src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  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"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base32",
 203   US"base32d",
 204   US"base62",
 205   US"base62d",
 206   US"base64",
 207   US"base64d",
 208   US"domain",
 209   US"escape",
 210   US"escape8bit",
 211   US"eval",
 212   US"eval10",
 213   US"expand",
 214   US"h",
 215   US"hash",
 216   US"hex2b64",
 217   US"hexquote",
 218   US"ipv6denorm",
 219   US"ipv6norm",
 220   US"l",
 221   US"lc",
 222   US"length",
 223   US"listcount",
 224   US"listnamed",
 225   US"mask",
 226   US"md5",
 227   US"nh",
 228   US"nhash",
 229   US"quote",
 230   US"randint",
 231   US"rfc2047",
 232   US"rfc2047d",
 233   US"rxquote",
 234   US"s",
 235   US"sha1",
 236   US"sha256",
 237   US"sha3",
 238   US"stat",
 239   US"str2b64",
 240   US"strlen",
 241   US"substr",
 242   US"uc",
 243   US"utf8clean" };
 244
 245 enum {
 246   EOP_ADDRESS =  nelem(op_table_underscore),
 247   EOP_ADDRESSES,
 248   EOP_BASE32,
 249   EOP_BASE32D,
 250   EOP_BASE62,
 251   EOP_BASE62D,
 252   EOP_BASE64,
 253   EOP_BASE64D,
 254   EOP_DOMAIN,
 255   EOP_ESCAPE,
 256   EOP_ESCAPE8BIT,
 257   EOP_EVAL,
 258   EOP_EVAL10,
 259   EOP_EXPAND,
 260   EOP_H,
 261   EOP_HASH,
 262   EOP_HEX2B64,
 263   EOP_HEXQUOTE,
 264   EOP_IPV6DENORM,
 265   EOP_IPV6NORM,
 266   EOP_L,
 267   EOP_LC,
 268   EOP_LENGTH,
 269   EOP_LISTCOUNT,
 270   EOP_LISTNAMED,
 271   EOP_MASK,
 272   EOP_MD5,
 273   EOP_NH,
 274   EOP_NHASH,
 275   EOP_QUOTE,
 276   EOP_RANDINT,
 277   EOP_RFC2047,
 278   EOP_RFC2047D,
 279   EOP_RXQUOTE,
 280   EOP_S,
 281   EOP_SHA1,
 282   EOP_SHA256,
 283   EOP_SHA3,
 284   EOP_STAT,
 285   EOP_STR2B64,
 286   EOP_STRLEN,
 287   EOP_SUBSTR,
 288   EOP_UC,
 289   EOP_UTF8CLEAN };
 290
 291
 292 /* Table of condition names, and corresponding switch numbers. The names must
 293 be in alphabetical order. */
 294
 295 static uschar *cond_table[] = {
 296   US"<",
 297   US"<=",
 298   US"=",
 299   US"==",     /* Backward compatibility */
 300   US">",
 301   US">=",
 302   US"acl",
 303   US"and",
 304   US"bool",
 305   US"bool_lax",
 306   US"crypteq",
 307   US"def",
 308   US"eq",
 309   US"eqi",
 310   US"exists",
 311   US"first_delivery",
 312   US"forall",
 313   US"forany",
 314   US"ge",
 315   US"gei",
 316   US"gt",
 317   US"gti",
 318   US"inlist",
 319   US"inlisti",
 320   US"isip",
 321   US"isip4",
 322   US"isip6",
 323   US"ldapauth",
 324   US"le",
 325   US"lei",
 326   US"lt",
 327   US"lti",
 328   US"match",
 329   US"match_address",
 330   US"match_domain",
 331   US"match_ip",
 332   US"match_local_part",
 333   US"or",
 334   US"pam",
 335   US"pwcheck",
 336   US"queue_running",
 337   US"radius",
 338   US"saslauthd"
 339 };
 340
 341 enum {
 342   ECOND_NUM_L,
 343   ECOND_NUM_LE,
 344   ECOND_NUM_E,
 345   ECOND_NUM_EE,
 346   ECOND_NUM_G,
 347   ECOND_NUM_GE,
 348   ECOND_ACL,
 349   ECOND_AND,
 350   ECOND_BOOL,
 351   ECOND_BOOL_LAX,
 352   ECOND_CRYPTEQ,
 353   ECOND_DEF,
 354   ECOND_STR_EQ,
 355   ECOND_STR_EQI,
 356   ECOND_EXISTS,
 357   ECOND_FIRST_DELIVERY,
 358   ECOND_FORALL,
 359   ECOND_FORANY,
 360   ECOND_STR_GE,
 361   ECOND_STR_GEI,
 362   ECOND_STR_GT,
 363   ECOND_STR_GTI,
 364   ECOND_INLIST,
 365   ECOND_INLISTI,
 366   ECOND_ISIP,
 367   ECOND_ISIP4,
 368   ECOND_ISIP6,
 369   ECOND_LDAPAUTH,
 370   ECOND_STR_LE,
 371   ECOND_STR_LEI,
 372   ECOND_STR_LT,
 373   ECOND_STR_LTI,
 374   ECOND_MATCH,
 375   ECOND_MATCH_ADDRESS,
 376   ECOND_MATCH_DOMAIN,
 377   ECOND_MATCH_IP,
 378   ECOND_MATCH_LOCAL_PART,
 379   ECOND_OR,
 380   ECOND_PAM,
 381   ECOND_PWCHECK,
 382   ECOND_QUEUE_RUNNING,
 383   ECOND_RADIUS,
 384   ECOND_SASLAUTHD
 385 };
 386
 387
 388 /* Types of table entry */
 389
 390 enum vtypes {
 391   vtype_int,            /* value is address of int */
 392   vtype_filter_int,     /* ditto, but recognized only when filtering */
 393   vtype_ino,            /* value is address of ino_t (not always an int) */
 394   vtype_uid,            /* value is address of uid_t (not always an int) */
 395   vtype_gid,            /* value is address of gid_t (not always an int) */
 396   vtype_bool,           /* value is address of bool */
 397   vtype_stringptr,      /* value is address of pointer to string */
 398   vtype_msgbody,        /* as stringptr, but read when first required */
 399   vtype_msgbody_end,    /* ditto, the end of the message */
 400   vtype_msgheaders,     /* the message's headers, processed */
 401   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 402   vtype_localpart,      /* extract local part from string */
 403   vtype_domain,         /* extract domain from string */
 404   vtype_string_func,    /* value is string returned by given function */
 405   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 406   vtype_tode,           /* value not used; generate tod in epoch format */
 407   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 408   vtype_todf,           /* value not used; generate full tod */
 409   vtype_todl,           /* value not used; generate log tod */
 410   vtype_todlf,          /* value not used; generate log file datestamp tod */
 411   vtype_todzone,        /* value not used; generate time zone only */
 412   vtype_todzulu,        /* value not used; generate zulu tod */
 413   vtype_reply,          /* value not used; get reply from headers */
 414   vtype_pid,            /* value not used; result is pid */
 415   vtype_host_lookup,    /* value not used; get host name */
 416   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 417   vtype_pspace,         /* partition space; value is T/F for spool/log */
 418   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 419   vtype_cert            /* SSL certificate */
 420   #ifndef DISABLE_DKIM
 421   ,vtype_dkim           /* Lookup of value in DKIM signature */
 422   #endif
 423 };
 424
 425 /* Type for main variable table */
 426
 427 typedef struct {
 428   const char *name;
 429   enum vtypes type;
 430   void       *value;
 431 } var_entry;
 432
 433 /* Type for entries pointing to address/length pairs. Not currently
 434 in use. */
 435
 436 typedef struct {
 437   uschar **address;
 438   int  *length;
 439 } alblock;
 440
 441 static uschar * fn_recipients(void);
 442
 443 /* This table must be kept in alphabetical order. */
 444
 445 static var_entry var_table[] = {
 446   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 447      they will be confused with user-creatable ACL variables. */
 448   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 449   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 450   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 451   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 452   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 453   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 454   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 455   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 456   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 457   { "acl_narg",            vtype_int,         &acl_narg },
 458   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 459   { "address_data",        vtype_stringptr,   &deliver_address_data },
 460   { "address_file",        vtype_stringptr,   &address_file },
 461   { "address_pipe",        vtype_stringptr,   &address_pipe },
 462   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 463   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 464   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 465   { "authentication_failed",vtype_int,        &authentication_failed },
