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_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 522   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 523   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 524   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 525   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 526 #endif
 527   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 528   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 529   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 530   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 531   { "domain",              vtype_stringptr,   &deliver_domain },
 532   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 533 #ifndef DISABLE_EVENT
 534   { "event_data",          vtype_stringptr,   &event_data },
 535
 536   /*XXX want to use generic vars for as many of these as possible*/
 537   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 538
 539   { "event_name",          vtype_stringptr,   &event_name },
 540 #endif
 541   { "exim_gid",            vtype_gid,         &exim_gid },
 542   { "exim_path",           vtype_stringptr,   &exim_path },
 543   { "exim_uid",            vtype_uid,         &exim_uid },
 544   { "exim_version",        vtype_stringptr,   &version_string },
 545   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 546   { "home",                vtype_stringptr,   &deliver_home },
 547   { "host",                vtype_stringptr,   &deliver_host },
 548   { "host_address",        vtype_stringptr,   &deliver_host_address },
 549   { "host_data",           vtype_stringptr,   &host_data },
 550   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 551   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 552   { "host_port",           vtype_int,         &deliver_host_port },
 553   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 554   { "inode",               vtype_ino,         &deliver_inode },
 555   { "interface_address",   vtype_stringptr,   &interface_address },
 556   { "interface_port",      vtype_int,         &interface_port },
 557   { "item",                vtype_stringptr,   &iterate_item },
 558   #ifdef LOOKUP_LDAP
 559   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 560   #endif
 561   { "load_average",        vtype_load_avg,    NULL },
 562   { "local_part",          vtype_stringptr,   &deliver_localpart },
 563   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 564   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 565   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 566   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 567   { "local_user_gid",      vtype_gid,         &local_user_gid },
 568   { "local_user_uid",      vtype_uid,         &local_user_uid },
 569   { "localhost_number",    vtype_int,         &host_number },
 570   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 571   { "log_space",           vtype_pspace,      (void *)FALSE },
 572   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 573   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 574 #ifdef WITH_CONTENT_SCAN
 575   { "malware_name",        vtype_stringptr,   &malware_name },
 576 #endif
 577   { "max_received_linelength", vtype_int,     &max_received_linelength },
 578   { "message_age",         vtype_int,         &message_age },
 579   { "message_body",        vtype_msgbody,     &message_body },
 580   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 581   { "message_body_size",   vtype_int,         &message_body_size },
 582   { "message_exim_id",     vtype_stringptr,   &message_id },
 583   { "message_headers",     vtype_msgheaders,  NULL },
 584   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 585   { "message_id",          vtype_stringptr,   &message_id },
 586   { "message_linecount",   vtype_int,         &message_linecount },
 587   { "message_size",        vtype_int,         &message_size },
 588 #ifdef SUPPORT_I18N
 589   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 590 #endif
 591 #ifdef WITH_CONTENT_SCAN
 592   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 593   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 594   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 595   { "mime_charset",        vtype_stringptr,   &mime_charset },
 596   { "mime_content_description", vtype_stringptr, &mime_content_description },
 597   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 598   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 599   { "mime_content_size",   vtype_int,         &mime_content_size },
 600   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 601   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 602   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 603   { "mime_filename",       vtype_stringptr,   &mime_filename },
 604   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 605   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 606   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 607   { "mime_part_count",     vtype_int,         &mime_part_count },
 608 #endif
 609   { "n0",                  vtype_filter_int,  &filter_n[0] },
 610   { "n1",                  vtype_filter_int,  &filter_n[1] },
 611   { "n2",                  vtype_filter_int,  &filter_n[2] },
 612   { "n3",                  vtype_filter_int,  &filter_n[3] },
 613   { "n4",                  vtype_filter_int,  &filter_n[4] },
 614   { "n5",                  vtype_filter_int,  &filter_n[5] },
 615   { "n6",                  vtype_filter_int,  &filter_n[6] },
 616   { "n7",                  vtype_filter_int,  &filter_n[7] },
 617   { "n8",                  vtype_filter_int,  &filter_n[8] },
 618   { "n9",                  vtype_filter_int,  &filter_n[9] },
 619   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 620   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 621   { "originator_gid",      vtype_gid,         &originator_gid },
 622   { "originator_uid",      vtype_uid,         &originator_uid },
 623   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 624   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 625   { "pid",                 vtype_pid,         NULL },
 626 #ifndef DISABLE_PRDR
 627   { "prdr_requested",      vtype_bool,        &prdr_requested },
 628 #endif
 629   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 630 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 631   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 632   { "proxy_external_port", vtype_int,         &proxy_external_port },
 633   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 634   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 635   { "proxy_session",       vtype_bool,        &proxy_session },
 636 #endif
 637   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 638   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 639   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 640   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 641   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 642   { "queue_name",          vtype_stringptr,   &queue_name },
 643   { "rcpt_count",          vtype_int,         &rcpt_count },
 644   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 645   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 646   { "received_count",      vtype_int,         &received_count },
 647   { "received_for",        vtype_stringptr,   &received_for },
 648   { "received_ip_address", vtype_stringptr,   &interface_address },
 649   { "received_port",       vtype_int,         &interface_port },
 650   { "received_protocol",   vtype_stringptr,   &received_protocol },
 651   { "received_time",       vtype_int,         &received_time.tv_sec },
 652   { "recipient_data",      vtype_stringptr,   &recipient_data },
 653   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 654   { "recipients",          vtype_string_func, &fn_recipients },
 655   { "recipients_count",    vtype_int,         &recipients_count },
 656 #ifdef WITH_CONTENT_SCAN
 657   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 658 #endif
 659   { "reply_address",       vtype_reply,       NULL },
 660   { "return_path",         vtype_stringptr,   &return_path },
 661   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 662   { "router_name",         vtype_stringptr,   &router_name },
 663   { "runrc",               vtype_int,         &runrc },
 664   { "self_hostname",       vtype_stringptr,   &self_hostname },
 665   { "sender_address",      vtype_stringptr,   &sender_address },
 666   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 667   { "sender_address_domain", vtype_domain,    &sender_address },
 668   { "sender_address_local_part", vtype_localpart, &sender_address },
 669   { "sender_data",         vtype_stringptr,   &sender_data },
 670   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 671   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 672   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 673   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 674   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 675   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 676   { "sender_host_name",    vtype_host_lookup, NULL },
 677   { "sender_host_port",    vtype_int,         &sender_host_port },
 678   { "sender_ident",        vtype_stringptr,   &sender_ident },
 679   { "sender_rate",         vtype_stringptr,   &sender_rate },
 680   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 681   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 682   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 683   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 684   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 685   { "sending_port",        vtype_int,         &sending_port },
 686   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 687   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 688   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 689   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 690   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 691   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 692   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 693   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 694   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 695   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 696   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 697   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 698   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 699   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 700   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 701   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 702 #ifdef WITH_CONTENT_SCAN
 703   { "spam_action",         vtype_stringptr,   &spam_action },
 704   { "spam_bar",            vtype_stringptr,   &spam_bar },
 705   { "spam_report",         vtype_stringptr,   &spam_report },
 706   { "spam_score",          vtype_stringptr,   &spam_score },
 707   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 708 #endif
 709 #ifdef SUPPORT_SPF
 710   { "spf_guess",           vtype_stringptr,   &spf_guess },
 711   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 712   { "spf_received",        vtype_stringptr,   &spf_received },
 713   { "spf_result",          vtype_stringptr,   &spf_result },
 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_ARC
4153       yield = authres_arc(yield);
4154 #endif
4155       continue;
4156       }
4157
4158     /* Handle conditionals - preserve the values of the numerical expansion
4159     variables in case they get changed by a regular expression match in the
4160     condition. If not, they retain their external settings. At the end
4161     of this "if" section, they get restored to their previous values. */
4162
4163     case EITEM_IF:
4164       {
4165       BOOL cond = FALSE;
4166       const uschar *next_s;
4167       int save_expand_nmax =
4168         save_expand_strings(save_expand_nstring, save_expand_nlength);
4169
4170       while (isspace(*s)) s++;
4171       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4172       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4173
4174       DEBUG(D_expand)
4175         {
4176         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4177           "condition: %.*s\n",
4178           (int)(next_s - s), s);
4179         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4180           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4181           "result: %s\n",
4182           cond ? "true" : "false");
4183         }
4184
4185       s = next_s;
4186
4187       /* The handling of "yes" and "no" result strings is now in a separate
4188       function that is also used by ${lookup} and ${extract} and ${run}. */
4189
4190       switch(process_yesno(
4191                skipping,                     /* were previously skipping */
4192                cond,                         /* success/failure indicator */
4193                lookup_value,                 /* value to reset for string2 */
4194                &s,                           /* input pointer */
4195                &yield,                       /* output pointer */
4196                US"if",                       /* condition type */
4197                &resetok))
4198         {
4199         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4200         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4201         }
4202
4203       /* Restore external setting of expansion variables for continuation
4204       at this level. */
4205
4206       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4207         save_expand_nlength);
4208       continue;
4209       }
4210
4211 #ifdef SUPPORT_I18N
4212     case EITEM_IMAPFOLDER:
4213       {                         /* ${imapfolder {name}{sep]{specials}} */
4214       uschar *sub_arg[3];
4215       uschar *encoded;
4216
4217       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4218                       &resetok))
4219         {
4220         case 1: goto EXPAND_FAILED_CURLY;
4221         case 2:
4222         case 3: goto EXPAND_FAILED;
4223         }
4224
4225       if (sub_arg[1] == NULL)           /* One argument */
4226         {
4227         sub_arg[1] = US"/";             /* default separator */
4228         sub_arg[2] = NULL;
4229         }
4230       else if (Ustrlen(sub_arg[1]) != 1)
4231         {
4232         expand_string_message =
4233           string_sprintf(
4234                 "IMAP folder separator must be one character, found \"%s\"",
4235                 sub_arg[1]);
4236         goto EXPAND_FAILED;
4237         }
4238
4239       if (!skipping)
4240         {
4241         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4242                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4243           goto EXPAND_FAILED;
4244         yield = string_cat(yield, encoded);
4245         }
4246       continue;
4247       }
4248 #endif
4249
4250     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4251     expanding an internal string that isn't actually going to be used. All we
4252     need to do is check the syntax, so don't do a lookup at all. Preserve the
4253     values of the numerical expansion variables in case they get changed by a
4254     partial lookup. If not, they retain their external settings. At the end
4255     of this "lookup" section, they get restored to their previous values. */
4256
4257     case EITEM_LOOKUP:
4258       {
4259       int stype, partial, affixlen, starflags;
4260       int expand_setup = 0;
4261       int nameptr = 0;
4262       uschar *key, *filename;
4263       const uschar *affix;
4264       uschar *save_lookup_value = lookup_value;
4265       int save_expand_nmax =
4266         save_expand_strings(save_expand_nstring, save_expand_nlength);
4267
4268       if ((expand_forbid & RDO_LOOKUP) != 0)
4269         {
4270         expand_string_message = US"lookup expansions are not permitted";
4271         goto EXPAND_FAILED;
4272         }
4273
4274       /* Get the key we are to look up for single-key+file style lookups.
4275       Otherwise set the key NULL pro-tem. */
4276
4277       while (isspace(*s)) s++;
4278       if (*s == '{')                                    /*}*/
4279         {
4280         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4281         if (!key) goto EXPAND_FAILED;                   /*{{*/
4282         if (*s++ != '}')
4283           {
4284           expand_string_message = US"missing '}' after lookup key";
4285           goto EXPAND_FAILED_CURLY;
4286           }
4287         while (isspace(*s)) s++;
4288         }
4289       else key = NULL;
4290
4291       /* Find out the type of database */
4292
4293       if (!isalpha(*s))
4294         {
4295         expand_string_message = US"missing lookup type";
4296         goto EXPAND_FAILED;
4297         }
4298
4299       /* The type is a string that may contain special characters of various
4300       kinds. Allow everything except space or { to appear; the actual content
4301       is checked by search_findtype_partial. */         /*}*/
4302
4303       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4304         {
4305         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4306         s++;
4307         }
4308       name[nameptr] = 0;
4309       while (isspace(*s)) s++;
4310
4311       /* Now check for the individual search type and any partial or default
4312       options. Only those types that are actually in the binary are valid. */
4313
4314       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4315         &starflags);
4316       if (stype < 0)
4317         {
4318         expand_string_message = search_error_message;
4319         goto EXPAND_FAILED;
4320         }
4321
4322       /* Check that a key was provided for those lookup types that need it,
4323       and was not supplied for those that use the query style. */
4324
4325       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4326         {
4327         if (key == NULL)
4328           {
4329           expand_string_message = string_sprintf("missing {key} for single-"
4330             "key \"%s\" lookup", name);
4331           goto EXPAND_FAILED;
4332           }
4333         }
4334       else
4335         {
4336         if (key != NULL)
4337           {
4338           expand_string_message = string_sprintf("a single key was given for "
4339             "lookup type \"%s\", which is not a single-key lookup type", name);
4340           goto EXPAND_FAILED;
4341           }
4342         }
4343
4344       /* Get the next string in brackets and expand it. It is the file name for
4345       single-key+file lookups, and the whole query otherwise. In the case of
4346       queries that also require a file name (e.g. sqlite), the file name comes
4347       first. */
4348
4349       if (*s != '{')
4350         {
4351         expand_string_message = US"missing '{' for lookup file-or-query arg";
4352         goto EXPAND_FAILED_CURLY;
4353         }
4354       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4355       if (filename == NULL) goto EXPAND_FAILED;
4356       if (*s++ != '}')
4357         {
4358         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4359         goto EXPAND_FAILED_CURLY;
4360         }
4361       while (isspace(*s)) s++;
4362
4363       /* If this isn't a single-key+file lookup, re-arrange the variables
4364       to be appropriate for the search_ functions. For query-style lookups,
4365       there is just a "key", and no file name. For the special query-style +
4366       file types, the query (i.e. "key") starts with a file name. */
4367
4368       if (!key)
4369         {
4370         while (isspace(*filename)) filename++;
4371         key = filename;
4372
4373         if (mac_islookup(stype, lookup_querystyle))
4374           filename = NULL;
4375         else
4376           {
4377           if (*filename != '/')
4378             {
4379             expand_string_message = string_sprintf(
4380               "absolute file name expected for \"%s\" lookup", name);
4381             goto EXPAND_FAILED;
4382             }
4383           while (*key != 0 && !isspace(*key)) key++;
4384           if (*key != 0) *key++ = 0;
4385           }
4386         }
4387
4388       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4389       the entry was not found. Note that there is no search_close() function.
4390       Files are left open in case of re-use. At suitable places in higher logic,
4391       search_tidyup() is called to tidy all open files. This can save opening
4392       the same file several times. However, files may also get closed when
4393       others are opened, if too many are open at once. The rule is that a
4394       handle should not be used after a second search_open().
