src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   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.  Characters 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"authresults",
 107   US"certextract",
 108   US"dlfunc",
 109   US"env",
 110   US"extract",
 111   US"filter",
 112   US"hash",
 113   US"hmac",
 114   US"if",
 115 #ifdef SUPPORT_I18N
 116   US"imapfolder",
 117 #endif
 118   US"length",
 119   US"listextract",
 120   US"lookup",
 121   US"map",
 122   US"nhash",
 123   US"perl",
 124   US"prvs",
 125   US"prvscheck",
 126   US"readfile",
 127   US"readsocket",
 128   US"reduce",
 129   US"run",
 130   US"sg",
 131   US"sort",
 132   US"substr",
 133   US"tr" };
 134
 135 enum {
 136   EITEM_ACL,
 137   EITEM_AUTHRESULTS,
 138   EITEM_CERTEXTRACT,
 139   EITEM_DLFUNC,
 140   EITEM_ENV,
 141   EITEM_EXTRACT,
 142   EITEM_FILTER,
 143   EITEM_HASH,
 144   EITEM_HMAC,
 145   EITEM_IF,
 146 #ifdef SUPPORT_I18N
 147   EITEM_IMAPFOLDER,
 148 #endif
 149   EITEM_LENGTH,
 150   EITEM_LISTEXTRACT,
 151   EITEM_LOOKUP,
 152   EITEM_MAP,
 153   EITEM_NHASH,
 154   EITEM_PERL,
 155   EITEM_PRVS,
 156   EITEM_PRVSCHECK,
 157   EITEM_READFILE,
 158   EITEM_READSOCK,
 159   EITEM_REDUCE,
 160   EITEM_RUN,
 161   EITEM_SG,
 162   EITEM_SORT,
 163   EITEM_SUBSTR,
 164   EITEM_TR };
 165
 166 /* Tables of operator names, and corresponding switch numbers. The names must be
 167 in alphabetical order. There are two tables, because underscore is used in some
 168 cases to introduce arguments, whereas for other it is part of the name. This is
 169 an historical mis-design. */
 170
 171 static uschar *op_table_underscore[] = {
 172   US"from_utf8",
 173   US"local_part",
 174   US"quote_local_part",
 175   US"reverse_ip",
 176   US"time_eval",
 177   US"time_interval"
 178 #ifdef SUPPORT_I18N
 179  ,US"utf8_domain_from_alabel",
 180   US"utf8_domain_to_alabel",
 181   US"utf8_localpart_from_alabel",
 182   US"utf8_localpart_to_alabel"
 183 #endif
 184   };
 185
 186 enum {
 187   EOP_FROM_UTF8,
 188   EOP_LOCAL_PART,
 189   EOP_QUOTE_LOCAL_PART,
 190   EOP_REVERSE_IP,
 191   EOP_TIME_EVAL,
 192   EOP_TIME_INTERVAL
 193 #ifdef SUPPORT_I18N
 194  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 195   EOP_UTF8_DOMAIN_TO_ALABEL,
 196   EOP_UTF8_LOCALPART_FROM_ALABEL,
 197   EOP_UTF8_LOCALPART_TO_ALABEL
 198 #endif
 199   };
 200
 201 static uschar *op_table_main[] = {
 202   US"address",
 203   US"addresses",
 204   US"base32",
 205   US"base32d",
 206   US"base62",
 207   US"base62d",
 208   US"base64",
 209   US"base64d",
 210   US"domain",
 211   US"escape",
 212   US"escape8bit",
 213   US"eval",
 214   US"eval10",
 215   US"expand",
 216   US"h",
 217   US"hash",
 218   US"hex2b64",
 219   US"hexquote",
 220   US"ipv6denorm",
 221   US"ipv6norm",
 222   US"l",
 223   US"lc",
 224   US"length",
 225   US"listcount",
 226   US"listnamed",
 227   US"mask",
 228   US"md5",
 229   US"nh",
 230   US"nhash",
 231   US"quote",
 232   US"randint",
 233   US"rfc2047",
 234   US"rfc2047d",
 235   US"rxquote",
 236   US"s",
 237   US"sha1",
 238   US"sha256",
 239   US"sha3",
 240   US"stat",
 241   US"str2b64",
 242   US"strlen",
 243   US"substr",
 244   US"uc",
 245   US"utf8clean" };
 246
 247 enum {
 248   EOP_ADDRESS =  nelem(op_table_underscore),
 249   EOP_ADDRESSES,
 250   EOP_BASE32,
 251   EOP_BASE32D,
 252   EOP_BASE62,
 253   EOP_BASE62D,
 254   EOP_BASE64,
 255   EOP_BASE64D,
 256   EOP_DOMAIN,
 257   EOP_ESCAPE,
 258   EOP_ESCAPE8BIT,
 259   EOP_EVAL,
 260   EOP_EVAL10,
 261   EOP_EXPAND,
 262   EOP_H,
 263   EOP_HASH,
 264   EOP_HEX2B64,
 265   EOP_HEXQUOTE,
 266   EOP_IPV6DENORM,
 267   EOP_IPV6NORM,
 268   EOP_L,
 269   EOP_LC,
 270   EOP_LENGTH,
 271   EOP_LISTCOUNT,
 272   EOP_LISTNAMED,
 273   EOP_MASK,
 274   EOP_MD5,
 275   EOP_NH,
 276   EOP_NHASH,
 277   EOP_QUOTE,
 278   EOP_RANDINT,
 279   EOP_RFC2047,
 280   EOP_RFC2047D,
 281   EOP_RXQUOTE,
 282   EOP_S,
 283   EOP_SHA1,
 284   EOP_SHA256,
 285   EOP_SHA3,
 286   EOP_STAT,
 287   EOP_STR2B64,
 288   EOP_STRLEN,
 289   EOP_SUBSTR,
 290   EOP_UC,
 291   EOP_UTF8CLEAN };
 292
 293
 294 /* Table of condition names, and corresponding switch numbers. The names must
 295 be in alphabetical order. */
 296
 297 static uschar *cond_table[] = {
 298   US"<",
 299   US"<=",
 300   US"=",
 301   US"==",     /* Backward compatibility */
 302   US">",
 303   US">=",
 304   US"acl",
 305   US"and",
 306   US"bool",
 307   US"bool_lax",
 308   US"crypteq",
 309   US"def",
 310   US"eq",
 311   US"eqi",
 312   US"exists",
 313   US"first_delivery",
 314   US"forall",
 315   US"forany",
 316   US"ge",
 317   US"gei",
 318   US"gt",
 319   US"gti",
 320   US"inlist",
 321   US"inlisti",
 322   US"isip",
 323   US"isip4",
 324   US"isip6",
 325   US"ldapauth",
 326   US"le",
 327   US"lei",
 328   US"lt",
 329   US"lti",
 330   US"match",
 331   US"match_address",
 332   US"match_domain",
 333   US"match_ip",
 334   US"match_local_part",
 335   US"or",
 336   US"pam",
 337   US"pwcheck",
 338   US"queue_running",
 339   US"radius",
 340   US"saslauthd"
 341 };
 342
 343 enum {
 344   ECOND_NUM_L,
 345   ECOND_NUM_LE,
 346   ECOND_NUM_E,
 347   ECOND_NUM_EE,
 348   ECOND_NUM_G,
 349   ECOND_NUM_GE,
 350   ECOND_ACL,
 351   ECOND_AND,
 352   ECOND_BOOL,
 353   ECOND_BOOL_LAX,
 354   ECOND_CRYPTEQ,
 355   ECOND_DEF,
 356   ECOND_STR_EQ,
 357   ECOND_STR_EQI,
 358   ECOND_EXISTS,
 359   ECOND_FIRST_DELIVERY,
 360   ECOND_FORALL,
 361   ECOND_FORANY,
 362   ECOND_STR_GE,
 363   ECOND_STR_GEI,
 364   ECOND_STR_GT,
 365   ECOND_STR_GTI,
 366   ECOND_INLIST,
 367   ECOND_INLISTI,
 368   ECOND_ISIP,
 369   ECOND_ISIP4,
 370   ECOND_ISIP6,
 371   ECOND_LDAPAUTH,
 372   ECOND_STR_LE,
 373   ECOND_STR_LEI,
 374   ECOND_STR_LT,
 375   ECOND_STR_LTI,
 376   ECOND_MATCH,
 377   ECOND_MATCH_ADDRESS,
 378   ECOND_MATCH_DOMAIN,
 379   ECOND_MATCH_IP,
 380   ECOND_MATCH_LOCAL_PART,
 381   ECOND_OR,
 382   ECOND_PAM,
 383   ECOND_PWCHECK,
 384   ECOND_QUEUE_RUNNING,
 385   ECOND_RADIUS,
 386   ECOND_SASLAUTHD
 387 };
 388
 389
 390 /* Types of table entry */
 391
 392 enum vtypes {
 393   vtype_int,            /* value is address of int */
 394   vtype_filter_int,     /* ditto, but recognized only when filtering */
 395   vtype_ino,            /* value is address of ino_t (not always an int) */
 396   vtype_uid,            /* value is address of uid_t (not always an int) */
 397   vtype_gid,            /* value is address of gid_t (not always an int) */
 398   vtype_bool,           /* value is address of bool */
 399   vtype_stringptr,      /* value is address of pointer to string */
 400   vtype_msgbody,        /* as stringptr, but read when first required */
 401   vtype_msgbody_end,    /* ditto, the end of the message */
 402   vtype_msgheaders,     /* the message's headers, processed */
 403   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 404   vtype_localpart,      /* extract local part from string */
 405   vtype_domain,         /* extract domain from string */
 406   vtype_string_func,    /* value is string returned by given function */
 407   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 408   vtype_tode,           /* value not used; generate tod in epoch format */
 409   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 410   vtype_todf,           /* value not used; generate full tod */
 411   vtype_todl,           /* value not used; generate log tod */
 412   vtype_todlf,          /* value not used; generate log file datestamp tod */
 413   vtype_todzone,        /* value not used; generate time zone only */
 414   vtype_todzulu,        /* value not used; generate zulu tod */
 415   vtype_reply,          /* value not used; get reply from headers */
 416   vtype_pid,            /* value not used; result is pid */
 417   vtype_host_lookup,    /* value not used; get host name */
 418   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 419   vtype_pspace,         /* partition space; value is T/F for spool/log */
 420   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 421   vtype_cert            /* SSL certificate */
 422   #ifndef DISABLE_DKIM
 423   ,vtype_dkim           /* Lookup of value in DKIM signature */
 424   #endif
 425 };
 426
 427 /* Type for main variable table */
 428
 429 typedef struct {
 430   const char *name;
 431   enum vtypes type;
 432   void       *value;
 433 } var_entry;
 434
 435 /* Type for entries pointing to address/length pairs. Not currently
 436 in use. */
 437
 438 typedef struct {
 439   uschar **address;
 440   int  *length;
 441 } alblock;
 442
 443 static uschar * fn_recipients(void);
 444
 445 /* This table must be kept in alphabetical order. */
 446
 447 static var_entry var_table[] = {
 448   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 449      they will be confused with user-creatable ACL variables. */
 450   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 451   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 452   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 453   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 454   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 455   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 456   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 457   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 458   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 459   { "acl_narg",            vtype_int,         &acl_narg },
 460   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 461   { "address_data",        vtype_stringptr,   &deliver_address_data },
 462   { "address_file",        vtype_stringptr,   &address_file },
 463   { "address_pipe",        vtype_stringptr,   &address_pipe },
 464   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 465   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 466   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 467   { "authentication_failed",vtype_int,        &authentication_failed },
 468 #ifdef WITH_CONTENT_SCAN
 469   { "av_failed",           vtype_int,         &av_failed },
 470 #endif
 471 #ifdef EXPERIMENTAL_BRIGHTMAIL
 472   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 473   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 474   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 475   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 476 #endif
 477   { "body_linecount",      vtype_int,         &body_linecount },
 478   { "body_zerocount",      vtype_int,         &body_zerocount },
 479   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 480   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 481   { "caller_gid",          vtype_gid,         &real_gid },
 482   { "caller_uid",          vtype_uid,         &real_uid },
 483   { "callout_address",     vtype_stringptr,   &callout_address },
 484   { "compile_date",        vtype_stringptr,   &version_date },
 485   { "compile_number",      vtype_stringptr,   &version_cnumber },
 486   { "config_dir",          vtype_stringptr,   &config_main_directory },
 487   { "config_file",         vtype_stringptr,   &config_main_filename },
 488   { "csa_status",          vtype_stringptr,   &csa_status },
 489 #ifdef EXPERIMENTAL_DCC
 490   { "dcc_header",          vtype_stringptr,   &dcc_header },
 491   { "dcc_result",          vtype_stringptr,   &dcc_result },
 492 #endif
 493 #ifndef DISABLE_DKIM
 494   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 495   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 496   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 497   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 498   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 499   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 500   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 501   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 502   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 503   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 504   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 505   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 506   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 507   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 508   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 509   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 510   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 511   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 512   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 513   { "dkim_verify_reason",  vtype_stringptr,   &dkim_verify_reason },
 514   { "dkim_verify_status",  vtype_stringptr,   &dkim_verify_status },
 515 #endif
 516 #ifdef EXPERIMENTAL_DMARC
 517   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 518   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 519   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 520   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 521   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 522 #endif
 523   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 524   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 525   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 526   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 527   { "domain",              vtype_stringptr,   &deliver_domain },
 528   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 529 #ifndef DISABLE_EVENT
 530   { "event_data",          vtype_stringptr,   &event_data },
 531
 532   /*XXX want to use generic vars for as many of these as possible*/
 533   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 534
 535   { "event_name",          vtype_stringptr,   &event_name },
 536 #endif
 537   { "exim_gid",            vtype_gid,         &exim_gid },
 538   { "exim_path",           vtype_stringptr,   &exim_path },
 539   { "exim_uid",            vtype_uid,         &exim_uid },
 540   { "exim_version",        vtype_stringptr,   &version_string },
 541   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 542   { "home",                vtype_stringptr,   &deliver_home },
 543   { "host",                vtype_stringptr,   &deliver_host },
 544   { "host_address",        vtype_stringptr,   &deliver_host_address },
 545   { "host_data",           vtype_stringptr,   &host_data },
 546   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 547   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 548   { "host_port",           vtype_int,         &deliver_host_port },
 549   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 550   { "inode",               vtype_ino,         &deliver_inode },
 551   { "interface_address",   vtype_stringptr,   &interface_address },
 552   { "interface_port",      vtype_int,         &interface_port },
 553   { "item",                vtype_stringptr,   &iterate_item },
 554   #ifdef LOOKUP_LDAP
 555   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 556   #endif
 557   { "load_average",        vtype_load_avg,    NULL },
 558   { "local_part",          vtype_stringptr,   &deliver_localpart },
 559   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 560   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 561   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 562   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 563   { "local_user_gid",      vtype_gid,         &local_user_gid },
 564   { "local_user_uid",      vtype_uid,         &local_user_uid },
 565   { "localhost_number",    vtype_int,         &host_number },
 566   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 567   { "log_space",           vtype_pspace,      (void *)FALSE },
 568   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 569   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 570 #ifdef WITH_CONTENT_SCAN
 571   { "malware_name",        vtype_stringptr,   &malware_name },
 572 #endif
 573   { "max_received_linelength", vtype_int,     &max_received_linelength },
 574   { "message_age",         vtype_int,         &message_age },
 575   { "message_body",        vtype_msgbody,     &message_body },
 576   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 577   { "message_body_size",   vtype_int,         &message_body_size },
 578   { "message_exim_id",     vtype_stringptr,   &message_id },
 579   { "message_headers",     vtype_msgheaders,  NULL },
 580   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 581   { "message_id",          vtype_stringptr,   &message_id },
 582   { "message_linecount",   vtype_int,         &message_linecount },
 583   { "message_size",        vtype_int,         &message_size },
 584 #ifdef SUPPORT_I18N
 585   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 586 #endif
 587 #ifdef WITH_CONTENT_SCAN
 588   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 589   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 590   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 591   { "mime_charset",        vtype_stringptr,   &mime_charset },
 592   { "mime_content_description", vtype_stringptr, &mime_content_description },
 593   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 594   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 595   { "mime_content_size",   vtype_int,         &mime_content_size },
 596   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 597   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 598   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 599   { "mime_filename",       vtype_stringptr,   &mime_filename },
 600   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 601   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 602   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 603   { "mime_part_count",     vtype_int,         &mime_part_count },
 604 #endif
 605   { "n0",                  vtype_filter_int,  &filter_n[0] },
 606   { "n1",                  vtype_filter_int,  &filter_n[1] },
 607   { "n2",                  vtype_filter_int,  &filter_n[2] },
 608   { "n3",                  vtype_filter_int,  &filter_n[3] },
 609   { "n4",                  vtype_filter_int,  &filter_n[4] },
 610   { "n5",                  vtype_filter_int,  &filter_n[5] },
 611   { "n6",                  vtype_filter_int,  &filter_n[6] },
 612   { "n7",                  vtype_filter_int,  &filter_n[7] },
 613   { "n8",                  vtype_filter_int,  &filter_n[8] },
 614   { "n9",                  vtype_filter_int,  &filter_n[9] },
 615   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 616   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 617   { "originator_gid",      vtype_gid,         &originator_gid },
 618   { "originator_uid",      vtype_uid,         &originator_uid },
 619   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 620   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 621   { "pid",                 vtype_pid,         NULL },
 622 #ifndef DISABLE_PRDR
 623   { "prdr_requested",      vtype_bool,        &prdr_requested },
 624 #endif
 625   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 626 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 627   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 628   { "proxy_external_port", vtype_int,         &proxy_external_port },
 629   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 630   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 631   { "proxy_session",       vtype_bool,        &proxy_session },
 632 #endif
 633   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 634   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 635   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 636   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 637   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 638   { "queue_name",          vtype_stringptr,   &queue_name },
 639   { "rcpt_count",          vtype_int,         &rcpt_count },
 640   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 641   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 642   { "received_count",      vtype_int,         &received_count },
 643   { "received_for",        vtype_stringptr,   &received_for },
 644   { "received_ip_address", vtype_stringptr,   &interface_address },
 645   { "received_port",       vtype_int,         &interface_port },
 646   { "received_protocol",   vtype_stringptr,   &received_protocol },
 647   { "received_time",       vtype_int,         &received_time.tv_sec },
 648   { "recipient_data",      vtype_stringptr,   &recipient_data },
 649   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 650   { "recipients",          vtype_string_func, &fn_recipients },
 651   { "recipients_count",    vtype_int,         &recipients_count },
 652 #ifdef WITH_CONTENT_SCAN
 653   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 654 #endif
 655   { "reply_address",       vtype_reply,       NULL },
 656   { "return_path",         vtype_stringptr,   &return_path },
 657   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 658   { "router_name",         vtype_stringptr,   &router_name },
 659   { "runrc",               vtype_int,         &runrc },
 660   { "self_hostname",       vtype_stringptr,   &self_hostname },
 661   { "sender_address",      vtype_stringptr,   &sender_address },
 662   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 663   { "sender_address_domain", vtype_domain,    &sender_address },
 664   { "sender_address_local_part", vtype_localpart, &sender_address },
 665   { "sender_data",         vtype_stringptr,   &sender_data },
 666   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 667   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 668   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 669   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 670   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 671   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 672   { "sender_host_name",    vtype_host_lookup, NULL },
 673   { "sender_host_port",    vtype_int,         &sender_host_port },
 674   { "sender_ident",        vtype_stringptr,   &sender_ident },
 675   { "sender_rate",         vtype_stringptr,   &sender_rate },
 676   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 677   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 678   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 679   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 680   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 681   { "sending_port",        vtype_int,         &sending_port },
 682   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 683   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 684   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 685   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 686   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 687   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 688   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 689   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 690   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 691   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 692   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 693   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 694   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 695   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 696   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 697   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 698 #ifdef WITH_CONTENT_SCAN
 699   { "spam_action",         vtype_stringptr,   &spam_action },
 700   { "spam_bar",            vtype_stringptr,   &spam_bar },
 701   { "spam_report",         vtype_stringptr,   &spam_report },
 702   { "spam_score",          vtype_stringptr,   &spam_score },
 703   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 704 #endif
 705 #ifdef SUPPORT_SPF
 706   { "spf_guess",           vtype_stringptr,   &spf_guess },
 707   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 708   { "spf_received",        vtype_stringptr,   &spf_received },
 709   { "spf_result",          vtype_stringptr,   &spf_result },
 710   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 711 #endif
 712   { "spool_directory",     vtype_stringptr,   &spool_directory },
 713   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 714   { "spool_space",         vtype_pspace,      (void *)TRUE },
 715 #ifdef EXPERIMENTAL_SRS
 716   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 717   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 718   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 719   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 720   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 721   { "srs_status",          vtype_stringptr,   &srs_status },
 722 #endif
 723   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 724
 725   /* The non-(in,out) variables are now deprecated */
 726   { "tls_bits",            vtype_int,         &tls_in.bits },
 727   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 728   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 729
 730   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 731   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 732   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 733   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 734   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 735   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 736   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 737 #if defined(SUPPORT_TLS)
 738   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 739 #endif
 740   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 741   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 742   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 743 #ifdef SUPPORT_DANE
 744   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 745 #endif
 746   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 747   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 748   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 749   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 750 #if defined(SUPPORT_TLS)
 751   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 752 #endif
 753 #ifdef SUPPORT_DANE
 754   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 755 #endif
 756
 757   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 758 #if defined(SUPPORT_TLS)
 759   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 760 #endif
 761
 762   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 763   { "tod_epoch",           vtype_tode,        NULL },
 764   { "tod_epoch_l",         vtype_todel,       NULL },
 765   { "tod_full",            vtype_todf,        NULL },
 766   { "tod_log",             vtype_todl,        NULL },
 767   { "tod_logfile",         vtype_todlf,       NULL },
 768   { "tod_zone",            vtype_todzone,     NULL },
 769   { "tod_zulu",            vtype_todzulu,     NULL },
 770   { "transport_name",      vtype_stringptr,   &transport_name },
 771   { "value",               vtype_stringptr,   &lookup_value },
 772   { "verify_mode",         vtype_stringptr,   &verify_mode },
 773   { "version_number",      vtype_stringptr,   &version_string },
 774   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 775   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 776   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 777   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 778   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 779   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 780 };
 781
 782 static int var_table_size = nelem(var_table);
 783 static uschar var_buffer[256];
 784 static BOOL malformed_header;
 785
 786 /* For textual hashes */
 787
 788 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 789                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 790                                "0123456789";
 791
 792 enum { HMAC_MD5, HMAC_SHA1 };
 793
 794 /* For numeric hashes */
 795
 796 static unsigned int prime[] = {
 797   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 798  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 799  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 800
 801 /* For printing modes in symbolic form */
 802
 803 static uschar *mtable_normal[] =
 804   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 805
 806 static uschar *mtable_setid[] =
 807   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 808
 809 static uschar *mtable_sticky[] =
 810   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 811
 812
 813
 814 /*************************************************
 815 *           Tables for UTF-8 support             *
 816 *************************************************/
 817
 818 /* Table of the number of extra characters, indexed by the first character
 819 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 820 0x3d. */
 821
 822 static uschar utf8_table1[] = {
 823   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 824   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 825   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 826   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 827
 828 /* These are the masks for the data bits in the first byte of a character,
 829 indexed by the number of additional bytes. */
 830
 831 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 832
 833 /* Get the next UTF-8 character, advancing the pointer. */
 834
 835 #define GETUTF8INC(c, ptr) \
 836   c = *ptr++; \
 837   if ((c & 0xc0) == 0xc0) \
 838     { \
 839     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 840     int s = 6*a; \
 841     c = (c & utf8_table2[a]) << s; \
 842     while (a-- > 0) \
 843       { \
 844       s -= 6; \
 845       c |= (*ptr++ & 0x3f) << s; \
 846       } \
 847     }
 848
 849
 850
 851 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 852
 853 /*************************************************
 854 *           Binary chop search on a table        *
 855 *************************************************/
 856
 857 /* This is used for matching expansion items and operators.
 858
 859 Arguments:
 860   name        the name that is being sought
 861   table       the table to search
 862   table_size  the number of items in the table
 863
 864 Returns:      the offset in the table, or -1
 865 */
 866
 867 static int
 868 chop_match(uschar *name, uschar **table, int table_size)
 869 {
 870 uschar **bot = table;
 871 uschar **top = table + table_size;
 872
 873 while (top > bot)
 874   {
 875   uschar **mid = bot + (top - bot)/2;
 876   int c = Ustrcmp(name, *mid);
 877   if (c == 0) return mid - table;
 878   if (c > 0) bot = mid + 1; else top = mid;
 879   }
 880
 881 return -1;
 882 }
 883
 884
 885
 886 /*************************************************
 887 *          Check a condition string              *
 888 *************************************************/
 889
 890 /* This function is called to expand a string, and test the result for a "true"
 891 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 892 forced fail or lookup defer.
 893
 894 We used to release all store used, but this is not not safe due
 895 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 896 is reasonably careful to release what it can.
 897
 898 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 899
 900 Arguments:
 901   condition     the condition string
 902   m1            text to be incorporated in panic error
 903   m2            ditto
 904
 905 Returns:        TRUE if condition is met, FALSE if not
 906 */
 907
 908 BOOL
 909 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 910 {
 911 int rc;
 912 uschar *ss = expand_string(condition);
 913 if (ss == NULL)
 914   {
 915   if (!expand_string_forcedfail && !search_find_defer)
 916     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 917       "for %s %s: %s", condition, m1, m2, expand_string_message);
 918   return FALSE;
 919   }
 920 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 921   strcmpic(ss, US"false") != 0;
 922 return rc;
 923 }
 924
 925
 926
 927
 928 /*************************************************
 929 *        Pseudo-random number generation         *
 930 *************************************************/
 931
 932 /* Pseudo-random number generation.  The result is not "expected" to be
 933 cryptographically strong but not so weak that someone will shoot themselves
 934 in the foot using it as a nonce in some email header scheme or whatever
 935 weirdness they'll twist this into.  The result should ideally handle fork().
 936
 937 However, if we're stuck unable to provide this, then we'll fall back to
 938 appallingly bad randomness.
 939
 940 If SUPPORT_TLS is defined then this will not be used except as an emergency
 941 fallback.
 942
 943 Arguments:
 944   max       range maximum
 945 Returns     a random number in range [0, max-1]
 946 */
 947
 948 #ifdef SUPPORT_TLS
 949 # define vaguely_random_number vaguely_random_number_fallback
 950 #endif
 951 int
 952 vaguely_random_number(int max)
 953 {
 954 #ifdef SUPPORT_TLS
 955 # undef vaguely_random_number
 956 #endif
 957   static pid_t pid = 0;
 958   pid_t p2;
 959 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 960   struct timeval tv;
 961 #endif
 962
 963   p2 = getpid();
 964   if (p2 != pid)
 965     {
 966     if (pid != 0)
 967       {
 968
 969 #ifdef HAVE_ARC4RANDOM
 970       /* cryptographically strong randomness, common on *BSD platforms, not
 971       so much elsewhere.  Alas. */
 972 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 973       arc4random_stir();
 974 #endif
 975 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 976 #ifdef HAVE_SRANDOMDEV
 977       /* uses random(4) for seeding */
 978       srandomdev();
 979 #else
 980       gettimeofday(&tv, NULL);
 981       srandom(tv.tv_sec | tv.tv_usec | getpid());
 982 #endif
 983 #else
 984       /* Poor randomness and no seeding here */
 985 #endif
 986
 987       }
 988     pid = p2;
 989     }
 990
 991 #ifdef HAVE_ARC4RANDOM
 992   return arc4random() % max;
 993 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 994   return random() % max;
 995 #else
 996   /* This one returns a 16-bit number, definitely not crypto-strong */
 997   return random_number(max);
 998 #endif
 999 }
1000
1001
1002
1003
1004 /*************************************************
1005 *             Pick out a name from a string      *
1006 *************************************************/
1007
1008 /* If the name is too long, it is silently truncated.
1009
1010 Arguments:
1011   name      points to a buffer into which to put the name
1012   max       is the length of the buffer
1013   s         points to the first alphabetic character of the name
1014   extras    chars other than alphanumerics to permit
1015
1016 Returns:    pointer to the first character after the name
1017
1018 Note: The test for *s != 0 in the while loop is necessary because
1019 Ustrchr() yields non-NULL if the character is zero (which is not something
1020 I expected). */
1021
1022 static const uschar *
1023 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1024 {
1025 int ptr = 0;
1026 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1027   {
1028   if (ptr < max-1) name[ptr++] = *s;
1029   s++;
1030   }
1031 name[ptr] = 0;
1032 return s;
1033 }
1034
1035
1036
1037 /*************************************************
1038 *     Pick out the rest of a header name         *
1039 *************************************************/
1040
1041 /* A variable name starting $header_ (or just $h_ for those who like
1042 abbreviations) might not be the complete header name because headers can
1043 contain any printing characters in their names, except ':'. This function is
1044 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1045 on the end, if the name was terminated by white space.