 466 #ifdef WITH_CONTENT_SCAN
 467   { "av_failed",           vtype_int,         &av_failed },
 468 #endif
 469 #ifdef EXPERIMENTAL_BRIGHTMAIL
 470   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 471   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 472   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 473   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 474 #endif
 475   { "body_linecount",      vtype_int,         &body_linecount },
 476   { "body_zerocount",      vtype_int,         &body_zerocount },
 477   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 478   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 479   { "caller_gid",          vtype_gid,         &real_gid },
 480   { "caller_uid",          vtype_uid,         &real_uid },
 481   { "callout_address",     vtype_stringptr,   &callout_address },
 482   { "compile_date",        vtype_stringptr,   &version_date },
 483   { "compile_number",      vtype_stringptr,   &version_cnumber },
 484   { "config_dir",          vtype_stringptr,   &config_main_directory },
 485   { "config_file",         vtype_stringptr,   &config_main_filename },
 486   { "csa_status",          vtype_stringptr,   &csa_status },
 487 #ifdef EXPERIMENTAL_DCC
 488   { "dcc_header",          vtype_stringptr,   &dcc_header },
 489   { "dcc_result",          vtype_stringptr,   &dcc_result },
 490 #endif
 491 #ifndef DISABLE_DKIM
 492   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 493   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 494   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 495   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 496   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 497   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 498   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 499   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 500   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 501   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 502   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 503   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 504   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 505   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 506   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 507   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 508   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 509   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 510   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 511   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 512   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 513 #endif
 514 #ifdef EXPERIMENTAL_DMARC
 515   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 516   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 517   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 518   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 519   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 520 #endif
 521   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 522   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 523   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 524   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 525   { "domain",              vtype_stringptr,   &deliver_domain },
 526   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 527 #ifndef DISABLE_EVENT
 528   { "event_data",          vtype_stringptr,   &event_data },
 529
 530   /*XXX want to use generic vars for as many of these as possible*/
 531   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 532
 533   { "event_name",          vtype_stringptr,   &event_name },
 534 #endif
 535   { "exim_gid",            vtype_gid,         &exim_gid },
 536   { "exim_path",           vtype_stringptr,   &exim_path },
 537   { "exim_uid",            vtype_uid,         &exim_uid },
 538   { "exim_version",        vtype_stringptr,   &version_string },
 539   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 540   { "home",                vtype_stringptr,   &deliver_home },
 541   { "host",                vtype_stringptr,   &deliver_host },
 542   { "host_address",        vtype_stringptr,   &deliver_host_address },
 543   { "host_data",           vtype_stringptr,   &host_data },
 544   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 545   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 546   { "host_port",           vtype_int,         &deliver_host_port },
 547   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 548   { "inode",               vtype_ino,         &deliver_inode },
 549   { "interface_address",   vtype_stringptr,   &interface_address },
 550   { "interface_port",      vtype_int,         &interface_port },
 551   { "item",                vtype_stringptr,   &iterate_item },
 552   #ifdef LOOKUP_LDAP
 553   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 554   #endif
 555   { "load_average",        vtype_load_avg,    NULL },
 556   { "local_part",          vtype_stringptr,   &deliver_localpart },
 557   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 558   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 559   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 560   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 561   { "local_user_gid",      vtype_gid,         &local_user_gid },
 562   { "local_user_uid",      vtype_uid,         &local_user_uid },
 563   { "localhost_number",    vtype_int,         &host_number },
 564   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 565   { "log_space",           vtype_pspace,      (void *)FALSE },
 566   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 567   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 568 #ifdef WITH_CONTENT_SCAN
 569   { "malware_name",        vtype_stringptr,   &malware_name },
 570 #endif
 571   { "max_received_linelength", vtype_int,     &max_received_linelength },
 572   { "message_age",         vtype_int,         &message_age },
 573   { "message_body",        vtype_msgbody,     &message_body },
 574   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 575   { "message_body_size",   vtype_int,         &message_body_size },
 576   { "message_exim_id",     vtype_stringptr,   &message_id },
 577   { "message_headers",     vtype_msgheaders,  NULL },
 578   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 579   { "message_id",          vtype_stringptr,   &message_id },
 580   { "message_linecount",   vtype_int,         &message_linecount },
 581   { "message_size",        vtype_int,         &message_size },
 582 #ifdef SUPPORT_I18N
 583   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 584 #endif
 585 #ifdef WITH_CONTENT_SCAN
 586   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 587   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 588   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 589   { "mime_charset",        vtype_stringptr,   &mime_charset },
 590   { "mime_content_description", vtype_stringptr, &mime_content_description },
 591   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 592   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 593   { "mime_content_size",   vtype_int,         &mime_content_size },
 594   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 595   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 596   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 597   { "mime_filename",       vtype_stringptr,   &mime_filename },
