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"sha3",
 235   US"stat",
 236   US"str2b64",
 237   US"strlen",
 238   US"substr",
 239   US"uc",
 240   US"utf8clean" };
 241
 242 enum {
 243   EOP_ADDRESS =  nelem(op_table_underscore),
 244   EOP_ADDRESSES,
 245   EOP_BASE62,
 246   EOP_BASE62D,
 247   EOP_BASE64,
 248   EOP_BASE64D,
 249   EOP_DOMAIN,
 250   EOP_ESCAPE,
 251   EOP_EVAL,
 252   EOP_EVAL10,
 253   EOP_EXPAND,
 254   EOP_H,
 255   EOP_HASH,
 256   EOP_HEX2B64,
 257   EOP_HEXQUOTE,
 258   EOP_IPV6DENORM,
 259   EOP_IPV6NORM,
 260   EOP_L,
 261   EOP_LC,
 262   EOP_LENGTH,
 263   EOP_LISTCOUNT,
 264   EOP_LISTNAMED,
 265   EOP_MASK,
 266   EOP_MD5,
 267   EOP_NH,
 268   EOP_NHASH,
 269   EOP_QUOTE,
 270   EOP_RANDINT,
 271   EOP_RFC2047,
 272   EOP_RFC2047D,
 273   EOP_RXQUOTE,
 274   EOP_S,
 275   EOP_SHA1,
 276   EOP_SHA256,
 277   EOP_SHA3,
 278   EOP_STAT,
 279   EOP_STR2B64,
 280   EOP_STRLEN,
 281   EOP_SUBSTR,
 282   EOP_UC,
 283   EOP_UTF8CLEAN };
 284
 285
 286 /* Table of condition names, and corresponding switch numbers. The names must
 287 be in alphabetical order. */
 288
 289 static uschar *cond_table[] = {
 290   US"<",
 291   US"<=",
 292   US"=",
 293   US"==",     /* Backward compatibility */
 294   US">",
 295   US">=",
 296   US"acl",
 297   US"and",
 298   US"bool",
 299   US"bool_lax",
 300   US"crypteq",
 301   US"def",
 302   US"eq",
 303   US"eqi",
 304   US"exists",
 305   US"first_delivery",
 306   US"forall",
 307   US"forany",
 308   US"ge",
 309   US"gei",
 310   US"gt",
 311   US"gti",
 312   US"inlist",
 313   US"inlisti",
 314   US"isip",
 315   US"isip4",
 316   US"isip6",
 317   US"ldapauth",
 318   US"le",
 319   US"lei",
 320   US"lt",
 321   US"lti",
 322   US"match",
 323   US"match_address",
 324   US"match_domain",
 325   US"match_ip",
 326   US"match_local_part",
 327   US"or",
 328   US"pam",
 329   US"pwcheck",
 330   US"queue_running",
 331   US"radius",
 332   US"saslauthd"
 333 };
 334
 335 enum {
 336   ECOND_NUM_L,
 337   ECOND_NUM_LE,
 338   ECOND_NUM_E,
 339   ECOND_NUM_EE,
 340   ECOND_NUM_G,
 341   ECOND_NUM_GE,
 342   ECOND_ACL,
 343   ECOND_AND,
 344   ECOND_BOOL,
 345   ECOND_BOOL_LAX,
 346   ECOND_CRYPTEQ,
 347   ECOND_DEF,
 348   ECOND_STR_EQ,
 349   ECOND_STR_EQI,
 350   ECOND_EXISTS,
 351   ECOND_FIRST_DELIVERY,
 352   ECOND_FORALL,
 353   ECOND_FORANY,
 354   ECOND_STR_GE,
 355   ECOND_STR_GEI,
 356   ECOND_STR_GT,
 357   ECOND_STR_GTI,
 358   ECOND_INLIST,
 359   ECOND_INLISTI,
 360   ECOND_ISIP,
 361   ECOND_ISIP4,
 362   ECOND_ISIP6,
 363   ECOND_LDAPAUTH,
 364   ECOND_STR_LE,
 365   ECOND_STR_LEI,
 366   ECOND_STR_LT,
 367   ECOND_STR_LTI,
 368   ECOND_MATCH,
 369   ECOND_MATCH_ADDRESS,
 370   ECOND_MATCH_DOMAIN,
 371   ECOND_MATCH_IP,
 372   ECOND_MATCH_LOCAL_PART,
 373   ECOND_OR,
 374   ECOND_PAM,
 375   ECOND_PWCHECK,
 376   ECOND_QUEUE_RUNNING,
 377   ECOND_RADIUS,
 378   ECOND_SASLAUTHD
 379 };
 380
 381
 382 /* Types of table entry */
 383
 384 enum vtypes {
 385   vtype_int,            /* value is address of int */
 386   vtype_filter_int,     /* ditto, but recognized only when filtering */
 387   vtype_ino,            /* value is address of ino_t (not always an int) */
 388   vtype_uid,            /* value is address of uid_t (not always an int) */
 389   vtype_gid,            /* value is address of gid_t (not always an int) */
 390   vtype_bool,           /* value is address of bool */
 391   vtype_stringptr,      /* value is address of pointer to string */
 392   vtype_msgbody,        /* as stringptr, but read when first required */
 393   vtype_msgbody_end,    /* ditto, the end of the message */
 394   vtype_msgheaders,     /* the message's headers, processed */
 395   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 396   vtype_localpart,      /* extract local part from string */
 397   vtype_domain,         /* extract domain from string */
 398   vtype_string_func,    /* value is string returned by given function */
 399   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 400   vtype_tode,           /* value not used; generate tod in epoch format */
 401   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 402   vtype_todf,           /* value not used; generate full tod */
 403   vtype_todl,           /* value not used; generate log tod */
 404   vtype_todlf,          /* value not used; generate log file datestamp tod */
 405   vtype_todzone,        /* value not used; generate time zone only */
 406   vtype_todzulu,        /* value not used; generate zulu tod */
 407   vtype_reply,          /* value not used; get reply from headers */
 408   vtype_pid,            /* value not used; result is pid */
 409   vtype_host_lookup,    /* value not used; get host name */
 410   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 411   vtype_pspace,         /* partition space; value is T/F for spool/log */
 412   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 413   vtype_cert            /* SSL certificate */
 414   #ifndef DISABLE_DKIM
 415   ,vtype_dkim           /* Lookup of value in DKIM signature */
 416   #endif
 417 };
 418
 419 /* Type for main variable table */
 420
 421 typedef struct {
 422   const char *name;
 423   enum vtypes type;
 424   void       *value;
 425 } var_entry;
 426
 427 /* Type for entries pointing to address/length pairs. Not currently
 428 in use. */
 429
 430 typedef struct {
 431   uschar **address;
 432   int  *length;
 433 } alblock;
 434
 435 static uschar * fn_recipients(void);
 436
 437 /* This table must be kept in alphabetical order. */
 438
 439 static var_entry var_table[] = {
 440   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 441      they will be confused with user-creatable ACL variables. */
 442   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 443   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 444   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 445   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 446   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 447   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 448   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 449   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 450   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 451   { "acl_narg",            vtype_int,         &acl_narg },
 452   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 453   { "address_data",        vtype_stringptr,   &deliver_address_data },
 454   { "address_file",        vtype_stringptr,   &address_file },
 455   { "address_pipe",        vtype_stringptr,   &address_pipe },
 456   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 457   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 458   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 459   { "authentication_failed",vtype_int,        &authentication_failed },
 460 #ifdef WITH_CONTENT_SCAN
 461   { "av_failed",           vtype_int,         &av_failed },
 462 #endif
 463 #ifdef EXPERIMENTAL_BRIGHTMAIL
 464   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 465   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 466   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 467   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 468 #endif
 469   { "body_linecount",      vtype_int,         &body_linecount },
 470   { "body_zerocount",      vtype_int,         &body_zerocount },
 471   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 472   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 473   { "caller_gid",          vtype_gid,         &real_gid },
 474   { "caller_uid",          vtype_uid,         &real_uid },
 475   { "callout_address",     vtype_stringptr,   &callout_address },
 476   { "compile_date",        vtype_stringptr,   &version_date },
 477   { "compile_number",      vtype_stringptr,   &version_cnumber },
 478   { "config_dir",          vtype_stringptr,   &config_main_directory },
 479   { "config_file",         vtype_stringptr,   &config_main_filename },
 480   { "csa_status",          vtype_stringptr,   &csa_status },
 481 #ifdef EXPERIMENTAL_DCC
 482   { "dcc_header",          vtype_stringptr,   &dcc_header },
 483   { "dcc_result",          vtype_stringptr,   &dcc_result },
 484 #endif
 485 #ifndef DISABLE_DKIM
 486   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 487   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 488   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 489   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 490   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 491   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 492   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 493   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 494   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 495   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 496   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 497   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 498   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 499   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 500   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 501   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 502   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 503   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 504   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 505   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 506   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 507 #endif
 508 #ifdef EXPERIMENTAL_DMARC
 509   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 510   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 511   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 512   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 513   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 514 #endif
 515   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 516   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 517   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 518   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 519   { "domain",              vtype_stringptr,   &deliver_domain },
 520   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 521 #ifndef DISABLE_EVENT
 522   { "event_data",          vtype_stringptr,   &event_data },
 523
 524   /*XXX want to use generic vars for as many of these as possible*/
 525   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 526
 527   { "event_name",          vtype_stringptr,   &event_name },
 528 #endif
 529   { "exim_gid",            vtype_gid,         &exim_gid },
 530   { "exim_path",           vtype_stringptr,   &exim_path },
 531   { "exim_uid",            vtype_uid,         &exim_uid },
 532   { "exim_version",        vtype_stringptr,   &version_string },
 533   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 534   { "home",                vtype_stringptr,   &deliver_home },
 535   { "host",                vtype_stringptr,   &deliver_host },
 536   { "host_address",        vtype_stringptr,   &deliver_host_address },
 537   { "host_data",           vtype_stringptr,   &host_data },
 538   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 539   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 540   { "host_port",           vtype_int,         &deliver_host_port },
 541   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 542   { "inode",               vtype_ino,         &deliver_inode },
 543   { "interface_address",   vtype_stringptr,   &interface_address },
 544   { "interface_port",      vtype_int,         &interface_port },
 545   { "item",                vtype_stringptr,   &iterate_item },
 546   #ifdef LOOKUP_LDAP
 547   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 548   #endif
 549   { "load_average",        vtype_load_avg,    NULL },
 550   { "local_part",          vtype_stringptr,   &deliver_localpart },
 551   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 552   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 553   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 554   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 555   { "local_user_gid",      vtype_gid,         &local_user_gid },
 556   { "local_user_uid",      vtype_uid,         &local_user_uid },
 557   { "localhost_number",    vtype_int,         &host_number },
 558   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 559   { "log_space",           vtype_pspace,      (void *)FALSE },
 560   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 561   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 562 #ifdef WITH_CONTENT_SCAN
 563   { "malware_name",        vtype_stringptr,   &malware_name },
 564 #endif
 565   { "max_received_linelength", vtype_int,     &max_received_linelength },
 566   { "message_age",         vtype_int,         &message_age },
 567   { "message_body",        vtype_msgbody,     &message_body },
 568   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 569   { "message_body_size",   vtype_int,         &message_body_size },
 570   { "message_exim_id",     vtype_stringptr,   &message_id },
 571   { "message_headers",     vtype_msgheaders,  NULL },
 572   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 573   { "message_id",          vtype_stringptr,   &message_id },
 574   { "message_linecount",   vtype_int,         &message_linecount },
 575   { "message_size",        vtype_int,         &message_size },
 576 #ifdef SUPPORT_I18N
 577   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 578 #endif
 579 #ifdef WITH_CONTENT_SCAN
 580   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 581   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 582   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 583   { "mime_charset",        vtype_stringptr,   &mime_charset },
 584   { "mime_content_description", vtype_stringptr, &mime_content_description },
 585   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 586   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 587   { "mime_content_size",   vtype_int,         &mime_content_size },
 588   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 589   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 590   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 591   { "mime_filename",       vtype_stringptr,   &mime_filename },
 592   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 593   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 594   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 595   { "mime_part_count",     vtype_int,         &mime_part_count },
 596 #endif
 597   { "n0",                  vtype_filter_int,  &filter_n[0] },
 598   { "n1",                  vtype_filter_int,  &filter_n[1] },
 599   { "n2",                  vtype_filter_int,  &filter_n[2] },
 600   { "n3",                  vtype_filter_int,  &filter_n[3] },
 601   { "n4",                  vtype_filter_int,  &filter_n[4] },
 602   { "n5",                  vtype_filter_int,  &filter_n[5] },
 603   { "n6",                  vtype_filter_int,  &filter_n[6] },
 604   { "n7",                  vtype_filter_int,  &filter_n[7] },
 605   { "n8",                  vtype_filter_int,  &filter_n[8] },
 606   { "n9",                  vtype_filter_int,  &filter_n[9] },
 607   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 608   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 609   { "originator_gid",      vtype_gid,         &originator_gid },
 610   { "originator_uid",      vtype_uid,         &originator_uid },
 611   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 612   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 613   { "pid",                 vtype_pid,         NULL },
 614 #ifndef DISABLE_PRDR
 615   { "prdr_requested",      vtype_bool,        &prdr_requested },
 616 #endif
 617   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 618 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 619   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 620   { "proxy_external_port", vtype_int,         &proxy_external_port },
 621   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 622   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 623   { "proxy_session",       vtype_bool,        &proxy_session },
 624 #endif
 625   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 626   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 627   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 628   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 629   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 630   { "queue_name",          vtype_stringptr,   &queue_name },
 631   { "rcpt_count",          vtype_int,         &rcpt_count },
 632   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 633   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 634   { "received_count",      vtype_int,         &received_count },
 635   { "received_for",        vtype_stringptr,   &received_for },
 636   { "received_ip_address", vtype_stringptr,   &interface_address },
 637   { "received_port",       vtype_int,         &interface_port },
 638   { "received_protocol",   vtype_stringptr,   &received_protocol },
 639   { "received_time",       vtype_int,         &received_time },
 640   { "recipient_data",      vtype_stringptr,   &recipient_data },
 641   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 642   { "recipients",          vtype_string_func, &fn_recipients },
 643   { "recipients_count",    vtype_int,         &recipients_count },
 644 #ifdef WITH_CONTENT_SCAN
 645   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 646 #endif
 647   { "reply_address",       vtype_reply,       NULL },
 648   { "return_path",         vtype_stringptr,   &return_path },
 649   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 650   { "router_name",         vtype_stringptr,   &router_name },
 651   { "runrc",               vtype_int,         &runrc },
 652   { "self_hostname",       vtype_stringptr,   &self_hostname },
 653   { "sender_address",      vtype_stringptr,   &sender_address },
 654   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 655   { "sender_address_domain", vtype_domain,    &sender_address },
 656   { "sender_address_local_part", vtype_localpart, &sender_address },
 657   { "sender_data",         vtype_stringptr,   &sender_data },
 658   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 659   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 660   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 661   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 662   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 663   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 664   { "sender_host_name",    vtype_host_lookup, NULL },
 665   { "sender_host_port",    vtype_int,         &sender_host_port },
 666   { "sender_ident",        vtype_stringptr,   &sender_ident },
 667   { "sender_rate",         vtype_stringptr,   &sender_rate },
 668   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 669   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 670   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 671   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 672   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 673   { "sending_port",        vtype_int,         &sending_port },
 674   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 675   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 676   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 677   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 678   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 679   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 680   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 681   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 682   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 683   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 684   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 685   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 686   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 687   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 688   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 689 #ifdef WITH_CONTENT_SCAN
 690   { "spam_action",         vtype_stringptr,   &spam_action },
 691   { "spam_bar",            vtype_stringptr,   &spam_bar },
 692   { "spam_report",         vtype_stringptr,   &spam_report },
 693   { "spam_score",          vtype_stringptr,   &spam_score },
 694   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 695 #endif
 696 #ifdef EXPERIMENTAL_SPF
 697   { "spf_guess",           vtype_stringptr,   &spf_guess },
 698   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 699   { "spf_received",        vtype_stringptr,   &spf_received },
 700   { "spf_result",          vtype_stringptr,   &spf_result },
 701   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 702 #endif
 703   { "spool_directory",     vtype_stringptr,   &spool_directory },
 704   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 705   { "spool_space",         vtype_pspace,      (void *)TRUE },
 706 #ifdef EXPERIMENTAL_SRS
 707   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 708   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 709   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 710   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 711   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 712   { "srs_status",          vtype_stringptr,   &srs_status },
 713 #endif
 714   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 715
 716   /* The non-(in,out) variables are now deprecated */
 717   { "tls_bits",            vtype_int,         &tls_in.bits },
 718   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 719   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 720
 721   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 722   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 723   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 724   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 725   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 726   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 727   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 728 #if defined(SUPPORT_TLS)
 729   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 730 #endif
 731   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 732   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 733   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 734 #ifdef EXPERIMENTAL_DANE
 735   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 736 #endif
 737   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 738   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 739   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 740   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 741 #if defined(SUPPORT_TLS)
 742   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 743 #endif
 744 #ifdef EXPERIMENTAL_DANE
 745   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 746 #endif
 747
 748   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 749 #if defined(SUPPORT_TLS)
 750   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 751 #endif
 752
 753   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 754   { "tod_epoch",           vtype_tode,        NULL },
 755   { "tod_epoch_l",         vtype_todel,       NULL },
 756   { "tod_full",            vtype_todf,        NULL },
 757   { "tod_log",             vtype_todl,        NULL },
 758   { "tod_logfile",         vtype_todlf,       NULL },
 759   { "tod_zone",            vtype_todzone,     NULL },
 760   { "tod_zulu",            vtype_todzulu,     NULL },
 761   { "transport_name",      vtype_stringptr,   &transport_name },
 762   { "value",               vtype_stringptr,   &lookup_value },
 763   { "verify_mode",         vtype_stringptr,   &verify_mode },
 764   { "version_number",      vtype_stringptr,   &version_string },
 765   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 766   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 767   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 768   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 769   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 770   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 771 };
 772
 773 static int var_table_size = nelem(var_table);
 774 static uschar var_buffer[256];
 775 static BOOL malformed_header;
 776
 777 /* For textual hashes */
 778
 779 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 780                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 781                                "0123456789";
 782
 783 enum { HMAC_MD5, HMAC_SHA1 };
 784
 785 /* For numeric hashes */
 786
 787 static unsigned int prime[] = {
 788   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 789  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 790  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 791
 792 /* For printing modes in symbolic form */
 793
 794 static uschar *mtable_normal[] =
 795   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 796
 797 static uschar *mtable_setid[] =
 798   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 799
 800 static uschar *mtable_sticky[] =
 801   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 802
 803
 804
 805 /*************************************************
 806 *           Tables for UTF-8 support             *
 807 *************************************************/
 808
 809 /* Table of the number of extra characters, indexed by the first character
 810 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 811 0x3d. */
 812
 813 static uschar utf8_table1[] = {
 814   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 815   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 816   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 817   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 818
 819 /* These are the masks for the data bits in the first byte of a character,
 820 indexed by the number of additional bytes. */
 821
 822 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 823
 824 /* Get the next UTF-8 character, advancing the pointer. */
 825
 826 #define GETUTF8INC(c, ptr) \
 827   c = *ptr++; \
 828   if ((c & 0xc0) == 0xc0) \
 829     { \
 830     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 831     int s = 6*a; \
 832     c = (c & utf8_table2[a]) << s; \
 833     while (a-- > 0) \
 834       { \
 835       s -= 6; \
 836       c |= (*ptr++ & 0x3f) << s; \
 837       } \
 838     }
 839
 840
 841 /*************************************************
 842 *           Binary chop search on a table        *
 843 *************************************************/
 844
 845 /* This is used for matching expansion items and operators.
