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 #ifdef EXPERIMENTAL_ARC
 465   { "arc_state",           vtype_stringptr,   &arc_state },
 466   { "arc_state_reason",    vtype_stringptr,   &arc_state_reason },
 467 #endif
 468   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 469   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 470   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 471   { "authentication_failed",vtype_int,        &authentication_failed },
 472 #ifdef WITH_CONTENT_SCAN
 473   { "av_failed",           vtype_int,         &av_failed },
 474 #endif
 475 #ifdef EXPERIMENTAL_BRIGHTMAIL
 476   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 477   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 478   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 479   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 480 #endif
 481   { "body_linecount",      vtype_int,         &body_linecount },
 482   { "body_zerocount",      vtype_int,         &body_zerocount },
 483   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 484   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 485   { "caller_gid",          vtype_gid,         &real_gid },
 486   { "caller_uid",          vtype_uid,         &real_uid },
 487   { "callout_address",     vtype_stringptr,   &callout_address },
 488   { "compile_date",        vtype_stringptr,   &version_date },
 489   { "compile_number",      vtype_stringptr,   &version_cnumber },
 490   { "config_dir",          vtype_stringptr,   &config_main_directory },
 491   { "config_file",         vtype_stringptr,   &config_main_filename },
 492   { "csa_status",          vtype_stringptr,   &csa_status },
 493 #ifdef EXPERIMENTAL_DCC
 494   { "dcc_header",          vtype_stringptr,   &dcc_header },
 495   { "dcc_result",          vtype_stringptr,   &dcc_result },
 496 #endif
 497 #ifndef DISABLE_DKIM
 498   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 499   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 500   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 501   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 502   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 503   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 504   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 505   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 506   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 507   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 508   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 509   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 510   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 511   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 512   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 513   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 514   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 515   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 516   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 517   { "dkim_verify_reason",  vtype_stringptr,   &dkim_verify_reason },
 518   { "dkim_verify_status",  vtype_stringptr,   &dkim_verify_status },
 519 #endif
 520 #ifdef EXPERIMENTAL_DMARC
 521   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 522   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 523   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 524   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 525 #endif
 526   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 527   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 528   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 529   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 530   { "domain",              vtype_stringptr,   &deliver_domain },
 531   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 532 #ifndef DISABLE_EVENT
 533   { "event_data",          vtype_stringptr,   &event_data },
 534
 535   /*XXX want to use generic vars for as many of these as possible*/
 536   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 537
 538   { "event_name",          vtype_stringptr,   &event_name },
 539 #endif
 540   { "exim_gid",            vtype_gid,         &exim_gid },
 541   { "exim_path",           vtype_stringptr,   &exim_path },
 542   { "exim_uid",            vtype_uid,         &exim_uid },
 543   { "exim_version",        vtype_stringptr,   &version_string },
 544   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 545   { "home",                vtype_stringptr,   &deliver_home },
 546   { "host",                vtype_stringptr,   &deliver_host },
 547   { "host_address",        vtype_stringptr,   &deliver_host_address },
 548   { "host_data",           vtype_stringptr,   &host_data },
 549   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 550   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 551   { "host_port",           vtype_int,         &deliver_host_port },
 552   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 553   { "inode",               vtype_ino,         &deliver_inode },
 554   { "interface_address",   vtype_stringptr,   &interface_address },
 555   { "interface_port",      vtype_int,         &interface_port },
 556   { "item",                vtype_stringptr,   &iterate_item },
 557   #ifdef LOOKUP_LDAP
 558   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 559   #endif
 560   { "load_average",        vtype_load_avg,    NULL },
 561   { "local_part",          vtype_stringptr,   &deliver_localpart },
 562   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 563   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 564   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 565   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 566   { "local_user_gid",      vtype_gid,         &local_user_gid },
 567   { "local_user_uid",      vtype_uid,         &local_user_uid },
 568   { "localhost_number",    vtype_int,         &host_number },
 569   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 570   { "log_space",           vtype_pspace,      (void *)FALSE },
 571   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 572   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 573 #ifdef WITH_CONTENT_SCAN
 574   { "malware_name",        vtype_stringptr,   &malware_name },
 575 #endif
 576   { "max_received_linelength", vtype_int,     &max_received_linelength },
 577   { "message_age",         vtype_int,         &message_age },
 578   { "message_body",        vtype_msgbody,     &message_body },
 579   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 580   { "message_body_size",   vtype_int,         &message_body_size },
 581   { "message_exim_id",     vtype_stringptr,   &message_id },
 582   { "message_headers",     vtype_msgheaders,  NULL },
 583   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 584   { "message_id",          vtype_stringptr,   &message_id },
 585   { "message_linecount",   vtype_int,         &message_linecount },
 586   { "message_size",        vtype_int,         &message_size },
 587 #ifdef SUPPORT_I18N
 588   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 589 #endif
 590 #ifdef WITH_CONTENT_SCAN
 591   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 592   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 593   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 594   { "mime_charset",        vtype_stringptr,   &mime_charset },
 595   { "mime_content_description", vtype_stringptr, &mime_content_description },
 596   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 597   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 598   { "mime_content_size",   vtype_int,         &mime_content_size },
 599   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 600   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 601   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 602   { "mime_filename",       vtype_stringptr,   &mime_filename },
 603   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 604   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 605   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 606   { "mime_part_count",     vtype_int,         &mime_part_count },
 607 #endif
 608   { "n0",                  vtype_filter_int,  &filter_n[0] },
 609   { "n1",                  vtype_filter_int,  &filter_n[1] },
 610   { "n2",                  vtype_filter_int,  &filter_n[2] },
 611   { "n3",                  vtype_filter_int,  &filter_n[3] },
 612   { "n4",                  vtype_filter_int,  &filter_n[4] },
 613   { "n5",                  vtype_filter_int,  &filter_n[5] },
 614   { "n6",                  vtype_filter_int,  &filter_n[6] },
 615   { "n7",                  vtype_filter_int,  &filter_n[7] },
 616   { "n8",                  vtype_filter_int,  &filter_n[8] },
 617   { "n9",                  vtype_filter_int,  &filter_n[9] },
 618   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 619   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 620   { "originator_gid",      vtype_gid,         &originator_gid },
 621   { "originator_uid",      vtype_uid,         &originator_uid },
 622   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 623   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 624   { "pid",                 vtype_pid,         NULL },
 625 #ifndef DISABLE_PRDR
 626   { "prdr_requested",      vtype_bool,        &prdr_requested },
 627 #endif
 628   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 629 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 630   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 631   { "proxy_external_port", vtype_int,         &proxy_external_port },
 632   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 633   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 634   { "proxy_session",       vtype_bool,        &proxy_session },
 635 #endif
 636   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 637   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 638   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 639   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 640   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 641   { "queue_name",          vtype_stringptr,   &queue_name },
 642   { "rcpt_count",          vtype_int,         &rcpt_count },
 643   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 644   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 645   { "received_count",      vtype_int,         &received_count },
 646   { "received_for",        vtype_stringptr,   &received_for },
 647   { "received_ip_address", vtype_stringptr,   &interface_address },
 648   { "received_port",       vtype_int,         &interface_port },
 649   { "received_protocol",   vtype_stringptr,   &received_protocol },
 650   { "received_time",       vtype_int,         &received_time.tv_sec },
 651   { "recipient_data",      vtype_stringptr,   &recipient_data },
 652   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 653   { "recipients",          vtype_string_func, &fn_recipients },
 654   { "recipients_count",    vtype_int,         &recipients_count },
 655 #ifdef WITH_CONTENT_SCAN
 656   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 657 #endif
 658   { "reply_address",       vtype_reply,       NULL },
 659   { "return_path",         vtype_stringptr,   &return_path },
 660   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 661   { "router_name",         vtype_stringptr,   &router_name },
 662   { "runrc",               vtype_int,         &runrc },
 663   { "self_hostname",       vtype_stringptr,   &self_hostname },
 664   { "sender_address",      vtype_stringptr,   &sender_address },
 665   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 666   { "sender_address_domain", vtype_domain,    &sender_address },
 667   { "sender_address_local_part", vtype_localpart, &sender_address },
 668   { "sender_data",         vtype_stringptr,   &sender_data },
 669   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 670   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 671   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 672   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 673   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 674   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 675   { "sender_host_name",    vtype_host_lookup, NULL },
 676   { "sender_host_port",    vtype_int,         &sender_host_port },
 677   { "sender_ident",        vtype_stringptr,   &sender_ident },
 678   { "sender_rate",         vtype_stringptr,   &sender_rate },
 679   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 680   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 681   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 682   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 683   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 684   { "sending_port",        vtype_int,         &sending_port },
 685   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 686   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 687   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 688   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 689   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 690   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 691   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 692   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 693   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 694   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 695   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 696   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 697   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 698   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 699   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 700   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 701 #ifdef WITH_CONTENT_SCAN
 702   { "spam_action",         vtype_stringptr,   &spam_action },
 703   { "spam_bar",            vtype_stringptr,   &spam_bar },
 704   { "spam_report",         vtype_stringptr,   &spam_report },
 705   { "spam_score",          vtype_stringptr,   &spam_score },
 706   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 707 #endif
 708 #ifdef SUPPORT_SPF
 709   { "spf_guess",           vtype_stringptr,   &spf_guess },
 710   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 711   { "spf_received",        vtype_stringptr,   &spf_received },
 712   { "spf_result",          vtype_stringptr,   &spf_result },
 713   { "spf_result_guessed",  vtype_bool,        &spf_result_guessed },
 714   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 715 #endif
 716   { "spool_directory",     vtype_stringptr,   &spool_directory },
 717   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 718   { "spool_space",         vtype_pspace,      (void *)TRUE },
 719 #ifdef EXPERIMENTAL_SRS
 720   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 721   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 722   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 723   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 724   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 725   { "srs_status",          vtype_stringptr,   &srs_status },
 726 #endif
 727   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 728
 729   /* The non-(in,out) variables are now deprecated */
 730   { "tls_bits",            vtype_int,         &tls_in.bits },
 731   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 732   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 733
 734   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 735   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 736   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 737   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 738   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 739   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 740   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 741 #if defined(SUPPORT_TLS)
 742   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 743 #endif
 744   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 745   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 746   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 747 #ifdef SUPPORT_DANE
 748   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 749 #endif
 750   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 751   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 752   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 753   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 754 #if defined(SUPPORT_TLS)
 755   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 756 #endif
 757 #ifdef SUPPORT_DANE
 758   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 759 #endif
 760
 761   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 762 #if defined(SUPPORT_TLS)
 763   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 764 #endif
 765
 766   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 767   { "tod_epoch",           vtype_tode,        NULL },
 768   { "tod_epoch_l",         vtype_todel,       NULL },
 769   { "tod_full",            vtype_todf,        NULL },
 770   { "tod_log",             vtype_todl,        NULL },
 771   { "tod_logfile",         vtype_todlf,       NULL },
 772   { "tod_zone",            vtype_todzone,     NULL },
 773   { "tod_zulu",            vtype_todzulu,     NULL },
 774   { "transport_name",      vtype_stringptr,   &transport_name },
 775   { "value",               vtype_stringptr,   &lookup_value },
 776   { "verify_mode",         vtype_stringptr,   &verify_mode },
 777   { "version_number",      vtype_stringptr,   &version_string },
 778   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 779   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 780   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 781   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 782   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 783   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 784 };
 785
 786 static int var_table_size = nelem(var_table);
 787 static uschar var_buffer[256];
 788 static BOOL malformed_header;
 789
 790 /* For textual hashes */
 791
 792 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 793                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 794                                "0123456789";
 795
 796 enum { HMAC_MD5, HMAC_SHA1 };
 797
 798 /* For numeric hashes */
 799
 800 static unsigned int prime[] = {
 801   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 802  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 803  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 804
 805 /* For printing modes in symbolic form */
 806
 807 static uschar *mtable_normal[] =
 808   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 809
 810 static uschar *mtable_setid[] =
 811   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 812
 813 static uschar *mtable_sticky[] =
 814   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 815
 816
 817
 818 /*************************************************
 819 *           Tables for UTF-8 support             *
 820 *************************************************/
 821
 822 /* Table of the number of extra characters, indexed by the first character
 823 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 824 0x3d. */
 825
 826 static uschar utf8_table1[] = {
 827   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 828   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 829   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 830   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 831
 832 /* These are the masks for the data bits in the first byte of a character,
 833 indexed by the number of additional bytes. */
 834
 835 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 836
 837 /* Get the next UTF-8 character, advancing the pointer. */
 838
 839 #define GETUTF8INC(c, ptr) \
 840   c = *ptr++; \
 841   if ((c & 0xc0) == 0xc0) \
 842     { \
 843     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 844     int s = 6*a; \
 845     c = (c & utf8_table2[a]) << s; \
 846     while (a-- > 0) \
 847       { \
 848       s -= 6; \
 849       c |= (*ptr++ & 0x3f) << s; \
 850       } \
 851     }
 852
 853
 854
 855 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 856
 857 /*************************************************
 858 *           Binary chop search on a table        *
 859 *************************************************/
 860
 861 /* This is used for matching expansion items and operators.
 862
 863 Arguments:
 864   name        the name that is being sought
 865   table       the table to search
 866   table_size  the number of items in the table
 867
 868 Returns:      the offset in the table, or -1
 869 */
 870
 871 static int
 872 chop_match(uschar *name, uschar **table, int table_size)
 873 {
 874 uschar **bot = table;
 875 uschar **top = table + table_size;
 876
 877 while (top > bot)
 878   {
 879   uschar **mid = bot + (top - bot)/2;
 880   int c = Ustrcmp(name, *mid);
 881   if (c == 0) return mid - table;
 882   if (c > 0) bot = mid + 1; else top = mid;
 883   }
 884
 885 return -1;
 886 }
 887
 888
 889
 890 /*************************************************
 891 *          Check a condition string              *
 892 *************************************************/
 893
 894 /* This function is called to expand a string, and test the result for a "true"
 895 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 896 forced fail or lookup defer.
 897
 898 We used to release all store used, but this is not not safe due
 899 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 900 is reasonably careful to release what it can.
 901
 902 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 903
 904 Arguments:
 905   condition     the condition string
 906   m1            text to be incorporated in panic error
 907   m2            ditto
 908
 909 Returns:        TRUE if condition is met, FALSE if not
 910 */
 911
 912 BOOL
 913 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 914 {
 915 int rc;
 916 uschar *ss = expand_string(condition);
 917 if (ss == NULL)
 918   {
 919   if (!expand_string_forcedfail && !search_find_defer)
 920     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 921       "for %s %s: %s", condition, m1, m2, expand_string_message);
 922   return FALSE;
 923   }
 924 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 925   strcmpic(ss, US"false") != 0;
 926 return rc;
 927 }
 928
 929
 930
 931
 932 /*************************************************
 933 *        Pseudo-random number generation         *
 934 *************************************************/
 935
 936 /* Pseudo-random number generation.  The result is not "expected" to be
 937 cryptographically strong but not so weak that someone will shoot themselves
 938 in the foot using it as a nonce in some email header scheme or whatever
 939 weirdness they'll twist this into.  The result should ideally handle fork().
 940
 941 However, if we're stuck unable to provide this, then we'll fall back to
 942 appallingly bad randomness.
 943
 944 If SUPPORT_TLS is defined then this will not be used except as an emergency
 945 fallback.
 946
 947 Arguments:
 948   max       range maximum
 949 Returns     a random number in range [0, max-1]
 950 */
 951
 952 #ifdef SUPPORT_TLS
 953 # define vaguely_random_number vaguely_random_number_fallback
 954 #endif
 955 int
 956 vaguely_random_number(int max)
 957 {
 958 #ifdef SUPPORT_TLS
 959 # undef vaguely_random_number
 960 #endif
 961   static pid_t pid = 0;
 962   pid_t p2;
 963 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 964   struct timeval tv;
 965 #endif
 966
 967   p2 = getpid();
 968   if (p2 != pid)
 969     {
 970     if (pid != 0)
 971       {
 972
 973 #ifdef HAVE_ARC4RANDOM
 974       /* cryptographically strong randomness, common on *BSD platforms, not
 975       so much elsewhere.  Alas. */
 976 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 977       arc4random_stir();
 978 #endif
 979 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 980 #ifdef HAVE_SRANDOMDEV
 981       /* uses random(4) for seeding */
 982       srandomdev();
 983 #else
 984       gettimeofday(&tv, NULL);
 985       srandom(tv.tv_sec | tv.tv_usec | getpid());
 986 #endif
 987 #else
 988       /* Poor randomness and no seeding here */
 989 #endif
 990
 991       }
 992     pid = p2;
 993     }
 994
 995 #ifdef HAVE_ARC4RANDOM
 996   return arc4random() % max;
 997 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 998   return random() % max;
 999 #else
1000   /* This one returns a 16-bit number, definitely not crypto-strong */
1001   return random_number(max);
1002 #endif
1003 }
1004
1005
1006
1007
1008 /*************************************************
1009 *             Pick out a name from a string      *
1010 *************************************************/
1011
1012 /* If the name is too long, it is silently truncated.
1013
1014 Arguments:
1015   name      points to a buffer into which to put the name
1016   max       is the length of the buffer
1017   s         points to the first alphabetic character of the name
1018   extras    chars other than alphanumerics to permit
1019
1020 Returns:    pointer to the first character after the name
1021
1022 Note: The test for *s != 0 in the while loop is necessary because
1023 Ustrchr() yields non-NULL if the character is zero (which is not something
1024 I expected). */
1025
1026 static const uschar *
1027 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1028 {
1029 int ptr = 0;
1030 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1031   {
1032   if (ptr < max-1) name[ptr++] = *s;
1033   s++;
1034   }
1035 name[ptr] = 0;
1036 return s;
1037 }
1038
1039
1040
1041 /*************************************************
1042 *     Pick out the rest of a header name         *
1043 *************************************************/
1044
1045 /* A variable name starting $header_ (or just $h_ for those who like
1046 abbreviations) might not be the complete header name because headers can
1047 contain any printing characters in their names, except ':'. This function is
1048 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1049 on the end, if the name was terminated by white space.
1050
1051 Arguments:
1052   name      points to a buffer in which the name read so far exists
1053   max       is the length of the buffer
1054   s         points to the first character after the name so far, i.e. the
1055             first non-alphameric character after $header_xxxxx
1056
1057 Returns:    a pointer to the first character after the header name
1058 */
1059
1060 static const uschar *
1061 read_header_name(uschar *name, int max, const uschar *s)
1062 {
1063 int prelen = Ustrchr(name, '_') - name + 1;
1064 int ptr = Ustrlen(name) - prelen;
1065 if (ptr > 0) memmove(name, name+prelen, ptr);
1066 while (mac_isgraph(*s) && *s != ':')
1067   {
1068   if (ptr < max-1) name[ptr++] = *s;
1069   s++;
1070   }
1071 if (*s == ':') s++;
1072 name[ptr++] = ':';
1073 name[ptr] = 0;
1074 return s;
1075 }
1076
1077
1078
1079 /*************************************************
1080 *           Pick out a number from a string      *
1081 *************************************************/
1082
1083 /* Arguments:
1084   n     points to an integer into which to put the number
1085   s     points to the first digit of the number
1086
1087 Returns:  a pointer to the character after the last digit
1088 */
1089 /*XXX consider expanding to int_eximarith_t.  But the test for
1090 "overbig numbers" in 0002 still needs to overflow it. */
1091
1092 static uschar *
1093 read_number(int *n, uschar *s)
1094 {
1095 *n = 0;
1096 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1097 return s;
1098 }
1099
1100 static const uschar *
1101 read_cnumber(int *n, const uschar *s)
1102 {
1103 *n = 0;
1104 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1105 return s;
1106 }
1107
1108
1109
1110 /*************************************************
1111 *        Extract keyed subfield from a string    *
1112 *************************************************/
1113
1114 /* The yield is in dynamic store; NULL means that the key was not found.
1115
1116 Arguments:
1117   key       points to the name of the key
1118   s         points to the string from which to extract the subfield
1119
1120 Returns:    NULL if the subfield was not found, or
1121             a pointer to the subfield's data
1122 */
1123
1124 static uschar *
1125 expand_getkeyed(uschar *key, const uschar *s)
1126 {
1127 int length = Ustrlen(key);
1128 while (isspace(*s)) s++;
1129
1130 /* Loop to search for the key */
1131
1132 while (*s != 0)
1133   {
1134   int dkeylength;
1135   uschar *data;
1136   const uschar *dkey = s;
1137
1138   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1139   dkeylength = s - dkey;
1140   while (isspace(*s)) s++;
1141   if (*s == '=') while (isspace((*(++s))));
1142
1143   data = string_dequote(&s);
1144   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1145     return data;
1146
1147   while (isspace(*s)) s++;
1148   }
1149
1150 return NULL;
1151 }
1152
1153
1154
1155 static var_entry *
1156 find_var_ent(uschar * name)
1157 {
1158 int first = 0;
1159 int last = var_table_size;
1160
1161 while (last > first)
1162   {
1163   int middle = (first + last)/2;
1164   int c = Ustrcmp(name, var_table[middle].name);
1165
1166   if (c > 0) { first = middle + 1; continue; }
1167   if (c < 0) { last = middle; continue; }
1168   return &var_table[middle];
1169   }
1170 return NULL;
1171 }
1172
1173 /*************************************************
1174 *   Extract numbered subfield from string        *
1175 *************************************************/
1176
1177 /* Extracts a numbered field from a string that is divided by tokens - for
1178 example a line from /etc/passwd is divided by colon characters.  First field is
1179 numbered one.  Negative arguments count from the right. Zero returns the whole
1180 string. Returns NULL if there are insufficient tokens in the string
1181
1182 ***WARNING***
1183 Modifies final argument - this is a dynamically generated string, so that's OK.
1184
1185 Arguments:
1186   field       number of field to be extracted,
1187                 first field = 1, whole string = 0, last field = -1
1188   separators  characters that are used to break string into tokens
1189   s           points to the string from which to extract the subfield
1190
1191 Returns:      NULL if the field was not found,
1192               a pointer to the field's data inside s (modified to add 0)
1193 */
1194
1195 static uschar *
1196 expand_gettokened (int field, uschar *separators, uschar *s)
1197 {
1198 int sep = 1;
1199 int count;
1200 uschar *ss = s;
1201 uschar *fieldtext = NULL;
1202
1203 if (field == 0) return s;
1204
1205 /* Break the line up into fields in place; for field > 0 we stop when we have
1206 done the number of fields we want. For field < 0 we continue till the end of
1207 the string, counting the number of fields. */
1208
1209 count = (field > 0)? field : INT_MAX;
1210
1211 while (count-- > 0)
1212   {
1213   size_t len;
1214
1215   /* Previous field was the last one in the string. For a positive field
1216   number, this means there are not enough fields. For a negative field number,
1217   check that there are enough, and scan back to find the one that is wanted. */
1218
1219   if (sep == 0)
1220     {
1221     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1222     if ((-field) == (INT_MAX - count - 1)) return s;
1223     while (field++ < 0)
1224       {
1225       ss--;
1226       while (ss[-1] != 0) ss--;
1227       }
1228     fieldtext = ss;
1229     break;
1230     }
1231
1232   /* Previous field was not last in the string; save its start and put a
1233   zero at its end. */
1234
1235   fieldtext = ss;
1236   len = Ustrcspn(ss, separators);
1237   sep = ss[len];
1238   ss[len] = 0;
1239   ss += len + 1;
1240   }
1241
1242 return fieldtext;
1243 }
1244
1245
1246 static uschar *
1247 expand_getlistele(int field, const uschar * list)
1248 {
1249 const uschar * tlist= list;
1250 int sep= 0;
1251 uschar dummy;
1252
1253 if(field<0)
1254   {
1255   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1256   sep= 0;
1257   }
1258 if(field==0) return NULL;
1259 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1260 return string_nextinlist(&list, &sep, NULL, 0);
1261 }
1262
1263
1264 /* Certificate fields, by name.  Worry about by-OID later */
1265 /* Names are chosen to not have common prefixes */
1266
1267 #ifdef SUPPORT_TLS
1268 typedef struct
1269 {
1270 uschar * name;
1271 int      namelen;
1272 uschar * (*getfn)(void * cert, uschar * mod);
1273 } certfield;
1274 static certfield certfields[] =
1275 {                       /* linear search; no special order */
1276   { US"version",         7,  &tls_cert_version },
1277   { US"serial_number",   13, &tls_cert_serial_number },
1278   { US"subject",         7,  &tls_cert_subject },
1279   { US"notbefore",       9,  &tls_cert_not_before },
1280   { US"notafter",        8,  &tls_cert_not_after },
1281   { US"issuer",          6,  &tls_cert_issuer },
1282   { US"signature",       9,  &tls_cert_signature },
1283   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1284   { US"subj_altname",    12, &tls_cert_subject_altname },
1285   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1286   { US"crl_uri",         7,  &tls_cert_crl_uri },
1287 };
1288
1289 static uschar *
1290 expand_getcertele(uschar * field, uschar * certvar)
1291 {
1292 var_entry * vp;
1293 certfield * cp;
1294
1295 if (!(vp = find_var_ent(certvar)))
1296   {
1297   expand_string_message =
1298     string_sprintf("no variable named \"%s\"", certvar);
1299   return NULL;          /* Unknown variable name */
1300   }
1301 /* NB this stops us passing certs around in variable.  Might
1302 want to do that in future */
1303 if (vp->type != vtype_cert)
1304   {
1305   expand_string_message =
1306     string_sprintf("\"%s\" is not a certificate", certvar);
1307   return NULL;          /* Unknown variable name */
1308   }
1309 if (!*(void **)vp->value)
1310   return NULL;
1311
1312 if (*field >= '0' && *field <= '9')
1313   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1314
1315 for(cp = certfields;
1316     cp < certfields + nelem(certfields);
1317     cp++)
1318   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1319     {
1320     uschar * modifier = *(field += cp->namelen) == ','
1321       ? ++field : NULL;
1322     return (*cp->getfn)( *(void **)vp->value, modifier );
1323     }
1324
1325 expand_string_message =
1326   string_sprintf("bad field selector \"%s\" for certextract", field);
1327 return NULL;
1328 }
1329 #endif  /*SUPPORT_TLS*/
1330
1331 /*************************************************
1332 *        Extract a substring from a string       *
1333 *************************************************/
1334
1335 /* Perform the ${substr or ${length expansion operations.
1336
1337 Arguments:
1338   subject     the input string
1339   value1      the offset from the start of the input string to the start of
1340                 the output string; if negative, count from the right.
1341   value2      the length of the output string, or negative (-1) for unset
1342                 if value1 is positive, unset means "all after"
1343                 if value1 is negative, unset means "all before"
1344   len         set to the length of the returned string
1345
1346 Returns:      pointer to the output string, or NULL if there is an error
1347 */
1348
1349 static uschar *
1350 extract_substr(uschar *subject, int value1, int value2, int *len)
1351 {
1352 int sublen = Ustrlen(subject);
1353
1354 if (value1 < 0)    /* count from right */
1355   {
1356   value1 += sublen;
1357
1358   /* If the position is before the start, skip to the start, and adjust the
1359   length. If the length ends up negative, the substring is null because nothing
1360   can precede. This falls out naturally when the length is unset, meaning "all
1361   to the left". */
1362
1363   if (value1 < 0)
1364     {
1365     value2 += value1;
1366     if (value2 < 0) value2 = 0;
1367     value1 = 0;
1368     }
1369
1370   /* Otherwise an unset length => characters before value1 */
1371
1372   else if (value2 < 0)
1373     {
1374     value2 = value1;
1375     value1 = 0;
1376     }
1377   }
1378
1379 /* For a non-negative offset, if the starting position is past the end of the
1380 string, the result will be the null string. Otherwise, an unset length means
1381 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1382
1383 else
1384   {
1385   if (value1 > sublen)
1386     {
1387     value1 = sublen;
1388     value2 = 0;
1389     }
1390   else if (value2 < 0) value2 = sublen;
1391   }
1392
1393 /* Cut the length down to the maximum possible for the offset value, and get
1394 the required characters. */
1395
1396 if (value1 + value2 > sublen) value2 = sublen - value1;
1397 *len = value2;
1398 return subject + value1;
1399 }
1400
1401
1402
1403
1404 /*************************************************
1405 *            Old-style hash of a string          *
1406 *************************************************/
1407
1408 /* Perform the ${hash expansion operation.