 598   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 599   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 600   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 601   { "mime_part_count",     vtype_int,         &mime_part_count },
 602 #endif
 603   { "n0",                  vtype_filter_int,  &filter_n[0] },
 604   { "n1",                  vtype_filter_int,  &filter_n[1] },
 605   { "n2",                  vtype_filter_int,  &filter_n[2] },
 606   { "n3",                  vtype_filter_int,  &filter_n[3] },
 607   { "n4",                  vtype_filter_int,  &filter_n[4] },
 608   { "n5",                  vtype_filter_int,  &filter_n[5] },
 609   { "n6",                  vtype_filter_int,  &filter_n[6] },
 610   { "n7",                  vtype_filter_int,  &filter_n[7] },
 611   { "n8",                  vtype_filter_int,  &filter_n[8] },
 612   { "n9",                  vtype_filter_int,  &filter_n[9] },
 613   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 614   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 615   { "originator_gid",      vtype_gid,         &originator_gid },
 616   { "originator_uid",      vtype_uid,         &originator_uid },
 617   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 618   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 619   { "pid",                 vtype_pid,         NULL },
 620 #ifndef DISABLE_PRDR
 621   { "prdr_requested",      vtype_bool,        &prdr_requested },
 622 #endif
 623   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 624 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 625   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 626   { "proxy_external_port", vtype_int,         &proxy_external_port },
 627   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 628   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 629   { "proxy_session",       vtype_bool,        &proxy_session },
 630 #endif
 631   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 632   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 633   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 634   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 635   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 636   { "queue_name",          vtype_stringptr,   &queue_name },
 637   { "rcpt_count",          vtype_int,         &rcpt_count },
 638   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 639   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 640   { "received_count",      vtype_int,         &received_count },
 641   { "received_for",        vtype_stringptr,   &received_for },
 642   { "received_ip_address", vtype_stringptr,   &interface_address },
 643   { "received_port",       vtype_int,         &interface_port },
 644   { "received_protocol",   vtype_stringptr,   &received_protocol },
 645   { "received_time",       vtype_int,         &received_time.tv_sec },
 646   { "recipient_data",      vtype_stringptr,   &recipient_data },
 647   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 648   { "recipients",          vtype_string_func, &fn_recipients },
 649   { "recipients_count",    vtype_int,         &recipients_count },
 650 #ifdef WITH_CONTENT_SCAN
 651   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 652 #endif
 653   { "reply_address",       vtype_reply,       NULL },
 654   { "return_path",         vtype_stringptr,   &return_path },
 655   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 656   { "router_name",         vtype_stringptr,   &router_name },
 657   { "runrc",               vtype_int,         &runrc },
 658   { "self_hostname",       vtype_stringptr,   &self_hostname },
 659   { "sender_address",      vtype_stringptr,   &sender_address },
 660   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 661   { "sender_address_domain", vtype_domain,    &sender_address },
 662   { "sender_address_local_part", vtype_localpart, &sender_address },
 663   { "sender_data",         vtype_stringptr,   &sender_data },
 664   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 665   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 666   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 667   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 668   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 669   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 670   { "sender_host_name",    vtype_host_lookup, NULL },
 671   { "sender_host_port",    vtype_int,         &sender_host_port },
 672   { "sender_ident",        vtype_stringptr,   &sender_ident },
 673   { "sender_rate",         vtype_stringptr,   &sender_rate },
 674   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 675   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 676   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 677   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 678   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 679   { "sending_port",        vtype_int,         &sending_port },
 680   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 681   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 682   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 683   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 684   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 685   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 686   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 687   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 688   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 689   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 690   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 691   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 692   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 693   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 694   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 695   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 696 #ifdef WITH_CONTENT_SCAN
 697   { "spam_action",         vtype_stringptr,   &spam_action },
 698   { "spam_bar",            vtype_stringptr,   &spam_bar },
 699   { "spam_report",         vtype_stringptr,   &spam_report },
 700   { "spam_score",          vtype_stringptr,   &spam_score },
 701   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 702 #endif
 703 #ifdef EXPERIMENTAL_SPF
 704   { "spf_guess",           vtype_stringptr,   &spf_guess },
 705   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 706   { "spf_received",        vtype_stringptr,   &spf_received },
 707   { "spf_result",          vtype_stringptr,   &spf_result },
 708   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 709 #endif
 710   { "spool_directory",     vtype_stringptr,   &spool_directory },
 711   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 712   { "spool_space",         vtype_pspace,      (void *)TRUE },
 713 #ifdef EXPERIMENTAL_SRS
 714   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 715   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 716   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 717   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 718   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 719   { "srs_status",          vtype_stringptr,   &srs_status },
 720 #endif
 721   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 722
 723   /* The non-(in,out) variables are now deprecated */
 724   { "tls_bits",            vtype_int,         &tls_in.bits },
 725   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 726   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 727