4395
4396       Request that a partial search sets up $1 and maybe $2 by passing
4397       expand_setup containing zero. If its value changes, reset expand_nmax,
4398       since new variables will have been set. Note that at the end of this
4399       "lookup" section, the old numeric variables are restored. */
4400
4401       if (skipping)
4402         lookup_value = NULL;
4403       else
4404         {
4405         void *handle = search_open(filename, stype, 0, NULL, NULL);
4406         if (handle == NULL)
4407           {
4408           expand_string_message = search_error_message;
4409           goto EXPAND_FAILED;
4410           }
4411         lookup_value = search_find(handle, filename, key, partial, affix,
4412           affixlen, starflags, &expand_setup);
4413         if (search_find_defer)
4414           {
4415           expand_string_message =
4416             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4417               string_printing2(key, FALSE), search_error_message);
4418           goto EXPAND_FAILED;
4419           }
4420         if (expand_setup > 0) expand_nmax = expand_setup;
4421         }
4422
4423       /* The handling of "yes" and "no" result strings is now in a separate
4424       function that is also used by ${if} and ${extract}. */
4425
4426       switch(process_yesno(
4427                skipping,                     /* were previously skipping */
4428                lookup_value != NULL,         /* success/failure indicator */
4429                save_lookup_value,            /* value to reset for string2 */
4430                &s,                           /* input pointer */
4431                &yield,                       /* output pointer */
4432                US"lookup",                   /* condition type */
4433                &resetok))
4434         {
4435         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4436         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4437         }
4438
4439       /* Restore external setting of expansion variables for carrying on
4440       at this level, and continue. */
4441
4442       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4443         save_expand_nlength);
4444       continue;
4445       }
4446
4447     /* If Perl support is configured, handle calling embedded perl subroutines,
4448     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4449     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4450     arguments (defined below). */
4451
4452     #define EXIM_PERL_MAX_ARGS 8
4453
4454     case EITEM_PERL:
4455     #ifndef EXIM_PERL
4456     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4457       "is not included in this binary";
4458     goto EXPAND_FAILED;
4459
4460     #else   /* EXIM_PERL */
4461       {
4462       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4463       gstring *new_yield;
4464
4465       if ((expand_forbid & RDO_PERL) != 0)
4466         {
4467         expand_string_message = US"Perl calls are not permitted";
4468         goto EXPAND_FAILED;
4469         }
4470
4471       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4472            US"perl", &resetok))
4473         {
4474         case 1: goto EXPAND_FAILED_CURLY;
4475         case 2:
4476         case 3: goto EXPAND_FAILED;
4477         }
4478
4479       /* If skipping, we don't actually do anything */
4480
4481       if (skipping) continue;
4482
4483       /* Start the interpreter if necessary */
4484
4485       if (!opt_perl_started)
4486         {
4487         uschar *initerror;
4488         if (opt_perl_startup == NULL)
4489           {
4490           expand_string_message = US"A setting of perl_startup is needed when "
4491             "using the Perl interpreter";
4492           goto EXPAND_FAILED;
4493           }
4494         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4495         initerror = init_perl(opt_perl_startup);
4496         if (initerror != NULL)
4497           {
4498           expand_string_message =
4499             string_sprintf("error in perl_startup code: %s\n", initerror);
4500           goto EXPAND_FAILED;
4501           }
4502         opt_perl_started = TRUE;
4503         }
4504
4505       /* Call the function */
4506
4507       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4508       new_yield = call_perl_cat(yield, &expand_string_message,
4509         sub_arg[0], sub_arg + 1);
4510
4511       /* NULL yield indicates failure; if the message pointer has been set to
4512       NULL, the yield was undef, indicating a forced failure. Otherwise the
4513       message will indicate some kind of Perl error. */
4514
4515       if (new_yield == NULL)
4516         {
4517         if (expand_string_message == NULL)
4518           {
4519           expand_string_message =
4520             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4521               "failure", sub_arg[0]);
4522           expand_string_forcedfail = TRUE;
4523           }
4524         goto EXPAND_FAILED;
4525         }
4526
4527       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4528       set during a callback from Perl. */
4529
4530       expand_string_forcedfail = FALSE;
4531       yield = new_yield;
4532       continue;
4533       }
4534     #endif /* EXIM_PERL */
4535
4536     /* Transform email address to "prvs" scheme to use
4537        as BATV-signed return path */
4538
4539     case EITEM_PRVS:
4540       {
4541       uschar *sub_arg[3];
4542       uschar *p,*domain;
4543
4544       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4545         {
4546         case 1: goto EXPAND_FAILED_CURLY;
4547         case 2:
4548         case 3: goto EXPAND_FAILED;
4549         }
4550
4551       /* If skipping, we don't actually do anything */
4552       if (skipping) continue;
4553
4554       /* sub_arg[0] is the address */
4555       if (  !(domain = Ustrrchr(sub_arg[0],'@'))
4556          || domain == sub_arg[0] || Ustrlen(domain) == 1)
4557         {
4558         expand_string_message = US"prvs first argument must be a qualified email address";
4559         goto EXPAND_FAILED;
4560         }
4561
4562       /* Calculate the hash. The third argument must be a single-digit
4563       key number, or unset. */
4564
4565       if (  sub_arg[2]
4566          && (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4567         {
4568         expand_string_message = US"prvs third argument must be a single digit";
4569         goto EXPAND_FAILED;
4570         }
4571
4572       p = prvs_hmac_sha1(sub_arg[0], sub_arg[1], sub_arg[2], prvs_daystamp(7));
4573       if (!p)
4574         {
4575         expand_string_message = US"prvs hmac-sha1 conversion failed";
4576         goto EXPAND_FAILED;
4577         }
4578
4579       /* Now separate the domain from the local part */
4580       *domain++ = '\0';
4581
4582       yield = string_catn(yield, US"prvs=", 5);
4583       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
4584       yield = string_catn(yield, prvs_daystamp(7), 3);
4585       yield = string_catn(yield, p, 6);
4586       yield = string_catn(yield, US"=", 1);
4587       yield = string_cat (yield, sub_arg[0]);
4588       yield = string_catn(yield, US"@", 1);
4589       yield = string_cat (yield, domain);
4590
4591       continue;
4592       }
4593
4594     /* Check a prvs-encoded address for validity */
4595
4596     case EITEM_PRVSCHECK:
4597       {
4598       uschar *sub_arg[3];
4599       gstring * g;
4600       const pcre *re;
4601       uschar *p;
4602
4603       /* TF: Ugliness: We want to expand parameter 1 first, then set
4604          up expansion variables that are used in the expansion of
4605          parameter 2. So we clone the string for the first
4606          expansion, where we only expand parameter 1.
4607
4608          PH: Actually, that isn't necessary. The read_subs() function is
4609          designed to work this way for the ${if and ${lookup expansions. I've
4610          tidied the code.
4611       */
4612
4613       /* Reset expansion variables */
4614       prvscheck_result = NULL;
4615       prvscheck_address = NULL;
4616       prvscheck_keynum = NULL;
4617
4618       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4619         {
4620         case 1: goto EXPAND_FAILED_CURLY;
4621         case 2:
4622         case 3: goto EXPAND_FAILED;
4623         }
4624
4625       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4626                               TRUE,FALSE);
4627
4628       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4629         {
4630         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4631         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4632         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4633         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4634         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4635
4636         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4637         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4638         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4639         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4640         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4641
4642         /* Set up expansion variables */
4643         g = string_cat (NULL, local_part);
4644         g = string_catn(g, US"@", 1);
4645         g = string_cat (g, domain);
4646         prvscheck_address = string_from_gstring(g);
4647         prvscheck_keynum = string_copy(key_num);
4648
4649         /* Now expand the second argument */
4650         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4651           {
4652           case 1: goto EXPAND_FAILED_CURLY;
4653           case 2:
4654           case 3: goto EXPAND_FAILED;
4655           }
4656
4657         /* Now we have the key and can check the address. */
4658
4659         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4660           daystamp);
4661
4662         if (!p)
4663           {
4664           expand_string_message = US"hmac-sha1 conversion failed";
4665           goto EXPAND_FAILED;
4666           }
4667
4668         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4669         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4670
4671         if (Ustrcmp(p,hash) == 0)
4672           {
4673           /* Success, valid BATV address. Now check the expiry date. */
4674           uschar *now = prvs_daystamp(0);
4675           unsigned int inow = 0,iexpire = 1;
4676
4677           (void)sscanf(CS now,"%u",&inow);
4678           (void)sscanf(CS daystamp,"%u",&iexpire);
4679
4680           /* When "iexpire" is < 7, a "flip" has occured.
4681              Adjust "inow" accordingly. */
4682           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4683
4684           if (iexpire >= inow)
4685             {
4686             prvscheck_result = US"1";
4687             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4688             }
4689           else
4690             {
4691             prvscheck_result = NULL;
4692             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4693             }
4694           }
4695         else
4696           {
4697           prvscheck_result = NULL;
4698           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4699           }
4700
4701         /* Now expand the final argument. We leave this till now so that
4702         it can include $prvscheck_result. */
4703
4704         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4705           {
4706           case 1: goto EXPAND_FAILED_CURLY;
4707           case 2:
4708           case 3: goto EXPAND_FAILED;
4709           }
4710
4711         yield = string_cat(yield,
4712           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4713
4714         /* Reset the "internal" variables afterwards, because they are in
4715         dynamic store that will be reclaimed if the expansion succeeded. */
4716
4717         prvscheck_address = NULL;
4718         prvscheck_keynum = NULL;
4719         }
4720       else
4721         /* Does not look like a prvs encoded address, return the empty string.
4722            We need to make sure all subs are expanded first, so as to skip over
4723            the entire item. */
4724
4725         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4726           {
4727           case 1: goto EXPAND_FAILED_CURLY;
4728           case 2:
4729           case 3: goto EXPAND_FAILED;
4730           }
4731
4732       continue;
4733       }
4734
4735     /* Handle "readfile" to insert an entire file */
4736
4737     case EITEM_READFILE:
4738       {
4739       FILE *f;
4740       uschar *sub_arg[2];
4741
4742       if ((expand_forbid & RDO_READFILE) != 0)
4743         {
4744         expand_string_message = US"file insertions are not permitted";
4745         goto EXPAND_FAILED;
4746         }
4747
4748       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4749         {
4750         case 1: goto EXPAND_FAILED_CURLY;
4751         case 2:
4752         case 3: goto EXPAND_FAILED;
4753         }
4754
4755       /* If skipping, we don't actually do anything */
4756
4757       if (skipping) continue;
4758
4759       /* Open the file and read it */
4760
4761       if (!(f = Ufopen(sub_arg[0], "rb")))
4762         {
4763         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4764         goto EXPAND_FAILED;
4765         }
4766
4767       yield = cat_file(f, yield, sub_arg[1]);
4768       (void)fclose(f);
4769       continue;
4770       }
4771
4772     /* Handle "readsocket" to insert data from a socket, either
4773     Inet or Unix domain */
4774
4775     case EITEM_READSOCK:
4776       {
4777       int fd;
4778       int timeout = 5;
4779       int save_ptr = yield->ptr;
4780       FILE *f;
4781       uschar *arg;
4782       uschar *sub_arg[4];
4783       BOOL do_shutdown = TRUE;
4784       blob reqstr;
4785
4786       if (expand_forbid & RDO_READSOCK)
4787         {
4788         expand_string_message = US"socket insertions are not permitted";
4789         goto EXPAND_FAILED;
4790         }
4791
4792       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4793       because there may be a string for expansion on failure. */
4794
4795       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4796         {
4797         case 1: goto EXPAND_FAILED_CURLY;
4798         case 2:                             /* Won't occur: no end check */
4799         case 3: goto EXPAND_FAILED;
4800         }
4801
4802       /* Grab the request string, if any */
4803
4804       reqstr.data = sub_arg[1];
4805       reqstr.len = Ustrlen(sub_arg[1]);
4806
4807       /* Sort out timeout, if given.  The second arg is a list with the first element
4808       being a time value.  Any more are options of form "name=value".  Currently the
4809       only option recognised is "shutdown". */
4810
4811       if (sub_arg[2])
4812         {
4813         const uschar * list = sub_arg[2];
4814         uschar * item;
4815         int sep = 0;
4816
4817         item = string_nextinlist(&list, &sep, NULL, 0);
4818         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4819           {
4820           expand_string_message = string_sprintf("bad time value %s", item);
4821           goto EXPAND_FAILED;
4822           }
4823
4824         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4825           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4826             if (Ustrcmp(item + 9, US"no") == 0)
4827               do_shutdown = FALSE;
4828         }
4829       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4830
4831       /* If skipping, we don't actually do anything. Otherwise, arrange to
4832       connect to either an IP or a Unix socket. */
4833
4834       if (!skipping)
4835         {
4836         /* Handle an IP (internet) domain */
4837
4838         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4839           {
4840           int port;
4841           uschar * server_name = sub_arg[0] + 5;
4842           uschar * port_name = Ustrrchr(server_name, ':');
4843
4844           /* Sort out the port */
4845
4846           if (!port_name)
4847             {
4848             expand_string_message =
4849               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4850             goto EXPAND_FAILED;
4851             }
4852           *port_name++ = 0;           /* Terminate server name */
4853
4854           if (isdigit(*port_name))
4855             {
4856             uschar *end;
4857             port = Ustrtol(port_name, &end, 0);
4858             if (end != port_name + Ustrlen(port_name))
4859               {
4860               expand_string_message =
4861                 string_sprintf("invalid port number %s", port_name);
4862               goto EXPAND_FAILED;
4863               }
4864             }
4865           else
4866             {
4867             struct servent *service_info = getservbyname(CS port_name, "tcp");
4868             if (!service_info)
4869               {
4870               expand_string_message = string_sprintf("unknown port \"%s\"",
4871                 port_name);
4872               goto EXPAND_FAILED;
4873               }
4874             port = ntohs(service_info->s_port);
4875             }
4876
4877           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4878                   timeout, NULL, &expand_string_message, &reqstr);
4879           callout_address = NULL;
4880           if (fd < 0)
4881               goto SOCK_FAIL;
4882           reqstr.len = 0;
4883           }
4884
4885         /* Handle a Unix domain socket */
4886
4887         else
4888           {
4889           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4890           int rc;
4891
4892           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4893             {
4894             expand_string_message = string_sprintf("failed to create socket: %s",
4895               strerror(errno));
4896             goto SOCK_FAIL;
4897             }
4898
4899           sockun.sun_family = AF_UNIX;
4900           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4901             sub_arg[0]);
4902
4903           sigalrm_seen = FALSE;
4904           alarm(timeout);
4905           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4906           alarm(0);
4907           if (sigalrm_seen)
4908             {
4909             expand_string_message = US "socket connect timed out";
4910             goto SOCK_FAIL;
4911             }
4912           if (rc < 0)
4913             {
4914             expand_string_message = string_sprintf("failed to connect to socket "
4915               "%s: %s", sub_arg[0], strerror(errno));
4916             goto SOCK_FAIL;
4917             }
4918           }
4919
4920         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4921
4922         /* Allow sequencing of test actions */
4923         if (running_in_test_harness) millisleep(100);
4924
4925         /* Write the request string, if not empty or already done */