1409
1410 Arguments:
1411   subject     the input string (an expanded substring)
1412   value1      the length of the output string; if greater or equal to the
1413                 length of the input string, the input string is returned
1414   value2      the number of hash characters to use, or 26 if negative
1415   len         set to the length of the returned string
1416
1417 Returns:      pointer to the output string, or NULL if there is an error
1418 */
1419
1420 static uschar *
1421 compute_hash(uschar *subject, int value1, int value2, int *len)
1422 {
1423 int sublen = Ustrlen(subject);
1424
1425 if (value2 < 0) value2 = 26;
1426 else if (value2 > Ustrlen(hashcodes))
1427   {
1428   expand_string_message =
1429     string_sprintf("hash count \"%d\" too big", value2);
1430   return NULL;
1431   }
1432
1433 /* Calculate the hash text. We know it is shorter than the original string, so
1434 can safely place it in subject[] (we know that subject is always itself an
1435 expanded substring). */
1436
1437 if (value1 < sublen)
1438   {
1439   int c;
1440   int i = 0;
1441   int j = value1;
1442   while ((c = (subject[j])) != 0)
1443     {
1444     int shift = (c + j++) & 7;
1445     subject[i] ^= (c << shift) | (c >> (8-shift));
1446     if (++i >= value1) i = 0;
1447     }
1448   for (i = 0; i < value1; i++)
1449     subject[i] = hashcodes[(subject[i]) % value2];
1450   }
1451 else value1 = sublen;
1452
1453 *len = value1;
1454 return subject;
1455 }
1456
1457
1458
1459
1460 /*************************************************
1461 *             Numeric hash of a string           *
1462 *************************************************/
1463
1464 /* Perform the ${nhash expansion operation. The first characters of the
1465 string are treated as most important, and get the highest prime numbers.
1466
1467 Arguments:
1468   subject     the input string
1469   value1      the maximum value of the first part of the result
1470   value2      the maximum value of the second part of the result,
1471                 or negative to produce only a one-part result
1472   len         set to the length of the returned string
1473
1474 Returns:  pointer to the output string, or NULL if there is an error.
1475 */
1476
1477 static uschar *
1478 compute_nhash (uschar *subject, int value1, int value2, int *len)
1479 {
1480 uschar *s = subject;
1481 int i = 0;
1482 unsigned long int total = 0; /* no overflow */
1483
1484 while (*s != 0)
1485   {
1486   if (i == 0) i = nelem(prime) - 1;
1487   total += prime[i--] * (unsigned int)(*s++);
1488   }
1489
1490 /* If value2 is unset, just compute one number */
1491
1492 if (value2 < 0)
1493   s = string_sprintf("%lu", total % value1);
1494
1495 /* Otherwise do a div/mod hash */
1496
1497 else
1498   {
1499   total = total % (value1 * value2);
1500   s = string_sprintf("%lu/%lu", total/value2, total % value2);
1501   }
1502
1503 *len = Ustrlen(s);
1504 return s;
1505 }
1506
1507
1508
1509
1510
1511 /*************************************************
1512 *     Find the value of a header or headers      *
1513 *************************************************/
1514
1515 /* Multiple instances of the same header get concatenated, and this function
1516 can also return a concatenation of all the header lines. When concatenating
1517 specific headers that contain lists of addresses, a comma is inserted between
1518 them. Otherwise we use a straight concatenation. Because some messages can have
1519 pathologically large number of lines, there is a limit on the length that is
1520 returned. Also, to avoid massive store use which would result from using
1521 string_cat() as it copies and extends strings, we do a preliminary pass to find
1522 out exactly how much store will be needed. On "normal" messages this will be
1523 pretty trivial.
1524
1525 Arguments:
1526   name          the name of the header, without the leading $header_ or $h_,
1527                 or NULL if a concatenation of all headers is required
1528   exists_only   TRUE if called from a def: test; don't need to build a string;
1529                 just return a string that is not "" and not "0" if the header
1530                 exists
1531   newsize       return the size of memory block that was obtained; may be NULL
1532                 if exists_only is TRUE
1533   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1534                 other than concatenating, will be done on the header. Also used
1535                 for $message_headers_raw.
1536   charset       name of charset to translate MIME words to; used only if
1537                 want_raw is false; if NULL, no translation is done (this is
1538                 used for $bh_ and $bheader_)
1539
1540 Returns:        NULL if the header does not exist, else a pointer to a new
1541                 store block
1542 */
1543
1544 static uschar *
1545 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1546   uschar *charset)
1547 {
1548 BOOL found = name == NULL;
1549 int comma = 0;
1550 int len = found? 0 : Ustrlen(name);
1551 int i;
1552 uschar *yield = NULL;
1553 uschar *ptr = NULL;
1554
1555 /* Loop for two passes - saves code repetition */
1556
1557 for (i = 0; i < 2; i++)
1558   {
1559   int size = 0;
1560   header_line *h;
1561
1562   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1563     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1564       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1565         {
1566         int ilen;
1567         uschar *t;
1568
1569         if (exists_only) return US"1";      /* don't need actual string */
1570         found = TRUE;
1571         t = h->text + len;                  /* text to insert */
1572         if (!want_raw)                      /* unless wanted raw, */
1573           while (isspace(*t)) t++;          /* remove leading white space */
1574         ilen = h->slen - (t - h->text);     /* length to insert */
1575
1576         /* Unless wanted raw, remove trailing whitespace, including the
1577         newline. */
1578
1579         if (!want_raw)
1580           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1581
1582         /* Set comma = 1 if handling a single header and it's one of those
1583         that contains an address list, except when asked for raw headers. Only
1584         need to do this once. */
1585
1586         if (!want_raw && name && comma == 0 &&
1587             Ustrchr("BCFRST", h->type) != NULL)
1588           comma = 1;
1589
1590         /* First pass - compute total store needed; second pass - compute
1591         total store used, including this header. */
1592
1593         size += ilen + comma + 1;  /* +1 for the newline */
1594
1595         /* Second pass - concatenate the data, up to a maximum. Note that
1596         the loop stops when size hits the limit. */
1597
1598         if (i != 0)
1599           {
1600           if (size > header_insert_maxlen)
1601             {
1602             ilen -= size - header_insert_maxlen - 1;
1603             comma = 0;
1604             }
1605           Ustrncpy(ptr, t, ilen);
1606           ptr += ilen;
1607
1608           /* For a non-raw header, put in the comma if needed, then add
1609           back the newline we removed above, provided there was some text in
1610           the header. */
1611
1612           if (!want_raw && ilen > 0)
1613             {
1614             if (comma != 0) *ptr++ = ',';
1615             *ptr++ = '\n';
1616             }
1617           }
1618         }
1619
1620   /* At end of first pass, return NULL if no header found. Then truncate size
1621   if necessary, and get the buffer to hold the data, returning the buffer size.
1622   */
1623
1624   if (i == 0)
1625     {
1626     if (!found) return NULL;
1627     if (size > header_insert_maxlen) size = header_insert_maxlen;
1628     *newsize = size + 1;
1629     ptr = yield = store_get(*newsize);
1630     }
1631   }
1632
1633 /* That's all we do for raw header expansion. */
1634
1635 if (want_raw)
1636   *ptr = 0;
1637
1638 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1639 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1640 function can return an error with decoded data if the charset translation
1641 fails. If decoding fails, it returns NULL. */
1642
1643 else
1644   {
1645   uschar *decoded, *error;
1646   if (ptr > yield && ptr[-1] == '\n') ptr--;
1647   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1648   *ptr = 0;
1649   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1650     newsize, &error);
1651   if (error != NULL)
1652     {
1653     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1654       "    input was: %s\n", error, yield);
1655     }
1656   if (decoded != NULL) yield = decoded;
1657   }
1658
1659 return yield;
1660 }
1661
1662
1663
1664
1665 /* Append an "iprev" element to an Autherntication-Results: header
1666 if we have attempted to get the calling host's name.
1667 */
1668
1669 static gstring *
1670 authres_iprev(gstring * g)
1671 {
1672 if (sender_host_name)
1673   return string_append(g, 3, US";\n\tiprev=pass (", sender_host_name, US")");
1674 if (host_lookup_deferred)
1675   return string_catn(g, US";\n\tiprev=temperror", 19);
1676 if (host_lookup_failed)
1677   return string_catn(g, US";\n\tiprev=fail", 13);
1678 return g;
1679 }
1680
1681
1682
1683 /*************************************************
1684 *               Return list of recipients        *
1685 *************************************************/
1686 /* A recipients list is available only during system message filtering,
1687 during ACL processing after DATA, and while expanding pipe commands
1688 generated from a system filter, but not elsewhere. */
1689
1690 static uschar *
1691 fn_recipients(void)
1692 {
1693 gstring * g = NULL;
1694 int i;
1695
1696 if (!enable_dollar_recipients) return NULL;
1697
1698 for (i = 0; i < recipients_count; i++)
1699   {
1700   /*XXX variant of list_appendele? */
1701   if (i != 0) g = string_catn(g, US", ", 2);
1702   g = string_cat(g, recipients_list[i].address);
1703   }
1704 return string_from_gstring(g);
1705 }
1706
1707
1708 /*************************************************
1709 *               Find value of a variable         *
1710 *************************************************/
1711
1712 /* The table of variables is kept in alphabetic order, so we can search it
1713 using a binary chop. The "choplen" variable is nothing to do with the binary
1714 chop.
1715
1716 Arguments:
1717   name          the name of the variable being sought
1718   exists_only   TRUE if this is a def: test; passed on to find_header()
1719   skipping      TRUE => skip any processing evaluation; this is not the same as
1720                   exists_only because def: may test for values that are first
1721                   evaluated here
1722   newsize       pointer to an int which is initially zero; if the answer is in
1723                 a new memory buffer, *newsize is set to its size
1724
1725 Returns:        NULL if the variable does not exist, or
1726                 a pointer to the variable's contents, or
1727                 something non-NULL if exists_only is TRUE
1728 */
1729
1730 static uschar *
1731 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1732 {
1733 var_entry * vp;
1734 uschar *s, *domain;
1735 uschar **ss;
1736 void * val;
1737
1738 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1739 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1740 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1741 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1742 (this gave backwards compatibility at the changeover). There may be built-in
1743 variables whose names start acl_ but they should never start in this way. This
1744 slightly messy specification is a consequence of the history, needless to say.
1745
1746 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1747 set, in which case give an error. */
1748
1749 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1750      !isalpha(name[5]))
1751   {
1752   tree_node *node =
1753     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1754   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1755   }
1756
1757 /* Handle $auth<n> variables. */
1758
1759 if (Ustrncmp(name, "auth", 4) == 0)
1760   {
1761   uschar *endptr;
1762   int n = Ustrtoul(name + 4, &endptr, 10);
1763   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1764     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1765   }
1766 else if (Ustrncmp(name, "regex", 5) == 0)
1767   {
1768   uschar *endptr;
1769   int n = Ustrtoul(name + 5, &endptr, 10);
1770   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1771     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1772   }
1773
1774 /* For all other variables, search the table */
1775
1776 if (!(vp = find_var_ent(name)))
1777   return NULL;          /* Unknown variable name */
1778
1779 /* Found an existing variable. If in skipping state, the value isn't needed,
1780 and we want to avoid processing (such as looking up the host name). */
1781
1782 if (skipping)
1783   return US"";
1784
1785 val = vp->value;
1786 switch (vp->type)
1787   {
1788   case vtype_filter_int:
1789     if (!filter_running) return NULL;
1790     /* Fall through */
1791     /* VVVVVVVVVVVV */
1792   case vtype_int:
1793     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1794     return var_buffer;
1795
1796   case vtype_ino:
1797     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1798     return var_buffer;
1799
1800   case vtype_gid:
1801     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1802     return var_buffer;
1803
1804   case vtype_uid:
1805     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1806     return var_buffer;
1807
1808   case vtype_bool:
1809     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1810     return var_buffer;
1811
1812   case vtype_stringptr:                      /* Pointer to string */
1813     return (s = *((uschar **)(val))) ? s : US"";
1814
1815   case vtype_pid:
1816     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1817     return var_buffer;
1818
1819   case vtype_load_avg:
1820     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1821     return var_buffer;
1822
1823   case vtype_host_lookup:                    /* Lookup if not done so */
1824     if (  !sender_host_name && sender_host_address
1825        && !host_lookup_failed && host_name_lookup() == OK)
1826       host_build_sender_fullhost();
1827     return sender_host_name ? sender_host_name : US"";
1828
1829   case vtype_localpart:                      /* Get local part from address */
1830     s = *((uschar **)(val));
1831     if (s == NULL) return US"";
1832     domain = Ustrrchr(s, '@');
1833     if (domain == NULL) return s;
1834     if (domain - s > sizeof(var_buffer) - 1)
1835       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1836           " in string expansion", sizeof(var_buffer));
1837     Ustrncpy(var_buffer, s, domain - s);
1838     var_buffer[domain - s] = 0;
1839     return var_buffer;
1840
1841   case vtype_domain:                         /* Get domain from address */
1842     s = *((uschar **)(val));
1843     if (s == NULL) return US"";
1844     domain = Ustrrchr(s, '@');
1845     return (domain == NULL)? US"" : domain + 1;
1846
1847   case vtype_msgheaders:
1848     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1849
1850   case vtype_msgheaders_raw:
1851     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1852
1853   case vtype_msgbody:                        /* Pointer to msgbody string */
1854   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1855     ss = (uschar **)(val);
1856     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1857       {
1858       uschar *body;
1859       off_t start_offset = SPOOL_DATA_START_OFFSET;
1860       int len = message_body_visible;
1861       if (len > message_size) len = message_size;
1862       *ss = body = store_malloc(len+1);
1863       body[0] = 0;
1864       if (vp->type == vtype_msgbody_end)
1865         {
1866         struct stat statbuf;
1867         if (fstat(deliver_datafile, &statbuf) == 0)
1868           {
1869           start_offset = statbuf.st_size - len;
1870           if (start_offset < SPOOL_DATA_START_OFFSET)
1871             start_offset = SPOOL_DATA_START_OFFSET;
1872           }
1873         }
1874       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1875         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1876           strerror(errno));
1877       len = read(deliver_datafile, body, len);
1878       if (len > 0)
1879         {
1880         body[len] = 0;
1881         if (message_body_newlines)   /* Separate loops for efficiency */
1882           while (len > 0)
1883             { if (body[--len] == 0) body[len] = ' '; }
1884         else
1885           while (len > 0)
1886             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1887         }
1888       }
1889     return *ss ? *ss : US"";
1890
1891   case vtype_todbsdin:                       /* BSD inbox time of day */
1892     return tod_stamp(tod_bsdin);
1893
1894   case vtype_tode:                           /* Unix epoch time of day */
1895     return tod_stamp(tod_epoch);
1896
1897   case vtype_todel:                          /* Unix epoch/usec time of day */
1898     return tod_stamp(tod_epoch_l);
1899
1900   case vtype_todf:                           /* Full time of day */
1901     return tod_stamp(tod_full);
1902
1903   case vtype_todl:                           /* Log format time of day */
1904     return tod_stamp(tod_log_bare);            /* (without timezone) */
1905
1906   case vtype_todzone:                        /* Time zone offset only */
1907     return tod_stamp(tod_zone);
1908
1909   case vtype_todzulu:                        /* Zulu time */
1910     return tod_stamp(tod_zulu);
1911
1912   case vtype_todlf:                          /* Log file datestamp tod */
1913     return tod_stamp(tod_log_datestamp_daily);
1914
1915   case vtype_reply:                          /* Get reply address */
1916     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1917       headers_charset);
1918     if (s != NULL) while (isspace(*s)) s++;
1919     if (s == NULL || *s == 0)
1920       {
1921       *newsize = 0;                            /* For the *s==0 case */
1922       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1923       }
1924     if (s != NULL)
1925       {
1926       uschar *t;
1927       while (isspace(*s)) s++;
1928       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1929       while (t > s && isspace(t[-1])) t--;
1930       *t = 0;
1931       }
1932     return (s == NULL)? US"" : s;
1933
1934   case vtype_string_func:
1935     {
1936     uschar * (*fn)() = val;
1937     return fn();
1938     }
1939
1940   case vtype_pspace:
1941     {
1942     int inodes;
1943     sprintf(CS var_buffer, "%d",
1944       receive_statvfs(val == (void *)TRUE, &inodes));
1945     }
1946   return var_buffer;
1947
1948   case vtype_pinodes:
1949     {
1950     int inodes;
1951     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1952     sprintf(CS var_buffer, "%d", inodes);
1953     }
1954   return var_buffer;
1955
1956   case vtype_cert:
1957     return *(void **)val ? US"<cert>" : US"";
1958
1959 #ifndef DISABLE_DKIM
1960   case vtype_dkim:
1961     return dkim_exim_expand_query((int)(long)val);
1962 #endif
1963
1964   }
1965
1966 return NULL;  /* Unknown variable. Silences static checkers. */
1967 }
1968
1969
1970
1971
1972 void
1973 modify_variable(uschar *name, void * value)
1974 {
1975 var_entry * vp;
1976 if ((vp = find_var_ent(name))) vp->value = value;
1977 return;          /* Unknown variable name, fail silently */
1978 }
1979
1980
1981
1982
1983
1984
1985 /*************************************************
1986 *           Read and expand substrings           *
1987 *************************************************/
1988
1989 /* This function is called to read and expand argument substrings for various
1990 expansion items. Some have a minimum requirement that is less than the maximum;
1991 in these cases, the first non-present one is set to NULL.
1992
1993 Arguments:
1994   sub        points to vector of pointers to set
1995   n          maximum number of substrings
1996   m          minimum required
1997   sptr       points to current string pointer
1998   skipping   the skipping flag
1999   check_end  if TRUE, check for final '}'
2000   name       name of item, for error message
2001   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
2002              the store.
2003
2004 Returns:     0 OK; string pointer updated
2005              1 curly bracketing error (too few arguments)
2006              2 too many arguments (only if check_end is set); message set
2007              3 other error (expansion failure)
2008 */
2009
2010 static int
2011 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
2012   BOOL check_end, uschar *name, BOOL *resetok)
2013 {
2014 int i;
2015 const uschar *s = *sptr;
2016
2017 while (isspace(*s)) s++;
2018 for (i = 0; i < n; i++)
2019   {
2020   if (*s != '{')
2021     {
2022     if (i < m)
2023       {
2024       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2025         "(min is %d)", name, m);
2026       return 1;
2027       }
2028     sub[i] = NULL;
2029     break;
2030     }
2031   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2032     return 3;
2033   if (*s++ != '}') return 1;
2034   while (isspace(*s)) s++;
2035   }
2036 if (check_end && *s++ != '}')
2037   {
2038   if (s[-1] == '{')
2039     {
2040     expand_string_message = string_sprintf("Too many arguments for '%s' "
2041       "(max is %d)", name, n);
2042     return 2;
2043     }
2044   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2045   return 1;
2046   }
2047
2048 *sptr = s;
2049 return 0;
2050 }
2051
2052
2053
2054
2055 /*************************************************
2056 *     Elaborate message for bad variable         *
2057 *************************************************/
2058
2059 /* For the "unknown variable" message, take a look at the variable's name, and
2060 give additional information about possible ACL variables. The extra information
2061 is added on to expand_string_message.
2062
2063 Argument:   the name of the variable
2064 Returns:    nothing
2065 */
2066
2067 static void
2068 check_variable_error_message(uschar *name)
2069 {
2070 if (Ustrncmp(name, "acl_", 4) == 0)
2071   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2072     (name[4] == 'c' || name[4] == 'm')?
2073       (isalpha(name[5])?
2074         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2075         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2076       ) :
2077       US"user-defined ACL variables must start acl_c or acl_m");
2078 }
2079
2080
2081
2082 /*
2083 Load args from sub array to globals, and call acl_check().
2084 Sub array will be corrupted on return.
2085
2086 Returns:       OK         access is granted by an ACCEPT verb
2087                DISCARD    access is (apparently) granted by a DISCARD verb
2088                FAIL       access is denied
2089                FAIL_DROP  access is denied; drop the connection
2090                DEFER      can't tell at the moment
2091                ERROR      disaster
2092 */
2093 static int
2094 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2095 {
2096 int i;
2097 int sav_narg = acl_narg;
2098 int ret;
2099 uschar * dummy_logmsg;
2100 extern int acl_where;
2101
2102 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2103 for (i = 0; i < nsub && sub[i+1]; i++)
2104   {
2105   uschar * tmp = acl_arg[i];
2106   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2107   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2108   }
2109 acl_narg = i;
2110 while (i < nsub)
2111   {
2112   sub[i+1] = acl_arg[i];
2113   acl_arg[i++] = NULL;
2114   }
2115
2116 DEBUG(D_expand)
2117   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2118     sub[0],
2119     acl_narg>0 ? acl_arg[0] : US"<none>",
2120     acl_narg>1 ? " +more"   : "");
2121
2122 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2123
2124 for (i = 0; i < nsub; i++)
2125   acl_arg[i] = sub[i+1];        /* restore old args */
2126 acl_narg = sav_narg;
2127
2128 return ret;
2129 }
2130
2131
2132
2133
2134 /*************************************************
2135 *        Read and evaluate a condition           *
2136 *************************************************/
2137
2138 /*
2139 Arguments:
2140   s        points to the start of the condition text
2141   resetok  points to a BOOL which is written false if it is unsafe to
2142            free memory. Certain condition types (acl) may have side-effect
2143            allocation which must be preserved.
2144   yield    points to a BOOL to hold the result of the condition test;
2145            if NULL, we are just reading through a condition that is
2146            part of an "or" combination to check syntax, or in a state
2147            where the answer isn't required
2148
2149 Returns:   a pointer to the first character after the condition, or
2150            NULL after an error
2151 */
2152
2153 static const uschar *
2154 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2155 {
2156 BOOL testfor = TRUE;
2157 BOOL tempcond, combined_cond;
2158 BOOL *subcondptr;
2159 BOOL sub2_honour_dollar = TRUE;
2160 int i, rc, cond_type, roffset;
2161 int_eximarith_t num[2];
2162 struct stat statbuf;
2163 uschar name[256];
2164 const uschar *sub[10];
2165
2166 const pcre *re;
2167 const uschar *rerror;
2168
2169 for (;;)
2170   {
2171   while (isspace(*s)) s++;
2172   if (*s == '!') { testfor = !testfor; s++; } else break;
2173   }
2174
2175 /* Numeric comparisons are symbolic */
2176
2177 if (*s == '=' || *s == '>' || *s == '<')
2178   {
2179   int p = 0;
2180   name[p++] = *s++;
2181   if (*s == '=')
2182     {
2183     name[p++] = '=';
2184     s++;
2185     }
2186   name[p] = 0;
2187   }
2188
2189 /* All other conditions are named */
2190
2191 else s = read_name(name, 256, s, US"_");
2192
2193 /* If we haven't read a name, it means some non-alpha character is first. */
2194
2195 if (name[0] == 0)
2196   {
2197   expand_string_message = string_sprintf("condition name expected, "
2198     "but found \"%.16s\"", s);
2199   return NULL;
2200   }
2201
2202 /* Find which condition we are dealing with, and switch on it */
2203
2204 cond_type = chop_match(name, cond_table, nelem(cond_table));
2205 switch(cond_type)
2206   {
2207   /* def: tests for a non-empty variable, or for the existence of a header. If
2208   yield == NULL we are in a skipping state, and don't care about the answer. */
2209
2210   case ECOND_DEF:
2211   if (*s != ':')
2212     {
2213     expand_string_message = US"\":\" expected after \"def\"";
2214     return NULL;
2215     }
2216
2217   s = read_name(name, 256, s+1, US"_");
2218
2219   /* Test for a header's existence. If the name contains a closing brace
2220   character, this may be a user error where the terminating colon has been
2221   omitted. Set a flag to adjust a subsequent error message in this case. */
2222
2223   if (Ustrncmp(name, "h_", 2) == 0 ||
2224       Ustrncmp(name, "rh_", 3) == 0 ||
2225       Ustrncmp(name, "bh_", 3) == 0 ||
2226       Ustrncmp(name, "header_", 7) == 0 ||
2227       Ustrncmp(name, "rheader_", 8) == 0 ||
2228       Ustrncmp(name, "bheader_", 8) == 0)
2229     {
2230     s = read_header_name(name, 256, s);
2231     /* {-for-text-editors */
2232     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2233     if (yield != NULL) *yield =
2234       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2235     }
2236
2237   /* Test for a variable's having a non-empty value. A non-existent variable
2238   causes an expansion failure. */
2239
2240   else
2241     {
2242     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2243     if (value == NULL)
2244       {
2245       expand_string_message = (name[0] == 0)?
2246         string_sprintf("variable name omitted after \"def:\"") :
2247         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2248       check_variable_error_message(name);
2249       return NULL;
2250       }
2251     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2252     }
2253
2254   return s;
2255
2256
2257   /* first_delivery tests for first delivery attempt */
2258
2259   case ECOND_FIRST_DELIVERY:
2260   if (yield != NULL) *yield = deliver_firsttime == testfor;
2261   return s;
2262
2263
2264   /* queue_running tests for any process started by a queue runner */
2265
2266   case ECOND_QUEUE_RUNNING:
2267   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2268   return s;
2269
2270
2271   /* exists:  tests for file existence
2272        isip:  tests for any IP address
2273       isip4:  tests for an IPv4 address
2274       isip6:  tests for an IPv6 address
2275         pam:  does PAM authentication
2276      radius:  does RADIUS authentication
2277    ldapauth:  does LDAP authentication
2278     pwcheck:  does Cyrus SASL pwcheck authentication
2279   */
2280
2281   case ECOND_EXISTS:
2282   case ECOND_ISIP:
2283   case ECOND_ISIP4:
2284   case ECOND_ISIP6:
2285   case ECOND_PAM:
2286   case ECOND_RADIUS:
2287   case ECOND_LDAPAUTH:
2288   case ECOND_PWCHECK:
2289
2290   while (isspace(*s)) s++;
2291   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2292
2293   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2294   if (sub[0] == NULL) return NULL;
2295   /* {-for-text-editors */
2296   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2297
2298   if (yield == NULL) return s;   /* No need to run the test if skipping */
2299
2300   switch(cond_type)
2301     {
2302     case ECOND_EXISTS:
2303     if ((expand_forbid & RDO_EXISTS) != 0)
2304       {
2305       expand_string_message = US"File existence tests are not permitted";
2306       return NULL;
2307       }
2308     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2309     break;
2310
2311     case ECOND_ISIP:
2312     case ECOND_ISIP4:
2313     case ECOND_ISIP6:
2314     rc = string_is_ip_address(sub[0], NULL);
2315     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2316              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2317     break;
2318
2319     /* Various authentication tests - all optionally compiled */
2320
2321     case ECOND_PAM:
2322     #ifdef SUPPORT_PAM
2323     rc = auth_call_pam(sub[0], &expand_string_message);
2324     goto END_AUTH;
2325     #else
2326     goto COND_FAILED_NOT_COMPILED;
2327     #endif  /* SUPPORT_PAM */
2328
2329     case ECOND_RADIUS:
2330     #ifdef RADIUS_CONFIG_FILE
2331     rc = auth_call_radius(sub[0], &expand_string_message);
2332     goto END_AUTH;
2333     #else
2334     goto COND_FAILED_NOT_COMPILED;
2335     #endif  /* RADIUS_CONFIG_FILE */
2336
2337     case ECOND_LDAPAUTH:
2338     #ifdef LOOKUP_LDAP
2339       {
2340       /* Just to keep the interface the same */
2341       BOOL do_cache;
2342       int old_pool = store_pool;
2343       store_pool = POOL_SEARCH;
2344       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2345         &expand_string_message, &do_cache);
2346       store_pool = old_pool;
2347       }
2348     goto END_AUTH;
2349     #else
2350     goto COND_FAILED_NOT_COMPILED;
2351     #endif  /* LOOKUP_LDAP */
2352
2353     case ECOND_PWCHECK:
2354     #ifdef CYRUS_PWCHECK_SOCKET
2355     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2356     goto END_AUTH;
2357     #else
2358     goto COND_FAILED_NOT_COMPILED;
2359     #endif  /* CYRUS_PWCHECK_SOCKET */
2360
2361     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2362         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2363     END_AUTH:
2364     if (rc == ERROR || rc == DEFER) return NULL;
2365     *yield = (rc == OK) == testfor;
2366     #endif
2367     }
2368   return s;
2369
2370
2371   /* call ACL (in a conditional context).  Accept true, deny false.