 728   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 729   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 730   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 731   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 732   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 733   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 734   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 735 #if defined(SUPPORT_TLS)
 736   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 737 #endif
 738   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 739   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 740   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 741 #ifdef EXPERIMENTAL_DANE
 742   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 743 #endif
 744   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 745   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 746   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 747   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 748 #if defined(SUPPORT_TLS)
 749   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 750 #endif
 751 #ifdef EXPERIMENTAL_DANE
 752   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 753 #endif
 754
 755   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 756 #if defined(SUPPORT_TLS)
 757   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 758 #endif
 759
 760   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 761   { "tod_epoch",           vtype_tode,        NULL },
 762   { "tod_epoch_l",         vtype_todel,       NULL },
 763   { "tod_full",            vtype_todf,        NULL },
 764   { "tod_log",             vtype_todl,        NULL },
 765   { "tod_logfile",         vtype_todlf,       NULL },
 766   { "tod_zone",            vtype_todzone,     NULL },
 767   { "tod_zulu",            vtype_todzulu,     NULL },
 768   { "transport_name",      vtype_stringptr,   &transport_name },
 769   { "value",               vtype_stringptr,   &lookup_value },
 770   { "verify_mode",         vtype_stringptr,   &verify_mode },
 771   { "version_number",      vtype_stringptr,   &version_string },
 772   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 773   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 774   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 775   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 776   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 777   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 778 };
 779
 780 static int var_table_size = nelem(var_table);
 781 static uschar var_buffer[256];
 782 static BOOL malformed_header;
 783
 784 /* For textual hashes */
 785
 786 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 787                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 788                                "0123456789";
 789
 790 enum { HMAC_MD5, HMAC_SHA1 };
 791
 792 /* For numeric hashes */
 793
 794 static unsigned int prime[] = {
 795   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 796  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 797  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 798
 799 /* For printing modes in symbolic form */
 800
 801 static uschar *mtable_normal[] =
 802   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 803
 804 static uschar *mtable_setid[] =
 805   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 806
 807 static uschar *mtable_sticky[] =
 808   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 809
 810
 811
 812 /*************************************************
 813 *           Tables for UTF-8 support             *
 814 *************************************************/
 815
 816 /* Table of the number of extra characters, indexed by the first character
 817 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 818 0x3d. */
 819
 820 static uschar utf8_table1[] = {
 821   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 822   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 823   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 824   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 825
 826 /* These are the masks for the data bits in the first byte of a character,
 827 indexed by the number of additional bytes. */
 828
 829 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 830
 831 /* Get the next UTF-8 character, advancing the pointer. */
 832
 833 #define GETUTF8INC(c, ptr) \
 834   c = *ptr++; \
 835   if ((c & 0xc0) == 0xc0) \
 836     { \
 837     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 838     int s = 6*a; \
 839     c = (c & utf8_table2[a]) << s; \
 840     while (a-- > 0) \
 841       { \
 842       s -= 6; \
 843       c |= (*ptr++ & 0x3f) << s; \
 844       } \
 845     }
 846
 847
 848
 849 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 850
 851 /*************************************************
 852 *           Binary chop search on a table        *
 853 *************************************************/
 854
 855 /* This is used for matching expansion items and operators.
 856
 857 Arguments:
 858   name        the name that is being sought
 859   table       the table to search
 860   table_size  the number of items in the table
 861
 862 Returns:      the offset in the table, or -1
 863 */
 864
 865 static int
 866 chop_match(uschar *name, uschar **table, int table_size)
 867 {
 868 uschar **bot = table;
 869 uschar **top = table + table_size;
 870
 871 while (top > bot)
 872   {
 873   uschar **mid = bot + (top - bot)/2;
 874   int c = Ustrcmp(name, *mid);
 875   if (c == 0) return mid - table;
 876   if (c > 0) bot = mid + 1; else top = mid;
 877   }
 878
 879 return -1;
 880 }
 881
 882
 883
 884 /*************************************************
 885 *          Check a condition string              *
 886 *************************************************/
 887
 888 /* This function is called to expand a string, and test the result for a "true"
 889 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 890 forced fail or lookup defer.
 891
 892 We used to release all store used, but this is not not safe due
 893 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 894 is reasonably careful to release what it can.
 895
 896 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 897
 898 Arguments:
 899   condition     the condition string
 900   m1            text to be incorporated in panic error
 901   m2            ditto
 902
 903 Returns:        TRUE if condition is met, FALSE if not
 904 */
 905
 906 BOOL
 907 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 908 {
 909 int rc;
 910 uschar *ss = expand_string(condition);
 911 if (ss == NULL)
 912   {
 913   if (!expand_string_forcedfail && !search_find_defer)
 914     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 915       "for %s %s: %s", condition, m1, m2, expand_string_message);
 916   return FALSE;
 917   }
 918 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 919   strcmpic(ss, US"false") != 0;
 920 return rc;
 921 }
 922
 923
 924
 925
 926 /*************************************************
 927 *        Pseudo-random number generation         *
 928 *************************************************/
 929
 930 /* Pseudo-random number generation.  The result is not "expected" to be
 931 cryptographically strong but not so weak that someone will shoot themselves
 932 in the foot using it as a nonce in some email header scheme or whatever
 933 weirdness they'll twist this into.  The result should ideally handle fork().
 934
 935 However, if we're stuck unable to provide this, then we'll fall back to
 936 appallingly bad randomness.
 937
 938 If SUPPORT_TLS is defined then this will not be used except as an emergency
 939 fallback.