1046
1047 Arguments:
1048   name      points to a buffer in which the name read so far exists
1049   max       is the length of the buffer
1050   s         points to the first character after the name so far, i.e. the
1051             first non-alphameric character after $header_xxxxx
1052
1053 Returns:    a pointer to the first character after the header name
1054 */
1055
1056 static const uschar *
1057 read_header_name(uschar *name, int max, const uschar *s)
1058 {
1059 int prelen = Ustrchr(name, '_') - name + 1;
1060 int ptr = Ustrlen(name) - prelen;
1061 if (ptr > 0) memmove(name, name+prelen, ptr);
1062 while (mac_isgraph(*s) && *s != ':')
1063   {
1064   if (ptr < max-1) name[ptr++] = *s;
1065   s++;
1066   }
1067 if (*s == ':') s++;
1068 name[ptr++] = ':';
1069 name[ptr] = 0;
1070 return s;
1071 }
1072
1073
1074
1075 /*************************************************
1076 *           Pick out a number from a string      *
1077 *************************************************/
1078
1079 /* Arguments:
1080   n     points to an integer into which to put the number
1081   s     points to the first digit of the number
1082
1083 Returns:  a pointer to the character after the last digit
1084 */
1085 /*XXX consider expanding to int_eximarith_t.  But the test for
1086 "overbig numbers" in 0002 still needs to overflow it. */
1087
1088 static uschar *
1089 read_number(int *n, uschar *s)
1090 {
1091 *n = 0;
1092 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1093 return s;
1094 }
1095
1096 static const uschar *
1097 read_cnumber(int *n, const uschar *s)
1098 {
1099 *n = 0;
1100 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1101 return s;
1102 }
1103
1104
1105
1106 /*************************************************
1107 *        Extract keyed subfield from a string    *
1108 *************************************************/
1109
1110 /* The yield is in dynamic store; NULL means that the key was not found.
1111
1112 Arguments:
1113   key       points to the name of the key
1114   s         points to the string from which to extract the subfield
1115
1116 Returns:    NULL if the subfield was not found, or
1117             a pointer to the subfield's data
1118 */
1119
1120 static uschar *
1121 expand_getkeyed(uschar *key, const uschar *s)
1122 {
1123 int length = Ustrlen(key);
1124 while (isspace(*s)) s++;
1125
1126 /* Loop to search for the key */
1127
1128 while (*s != 0)
1129   {
1130   int dkeylength;
1131   uschar *data;
1132   const uschar *dkey = s;
1133
1134   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1135   dkeylength = s - dkey;
1136   while (isspace(*s)) s++;
1137   if (*s == '=') while (isspace((*(++s))));
1138
1139   data = string_dequote(&s);
1140   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1141     return data;
1142
1143   while (isspace(*s)) s++;
1144   }
1145
1146 return NULL;
1147 }
1148
1149
1150
1151 static var_entry *
1152 find_var_ent(uschar * name)
1153 {
1154 int first = 0;
1155 int last = var_table_size;
1156
1157 while (last > first)
1158   {
1159   int middle = (first + last)/2;
1160   int c = Ustrcmp(name, var_table[middle].name);
1161
1162   if (c > 0) { first = middle + 1; continue; }
1163   if (c < 0) { last = middle; continue; }
1164   return &var_table[middle];
1165   }
1166 return NULL;
1167 }
1168
1169 /*************************************************
1170 *   Extract numbered subfield from string        *
1171 *************************************************/
1172
1173 /* Extracts a numbered field from a string that is divided by tokens - for
1174 example a line from /etc/passwd is divided by colon characters.  First field is
1175 numbered one.  Negative arguments count from the right. Zero returns the whole
1176 string. Returns NULL if there are insufficient tokens in the string
1177
1178 ***WARNING***
1179 Modifies final argument - this is a dynamically generated string, so that's OK.
1180
1181 Arguments:
1182   field       number of field to be extracted,
1183                 first field = 1, whole string = 0, last field = -1
1184   separators  characters that are used to break string into tokens
1185   s           points to the string from which to extract the subfield
1186
1187 Returns:      NULL if the field was not found,
1188               a pointer to the field's data inside s (modified to add 0)
1189 */
1190
1191 static uschar *
1192 expand_gettokened (int field, uschar *separators, uschar *s)
1193 {
1194 int sep = 1;
1195 int count;
1196 uschar *ss = s;
1197 uschar *fieldtext = NULL;
1198
1199 if (field == 0) return s;
1200
1201 /* Break the line up into fields in place; for field > 0 we stop when we have
1202 done the number of fields we want. For field < 0 we continue till the end of
1203 the string, counting the number of fields. */
1204
1205 count = (field > 0)? field : INT_MAX;
1206
1207 while (count-- > 0)
1208   {
1209   size_t len;
1210
1211   /* Previous field was the last one in the string. For a positive field
1212   number, this means there are not enough fields. For a negative field number,
1213   check that there are enough, and scan back to find the one that is wanted. */
1214
1215   if (sep == 0)
1216     {
1217     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1218     if ((-field) == (INT_MAX - count - 1)) return s;
1219     while (field++ < 0)
1220       {
1221       ss--;
1222       while (ss[-1] != 0) ss--;
1223       }
1224     fieldtext = ss;
1225     break;
1226     }
1227
1228   /* Previous field was not last in the string; save its start and put a
1229   zero at its end. */
1230
1231   fieldtext = ss;
1232   len = Ustrcspn(ss, separators);
1233   sep = ss[len];
1234   ss[len] = 0;
1235   ss += len + 1;
1236   }
1237
1238 return fieldtext;
1239 }
1240
1241
1242 static uschar *
1243 expand_getlistele(int field, const uschar * list)
1244 {
1245 const uschar * tlist= list;
1246 int sep= 0;
1247 uschar dummy;
1248
1249 if(field<0)
1250   {
1251   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1252   sep= 0;
1253   }
1254 if(field==0) return NULL;
1255 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1256 return string_nextinlist(&list, &sep, NULL, 0);
1257 }
1258
1259
1260 /* Certificate fields, by name.  Worry about by-OID later */
1261 /* Names are chosen to not have common prefixes */
1262
1263 #ifdef SUPPORT_TLS
1264 typedef struct
1265 {
1266 uschar * name;
1267 int      namelen;
1268 uschar * (*getfn)(void * cert, uschar * mod);
1269 } certfield;
1270 static certfield certfields[] =
1271 {                       /* linear search; no special order */
1272   { US"version",         7,  &tls_cert_version },
1273   { US"serial_number",   13, &tls_cert_serial_number },
1274   { US"subject",         7,  &tls_cert_subject },
1275   { US"notbefore",       9,  &tls_cert_not_before },
1276   { US"notafter",        8,  &tls_cert_not_after },
1277   { US"issuer",          6,  &tls_cert_issuer },
1278   { US"signature",       9,  &tls_cert_signature },
1279   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1280   { US"subj_altname",    12, &tls_cert_subject_altname },
1281   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1282   { US"crl_uri",         7,  &tls_cert_crl_uri },
1283 };
1284
1285 static uschar *
1286 expand_getcertele(uschar * field, uschar * certvar)
1287 {
1288 var_entry * vp;
1289 certfield * cp;
1290
1291 if (!(vp = find_var_ent(certvar)))
1292   {
1293   expand_string_message =
1294     string_sprintf("no variable named \"%s\"", certvar);
1295   return NULL;          /* Unknown variable name */
1296   }
1297 /* NB this stops us passing certs around in variable.  Might
1298 want to do that in future */
1299 if (vp->type != vtype_cert)
1300   {
1301   expand_string_message =
1302     string_sprintf("\"%s\" is not a certificate", certvar);
1303   return NULL;          /* Unknown variable name */
1304   }
1305 if (!*(void **)vp->value)
1306   return NULL;
1307
1308 if (*field >= '0' && *field <= '9')
1309   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1310
1311 for(cp = certfields;
1312     cp < certfields + nelem(certfields);
1313     cp++)
1314   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1315     {
1316     uschar * modifier = *(field += cp->namelen) == ','
1317       ? ++field : NULL;
1318     return (*cp->getfn)( *(void **)vp->value, modifier );
1319     }
1320
1321 expand_string_message =
1322   string_sprintf("bad field selector \"%s\" for certextract", field);
1323 return NULL;
1324 }
1325 #endif  /*SUPPORT_TLS*/
1326
1327 /*************************************************
1328 *        Extract a substring from a string       *
1329 *************************************************/
1330
1331 /* Perform the ${substr or ${length expansion operations.
1332
1333 Arguments:
1334   subject     the input string
1335   value1      the offset from the start of the input string to the start of
1336                 the output string; if negative, count from the right.
1337   value2      the length of the output string, or negative (-1) for unset
1338                 if value1 is positive, unset means "all after"
1339                 if value1 is negative, unset means "all before"
1340   len         set to the length of the returned string
1341
1342 Returns:      pointer to the output string, or NULL if there is an error
1343 */
1344
1345 static uschar *
1346 extract_substr(uschar *subject, int value1, int value2, int *len)
1347 {
1348 int sublen = Ustrlen(subject);
1349
1350 if (value1 < 0)    /* count from right */
1351   {
1352   value1 += sublen;
1353
1354   /* If the position is before the start, skip to the start, and adjust the
1355   length. If the length ends up negative, the substring is null because nothing
1356   can precede. This falls out naturally when the length is unset, meaning "all
1357   to the left". */
1358
1359   if (value1 < 0)
1360     {
1361     value2 += value1;
1362     if (value2 < 0) value2 = 0;
1363     value1 = 0;
1364     }
1365
1366   /* Otherwise an unset length => characters before value1 */
1367
1368   else if (value2 < 0)
1369     {
1370     value2 = value1;
1371     value1 = 0;
1372     }
1373   }
1374
1375 /* For a non-negative offset, if the starting position is past the end of the
1376 string, the result will be the null string. Otherwise, an unset length means
1377 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1378
1379 else
1380   {
1381   if (value1 > sublen)
1382     {
1383     value1 = sublen;
1384     value2 = 0;
1385     }
1386   else if (value2 < 0) value2 = sublen;
1387   }
1388
1389 /* Cut the length down to the maximum possible for the offset value, and get
1390 the required characters. */
1391
1392 if (value1 + value2 > sublen) value2 = sublen - value1;
1393 *len = value2;
1394 return subject + value1;
1395 }
1396
1397
1398
1399
1400 /*************************************************
1401 *            Old-style hash of a string          *
1402 *************************************************/
1403
1404 /* Perform the ${hash expansion operation.
1405
1406 Arguments:
1407   subject     the input string (an expanded substring)
1408   value1      the length of the output string; if greater or equal to the
1409                 length of the input string, the input string is returned
1410   value2      the number of hash characters to use, or 26 if negative
1411   len         set to the length of the returned string
1412
1413 Returns:      pointer to the output string, or NULL if there is an error
1414 */
1415
1416 static uschar *
1417 compute_hash(uschar *subject, int value1, int value2, int *len)
1418 {
1419 int sublen = Ustrlen(subject);
1420
1421 if (value2 < 0) value2 = 26;
1422 else if (value2 > Ustrlen(hashcodes))
1423   {
1424   expand_string_message =
1425     string_sprintf("hash count \"%d\" too big", value2);
1426   return NULL;
1427   }
1428
1429 /* Calculate the hash text. We know it is shorter than the original string, so
1430 can safely place it in subject[] (we know that subject is always itself an
1431 expanded substring). */
1432
1433 if (value1 < sublen)
1434   {
1435   int c;
1436   int i = 0;
1437   int j = value1;
1438   while ((c = (subject[j])) != 0)
1439     {
1440     int shift = (c + j++) & 7;
1441     subject[i] ^= (c << shift) | (c >> (8-shift));
1442     if (++i >= value1) i = 0;
1443     }
1444   for (i = 0; i < value1; i++)
1445     subject[i] = hashcodes[(subject[i]) % value2];
1446   }
1447 else value1 = sublen;
1448
1449 *len = value1;
1450 return subject;
1451 }
1452
1453
1454
1455
1456 /*************************************************
1457 *             Numeric hash of a string           *
1458 *************************************************/
1459
1460 /* Perform the ${nhash expansion operation. The first characters of the
1461 string are treated as most important, and get the highest prime numbers.
1462
1463 Arguments:
1464   subject     the input string
1465   value1      the maximum value of the first part of the result
1466   value2      the maximum value of the second part of the result,
1467                 or negative to produce only a one-part result
1468   len         set to the length of the returned string
1469
1470 Returns:  pointer to the output string, or NULL if there is an error.
1471 */
1472
1473 static uschar *
1474 compute_nhash (uschar *subject, int value1, int value2, int *len)
1475 {
1476 uschar *s = subject;
1477 int i = 0;
1478 unsigned long int total = 0; /* no overflow */
1479
1480 while (*s != 0)
1481   {
1482   if (i == 0) i = nelem(prime) - 1;
1483   total += prime[i--] * (unsigned int)(*s++);
1484   }
1485
1486 /* If value2 is unset, just compute one number */
1487
1488 if (value2 < 0)
1489   s = string_sprintf("%lu", total % value1);
1490
1491 /* Otherwise do a div/mod hash */
1492
1493 else
1494   {
1495   total = total % (value1 * value2);
1496   s = string_sprintf("%lu/%lu", total/value2, total % value2);
1497   }
1498
1499 *len = Ustrlen(s);
1500 return s;
1501 }
1502
1503
1504
1505
1506
1507 /*************************************************
1508 *     Find the value of a header or headers      *
1509 *************************************************/
1510
1511 /* Multiple instances of the same header get concatenated, and this function
1512 can also return a concatenation of all the header lines. When concatenating
1513 specific headers that contain lists of addresses, a comma is inserted between
1514 them. Otherwise we use a straight concatenation. Because some messages can have
1515 pathologically large number of lines, there is a limit on the length that is
1516 returned. Also, to avoid massive store use which would result from using
1517 string_cat() as it copies and extends strings, we do a preliminary pass to find
1518 out exactly how much store will be needed. On "normal" messages this will be
1519 pretty trivial.
1520
1521 Arguments:
1522   name          the name of the header, without the leading $header_ or $h_,
1523                 or NULL if a concatenation of all headers is required
1524   exists_only   TRUE if called from a def: test; don't need to build a string;
1525                 just return a string that is not "" and not "0" if the header
1526                 exists
1527   newsize       return the size of memory block that was obtained; may be NULL
1528                 if exists_only is TRUE
1529   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1530                 other than concatenating, will be done on the header. Also used
1531                 for $message_headers_raw.
1532   charset       name of charset to translate MIME words to; used only if
1533                 want_raw is false; if NULL, no translation is done (this is
1534                 used for $bh_ and $bheader_)
1535
1536 Returns:        NULL if the header does not exist, else a pointer to a new
1537                 store block
1538 */
1539
1540 static uschar *
1541 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1542   uschar *charset)
1543 {
1544 BOOL found = name == NULL;
1545 int comma = 0;
1546 int len = found? 0 : Ustrlen(name);
1547 int i;
1548 uschar *yield = NULL;
1549 uschar *ptr = NULL;
1550
1551 /* Loop for two passes - saves code repetition */
1552
1553 for (i = 0; i < 2; i++)
1554   {
1555   int size = 0;
1556   header_line *h;
1557
1558   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1559     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1560       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1561         {
1562         int ilen;
1563         uschar *t;
1564
1565         if (exists_only) return US"1";      /* don't need actual string */
1566         found = TRUE;
1567         t = h->text + len;                  /* text to insert */
1568         if (!want_raw)                      /* unless wanted raw, */
1569           while (isspace(*t)) t++;          /* remove leading white space */
1570         ilen = h->slen - (t - h->text);     /* length to insert */
1571
1572         /* Unless wanted raw, remove trailing whitespace, including the
1573         newline. */
1574
1575         if (!want_raw)
1576           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1577
1578         /* Set comma = 1 if handling a single header and it's one of those
1579         that contains an address list, except when asked for raw headers. Only
1580         need to do this once. */
1581
1582         if (!want_raw && name && comma == 0 &&
1583             Ustrchr("BCFRST", h->type) != NULL)
1584           comma = 1;
1585
1586         /* First pass - compute total store needed; second pass - compute
1587         total store used, including this header. */
1588
1589         size += ilen + comma + 1;  /* +1 for the newline */
1590
1591         /* Second pass - concatenate the data, up to a maximum. Note that
1592         the loop stops when size hits the limit. */
1593
1594         if (i != 0)
1595           {
1596           if (size > header_insert_maxlen)
1597             {
1598             ilen -= size - header_insert_maxlen - 1;
1599             comma = 0;
1600             }
1601           Ustrncpy(ptr, t, ilen);
1602           ptr += ilen;
1603
1604           /* For a non-raw header, put in the comma if needed, then add
1605           back the newline we removed above, provided there was some text in
1606           the header. */
1607
1608           if (!want_raw && ilen > 0)
1609             {
1610             if (comma != 0) *ptr++ = ',';
1611             *ptr++ = '\n';
1612             }
1613           }
1614         }
1615
1616   /* At end of first pass, return NULL if no header found. Then truncate size
1617   if necessary, and get the buffer to hold the data, returning the buffer size.
1618   */
1619
1620   if (i == 0)
1621     {
1622     if (!found) return NULL;
1623     if (size > header_insert_maxlen) size = header_insert_maxlen;
1624     *newsize = size + 1;
1625     ptr = yield = store_get(*newsize);
1626     }
1627   }
1628
1629 /* That's all we do for raw header expansion. */
1630
1631 if (want_raw)
1632   *ptr = 0;
1633
1634 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1635 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1636 function can return an error with decoded data if the charset translation
1637 fails. If decoding fails, it returns NULL. */
1638
1639 else
1640   {
1641   uschar *decoded, *error;
1642   if (ptr > yield && ptr[-1] == '\n') ptr--;
1643   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1644   *ptr = 0;
1645   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1646     newsize, &error);
1647   if (error != NULL)
1648     {
1649     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1650       "    input was: %s\n", error, yield);
1651     }
1652   if (decoded != NULL) yield = decoded;
1653   }
1654
1655 return yield;
1656 }
1657
1658
1659
1660
1661 /* Append an "iprev" element to an Autherntication-Results: header
1662 if we have attempted to get the calling host's name.
1663 */
1664
1665 static gstring *
1666 authres_iprev(gstring * g)
1667 {
1668 if (sender_host_name)
1669   return string_append(g, 3, US";\n\tiprev=pass (", sender_host_name, US")");
1670 if (host_lookup_deferred)
1671   return string_catn(g, US";\n\tiprev=temperror", 19);
1672 if (host_lookup_failed)
1673   return string_catn(g, US";\n\tiprev=fail", 13);
1674 return g;
1675 }
1676
1677
1678
1679 /*************************************************
1680 *               Return list of recipients        *
1681 *************************************************/
1682 /* A recipients list is available only during system message filtering,
1683 during ACL processing after DATA, and while expanding pipe commands
1684 generated from a system filter, but not elsewhere. */
1685
1686 static uschar *
1687 fn_recipients(void)
1688 {
1689 gstring * g = NULL;
1690 int i;
1691
1692 if (!enable_dollar_recipients) return NULL;
1693
1694 for (i = 0; i < recipients_count; i++)
1695   {
1696   /*XXX variant of list_appendele? */
1697   if (i != 0) g = string_catn(g, US", ", 2);
1698   g = string_cat(g, recipients_list[i].address);
1699   }
1700 return string_from_gstring(g);
1701 }
1702
1703
1704 /*************************************************
1705 *               Find value of a variable         *
1706 *************************************************/
1707
1708 /* The table of variables is kept in alphabetic order, so we can search it
1709 using a binary chop. The "choplen" variable is nothing to do with the binary
1710 chop.
1711
1712 Arguments:
1713   name          the name of the variable being sought
1714   exists_only   TRUE if this is a def: test; passed on to find_header()
1715   skipping      TRUE => skip any processing evaluation; this is not the same as
1716                   exists_only because def: may test for values that are first
1717                   evaluated here
1718   newsize       pointer to an int which is initially zero; if the answer is in
1719                 a new memory buffer, *newsize is set to its size
1720
1721 Returns:        NULL if the variable does not exist, or
1722                 a pointer to the variable's contents, or
1723                 something non-NULL if exists_only is TRUE
1724 */
1725
1726 static uschar *
1727 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1728 {
1729 var_entry * vp;
1730 uschar *s, *domain;
1731 uschar **ss;
1732 void * val;
1733
1734 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1735 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1736 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1737 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1738 (this gave backwards compatibility at the changeover). There may be built-in
1739 variables whose names start acl_ but they should never start in this way. This
1740 slightly messy specification is a consequence of the history, needless to say.
1741
1742 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1743 set, in which case give an error. */
1744
1745 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1746      !isalpha(name[5]))
1747   {
1748   tree_node *node =
1749     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1750   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1751   }
1752
1753 /* Handle $auth<n> variables. */
1754
1755 if (Ustrncmp(name, "auth", 4) == 0)
1756   {
1757   uschar *endptr;
1758   int n = Ustrtoul(name + 4, &endptr, 10);
1759   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1760     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1761   }
1762 else if (Ustrncmp(name, "regex", 5) == 0)
1763   {
1764   uschar *endptr;
1765   int n = Ustrtoul(name + 5, &endptr, 10);
1766   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1767     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1768   }
1769
1770 /* For all other variables, search the table */
1771
1772 if (!(vp = find_var_ent(name)))
1773   return NULL;          /* Unknown variable name */
1774
1775 /* Found an existing variable. If in skipping state, the value isn't needed,
1776 and we want to avoid processing (such as looking up the host name). */
1777
1778 if (skipping)
1779   return US"";
1780
1781 val = vp->value;
1782 switch (vp->type)
1783   {
1784   case vtype_filter_int:
1785     if (!filter_running) return NULL;
1786     /* Fall through */
1787     /* VVVVVVVVVVVV */
1788   case vtype_int:
1789     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1790     return var_buffer;
1791
1792   case vtype_ino:
1793     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1794     return var_buffer;
1795
1796   case vtype_gid:
1797     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1798     return var_buffer;
1799
1800   case vtype_uid:
1801     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1802     return var_buffer;
1803
1804   case vtype_bool:
1805     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1806     return var_buffer;
1807
1808   case vtype_stringptr:                      /* Pointer to string */
1809     return (s = *((uschar **)(val))) ? s : US"";
1810
1811   case vtype_pid:
1812     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1813     return var_buffer;
1814
1815   case vtype_load_avg:
1816     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1817     return var_buffer;
1818
1819   case vtype_host_lookup:                    /* Lookup if not done so */
1820     if (  !sender_host_name && sender_host_address
1821        && !host_lookup_failed && host_name_lookup() == OK)
1822       host_build_sender_fullhost();
1823     return sender_host_name ? sender_host_name : US"";
1824
1825   case vtype_localpart:                      /* Get local part from address */
1826     s = *((uschar **)(val));
1827     if (s == NULL) return US"";
1828     domain = Ustrrchr(s, '@');
1829     if (domain == NULL) return s;
1830     if (domain - s > sizeof(var_buffer) - 1)
1831       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1832           " in string expansion", sizeof(var_buffer));
1833     Ustrncpy(var_buffer, s, domain - s);
1834     var_buffer[domain - s] = 0;
1835     return var_buffer;
1836
1837   case vtype_domain:                         /* Get domain from address */
1838     s = *((uschar **)(val));
1839     if (s == NULL) return US"";
1840     domain = Ustrrchr(s, '@');
1841     return (domain == NULL)? US"" : domain + 1;
1842
1843   case vtype_msgheaders:
1844     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1845
1846   case vtype_msgheaders_raw:
1847     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1848
1849   case vtype_msgbody:                        /* Pointer to msgbody string */
1850   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1851     ss = (uschar **)(val);
1852     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1853       {
1854       uschar *body;
1855       off_t start_offset = SPOOL_DATA_START_OFFSET;
1856       int len = message_body_visible;
1857       if (len > message_size) len = message_size;
1858       *ss = body = store_malloc(len+1);
1859       body[0] = 0;
1860       if (vp->type == vtype_msgbody_end)
1861         {
1862         struct stat statbuf;
1863         if (fstat(deliver_datafile, &statbuf) == 0)
1864           {
1865           start_offset = statbuf.st_size - len;
1866           if (start_offset < SPOOL_DATA_START_OFFSET)
1867             start_offset = SPOOL_DATA_START_OFFSET;
1868           }
1869         }
1870       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1871         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1872           strerror(errno));
1873       len = read(deliver_datafile, body, len);
1874       if (len > 0)
1875         {
1876         body[len] = 0;
1877         if (message_body_newlines)   /* Separate loops for efficiency */
1878           while (len > 0)
1879             { if (body[--len] == 0) body[len] = ' '; }
1880         else
1881           while (len > 0)
1882             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1883         }
1884       }
1885     return *ss ? *ss : US"";
1886
1887   case vtype_todbsdin:                       /* BSD inbox time of day */
1888     return tod_stamp(tod_bsdin);
1889
1890   case vtype_tode:                           /* Unix epoch time of day */
1891     return tod_stamp(tod_epoch);
1892
1893   case vtype_todel:                          /* Unix epoch/usec time of day */
1894     return tod_stamp(tod_epoch_l);
1895
1896   case vtype_todf:                           /* Full time of day */
1897     return tod_stamp(tod_full);
1898
1899   case vtype_todl:                           /* Log format time of day */
1900     return tod_stamp(tod_log_bare);            /* (without timezone) */
1901
1902   case vtype_todzone:                        /* Time zone offset only */
1903     return tod_stamp(tod_zone);
1904
1905   case vtype_todzulu:                        /* Zulu time */
1906     return tod_stamp(tod_zulu);
1907
1908   case vtype_todlf:                          /* Log file datestamp tod */
1909     return tod_stamp(tod_log_datestamp_daily);
1910
1911   case vtype_reply:                          /* Get reply address */
1912     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1913       headers_charset);
1914     if (s != NULL) while (isspace(*s)) s++;
1915     if (s == NULL || *s == 0)
1916       {
1917       *newsize = 0;                            /* For the *s==0 case */
1918       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1919       }
1920     if (s != NULL)
1921       {
1922       uschar *t;
1923       while (isspace(*s)) s++;
1924       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1925       while (t > s && isspace(t[-1])) t--;
1926       *t = 0;
1927       }
1928     return (s == NULL)? US"" : s;
1929
1930   case vtype_string_func:
1931     {
1932     uschar * (*fn)() = val;
1933     return fn();
1934     }
1935
1936   case vtype_pspace:
1937     {
1938     int inodes;
1939     sprintf(CS var_buffer, "%d",
1940       receive_statvfs(val == (void *)TRUE, &inodes));
1941     }
1942   return var_buffer;
1943
1944   case vtype_pinodes:
1945     {
1946     int inodes;
1947     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1948     sprintf(CS var_buffer, "%d", inodes);
1949     }
1950   return var_buffer;
1951
1952   case vtype_cert:
1953     return *(void **)val ? US"<cert>" : US"";
1954
1955 #ifndef DISABLE_DKIM
1956   case vtype_dkim:
1957     return dkim_exim_expand_query((int)(long)val);
1958 #endif
1959
1960   }
1961
1962 return NULL;  /* Unknown variable. Silences static checkers. */
1963 }
1964
1965
1966
1967
1968 void
1969 modify_variable(uschar *name, void * value)
1970 {
1971 var_entry * vp;
1972 if ((vp = find_var_ent(name))) vp->value = value;
1973 return;          /* Unknown variable name, fail silently */
1974 }
1975
1976
1977
1978
1979
1980
1981 /*************************************************
1982 *           Read and expand substrings           *
1983 *************************************************/
1984
1985 /* This function is called to read and expand argument substrings for various
1986 expansion items. Some have a minimum requirement that is less than the maximum;
1987 in these cases, the first non-present one is set to NULL.
1988
1989 Arguments:
1990   sub        points to vector of pointers to set
1991   n          maximum number of substrings
1992   m          minimum required
1993   sptr       points to current string pointer
1994   skipping   the skipping flag
1995   check_end  if TRUE, check for final '}'
1996   name       name of item, for error message
1997   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1998              the store.
1999
2000 Returns:     0 OK; string pointer updated
2001              1 curly bracketing error (too few arguments)
2002              2 too many arguments (only if check_end is set); message set
2003              3 other error (expansion failure)
2004 */
2005
2006 static int
2007 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
2008   BOOL check_end, uschar *name, BOOL *resetok)
2009 {
2010 int i;
2011 const uschar *s = *sptr;
2012
2013 while (isspace(*s)) s++;
2014 for (i = 0; i < n; i++)
2015   {
2016   if (*s != '{')
2017     {
2018     if (i < m)
2019       {
2020       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2021         "(min is %d)", name, m);
2022       return 1;
2023       }
2024     sub[i] = NULL;
2025     break;
2026     }
2027   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2028     return 3;
2029   if (*s++ != '}') return 1;
2030   while (isspace(*s)) s++;
2031   }
2032 if (check_end && *s++ != '}')
2033   {
2034   if (s[-1] == '{')
2035     {
2036     expand_string_message = string_sprintf("Too many arguments for '%s' "
2037       "(max is %d)", name, n);
2038     return 2;
2039     }
2040   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2041   return 1;
2042   }
2043
2044 *sptr = s;
2045 return 0;
2046 }
2047
2048
2049
2050
2051 /*************************************************
2052 *     Elaborate message for bad variable         *
2053 *************************************************/
2054
2055 /* For the "unknown variable" message, take a look at the variable's name, and
2056 give additional information about possible ACL variables. The extra information
2057 is added on to expand_string_message.