2372   Defer is a forced-fail.  Anything set by message= goes to $value.
2373   Up to ten parameters are used; we use the braces round the name+args
2374   like the saslauthd condition does, to permit a variable number of args.
2375   See also the expansion-item version EITEM_ACL and the traditional
2376   acl modifier ACLC_ACL.
2377   Since the ACL may allocate new global variables, tell our caller to not
2378   reclaim memory.
2379   */
2380
2381   case ECOND_ACL:
2382     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2383     {
2384     uschar *sub[10];
2385     uschar *user_msg;
2386     BOOL cond = FALSE;
2387
2388     while (isspace(*s)) s++;
2389     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2390
2391     switch(read_subs(sub, nelem(sub), 1,
2392       &s, yield == NULL, TRUE, US"acl", resetok))
2393       {
2394       case 1: expand_string_message = US"too few arguments or bracketing "
2395         "error for acl";
2396       case 2:
2397       case 3: return NULL;
2398       }
2399
2400     if (yield != NULL)
2401       {
2402       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2403       switch(eval_acl(sub, nelem(sub), &user_msg))
2404         {
2405         case OK:
2406           cond = TRUE;
2407         case FAIL:
2408           lookup_value = NULL;
2409           if (user_msg)
2410             lookup_value = string_copy(user_msg);
2411           *yield = cond == testfor;
2412           break;
2413
2414         case DEFER:
2415           expand_string_forcedfail = TRUE;
2416           /*FALLTHROUGH*/
2417         default:
2418           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2419           return NULL;
2420         }
2421       }
2422     return s;
2423     }
2424
2425
2426   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2427
2428      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2429
2430   However, the last two are optional. That is why the whole set is enclosed
2431   in their own set of braces. */
2432
2433   case ECOND_SASLAUTHD:
2434 #ifndef CYRUS_SASLAUTHD_SOCKET
2435     goto COND_FAILED_NOT_COMPILED;
2436 #else
2437     {
2438     uschar *sub[4];
2439     while (isspace(*s)) s++;
2440     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2441     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2442                     resetok))
2443       {
2444       case 1: expand_string_message = US"too few arguments or bracketing "
2445         "error for saslauthd";
2446       case 2:
2447       case 3: return NULL;
2448       }
2449     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2450     if (yield != NULL)
2451       {
2452       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2453         &expand_string_message);
2454       if (rc == ERROR || rc == DEFER) return NULL;
2455       *yield = (rc == OK) == testfor;
2456       }
2457     return s;
2458     }
2459 #endif /* CYRUS_SASLAUTHD_SOCKET */
2460
2461
2462   /* symbolic operators for numeric and string comparison, and a number of
2463   other operators, all requiring two arguments.
2464
2465   crypteq:           encrypts plaintext and compares against an encrypted text,
2466                        using crypt(), crypt16(), MD5 or SHA-1
2467   inlist/inlisti:    checks if first argument is in the list of the second
2468   match:             does a regular expression match and sets up the numerical
2469                        variables if it succeeds
2470   match_address:     matches in an address list
2471   match_domain:      matches in a domain list
2472   match_ip:          matches a host list that is restricted to IP addresses
2473   match_local_part:  matches in a local part list
2474   */
2475
2476   case ECOND_MATCH_ADDRESS:
2477   case ECOND_MATCH_DOMAIN:
2478   case ECOND_MATCH_IP:
2479   case ECOND_MATCH_LOCAL_PART:
2480 #ifndef EXPAND_LISTMATCH_RHS
2481     sub2_honour_dollar = FALSE;
2482 #endif
2483     /* FALLTHROUGH */
2484
2485   case ECOND_CRYPTEQ:
2486   case ECOND_INLIST:
2487   case ECOND_INLISTI:
2488   case ECOND_MATCH:
2489
2490   case ECOND_NUM_L:     /* Numerical comparisons */
2491   case ECOND_NUM_LE:
2492   case ECOND_NUM_E:
2493   case ECOND_NUM_EE:
2494   case ECOND_NUM_G:
2495   case ECOND_NUM_GE:
2496
2497   case ECOND_STR_LT:    /* String comparisons */
2498   case ECOND_STR_LTI:
2499   case ECOND_STR_LE:
2500   case ECOND_STR_LEI:
2501   case ECOND_STR_EQ:
2502   case ECOND_STR_EQI:
2503   case ECOND_STR_GT:
2504   case ECOND_STR_GTI:
2505   case ECOND_STR_GE:
2506   case ECOND_STR_GEI:
2507
2508   for (i = 0; i < 2; i++)
2509     {
2510     /* Sometimes, we don't expand substrings; too many insecure configurations
2511     created using match_address{}{} and friends, where the second param
2512     includes information from untrustworthy sources. */
2513     BOOL honour_dollar = TRUE;
2514     if ((i > 0) && !sub2_honour_dollar)
2515       honour_dollar = FALSE;
2516
2517     while (isspace(*s)) s++;
2518     if (*s != '{')
2519       {
2520       if (i == 0) goto COND_FAILED_CURLY_START;
2521       expand_string_message = string_sprintf("missing 2nd string in {} "
2522         "after \"%s\"", name);
2523       return NULL;
2524       }
2525     if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2526         honour_dollar, resetok)))
2527       return NULL;
2528     DEBUG(D_expand) if (i == 1 && !sub2_honour_dollar && Ustrchr(sub[1], '$'))
2529       debug_printf_indent("WARNING: the second arg is NOT expanded,"
2530                         " for security reasons\n");
2531     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2532
2533     /* Convert to numerical if required; we know that the names of all the
2534     conditions that compare numbers do not start with a letter. This just saves
2535     checking for them individually. */
2536
2537     if (!isalpha(name[0]) && yield != NULL)
2538       if (sub[i][0] == 0)
2539         {
2540         num[i] = 0;
2541         DEBUG(D_expand)
2542           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2543         }
2544       else
2545         {
2546         num[i] = expanded_string_integer(sub[i], FALSE);
2547         if (expand_string_message != NULL) return NULL;
2548         }
2549     }
2550
2551   /* Result not required */
2552
2553   if (yield == NULL) return s;
2554
2555   /* Do an appropriate comparison */
2556
2557   switch(cond_type)
2558     {
2559     case ECOND_NUM_E:
2560     case ECOND_NUM_EE:
2561     tempcond = (num[0] == num[1]);
2562     break;
2563
2564     case ECOND_NUM_G:
2565     tempcond = (num[0] > num[1]);
2566     break;
2567
2568     case ECOND_NUM_GE:
2569     tempcond = (num[0] >= num[1]);
2570     break;
2571
2572     case ECOND_NUM_L:
2573     tempcond = (num[0] < num[1]);
2574     break;
2575
2576     case ECOND_NUM_LE:
2577     tempcond = (num[0] <= num[1]);
2578     break;
2579
2580     case ECOND_STR_LT:
2581     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2582     break;
2583
2584     case ECOND_STR_LTI:
2585     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2586     break;
2587
2588     case ECOND_STR_LE:
2589     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2590     break;
2591
2592     case ECOND_STR_LEI:
2593     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2594     break;
2595
2596     case ECOND_STR_EQ:
2597     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2598     break;
2599
2600     case ECOND_STR_EQI:
2601     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2602     break;
2603
2604     case ECOND_STR_GT:
2605     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2606     break;
2607
2608     case ECOND_STR_GTI:
2609     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2610     break;
2611
2612     case ECOND_STR_GE:
2613     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2614     break;
2615
2616     case ECOND_STR_GEI:
2617     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2618     break;
2619
2620     case ECOND_MATCH:   /* Regular expression match */
2621     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2622       NULL);
2623     if (re == NULL)
2624       {
2625       expand_string_message = string_sprintf("regular expression error in "
2626         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2627       return NULL;
2628       }
2629     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2630     break;
2631
2632     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2633     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2634     goto MATCHED_SOMETHING;
2635
2636     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2637     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2638       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2639     goto MATCHED_SOMETHING;
2640
2641     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2642     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2643       {
2644       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2645         sub[0]);
2646       return NULL;
2647       }
2648     else
2649       {
2650       unsigned int *nullcache = NULL;
2651       check_host_block cb;
2652
2653       cb.host_name = US"";
2654       cb.host_address = sub[0];
2655
2656       /* If the host address starts off ::ffff: it is an IPv6 address in
2657       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2658       addresses. */
2659
2660       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2661         cb.host_address + 7 : cb.host_address;
2662
2663       rc = match_check_list(
2664              &sub[1],                   /* the list */
2665              0,                         /* separator character */
2666              &hostlist_anchor,          /* anchor pointer */
2667              &nullcache,                /* cache pointer */
2668              check_host,                /* function for testing */
2669              &cb,                       /* argument for function */
2670              MCL_HOST,                  /* type of check */
2671              sub[0],                    /* text for debugging */
2672              NULL);                     /* where to pass back data */
2673       }
2674     goto MATCHED_SOMETHING;
2675
2676     case ECOND_MATCH_LOCAL_PART:
2677     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2678       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2679     /* Fall through */
2680     /* VVVVVVVVVVVV */
2681     MATCHED_SOMETHING:
2682     switch(rc)
2683       {
2684       case OK:
2685       tempcond = TRUE;
2686       break;
2687
2688       case FAIL:
2689       tempcond = FALSE;
2690       break;
2691
2692       case DEFER:
2693       expand_string_message = string_sprintf("unable to complete match "
2694         "against \"%s\": %s", sub[1], search_error_message);
2695       return NULL;
2696       }
2697
2698     break;
2699
2700     /* Various "encrypted" comparisons. If the second string starts with
2701     "{" then an encryption type is given. Default to crypt() or crypt16()
2702     (build-time choice). */
2703     /* }-for-text-editors */
2704
2705     case ECOND_CRYPTEQ:
2706     #ifndef SUPPORT_CRYPTEQ
2707     goto COND_FAILED_NOT_COMPILED;
2708     #else
2709     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2710       {
2711       int sublen = Ustrlen(sub[1]+5);
2712       md5 base;
2713       uschar digest[16];
2714
2715       md5_start(&base);
2716       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2717
2718       /* If the length that we are comparing against is 24, the MD5 digest
2719       is expressed as a base64 string. This is the way LDAP does it. However,
2720       some other software uses a straightforward hex representation. We assume
2721       this if the length is 32. Other lengths fail. */
2722
2723       if (sublen == 24)
2724         {
2725         uschar *coded = b64encode(digest, 16);
2726         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2727           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2728         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2729         }
2730       else if (sublen == 32)
2731         {
2732         int i;
2733         uschar coded[36];
2734         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2735         coded[32] = 0;
2736         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2737           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2738         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2739         }
2740       else
2741         {
2742         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2743           "fail\n  crypted=%s\n", sub[1]+5);
2744         tempcond = FALSE;
2745         }
2746       }
2747
2748     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2749       {
2750       int sublen = Ustrlen(sub[1]+6);
2751       hctx h;
2752       uschar digest[20];
2753
2754       sha1_start(&h);
2755       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2756
2757       /* If the length that we are comparing against is 28, assume the SHA1
2758       digest is expressed as a base64 string. If the length is 40, assume a
2759       straightforward hex representation. Other lengths fail. */
2760
2761       if (sublen == 28)
2762         {
2763         uschar *coded = b64encode(digest, 20);
2764         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2765           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2766         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2767         }
2768       else if (sublen == 40)
2769         {
2770         int i;
2771         uschar coded[44];
2772         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2773         coded[40] = 0;
2774         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2775           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2776         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2777         }
2778       else
2779         {
2780         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2781           "fail\n  crypted=%s\n", sub[1]+6);
2782         tempcond = FALSE;
2783         }
2784       }
2785
2786     else   /* {crypt} or {crypt16} and non-{ at start */
2787            /* }-for-text-editors */
2788       {
2789       int which = 0;
2790       uschar *coded;
2791
2792       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2793         {
2794         sub[1] += 7;
2795         which = 1;
2796         }
2797       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2798         {
2799         sub[1] += 9;
2800         which = 2;
2801         }
2802       else if (sub[1][0] == '{')                /* }-for-text-editors */
2803         {
2804         expand_string_message = string_sprintf("unknown encryption mechanism "
2805           "in \"%s\"", sub[1]);
2806         return NULL;
2807         }
2808
2809       switch(which)
2810         {
2811         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2812         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2813         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2814         }
2815
2816       #define STR(s) # s
2817       #define XSTR(s) STR(s)
2818       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2819         "  subject=%s\n  crypted=%s\n",
2820         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2821         coded, sub[1]);
2822       #undef STR
2823       #undef XSTR
2824
2825       /* If the encrypted string contains fewer than two characters (for the
2826       salt), force failure. Otherwise we get false positives: with an empty
2827       string the yield of crypt() is an empty string! */
2828
2829       if (coded)
2830         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2831       else if (errno == EINVAL)
2832         tempcond = FALSE;
2833       else
2834         {
2835         expand_string_message = string_sprintf("crypt error: %s\n",
2836           US strerror(errno));
2837         return NULL;
2838         }
2839       }
2840     break;
2841     #endif  /* SUPPORT_CRYPTEQ */
2842
2843     case ECOND_INLIST:
2844     case ECOND_INLISTI:
2845       {
2846       const uschar * list = sub[1];
2847       int sep = 0;
2848       uschar *save_iterate_item = iterate_item;
2849       int (*compare)(const uschar *, const uschar *);
2850
2851       DEBUG(D_expand) debug_printf_indent("condition: %s  item: %s\n", name, sub[0]);
2852
2853       tempcond = FALSE;
2854       compare = cond_type == ECOND_INLISTI
2855         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2856
2857       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2858         {
2859         DEBUG(D_expand) debug_printf_indent(" compare %s\n", iterate_item);
2860         if (compare(sub[0], iterate_item) == 0)
2861           {
2862           tempcond = TRUE;
2863           break;
2864           }
2865         }
2866       iterate_item = save_iterate_item;
2867       }
2868
2869     }   /* Switch for comparison conditions */
2870
2871   *yield = tempcond == testfor;
2872   return s;    /* End of comparison conditions */
2873
2874
2875   /* and/or: computes logical and/or of several conditions */
2876
2877   case ECOND_AND:
2878   case ECOND_OR:
2879   subcondptr = (yield == NULL)? NULL : &tempcond;
2880   combined_cond = (cond_type == ECOND_AND);
2881
2882   while (isspace(*s)) s++;
2883   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2884
2885   for (;;)
2886     {
2887     while (isspace(*s)) s++;
2888     /* {-for-text-editors */
2889     if (*s == '}') break;
2890     if (*s != '{')                                      /* }-for-text-editors */
2891       {
2892       expand_string_message = string_sprintf("each subcondition "
2893         "inside an \"%s{...}\" condition must be in its own {}", name);
2894       return NULL;
2895       }
2896
2897     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2898       {
2899       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2900         expand_string_message, name);
2901       return NULL;
2902       }
2903     while (isspace(*s)) s++;
2904
2905     /* {-for-text-editors */
2906     if (*s++ != '}')
2907       {
2908       /* {-for-text-editors */
2909       expand_string_message = string_sprintf("missing } at end of condition "
2910         "inside \"%s\" group", name);
2911       return NULL;
2912       }
2913
2914     if (yield != NULL)
2915       {
2916       if (cond_type == ECOND_AND)
2917         {
2918         combined_cond &= tempcond;
2919         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2920         }                                       /* evaluate any more */
2921       else
2922         {
2923         combined_cond |= tempcond;
2924         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2925         }                                       /* evaluate any more */
2926       }
2927     }
2928
2929   if (yield != NULL) *yield = (combined_cond == testfor);
2930   return ++s;
2931
2932
2933   /* forall/forany: iterates a condition with different values */
2934
2935   case ECOND_FORALL:
2936   case ECOND_FORANY:
2937     {
2938     const uschar * list;
2939     int sep = 0;
2940     uschar *save_iterate_item = iterate_item;
2941
2942     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2943
2944     while (isspace(*s)) s++;
2945     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2946     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2947     if (sub[0] == NULL) return NULL;
2948     /* {-for-text-editors */
2949     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2950
2951     while (isspace(*s)) s++;
2952     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2953
2954     sub[1] = s;
2955
2956     /* Call eval_condition once, with result discarded (as if scanning a
2957     "false" part). This allows us to find the end of the condition, because if
2958     the list it empty, we won't actually evaluate the condition for real. */
2959
2960     if (!(s = eval_condition(sub[1], resetok, NULL)))
2961       {
2962       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2963         expand_string_message, name);
2964       return NULL;
2965       }
2966     while (isspace(*s)) s++;
2967
2968     /* {-for-text-editors */
2969     if (*s++ != '}')
2970       {
2971       /* {-for-text-editors */
2972       expand_string_message = string_sprintf("missing } at end of condition "
2973         "inside \"%s\"", name);
2974       return NULL;
2975       }
2976
2977     if (yield != NULL) *yield = !testfor;
2978     list = sub[0];
2979     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2980       {
2981       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2982       if (!eval_condition(sub[1], resetok, &tempcond))
2983         {
2984         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2985           expand_string_message, name);
2986         iterate_item = save_iterate_item;
2987         return NULL;
2988         }
2989       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2990         tempcond? "true":"false");
2991
2992       if (yield != NULL) *yield = (tempcond == testfor);
2993       if (tempcond == (cond_type == ECOND_FORANY)) break;
2994       }
2995
2996     iterate_item = save_iterate_item;
2997     return s;
2998     }
2999
3000
3001   /* The bool{} expansion condition maps a string to boolean.
3002   The values supported should match those supported by the ACL condition
3003   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
3004   of true/false.  Note that Router "condition" rules have a different
3005   interpretation, where general data can be used and only a few values
3006   map to FALSE.
3007   Note that readconf.c boolean matching, for boolean configuration options,
3008   only matches true/yes/false/no.
3009   The bool_lax{} condition matches the Router logic, which is much more
3010   liberal. */
3011   case ECOND_BOOL:
3012   case ECOND_BOOL_LAX:
3013     {
3014     uschar *sub_arg[1];
3015     uschar *t, *t2;
3016     uschar *ourname;
3017     size_t len;
3018     BOOL boolvalue = FALSE;
3019     while (isspace(*s)) s++;
3020     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3021     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3022     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3023       {
3024       case 1: expand_string_message = string_sprintf(
3025                   "too few arguments or bracketing error for %s",
3026                   ourname);
3027       /*FALLTHROUGH*/
3028       case 2:
3029       case 3: return NULL;
3030       }
3031     t = sub_arg[0];
3032     while (isspace(*t)) t++;
3033     len = Ustrlen(t);
3034     if (len)
3035       {
3036       /* trailing whitespace: seems like a good idea to ignore it too */
3037       t2 = t + len - 1;
3038       while (isspace(*t2)) t2--;
3039       if (t2 != (t + len))
3040         {
3041         *++t2 = '\0';
3042         len = t2 - t;
3043         }
3044       }
3045     DEBUG(D_expand)
3046       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3047     /* logic for the lax case from expand_check_condition(), which also does
3048     expands, and the logic is both short and stable enough that there should
3049     be no maintenance burden from replicating it. */
3050     if (len == 0)
3051       boolvalue = FALSE;
3052     else if (*t == '-'
3053              ? Ustrspn(t+1, "0123456789") == len-1
3054              : Ustrspn(t,   "0123456789") == len)
3055       {
3056       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3057       /* expand_check_condition only does a literal string "0" check */
3058       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3059         boolvalue = TRUE;
3060       }
3061     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3062       boolvalue = TRUE;
3063     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3064       boolvalue = FALSE;
3065     else if (cond_type == ECOND_BOOL_LAX)
3066       boolvalue = TRUE;
3067     else
3068       {
3069       expand_string_message = string_sprintf("unrecognised boolean "
3070        "value \"%s\"", t);
3071       return NULL;
3072       }
3073     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3074         boolvalue? "true":"false");
3075     if (yield != NULL) *yield = (boolvalue == testfor);
3076     return s;
3077     }
3078
3079   /* Unknown condition */
3080
3081   default:
3082   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3083   return NULL;
3084   }   /* End switch on condition type */
3085
3086 /* Missing braces at start and end of data */
3087
3088 COND_FAILED_CURLY_START:
3089 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3090 return NULL;
3091
3092 COND_FAILED_CURLY_END:
3093 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3094   name);
3095 return NULL;
3096
3097 /* A condition requires code that is not compiled */
3098
3099 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3100     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3101     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3102 COND_FAILED_NOT_COMPILED:
3103 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3104   name);
3105 return NULL;
3106 #endif
3107 }
3108
3109
3110
3111
3112 /*************************************************
3113 *          Save numerical variables              *
3114 *************************************************/
3115
3116 /* This function is called from items such as "if" that want to preserve and
3117 restore the numbered variables.
3118
3119 Arguments:
3120   save_expand_string    points to an array of pointers to set
3121   save_expand_nlength   points to an array of ints for the lengths
3122
3123 Returns:                the value of expand max to save
3124 */
3125
3126 static int
3127 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3128 {
3129 int i;
3130 for (i = 0; i <= expand_nmax; i++)
3131   {
3132   save_expand_nstring[i] = expand_nstring[i];
3133   save_expand_nlength[i] = expand_nlength[i];
3134   }
3135 return expand_nmax;
3136 }
3137
3138
3139
3140 /*************************************************
3141 *           Restore numerical variables          *
3142 *************************************************/
3143
3144 /* This function restored saved values of numerical strings.
3145
3146 Arguments:
3147   save_expand_nmax      the number of strings to restore
3148   save_expand_string    points to an array of pointers
3149   save_expand_nlength   points to an array of ints
3150
3151 Returns:                nothing
3152 */
3153
3154 static void
3155 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3156   int *save_expand_nlength)
3157 {
3158 int i;
3159 expand_nmax = save_expand_nmax;
3160 for (i = 0; i <= expand_nmax; i++)
3161   {
3162   expand_nstring[i] = save_expand_nstring[i];
3163   expand_nlength[i] = save_expand_nlength[i];
3164   }
3165 }
3166
3167
3168
3169
3170
3171 /*************************************************
3172 *            Handle yes/no substrings            *
3173 *************************************************/
3174
3175 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3176 alternative substrings that depend on whether or not the condition was true,
3177 or the lookup or extraction succeeded. The substrings always have to be
3178 expanded, to check their syntax, but "skipping" is set when the result is not
3179 needed - this avoids unnecessary nested lookups.
3180
3181 Arguments:
3182   skipping       TRUE if we were skipping when this item was reached
3183   yes            TRUE if the first string is to be used, else use the second
3184   save_lookup    a value to put back into lookup_value before the 2nd expansion
3185   sptr           points to the input string pointer
3186   yieldptr       points to the output growable-string pointer
3187   type           "lookup", "if", "extract", "run", "env", "listextract" or
3188                  "certextract" for error message
3189   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3190                 the store.
3191
3192 Returns:         0 OK; lookup_value has been reset to save_lookup
3193                  1 expansion failed
3194                  2 expansion failed because of bracketing error
3195 */
3196
3197 static int
3198 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3199   gstring ** yieldptr, uschar *type, BOOL *resetok)
3200 {
3201 int rc = 0;
3202 const uschar *s = *sptr;    /* Local value */
3203 uschar *sub1, *sub2;
3204 const uschar * errwhere;
3205
3206 /* If there are no following strings, we substitute the contents of $value for
3207 lookups and for extractions in the success case. For the ${if item, the string
3208 "true" is substituted. In the fail case, nothing is substituted for all three
3209 items. */
3210
3211 while (isspace(*s)) s++;
3212 if (*s == '}')
3213   {
3214   if (type[0] == 'i')
3215     {
3216     if (yes && !skipping)
3217       *yieldptr = string_catn(*yieldptr, US"true", 4);
3218     }
3219   else
3220     {
3221     if (yes && lookup_value && !skipping)
3222       *yieldptr = string_cat(*yieldptr, lookup_value);
3223     lookup_value = save_lookup;
3224     }
3225   s++;
3226   goto RETURN;
3227   }
3228
3229 /* The first following string must be braced. */
3230
3231 if (*s++ != '{')
3232   {
3233   errwhere = US"'yes' part did not start with '{'";
3234   goto FAILED_CURLY;
3235   }
3236
3237 /* Expand the first substring. Forced failures are noticed only if we actually
3238 want this string. Set skipping in the call in the fail case (this will always
3239 be the case if we were already skipping). */
3240
3241 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3242 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3243 expand_string_forcedfail = FALSE;
3244 if (*s++ != '}')
3245   {
3246   errwhere = US"'yes' part did not end with '}'";
3247   goto FAILED_CURLY;
3248   }
3249
3250 /* If we want the first string, add it to the output */
3251
3252 if (yes)
3253   *yieldptr = string_cat(*yieldptr, sub1);
3254
3255 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3256 $value to what it was at the start of the item, so that it has this value
3257 during the second string expansion. For the call from "if" or "run" to this
3258 function, save_lookup is set to lookup_value, so that this statement does
3259 nothing. */
3260
3261 lookup_value = save_lookup;
3262
3263 /* There now follows either another substring, or "fail", or nothing. This
3264 time, forced failures are noticed only if we want the second string. We must
3265 set skipping in the nested call if we don't want this string, or if we were
3266 already skipping. */
3267
3268 while (isspace(*s)) s++;
3269 if (*s == '{')
3270   {
3271   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3272   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3273   expand_string_forcedfail = FALSE;
3274   if (*s++ != '}')
3275     {
3276     errwhere = US"'no' part did not start with '{'";
3277     goto FAILED_CURLY;
3278     }
3279
3280   /* If we want the second string, add it to the output */
3281
3282   if (!yes)
3283     *yieldptr = string_cat(*yieldptr, sub2);
3284   }
3285
3286 /* If there is no second string, but the word "fail" is present when the use of
3287 the second string is wanted, set a flag indicating it was a forced failure
3288 rather than a syntactic error. Swallow the terminating } in case this is nested
3289 inside another lookup or if or extract. */
3290
3291 else if (*s != '}')
3292   {
3293   uschar name[256];
3294   /* deconst cast ok here as source is s anyway */
3295   s = US read_name(name, sizeof(name), s, US"_");
3296   if (Ustrcmp(name, "fail") == 0)
3297     {
3298     if (!yes && !skipping)
3299       {
3300       while (isspace(*s)) s++;
3301       if (*s++ != '}')
3302         {
3303         errwhere = US"did not close with '}' after forcedfail";
3304         goto FAILED_CURLY;
3305         }
3306       expand_string_message =
3307         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3308       expand_string_forcedfail = TRUE;
3309       goto FAILED;
3310       }
3311     }
3312   else
3313     {
3314     expand_string_message =
3315       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3316     goto FAILED;
3317     }
3318   }
3319
3320 /* All we have to do now is to check on the final closing brace. */
3321
3322 while (isspace(*s)) s++;
3323 if (*s++ != '}')
3324   {
3325   errwhere = US"did not close with '}'";
3326   goto FAILED_CURLY;
3327   }
3328
3329
3330 RETURN:
3331 /* Update the input pointer value before returning */
3332 *sptr = s;
3333 return rc;
3334
3335 FAILED_CURLY:
3336   /* Get here if there is a bracketing failure */
3337   expand_string_message = string_sprintf(
3338     "curly-bracket problem in conditional yes/no parsing: %s\n"
3339     " remaining string is '%s'", errwhere, --s);
3340   rc = 2;
3341   goto RETURN;
3342
3343 FAILED:
3344   /* Get here for other failures */
3345   rc = 1;
3346   goto RETURN;
3347 }
3348
3349
3350
3351
3352 /*************************************************
3353 *    Handle MD5 or SHA-1 computation for HMAC    *
3354 *************************************************/
3355
3356 /* These are some wrapping functions that enable the HMAC code to be a bit
3357 cleaner. A good compiler will spot the tail recursion.