 940
 941 Arguments:
 942   max       range maximum
 943 Returns     a random number in range [0, max-1]
 944 */
 945
 946 #ifdef SUPPORT_TLS
 947 # define vaguely_random_number vaguely_random_number_fallback
 948 #endif
 949 int
 950 vaguely_random_number(int max)
 951 {
 952 #ifdef SUPPORT_TLS
 953 # undef vaguely_random_number
 954 #endif
 955   static pid_t pid = 0;
 956   pid_t p2;
 957 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 958   struct timeval tv;
 959 #endif
 960
 961   p2 = getpid();
 962   if (p2 != pid)
 963     {
 964     if (pid != 0)
 965       {
 966
 967 #ifdef HAVE_ARC4RANDOM
 968       /* cryptographically strong randomness, common on *BSD platforms, not
 969       so much elsewhere.  Alas. */
 970 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 971       arc4random_stir();
 972 #endif
 973 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 974 #ifdef HAVE_SRANDOMDEV
 975       /* uses random(4) for seeding */
 976       srandomdev();
 977 #else
 978       gettimeofday(&tv, NULL);
 979       srandom(tv.tv_sec | tv.tv_usec | getpid());
 980 #endif
 981 #else
 982       /* Poor randomness and no seeding here */
 983 #endif
 984
 985       }
 986     pid = p2;
 987     }
 988
 989 #ifdef HAVE_ARC4RANDOM
 990   return arc4random() % max;
 991 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 992   return random() % max;
 993 #else
 994   /* This one returns a 16-bit number, definitely not crypto-strong */
 995   return random_number(max);
 996 #endif
 997 }
 998
 999
1000
1001
1002 /*************************************************
1003 *             Pick out a name from a string      *
1004 *************************************************/
1005
1006 /* If the name is too long, it is silently truncated.
1007
1008 Arguments:
1009   name      points to a buffer into which to put the name
1010   max       is the length of the buffer
1011   s         points to the first alphabetic character of the name
1012   extras    chars other than alphanumerics to permit
1013
1014 Returns:    pointer to the first character after the name
1015
1016 Note: The test for *s != 0 in the while loop is necessary because
1017 Ustrchr() yields non-NULL if the character is zero (which is not something
1018 I expected). */
1019
1020 static const uschar *
1021 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1022 {
1023 int ptr = 0;
1024 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1025   {
1026   if (ptr < max-1) name[ptr++] = *s;
1027   s++;
1028   }
1029 name[ptr] = 0;
1030 return s;
1031 }
1032
1033
1034
1035 /*************************************************
1036 *     Pick out the rest of a header name         *
1037 *************************************************/
1038
1039 /* A variable name starting $header_ (or just $h_ for those who like
1040 abbreviations) might not be the complete header name because headers can
1041 contain any printing characters in their names, except ':'. This function is
1042 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1043 on the end, if the name was terminated by white space.
1044
1045 Arguments:
1046   name      points to a buffer in which the name read so far exists
1047   max       is the length of the buffer
1048   s         points to the first character after the name so far, i.e. the
1049             first non-alphameric character after $header_xxxxx
1050
1051 Returns:    a pointer to the first character after the header name
1052 */
1053
1054 static const uschar *
1055 read_header_name(uschar *name, int max, const uschar *s)
1056 {
1057 int prelen = Ustrchr(name, '_') - name + 1;
1058 int ptr = Ustrlen(name) - prelen;
1059 if (ptr > 0) memmove(name, name+prelen, ptr);
1060 while (mac_isgraph(*s) && *s != ':')
1061   {
1062   if (ptr < max-1) name[ptr++] = *s;
1063   s++;
1064   }
1065 if (*s == ':') s++;
1066 name[ptr++] = ':';
1067 name[ptr] = 0;
1068 return s;
1069 }
1070
1071
1072
1073 /*************************************************
1074 *           Pick out a number from a string      *
1075 *************************************************/
1076
1077 /* Arguments:
1078   n     points to an integer into which to put the number
1079   s     points to the first digit of the number
1080
1081 Returns:  a pointer to the character after the last digit
1082 */
1083 /*XXX consider expanding to int_eximarith_t.  But the test for
1084 "overbig numbers" in 0002 still needs to overflow it. */
1085
1086 static uschar *
1087 read_number(int *n, uschar *s)
1088 {
1089 *n = 0;
1090 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1091 return s;
1092 }
1093
1094 static const uschar *
1095 read_cnumber(int *n, const uschar *s)
1096 {
1097 *n = 0;
1098 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1099 return s;
1100 }
1101
1102
1103
1104 /*************************************************
1105 *        Extract keyed subfield from a string    *
1106 *************************************************/
1107
1108 /* The yield is in dynamic store; NULL means that the key was not found.
1109
1110 Arguments:
1111   key       points to the name of the key
1112   s         points to the string from which to extract the subfield
1113
1114 Returns:    NULL if the subfield was not found, or
1115             a pointer to the subfield's data
1116 */
1117
1118 static uschar *
1119 expand_getkeyed(uschar *key, const uschar *s)
1120 {
1121 int length = Ustrlen(key);
1122 while (isspace(*s)) s++;
1123
1124 /* Loop to search for the key */
1125
1126 while (*s != 0)
1127   {
1128   int dkeylength;
1129   uschar *data;
1130   const uschar *dkey = s;
1131
1132   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1133   dkeylength = s - dkey;
1134   while (isspace(*s)) s++;
1135   if (*s == '=') while (isspace((*(++s))));
1136
1137   data = string_dequote(&s);
1138   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1139     return data;
1140
1141   while (isspace(*s)) s++;
1142   }
1143
1144 return NULL;
1145 }
1146
1147
1148
1149 static var_entry *
1150 find_var_ent(uschar * name)
1151 {
1152 int first = 0;
1153 int last = var_table_size;
1154
1155 while (last > first)
1156   {
1157   int middle = (first + last)/2;
1158   int c = Ustrcmp(name, var_table[middle].name);
1159
1160   if (c > 0) { first = middle + 1; continue; }
1161   if (c < 0) { last = middle; continue; }
1162   return &var_table[middle];
1163   }
1164 return NULL;
1165 }
1166
1167 /*************************************************
1168 *   Extract numbered subfield from string        *
1169 *************************************************/
1170
1171 /* Extracts a numbered field from a string that is divided by tokens - for
1172 example a line from /etc/passwd is divided by colon characters.  First field is
1173 numbered one.  Negative arguments count from the right. Zero returns the whole