 846
 847 Arguments:
 848   name        the name that is being sought
 849   table       the table to search
 850   table_size  the number of items in the table
 851
 852 Returns:      the offset in the table, or -1
 853 */
 854
 855 static int
 856 chop_match(uschar *name, uschar **table, int table_size)
 857 {
 858 uschar **bot = table;
 859 uschar **top = table + table_size;
 860
 861 while (top > bot)
 862   {
 863   uschar **mid = bot + (top - bot)/2;
 864   int c = Ustrcmp(name, *mid);
 865   if (c == 0) return mid - table;
 866   if (c > 0) bot = mid + 1; else top = mid;
 867   }
 868
 869 return -1;
 870 }
 871
 872
 873
 874 /*************************************************
 875 *          Check a condition string              *
 876 *************************************************/
 877
 878 /* This function is called to expand a string, and test the result for a "true"
 879 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 880 forced fail or lookup defer.
 881
 882 We used to release all store used, but this is not not safe due
 883 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 884 is reasonably careful to release what it can.
 885
 886 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 887
 888 Arguments:
 889   condition     the condition string
 890   m1            text to be incorporated in panic error
 891   m2            ditto
 892
 893 Returns:        TRUE if condition is met, FALSE if not
 894 */
 895
 896 BOOL
 897 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 898 {
 899 int rc;
 900 uschar *ss = expand_string(condition);
 901 if (ss == NULL)
 902   {
 903   if (!expand_string_forcedfail && !search_find_defer)
 904     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 905       "for %s %s: %s", condition, m1, m2, expand_string_message);
 906   return FALSE;
 907   }
 908 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 909   strcmpic(ss, US"false") != 0;
 910 return rc;
 911 }
 912
 913
 914
 915
 916 /*************************************************
 917 *        Pseudo-random number generation         *
 918 *************************************************/
 919
 920 /* Pseudo-random number generation.  The result is not "expected" to be
 921 cryptographically strong but not so weak that someone will shoot themselves
 922 in the foot using it as a nonce in some email header scheme or whatever
 923 weirdness they'll twist this into.  The result should ideally handle fork().
 924
 925 However, if we're stuck unable to provide this, then we'll fall back to
 926 appallingly bad randomness.
 927
 928 If SUPPORT_TLS is defined then this will not be used except as an emergency
 929 fallback.
 930
 931 Arguments:
 932   max       range maximum
 933 Returns     a random number in range [0, max-1]
 934 */
 935
 936 #ifdef SUPPORT_TLS
 937 # define vaguely_random_number vaguely_random_number_fallback
 938 #endif
 939 int
 940 vaguely_random_number(int max)
 941 {
 942 #ifdef SUPPORT_TLS
 943 # undef vaguely_random_number
 944 #endif
 945   static pid_t pid = 0;
 946   pid_t p2;
 947 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 948   struct timeval tv;
 949 #endif
 950
 951   p2 = getpid();
 952   if (p2 != pid)
 953     {
 954     if (pid != 0)
 955       {
 956
 957 #ifdef HAVE_ARC4RANDOM
 958       /* cryptographically strong randomness, common on *BSD platforms, not
 959       so much elsewhere.  Alas. */
 960 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 961       arc4random_stir();
 962 #endif
 963 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 964 #ifdef HAVE_SRANDOMDEV
 965       /* uses random(4) for seeding */
 966       srandomdev();
 967 #else
 968       gettimeofday(&tv, NULL);
 969       srandom(tv.tv_sec | tv.tv_usec | getpid());
 970 #endif
 971 #else
 972       /* Poor randomness and no seeding here */
 973 #endif
 974
 975       }
 976     pid = p2;
 977     }
 978
 979 #ifdef HAVE_ARC4RANDOM
 980   return arc4random() % max;
 981 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 982   return random() % max;
 983 #else
 984   /* This one returns a 16-bit number, definitely not crypto-strong */
 985   return random_number(max);
 986 #endif
 987 }
 988
 989
 990
 991
 992 /*************************************************
 993 *             Pick out a name from a string      *
 994 *************************************************/
 995
 996 /* If the name is too long, it is silently truncated.
 997
 998 Arguments:
 999   name      points to a buffer into which to put the name
1000   max       is the length of the buffer
1001   s         points to the first alphabetic character of the name
1002   extras    chars other than alphanumerics to permit
1003
1004 Returns:    pointer to the first character after the name
1005
1006 Note: The test for *s != 0 in the while loop is necessary because
1007 Ustrchr() yields non-NULL if the character is zero (which is not something
1008 I expected). */
1009
1010 static const uschar *
1011 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1012 {
1013 int ptr = 0;
1014 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1015   {
1016   if (ptr < max-1) name[ptr++] = *s;
1017   s++;
1018   }
1019 name[ptr] = 0;
1020 return s;
1021 }
1022
1023
1024
1025 /*************************************************
1026 *     Pick out the rest of a header name         *
1027 *************************************************/
1028
1029 /* A variable name starting $header_ (or just $h_ for those who like
1030 abbreviations) might not be the complete header name because headers can
1031 contain any printing characters in their names, except ':'. This function is
1032 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1033 on the end, if the name was terminated by white space.
1034
1035 Arguments:
1036   name      points to a buffer in which the name read so far exists
1037   max       is the length of the buffer
1038   s         points to the first character after the name so far, i.e. the
1039             first non-alphameric character after $header_xxxxx
1040
1041 Returns:    a pointer to the first character after the header name
1042 */
1043
1044 static const uschar *
1045 read_header_name(uschar *name, int max, const uschar *s)
1046 {
1047 int prelen = Ustrchr(name, '_') - name + 1;
1048 int ptr = Ustrlen(name) - prelen;
1049 if (ptr > 0) memmove(name, name+prelen, ptr);
1050 while (mac_isgraph(*s) && *s != ':')
1051   {
1052   if (ptr < max-1) name[ptr++] = *s;
1053   s++;
1054   }
1055 if (*s == ':') s++;
1056 name[ptr++] = ':';
1057 name[ptr] = 0;
1058 return s;
1059 }
1060
1061
1062
1063 /*************************************************
1064 *           Pick out a number from a string      *
1065 *************************************************/
1066
1067 /* Arguments:
1068   n     points to an integer into which to put the number
1069   s     points to the first digit of the number
1070
1071 Returns:  a pointer to the character after the last digit
1072 */
1073 /*XXX consider expanding to int_eximarith_t.  But the test for
1074 "overbig numbers" in 0002 still needs to overflow it. */
1075
1076 static uschar *
1077 read_number(int *n, uschar *s)
1078 {
1079 *n = 0;
1080 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1081 return s;
1082 }
1083
1084 static const uschar *
1085 read_cnumber(int *n, const uschar *s)
1086 {
1087 *n = 0;
1088 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1089 return s;
1090 }
1091
1092
1093
1094 /*************************************************
1095 *        Extract keyed subfield from a string    *
1096 *************************************************/
1097
1098 /* The yield is in dynamic store; NULL means that the key was not found.
1099
1100 Arguments:
1101   key       points to the name of the key
1102   s         points to the string from which to extract the subfield
1103
1104 Returns:    NULL if the subfield was not found, or
1105             a pointer to the subfield's data
1106 */
1107
1108 static uschar *
1109 expand_getkeyed(uschar *key, const uschar *s)
1110 {
1111 int length = Ustrlen(key);
1112 while (isspace(*s)) s++;
1113
1114 /* Loop to search for the key */
1115
1116 while (*s != 0)
1117   {
1118   int dkeylength;
1119   uschar *data;
1120   const uschar *dkey = s;
1121
1122   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1123   dkeylength = s - dkey;
1124   while (isspace(*s)) s++;
1125   if (*s == '=') while (isspace((*(++s))));
1126
1127   data = string_dequote(&s);
1128   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1129     return data;
1130
1131   while (isspace(*s)) s++;
1132   }
1133
1134 return NULL;
1135 }
1136
1137
1138
1139 static var_entry *
1140 find_var_ent(uschar * name)
1141 {
1142 int first = 0;
1143 int last = var_table_size;
1144
1145 while (last > first)
1146   {
1147   int middle = (first + last)/2;
1148   int c = Ustrcmp(name, var_table[middle].name);
1149
1150   if (c > 0) { first = middle + 1; continue; }
1151   if (c < 0) { last = middle; continue; }
1152   return &var_table[middle];
1153   }
1154 return NULL;
1155 }
1156
1157 /*************************************************
1158 *   Extract numbered subfield from string        *
1159 *************************************************/
1160
1161 /* Extracts a numbered field from a string that is divided by tokens - for
1162 example a line from /etc/passwd is divided by colon characters.  First field is
1163 numbered one.  Negative arguments count from the right. Zero returns the whole
1164 string. Returns NULL if there are insufficient tokens in the string
1165
1166 ***WARNING***
1167 Modifies final argument - this is a dynamically generated string, so that's OK.
1168
1169 Arguments:
1170   field       number of field to be extracted,
1171                 first field = 1, whole string = 0, last field = -1
1172   separators  characters that are used to break string into tokens
1173   s           points to the string from which to extract the subfield
1174
1175 Returns:      NULL if the field was not found,
1176               a pointer to the field's data inside s (modified to add 0)
1177 */
1178
1179 static uschar *
1180 expand_gettokened (int field, uschar *separators, uschar *s)
1181 {
1182 int sep = 1;
1183 int count;
1184 uschar *ss = s;
1185 uschar *fieldtext = NULL;
1186
1187 if (field == 0) return s;
1188
1189 /* Break the line up into fields in place; for field > 0 we stop when we have
1190 done the number of fields we want. For field < 0 we continue till the end of
1191 the string, counting the number of fields. */
1192
1193 count = (field > 0)? field : INT_MAX;
1194
1195 while (count-- > 0)
1196   {
1197   size_t len;
1198
1199   /* Previous field was the last one in the string. For a positive field
1200   number, this means there are not enough fields. For a negative field number,
1201   check that there are enough, and scan back to find the one that is wanted. */
1202
1203   if (sep == 0)
1204     {
1205     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1206     if ((-field) == (INT_MAX - count - 1)) return s;
1207     while (field++ < 0)
1208       {
1209       ss--;
1210       while (ss[-1] != 0) ss--;
1211       }
1212     fieldtext = ss;
1213     break;
1214     }
1215
1216   /* Previous field was not last in the string; save its start and put a
1217   zero at its end. */
1218
1219   fieldtext = ss;
1220   len = Ustrcspn(ss, separators);
1221   sep = ss[len];
1222   ss[len] = 0;
1223   ss += len + 1;
1224   }
1225
1226 return fieldtext;
1227 }
1228
1229
1230 static uschar *
1231 expand_getlistele(int field, const uschar * list)
1232 {
1233 const uschar * tlist= list;
1234 int sep= 0;
1235 uschar dummy;
1236
1237 if(field<0)
1238   {
1239   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1240   sep= 0;
1241   }
1242 if(field==0) return NULL;
1243 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1244 return string_nextinlist(&list, &sep, NULL, 0);
1245 }
1246
1247
1248 /* Certificate fields, by name.  Worry about by-OID later */
1249 /* Names are chosen to not have common prefixes */
1250
1251 #ifdef SUPPORT_TLS
1252 typedef struct
1253 {
1254 uschar * name;
1255 int      namelen;
1256 uschar * (*getfn)(void * cert, uschar * mod);
1257 } certfield;
1258 static certfield certfields[] =
1259 {                       /* linear search; no special order */
1260   { US"version",         7,  &tls_cert_version },
1261   { US"serial_number",   13, &tls_cert_serial_number },
1262   { US"subject",         7,  &tls_cert_subject },
1263   { US"notbefore",       9,  &tls_cert_not_before },
1264   { US"notafter",        8,  &tls_cert_not_after },
1265   { US"issuer",          6,  &tls_cert_issuer },
1266   { US"signature",       9,  &tls_cert_signature },
1267   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1268   { US"subj_altname",    12, &tls_cert_subject_altname },
1269   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1270   { US"crl_uri",         7,  &tls_cert_crl_uri },
1271 };
1272
1273 static uschar *
1274 expand_getcertele(uschar * field, uschar * certvar)
1275 {
1276 var_entry * vp;
1277 certfield * cp;
1278
1279 if (!(vp = find_var_ent(certvar)))
1280   {
1281   expand_string_message =
1282     string_sprintf("no variable named \"%s\"", certvar);
1283   return NULL;          /* Unknown variable name */
1284   }
1285 /* NB this stops us passing certs around in variable.  Might
1286 want to do that in future */
1287 if (vp->type != vtype_cert)
1288   {
1289   expand_string_message =
1290     string_sprintf("\"%s\" is not a certificate", certvar);
1291   return NULL;          /* Unknown variable name */
1292   }
1293 if (!*(void **)vp->value)
1294   return NULL;
1295
1296 if (*field >= '0' && *field <= '9')
1297   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1298
1299 for(cp = certfields;
1300     cp < certfields + nelem(certfields);
1301     cp++)
1302   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1303     {
1304     uschar * modifier = *(field += cp->namelen) == ','
1305       ? ++field : NULL;
1306     return (*cp->getfn)( *(void **)vp->value, modifier );
1307     }
1308
1309 expand_string_message =
1310   string_sprintf("bad field selector \"%s\" for certextract", field);
1311 return NULL;
1312 }
1313 #endif  /*SUPPORT_TLS*/
1314
1315 /*************************************************
1316 *        Extract a substring from a string       *
1317 *************************************************/
1318
1319 /* Perform the ${substr or ${length expansion operations.
1320
1321 Arguments:
1322   subject     the input string
1323   value1      the offset from the start of the input string to the start of
1324                 the output string; if negative, count from the right.