3358
3359 Arguments:
3360   type         HMAC_MD5 or HMAC_SHA1
3361   remaining    are as for the cryptographic hash functions
3362
3363 Returns:       nothing
3364 */
3365
3366 static void
3367 chash_start(int type, void *base)
3368 {
3369 if (type == HMAC_MD5)
3370   md5_start((md5 *)base);
3371 else
3372   sha1_start((hctx *)base);
3373 }
3374
3375 static void
3376 chash_mid(int type, void *base, uschar *string)
3377 {
3378 if (type == HMAC_MD5)
3379   md5_mid((md5 *)base, string);
3380 else
3381   sha1_mid((hctx *)base, string);
3382 }
3383
3384 static void
3385 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3386 {
3387 if (type == HMAC_MD5)
3388   md5_end((md5 *)base, string, length, digest);
3389 else
3390   sha1_end((hctx *)base, string, length, digest);
3391 }
3392
3393
3394
3395
3396
3397 /********************************************************
3398 * prvs: Get last three digits of days since Jan 1, 1970 *
3399 ********************************************************/
3400
3401 /* This is needed to implement the "prvs" BATV reverse
3402    path signing scheme
3403
3404 Argument: integer "days" offset to add or substract to
3405           or from the current number of days.
3406
3407 Returns:  pointer to string containing the last three
3408           digits of the number of days since Jan 1, 1970,
3409           modified by the offset argument, NULL if there
3410           was an error in the conversion.
3411
3412 */
3413
3414 static uschar *
3415 prvs_daystamp(int day_offset)
3416 {
3417 uschar *days = store_get(32);                /* Need at least 24 for cases */
3418 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3419   (time(NULL) + day_offset*86400)/86400);
3420 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3421 }
3422
3423
3424
3425 /********************************************************
3426 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3427 ********************************************************/
3428
3429 /* This is needed to implement the "prvs" BATV reverse
3430    path signing scheme
3431
3432 Arguments:
3433   address RFC2821 Address to use
3434       key The key to use (must be less than 64 characters
3435           in size)
3436   key_num Single-digit key number to use. Defaults to
3437           '0' when NULL.
3438
3439 Returns:  pointer to string containing the first three
3440           bytes of the final hash in hex format, NULL if
3441           there was an error in the process.
3442 */
3443
3444 static uschar *
3445 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3446 {
3447 gstring * hash_source;
3448 uschar * p;
3449 int i;
3450 hctx h;
3451 uschar innerhash[20];
3452 uschar finalhash[20];
3453 uschar innerkey[64];
3454 uschar outerkey[64];
3455 uschar *finalhash_hex = store_get(40);
3456
3457 if (key_num == NULL)
3458   key_num = US"0";
3459
3460 if (Ustrlen(key) > 64)
3461   return NULL;
3462
3463 hash_source = string_catn(NULL, key_num, 1);
3464 hash_source = string_catn(hash_source, daystamp, 3);
3465 hash_source = string_cat(hash_source, address);
3466 (void) string_from_gstring(hash_source);
3467
3468 DEBUG(D_expand)
3469   debug_printf_indent("prvs: hash source is '%s'\n", hash_source->s);
3470
3471 memset(innerkey, 0x36, 64);
3472 memset(outerkey, 0x5c, 64);
3473
3474 for (i = 0; i < Ustrlen(key); i++)
3475   {
3476   innerkey[i] ^= key[i];
3477   outerkey[i] ^= key[i];
3478   }
3479
3480 chash_start(HMAC_SHA1, &h);
3481 chash_mid(HMAC_SHA1, &h, innerkey);
3482 chash_end(HMAC_SHA1, &h, hash_source->s, hash_source->ptr, innerhash);
3483
3484 chash_start(HMAC_SHA1, &h);
3485 chash_mid(HMAC_SHA1, &h, outerkey);
3486 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3487
3488 p = finalhash_hex;
3489 for (i = 0; i < 3; i++)
3490   {
3491   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3492   *p++ = hex_digits[finalhash[i] & 0x0f];
3493   }
3494 *p = '\0';
3495
3496 return finalhash_hex;
3497 }
3498
3499
3500
3501
3502 /*************************************************
3503 *        Join a file onto the output string      *
3504 *************************************************/
3505
3506 /* This is used for readfile/readsock and after a run expansion.
3507 It joins the contents of a file onto the output string, globally replacing
3508 newlines with a given string (optionally).
3509
3510 Arguments:
3511   f            the FILE
3512   yield        pointer to the expandable string struct
3513   eol          newline replacement string, or NULL
3514
3515 Returns:       new pointer for expandable string, terminated if non-null
3516 */
3517
3518 static gstring *
3519 cat_file(FILE *f, gstring *yield, uschar *eol)
3520 {
3521 uschar buffer[1024];
3522
3523 while (Ufgets(buffer, sizeof(buffer), f))
3524   {
3525   int len = Ustrlen(buffer);
3526   if (eol && buffer[len-1] == '\n') len--;
3527   yield = string_catn(yield, buffer, len);
3528   if (eol && buffer[len])
3529     yield = string_cat(yield, eol);
3530   }
3531
3532 (void) string_from_gstring(yield);
3533 return yield;
3534 }
3535
3536
3537
3538
3539 /*************************************************
3540 *          Evaluate numeric expression           *
3541 *************************************************/
3542
3543 /* This is a set of mutually recursive functions that evaluate an arithmetic
3544 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3545 these functions that is called from elsewhere is eval_expr, whose interface is:
3546
3547 Arguments:
3548   sptr        pointer to the pointer to the string - gets updated
3549   decimal     TRUE if numbers are to be assumed decimal
3550   error       pointer to where to put an error message - must be NULL on input
3551   endket      TRUE if ')' must terminate - FALSE for external call
3552
3553 Returns:      on success: the value of the expression, with *error still NULL
3554               on failure: an undefined value, with *error = a message
3555 */
3556
3557 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3558
3559
3560 static int_eximarith_t
3561 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3562 {
3563 uschar *s = *sptr;
3564 int_eximarith_t x = eval_op_or(&s, decimal, error);
3565 if (*error == NULL)
3566   {
3567   if (endket)
3568     {
3569     if (*s != ')')
3570       *error = US"expecting closing parenthesis";
3571     else
3572       while (isspace(*(++s)));
3573     }
3574   else if (*s != 0) *error = US"expecting operator";
3575   }
3576 *sptr = s;
3577 return x;
3578 }
3579
3580
3581 static int_eximarith_t
3582 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3583 {
3584 register int c;
3585 int_eximarith_t n;
3586 uschar *s = *sptr;
3587 while (isspace(*s)) s++;
3588 c = *s;
3589 if (isdigit(c))
3590   {
3591   int count;
3592   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3593   s += count;
3594   switch (tolower(*s))
3595     {
3596     default: break;
3597     case 'k': n *= 1024; s++; break;
3598     case 'm': n *= 1024*1024; s++; break;
3599     case 'g': n *= 1024*1024*1024; s++; break;
3600     }
3601   while (isspace (*s)) s++;
3602   }
3603 else if (c == '(')
3604   {
3605   s++;
3606   n = eval_expr(&s, decimal, error, 1);
3607   }
3608 else
3609   {
3610   *error = US"expecting number or opening parenthesis";
3611   n = 0;
3612   }
3613 *sptr = s;
3614 return n;
3615 }
3616
3617
3618 static int_eximarith_t
3619 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3620 {
3621 uschar *s = *sptr;
3622 int_eximarith_t x;
3623 while (isspace(*s)) s++;
3624 if (*s == '+' || *s == '-' || *s == '~')
3625   {
3626   int op = *s++;
3627   x = eval_op_unary(&s, decimal, error);
3628   if (op == '-') x = -x;
3629     else if (op == '~') x = ~x;
3630   }
3631 else
3632   {
3633   x = eval_number(&s, decimal, error);
3634   }
3635 *sptr = s;
3636 return x;
3637 }
3638
3639
3640 static int_eximarith_t
3641 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3642 {
3643 uschar *s = *sptr;
3644 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3645 if (*error == NULL)
3646   {
3647   while (*s == '*' || *s == '/' || *s == '%')
3648     {
3649     int op = *s++;
3650     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3651     if (*error != NULL) break;
3652     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3653      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3654      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3655      * -N*M is INT_MIN will yield INT_MIN.
3656      * Since we don't support floating point, this is somewhat simpler.
3657      * Ideally, we'd return an error, but since we overflow for all other
3658      * arithmetic, consistency suggests otherwise, but what's the correct value
3659      * to use?  There is none.
3660      * The C standard guarantees overflow for unsigned arithmetic but signed
3661      * overflow invokes undefined behaviour; in practice, this is overflow
3662      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3663      * that long/longlong larger than int are available, or we could just work
3664      * with larger types.  We should consider whether to guarantee 32bit eval
3665      * and 64-bit working variables, with errors returned.  For now ...
3666      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3667      * can just let the other invalid results occur otherwise, as they have
3668      * until now.  For this one case, we can coerce.
3669      */
3670     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3671       {
3672       DEBUG(D_expand)
3673         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3674             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3675       x = EXIM_ARITH_MAX;
3676       continue;
3677       }
3678     if (op == '*')
3679       x *= y;
3680     else
3681       {
3682       if (y == 0)
3683         {
3684         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3685         x = 0;
3686         break;
3687         }
3688       if (op == '/')
3689         x /= y;
3690       else
3691         x %= y;
3692       }
3693     }
3694   }
3695 *sptr = s;
3696 return x;
3697 }
3698
3699
3700 static int_eximarith_t
3701 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3702 {
3703 uschar *s = *sptr;
3704 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3705 if (!*error)
3706   {
3707   while (*s == '+' || *s == '-')
3708     {
3709     int op = *s++;
3710     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3711     if (*error) break;
3712     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3713        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3714       {                 /* over-conservative check */
3715       *error = op == '+'
3716         ? US"overflow in sum" : US"overflow in difference";
3717       break;
3718       }
3719     if (op == '+') x += y; else x -= y;
3720     }
3721   }
3722 *sptr = s;
3723 return x;
3724 }
3725
3726
3727 static int_eximarith_t
3728 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3729 {
3730 uschar *s = *sptr;
3731 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3732 if (*error == NULL)
3733   {
3734   while ((*s == '<' || *s == '>') && s[1] == s[0])
3735     {
3736     int_eximarith_t y;
3737     int op = *s++;
3738     s++;
3739     y = eval_op_sum(&s, decimal, error);
3740     if (*error != NULL) break;
3741     if (op == '<') x <<= y; else x >>= y;
3742     }
3743   }
3744 *sptr = s;
3745 return x;
3746 }
3747
3748
3749 static int_eximarith_t
3750 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3751 {
3752 uschar *s = *sptr;
3753 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3754 if (*error == NULL)
3755   {
3756   while (*s == '&')
3757     {
3758     int_eximarith_t y;
3759     s++;
3760     y = eval_op_shift(&s, decimal, error);
3761     if (*error != NULL) break;
3762     x &= y;
3763     }
3764   }
3765 *sptr = s;
3766 return x;
3767 }
3768
3769
3770 static int_eximarith_t
3771 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3772 {
3773 uschar *s = *sptr;
3774 int_eximarith_t x = eval_op_and(&s, decimal, error);
3775 if (*error == NULL)
3776   {
3777   while (*s == '^')
3778     {
3779     int_eximarith_t y;
3780     s++;
3781     y = eval_op_and(&s, decimal, error);
3782     if (*error != NULL) break;
3783     x ^= y;
3784     }
3785   }
3786 *sptr = s;
3787 return x;
3788 }
3789
3790
3791 static int_eximarith_t
3792 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3793 {
3794 uschar *s = *sptr;
3795 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3796 if (*error == NULL)
3797   {
3798   while (*s == '|')
3799     {
3800     int_eximarith_t y;
3801     s++;
3802     y = eval_op_xor(&s, decimal, error);
3803     if (*error != NULL) break;
3804     x |= y;
3805     }
3806   }
3807 *sptr = s;
3808 return x;
3809 }
3810
3811
3812
3813 /*************************************************
3814 *                 Expand string                  *
3815 *************************************************/
3816
3817 /* Returns either an unchanged string, or the expanded string in stacking pool
3818 store. Interpreted sequences are:
3819
3820    \...                    normal escaping rules
3821    $name                   substitutes the variable
3822    ${name}                 ditto
3823    ${op:string}            operates on the expanded string value
3824    ${item{arg1}{arg2}...}  expands the args and then does the business
3825                              some literal args are not enclosed in {}
3826
3827 There are now far too many operators and item types to make it worth listing
3828 them here in detail any more.
3829
3830 We use an internal routine recursively to handle embedded substrings. The
3831 external function follows. The yield is NULL if the expansion failed, and there
3832 are two cases: if something collapsed syntactically, or if "fail" was given
3833 as the action on a lookup failure. These can be distinguished by looking at the
3834 variable expand_string_forcedfail, which is TRUE in the latter case.
3835
3836 The skipping flag is set true when expanding a substring that isn't actually
3837 going to be used (after "if" or "lookup") and it prevents lookups from
3838 happening lower down.
3839
3840 Store usage: At start, a store block of the length of the input plus 64
3841 is obtained. This is expanded as necessary by string_cat(), which might have to
3842 get a new block, or might be able to expand the original. At the end of the
3843 function we can release any store above that portion of the yield block that
3844 was actually used. In many cases this will be optimal.
3845
3846 However: if the first item in the expansion is a variable name or header name,
3847 we reset the store before processing it; if the result is in fresh store, we
3848 use that without copying. This is helpful for expanding strings like
3849 $message_headers which can get very long.
3850
3851 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3852 since resetting the store at the end of the expansion will free store that was
3853 allocated by the plugin code as well as the slop after the expanded string. So
3854 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3855 and, given the acl condition, ${if }. This is an unfortunate consequence of
3856 string expansion becoming too powerful.
3857
3858 Arguments:
3859   string         the string to be expanded
3860   ket_ends       true if expansion is to stop at }
3861   left           if not NULL, a pointer to the first character after the
3862                  expansion is placed here (typically used with ket_ends)
3863   skipping       TRUE for recursive calls when the value isn't actually going
3864                  to be used (to allow for optimisation)
3865   honour_dollar  TRUE if $ is to be expanded,
3866                  FALSE if it's just another character
3867   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3868                  the store.
3869
3870 Returns:         NULL if expansion fails:
3871                    expand_string_forcedfail is set TRUE if failure was forced
3872                    expand_string_message contains a textual error message
3873                  a pointer to the expanded string on success
3874 */
3875
3876 static uschar *
3877 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3878   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3879 {
3880 gstring * yield = string_get(Ustrlen(string) + 64);
3881 int item_type;
3882 const uschar *s = string;
3883 uschar *save_expand_nstring[EXPAND_MAXN+1];
3884 int save_expand_nlength[EXPAND_MAXN+1];
3885 BOOL resetok = TRUE;
3886
3887 expand_level++;
3888 DEBUG(D_expand)
3889   debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
3890     skipping
3891     ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
3892     : "considering",
3893     string);
3894
3895 expand_string_forcedfail = FALSE;
3896 expand_string_message = US"";
3897
3898 while (*s != 0)
3899   {
3900   uschar *value;
3901   uschar name[256];
3902
3903   /* \ escapes the next character, which must exist, or else
3904   the expansion fails. There's a special escape, \N, which causes
3905   copying of the subject verbatim up to the next \N. Otherwise,
3906   the escapes are the standard set. */
3907
3908   if (*s == '\\')
3909     {
3910     if (s[1] == 0)
3911       {
3912       expand_string_message = US"\\ at end of string";
3913       goto EXPAND_FAILED;
3914       }
3915
3916     if (s[1] == 'N')
3917       {
3918       const uschar * t = s + 2;
3919       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3920       yield = string_catn(yield, t, s - t);
3921       if (*s != 0) s += 2;
3922       }
3923
3924     else
3925       {
3926       uschar ch[1];
3927       ch[0] = string_interpret_escape(&s);
3928       s++;
3929       yield = string_catn(yield, ch, 1);
3930       }
3931
3932     continue;
3933     }
3934
3935   /*{*/
3936   /* Anything other than $ is just copied verbatim, unless we are
3937   looking for a terminating } character. */
3938
3939   /*{*/
3940   if (ket_ends && *s == '}') break;
3941
3942   if (*s != '$' || !honour_dollar)
3943     {
3944     yield = string_catn(yield, s++, 1);
3945     continue;
3946     }
3947
3948   /* No { after the $ - must be a plain name or a number for string
3949   match variable. There has to be a fudge for variables that are the
3950   names of header fields preceded by "$header_" because header field
3951   names can contain any printing characters except space and colon.
3952   For those that don't like typing this much, "$h_" is a synonym for
3953   "$header_". A non-existent header yields a NULL value; nothing is
3954   inserted. */  /*}*/
3955
3956   if (isalpha((*(++s))))
3957     {
3958     int len;
3959     int newsize = 0;
3960     gstring * g = NULL;
3961
3962     s = read_name(name, sizeof(name), s, US"_");
3963
3964     /* If this is the first thing to be expanded, release the pre-allocated
3965     buffer. */
3966
3967     if (!yield)
3968       g = store_get(sizeof(gstring));
3969     else if (yield->ptr == 0)
3970       {
3971       if (resetok) store_reset(yield);
3972       yield = NULL;
3973       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
3974       }
3975
3976     /* Header */
3977
3978     if (Ustrncmp(name, "h_", 2) == 0 ||
3979         Ustrncmp(name, "rh_", 3) == 0 ||
3980         Ustrncmp(name, "bh_", 3) == 0 ||
3981         Ustrncmp(name, "header_", 7) == 0 ||
3982         Ustrncmp(name, "rheader_", 8) == 0 ||
3983         Ustrncmp(name, "bheader_", 8) == 0)
3984       {
3985       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3986       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3987       s = read_header_name(name, sizeof(name), s);
3988       value = find_header(name, FALSE, &newsize, want_raw, charset);
3989
3990       /* If we didn't find the header, and the header contains a closing brace
3991       character, this may be a user error where the terminating colon
3992       has been omitted. Set a flag to adjust the error message in this case.
3993       But there is no error here - nothing gets inserted. */
3994
3995       if (!value)
3996         {
3997         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3998         continue;
3999         }
4000       }
4001
4002     /* Variable */
4003
4004     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
4005       {
4006       expand_string_message =
4007         string_sprintf("unknown variable name \"%s\"", name);
4008         check_variable_error_message(name);
4009       goto EXPAND_FAILED;
4010       }
4011
4012     /* If the data is known to be in a new buffer, newsize will be set to the
4013     size of that buffer. If this is the first thing in an expansion string,
4014     yield will be NULL; just point it at the new store instead of copying. Many
4015     expansion strings contain just one reference, so this is a useful
4016     optimization, especially for humungous headers.  We need to use a gstring
4017     structure that is not allocated after that new-buffer, else a later store
4018     reset in the middle of the buffer will make it inaccessible. */
4019
4020     len = Ustrlen(value);
4021     if (!yield && newsize != 0)
4022       {
4023       yield = g;
4024       yield->size = newsize;
4025       yield->ptr = len;
4026       yield->s = value;
4027       }
4028     else
4029       yield = string_catn(yield, value, len);
4030
4031     continue;
4032     }
4033
4034   if (isdigit(*s))
4035     {
4036     int n;
4037     s = read_cnumber(&n, s);
4038     if (n >= 0 && n <= expand_nmax)
4039       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4040     continue;
4041     }
4042
4043   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4044
4045   if (*s != '{')                                                        /*}*/
4046     {
4047     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4048     goto EXPAND_FAILED;
4049     }
4050
4051   /* After { there can be various things, but they all start with
4052   an initial word, except for a number for a string match variable. */
4053
4054   if (isdigit((*(++s))))
4055     {
4056     int n;
4057     s = read_cnumber(&n, s);            /*{*/
4058     if (*s++ != '}')
4059       {                                 /*{*/
4060       expand_string_message = US"} expected after number";
4061       goto EXPAND_FAILED;
4062       }
4063     if (n >= 0 && n <= expand_nmax)
4064       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4065     continue;
4066     }
4067
4068   if (!isalpha(*s))
4069     {
4070     expand_string_message = US"letter or digit expected after ${";      /*}*/
4071     goto EXPAND_FAILED;
4072     }
4073
4074   /* Allow "-" in names to cater for substrings with negative
4075   arguments. Since we are checking for known names after { this is
4076   OK. */
4077
4078   s = read_name(name, sizeof(name), s, US"_-");
4079   item_type = chop_match(name, item_table, nelem(item_table));
4080
4081   switch(item_type)
4082     {
4083     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4084     If the ACL returns accept or reject we return content set by "message ="
4085     There is currently no limit on recursion; this would have us call
4086     acl_check_internal() directly and get a current level from somewhere.
4087     See also the acl expansion condition ECOND_ACL and the traditional
4088     acl modifier ACLC_ACL.
4089     Assume that the function has side-effects on the store that must be preserved.
4090     */
4091
4092     case EITEM_ACL:
4093       /* ${acl {name} {arg1}{arg2}...} */
4094       {
4095       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4096       uschar *user_msg;
4097
4098       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4099                       &resetok))
4100         {
4101         case 1: goto EXPAND_FAILED_CURLY;
4102         case 2:
4103         case 3: goto EXPAND_FAILED;
4104         }
4105       if (skipping) continue;
4106
4107       resetok = FALSE;
4108       switch(eval_acl(sub, nelem(sub), &user_msg))
4109         {
4110         case OK:
4111         case FAIL:
4112           DEBUG(D_expand)
4113             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4114           if (user_msg)
4115             yield = string_cat(yield, user_msg);
4116           continue;
4117
4118         case DEFER:
4119           expand_string_forcedfail = TRUE;
4120           /*FALLTHROUGH*/
4121         default:
4122           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4123           goto EXPAND_FAILED;
4124         }
4125       }
4126
4127     case EITEM_AUTHRESULTS:
4128       /* ${authresults {mysystemname}} */
4129       {
4130       uschar *sub_arg[1];
4131
4132       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4133                       &resetok))
4134         {
4135         case 1: goto EXPAND_FAILED_CURLY;
4136         case 2:
4137         case 3: goto EXPAND_FAILED;
4138         }
4139
4140       yield = string_append(yield, 3,
4141                         US"Authentication-Results: ", sub_arg[0], US"; none");
4142       yield->ptr -= 6;
4143
4144       yield = authres_iprev(yield);
4145       yield = authres_smtpauth(yield);
4146 #ifdef SUPPORT_SPF
4147       yield = authres_spf(yield);
4148 #endif
4149 #ifndef DISABLE_DKIM
4150       yield = authres_dkim(yield);
4151 #endif
4152 #ifdef EXPERIMENTAL_DMARC
4153       yield = authres_dmarc(yield);
4154 #endif
4155 #ifdef EXPERIMENTAL_ARC
4156       yield = authres_arc(yield);
4157 #endif
4158       continue;
4159       }
4160
4161     /* Handle conditionals - preserve the values of the numerical expansion
4162     variables in case they get changed by a regular expression match in the
4163     condition. If not, they retain their external settings. At the end
4164     of this "if" section, they get restored to their previous values. */
4165
4166     case EITEM_IF:
4167       {
4168       BOOL cond = FALSE;
4169       const uschar *next_s;
4170       int save_expand_nmax =
4171         save_expand_strings(save_expand_nstring, save_expand_nlength);
4172
4173       while (isspace(*s)) s++;
4174       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4175       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4176
4177       DEBUG(D_expand)
4178         {
4179         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4180           "condition: %.*s\n",
4181           (int)(next_s - s), s);
4182         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4183           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4184           "result: %s\n",
4185           cond ? "true" : "false");
4186         }
4187
4188       s = next_s;
4189
4190       /* The handling of "yes" and "no" result strings is now in a separate
4191       function that is also used by ${lookup} and ${extract} and ${run}. */
4192
4193       switch(process_yesno(
4194                skipping,                     /* were previously skipping */
4195                cond,                         /* success/failure indicator */
4196                lookup_value,                 /* value to reset for string2 */
4197                &s,                           /* input pointer */
4198                &yield,                       /* output pointer */
4199                US"if",                       /* condition type */
4200                &resetok))
4201         {
4202         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4203         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4204         }
4205
4206       /* Restore external setting of expansion variables for continuation
4207       at this level. */
4208
4209       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4210         save_expand_nlength);
4211       continue;
4212       }
4213
4214 #ifdef SUPPORT_I18N
4215     case EITEM_IMAPFOLDER:
4216       {                         /* ${imapfolder {name}{sep]{specials}} */
4217       uschar *sub_arg[3];
4218       uschar *encoded;
4219
4220       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4221                       &resetok))
4222         {
4223         case 1: goto EXPAND_FAILED_CURLY;
4224         case 2:
4225         case 3: goto EXPAND_FAILED;
4226         }
4227
4228       if (sub_arg[1] == NULL)           /* One argument */
4229         {
4230         sub_arg[1] = US"/";             /* default separator */
4231         sub_arg[2] = NULL;
4232         }
4233       else if (Ustrlen(sub_arg[1]) != 1)
4234         {
4235         expand_string_message =
4236           string_sprintf(
4237                 "IMAP folder separator must be one character, found \"%s\"",
4238                 sub_arg[1]);
4239         goto EXPAND_FAILED;
4240         }
4241
4242       if (!skipping)
4243         {
4244         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4245                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4246           goto EXPAND_FAILED;
4247         yield = string_cat(yield, encoded);
4248         }
4249       continue;
4250       }
4251 #endif
4252
4253     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4254     expanding an internal string that isn't actually going to be used. All we
4255     need to do is check the syntax, so don't do a lookup at all. Preserve the
4256     values of the numerical expansion variables in case they get changed by a
4257     partial lookup. If not, they retain their external settings. At the end
4258     of this "lookup" section, they get restored to their previous values. */
4259
4260     case EITEM_LOOKUP:
4261       {
4262       int stype, partial, affixlen, starflags;
4263       int expand_setup = 0;
4264       int nameptr = 0;
4265       uschar *key, *filename;
4266       const uschar *affix;
4267       uschar *save_lookup_value = lookup_value;
4268       int save_expand_nmax =
4269         save_expand_strings(save_expand_nstring, save_expand_nlength);
4270
4271       if ((expand_forbid & RDO_LOOKUP) != 0)
4272         {
4273         expand_string_message = US"lookup expansions are not permitted";
4274         goto EXPAND_FAILED;
4275         }
4276
4277       /* Get the key we are to look up for single-key+file style lookups.