1174 string. Returns NULL if there are insufficient tokens in the string
1175
1176 ***WARNING***
1177 Modifies final argument - this is a dynamically generated string, so that's OK.
1178
1179 Arguments:
1180   field       number of field to be extracted,
1181                 first field = 1, whole string = 0, last field = -1
1182   separators  characters that are used to break string into tokens
1183   s           points to the string from which to extract the subfield
1184
1185 Returns:      NULL if the field was not found,
1186               a pointer to the field's data inside s (modified to add 0)
1187 */
1188
1189 static uschar *
1190 expand_gettokened (int field, uschar *separators, uschar *s)
1191 {
1192 int sep = 1;
1193 int count;
1194 uschar *ss = s;
1195 uschar *fieldtext = NULL;
1196
1197 if (field == 0) return s;
1198
1199 /* Break the line up into fields in place; for field > 0 we stop when we have
1200 done the number of fields we want. For field < 0 we continue till the end of
1201 the string, counting the number of fields. */
1202
1203 count = (field > 0)? field : INT_MAX;
1204
1205 while (count-- > 0)
1206   {
1207   size_t len;
1208
1209   /* Previous field was the last one in the string. For a positive field
1210   number, this means there are not enough fields. For a negative field number,
1211   check that there are enough, and scan back to find the one that is wanted. */
1212
1213   if (sep == 0)
1214     {
1215     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1216     if ((-field) == (INT_MAX - count - 1)) return s;
1217     while (field++ < 0)
1218       {
1219       ss--;
1220       while (ss[-1] != 0) ss--;
1221       }
1222     fieldtext = ss;
1223     break;
1224     }
1225
1226   /* Previous field was not last in the string; save its start and put a
1227   zero at its end. */
1228
1229   fieldtext = ss;
1230   len = Ustrcspn(ss, separators);
1231   sep = ss[len];
1232   ss[len] = 0;
1233   ss += len + 1;
1234   }
1235
1236 return fieldtext;
1237 }
1238
1239
1240 static uschar *
1241 expand_getlistele(int field, const uschar * list)
1242 {
1243 const uschar * tlist= list;
1244 int sep= 0;
1245 uschar dummy;
1246
1247 if(field<0)
1248   {
1249   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1250   sep= 0;
1251   }
1252 if(field==0) return NULL;
1253 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1254 return string_nextinlist(&list, &sep, NULL, 0);
1255 }
1256
1257
1258 /* Certificate fields, by name.  Worry about by-OID later */
1259 /* Names are chosen to not have common prefixes */
1260
1261 #ifdef SUPPORT_TLS
1262 typedef struct
1263 {
1264 uschar * name;
1265 int      namelen;
1266 uschar * (*getfn)(void * cert, uschar * mod);
1267 } certfield;
1268 static certfield certfields[] =
1269 {                       /* linear search; no special order */
1270   { US"version",         7,  &tls_cert_version },
1271   { US"serial_number",   13, &tls_cert_serial_number },
1272   { US"subject",         7,  &tls_cert_subject },
1273   { US"notbefore",       9,  &tls_cert_not_before },
1274   { US"notafter",        8,  &tls_cert_not_after },
1275   { US"issuer",          6,  &tls_cert_issuer },
1276   { US"signature",       9,  &tls_cert_signature },
1277   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1278   { US"subj_altname",    12, &tls_cert_subject_altname },
1279   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1280   { US"crl_uri",         7,  &tls_cert_crl_uri },
1281 };
1282
1283 static uschar *
1284 expand_getcertele(uschar * field, uschar * certvar)
1285 {
1286 var_entry * vp;
1287 certfield * cp;
1288
1289 if (!(vp = find_var_ent(certvar)))
1290   {
1291   expand_string_message =
1292     string_sprintf("no variable named \"%s\"", certvar);
1293   return NULL;          /* Unknown variable name */
1294   }
1295 /* NB this stops us passing certs around in variable.  Might
1296 want to do that in future */
1297 if (vp->type != vtype_cert)
1298   {
1299   expand_string_message =
1300     string_sprintf("\"%s\" is not a certificate", certvar);
1301   return NULL;          /* Unknown variable name */
1302   }
1303 if (!*(void **)vp->value)
1304   return NULL;
1305
1306 if (*field >= '0' && *field <= '9')
1307   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1308
1309 for(cp = certfields;
1310     cp < certfields + nelem(certfields);
1311     cp++)
1312   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1313     {
1314     uschar * modifier = *(field += cp->namelen) == ','
1315       ? ++field : NULL;
1316     return (*cp->getfn)( *(void **)vp->value, modifier );
1317     }
1318
1319 expand_string_message =
1320   string_sprintf("bad field selector \"%s\" for certextract", field);
1321 return NULL;
1322 }
1323 #endif  /*SUPPORT_TLS*/
1324
1325 /*************************************************
1326 *        Extract a substring from a string       *
1327 *************************************************/
1328
1329 /* Perform the ${substr or ${length expansion operations.
1330
1331 Arguments:
1332   subject     the input string
1333   value1      the offset from the start of the input string to the start of
1334                 the output string; if negative, count from the right.