1325   value2      the length of the output string, or negative (-1) for unset
1326                 if value1 is positive, unset means "all after"
1327                 if value1 is negative, unset means "all before"
1328   len         set to the length of the returned string
1329
1330 Returns:      pointer to the output string, or NULL if there is an error
1331 */
1332
1333 static uschar *
1334 extract_substr(uschar *subject, int value1, int value2, int *len)
1335 {
1336 int sublen = Ustrlen(subject);
1337
1338 if (value1 < 0)    /* count from right */
1339   {
1340   value1 += sublen;
1341
1342   /* If the position is before the start, skip to the start, and adjust the
1343   length. If the length ends up negative, the substring is null because nothing
1344   can precede. This falls out naturally when the length is unset, meaning "all
1345   to the left". */
1346
1347   if (value1 < 0)
1348     {
1349     value2 += value1;
1350     if (value2 < 0) value2 = 0;
1351     value1 = 0;
1352     }
1353
1354   /* Otherwise an unset length => characters before value1 */
1355
1356   else if (value2 < 0)
1357     {
1358     value2 = value1;
1359     value1 = 0;
1360     }
1361   }
1362
1363 /* For a non-negative offset, if the starting position is past the end of the
1364 string, the result will be the null string. Otherwise, an unset length means
1365 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1366
1367 else
1368   {
1369   if (value1 > sublen)
1370     {
1371     value1 = sublen;
1372     value2 = 0;
1373     }
1374   else if (value2 < 0) value2 = sublen;
1375   }
1376
1377 /* Cut the length down to the maximum possible for the offset value, and get
1378 the required characters. */
1379
1380 if (value1 + value2 > sublen) value2 = sublen - value1;
1381 *len = value2;
1382 return subject + value1;
1383 }
1384
1385
1386
1387
1388 /*************************************************
1389 *            Old-style hash of a string          *
1390 *************************************************/
1391
1392 /* Perform the ${hash expansion operation.
1393
1394 Arguments:
1395   subject     the input string (an expanded substring)
1396   value1      the length of the output string; if greater or equal to the
1397                 length of the input string, the input string is returned
1398   value2      the number of hash characters to use, or 26 if negative
1399   len         set to the length of the returned string
1400
1401 Returns:      pointer to the output string, or NULL if there is an error
1402 */
1403
1404 static uschar *
1405 compute_hash(uschar *subject, int value1, int value2, int *len)
1406 {
1407 int sublen = Ustrlen(subject);
1408
1409 if (value2 < 0) value2 = 26;
1410 else if (value2 > Ustrlen(hashcodes))
1411   {
1412   expand_string_message =
1413     string_sprintf("hash count \"%d\" too big", value2);
1414   return NULL;
1415   }
1416
1417 /* Calculate the hash text. We know it is shorter than the original string, so
1418 can safely place it in subject[] (we know that subject is always itself an
1419 expanded substring). */
1420
1421 if (value1 < sublen)
1422   {
1423   int c;
1424   int i = 0;
1425   int j = value1;
1426   while ((c = (subject[j])) != 0)
1427     {
1428     int shift = (c + j++) & 7;
1429     subject[i] ^= (c << shift) | (c >> (8-shift));
1430     if (++i >= value1) i = 0;
1431     }
1432   for (i = 0; i < value1; i++)
1433     subject[i] = hashcodes[(subject[i]) % value2];
1434   }
1435 else value1 = sublen;
1436
1437 *len = value1;
1438 return subject;
1439 }
1440
1441
1442
1443
1444 /*************************************************
1445 *             Numeric hash of a string           *
1446 *************************************************/
1447
1448 /* Perform the ${nhash expansion operation. The first characters of the
1449 string are treated as most important, and get the highest prime numbers.
1450
1451 Arguments:
1452   subject     the input string
1453   value1      the maximum value of the first part of the result
1454   value2      the maximum value of the second part of the result,
1455                 or negative to produce only a one-part result
1456   len         set to the length of the returned string
1457
1458 Returns:  pointer to the output string, or NULL if there is an error.
1459 */
1460
1461 static uschar *
1462 compute_nhash (uschar *subject, int value1, int value2, int *len)
1463 {
1464 uschar *s = subject;
1465 int i = 0;
1466 unsigned long int total = 0; /* no overflow */
1467
1468 while (*s != 0)
1469   {
1470   if (i == 0) i = nelem(prime) - 1;
1471   total += prime[i--] * (unsigned int)(*s++);
1472   }
1473
1474 /* If value2 is unset, just compute one number */
1475
1476 if (value2 < 0)
1477   {
1478   s = string_sprintf("%d", total % value1);
1479   }
1480
1481 /* Otherwise do a div/mod hash */
1482
1483 else
1484   {
1485   total = total % (value1 * value2);
1486   s = string_sprintf("%d/%d", total/value2, total % value2);
1487   }
1488
1489 *len = Ustrlen(s);
1490 return s;
1491 }
1492
1493
1494
1495
1496
1497 /*************************************************
1498 *     Find the value of a header or headers      *
1499 *************************************************/
1500
1501 /* Multiple instances of the same header get concatenated, and this function
1502 can also return a concatenation of all the header lines. When concatenating
1503 specific headers that contain lists of addresses, a comma is inserted between
1504 them. Otherwise we use a straight concatenation. Because some messages can have
1505 pathologically large number of lines, there is a limit on the length that is
1506 returned. Also, to avoid massive store use which would result from using
1507 string_cat() as it copies and extends strings, we do a preliminary pass to find
1508 out exactly how much store will be needed. On "normal" messages this will be
1509 pretty trivial.
1510
1511 Arguments:
1512   name          the name of the header, without the leading $header_ or $h_,
1513                 or NULL if a concatenation of all headers is required
1514   exists_only   TRUE if called from a def: test; don't need to build a string;
1515                 just return a string that is not "" and not "0" if the header
1516                 exists
1517   newsize       return the size of memory block that was obtained; may be NULL
1518                 if exists_only is TRUE
1519   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1520                 other than concatenating, will be done on the header. Also used
1521                 for $message_headers_raw.
1522   charset       name of charset to translate MIME words to; used only if
1523                 want_raw is false; if NULL, no translation is done (this is
1524                 used for $bh_ and $bheader_)
1525
1526 Returns:        NULL if the header does not exist, else a pointer to a new
1527                 store block
1528 */
1529
1530 static uschar *
1531 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1532   uschar *charset)
1533 {
1534 BOOL found = name == NULL;
1535 int comma = 0;
1536 int len = found? 0 : Ustrlen(name);
1537 int i;
1538 uschar *yield = NULL;
1539 uschar *ptr = NULL;
1540
1541 /* Loop for two passes - saves code repetition */
1542
1543 for (i = 0; i < 2; i++)
1544   {
1545   int size = 0;
1546   header_line *h;
1547
1548   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1549     {
1550     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1551       {
1552       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1553         {
1554         int ilen;
1555         uschar *t;
1556
1557         if (exists_only) return US"1";      /* don't need actual string */
1558         found = TRUE;
1559         t = h->text + len;                  /* text to insert */
1560         if (!want_raw)                      /* unless wanted raw, */
1561           while (isspace(*t)) t++;          /* remove leading white space */
1562         ilen = h->slen - (t - h->text);     /* length to insert */
1563
1564         /* Unless wanted raw, remove trailing whitespace, including the
1565         newline. */
1566
1567         if (!want_raw)
1568           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1569
1570         /* Set comma = 1 if handling a single header and it's one of those
1571         that contains an address list, except when asked for raw headers. Only
1572         need to do this once. */
1573
1574         if (!want_raw && name != NULL && comma == 0 &&
1575             Ustrchr("BCFRST", h->type) != NULL)
1576           comma = 1;
1577
1578         /* First pass - compute total store needed; second pass - compute
1579         total store used, including this header. */
1580
1581         size += ilen + comma + 1;  /* +1 for the newline */
1582
1583         /* Second pass - concatentate the data, up to a maximum. Note that
1584         the loop stops when size hits the limit. */
1585
1586         if (i != 0)
1587           {
1588           if (size > header_insert_maxlen)
1589             {
1590             ilen -= size - header_insert_maxlen - 1;
1591             comma = 0;
1592             }
1593           Ustrncpy(ptr, t, ilen);
1594           ptr += ilen;
1595
1596           /* For a non-raw header, put in the comma if needed, then add
1597           back the newline we removed above, provided there was some text in
1598           the header. */
1599
1600           if (!want_raw && ilen > 0)
1601             {
1602             if (comma != 0) *ptr++ = ',';
1603             *ptr++ = '\n';
1604             }
1605           }
1606         }
1607       }
1608     }
1609
1610   /* At end of first pass, return NULL if no header found. Then truncate size
1611   if necessary, and get the buffer to hold the data, returning the buffer size.
1612   */
1613
1614   if (i == 0)
1615     {
1616     if (!found) return NULL;
1617     if (size > header_insert_maxlen) size = header_insert_maxlen;
1618     *newsize = size + 1;
1619     ptr = yield = store_get(*newsize);
1620     }
1621   }
1622
1623 /* That's all we do for raw header expansion. */
1624
1625 if (want_raw)
1626   {
1627   *ptr = 0;
1628   }
1629
1630 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1631 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1632 function can return an error with decoded data if the charset translation
1633 fails. If decoding fails, it returns NULL. */
1634
1635 else
1636   {
1637   uschar *decoded, *error;
1638   if (ptr > yield && ptr[-1] == '\n') ptr--;
1639   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1640   *ptr = 0;
1641   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1642     newsize, &error);
1643   if (error != NULL)
1644     {
1645     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1646       "    input was: %s\n", error, yield);
1647     }
1648   if (decoded != NULL) yield = decoded;
1649   }
1650
1651 return yield;
1652 }
1653
1654
1655
1656
1657 /*************************************************
1658 *               Return list of recipients        *
1659 *************************************************/
1660 /* A recipients list is available only during system message filtering,
1661 during ACL processing after DATA, and while expanding pipe commands
1662 generated from a system filter, but not elsewhere. */
1663
1664 static uschar *
1665 fn_recipients(void)
1666 {
1667 if (!enable_dollar_recipients) return NULL; else
1668   {
1669   int size = 128;
1670   int ptr = 0;
1671   int i;
1672   uschar * s = store_get(size);
1673   for (i = 0; i < recipients_count; i++)
1674     {
1675     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1676     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1677     }
1678   s[ptr] = 0;     /* string_cat() leaves room */
1679   return s;
1680   }
1681 }
1682
1683
1684 /*************************************************
1685 *               Find value of a variable         *
1686 *************************************************/
1687
1688 /* The table of variables is kept in alphabetic order, so we can search it
1689 using a binary chop. The "choplen" variable is nothing to do with the binary
1690 chop.
1691
1692 Arguments:
1693   name          the name of the variable being sought
1694   exists_only   TRUE if this is a def: test; passed on to find_header()
1695   skipping      TRUE => skip any processing evaluation; this is not the same as
1696                   exists_only because def: may test for values that are first
1697                   evaluated here
1698   newsize       pointer to an int which is initially zero; if the answer is in
1699                 a new memory buffer, *newsize is set to its size
1700
1701 Returns:        NULL if the variable does not exist, or
1702                 a pointer to the variable's contents, or
1703                 something non-NULL if exists_only is TRUE
1704 */
1705
1706 static uschar *
1707 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1708 {
1709 var_entry * vp;
1710 uschar *s, *domain;
1711 uschar **ss;
1712 void * val;
1713
1714 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1715 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1716 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1717 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1718 (this gave backwards compatibility at the changeover). There may be built-in
1719 variables whose names start acl_ but they should never start in this way. This
1720 slightly messy specification is a consequence of the history, needless to say.
1721
1722 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1723 set, in which case give an error. */
1724
1725 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1726      !isalpha(name[5]))
1727   {
1728   tree_node *node =
1729     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1730   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1731   }
1732
1733 /* Handle $auth<n> variables. */
1734
1735 if (Ustrncmp(name, "auth", 4) == 0)
1736   {
1737   uschar *endptr;
1738   int n = Ustrtoul(name + 4, &endptr, 10);
1739   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1740     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1741   }
1742 else if (Ustrncmp(name, "regex", 5) == 0)
1743   {
1744   uschar *endptr;
1745   int n = Ustrtoul(name + 5, &endptr, 10);
1746   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1747     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1748   }
1749
1750 /* For all other variables, search the table */
1751
1752 if (!(vp = find_var_ent(name)))
1753   return NULL;          /* Unknown variable name */
1754
1755 /* Found an existing variable. If in skipping state, the value isn't needed,
1756 and we want to avoid processing (such as looking up the host name). */
1757
1758 if (skipping)
1759   return US"";
1760
1761 val = vp->value;
1762 switch (vp->type)
1763   {
1764   case vtype_filter_int:
1765     if (!filter_running) return NULL;
1766     /* Fall through */
1767     /* VVVVVVVVVVVV */
1768   case vtype_int:
1769     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1770     return var_buffer;
1771
1772   case vtype_ino:
1773     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1774     return var_buffer;
1775
1776   case vtype_gid:
1777     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1778     return var_buffer;
1779
1780   case vtype_uid:
1781     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1782     return var_buffer;
1783
1784   case vtype_bool:
1785     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1786     return var_buffer;
1787
1788   case vtype_stringptr:                      /* Pointer to string */
1789     return (s = *((uschar **)(val))) ? s : US"";
1790
1791   case vtype_pid:
1792     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1793     return var_buffer;
1794
1795   case vtype_load_avg:
1796     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1797     return var_buffer;
1798
1799   case vtype_host_lookup:                    /* Lookup if not done so */
1800     if (sender_host_name == NULL && sender_host_address != NULL &&
1801         !host_lookup_failed && host_name_lookup() == OK)
1802       host_build_sender_fullhost();
1803     return (sender_host_name == NULL)? US"" : sender_host_name;
1804
1805   case vtype_localpart:                      /* Get local part from address */
1806     s = *((uschar **)(val));
1807     if (s == NULL) return US"";
1808     domain = Ustrrchr(s, '@');
1809     if (domain == NULL) return s;
1810     if (domain - s > sizeof(var_buffer) - 1)
1811       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1812           " in string expansion", sizeof(var_buffer));
1813     Ustrncpy(var_buffer, s, domain - s);
1814     var_buffer[domain - s] = 0;
1815     return var_buffer;
1816
1817   case vtype_domain:                         /* Get domain from address */
1818     s = *((uschar **)(val));
1819     if (s == NULL) return US"";
1820     domain = Ustrrchr(s, '@');
1821     return (domain == NULL)? US"" : domain + 1;
1822
1823   case vtype_msgheaders:
1824     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1825
1826   case vtype_msgheaders_raw:
1827     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1828
1829   case vtype_msgbody:                        /* Pointer to msgbody string */
1830   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1831     ss = (uschar **)(val);
1832     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1833       {
1834       uschar *body;
1835       off_t start_offset = SPOOL_DATA_START_OFFSET;
1836       int len = message_body_visible;
1837       if (len > message_size) len = message_size;
1838       *ss = body = store_malloc(len+1);
1839       body[0] = 0;
1840       if (vp->type == vtype_msgbody_end)
1841         {
1842         struct stat statbuf;
1843         if (fstat(deliver_datafile, &statbuf) == 0)
1844           {
1845           start_offset = statbuf.st_size - len;
1846           if (start_offset < SPOOL_DATA_START_OFFSET)
1847             start_offset = SPOOL_DATA_START_OFFSET;
1848           }
1849         }
1850       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1851         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1852           strerror(errno));
1853       len = read(deliver_datafile, body, len);
1854       if (len > 0)
1855         {
1856         body[len] = 0;
1857         if (message_body_newlines)   /* Separate loops for efficiency */
1858           while (len > 0)
1859             { if (body[--len] == 0) body[len] = ' '; }
1860         else
1861           while (len > 0)
1862             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1863         }
1864       }
1865     return (*ss == NULL)? US"" : *ss;
1866
1867   case vtype_todbsdin:                       /* BSD inbox time of day */
1868     return tod_stamp(tod_bsdin);
1869
1870   case vtype_tode:                           /* Unix epoch time of day */
1871     return tod_stamp(tod_epoch);
1872
1873   case vtype_todel:                          /* Unix epoch/usec time of day */
1874     return tod_stamp(tod_epoch_l);
1875
1876   case vtype_todf:                           /* Full time of day */
1877     return tod_stamp(tod_full);
1878
1879   case vtype_todl:                           /* Log format time of day */
1880     return tod_stamp(tod_log_bare);            /* (without timezone) */
1881
1882   case vtype_todzone:                        /* Time zone offset only */
1883     return tod_stamp(tod_zone);
1884
1885   case vtype_todzulu:                        /* Zulu time */
1886     return tod_stamp(tod_zulu);
1887
1888   case vtype_todlf:                          /* Log file datestamp tod */
1889     return tod_stamp(tod_log_datestamp_daily);
1890
1891   case vtype_reply:                          /* Get reply address */
1892     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1893       headers_charset);
1894     if (s != NULL) while (isspace(*s)) s++;
1895     if (s == NULL || *s == 0)
1896       {
1897       *newsize = 0;                            /* For the *s==0 case */
1898       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1899       }
1900     if (s != NULL)
1901       {
1902       uschar *t;
1903       while (isspace(*s)) s++;
1904       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1905       while (t > s && isspace(t[-1])) t--;
1906       *t = 0;
1907       }
1908     return (s == NULL)? US"" : s;
1909
1910   case vtype_string_func:
1911     {
1912     uschar * (*fn)() = val;
1913     return fn();
1914     }
1915
1916   case vtype_pspace:
1917     {
1918     int inodes;
1919     sprintf(CS var_buffer, "%d",
1920       receive_statvfs(val == (void *)TRUE, &inodes));
1921     }
1922   return var_buffer;
1923
1924   case vtype_pinodes:
1925     {
1926     int inodes;
1927     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1928     sprintf(CS var_buffer, "%d", inodes);
1929     }
1930   return var_buffer;
1931
1932   case vtype_cert:
1933     return *(void **)val ? US"<cert>" : US"";
1934
1935 #ifndef DISABLE_DKIM
1936   case vtype_dkim:
1937     return dkim_exim_expand_query((int)(long)val);
1938 #endif
1939
1940   }
1941
1942 return NULL;  /* Unknown variable. Silences static checkers. */
1943 }
1944
1945
1946
1947
1948 void
1949 modify_variable(uschar *name, void * value)
1950 {
1951 var_entry * vp;
1952 if ((vp = find_var_ent(name))) vp->value = value;
1953 return;          /* Unknown variable name, fail silently */
1954 }
1955
1956
1957
1958
1959
1960 /*************************************************
1961 *           Read and expand substrings           *
1962 *************************************************/
1963
1964 /* This function is called to read and expand argument substrings for various
1965 expansion items. Some have a minimum requirement that is less than the maximum;
1966 in these cases, the first non-present one is set to NULL.