4278       Otherwise set the key NULL pro-tem. */
4279
4280       while (isspace(*s)) s++;
4281       if (*s == '{')                                    /*}*/
4282         {
4283         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4284         if (!key) goto EXPAND_FAILED;                   /*{{*/
4285         if (*s++ != '}')
4286           {
4287           expand_string_message = US"missing '}' after lookup key";
4288           goto EXPAND_FAILED_CURLY;
4289           }
4290         while (isspace(*s)) s++;
4291         }
4292       else key = NULL;
4293
4294       /* Find out the type of database */
4295
4296       if (!isalpha(*s))
4297         {
4298         expand_string_message = US"missing lookup type";
4299         goto EXPAND_FAILED;
4300         }
4301
4302       /* The type is a string that may contain special characters of various
4303       kinds. Allow everything except space or { to appear; the actual content
4304       is checked by search_findtype_partial. */         /*}*/
4305
4306       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4307         {
4308         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4309         s++;
4310         }
4311       name[nameptr] = 0;
4312       while (isspace(*s)) s++;
4313
4314       /* Now check for the individual search type and any partial or default
4315       options. Only those types that are actually in the binary are valid. */
4316
4317       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4318         &starflags);
4319       if (stype < 0)
4320         {
4321         expand_string_message = search_error_message;
4322         goto EXPAND_FAILED;
4323         }
4324
4325       /* Check that a key was provided for those lookup types that need it,
4326       and was not supplied for those that use the query style. */
4327
4328       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4329         {
4330         if (key == NULL)
4331           {
4332           expand_string_message = string_sprintf("missing {key} for single-"
4333             "key \"%s\" lookup", name);
4334           goto EXPAND_FAILED;
4335           }
4336         }
4337       else
4338         {
4339         if (key != NULL)
4340           {
4341           expand_string_message = string_sprintf("a single key was given for "
4342             "lookup type \"%s\", which is not a single-key lookup type", name);
4343           goto EXPAND_FAILED;
4344           }
4345         }
4346
4347       /* Get the next string in brackets and expand it. It is the file name for
4348       single-key+file lookups, and the whole query otherwise. In the case of
4349       queries that also require a file name (e.g. sqlite), the file name comes
4350       first. */
4351
4352       if (*s != '{')
4353         {
4354         expand_string_message = US"missing '{' for lookup file-or-query arg";
4355         goto EXPAND_FAILED_CURLY;
4356         }
4357       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4358       if (filename == NULL) goto EXPAND_FAILED;
4359       if (*s++ != '}')
4360         {
4361         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4362         goto EXPAND_FAILED_CURLY;
4363         }
4364       while (isspace(*s)) s++;
4365
4366       /* If this isn't a single-key+file lookup, re-arrange the variables
4367       to be appropriate for the search_ functions. For query-style lookups,
4368       there is just a "key", and no file name. For the special query-style +
4369       file types, the query (i.e. "key") starts with a file name. */
4370
4371       if (!key)
4372         {
4373         while (isspace(*filename)) filename++;
4374         key = filename;
4375
4376         if (mac_islookup(stype, lookup_querystyle))
4377           filename = NULL;
4378         else
4379           {
4380           if (*filename != '/')
4381             {
4382             expand_string_message = string_sprintf(
4383               "absolute file name expected for \"%s\" lookup", name);
4384             goto EXPAND_FAILED;
4385             }
4386           while (*key != 0 && !isspace(*key)) key++;
4387           if (*key != 0) *key++ = 0;
4388           }
4389         }
4390
4391       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4392       the entry was not found. Note that there is no search_close() function.
4393       Files are left open in case of re-use. At suitable places in higher logic,
4394       search_tidyup() is called to tidy all open files. This can save opening
4395       the same file several times. However, files may also get closed when
4396       others are opened, if too many are open at once. The rule is that a
4397       handle should not be used after a second search_open().
4398
4399       Request that a partial search sets up $1 and maybe $2 by passing
4400       expand_setup containing zero. If its value changes, reset expand_nmax,
4401       since new variables will have been set. Note that at the end of this
4402       "lookup" section, the old numeric variables are restored. */
4403
4404       if (skipping)
4405         lookup_value = NULL;
4406       else
4407         {
4408         void *handle = search_open(filename, stype, 0, NULL, NULL);
4409         if (handle == NULL)
4410           {
4411           expand_string_message = search_error_message;
4412           goto EXPAND_FAILED;
4413           }
4414         lookup_value = search_find(handle, filename, key, partial, affix,
4415           affixlen, starflags, &expand_setup);
4416         if (search_find_defer)
4417           {
4418           expand_string_message =
4419             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4420               string_printing2(key, FALSE), search_error_message);
4421           goto EXPAND_FAILED;
4422           }
4423         if (expand_setup > 0) expand_nmax = expand_setup;
4424         }
4425
4426       /* The handling of "yes" and "no" result strings is now in a separate
4427       function that is also used by ${if} and ${extract}. */
4428
4429       switch(process_yesno(
4430                skipping,                     /* were previously skipping */
4431                lookup_value != NULL,         /* success/failure indicator */
4432                save_lookup_value,            /* value to reset for string2 */
4433                &s,                           /* input pointer */
4434                &yield,                       /* output pointer */
4435                US"lookup",                   /* condition type */
4436                &resetok))
4437         {
4438         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4439         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4440         }
4441
4442       /* Restore external setting of expansion variables for carrying on
4443       at this level, and continue. */
4444
4445       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4446         save_expand_nlength);
4447       continue;
4448       }
4449
4450     /* If Perl support is configured, handle calling embedded perl subroutines,
4451     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4452     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4453     arguments (defined below). */
4454
4455     #define EXIM_PERL_MAX_ARGS 8
4456
4457     case EITEM_PERL:
4458     #ifndef EXIM_PERL
4459     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4460       "is not included in this binary";
4461     goto EXPAND_FAILED;
4462
4463     #else   /* EXIM_PERL */
4464       {
4465       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4466       gstring *new_yield;
4467
4468       if ((expand_forbid & RDO_PERL) != 0)
4469         {
4470         expand_string_message = US"Perl calls are not permitted";
4471         goto EXPAND_FAILED;
4472         }
4473
4474       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4475            US"perl", &resetok))
4476         {
4477         case 1: goto EXPAND_FAILED_CURLY;
4478         case 2:
4479         case 3: goto EXPAND_FAILED;
4480         }
4481
4482       /* If skipping, we don't actually do anything */
4483
4484       if (skipping) continue;
4485
4486       /* Start the interpreter if necessary */
4487
4488       if (!opt_perl_started)
4489         {
4490         uschar *initerror;
4491         if (opt_perl_startup == NULL)
4492           {
4493           expand_string_message = US"A setting of perl_startup is needed when "
4494             "using the Perl interpreter";
4495           goto EXPAND_FAILED;
4496           }
4497         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4498         initerror = init_perl(opt_perl_startup);
4499         if (initerror != NULL)
4500           {
4501           expand_string_message =
4502             string_sprintf("error in perl_startup code: %s\n", initerror);
4503           goto EXPAND_FAILED;
4504           }
4505         opt_perl_started = TRUE;
4506         }
4507
4508       /* Call the function */
4509
4510       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4511       new_yield = call_perl_cat(yield, &expand_string_message,
4512         sub_arg[0], sub_arg + 1);
4513
4514       /* NULL yield indicates failure; if the message pointer has been set to
4515       NULL, the yield was undef, indicating a forced failure. Otherwise the
4516       message will indicate some kind of Perl error. */
4517
4518       if (new_yield == NULL)
4519         {
4520         if (expand_string_message == NULL)
4521           {
4522           expand_string_message =
4523             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4524               "failure", sub_arg[0]);
4525           expand_string_forcedfail = TRUE;
4526           }
4527         goto EXPAND_FAILED;
4528         }
4529
4530       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4531       set during a callback from Perl. */
4532
4533       expand_string_forcedfail = FALSE;
4534       yield = new_yield;
4535       continue;
4536       }
4537     #endif /* EXIM_PERL */
4538
4539     /* Transform email address to "prvs" scheme to use
4540        as BATV-signed return path */
4541
4542     case EITEM_PRVS:
4543       {
4544       uschar *sub_arg[3];
4545       uschar *p,*domain;
4546
4547       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4548         {
4549         case 1: goto EXPAND_FAILED_CURLY;
4550         case 2:
4551         case 3: goto EXPAND_FAILED;
4552         }
4553
4554       /* If skipping, we don't actually do anything */
4555       if (skipping) continue;
4556
4557       /* sub_arg[0] is the address */
4558       if (  !(domain = Ustrrchr(sub_arg[0],'@'))
4559          || domain == sub_arg[0] || Ustrlen(domain) == 1)
4560         {
4561         expand_string_message = US"prvs first argument must be a qualified email address";
4562         goto EXPAND_FAILED;
4563         }
4564
4565       /* Calculate the hash. The third argument must be a single-digit
4566       key number, or unset. */
4567
4568       if (  sub_arg[2]
4569          && (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4570         {
4571         expand_string_message = US"prvs third argument must be a single digit";
4572         goto EXPAND_FAILED;
4573         }
4574
4575       p = prvs_hmac_sha1(sub_arg[0], sub_arg[1], sub_arg[2], prvs_daystamp(7));
4576       if (!p)
4577         {
4578         expand_string_message = US"prvs hmac-sha1 conversion failed";
4579         goto EXPAND_FAILED;
4580         }
4581
4582       /* Now separate the domain from the local part */
4583       *domain++ = '\0';
4584
4585       yield = string_catn(yield, US"prvs=", 5);
4586       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
4587       yield = string_catn(yield, prvs_daystamp(7), 3);
4588       yield = string_catn(yield, p, 6);
4589       yield = string_catn(yield, US"=", 1);
4590       yield = string_cat (yield, sub_arg[0]);
4591       yield = string_catn(yield, US"@", 1);
4592       yield = string_cat (yield, domain);
4593
4594       continue;
4595       }
4596
4597     /* Check a prvs-encoded address for validity */
4598
4599     case EITEM_PRVSCHECK:
4600       {
4601       uschar *sub_arg[3];
4602       gstring * g;
4603       const pcre *re;
4604       uschar *p;
4605
4606       /* TF: Ugliness: We want to expand parameter 1 first, then set
4607          up expansion variables that are used in the expansion of
4608          parameter 2. So we clone the string for the first
4609          expansion, where we only expand parameter 1.
4610
4611          PH: Actually, that isn't necessary. The read_subs() function is
4612          designed to work this way for the ${if and ${lookup expansions. I've
4613          tidied the code.
4614       */
4615
4616       /* Reset expansion variables */
4617       prvscheck_result = NULL;
4618       prvscheck_address = NULL;
4619       prvscheck_keynum = NULL;
4620
4621       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4622         {
4623         case 1: goto EXPAND_FAILED_CURLY;
4624         case 2:
4625         case 3: goto EXPAND_FAILED;
4626         }
4627
4628       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4629                               TRUE,FALSE);
4630
4631       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4632         {
4633         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4634         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4635         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4636         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4637         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4638
4639         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4640         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4641         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4642         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4643         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4644
4645         /* Set up expansion variables */
4646         g = string_cat (NULL, local_part);
4647         g = string_catn(g, US"@", 1);
4648         g = string_cat (g, domain);
4649         prvscheck_address = string_from_gstring(g);
4650         prvscheck_keynum = string_copy(key_num);
4651
4652         /* Now expand the second argument */
4653         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4654           {
4655           case 1: goto EXPAND_FAILED_CURLY;
4656           case 2:
4657           case 3: goto EXPAND_FAILED;
4658           }
4659
4660         /* Now we have the key and can check the address. */
4661
4662         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4663           daystamp);
4664
4665         if (!p)
4666           {
4667           expand_string_message = US"hmac-sha1 conversion failed";
4668           goto EXPAND_FAILED;
4669           }
4670
4671         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4672         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4673
4674         if (Ustrcmp(p,hash) == 0)
4675           {
4676           /* Success, valid BATV address. Now check the expiry date. */
4677           uschar *now = prvs_daystamp(0);
4678           unsigned int inow = 0,iexpire = 1;
4679
4680           (void)sscanf(CS now,"%u",&inow);
4681           (void)sscanf(CS daystamp,"%u",&iexpire);
4682
4683           /* When "iexpire" is < 7, a "flip" has occured.
4684              Adjust "inow" accordingly. */
4685           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4686
4687           if (iexpire >= inow)
4688             {
4689             prvscheck_result = US"1";
4690             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4691             }
4692           else
4693             {
4694             prvscheck_result = NULL;
4695             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4696             }
4697           }
4698         else
4699           {
4700           prvscheck_result = NULL;
4701           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4702           }
4703
4704         /* Now expand the final argument. We leave this till now so that
4705         it can include $prvscheck_result. */
4706
4707         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4708           {
4709           case 1: goto EXPAND_FAILED_CURLY;
4710           case 2:
4711           case 3: goto EXPAND_FAILED;
4712           }
4713
4714         yield = string_cat(yield,
4715           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4716
4717         /* Reset the "internal" variables afterwards, because they are in
4718         dynamic store that will be reclaimed if the expansion succeeded. */
4719
4720         prvscheck_address = NULL;
4721         prvscheck_keynum = NULL;
4722         }
4723       else
4724         /* Does not look like a prvs encoded address, return the empty string.
4725            We need to make sure all subs are expanded first, so as to skip over
4726            the entire item. */
4727
4728         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4729           {
4730           case 1: goto EXPAND_FAILED_CURLY;
4731           case 2:
4732           case 3: goto EXPAND_FAILED;
4733           }
4734
4735       continue;
4736       }
4737
4738     /* Handle "readfile" to insert an entire file */
4739
4740     case EITEM_READFILE:
4741       {
4742       FILE *f;
4743       uschar *sub_arg[2];
4744
4745       if ((expand_forbid & RDO_READFILE) != 0)
4746         {
4747         expand_string_message = US"file insertions are not permitted";
4748         goto EXPAND_FAILED;
4749         }
4750
4751       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4752         {
4753         case 1: goto EXPAND_FAILED_CURLY;
4754         case 2:
4755         case 3: goto EXPAND_FAILED;
4756         }
4757
4758       /* If skipping, we don't actually do anything */
4759
4760       if (skipping) continue;
4761
4762       /* Open the file and read it */
4763
4764       if (!(f = Ufopen(sub_arg[0], "rb")))
4765         {
4766         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4767         goto EXPAND_FAILED;
4768         }
4769
4770       yield = cat_file(f, yield, sub_arg[1]);
4771       (void)fclose(f);
4772       continue;
4773       }
4774
4775     /* Handle "readsocket" to insert data from a socket, either
4776     Inet or Unix domain */
4777
4778     case EITEM_READSOCK:
4779       {
4780       int fd;
4781       int timeout = 5;
4782       int save_ptr = yield->ptr;
4783       FILE *f;
4784       uschar *arg;
4785       uschar *sub_arg[4];
4786       BOOL do_shutdown = TRUE;
4787       blob reqstr;
4788
4789       if (expand_forbid & RDO_READSOCK)
4790         {
4791         expand_string_message = US"socket insertions are not permitted";
4792         goto EXPAND_FAILED;
4793         }
4794
4795       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4796       because there may be a string for expansion on failure. */
4797
4798       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4799         {
4800         case 1: goto EXPAND_FAILED_CURLY;
4801         case 2:                             /* Won't occur: no end check */
4802         case 3: goto EXPAND_FAILED;
4803         }
4804
4805       /* Grab the request string, if any */
4806
4807       reqstr.data = sub_arg[1];
4808       reqstr.len = Ustrlen(sub_arg[1]);
4809
4810       /* Sort out timeout, if given.  The second arg is a list with the first element
4811       being a time value.  Any more are options of form "name=value".  Currently the
4812       only option recognised is "shutdown". */
4813
4814       if (sub_arg[2])
4815         {
4816         const uschar * list = sub_arg[2];
4817         uschar * item;
4818         int sep = 0;
4819
4820         item = string_nextinlist(&list, &sep, NULL, 0);
4821         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4822           {
4823           expand_string_message = string_sprintf("bad time value %s", item);
4824           goto EXPAND_FAILED;
4825           }
4826
4827         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4828           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4829             if (Ustrcmp(item + 9, US"no") == 0)
4830               do_shutdown = FALSE;
4831         }
4832       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4833
4834       /* If skipping, we don't actually do anything. Otherwise, arrange to
4835       connect to either an IP or a Unix socket. */
4836
4837       if (!skipping)
4838         {
4839         /* Handle an IP (internet) domain */
4840
4841         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4842           {
4843           int port;
4844           uschar * server_name = sub_arg[0] + 5;
4845           uschar * port_name = Ustrrchr(server_name, ':');
4846
4847           /* Sort out the port */
4848
4849           if (!port_name)
4850             {
4851             expand_string_message =
4852               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4853             goto EXPAND_FAILED;
4854             }
4855           *port_name++ = 0;           /* Terminate server name */
4856
4857           if (isdigit(*port_name))
4858             {
4859             uschar *end;
4860             port = Ustrtol(port_name, &end, 0);
4861             if (end != port_name + Ustrlen(port_name))
4862               {
4863               expand_string_message =
4864                 string_sprintf("invalid port number %s", port_name);
4865               goto EXPAND_FAILED;
4866               }
4867             }
4868           else
4869             {
4870             struct servent *service_info = getservbyname(CS port_name, "tcp");
4871             if (!service_info)
4872               {
4873               expand_string_message = string_sprintf("unknown port \"%s\"",
4874                 port_name);
4875               goto EXPAND_FAILED;
4876               }
4877             port = ntohs(service_info->s_port);
4878             }
4879
4880           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4881                   timeout, NULL, &expand_string_message, &reqstr);
4882           callout_address = NULL;
4883           if (fd < 0)
4884               goto SOCK_FAIL;
4885           reqstr.len = 0;
4886           }
4887
4888         /* Handle a Unix domain socket */
4889
4890         else
4891           {
4892           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4893           int rc;
4894
4895           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4896             {
4897             expand_string_message = string_sprintf("failed to create socket: %s",
4898               strerror(errno));
4899             goto SOCK_FAIL;
4900             }
4901
4902           sockun.sun_family = AF_UNIX;
4903           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4904             sub_arg[0]);
4905
4906           sigalrm_seen = FALSE;
4907           alarm(timeout);
4908           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4909           alarm(0);
4910           if (sigalrm_seen)
4911             {
4912             expand_string_message = US "socket connect timed out";
4913             goto SOCK_FAIL;
4914             }
4915           if (rc < 0)
4916             {
4917             expand_string_message = string_sprintf("failed to connect to socket "
4918               "%s: %s", sub_arg[0], strerror(errno));
4919             goto SOCK_FAIL;
4920             }
4921           }
4922
4923         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4924
4925         /* Allow sequencing of test actions */
4926         if (running_in_test_harness) millisleep(100);
4927
4928         /* Write the request string, if not empty or already done */
4929
4930         if (reqstr.len)
4931           {
4932           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4933             reqstr.data);
4934           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4935             {
4936             expand_string_message = string_sprintf("request write to socket "
4937               "failed: %s", strerror(errno));
4938             goto SOCK_FAIL;
4939             }
4940           }
4941
4942         /* Shut down the sending side of the socket. This helps some servers to
4943         recognise that it is their turn to do some work. Just in case some
4944         system doesn't have this function, make it conditional. */
4945
4946 #ifdef SHUT_WR
4947         if (do_shutdown) shutdown(fd, SHUT_WR);
4948 #endif
4949
4950         if (running_in_test_harness) millisleep(100);
4951
4952         /* Now we need to read from the socket, under a timeout. The function
4953         that reads a file can be used. */
4954
4955         f = fdopen(fd, "rb");
4956         sigalrm_seen = FALSE;
4957         alarm(timeout);
4958         yield = cat_file(f, yield, sub_arg[3]);
4959         alarm(0);
4960         (void)fclose(f);
4961
4962         /* After a timeout, we restore the pointer in the result, that is,
4963         make sure we add nothing from the socket. */
4964
4965         if (sigalrm_seen)
4966           {
4967           yield->ptr = save_ptr;
4968           expand_string_message = US "socket read timed out";
4969           goto SOCK_FAIL;
4970           }
4971         }
4972
4973       /* The whole thing has worked (or we were skipping). If there is a
4974       failure string following, we need to skip it. */
4975
4976       if (*s == '{')
4977         {
4978         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4979           goto EXPAND_FAILED;
4980         if (*s++ != '}')
4981           {
4982           expand_string_message = US"missing '}' closing failstring for readsocket";
4983           goto EXPAND_FAILED_CURLY;
4984           }
4985         while (isspace(*s)) s++;
4986         }
4987
4988     READSOCK_DONE:
4989       if (*s++ != '}')
4990         {
4991         expand_string_message = US"missing '}' closing readsocket";
4992         goto EXPAND_FAILED_CURLY;
4993         }
4994       continue;
4995
4996       /* Come here on failure to create socket, connect socket, write to the
4997       socket, or timeout on reading. If another substring follows, expand and
4998       use it. Otherwise, those conditions give expand errors. */
4999
5000     SOCK_FAIL:
5001       if (*s != '{') goto EXPAND_FAILED;
5002       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
5003       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
5004         goto EXPAND_FAILED;
5005       yield = string_cat(yield, arg);
5006       if (*s++ != '}')
5007         {
5008         expand_string_message = US"missing '}' closing failstring for readsocket";
5009         goto EXPAND_FAILED_CURLY;
5010         }
5011       while (isspace(*s)) s++;
5012       goto READSOCK_DONE;
5013       }
5014
5015     /* Handle "run" to execute a program. */
5016
5017     case EITEM_RUN:
5018       {
5019       FILE *f;
5020       uschar *arg;
5021       const uschar **argv;
5022       pid_t pid;
5023       int fd_in, fd_out;
5024
5025       if ((expand_forbid & RDO_RUN) != 0)
5026         {
5027         expand_string_message = US"running a command is not permitted";
5028         goto EXPAND_FAILED;
5029         }
5030
5031       while (isspace(*s)) s++;
5032       if (*s != '{')
5033         {
5034         expand_string_message = US"missing '{' for command arg of run";
5035         goto EXPAND_FAILED_CURLY;
5036         }
5037       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5038       if (arg == NULL) goto EXPAND_FAILED;
5039       while (isspace(*s)) s++;
5040       if (*s++ != '}')
5041         {
5042         expand_string_message = US"missing '}' closing command arg of run";
5043         goto EXPAND_FAILED_CURLY;
5044         }
5045
5046       if (skipping)   /* Just pretend it worked when we're skipping */
5047         {
5048         runrc = 0;
5049         lookup_value = NULL;
5050         }
5051       else
5052         {
5053         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5054             arg,                                /* raw command */
5055             FALSE,                              /* don't expand the arguments */
5056             0,                                  /* not relevant when... */
5057             NULL,                               /* no transporting address */
5058             US"${run} expansion",               /* for error messages */
5059             &expand_string_message))            /* where to put error message */
5060           goto EXPAND_FAILED;
5061
5062         /* Create the child process, making it a group leader. */
5063
5064         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5065           {
5066           expand_string_message =
5067             string_sprintf("couldn't create child process: %s", strerror(errno));
5068           goto EXPAND_FAILED;
5069           }
5070
5071         /* Nothing is written to the standard input. */
5072
5073         (void)close(fd_in);
5074
5075         /* Read the pipe to get the command's output into $value (which is kept
5076         in lookup_value). Read during execution, so that if the output exceeds
5077         the OS pipe buffer limit, we don't block forever. Remember to not release
5078         memory just allocated for $value. */
5079
5080         resetok = FALSE;
5081         f = fdopen(fd_out, "rb");
5082         sigalrm_seen = FALSE;
5083         alarm(60);
5084         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5085         alarm(0);
5086         (void)fclose(f);
5087
5088         /* Wait for the process to finish, applying the timeout, and inspect its
5089         return code for serious disasters. Simple non-zero returns are passed on.
5090         */
5091
5092         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5093           {
5094           if (sigalrm_seen || runrc == -256)
5095             {
5096             expand_string_message = string_sprintf("command timed out");
5097             killpg(pid, SIGKILL);       /* Kill the whole process group */
5098             }
5099
5100           else if (runrc == -257)
5101             expand_string_message = string_sprintf("wait() failed: %s",
5102               strerror(errno));
5103
5104           else
5105             expand_string_message = string_sprintf("command killed by signal %d",
5106               -runrc);
5107
5108           goto EXPAND_FAILED;
5109           }
5110         }
5111
5112       /* Process the yes/no strings; $value may be useful in both cases */
5113
5114       switch(process_yesno(
5115                skipping,                     /* were previously skipping */
5116                runrc == 0,                   /* success/failure indicator */
5117                lookup_value,                 /* value to reset for string2 */
5118                &s,                           /* input pointer */
5119                &yield,                       /* output pointer */
5120                US"run",                      /* condition type */
5121                &resetok))
5122         {
5123         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5124         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5125         }
5126
5127       continue;
5128       }
5129
5130     /* Handle character translation for "tr" */
5131
5132     case EITEM_TR:
5133       {
5134       int oldptr = yield->ptr;
5135       int o2m;
5136       uschar *sub[3];
5137
5138       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5139         {
5140         case 1: goto EXPAND_FAILED_CURLY;
5141         case 2:
5142         case 3: goto EXPAND_FAILED;
5143         }
5144
5145       yield = string_cat(yield, sub[0]);
5146       o2m = Ustrlen(sub[2]) - 1;
5147
5148       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5149         {
5150         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5151         if (m != NULL)
5152           {
5153           int o = m - sub[1];
5154           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5155           }
5156         }
5157
5158       continue;
5159       }
5160
5161     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5162     expanded arguments. */
5163
5164     case EITEM_HASH:
5165     case EITEM_LENGTH:
5166     case EITEM_NHASH:
5167     case EITEM_SUBSTR:
5168       {
5169       int i;
5170       int len;
5171       uschar *ret;
5172       int val[2] = { 0, -1 };
5173       uschar *sub[3];
5174
5175       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5176       Ensure that sub[2] is set in the ${length } case. */
5177
5178       sub[2] = NULL;
5179       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5180              TRUE, name, &resetok))
5181         {
5182         case 1: goto EXPAND_FAILED_CURLY;
5183         case 2:
5184         case 3: goto EXPAND_FAILED;
5185         }
5186
5187       /* Juggle the arguments if there are only two of them: always move the
5188       string to the last position and make ${length{n}{str}} equivalent to
5189       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5190
5191       if (sub[2] == NULL)
5192         {
5193         sub[2] = sub[1];
5194         sub[1] = NULL;
5195         if (item_type == EITEM_LENGTH)
5196           {
5197           sub[1] = sub[0];
5198           sub[0] = NULL;
5199           }
5200         }
5201
5202       for (i = 0; i < 2; i++)
5203         {
5204         if (sub[i] == NULL) continue;
5205         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5206         if (*ret != 0 || (i != 0 && val[i] < 0))
5207           {
5208           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5209             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5210           goto EXPAND_FAILED;
5211           }
5212         }
5213
5214       ret =
5215         (item_type == EITEM_HASH)?