2058
2059 Argument:   the name of the variable
2060 Returns:    nothing
2061 */
2062
2063 static void
2064 check_variable_error_message(uschar *name)
2065 {
2066 if (Ustrncmp(name, "acl_", 4) == 0)
2067   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2068     (name[4] == 'c' || name[4] == 'm')?
2069       (isalpha(name[5])?
2070         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2071         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2072       ) :
2073       US"user-defined ACL variables must start acl_c or acl_m");
2074 }
2075
2076
2077
2078 /*
2079 Load args from sub array to globals, and call acl_check().
2080 Sub array will be corrupted on return.
2081
2082 Returns:       OK         access is granted by an ACCEPT verb
2083                DISCARD    access is (apparently) granted by a DISCARD verb
2084                FAIL       access is denied
2085                FAIL_DROP  access is denied; drop the connection
2086                DEFER      can't tell at the moment
2087                ERROR      disaster
2088 */
2089 static int
2090 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2091 {
2092 int i;
2093 int sav_narg = acl_narg;
2094 int ret;
2095 uschar * dummy_logmsg;
2096 extern int acl_where;
2097
2098 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2099 for (i = 0; i < nsub && sub[i+1]; i++)
2100   {
2101   uschar * tmp = acl_arg[i];
2102   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2103   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2104   }
2105 acl_narg = i;
2106 while (i < nsub)
2107   {
2108   sub[i+1] = acl_arg[i];
2109   acl_arg[i++] = NULL;
2110   }
2111
2112 DEBUG(D_expand)
2113   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2114     sub[0],
2115     acl_narg>0 ? acl_arg[0] : US"<none>",
2116     acl_narg>1 ? " +more"   : "");
2117
2118 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2119
2120 for (i = 0; i < nsub; i++)
2121   acl_arg[i] = sub[i+1];        /* restore old args */
2122 acl_narg = sav_narg;
2123
2124 return ret;
2125 }
2126
2127
2128
2129
2130 /*************************************************
2131 *        Read and evaluate a condition           *
2132 *************************************************/
2133
2134 /*
2135 Arguments:
2136   s        points to the start of the condition text
2137   resetok  points to a BOOL which is written false if it is unsafe to
2138            free memory. Certain condition types (acl) may have side-effect
2139            allocation which must be preserved.
2140   yield    points to a BOOL to hold the result of the condition test;
2141            if NULL, we are just reading through a condition that is
2142            part of an "or" combination to check syntax, or in a state
2143            where the answer isn't required
2144
2145 Returns:   a pointer to the first character after the condition, or
2146            NULL after an error
2147 */
2148
2149 static const uschar *
2150 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2151 {
2152 BOOL testfor = TRUE;
2153 BOOL tempcond, combined_cond;
2154 BOOL *subcondptr;
2155 BOOL sub2_honour_dollar = TRUE;
2156 int i, rc, cond_type, roffset;
2157 int_eximarith_t num[2];
2158 struct stat statbuf;
2159 uschar name[256];
2160 const uschar *sub[10];
2161
2162 const pcre *re;
2163 const uschar *rerror;
2164
2165 for (;;)
2166   {
2167   while (isspace(*s)) s++;
2168   if (*s == '!') { testfor = !testfor; s++; } else break;
2169   }
2170
2171 /* Numeric comparisons are symbolic */
2172
2173 if (*s == '=' || *s == '>' || *s == '<')
2174   {
2175   int p = 0;
2176   name[p++] = *s++;
2177   if (*s == '=')
2178     {
2179     name[p++] = '=';
2180     s++;
2181     }
2182   name[p] = 0;
2183   }
2184
2185 /* All other conditions are named */
2186
2187 else s = read_name(name, 256, s, US"_");
2188
2189 /* If we haven't read a name, it means some non-alpha character is first. */
2190
2191 if (name[0] == 0)
2192   {
2193   expand_string_message = string_sprintf("condition name expected, "
2194     "but found \"%.16s\"", s);
2195   return NULL;
2196   }
2197
2198 /* Find which condition we are dealing with, and switch on it */
2199
2200 cond_type = chop_match(name, cond_table, nelem(cond_table));
2201 switch(cond_type)
2202   {
2203   /* def: tests for a non-empty variable, or for the existence of a header. If
2204   yield == NULL we are in a skipping state, and don't care about the answer. */
2205
2206   case ECOND_DEF:
2207   if (*s != ':')
2208     {
2209     expand_string_message = US"\":\" expected after \"def\"";
2210     return NULL;
2211     }
2212
2213   s = read_name(name, 256, s+1, US"_");
2214
2215   /* Test for a header's existence. If the name contains a closing brace
2216   character, this may be a user error where the terminating colon has been
2217   omitted. Set a flag to adjust a subsequent error message in this case. */
2218
2219   if (Ustrncmp(name, "h_", 2) == 0 ||
2220       Ustrncmp(name, "rh_", 3) == 0 ||
2221       Ustrncmp(name, "bh_", 3) == 0 ||
2222       Ustrncmp(name, "header_", 7) == 0 ||
2223       Ustrncmp(name, "rheader_", 8) == 0 ||
2224       Ustrncmp(name, "bheader_", 8) == 0)
2225     {
2226     s = read_header_name(name, 256, s);
2227     /* {-for-text-editors */
2228     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2229     if (yield != NULL) *yield =
2230       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2231     }
2232
2233   /* Test for a variable's having a non-empty value. A non-existent variable
2234   causes an expansion failure. */
2235
2236   else
2237     {
2238     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2239     if (value == NULL)
2240       {
2241       expand_string_message = (name[0] == 0)?
2242         string_sprintf("variable name omitted after \"def:\"") :
2243         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2244       check_variable_error_message(name);
2245       return NULL;
2246       }
2247     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2248     }
2249
2250   return s;
2251
2252
2253   /* first_delivery tests for first delivery attempt */
2254
2255   case ECOND_FIRST_DELIVERY:
2256   if (yield != NULL) *yield = deliver_firsttime == testfor;
2257   return s;
2258
2259
2260   /* queue_running tests for any process started by a queue runner */
2261
2262   case ECOND_QUEUE_RUNNING:
2263   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2264   return s;
2265
2266
2267   /* exists:  tests for file existence
2268        isip:  tests for any IP address
2269       isip4:  tests for an IPv4 address
2270       isip6:  tests for an IPv6 address
2271         pam:  does PAM authentication
2272      radius:  does RADIUS authentication
2273    ldapauth:  does LDAP authentication
2274     pwcheck:  does Cyrus SASL pwcheck authentication
2275   */
2276
2277   case ECOND_EXISTS:
2278   case ECOND_ISIP:
2279   case ECOND_ISIP4:
2280   case ECOND_ISIP6:
2281   case ECOND_PAM:
2282   case ECOND_RADIUS:
2283   case ECOND_LDAPAUTH:
2284   case ECOND_PWCHECK:
2285
2286   while (isspace(*s)) s++;
2287   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2288
2289   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2290   if (sub[0] == NULL) return NULL;
2291   /* {-for-text-editors */
2292   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2293
2294   if (yield == NULL) return s;   /* No need to run the test if skipping */
2295
2296   switch(cond_type)
2297     {
2298     case ECOND_EXISTS:
2299     if ((expand_forbid & RDO_EXISTS) != 0)
2300       {
2301       expand_string_message = US"File existence tests are not permitted";
2302       return NULL;
2303       }
2304     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2305     break;
2306
2307     case ECOND_ISIP:
2308     case ECOND_ISIP4:
2309     case ECOND_ISIP6:
2310     rc = string_is_ip_address(sub[0], NULL);
2311     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2312              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2313     break;
2314
2315     /* Various authentication tests - all optionally compiled */
2316
2317     case ECOND_PAM:
2318     #ifdef SUPPORT_PAM
2319     rc = auth_call_pam(sub[0], &expand_string_message);
2320     goto END_AUTH;
2321     #else
2322     goto COND_FAILED_NOT_COMPILED;
2323     #endif  /* SUPPORT_PAM */
2324
2325     case ECOND_RADIUS:
2326     #ifdef RADIUS_CONFIG_FILE
2327     rc = auth_call_radius(sub[0], &expand_string_message);
2328     goto END_AUTH;
2329     #else
2330     goto COND_FAILED_NOT_COMPILED;
2331     #endif  /* RADIUS_CONFIG_FILE */
2332
2333     case ECOND_LDAPAUTH:
2334     #ifdef LOOKUP_LDAP
2335       {
2336       /* Just to keep the interface the same */
2337       BOOL do_cache;
2338       int old_pool = store_pool;
2339       store_pool = POOL_SEARCH;
2340       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2341         &expand_string_message, &do_cache);
2342       store_pool = old_pool;
2343       }
2344     goto END_AUTH;
2345     #else
2346     goto COND_FAILED_NOT_COMPILED;
2347     #endif  /* LOOKUP_LDAP */
2348
2349     case ECOND_PWCHECK:
2350     #ifdef CYRUS_PWCHECK_SOCKET
2351     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2352     goto END_AUTH;
2353     #else
2354     goto COND_FAILED_NOT_COMPILED;
2355     #endif  /* CYRUS_PWCHECK_SOCKET */
2356
2357     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2358         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2359     END_AUTH:
2360     if (rc == ERROR || rc == DEFER) return NULL;
2361     *yield = (rc == OK) == testfor;
2362     #endif
2363     }
2364   return s;
2365
2366
2367   /* call ACL (in a conditional context).  Accept true, deny false.
2368   Defer is a forced-fail.  Anything set by message= goes to $value.
2369   Up to ten parameters are used; we use the braces round the name+args
2370   like the saslauthd condition does, to permit a variable number of args.
2371   See also the expansion-item version EITEM_ACL and the traditional
2372   acl modifier ACLC_ACL.
2373   Since the ACL may allocate new global variables, tell our caller to not
2374   reclaim memory.
2375   */
2376
2377   case ECOND_ACL:
2378     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2379     {
2380     uschar *sub[10];
2381     uschar *user_msg;
2382     BOOL cond = FALSE;
2383
2384     while (isspace(*s)) s++;
2385     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2386
2387     switch(read_subs(sub, nelem(sub), 1,
2388       &s, yield == NULL, TRUE, US"acl", resetok))
2389       {
2390       case 1: expand_string_message = US"too few arguments or bracketing "
2391         "error for acl";
2392       case 2:
2393       case 3: return NULL;
2394       }
2395
2396     if (yield != NULL)
2397       {
2398       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2399       switch(eval_acl(sub, nelem(sub), &user_msg))
2400         {
2401         case OK:
2402           cond = TRUE;
2403         case FAIL:
2404           lookup_value = NULL;
2405           if (user_msg)
2406             lookup_value = string_copy(user_msg);
2407           *yield = cond == testfor;
2408           break;
2409
2410         case DEFER:
2411           expand_string_forcedfail = TRUE;
2412           /*FALLTHROUGH*/
2413         default:
2414           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2415           return NULL;
2416         }
2417       }
2418     return s;
2419     }
2420
2421
2422   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2423
2424      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2425
2426   However, the last two are optional. That is why the whole set is enclosed
2427   in their own set of braces. */
2428
2429   case ECOND_SASLAUTHD:
2430 #ifndef CYRUS_SASLAUTHD_SOCKET
2431     goto COND_FAILED_NOT_COMPILED;
2432 #else
2433     {
2434     uschar *sub[4];
2435     while (isspace(*s)) s++;
2436     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2437     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2438                     resetok))
2439       {
2440       case 1: expand_string_message = US"too few arguments or bracketing "
2441         "error for saslauthd";
2442       case 2:
2443       case 3: return NULL;
2444       }
2445     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2446     if (yield != NULL)
2447       {
2448       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2449         &expand_string_message);
2450       if (rc == ERROR || rc == DEFER) return NULL;
2451       *yield = (rc == OK) == testfor;
2452       }
2453     return s;
2454     }
2455 #endif /* CYRUS_SASLAUTHD_SOCKET */
2456
2457
2458   /* symbolic operators for numeric and string comparison, and a number of
2459   other operators, all requiring two arguments.
2460
2461   crypteq:           encrypts plaintext and compares against an encrypted text,
2462                        using crypt(), crypt16(), MD5 or SHA-1
2463   inlist/inlisti:    checks if first argument is in the list of the second
2464   match:             does a regular expression match and sets up the numerical
2465                        variables if it succeeds
2466   match_address:     matches in an address list
2467   match_domain:      matches in a domain list
2468   match_ip:          matches a host list that is restricted to IP addresses
2469   match_local_part:  matches in a local part list
2470   */
2471
2472   case ECOND_MATCH_ADDRESS:
2473   case ECOND_MATCH_DOMAIN:
2474   case ECOND_MATCH_IP:
2475   case ECOND_MATCH_LOCAL_PART:
2476 #ifndef EXPAND_LISTMATCH_RHS
2477     sub2_honour_dollar = FALSE;
2478 #endif
2479     /* FALLTHROUGH */
2480
2481   case ECOND_CRYPTEQ:
2482   case ECOND_INLIST:
2483   case ECOND_INLISTI:
2484   case ECOND_MATCH:
2485
2486   case ECOND_NUM_L:     /* Numerical comparisons */
2487   case ECOND_NUM_LE:
2488   case ECOND_NUM_E:
2489   case ECOND_NUM_EE:
2490   case ECOND_NUM_G:
2491   case ECOND_NUM_GE:
2492
2493   case ECOND_STR_LT:    /* String comparisons */
2494   case ECOND_STR_LTI:
2495   case ECOND_STR_LE:
2496   case ECOND_STR_LEI:
2497   case ECOND_STR_EQ:
2498   case ECOND_STR_EQI:
2499   case ECOND_STR_GT:
2500   case ECOND_STR_GTI:
2501   case ECOND_STR_GE:
2502   case ECOND_STR_GEI:
2503
2504   for (i = 0; i < 2; i++)
2505     {
2506     /* Sometimes, we don't expand substrings; too many insecure configurations
2507     created using match_address{}{} and friends, where the second param
2508     includes information from untrustworthy sources. */
2509     BOOL honour_dollar = TRUE;
2510     if ((i > 0) && !sub2_honour_dollar)
2511       honour_dollar = FALSE;
2512
2513     while (isspace(*s)) s++;
2514     if (*s != '{')
2515       {
2516       if (i == 0) goto COND_FAILED_CURLY_START;
2517       expand_string_message = string_sprintf("missing 2nd string in {} "
2518         "after \"%s\"", name);
2519       return NULL;
2520       }
2521     if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2522         honour_dollar, resetok)))
2523       return NULL;
2524     DEBUG(D_expand) if (i == 1 && !sub2_honour_dollar && Ustrchr(sub[1], '$'))
2525       debug_printf_indent("WARNING: the second arg is NOT expanded,"
2526                         " for security reasons\n");
2527     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2528
2529     /* Convert to numerical if required; we know that the names of all the
2530     conditions that compare numbers do not start with a letter. This just saves
2531     checking for them individually. */
2532
2533     if (!isalpha(name[0]) && yield != NULL)
2534       if (sub[i][0] == 0)
2535         {
2536         num[i] = 0;
2537         DEBUG(D_expand)
2538           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2539         }
2540       else
2541         {
2542         num[i] = expanded_string_integer(sub[i], FALSE);
2543         if (expand_string_message != NULL) return NULL;
2544         }
2545     }
2546
2547   /* Result not required */
2548
2549   if (yield == NULL) return s;
2550
2551   /* Do an appropriate comparison */
2552
2553   switch(cond_type)
2554     {
2555     case ECOND_NUM_E:
2556     case ECOND_NUM_EE:
2557     tempcond = (num[0] == num[1]);
2558     break;
2559
2560     case ECOND_NUM_G:
2561     tempcond = (num[0] > num[1]);
2562     break;
2563
2564     case ECOND_NUM_GE:
2565     tempcond = (num[0] >= num[1]);
2566     break;
2567
2568     case ECOND_NUM_L:
2569     tempcond = (num[0] < num[1]);
2570     break;
2571
2572     case ECOND_NUM_LE:
2573     tempcond = (num[0] <= num[1]);
2574     break;
2575
2576     case ECOND_STR_LT:
2577     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2578     break;
2579
2580     case ECOND_STR_LTI:
2581     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2582     break;
2583
2584     case ECOND_STR_LE:
2585     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2586     break;
2587
2588     case ECOND_STR_LEI:
2589     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2590     break;
2591
2592     case ECOND_STR_EQ:
2593     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2594     break;
2595
2596     case ECOND_STR_EQI:
2597     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2598     break;
2599
2600     case ECOND_STR_GT:
2601     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2602     break;
2603
2604     case ECOND_STR_GTI:
2605     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2606     break;
2607
2608     case ECOND_STR_GE:
2609     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2610     break;
2611
2612     case ECOND_STR_GEI:
2613     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2614     break;
2615
2616     case ECOND_MATCH:   /* Regular expression match */
2617     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2618       NULL);
2619     if (re == NULL)
2620       {
2621       expand_string_message = string_sprintf("regular expression error in "
2622         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2623       return NULL;
2624       }
2625     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2626     break;
2627
2628     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2629     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2630     goto MATCHED_SOMETHING;
2631
2632     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2633     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2634       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2635     goto MATCHED_SOMETHING;
2636
2637     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2638     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2639       {
2640       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2641         sub[0]);
2642       return NULL;
2643       }
2644     else
2645       {
2646       unsigned int *nullcache = NULL;
2647       check_host_block cb;
2648
2649       cb.host_name = US"";
2650       cb.host_address = sub[0];
2651
2652       /* If the host address starts off ::ffff: it is an IPv6 address in
2653       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2654       addresses. */
2655
2656       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2657         cb.host_address + 7 : cb.host_address;
2658
2659       rc = match_check_list(
2660              &sub[1],                   /* the list */
2661              0,                         /* separator character */
2662              &hostlist_anchor,          /* anchor pointer */
2663              &nullcache,                /* cache pointer */
2664              check_host,                /* function for testing */
2665              &cb,                       /* argument for function */
2666              MCL_HOST,                  /* type of check */
2667              sub[0],                    /* text for debugging */
2668              NULL);                     /* where to pass back data */
2669       }
2670     goto MATCHED_SOMETHING;
2671
2672     case ECOND_MATCH_LOCAL_PART:
2673     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2674       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2675     /* Fall through */
2676     /* VVVVVVVVVVVV */
2677     MATCHED_SOMETHING:
2678     switch(rc)
2679       {
2680       case OK:
2681       tempcond = TRUE;
2682       break;
2683
2684       case FAIL:
2685       tempcond = FALSE;
2686       break;
2687
2688       case DEFER:
2689       expand_string_message = string_sprintf("unable to complete match "
2690         "against \"%s\": %s", sub[1], search_error_message);
2691       return NULL;
2692       }
2693
2694     break;
2695
2696     /* Various "encrypted" comparisons. If the second string starts with
2697     "{" then an encryption type is given. Default to crypt() or crypt16()
2698     (build-time choice). */
2699     /* }-for-text-editors */
2700
2701     case ECOND_CRYPTEQ:
2702     #ifndef SUPPORT_CRYPTEQ
2703     goto COND_FAILED_NOT_COMPILED;
2704     #else
2705     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2706       {
2707       int sublen = Ustrlen(sub[1]+5);
2708       md5 base;
2709       uschar digest[16];
2710
2711       md5_start(&base);
2712       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2713
2714       /* If the length that we are comparing against is 24, the MD5 digest
2715       is expressed as a base64 string. This is the way LDAP does it. However,
2716       some other software uses a straightforward hex representation. We assume
2717       this if the length is 32. Other lengths fail. */
2718
2719       if (sublen == 24)
2720         {
2721         uschar *coded = b64encode(digest, 16);
2722         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2723           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2724         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2725         }
2726       else if (sublen == 32)
2727         {
2728         int i;
2729         uschar coded[36];
2730         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2731         coded[32] = 0;
2732         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2733           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2734         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2735         }
2736       else
2737         {
2738         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2739           "fail\n  crypted=%s\n", sub[1]+5);
2740         tempcond = FALSE;
2741         }
2742       }
2743
2744     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2745       {
2746       int sublen = Ustrlen(sub[1]+6);
2747       hctx h;
2748       uschar digest[20];
2749
2750       sha1_start(&h);
2751       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2752
2753       /* If the length that we are comparing against is 28, assume the SHA1
2754       digest is expressed as a base64 string. If the length is 40, assume a
2755       straightforward hex representation. Other lengths fail. */
2756
2757       if (sublen == 28)
2758         {
2759         uschar *coded = b64encode(digest, 20);
2760         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2761           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2762         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2763         }
2764       else if (sublen == 40)
2765         {
2766         int i;
2767         uschar coded[44];
2768         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2769         coded[40] = 0;
2770         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2771           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2772         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2773         }
2774       else
2775         {
2776         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2777           "fail\n  crypted=%s\n", sub[1]+6);
2778         tempcond = FALSE;
2779         }
2780       }
2781
2782     else   /* {crypt} or {crypt16} and non-{ at start */
2783            /* }-for-text-editors */
2784       {
2785       int which = 0;
2786       uschar *coded;
2787
2788       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2789         {
2790         sub[1] += 7;
2791         which = 1;
2792         }
2793       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2794         {
2795         sub[1] += 9;
2796         which = 2;
2797         }
2798       else if (sub[1][0] == '{')                /* }-for-text-editors */
2799         {
2800         expand_string_message = string_sprintf("unknown encryption mechanism "
2801           "in \"%s\"", sub[1]);
2802         return NULL;
2803         }
2804
2805       switch(which)
2806         {
2807         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2808         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2809         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2810         }
2811
2812       #define STR(s) # s
2813       #define XSTR(s) STR(s)
2814       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2815         "  subject=%s\n  crypted=%s\n",
2816         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2817         coded, sub[1]);
2818       #undef STR
2819       #undef XSTR
2820
2821       /* If the encrypted string contains fewer than two characters (for the
2822       salt), force failure. Otherwise we get false positives: with an empty
2823       string the yield of crypt() is an empty string! */
2824
2825       if (coded)
2826         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2827       else if (errno == EINVAL)
2828         tempcond = FALSE;
2829       else
2830         {
2831         expand_string_message = string_sprintf("crypt error: %s\n",
2832           US strerror(errno));
2833         return NULL;
2834         }
2835       }
2836     break;
2837     #endif  /* SUPPORT_CRYPTEQ */
2838
2839     case ECOND_INLIST:
2840     case ECOND_INLISTI:
2841       {
2842       const uschar * list = sub[1];
2843       int sep = 0;
2844       uschar *save_iterate_item = iterate_item;
2845       int (*compare)(const uschar *, const uschar *);
2846
2847       DEBUG(D_expand) debug_printf_indent("condition: %s  item: %s\n", name, sub[0]);
2848
2849       tempcond = FALSE;
2850       compare = cond_type == ECOND_INLISTI
2851         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2852
2853       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2854         {
2855         DEBUG(D_expand) debug_printf_indent(" compare %s\n", iterate_item);
2856         if (compare(sub[0], iterate_item) == 0)
2857           {
2858           tempcond = TRUE;
2859           break;
2860           }
2861         }
2862       iterate_item = save_iterate_item;
2863       }
2864
2865     }   /* Switch for comparison conditions */
2866
2867   *yield = tempcond == testfor;
2868   return s;    /* End of comparison conditions */
2869
2870
2871   /* and/or: computes logical and/or of several conditions */
2872
2873   case ECOND_AND:
2874   case ECOND_OR:
2875   subcondptr = (yield == NULL)? NULL : &tempcond;
2876   combined_cond = (cond_type == ECOND_AND);
2877
2878   while (isspace(*s)) s++;
2879   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2880
2881   for (;;)
2882     {
2883     while (isspace(*s)) s++;
2884     /* {-for-text-editors */
2885     if (*s == '}') break;
2886     if (*s != '{')                                      /* }-for-text-editors */
2887       {
2888       expand_string_message = string_sprintf("each subcondition "
2889         "inside an \"%s{...}\" condition must be in its own {}", name);
2890       return NULL;
2891       }
2892
2893     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2894       {
2895       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2896         expand_string_message, name);
2897       return NULL;
2898       }
2899     while (isspace(*s)) s++;
2900
2901     /* {-for-text-editors */
2902     if (*s++ != '}')
2903       {
2904       /* {-for-text-editors */
2905       expand_string_message = string_sprintf("missing } at end of condition "
2906         "inside \"%s\" group", name);
2907       return NULL;
2908       }
2909
2910     if (yield != NULL)
2911       {
2912       if (cond_type == ECOND_AND)
2913         {
2914         combined_cond &= tempcond;
2915         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2916         }                                       /* evaluate any more */
2917       else
2918         {
2919         combined_cond |= tempcond;
2920         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2921         }                                       /* evaluate any more */
2922       }
2923     }
2924
2925   if (yield != NULL) *yield = (combined_cond == testfor);
2926   return ++s;
2927
2928
2929   /* forall/forany: iterates a condition with different values */
2930
2931   case ECOND_FORALL:
2932   case ECOND_FORANY:
2933     {
2934     const uschar * list;
2935     int sep = 0;
2936     uschar *save_iterate_item = iterate_item;
2937
2938     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2939
2940     while (isspace(*s)) s++;
2941     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2942     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2943     if (sub[0] == NULL) return NULL;
2944     /* {-for-text-editors */
2945     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2946
2947     while (isspace(*s)) s++;
2948     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2949
2950     sub[1] = s;
2951
2952     /* Call eval_condition once, with result discarded (as if scanning a
2953     "false" part). This allows us to find the end of the condition, because if
2954     the list it empty, we won't actually evaluate the condition for real. */
2955
2956     if (!(s = eval_condition(sub[1], resetok, NULL)))
2957       {
2958       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2959         expand_string_message, name);
2960       return NULL;
2961       }
2962     while (isspace(*s)) s++;
2963
2964     /* {-for-text-editors */
2965     if (*s++ != '}')
2966       {
2967       /* {-for-text-editors */
2968       expand_string_message = string_sprintf("missing } at end of condition "
2969         "inside \"%s\"", name);
2970       return NULL;
2971       }
2972
2973     if (yield != NULL) *yield = !testfor;
2974     list = sub[0];
2975     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2976       {
2977       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2978       if (!eval_condition(sub[1], resetok, &tempcond))
2979         {
2980         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2981           expand_string_message, name);
2982         iterate_item = save_iterate_item;
2983         return NULL;
2984         }
2985       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2986         tempcond? "true":"false");
2987
2988       if (yield != NULL) *yield = (tempcond == testfor);
2989       if (tempcond == (cond_type == ECOND_FORANY)) break;
2990       }
2991
2992     iterate_item = save_iterate_item;
2993     return s;
2994     }
2995
2996
2997   /* The bool{} expansion condition maps a string to boolean.
2998   The values supported should match those supported by the ACL condition
2999   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
3000   of true/false.  Note that Router "condition" rules have a different
3001   interpretation, where general data can be used and only a few values
3002   map to FALSE.
3003   Note that readconf.c boolean matching, for boolean configuration options,
3004   only matches true/yes/false/no.