1967
1968 Arguments:
1969   sub        points to vector of pointers to set
1970   n          maximum number of substrings
1971   m          minimum required
1972   sptr       points to current string pointer
1973   skipping   the skipping flag
1974   check_end  if TRUE, check for final '}'
1975   name       name of item, for error message
1976   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1977              the store.
1978
1979 Returns:     0 OK; string pointer updated
1980              1 curly bracketing error (too few arguments)
1981              2 too many arguments (only if check_end is set); message set
1982              3 other error (expansion failure)
1983 */
1984
1985 static int
1986 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1987   BOOL check_end, uschar *name, BOOL *resetok)
1988 {
1989 int i;
1990 const uschar *s = *sptr;
1991
1992 while (isspace(*s)) s++;
1993 for (i = 0; i < n; i++)
1994   {
1995   if (*s != '{')
1996     {
1997     if (i < m)
1998       {
1999       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2000         "(min is %d)", name, m);
2001       return 1;
2002       }
2003     sub[i] = NULL;
2004     break;
2005     }
2006   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2007     return 3;
2008   if (*s++ != '}') return 1;
2009   while (isspace(*s)) s++;
2010   }
2011 if (check_end && *s++ != '}')
2012   {
2013   if (s[-1] == '{')
2014     {
2015     expand_string_message = string_sprintf("Too many arguments for '%s' "
2016       "(max is %d)", name, n);
2017     return 2;
2018     }
2019   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2020   return 1;
2021   }
2022
2023 *sptr = s;
2024 return 0;
2025 }
2026
2027
2028
2029
2030 /*************************************************
2031 *     Elaborate message for bad variable         *
2032 *************************************************/
2033
2034 /* For the "unknown variable" message, take a look at the variable's name, and
2035 give additional information about possible ACL variables. The extra information
2036 is added on to expand_string_message.
2037
2038 Argument:   the name of the variable
2039 Returns:    nothing
2040 */
2041
2042 static void
2043 check_variable_error_message(uschar *name)
2044 {
2045 if (Ustrncmp(name, "acl_", 4) == 0)
2046   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2047     (name[4] == 'c' || name[4] == 'm')?
2048       (isalpha(name[5])?
2049         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2050         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2051       ) :
2052       US"user-defined ACL variables must start acl_c or acl_m");
2053 }
2054
2055
2056
2057 /*
2058 Load args from sub array to globals, and call acl_check().
2059 Sub array will be corrupted on return.
2060
2061 Returns:       OK         access is granted by an ACCEPT verb
2062                DISCARD    access is (apparently) granted by a DISCARD verb
2063                FAIL       access is denied
2064                FAIL_DROP  access is denied; drop the connection
2065                DEFER      can't tell at the moment
2066                ERROR      disaster
2067 */
2068 static int
2069 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2070 {
2071 int i;
2072 int sav_narg = acl_narg;
2073 int ret;
2074 uschar * dummy_logmsg;
2075 extern int acl_where;
2076
2077 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2078 for (i = 0; i < nsub && sub[i+1]; i++)
2079   {
2080   uschar * tmp = acl_arg[i];
2081   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2082   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2083   }
2084 acl_narg = i;
2085 while (i < nsub)
2086   {
2087   sub[i+1] = acl_arg[i];
2088   acl_arg[i++] = NULL;
2089   }
2090
2091 DEBUG(D_expand)
2092   debug_printf("expanding: acl: %s  arg: %s%s\n",
2093     sub[0],
2094     acl_narg>0 ? acl_arg[0] : US"<none>",
2095     acl_narg>1 ? " +more"   : "");
2096
2097 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2098
2099 for (i = 0; i < nsub; i++)
2100   acl_arg[i] = sub[i+1];        /* restore old args */
2101 acl_narg = sav_narg;
2102
2103 return ret;
2104 }
2105
2106
2107
2108
2109 /*************************************************
2110 *        Read and evaluate a condition           *
2111 *************************************************/
2112
2113 /*
2114 Arguments:
2115   s        points to the start of the condition text
2116   resetok  points to a BOOL which is written false if it is unsafe to
2117            free memory. Certain condition types (acl) may have side-effect
2118            allocation which must be preserved.
2119   yield    points to a BOOL to hold the result of the condition test;
2120            if NULL, we are just reading through a condition that is
2121            part of an "or" combination to check syntax, or in a state
2122            where the answer isn't required
2123
2124 Returns:   a pointer to the first character after the condition, or
2125            NULL after an error
2126 */
2127
2128 static const uschar *
2129 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2130 {
2131 BOOL testfor = TRUE;
2132 BOOL tempcond, combined_cond;
2133 BOOL *subcondptr;
2134 BOOL sub2_honour_dollar = TRUE;
2135 int i, rc, cond_type, roffset;
2136 int_eximarith_t num[2];
2137 struct stat statbuf;
2138 uschar name[256];
2139 const uschar *sub[10];
2140
2141 const pcre *re;
2142 const uschar *rerror;
2143
2144 for (;;)
2145   {
2146   while (isspace(*s)) s++;
2147   if (*s == '!') { testfor = !testfor; s++; } else break;
2148   }
2149
2150 /* Numeric comparisons are symbolic */
2151
2152 if (*s == '=' || *s == '>' || *s == '<')
2153   {
2154   int p = 0;
2155   name[p++] = *s++;
2156   if (*s == '=')
2157     {
2158     name[p++] = '=';
2159     s++;
2160     }
2161   name[p] = 0;
2162   }
2163
2164 /* All other conditions are named */
2165
2166 else s = read_name(name, 256, s, US"_");
2167
2168 /* If we haven't read a name, it means some non-alpha character is first. */
2169
2170 if (name[0] == 0)
2171   {
2172   expand_string_message = string_sprintf("condition name expected, "
2173     "but found \"%.16s\"", s);
2174   return NULL;
2175   }
2176
2177 /* Find which condition we are dealing with, and switch on it */
2178
2179 cond_type = chop_match(name, cond_table, nelem(cond_table));
2180 switch(cond_type)
2181   {
2182   /* def: tests for a non-empty variable, or for the existence of a header. If
2183   yield == NULL we are in a skipping state, and don't care about the answer. */
2184
2185   case ECOND_DEF:
2186   if (*s != ':')
2187     {
2188     expand_string_message = US"\":\" expected after \"def\"";
2189     return NULL;
2190     }
2191
2192   s = read_name(name, 256, s+1, US"_");
2193
2194   /* Test for a header's existence. If the name contains a closing brace
2195   character, this may be a user error where the terminating colon has been
2196   omitted. Set a flag to adjust a subsequent error message in this case. */
2197
2198   if (Ustrncmp(name, "h_", 2) == 0 ||
2199       Ustrncmp(name, "rh_", 3) == 0 ||
2200       Ustrncmp(name, "bh_", 3) == 0 ||
2201       Ustrncmp(name, "header_", 7) == 0 ||
2202       Ustrncmp(name, "rheader_", 8) == 0 ||
2203       Ustrncmp(name, "bheader_", 8) == 0)
2204     {
2205     s = read_header_name(name, 256, s);
2206     /* {-for-text-editors */
2207     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2208     if (yield != NULL) *yield =
2209       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2210     }
2211
2212   /* Test for a variable's having a non-empty value. A non-existent variable
2213   causes an expansion failure. */
2214
2215   else
2216     {
2217     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2218     if (value == NULL)
2219       {
2220       expand_string_message = (name[0] == 0)?
2221         string_sprintf("variable name omitted after \"def:\"") :
2222         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2223       check_variable_error_message(name);
2224       return NULL;
2225       }
2226     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2227     }
2228
2229   return s;
2230
2231
2232   /* first_delivery tests for first delivery attempt */
2233
2234   case ECOND_FIRST_DELIVERY:
2235   if (yield != NULL) *yield = deliver_firsttime == testfor;
2236   return s;
2237
2238
2239   /* queue_running tests for any process started by a queue runner */
2240
2241   case ECOND_QUEUE_RUNNING:
2242   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2243   return s;
2244
2245
2246   /* exists:  tests for file existence
2247        isip:  tests for any IP address
2248       isip4:  tests for an IPv4 address
2249       isip6:  tests for an IPv6 address
2250         pam:  does PAM authentication
2251      radius:  does RADIUS authentication
2252    ldapauth:  does LDAP authentication
2253     pwcheck:  does Cyrus SASL pwcheck authentication
2254   */
2255
2256   case ECOND_EXISTS:
2257   case ECOND_ISIP:
2258   case ECOND_ISIP4:
2259   case ECOND_ISIP6:
2260   case ECOND_PAM:
2261   case ECOND_RADIUS:
2262   case ECOND_LDAPAUTH:
2263   case ECOND_PWCHECK:
2264
2265   while (isspace(*s)) s++;
2266   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2267
2268   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2269   if (sub[0] == NULL) return NULL;
2270   /* {-for-text-editors */
2271   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2272
2273   if (yield == NULL) return s;   /* No need to run the test if skipping */
2274
2275   switch(cond_type)
2276     {
2277     case ECOND_EXISTS:
2278     if ((expand_forbid & RDO_EXISTS) != 0)
2279       {
2280       expand_string_message = US"File existence tests are not permitted";
2281       return NULL;
2282       }
2283     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2284     break;
2285
2286     case ECOND_ISIP:
2287     case ECOND_ISIP4:
2288     case ECOND_ISIP6:
2289     rc = string_is_ip_address(sub[0], NULL);
2290     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2291              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2292     break;
2293
2294     /* Various authentication tests - all optionally compiled */
2295
2296     case ECOND_PAM:
2297     #ifdef SUPPORT_PAM
2298     rc = auth_call_pam(sub[0], &expand_string_message);
2299     goto END_AUTH;
2300     #else
2301     goto COND_FAILED_NOT_COMPILED;
2302     #endif  /* SUPPORT_PAM */
2303
2304     case ECOND_RADIUS:
2305     #ifdef RADIUS_CONFIG_FILE
2306     rc = auth_call_radius(sub[0], &expand_string_message);
2307     goto END_AUTH;
2308     #else
2309     goto COND_FAILED_NOT_COMPILED;
2310     #endif  /* RADIUS_CONFIG_FILE */
2311
2312     case ECOND_LDAPAUTH:
2313     #ifdef LOOKUP_LDAP
2314       {
2315       /* Just to keep the interface the same */
2316       BOOL do_cache;
2317       int old_pool = store_pool;
2318       store_pool = POOL_SEARCH;
2319       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2320         &expand_string_message, &do_cache);
2321       store_pool = old_pool;
2322       }
2323     goto END_AUTH;
2324     #else
2325     goto COND_FAILED_NOT_COMPILED;
2326     #endif  /* LOOKUP_LDAP */
2327
2328     case ECOND_PWCHECK:
2329     #ifdef CYRUS_PWCHECK_SOCKET
2330     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2331     goto END_AUTH;
2332     #else
2333     goto COND_FAILED_NOT_COMPILED;
2334     #endif  /* CYRUS_PWCHECK_SOCKET */
2335
2336     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2337         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2338     END_AUTH:
2339     if (rc == ERROR || rc == DEFER) return NULL;
2340     *yield = (rc == OK) == testfor;
2341     #endif
2342     }
2343   return s;
2344
2345
2346   /* call ACL (in a conditional context).  Accept true, deny false.
2347   Defer is a forced-fail.  Anything set by message= goes to $value.
2348   Up to ten parameters are used; we use the braces round the name+args
2349   like the saslauthd condition does, to permit a variable number of args.
2350   See also the expansion-item version EITEM_ACL and the traditional
2351   acl modifier ACLC_ACL.
2352   Since the ACL may allocate new global variables, tell our caller to not
2353   reclaim memory.
2354   */
2355
2356   case ECOND_ACL:
2357     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2358     {
2359     uschar *sub[10];
2360     uschar *user_msg;
2361     BOOL cond = FALSE;
2362     int size = 0;
2363     int ptr = 0;
2364
2365     while (isspace(*s)) s++;
2366     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2367
2368     switch(read_subs(sub, nelem(sub), 1,
2369       &s, yield == NULL, TRUE, US"acl", resetok))
2370       {
2371       case 1: expand_string_message = US"too few arguments or bracketing "
2372         "error for acl";
2373       case 2:
2374       case 3: return NULL;
2375       }
2376
2377     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2378     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2379         {
2380         case OK:
2381           cond = TRUE;
2382         case FAIL:
2383           lookup_value = NULL;
2384           if (user_msg)
2385             {
2386             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2387             lookup_value[ptr] = '\0';
2388             }
2389           *yield = cond == testfor;
2390           break;
2391
2392         case DEFER:
2393           expand_string_forcedfail = TRUE;
2394           /*FALLTHROUGH*/
2395         default:
2396           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2397           return NULL;
2398         }
2399     return s;
2400     }
2401
2402
2403   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2404
2405      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2406
2407   However, the last two are optional. That is why the whole set is enclosed
2408   in their own set of braces. */
2409
2410   case ECOND_SASLAUTHD:
2411 #ifndef CYRUS_SASLAUTHD_SOCKET
2412     goto COND_FAILED_NOT_COMPILED;
2413 #else
2414     {
2415     uschar *sub[4];
2416     while (isspace(*s)) s++;
2417     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2418     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2419                     resetok))
2420       {
2421       case 1: expand_string_message = US"too few arguments or bracketing "
2422         "error for saslauthd";
2423       case 2:
2424       case 3: return NULL;
2425       }
2426     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2427     if (yield != NULL)
2428       {
2429       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2430         &expand_string_message);
2431       if (rc == ERROR || rc == DEFER) return NULL;
2432       *yield = (rc == OK) == testfor;
2433       }
2434     return s;
2435     }
2436 #endif /* CYRUS_SASLAUTHD_SOCKET */
2437
2438
2439   /* symbolic operators for numeric and string comparison, and a number of
2440   other operators, all requiring two arguments.