4926
4927         if (reqstr.len)
4928           {
4929           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4930             reqstr.data);
4931           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4932             {
4933             expand_string_message = string_sprintf("request write to socket "
4934               "failed: %s", strerror(errno));
4935             goto SOCK_FAIL;
4936             }
4937           }
4938
4939         /* Shut down the sending side of the socket. This helps some servers to
4940         recognise that it is their turn to do some work. Just in case some
4941         system doesn't have this function, make it conditional. */
4942
4943 #ifdef SHUT_WR
4944         if (do_shutdown) shutdown(fd, SHUT_WR);
4945 #endif
4946
4947         if (running_in_test_harness) millisleep(100);
4948
4949         /* Now we need to read from the socket, under a timeout. The function
4950         that reads a file can be used. */
4951
4952         f = fdopen(fd, "rb");
4953         sigalrm_seen = FALSE;
4954         alarm(timeout);
4955         yield = cat_file(f, yield, sub_arg[3]);
4956         alarm(0);
4957         (void)fclose(f);
4958
4959         /* After a timeout, we restore the pointer in the result, that is,
4960         make sure we add nothing from the socket. */
4961
4962         if (sigalrm_seen)
4963           {
4964           yield->ptr = save_ptr;
4965           expand_string_message = US "socket read timed out";
4966           goto SOCK_FAIL;
4967           }
4968         }
4969
4970       /* The whole thing has worked (or we were skipping). If there is a
4971       failure string following, we need to skip it. */
4972
4973       if (*s == '{')
4974         {
4975         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4976           goto EXPAND_FAILED;
4977         if (*s++ != '}')
4978           {
4979           expand_string_message = US"missing '}' closing failstring for readsocket";
4980           goto EXPAND_FAILED_CURLY;
4981           }
4982         while (isspace(*s)) s++;
4983         }
4984
4985     READSOCK_DONE:
4986       if (*s++ != '}')
4987         {
4988         expand_string_message = US"missing '}' closing readsocket";
4989         goto EXPAND_FAILED_CURLY;
4990         }
4991       continue;
4992
4993       /* Come here on failure to create socket, connect socket, write to the
4994       socket, or timeout on reading. If another substring follows, expand and
4995       use it. Otherwise, those conditions give expand errors. */
4996
4997     SOCK_FAIL:
4998       if (*s != '{') goto EXPAND_FAILED;
4999       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
5000       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
5001         goto EXPAND_FAILED;
5002       yield = string_cat(yield, arg);
5003       if (*s++ != '}')
5004         {
5005         expand_string_message = US"missing '}' closing failstring for readsocket";
5006         goto EXPAND_FAILED_CURLY;
5007         }
5008       while (isspace(*s)) s++;
5009       goto READSOCK_DONE;
5010       }
5011
5012     /* Handle "run" to execute a program. */
5013
5014     case EITEM_RUN:
5015       {
5016       FILE *f;
5017       uschar *arg;
5018       const uschar **argv;
5019       pid_t pid;
5020       int fd_in, fd_out;
5021
5022       if ((expand_forbid & RDO_RUN) != 0)
5023         {
5024         expand_string_message = US"running a command is not permitted";
5025         goto EXPAND_FAILED;
5026         }
5027
5028       while (isspace(*s)) s++;
5029       if (*s != '{')
5030         {
5031         expand_string_message = US"missing '{' for command arg of run";
5032         goto EXPAND_FAILED_CURLY;
5033         }
5034       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5035       if (arg == NULL) goto EXPAND_FAILED;
5036       while (isspace(*s)) s++;
5037       if (*s++ != '}')
5038         {
5039         expand_string_message = US"missing '}' closing command arg of run";
5040         goto EXPAND_FAILED_CURLY;
5041         }
5042
5043       if (skipping)   /* Just pretend it worked when we're skipping */
5044         {
5045         runrc = 0;
5046         lookup_value = NULL;
5047         }
5048       else
5049         {
5050         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5051             arg,                                /* raw command */
5052             FALSE,                              /* don't expand the arguments */
5053             0,                                  /* not relevant when... */
5054             NULL,                               /* no transporting address */
5055             US"${run} expansion",               /* for error messages */
5056             &expand_string_message))            /* where to put error message */
5057           goto EXPAND_FAILED;
5058
5059         /* Create the child process, making it a group leader. */
5060
5061         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5062           {
5063           expand_string_message =
5064             string_sprintf("couldn't create child process: %s", strerror(errno));
5065           goto EXPAND_FAILED;
5066           }
5067
5068         /* Nothing is written to the standard input. */
5069
5070         (void)close(fd_in);
5071
5072         /* Read the pipe to get the command's output into $value (which is kept
5073         in lookup_value). Read during execution, so that if the output exceeds
5074         the OS pipe buffer limit, we don't block forever. Remember to not release
5075         memory just allocated for $value. */
5076
5077         resetok = FALSE;
5078         f = fdopen(fd_out, "rb");
5079         sigalrm_seen = FALSE;
5080         alarm(60);
5081         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5082         alarm(0);
5083         (void)fclose(f);
5084
5085         /* Wait for the process to finish, applying the timeout, and inspect its
5086         return code for serious disasters. Simple non-zero returns are passed on.
5087         */
5088
5089         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5090           {
5091           if (sigalrm_seen || runrc == -256)
5092             {
5093             expand_string_message = string_sprintf("command timed out");
5094             killpg(pid, SIGKILL);       /* Kill the whole process group */
5095             }
5096
5097           else if (runrc == -257)
5098             expand_string_message = string_sprintf("wait() failed: %s",
5099               strerror(errno));
5100
5101           else
5102             expand_string_message = string_sprintf("command killed by signal %d",
5103               -runrc);
5104
5105           goto EXPAND_FAILED;
5106           }
5107         }
5108
5109       /* Process the yes/no strings; $value may be useful in both cases */
5110
5111       switch(process_yesno(
5112                skipping,                     /* were previously skipping */
5113                runrc == 0,                   /* success/failure indicator */
5114                lookup_value,                 /* value to reset for string2 */
5115                &s,                           /* input pointer */
5116                &yield,                       /* output pointer */
5117                US"run",                      /* condition type */
5118                &resetok))
5119         {
5120         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5121         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5122         }
5123
5124       continue;
5125       }
5126
5127     /* Handle character translation for "tr" */
5128
5129     case EITEM_TR:
5130       {
5131       int oldptr = yield->ptr;
5132       int o2m;
5133       uschar *sub[3];
5134
5135       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5136         {
5137         case 1: goto EXPAND_FAILED_CURLY;
5138         case 2:
5139         case 3: goto EXPAND_FAILED;
5140         }
5141
5142       yield = string_cat(yield, sub[0]);
5143       o2m = Ustrlen(sub[2]) - 1;
5144
5145       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5146         {
5147         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5148         if (m != NULL)
5149           {
5150           int o = m - sub[1];
5151           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5152           }
5153         }
5154
5155       continue;
5156       }
5157
5158     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5159     expanded arguments. */
5160
5161     case EITEM_HASH:
5162     case EITEM_LENGTH:
5163     case EITEM_NHASH:
5164     case EITEM_SUBSTR:
5165       {
5166       int i;
5167       int len;
5168       uschar *ret;
5169       int val[2] = { 0, -1 };
5170       uschar *sub[3];
5171
5172       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5173       Ensure that sub[2] is set in the ${length } case. */
5174
5175       sub[2] = NULL;
5176       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5177              TRUE, name, &resetok))
5178         {
5179         case 1: goto EXPAND_FAILED_CURLY;
5180         case 2:
5181         case 3: goto EXPAND_FAILED;
5182         }
5183
5184       /* Juggle the arguments if there are only two of them: always move the
5185       string to the last position and make ${length{n}{str}} equivalent to
5186       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5187
5188       if (sub[2] == NULL)
5189         {
5190         sub[2] = sub[1];
5191         sub[1] = NULL;
5192         if (item_type == EITEM_LENGTH)
5193           {
5194           sub[1] = sub[0];
5195           sub[0] = NULL;
5196           }
5197         }
5198
5199       for (i = 0; i < 2; i++)
5200         {
5201         if (sub[i] == NULL) continue;
5202         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5203         if (*ret != 0 || (i != 0 && val[i] < 0))
5204           {
5205           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5206             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5207           goto EXPAND_FAILED;
5208           }
5209         }
5210
5211       ret =
5212         (item_type == EITEM_HASH)?
5213           compute_hash(sub[2], val[0], val[1], &len) :
5214         (item_type == EITEM_NHASH)?
5215           compute_nhash(sub[2], val[0], val[1], &len) :
5216           extract_substr(sub[2], val[0], val[1], &len);
5217
5218       if (ret == NULL) goto EXPAND_FAILED;
5219       yield = string_catn(yield, ret, len);
5220       continue;
5221       }
5222
5223     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5224     This code originally contributed by Steve Haslam. It currently supports
5225     the use of MD5 and SHA-1 hashes.
5226
5227     We need some workspace that is large enough to handle all the supported
5228     hash types. Use macros to set the sizes rather than be too elaborate. */
5229
5230     #define MAX_HASHLEN      20
5231     #define MAX_HASHBLOCKLEN 64
5232
5233     case EITEM_HMAC:
5234       {
5235       uschar *sub[3];
5236       md5 md5_base;
5237       hctx sha1_ctx;
5238       void *use_base;
5239       int type, i;
5240       int hashlen;      /* Number of octets for the hash algorithm's output */
5241       int hashblocklen; /* Number of octets the hash algorithm processes */
5242       uschar *keyptr, *p;
5243       unsigned int keylen;
5244
5245       uschar keyhash[MAX_HASHLEN];
5246       uschar innerhash[MAX_HASHLEN];
5247       uschar finalhash[MAX_HASHLEN];
5248       uschar finalhash_hex[2*MAX_HASHLEN];
5249       uschar innerkey[MAX_HASHBLOCKLEN];
5250       uschar outerkey[MAX_HASHBLOCKLEN];
5251
5252       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5253         {
5254         case 1: goto EXPAND_FAILED_CURLY;
5255         case 2:
5256         case 3: goto EXPAND_FAILED;
5257         }
5258
5259       if (!skipping)
5260         {
5261         if (Ustrcmp(sub[0], "md5") == 0)
5262           {
5263           type = HMAC_MD5;
5264           use_base = &md5_base;
5265           hashlen = 16;
5266           hashblocklen = 64;
5267           }
5268         else if (Ustrcmp(sub[0], "sha1") == 0)
5269           {
5270           type = HMAC_SHA1;
5271           use_base = &sha1_ctx;
5272           hashlen = 20;
5273           hashblocklen = 64;
5274           }
5275         else
5276           {
5277           expand_string_message =
5278             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5279           goto EXPAND_FAILED;
5280           }
5281
5282         keyptr = sub[1];
5283         keylen = Ustrlen(keyptr);
5284
5285         /* If the key is longer than the hash block length, then hash the key
5286         first */
5287
5288         if (keylen > hashblocklen)
5289           {
5290           chash_start(type, use_base);
5291           chash_end(type, use_base, keyptr, keylen, keyhash);
5292           keyptr = keyhash;
5293           keylen = hashlen;
5294           }
5295
5296         /* Now make the inner and outer key values */
5297
5298         memset(innerkey, 0x36, hashblocklen);
5299         memset(outerkey, 0x5c, hashblocklen);
5300
5301         for (i = 0; i < keylen; i++)
5302           {
5303           innerkey[i] ^= keyptr[i];
5304           outerkey[i] ^= keyptr[i];
5305           }
5306
5307         /* Now do the hashes */
5308
5309         chash_start(type, use_base);
5310         chash_mid(type, use_base, innerkey);
5311         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5312
5313         chash_start(type, use_base);
5314         chash_mid(type, use_base, outerkey);
5315         chash_end(type, use_base, innerhash, hashlen, finalhash);
5316
5317         /* Encode the final hash as a hex string */
5318
5319         p = finalhash_hex;
5320         for (i = 0; i < hashlen; i++)
5321           {
5322           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5323           *p++ = hex_digits[finalhash[i] & 0x0f];
5324           }
5325
5326         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5327           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5328
5329         yield = string_catn(yield, finalhash_hex, hashlen*2);
5330         }
5331       continue;
5332       }
5333
5334     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5335     We have to save the numerical variables and restore them afterwards. */
5336
5337     case EITEM_SG:
5338       {
5339       const pcre *re;
5340       int moffset, moffsetextra, slen;
5341       int roffset;
5342       int emptyopt;
5343       const uschar *rerror;
5344       uschar *subject;
5345       uschar *sub[3];
5346       int save_expand_nmax =
5347         save_expand_strings(save_expand_nstring, save_expand_nlength);
5348
5349       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5350         {
5351         case 1: goto EXPAND_FAILED_CURLY;
5352         case 2:
5353         case 3: goto EXPAND_FAILED;
5354         }
5355
5356       /* Compile the regular expression */
5357
5358       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5359         NULL);
5360
5361       if (re == NULL)
5362         {
5363         expand_string_message = string_sprintf("regular expression error in "
5364           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5365         goto EXPAND_FAILED;
5366         }
5367
5368       /* Now run a loop to do the substitutions as often as necessary. It ends
5369       when there are no more matches. Take care over matches of the null string;
5370       do the same thing as Perl does. */
5371
5372       subject = sub[0];
5373       slen = Ustrlen(sub[0]);
5374       moffset = moffsetextra = 0;
5375       emptyopt = 0;
5376
5377       for (;;)
5378         {
5379         int ovector[3*(EXPAND_MAXN+1)];
5380         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5381           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5382         int nn;
5383         uschar *insert;
5384
5385         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5386         is not necessarily the end. We want to repeat the match from one
5387         character further along, but leaving the basic offset the same (for
5388         copying below). We can't be at the end of the string - that was checked
5389         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5390         finished; copy the remaining string and end the loop. */
5391
5392         if (n < 0)
5393           {
5394           if (emptyopt != 0)
5395             {
5396             moffsetextra = 1;
5397             emptyopt = 0;
5398             continue;
5399             }
5400           yield = string_catn(yield, subject+moffset, slen-moffset);
5401           break;
5402           }
5403
5404         /* Match - set up for expanding the replacement. */
5405
5406         if (n == 0) n = EXPAND_MAXN + 1;
5407         expand_nmax = 0;
5408         for (nn = 0; nn < n*2; nn += 2)
5409           {
5410           expand_nstring[expand_nmax] = subject + ovector[nn];
5411           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5412           }
5413         expand_nmax--;
5414
5415         /* Copy the characters before the match, plus the expanded insertion. */
5416
5417         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5418         insert = expand_string(sub[2]);
5419         if (insert == NULL) goto EXPAND_FAILED;
5420         yield = string_cat(yield, insert);
5421
5422         moffset = ovector[1];
5423         moffsetextra = 0;
5424         emptyopt = 0;
5425
5426         /* If we have matched an empty string, first check to see if we are at
5427         the end of the subject. If so, the loop is over. Otherwise, mimic
5428         what Perl's /g options does. This turns out to be rather cunning. First
5429         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5430         string at the same point. If this fails (picked up above) we advance to
5431         the next character. */
5432
5433         if (ovector[0] == ovector[1])
5434           {
5435           if (ovector[0] == slen) break;
5436           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5437           }
5438         }
5439
5440       /* All done - restore numerical variables. */
5441
5442       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5443         save_expand_nlength);
5444       continue;
5445       }
5446
5447     /* Handle keyed and numbered substring extraction. If the first argument
5448     consists entirely of digits, then a numerical extraction is assumed. */
5449
5450     case EITEM_EXTRACT:
5451       {
5452       int i;
5453       int j;
5454       int field_number = 1;
5455       BOOL field_number_set = FALSE;
5456       uschar *save_lookup_value = lookup_value;
5457       uschar *sub[3];
5458       int save_expand_nmax =
5459         save_expand_strings(save_expand_nstring, save_expand_nlength);
5460
5461       /* While skipping we cannot rely on the data for expansions being
5462       available (eg. $item) hence cannot decide on numeric vs. keyed.