3005   The bool_lax{} condition matches the Router logic, which is much more
3006   liberal. */
3007   case ECOND_BOOL:
3008   case ECOND_BOOL_LAX:
3009     {
3010     uschar *sub_arg[1];
3011     uschar *t, *t2;
3012     uschar *ourname;
3013     size_t len;
3014     BOOL boolvalue = FALSE;
3015     while (isspace(*s)) s++;
3016     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3017     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3018     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3019       {
3020       case 1: expand_string_message = string_sprintf(
3021                   "too few arguments or bracketing error for %s",
3022                   ourname);
3023       /*FALLTHROUGH*/
3024       case 2:
3025       case 3: return NULL;
3026       }
3027     t = sub_arg[0];
3028     while (isspace(*t)) t++;
3029     len = Ustrlen(t);
3030     if (len)
3031       {
3032       /* trailing whitespace: seems like a good idea to ignore it too */
3033       t2 = t + len - 1;
3034       while (isspace(*t2)) t2--;
3035       if (t2 != (t + len))
3036         {
3037         *++t2 = '\0';
3038         len = t2 - t;
3039         }
3040       }
3041     DEBUG(D_expand)
3042       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3043     /* logic for the lax case from expand_check_condition(), which also does
3044     expands, and the logic is both short and stable enough that there should
3045     be no maintenance burden from replicating it. */
3046     if (len == 0)
3047       boolvalue = FALSE;
3048     else if (*t == '-'
3049              ? Ustrspn(t+1, "0123456789") == len-1
3050              : Ustrspn(t,   "0123456789") == len)
3051       {
3052       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3053       /* expand_check_condition only does a literal string "0" check */
3054       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3055         boolvalue = TRUE;
3056       }
3057     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3058       boolvalue = TRUE;
3059     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3060       boolvalue = FALSE;
3061     else if (cond_type == ECOND_BOOL_LAX)
3062       boolvalue = TRUE;
3063     else
3064       {
3065       expand_string_message = string_sprintf("unrecognised boolean "
3066        "value \"%s\"", t);
3067       return NULL;
3068       }
3069     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3070         boolvalue? "true":"false");
3071     if (yield != NULL) *yield = (boolvalue == testfor);
3072     return s;
3073     }
3074
3075   /* Unknown condition */
3076
3077   default:
3078   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3079   return NULL;
3080   }   /* End switch on condition type */
3081
3082 /* Missing braces at start and end of data */
3083
3084 COND_FAILED_CURLY_START:
3085 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3086 return NULL;
3087
3088 COND_FAILED_CURLY_END:
3089 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3090   name);
3091 return NULL;
3092
3093 /* A condition requires code that is not compiled */
3094
3095 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3096     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3097     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3098 COND_FAILED_NOT_COMPILED:
3099 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3100   name);
3101 return NULL;
3102 #endif
3103 }
3104
3105
3106
3107
3108 /*************************************************
3109 *          Save numerical variables              *
3110 *************************************************/
3111
3112 /* This function is called from items such as "if" that want to preserve and
3113 restore the numbered variables.
3114
3115 Arguments:
3116   save_expand_string    points to an array of pointers to set
3117   save_expand_nlength   points to an array of ints for the lengths
3118
3119 Returns:                the value of expand max to save
3120 */
3121
3122 static int
3123 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3124 {
3125 int i;
3126 for (i = 0; i <= expand_nmax; i++)
3127   {
3128   save_expand_nstring[i] = expand_nstring[i];
3129   save_expand_nlength[i] = expand_nlength[i];
3130   }
3131 return expand_nmax;
3132 }
3133
3134
3135
3136 /*************************************************
3137 *           Restore numerical variables          *
3138 *************************************************/
3139
3140 /* This function restored saved values of numerical strings.
3141
3142 Arguments:
3143   save_expand_nmax      the number of strings to restore
3144   save_expand_string    points to an array of pointers
3145   save_expand_nlength   points to an array of ints
3146
3147 Returns:                nothing
3148 */
3149
3150 static void
3151 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3152   int *save_expand_nlength)
3153 {
3154 int i;
3155 expand_nmax = save_expand_nmax;
3156 for (i = 0; i <= expand_nmax; i++)
3157   {
3158   expand_nstring[i] = save_expand_nstring[i];
3159   expand_nlength[i] = save_expand_nlength[i];
3160   }
3161 }
3162
3163
3164
3165
3166
3167 /*************************************************
3168 *            Handle yes/no substrings            *
3169 *************************************************/
3170
3171 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3172 alternative substrings that depend on whether or not the condition was true,
3173 or the lookup or extraction succeeded. The substrings always have to be
3174 expanded, to check their syntax, but "skipping" is set when the result is not
3175 needed - this avoids unnecessary nested lookups.
3176
3177 Arguments:
3178   skipping       TRUE if we were skipping when this item was reached
3179   yes            TRUE if the first string is to be used, else use the second
3180   save_lookup    a value to put back into lookup_value before the 2nd expansion
3181   sptr           points to the input string pointer
3182   yieldptr       points to the output growable-string pointer
3183   type           "lookup", "if", "extract", "run", "env", "listextract" or
3184                  "certextract" for error message
3185   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3186                 the store.
3187
3188 Returns:         0 OK; lookup_value has been reset to save_lookup
3189                  1 expansion failed
3190                  2 expansion failed because of bracketing error
3191 */
3192
3193 static int
3194 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3195   gstring ** yieldptr, uschar *type, BOOL *resetok)
3196 {
3197 int rc = 0;
3198 const uschar *s = *sptr;    /* Local value */
3199 uschar *sub1, *sub2;
3200 const uschar * errwhere;
3201
3202 /* If there are no following strings, we substitute the contents of $value for
3203 lookups and for extractions in the success case. For the ${if item, the string
3204 "true" is substituted. In the fail case, nothing is substituted for all three
3205 items. */
3206
3207 while (isspace(*s)) s++;
3208 if (*s == '}')
3209   {
3210   if (type[0] == 'i')
3211     {
3212     if (yes && !skipping)
3213       *yieldptr = string_catn(*yieldptr, US"true", 4);
3214     }
3215   else
3216     {
3217     if (yes && lookup_value && !skipping)
3218       *yieldptr = string_cat(*yieldptr, lookup_value);
3219     lookup_value = save_lookup;
3220     }
3221   s++;
3222   goto RETURN;
3223   }
3224
3225 /* The first following string must be braced. */
3226
3227 if (*s++ != '{')
3228   {
3229   errwhere = US"'yes' part did not start with '{'";
3230   goto FAILED_CURLY;
3231   }
3232
3233 /* Expand the first substring. Forced failures are noticed only if we actually
3234 want this string. Set skipping in the call in the fail case (this will always
3235 be the case if we were already skipping). */
3236
3237 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3238 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3239 expand_string_forcedfail = FALSE;
3240 if (*s++ != '}')
3241   {
3242   errwhere = US"'yes' part did not end with '}'";
3243   goto FAILED_CURLY;
3244   }
3245
3246 /* If we want the first string, add it to the output */
3247
3248 if (yes)
3249   *yieldptr = string_cat(*yieldptr, sub1);
3250
3251 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3252 $value to what it was at the start of the item, so that it has this value
3253 during the second string expansion. For the call from "if" or "run" to this
3254 function, save_lookup is set to lookup_value, so that this statement does
3255 nothing. */
3256
3257 lookup_value = save_lookup;
3258
3259 /* There now follows either another substring, or "fail", or nothing. This
3260 time, forced failures are noticed only if we want the second string. We must
3261 set skipping in the nested call if we don't want this string, or if we were
3262 already skipping. */
3263
3264 while (isspace(*s)) s++;
3265 if (*s == '{')
3266   {
3267   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3268   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3269   expand_string_forcedfail = FALSE;
3270   if (*s++ != '}')
3271     {
3272     errwhere = US"'no' part did not start with '{'";
3273     goto FAILED_CURLY;
3274     }
3275
3276   /* If we want the second string, add it to the output */
3277
3278   if (!yes)
3279     *yieldptr = string_cat(*yieldptr, sub2);
3280   }
3281
3282 /* If there is no second string, but the word "fail" is present when the use of
3283 the second string is wanted, set a flag indicating it was a forced failure
3284 rather than a syntactic error. Swallow the terminating } in case this is nested
3285 inside another lookup or if or extract. */
3286
3287 else if (*s != '}')
3288   {
3289   uschar name[256];
3290   /* deconst cast ok here as source is s anyway */
3291   s = US read_name(name, sizeof(name), s, US"_");
3292   if (Ustrcmp(name, "fail") == 0)
3293     {
3294     if (!yes && !skipping)
3295       {
3296       while (isspace(*s)) s++;
3297       if (*s++ != '}')
3298         {
3299         errwhere = US"did not close with '}' after forcedfail";
3300         goto FAILED_CURLY;
3301         }
3302       expand_string_message =
3303         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3304       expand_string_forcedfail = TRUE;
3305       goto FAILED;
3306       }
3307     }
3308   else
3309     {
3310     expand_string_message =
3311       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3312     goto FAILED;
3313     }
3314   }
3315
3316 /* All we have to do now is to check on the final closing brace. */
3317
3318 while (isspace(*s)) s++;
3319 if (*s++ != '}')
3320   {
3321   errwhere = US"did not close with '}'";
3322   goto FAILED_CURLY;
3323   }
3324
3325
3326 RETURN:
3327 /* Update the input pointer value before returning */
3328 *sptr = s;
3329 return rc;
3330
3331 FAILED_CURLY:
3332   /* Get here if there is a bracketing failure */
3333   expand_string_message = string_sprintf(
3334     "curly-bracket problem in conditional yes/no parsing: %s\n"
3335     " remaining string is '%s'", errwhere, --s);
3336   rc = 2;
3337   goto RETURN;
3338
3339 FAILED:
3340   /* Get here for other failures */
3341   rc = 1;
3342   goto RETURN;
3343 }
3344
3345
3346
3347
3348 /*************************************************
3349 *    Handle MD5 or SHA-1 computation for HMAC    *
3350 *************************************************/
3351
3352 /* These are some wrapping functions that enable the HMAC code to be a bit
3353 cleaner. A good compiler will spot the tail recursion.
3354
3355 Arguments:
3356   type         HMAC_MD5 or HMAC_SHA1
3357   remaining    are as for the cryptographic hash functions
3358
3359 Returns:       nothing
3360 */
3361
3362 static void
3363 chash_start(int type, void *base)
3364 {
3365 if (type == HMAC_MD5)
3366   md5_start((md5 *)base);
3367 else
3368   sha1_start((hctx *)base);
3369 }
3370
3371 static void
3372 chash_mid(int type, void *base, uschar *string)
3373 {
3374 if (type == HMAC_MD5)
3375   md5_mid((md5 *)base, string);
3376 else
3377   sha1_mid((hctx *)base, string);
3378 }
3379
3380 static void
3381 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3382 {
3383 if (type == HMAC_MD5)
3384   md5_end((md5 *)base, string, length, digest);
3385 else
3386   sha1_end((hctx *)base, string, length, digest);
3387 }
3388
3389
3390
3391
3392
3393 /********************************************************
3394 * prvs: Get last three digits of days since Jan 1, 1970 *
3395 ********************************************************/
3396
3397 /* This is needed to implement the "prvs" BATV reverse
3398    path signing scheme
3399
3400 Argument: integer "days" offset to add or substract to
3401           or from the current number of days.
3402
3403 Returns:  pointer to string containing the last three
3404           digits of the number of days since Jan 1, 1970,
3405           modified by the offset argument, NULL if there
3406           was an error in the conversion.
3407
3408 */
3409
3410 static uschar *
3411 prvs_daystamp(int day_offset)
3412 {
3413 uschar *days = store_get(32);                /* Need at least 24 for cases */
3414 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3415   (time(NULL) + day_offset*86400)/86400);
3416 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3417 }
3418
3419
3420
3421 /********************************************************
3422 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3423 ********************************************************/
3424
3425 /* This is needed to implement the "prvs" BATV reverse
3426    path signing scheme
3427
3428 Arguments:
3429   address RFC2821 Address to use
3430       key The key to use (must be less than 64 characters
3431           in size)
3432   key_num Single-digit key number to use. Defaults to
3433           '0' when NULL.
3434
3435 Returns:  pointer to string containing the first three
3436           bytes of the final hash in hex format, NULL if
3437           there was an error in the process.
3438 */
3439
3440 static uschar *
3441 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3442 {
3443 gstring * hash_source;
3444 uschar * p;
3445 int i;
3446 hctx h;
3447 uschar innerhash[20];
3448 uschar finalhash[20];
3449 uschar innerkey[64];
3450 uschar outerkey[64];
3451 uschar *finalhash_hex = store_get(40);
3452
3453 if (key_num == NULL)
3454   key_num = US"0";
3455
3456 if (Ustrlen(key) > 64)
3457   return NULL;
3458
3459 hash_source = string_catn(NULL, key_num, 1);
3460 hash_source = string_catn(hash_source, daystamp, 3);
3461 hash_source = string_cat(hash_source, address);
3462 (void) string_from_gstring(hash_source);
3463
3464 DEBUG(D_expand)
3465   debug_printf_indent("prvs: hash source is '%s'\n", hash_source->s);
3466
3467 memset(innerkey, 0x36, 64);
3468 memset(outerkey, 0x5c, 64);
3469
3470 for (i = 0; i < Ustrlen(key); i++)
3471   {
3472   innerkey[i] ^= key[i];
3473   outerkey[i] ^= key[i];
3474   }
3475
3476 chash_start(HMAC_SHA1, &h);
3477 chash_mid(HMAC_SHA1, &h, innerkey);
3478 chash_end(HMAC_SHA1, &h, hash_source->s, hash_source->ptr, innerhash);
3479
3480 chash_start(HMAC_SHA1, &h);
3481 chash_mid(HMAC_SHA1, &h, outerkey);
3482 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3483
3484 p = finalhash_hex;
3485 for (i = 0; i < 3; i++)
3486   {
3487   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3488   *p++ = hex_digits[finalhash[i] & 0x0f];
3489   }
3490 *p = '\0';
3491
3492 return finalhash_hex;
3493 }
3494
3495
3496
3497
3498 /*************************************************
3499 *        Join a file onto the output string      *
3500 *************************************************/
3501
3502 /* This is used for readfile/readsock and after a run expansion.
3503 It joins the contents of a file onto the output string, globally replacing
3504 newlines with a given string (optionally).
3505
3506 Arguments:
3507   f            the FILE
3508   yield        pointer to the expandable string struct
3509   eol          newline replacement string, or NULL
3510
3511 Returns:       new pointer for expandable string, terminated if non-null
3512 */
3513
3514 static gstring *
3515 cat_file(FILE *f, gstring *yield, uschar *eol)
3516 {
3517 uschar buffer[1024];
3518
3519 while (Ufgets(buffer, sizeof(buffer), f))
3520   {
3521   int len = Ustrlen(buffer);
3522   if (eol && buffer[len-1] == '\n') len--;
3523   yield = string_catn(yield, buffer, len);
3524   if (eol && buffer[len])
3525     yield = string_cat(yield, eol);
3526   }
3527
3528 (void) string_from_gstring(yield);
3529 return yield;
3530 }
3531
3532
3533
3534
3535 /*************************************************
3536 *          Evaluate numeric expression           *
3537 *************************************************/
3538
3539 /* This is a set of mutually recursive functions that evaluate an arithmetic
3540 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3541 these functions that is called from elsewhere is eval_expr, whose interface is:
3542
3543 Arguments:
3544   sptr        pointer to the pointer to the string - gets updated
3545   decimal     TRUE if numbers are to be assumed decimal
3546   error       pointer to where to put an error message - must be NULL on input
3547   endket      TRUE if ')' must terminate - FALSE for external call
3548
3549 Returns:      on success: the value of the expression, with *error still NULL
3550               on failure: an undefined value, with *error = a message
3551 */
3552
3553 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3554
3555
3556 static int_eximarith_t
3557 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3558 {
3559 uschar *s = *sptr;
3560 int_eximarith_t x = eval_op_or(&s, decimal, error);
3561 if (*error == NULL)
3562   {
3563   if (endket)
3564     {
3565     if (*s != ')')
3566       *error = US"expecting closing parenthesis";
3567     else
3568       while (isspace(*(++s)));
3569     }
3570   else if (*s != 0) *error = US"expecting operator";
3571   }
3572 *sptr = s;
3573 return x;
3574 }
3575
3576
3577 static int_eximarith_t
3578 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3579 {
3580 register int c;
3581 int_eximarith_t n;
3582 uschar *s = *sptr;
3583 while (isspace(*s)) s++;
3584 c = *s;
3585 if (isdigit(c))
3586   {
3587   int count;
3588   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3589   s += count;
3590   switch (tolower(*s))
3591     {
3592     default: break;
3593     case 'k': n *= 1024; s++; break;
3594     case 'm': n *= 1024*1024; s++; break;
3595     case 'g': n *= 1024*1024*1024; s++; break;
3596     }
3597   while (isspace (*s)) s++;
3598   }
3599 else if (c == '(')
3600   {
3601   s++;
3602   n = eval_expr(&s, decimal, error, 1);
3603   }
3604 else
3605   {
3606   *error = US"expecting number or opening parenthesis";
3607   n = 0;
3608   }
3609 *sptr = s;
3610 return n;
3611 }
3612
3613
3614 static int_eximarith_t
3615 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3616 {
3617 uschar *s = *sptr;
3618 int_eximarith_t x;
3619 while (isspace(*s)) s++;
3620 if (*s == '+' || *s == '-' || *s == '~')
3621   {
3622   int op = *s++;
3623   x = eval_op_unary(&s, decimal, error);
3624   if (op == '-') x = -x;
3625     else if (op == '~') x = ~x;
3626   }
3627 else
3628   {
3629   x = eval_number(&s, decimal, error);
3630   }
3631 *sptr = s;
3632 return x;
3633 }
3634
3635
3636 static int_eximarith_t
3637 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3638 {
3639 uschar *s = *sptr;
3640 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3641 if (*error == NULL)
3642   {
3643   while (*s == '*' || *s == '/' || *s == '%')
3644     {
3645     int op = *s++;
3646     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3647     if (*error != NULL) break;
3648     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3649      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3650      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3651      * -N*M is INT_MIN will yield INT_MIN.
3652      * Since we don't support floating point, this is somewhat simpler.
3653      * Ideally, we'd return an error, but since we overflow for all other
3654      * arithmetic, consistency suggests otherwise, but what's the correct value
3655      * to use?  There is none.
3656      * The C standard guarantees overflow for unsigned arithmetic but signed
3657      * overflow invokes undefined behaviour; in practice, this is overflow
3658      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3659      * that long/longlong larger than int are available, or we could just work
3660      * with larger types.  We should consider whether to guarantee 32bit eval
3661      * and 64-bit working variables, with errors returned.  For now ...
3662      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3663      * can just let the other invalid results occur otherwise, as they have
3664      * until now.  For this one case, we can coerce.
3665      */
3666     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3667       {
3668       DEBUG(D_expand)
3669         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3670             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3671       x = EXIM_ARITH_MAX;
3672       continue;
3673       }
3674     if (op == '*')
3675       x *= y;
3676     else
3677       {
3678       if (y == 0)
3679         {
3680         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3681         x = 0;
3682         break;
3683         }
3684       if (op == '/')
3685         x /= y;
3686       else
3687         x %= y;
3688       }
3689     }
3690   }
3691 *sptr = s;
3692 return x;
3693 }
3694
3695
3696 static int_eximarith_t
3697 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3698 {
3699 uschar *s = *sptr;
3700 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3701 if (!*error)
3702   {
3703   while (*s == '+' || *s == '-')
3704     {
3705     int op = *s++;
3706     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3707     if (*error) break;
3708     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3709        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3710       {                 /* over-conservative check */
3711       *error = op == '+'
3712         ? US"overflow in sum" : US"overflow in difference";
3713       break;
3714       }
3715     if (op == '+') x += y; else x -= y;
3716     }
3717   }
3718 *sptr = s;
3719 return x;
3720 }
3721
3722
3723 static int_eximarith_t
3724 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3725 {
3726 uschar *s = *sptr;
3727 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3728 if (*error == NULL)
3729   {
3730   while ((*s == '<' || *s == '>') && s[1] == s[0])
3731     {
3732     int_eximarith_t y;
3733     int op = *s++;
3734     s++;
3735     y = eval_op_sum(&s, decimal, error);
3736     if (*error != NULL) break;
3737     if (op == '<') x <<= y; else x >>= y;
3738     }
3739   }
3740 *sptr = s;
3741 return x;
3742 }
3743
3744
3745 static int_eximarith_t
3746 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3747 {
3748 uschar *s = *sptr;
3749 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3750 if (*error == NULL)
3751   {
3752   while (*s == '&')
3753     {
3754     int_eximarith_t y;
3755     s++;
3756     y = eval_op_shift(&s, decimal, error);
3757     if (*error != NULL) break;
3758     x &= y;
3759     }
3760   }
3761 *sptr = s;
3762 return x;
3763 }
3764
3765
3766 static int_eximarith_t
3767 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3768 {
3769 uschar *s = *sptr;
3770 int_eximarith_t x = eval_op_and(&s, decimal, error);
3771 if (*error == NULL)
3772   {
3773   while (*s == '^')
3774     {
3775     int_eximarith_t y;
3776     s++;
3777     y = eval_op_and(&s, decimal, error);
3778     if (*error != NULL) break;
3779     x ^= y;
3780     }
3781   }
3782 *sptr = s;
3783 return x;
3784 }
3785
3786
3787 static int_eximarith_t
3788 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3789 {
3790 uschar *s = *sptr;
3791 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3792 if (*error == NULL)
3793   {
3794   while (*s == '|')
3795     {
3796     int_eximarith_t y;
3797     s++;
3798     y = eval_op_xor(&s, decimal, error);
3799     if (*error != NULL) break;
3800     x |= y;
3801     }
3802   }
3803 *sptr = s;
3804 return x;
3805 }
3806
3807
3808
3809 /*************************************************
3810 *                 Expand string                  *
3811 *************************************************/
3812
3813 /* Returns either an unchanged string, or the expanded string in stacking pool
3814 store. Interpreted sequences are:
3815
3816    \...                    normal escaping rules
3817    $name                   substitutes the variable
3818    ${name}                 ditto
3819    ${op:string}            operates on the expanded string value
3820    ${item{arg1}{arg2}...}  expands the args and then does the business
3821                              some literal args are not enclosed in {}
3822
3823 There are now far too many operators and item types to make it worth listing
3824 them here in detail any more.
3825
3826 We use an internal routine recursively to handle embedded substrings. The
3827 external function follows. The yield is NULL if the expansion failed, and there
3828 are two cases: if something collapsed syntactically, or if "fail" was given
3829 as the action on a lookup failure. These can be distinguished by looking at the
3830 variable expand_string_forcedfail, which is TRUE in the latter case.
3831
3832 The skipping flag is set true when expanding a substring that isn't actually
3833 going to be used (after "if" or "lookup") and it prevents lookups from
3834 happening lower down.
3835
3836 Store usage: At start, a store block of the length of the input plus 64
3837 is obtained. This is expanded as necessary by string_cat(), which might have to
3838 get a new block, or might be able to expand the original. At the end of the
3839 function we can release any store above that portion of the yield block that
3840 was actually used. In many cases this will be optimal.
3841
3842 However: if the first item in the expansion is a variable name or header name,
3843 we reset the store before processing it; if the result is in fresh store, we
3844 use that without copying. This is helpful for expanding strings like
3845 $message_headers which can get very long.
3846
3847 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3848 since resetting the store at the end of the expansion will free store that was
3849 allocated by the plugin code as well as the slop after the expanded string. So
3850 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3851 and, given the acl condition, ${if }. This is an unfortunate consequence of
3852 string expansion becoming too powerful.
3853
3854 Arguments:
3855   string         the string to be expanded
3856   ket_ends       true if expansion is to stop at }
3857   left           if not NULL, a pointer to the first character after the
3858                  expansion is placed here (typically used with ket_ends)
3859   skipping       TRUE for recursive calls when the value isn't actually going
3860                  to be used (to allow for optimisation)
3861   honour_dollar  TRUE if $ is to be expanded,
3862                  FALSE if it's just another character
3863   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3864                  the store.
3865
3866 Returns:         NULL if expansion fails:
3867                    expand_string_forcedfail is set TRUE if failure was forced
3868                    expand_string_message contains a textual error message
3869                  a pointer to the expanded string on success
3870 */
3871
3872 static uschar *
3873 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3874   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3875 {
3876 gstring * yield = string_get(Ustrlen(string) + 64);
3877 int item_type;
3878 const uschar *s = string;
3879 uschar *save_expand_nstring[EXPAND_MAXN+1];
3880 int save_expand_nlength[EXPAND_MAXN+1];
3881 BOOL resetok = TRUE;
3882
3883 expand_level++;
3884 DEBUG(D_expand)
3885   debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
3886     skipping
3887     ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
3888     : "considering",
3889     string);
3890
3891 expand_string_forcedfail = FALSE;
3892 expand_string_message = US"";
3893
3894 while (*s != 0)
3895   {
3896   uschar *value;
3897   uschar name[256];
3898
3899   /* \ escapes the next character, which must exist, or else
3900   the expansion fails. There's a special escape, \N, which causes
3901   copying of the subject verbatim up to the next \N. Otherwise,
3902   the escapes are the standard set. */
3903
3904   if (*s == '\\')
3905     {
3906     if (s[1] == 0)
3907       {
3908       expand_string_message = US"\\ at end of string";
3909       goto EXPAND_FAILED;
3910       }
3911
3912     if (s[1] == 'N')
3913       {
3914       const uschar * t = s + 2;
3915       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3916       yield = string_catn(yield, t, s - t);
3917       if (*s != 0) s += 2;
3918       }
3919
3920     else
3921       {
3922       uschar ch[1];
3923       ch[0] = string_interpret_escape(&s);
3924       s++;
3925       yield = string_catn(yield, ch, 1);
3926       }
3927
3928     continue;
3929     }
3930
3931   /*{*/
3932   /* Anything other than $ is just copied verbatim, unless we are
3933   looking for a terminating } character. */
3934
3935   /*{*/
3936   if (ket_ends && *s == '}') break;
3937
3938   if (*s != '$' || !honour_dollar)
3939     {
3940     yield = string_catn(yield, s++, 1);
3941     continue;
3942     }
3943
3944   /* No { after the $ - must be a plain name or a number for string
3945   match variable. There has to be a fudge for variables that are the
3946   names of header fields preceded by "$header_" because header field
3947   names can contain any printing characters except space and colon.
3948   For those that don't like typing this much, "$h_" is a synonym for
3949   "$header_". A non-existent header yields a NULL value; nothing is
3950   inserted. */  /*}*/
3951
3952   if (isalpha((*(++s))))
3953     {
3954     int len;
3955     int newsize = 0;
3956     gstring * g = NULL;
3957
3958     s = read_name(name, sizeof(name), s, US"_");
3959
3960     /* If this is the first thing to be expanded, release the pre-allocated
3961     buffer. */
3962
3963     if (!yield)
3964       g = store_get(sizeof(gstring));
3965     else if (yield->ptr == 0)
3966       {
3967       if (resetok) store_reset(yield);
3968       yield = NULL;
3969       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
3970       }
3971
3972     /* Header */
3973
3974     if (Ustrncmp(name, "h_", 2) == 0 ||
3975         Ustrncmp(name, "rh_", 3) == 0 ||
3976         Ustrncmp(name, "bh_", 3) == 0 ||
3977         Ustrncmp(name, "header_", 7) == 0 ||
3978         Ustrncmp(name, "rheader_", 8) == 0 ||
3979         Ustrncmp(name, "bheader_", 8) == 0)
3980       {
3981       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3982       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3983       s = read_header_name(name, sizeof(name), s);
3984       value = find_header(name, FALSE, &newsize, want_raw, charset);
3985
3986       /* If we didn't find the header, and the header contains a closing brace
3987       character, this may be a user error where the terminating colon
3988       has been omitted. Set a flag to adjust the error message in this case.
3989       But there is no error here - nothing gets inserted. */
3990
3991       if (!value)
3992         {
3993         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3994         continue;
3995         }
3996       }
3997
3998     /* Variable */
3999
4000     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
4001       {
4002       expand_string_message =
4003         string_sprintf("unknown variable name \"%s\"", name);
4004         check_variable_error_message(name);
4005       goto EXPAND_FAILED;
4006       }
4007
4008     /* If the data is known to be in a new buffer, newsize will be set to the
4009     size of that buffer. If this is the first thing in an expansion string,
4010     yield will be NULL; just point it at the new store instead of copying. Many
4011     expansion strings contain just one reference, so this is a useful
4012     optimization, especially for humungous headers.  We need to use a gstring
4013     structure that is not allocated after that new-buffer, else a later store
4014     reset in the middle of the buffer will make it inaccessible. */
4015
4016     len = Ustrlen(value);
4017     if (!yield && newsize != 0)
4018       {
4019       yield = g;
4020       yield->size = newsize;
4021       yield->ptr = len;
4022       yield->s = value;
4023       }
4024     else
4025       yield = string_catn(yield, value, len);
4026
4027     continue;
4028     }
4029
4030   if (isdigit(*s))
4031     {
4032     int n;
4033     s = read_cnumber(&n, s);
4034     if (n >= 0 && n <= expand_nmax)
4035       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4036     continue;
4037     }
4038
4039   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4040
4041   if (*s != '{')                                                        /*}*/
4042     {
4043     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4044     goto EXPAND_FAILED;
4045     }
4046
4047   /* After { there can be various things, but they all start with
4048   an initial word, except for a number for a string match variable. */
4049
4050   if (isdigit((*(++s))))
4051     {
4052     int n;
4053     s = read_cnumber(&n, s);            /*{*/
4054     if (*s++ != '}')
4055       {                                 /*{*/
4056       expand_string_message = US"} expected after number";
4057       goto EXPAND_FAILED;
4058       }
4059     if (n >= 0 && n <= expand_nmax)
4060       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4061     continue;
4062     }
4063
4064   if (!isalpha(*s))
4065     {
4066     expand_string_message = US"letter or digit expected after ${";      /*}*/
4067     goto EXPAND_FAILED;
4068     }
4069
4070   /* Allow "-" in names to cater for substrings with negative
4071   arguments. Since we are checking for known names after { this is
4072   OK. */
4073
4074   s = read_name(name, sizeof(name), s, US"_-");
4075   item_type = chop_match(name, item_table, nelem(item_table));
4076
4077   switch(item_type)
4078     {
4079     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4080     If the ACL returns accept or reject we return content set by "message ="
4081     There is currently no limit on recursion; this would have us call
4082     acl_check_internal() directly and get a current level from somewhere.