2441
2442   crypteq:           encrypts plaintext and compares against an encrypted text,
2443                        using crypt(), crypt16(), MD5 or SHA-1
2444   inlist/inlisti:    checks if first argument is in the list of the second
2445   match:             does a regular expression match and sets up the numerical
2446                        variables if it succeeds
2447   match_address:     matches in an address list
2448   match_domain:      matches in a domain list
2449   match_ip:          matches a host list that is restricted to IP addresses
2450   match_local_part:  matches in a local part list
2451   */
2452
2453   case ECOND_MATCH_ADDRESS:
2454   case ECOND_MATCH_DOMAIN:
2455   case ECOND_MATCH_IP:
2456   case ECOND_MATCH_LOCAL_PART:
2457 #ifndef EXPAND_LISTMATCH_RHS
2458     sub2_honour_dollar = FALSE;
2459 #endif
2460     /* FALLTHROUGH */
2461
2462   case ECOND_CRYPTEQ:
2463   case ECOND_INLIST:
2464   case ECOND_INLISTI:
2465   case ECOND_MATCH:
2466
2467   case ECOND_NUM_L:     /* Numerical comparisons */
2468   case ECOND_NUM_LE:
2469   case ECOND_NUM_E:
2470   case ECOND_NUM_EE:
2471   case ECOND_NUM_G:
2472   case ECOND_NUM_GE:
2473
2474   case ECOND_STR_LT:    /* String comparisons */
2475   case ECOND_STR_LTI:
2476   case ECOND_STR_LE:
2477   case ECOND_STR_LEI:
2478   case ECOND_STR_EQ:
2479   case ECOND_STR_EQI:
2480   case ECOND_STR_GT:
2481   case ECOND_STR_GTI:
2482   case ECOND_STR_GE:
2483   case ECOND_STR_GEI:
2484
2485   for (i = 0; i < 2; i++)
2486     {
2487     /* Sometimes, we don't expand substrings; too many insecure configurations
2488     created using match_address{}{} and friends, where the second param
2489     includes information from untrustworthy sources. */
2490     BOOL honour_dollar = TRUE;
2491     if ((i > 0) && !sub2_honour_dollar)
2492       honour_dollar = FALSE;
2493
2494     while (isspace(*s)) s++;
2495     if (*s != '{')
2496       {
2497       if (i == 0) goto COND_FAILED_CURLY_START;
2498       expand_string_message = string_sprintf("missing 2nd string in {} "
2499         "after \"%s\"", name);
2500       return NULL;
2501       }
2502     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2503         honour_dollar, resetok);
2504     if (sub[i] == NULL) return NULL;
2505     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2506
2507     /* Convert to numerical if required; we know that the names of all the
2508     conditions that compare numbers do not start with a letter. This just saves
2509     checking for them individually. */
2510
2511     if (!isalpha(name[0]) && yield != NULL)
2512       if (sub[i][0] == 0)
2513         {
2514         num[i] = 0;
2515         DEBUG(D_expand)
2516           debug_printf("empty string cast to zero for numerical comparison\n");
2517         }
2518       else
2519         {
2520         num[i] = expanded_string_integer(sub[i], FALSE);
2521         if (expand_string_message != NULL) return NULL;
2522         }
2523     }
2524
2525   /* Result not required */
2526
2527   if (yield == NULL) return s;
2528
2529   /* Do an appropriate comparison */
2530
2531   switch(cond_type)
2532     {
2533     case ECOND_NUM_E:
2534     case ECOND_NUM_EE:
2535     tempcond = (num[0] == num[1]);
2536     break;
2537
2538     case ECOND_NUM_G:
2539     tempcond = (num[0] > num[1]);
2540     break;
2541
2542     case ECOND_NUM_GE:
2543     tempcond = (num[0] >= num[1]);
2544     break;
2545
2546     case ECOND_NUM_L:
2547     tempcond = (num[0] < num[1]);
2548     break;
2549
2550     case ECOND_NUM_LE:
2551     tempcond = (num[0] <= num[1]);
2552     break;
2553
2554     case ECOND_STR_LT:
2555     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2556     break;
2557
2558     case ECOND_STR_LTI:
2559     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2560     break;
2561
2562     case ECOND_STR_LE:
2563     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2564     break;
2565
2566     case ECOND_STR_LEI:
2567     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2568     break;
2569
2570     case ECOND_STR_EQ:
2571     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2572     break;
2573
2574     case ECOND_STR_EQI:
2575     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2576     break;
2577
2578     case ECOND_STR_GT:
2579     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2580     break;
2581
2582     case ECOND_STR_GTI:
2583     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2584     break;
2585
2586     case ECOND_STR_GE:
2587     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2588     break;
2589
2590     case ECOND_STR_GEI:
2591     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2592     break;
2593
2594     case ECOND_MATCH:   /* Regular expression match */
2595     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2596       NULL);
2597     if (re == NULL)
2598       {
2599       expand_string_message = string_sprintf("regular expression error in "
2600         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2601       return NULL;
2602       }
2603     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2604     break;
2605
2606     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2607     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2608     goto MATCHED_SOMETHING;
2609
2610     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2611     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2612       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2613     goto MATCHED_SOMETHING;
2614
2615     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2616     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2617       {
2618       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2619         sub[0]);
2620       return NULL;
2621       }
2622     else
2623       {
2624       unsigned int *nullcache = NULL;
2625       check_host_block cb;
2626
2627       cb.host_name = US"";
2628       cb.host_address = sub[0];
2629
2630       /* If the host address starts off ::ffff: it is an IPv6 address in
2631       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2632       addresses. */
2633
2634       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2635         cb.host_address + 7 : cb.host_address;
2636
2637       rc = match_check_list(
2638              &sub[1],                   /* the list */
2639              0,                         /* separator character */
2640              &hostlist_anchor,          /* anchor pointer */
2641              &nullcache,                /* cache pointer */
2642              check_host,                /* function for testing */
2643              &cb,                       /* argument for function */
2644              MCL_HOST,                  /* type of check */
2645              sub[0],                    /* text for debugging */
2646              NULL);                     /* where to pass back data */
2647       }
2648     goto MATCHED_SOMETHING;
2649
2650     case ECOND_MATCH_LOCAL_PART:
2651     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2652       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2653     /* Fall through */
2654     /* VVVVVVVVVVVV */
2655     MATCHED_SOMETHING:
2656     switch(rc)
2657       {
2658       case OK:
2659       tempcond = TRUE;
2660       break;
2661
2662       case FAIL:
2663       tempcond = FALSE;
2664       break;
2665
2666       case DEFER:
2667       expand_string_message = string_sprintf("unable to complete match "
2668         "against \"%s\": %s", sub[1], search_error_message);
2669       return NULL;
2670       }
2671
2672     break;
2673
2674     /* Various "encrypted" comparisons. If the second string starts with
2675     "{" then an encryption type is given. Default to crypt() or crypt16()
2676     (build-time choice). */
2677     /* }-for-text-editors */
2678
2679     case ECOND_CRYPTEQ:
2680     #ifndef SUPPORT_CRYPTEQ
2681     goto COND_FAILED_NOT_COMPILED;
2682     #else
2683     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2684       {
2685       int sublen = Ustrlen(sub[1]+5);
2686       md5 base;
2687       uschar digest[16];
2688
2689       md5_start(&base);
2690       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2691
2692       /* If the length that we are comparing against is 24, the MD5 digest
2693       is expressed as a base64 string. This is the way LDAP does it. However,
2694       some other software uses a straightforward hex representation. We assume
2695       this if the length is 32. Other lengths fail. */
2696
2697       if (sublen == 24)
2698         {
2699         uschar *coded = b64encode(digest, 16);
2700         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2701           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2702         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2703         }
2704       else if (sublen == 32)
2705         {
2706         int i;
2707         uschar coded[36];
2708         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2709         coded[32] = 0;
2710         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2711           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2712         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2713         }
2714       else
2715         {
2716         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2717           "fail\n  crypted=%s\n", sub[1]+5);
2718         tempcond = FALSE;
2719         }
2720       }
2721
2722     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2723       {
2724       int sublen = Ustrlen(sub[1]+6);
2725       hctx h;
2726       uschar digest[20];
2727
2728       sha1_start(&h);
2729       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2730
2731       /* If the length that we are comparing against is 28, assume the SHA1
2732       digest is expressed as a base64 string. If the length is 40, assume a
2733       straightforward hex representation. Other lengths fail. */
2734
2735       if (sublen == 28)
2736         {
2737         uschar *coded = b64encode(digest, 20);
2738         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2739           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2740         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2741         }
2742       else if (sublen == 40)
2743         {
2744         int i;
2745         uschar coded[44];
2746         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2747         coded[40] = 0;
2748         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2749           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2750         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2751         }
2752       else
2753         {
2754         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2755           "fail\n  crypted=%s\n", sub[1]+6);
2756         tempcond = FALSE;
2757         }
2758       }
2759
2760     else   /* {crypt} or {crypt16} and non-{ at start */
2761            /* }-for-text-editors */
2762       {
2763       int which = 0;
2764       uschar *coded;
2765
2766       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2767         {
2768         sub[1] += 7;
2769         which = 1;
2770         }
2771       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2772         {
2773         sub[1] += 9;
2774         which = 2;
2775         }
2776       else if (sub[1][0] == '{')                /* }-for-text-editors */
2777         {
2778         expand_string_message = string_sprintf("unknown encryption mechanism "
2779           "in \"%s\"", sub[1]);
2780         return NULL;
2781         }
2782
2783       switch(which)
2784         {
2785         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2786         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2787         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2788         }
2789
2790       #define STR(s) # s
2791       #define XSTR(s) STR(s)
2792       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2793         "  subject=%s\n  crypted=%s\n",
2794         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2795         coded, sub[1]);
2796       #undef STR
2797       #undef XSTR
2798
2799       /* If the encrypted string contains fewer than two characters (for the
2800       salt), force failure. Otherwise we get false positives: with an empty
2801       string the yield of crypt() is an empty string! */
2802
2803       if (coded)
2804         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2805       else if (errno == EINVAL)
2806         tempcond = FALSE;
2807       else
2808         {
2809         expand_string_message = string_sprintf("crypt error: %s\n",
2810           US strerror(errno));
2811         return NULL;
2812         }
2813       }
2814     break;
2815     #endif  /* SUPPORT_CRYPTEQ */
2816
2817     case ECOND_INLIST:
2818     case ECOND_INLISTI:
2819       {
2820       const uschar * list = sub[1];
2821       int sep = 0;
2822       uschar *save_iterate_item = iterate_item;
2823       int (*compare)(const uschar *, const uschar *);
2824
2825       DEBUG(D_expand) debug_printf("condition: %s\n", name);
2826
2827       tempcond = FALSE;
2828       compare = cond_type == ECOND_INLISTI
2829         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2830
2831       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2832         if (compare(sub[0], iterate_item) == 0)
2833           {
2834           tempcond = TRUE;
2835           break;
2836           }
2837       iterate_item = save_iterate_item;
2838       }
2839
2840     }   /* Switch for comparison conditions */
2841
2842   *yield = tempcond == testfor;
2843   return s;    /* End of comparison conditions */
2844
2845
2846   /* and/or: computes logical and/or of several conditions */
2847
2848   case ECOND_AND:
2849   case ECOND_OR:
2850   subcondptr = (yield == NULL)? NULL : &tempcond;
2851   combined_cond = (cond_type == ECOND_AND);
2852
2853   while (isspace(*s)) s++;
2854   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2855
2856   for (;;)
2857     {
2858     while (isspace(*s)) s++;
2859     /* {-for-text-editors */
2860     if (*s == '}') break;
2861     if (*s != '{')                                      /* }-for-text-editors */
2862       {
2863       expand_string_message = string_sprintf("each subcondition "
2864         "inside an \"%s{...}\" condition must be in its own {}", name);
2865       return NULL;
2866       }
2867
2868     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2869       {
2870       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2871         expand_string_message, name);
2872       return NULL;
2873       }
2874     while (isspace(*s)) s++;
2875
2876     /* {-for-text-editors */
2877     if (*s++ != '}')
2878       {
2879       /* {-for-text-editors */
2880       expand_string_message = string_sprintf("missing } at end of condition "
2881         "inside \"%s\" group", name);
2882       return NULL;
2883       }
2884
2885     if (yield != NULL)
2886       {
2887       if (cond_type == ECOND_AND)
2888         {
2889         combined_cond &= tempcond;
2890         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2891         }                                       /* evaluate any more */
2892       else
2893         {
2894         combined_cond |= tempcond;
2895         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2896         }                                       /* evaluate any more */
2897       }
2898     }
2899
2900   if (yield != NULL) *yield = (combined_cond == testfor);
2901   return ++s;
2902
2903
2904   /* forall/forany: iterates a condition with different values */
2905
2906   case ECOND_FORALL:
2907   case ECOND_FORANY:
2908     {
2909     const uschar * list;
2910     int sep = 0;
2911     uschar *save_iterate_item = iterate_item;
2912
2913     DEBUG(D_expand) debug_printf("condition: %s\n", name);
2914
2915     while (isspace(*s)) s++;
2916     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2917     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2918     if (sub[0] == NULL) return NULL;
2919     /* {-for-text-editors */
2920     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2921
2922     while (isspace(*s)) s++;
2923     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2924
2925     sub[1] = s;
2926
2927     /* Call eval_condition once, with result discarded (as if scanning a
2928     "false" part). This allows us to find the end of the condition, because if
2929     the list it empty, we won't actually evaluate the condition for real. */
2930
2931     if (!(s = eval_condition(sub[1], resetok, NULL)))
2932       {
2933       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2934         expand_string_message, name);
2935       return NULL;
2936       }
2937     while (isspace(*s)) s++;
2938
2939     /* {-for-text-editors */
2940     if (*s++ != '}')
2941       {
2942       /* {-for-text-editors */
2943       expand_string_message = string_sprintf("missing } at end of condition "
2944         "inside \"%s\"", name);
2945       return NULL;
2946       }
2947
2948     if (yield != NULL) *yield = !testfor;
2949     list = sub[0];
2950     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2951       {
2952       DEBUG(D_expand) debug_printf("%s: $item = \"%s\"\n", name, iterate_item);
2953       if (!eval_condition(sub[1], resetok, &tempcond))
2954         {
2955         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2956           expand_string_message, name);
2957         iterate_item = save_iterate_item;
2958         return NULL;
2959         }
2960       DEBUG(D_expand) debug_printf("%s: condition evaluated to %s\n", name,
2961         tempcond? "true":"false");
2962
2963       if (yield != NULL) *yield = (tempcond == testfor);
2964       if (tempcond == (cond_type == ECOND_FORANY)) break;
2965       }
2966
2967     iterate_item = save_iterate_item;
2968     return s;
2969     }
2970
2971
2972   /* The bool{} expansion condition maps a string to boolean.
2973   The values supported should match those supported by the ACL condition
2974   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2975   of true/false.  Note that Router "condition" rules have a different
2976   interpretation, where general data can be used and only a few values
2977   map to FALSE.
2978   Note that readconf.c boolean matching, for boolean configuration options,
2979   only matches true/yes/false/no.
2980   The bool_lax{} condition matches the Router logic, which is much more
2981   liberal. */
2982   case ECOND_BOOL:
2983   case ECOND_BOOL_LAX:
2984     {
2985     uschar *sub_arg[1];
2986     uschar *t, *t2;
2987     uschar *ourname;
2988     size_t len;
2989     BOOL boolvalue = FALSE;
2990     while (isspace(*s)) s++;
2991     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2992     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2993     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2994       {
2995       case 1: expand_string_message = string_sprintf(
2996                   "too few arguments or bracketing error for %s",
2997                   ourname);
2998       /*FALLTHROUGH*/
2999       case 2:
3000       case 3: return NULL;
3001       }
3002     t = sub_arg[0];
3003     while (isspace(*t)) t++;
3004     len = Ustrlen(t);
3005     if (len)
3006       {
3007       /* trailing whitespace: seems like a good idea to ignore it too */
3008       t2 = t + len - 1;
3009       while (isspace(*t2)) t2--;
3010       if (t2 != (t + len))
3011         {
3012         *++t2 = '\0';
3013         len = t2 - t;
3014         }
3015       }
3016     DEBUG(D_expand)
3017       debug_printf("considering %s: %s\n", ourname, len ? t : US"<empty>");
3018     /* logic for the lax case from expand_check_condition(), which also does
3019     expands, and the logic is both short and stable enough that there should
3020     be no maintenance burden from replicating it. */
3021     if (len == 0)
3022       boolvalue = FALSE;
3023     else if (*t == '-'
3024              ? Ustrspn(t+1, "0123456789") == len-1
3025              : Ustrspn(t,   "0123456789") == len)
3026       {
3027       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3028       /* expand_check_condition only does a literal string "0" check */
3029       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3030         boolvalue = TRUE;
3031       }
3032     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3033       boolvalue = TRUE;
3034     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3035       boolvalue = FALSE;
3036     else if (cond_type == ECOND_BOOL_LAX)
3037       boolvalue = TRUE;
3038     else
3039       {
3040       expand_string_message = string_sprintf("unrecognised boolean "
3041        "value \"%s\"", t);
3042       return NULL;
3043       }
3044     if (yield != NULL) *yield = (boolvalue == testfor);
3045     return s;
3046     }
3047
3048   /* Unknown condition */
3049
3050   default:
3051   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3052   return NULL;
3053   }   /* End switch on condition type */
3054
3055 /* Missing braces at start and end of data */
3056
3057 COND_FAILED_CURLY_START:
3058 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3059 return NULL;
3060
3061 COND_FAILED_CURLY_END:
3062 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3063   name);
3064 return NULL;
3065
3066 /* A condition requires code that is not compiled */
3067
3068 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3069     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3070     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3071 COND_FAILED_NOT_COMPILED:
3072 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3073   name);
3074 return NULL;
3075 #endif
3076 }
3077
3078
3079
3080
3081 /*************************************************
3082 *          Save numerical variables              *
3083 *************************************************/
3084
3085 /* This function is called from items such as "if" that want to preserve and
3086 restore the numbered variables.
3087
3088 Arguments:
3089   save_expand_string    points to an array of pointers to set
3090   save_expand_nlength   points to an array of ints for the lengths
3091
3092 Returns:                the value of expand max to save
3093 */
3094
3095 static int
3096 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3097 {
3098 int i;
3099 for (i = 0; i <= expand_nmax; i++)
3100   {
3101   save_expand_nstring[i] = expand_nstring[i];
3102   save_expand_nlength[i] = expand_nlength[i];
3103   }
3104 return expand_nmax;
3105 }
3106
3107
3108
3109 /*************************************************
3110 *           Restore numerical variables          *
3111 *************************************************/
3112
3113 /* This function restored saved values of numerical strings.