5463       Read a maximum of 5 arguments (including the yes/no) */
5464
5465       if (skipping)
5466         {
5467         while (isspace(*s)) s++;
5468         for (j = 5; j > 0 && *s == '{'; j--)
5469           {
5470           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5471             goto EXPAND_FAILED;                                 /*{*/
5472           if (*s++ != '}')
5473             {
5474             expand_string_message = US"missing '{' for arg of extract";
5475             goto EXPAND_FAILED_CURLY;
5476             }
5477           while (isspace(*s)) s++;
5478           }
5479         if (  Ustrncmp(s, "fail", 4) == 0
5480            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5481            )
5482           {
5483           s += 4;
5484           while (isspace(*s)) s++;
5485           }
5486         if (*s != '}')
5487           {
5488           expand_string_message = US"missing '}' closing extract";
5489           goto EXPAND_FAILED_CURLY;
5490           }
5491         }
5492
5493       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5494         {
5495         while (isspace(*s)) s++;
5496         if (*s == '{')                                          /*}*/
5497           {
5498           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5499           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5500           if (*s++ != '}')
5501             {
5502             expand_string_message = string_sprintf(
5503               "missing '}' closing arg %d of extract", i+1);
5504             goto EXPAND_FAILED_CURLY;
5505             }
5506
5507           /* After removal of leading and trailing white space, the first
5508           argument must not be empty; if it consists entirely of digits
5509           (optionally preceded by a minus sign), this is a numerical
5510           extraction, and we expect 3 arguments. */
5511
5512           if (i == 0)
5513             {
5514             int len;
5515             int x = 0;
5516             uschar *p = sub[0];
5517
5518             while (isspace(*p)) p++;
5519             sub[0] = p;
5520
5521             len = Ustrlen(p);
5522             while (len > 0 && isspace(p[len-1])) len--;
5523             p[len] = 0;
5524
5525             if (*p == 0)
5526               {
5527               expand_string_message = US"first argument of \"extract\" must "
5528                 "not be empty";
5529               goto EXPAND_FAILED;
5530               }
5531
5532             if (*p == '-')
5533               {
5534               field_number = -1;
5535               p++;
5536               }
5537             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5538             if (*p == 0)
5539               {
5540               field_number *= x;
5541               j = 3;               /* Need 3 args */
5542               field_number_set = TRUE;
5543               }
5544             }
5545           }
5546         else
5547           {
5548           expand_string_message = string_sprintf(
5549             "missing '{' for arg %d of extract", i+1);
5550           goto EXPAND_FAILED_CURLY;
5551           }
5552         }
5553
5554       /* Extract either the numbered or the keyed substring into $value. If
5555       skipping, just pretend the extraction failed. */
5556
5557       lookup_value = skipping? NULL : field_number_set?
5558         expand_gettokened(field_number, sub[1], sub[2]) :
5559         expand_getkeyed(sub[0], sub[1]);
5560
5561       /* If no string follows, $value gets substituted; otherwise there can
5562       be yes/no strings, as for lookup or if. */
5563
5564       switch(process_yesno(
5565                skipping,                     /* were previously skipping */
5566                lookup_value != NULL,         /* success/failure indicator */
5567                save_lookup_value,            /* value to reset for string2 */
5568                &s,                           /* input pointer */
5569                &yield,                       /* output pointer */
5570                US"extract",                  /* condition type */
5571                &resetok))
5572         {
5573         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5574         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5575         }
5576
5577       /* All done - restore numerical variables. */
5578
5579       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5580         save_expand_nlength);
5581
5582       continue;
5583       }
5584
5585     /* return the Nth item from a list */
5586
5587     case EITEM_LISTEXTRACT:
5588       {
5589       int i;
5590       int field_number = 1;
5591       uschar *save_lookup_value = lookup_value;
5592       uschar *sub[2];
5593       int save_expand_nmax =
5594         save_expand_strings(save_expand_nstring, save_expand_nlength);
5595
5596       /* Read the field & list arguments */
5597
5598       for (i = 0; i < 2; i++)
5599         {
5600         while (isspace(*s)) s++;
5601         if (*s != '{')                                  /*}*/
5602           {
5603           expand_string_message = string_sprintf(
5604             "missing '{' for arg %d of listextract", i+1);
5605           goto EXPAND_FAILED_CURLY;
5606           }
5607
5608         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5609         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5610         if (*s++ != '}')
5611           {
5612           expand_string_message = string_sprintf(
5613             "missing '}' closing arg %d of listextract", i+1);
5614           goto EXPAND_FAILED_CURLY;
5615           }
5616
5617         /* After removal of leading and trailing white space, the first
5618         argument must be numeric and nonempty. */
5619
5620         if (i == 0)
5621           {
5622           int len;
5623           int x = 0;
5624           uschar *p = sub[0];
5625
5626           while (isspace(*p)) p++;
5627           sub[0] = p;
5628
5629           len = Ustrlen(p);
5630           while (len > 0 && isspace(p[len-1])) len--;
5631           p[len] = 0;
5632
5633           if (!*p && !skipping)
5634             {
5635             expand_string_message = US"first argument of \"listextract\" must "
5636               "not be empty";
5637             goto EXPAND_FAILED;
5638             }
5639
5640           if (*p == '-')
5641             {
5642             field_number = -1;
5643             p++;
5644             }
5645           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5646           if (*p)
5647             {
5648             expand_string_message = US"first argument of \"listextract\" must "
5649               "be numeric";
5650             goto EXPAND_FAILED;
5651             }
5652           field_number *= x;
5653           }
5654         }
5655
5656       /* Extract the numbered element into $value. If
5657       skipping, just pretend the extraction failed. */
5658
5659       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5660
5661       /* If no string follows, $value gets substituted; otherwise there can
5662       be yes/no strings, as for lookup or if. */
5663
5664       switch(process_yesno(
5665                skipping,                     /* were previously skipping */
5666                lookup_value != NULL,         /* success/failure indicator */
5667                save_lookup_value,            /* value to reset for string2 */
5668                &s,                           /* input pointer */
5669                &yield,                       /* output pointer */
5670                US"listextract",              /* condition type */
5671                &resetok))
5672         {
5673         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5674         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5675         }
5676
5677       /* All done - restore numerical variables. */
5678
5679       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5680         save_expand_nlength);
5681
5682       continue;
5683       }
5684
5685 #ifdef SUPPORT_TLS
5686     case EITEM_CERTEXTRACT:
5687       {
5688       uschar *save_lookup_value = lookup_value;
5689       uschar *sub[2];
5690       int save_expand_nmax =
5691         save_expand_strings(save_expand_nstring, save_expand_nlength);
5692
5693       /* Read the field argument */
5694       while (isspace(*s)) s++;
5695       if (*s != '{')                                    /*}*/
5696         {
5697         expand_string_message = US"missing '{' for field arg of certextract";
5698         goto EXPAND_FAILED_CURLY;
5699         }
5700       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5701       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5702       if (*s++ != '}')
5703         {
5704         expand_string_message = US"missing '}' closing field arg of certextract";
5705         goto EXPAND_FAILED_CURLY;
5706         }
5707       /* strip spaces fore & aft */
5708       {
5709       int len;
5710       uschar *p = sub[0];
5711
5712       while (isspace(*p)) p++;
5713       sub[0] = p;
5714
5715       len = Ustrlen(p);
5716       while (len > 0 && isspace(p[len-1])) len--;
5717       p[len] = 0;
5718       }
5719
5720       /* inspect the cert argument */
5721       while (isspace(*s)) s++;
5722       if (*s != '{')                                    /*}*/
5723         {
5724         expand_string_message = US"missing '{' for cert variable arg of certextract";
5725         goto EXPAND_FAILED_CURLY;
5726         }
5727       if (*++s != '$')
5728         {
5729         expand_string_message = US"second argument of \"certextract\" must "
5730           "be a certificate variable";
5731         goto EXPAND_FAILED;
5732         }
5733       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5734       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5735       if (*s++ != '}')
5736         {
5737         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5738         goto EXPAND_FAILED_CURLY;
5739         }
5740
5741       if (skipping)
5742         lookup_value = NULL;
5743       else
5744         {
5745         lookup_value = expand_getcertele(sub[0], sub[1]);
5746         if (*expand_string_message) goto EXPAND_FAILED;
5747         }
5748       switch(process_yesno(
5749                skipping,                     /* were previously skipping */
5750                lookup_value != NULL,         /* success/failure indicator */
5751                save_lookup_value,            /* value to reset for string2 */
5752                &s,                           /* input pointer */
5753                &yield,                       /* output pointer */
5754                US"certextract",              /* condition type */
5755                &resetok))
5756         {
5757         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5758         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5759         }
5760
5761       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5762         save_expand_nlength);
5763       continue;
5764       }
5765 #endif  /*SUPPORT_TLS*/
5766
5767     /* Handle list operations */
5768
5769     case EITEM_FILTER:
5770     case EITEM_MAP:
5771     case EITEM_REDUCE:
5772       {
5773       int sep = 0;
5774       int save_ptr = yield->ptr;
5775       uschar outsep[2] = { '\0', '\0' };
5776       const uschar *list, *expr, *temp;
5777       uschar *save_iterate_item = iterate_item;
5778       uschar *save_lookup_value = lookup_value;
5779
5780       while (isspace(*s)) s++;
5781       if (*s++ != '{')
5782         {
5783         expand_string_message =
5784           string_sprintf("missing '{' for first arg of %s", name);
5785         goto EXPAND_FAILED_CURLY;
5786         }
5787
5788       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5789       if (list == NULL) goto EXPAND_FAILED;
5790       if (*s++ != '}')
5791         {
5792         expand_string_message =
5793           string_sprintf("missing '}' closing first arg of %s", name);
5794         goto EXPAND_FAILED_CURLY;
5795         }
5796
5797       if (item_type == EITEM_REDUCE)
5798         {
5799         uschar * t;
5800         while (isspace(*s)) s++;
5801         if (*s++ != '{')
5802           {
5803           expand_string_message = US"missing '{' for second arg of reduce";
5804           goto EXPAND_FAILED_CURLY;
5805           }
5806         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5807         if (!t) goto EXPAND_FAILED;
5808         lookup_value = t;
5809         if (*s++ != '}')
5810           {
5811           expand_string_message = US"missing '}' closing second arg of reduce";
5812           goto EXPAND_FAILED_CURLY;
5813           }
5814         }
5815
5816       while (isspace(*s)) s++;
5817       if (*s++ != '{')
5818         {
5819         expand_string_message =
5820           string_sprintf("missing '{' for last arg of %s", name);
5821         goto EXPAND_FAILED_CURLY;
5822         }
5823
5824       expr = s;
5825
5826       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5827       if scanning a "false" part). This allows us to find the end of the
5828       condition, because if the list is empty, we won't actually evaluate the
5829       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5830       the normal internal expansion function. */
5831
5832       if (item_type == EITEM_FILTER)
5833         {
5834         temp = eval_condition(expr, &resetok, NULL);
5835         if (temp != NULL) s = temp;
5836         }
5837       else
5838         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5839
5840       if (temp == NULL)
5841         {
5842         expand_string_message = string_sprintf("%s inside \"%s\" item",
5843           expand_string_message, name);
5844         goto EXPAND_FAILED;
5845         }
5846
5847       while (isspace(*s)) s++;
5848       if (*s++ != '}')
5849         {                                               /*{*/
5850         expand_string_message = string_sprintf("missing } at end of condition "
5851           "or expression inside \"%s\"; could be an unquoted } in the content",
5852           name);
5853         goto EXPAND_FAILED;
5854         }
5855
5856       while (isspace(*s)) s++;                          /*{*/
5857       if (*s++ != '}')
5858         {                                               /*{*/
5859         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5860           name);
5861         goto EXPAND_FAILED;
5862         }
5863
5864       /* If we are skipping, we can now just move on to the next item. When
5865       processing for real, we perform the iteration. */
5866
5867       if (skipping) continue;
5868       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5869         {
5870         *outsep = (uschar)sep;      /* Separator as a string */
5871
5872         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5873                           name, iterate_item, lookup_value);
5874
5875         if (item_type == EITEM_FILTER)
5876           {
5877           BOOL condresult;
5878           if (eval_condition(expr, &resetok, &condresult) == NULL)
5879             {
5880             iterate_item = save_iterate_item;
5881             lookup_value = save_lookup_value;
5882             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5883               expand_string_message, name);
5884             goto EXPAND_FAILED;
5885             }
5886           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5887             condresult? "true":"false");
5888           if (condresult)
5889             temp = iterate_item;    /* TRUE => include this item */
5890           else
5891             continue;               /* FALSE => skip this item */
5892           }
5893
5894         /* EITEM_MAP and EITEM_REDUCE */
5895
5896         else
5897           {
5898           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5899           temp = t;
5900           if (temp == NULL)
5901             {
5902             iterate_item = save_iterate_item;
5903             expand_string_message = string_sprintf("%s inside \"%s\" item",