4083     See also the acl expansion condition ECOND_ACL and the traditional
4084     acl modifier ACLC_ACL.
4085     Assume that the function has side-effects on the store that must be preserved.
4086     */
4087
4088     case EITEM_ACL:
4089       /* ${acl {name} {arg1}{arg2}...} */
4090       {
4091       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4092       uschar *user_msg;
4093
4094       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4095                       &resetok))
4096         {
4097         case 1: goto EXPAND_FAILED_CURLY;
4098         case 2:
4099         case 3: goto EXPAND_FAILED;
4100         }
4101       if (skipping) continue;
4102
4103       resetok = FALSE;
4104       switch(eval_acl(sub, nelem(sub), &user_msg))
4105         {
4106         case OK:
4107         case FAIL:
4108           DEBUG(D_expand)
4109             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4110           if (user_msg)
4111             yield = string_cat(yield, user_msg);
4112           continue;
4113
4114         case DEFER:
4115           expand_string_forcedfail = TRUE;
4116           /*FALLTHROUGH*/
4117         default:
4118           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4119           goto EXPAND_FAILED;
4120         }
4121       }
4122
4123     case EITEM_AUTHRESULTS:
4124       /* ${authresults {mysystemname}} */
4125       {
4126       uschar *sub_arg[1];
4127
4128       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4129                       &resetok))
4130         {
4131         case 1: goto EXPAND_FAILED_CURLY;
4132         case 2:
4133         case 3: goto EXPAND_FAILED;
4134         }
4135
4136       yield = string_append(yield, 3,
4137                         US"Authentication-Results: ", sub_arg[0], US"; none");
4138       yield->ptr -= 6;
4139
4140       yield = authres_iprev(yield);
4141       yield = authres_smtpauth(yield);
4142 #ifdef SUPPORT_SPF
4143       yield = authres_spf(yield);
4144 #endif
4145 #ifndef DISABLE_DKIM
4146       yield = authres_dkim(yield);
4147 #endif
4148 #ifdef EXPERIMENTAL_ARC
4149       yield = authres_arc(yield);
4150 #endif
4151       continue;
4152       }
4153
4154     /* Handle conditionals - preserve the values of the numerical expansion
4155     variables in case they get changed by a regular expression match in the
4156     condition. If not, they retain their external settings. At the end
4157     of this "if" section, they get restored to their previous values. */
4158
4159     case EITEM_IF:
4160       {
4161       BOOL cond = FALSE;
4162       const uschar *next_s;
4163       int save_expand_nmax =
4164         save_expand_strings(save_expand_nstring, save_expand_nlength);
4165
4166       while (isspace(*s)) s++;
4167       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4168       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4169
4170       DEBUG(D_expand)
4171         {
4172         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4173           "condition: %.*s\n",
4174           (int)(next_s - s), s);
4175         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4176           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4177           "result: %s\n",
4178           cond ? "true" : "false");
4179         }
4180
4181       s = next_s;
4182
4183       /* The handling of "yes" and "no" result strings is now in a separate
4184       function that is also used by ${lookup} and ${extract} and ${run}. */
4185
4186       switch(process_yesno(
4187                skipping,                     /* were previously skipping */
4188                cond,                         /* success/failure indicator */
4189                lookup_value,                 /* value to reset for string2 */
4190                &s,                           /* input pointer */
4191                &yield,                       /* output pointer */
4192                US"if",                       /* condition type */
4193                &resetok))
4194         {
4195         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4196         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4197         }
4198
4199       /* Restore external setting of expansion variables for continuation
4200       at this level. */
4201
4202       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4203         save_expand_nlength);
4204       continue;
4205       }
4206
4207 #ifdef SUPPORT_I18N
4208     case EITEM_IMAPFOLDER:
4209       {                         /* ${imapfolder {name}{sep]{specials}} */
4210       uschar *sub_arg[3];
4211       uschar *encoded;
4212
4213       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4214                       &resetok))
4215         {
4216         case 1: goto EXPAND_FAILED_CURLY;
4217         case 2:
4218         case 3: goto EXPAND_FAILED;
4219         }
4220
4221       if (sub_arg[1] == NULL)           /* One argument */
4222         {
4223         sub_arg[1] = US"/";             /* default separator */
4224         sub_arg[2] = NULL;
4225         }
4226       else if (Ustrlen(sub_arg[1]) != 1)
4227         {
4228         expand_string_message =
4229           string_sprintf(
4230                 "IMAP folder separator must be one character, found \"%s\"",
4231                 sub_arg[1]);
4232         goto EXPAND_FAILED;
4233         }
4234
4235       if (!skipping)
4236         {
4237         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4238                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4239           goto EXPAND_FAILED;
4240         yield = string_cat(yield, encoded);
4241         }
4242       continue;
4243       }
4244 #endif
4245
4246     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4247     expanding an internal string that isn't actually going to be used. All we
4248     need to do is check the syntax, so don't do a lookup at all. Preserve the
4249     values of the numerical expansion variables in case they get changed by a
4250     partial lookup. If not, they retain their external settings. At the end
4251     of this "lookup" section, they get restored to their previous values. */
4252
4253     case EITEM_LOOKUP:
4254       {
4255       int stype, partial, affixlen, starflags;
4256       int expand_setup = 0;
4257       int nameptr = 0;
4258       uschar *key, *filename;
4259       const uschar *affix;
4260       uschar *save_lookup_value = lookup_value;
4261       int save_expand_nmax =
4262         save_expand_strings(save_expand_nstring, save_expand_nlength);
4263
4264       if ((expand_forbid & RDO_LOOKUP) != 0)
4265         {
4266         expand_string_message = US"lookup expansions are not permitted";
4267         goto EXPAND_FAILED;
4268         }
4269
4270       /* Get the key we are to look up for single-key+file style lookups.
4271       Otherwise set the key NULL pro-tem. */
4272
4273       while (isspace(*s)) s++;
4274       if (*s == '{')                                    /*}*/
4275         {
4276         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4277         if (!key) goto EXPAND_FAILED;                   /*{{*/
4278         if (*s++ != '}')
4279           {
4280           expand_string_message = US"missing '}' after lookup key";
4281           goto EXPAND_FAILED_CURLY;
4282           }
4283         while (isspace(*s)) s++;
4284         }
4285       else key = NULL;
4286
4287       /* Find out the type of database */
4288
4289       if (!isalpha(*s))
4290         {
4291         expand_string_message = US"missing lookup type";
4292         goto EXPAND_FAILED;
4293         }
4294
4295       /* The type is a string that may contain special characters of various
4296       kinds. Allow everything except space or { to appear; the actual content
4297       is checked by search_findtype_partial. */         /*}*/
4298
4299       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4300         {
4301         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4302         s++;
4303         }
4304       name[nameptr] = 0;
4305       while (isspace(*s)) s++;
4306
4307       /* Now check for the individual search type and any partial or default
4308       options. Only those types that are actually in the binary are valid. */
4309
4310       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4311         &starflags);
4312       if (stype < 0)
4313         {
4314         expand_string_message = search_error_message;
4315         goto EXPAND_FAILED;
4316         }
4317
4318       /* Check that a key was provided for those lookup types that need it,
4319       and was not supplied for those that use the query style. */
4320
4321       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4322         {
4323         if (key == NULL)
4324           {
4325           expand_string_message = string_sprintf("missing {key} for single-"
4326             "key \"%s\" lookup", name);
4327           goto EXPAND_FAILED;
4328           }
4329         }
4330       else
4331         {
4332         if (key != NULL)
4333           {
4334           expand_string_message = string_sprintf("a single key was given for "
4335             "lookup type \"%s\", which is not a single-key lookup type", name);
4336           goto EXPAND_FAILED;
4337           }
4338         }
4339
4340       /* Get the next string in brackets and expand it. It is the file name for
4341       single-key+file lookups, and the whole query otherwise. In the case of
4342       queries that also require a file name (e.g. sqlite), the file name comes
4343       first. */
4344
4345       if (*s != '{')
4346         {
4347         expand_string_message = US"missing '{' for lookup file-or-query arg";
4348         goto EXPAND_FAILED_CURLY;
4349         }
4350       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4351       if (filename == NULL) goto EXPAND_FAILED;
4352       if (*s++ != '}')
4353         {
4354         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4355         goto EXPAND_FAILED_CURLY;
4356         }
4357       while (isspace(*s)) s++;
4358
4359       /* If this isn't a single-key+file lookup, re-arrange the variables
4360       to be appropriate for the search_ functions. For query-style lookups,
4361       there is just a "key", and no file name. For the special query-style +
4362       file types, the query (i.e. "key") starts with a file name. */
4363
4364       if (!key)
4365         {
4366         while (isspace(*filename)) filename++;
4367         key = filename;
4368
4369         if (mac_islookup(stype, lookup_querystyle))
4370           filename = NULL;
4371         else
4372           {
4373           if (*filename != '/')
4374             {
4375             expand_string_message = string_sprintf(
4376               "absolute file name expected for \"%s\" lookup", name);
4377             goto EXPAND_FAILED;
4378             }
4379           while (*key != 0 && !isspace(*key)) key++;
4380           if (*key != 0) *key++ = 0;
4381           }
4382         }
4383
4384       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4385       the entry was not found. Note that there is no search_close() function.
4386       Files are left open in case of re-use. At suitable places in higher logic,
4387       search_tidyup() is called to tidy all open files. This can save opening
4388       the same file several times. However, files may also get closed when
4389       others are opened, if too many are open at once. The rule is that a
4390       handle should not be used after a second search_open().
4391
4392       Request that a partial search sets up $1 and maybe $2 by passing
4393       expand_setup containing zero. If its value changes, reset expand_nmax,
4394       since new variables will have been set. Note that at the end of this
4395       "lookup" section, the old numeric variables are restored. */
4396
4397       if (skipping)
4398         lookup_value = NULL;
4399       else
4400         {
4401         void *handle = search_open(filename, stype, 0, NULL, NULL);
4402         if (handle == NULL)
4403           {
4404           expand_string_message = search_error_message;
4405           goto EXPAND_FAILED;
4406           }
4407         lookup_value = search_find(handle, filename, key, partial, affix,
4408           affixlen, starflags, &expand_setup);
4409         if (search_find_defer)
4410           {
4411           expand_string_message =
4412             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4413               string_printing2(key, FALSE), search_error_message);
4414           goto EXPAND_FAILED;
4415           }
4416         if (expand_setup > 0) expand_nmax = expand_setup;
4417         }
4418
4419       /* The handling of "yes" and "no" result strings is now in a separate
4420       function that is also used by ${if} and ${extract}. */
4421
4422       switch(process_yesno(
4423                skipping,                     /* were previously skipping */
4424                lookup_value != NULL,         /* success/failure indicator */
4425                save_lookup_value,            /* value to reset for string2 */
4426                &s,                           /* input pointer */
4427                &yield,                       /* output pointer */
4428                US"lookup",                   /* condition type */
4429                &resetok))
4430         {
4431         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4432         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4433         }
4434
4435       /* Restore external setting of expansion variables for carrying on
4436       at this level, and continue. */
4437
4438       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4439         save_expand_nlength);
4440       continue;
4441       }
4442
4443     /* If Perl support is configured, handle calling embedded perl subroutines,
4444     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4445     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4446     arguments (defined below). */
4447
4448     #define EXIM_PERL_MAX_ARGS 8
4449
4450     case EITEM_PERL:
4451     #ifndef EXIM_PERL
4452     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4453       "is not included in this binary";
4454     goto EXPAND_FAILED;
4455
4456     #else   /* EXIM_PERL */
4457       {
4458       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4459       gstring *new_yield;
4460
4461       if ((expand_forbid & RDO_PERL) != 0)
4462         {
4463         expand_string_message = US"Perl calls are not permitted";
4464         goto EXPAND_FAILED;
4465         }
4466
4467       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4468            US"perl", &resetok))
4469         {
4470         case 1: goto EXPAND_FAILED_CURLY;
4471         case 2:
4472         case 3: goto EXPAND_FAILED;
4473         }
4474
4475       /* If skipping, we don't actually do anything */
4476
4477       if (skipping) continue;
4478
4479       /* Start the interpreter if necessary */
4480
4481       if (!opt_perl_started)
4482         {
4483         uschar *initerror;
4484         if (opt_perl_startup == NULL)
4485           {
4486           expand_string_message = US"A setting of perl_startup is needed when "
4487             "using the Perl interpreter";
4488           goto EXPAND_FAILED;
4489           }
4490         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4491         initerror = init_perl(opt_perl_startup);
4492         if (initerror != NULL)
4493           {
4494           expand_string_message =
4495             string_sprintf("error in perl_startup code: %s\n", initerror);
4496           goto EXPAND_FAILED;
4497           }
4498         opt_perl_started = TRUE;
4499         }
4500
4501       /* Call the function */
4502
4503       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4504       new_yield = call_perl_cat(yield, &expand_string_message,
4505         sub_arg[0], sub_arg + 1);
4506
4507       /* NULL yield indicates failure; if the message pointer has been set to
4508       NULL, the yield was undef, indicating a forced failure. Otherwise the
4509       message will indicate some kind of Perl error. */
4510
4511       if (new_yield == NULL)
4512         {
4513         if (expand_string_message == NULL)
4514           {
4515           expand_string_message =
4516             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4517               "failure", sub_arg[0]);
4518           expand_string_forcedfail = TRUE;
4519           }
4520         goto EXPAND_FAILED;
4521         }
4522
4523       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4524       set during a callback from Perl. */
4525
4526       expand_string_forcedfail = FALSE;
4527       yield = new_yield;
4528       continue;
4529       }
4530     #endif /* EXIM_PERL */
4531
4532     /* Transform email address to "prvs" scheme to use
4533        as BATV-signed return path */
4534
4535     case EITEM_PRVS:
4536       {
4537       uschar *sub_arg[3];
4538       uschar *p,*domain;
4539
4540       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4541         {
4542         case 1: goto EXPAND_FAILED_CURLY;
4543         case 2:
4544         case 3: goto EXPAND_FAILED;
4545         }
4546
4547       /* If skipping, we don't actually do anything */
4548       if (skipping) continue;
4549
4550       /* sub_arg[0] is the address */
4551       if (  !(domain = Ustrrchr(sub_arg[0],'@'))
4552          || domain == sub_arg[0] || Ustrlen(domain) == 1)
4553         {
4554         expand_string_message = US"prvs first argument must be a qualified email address";
4555         goto EXPAND_FAILED;
4556         }
4557
4558       /* Calculate the hash. The third argument must be a single-digit
4559       key number, or unset. */
4560
4561       if (  sub_arg[2]
4562          && (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4563         {
4564         expand_string_message = US"prvs third argument must be a single digit";
4565         goto EXPAND_FAILED;
4566         }
4567
4568       p = prvs_hmac_sha1(sub_arg[0], sub_arg[1], sub_arg[2], prvs_daystamp(7));
4569       if (!p)
4570         {
4571         expand_string_message = US"prvs hmac-sha1 conversion failed";
4572         goto EXPAND_FAILED;
4573         }
4574
4575       /* Now separate the domain from the local part */
4576       *domain++ = '\0';
4577
4578       yield = string_catn(yield, US"prvs=", 5);
4579       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
4580       yield = string_catn(yield, prvs_daystamp(7), 3);
4581       yield = string_catn(yield, p, 6);
4582       yield = string_catn(yield, US"=", 1);
4583       yield = string_cat (yield, sub_arg[0]);
4584       yield = string_catn(yield, US"@", 1);
4585       yield = string_cat (yield, domain);
4586
4587       continue;
4588       }
4589
4590     /* Check a prvs-encoded address for validity */
4591
4592     case EITEM_PRVSCHECK:
4593       {
4594       uschar *sub_arg[3];
4595       gstring * g;
4596       const pcre *re;
4597       uschar *p;
4598
4599       /* TF: Ugliness: We want to expand parameter 1 first, then set
4600          up expansion variables that are used in the expansion of
4601          parameter 2. So we clone the string for the first
4602          expansion, where we only expand parameter 1.
4603
4604          PH: Actually, that isn't necessary. The read_subs() function is
4605          designed to work this way for the ${if and ${lookup expansions. I've
4606          tidied the code.
4607       */
4608
4609       /* Reset expansion variables */
4610       prvscheck_result = NULL;
4611       prvscheck_address = NULL;
4612       prvscheck_keynum = NULL;
4613
4614       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4615         {
4616         case 1: goto EXPAND_FAILED_CURLY;
4617         case 2:
4618         case 3: goto EXPAND_FAILED;
4619         }
4620
4621       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4622                               TRUE,FALSE);
4623
4624       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4625         {
4626         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4627         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4628         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4629         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4630         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4631
4632         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4633         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4634         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4635         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4636         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4637
4638         /* Set up expansion variables */
4639         g = string_cat (NULL, local_part);
4640         g = string_catn(g, US"@", 1);
4641         g = string_cat (g, domain);
4642         prvscheck_address = string_from_gstring(g);
4643         prvscheck_keynum = string_copy(key_num);
4644
4645         /* Now expand the second argument */
4646         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4647           {
4648           case 1: goto EXPAND_FAILED_CURLY;
4649           case 2:
4650           case 3: goto EXPAND_FAILED;
4651           }
4652
4653         /* Now we have the key and can check the address. */
4654
4655         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4656           daystamp);
4657
4658         if (!p)
4659           {
4660           expand_string_message = US"hmac-sha1 conversion failed";
4661           goto EXPAND_FAILED;
4662           }
4663
4664         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4665         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4666
4667         if (Ustrcmp(p,hash) == 0)
4668           {
4669           /* Success, valid BATV address. Now check the expiry date. */
4670           uschar *now = prvs_daystamp(0);
4671           unsigned int inow = 0,iexpire = 1;
4672
4673           (void)sscanf(CS now,"%u",&inow);
4674           (void)sscanf(CS daystamp,"%u",&iexpire);
4675
4676           /* When "iexpire" is < 7, a "flip" has occured.
4677              Adjust "inow" accordingly. */
4678           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4679
4680           if (iexpire >= inow)
4681             {
4682             prvscheck_result = US"1";
4683             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4684             }
4685           else
4686             {
4687             prvscheck_result = NULL;
4688             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4689             }
4690           }
4691         else
4692           {
4693           prvscheck_result = NULL;
4694           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4695           }
4696
4697         /* Now expand the final argument. We leave this till now so that
4698         it can include $prvscheck_result. */
4699
4700         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4701           {
4702           case 1: goto EXPAND_FAILED_CURLY;
4703           case 2:
4704           case 3: goto EXPAND_FAILED;
4705           }
4706
4707         yield = string_cat(yield,
4708           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4709
4710         /* Reset the "internal" variables afterwards, because they are in
4711         dynamic store that will be reclaimed if the expansion succeeded. */
4712
4713         prvscheck_address = NULL;
4714         prvscheck_keynum = NULL;
4715         }
4716       else
4717         /* Does not look like a prvs encoded address, return the empty string.
4718            We need to make sure all subs are expanded first, so as to skip over
4719            the entire item. */
4720
4721         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4722           {
4723           case 1: goto EXPAND_FAILED_CURLY;
4724           case 2:
4725           case 3: goto EXPAND_FAILED;
4726           }
4727
4728       continue;
4729       }
4730
4731     /* Handle "readfile" to insert an entire file */
4732
4733     case EITEM_READFILE:
4734       {
4735       FILE *f;
4736       uschar *sub_arg[2];
4737
4738       if ((expand_forbid & RDO_READFILE) != 0)
4739         {
4740         expand_string_message = US"file insertions are not permitted";
4741         goto EXPAND_FAILED;
4742         }
4743
4744       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4745         {
4746         case 1: goto EXPAND_FAILED_CURLY;
4747         case 2:
4748         case 3: goto EXPAND_FAILED;
4749         }
4750
4751       /* If skipping, we don't actually do anything */
4752
4753       if (skipping) continue;
4754
4755       /* Open the file and read it */
4756
4757       if (!(f = Ufopen(sub_arg[0], "rb")))
4758         {
4759         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4760         goto EXPAND_FAILED;
4761         }
4762
4763       yield = cat_file(f, yield, sub_arg[1]);
4764       (void)fclose(f);
4765       continue;
4766       }
4767
4768     /* Handle "readsocket" to insert data from a socket, either
4769     Inet or Unix domain */
4770
4771     case EITEM_READSOCK:
4772       {
4773       int fd;
4774       int timeout = 5;
4775       int save_ptr = yield->ptr;
4776       FILE *f;
4777       uschar *arg;
4778       uschar *sub_arg[4];
4779       BOOL do_shutdown = TRUE;
4780       blob reqstr;
4781
4782       if (expand_forbid & RDO_READSOCK)
4783         {
4784         expand_string_message = US"socket insertions are not permitted";
4785         goto EXPAND_FAILED;
4786         }
4787
4788       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4789       because there may be a string for expansion on failure. */
4790
4791       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4792         {
4793         case 1: goto EXPAND_FAILED_CURLY;
4794         case 2:                             /* Won't occur: no end check */
4795         case 3: goto EXPAND_FAILED;
4796         }
4797
4798       /* Grab the request string, if any */
4799
4800       reqstr.data = sub_arg[1];
4801       reqstr.len = Ustrlen(sub_arg[1]);
4802
4803       /* Sort out timeout, if given.  The second arg is a list with the first element
4804       being a time value.  Any more are options of form "name=value".  Currently the
4805       only option recognised is "shutdown". */
4806
4807       if (sub_arg[2])
4808         {
4809         const uschar * list = sub_arg[2];
4810         uschar * item;
4811         int sep = 0;
4812
4813         item = string_nextinlist(&list, &sep, NULL, 0);
4814         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4815           {
4816           expand_string_message = string_sprintf("bad time value %s", item);
4817           goto EXPAND_FAILED;
4818           }
4819
4820         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4821           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4822             if (Ustrcmp(item + 9, US"no") == 0)
4823               do_shutdown = FALSE;
4824         }
4825       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4826
4827       /* If skipping, we don't actually do anything. Otherwise, arrange to
4828       connect to either an IP or a Unix socket. */
4829
4830       if (!skipping)
4831         {
4832         /* Handle an IP (internet) domain */
4833
4834         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4835           {
4836           int port;
4837           uschar * server_name = sub_arg[0] + 5;
4838           uschar * port_name = Ustrrchr(server_name, ':');
4839
4840           /* Sort out the port */
4841
4842           if (!port_name)
4843             {
4844             expand_string_message =
4845               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4846             goto EXPAND_FAILED;
4847             }
4848           *port_name++ = 0;           /* Terminate server name */
4849
4850           if (isdigit(*port_name))
4851             {
4852             uschar *end;
4853             port = Ustrtol(port_name, &end, 0);
4854             if (end != port_name + Ustrlen(port_name))
4855               {
4856               expand_string_message =
4857                 string_sprintf("invalid port number %s", port_name);
4858               goto EXPAND_FAILED;
4859               }
4860             }
4861           else
4862             {
4863             struct servent *service_info = getservbyname(CS port_name, "tcp");
4864             if (!service_info)
4865               {
4866               expand_string_message = string_sprintf("unknown port \"%s\"",
4867                 port_name);
4868               goto EXPAND_FAILED;
4869               }
4870             port = ntohs(service_info->s_port);
4871             }
4872
4873           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4874                   timeout, NULL, &expand_string_message, &reqstr);
4875           callout_address = NULL;
4876           if (fd < 0)
4877               goto SOCK_FAIL;
4878           reqstr.len = 0;
4879           }
4880
4881         /* Handle a Unix domain socket */
4882
4883         else
4884           {
4885           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4886           int rc;
4887
4888           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4889             {
4890             expand_string_message = string_sprintf("failed to create socket: %s",
4891               strerror(errno));
4892             goto SOCK_FAIL;
4893             }
4894
4895           sockun.sun_family = AF_UNIX;
4896           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4897             sub_arg[0]);
4898
4899           sigalrm_seen = FALSE;
4900           alarm(timeout);
4901           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4902           alarm(0);
4903           if (sigalrm_seen)
4904             {
4905             expand_string_message = US "socket connect timed out";
4906             goto SOCK_FAIL;
4907             }
4908           if (rc < 0)
4909             {
4910             expand_string_message = string_sprintf("failed to connect to socket "
4911               "%s: %s", sub_arg[0], strerror(errno));
4912             goto SOCK_FAIL;
4913             }
4914           }
4915
4916         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4917
4918         /* Allow sequencing of test actions */
4919         if (running_in_test_harness) millisleep(100);
4920
4921         /* Write the request string, if not empty or already done */
4922
4923         if (reqstr.len)
4924           {
4925           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4926             reqstr.data);
4927           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4928             {
4929             expand_string_message = string_sprintf("request write to socket "
4930               "failed: %s", strerror(errno));
4931             goto SOCK_FAIL;
4932             }
4933           }
4934
4935         /* Shut down the sending side of the socket. This helps some servers to
4936         recognise that it is their turn to do some work. Just in case some
4937         system doesn't have this function, make it conditional. */
4938
4939 #ifdef SHUT_WR
4940         if (do_shutdown) shutdown(fd, SHUT_WR);
4941 #endif
4942
4943         if (running_in_test_harness) millisleep(100);
4944
4945         /* Now we need to read from the socket, under a timeout. The function
4946         that reads a file can be used. */
4947
4948         f = fdopen(fd, "rb");
4949         sigalrm_seen = FALSE;
4950         alarm(timeout);
4951         yield = cat_file(f, yield, sub_arg[3]);
4952         alarm(0);
4953         (void)fclose(f);
4954
4955         /* After a timeout, we restore the pointer in the result, that is,
4956         make sure we add nothing from the socket. */
4957
4958         if (sigalrm_seen)
4959           {
4960           yield->ptr = save_ptr;
4961           expand_string_message = US "socket read timed out";
4962           goto SOCK_FAIL;
4963           }
4964         }
4965
4966       /* The whole thing has worked (or we were skipping). If there is a
4967       failure string following, we need to skip it. */
4968
4969       if (*s == '{')
4970         {
4971         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4972           goto EXPAND_FAILED;
4973         if (*s++ != '}')
4974           {
4975           expand_string_message = US"missing '}' closing failstring for readsocket";
4976           goto EXPAND_FAILED_CURLY;
4977           }
4978         while (isspace(*s)) s++;
4979         }
4980
4981     READSOCK_DONE:
4982       if (*s++ != '}')
4983         {
4984         expand_string_message = US"missing '}' closing readsocket";
4985         goto EXPAND_FAILED_CURLY;
4986         }
4987       continue;
4988
4989       /* Come here on failure to create socket, connect socket, write to the
4990       socket, or timeout on reading. If another substring follows, expand and
4991       use it. Otherwise, those conditions give expand errors. */
4992
4993     SOCK_FAIL:
4994       if (*s != '{') goto EXPAND_FAILED;
4995       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4996       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4997         goto EXPAND_FAILED;
4998       yield = string_cat(yield, arg);
4999       if (*s++ != '}')
5000         {
5001         expand_string_message = US"missing '}' closing failstring for readsocket";
5002         goto EXPAND_FAILED_CURLY;
5003         }
5004       while (isspace(*s)) s++;
5005       goto READSOCK_DONE;
5006       }
5007
5008     /* Handle "run" to execute a program. */
5009
5010     case EITEM_RUN:
5011       {
5012       FILE *f;
5013       uschar *arg;
5014       const uschar **argv;
5015       pid_t pid;
5016       int fd_in, fd_out;
5017
5018       if ((expand_forbid & RDO_RUN) != 0)
5019         {
5020         expand_string_message = US"running a command is not permitted";
5021         goto EXPAND_FAILED;
5022         }
5023
5024       while (isspace(*s)) s++;
5025       if (*s != '{')
5026         {
5027         expand_string_message = US"missing '{' for command arg of run";
5028         goto EXPAND_FAILED_CURLY;
5029         }
5030       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5031       if (arg == NULL) goto EXPAND_FAILED;
5032       while (isspace(*s)) s++;
5033       if (*s++ != '}')
5034         {
5035         expand_string_message = US"missing '}' closing command arg of run";
5036         goto EXPAND_FAILED_CURLY;
5037         }
5038
5039       if (skipping)   /* Just pretend it worked when we're skipping */
5040         {
5041         runrc = 0;
5042         lookup_value = NULL;
5043         }
5044       else
5045         {
5046         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5047             arg,                                /* raw command */
5048             FALSE,                              /* don't expand the arguments */
5049             0,                                  /* not relevant when... */
5050             NULL,                               /* no transporting address */
5051             US"${run} expansion",               /* for error messages */
5052             &expand_string_message))            /* where to put error message */
5053           goto EXPAND_FAILED;
5054
5055         /* Create the child process, making it a group leader. */
5056
5057         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5058           {
5059           expand_string_message =
5060             string_sprintf("couldn't create child process: %s", strerror(errno));
5061           goto EXPAND_FAILED;
5062           }
5063
5064         /* Nothing is written to the standard input. */
5065
5066         (void)close(fd_in);
5067
5068         /* Read the pipe to get the command's output into $value (which is kept
5069         in lookup_value). Read during execution, so that if the output exceeds
5070         the OS pipe buffer limit, we don't block forever. Remember to not release
5071         memory just allocated for $value. */
5072
5073         resetok = FALSE;
5074         f = fdopen(fd_out, "rb");
5075         sigalrm_seen = FALSE;
5076         alarm(60);
5077         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5078         alarm(0);
5079         (void)fclose(f);
5080
5081         /* Wait for the process to finish, applying the timeout, and inspect its
5082         return code for serious disasters. Simple non-zero returns are passed on.
