expand_nstring[expand_nmax] = subject + ovector[nn];
7683     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7684     }
7685   expand_nmax--;
7686   }
7687 return yield;
7688 }
7689
7690
7691 int main(int argc, uschar **argv)
7692 {
7693 int i;
7694 uschar buffer[1024];
7695
7696 debug_selector = D_v;
7697 debug_file = stderr;
7698 debug_fd = fileno(debug_file);
7699 big_buffer = malloc(big_buffer_size);
7700
7701 for (i = 1; i < argc; i++)
7702   {
7703   if (argv[i][0] == '+')
7704     {
7705     debug_trace_memory = 2;
7706     argv[i]++;
7707     }
7708   if (isdigit(argv[i][0]))
7709     debug_selector = Ustrtol(argv[i], NULL, 0);
7710   else
7711     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7712         Ustrlen(argv[i]))
7713       {
7714 #ifdef LOOKUP_LDAP
7715       eldap_default_servers = argv[i];
7716 #endif
7717 #ifdef LOOKUP_MYSQL
7718       mysql_servers = argv[i];
7719 #endif
7720 #ifdef LOOKUP_PGSQL
7721       pgsql_servers = argv[i];
7722 #endif
7723 #ifdef LOOKUP_REDIS
7724       redis_servers = argv[i];
7725 #endif
7726       }
7727 #ifdef EXIM_PERL
7728   else opt_perl_startup = argv[i];
7729 #endif
7730   }
7731
7732 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7733
7734 expand_nstring[1] = US"string 1....";
7735 expand_nlength[1] = 8;
7736 expand_nmax = 1;
7737
7738 #ifdef EXIM_PERL
7739 if (opt_perl_startup != NULL)
7740   {
7741   uschar *errstr;
7742   printf("Starting Perl interpreter\n");
7743   errstr = init_perl(opt_perl_startup);
7744   if (errstr != NULL)
7745     {
7746     printf("** error in perl_startup code: %s\n", errstr);
7747     return EXIT_FAILURE;
7748     }
7749   }
7750 #endif /* EXIM_PERL */
7751
7752 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7753   {
7754   void *reset_point = store_get(0);
7755   uschar *yield = expand_string(buffer);
7756   if (yield != NULL)
7757     {
7758     printf("%s\n", yield);
7759     store_reset(reset_point);
7760     }
7761   else
7762     {
7763     if (search_find_defer) printf("search_find deferred\n");
7764     printf("Failed: %s\n", expand_string_message);
7765     if (expand_string_forcedfail) printf("Forced failure\n");
7766     printf("\n");
7767     }
7768   }
7769
7770 search_tidyup();
7771
7772 return 0;
7773 }
7774
7775 #endif
7776
7777 /* vi: aw ai sw=2
7778 */
7779 /* End of expand.c */