3114
3115 Arguments:
3116   save_expand_nmax      the number of strings to restore
3117   save_expand_string    points to an array of pointers
3118   save_expand_nlength   points to an array of ints
3119
3120 Returns:                nothing
3121 */
3122
3123 static void
3124 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3125   int *save_expand_nlength)
3126 {
3127 int i;
3128 expand_nmax = save_expand_nmax;
3129 for (i = 0; i <= expand_nmax; i++)
3130   {
3131   expand_nstring[i] = save_expand_nstring[i];
3132   expand_nlength[i] = save_expand_nlength[i];
3133   }
3134 }
3135
3136
3137
3138
3139
3140 /*************************************************
3141 *            Handle yes/no substrings            *
3142 *************************************************/
3143
3144 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3145 alternative substrings that depend on whether or not the condition was true,
3146 or the lookup or extraction succeeded. The substrings always have to be
3147 expanded, to check their syntax, but "skipping" is set when the result is not
3148 needed - this avoids unnecessary nested lookups.
3149
3150 Arguments:
3151   skipping       TRUE if we were skipping when this item was reached
3152   yes            TRUE if the first string is to be used, else use the second
3153   save_lookup    a value to put back into lookup_value before the 2nd expansion
3154   sptr           points to the input string pointer
3155   yieldptr       points to the output string pointer
3156   sizeptr        points to the output string size
3157   ptrptr         points to the output string pointer
3158   type           "lookup", "if", "extract", "run", "env", "listextract" or
3159                  "certextract" for error message
3160   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3161                 the store.
3162
3163 Returns:         0 OK; lookup_value has been reset to save_lookup
3164                  1 expansion failed
3165                  2 expansion failed because of bracketing error
3166 */
3167
3168 static int
3169 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3170   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3171 {
3172 int rc = 0;
3173 const uschar *s = *sptr;    /* Local value */
3174 uschar *sub1, *sub2;
3175 const uschar * errwhere;
3176
3177 /* If there are no following strings, we substitute the contents of $value for
3178 lookups and for extractions in the success case. For the ${if item, the string
3179 "true" is substituted. In the fail case, nothing is substituted for all three
3180 items. */
3181
3182 while (isspace(*s)) s++;
3183 if (*s == '}')
3184   {
3185   if (type[0] == 'i')
3186     {
3187     if (yes) *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3188     }
3189   else
3190     {
3191     if (yes && lookup_value)
3192       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3193     lookup_value = save_lookup;
3194     }
3195   s++;
3196   goto RETURN;
3197   }
3198
3199 /* The first following string must be braced. */
3200
3201 if (*s++ != '{')
3202   {
3203   errwhere = US"'yes' part did not start with '{'";
3204   goto FAILED_CURLY;
3205   }
3206
3207 /* Expand the first substring. Forced failures are noticed only if we actually
3208 want this string. Set skipping in the call in the fail case (this will always
3209 be the case if we were already skipping). */
3210
3211 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3212 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3213 expand_string_forcedfail = FALSE;
3214 if (*s++ != '}')
3215   {
3216   errwhere = US"'yes' part did not end with '}'";
3217   goto FAILED_CURLY;
3218   }
3219
3220 /* If we want the first string, add it to the output */
3221
3222 if (yes)
3223   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3224
3225 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3226 $value to what it was at the start of the item, so that it has this value
3227 during the second string expansion. For the call from "if" or "run" to this
3228 function, save_lookup is set to lookup_value, so that this statement does
3229 nothing. */
3230
3231 lookup_value = save_lookup;
3232
3233 /* There now follows either another substring, or "fail", or nothing. This
3234 time, forced failures are noticed only if we want the second string. We must
3235 set skipping in the nested call if we don't want this string, or if we were
3236 already skipping. */
3237
3238 while (isspace(*s)) s++;
3239 if (*s == '{')
3240   {
3241   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3242   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3243   expand_string_forcedfail = FALSE;
3244   if (*s++ != '}')
3245     {
3246     errwhere = US"'no' part did not start with '{'";
3247     goto FAILED_CURLY;
3248     }
3249
3250   /* If we want the second string, add it to the output */
3251
3252   if (!yes)
3253     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3254   }
3255
3256 /* If there is no second string, but the word "fail" is present when the use of
3257 the second string is wanted, set a flag indicating it was a forced failure
3258 rather than a syntactic error. Swallow the terminating } in case this is nested
3259 inside another lookup or if or extract. */
3260
3261 else if (*s != '}')
3262   {
3263   uschar name[256];
3264   /* deconst cast ok here as source is s anyway */
3265   s = US read_name(name, sizeof(name), s, US"_");
3266   if (Ustrcmp(name, "fail") == 0)
3267     {
3268     if (!yes && !skipping)
3269       {
3270       while (isspace(*s)) s++;
3271       if (*s++ != '}')
3272         {
3273         errwhere = US"did not close with '}' after forcedfail";
3274         goto FAILED_CURLY;
3275         }
3276       expand_string_message =
3277         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3278       expand_string_forcedfail = TRUE;
3279       goto FAILED;
3280       }
3281     }
3282   else
3283     {
3284     expand_string_message =
3285       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3286     goto FAILED;
3287     }
3288   }
3289
3290 /* All we have to do now is to check on the final closing brace. */
3291
3292 while (isspace(*s)) s++;
3293 if (*s++ != '}')
3294   {
3295   errwhere = US"did not close with '}'";
3296   goto FAILED_CURLY;
3297   }
3298
3299
3300 RETURN:
3301 /* Update the input pointer value before returning */
3302 *sptr = s;
3303 return rc;
3304
3305 FAILED_CURLY:
3306   /* Get here if there is a bracketing failure */
3307   expand_string_message = string_sprintf(
3308     "curly-bracket problem in conditional yes/no parsing: %s\n"
3309     " remaining string is '%s'", errwhere, --s);
3310   rc = 2;
3311   goto RETURN;
3312
3313 FAILED:
3314   /* Get here for other failures */
3315   rc = 1;
3316   goto RETURN;
3317 }
3318
3319
3320
3321
3322 /*************************************************
3323 *    Handle MD5 or SHA-1 computation for HMAC    *
3324 *************************************************/
3325
3326 /* These are some wrapping functions that enable the HMAC code to be a bit
3327 cleaner. A good compiler will spot the tail recursion.
3328
3329 Arguments:
3330   type         HMAC_MD5 or HMAC_SHA1
3331   remaining    are as for the cryptographic hash functions
3332
3333 Returns:       nothing
3334 */
3335
3336 static void
3337 chash_start(int type, void *base)
3338 {
3339 if (type == HMAC_MD5)
3340   md5_start((md5 *)base);
3341 else
3342   sha1_start((hctx *)base);
3343 }
3344
3345 static void
3346 chash_mid(int type, void *base, uschar *string)
3347 {
3348 if (type == HMAC_MD5)
3349   md5_mid((md5 *)base, string);
3350 else
3351   sha1_mid((hctx *)base, string);
3352 }
3353
3354 static void
3355 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3356 {
3357 if (type == HMAC_MD5)
3358   md5_end((md5 *)base, string, length, digest);
3359 else
3360   sha1_end((hctx *)base, string, length, digest);
3361 }
3362
3363
3364
3365
3366
3367 /********************************************************
3368 * prvs: Get last three digits of days since Jan 1, 1970 *
3369 ********************************************************/
3370
3371 /* This is needed to implement the "prvs" BATV reverse
3372    path signing scheme
3373
3374 Argument: integer "days" offset to add or substract to
3375           or from the current number of days.
3376
3377 Returns:  pointer to string containing the last three
3378           digits of the number of days since Jan 1, 1970,
3379           modified by the offset argument, NULL if there
3380           was an error in the conversion.
3381
3382 */
3383
3384 static uschar *
3385 prvs_daystamp(int day_offset)
3386 {
3387 uschar *days = store_get(32);                /* Need at least 24 for cases */
3388 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3389   (time(NULL) + day_offset*86400)/86400);
3390 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3391 }
3392
3393
3394
3395 /********************************************************
3396 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3397 ********************************************************/
3398
3399 /* This is needed to implement the "prvs" BATV reverse
3400    path signing scheme
3401
3402 Arguments:
3403   address RFC2821 Address to use
3404       key The key to use (must be less than 64 characters
3405           in size)
3406   key_num Single-digit key number to use. Defaults to
3407           '0' when NULL.
3408
3409 Returns:  pointer to string containing the first three
3410           bytes of the final hash in hex format, NULL if
3411           there was an error in the process.
3412 */
3413
3414 static uschar *
3415 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3416 {
3417 uschar *hash_source, *p;
3418 int size = 0,offset = 0,i;
3419 hctx h;
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, &h);
3449 chash_mid(HMAC_SHA1, &h, innerkey);
3450 chash_end(HMAC_SHA1, &h, hash_source, offset, innerhash);
3451
3452 chash_start(HMAC_SHA1, &h);
3453 chash_mid(HMAC_SHA1, &h, outerkey);
3454 chash_end(HMAC_SHA1, &h, 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       hctx sha1_ctx;
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_ctx;
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           hctx h;
6362           uschar digest[20];
6363           int j;
6364           char st[41];
6365           sha1_start(&h);
6366           sha1_end(&h, sub, Ustrlen(sub), digest);
6367           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6368           yield = string_catn(yield, &size, &ptr, US st, 40);
6369           }
6370         continue;
6371
6372       case EOP_SHA256:
6373 #ifdef EXIM_HAVE_SHA2
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           {
6381           hctx h;
6382           blob b;
6383           char st[3];
6384
6385           exim_sha_init(&h, HASH_SHA256);
6386           exim_sha_update(&h, sub, Ustrlen(sub));
6387           exim_sha_finish(&h, &b);
6388           while (b.len-- > 0)
6389             {
6390             sprintf(st, "%02X", *b.data++);
6391             yield = string_catn(yield, &size, &ptr, US st, 2);
6392             }
6393           }
6394 #else
6395           expand_string_message = US"sha256 only supported with TLS";
6396 #endif
6397         continue;
6398
6399       case EOP_SHA3:
6400 #ifdef EXIM_HAVE_SHA3
6401         {
6402         hctx h;
6403         blob b;
6404         char st[3];
6405         hashmethod m = !arg ? HASH_SHA3_256
6406           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6407           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6408           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6409           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6410           : HASH_BADTYPE;
6411
6412         if (m == HASH_BADTYPE)
6413           {
6414           expand_string_message = US"unrecognised sha3 variant";
6415           goto EXPAND_FAILED;
6416           }
6417
6418         exim_sha_init(&h, m);
6419         exim_sha_update(&h, sub, Ustrlen(sub));
6420         exim_sha_finish(&h, &b);
6421         while (b.len-- > 0)
6422           {
6423           sprintf(st, "%02X", *b.data++);
6424           yield = string_catn(yield, &size, &ptr, US st, 2);
6425           }
6426         }
6427         continue;
6428 #else
6429         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6430         goto EXPAND_FAILED;
6431 #endif
6432
6433       /* Convert hex encoding to base64 encoding */
6434
6435       case EOP_HEX2B64:
6436         {
6437         int c = 0;
6438         int b = -1;
6439         uschar *in = sub;
6440         uschar *out = sub;
6441         uschar *enc;
6442
6443         for (enc = sub; *enc != 0; enc++)
6444           {
6445           if (!isxdigit(*enc))
6446             {
6447             expand_string_message = string_sprintf("\"%s\" is not a hex "
6448               "string", sub);
6449             goto EXPAND_FAILED;
6450             }
6451           c++;
6452           }
6453
6454         if ((c & 1) != 0)
6455           {
6456           expand_string_message = string_sprintf("\"%s\" contains an odd "
6457             "number of characters", sub);
6458           goto EXPAND_FAILED;
6459           }
6460
6461         while ((c = *in++) != 0)
6462           {
6463           if (isdigit(c)) c -= '0';
6464           else c = toupper(c) - 'A' + 10;
6465           if (b == -1)
6466             {
6467             b = c << 4;
6468             }
6469           else
6470             {
6471             *out++ = b | c;
6472             b = -1;
6473             }
6474           }
6475
6476         enc = b64encode(sub, out - sub);
6477         yield = string_cat(yield, &size, &ptr, enc);
6478         continue;
6479         }
6480
6481       /* Convert octets outside 0x21..0x7E to \xXX form */
6482
6483       case EOP_HEXQUOTE:
6484         {
6485         uschar *t = sub - 1;
6486         while (*(++t) != 0)
6487           {
6488           if (*t < 0x21 || 0x7E < *t)
6489             yield = string_catn(yield, &size, &ptr,
6490               string_sprintf("\\x%02x", *t), 4);
6491           else
6492             yield = string_catn(yield, &size, &ptr, t, 1);
6493           }
6494         continue;
6495         }
6496
6497       /* count the number of list elements */
6498
6499       case EOP_LISTCOUNT:
6500         {
6501         int cnt = 0;
6502         int sep = 0;
6503         uschar * cp;
6504         uschar buffer[256];
6505
6506         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6507         cp = string_sprintf("%d", cnt);
6508         yield = string_cat(yield, &size, &ptr, cp);
6509         continue;
6510         }
6511
6512       /* expand a named list given the name */
6513       /* handles nested named lists; requotes as colon-sep list */
6514
6515       case EOP_LISTNAMED:
6516         {
6517         tree_node *t = NULL;
6518         const uschar * list;
6519         int sep = 0;
6520         uschar * item;
6521         uschar * suffix = US"";
6522         BOOL needsep = FALSE;
6523         uschar buffer[256];
6524
6525         if (*sub == '+') sub++;
6526         if (arg == NULL)        /* no-argument version */
6527           {
6528           if (!(t = tree_search(addresslist_anchor, sub)) &&
6529               !(t = tree_search(domainlist_anchor,  sub)) &&
6530               !(t = tree_search(hostlist_anchor,    sub)))
6531             t = tree_search(localpartlist_anchor, sub);
6532           }
6533         else switch(*arg)       /* specific list-type version */
6534           {
6535           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6536           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6537           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6538           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6539           default:
6540             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6541             goto EXPAND_FAILED;
6542           }
6543
6544         if(!t)
6545           {
6546           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6547             sub, !arg?""