1335   value2      the length of the output string, or negative (-1) for unset
1336                 if value1 is positive, unset means "all after"
1337                 if value1 is negative, unset means "all before"
1338   len         set to the length of the returned string
1339
1340 Returns:      pointer to the output string, or NULL if there is an error
1341 */
1342
1343 static uschar *
1344 extract_substr(uschar *subject, int value1, int value2, int *len)
1345 {
1346 int sublen = Ustrlen(subject);
1347
1348 if (value1 < 0)    /* count from right */
1349   {
1350   value1 += sublen;
1351
1352   /* If the position is before the start, skip to the start, and adjust the
1353   length. If the length ends up negative, the substring is null because nothing
1354   can precede. This falls out naturally when the length is unset, meaning "all
1355   to the left". */
1356
1357   if (value1 < 0)
1358     {
1359     value2 += value1;
1360     if (value2 < 0) value2 = 0;
1361     value1 = 0;
1362     }
1363
1364   /* Otherwise an unset length => characters before value1 */
1365
1366   else if (value2 < 0)
1367     {
1368     value2 = value1;
1369     value1 = 0;
1370     }
1371   }
1372
1373 /* For a non-negative offset, if the starting position is past the end of the
1374 string, the result will be the null string. Otherwise, an unset length means
1375 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1376
1377 else
1378   {
1379   if (value1 > sublen)
1380     {
1381     value1 = sublen;
1382     value2 = 0;
1383     }
1384   else if (value2 < 0) value2 = sublen;
1385   }
1386
1387 /* Cut the length down to the maximum possible for the offset value, and get
1388 the required characters. */
1389
1390 if (value1 + value2 > sublen) value2 = sublen - value1;
1391 *len = value2;
1392 return subject + value1;
1393 }
1394
1395
1396
1397
1398 /*************************************************
1399 *            Old-style hash of a string          *
1400 *************************************************/
1401
1402 /* Perform the ${hash expansion operation.
1403
1404 Arguments:
1405   subject     the input string (an expanded substring)
1406   value1      the length of the output string; if greater or equal to the
1407                 length of the input string, the input string is returned
1408   value2      the number of hash characters to use, or 26 if negative
1409   len         set to the length of the returned string
1410
1411 Returns:      pointer to the output string, or NULL if there is an error
1412 */
1413
1414 static uschar *
1415 compute_hash(uschar *subject, int value1, int value2, int *len)
1416 {
1417 int sublen = Ustrlen(subject);
1418
1419 if (value2 < 0) value2 = 26;
1420 else if (value2 > Ustrlen(hashcodes))
1421   {
1422   expand_string_message =
1423     string_sprintf("hash count \"%d\" too big", value2);
1424   return NULL;
1425   }
1426
1427 /* Calculate the hash text. We know it is shorter than the original string, so
1428 can safely place it in subject[] (we know that subject is always itself an
1429 expanded substring). */
1430
1431 if (value1 < sublen)
1432   {
1433   int c;
1434   int i = 0;
1435   int j = value1;
1436   while ((c = (subject[j])) != 0)
1437     {
1438     int shift = (c + j++) & 7;
1439     subject[i] ^= (c << shift) | (c >> (8-shift));
1440     if (++i >= value1) i = 0;
1441     }
1442   for (i = 0; i < value1; i++)
1443     subject[i] = hashcodes[(subject[i]) % value2];
1444   }
1445 else value1 = sublen;
1446
1447 *len = value1;
1448 return subject;
1449 }
1450
1451
1452
1453
1454 /*************************************************
1455 *             Numeric hash of a string           *
1456 *************************************************/
1457
1458 /* Perform the ${nhash expansion operation. The first characters of the
1459 string are treated as most important, and get the highest prime numbers.
1460
1461 Arguments:
1462   subject     the input string
1463   value1      the maximum value of the first part of the result
1464   value2      the maximum value of the second part of the result,
1465                 or negative to produce only a one-part result
1466   len         set to the length of the returned string
1467
1468 Returns:  pointer to the output string, or NULL if there is an error.
1469 */
1470
1471 static uschar *
1472 compute_nhash (uschar *subject, int value1, int value2, int *len)
1473 {
1474 uschar *s = subject;
1475 int i = 0;
1476 unsigned long int total = 0; /* no overflow */
1477
1478 while (*s != 0)
1479   {
1480   if (i == 0) i = nelem(prime) - 1;
1481   total += prime[i--] * (unsigned int)(*s++);
1482   }
1483
1484 /* If value2 is unset, just compute one number */
1485
1486 if (value2 < 0)
1487   s = string_sprintf("%d", total % value1);
1488
1489 /* Otherwise do a div/mod hash */
1490
1491 else
1492   {
1493   total = total % (value1 * value2);
1494   s = string_sprintf("%d/%d", total/value2, total % value2);
1495   }
1496
1497 *len = Ustrlen(s);
1498 return s;
1499 }
1500
1501
1502
1503
1504
1505 /*************************************************
1506 *     Find the value of a header or headers      *
1507 *************************************************/
1508
1509 /* Multiple instances of the same header get concatenated, and this function
1510 can also return a concatenation of all the header lines. When concatenating
1511 specific headers that contain lists of addresses, a comma is inserted between
1512 them. Otherwise we use a straight concatenation. Because some messages can have
1513 pathologically large number of lines, there is a limit on the length that is
1514 returned. Also, to avoid massive store use which would result from using
1515 string_cat() as it copies and extends strings, we do a preliminary pass to find
1516 out exactly how much store will be needed. On "normal" messages this will be
1517 pretty trivial.
1518
1519 Arguments:
1520   name          the name of the header, without the leading $header_ or $h_,
1521                 or NULL if a concatenation of all headers is required
1522   exists_only   TRUE if called from a def: test; don't need to build a string;
1523                 just return a string that is not "" and not "0" if the header
1524                 exists
1525   newsize       return the size of memory block that was obtained; may be NULL
1526                 if exists_only is TRUE
1527   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1528                 other than concatenating, will be done on the header. Also used
1529                 for $message_headers_raw.
