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