5083         */
5084
5085         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5086           {
5087           if (sigalrm_seen || runrc == -256)
5088             {
5089             expand_string_message = string_sprintf("command timed out");
5090             killpg(pid, SIGKILL);       /* Kill the whole process group */
5091             }
5092
5093           else if (runrc == -257)
5094             expand_string_message = string_sprintf("wait() failed: %s",
5095               strerror(errno));
5096
5097           else
5098             expand_string_message = string_sprintf("command killed by signal %d",
5099               -runrc);
5100
5101           goto EXPAND_FAILED;
5102           }
5103         }
5104
5105       /* Process the yes/no strings; $value may be useful in both cases */
5106
5107       switch(process_yesno(
5108                skipping,                     /* were previously skipping */
5109                runrc == 0,                   /* success/failure indicator */
5110                lookup_value,                 /* value to reset for string2 */
5111                &s,                           /* input pointer */
5112                &yield,                       /* output pointer */
5113                US"run",                      /* condition type */
5114                &resetok))
5115         {
5116         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5117         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5118         }
5119
5120       continue;
5121       }
5122
5123     /* Handle character translation for "tr" */
5124
5125     case EITEM_TR:
5126       {
5127       int oldptr = yield->ptr;
5128       int o2m;
5129       uschar *sub[3];
5130
5131       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5132         {
5133         case 1: goto EXPAND_FAILED_CURLY;
5134         case 2:
5135         case 3: goto EXPAND_FAILED;
5136         }
5137
5138       yield = string_cat(yield, sub[0]);
5139       o2m = Ustrlen(sub[2]) - 1;
5140
5141       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5142         {
5143         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5144         if (m != NULL)
5145           {
5146           int o = m - sub[1];
5147           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5148           }
5149         }
5150
5151       continue;
5152       }
5153
5154     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5155     expanded arguments. */
5156
5157     case EITEM_HASH:
5158     case EITEM_LENGTH:
5159     case EITEM_NHASH:
5160     case EITEM_SUBSTR:
5161       {
5162       int i;
5163       int len;
5164       uschar *ret;
5165       int val[2] = { 0, -1 };
5166       uschar *sub[3];
5167
5168       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5169       Ensure that sub[2] is set in the ${length } case. */
5170
5171       sub[2] = NULL;
5172       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5173              TRUE, name, &resetok))
5174         {
5175         case 1: goto EXPAND_FAILED_CURLY;
5176         case 2:
5177         case 3: goto EXPAND_FAILED;
5178         }
5179
5180       /* Juggle the arguments if there are only two of them: always move the
5181       string to the last position and make ${length{n}{str}} equivalent to
5182       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5183
5184       if (sub[2] == NULL)
5185         {
5186         sub[2] = sub[1];
5187         sub[1] = NULL;
5188         if (item_type == EITEM_LENGTH)
5189           {
5190           sub[1] = sub[0];
5191           sub[0] = NULL;
5192           }
5193         }
5194
5195       for (i = 0; i < 2; i++)
5196         {
5197         if (sub[i] == NULL) continue;
5198         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5199         if (*ret != 0 || (i != 0 && val[i] < 0))
5200           {
5201           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5202             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5203           goto EXPAND_FAILED;
5204           }
5205         }
5206
5207       ret =
5208         (item_type == EITEM_HASH)?
5209           compute_hash(sub[2], val[0], val[1], &len) :
5210         (item_type == EITEM_NHASH)?
5211           compute_nhash(sub[2], val[0], val[1], &len) :
5212           extract_substr(sub[2], val[0], val[1], &len);
5213
5214       if (ret == NULL) goto EXPAND_FAILED;
5215       yield = string_catn(yield, ret, len);
5216       continue;
5217       }
5218
5219     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5220     This code originally contributed by Steve Haslam. It currently supports
5221     the use of MD5 and SHA-1 hashes.
5222
5223     We need some workspace that is large enough to handle all the supported
5224     hash types. Use macros to set the sizes rather than be too elaborate. */
5225
5226     #define MAX_HASHLEN      20
5227     #define MAX_HASHBLOCKLEN 64
5228
5229     case EITEM_HMAC:
5230       {
5231       uschar *sub[3];
5232       md5 md5_base;
5233       hctx sha1_ctx;
5234       void *use_base;
5235       int type, i;
5236       int hashlen;      /* Number of octets for the hash algorithm's output */
5237       int hashblocklen; /* Number of octets the hash algorithm processes */
5238       uschar *keyptr, *p;
5239       unsigned int keylen;
5240
5241       uschar keyhash[MAX_HASHLEN];
5242       uschar innerhash[MAX_HASHLEN];
5243       uschar finalhash[MAX_HASHLEN];
5244       uschar finalhash_hex[2*MAX_HASHLEN];
5245       uschar innerkey[MAX_HASHBLOCKLEN];
5246       uschar outerkey[MAX_HASHBLOCKLEN];
5247
5248       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5249         {
5250         case 1: goto EXPAND_FAILED_CURLY;
5251         case 2:
5252         case 3: goto EXPAND_FAILED;
5253         }
5254
5255       if (!skipping)
5256         {
5257         if (Ustrcmp(sub[0], "md5") == 0)
5258           {
5259           type = HMAC_MD5;
5260           use_base = &md5_base;
5261           hashlen = 16;
5262           hashblocklen = 64;
5263           }
5264         else if (Ustrcmp(sub[0], "sha1") == 0)
5265           {
5266           type = HMAC_SHA1;
5267           use_base = &sha1_ctx;
5268           hashlen = 20;
5269           hashblocklen = 64;
5270           }
5271         else
5272           {
5273           expand_string_message =
5274             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5275           goto EXPAND_FAILED;
5276           }
5277
5278         keyptr = sub[1];
5279         keylen = Ustrlen(keyptr);
5280
5281         /* If the key is longer than the hash block length, then hash the key
5282         first */
5283
5284         if (keylen > hashblocklen)
5285           {
5286           chash_start(type, use_base);
5287           chash_end(type, use_base, keyptr, keylen, keyhash);
5288           keyptr = keyhash;
5289           keylen = hashlen;
5290           }
5291
5292         /* Now make the inner and outer key values */
5293
5294         memset(innerkey, 0x36, hashblocklen);
5295         memset(outerkey, 0x5c, hashblocklen);
5296
5297         for (i = 0; i < keylen; i++)
5298           {
5299           innerkey[i] ^= keyptr[i];
5300           outerkey[i] ^= keyptr[i];
5301           }
5302
5303         /* Now do the hashes */
5304
5305         chash_start(type, use_base);
5306         chash_mid(type, use_base, innerkey);
5307         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5308
5309         chash_start(type, use_base);
5310         chash_mid(type, use_base, outerkey);
5311         chash_end(type, use_base, innerhash, hashlen, finalhash);
5312
5313         /* Encode the final hash as a hex string */
5314
5315         p = finalhash_hex;
5316         for (i = 0; i < hashlen; i++)
5317           {
5318           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5319           *p++ = hex_digits[finalhash[i] & 0x0f];
5320           }
5321
5322         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5323           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5324
5325         yield = string_catn(yield, finalhash_hex, hashlen*2);
5326         }
5327       continue;
5328       }
5329
5330     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5331     We have to save the numerical variables and restore them afterwards. */
5332
5333     case EITEM_SG:
5334       {
5335       const pcre *re;
5336       int moffset, moffsetextra, slen;
5337       int roffset;
5338       int emptyopt;
5339       const uschar *rerror;
5340       uschar *subject;
5341       uschar *sub[3];
5342       int save_expand_nmax =
5343         save_expand_strings(save_expand_nstring, save_expand_nlength);
5344
5345       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5346         {
5347         case 1: goto EXPAND_FAILED_CURLY;
5348         case 2:
5349         case 3: goto EXPAND_FAILED;
5350         }
5351
5352       /* Compile the regular expression */
5353
5354       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5355         NULL);
5356
5357       if (re == NULL)
5358         {
5359         expand_string_message = string_sprintf("regular expression error in "
5360           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5361         goto EXPAND_FAILED;
5362         }
5363
5364       /* Now run a loop to do the substitutions as often as necessary. It ends
5365       when there are no more matches. Take care over matches of the null string;
5366       do the same thing as Perl does. */
5367
5368       subject = sub[0];
5369       slen = Ustrlen(sub[0]);
5370       moffset = moffsetextra = 0;
5371       emptyopt = 0;
5372
5373       for (;;)
5374         {
5375         int ovector[3*(EXPAND_MAXN+1)];
5376         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5377           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5378         int nn;
5379         uschar *insert;
5380
5381         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5382         is not necessarily the end. We want to repeat the match from one
5383         character further along, but leaving the basic offset the same (for
5384         copying below). We can't be at the end of the string - that was checked
5385         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5386         finished; copy the remaining string and end the loop. */
5387
5388         if (n < 0)
5389           {
5390           if (emptyopt != 0)
5391             {
5392             moffsetextra = 1;
5393             emptyopt = 0;
5394             continue;
5395             }
5396           yield = string_catn(yield, subject+moffset, slen-moffset);
5397           break;
5398           }
5399
5400         /* Match - set up for expanding the replacement. */
5401
5402         if (n == 0) n = EXPAND_MAXN + 1;
5403         expand_nmax = 0;
5404         for (nn = 0; nn < n*2; nn += 2)
5405           {
5406           expand_nstring[expand_nmax] = subject + ovector[nn];
5407           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5408           }
5409         expand_nmax--;
5410
5411         /* Copy the characters before the match, plus the expanded insertion. */
5412
5413         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5414         insert = expand_string(sub[2]);
5415         if (insert == NULL) goto EXPAND_FAILED;
5416         yield = string_cat(yield, insert);
5417
5418         moffset = ovector[1];
5419         moffsetextra = 0;
5420         emptyopt = 0;
5421
5422         /* If we have matched an empty string, first check to see if we are at
5423         the end of the subject. If so, the loop is over. Otherwise, mimic
5424         what Perl's /g options does. This turns out to be rather cunning. First
5425         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5426         string at the same point. If this fails (picked up above) we advance to
5427         the next character. */
5428
5429         if (ovector[0] == ovector[1])
5430           {
5431           if (ovector[0] == slen) break;
5432           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5433           }
5434         }
5435
5436       /* All done - restore numerical variables. */
5437
5438       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5439         save_expand_nlength);
5440       continue;
5441       }
5442
5443     /* Handle keyed and numbered substring extraction. If the first argument
5444     consists entirely of digits, then a numerical extraction is assumed. */
5445
5446     case EITEM_EXTRACT:
5447       {
5448       int i;
5449       int j;
5450       int field_number = 1;
5451       BOOL field_number_set = FALSE;
5452       uschar *save_lookup_value = lookup_value;
5453       uschar *sub[3];
5454       int save_expand_nmax =
5455         save_expand_strings(save_expand_nstring, save_expand_nlength);
5456
5457       /* While skipping we cannot rely on the data for expansions being
5458       available (eg. $item) hence cannot decide on numeric vs. keyed.
5459       Read a maximum of 5 arguments (including the yes/no) */
5460
5461       if (skipping)
5462         {
5463         while (isspace(*s)) s++;
5464         for (j = 5; j > 0 && *s == '{'; j--)
5465           {
5466           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5467             goto EXPAND_FAILED;                                 /*{*/
5468           if (*s++ != '}')
5469             {
5470             expand_string_message = US"missing '{' for arg of extract";
5471             goto EXPAND_FAILED_CURLY;
5472             }
5473           while (isspace(*s)) s++;
5474           }
5475         if (  Ustrncmp(s, "fail", 4) == 0
5476            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5477            )
5478           {
5479           s += 4;
5480           while (isspace(*s)) s++;
5481           }
5482         if (*s != '}')
5483           {
5484           expand_string_message = US"missing '}' closing extract";
5485           goto EXPAND_FAILED_CURLY;
5486           }
5487         }
5488
5489       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5490         {
5491         while (isspace(*s)) s++;
5492         if (*s == '{')                                          /*}*/
5493           {
5494           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5495           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5496           if (*s++ != '}')
5497             {
5498             expand_string_message = string_sprintf(
5499               "missing '}' closing arg %d of extract", i+1);
5500             goto EXPAND_FAILED_CURLY;
5501             }
5502
5503           /* After removal of leading and trailing white space, the first
5504           argument must not be empty; if it consists entirely of digits
5505           (optionally preceded by a minus sign), this is a numerical
5506           extraction, and we expect 3 arguments. */
5507
5508           if (i == 0)
5509             {
5510             int len;
5511             int x = 0;
5512             uschar *p = sub[0];
5513
5514             while (isspace(*p)) p++;
5515             sub[0] = p;
5516
5517             len = Ustrlen(p);
5518             while (len > 0 && isspace(p[len-1])) len--;
5519             p[len] = 0;
5520
5521             if (*p == 0)
5522               {
5523               expand_string_message = US"first argument of \"extract\" must "
5524                 "not be empty";
5525               goto EXPAND_FAILED;
5526               }
5527
5528             if (*p == '-')
5529               {
5530               field_number = -1;
5531               p++;
5532               }
5533             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5534             if (*p == 0)
5535               {
5536               field_number *= x;
5537               j = 3;               /* Need 3 args */
5538               field_number_set = TRUE;
5539               }
5540             }
5541           }
5542         else
5543           {
5544           expand_string_message = string_sprintf(
5545             "missing '{' for arg %d of extract", i+1);
5546           goto EXPAND_FAILED_CURLY;
5547           }
5548         }
5549
5550       /* Extract either the numbered or the keyed substring into $value. If
5551       skipping, just pretend the extraction failed. */
5552
5553       lookup_value = skipping? NULL : field_number_set?
5554         expand_gettokened(field_number, sub[1], sub[2]) :
5555         expand_getkeyed(sub[0], sub[1]);
5556
5557       /* If no string follows, $value gets substituted; otherwise there can
5558       be yes/no strings, as for lookup or if. */
5559
5560       switch(process_yesno(
5561                skipping,                     /* were previously skipping */
5562                lookup_value != NULL,         /* success/failure indicator */
5563                save_lookup_value,            /* value to reset for string2 */
5564                &s,                           /* input pointer */
5565                &yield,                       /* output pointer */
5566                US"extract",                  /* condition type */
5567                &resetok))
5568         {
5569         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5570         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5571         }
5572
5573       /* All done - restore numerical variables. */
5574
5575       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5576         save_expand_nlength);
5577
5578       continue;
5579       }
5580
5581     /* return the Nth item from a list */
5582
5583     case EITEM_LISTEXTRACT:
5584       {
5585       int i;
5586       int field_number = 1;
5587       uschar *save_lookup_value = lookup_value;
5588       uschar *sub[2];
5589       int save_expand_nmax =
5590         save_expand_strings(save_expand_nstring, save_expand_nlength);
5591
5592       /* Read the field & list arguments */
5593
5594       for (i = 0; i < 2; i++)
5595         {
5596         while (isspace(*s)) s++;
5597         if (*s != '{')                                  /*}*/
5598           {
5599           expand_string_message = string_sprintf(
5600             "missing '{' for arg %d of listextract", i+1);
5601           goto EXPAND_FAILED_CURLY;
5602           }
5603
5604         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5605         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5606         if (*s++ != '}')
5607           {
5608           expand_string_message = string_sprintf(
5609             "missing '}' closing arg %d of listextract", i+1);
5610           goto EXPAND_FAILED_CURLY;
5611           }
5612
5613         /* After removal of leading and trailing white space, the first
5614         argument must be numeric and nonempty. */
5615
5616         if (i == 0)
5617           {
5618           int len;
5619           int x = 0;
5620           uschar *p = sub[0];
5621
5622           while (isspace(*p)) p++;
5623           sub[0] = p;
5624
5625           len = Ustrlen(p);
5626           while (len > 0 && isspace(p[len-1])) len--;
5627           p[len] = 0;
5628
5629           if (!*p && !skipping)
5630             {
5631             expand_string_message = US"first argument of \"listextract\" must "
5632               "not be empty";
5633             goto EXPAND_FAILED;
5634             }
5635
5636           if (*p == '-')
5637             {
5638             field_number = -1;
5639             p++;
5640             }
5641           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5642           if (*p)
5643             {
5644             expand_string_message = US"first argument of \"listextract\" must "
5645               "be numeric";
5646             goto EXPAND_FAILED;
5647             }
5648           field_number *= x;
5649           }
5650         }
5651
5652       /* Extract the numbered element into $value. If
5653       skipping, just pretend the extraction failed. */
5654
5655       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5656
5657       /* If no string follows, $value gets substituted; otherwise there can
5658       be yes/no strings, as for lookup or if. */
5659
5660       switch(process_yesno(
5661                skipping,                     /* were previously skipping */
5662                lookup_value != NULL,         /* success/failure indicator */
5663                save_lookup_value,            /* value to reset for string2 */
5664                &s,                           /* input pointer */
5665                &yield,                       /* output pointer */
5666                US"listextract",              /* condition type */
5667                &resetok))
5668         {
5669         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5670         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5671         }
5672
5673       /* All done - restore numerical variables. */
5674
5675       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5676         save_expand_nlength);
5677
5678       continue;
5679       }
5680
5681 #ifdef SUPPORT_TLS
5682     case EITEM_CERTEXTRACT:
5683       {
5684       uschar *save_lookup_value = lookup_value;
5685       uschar *sub[2];
5686       int save_expand_nmax =
5687         save_expand_strings(save_expand_nstring, save_expand_nlength);
5688
5689       /* Read the field argument */
5690       while (isspace(*s)) s++;
5691       if (*s != '{')                                    /*}*/
5692         {
5693         expand_string_message = US"missing '{' for field arg of certextract";
5694         goto EXPAND_FAILED_CURLY;
5695         }
5696       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5697       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5698       if (*s++ != '}')
5699         {
5700         expand_string_message = US"missing '}' closing field arg of certextract";
5701         goto EXPAND_FAILED_CURLY;
5702         }
5703       /* strip spaces fore & aft */
5704       {
5705       int len;
5706       uschar *p = sub[0];
5707
5708       while (isspace(*p)) p++;
5709       sub[0] = p;
5710
5711       len = Ustrlen(p);
5712       while (len > 0 && isspace(p[len-1])) len--;
5713       p[len] = 0;
5714       }
5715
5716       /* inspect the cert argument */
5717       while (isspace(*s)) s++;
5718       if (*s != '{')                                    /*}*/
5719         {
5720         expand_string_message = US"missing '{' for cert variable arg of certextract";
5721         goto EXPAND_FAILED_CURLY;
5722         }
5723       if (*++s != '$')
5724         {
5725         expand_string_message = US"second argument of \"certextract\" must "
5726           "be a certificate variable";
5727         goto EXPAND_FAILED;
5728         }
5729       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5730       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5731       if (*s++ != '}')
5732         {
5733         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5734         goto EXPAND_FAILED_CURLY;
5735         }
5736
5737       if (skipping)
5738         lookup_value = NULL;
5739       else
5740         {
5741         lookup_value = expand_getcertele(sub[0], sub[1]);
5742         if (*expand_string_message) goto EXPAND_FAILED;
5743         }
5744       switch(process_yesno(
5745                skipping,                     /* were previously skipping */
5746                lookup_value != NULL,         /* success/failure indicator */
5747                save_lookup_value,            /* value to reset for string2 */
5748                &s,                           /* input pointer */
5749                &yield,                       /* output pointer */
5750                US"certextract",              /* condition type */
5751                &resetok))
5752         {
5753         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5754         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5755         }
5756
5757       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5758         save_expand_nlength);
5759       continue;
5760       }
5761 #endif  /*SUPPORT_TLS*/
5762
5763     /* Handle list operations */
5764
5765     case EITEM_FILTER:
5766     case EITEM_MAP:
5767     case EITEM_REDUCE:
5768       {
5769       int sep = 0;
5770       int save_ptr = yield->ptr;
5771       uschar outsep[2] = { '\0', '\0' };
5772       const uschar *list, *expr, *temp;
5773       uschar *save_iterate_item = iterate_item;
5774       uschar *save_lookup_value = lookup_value;
5775
5776       while (isspace(*s)) s++;
5777       if (*s++ != '{')
5778         {
5779         expand_string_message =
5780           string_sprintf("missing '{' for first arg of %s", name);
5781         goto EXPAND_FAILED_CURLY;
5782         }
5783
5784       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5785       if (list == NULL) goto EXPAND_FAILED;
5786       if (*s++ != '}')
5787         {
5788         expand_string_message =
5789           string_sprintf("missing '}' closing first arg of %s", name);
5790         goto EXPAND_FAILED_CURLY;
5791         }
5792
5793       if (item_type == EITEM_REDUCE)
5794         {
5795         uschar * t;
5796         while (isspace(*s)) s++;
5797         if (*s++ != '{')
5798           {
5799           expand_string_message = US"missing '{' for second arg of reduce";
5800           goto EXPAND_FAILED_CURLY;
5801           }
5802         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5803         if (!t) goto EXPAND_FAILED;
5804         lookup_value = t;
5805         if (*s++ != '}')
5806           {
5807           expand_string_message = US"missing '}' closing second arg of reduce";
5808           goto EXPAND_FAILED_CURLY;
5809           }
5810         }
5811
5812       while (isspace(*s)) s++;
5813       if (*s++ != '{')
5814         {
5815         expand_string_message =
5816           string_sprintf("missing '{' for last arg of %s", name);
5817         goto EXPAND_FAILED_CURLY;
5818         }
5819
5820       expr = s;
5821
5822       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5823       if scanning a "false" part). This allows us to find the end of the
5824       condition, because if the list is empty, we won't actually evaluate the
5825       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5826       the normal internal expansion function. */
5827
5828       if (item_type == EITEM_FILTER)
5829         {
5830         temp = eval_condition(expr, &resetok, NULL);
5831         if (temp != NULL) s = temp;
5832         }
5833       else
5834         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5835
5836       if (temp == NULL)
5837         {
5838         expand_string_message = string_sprintf("%s inside \"%s\" item",
5839           expand_string_message, name);
5840         goto EXPAND_FAILED;
5841         }
5842
5843       while (isspace(*s)) s++;
5844       if (*s++ != '}')
5845         {                                               /*{*/
5846         expand_string_message = string_sprintf("missing } at end of condition "
5847           "or expression inside \"%s\"; could be an unquoted } in the content",
5848           name);
5849         goto EXPAND_FAILED;
5850         }
5851
5852       while (isspace(*s)) s++;                          /*{*/
5853       if (*s++ != '}')
5854         {                                               /*{*/
5855         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5856           name);
5857         goto EXPAND_FAILED;
5858         }
5859
5860       /* If we are skipping, we can now just move on to the next item. When
5861       processing for real, we perform the iteration. */
5862
5863       if (skipping) continue;
5864       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5865         {
5866         *outsep = (uschar)sep;      /* Separator as a string */
5867
5868         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5869                           name, iterate_item, lookup_value);
5870
5871         if (item_type == EITEM_FILTER)
5872           {
5873           BOOL condresult;
5874           if (eval_condition(expr, &resetok, &condresult) == NULL)
5875             {
5876             iterate_item = save_iterate_item;
5877             lookup_value = save_lookup_value;
5878             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5879               expand_string_message, name);
5880             goto EXPAND_FAILED;
5881             }
5882           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5883             condresult? "true":"false");
5884           if (condresult)
5885             temp = iterate_item;    /* TRUE => include this item */
5886           else
5887             continue;               /* FALSE => skip this item */
5888           }
5889
5890         /* EITEM_MAP and EITEM_REDUCE */
5891
5892         else
5893           {
5894           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5895           temp = t;
5896           if (temp == NULL)
5897             {
5898             iterate_item = save_iterate_item;
5899             expand_string_message = string_sprintf("%s inside \"%s\" item",
5900               expand_string_message, name);
5901             goto EXPAND_FAILED;
5902             }
5903           if (item_type == EITEM_REDUCE)
5904             {
5905             lookup_value = t;         /* Update the value of $value */
5906             continue;                 /* and continue the iteration */
5907             }
5908           }
5909
5910         /* We reach here for FILTER if the condition is true, always for MAP,
5911         and never for REDUCE. The value in "temp" is to be added to the output
5912         list that is being created, ensuring that any occurrences of the
5913         separator character are doubled. Unless we are dealing with the first
5914         item of the output list, add in a space if the new item begins with the
5915         separator character, or is an empty string. */
5916
5917         if (yield->ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5918           yield = string_catn(yield, US" ", 1);
5919
5920         /* Add the string in "temp" to the output list that we are building,
5921         This is done in chunks by searching for the separator character. */
5922
5923         for (;;)
5924           {
5925           size_t seglen = Ustrcspn(temp, outsep);
5926
5927           yield = string_catn(yield, temp, seglen + 1);
5928
5929           /* If we got to the end of the string we output one character
5930           too many; backup and end the loop. Otherwise arrange to double the
5931           separator. */
5932
5933           if (temp[seglen] == '\0') { yield->ptr--; break; }
5934           yield = string_catn(yield, outsep, 1);
5935           temp += seglen + 1;
5936           }
5937
5938         /* Output a separator after the string: we will remove the redundant
5939         final one at the end. */
5940
5941         yield = string_catn(yield, outsep, 1);
5942         }   /* End of iteration over the list loop */
5943
5944       /* REDUCE has generated no output above: output the final value of
5945       $value. */
5946
5947       if (item_type == EITEM_REDUCE)
5948         {
5949         yield = string_cat(yield, lookup_value);
5950         lookup_value = save_lookup_value;  /* Restore $value */
5951         }
5952
5953       /* FILTER and MAP generate lists: if they have generated anything, remove
5954       the redundant final separator. Even though an empty item at the end of a
5955       list does not count, this is tidier. */
5956
5957       else if (yield->ptr != save_ptr) yield->ptr--;
5958
5959       /* Restore preserved $item */
5960
5961       iterate_item = save_iterate_item;
5962       continue;
5963       }
5964
5965     case EITEM_SORT:
5966       {
5967       int sep = 0;
5968       const uschar *srclist, *cmp, *xtract;
5969       uschar *srcitem;
5970       const uschar *dstlist = NULL, *dstkeylist = NULL;
5971       uschar * tmp;
5972       uschar *save_iterate_item = iterate_item;
5973
5974       while (isspace(*s)) s++;
5975       if (*s++ != '{')
5976         {
5977         expand_string_message = US"missing '{' for list arg of sort";
5978         goto EXPAND_FAILED_CURLY;
5979         }
5980
5981       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5982       if (!srclist) goto EXPAND_FAILED;
5983       if (*s++ != '}')
5984         {
5985         expand_string_message = US"missing '}' closing list arg of sort";
5986         goto EXPAND_FAILED_CURLY;
5987         }
5988
5989       while (isspace(*s)) s++;
5990       if (*s++ != '{')
5991         {
5992         expand_string_message = US"missing '{' for comparator arg of sort";
5993         goto EXPAND_FAILED_CURLY;
5994         }
5995
5996       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5997       if (!cmp) goto EXPAND_FAILED;
5998       if (*s++ != '}')
5999         {
6000         expand_string_message = US"missing '}' closing comparator arg of sort";
6001         goto EXPAND_FAILED_CURLY;
6002         }
6003
6004       while (isspace(*s)) s++;
6005       if (*s++ != '{')
6006         {
6007         expand_string_message = US"missing '{' for extractor arg of sort";
6008         goto EXPAND_FAILED_CURLY;
6009         }
6010
6011       xtract = s;
6012       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
6013       if (!tmp) goto EXPAND_FAILED;
6014       xtract = string_copyn(xtract, s - xtract);
6015
6016       if (*s++ != '}')
6017         {
6018         expand_string_message = US"missing '}' closing extractor arg of sort";
6019         goto EXPAND_FAILED_CURLY;
6020         }
6021                                                         /*{*/
6022       if (*s++ != '}')
6023         {                                               /*{*/
6024         expand_string_message = US"missing } at end of \"sort\"";
6025         goto EXPAND_FAILED;
6026         }
6027
6028       if (skipping) continue;
6029
6030       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
6031         {
6032         uschar * dstitem;
6033         gstring * newlist = NULL;
6034         gstring * newkeylist = NULL;
6035         uschar * srcfield;
6036
6037         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6038
6039         /* extract field for comparisons */
6040         iterate_item = srcitem;
6041         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6042                                           TRUE, &resetok))
6043            || !*srcfield)
6044           {
6045           expand_string_message = string_sprintf(
6046               "field-extract in sort: \"%s\"", xtract);
6047           goto EXPAND_FAILED;
6048           }
6049
6050         /* Insertion sort */
6051
6052         /* copy output list until new-item < list-item */
6053         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6054           {
6055           uschar * dstfield;
6056           uschar * expr;
6057           BOOL before;
6058
6059           /* field for comparison */
6060           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6061             goto sort_mismatch;
6062
6063           /* build and run condition string */
6064           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6065
6066           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6067           if (!eval_condition(expr, &resetok, &before))
6068             {
6069             expand_string_message = string_sprintf("comparison in sort: %s",
6070                 expr);
6071             goto EXPAND_FAILED;
6072             }
6073
6074           if (before)
6075             {
6076             /* New-item sorts before this dst-item.  Append new-item,
6077             then dst-item, then remainder of dst list. */
6078
6079             newlist = string_append_listele(newlist, sep, srcitem);
6080             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6081             srcitem = NULL;
6082
6083             newlist = string_append_listele(newlist, sep, dstitem);
6084             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6085
6086             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6087               {
6088               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6089                 goto sort_mismatch;
6090               newlist = string_append_listele(newlist, sep, dstitem);
6091               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6092               }
6093
6094             break;
6095             }
6096
6097           newlist = string_append_listele(newlist, sep, dstitem);
6098           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6099           }
6100
6101         /* If we ran out of dstlist without consuming srcitem, append it */
6102         if (srcitem)
6103           {
6104           newlist = string_append_listele(newlist, sep, srcitem);
6105           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6106           }
6107
6108         dstlist = newlist->s;
6109         dstkeylist = newkeylist->s;
6110
6111         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6112         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6113         }
6114
6115       if (dstlist)
6116         yield = string_cat(yield, dstlist);
6117
6118       /* Restore preserved $item */
6119       iterate_item = save_iterate_item;
6120       continue;
6121
6122       sort_mismatch:
6123         expand_string_message = US"Internal error in sort (list mismatch)";
6124         goto EXPAND_FAILED;
6125       }
6126
6127
6128     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6129     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6130     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6131     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6132
6133     #define EXPAND_DLFUNC_MAX_ARGS 8
6134
6135     case EITEM_DLFUNC:
6136 #ifndef EXPAND_DLFUNC
6137       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6138         "is not included in this binary";
6139       goto EXPAND_FAILED;
6140
6141 #else   /* EXPAND_DLFUNC */
6142       {
6143       tree_node *t;
6144       exim_dlfunc_t *func;
6145       uschar *result;
6146       int status, argc;
6147       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6148
6149       if ((expand_forbid & RDO_DLFUNC) != 0)
6150         {
6151         expand_string_message =
6152           US"dynamically-loaded functions are not permitted";
6153         goto EXPAND_FAILED;
6154         }
6155
6156       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6157            TRUE, US"dlfunc", &resetok))
6158         {
6159         case 1: goto EXPAND_FAILED_CURLY;
6160         case 2:
6161         case 3: goto EXPAND_FAILED;
6162         }
6163
6164       /* If skipping, we don't actually do anything */
6165
6166       if (skipping) continue;
6167
6168       /* Look up the dynamically loaded object handle in the tree. If it isn't
6169       found, dlopen() the file and put the handle in the tree for next time. */
6170
6171       t = tree_search(dlobj_anchor, argv[0]);
6172       if (t == NULL)
6173         {
6174         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6175         if (handle == NULL)
6176           {
6177           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6178             argv[0], dlerror());
6179           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6180           goto EXPAND_FAILED;
6181           }
6182         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6183         Ustrcpy(t->name, argv[0]);
6184         t->data.ptr = handle;
6185         (void)tree_insertnode(&dlobj_anchor, t);
6186         }
6187
6188       /* Having obtained the dynamically loaded object handle, look up the
6189       function pointer. */
6190
6191       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6192       if (func == NULL)
6193         {
6194         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6195           "%s", argv[1], argv[0], dlerror());
6196         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6197         goto EXPAND_FAILED;
6198         }
6199
6200       /* Call the function and work out what to do with the result. If it
6201       returns OK, we have a replacement string; if it returns DEFER then
6202       expansion has failed in a non-forced manner; if it returns FAIL then
6203       failure was forced; if it returns ERROR or any other value there's a
6204       problem, so panic slightly. In any case, assume that the function has
6205       side-effects on the store that must be preserved. */
6206
6207       resetok = FALSE;
6208       result = NULL;
6209       for (argc = 0; argv[argc] != NULL; argc++);
6210       status = func(&result, argc - 2, &argv[2]);
6211       if(status == OK)
6212         {
6213         if (result == NULL) result = US"";
6214         yield = string_cat(yield, result);
6215         continue;
6216         }
6217       else
6218         {
6219         expand_string_message = result == NULL ? US"(no message)" : result;
6220         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6221           else if(status != FAIL)
6222             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6223               argv[0], argv[1], status, expand_string_message);
6224         goto EXPAND_FAILED;
6225         }
6226       }
6227 #endif /* EXPAND_DLFUNC */
6228
6229     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6230       {
6231       uschar * key;
6232       uschar *save_lookup_value = lookup_value;
6233
6234       while (isspace(*s)) s++;
6235       if (*s != '{')                                    /*}*/
6236         goto EXPAND_FAILED;
6237
6238       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6239       if (!key) goto EXPAND_FAILED;                     /*{*/
6240       if (*s++ != '}')
6241         {
6242         expand_string_message = US"missing '{' for name arg of env";
6243         goto EXPAND_FAILED_CURLY;
6244         }
6245
6246       lookup_value = US getenv(CS key);
6247
6248       switch(process_yesno(
6249                skipping,                     /* were previously skipping */
6250                lookup_value != NULL,         /* success/failure indicator */
6251                save_lookup_value,            /* value to reset for string2 */
6252                &s,                           /* input pointer */
6253                &yield,                       /* output pointer */
6254                US"env",                      /* condition type */
6255                &resetok))
6256         {
6257         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6258         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6259         }
6260       continue;
6261       }
6262     }   /* EITEM_* switch */
6263
6264   /* Control reaches here if the name is not recognized as one of the more
6265   complicated expansion items. Check for the "operator" syntax (name terminated
6266   by a colon). Some of the operators have arguments, separated by _ from the
6267   name. */
6268
6269   if (*s == ':')
6270     {
6271     int c;
6272     uschar *arg = NULL;
6273     uschar *sub;
6274     var_entry *vp = NULL;
6275
6276     /* Owing to an historical mis-design, an underscore may be part of the
6277     operator name, or it may introduce arguments.  We therefore first scan the
6278     table of names that contain underscores. If there is no match, we cut off
6279     the arguments and then scan the main table. */
6280
6281     if ((c = chop_match(name, op_table_underscore,
6282                         nelem(op_table_underscore))) < 0)
6283       {
6284       arg = Ustrchr(name, '_');
6285       if (arg != NULL) *arg = 0;
6286       c = chop_match(name, op_table_main, nelem(op_table_main));
6287       if (c >= 0) c += nelem(op_table_underscore);
6288       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6289       }
6290
6291     /* Deal specially with operators that might take a certificate variable
6292     as we do not want to do the usual expansion. For most, expand the string.*/
6293     switch(c)
6294       {
6295 #ifdef SUPPORT_TLS
6296       case EOP_MD5:
6297       case EOP_SHA1:
6298       case EOP_SHA256:
6299       case EOP_BASE64:
6300         if (s[1] == '$')
6301           {
6302           const uschar * s1 = s;
6303           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6304                   FALSE, &resetok);
6305           if (!sub)       goto EXPAND_FAILED;           /*{*/
6306           if (*s1 != '}')
6307             {
6308             expand_string_message =
6309               string_sprintf("missing '}' closing cert arg of %s", name);
6310             goto EXPAND_FAILED_CURLY;
6311             }
6312           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6313             {
6314             s = s1+1;
6315             break;
6316             }
6317           vp = NULL;
6318           }
6319         /*FALLTHROUGH*/
6320 #endif
6321       default:
6322         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6323         if (!sub) goto EXPAND_FAILED;
6324         s++;
6325         break;
6326       }
6327
6328     /* If we are skipping, we don't need to perform the operation at all.