5216           compute_hash(sub[2], val[0], val[1], &len) :
5217         (item_type == EITEM_NHASH)?
5218           compute_nhash(sub[2], val[0], val[1], &len) :
5219           extract_substr(sub[2], val[0], val[1], &len);
5220
5221       if (ret == NULL) goto EXPAND_FAILED;
5222       yield = string_catn(yield, ret, len);
5223       continue;
5224       }
5225
5226     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5227     This code originally contributed by Steve Haslam. It currently supports
5228     the use of MD5 and SHA-1 hashes.
5229
5230     We need some workspace that is large enough to handle all the supported
5231     hash types. Use macros to set the sizes rather than be too elaborate. */
5232
5233     #define MAX_HASHLEN      20
5234     #define MAX_HASHBLOCKLEN 64
5235
5236     case EITEM_HMAC:
5237       {
5238       uschar *sub[3];
5239       md5 md5_base;
5240       hctx sha1_ctx;
5241       void *use_base;
5242       int type, i;
5243       int hashlen;      /* Number of octets for the hash algorithm's output */
5244       int hashblocklen; /* Number of octets the hash algorithm processes */
5245       uschar *keyptr, *p;
5246       unsigned int keylen;
5247
5248       uschar keyhash[MAX_HASHLEN];
5249       uschar innerhash[MAX_HASHLEN];
5250       uschar finalhash[MAX_HASHLEN];
5251       uschar finalhash_hex[2*MAX_HASHLEN];
5252       uschar innerkey[MAX_HASHBLOCKLEN];
5253       uschar outerkey[MAX_HASHBLOCKLEN];
5254
5255       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5256         {
5257         case 1: goto EXPAND_FAILED_CURLY;
5258         case 2:
5259         case 3: goto EXPAND_FAILED;
5260         }
5261
5262       if (!skipping)
5263         {
5264         if (Ustrcmp(sub[0], "md5") == 0)
5265           {
5266           type = HMAC_MD5;
5267           use_base = &md5_base;
5268           hashlen = 16;
5269           hashblocklen = 64;
5270           }
5271         else if (Ustrcmp(sub[0], "sha1") == 0)
5272           {
5273           type = HMAC_SHA1;
5274           use_base = &sha1_ctx;
5275           hashlen = 20;
5276           hashblocklen = 64;
5277           }
5278         else
5279           {
5280           expand_string_message =
5281             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5282           goto EXPAND_FAILED;
5283           }
5284
5285         keyptr = sub[1];
5286         keylen = Ustrlen(keyptr);
5287
5288         /* If the key is longer than the hash block length, then hash the key
5289         first */
5290
5291         if (keylen > hashblocklen)
5292           {
5293           chash_start(type, use_base);
5294           chash_end(type, use_base, keyptr, keylen, keyhash);
5295           keyptr = keyhash;
5296           keylen = hashlen;
5297           }
5298
5299         /* Now make the inner and outer key values */
5300
5301         memset(innerkey, 0x36, hashblocklen);
5302         memset(outerkey, 0x5c, hashblocklen);
5303
5304         for (i = 0; i < keylen; i++)
5305           {
5306           innerkey[i] ^= keyptr[i];
5307           outerkey[i] ^= keyptr[i];
5308           }
5309
5310         /* Now do the hashes */
5311
5312         chash_start(type, use_base);
5313         chash_mid(type, use_base, innerkey);
5314         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5315
5316         chash_start(type, use_base);
5317         chash_mid(type, use_base, outerkey);
5318         chash_end(type, use_base, innerhash, hashlen, finalhash);
5319
5320         /* Encode the final hash as a hex string */
5321
5322         p = finalhash_hex;
5323         for (i = 0; i < hashlen; i++)
5324           {
5325           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5326           *p++ = hex_digits[finalhash[i] & 0x0f];
5327           }
5328
5329         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5330           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5331
5332         yield = string_catn(yield, finalhash_hex, hashlen*2);
5333         }
5334       continue;
5335       }
5336
5337     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5338     We have to save the numerical variables and restore them afterwards. */
5339
5340     case EITEM_SG:
5341       {
5342       const pcre *re;
5343       int moffset, moffsetextra, slen;
5344       int roffset;
5345       int emptyopt;
5346       const uschar *rerror;
5347       uschar *subject;
5348       uschar *sub[3];
5349       int save_expand_nmax =
5350         save_expand_strings(save_expand_nstring, save_expand_nlength);
5351
5352       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5353         {
5354         case 1: goto EXPAND_FAILED_CURLY;
5355         case 2:
5356         case 3: goto EXPAND_FAILED;
5357         }
5358
5359       /* Compile the regular expression */
5360
5361       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5362         NULL);
5363
5364       if (re == NULL)
5365         {
5366         expand_string_message = string_sprintf("regular expression error in "
5367           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5368         goto EXPAND_FAILED;
5369         }
5370
5371       /* Now run a loop to do the substitutions as often as necessary. It ends
5372       when there are no more matches. Take care over matches of the null string;
5373       do the same thing as Perl does. */
5374
5375       subject = sub[0];
5376       slen = Ustrlen(sub[0]);
5377       moffset = moffsetextra = 0;
5378       emptyopt = 0;
5379
5380       for (;;)
5381         {
5382         int ovector[3*(EXPAND_MAXN+1)];
5383         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5384           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5385         int nn;
5386         uschar *insert;
5387
5388         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5389         is not necessarily the end. We want to repeat the match from one
5390         character further along, but leaving the basic offset the same (for
5391         copying below). We can't be at the end of the string - that was checked
5392         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5393         finished; copy the remaining string and end the loop. */
5394
5395         if (n < 0)
5396           {
5397           if (emptyopt != 0)
5398             {
5399             moffsetextra = 1;
5400             emptyopt = 0;
5401             continue;
5402             }
5403           yield = string_catn(yield, subject+moffset, slen-moffset);
5404           break;
5405           }
5406
5407         /* Match - set up for expanding the replacement. */
5408
5409         if (n == 0) n = EXPAND_MAXN + 1;
5410         expand_nmax = 0;
5411         for (nn = 0; nn < n*2; nn += 2)
5412           {
5413           expand_nstring[expand_nmax] = subject + ovector[nn];
5414           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5415           }
5416         expand_nmax--;
5417
5418         /* Copy the characters before the match, plus the expanded insertion. */
5419
5420         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5421         insert = expand_string(sub[2]);
5422         if (insert == NULL) goto EXPAND_FAILED;
5423         yield = string_cat(yield, insert);
5424
5425         moffset = ovector[1];
5426         moffsetextra = 0;
5427         emptyopt = 0;
5428
5429         /* If we have matched an empty string, first check to see if we are at
5430         the end of the subject. If so, the loop is over. Otherwise, mimic
5431         what Perl's /g options does. This turns out to be rather cunning. First
5432         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5433         string at the same point. If this fails (picked up above) we advance to
5434         the next character. */
5435
5436         if (ovector[0] == ovector[1])
5437           {
5438           if (ovector[0] == slen) break;
5439           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5440           }
5441         }
5442
5443       /* All done - restore numerical variables. */
5444
5445       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5446         save_expand_nlength);
5447       continue;
5448       }
5449
5450     /* Handle keyed and numbered substring extraction. If the first argument
5451     consists entirely of digits, then a numerical extraction is assumed. */
5452
5453     case EITEM_EXTRACT:
5454       {
5455       int i;
5456       int j;
5457       int field_number = 1;
5458       BOOL field_number_set = FALSE;
5459       uschar *save_lookup_value = lookup_value;
5460       uschar *sub[3];
5461       int save_expand_nmax =
5462         save_expand_strings(save_expand_nstring, save_expand_nlength);
5463
5464       /* While skipping we cannot rely on the data for expansions being
5465       available (eg. $item) hence cannot decide on numeric vs. keyed.
5466       Read a maximum of 5 arguments (including the yes/no) */
5467
5468       if (skipping)
5469         {
5470         while (isspace(*s)) s++;
5471         for (j = 5; j > 0 && *s == '{'; j--)
5472           {
5473           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5474             goto EXPAND_FAILED;                                 /*{*/
5475           if (*s++ != '}')
5476             {
5477             expand_string_message = US"missing '{' for arg of extract";
5478             goto EXPAND_FAILED_CURLY;
5479             }
5480           while (isspace(*s)) s++;
5481           }
5482         if (  Ustrncmp(s, "fail", 4) == 0
5483            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5484            )
5485           {
5486           s += 4;
5487           while (isspace(*s)) s++;
5488           }
5489         if (*s != '}')
5490           {
5491           expand_string_message = US"missing '}' closing extract";
5492           goto EXPAND_FAILED_CURLY;
5493           }
5494         }
5495
5496       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5497         {
5498         while (isspace(*s)) s++;
5499         if (*s == '{')                                          /*}*/
5500           {
5501           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5502           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5503           if (*s++ != '}')
5504             {
5505             expand_string_message = string_sprintf(
5506               "missing '}' closing arg %d of extract", i+1);
5507             goto EXPAND_FAILED_CURLY;
5508             }
5509
5510           /* After removal of leading and trailing white space, the first
5511           argument must not be empty; if it consists entirely of digits
5512           (optionally preceded by a minus sign), this is a numerical
5513           extraction, and we expect 3 arguments. */
5514
5515           if (i == 0)
5516             {
5517             int len;
5518             int x = 0;
5519             uschar *p = sub[0];
5520
5521             while (isspace(*p)) p++;
5522             sub[0] = p;
5523
5524             len = Ustrlen(p);
5525             while (len > 0 && isspace(p[len-1])) len--;
5526             p[len] = 0;
5527
5528             if (*p == 0)
5529               {
5530               expand_string_message = US"first argument of \"extract\" must "
5531                 "not be empty";
5532               goto EXPAND_FAILED;
5533               }
5534
5535             if (*p == '-')
5536               {
5537               field_number = -1;
5538               p++;
5539               }
5540             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5541             if (*p == 0)
5542               {
5543               field_number *= x;
5544               j = 3;               /* Need 3 args */
5545               field_number_set = TRUE;
5546               }
5547             }
5548           }
5549         else
5550           {
5551           expand_string_message = string_sprintf(
5552             "missing '{' for arg %d of extract", i+1);
5553           goto EXPAND_FAILED_CURLY;
5554           }
5555         }
5556
5557       /* Extract either the numbered or the keyed substring into $value. If
5558       skipping, just pretend the extraction failed. */
5559
5560       lookup_value = skipping? NULL : field_number_set?
5561         expand_gettokened(field_number, sub[1], sub[2]) :
5562         expand_getkeyed(sub[0], sub[1]);
5563
5564       /* If no string follows, $value gets substituted; otherwise there can
5565       be yes/no strings, as for lookup or if. */
5566
5567       switch(process_yesno(
5568                skipping,                     /* were previously skipping */
5569                lookup_value != NULL,         /* success/failure indicator */
5570                save_lookup_value,            /* value to reset for string2 */
5571                &s,                           /* input pointer */
5572                &yield,                       /* output pointer */
5573                US"extract",                  /* condition type */
5574                &resetok))
5575         {
5576         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5577         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5578         }
5579
5580       /* All done - restore numerical variables. */
5581
5582       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5583         save_expand_nlength);
5584
5585       continue;
5586       }
5587
5588     /* return the Nth item from a list */
5589
5590     case EITEM_LISTEXTRACT:
5591       {
5592       int i;
5593       int field_number = 1;
5594       uschar *save_lookup_value = lookup_value;
5595       uschar *sub[2];
5596       int save_expand_nmax =
5597         save_expand_strings(save_expand_nstring, save_expand_nlength);
5598
5599       /* Read the field & list arguments */
5600
5601       for (i = 0; i < 2; i++)
5602         {
5603         while (isspace(*s)) s++;
5604         if (*s != '{')                                  /*}*/
5605           {
5606           expand_string_message = string_sprintf(
5607             "missing '{' for arg %d of listextract", i+1);
5608           goto EXPAND_FAILED_CURLY;
5609           }
5610
5611         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5612         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5613         if (*s++ != '}')
5614           {
5615           expand_string_message = string_sprintf(
5616             "missing '}' closing arg %d of listextract", i+1);
5617           goto EXPAND_FAILED_CURLY;
5618           }
5619
5620         /* After removal of leading and trailing white space, the first
5621         argument must be numeric and nonempty. */
5622
5623         if (i == 0)
5624           {
5625           int len;
5626           int x = 0;
5627           uschar *p = sub[0];
5628
5629           while (isspace(*p)) p++;
5630           sub[0] = p;
5631
5632           len = Ustrlen(p);
5633           while (len > 0 && isspace(p[len-1])) len--;
5634           p[len] = 0;
5635
5636           if (!*p && !skipping)
5637             {
5638             expand_string_message = US"first argument of \"listextract\" must "
5639               "not be empty";
5640             goto EXPAND_FAILED;
5641             }
5642
5643           if (*p == '-')
5644             {
5645             field_number = -1;
5646             p++;
5647             }
5648           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5649           if (*p)
5650             {
5651             expand_string_message = US"first argument of \"listextract\" must "
5652               "be numeric";
5653             goto EXPAND_FAILED;
5654             }
5655           field_number *= x;
5656           }
5657         }
5658
5659       /* Extract the numbered element into $value. If
5660       skipping, just pretend the extraction failed. */
5661
5662       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5663
5664       /* If no string follows, $value gets substituted; otherwise there can
5665       be yes/no strings, as for lookup or if. */
5666
5667       switch(process_yesno(
5668                skipping,                     /* were previously skipping */
5669                lookup_value != NULL,         /* success/failure indicator */
5670                save_lookup_value,            /* value to reset for string2 */
5671                &s,                           /* input pointer */
5672                &yield,                       /* output pointer */
5673                US"listextract",              /* condition type */
5674                &resetok))
5675         {
5676         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5677         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5678         }
5679
5680       /* All done - restore numerical variables. */
5681
5682       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5683         save_expand_nlength);
5684
5685       continue;
5686       }
5687
5688 #ifdef SUPPORT_TLS
5689     case EITEM_CERTEXTRACT:
5690       {
5691       uschar *save_lookup_value = lookup_value;
5692       uschar *sub[2];
5693       int save_expand_nmax =
5694         save_expand_strings(save_expand_nstring, save_expand_nlength);
5695
5696       /* Read the field argument */
5697       while (isspace(*s)) s++;
5698       if (*s != '{')                                    /*}*/
5699         {
5700         expand_string_message = US"missing '{' for field arg of certextract";
5701         goto EXPAND_FAILED_CURLY;
5702         }
5703       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5704       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5705       if (*s++ != '}')
5706         {
5707         expand_string_message = US"missing '}' closing field arg of certextract";
5708         goto EXPAND_FAILED_CURLY;
5709         }
5710       /* strip spaces fore & aft */
5711       {
5712       int len;
5713       uschar *p = sub[0];
5714
5715       while (isspace(*p)) p++;
5716       sub[0] = p;
5717
5718       len = Ustrlen(p);
5719       while (len > 0 && isspace(p[len-1])) len--;
5720       p[len] = 0;
5721       }
5722
5723       /* inspect the cert argument */
5724       while (isspace(*s)) s++;
5725       if (*s != '{')                                    /*}*/
5726         {
5727         expand_string_message = US"missing '{' for cert variable arg of certextract";
5728         goto EXPAND_FAILED_CURLY;
5729         }
5730       if (*++s != '$')
5731         {
5732         expand_string_message = US"second argument of \"certextract\" must "
5733           "be a certificate variable";
5734         goto EXPAND_FAILED;
5735         }
5736       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5737       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5738       if (*s++ != '}')
5739         {
5740         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5741         goto EXPAND_FAILED_CURLY;
5742         }
5743
5744       if (skipping)
5745         lookup_value = NULL;
5746       else
5747         {
5748         lookup_value = expand_getcertele(sub[0], sub[1]);
5749         if (*expand_string_message) goto EXPAND_FAILED;
5750         }
5751       switch(process_yesno(
5752                skipping,                     /* were previously skipping */
5753                lookup_value != NULL,         /* success/failure indicator */
5754                save_lookup_value,            /* value to reset for string2 */
5755                &s,                           /* input pointer */
5756                &yield,                       /* output pointer */
5757                US"certextract",              /* condition type */
5758                &resetok))
5759         {
5760         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5761         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5762         }
5763
5764       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5765         save_expand_nlength);
5766       continue;
5767       }
5768 #endif  /*SUPPORT_TLS*/
5769
5770     /* Handle list operations */
5771
5772     case EITEM_FILTER:
5773     case EITEM_MAP:
5774     case EITEM_REDUCE:
5775       {
5776       int sep = 0;
5777       int save_ptr = yield->ptr;
5778       uschar outsep[2] = { '\0', '\0' };
5779       const uschar *list, *expr, *temp;
5780       uschar *save_iterate_item = iterate_item;
5781       uschar *save_lookup_value = lookup_value;
5782
5783       while (isspace(*s)) s++;
5784       if (*s++ != '{')
5785         {
5786         expand_string_message =
5787           string_sprintf("missing '{' for first arg of %s", name);
5788         goto EXPAND_FAILED_CURLY;
5789         }
5790
5791       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5792       if (list == NULL) goto EXPAND_FAILED;
5793       if (*s++ != '}')
5794         {
5795         expand_string_message =
5796           string_sprintf("missing '}' closing first arg of %s", name);
5797         goto EXPAND_FAILED_CURLY;
5798         }
5799
5800       if (item_type == EITEM_REDUCE)
5801         {
5802         uschar * t;
5803         while (isspace(*s)) s++;
5804         if (*s++ != '{')
5805           {
5806           expand_string_message = US"missing '{' for second arg of reduce";
5807           goto EXPAND_FAILED_CURLY;
5808           }
5809         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5810         if (!t) goto EXPAND_FAILED;
5811         lookup_value = t;
5812         if (*s++ != '}')
5813           {
5814           expand_string_message = US"missing '}' closing second arg of reduce";
5815           goto EXPAND_FAILED_CURLY;
5816           }
5817         }
5818
5819       while (isspace(*s)) s++;
5820       if (*s++ != '{')
5821         {
5822         expand_string_message =
5823           string_sprintf("missing '{' for last arg of %s", name);
5824         goto EXPAND_FAILED_CURLY;
5825         }
5826
5827       expr = s;
5828
5829       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5830       if scanning a "false" part). This allows us to find the end of the
5831       condition, because if the list is empty, we won't actually evaluate the
5832       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5833       the normal internal expansion function. */
5834
5835       if (item_type == EITEM_FILTER)
5836         {
5837         temp = eval_condition(expr, &resetok, NULL);
5838         if (temp != NULL) s = temp;
5839         }
5840       else
5841         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5842
5843       if (temp == NULL)
5844         {
5845         expand_string_message = string_sprintf("%s inside \"%s\" item",
5846           expand_string_message, name);
5847         goto EXPAND_FAILED;
5848         }
5849
5850       while (isspace(*s)) s++;
5851       if (*s++ != '}')
5852         {                                               /*{*/
5853         expand_string_message = string_sprintf("missing } at end of condition "
5854           "or expression inside \"%s\"; could be an unquoted } in the content",
5855           name);
5856         goto EXPAND_FAILED;
5857         }
5858
5859       while (isspace(*s)) s++;                          /*{*/
5860       if (*s++ != '}')
5861         {                                               /*{*/
5862         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5863           name);
5864         goto EXPAND_FAILED;
5865         }
5866
5867       /* If we are skipping, we can now just move on to the next item. When
5868       processing for real, we perform the iteration. */
5869
5870       if (skipping) continue;
5871       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5872         {
5873         *outsep = (uschar)sep;      /* Separator as a string */
5874
5875         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5876                           name, iterate_item, lookup_value);
5877
5878         if (item_type == EITEM_FILTER)
5879           {
5880           BOOL condresult;
5881           if (eval_condition(expr, &resetok, &condresult) == NULL)
5882             {
5883             iterate_item = save_iterate_item;
5884             lookup_value = save_lookup_value;
5885             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5886               expand_string_message, name);
5887             goto EXPAND_FAILED;
5888             }
5889           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5890             condresult? "true":"false");
5891           if (condresult)
5892             temp = iterate_item;    /* TRUE => include this item */
5893           else
5894             continue;               /* FALSE => skip this item */
5895           }
5896
5897         /* EITEM_MAP and EITEM_REDUCE */
5898
5899         else
5900           {
5901           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5902           temp = t;
5903           if (temp == NULL)
5904             {
5905             iterate_item = save_iterate_item;
5906             expand_string_message = string_sprintf("%s inside \"%s\" item",
5907               expand_string_message, name);
5908             goto EXPAND_FAILED;
5909             }
5910           if (item_type == EITEM_REDUCE)
5911             {
5912             lookup_value = t;         /* Update the value of $value */
5913             continue;                 /* and continue the iteration */
5914             }
5915           }
5916
5917         /* We reach here for FILTER if the condition is true, always for MAP,
5918         and never for REDUCE. The value in "temp" is to be added to the output
5919         list that is being created, ensuring that any occurrences of the
5920         separator character are doubled. Unless we are dealing with the first
5921         item of the output list, add in a space if the new item begins with the
5922         separator character, or is an empty string. */
5923
5924         if (yield->ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5925           yield = string_catn(yield, US" ", 1);
5926
5927         /* Add the string in "temp" to the output list that we are building,
5928         This is done in chunks by searching for the separator character. */
5929
5930         for (;;)
5931           {
5932           size_t seglen = Ustrcspn(temp, outsep);
5933
5934           yield = string_catn(yield, temp, seglen + 1);
5935
5936           /* If we got to the end of the string we output one character
5937           too many; backup and end the loop. Otherwise arrange to double the
5938           separator. */
5939
5940           if (temp[seglen] == '\0') { yield->ptr--; break; }
5941           yield = string_catn(yield, outsep, 1);
5942           temp += seglen + 1;
5943           }
5944
5945         /* Output a separator after the string: we will remove the redundant
5946         final one at the end. */
5947
5948         yield = string_catn(yield, outsep, 1);
5949         }   /* End of iteration over the list loop */
5950
5951       /* REDUCE has generated no output above: output the final value of
5952       $value. */
5953
5954       if (item_type == EITEM_REDUCE)
5955         {
5956         yield = string_cat(yield, lookup_value);
5957         lookup_value = save_lookup_value;  /* Restore $value */
5958         }
5959
5960       /* FILTER and MAP generate lists: if they have generated anything, remove
5961       the redundant final separator. Even though an empty item at the end of a
5962       list does not count, this is tidier. */
5963
5964       else if (yield->ptr != save_ptr) yield->ptr--;
5965
5966       /* Restore preserved $item */
5967
5968       iterate_item = save_iterate_item;
5969       continue;
5970       }
5971
5972     case EITEM_SORT:
5973       {
5974       int sep = 0;
5975       const uschar *srclist, *cmp, *xtract;
5976       uschar *srcitem;
5977       const uschar *dstlist = NULL, *dstkeylist = NULL;
5978       uschar * tmp;
5979       uschar *save_iterate_item = iterate_item;
5980
5981       while (isspace(*s)) s++;
5982       if (*s++ != '{')
5983         {
5984         expand_string_message = US"missing '{' for list arg of sort";
5985         goto EXPAND_FAILED_CURLY;
5986         }
5987
5988       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5989       if (!srclist) goto EXPAND_FAILED;
5990       if (*s++ != '}')
5991         {
5992         expand_string_message = US"missing '}' closing list arg of sort";
5993         goto EXPAND_FAILED_CURLY;
5994         }
5995
5996       while (isspace(*s)) s++;
5997       if (*s++ != '{')
5998         {
5999         expand_string_message = US"missing '{' for comparator arg of sort";
6000         goto EXPAND_FAILED_CURLY;
6001         }
6002
6003       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
6004       if (!cmp) goto EXPAND_FAILED;
6005       if (*s++ != '}')
6006         {
6007         expand_string_message = US"missing '}' closing comparator arg of sort";
6008         goto EXPAND_FAILED_CURLY;
6009         }
6010
6011       while (isspace(*s)) s++;
6012       if (*s++ != '{')
6013         {
6014         expand_string_message = US"missing '{' for extractor arg of sort";
6015         goto EXPAND_FAILED_CURLY;
6016         }
6017
6018       xtract = s;
6019       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
6020       if (!tmp) goto EXPAND_FAILED;
6021       xtract = string_copyn(xtract, s - xtract);
6022
6023       if (*s++ != '}')
6024         {
6025         expand_string_message = US"missing '}' closing extractor arg of sort";
6026         goto EXPAND_FAILED_CURLY;
6027         }
6028                                                         /*{*/
6029       if (*s++ != '}')
6030         {                                               /*{*/
6031         expand_string_message = US"missing } at end of \"sort\"";
6032         goto EXPAND_FAILED;
6033         }
6034
6035       if (skipping) continue;
6036
6037       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
6038         {
6039         uschar * dstitem;
6040         gstring * newlist = NULL;
6041         gstring * newkeylist = NULL;
6042         uschar * srcfield;
6043
6044         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6045
6046         /* extract field for comparisons */
6047         iterate_item = srcitem;
6048         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6049                                           TRUE, &resetok))
6050            || !*srcfield)
6051           {
6052           expand_string_message = string_sprintf(
6053               "field-extract in sort: \"%s\"", xtract);
6054           goto EXPAND_FAILED;
6055           }
6056
6057         /* Insertion sort */
6058
6059         /* copy output list until new-item < list-item */
6060         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6061           {
6062           uschar * dstfield;
6063           uschar * expr;
6064           BOOL before;
6065
6066           /* field for comparison */
6067           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6068             goto sort_mismatch;
6069
6070           /* build and run condition string */
6071           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6072
6073           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6074           if (!eval_condition(expr, &resetok, &before))
6075             {
6076             expand_string_message = string_sprintf("comparison in sort: %s",
6077                 expr);
6078             goto EXPAND_FAILED;
6079             }
6080
6081           if (before)
6082             {
6083             /* New-item sorts before this dst-item.  Append new-item,
6084             then dst-item, then remainder of dst list. */
6085
6086             newlist = string_append_listele(newlist, sep, srcitem);
6087             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6088             srcitem = NULL;
6089
6090             newlist = string_append_listele(newlist, sep, dstitem);
6091             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6092
6093             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6094               {
6095               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6096                 goto sort_mismatch;
6097               newlist = string_append_listele(newlist, sep, dstitem);
6098               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6099               }
6100
6101             break;
6102             }
6103
6104           newlist = string_append_listele(newlist, sep, dstitem);
6105           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6106           }
6107
6108         /* If we ran out of dstlist without consuming srcitem, append it */
6109         if (srcitem)
6110           {
6111           newlist = string_append_listele(newlist, sep, srcitem);
6112           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6113           }
6114
6115         dstlist = newlist->s;
6116         dstkeylist = newkeylist->s;
6117
6118         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6119         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6120         }
6121
6122       if (dstlist)
6123         yield = string_cat(yield, dstlist);
6124
6125       /* Restore preserved $item */
6126       iterate_item = save_iterate_item;
6127       continue;
6128
6129       sort_mismatch:
6130         expand_string_message = US"Internal error in sort (list mismatch)";
6131         goto EXPAND_FAILED;
6132       }
6133
6134
6135     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6136     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6137     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6138     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6139
6140     #define EXPAND_DLFUNC_MAX_ARGS 8
6141
6142     case EITEM_DLFUNC:
6143 #ifndef EXPAND_DLFUNC
6144       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6145         "is not included in this binary";
6146       goto EXPAND_FAILED;
6147
6148 #else   /* EXPAND_DLFUNC */
6149       {
6150       tree_node *t;
6151       exim_dlfunc_t *func;
6152       uschar *result;
6153       int status, argc;
6154       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6155
6156       if ((expand_forbid & RDO_DLFUNC) != 0)
6157         {
6158         expand_string_message =
6159           US"dynamically-loaded functions are not permitted";
6160         goto EXPAND_FAILED;
6161         }
6162
6163       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6164            TRUE, US"dlfunc", &resetok))
6165         {
6166         case 1: goto EXPAND_FAILED_CURLY;
6167         case 2:
6168         case 3: goto EXPAND_FAILED;
6169         }
6170
6171       /* If skipping, we don't actually do anything */
6172
6173       if (skipping) continue;
6174
6175       /* Look up the dynamically loaded object handle in the tree. If it isn't
6176       found, dlopen() the file and put the handle in the tree for next time. */
6177
6178       t = tree_search(dlobj_anchor, argv[0]);
6179       if (t == NULL)
6180         {
6181         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6182         if (handle == NULL)
6183           {
6184           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6185             argv[0], dlerror());
6186           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6187           goto EXPAND_FAILED;
6188           }
6189         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6190         Ustrcpy(t->name, argv[0]);
6191         t->data.ptr = handle;
6192         (void)tree_insertnode(&dlobj_anchor, t);
6193         }
6194
6195       /* Having obtained the dynamically loaded object handle, look up the
6196       function pointer. */
6197
6198       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6199       if (func == NULL)
6200         {
6201         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6202           "%s", argv[1], argv[0], dlerror());
6203         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6204         goto EXPAND_FAILED;
6205         }
6206
6207       /* Call the function and work out what to do with the result. If it
6208       returns OK, we have a replacement string; if it returns DEFER then
6209       expansion has failed in a non-forced manner; if it returns FAIL then
6210       failure was forced; if it returns ERROR or any other value there's a
6211       problem, so panic slightly. In any case, assume that the function has
6212       side-effects on the store that must be preserved. */
6213
6214       resetok = FALSE;
6215       result = NULL;
6216       for (argc = 0; argv[argc] != NULL; argc++);
6217       status = func(&result, argc - 2, &argv[2]);
6218       if(status == OK)
6219         {
6220         if (result == NULL) result = US"";
6221         yield = string_cat(yield, result);
6222         continue;
6223         }
6224       else
6225         {
6226         expand_string_message = result == NULL ? US"(no message)" : result;
6227         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6228           else if(status != FAIL)
6229             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6230               argv[0], argv[1], status, expand_string_message);
6231         goto EXPAND_FAILED;
6232         }
6233       }
6234 #endif /* EXPAND_DLFUNC */
6235
6236     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6237       {
6238       uschar * key;
6239       uschar *save_lookup_value = lookup_value;
6240
6241       while (isspace(*s)) s++;
6242       if (*s != '{')                                    /*}*/
6243         goto EXPAND_FAILED;
6244
6245       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6246       if (!key) goto EXPAND_FAILED;                     /*{*/
6247       if (*s++ != '}')
6248         {
6249         expand_string_message = US"missing '{' for name arg of env";
6250         goto EXPAND_FAILED_CURLY;
6251         }
6252
6253       lookup_value = US getenv(CS key);
6254
6255       switch(process_yesno(
6256                skipping,                     /* were previously skipping */
6257                lookup_value != NULL,         /* success/failure indicator */
6258                save_lookup_value,            /* value to reset for string2 */
6259                &s,                           /* input pointer */
6260                &yield,                       /* output pointer */
6261                US"env",                      /* condition type */
6262                &resetok))
6263         {
6264         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6265         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6266         }
6267       continue;
6268       }
6269     }   /* EITEM_* switch */
6270
6271   /* Control reaches here if the name is not recognized as one of the more
6272   complicated expansion items. Check for the "operator" syntax (name terminated
6273   by a colon). Some of the operators have arguments, separated by _ from the
6274   name. */
6275
6276   if (*s == ':')
6277     {
6278     int c;
6279     uschar *arg = NULL;
6280     uschar *sub;
6281     var_entry *vp = NULL;
6282
6283     /* Owing to an historical mis-design, an underscore may be part of the
6284     operator name, or it may introduce arguments.  We therefore first scan the
6285     table of names that contain underscores. If there is no match, we cut off
6286     the arguments and then scan the main table. */
6287
6288     if ((c = chop_match(name, op_table_underscore,
6289                         nelem(op_table_underscore))) < 0)
6290       {
6291       arg = Ustrchr(name, '_');
6292       if (arg != NULL) *arg = 0;
6293       c = chop_match(name, op_table_main, nelem(op_table_main));
6294       if (c >= 0) c += nelem(op_table_underscore);
6295       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6296       }
6297
6298     /* Deal specially with operators that might take a certificate variable
6299     as we do not want to do the usual expansion. For most, expand the string.*/
6300     switch(c)
6301       {
6302 #ifdef SUPPORT_TLS
6303       case EOP_MD5:
6304       case EOP_SHA1:
6305       case EOP_SHA256:
6306       case EOP_BASE64:
6307         if (s[1] == '$')
6308           {
6309           const uschar * s1 = s;
6310           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6311                   FALSE, &resetok);
6312           if (!sub)       goto EXPAND_FAILED;           /*{*/
6313           if (*s1 != '}')
6314             {
6315             expand_string_message =
6316               string_sprintf("missing '}' closing cert arg of %s", name);
6317             goto EXPAND_FAILED_CURLY;
6318             }
6319           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6320             {
6321             s = s1+1;
6322             break;
6323             }
6324           vp = NULL;
6325           }
6326         /*FALLTHROUGH*/
6327 #endif
6328       default:
6329         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6330         if (!sub) goto EXPAND_FAILED;
6331         s++;
6332         break;
6333       }
6334
6335     /* If we are skipping, we don't need to perform the operation at all.