5904               expand_string_message, name);
5905             goto EXPAND_FAILED;
5906             }
5907           if (item_type == EITEM_REDUCE)
5908             {
5909             lookup_value = t;         /* Update the value of $value */
5910             continue;                 /* and continue the iteration */
5911             }
5912           }
5913
5914         /* We reach here for FILTER if the condition is true, always for MAP,
5915         and never for REDUCE. The value in "temp" is to be added to the output
5916         list that is being created, ensuring that any occurrences of the
5917         separator character are doubled. Unless we are dealing with the first
5918         item of the output list, add in a space if the new item begins with the
5919         separator character, or is an empty string. */
5920
5921         if (yield->ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5922           yield = string_catn(yield, US" ", 1);
5923
5924         /* Add the string in "temp" to the output list that we are building,
5925         This is done in chunks by searching for the separator character. */
5926
5927         for (;;)
5928           {
5929           size_t seglen = Ustrcspn(temp, outsep);
5930
5931           yield = string_catn(yield, temp, seglen + 1);
5932
5933           /* If we got to the end of the string we output one character
5934           too many; backup and end the loop. Otherwise arrange to double the
5935           separator. */
5936
5937           if (temp[seglen] == '\0') { yield->ptr--; break; }
5938           yield = string_catn(yield, outsep, 1);
5939           temp += seglen + 1;
5940           }
5941
5942         /* Output a separator after the string: we will remove the redundant
5943         final one at the end. */
5944
5945         yield = string_catn(yield, outsep, 1);
5946         }   /* End of iteration over the list loop */
5947
5948       /* REDUCE has generated no output above: output the final value of
5949       $value. */
5950
5951       if (item_type == EITEM_REDUCE)
5952         {
5953         yield = string_cat(yield, lookup_value);
5954         lookup_value = save_lookup_value;  /* Restore $value */
5955         }
5956
5957       /* FILTER and MAP generate lists: if they have generated anything, remove
5958       the redundant final separator. Even though an empty item at the end of a
5959       list does not count, this is tidier. */
5960
5961       else if (yield->ptr != save_ptr) yield->ptr--;
5962
5963       /* Restore preserved $item */
5964
5965       iterate_item = save_iterate_item;
5966       continue;
5967       }
5968
5969     case EITEM_SORT:
5970       {
5971       int sep = 0;
5972       const uschar *srclist, *cmp, *xtract;
5973       uschar *srcitem;
5974       const uschar *dstlist = NULL, *dstkeylist = NULL;
5975       uschar * tmp;
5976       uschar *save_iterate_item = iterate_item;
5977
5978       while (isspace(*s)) s++;
5979       if (*s++ != '{')
5980         {
5981         expand_string_message = US"missing '{' for list arg of sort";
5982         goto EXPAND_FAILED_CURLY;
5983         }
5984
5985       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5986       if (!srclist) goto EXPAND_FAILED;
5987       if (*s++ != '}')
5988         {
5989         expand_string_message = US"missing '}' closing list arg of sort";
5990         goto EXPAND_FAILED_CURLY;
5991         }
5992
5993       while (isspace(*s)) s++;
5994       if (*s++ != '{')
5995         {
5996         expand_string_message = US"missing '{' for comparator arg of sort";
5997         goto EXPAND_FAILED_CURLY;
5998         }
5999
6000       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
6001       if (!cmp) goto EXPAND_FAILED;
6002       if (*s++ != '}')
6003         {
6004         expand_string_message = US"missing '}' closing comparator arg of sort";
6005         goto EXPAND_FAILED_CURLY;
6006         }
6007
6008       while (isspace(*s)) s++;
6009       if (*s++ != '{')
6010         {
6011         expand_string_message = US"missing '{' for extractor arg of sort";
6012         goto EXPAND_FAILED_CURLY;
6013         }
6014
6015       xtract = s;
6016       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
6017       if (!tmp) goto EXPAND_FAILED;
6018       xtract = string_copyn(xtract, s - xtract);
6019
6020       if (*s++ != '}')
6021         {
6022         expand_string_message = US"missing '}' closing extractor arg of sort";
6023         goto EXPAND_FAILED_CURLY;
6024         }
6025                                                         /*{*/
6026       if (*s++ != '}')
6027         {                                               /*{*/
6028         expand_string_message = US"missing } at end of \"sort\"";
6029         goto EXPAND_FAILED;
6030         }
6031
6032       if (skipping) continue;
6033
6034       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
6035         {
6036         uschar * dstitem;
6037         gstring * newlist = NULL;
6038         gstring * newkeylist = NULL;
6039         uschar * srcfield;
6040
6041         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6042
6043         /* extract field for comparisons */
6044         iterate_item = srcitem;
6045         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6046                                           TRUE, &resetok))
6047            || !*srcfield)
6048           {
6049           expand_string_message = string_sprintf(
6050               "field-extract in sort: \"%s\"", xtract);
6051           goto EXPAND_FAILED;
6052           }
6053
6054         /* Insertion sort */
6055
6056         /* copy output list until new-item < list-item */
6057         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6058           {
6059           uschar * dstfield;
6060           uschar * expr;
6061           BOOL before;
6062
6063           /* field for comparison */
6064           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6065             goto sort_mismatch;
6066
6067           /* build and run condition string */
6068           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6069
6070           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6071           if (!eval_condition(expr, &resetok, &before))
6072             {
6073             expand_string_message = string_sprintf("comparison in sort: %s",
6074                 expr);
6075             goto EXPAND_FAILED;
6076             }
6077
6078           if (before)
6079             {
6080             /* New-item sorts before this dst-item.  Append new-item,
6081             then dst-item, then remainder of dst list. */
6082
6083             newlist = string_append_listele(newlist, sep, srcitem);
6084             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6085             srcitem = NULL;
6086
6087             newlist = string_append_listele(newlist, sep, dstitem);
6088             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6089
6090             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6091               {
6092               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6093                 goto sort_mismatch;
6094               newlist = string_append_listele(newlist, sep, dstitem);
6095               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6096               }
6097
6098             break;
6099             }
6100
6101           newlist = string_append_listele(newlist, sep, dstitem);
6102           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6103           }
6104
6105         /* If we ran out of dstlist without consuming srcitem, append it */
6106         if (srcitem)
6107           {
6108           newlist = string_append_listele(newlist, sep, srcitem);
6109           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6110           }
6111
6112         dstlist = newlist->s;
6113         dstkeylist = newkeylist->s;
6114
6115         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6116         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6117         }
6118
6119       if (dstlist)
6120         yield = string_cat(yield, dstlist);
6121
6122       /* Restore preserved $item */
6123       iterate_item = save_iterate_item;
6124       continue;
6125
6126       sort_mismatch:
6127         expand_string_message = US"Internal error in sort (list mismatch)";
6128         goto EXPAND_FAILED;
6129       }
6130
6131
6132     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6133     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6134     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6135     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6136
6137     #define EXPAND_DLFUNC_MAX_ARGS 8
6138
6139     case EITEM_DLFUNC:
6140 #ifndef EXPAND_DLFUNC
6141       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6142         "is not included in this binary";
6143       goto EXPAND_FAILED;
6144
6145 #else   /* EXPAND_DLFUNC */
6146       {
6147       tree_node *t;
6148       exim_dlfunc_t *func;
6149       uschar *result;
6150       int status, argc;
6151       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6152
6153       if ((expand_forbid & RDO_DLFUNC) != 0)
6154         {
6155         expand_string_message =
6156           US"dynamically-loaded functions are not permitted";
6157         goto EXPAND_FAILED;
6158         }
6159
6160       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6161            TRUE, US"dlfunc", &resetok))
6162         {
6163         case 1: goto EXPAND_FAILED_CURLY;
6164         case 2:
6165         case 3: goto EXPAND_FAILED;
6166         }
6167
6168       /* If skipping, we don't actually do anything */
6169
6170       if (skipping) continue;
6171
6172       /* Look up the dynamically loaded object handle in the tree. If it isn't
6173       found, dlopen() the file and put the handle in the tree for next time. */
6174
6175       t = tree_search(dlobj_anchor, argv[0]);
6176       if (t == NULL)
6177         {
6178         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6179         if (handle == NULL)
6180           {
6181           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6182             argv[0], dlerror());
6183           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6184           goto EXPAND_FAILED;
6185           }
6186         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6187         Ustrcpy(t->name, argv[0]);
6188         t->data.ptr = handle;
6189         (void)tree_insertnode(&dlobj_anchor, t);
6190         }
6191
6192       /* Having obtained the dynamically loaded object handle, look up the
6193       function pointer. */
6194
6195       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6196       if (func == NULL)
6197         {
6198         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6199           "%s", argv[1], argv[0], dlerror());
6200         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6201         goto EXPAND_FAILED;
6202         }
6203
6204       /* Call the function and work out what to do with the result. If it
6205       returns OK, we have a replacement string; if it returns DEFER then
6206       expansion has failed in a non-forced manner; if it returns FAIL then
6207       failure was forced; if it returns ERROR or any other value there's a
6208       problem, so panic slightly. In any case, assume that the function has
6209       side-effects on the store that must be preserved. */
6210
6211       resetok = FALSE;
6212       result = NULL;
6213       for (argc = 0; argv[argc] != NULL; argc++);
6214       status = func(&result, argc - 2, &argv[2]);
6215       if(status == OK)
6216         {
6217         if (result == NULL) result = US"";
6218         yield = string_cat(yield, result);
6219         continue;
6220         }
6221       else
6222         {
6223         expand_string_message = result == NULL ? US"(no message)" : result;
6224         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6225           else if(status != FAIL)
6226             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6227               argv[0], argv[1], status, expand_string_message);
6228         goto EXPAND_FAILED;
6229         }
6230       }
6231 #endif /* EXPAND_DLFUNC */
6232
6233     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6234       {
6235       uschar * key;
6236       uschar *save_lookup_value = lookup_value;
6237
6238       while (isspace(*s)) s++;
6239       if (*s != '{')                                    /*}*/
6240         goto EXPAND_FAILED;
6241
6242       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6243       if (!key) goto EXPAND_FAILED;                     /*{*/
6244       if (*s++ != '}')
6245         {
6246         expand_string_message = US"missing '{' for name arg of env";
6247         goto EXPAND_FAILED_CURLY;
6248         }
6249
6250       lookup_value = US getenv(CS key);
6251
6252       switch(process_yesno(
6253                skipping,                     /* were previously skipping */
6254                lookup_value != NULL,         /* success/failure indicator */
6255                save_lookup_value,            /* value to reset for string2 */
6256                &s,                           /* input pointer */
6257                &yield,                       /* output pointer */
6258                US"env",                      /* condition type */
6259                &resetok))
6260         {
6261         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6262         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6263         }
6264       continue;
6265       }
6266     }   /* EITEM_* switch */
6267
6268   /* Control reaches here if the name is not recognized as one of the more
6269   complicated expansion items. Check for the "operator" syntax (name terminated
6270   by a colon). Some of the operators have arguments, separated by _ from the
6271   name. */
6272
6273   if (*s == ':')
6274     {
6275     int c;
6276     uschar *arg = NULL;
6277     uschar *sub;
6278     var_entry *vp = NULL;
6279
6280     /* Owing to an historical mis-design, an underscore may be part of the
6281     operator name, or it may introduce arguments.  We therefore first scan the
6282     table of names that contain underscores. If there is no match, we cut off
6283     the arguments and then scan the main table. */
6284
6285     if ((c = chop_match(name, op_table_underscore,
6286                         nelem(op_table_underscore))) < 0)
6287       {
6288       arg = Ustrchr(name, '_');
6289       if (arg != NULL) *arg = 0;
6290       c = chop_match(name, op_table_main, nelem(op_table_main));
6291       if (c >= 0) c += nelem(op_table_underscore);
6292       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6293       }
6294
6295     /* Deal specially with operators that might take a certificate variable
6296     as we do not want to do the usual expansion. For most, expand the string.*/
6297     switch(c)
6298       {
6299 #ifdef SUPPORT_TLS
6300       case EOP_MD5:
6301       case EOP_SHA1:
6302       case EOP_SHA256:
6303       case EOP_BASE64:
6304         if (s[1] == '$')
6305           {
6306           const uschar * s1 = s;
6307           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6308                   FALSE, &resetok);
6309           if (!sub)       goto EXPAND_FAILED;           /*{*/
6310           if (*s1 != '}')
6311             {
6312             expand_string_message =
6313               string_sprintf("missing '}' closing cert arg of %s", name);
6314             goto EXPAND_FAILED_CURLY;
6315             }
6316           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6317             {
6318             s = s1+1;
6319             break;
6320             }
6321           vp = NULL;
6322           }
6323         /*FALLTHROUGH*/
6324 #endif
6325       default:
6326         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6327         if (!sub) goto EXPAND_FAILED;
6328         s++;
6329         break;
6330       }
6331
6332     /* If we are skipping, we don't need to perform the operation at all.