6329     This matters for operations like "mask", because the data may not be
6330     in the correct format when skipping. For example, the expression may test
6331     for the existence of $sender_host_address before trying to mask it. For
6332     other operations, doing them may not fail, but it is a waste of time. */
6333
6334     if (skipping && c >= 0) continue;
6335
6336     /* Otherwise, switch on the operator type */
6337
6338     switch(c)
6339       {
6340       case EOP_BASE32:
6341         {
6342         uschar *t;
6343         unsigned long int n = Ustrtoul(sub, &t, 10);
6344         gstring * g = NULL;
6345
6346         if (*t != 0)
6347           {
6348           expand_string_message = string_sprintf("argument for base32 "
6349             "operator is \"%s\", which is not a decimal number", sub);
6350           goto EXPAND_FAILED;
6351           }
6352         for ( ; n; n >>= 5)
6353           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6354
6355         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6356         continue;
6357         }
6358
6359       case EOP_BASE32D:
6360         {
6361         uschar *tt = sub;
6362         unsigned long int n = 0;
6363         uschar * s;
6364         while (*tt)
6365           {
6366           uschar * t = Ustrchr(base32_chars, *tt++);
6367           if (t == NULL)
6368             {
6369             expand_string_message = string_sprintf("argument for base32d "
6370               "operator is \"%s\", which is not a base 32 number", sub);
6371             goto EXPAND_FAILED;
6372             }
6373           n = n * 32 + (t - base32_chars);
6374           }
6375         s = string_sprintf("%ld", n);
6376         yield = string_cat(yield, s);
6377         continue;
6378         }
6379
6380       case EOP_BASE62:
6381         {
6382         uschar *t;
6383         unsigned long int n = Ustrtoul(sub, &t, 10);
6384         if (*t != 0)
6385           {
6386           expand_string_message = string_sprintf("argument for base62 "
6387             "operator is \"%s\", which is not a decimal number", sub);
6388           goto EXPAND_FAILED;
6389           }
6390         t = string_base62(n);
6391         yield = string_cat(yield, t);
6392         continue;
6393         }
6394
6395       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6396
6397       case EOP_BASE62D:
6398         {
6399         uschar buf[16];
6400         uschar *tt = sub;
6401         unsigned long int n = 0;
6402         while (*tt != 0)
6403           {
6404           uschar *t = Ustrchr(base62_chars, *tt++);
6405           if (t == NULL)
6406             {
6407             expand_string_message = string_sprintf("argument for base62d "
6408               "operator is \"%s\", which is not a base %d number", sub,
6409               BASE_62);
6410             goto EXPAND_FAILED;
6411             }
6412           n = n * BASE_62 + (t - base62_chars);
6413           }
6414         (void)sprintf(CS buf, "%ld", n);
6415         yield = string_cat(yield, buf);
6416         continue;
6417         }
6418
6419       case EOP_EXPAND:
6420         {
6421         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6422         if (expanded == NULL)
6423           {
6424           expand_string_message =
6425             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6426               expand_string_message);
6427           goto EXPAND_FAILED;
6428           }
6429         yield = string_cat(yield, expanded);
6430         continue;
6431         }
6432
6433       case EOP_LC:
6434         {
6435         int count = 0;
6436         uschar *t = sub - 1;
6437         while (*(++t) != 0) { *t = tolower(*t); count++; }
6438         yield = string_catn(yield, sub, count);
6439         continue;
6440         }
6441
6442       case EOP_UC:
6443         {
6444         int count = 0;
6445         uschar *t = sub - 1;
6446         while (*(++t) != 0) { *t = toupper(*t); count++; }
6447         yield = string_catn(yield, sub, count);
6448         continue;
6449         }
6450
6451       case EOP_MD5:
6452 #ifdef SUPPORT_TLS
6453         if (vp && *(void **)vp->value)
6454           {
6455           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6456           yield = string_cat(yield, cp);
6457           }
6458         else
6459 #endif
6460           {
6461           md5 base;
6462           uschar digest[16];
6463           int j;
6464           char st[33];
6465           md5_start(&base);
6466           md5_end(&base, sub, Ustrlen(sub), digest);
6467           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6468           yield = string_cat(yield, US st);
6469           }
6470         continue;
6471
6472       case EOP_SHA1:
6473 #ifdef SUPPORT_TLS
6474         if (vp && *(void **)vp->value)
6475           {
6476           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6477           yield = string_cat(yield, cp);
6478           }
6479         else
6480 #endif
6481           {
6482           hctx h;
6483           uschar digest[20];
6484           int j;
6485           char st[41];
6486           sha1_start(&h);
6487           sha1_end(&h, sub, Ustrlen(sub), digest);
6488           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6489           yield = string_catn(yield, US st, 40);
6490           }
6491         continue;
6492
6493       case EOP_SHA256:
6494 #ifdef EXIM_HAVE_SHA2
6495         if (vp && *(void **)vp->value)
6496           {
6497           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6498           yield = string_cat(yield, cp);
6499           }
6500         else
6501           {
6502           hctx h;
6503           blob b;
6504           char st[3];
6505
6506           if (!exim_sha_init(&h, HASH_SHA2_256))
6507             {
6508             expand_string_message = US"unrecognised sha256 variant";
6509             goto EXPAND_FAILED;
6510             }
6511           exim_sha_update(&h, sub, Ustrlen(sub));
6512           exim_sha_finish(&h, &b);
6513           while (b.len-- > 0)
6514             {
6515             sprintf(st, "%02X", *b.data++);
6516             yield = string_catn(yield, US st, 2);
6517             }
6518           }
6519 #else
6520           expand_string_message = US"sha256 only supported with TLS";
6521 #endif
6522         continue;
6523
6524       case EOP_SHA3:
6525 #ifdef EXIM_HAVE_SHA3
6526         {
6527         hctx h;
6528         blob b;
6529         char st[3];
6530         hashmethod m = !arg ? HASH_SHA3_256
6531           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6532           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6533           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6534           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6535           : HASH_BADTYPE;
6536
6537         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6538           {
6539           expand_string_message = US"unrecognised sha3 variant";
6540           goto EXPAND_FAILED;
6541           }
6542
6543         exim_sha_update(&h, sub, Ustrlen(sub));
6544         exim_sha_finish(&h, &b);
6545         while (b.len-- > 0)
6546           {
6547           sprintf(st, "%02X", *b.data++);
6548           yield = string_catn(yield, US st, 2);
6549           }
6550         }
6551         continue;
6552 #else
6553         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 + or OpenSSL 1.1.1 +";
6554         goto EXPAND_FAILED;
6555 #endif
6556
6557       /* Convert hex encoding to base64 encoding */
6558
6559       case EOP_HEX2B64:
6560         {
6561         int c = 0;
6562         int b = -1;
6563         uschar *in = sub;
6564         uschar *out = sub;
6565         uschar *enc;
6566
6567         for (enc = sub; *enc != 0; enc++)
6568           {
6569           if (!isxdigit(*enc))
6570             {
6571             expand_string_message = string_sprintf("\"%s\" is not a hex "
6572               "string", sub);
6573             goto EXPAND_FAILED;
6574             }
6575           c++;
6576           }
6577
6578         if ((c & 1) != 0)
6579           {
6580           expand_string_message = string_sprintf("\"%s\" contains an odd "
6581             "number of characters", sub);
6582           goto EXPAND_FAILED;
6583           }
6584
6585         while ((c = *in++) != 0)
6586           {
6587           if (isdigit(c)) c -= '0';
6588           else c = toupper(c) - 'A' + 10;
6589           if (b == -1)
6590             {
6591             b = c << 4;
6592             }
6593           else
6594             {
6595             *out++ = b | c;
6596             b = -1;
6597             }
6598           }
6599
6600         enc = b64encode(sub, out - sub);
6601         yield = string_cat(yield, enc);
6602         continue;
6603         }
6604
6605       /* Convert octets outside 0x21..0x7E to \xXX form */
6606
6607       case EOP_HEXQUOTE:
6608         {
6609         uschar *t = sub - 1;
6610         while (*(++t) != 0)
6611           {
6612           if (*t < 0x21 || 0x7E < *t)
6613             yield = string_catn(yield, string_sprintf("\\x%02x", *t), 4);
6614           else
6615             yield = string_catn(yield, t, 1);
6616           }
6617         continue;
6618         }
6619
6620       /* count the number of list elements */
6621
6622       case EOP_LISTCOUNT:
6623         {
6624         int cnt = 0;
6625         int sep = 0;
6626         uschar * cp;
6627         uschar buffer[256];
6628
6629         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6630         cp = string_sprintf("%d", cnt);
6631         yield = string_cat(yield, cp);
6632         continue;
6633         }
6634
6635       /* expand a named list given the name */
6636       /* handles nested named lists; requotes as colon-sep list */
6637
6638       case EOP_LISTNAMED:
6639         {
6640         tree_node *t = NULL;
6641         const uschar * list;
6642         int sep = 0;
6643         uschar * item;
6644         uschar * suffix = US"";
6645         BOOL needsep = FALSE;
6646         uschar buffer[256];
6647
6648         if (*sub == '+') sub++;
6649         if (arg == NULL)        /* no-argument version */
6650           {
6651           if (!(t = tree_search(addresslist_anchor, sub)) &&
6652               !(t = tree_search(domainlist_anchor,  sub)) &&
6653               !(t = tree_search(hostlist_anchor,    sub)))
6654             t = tree_search(localpartlist_anchor, sub);
6655           }
6656         else switch(*arg)       /* specific list-type version */
6657           {
6658           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6659           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6660           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6661           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6662           default:
6663             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6664             goto EXPAND_FAILED;
6665           }
6666
6667         if(!t)
6668           {
6669           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6670             sub, !arg?""
6671               : *arg=='a'?"address "
6672               : *arg=='d'?"domain "
6673               : *arg=='h'?"host "
6674               : *arg=='l'?"localpart "
6675               : 0);
6676           goto EXPAND_FAILED;
6677           }
6678
6679         list = ((namedlist_block *)(t->data.ptr))->string;
6680
6681         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
6682           {
6683           uschar * buf = US" : ";
6684           if (needsep)
6685             yield = string_catn(yield, buf, 3);
6686           else
6687             needsep = TRUE;
6688
6689           if (*item == '+')     /* list item is itself a named list */
6690             {
6691             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6692             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6693             }
6694           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6695             {
6696             char * cp;
6697             char tok[3];
6698             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6699             while ((cp= strpbrk(CCS item, tok)))
6700               {
6701               yield = string_catn(yield, item, cp - CS item);
6702               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6703                 {
6704                 yield = string_catn(yield, US"::", 2);
6705                 item = US cp;
6706                 }
6707               else              /* sep in item; should already be doubled; emit once */
6708                 {
6709                 yield = string_catn(yield, US tok, 1);
6710                 if (*cp == sep) cp++;
6711                 item = US cp;
6712                 }
6713               }
6714             }
6715           yield = string_cat(yield, item);
6716           }
6717         continue;
6718         }
6719
6720       /* mask applies a mask to an IP address; for example the result of
6721       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6722
6723       case EOP_MASK:
6724         {
6725         int count;
6726         uschar *endptr;
6727         int binary[4];
6728         int mask, maskoffset;
6729         int type = string_is_ip_address(sub, &maskoffset);
6730         uschar buffer[64];
6731
6732         if (type == 0)
6733           {
6734           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6735            sub);
6736           goto EXPAND_FAILED;
6737           }
6738
6739         if (maskoffset == 0)
6740           {
6741           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6742             sub);
6743           goto EXPAND_FAILED;
6744           }
6745
6746         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6747
6748         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6749           {
6750           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6751             sub);
6752           goto EXPAND_FAILED;
6753           }
6754
6755         /* Convert the address to binary integer(s) and apply the mask */
6756
6757         sub[maskoffset] = 0;
6758         count = host_aton(sub, binary);
6759         host_mask(count, binary, mask);
6760
6761         /* Convert to masked textual format and add to output. */
6762
6763         yield = string_catn(yield, buffer,
6764           host_nmtoa(count, binary, mask, buffer, '.'));
6765         continue;
6766         }
6767
6768       case EOP_IPV6NORM:
6769       case EOP_IPV6DENORM:
6770         {
6771         int type = string_is_ip_address(sub, NULL);
6772         int binary[4];
6773         uschar buffer[44];
6774
6775         switch (type)
6776           {
6777           case 6:
6778             (void) host_aton(sub, binary);
6779             break;
6780
6781           case 4:       /* convert to IPv4-mapped IPv6 */
6782             binary[0] = binary[1] = 0;
6783             binary[2] = 0x0000ffff;
6784             (void) host_aton(sub, binary+3);
6785             break;
6786
6787           case 0:
6788             expand_string_message =
6789               string_sprintf("\"%s\" is not an IP address", sub);
6790             goto EXPAND_FAILED;
6791           }
6792
6793         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
6794                     ? ipv6_nmtoa(binary, buffer)
6795                     : host_nmtoa(4, binary, -1, buffer, ':')
6796                   );
6797         continue;
6798         }
6799
6800       case EOP_ADDRESS:
6801       case EOP_LOCAL_PART:
6802       case EOP_DOMAIN:
6803         {
6804         uschar * error;
6805         int start, end, domain;
6806         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6807           FALSE);
6808         if (t)
6809           if (c != EOP_DOMAIN)
6810             {
6811             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6812             yield = string_catn(yield, sub+start, end-start);
6813             }
6814           else if (domain != 0)
6815             {
6816             domain += start;
6817             yield = string_catn(yield, sub+domain, end-domain);
6818             }
6819         continue;
6820         }
6821
6822       case EOP_ADDRESSES:
6823         {
6824         uschar outsep[2] = { ':', '\0' };
6825         uschar *address, *error;
6826         int save_ptr = yield->ptr;
6827         int start, end, domain;  /* Not really used */
6828
6829         while (isspace(*sub)) sub++;
6830         if (*sub == '>')
6831           if (*outsep = *++sub) ++sub;
6832           else
6833             {
6834             expand_string_message = string_sprintf("output separator "
6835               "missing in expanding ${addresses:%s}", --sub);
6836             goto EXPAND_FAILED;
6837             }
6838         parse_allow_group = TRUE;
6839
6840         for (;;)
6841           {
6842           uschar *p = parse_find_address_end(sub, FALSE);
6843           uschar saveend = *p;
6844           *p = '\0';
6845           address = parse_extract_address(sub, &error, &start, &end, &domain,
6846             FALSE);
6847           *p = saveend;
6848
6849           /* Add the address to the output list that we are building. This is
6850           done in chunks by searching for the separator character. At the
6851           start, unless we are dealing with the first address of the output
6852           list, add in a space if the new address begins with the separator
6853           character, or is an empty string. */
6854
6855           if (address != NULL)
6856             {
6857             if (yield->ptr != save_ptr && address[0] == *outsep)
6858               yield = string_catn(yield, US" ", 1);
6859
6860             for (;;)
6861               {
6862               size_t seglen = Ustrcspn(address, outsep);
6863               yield = string_catn(yield, address, seglen + 1);
6864
6865               /* If we got to the end of the string we output one character
6866               too many. */
6867
6868               if (address[seglen] == '\0') { yield->ptr--; break; }
6869               yield = string_catn(yield, outsep, 1);
6870               address += seglen + 1;
6871               }
6872
6873             /* Output a separator after the string: we will remove the
6874             redundant final one at the end. */
6875
6876             yield = string_catn(yield, outsep, 1);
6877             }
6878
6879           if (saveend == '\0') break;
6880           sub = p + 1;
6881           }
6882
6883         /* If we have generated anything, remove the redundant final
6884         separator. */
6885
6886         if (yield->ptr != save_ptr) yield->ptr--;
6887         parse_allow_group = FALSE;
6888         continue;
6889         }
6890
6891
6892       /* quote puts a string in quotes if it is empty or contains anything
6893       other than alphamerics, underscore, dot, or hyphen.
6894
6895       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6896       be quoted in order to be a valid local part.
6897
6898       In both cases, newlines and carriage returns are converted into \n and \r
6899       respectively */
6900
6901       case EOP_QUOTE:
6902       case EOP_QUOTE_LOCAL_PART:
6903       if (arg == NULL)
6904         {
6905         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6906         uschar *t = sub - 1;
6907
6908         if (c == EOP_QUOTE)
6909           {
6910           while (!needs_quote && *(++t) != 0)
6911             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6912           }
6913         else  /* EOP_QUOTE_LOCAL_PART */
6914           {
6915           while (!needs_quote && *(++t) != 0)
6916             needs_quote = !isalnum(*t) &&
6917               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6918               (*t != '.' || t == sub || t[1] == 0);
6919           }
6920
6921         if (needs_quote)
6922           {
6923           yield = string_catn(yield, US"\"", 1);
6924           t = sub - 1;
6925           while (*(++t) != 0)
6926             {
6927             if (*t == '\n')
6928               yield = string_catn(yield, US"\\n", 2);
6929             else if (*t == '\r')
6930               yield = string_catn(yield, US"\\r", 2);
6931             else
6932               {
6933               if (*t == '\\' || *t == '"')
6934                 yield = string_catn(yield, US"\\", 1);
6935               yield = string_catn(yield, t, 1);
6936               }
6937             }
6938           yield = string_catn(yield, US"\"", 1);
6939           }
6940         else yield = string_cat(yield, sub);
6941         continue;
6942         }
6943
6944       /* quote_lookuptype does lookup-specific quoting */
6945
6946       else
6947         {
6948         int n;
6949         uschar *opt = Ustrchr(arg, '_');
6950
6951         if (opt != NULL) *opt++ = 0;
6952
6953         n = search_findtype(arg, Ustrlen(arg));
6954         if (n < 0)
6955           {
6956           expand_string_message = search_error_message;
6957           goto EXPAND_FAILED;
6958           }
6959
6960         if (lookup_list[n]->quote != NULL)
6961           sub = (lookup_list[n]->quote)(sub, opt);
6962         else if (opt != NULL) sub = NULL;
6963
6964         if (sub == NULL)
6965           {
6966           expand_string_message = string_sprintf(
6967             "\"%s\" unrecognized after \"${quote_%s\"",
6968             opt, arg);
6969           goto EXPAND_FAILED;
6970           }
6971
6972         yield = string_cat(yield, sub);
6973         continue;
6974         }
6975
6976       /* rx quote sticks in \ before any non-alphameric character so that
6977       the insertion works in a regular expression. */
6978
6979       case EOP_RXQUOTE:
6980         {
6981         uschar *t = sub - 1;
6982         while (*(++t) != 0)
6983           {
6984           if (!isalnum(*t))
6985             yield = string_catn(yield, US"\\", 1);
6986           yield = string_catn(yield, t, 1);
6987           }
6988         continue;
6989         }
6990
6991       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6992       prescribed by the RFC, if there are characters that need to be encoded */
6993
6994       case EOP_RFC2047:
6995         {
6996         uschar buffer[2048];
6997         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6998           buffer, sizeof(buffer), FALSE);
6999         yield = string_cat(yield, string);
7000         continue;
7001         }
7002
7003       /* RFC 2047 decode */
7004
7005       case EOP_RFC2047D:
7006         {
7007         int len;
7008         uschar *error;
7009         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
7010           headers_charset, '?', &len, &error);
7011         if (error != NULL)
7012           {
7013           expand_string_message = error;
7014           goto EXPAND_FAILED;
7015           }
7016         yield = string_catn(yield, decoded, len);
7017         continue;
7018         }
7019
7020       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
7021       underscores */
7022
7023       case EOP_FROM_UTF8:
7024         {
7025         while (*sub != 0)
7026           {
7027           int c;
7028           uschar buff[4];
7029           GETUTF8INC(c, sub);
7030           if (c > 255) c = '_';
7031           buff[0] = c;
7032           yield = string_catn(yield, buff, 1);
7033           }
7034         continue;
7035         }
7036
7037           /* replace illegal UTF-8 sequences by replacement character  */
7038
7039       #define UTF8_REPLACEMENT_CHAR US"?"