6336     This matters for operations like "mask", because the data may not be
6337     in the correct format when skipping. For example, the expression may test
6338     for the existence of $sender_host_address before trying to mask it. For
6339     other operations, doing them may not fail, but it is a waste of time. */
6340
6341     if (skipping && c >= 0) continue;
6342
6343     /* Otherwise, switch on the operator type */
6344
6345     switch(c)
6346       {
6347       case EOP_BASE32:
6348         {
6349         uschar *t;
6350         unsigned long int n = Ustrtoul(sub, &t, 10);
6351         gstring * g = NULL;
6352
6353         if (*t != 0)
6354           {
6355           expand_string_message = string_sprintf("argument for base32 "
6356             "operator is \"%s\", which is not a decimal number", sub);
6357           goto EXPAND_FAILED;
6358           }
6359         for ( ; n; n >>= 5)
6360           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6361
6362         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6363         continue;
6364         }
6365
6366       case EOP_BASE32D:
6367         {
6368         uschar *tt = sub;
6369         unsigned long int n = 0;
6370         uschar * s;
6371         while (*tt)
6372           {
6373           uschar * t = Ustrchr(base32_chars, *tt++);
6374           if (t == NULL)
6375             {
6376             expand_string_message = string_sprintf("argument for base32d "
6377               "operator is \"%s\", which is not a base 32 number", sub);
6378             goto EXPAND_FAILED;
6379             }
6380           n = n * 32 + (t - base32_chars);
6381           }
6382         s = string_sprintf("%ld", n);
6383         yield = string_cat(yield, s);
6384         continue;
6385         }
6386
6387       case EOP_BASE62:
6388         {
6389         uschar *t;
6390         unsigned long int n = Ustrtoul(sub, &t, 10);
6391         if (*t != 0)
6392           {
6393           expand_string_message = string_sprintf("argument for base62 "
6394             "operator is \"%s\", which is not a decimal number", sub);
6395           goto EXPAND_FAILED;
6396           }
6397         t = string_base62(n);
6398         yield = string_cat(yield, t);
6399         continue;
6400         }
6401
6402       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6403
6404       case EOP_BASE62D:
6405         {
6406         uschar buf[16];
6407         uschar *tt = sub;
6408         unsigned long int n = 0;
6409         while (*tt != 0)
6410           {
6411           uschar *t = Ustrchr(base62_chars, *tt++);
6412           if (t == NULL)
6413             {
6414             expand_string_message = string_sprintf("argument for base62d "
6415               "operator is \"%s\", which is not a base %d number", sub,
6416               BASE_62);
6417             goto EXPAND_FAILED;
6418             }
6419           n = n * BASE_62 + (t - base62_chars);
6420           }
6421         (void)sprintf(CS buf, "%ld", n);
6422         yield = string_cat(yield, buf);
6423         continue;
6424         }
6425
6426       case EOP_EXPAND:
6427         {
6428         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6429         if (expanded == NULL)
6430           {
6431           expand_string_message =
6432             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6433               expand_string_message);
6434           goto EXPAND_FAILED;
6435           }
6436         yield = string_cat(yield, expanded);
6437         continue;
6438         }
6439
6440       case EOP_LC:
6441         {
6442         int count = 0;
6443         uschar *t = sub - 1;
6444         while (*(++t) != 0) { *t = tolower(*t); count++; }
6445         yield = string_catn(yield, sub, count);
6446         continue;
6447         }
6448
6449       case EOP_UC:
6450         {
6451         int count = 0;
6452         uschar *t = sub - 1;
6453         while (*(++t) != 0) { *t = toupper(*t); count++; }
6454         yield = string_catn(yield, sub, count);
6455         continue;
6456         }
6457
6458       case EOP_MD5:
6459 #ifdef SUPPORT_TLS
6460         if (vp && *(void **)vp->value)
6461           {
6462           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6463           yield = string_cat(yield, cp);
6464           }
6465         else
6466 #endif
6467           {
6468           md5 base;
6469           uschar digest[16];
6470           int j;
6471           char st[33];
6472           md5_start(&base);
6473           md5_end(&base, sub, Ustrlen(sub), digest);
6474           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6475           yield = string_cat(yield, US st);
6476           }
6477         continue;
6478
6479       case EOP_SHA1:
6480 #ifdef SUPPORT_TLS
6481         if (vp && *(void **)vp->value)
6482           {
6483           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6484           yield = string_cat(yield, cp);
6485           }
6486         else
6487 #endif
6488           {
6489           hctx h;
6490           uschar digest[20];
6491           int j;
6492           char st[41];
6493           sha1_start(&h);
6494           sha1_end(&h, sub, Ustrlen(sub), digest);
6495           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6496           yield = string_catn(yield, US st, 40);
6497           }
6498         continue;
6499
6500       case EOP_SHA256:
6501 #ifdef EXIM_HAVE_SHA2
6502         if (vp && *(void **)vp->value)
6503           {
6504           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6505           yield = string_cat(yield, cp);
6506           }
6507         else
6508           {
6509           hctx h;
6510           blob b;
6511           char st[3];
6512
6513           if (!exim_sha_init(&h, HASH_SHA2_256))
6514             {
6515             expand_string_message = US"unrecognised sha256 variant";
6516             goto EXPAND_FAILED;
6517             }
6518           exim_sha_update(&h, sub, Ustrlen(sub));
6519           exim_sha_finish(&h, &b);
6520           while (b.len-- > 0)
6521             {
6522             sprintf(st, "%02X", *b.data++);
6523             yield = string_catn(yield, US st, 2);
6524             }
6525           }
6526 #else
6527           expand_string_message = US"sha256 only supported with TLS";
6528 #endif
6529         continue;
6530
6531       case EOP_SHA3:
6532 #ifdef EXIM_HAVE_SHA3
6533         {
6534         hctx h;
6535         blob b;
6536         char st[3];
6537         hashmethod m = !arg ? HASH_SHA3_256
6538           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6539           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6540           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6541           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6542           : HASH_BADTYPE;
6543
6544         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6545           {
6546           expand_string_message = US"unrecognised sha3 variant";
6547           goto EXPAND_FAILED;
6548           }
6549
6550         exim_sha_update(&h, sub, Ustrlen(sub));
6551         exim_sha_finish(&h, &b);
6552         while (b.len-- > 0)
6553           {
6554           sprintf(st, "%02X", *b.data++);
6555           yield = string_catn(yield, US st, 2);
6556           }
6557         }
6558         continue;
6559 #else
6560         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 + or OpenSSL 1.1.1 +";
6561         goto EXPAND_FAILED;
6562 #endif
6563
6564       /* Convert hex encoding to base64 encoding */
6565
6566       case EOP_HEX2B64:
6567         {
6568         int c = 0;
6569         int b = -1;
6570         uschar *in = sub;
6571         uschar *out = sub;
6572         uschar *enc;
6573
6574         for (enc = sub; *enc != 0; enc++)
6575           {
6576           if (!isxdigit(*enc))
6577             {
6578             expand_string_message = string_sprintf("\"%s\" is not a hex "
6579               "string", sub);
6580             goto EXPAND_FAILED;
6581             }
6582           c++;
6583           }
6584
6585         if ((c & 1) != 0)
6586           {
6587           expand_string_message = string_sprintf("\"%s\" contains an odd "
6588             "number of characters", sub);
6589           goto EXPAND_FAILED;
6590           }
6591
6592         while ((c = *in++) != 0)
6593           {
6594           if (isdigit(c)) c -= '0';
6595           else c = toupper(c) - 'A' + 10;
6596           if (b == -1)
6597             {
6598             b = c << 4;
6599             }
6600           else
6601             {
6602             *out++ = b | c;
6603             b = -1;
6604             }
6605           }
6606
6607         enc = b64encode(sub, out - sub);
6608         yield = string_cat(yield, enc);
6609         continue;
6610         }
6611
6612       /* Convert octets outside 0x21..0x7E to \xXX form */
6613
6614       case EOP_HEXQUOTE:
6615         {
6616         uschar *t = sub - 1;
6617         while (*(++t) != 0)
6618           {
6619           if (*t < 0x21 || 0x7E < *t)
6620             yield = string_catn(yield, string_sprintf("\\x%02x", *t), 4);
6621           else
6622             yield = string_catn(yield, t, 1);
6623           }
6624         continue;
6625         }
6626
6627       /* count the number of list elements */
6628
6629       case EOP_LISTCOUNT:
6630         {
6631         int cnt = 0;
6632         int sep = 0;
6633         uschar * cp;
6634         uschar buffer[256];
6635
6636         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6637         cp = string_sprintf("%d", cnt);
6638         yield = string_cat(yield, cp);
6639         continue;
6640         }
6641
6642       /* expand a named list given the name */
6643       /* handles nested named lists; requotes as colon-sep list */
6644
6645       case EOP_LISTNAMED:
6646         {
6647         tree_node *t = NULL;
6648         const uschar * list;
6649         int sep = 0;
6650         uschar * item;
6651         uschar * suffix = US"";
6652         BOOL needsep = FALSE;
6653         uschar buffer[256];
6654
6655         if (*sub == '+') sub++;
6656         if (arg == NULL)        /* no-argument version */
6657           {
6658           if (!(t = tree_search(addresslist_anchor, sub)) &&
6659               !(t = tree_search(domainlist_anchor,  sub)) &&
6660               !(t = tree_search(hostlist_anchor,    sub)))
6661             t = tree_search(localpartlist_anchor, sub);
6662           }
6663         else switch(*arg)       /* specific list-type version */
6664           {
6665           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6666           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6667           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6668           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6669           default:
6670             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6671             goto EXPAND_FAILED;
6672           }
6673
6674         if(!t)
6675           {
6676           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6677             sub, !arg?""
6678               : *arg=='a'?"address "
6679               : *arg=='d'?"domain "
6680               : *arg=='h'?"host "
6681               : *arg=='l'?"localpart "
6682               : 0);
6683           goto EXPAND_FAILED;
6684           }
6685
6686         list = ((namedlist_block *)(t->data.ptr))->string;
6687
6688         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
6689           {
6690           uschar * buf = US" : ";
6691           if (needsep)
6692             yield = string_catn(yield, buf, 3);
6693           else
6694             needsep = TRUE;
6695
6696           if (*item == '+')     /* list item is itself a named list */
6697             {
6698             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6699             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6700             }
6701           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6702             {
6703             char * cp;
6704             char tok[3];
6705             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6706             while ((cp= strpbrk(CCS item, tok)))
6707               {
6708               yield = string_catn(yield, item, cp - CS item);
6709               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6710                 {
6711                 yield = string_catn(yield, US"::", 2);
6712                 item = US cp;
6713                 }
6714               else              /* sep in item; should already be doubled; emit once */
6715                 {
6716                 yield = string_catn(yield, US tok, 1);
6717                 if (*cp == sep) cp++;
6718                 item = US cp;
6719                 }
6720               }
6721             }
6722           yield = string_cat(yield, item);
6723           }
6724         continue;
6725         }
6726
6727       /* mask applies a mask to an IP address; for example the result of
6728       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6729
6730       case EOP_MASK:
6731         {
6732         int count;
6733         uschar *endptr;
6734         int binary[4];
6735         int mask, maskoffset;
6736         int type = string_is_ip_address(sub, &maskoffset);
6737         uschar buffer[64];
6738
6739         if (type == 0)
6740           {
6741           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6742            sub);
6743           goto EXPAND_FAILED;
6744           }
6745
6746         if (maskoffset == 0)
6747           {
6748           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6749             sub);
6750           goto EXPAND_FAILED;
6751           }
6752
6753         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6754
6755         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6756           {
6757           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6758             sub);
6759           goto EXPAND_FAILED;
6760           }
6761
6762         /* Convert the address to binary integer(s) and apply the mask */
6763
6764         sub[maskoffset] = 0;
6765         count = host_aton(sub, binary);
6766         host_mask(count, binary, mask);
6767
6768         /* Convert to masked textual format and add to output. */
6769
6770         yield = string_catn(yield, buffer,
6771           host_nmtoa(count, binary, mask, buffer, '.'));
6772         continue;
6773         }
6774
6775       case EOP_IPV6NORM:
6776       case EOP_IPV6DENORM:
6777         {
6778         int type = string_is_ip_address(sub, NULL);
6779         int binary[4];
6780         uschar buffer[44];
6781
6782         switch (type)
6783           {
6784           case 6:
6785             (void) host_aton(sub, binary);
6786             break;
6787
6788           case 4:       /* convert to IPv4-mapped IPv6 */
6789             binary[0] = binary[1] = 0;
6790             binary[2] = 0x0000ffff;
6791             (void) host_aton(sub, binary+3);
6792             break;
6793
6794           case 0:
6795             expand_string_message =
6796               string_sprintf("\"%s\" is not an IP address", sub);
6797             goto EXPAND_FAILED;
6798           }
6799
6800         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
6801                     ? ipv6_nmtoa(binary, buffer)
6802                     : host_nmtoa(4, binary, -1, buffer, ':')
6803                   );
6804         continue;
6805         }
6806
6807       case EOP_ADDRESS:
6808       case EOP_LOCAL_PART:
6809       case EOP_DOMAIN:
6810         {
6811         uschar * error;
6812         int start, end, domain;
6813         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6814           FALSE);
6815         if (t)
6816           if (c != EOP_DOMAIN)
6817             {
6818             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6819             yield = string_catn(yield, sub+start, end-start);
6820             }
6821           else if (domain != 0)
6822             {
6823             domain += start;
6824             yield = string_catn(yield, sub+domain, end-domain);
6825             }
6826         continue;
6827         }
6828
6829       case EOP_ADDRESSES:
6830         {
6831         uschar outsep[2] = { ':', '\0' };
6832         uschar *address, *error;
6833         int save_ptr = yield->ptr;
6834         int start, end, domain;  /* Not really used */
6835
6836         while (isspace(*sub)) sub++;
6837         if (*sub == '>')
6838           if (*outsep = *++sub) ++sub;
6839           else
6840             {
6841             expand_string_message = string_sprintf("output separator "
6842               "missing in expanding ${addresses:%s}", --sub);
6843             goto EXPAND_FAILED;
6844             }
6845         parse_allow_group = TRUE;
6846
6847         for (;;)
6848           {
6849           uschar *p = parse_find_address_end(sub, FALSE);
6850           uschar saveend = *p;
6851           *p = '\0';
6852           address = parse_extract_address(sub, &error, &start, &end, &domain,
6853             FALSE);
6854           *p = saveend;
6855
6856           /* Add the address to the output list that we are building. This is
6857           done in chunks by searching for the separator character. At the
6858           start, unless we are dealing with the first address of the output
6859           list, add in a space if the new address begins with the separator
6860           character, or is an empty string. */
6861
6862           if (address != NULL)
6863             {
6864             if (yield->ptr != save_ptr && address[0] == *outsep)
6865               yield = string_catn(yield, US" ", 1);
6866
6867             for (;;)
6868               {
6869               size_t seglen = Ustrcspn(address, outsep);
6870               yield = string_catn(yield, address, seglen + 1);
6871
6872               /* If we got to the end of the string we output one character
6873               too many. */
6874
6875               if (address[seglen] == '\0') { yield->ptr--; break; }
6876               yield = string_catn(yield, outsep, 1);
6877               address += seglen + 1;
6878               }
6879
6880             /* Output a separator after the string: we will remove the
6881             redundant final one at the end. */
6882
6883             yield = string_catn(yield, outsep, 1);
6884             }
6885
6886           if (saveend == '\0') break;
6887           sub = p + 1;
6888           }
6889
6890         /* If we have generated anything, remove the redundant final
6891         separator. */
6892
6893         if (yield->ptr != save_ptr) yield->ptr--;
6894         parse_allow_group = FALSE;
6895         continue;
6896         }
6897
6898
6899       /* quote puts a string in quotes if it is empty or contains anything
6900       other than alphamerics, underscore, dot, or hyphen.
6901
6902       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6903       be quoted in order to be a valid local part.
6904
6905       In both cases, newlines and carriage returns are converted into \n and \r
6906       respectively */
6907
6908       case EOP_QUOTE:
6909       case EOP_QUOTE_LOCAL_PART:
6910       if (arg == NULL)
6911         {
6912         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6913         uschar *t = sub - 1;
6914
6915         if (c == EOP_QUOTE)
6916           {
6917           while (!needs_quote && *(++t) != 0)
6918             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6919           }
6920         else  /* EOP_QUOTE_LOCAL_PART */
6921           {
6922           while (!needs_quote && *(++t) != 0)
6923             needs_quote = !isalnum(*t) &&
6924               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6925               (*t != '.' || t == sub || t[1] == 0);
6926           }
6927
6928         if (needs_quote)
6929           {
6930           yield = string_catn(yield, US"\"", 1);
6931           t = sub - 1;
6932           while (*(++t) != 0)
6933             {
6934             if (*t == '\n')
6935               yield = string_catn(yield, US"\\n", 2);
6936             else if (*t == '\r')
6937               yield = string_catn(yield, US"\\r", 2);
6938             else
6939               {
6940               if (*t == '\\' || *t == '"')
6941                 yield = string_catn(yield, US"\\", 1);
6942               yield = string_catn(yield, t, 1);
6943               }
6944             }
6945           yield = string_catn(yield, US"\"", 1);
6946           }
6947         else yield = string_cat(yield, sub);
6948         continue;
6949         }
6950
6951       /* quote_lookuptype does lookup-specific quoting */
6952
6953       else
6954         {
6955         int n;
6956         uschar *opt = Ustrchr(arg, '_');
6957
6958         if (opt != NULL) *opt++ = 0;
6959
6960         n = search_findtype(arg, Ustrlen(arg));
6961         if (n < 0)
6962           {
6963           expand_string_message = search_error_message;
6964           goto EXPAND_FAILED;
6965           }
6966
6967         if (lookup_list[n]->quote != NULL)
6968           sub = (lookup_list[n]->quote)(sub, opt);
6969         else if (opt != NULL) sub = NULL;
6970
6971         if (sub == NULL)
6972           {
6973           expand_string_message = string_sprintf(
6974             "\"%s\" unrecognized after \"${quote_%s\"",
6975             opt, arg);
6976           goto EXPAND_FAILED;
6977           }
6978
6979         yield = string_cat(yield, sub);
6980         continue;
6981         }
6982
6983       /* rx quote sticks in \ before any non-alphameric character so that
6984       the insertion works in a regular expression. */
6985
6986       case EOP_RXQUOTE:
6987         {
6988         uschar *t = sub - 1;
6989         while (*(++t) != 0)
6990           {
6991           if (!isalnum(*t))
6992             yield = string_catn(yield, US"\\", 1);
6993           yield = string_catn(yield, t, 1);
6994           }
6995         continue;
6996         }
6997
6998       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6999       prescribed by the RFC, if there are characters that need to be encoded */
7000
7001       case EOP_RFC2047:
7002         {
7003         uschar buffer[2048];
7004         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
7005           buffer, sizeof(buffer), FALSE);
7006         yield = string_cat(yield, string);
7007         continue;
7008         }
7009
7010       /* RFC 2047 decode */
7011
7012       case EOP_RFC2047D:
7013         {
7014         int len;
7015         uschar *error;
7016         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
7017           headers_charset, '?', &len, &error);
7018         if (error != NULL)
7019           {
7020           expand_string_message = error;
7021           goto EXPAND_FAILED;
7022           }
7023         yield = string_catn(yield, decoded, len);
7024         continue;
7025         }
7026
7027       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
7028       underscores */
7029
7030       case EOP_FROM_UTF8:
7031         {
7032         while (*sub != 0)
7033           {
7034           int c;
7035           uschar buff[4];
7036           GETUTF8INC(c, sub);
7037           if (c > 255) c = '_';
7038           buff[0] = c;
7039           yield = string_catn(yield, buff, 1);
7040           }
7041         continue;
7042         }
7043
7044           /* replace illegal UTF-8 sequences by replacement character  */
7045
7046       #define UTF8_REPLACEMENT_CHAR US"?"