6333     This matters for operations like "mask", because the data may not be
6334     in the correct format when skipping. For example, the expression may test
6335     for the existence of $sender_host_address before trying to mask it. For
6336     other operations, doing them may not fail, but it is a waste of time. */
6337
6338     if (skipping && c >= 0) continue;
6339
6340     /* Otherwise, switch on the operator type */
6341
6342     switch(c)
6343       {
6344       case EOP_BASE32:
6345         {
6346         uschar *t;
6347         unsigned long int n = Ustrtoul(sub, &t, 10);
6348         gstring * g = NULL;
6349
6350         if (*t != 0)
6351           {
6352           expand_string_message = string_sprintf("argument for base32 "
6353             "operator is \"%s\", which is not a decimal number", sub);
6354           goto EXPAND_FAILED;
6355           }
6356         for ( ; n; n >>= 5)
6357           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6358
6359         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6360         continue;
6361         }
6362
6363       case EOP_BASE32D:
6364         {
6365         uschar *tt = sub;
6366         unsigned long int n = 0;
6367         uschar * s;
6368         while (*tt)
6369           {
6370           uschar * t = Ustrchr(base32_chars, *tt++);
6371           if (t == NULL)
6372             {
6373             expand_string_message = string_sprintf("argument for base32d "
6374               "operator is \"%s\", which is not a base 32 number", sub);
6375             goto EXPAND_FAILED;
6376             }
6377           n = n * 32 + (t - base32_chars);
6378           }
6379         s = string_sprintf("%ld", n);
6380         yield = string_cat(yield, s);
6381         continue;
6382         }
6383
6384       case EOP_BASE62:
6385         {
6386         uschar *t;
6387         unsigned long int n = Ustrtoul(sub, &t, 10);
6388         if (*t != 0)
6389           {
6390           expand_string_message = string_sprintf("argument for base62 "
6391             "operator is \"%s\", which is not a decimal number", sub);
6392           goto EXPAND_FAILED;
6393           }
6394         t = string_base62(n);
6395         yield = string_cat(yield, t);
6396         continue;
6397         }
6398
6399       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6400
6401       case EOP_BASE62D:
6402         {
6403         uschar buf[16];
6404         uschar *tt = sub;
6405         unsigned long int n = 0;
6406         while (*tt != 0)
6407           {
6408           uschar *t = Ustrchr(base62_chars, *tt++);
6409           if (t == NULL)
6410             {
6411             expand_string_message = string_sprintf("argument for base62d "
6412               "operator is \"%s\", which is not a base %d number", sub,
6413               BASE_62);
6414             goto EXPAND_FAILED;
6415             }
6416           n = n * BASE_62 + (t - base62_chars);
6417           }
6418         (void)sprintf(CS buf, "%ld", n);
6419         yield = string_cat(yield, buf);
6420         continue;
6421         }
6422
6423       case EOP_EXPAND:
6424         {
6425         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6426         if (expanded == NULL)
6427           {
6428           expand_string_message =
6429             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6430               expand_string_message);
6431           goto EXPAND_FAILED;
6432           }
6433         yield = string_cat(yield, expanded);
6434         continue;
6435         }
6436
6437       case EOP_LC:
6438         {
6439         int count = 0;
6440         uschar *t = sub - 1;
6441         while (*(++t) != 0) { *t = tolower(*t); count++; }
6442         yield = string_catn(yield, sub, count);
6443         continue;
6444         }
6445
6446       case EOP_UC:
6447         {
6448         int count = 0;
6449         uschar *t = sub - 1;
6450         while (*(++t) != 0) { *t = toupper(*t); count++; }
6451         yield = string_catn(yield, sub, count);
6452         continue;
6453         }
6454
6455       case EOP_MD5:
6456 #ifdef SUPPORT_TLS
6457         if (vp && *(void **)vp->value)
6458           {
6459           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6460           yield = string_cat(yield, cp);
6461           }
6462         else
6463 #endif
6464           {
6465           md5 base;
6466           uschar digest[16];
6467           int j;
6468           char st[33];
6469           md5_start(&base);
6470           md5_end(&base, sub, Ustrlen(sub), digest);
6471           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6472           yield = string_cat(yield, US st);
6473           }
6474         continue;
6475
6476       case EOP_SHA1:
6477 #ifdef SUPPORT_TLS
6478         if (vp && *(void **)vp->value)
6479           {
6480           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6481           yield = string_cat(yield, cp);
6482           }
6483         else
6484 #endif
6485           {
6486           hctx h;
6487           uschar digest[20];
6488           int j;
6489           char st[41];
6490           sha1_start(&h);
6491           sha1_end(&h, sub, Ustrlen(sub), digest);
6492           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6493           yield = string_catn(yield, US st, 40);
6494           }
6495         continue;
6496
6497       case EOP_SHA256:
6498 #ifdef EXIM_HAVE_SHA2
6499         if (vp && *(void **)vp->value)
6500           {
6501           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6502           yield = string_cat(yield, cp);
6503           }
6504         else
6505           {
6506           hctx h;
6507           blob b;
6508           char st[3];
6509
6510           if (!exim_sha_init(&h, HASH_SHA2_256))
6511             {
6512             expand_string_message = US"unrecognised sha256 variant";
6513             goto EXPAND_FAILED;
6514             }
6515           exim_sha_update(&h, sub, Ustrlen(sub));
6516           exim_sha_finish(&h, &b);
6517           while (b.len-- > 0)
6518             {
6519             sprintf(st, "%02X", *b.data++);
6520             yield = string_catn(yield, US st, 2);
6521             }
6522           }
6523 #else
6524           expand_string_message = US"sha256 only supported with TLS";
6525 #endif
6526         continue;
6527
6528       case EOP_SHA3:
6529 #ifdef EXIM_HAVE_SHA3
6530         {
6531         hctx h;
6532         blob b;
6533         char st[3];
6534         hashmethod m = !arg ? HASH_SHA3_256
6535           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6536           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6537           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6538           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6539           : HASH_BADTYPE;
6540
6541         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6542           {
6543           expand_string_message = US"unrecognised sha3 variant";
6544           goto EXPAND_FAILED;
6545           }
6546
6547         exim_sha_update(&h, sub, Ustrlen(sub));
6548         exim_sha_finish(&h, &b);
6549         while (b.len-- > 0)
6550           {
6551           sprintf(st, "%02X", *b.data++);
6552           yield = string_catn(yield, US st, 2);
6553           }
6554         }
6555         continue;
6556 #else
6557         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 + or OpenSSL 1.1.1 +";
6558         goto EXPAND_FAILED;
6559 #endif
6560
6561       /* Convert hex encoding to base64 encoding */
6562
6563       case EOP_HEX2B64:
6564         {
6565         int c = 0;
6566         int b = -1;
6567         uschar *in = sub;
6568         uschar *out = sub;
6569         uschar *enc;
6570
6571         for (enc = sub; *enc != 0; enc++)
6572           {
6573           if (!isxdigit(*enc))
6574             {
6575             expand_string_message = string_sprintf("\"%s\" is not a hex "
6576               "string", sub);
6577             goto EXPAND_FAILED;
6578             }
6579           c++;
6580           }
6581
6582         if ((c & 1) != 0)
6583           {
6584           expand_string_message = string_sprintf("\"%s\" contains an odd "
6585             "number of characters", sub);
6586           goto EXPAND_FAILED;
6587           }
6588
6589         while ((c = *in++) != 0)
6590           {
6591           if (isdigit(c)) c -= '0';
6592           else c = toupper(c) - 'A' + 10;
6593           if (b == -1)
6594             {
6595             b = c << 4;
6596             }
6597           else
6598             {
6599             *out++ = b | c;
6600             b = -1;
6601             }
6602           }
6603
6604         enc = b64encode(sub, out - sub);
6605         yield = string_cat(yield, enc);
6606         continue;
6607         }
6608
6609       /* Convert octets outside 0x21..0x7E to \xXX form */
6610
6611       case EOP_HEXQUOTE:
6612         {
6613         uschar *t = sub - 1;
6614         while (*(++t) != 0)
6615           {
6616           if (*t < 0x21 || 0x7E < *t)
6617             yield = string_catn(yield, string_sprintf("\\x%02x", *t), 4);
6618           else
6619             yield = string_catn(yield, t, 1);
6620           }
6621         continue;
6622         }
6623
6624       /* count the number of list elements */
6625
6626       case EOP_LISTCOUNT:
6627         {
6628         int cnt = 0;
6629         int sep = 0;
6630         uschar * cp;
6631         uschar buffer[256];
6632
6633         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6634         cp = string_sprintf("%d", cnt);
6635         yield = string_cat(yield, cp);
6636         continue;
6637         }
6638
6639       /* expand a named list given the name */
6640       /* handles nested named lists; requotes as colon-sep list */
6641
6642       case EOP_LISTNAMED:
6643         {
6644         tree_node *t = NULL;
6645         const uschar * list;
6646         int sep = 0;
6647         uschar * item;
6648         uschar * suffix = US"";
6649         BOOL needsep = FALSE;
6650         uschar buffer[256];
6651
6652         if (*sub == '+') sub++;
6653         if (arg == NULL)        /* no-argument version */
6654           {
6655           if (!(t = tree_search(addresslist_anchor, sub)) &&
6656               !(t = tree_search(domainlist_anchor,  sub)) &&
6657               !(t = tree_search(hostlist_anchor,    sub)))
6658             t = tree_search(localpartlist_anchor, sub);
6659           }
6660         else switch(*arg)       /* specific list-type version */
6661           {
6662           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6663           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6664           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6665           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6666           default:
6667             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6668             goto EXPAND_FAILED;
6669           }
6670
6671         if(!t)
6672           {
6673           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6674             sub, !arg?""
6675               : *arg=='a'?"address "
6676               : *arg=='d'?"domain "
6677               : *arg=='h'?"host "
6678               : *arg=='l'?"localpart "
6679               : 0);
6680           goto EXPAND_FAILED;
6681           }
6682
6683         list = ((namedlist_block *)(t->data.ptr))->string;
6684
6685         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
6686           {
6687           uschar * buf = US" : ";
6688           if (needsep)
6689             yield = string_catn(yield, buf, 3);
6690           else
6691             needsep = TRUE;
6692
6693           if (*item == '+')     /* list item is itself a named list */
6694             {
6695             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6696             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6697             }
6698           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6699             {
6700             char * cp;
6701             char tok[3];
6702             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6703             while ((cp= strpbrk(CCS item, tok)))
6704               {
6705               yield = string_catn(yield, item, cp - CS item);
6706               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6707                 {
6708                 yield = string_catn(yield, US"::", 2);
6709                 item = US cp;
6710                 }
6711               else              /* sep in item; should already be doubled; emit once */
6712                 {
6713                 yield = string_catn(yield, US tok, 1);
6714                 if (*cp == sep) cp++;
6715                 item = US cp;
6716                 }
6717               }
6718             }
6719           yield = string_cat(yield, item);
6720           }
6721         continue;
6722         }
6723
6724       /* mask applies a mask to an IP address; for example the result of
6725       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6726
6727       case EOP_MASK:
6728         {
6729         int count;
6730         uschar *endptr;
6731         int binary[4];
6732         int mask, maskoffset;
6733         int type = string_is_ip_address(sub, &maskoffset);
6734         uschar buffer[64];
6735
6736         if (type == 0)
6737           {
6738           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6739            sub);
6740           goto EXPAND_FAILED;
6741           }
6742
6743         if (maskoffset == 0)
6744           {
6745           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6746             sub);
6747           goto EXPAND_FAILED;
6748           }
6749
6750         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6751
6752         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6753           {
6754           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6755             sub);
6756           goto EXPAND_FAILED;
6757           }
6758
6759         /* Convert the address to binary integer(s) and apply the mask */
6760
6761         sub[maskoffset] = 0;
6762         count = host_aton(sub, binary);
6763         host_mask(count, binary, mask);
6764
6765         /* Convert to masked textual format and add to output. */
6766
6767         yield = string_catn(yield, buffer,
6768           host_nmtoa(count, binary, mask, buffer, '.'));
6769         continue;
6770         }
6771
6772       case EOP_IPV6NORM:
6773       case EOP_IPV6DENORM:
6774         {
6775         int type = string_is_ip_address(sub, NULL);
6776         int binary[4];
6777         uschar buffer[44];
6778
6779         switch (type)
6780           {
6781           case 6:
6782             (void) host_aton(sub, binary);
6783             break;
6784
6785           case 4:       /* convert to IPv4-mapped IPv6 */
6786             binary[0] = binary[1] = 0;
6787             binary[2] = 0x0000ffff;
6788             (void) host_aton(sub, binary+3);
6789             break;
6790
6791           case 0:
6792             expand_string_message =
6793               string_sprintf("\"%s\" is not an IP address", sub);
6794             goto EXPAND_FAILED;
6795           }
6796
6797         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
6798                     ? ipv6_nmtoa(binary, buffer)
6799                     : host_nmtoa(4, binary, -1, buffer, ':')
6800                   );
6801         continue;
6802         }
6803
6804       case EOP_ADDRESS:
6805       case EOP_LOCAL_PART:
6806       case EOP_DOMAIN:
6807         {
6808         uschar * error;
6809         int start, end, domain;
6810         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6811           FALSE);
6812         if (t)
6813           if (c != EOP_DOMAIN)
6814             {
6815             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6816             yield = string_catn(yield, sub+start, end-start);
6817             }
6818           else if (domain != 0)
6819             {
6820             domain += start;
6821             yield = string_catn(yield, sub+domain, end-domain);
6822             }
6823         continue;
6824         }
6825
6826       case EOP_ADDRESSES:
6827         {
6828         uschar outsep[2] = { ':', '\0' };
6829         uschar *address, *error;
6830         int save_ptr = yield->ptr;
6831         int start, end, domain;  /* Not really used */
6832
6833         while (isspace(*sub)) sub++;
6834         if (*sub == '>')
6835           if (*outsep = *++sub) ++sub;
6836           else
6837             {
6838             expand_string_message = string_sprintf("output separator "
6839               "missing in expanding ${addresses:%s}", --sub);
6840             goto EXPAND_FAILED;
6841             }
6842         parse_allow_group = TRUE;
6843
6844         for (;;)
6845           {
6846           uschar *p = parse_find_address_end(sub, FALSE);
6847           uschar saveend = *p;
6848           *p = '\0';
6849           address = parse_extract_address(sub, &error, &start, &end, &domain,
6850             FALSE);
6851           *p = saveend;
6852
6853           /* Add the address to the output list that we are building. This is
6854           done in chunks by searching for the separator character. At the
6855           start, unless we are dealing with the first address of the output
6856           list, add in a space if the new address begins with the separator
6857           character, or is an empty string. */
6858
6859           if (address != NULL)
6860             {
6861             if (yield->ptr != save_ptr && address[0] == *outsep)
6862               yield = string_catn(yield, US" ", 1);
6863
6864             for (;;)
6865               {
6866               size_t seglen = Ustrcspn(address, outsep);
6867               yield = string_catn(yield, address, seglen + 1);
6868
6869               /* If we got to the end of the string we output one character
6870               too many. */
6871
6872               if (address[seglen] == '\0') { yield->ptr--; break; }
6873               yield = string_catn(yield, outsep, 1);
6874               address += seglen + 1;
6875               }
6876
6877             /* Output a separator after the string: we will remove the
6878             redundant final one at the end. */
6879
6880             yield = string_catn(yield, outsep, 1);
6881             }
6882
6883           if (saveend == '\0') break;
6884           sub = p + 1;
6885           }
6886
6887         /* If we have generated anything, remove the redundant final
6888         separator. */
6889
6890         if (yield->ptr != save_ptr) yield->ptr--;
6891         parse_allow_group = FALSE;
6892         continue;
6893         }
6894
6895
6896       /* quote puts a string in quotes if it is empty or contains anything
6897       other than alphamerics, underscore, dot, or hyphen.
6898
6899       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6900       be quoted in order to be a valid local part.
6901
6902       In both cases, newlines and carriage returns are converted into \n and \r
6903       respectively */
6904
6905       case EOP_QUOTE:
6906       case EOP_QUOTE_LOCAL_PART:
6907       if (arg == NULL)
6908         {
6909         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6910         uschar *t = sub - 1;
6911
6912         if (c == EOP_QUOTE)
6913           {
6914           while (!needs_quote && *(++t) != 0)
6915             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6916           }
6917         else  /* EOP_QUOTE_LOCAL_PART */
6918           {
6919           while (!needs_quote && *(++t) != 0)
6920             needs_quote = !isalnum(*t) &&
6921               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6922               (*t != '.' || t == sub || t[1] == 0);
6923           }
6924
6925         if (needs_quote)
6926           {
6927           yield = string_catn(yield, US"\"", 1);
6928           t = sub - 1;
6929           while (*(++t) != 0)
6930             {
6931             if (*t == '\n')
6932               yield = string_catn(yield, US"\\n", 2);
6933             else if (*t == '\r')
6934               yield = string_catn(yield, US"\\r", 2);
6935             else
6936               {
6937               if (*t == '\\' || *t == '"')
6938                 yield = string_catn(yield, US"\\", 1);
6939               yield = string_catn(yield, t, 1);
6940               }
6941             }
6942           yield = string_catn(yield, US"\"", 1);
6943           }
6944         else yield = string_cat(yield, sub);
6945         continue;
6946         }
6947
6948       /* quote_lookuptype does lookup-specific quoting */
6949
6950       else
6951         {
6952         int n;
6953         uschar *opt = Ustrchr(arg, '_');
6954
6955         if (opt != NULL) *opt++ = 0;
6956
6957         n = search_findtype(arg, Ustrlen(arg));
6958         if (n < 0)
6959           {
6960           expand_string_message = search_error_message;
6961           goto EXPAND_FAILED;
6962           }
6963
6964         if (lookup_list[n]->quote != NULL)
6965           sub = (lookup_list[n]->quote)(sub, opt);
6966         else if (opt != NULL) sub = NULL;
6967
6968         if (sub == NULL)
6969           {
6970           expand_string_message = string_sprintf(
6971             "\"%s\" unrecognized after \"${quote_%s\"",
6972             opt, arg);
6973           goto EXPAND_FAILED;
6974           }
6975
6976         yield = string_cat(yield, sub);
6977         continue;
6978         }
6979
6980       /* rx quote sticks in \ before any non-alphameric character so that
6981       the insertion works in a regular expression. */
6982
6983       case EOP_RXQUOTE:
6984         {
6985         uschar *t = sub - 1;
6986         while (*(++t) != 0)
6987           {
6988           if (!isalnum(*t))
6989             yield = string_catn(yield, US"\\", 1);
6990           yield = string_catn(yield, t, 1);
6991           }
6992         continue;
6993         }
6994
6995       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6996       prescribed by the RFC, if there are characters that need to be encoded */
6997
6998       case EOP_RFC2047:
6999         {
7000         uschar buffer[2048];
7001         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
7002           buffer, sizeof(buffer), FALSE);
7003         yield = string_cat(yield, string);
7004         continue;
7005         }
7006
7007       /* RFC 2047 decode */
7008
7009       case EOP_RFC2047D:
7010         {
7011         int len;
7012         uschar *error;
7013         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
7014           headers_charset, '?', &len, &error);
7015         if (error != NULL)
7016           {
7017           expand_string_message = error;
7018           goto EXPAND_FAILED;
7019           }
7020         yield = string_catn(yield, decoded, len);
7021         continue;
7022         }
7023
7024       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
7025       underscores */
7026
7027       case EOP_FROM_UTF8:
7028         {
7029         while (*sub != 0)
7030           {
7031           int c;
7032           uschar buff[4];
7033           GETUTF8INC(c, sub);
7034           if (c > 255) c = '_';
7035           buff[0] = c;
7036           yield = string_catn(yield, buff, 1);
7037           }
7038         continue;
7039         }
7040
7041           /* replace illegal UTF-8 sequences by replacement character  */
7042
7043       #define UTF8_REPLACEMENT_CHAR US"?"