6548               : *arg=='a'?"address "
6549               : *arg=='d'?"domain "
6550               : *arg=='h'?"host "
6551               : *arg=='l'?"localpart "
6552               : 0);
6553           goto EXPAND_FAILED;
6554           }
6555
6556         list = ((namedlist_block *)(t->data.ptr))->string;
6557
6558         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6559           {
6560           uschar * buf = US" : ";
6561           if (needsep)
6562             yield = string_catn(yield, &size, &ptr, buf, 3);
6563           else
6564             needsep = TRUE;
6565
6566           if (*item == '+')     /* list item is itself a named list */
6567             {
6568             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6569             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6570             }
6571           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6572             {
6573             char * cp;
6574             char tok[3];
6575             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6576             while ((cp= strpbrk((const char *)item, tok)))
6577               {
6578               yield = string_catn(yield, &size, &ptr, item, cp-(char *)item);
6579               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6580                 {
6581                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6582                 item = (uschar *)cp;
6583                 }
6584               else              /* sep in item; should already be doubled; emit once */
6585                 {
6586                 yield = string_catn(yield, &size, &ptr, (uschar *)tok, 1);
6587                 if (*cp == sep) cp++;
6588                 item = (uschar *)cp;
6589                 }
6590               }
6591             }
6592           yield = string_cat(yield, &size, &ptr, item);
6593           }
6594         continue;
6595         }
6596
6597       /* mask applies a mask to an IP address; for example the result of
6598       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6599
6600       case EOP_MASK:
6601         {
6602         int count;
6603         uschar *endptr;
6604         int binary[4];
6605         int mask, maskoffset;
6606         int type = string_is_ip_address(sub, &maskoffset);
6607         uschar buffer[64];
6608
6609         if (type == 0)
6610           {
6611           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6612            sub);
6613           goto EXPAND_FAILED;
6614           }
6615
6616         if (maskoffset == 0)
6617           {
6618           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6619             sub);
6620           goto EXPAND_FAILED;
6621           }
6622
6623         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6624
6625         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6626           {
6627           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6628             sub);
6629           goto EXPAND_FAILED;
6630           }
6631
6632         /* Convert the address to binary integer(s) and apply the mask */
6633
6634         sub[maskoffset] = 0;
6635         count = host_aton(sub, binary);
6636         host_mask(count, binary, mask);
6637
6638         /* Convert to masked textual format and add to output. */
6639
6640         yield = string_catn(yield, &size, &ptr, buffer,
6641           host_nmtoa(count, binary, mask, buffer, '.'));
6642         continue;
6643         }
6644
6645       case EOP_IPV6NORM:
6646       case EOP_IPV6DENORM:
6647         {
6648         int type = string_is_ip_address(sub, NULL);
6649         int binary[4];
6650         uschar buffer[44];
6651
6652         switch (type)
6653           {
6654           case 6:
6655             (void) host_aton(sub, binary);
6656             break;
6657
6658           case 4:       /* convert to IPv4-mapped IPv6 */
6659             binary[0] = binary[1] = 0;
6660             binary[2] = 0x0000ffff;
6661             (void) host_aton(sub, binary+3);
6662             break;
6663
6664           case 0:
6665             expand_string_message =
6666               string_sprintf("\"%s\" is not an IP address", sub);
6667             goto EXPAND_FAILED;
6668           }
6669
6670         yield = string_catn(yield, &size, &ptr, buffer,
6671                   c == EOP_IPV6NORM
6672                     ? ipv6_nmtoa(binary, buffer)
6673                     : host_nmtoa(4, binary, -1, buffer, ':')
6674                   );
6675         continue;
6676         }
6677
6678       case EOP_ADDRESS:
6679       case EOP_LOCAL_PART:
6680       case EOP_DOMAIN:
6681         {
6682         uschar *error;
6683         int start, end, domain;
6684         uschar *t = parse_extract_address(sub, &error, &start, &end, &domain,
6685           FALSE);
6686         if (t != NULL)
6687           {
6688           if (c != EOP_DOMAIN)
6689             {
6690             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6691             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6692             }
6693           else if (domain != 0)
6694             {
6695             domain += start;
6696             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6697             }
6698           }
6699         continue;
6700         }
6701
6702       case EOP_ADDRESSES:
6703         {
6704         uschar outsep[2] = { ':', '\0' };
6705         uschar *address, *error;
6706         int save_ptr = ptr;
6707         int start, end, domain;  /* Not really used */
6708
6709         while (isspace(*sub)) sub++;
6710         if (*sub == '>') { *outsep = *++sub; ++sub; }
6711         parse_allow_group = TRUE;
6712
6713         for (;;)
6714           {
6715           uschar *p = parse_find_address_end(sub, FALSE);
6716           uschar saveend = *p;
6717           *p = '\0';
6718           address = parse_extract_address(sub, &error, &start, &end, &domain,
6719             FALSE);
6720           *p = saveend;
6721
6722           /* Add the address to the output list that we are building. This is
6723           done in chunks by searching for the separator character. At the
6724           start, unless we are dealing with the first address of the output
6725           list, add in a space if the new address begins with the separator
6726           character, or is an empty string. */
6727
6728           if (address != NULL)
6729             {
6730             if (ptr != save_ptr && address[0] == *outsep)
6731               yield = string_catn(yield, &size, &ptr, US" ", 1);
6732
6733             for (;;)
6734               {
6735               size_t seglen = Ustrcspn(address, outsep);
6736               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6737
6738               /* If we got to the end of the string we output one character
6739               too many. */
6740
6741               if (address[seglen] == '\0') { ptr--; break; }
6742               yield = string_catn(yield, &size, &ptr, outsep, 1);
6743               address += seglen + 1;
6744               }
6745
6746             /* Output a separator after the string: we will remove the
6747             redundant final one at the end. */
6748
6749             yield = string_catn(yield, &size, &ptr, outsep, 1);
6750             }
6751
6752           if (saveend == '\0') break;
6753           sub = p + 1;
6754           }
6755
6756         /* If we have generated anything, remove the redundant final
6757         separator. */
6758
6759         if (ptr != save_ptr) ptr--;
6760         parse_allow_group = FALSE;
6761         continue;
6762         }
6763
6764
6765       /* quote puts a string in quotes if it is empty or contains anything
6766       other than alphamerics, underscore, dot, or hyphen.
6767
6768       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6769       be quoted in order to be a valid local part.
6770
6771       In both cases, newlines and carriage returns are converted into \n and \r
6772       respectively */
6773
6774       case EOP_QUOTE:
6775       case EOP_QUOTE_LOCAL_PART:
6776       if (arg == NULL)
6777         {
6778         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6779         uschar *t = sub - 1;
6780
6781         if (c == EOP_QUOTE)
6782           {
6783           while (!needs_quote && *(++t) != 0)
6784             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6785           }
6786         else  /* EOP_QUOTE_LOCAL_PART */
6787           {
6788           while (!needs_quote && *(++t) != 0)
6789             needs_quote = !isalnum(*t) &&
6790               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6791               (*t != '.' || t == sub || t[1] == 0);
6792           }
6793
6794         if (needs_quote)
6795           {
6796           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6797           t = sub - 1;
6798           while (*(++t) != 0)
6799             {
6800             if (*t == '\n')
6801               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6802             else if (*t == '\r')
6803               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6804             else
6805               {
6806               if (*t == '\\' || *t == '"')
6807                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6808               yield = string_catn(yield, &size, &ptr, t, 1);
6809               }
6810             }
6811           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6812           }
6813         else yield = string_cat(yield, &size, &ptr, sub);
6814         continue;
6815         }
6816
6817       /* quote_lookuptype does lookup-specific quoting */
6818
6819       else
6820         {
6821         int n;
6822         uschar *opt = Ustrchr(arg, '_');
6823
6824         if (opt != NULL) *opt++ = 0;
6825
6826         n = search_findtype(arg, Ustrlen(arg));
6827         if (n < 0)
6828           {
6829           expand_string_message = search_error_message;
6830           goto EXPAND_FAILED;
6831           }
6832
6833         if (lookup_list[n]->quote != NULL)
6834           sub = (lookup_list[n]->quote)(sub, opt);
6835         else if (opt != NULL) sub = NULL;
6836
6837         if (sub == NULL)
6838           {
6839           expand_string_message = string_sprintf(
6840             "\"%s\" unrecognized after \"${quote_%s\"",
6841             opt, arg);
6842           goto EXPAND_FAILED;
6843           }
6844
6845         yield = string_cat(yield, &size, &ptr, sub);
6846         continue;
6847         }
6848
6849       /* rx quote sticks in \ before any non-alphameric character so that
6850       the insertion works in a regular expression. */
6851
6852       case EOP_RXQUOTE:
6853         {
6854         uschar *t = sub - 1;
6855         while (*(++t) != 0)
6856           {
6857           if (!isalnum(*t))
6858             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6859           yield = string_catn(yield, &size, &ptr, t, 1);
6860           }
6861         continue;
6862         }
6863
6864       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6865       prescribed by the RFC, if there are characters that need to be encoded */
6866
6867       case EOP_RFC2047:
6868         {
6869         uschar buffer[2048];
6870         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6871           buffer, sizeof(buffer), FALSE);
6872         yield = string_cat(yield, &size, &ptr, string);
6873         continue;
6874         }
6875
6876       /* RFC 2047 decode */
6877
6878       case EOP_RFC2047D:
6879         {
6880         int len;
6881         uschar *error;
6882         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6883           headers_charset, '?', &len, &error);
6884         if (error != NULL)
6885           {
6886           expand_string_message = error;
6887           goto EXPAND_FAILED;
6888           }
6889         yield = string_catn(yield, &size, &ptr, decoded, len);
6890         continue;
6891         }
6892
6893       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6894       underscores */
6895
6896       case EOP_FROM_UTF8:
6897         {
6898         while (*sub != 0)
6899           {
6900           int c;
6901           uschar buff[4];
6902           GETUTF8INC(c, sub);
6903           if (c > 255) c = '_';
6904           buff[0] = c;
6905           yield = string_catn(yield, &size, &ptr, buff, 1);
6906           }
6907         continue;
6908         }
6909
6910           /* replace illegal UTF-8 sequences by replacement character  */
6911
6912       #define UTF8_REPLACEMENT_CHAR US"?"
6913
6914       case EOP_UTF8CLEAN:
6915         {
6916         int seq_len = 0, index = 0;
6917         int bytes_left = 0;
6918         long codepoint = -1;
6919         uschar seq_buff[4];                     /* accumulate utf-8 here */
6920
6921         while (*sub != 0)
6922           {
6923           int complete = 0;
6924           uschar c = *sub++;
6925
6926           if (bytes_left)
6927             {
6928             if ((c & 0xc0) != 0x80)
6929                     /* wrong continuation byte; invalidate all bytes */
6930               complete = 1; /* error */
6931             else
6932               {
6933               codepoint = (codepoint << 6) | (c & 0x3f);
6934               seq_buff[index++] = c;
6935               if (--bytes_left == 0)            /* codepoint complete */
6936                 if(codepoint > 0x10FFFF)        /* is it too large? */
6937                   complete = -1;        /* error (RFC3629 limit) */
6938                 else
6939                   {             /* finished; output utf-8 sequence */
6940                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
6941                   index = 0;
6942                   }
6943               }
6944             }
6945           else  /* no bytes left: new sequence */
6946             {
6947             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
6948               {
6949               yield = string_catn(yield, &size, &ptr, &c, 1);
6950               continue;
6951               }
6952             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
6953               {
6954               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
6955                 complete = -1;
6956               else
6957                 {
6958                   bytes_left = 1;
6959                   codepoint = c & 0x1f;
6960                 }
6961               }
6962             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
6963               {
6964               bytes_left = 2;
6965               codepoint = c & 0x0f;
6966               }
6967             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
6968               {
6969               bytes_left = 3;
6970               codepoint = c & 0x07;
6971               }
6972             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
6973               complete = -1;
6974
6975             seq_buff[index++] = c;
6976             seq_len = bytes_left + 1;
6977             }           /* if(bytes_left) */
6978
6979           if (complete != 0)
6980             {
6981             bytes_left = index = 0;
6982             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
6983             }
6984           if ((complete == 1) && ((c & 0x80) == 0))
6985                         /* ASCII character follows incomplete sequence */
6986               yield = string_catn(yield, &size, &ptr, &c, 1);
6987           }
6988         continue;
6989         }
6990
6991 #ifdef SUPPORT_I18N
6992       case EOP_UTF8_DOMAIN_TO_ALABEL:
6993         {
6994         uschar * error = NULL;
6995         uschar * s = string_domain_utf8_to_alabel(sub, &error);
6996         if (error)
6997           {
6998           expand_string_message = string_sprintf(
6999             "error converting utf8 (%s) to alabel: %s",
7000             string_printing(sub), error);
7001           goto EXPAND_FAILED;
7002           }
7003         yield = string_cat(yield, &size, &ptr, s);
7004         continue;
7005         }
7006
7007       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7008         {
7009         uschar * error = NULL;
7010         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7011         if (error)
7012           {
7013           expand_string_message = string_sprintf(
7014             "error converting alabel (%s) to utf8: %s",
7015             string_printing(sub), error);
7016           goto EXPAND_FAILED;
7017           }
7018         yield = string_cat(yield, &size, &ptr, s);
7019         continue;
7020         }
7021
7022       case EOP_UTF8_LOCALPART_TO_ALABEL:
7023         {
7024         uschar * error = NULL;
7025         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7026         if (error)
7027           {
7028           expand_string_message = string_sprintf(
7029             "error converting utf8 (%s) to alabel: %s",
7030             string_printing(sub), error);
7031           goto EXPAND_FAILED;
7032           }
7033         yield = string_cat(yield, &size, &ptr, s);
7034         DEBUG(D_expand) debug_printf("yield: '%s'\n", yield);
7035         continue;
7036         }
7037
7038       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7039         {
7040         uschar * error = NULL;
7041         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7042         if (error)
7043           {
7044           expand_string_message = string_sprintf(
7045             "error converting alabel (%s) to utf8: %s",
7046             string_printing(sub), error);
7047           goto EXPAND_FAILED;
7048           }
7049         yield = string_cat(yield, &size, &ptr, s);
7050         continue;
7051         }
7052 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7053
7054       /* escape turns all non-printing characters into escape sequences. */
7055
7056       case EOP_ESCAPE:
7057         {
7058         const uschar *t = string_printing(sub);
7059         yield = string_cat(yield, &size, &ptr, t);
7060         continue;
7061         }
7062
7063       /* Handle numeric expression evaluation */
7064
7065       case EOP_EVAL:
7066       case EOP_EVAL10:
7067         {
7068         uschar *save_sub = sub;
7069         uschar *error = NULL;
7070         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7071         if (error != NULL)
7072           {
7073           expand_string_message = string_sprintf("error in expression "
7074             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7075               save_sub);
7076           goto EXPAND_FAILED;
7077           }
7078         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7079         yield = string_cat(yield, &size, &ptr, var_buffer);
7080         continue;
7081         }
7082
7083       /* Handle time period formating */
7084
7085       case EOP_TIME_EVAL:
7086         {
7087         int n = readconf_readtime(sub, 0, FALSE);
7088         if (n < 0)
7089           {
7090           expand_string_message = string_sprintf("string \"%s\" is not an "
7091             "Exim time interval in \"%s\" operator", sub, name);
7092           goto EXPAND_FAILED;
7093           }
7094         sprintf(CS var_buffer, "%d", n);
7095         yield = string_cat(yield, &size, &ptr, var_buffer);
7096         continue;
7097         }
7098
7099       case EOP_TIME_INTERVAL:
7100         {
7101         int n;
7102         uschar *t = read_number(&n, sub);
7103         if (*t != 0) /* Not A Number*/
7104           {
7105           expand_string_message = string_sprintf("string \"%s\" is not a "
7106             "positive number in \"%s\" operator", sub, name);
7107           goto EXPAND_FAILED;
7108           }
7109         t = readconf_printtime(n);
7110         yield = string_cat(yield, &size, &ptr, t);
7111         continue;
7112         }
7113
7114       /* Convert string to base64 encoding */
7115
7116       case EOP_STR2B64:
7117       case EOP_BASE64:
7118         {
7119 #ifdef SUPPORT_TLS
7120         uschar * s = vp && *(void **)vp->value
7121           ? tls_cert_der_b64(*(void **)vp->value)
7122           : b64encode(sub, Ustrlen(sub));
7123 #else
7124         uschar * s = b64encode(sub, Ustrlen(sub));
7125 #endif
7126         yield = string_cat(yield, &size, &ptr, s);
7127         continue;
7128         }
7129
7130       case EOP_BASE64D:
7131         {
7132         uschar * s;
7133         int len = b64decode(sub, &s);
7134         if (len < 0)
7135           {
7136           expand_string_message = string_sprintf("string \"%s\" is not "
7137             "well-formed for \"%s\" operator", sub, name);
7138           goto EXPAND_FAILED;
7139           }
7140         yield = string_cat(yield, &size, &ptr, s);
7141         continue;
7142         }
7143
7144       /* strlen returns the length of the string */
7145
7146       case EOP_STRLEN:
7147         {
7148         uschar buff[24];
7149         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7150         yield = string_cat(yield, &size, &ptr, buff);
7151         continue;
7152         }
7153
7154       /* length_n or l_n takes just the first n characters or the whole string,
7155       whichever is the shorter;
7156
7157       substr_m_n, and s_m_n take n characters from offset m; negative m take
7158       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7159       takes the rest, either to the right or to the left.
7160
7161       hash_n or h_n makes a hash of length n from the string, yielding n
7162       characters from the set a-z; hash_n_m makes a hash of length n, but
7163       uses m characters from the set a-zA-Z0-9.
7164
7165       nhash_n returns a single number between 0 and n-1 (in text form), while
7166       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7167       between 0 and n-1 and the second between 0 and m-1. */
7168
7169       case EOP_LENGTH:
7170       case EOP_L:
7171       case EOP_SUBSTR:
7172       case EOP_S:
7173       case EOP_HASH:
7174       case EOP_H:
7175       case EOP_NHASH:
7176       case EOP_NH:
7177         {
7178         int sign = 1;
7179         int value1 = 0;
7180         int value2 = -1;
7181         int *pn;
7182         int len;
7183         uschar *ret;
7184
7185         if (arg == NULL)
7186           {
7187           expand_string_message = string_sprintf("missing values after %s",
7188             name);
7189           goto EXPAND_FAILED;
7190           }
7191
7192         /* "length" has only one argument, effectively being synonymous with
7193         substr_0_n. */
7194
7195         if (c == EOP_LENGTH || c == EOP_L)
7196           {
7197           pn = &value2;
7198           value2 = 0;
7199           }
7200
7201         /* The others have one or two arguments; for "substr" the first may be
7202         negative. The second being negative means "not supplied". */
7203
7204         else
7205           {
7206           pn = &value1;
7207           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7208           }
7209
7210         /* Read up to two numbers, separated by underscores */
7211
7212         ret = arg;
7213         while (*arg != 0)
7214           {
7215           if (arg != ret && *arg == '_' && pn == &value1)
7216             {
7217             pn = &value2;
7218             value2 = 0;
7219             if (arg[1] != 0) arg++;
7220             }
7221           else if (!isdigit(*arg))
7222             {
7223             expand_string_message =
7224               string_sprintf("non-digit after underscore in \"%s\"", name);
7225             goto EXPAND_FAILED;
7226             }
7227           else *pn = (*pn)*10 + *arg++ - '0';
7228           }
7229         value1 *= sign;
7230
7231         /* Perform the required operation */
7232
7233         ret =
7234           (c == EOP_HASH || c == EOP_H)?
7235              compute_hash(sub, value1, value2, &len) :
7236           (c == EOP_NHASH || c == EOP_NH)?