7047
7048       case EOP_UTF8CLEAN:
7049         {
7050         int seq_len = 0, index = 0;
7051         int bytes_left = 0;
7052         long codepoint = -1;
7053         uschar seq_buff[4];                     /* accumulate utf-8 here */
7054
7055         while (*sub != 0)
7056           {
7057           int complete = 0;
7058           uschar c = *sub++;
7059
7060           if (bytes_left)
7061             {
7062             if ((c & 0xc0) != 0x80)
7063                     /* wrong continuation byte; invalidate all bytes */
7064               complete = 1; /* error */
7065             else
7066               {
7067               codepoint = (codepoint << 6) | (c & 0x3f);
7068               seq_buff[index++] = c;
7069               if (--bytes_left == 0)            /* codepoint complete */
7070                 if(codepoint > 0x10FFFF)        /* is it too large? */
7071                   complete = -1;        /* error (RFC3629 limit) */
7072                 else
7073                   {             /* finished; output utf-8 sequence */
7074                   yield = string_catn(yield, seq_buff, seq_len);
7075                   index = 0;
7076                   }
7077               }
7078             }
7079           else  /* no bytes left: new sequence */
7080             {
7081             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7082               {
7083               yield = string_catn(yield, &c, 1);
7084               continue;
7085               }
7086             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7087               {
7088               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7089                 complete = -1;
7090               else
7091                 {
7092                   bytes_left = 1;
7093                   codepoint = c & 0x1f;
7094                 }
7095               }
7096             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7097               {
7098               bytes_left = 2;
7099               codepoint = c & 0x0f;
7100               }
7101             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7102               {
7103               bytes_left = 3;
7104               codepoint = c & 0x07;
7105               }
7106             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7107               complete = -1;
7108
7109             seq_buff[index++] = c;
7110             seq_len = bytes_left + 1;
7111             }           /* if(bytes_left) */
7112
7113           if (complete != 0)
7114             {
7115             bytes_left = index = 0;
7116             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7117             }
7118           if ((complete == 1) && ((c & 0x80) == 0))
7119                         /* ASCII character follows incomplete sequence */
7120               yield = string_catn(yield, &c, 1);
7121           }
7122         continue;
7123         }
7124
7125 #ifdef SUPPORT_I18N
7126       case EOP_UTF8_DOMAIN_TO_ALABEL:
7127         {
7128         uschar * error = NULL;
7129         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7130         if (error)
7131           {
7132           expand_string_message = string_sprintf(
7133             "error converting utf8 (%s) to alabel: %s",
7134             string_printing(sub), error);
7135           goto EXPAND_FAILED;
7136           }
7137         yield = string_cat(yield, s);
7138         continue;
7139         }
7140
7141       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7142         {
7143         uschar * error = NULL;
7144         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7145         if (error)
7146           {
7147           expand_string_message = string_sprintf(
7148             "error converting alabel (%s) to utf8: %s",
7149             string_printing(sub), error);
7150           goto EXPAND_FAILED;
7151           }
7152         yield = string_cat(yield, s);
7153         continue;
7154         }
7155
7156       case EOP_UTF8_LOCALPART_TO_ALABEL:
7157         {
7158         uschar * error = NULL;
7159         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7160         if (error)
7161           {
7162           expand_string_message = string_sprintf(
7163             "error converting utf8 (%s) to alabel: %s",
7164             string_printing(sub), error);
7165           goto EXPAND_FAILED;
7166           }
7167         yield = string_cat(yield, s);
7168         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7169         continue;
7170         }
7171
7172       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7173         {
7174         uschar * error = NULL;
7175         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7176         if (error)
7177           {
7178           expand_string_message = string_sprintf(
7179             "error converting alabel (%s) to utf8: %s",
7180             string_printing(sub), error);
7181           goto EXPAND_FAILED;
7182           }
7183         yield = string_cat(yield, s);
7184         continue;
7185         }
7186 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7187
7188       /* escape turns all non-printing characters into escape sequences. */
7189
7190       case EOP_ESCAPE:
7191         {
7192         const uschar * t = string_printing(sub);
7193         yield = string_cat(yield, t);
7194         continue;
7195         }
7196
7197       case EOP_ESCAPE8BIT:
7198         {
7199         const uschar * s = sub;
7200         uschar c;
7201
7202         for (s = sub; (c = *s); s++)
7203           yield = c < 127 && c != '\\'
7204             ? string_catn(yield, s, 1)
7205             : string_catn(yield, string_sprintf("\\%03o", c), 4);
7206         continue;
7207         }
7208
7209       /* Handle numeric expression evaluation */
7210
7211       case EOP_EVAL:
7212       case EOP_EVAL10:
7213         {
7214         uschar *save_sub = sub;
7215         uschar *error = NULL;
7216         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7217         if (error != NULL)
7218           {
7219           expand_string_message = string_sprintf("error in expression "
7220             "evaluation: %s (after processing \"%.*s\")", error,
7221             (int)(sub-save_sub), save_sub);
7222           goto EXPAND_FAILED;
7223           }
7224         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7225         yield = string_cat(yield, var_buffer);
7226         continue;
7227         }
7228
7229       /* Handle time period formating */
7230
7231       case EOP_TIME_EVAL:
7232         {
7233         int n = readconf_readtime(sub, 0, FALSE);
7234         if (n < 0)
7235           {
7236           expand_string_message = string_sprintf("string \"%s\" is not an "
7237             "Exim time interval in \"%s\" operator", sub, name);
7238           goto EXPAND_FAILED;
7239           }
7240         sprintf(CS var_buffer, "%d", n);
7241         yield = string_cat(yield, var_buffer);
7242         continue;
7243         }
7244
7245       case EOP_TIME_INTERVAL:
7246         {
7247         int n;
7248         uschar *t = read_number(&n, sub);
7249         if (*t != 0) /* Not A Number*/
7250           {
7251           expand_string_message = string_sprintf("string \"%s\" is not a "
7252             "positive number in \"%s\" operator", sub, name);
7253           goto EXPAND_FAILED;
7254           }
7255         t = readconf_printtime(n);
7256         yield = string_cat(yield, t);
7257         continue;
7258         }
7259
7260       /* Convert string to base64 encoding */
7261
7262       case EOP_STR2B64:
7263       case EOP_BASE64:
7264         {
7265 #ifdef SUPPORT_TLS
7266         uschar * s = vp && *(void **)vp->value
7267           ? tls_cert_der_b64(*(void **)vp->value)
7268           : b64encode(sub, Ustrlen(sub));
7269 #else
7270         uschar * s = b64encode(sub, Ustrlen(sub));
7271 #endif
7272         yield = string_cat(yield, s);
7273         continue;
7274         }
7275
7276       case EOP_BASE64D:
7277         {
7278         uschar * s;
7279         int len = b64decode(sub, &s);
7280         if (len < 0)
7281           {
7282           expand_string_message = string_sprintf("string \"%s\" is not "
7283             "well-formed for \"%s\" operator", sub, name);
7284           goto EXPAND_FAILED;
7285           }
7286         yield = string_cat(yield, s);
7287         continue;
7288         }
7289
7290       /* strlen returns the length of the string */
7291
7292       case EOP_STRLEN:
7293         {
7294         uschar buff[24];
7295         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7296         yield = string_cat(yield, buff);
7297         continue;
7298         }
7299
7300       /* length_n or l_n takes just the first n characters or the whole string,
7301       whichever is the shorter;
7302
7303       substr_m_n, and s_m_n take n characters from offset m; negative m take
7304       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7305       takes the rest, either to the right or to the left.
7306
7307       hash_n or h_n makes a hash of length n from the string, yielding n
7308       characters from the set a-z; hash_n_m makes a hash of length n, but
7309       uses m characters from the set a-zA-Z0-9.
7310
7311       nhash_n returns a single number between 0 and n-1 (in text form), while
7312       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7313       between 0 and n-1 and the second between 0 and m-1. */
7314
7315       case EOP_LENGTH:
7316       case EOP_L:
7317       case EOP_SUBSTR:
7318       case EOP_S:
7319       case EOP_HASH:
7320       case EOP_H:
7321       case EOP_NHASH:
7322       case EOP_NH:
7323         {
7324         int sign = 1;
7325         int value1 = 0;
7326         int value2 = -1;
7327         int *pn;
7328         int len;
7329         uschar *ret;
7330
7331         if (arg == NULL)
7332           {
7333           expand_string_message = string_sprintf("missing values after %s",
7334             name);
7335           goto EXPAND_FAILED;
7336           }
7337
7338         /* "length" has only one argument, effectively being synonymous with
7339         substr_0_n. */
7340
7341         if (c == EOP_LENGTH || c == EOP_L)
7342           {
7343           pn = &value2;
7344           value2 = 0;
7345           }
7346
7347         /* The others have one or two arguments; for "substr" the first may be
7348         negative. The second being negative means "not supplied". */
7349
7350         else
7351           {
7352           pn = &value1;
7353           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7354           }
7355
7356         /* Read up to two numbers, separated by underscores */
7357
7358         ret = arg;
7359         while (*arg != 0)
7360           {
7361           if (arg != ret && *arg == '_' && pn == &value1)
7362             {
7363             pn = &value2;
7364             value2 = 0;
7365             if (arg[1] != 0) arg++;
7366             }
7367           else if (!isdigit(*arg))
7368             {
7369             expand_string_message =
7370               string_sprintf("non-digit after underscore in \"%s\"", name);
7371             goto EXPAND_FAILED;
7372             }
7373           else *pn = (*pn)*10 + *arg++ - '0';
7374           }
7375         value1 *= sign;
7376
7377         /* Perform the required operation */
7378
7379         ret =
7380           (c == EOP_HASH || c == EOP_H)?
7381              compute_hash(sub, value1, value2, &len) :
7382           (c == EOP_NHASH || c == EOP_NH)?
7383              compute_nhash(sub, value1, value2, &len) :
7384              extract_substr(sub, value1, value2, &len);
7385
7386         if (ret == NULL) goto EXPAND_FAILED;
7387         yield = string_catn(yield, ret, len);
7388         continue;
7389         }
7390
7391       /* Stat a path */
7392
7393       case EOP_STAT:
7394         {
7395         uschar *s;
7396         uschar smode[12];
7397         uschar **modetable[3];
7398         int i;
7399         mode_t mode;
7400         struct stat st;
7401
7402         if ((expand_forbid & RDO_EXISTS) != 0)
7403           {
7404           expand_string_message = US"Use of the stat() expansion is not permitted";
7405           goto EXPAND_FAILED;
7406           }
7407
7408         if (stat(CS sub, &st) < 0)
7409           {
7410           expand_string_message = string_sprintf("stat(%s) failed: %s",
7411             sub, strerror(errno));
7412           goto EXPAND_FAILED;
7413           }
7414         mode = st.st_mode;
7415         switch (mode & S_IFMT)
7416           {
7417           case S_IFIFO: smode[0] = 'p'; break;
7418           case S_IFCHR: smode[0] = 'c'; break;
7419           case S_IFDIR: smode[0] = 'd'; break;
7420           case S_IFBLK: smode[0] = 'b'; break;
7421           case S_IFREG: smode[0] = '-'; break;
7422           default: smode[0] = '?'; break;
7423           }
7424
7425         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7426         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7427         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7428
7429         for (i = 0; i < 3; i++)
7430           {
7431           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7432           mode >>= 3;
7433           }
7434
7435         smode[10] = 0;
7436         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7437           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7438           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7439           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7440           (long)st.st_gid, st.st_size, (long)st.st_atime,
7441           (long)st.st_mtime, (long)st.st_ctime);
7442         yield = string_cat(yield, s);
7443         continue;
7444         }
7445
7446       /* vaguely random number less than N */
7447
7448       case EOP_RANDINT:
7449         {
7450         int_eximarith_t max;
7451         uschar *s;
7452
7453         max = expanded_string_integer(sub, TRUE);
7454         if (expand_string_message != NULL)
7455           goto EXPAND_FAILED;
7456         s = string_sprintf("%d", vaguely_random_number((int)max));
7457         yield = string_cat(yield, s);
7458         continue;
7459         }
7460
7461       /* Reverse IP, including IPv6 to dotted-nibble */
7462
7463       case EOP_REVERSE_IP:
7464         {
7465         int family, maskptr;
7466         uschar reversed[128];
7467
7468         family = string_is_ip_address(sub, &maskptr);
7469         if (family == 0)
7470           {
7471           expand_string_message = string_sprintf(
7472               "reverse_ip() not given an IP address [%s]", sub);
7473           goto EXPAND_FAILED;
7474           }
7475         invert_address(reversed, sub);
7476         yield = string_cat(yield, reversed);
7477         continue;
7478         }
7479
7480       /* Unknown operator */
7481
7482       default:
7483       expand_string_message =
7484         string_sprintf("unknown expansion operator \"%s\"", name);
7485       goto EXPAND_FAILED;
7486       }
7487     }
7488
7489   /* Handle a plain name. If this is the first thing in the expansion, release
7490   the pre-allocated buffer. If the result data is known to be in a new buffer,
7491   newsize will be set to the size of that buffer, and we can just point at that
7492   store instead of copying. Many expansion strings contain just one reference,
7493   so this is a useful optimization, especially for humungous headers
7494   ($message_headers). */
7495                                                 /*{*/
7496   if (*s++ == '}')
7497     {
7498     int len;
7499     int newsize = 0;
7500     gstring * g = NULL;
7501
7502     if (!yield)
7503       g = store_get(sizeof(gstring));
7504     else if (yield->ptr == 0)
7505       {
7506       if (resetok) store_reset(yield);
7507       yield = NULL;
7508       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
7509       }
7510     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7511       {
7512       expand_string_message =
7513         string_sprintf("unknown variable in \"${%s}\"", name);
7514       check_variable_error_message(name);
7515       goto EXPAND_FAILED;
7516       }
7517     len = Ustrlen(value);
7518     if (!yield && newsize)
7519       {
7520       yield = g;
7521       yield->size = newsize;
7522       yield->ptr = len;
7523       yield->s = value;
7524       }
7525     else
7526       yield = string_catn(yield, value, len);
7527     continue;
7528     }
7529
7530   /* Else there's something wrong */
7531
7532   expand_string_message =
7533     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7534     "in a variable reference)", name);
7535   goto EXPAND_FAILED;
7536   }
7537
7538 /* If we hit the end of the string when ket_ends is set, there is a missing
7539 terminating brace. */
7540
7541 if (ket_ends && *s == 0)
7542   {
7543   expand_string_message = malformed_header
7544     ? US"missing } at end of string - could be header name not terminated by colon"
7545     : US"missing } at end of string";
7546   goto EXPAND_FAILED;
7547   }
7548
7549 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7550 added to the string. If so, set up an empty string. Add a terminating zero. If
7551 left != NULL, return a pointer to the terminator. */
7552
7553 if (!yield)
7554   yield = string_get(1);
7555 (void) string_from_gstring(yield);
7556 if (left) *left = s;
7557
7558 /* Any stacking store that was used above the final string is no longer needed.
7559 In many cases the final string will be the first one that was got and so there
7560 will be optimal store usage. */
7561
7562 if (resetok) store_reset(yield->s + (yield->size = yield->ptr + 1));
7563 else if (resetok_p) *resetok_p = FALSE;
7564
7565 DEBUG(D_expand)
7566   {
7567   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7568     "expanding: %.*s\n",
7569     (int)(s - string), string);
7570   debug_printf_indent("%s"
7571     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7572     "result: %s\n",
7573     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7574     yield->s);
7575   if (skipping)
7576     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7577       "skipping: result is not used\n");
7578   }
7579 expand_level--;
7580 return yield->s;
7581
7582 /* This is the failure exit: easiest to program with a goto. We still need
7583 to update the pointer to the terminator, for cases of nested calls with "fail".
7584 */
7585
7586 EXPAND_FAILED_CURLY:
7587 if (malformed_header)
7588   expand_string_message =
7589     US"missing or misplaced { or } - could be header name not terminated by colon";
7590
7591 else if (!expand_string_message || !*expand_string_message)
7592   expand_string_message = US"missing or misplaced { or }";
7593
7594 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7595 that is a bad idea, because expand_string_message is in dynamic store. */
7596
7597 EXPAND_FAILED:
7598 if (left) *left = s;
7599 DEBUG(D_expand)
7600   {
7601   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7602     string);
7603   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7604     "error message: %s\n",
7605     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7606     expand_string_message);
7607   if (expand_string_forcedfail)
7608     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7609   }
7610 if (resetok_p && !resetok) *resetok_p = FALSE;
7611 expand_level--;
7612 return NULL;
7613 }
7614
7615
7616 /* This is the external function call. Do a quick check for any expansion
7617 metacharacters, and if there are none, just return the input string.
7618
7619 Argument: the string to be expanded
7620 Returns:  the expanded string, or NULL if expansion failed; if failure was
7621           due to a lookup deferring, search_find_defer will be TRUE
7622 */
7623
7624 const uschar *
7625 expand_cstring(const uschar * string)
7626 {
7627 if (Ustrpbrk(string, "$\\") != NULL)
7628   {
7629   int old_pool = store_pool;
7630   uschar * s;
7631
7632   search_find_defer = FALSE;
7633   malformed_header = FALSE;
7634   store_pool = POOL_MAIN;
7635     s = expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7636   store_pool = old_pool;
7637   return s;
7638   }
7639 return string;
7640 }
7641
7642
7643 uschar *
7644 expand_string(uschar * string)
7645 {
7646 return US expand_cstring(CUS string);
7647 }
7648
7649
7650
7651
7652
7653 /*************************************************
7654 *              Expand and copy                   *
7655 *************************************************/
7656
7657 /* Now and again we want to expand a string and be sure that the result is in a
7658 new bit of store. This function does that.
7659 Since we know it has been copied, the de-const cast is safe.
7660
7661 Argument: the string to be expanded
7662 Returns:  the expanded string, always in a new bit of store, or NULL
7663 */
7664
7665 uschar *
7666 expand_string_copy(const uschar *string)
7667 {
7668 const uschar *yield = expand_cstring(string);
7669 if (yield == string) yield = string_copy(string);
7670 return US yield;
7671 }
7672
7673
7674
7675 /*************************************************
7676 *        Expand and interpret as an integer      *
7677 *************************************************/
7678
7679 /* Expand a string, and convert the result into an integer.
7680
7681 Arguments:
7682   string  the string to be expanded
7683   isplus  TRUE if a non-negative number is expected
7684
7685 Returns:  the integer value, or
7686           -1 for an expansion error               ) in both cases, message in
7687           -2 for an integer interpretation error  ) expand_string_message
7688           expand_string_message is set NULL for an OK integer
7689 */
7690
7691 int_eximarith_t
7692 expand_string_integer(uschar *string, BOOL isplus)
7693 {
7694 return expanded_string_integer(expand_string(string), isplus);
7695 }
7696
7697
7698 /*************************************************
7699  *         Interpret string as an integer        *
7700  *************************************************/
7701
7702 /* Convert a string (that has already been expanded) into an integer.
7703
7704 This function is used inside the expansion code.
7705
7706 Arguments:
7707   s       the string to be expanded
7708   isplus  TRUE if a non-negative number is expected
7709
7710 Returns:  the integer value, or
7711           -1 if string is NULL (which implies an expansion error)
7712           -2 for an integer interpretation error
7713           expand_string_message is set NULL for an OK integer
7714 */
7715
7716 static int_eximarith_t
7717 expanded_string_integer(const uschar *s, BOOL isplus)
7718 {
7719 int_eximarith_t value;
7720 uschar *msg = US"invalid integer \"%s\"";
7721 uschar *endptr;
7722
7723 /* If expansion failed, expand_string_message will be set. */
7724
7725 if (s == NULL) return -1;
7726
7727 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7728 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7729 systems, so we set it zero ourselves. */
7730
7731 errno = 0;
7732 expand_string_message = NULL;               /* Indicates no error */
7733
7734 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7735 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7736 the behaviour explicitly.  Stripping leading whitespace is a harmless
7737 noop change since strtol skips it anyway (provided that there is a number
7738 to find at all). */
7739 if (isspace(*s))
7740   {
7741   while (isspace(*s)) ++s;
7742   if (*s == '\0')
7743     {
7744       DEBUG(D_expand)
7745        debug_printf_indent("treating blank string as number 0\n");
7746       return 0;
7747     }
7748   }
7749
7750 value = strtoll(CS s, CSS &endptr, 10);
7751
7752 if (endptr == s)
7753   {
7754   msg = US"integer expected but \"%s\" found";
7755   }
7756 else if (value < 0 && isplus)
7757   {
7758   msg = US"non-negative integer expected but \"%s\" found";
7759   }
7760 else
7761   {
7762   switch (tolower(*endptr))
7763     {
7764     default:
7765       break;
7766     case 'k':
7767       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7768       else value *= 1024;
7769       endptr++;
7770       break;
7771     case 'm':
7772       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7773       else value *= 1024*1024;
7774       endptr++;
7775       break;
7776     case 'g':
7777       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7778       else value *= 1024*1024*1024;
7779       endptr++;
7780       break;
7781     }
7782   if (errno == ERANGE)
7783     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7784   else
7785     {
7786     while (isspace(*endptr)) endptr++;
7787     if (*endptr == 0) return value;
7788     }
7789   }
7790
7791 expand_string_message = string_sprintf(CS msg, s);
7792 return -2;
7793 }
7794
7795
7796 /* These values are usually fixed boolean values, but they are permitted to be
7797 expanded strings.
7798
7799 Arguments:
7800   addr       address being routed
7801   mtype      the module type
7802   mname      the module name
7803   dbg_opt    debug selectors
7804   oname      the option name
7805   bvalue     the router's boolean value
7806   svalue     the router's string value
7807   rvalue     where to put the returned value
7808
7809 Returns:     OK     value placed in rvalue
7810              DEFER  expansion failed
7811 */
7812
7813 int
7814 exp_bool(address_item *addr,
7815   uschar *mtype, uschar *mname, unsigned dbg_opt,
7816   uschar *oname, BOOL bvalue,
7817   uschar *svalue, BOOL *rvalue)
7818 {
7819 uschar *expanded;
7820 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7821
7822 expanded = expand_string(svalue);
7823 if (expanded == NULL)
7824   {
7825   if (expand_string_forcedfail)
7826     {
7827     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7828     *rvalue = bvalue;
7829     return OK;
7830     }
7831   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7832       oname, mname, mtype, expand_string_message);
7833   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7834   return DEFER;
7835   }
7836
7837 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7838   expanded);
7839
7840 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7841   *rvalue = TRUE;
7842 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7843   *rvalue = FALSE;
7844 else
7845   {
7846   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7847     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7848   return DEFER;
7849   }
7850
7851 return OK;
7852 }
7853
7854
7855
7856 /* Avoid potentially exposing a password in a string about to be logged */
7857
7858 uschar *
7859 expand_hide_passwords(uschar * s)
7860 {
7861 return (  (  Ustrstr(s, "failed to expand") != NULL
7862           || Ustrstr(s, "expansion of ")    != NULL
7863           )
7864        && (  Ustrstr(s, "mysql")   != NULL
7865           || Ustrstr(s, "pgsql")   != NULL
7866           || Ustrstr(s, "redis")   != NULL
7867           || Ustrstr(s, "sqlite")  != NULL
7868           || Ustrstr(s, "ldap:")   != NULL
7869           || Ustrstr(s, "ldaps:")  != NULL
7870           || Ustrstr(s, "ldapi:")  != NULL
7871           || Ustrstr(s, "ldapdn:") != NULL
7872           || Ustrstr(s, "ldapm:")  != NULL
7873        )  )
7874   ? US"Temporary internal error" : s;
7875 }
7876
7877
7878 /* Read given named file into big_buffer.  Use for keying material etc.
7879 The content will have an ascii NUL appended.
7880
7881 Arguments:
7882  filename       as it says
7883
7884 Return:  pointer to buffer, or NULL on error.
7885 */
7886
7887 uschar *
7888 expand_file_big_buffer(const uschar * filename)
7889 {
7890 int fd, off = 0, len;
7891
7892 if ((fd = open(CS filename, O_RDONLY)) < 0)
7893   {
7894   log_write(0, LOG_MAIN | LOG_PANIC, "unable to open file for reading: %s",
7895              filename);
7896   return NULL;
7897   }
7898
7899 do
7900   {
7901   if ((len = read(fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
7902     {
7903     (void) close(fd);
7904     log_write(0, LOG_MAIN|LOG_PANIC, "unable to read file: %s", filename);
7905     return NULL;
7906     }
7907   off += len;
7908   }
7909 while (len > 0);
7910
7911 (void) close(fd);
7912 big_buffer[off] = '\0';
7913 return big_buffer;
7914 }
7915
7916
7917
7918 /*************************************************
7919 * Error-checking for testsuite                   *
7920 *************************************************/
7921 typedef struct {
7922   uschar *      region_start;
7923   uschar *      region_end;
7924   const uschar *var_name;
7925   const uschar *var_data;
7926 } err_ctx;
7927
7928 static void
7929 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7930 {
7931 err_ctx * e = ctx;
7932 if (var_data >= e->region_start  &&  var_data < e->region_end)
7933   {
7934   e->var_name = CUS var_name;
7935   e->var_data = CUS var_data;
7936   }
7937 }
7938
7939 void
7940 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7941 {
7942 err_ctx e = { .region_start = ptr, .region_end = US ptr + len,
7943               .var_name = NULL, .var_data = NULL };
7944 int i;
7945 var_entry * v;
7946
7947 /* check acl_ variables */
7948 tree_walk(acl_var_c, assert_variable_notin, &e);
7949 tree_walk(acl_var_m, assert_variable_notin, &e);
7950
7951 /* check auth<n> variables */
7952 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7953   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7954
7955 /* check regex<n> variables */
7956 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7957   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7958
7959 /* check known-name variables */
7960 for (v = var_table; v < var_table + var_table_size; v++)
7961   if (v->type == vtype_stringptr)
7962     assert_variable_notin(US v->name, *(USS v->value), &e);
7963
7964 /* check dns and address trees */
7965 tree_walk(tree_dns_fails,     assert_variable_notin, &e);
7966 tree_walk(tree_duplicates,    assert_variable_notin, &e);
7967 tree_walk(tree_nonrecipients, assert_variable_notin, &e);
7968 tree_walk(tree_unusable,      assert_variable_notin, &e);
7969
7970 if (e.var_name)
7971   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7972     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7973     e.var_name, filename, linenumber, e.var_data);
7974 }
7975
7976
7977
7978 /*************************************************
7979 **************************************************
7980 *             Stand-alone test program           *
7981 **************************************************
7982 *************************************************/
7983
7984 #ifdef STAND_ALONE
7985
7986
7987 BOOL
7988 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7989 {
7990 int ovector[3*(EXPAND_MAXN+1)];
7991 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7992   ovector, nelem(ovector));
7993 BOOL yield = n >= 0;
7994 if (n == 0) n = EXPAND_MAXN + 1;
7995 if (yield)
7996   {
7997   int nn;
7998   expand_nmax = (setup < 0)? 0 : setup + 1;
7999   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
8000     {
8001     expand_nstring[expand_nmax] = subject + ovector[nn];
8002     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
8003     }
8004   expand_nmax--;
8005   }
8006 return yield;
8007 }
8008
8009
8010 int main(int argc, uschar **argv)
8011 {
8012 int i;
8013 uschar buffer[1024];
8014
8015 debug_selector = D_v;
8016 debug_file = stderr;
8017 debug_fd = fileno(debug_file);
8018 big_buffer = malloc(big_buffer_size);
8019
8020 for (i = 1; i < argc; i++)
8021   {
8022   if (argv[i][0] == '+')
8023     {
8024     debug_trace_memory = 2;
8025     argv[i]++;
8026     }
8027   if (isdigit(argv[i][0]))
8028     debug_selector = Ustrtol(argv[i], NULL, 0);
8029   else
8030     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
8031         Ustrlen(argv[i]))
8032       {
8033 #ifdef LOOKUP_LDAP
8034       eldap_default_servers = argv[i];
8035 #endif
8036 #ifdef LOOKUP_MYSQL
8037       mysql_servers = argv[i];
8038 #endif
8039 #ifdef LOOKUP_PGSQL
8040       pgsql_servers = argv[i];
8041 #endif
8042 #ifdef LOOKUP_REDIS
8043       redis_servers = argv[i];
8044 #endif
8045       }
8046 #ifdef EXIM_PERL
8047   else opt_perl_startup = argv[i];
8048 #endif
8049   }
8050
8051 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
8052
8053 expand_nstring[1] = US"string 1....";
8054 expand_nlength[1] = 8;
8055 expand_nmax = 1;
8056
8057 #ifdef EXIM_PERL
8058 if (opt_perl_startup != NULL)
8059   {
8060   uschar *errstr;
8061   printf("Starting Perl interpreter\n");
8062   errstr = init_perl(opt_perl_startup);
8063   if (errstr != NULL)
8064     {
8065     printf("** error in perl_startup code: %s\n", errstr);
8066     return EXIT_FAILURE;
8067     }
8068   }
8069 #endif /* EXIM_PERL */
8070
8071 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
8072   {
8073   void *reset_point = store_get(0);
8074   uschar *yield = expand_string(buffer);
8075   if (yield != NULL)
8076     {
8077     printf("%s\n", yield);
8078     store_reset(reset_point);
8079     }
8080   else
8081     {
8082     if (search_find_defer) printf("search_find deferred\n");
8083     printf("Failed: %s\n", expand_string_message);
8084     if (expand_string_forcedfail) printf("Forced failure\n");
8085     printf("\n");
8086     }
8087   }
8088
8089 search_tidyup();
8090
8091 return 0;
8092 }
8093
8094 #endif
8095
8096 /* vi: aw ai sw=2
8097 */
8098 /* End of expand.c */