7044
7045       case EOP_UTF8CLEAN:
7046         {
7047         int seq_len = 0, index = 0;
7048         int bytes_left = 0;
7049         long codepoint = -1;
7050         uschar seq_buff[4];                     /* accumulate utf-8 here */
7051
7052         while (*sub != 0)
7053           {
7054           int complete = 0;
7055           uschar c = *sub++;
7056
7057           if (bytes_left)
7058             {
7059             if ((c & 0xc0) != 0x80)
7060                     /* wrong continuation byte; invalidate all bytes */
7061               complete = 1; /* error */
7062             else
7063               {
7064               codepoint = (codepoint << 6) | (c & 0x3f);
7065               seq_buff[index++] = c;
7066               if (--bytes_left == 0)            /* codepoint complete */
7067                 if(codepoint > 0x10FFFF)        /* is it too large? */
7068                   complete = -1;        /* error (RFC3629 limit) */
7069                 else
7070                   {             /* finished; output utf-8 sequence */
7071                   yield = string_catn(yield, seq_buff, seq_len);
7072                   index = 0;
7073                   }
7074               }
7075             }
7076           else  /* no bytes left: new sequence */
7077             {
7078             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7079               {
7080               yield = string_catn(yield, &c, 1);
7081               continue;
7082               }
7083             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7084               {
7085               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7086                 complete = -1;
7087               else
7088                 {
7089                   bytes_left = 1;
7090                   codepoint = c & 0x1f;
7091                 }
7092               }
7093             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7094               {
7095               bytes_left = 2;
7096               codepoint = c & 0x0f;
7097               }
7098             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7099               {
7100               bytes_left = 3;
7101               codepoint = c & 0x07;
7102               }
7103             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7104               complete = -1;
7105
7106             seq_buff[index++] = c;
7107             seq_len = bytes_left + 1;
7108             }           /* if(bytes_left) */
7109
7110           if (complete != 0)
7111             {
7112             bytes_left = index = 0;
7113             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7114             }
7115           if ((complete == 1) && ((c & 0x80) == 0))
7116                         /* ASCII character follows incomplete sequence */
7117               yield = string_catn(yield, &c, 1);
7118           }
7119         continue;
7120         }
7121
7122 #ifdef SUPPORT_I18N
7123       case EOP_UTF8_DOMAIN_TO_ALABEL:
7124         {
7125         uschar * error = NULL;
7126         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7127         if (error)
7128           {
7129           expand_string_message = string_sprintf(
7130             "error converting utf8 (%s) to alabel: %s",
7131             string_printing(sub), error);
7132           goto EXPAND_FAILED;
7133           }
7134         yield = string_cat(yield, s);
7135         continue;
7136         }
7137
7138       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7139         {
7140         uschar * error = NULL;
7141         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7142         if (error)
7143           {
7144           expand_string_message = string_sprintf(
7145             "error converting alabel (%s) to utf8: %s",
7146             string_printing(sub), error);
7147           goto EXPAND_FAILED;
7148           }
7149         yield = string_cat(yield, s);
7150         continue;
7151         }
7152
7153       case EOP_UTF8_LOCALPART_TO_ALABEL:
7154         {
7155         uschar * error = NULL;
7156         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7157         if (error)
7158           {
7159           expand_string_message = string_sprintf(
7160             "error converting utf8 (%s) to alabel: %s",
7161             string_printing(sub), error);
7162           goto EXPAND_FAILED;
7163           }
7164         yield = string_cat(yield, s);
7165         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7166         continue;
7167         }
7168
7169       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7170         {
7171         uschar * error = NULL;
7172         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7173         if (error)
7174           {
7175           expand_string_message = string_sprintf(
7176             "error converting alabel (%s) to utf8: %s",
7177             string_printing(sub), error);
7178           goto EXPAND_FAILED;
7179           }
7180         yield = string_cat(yield, s);
7181         continue;
7182         }
7183 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7184
7185       /* escape turns all non-printing characters into escape sequences. */
7186
7187       case EOP_ESCAPE:
7188         {
7189         const uschar * t = string_printing(sub);
7190         yield = string_cat(yield, t);
7191         continue;
7192         }
7193
7194       case EOP_ESCAPE8BIT:
7195         {
7196         const uschar * s = sub;
7197         uschar c;
7198
7199         for (s = sub; (c = *s); s++)
7200           yield = c < 127 && c != '\\'
7201             ? string_catn(yield, s, 1)
7202             : string_catn(yield, string_sprintf("\\%03o", c), 4);
7203         continue;
7204         }
7205
7206       /* Handle numeric expression evaluation */
7207
7208       case EOP_EVAL:
7209       case EOP_EVAL10:
7210         {
7211         uschar *save_sub = sub;
7212         uschar *error = NULL;
7213         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7214         if (error != NULL)
7215           {
7216           expand_string_message = string_sprintf("error in expression "
7217             "evaluation: %s (after processing \"%.*s\")", error,
7218             (int)(sub-save_sub), save_sub);
7219           goto EXPAND_FAILED;
7220           }
7221         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7222         yield = string_cat(yield, var_buffer);
7223         continue;
7224         }
7225
7226       /* Handle time period formating */
7227
7228       case EOP_TIME_EVAL:
7229         {
7230         int n = readconf_readtime(sub, 0, FALSE);
7231         if (n < 0)
7232           {
7233           expand_string_message = string_sprintf("string \"%s\" is not an "
7234             "Exim time interval in \"%s\" operator", sub, name);
7235           goto EXPAND_FAILED;
7236           }
7237         sprintf(CS var_buffer, "%d", n);
7238         yield = string_cat(yield, var_buffer);
7239         continue;
7240         }
7241
7242       case EOP_TIME_INTERVAL:
7243         {
7244         int n;
7245         uschar *t = read_number(&n, sub);
7246         if (*t != 0) /* Not A Number*/
7247           {
7248           expand_string_message = string_sprintf("string \"%s\" is not a "
7249             "positive number in \"%s\" operator", sub, name);
7250           goto EXPAND_FAILED;
7251           }
7252         t = readconf_printtime(n);
7253         yield = string_cat(yield, t);
7254         continue;
7255         }
7256
7257       /* Convert string to base64 encoding */
7258
7259       case EOP_STR2B64:
7260       case EOP_BASE64:
7261         {
7262 #ifdef SUPPORT_TLS
7263         uschar * s = vp && *(void **)vp->value
7264           ? tls_cert_der_b64(*(void **)vp->value)
7265           : b64encode(sub, Ustrlen(sub));
7266 #else
7267         uschar * s = b64encode(sub, Ustrlen(sub));
7268 #endif
7269         yield = string_cat(yield, s);
7270         continue;
7271         }
7272
7273       case EOP_BASE64D:
7274         {
7275         uschar * s;
7276         int len = b64decode(sub, &s);
7277         if (len < 0)
7278           {
7279           expand_string_message = string_sprintf("string \"%s\" is not "
7280             "well-formed for \"%s\" operator", sub, name);
7281           goto EXPAND_FAILED;
7282           }
7283         yield = string_cat(yield, s);
7284         continue;
7285         }
7286
7287       /* strlen returns the length of the string */
7288
7289       case EOP_STRLEN:
7290         {
7291         uschar buff[24];
7292         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7293         yield = string_cat(yield, buff);
7294         continue;
7295         }
7296
7297       /* length_n or l_n takes just the first n characters or the whole string,
7298       whichever is the shorter;
7299
7300       substr_m_n, and s_m_n take n characters from offset m; negative m take
7301       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7302       takes the rest, either to the right or to the left.
7303
7304       hash_n or h_n makes a hash of length n from the string, yielding n
7305       characters from the set a-z; hash_n_m makes a hash of length n, but
7306       uses m characters from the set a-zA-Z0-9.
7307
7308       nhash_n returns a single number between 0 and n-1 (in text form), while
7309       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7310       between 0 and n-1 and the second between 0 and m-1. */
7311
7312       case EOP_LENGTH:
7313       case EOP_L:
7314       case EOP_SUBSTR:
7315       case EOP_S:
7316       case EOP_HASH:
7317       case EOP_H:
7318       case EOP_NHASH:
7319       case EOP_NH:
7320         {
7321         int sign = 1;
7322         int value1 = 0;
7323         int value2 = -1;
7324         int *pn;
7325         int len;
7326         uschar *ret;
7327
7328         if (arg == NULL)
7329           {
7330           expand_string_message = string_sprintf("missing values after %s",
7331             name);
7332           goto EXPAND_FAILED;
7333           }
7334
7335         /* "length" has only one argument, effectively being synonymous with
7336         substr_0_n. */
7337
7338         if (c == EOP_LENGTH || c == EOP_L)
7339           {
7340           pn = &value2;
7341           value2 = 0;
7342           }
7343
7344         /* The others have one or two arguments; for "substr" the first may be
7345         negative. The second being negative means "not supplied". */
7346
7347         else
7348           {
7349           pn = &value1;
7350           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7351           }
7352
7353         /* Read up to two numbers, separated by underscores */
7354
7355         ret = arg;
7356         while (*arg != 0)
7357           {
7358           if (arg != ret && *arg == '_' && pn == &value1)
7359             {
7360             pn = &value2;
7361             value2 = 0;
7362             if (arg[1] != 0) arg++;
7363             }
7364           else if (!isdigit(*arg))
7365             {
7366             expand_string_message =
7367               string_sprintf("non-digit after underscore in \"%s\"", name);
7368             goto EXPAND_FAILED;
7369             }
7370           else *pn = (*pn)*10 + *arg++ - '0';
7371           }
7372         value1 *= sign;
7373
7374         /* Perform the required operation */
7375
7376         ret =
7377           (c == EOP_HASH || c == EOP_H)?
7378              compute_hash(sub, value1, value2, &len) :
7379           (c == EOP_NHASH || c == EOP_NH)?
7380              compute_nhash(sub, value1, value2, &len) :
7381              extract_substr(sub, value1, value2, &len);
7382
7383         if (ret == NULL) goto EXPAND_FAILED;
7384         yield = string_catn(yield, ret, len);
7385         continue;
7386         }
7387
7388       /* Stat a path */
7389
7390       case EOP_STAT:
7391         {
7392         uschar *s;
7393         uschar smode[12];
7394         uschar **modetable[3];
7395         int i;
7396         mode_t mode;
7397         struct stat st;
7398
7399         if ((expand_forbid & RDO_EXISTS) != 0)
7400           {
7401           expand_string_message = US"Use of the stat() expansion is not permitted";
7402           goto EXPAND_FAILED;
7403           }
7404
7405         if (stat(CS sub, &st) < 0)
7406           {
7407           expand_string_message = string_sprintf("stat(%s) failed: %s",
7408             sub, strerror(errno));
7409           goto EXPAND_FAILED;
7410           }
7411         mode = st.st_mode;
7412         switch (mode & S_IFMT)
7413           {
7414           case S_IFIFO: smode[0] = 'p'; break;
7415           case S_IFCHR: smode[0] = 'c'; break;
7416           case S_IFDIR: smode[0] = 'd'; break;
7417           case S_IFBLK: smode[0] = 'b'; break;
7418           case S_IFREG: smode[0] = '-'; break;
7419           default: smode[0] = '?'; break;
7420           }
7421
7422         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7423         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7424         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7425
7426         for (i = 0; i < 3; i++)
7427           {
7428           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7429           mode >>= 3;
7430           }
7431
7432         smode[10] = 0;
7433         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7434           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7435           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7436           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7437           (long)st.st_gid, st.st_size, (long)st.st_atime,
7438           (long)st.st_mtime, (long)st.st_ctime);
7439         yield = string_cat(yield, s);
7440         continue;
7441         }
7442
7443       /* vaguely random number less than N */
7444
7445       case EOP_RANDINT:
7446         {
7447         int_eximarith_t max;
7448         uschar *s;
7449
7450         max = expanded_string_integer(sub, TRUE);
7451         if (expand_string_message != NULL)
7452           goto EXPAND_FAILED;
7453         s = string_sprintf("%d", vaguely_random_number((int)max));
7454         yield = string_cat(yield, s);
7455         continue;
7456         }
7457
7458       /* Reverse IP, including IPv6 to dotted-nibble */
7459
7460       case EOP_REVERSE_IP:
7461         {
7462         int family, maskptr;
7463         uschar reversed[128];
7464
7465         family = string_is_ip_address(sub, &maskptr);
7466         if (family == 0)
7467           {
7468           expand_string_message = string_sprintf(
7469               "reverse_ip() not given an IP address [%s]", sub);
7470           goto EXPAND_FAILED;
7471           }
7472         invert_address(reversed, sub);
7473         yield = string_cat(yield, reversed);
7474         continue;
7475         }
7476
7477       /* Unknown operator */
7478
7479       default:
7480       expand_string_message =
7481         string_sprintf("unknown expansion operator \"%s\"", name);
7482       goto EXPAND_FAILED;
7483       }
7484     }
7485
7486   /* Handle a plain name. If this is the first thing in the expansion, release
7487   the pre-allocated buffer. If the result data is known to be in a new buffer,
7488   newsize will be set to the size of that buffer, and we can just point at that
7489   store instead of copying. Many expansion strings contain just one reference,
7490   so this is a useful optimization, especially for humungous headers
7491   ($message_headers). */
7492                                                 /*{*/
7493   if (*s++ == '}')
7494     {
7495     int len;
7496     int newsize = 0;
7497     gstring * g = NULL;
7498
7499     if (!yield)
7500       g = store_get(sizeof(gstring));
7501     else if (yield->ptr == 0)
7502       {
7503       if (resetok) store_reset(yield);
7504       yield = NULL;
7505       g = store_get(sizeof(gstring));   /* alloc _before_ calling find_variable() */
7506       }
7507     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7508       {
7509       expand_string_message =
7510         string_sprintf("unknown variable in \"${%s}\"", name);
7511       check_variable_error_message(name);
7512       goto EXPAND_FAILED;
7513       }
7514     len = Ustrlen(value);
7515     if (!yield && newsize)
7516       {
7517       yield = g;
7518       yield->size = newsize;
7519       yield->ptr = len;
7520       yield->s = value;
7521       }
7522     else
7523       yield = string_catn(yield, value, len);
7524     continue;
7525     }
7526
7527   /* Else there's something wrong */
7528
7529   expand_string_message =
7530     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7531     "in a variable reference)", name);
7532   goto EXPAND_FAILED;
7533   }
7534
7535 /* If we hit the end of the string when ket_ends is set, there is a missing
7536 terminating brace. */
7537
7538 if (ket_ends && *s == 0)
7539   {
7540   expand_string_message = malformed_header
7541     ? US"missing } at end of string - could be header name not terminated by colon"
7542     : US"missing } at end of string";
7543   goto EXPAND_FAILED;
7544   }
7545
7546 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7547 added to the string. If so, set up an empty string. Add a terminating zero. If
7548 left != NULL, return a pointer to the terminator. */
7549
7550 if (!yield)
7551   yield = string_get(1);
7552 (void) string_from_gstring(yield);
7553 if (left) *left = s;
7554
7555 /* Any stacking store that was used above the final string is no longer needed.