7237              compute_nhash(sub, value1, value2, &len) :
7238              extract_substr(sub, value1, value2, &len);
7239
7240         if (ret == NULL) goto EXPAND_FAILED;
7241         yield = string_catn(yield, &size, &ptr, ret, len);
7242         continue;
7243         }
7244
7245       /* Stat a path */
7246
7247       case EOP_STAT:
7248         {
7249         uschar *s;
7250         uschar smode[12];
7251         uschar **modetable[3];
7252         int i;
7253         mode_t mode;
7254         struct stat st;
7255
7256         if ((expand_forbid & RDO_EXISTS) != 0)
7257           {
7258           expand_string_message = US"Use of the stat() expansion is not permitted";
7259           goto EXPAND_FAILED;
7260           }
7261
7262         if (stat(CS sub, &st) < 0)
7263           {
7264           expand_string_message = string_sprintf("stat(%s) failed: %s",
7265             sub, strerror(errno));
7266           goto EXPAND_FAILED;
7267           }
7268         mode = st.st_mode;
7269         switch (mode & S_IFMT)
7270           {
7271           case S_IFIFO: smode[0] = 'p'; break;
7272           case S_IFCHR: smode[0] = 'c'; break;
7273           case S_IFDIR: smode[0] = 'd'; break;
7274           case S_IFBLK: smode[0] = 'b'; break;
7275           case S_IFREG: smode[0] = '-'; break;
7276           default: smode[0] = '?'; break;
7277           }
7278
7279         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7280         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7281         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7282
7283         for (i = 0; i < 3; i++)
7284           {
7285           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7286           mode >>= 3;
7287           }
7288
7289         smode[10] = 0;
7290         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7291           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7292           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7293           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7294           (long)st.st_gid, st.st_size, (long)st.st_atime,
7295           (long)st.st_mtime, (long)st.st_ctime);
7296         yield = string_cat(yield, &size, &ptr, s);
7297         continue;
7298         }
7299
7300       /* vaguely random number less than N */
7301
7302       case EOP_RANDINT:
7303         {
7304         int_eximarith_t max;
7305         uschar *s;
7306
7307         max = expanded_string_integer(sub, TRUE);
7308         if (expand_string_message != NULL)
7309           goto EXPAND_FAILED;
7310         s = string_sprintf("%d", vaguely_random_number((int)max));
7311         yield = string_cat(yield, &size, &ptr, s);
7312         continue;
7313         }
7314
7315       /* Reverse IP, including IPv6 to dotted-nibble */
7316
7317       case EOP_REVERSE_IP:
7318         {
7319         int family, maskptr;
7320         uschar reversed[128];
7321
7322         family = string_is_ip_address(sub, &maskptr);
7323         if (family == 0)
7324           {
7325           expand_string_message = string_sprintf(
7326               "reverse_ip() not given an IP address [%s]", sub);
7327           goto EXPAND_FAILED;
7328           }
7329         invert_address(reversed, sub);
7330         yield = string_cat(yield, &size, &ptr, reversed);
7331         continue;
7332         }
7333
7334       /* Unknown operator */
7335
7336       default:
7337       expand_string_message =
7338         string_sprintf("unknown expansion operator \"%s\"", name);
7339       goto EXPAND_FAILED;
7340       }
7341     }
7342
7343   /* Handle a plain name. If this is the first thing in the expansion, release
7344   the pre-allocated buffer. If the result data is known to be in a new buffer,
7345   newsize will be set to the size of that buffer, and we can just point at that
7346   store instead of copying. Many expansion strings contain just one reference,
7347   so this is a useful optimization, especially for humungous headers
7348   ($message_headers). */
7349                                                 /*{*/
7350   if (*s++ == '}')
7351     {
7352     int len;
7353     int newsize = 0;
7354     if (ptr == 0)
7355       {
7356       if (resetok) store_reset(yield);
7357       yield = NULL;
7358       size = 0;
7359       }
7360     value = find_variable(name, FALSE, skipping, &newsize);
7361     if (value == NULL)
7362       {
7363       expand_string_message =
7364         string_sprintf("unknown variable in \"${%s}\"", name);
7365       check_variable_error_message(name);
7366       goto EXPAND_FAILED;
7367       }
7368     len = Ustrlen(value);
7369     if (yield == NULL && newsize != 0)
7370       {
7371       yield = value;
7372       size = newsize;
7373       ptr = len;
7374       }
7375     else yield = string_catn(yield, &size, &ptr, value, len);
7376     continue;
7377     }
7378
7379   /* Else there's something wrong */
7380
7381   expand_string_message =
7382     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7383     "in a variable reference)", name);
7384   goto EXPAND_FAILED;
7385   }
7386
7387 /* If we hit the end of the string when ket_ends is set, there is a missing
7388 terminating brace. */
7389
7390 if (ket_ends && *s == 0)
7391   {
7392   expand_string_message = malformed_header?
7393     US"missing } at end of string - could be header name not terminated by colon"
7394     :
7395     US"missing } at end of string";
7396   goto EXPAND_FAILED;
7397   }
7398
7399 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7400 added to the string. If so, set up an empty string. Add a terminating zero. If
7401 left != NULL, return a pointer to the terminator. */
7402
7403 if (yield == NULL) yield = store_get(1);
7404 yield[ptr] = 0;
7405 if (left != NULL) *left = s;
7406
7407 /* Any stacking store that was used above the final string is no longer needed.
7408 In many cases the final string will be the first one that was got and so there
7409 will be optimal store usage. */
7410
7411 if (resetok) store_reset(yield + ptr + 1);
7412 else if (resetok_p) *resetok_p = FALSE;
7413
7414 DEBUG(D_expand)
7415   {
7416   debug_printf("  expanding: %.*s\n     result: %s\n", (int)(s - string), string,
7417     yield);
7418   if (skipping) debug_printf("   skipping: result is not used\n");
7419   }
7420 return yield;
7421
7422 /* This is the failure exit: easiest to program with a goto. We still need
7423 to update the pointer to the terminator, for cases of nested calls with "fail".
7424 */
7425
7426 EXPAND_FAILED_CURLY:
7427 if (malformed_header)
7428   expand_string_message =
7429     US"missing or misplaced { or } - could be header name not terminated by colon";
7430
7431 else if (!expand_string_message || !*expand_string_message)
7432   expand_string_message = US"missing or misplaced { or }";
7433
7434 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7435 that is a bad idea, because expand_string_message is in dynamic store. */
7436
7437 EXPAND_FAILED:
7438 if (left != NULL) *left = s;
7439 DEBUG(D_expand)
7440   {
7441   debug_printf("failed to expand: %s\n", string);
7442   debug_printf("   error message: %s\n", expand_string_message);
7443   if (expand_string_forcedfail) debug_printf("failure was forced\n");
7444   }
7445 if (resetok_p) *resetok_p = resetok;
7446 return NULL;
7447 }
7448
7449
7450 /* This is the external function call. Do a quick check for any expansion
7451 metacharacters, and if there are none, just return the input string.
7452
7453 Argument: the string to be expanded
7454 Returns:  the expanded string, or NULL if expansion failed; if failure was
7455           due to a lookup deferring, search_find_defer will be TRUE
7456 */
7457
7458 uschar *
7459 expand_string(uschar *string)
7460 {
7461 search_find_defer = FALSE;
7462 malformed_header = FALSE;
7463 return (Ustrpbrk(string, "$\\") == NULL)? string :
7464   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7465 }
7466
7467
7468
7469 const uschar *
7470 expand_cstring(const uschar *string)
7471 {
7472 search_find_defer = FALSE;
7473 malformed_header = FALSE;
7474 return (Ustrpbrk(string, "$\\") == NULL)? string :
7475   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7476 }
7477
7478
7479
7480 /*************************************************
7481 *              Expand and copy                   *
7482 *************************************************/
7483
7484 /* Now and again we want to expand a string and be sure that the result is in a
7485 new bit of store. This function does that.
7486 Since we know it has been copied, the de-const cast is safe.
7487
7488 Argument: the string to be expanded
7489 Returns:  the expanded string, always in a new bit of store, or NULL
7490 */
7491
7492 uschar *
7493 expand_string_copy(const uschar *string)
7494 {
7495 const uschar *yield = expand_cstring(string);
7496 if (yield == string) yield = string_copy(string);
7497 return US yield;
7498 }
7499
7500
7501
7502 /*************************************************
7503 *        Expand and interpret as an integer      *
7504 *************************************************/
7505
7506 /* Expand a string, and convert the result into an integer.
7507
7508 Arguments:
7509   string  the string to be expanded
7510   isplus  TRUE if a non-negative number is expected
7511
7512 Returns:  the integer value, or
7513           -1 for an expansion error               ) in both cases, message in
7514           -2 for an integer interpretation error  ) expand_string_message
7515           expand_string_message is set NULL for an OK integer
7516 */
7517
7518 int_eximarith_t
7519 expand_string_integer(uschar *string, BOOL isplus)
7520 {
7521 return expanded_string_integer(expand_string(string), isplus);
7522 }
7523
7524
7525 /*************************************************
7526  *         Interpret string as an integer        *
7527  *************************************************/
7528
7529 /* Convert a string (that has already been expanded) into an integer.
7530
7531 This function is used inside the expansion code.
7532
7533 Arguments:
7534   s       the string to be expanded
7535   isplus  TRUE if a non-negative number is expected
7536
7537 Returns:  the integer value, or
7538           -1 if string is NULL (which implies an expansion error)
7539           -2 for an integer interpretation error
7540           expand_string_message is set NULL for an OK integer
7541 */
7542
7543 static int_eximarith_t
7544 expanded_string_integer(const uschar *s, BOOL isplus)
7545 {
7546 int_eximarith_t value;
7547 uschar *msg = US"invalid integer \"%s\"";
7548 uschar *endptr;
7549
7550 /* If expansion failed, expand_string_message will be set. */
7551
7552 if (s == NULL) return -1;
7553
7554 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7555 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7556 systems, so we set it zero ourselves. */
7557
7558 errno = 0;
7559 expand_string_message = NULL;               /* Indicates no error */
7560
7561 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7562 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7563 the behaviour explicitly.  Stripping leading whitespace is a harmless
7564 noop change since strtol skips it anyway (provided that there is a number
7565 to find at all). */
7566 if (isspace(*s))
7567   {
7568   while (isspace(*s)) ++s;
7569   if (*s == '\0')
7570     {
7571       DEBUG(D_expand)
7572        debug_printf("treating blank string as number 0\n");
7573       return 0;
7574     }
7575   }
7576
7577 value = strtoll(CS s, CSS &endptr, 10);
7578
7579 if (endptr == s)
7580   {
7581   msg = US"integer expected but \"%s\" found";
7582   }
7583 else if (value < 0 && isplus)
7584   {
7585   msg = US"non-negative integer expected but \"%s\" found";
7586   }
7587 else
7588   {
7589   switch (tolower(*endptr))
7590     {
7591     default:
7592       break;
7593     case 'k':
7594       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7595       else value *= 1024;
7596       endptr++;
7597       break;
7598     case 'm':
7599       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7600       else value *= 1024*1024;
7601       endptr++;
7602       break;
7603     case 'g':
7604       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7605       else value *= 1024*1024*1024;
7606       endptr++;
7607       break;
7608     }
7609   if (errno == ERANGE)
7610     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7611   else
7612     {
7613     while (isspace(*endptr)) endptr++;
7614     if (*endptr == 0) return value;
7615     }
7616   }
7617
7618 expand_string_message = string_sprintf(CS msg, s);
7619 return -2;
7620 }
7621
7622
7623 /* These values are usually fixed boolean values, but they are permitted to be
7624 expanded strings.
7625
7626 Arguments:
7627   addr       address being routed
7628   mtype      the module type
7629   mname      the module name
7630   dbg_opt    debug selectors
7631   oname      the option name
7632   bvalue     the router's boolean value
7633   svalue     the router's string value
7634   rvalue     where to put the returned value
7635
7636 Returns:     OK     value placed in rvalue
7637              DEFER  expansion failed
7638 */
7639
7640 int
7641 exp_bool(address_item *addr,
7642   uschar *mtype, uschar *mname, unsigned dbg_opt,
7643   uschar *oname, BOOL bvalue,
7644   uschar *svalue, BOOL *rvalue)
7645 {
7646 uschar *expanded;
7647 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7648
7649 expanded = expand_string(svalue);
7650 if (expanded == NULL)
7651   {
7652   if (expand_string_forcedfail)
7653     {
7654     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7655     *rvalue = bvalue;
7656     return OK;
7657     }
7658   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7659       oname, mname, mtype, expand_string_message);
7660   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7661   return DEFER;
7662   }
7663
7664 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7665   expanded);
7666
7667 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7668   *rvalue = TRUE;
7669 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7670   *rvalue = FALSE;
7671 else
7672   {
7673   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7674     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7675   return DEFER;
7676   }
7677
7678 return OK;
7679 }
7680
7681
7682
7683 /* Avoid potentially exposing a password in a string about to be logged */
7684
7685 uschar *
7686 expand_hide_passwords(uschar * s)
7687 {
7688 return (  (  Ustrstr(s, "failed to expand") != NULL
7689           || Ustrstr(s, "expansion of ")    != NULL
7690           )
7691        && (  Ustrstr(s, "mysql")   != NULL
7692           || Ustrstr(s, "pgsql")   != NULL
7693           || Ustrstr(s, "redis")   != NULL
7694           || Ustrstr(s, "sqlite")  != NULL
7695           || Ustrstr(s, "ldap:")   != NULL
7696           || Ustrstr(s, "ldaps:")  != NULL
7697           || Ustrstr(s, "ldapi:")  != NULL
7698           || Ustrstr(s, "ldapdn:") != NULL
7699           || Ustrstr(s, "ldapm:")  != NULL
7700        )  )
7701   ? US"Temporary internal error" : s;
7702 }
7703
7704
7705
7706
7707 /*************************************************
7708 **************************************************
7709 *             Stand-alone test program           *
7710 **************************************************
7711 *************************************************/
7712
7713 #ifdef STAND_ALONE
7714
7715
7716 BOOL
7717 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7718 {
7719 int ovector[3*(EXPAND_MAXN+1)];
7720 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7721   ovector, nelem(ovector));
7722 BOOL yield = n >= 0;
7723 if (n == 0) n = EXPAND_MAXN + 1;
7724 if (yield)
7725   {
7726   int nn;
7727   expand_nmax = (setup < 0)? 0 : setup + 1;
7728   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7729     {
7730     expand_nstring[expand_nmax] = subject + ovector[nn];
7731     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7732     }
7733   expand_nmax--;
7734   }
7735 return yield;
7736 }
7737
7738
7739 int main(int argc, uschar **argv)
7740 {
7741 int i;
7742 uschar buffer[1024];
7743
7744 debug_selector = D_v;
7745 debug_file = stderr;
7746 debug_fd = fileno(debug_file);
7747 big_buffer = malloc(big_buffer_size);
7748
7749 for (i = 1; i < argc; i++)
7750   {
7751   if (argv[i][0] == '+')
7752     {
7753     debug_trace_memory = 2;
7754     argv[i]++;
7755     }
7756   if (isdigit(argv[i][0]))
7757     debug_selector = Ustrtol(argv[i], NULL, 0);
7758   else
7759     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7760         Ustrlen(argv[i]))
7761       {
7762 #ifdef LOOKUP_LDAP
7763       eldap_default_servers = argv[i];
7764 #endif
7765 #ifdef LOOKUP_MYSQL
7766       mysql_servers = argv[i];
7767 #endif
7768 #ifdef LOOKUP_PGSQL
7769       pgsql_servers = argv[i];
7770 #endif
7771 #ifdef LOOKUP_REDIS
7772       redis_servers = argv[i];
7773 #endif
7774       }
7775 #ifdef EXIM_PERL
7776   else opt_perl_startup = argv[i];
7777 #endif
7778   }
7779
7780 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7781
7782 expand_nstring[1] = US"string 1....";
7783 expand_nlength[1] = 8;
7784 expand_nmax = 1;
7785
7786 #ifdef EXIM_PERL
7787 if (opt_perl_startup != NULL)
7788   {
7789   uschar *errstr;
7790   printf("Starting Perl interpreter\n");
7791   errstr = init_perl(opt_perl_startup);
7792   if (errstr != NULL)
7793     {
7794     printf("** error in perl_startup code: %s\n", errstr);
7795     return EXIT_FAILURE;
7796     }
7797   }
7798 #endif /* EXIM_PERL */
7799
7800 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7801   {
7802   void *reset_point = store_get(0);
7803   uschar *yield = expand_string(buffer);
7804   if (yield != NULL)
7805     {
7806     printf("%s\n", yield);
7807     store_reset(reset_point);
7808     }
7809   else
7810     {
7811     if (search_find_defer) printf("search_find deferred\n");
7812     printf("Failed: %s\n", expand_string_message);
7813     if (expand_string_forcedfail) printf("Forced failure\n");
7814     printf("\n");
7815     }
7816   }
7817
7818 search_tidyup();
7819
7820 return 0;
7821 }
7822
7823 #endif
7824
7825 /* vi: aw ai sw=2
7826 */
7827 /* End of expand.c */