7040
7041       case EOP_UTF8CLEAN:
7042         {
7043         int seq_len = 0, index = 0;
7044         int bytes_left = 0;
7045         long codepoint = -1;
7046         uschar seq_buff[4];                     /* accumulate utf-8 here */
7047
7048         while (*sub != 0)
7049           {
7050           int complete = 0;
7051           uschar c = *sub++;
7052
7053           if (bytes_left)
7054             {
7055             if ((c & 0xc0) != 0x80)
7056                     /* wrong continuation byte; invalidate all bytes */
7057               complete = 1; /* error */
7058             else
7059               {
7060               codepoint = (codepoint << 6) | (c & 0x3f);
7061               seq_buff[index++] = c;
7062               if (--bytes_left == 0)            /* codepoint complete */
7063                 if(codepoint > 0x10FFFF)        /* is it too large? */
7064                   complete = -1;        /* error (RFC3629 limit) */
7065                 else
7066                   {             /* finished; output utf-8 sequence */
7067                   yield = string_catn(yield, seq_buff, seq_len);
7068                   index = 0;
7069                   }
7070               }
7071             }
7072           else  /* no bytes left: new sequence */
7073             {
7074             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7075               {
7076               yield = string_catn(yield, &c, 1);
7077               continue;
7078               }
7079             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7080               {
7081               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7082                 complete = -1;
7083               else
7084                 {
7085                   bytes_left = 1;
7086                   codepoint = c & 0x1f;
7087                 }
7088               }
7089             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7090               {
7091               bytes_left = 2;
7092               codepoint = c & 0x0f;
7093               }
7094             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7095               {
7096               bytes_left = 3;
7097               codepoint = c & 0x07;
7098               }
7099             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7100               complete = -1;
7101
7102             seq_buff[index++] = c;
7103             seq_len = bytes_left + 1;
7104             }           /* if(bytes_left) */
7105
7106           if (complete != 0)
7107             {
7108             bytes_left = index = 0;
7109             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7110             }
7111           if ((complete == 1) && ((c & 0x80) == 0))
7112                         /* ASCII character follows incomplete sequence */
7113               yield = string_catn(yield, &c, 1);
7114           }
7115         continue;
7116         }
7117
7118 #ifdef SUPPORT_I18N
7119       case EOP_UTF8_DOMAIN_TO_ALABEL:
7120         {
7121         uschar * error = NULL;
7122         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7123         if (error)
7124           {
7125           expand_string_message = string_sprintf(
7126             "error converting utf8 (%s) to alabel: %s",
7127             string_printing(sub), error);
7128           goto EXPAND_FAILED;
7129           }
7130         yield = string_cat(yield, s);
7131         continue;
7132         }
7133
7134       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7135         {
7136         uschar * error = NULL;
7137         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7138         if (error)
7139           {
7140           expand_string_message = string_sprintf(
7141             "error converting alabel (%s) to utf8: %s",
7142             string_printing(sub), error);
7143           goto EXPAND_FAILED;
7144           }
7145         yield = string_cat(yield, s);
7146         continue;
7147         }
7148
7149       case EOP_UTF8_LOCALPART_TO_ALABEL:
7150         {
7151         uschar * error = NULL;
7152         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7153         if (error)
7154           {
7155           expand_string_message = string_sprintf(
7156             "error converting utf8 (%s) to alabel: %s",
7157             string_printing(sub), error);
7158           goto EXPAND_FAILED;
7159           }
7160         yield = string_cat(yield, s);
7161         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7162         continue;
7163         }
7164
7165       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7166         {
7167         uschar * error = NULL;
7168         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7169         if (error)
7170           {
7171           expand_string_message = string_sprintf(
7172             "error converting alabel (%s) to utf8: %s",
7173             string_printing(sub), error);
7174           goto EXPAND_FAILED;
7175           }
7176         yield = string_cat(yield, s);
7177         continue;
7178         }
7179 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7180
7181       /* escape turns all non-printing characters into escape sequences. */
7182
7183       case EOP_ESCAPE:
7184         {
7185         const uschar * t = string_printing(sub);
7186         yield = string_cat(yield, t);
7187         continue;
7188         }
7189
7190       case EOP_ESCAPE8BIT:
7191         {
7192         const uschar * s = sub;
7193         uschar c;
7194
7195         for (s = sub; (c = *s); s++)
7196           yield = c < 127 && c != '\\'
7197             ? string_catn(yield, s, 1)
7198             : string_catn(yield, string_sprintf("\\%03o", c), 4);
7199         continue;
7200         }
7201
7202       /* Handle numeric expression evaluation */
7203
7204       case EOP_EVAL:
7205       case EOP_EVAL10:
7206         {
7207         uschar *save_sub = sub;
7208         uschar *error = NULL;
7209         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7210         if (error != NULL)
7211           {
7212           expand_string_message = string_sprintf("error in expression "
7213             "evaluation: %s (after processing \"%.*s\")", error,
7214             (int)(sub-save_sub), save_sub);
7215           goto EXPAND_FAILED;
7216           }
7217         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7218         yield = string_cat(yield, var_buffer);
7219         continue;
7220         }
7221
7222       /* Handle time period formating */
7223
7224       case EOP_TIME_EVAL:
7225         {
7226         int n = readconf_readtime(sub, 0, FALSE);
7227         if (n < 0)
7228           {
7229           expand_string_message = string_sprintf("string \"%s\" is not an "
7230             "Exim time interval in \"%s\" operator", sub, name);
7231           goto EXPAND_FAILED;
7232           }
7233         sprintf(CS var_buffer, "%d", n);
7234         yield = string_cat(yield, var_buffer);
7235         continue;
7236         }
7237
7238       case EOP_TIME_INTERVAL:
7239         {
7240         int n;
7241         uschar *t = read_number(&n, sub);
7242         if (*t != 0) /* Not A Number*/
7243           {
7244           expand_string_message = string_sprintf("string \"%s\" is not a "
7245             "positive number in \"%s\" operator", sub, name);
7246           goto EXPAND_FAILED;
7247           }
7248         t = readconf_printtime(n);
7249         yield = string_cat(yield, t);
7250         continue;
7251         }
7252
7253       /* Convert string to base64 encoding */
7254
7255       case EOP_STR2B64:
7256       case EOP_BASE64:
7257         {
7258 #ifdef SUPPORT_TLS
7259         uschar * s = vp && *(void **)vp->value
7260           ? tls_cert_der_b64(*(void **)vp->value)
7261           : b64encode(sub, Ustrlen(sub));
7262 #else
7263         uschar * s = b64encode(sub, Ustrlen(sub));
7264 #endif
7265         yield = string_cat(yield, s);
7266         continue;
7267         }
7268
7269       case EOP_BASE64D:
7270         {
7271         uschar * s;
7272         int len = b64decode(sub, &s);
7273         if (len < 0)
7274           {
7275           expand_string_message = string_sprintf("string \"%s\" is not "
7276             "well-formed for \"%s\" operator", sub, name);
7277           goto EXPAND_FAILED;
7278           }
7279         yield = string_cat(yield, s);
7280         continue;
7281         }
7282
7283       /* strlen returns the length of the string */
7284
7285       case EOP_STRLEN:
7286         {
7287         uschar buff[24];
7288         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7289         yield = string_cat(yield, buff);
7290         continue;
7291         }
7292
7293       /* length_n or l_n takes just the first n characters or the whole string,
7294       whichever is the shorter;
7295
7296       substr_m_n, and s_m_n take n characters from offset m; negative m take
7297       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7298       takes the rest, either to the right or to the left.
7299
7300       hash_n or h_n makes a hash of length n from the string, yielding n
7301       characters from the set a-z; hash_n_m makes a hash of length n, but
7302       uses m characters from the set a-zA-Z0-9.
7303
7304       nhash_n returns a single number between 0 and n-1 (in text form), while
7305       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7306       between 0 and n-1 and the second between 0 and m-1. */
7307
7308       case EOP_LENGTH:
7309       case EOP_L:
7310       case EOP_SUBSTR:
7311       case EOP_S:
7312       case EOP_HASH:
7313       case EOP_H:
7314       case EOP_NHASH:
7315       case EOP_NH:
7316         {
7317         int sign = 1;
7318         int value1 = 0;
7319         int value2 = -1;
7320         int *pn;
7321         int len;
7322         uschar *ret;
7323
7324         if (arg == NULL)
7325           {
7326           expand_string_message = string_sprintf("missing values after %s",
7327             name);
7328           goto EXPAND_FAILED;
7329           }
7330
7331         /* "length" has only one argument, effectively being synonymous with
7332         substr_0_n. */
7333
7334         if (c == EOP_LENGTH || c == EOP_L)
7335           {
7336           pn = &value2;
7337           value2 = 0;
7338           }
7339
7340         /* The others have one or two arguments; for "substr" the first may be
7341         negative. The second being negative means "not supplied". */
7342
7343         else
7344           {
7345           pn = &value1;
7346           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7347           }
7348
7349         /* Read up to two numbers, separated by underscores */
7350
7351         ret = arg;
7352         while (*arg != 0)
7353           {
7354           if (arg != ret && *arg == '_' && pn == &value1)
7355             {
7356             pn = &value2;
7357             value2 = 0;
7358             if (arg[1] != 0) arg++;
7359             }
7360           else if (!isdigit(*arg))
7361             {
7362             expand_string_message =
7363               string_sprintf("non-digit after underscore in \"%s\"", name);
7364             goto EXPAND_FAILED;
7365             }
7366           else *pn = (*pn)*10 + *arg++ - '0';
7367           }
7368         value1 *= sign;
7369
7370         /* Perform the required operation */
7371
7372         ret =
7373           (c == EOP_HASH || c == EOP_H)?
7374              compute_hash(sub, value1, value2, &len) :
7375           (c == EOP_NHASH || c == EOP_NH)?
7376              compute_nhash(sub, value1, value2, &len) :
7377              extract_substr(sub, value1, value2, &len);
7378
7379         if (ret == NULL) goto EXPAND_FAILED;
7380         yield = string_catn(yield, ret, len);
7381         continue;
7382         }
7383
7384       /* Stat a path */
7385
7386       case EOP_STAT:
7387         {
7388         uschar *s;
7389         uschar smode[12];
7390         uschar **modetable[3];
7391         int i;
7392         mode_t mode;
7393         struct stat st;
7394
7395         if ((expand_forbid & RDO_EXISTS) != 0)
7396           {
7397           expand_string_message = US"Use of the stat() expansion is not permitted";
7398           goto EXPAND_FAILED;
7399           }
7400
7401         if (stat(CS sub, &st) < 0)
7402           {
7403           expand_string_message = string_sprintf("stat(%s) failed: %s",
7404             sub, strerror(errno));
7405           goto EXPAND_FAILED;
7406           }
7407         mode = st.st_mode;
7408         switch (mode & S_IFMT)
7409           {
7410           case S_IFIFO: smode[0] = 'p'; break;
7411           case S_IFCHR: smode[0] = 'c'; break;
7412           case S_IFDIR: smode[0] = 'd'; break;
7413           case S_IFBLK: smode[0] = 'b'; break;
7414           case S_IFREG: smode[0] = '-'; break;
7415           default: smode[0] = '?'; break;
7416           }
7417
7418         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7419         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7420         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7421
7422         for (i = 0; i < 3; i++)
7423           {
7424           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7425           mode >>= 3;
7426           }
7427
7428         smode[10] = 0;
7429         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7430           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7431           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7432           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7433           (long)st.st_gid, st.st_size, (long)st.st_atime,
7434           (long)st.st_mtime, (long)st.st_ctime);
7435         yield = string_cat(yield, s);
7436         continue;
7437         }
7438
7439       /* vaguely random number less than N */
7440
7441       case EOP_RANDINT:
7442         {
7443         int_eximarith_t max;
7444         uschar *s;
7445
7446         max = expanded_string_integer(sub, TRUE);
7447         if (expand_string_message != NULL)
7448           goto EXPAND_FAILED;
7449         s = string_sprintf("%d", vaguely_random_number((int)max));
7450         yield = string_cat(yield, s);
7451         continue;
7452         }
7453
7454       /* Reverse IP, including IPv6 to dotted-nibble */
7455
7456       case EOP_REVERSE_IP:
7457         {
7458         int family, maskptr;
7459         uschar reversed[128];
7460
7461         family = string_is_ip_address(sub, &maskptr);
7462         if (family == 0)
7463           {
7464           expand_string_message = string_sprintf(
7465               "reverse_ip() not given an IP address [%s]", sub);
7466           goto EXPAND_FAILED;
7467           }
7468         invert_address(reversed, sub);
7469         yield = string_cat(yield, reversed);
7470         continue;
7471         }
7472
7473       /* Unknown operator */
7474
7475       default:
7476       expand_string_message =
7477         string_sprintf("unknown expansion operator \"%s\"", name);
7478       goto EXPAND_FAILED;
7479       }
7480     }
7481
7482   /* Handle a plain name. If this is the first thing in the expansion, release
7483   the pre-allocated buffer. If the result data is known to be in a new buffer,
7484   newsize will be set to the size of that buffer, and we can just point at that
7485   store instead of copying. Many expansion strings contain just one reference,
7486   so this is a useful optimization, especially for humungous headers
7487   ($message_headers). */
7488                                                 /*{*/
7489   if (*s++ == '}')
7490     {
7491     int len;
7492     int newsize = 0;
7493     gstring * g = NULL;
7494
7495     if (!yield)
7496       g = store_get(sizeof(gstring));
7497     else if (yield->ptr == 0)
7498       {
7499       if (resetok) store_reset(yield);
7500       yield = NULL;
7501       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
7502       }
7503     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7504       {
7505       expand_string_message =
7506         string_sprintf("unknown variable in \"${%s}\"", name);
7507       check_variable_error_message(name);
7508       goto EXPAND_FAILED;
7509       }
7510     len = Ustrlen(value);
7511     if (!yield && newsize)
7512       {
7513       yield = g;
7514       yield->size = newsize;
7515       yield->ptr = len;
7516       yield->s = value;
7517       }
7518     else
7519       yield = string_catn(yield, value, len);
7520     continue;
7521     }
7522
7523   /* Else there's something wrong */
7524
7525   expand_string_message =
7526     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7527     "in a variable reference)", name);
7528   goto EXPAND_FAILED;
7529   }
7530
7531 /* If we hit the end of the string when ket_ends is set, there is a missing
7532 terminating brace. */
7533
7534 if (ket_ends && *s == 0)
7535   {
7536   expand_string_message = malformed_header
7537     ? US"missing } at end of string - could be header name not terminated by colon"
7538     : US"missing } at end of string";
7539   goto EXPAND_FAILED;
7540   }
7541
7542 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7543 added to the string. If so, set up an empty string. Add a terminating zero. If
7544 left != NULL, return a pointer to the terminator. */
7545
7546 if (!yield)
7547   yield = string_get(1);
7548 (void) string_from_gstring(yield);
7549 if (left) *left = s;
7550
7551 /* Any stacking store that was used above the final string is no longer needed.
7552 In many cases the final string will be the first one that was got and so there
7553 will be optimal store usage. */
7554
7555 if (resetok) store_reset(yield->s + (yield->size = yield->ptr + 1));
7556 else if (resetok_p) *resetok_p = FALSE;
7557
7558 DEBUG(D_expand)
7559   {
7560   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7561     "expanding: %.*s\n",
7562     (int)(s - string), string);
7563   debug_printf_indent("%s"
7564     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7565     "result: %s\n",
7566     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7567     yield->s);
7568   if (skipping)
7569     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7570       "skipping: result is not used\n");
7571   }
7572 expand_level--;
7573 return yield->s;
7574
7575 /* This is the failure exit: easiest to program with a goto. We still need
7576 to update the pointer to the terminator, for cases of nested calls with "fail".
7577 */
7578
7579 EXPAND_FAILED_CURLY:
7580 if (malformed_header)
7581   expand_string_message =
7582     US"missing or misplaced { or } - could be header name not terminated by colon";
7583
7584 else if (!expand_string_message || !*expand_string_message)
7585   expand_string_message = US"missing or misplaced { or }";
7586
7587 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7588 that is a bad idea, because expand_string_message is in dynamic store. */
7589
7590 EXPAND_FAILED:
7591 if (left) *left = s;
7592 DEBUG(D_expand)
7593   {
7594   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7595     string);
7596   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7597     "error message: %s\n",
7598     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7599     expand_string_message);
7600   if (expand_string_forcedfail)
7601     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7602   }
7603 if (resetok_p && !resetok) *resetok_p = FALSE;
7604 expand_level--;
7605 return NULL;
7606 }
7607
7608
7609 /* This is the external function call. Do a quick check for any expansion
7610 metacharacters, and if there are none, just return the input string.
7611
7612 Argument: the string to be expanded
7613 Returns:  the expanded string, or NULL if expansion failed; if failure was
7614           due to a lookup deferring, search_find_defer will be TRUE
7615 */
7616
7617 const uschar *
7618 expand_cstring(const uschar * string)
7619 {
7620 if (Ustrpbrk(string, "$\\") != NULL)
7621   {
7622   int old_pool = store_pool;
7623   uschar * s;
7624
7625   search_find_defer = FALSE;
7626   malformed_header = FALSE;
7627   store_pool = POOL_MAIN;
7628     s = expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7629   store_pool = old_pool;
7630   return s;
7631   }
7632 return string;
7633 }
7634
7635
7636 uschar *
7637 expand_string(uschar * string)
7638 {
7639 return US expand_cstring(CUS string);
7640 }
7641
7642
7643
7644
7645
7646 /*************************************************
7647 *              Expand and copy                   *
7648 *************************************************/
7649
7650 /* Now and again we want to expand a string and be sure that the result is in a
7651 new bit of store. This function does that.
7652 Since we know it has been copied, the de-const cast is safe.
7653
7654 Argument: the string to be expanded
7655 Returns:  the expanded string, always in a new bit of store, or NULL
7656 */
7657
7658 uschar *
7659 expand_string_copy(const uschar *string)
7660 {
7661 const uschar *yield = expand_cstring(string);
7662 if (yield == string) yield = string_copy(string);
7663 return US yield;
7664 }
7665
7666
7667
7668 /*************************************************
7669 *        Expand and interpret as an integer      *
7670 *************************************************/
7671
7672 /* Expand a string, and convert the result into an integer.
7673
7674 Arguments:
7675   string  the string to be expanded
7676   isplus  TRUE if a non-negative number is expected
7677
7678 Returns:  the integer value, or
7679           -1 for an expansion error               ) in both cases, message in
7680           -2 for an integer interpretation error  ) expand_string_message
7681           expand_string_message is set NULL for an OK integer
7682 */
7683
7684 int_eximarith_t
7685 expand_string_integer(uschar *string, BOOL isplus)
7686 {
7687 return expanded_string_integer(expand_string(string), isplus);
7688 }
7689
7690
7691 /*************************************************
7692  *         Interpret string as an integer        *
7693  *************************************************/
7694
7695 /* Convert a string (that has already been expanded) into an integer.
7696
7697 This function is used inside the expansion code.
7698
7699 Arguments:
7700   s       the string to be expanded
7701   isplus  TRUE if a non-negative number is expected
7702
7703 Returns:  the integer value, or
7704           -1 if string is NULL (which implies an expansion error)
7705           -2 for an integer interpretation error
7706           expand_string_message is set NULL for an OK integer
7707 */
7708
7709 static int_eximarith_t
7710 expanded_string_integer(const uschar *s, BOOL isplus)
7711 {
7712 int_eximarith_t value;
7713 uschar *msg = US"invalid integer \"%s\"";
7714 uschar *endptr;
7715
7716 /* If expansion failed, expand_string_message will be set. */
7717
7718 if (s == NULL) return -1;
7719
7720 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7721 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7722 systems, so we set it zero ourselves. */
7723
7724 errno = 0;
7725 expand_string_message = NULL;               /* Indicates no error */
7726
7727 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7728 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7729 the behaviour explicitly.  Stripping leading whitespace is a harmless
7730 noop change since strtol skips it anyway (provided that there is a number
7731 to find at all). */
7732 if (isspace(*s))
7733   {
7734   while (isspace(*s)) ++s;
7735   if (*s == '\0')
7736     {
7737       DEBUG(D_expand)
7738        debug_printf_indent("treating blank string as number 0\n");
7739       return 0;
7740     }
7741   }
7742
7743 value = strtoll(CS s, CSS &endptr, 10);
7744
7745 if (endptr == s)
7746   {
7747   msg = US"integer expected but \"%s\" found";
7748   }
7749 else if (value < 0 && isplus)
7750   {
7751   msg = US"non-negative integer expected but \"%s\" found";
7752   }
7753 else
7754   {
7755   switch (tolower(*endptr))
7756     {
7757     default:
7758       break;
7759     case 'k':
7760       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7761       else value *= 1024;
7762       endptr++;
7763       break;
7764     case 'm':
7765       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7766       else value *= 1024*1024;
7767       endptr++;
7768       break;
7769     case 'g':
7770       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7771       else value *= 1024*1024*1024;
7772       endptr++;
7773       break;
7774     }
7775   if (errno == ERANGE)
7776     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7777   else
7778     {
7779     while (isspace(*endptr)) endptr++;
7780     if (*endptr == 0) return value;
7781     }
7782   }
7783
7784 expand_string_message = string_sprintf(CS msg, s);
7785 return -2;
7786 }
7787
7788
7789 /* These values are usually fixed boolean values, but they are permitted to be
7790 expanded strings.
7791
7792 Arguments:
7793   addr       address being routed
7794   mtype      the module type
7795   mname      the module name
7796   dbg_opt    debug selectors
7797   oname      the option name
7798   bvalue     the router's boolean value
7799   svalue     the router's string value
7800   rvalue     where to put the returned value
7801
7802 Returns:     OK     value placed in rvalue
7803              DEFER  expansion failed
7804 */
7805
7806 int
7807 exp_bool(address_item *addr,
7808   uschar *mtype, uschar *mname, unsigned dbg_opt,
7809   uschar *oname, BOOL bvalue,
7810   uschar *svalue, BOOL *rvalue)
7811 {
7812 uschar *expanded;
7813 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7814
7815 expanded = expand_string(svalue);
7816 if (expanded == NULL)
7817   {
7818   if (expand_string_forcedfail)
7819     {
7820     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7821     *rvalue = bvalue;
7822     return OK;
7823     }
7824   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7825       oname, mname, mtype, expand_string_message);
7826   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7827   return DEFER;
7828   }
7829
7830 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7831   expanded);
7832
7833 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7834   *rvalue = TRUE;
7835 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7836   *rvalue = FALSE;
7837 else
7838   {
7839   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7840     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7841   return DEFER;
7842   }
7843
7844 return OK;
7845 }
7846
7847
7848
7849 /* Avoid potentially exposing a password in a string about to be logged */
7850
7851 uschar *
7852 expand_hide_passwords(uschar * s)
7853 {
7854 return (  (  Ustrstr(s, "failed to expand") != NULL
7855           || Ustrstr(s, "expansion of ")    != NULL
7856           )
7857        && (  Ustrstr(s, "mysql")   != NULL
7858           || Ustrstr(s, "pgsql")   != NULL
7859           || Ustrstr(s, "redis")   != NULL
7860           || Ustrstr(s, "sqlite")  != NULL
7861           || Ustrstr(s, "ldap:")   != NULL
7862           || Ustrstr(s, "ldaps:")  != NULL
7863           || Ustrstr(s, "ldapi:")  != NULL
7864           || Ustrstr(s, "ldapdn:") != NULL
7865           || Ustrstr(s, "ldapm:")  != NULL
7866        )  )
7867   ? US"Temporary internal error" : s;
7868 }
7869
7870
7871 /* Read given named file into big_buffer.  Use for keying material etc.
7872 The content will have an ascii NUL appended.
7873
7874 Arguments:
7875  filename       as it says
7876
7877 Return:  pointer to buffer, or NULL on error.
7878 */
7879
7880 uschar *
7881 expand_file_big_buffer(const uschar * filename)
7882 {
7883 int fd, off = 0, len;
7884
7885 if ((fd = open(CS filename, O_RDONLY)) < 0)
7886   {
7887   log_write(0, LOG_MAIN | LOG_PANIC, "unable to open file for reading: %s",
7888              filename);
7889   return NULL;
7890   }
7891
7892 do
7893   {
7894   if ((len = read(fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
7895     {
7896     (void) close(fd);
7897     log_write(0, LOG_MAIN|LOG_PANIC, "unable to read file: %s", filename);
7898     return NULL;
7899     }
7900   off += len;
7901   }
7902 while (len > 0);
7903
7904 (void) close(fd);
7905 big_buffer[off] = '\0';
7906 return big_buffer;
7907 }
7908
7909
7910
7911 /*************************************************
7912 * Error-checking for testsuite                   *
7913 *************************************************/
7914 typedef struct {
7915   uschar *      region_start;
7916   uschar *      region_end;
7917   const uschar *var_name;
7918   const uschar *var_data;
7919 } err_ctx;
7920
7921 static void
7922 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7923 {
7924 err_ctx * e = ctx;
7925 if (var_data >= e->region_start  &&  var_data < e->region_end)
7926   {
7927   e->var_name = CUS var_name;
7928   e->var_data = CUS var_data;
7929   }
7930 }
7931
7932 void
7933 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7934 {
7935 err_ctx e = { .region_start = ptr, .region_end = US ptr + len,
7936               .var_name = NULL, .var_data = NULL };
7937 int i;
7938 var_entry * v;
7939
7940 /* check acl_ variables */
7941 tree_walk(acl_var_c, assert_variable_notin, &e);
7942 tree_walk(acl_var_m, assert_variable_notin, &e);
7943
7944 /* check auth<n> variables */
7945 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7946   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7947
7948 /* check regex<n> variables */
7949 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7950   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7951
7952 /* check known-name variables */
7953 for (v = var_table; v < var_table + var_table_size; v++)
7954   if (v->type == vtype_stringptr)
7955     assert_variable_notin(US v->name, *(USS v->value), &e);
7956
7957 /* check dns and address trees */
7958 tree_walk(tree_dns_fails,     assert_variable_notin, &e);
7959 tree_walk(tree_duplicates,    assert_variable_notin, &e);
7960 tree_walk(tree_nonrecipients, assert_variable_notin, &e);
7961 tree_walk(tree_unusable,      assert_variable_notin, &e);
7962
7963 if (e.var_name)
7964   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7965     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7966     e.var_name, filename, linenumber, e.var_data);
7967 }
7968
7969
7970
7971 /*************************************************
7972 **************************************************
7973 *             Stand-alone test program           *
7974 **************************************************
7975 *************************************************/
7976
7977 #ifdef STAND_ALONE
7978
7979
7980 BOOL
7981 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7982 {
7983 int ovector[3*(EXPAND_MAXN+1)];
7984 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7985   ovector, nelem(ovector));
7986 BOOL yield = n >= 0;
7987 if (n == 0) n = EXPAND_MAXN + 1;
7988 if (yield)
7989   {
7990   int nn;
7991   expand_nmax = (setup < 0)? 0 : setup + 1;
7992   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7993     {
7994     expand_nstring[expand_nmax] = subject + ovector[nn];
7995     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7996     }
7997   expand_nmax--;
7998   }
7999 return yield;
8000 }
8001
8002
8003 int main(int argc, uschar **argv)
8004 {
8005 int i;
8006 uschar buffer[1024];
8007
8008 debug_selector = D_v;
8009 debug_file = stderr;
8010 debug_fd = fileno(debug_file);
8011 big_buffer = malloc(big_buffer_size);
8012
8013 for (i = 1; i < argc; i++)
8014   {
8015   if (argv[i][0] == '+')
8016     {
8017     debug_trace_memory = 2;
8018     argv[i]++;
8019     }
8020   if (isdigit(argv[i][0]))
8021     debug_selector = Ustrtol(argv[i], NULL, 0);
8022   else
8023     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
8024         Ustrlen(argv[i]))
8025       {
8026 #ifdef LOOKUP_LDAP
8027       eldap_default_servers = argv[i];
8028 #endif
8029 #ifdef LOOKUP_MYSQL
8030       mysql_servers = argv[i];
8031 #endif
8032 #ifdef LOOKUP_PGSQL
8033       pgsql_servers = argv[i];
8034 #endif
8035 #ifdef LOOKUP_REDIS
8036       redis_servers = argv[i];
8037 #endif
8038       }
8039 #ifdef EXIM_PERL
8040   else opt_perl_startup = argv[i];
8041 #endif
8042   }
8043
8044 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
8045
8046 expand_nstring[1] = US"string 1....";
8047 expand_nlength[1] = 8;
8048 expand_nmax = 1;
8049
8050 #ifdef EXIM_PERL
8051 if (opt_perl_startup != NULL)
8052   {
8053   uschar *errstr;
8054   printf("Starting Perl interpreter\n");
8055   errstr = init_perl(opt_perl_startup);
8056   if (errstr != NULL)
8057     {
8058     printf("** error in perl_startup code: %s\n", errstr);
8059     return EXIT_FAILURE;
8060     }
8061   }
8062 #endif /* EXIM_PERL */
8063
8064 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
8065   {
8066   void *reset_point = store_get(0);
8067   uschar *yield = expand_string(buffer);
8068   if (yield != NULL)
8069     {
8070     printf("%s\n", yield);
8071     store_reset(reset_point);
8072     }
8073   else
8074     {
8075     if (search_find_defer) printf("search_find deferred\n");
8076     printf("Failed: %s\n", expand_string_message);
8077     if (expand_string_forcedfail) printf("Forced failure\n");
8078     printf("\n");
8079     }
8080   }
8081
8082 search_tidyup();
8083
8084 return 0;
8085 }
8086
8087 #endif
8088
8089 /* vi: aw ai sw=2
8090 */
8091 /* End of expand.c */