7556 In many cases the final string will be the first one that was got and so there
7557 will be optimal store usage. */
7558
7559 if (resetok) store_reset(yield->s + (yield->size = yield->ptr + 1));
7560 else if (resetok_p) *resetok_p = FALSE;
7561
7562 DEBUG(D_expand)
7563   {
7564   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7565     "expanding: %.*s\n",
7566     (int)(s - string), string);
7567   debug_printf_indent("%s"
7568     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7569     "result: %s\n",
7570     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7571     yield->s);
7572   if (skipping)
7573     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7574       "skipping: result is not used\n");
7575   }
7576 expand_level--;
7577 return yield->s;
7578
7579 /* This is the failure exit: easiest to program with a goto. We still need
7580 to update the pointer to the terminator, for cases of nested calls with "fail".
7581 */
7582
7583 EXPAND_FAILED_CURLY:
7584 if (malformed_header)
7585   expand_string_message =
7586     US"missing or misplaced { or } - could be header name not terminated by colon";
7587
7588 else if (!expand_string_message || !*expand_string_message)
7589   expand_string_message = US"missing or misplaced { or }";
7590
7591 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7592 that is a bad idea, because expand_string_message is in dynamic store. */
7593
7594 EXPAND_FAILED:
7595 if (left) *left = s;
7596 DEBUG(D_expand)
7597   {
7598   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7599     string);
7600   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7601     "error message: %s\n",
7602     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7603     expand_string_message);
7604   if (expand_string_forcedfail)
7605     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7606   }
7607 if (resetok_p && !resetok) *resetok_p = FALSE;
7608 expand_level--;
7609 return NULL;
7610 }
7611
7612
7613 /* This is the external function call. Do a quick check for any expansion
7614 metacharacters, and if there are none, just return the input string.
7615
7616 Argument: the string to be expanded
7617 Returns:  the expanded string, or NULL if expansion failed; if failure was
7618           due to a lookup deferring, search_find_defer will be TRUE
7619 */
7620
7621 const uschar *
7622 expand_cstring(const uschar * string)
7623 {
7624 if (Ustrpbrk(string, "$\\") != NULL)
7625   {
7626   int old_pool = store_pool;
7627   uschar * s;
7628
7629   search_find_defer = FALSE;
7630   malformed_header = FALSE;
7631   store_pool = POOL_MAIN;
7632     s = expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7633   store_pool = old_pool;
7634   return s;
7635   }
7636 return string;
7637 }
7638
7639
7640 uschar *
7641 expand_string(uschar * string)
7642 {
7643 return US expand_cstring(CUS string);
7644 }
7645
7646
7647
7648
7649
7650 /*************************************************
7651 *              Expand and copy                   *
7652 *************************************************/
7653
7654 /* Now and again we want to expand a string and be sure that the result is in a
7655 new bit of store. This function does that.
7656 Since we know it has been copied, the de-const cast is safe.
7657
7658 Argument: the string to be expanded
7659 Returns:  the expanded string, always in a new bit of store, or NULL
7660 */
7661
7662 uschar *
7663 expand_string_copy(const uschar *string)
7664 {
7665 const uschar *yield = expand_cstring(string);
7666 if (yield == string) yield = string_copy(string);
7667 return US yield;
7668 }
7669
7670
7671
7672 /*************************************************
7673 *        Expand and interpret as an integer      *
7674 *************************************************/
7675
7676 /* Expand a string, and convert the result into an integer.
7677
7678 Arguments:
7679   string  the string to be expanded
7680   isplus  TRUE if a non-negative number is expected
7681
7682 Returns:  the integer value, or
7683           -1 for an expansion error               ) in both cases, message in
7684           -2 for an integer interpretation error  ) expand_string_message
7685           expand_string_message is set NULL for an OK integer
7686 */
7687
7688 int_eximarith_t
7689 expand_string_integer(uschar *string, BOOL isplus)
7690 {
7691 return expanded_string_integer(expand_string(string), isplus);
7692 }
7693
7694
7695 /*************************************************
7696  *         Interpret string as an integer        *
7697  *************************************************/
7698
7699 /* Convert a string (that has already been expanded) into an integer.
7700
7701 This function is used inside the expansion code.
7702
7703 Arguments:
7704   s       the string to be expanded
7705   isplus  TRUE if a non-negative number is expected
7706
7707 Returns:  the integer value, or
7708           -1 if string is NULL (which implies an expansion error)
7709           -2 for an integer interpretation error
7710           expand_string_message is set NULL for an OK integer
7711 */
7712
7713 static int_eximarith_t
7714 expanded_string_integer(const uschar *s, BOOL isplus)
7715 {
7716 int_eximarith_t value;
7717 uschar *msg = US"invalid integer \"%s\"";
7718 uschar *endptr;
7719
7720 /* If expansion failed, expand_string_message will be set. */
7721
7722 if (s == NULL) return -1;
7723
7724 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7725 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7726 systems, so we set it zero ourselves. */
7727
7728 errno = 0;
7729 expand_string_message = NULL;               /* Indicates no error */
7730
7731 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7732 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7733 the behaviour explicitly.  Stripping leading whitespace is a harmless
7734 noop change since strtol skips it anyway (provided that there is a number
7735 to find at all). */
7736 if (isspace(*s))
7737   {
7738   while (isspace(*s)) ++s;
7739   if (*s == '\0')
7740     {
7741       DEBUG(D_expand)
7742        debug_printf_indent("treating blank string as number 0\n");
7743       return 0;
7744     }
7745   }
7746
7747 value = strtoll(CS s, CSS &endptr, 10);
7748
7749 if (endptr == s)
7750   {
7751   msg = US"integer expected but \"%s\" found";
7752   }
7753 else if (value < 0 && isplus)
7754   {
7755   msg = US"non-negative integer expected but \"%s\" found";
7756   }
7757 else
7758   {
7759   switch (tolower(*endptr))
7760     {
7761     default:
7762       break;
7763     case 'k':
7764       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7765       else value *= 1024;
7766       endptr++;
7767       break;
7768     case 'm':
7769       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7770       else value *= 1024*1024;
7771       endptr++;
7772       break;
7773     case 'g':
7774       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7775       else value *= 1024*1024*1024;
7776       endptr++;
7777       break;
7778     }
7779   if (errno == ERANGE)
7780     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7781   else
7782     {
7783     while (isspace(*endptr)) endptr++;
7784     if (*endptr == 0) return value;
7785     }
7786   }
7787
7788 expand_string_message = string_sprintf(CS msg, s);
7789 return -2;
7790 }
7791
7792
7793 /* These values are usually fixed boolean values, but they are permitted to be
7794 expanded strings.
7795
7796 Arguments:
7797   addr       address being routed
7798   mtype      the module type
7799   mname      the module name
7800   dbg_opt    debug selectors
7801   oname      the option name
7802   bvalue     the router's boolean value
7803   svalue     the router's string value
7804   rvalue     where to put the returned value
7805
7806 Returns:     OK     value placed in rvalue
7807              DEFER  expansion failed
7808 */
7809
7810 int
7811 exp_bool(address_item *addr,
7812   uschar *mtype, uschar *mname, unsigned dbg_opt,
7813   uschar *oname, BOOL bvalue,
7814   uschar *svalue, BOOL *rvalue)
7815 {
7816 uschar *expanded;
7817 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7818
7819 expanded = expand_string(svalue);
7820 if (expanded == NULL)
7821   {
7822   if (expand_string_forcedfail)
7823     {
7824     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7825     *rvalue = bvalue;
7826     return OK;
7827     }
7828   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7829       oname, mname, mtype, expand_string_message);
7830   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7831   return DEFER;
7832   }
7833
7834 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7835   expanded);
7836
7837 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7838   *rvalue = TRUE;
7839 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7840   *rvalue = FALSE;
7841 else
7842   {
7843   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7844     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7845   return DEFER;
7846   }
7847
7848 return OK;
7849 }
7850
7851
7852
7853 /* Avoid potentially exposing a password in a string about to be logged */
7854
7855 uschar *
7856 expand_hide_passwords(uschar * s)
7857 {
7858 return (  (  Ustrstr(s, "failed to expand") != NULL
7859           || Ustrstr(s, "expansion of ")    != NULL
7860           )
7861        && (  Ustrstr(s, "mysql")   != NULL
7862           || Ustrstr(s, "pgsql")   != NULL
7863           || Ustrstr(s, "redis")   != NULL
7864           || Ustrstr(s, "sqlite")  != NULL
7865           || Ustrstr(s, "ldap:")   != NULL
7866           || Ustrstr(s, "ldaps:")  != NULL
7867           || Ustrstr(s, "ldapi:")  != NULL
7868           || Ustrstr(s, "ldapdn:") != NULL
7869           || Ustrstr(s, "ldapm:")  != NULL
7870        )  )
7871   ? US"Temporary internal error" : s;
7872 }
7873
7874
7875 /* Read given named file into big_buffer.  Use for keying material etc.
7876 The content will have an ascii NUL appended.
7877
7878 Arguments:
7879  filename       as it says
7880
7881 Return:  pointer to buffer, or NULL on error.
7882 */
7883
7884 uschar *
7885 expand_file_big_buffer(const uschar * filename)
7886 {
7887 int fd, off = 0, len;
7888
7889 if ((fd = open(CS filename, O_RDONLY)) < 0)
7890   {
7891   log_write(0, LOG_MAIN | LOG_PANIC, "unable to open file for reading: %s",
7892              filename);
7893   return NULL;
7894   }
7895
7896 do
7897   {
7898   if ((len = read(fd, big_buffer + off, big_buffer_size - 2 - off)) < 0)
7899     {
7900     (void) close(fd);
7901     log_write(0, LOG_MAIN|LOG_PANIC, "unable to read file: %s", filename);
7902     return NULL;
7903     }
7904   off += len;
7905   }
7906 while (len > 0);
7907
7908 (void) close(fd);
7909 big_buffer[off] = '\0';
7910 return big_buffer;
7911 }
7912
7913
7914
7915 /*************************************************
7916 * Error-checking for testsuite                   *
7917 *************************************************/
7918 typedef struct {
7919   uschar *      region_start;
7920   uschar *      region_end;
7921   const uschar *var_name;
7922   const uschar *var_data;
7923 } err_ctx;
7924
7925 static void
7926 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7927 {
7928 err_ctx * e = ctx;
7929 if (var_data >= e->region_start  &&  var_data < e->region_end)
7930   {
7931   e->var_name = CUS var_name;
7932   e->var_data = CUS var_data;
7933   }
7934 }
7935
7936 void
7937 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7938 {
7939 err_ctx e = { .region_start = ptr, .region_end = US ptr + len,
7940               .var_name = NULL, .var_data = NULL };
7941 int i;
7942 var_entry * v;
7943
7944 /* check acl_ variables */
7945 tree_walk(acl_var_c, assert_variable_notin, &e);
7946 tree_walk(acl_var_m, assert_variable_notin, &e);
7947
7948 /* check auth<n> variables */
7949 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7950   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7951
7952 /* check regex<n> variables */
7953 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7954   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7955
7956 /* check known-name variables */
7957 for (v = var_table; v < var_table + var_table_size; v++)
7958   if (v->type == vtype_stringptr)
7959     assert_variable_notin(US v->name, *(USS v->value), &e);
7960
7961 /* check dns and address trees */
7962 tree_walk(tree_dns_fails,     assert_variable_notin, &e);
7963 tree_walk(tree_duplicates,    assert_variable_notin, &e);
7964 tree_walk(tree_nonrecipients, assert_variable_notin, &e);
7965 tree_walk(tree_unusable,      assert_variable_notin, &e);
7966
7967 if (e.var_name)
7968   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7969     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7970     e.var_name, filename, linenumber, e.var_data);
7971 }
7972
7973
7974
7975 /*************************************************
7976 **************************************************
7977 *             Stand-alone test program           *
7978 **************************************************
7979 *************************************************/
7980
7981 #ifdef STAND_ALONE
7982
7983
7984 BOOL
7985 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7986 {
7987 int ovector[3*(EXPAND_MAXN+1)];
7988 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7989   ovector, nelem(ovector));
7990 BOOL yield = n >= 0;
7991 if (n == 0) n = EXPAND_MAXN + 1;
7992 if (yield)
7993   {
7994   int nn;
7995   expand_nmax = (setup < 0)? 0 : setup + 1;
7996   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7997     {
7998     expand_nstring[expand_nmax] = subject + ovector[nn];
7999     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
8000     }
8001   expand_nmax--;
8002   }
8003 return yield;
8004 }
8005
8006
8007 int main(int argc, uschar **argv)
8008 {
8009 int i;
8010 uschar buffer[1024];
8011
8012 debug_selector = D_v;
8013 debug_file = stderr;
8014 debug_fd = fileno(debug_file);
8015 big_buffer = malloc(big_buffer_size);
8016
8017 for (i = 1; i < argc; i++)
8018   {
8019   if (argv[i][0] == '+')
8020     {
8021     debug_trace_memory = 2;
8022     argv[i]++;
8023     }
8024   if (isdigit(argv[i][0]))
8025     debug_selector = Ustrtol(argv[i], NULL, 0);
8026   else
8027     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
8028         Ustrlen(argv[i]))
8029       {
8030 #ifdef LOOKUP_LDAP
8031       eldap_default_servers = argv[i];
8032 #endif
8033 #ifdef LOOKUP_MYSQL
8034       mysql_servers = argv[i];
8035 #endif
8036 #ifdef LOOKUP_PGSQL
8037       pgsql_servers = argv[i];
8038 #endif
8039 #ifdef LOOKUP_REDIS
8040       redis_servers = argv[i];
8041 #endif
8042       }
8043 #ifdef EXIM_PERL
8044   else opt_perl_startup = argv[i];
8045 #endif
8046   }
8047
8048 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
8049
8050 expand_nstring[1] = US"string 1....";
8051 expand_nlength[1] = 8;
8052 expand_nmax = 1;
8053
8054 #ifdef EXIM_PERL
8055 if (opt_perl_startup != NULL)
8056   {
8057   uschar *errstr;
8058   printf("Starting Perl interpreter\n");
8059   errstr = init_perl(opt_perl_startup);
8060   if (errstr != NULL)
8061     {
8062     printf("** error in perl_startup code: %s\n", errstr);
8063     return EXIT_FAILURE;
8064     }
8065   }
8066 #endif /* EXIM_PERL */
8067
8068 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
8069   {
8070   void *reset_point = store_get(0);
8071   uschar *yield = expand_string(buffer);
8072   if (yield != NULL)
8073     {
8074     printf("%s\n", yield);
8075     store_reset(reset_point);
8076     }
8077   else
8078     {
8079     if (search_find_defer) printf("search_find deferred\n");
8080     printf("Failed: %s\n", expand_string_message);
8081     if (expand_string_forcedfail) printf("Forced failure\n");
8082     printf("\n");
8083     }
8084   }
8085
8086 search_tidyup();
8087
8088 return 0;
8089 }
8090
8091 #endif
8092
8093 /* vi: aw ai sw=2
8094 */
8095 /* End of expand.c */