1530   charset       name of charset to translate MIME words to; used only if
1531                 want_raw is false; if NULL, no translation is done (this is
1532                 used for $bh_ and $bheader_)
1533
1534 Returns:        NULL if the header does not exist, else a pointer to a new
1535                 store block
1536 */
1537
1538 static uschar *
1539 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1540   uschar *charset)
1541 {
1542 BOOL found = name == NULL;
1543 int comma = 0;
1544 int len = found? 0 : Ustrlen(name);
1545 int i;
1546 uschar *yield = NULL;
1547 uschar *ptr = NULL;
1548
1549 /* Loop for two passes - saves code repetition */
1550
1551 for (i = 0; i < 2; i++)
1552   {
1553   int size = 0;
1554   header_line *h;
1555
1556   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1557     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1558       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1559         {
1560         int ilen;
1561         uschar *t;
1562
1563         if (exists_only) return US"1";      /* don't need actual string */
1564         found = TRUE;
1565         t = h->text + len;                  /* text to insert */
1566         if (!want_raw)                      /* unless wanted raw, */
1567           while (isspace(*t)) t++;          /* remove leading white space */
1568         ilen = h->slen - (t - h->text);     /* length to insert */
1569
1570         /* Unless wanted raw, remove trailing whitespace, including the
1571         newline. */
1572
1573         if (!want_raw)
1574           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1575
1576         /* Set comma = 1 if handling a single header and it's one of those
1577         that contains an address list, except when asked for raw headers. Only
1578         need to do this once. */
1579
1580         if (!want_raw && name && comma == 0 &&
1581             Ustrchr("BCFRST", h->type) != NULL)
1582           comma = 1;
1583
1584         /* First pass - compute total store needed; second pass - compute
1585         total store used, including this header. */
1586
1587         size += ilen + comma + 1;  /* +1 for the newline */
1588
1589         /* Second pass - concatenate the data, up to a maximum. Note that
1590         the loop stops when size hits the limit. */
1591
1592         if (i != 0)
1593           {
1594           if (size > header_insert_maxlen)
1595             {
1596             ilen -= size - header_insert_maxlen - 1;
1597             comma = 0;
1598             }
1599           Ustrncpy(ptr, t, ilen);
1600           ptr += ilen;
1601
1602           /* For a non-raw header, put in the comma if needed, then add
1603           back the newline we removed above, provided there was some text in
1604           the header. */
1605
1606           if (!want_raw && ilen > 0)
1607             {
1608             if (comma != 0) *ptr++ = ',';
1609             *ptr++ = '\n';
1610             }
1611           }
1612         }
1613
1614   /* At end of first pass, return NULL if no header found. Then truncate size
1615   if necessary, and get the buffer to hold the data, returning the buffer size.
1616   */
1617
1618   if (i == 0)
1619     {
1620     if (!found) return NULL;
1621     if (size > header_insert_maxlen) size = header_insert_maxlen;
1622     *newsize = size + 1;
1623     ptr = yield = store_get(*newsize);
1624     }
1625   }
1626
1627 /* That's all we do for raw header expansion. */
1628
1629 if (want_raw)
1630   *ptr = 0;
1631
1632 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1633 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1634 function can return an error with decoded data if the charset translation
1635 fails. If decoding fails, it returns NULL. */
1636
1637 else
1638   {
1639   uschar *decoded, *error;
1640   if (ptr > yield && ptr[-1] == '\n') ptr--;
1641   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1642   *ptr = 0;
1643   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1644     newsize, &error);
1645   if (error != NULL)
1646     {
1647     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1648       "    input was: %s\n", error, yield);
1649     }
1650   if (decoded != NULL) yield = decoded;
1651   }
1652
1653 return yield;
1654 }
1655
1656
1657
1658
1659 /*************************************************
1660 *               Return list of recipients        *
1661 *************************************************/
1662 /* A recipients list is available only during system message filtering,
1663 during ACL processing after DATA, and while expanding pipe commands
1664 generated from a system filter, but not elsewhere. */
1665
1666 static uschar *
1667 fn_recipients(void)
1668 {
1669 gstring * g = NULL;
1670 int i;
1671
1672 if (!enable_dollar_recipients) return NULL;
1673
1674 for (i = 0; i < recipients_count; i++)
1675   {
1676   /*XXX variant of list_appendele? */
1677   if (i != 0) g = string_catn(g, US", ", 2);
1678   g = string_cat(g, recipients_list[i].address);
1679   }
1680 return string_from_gstring(g);
1681 }
1682
1683
1684 /*************************************************
1685 *               Find value of a variable         *
1686 *************************************************/
1687
1688 /* The table of variables is kept in alphabetic order, so we can search it
1689 using a binary chop. The "choplen" variable is nothing to do with the binary
1690 chop.
1691
1692 Arguments:
1693   name          the name of the variable being sought
1694   exists_only   TRUE if this is a def: test; passed on to find_header()
1695   skipping      TRUE => skip any processing evaluation; this is not the same as
1696                   exists_only because def: may test for values that are first
1697                   evaluated here
1698   newsize       pointer to an int which is initially zero; if the answer is in
1699                 a new memory buffer, *newsize is set to its size
1700
1701 Returns:        NULL if the variable does not exist, or
1702                 a pointer to the variable's contents, or
1703                 something non-NULL if exists_only is TRUE
1704 */
1705
1706 static uschar *
1707 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1708 {
1709 var_entry * vp;
1710 uschar *s, *domain;
1711 uschar **ss;
1712 void * val;
1713
1714 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1715 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1716 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1717 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1718 (this gave backwards compatibility at the changeover). There may be built-in
1719 variables whose names start acl_ but they should never start in this way. This
1720 slightly messy specification is a consequence of the history, needless to say.
1721
1722 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1723 set, in which case give an error. */
1724
1725 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1726      !isalpha(name[5]))
1727   {
1728   tree_node *node =
1729     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1730   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1731   }
1732
1733 /* Handle $auth<n> variables. */
1734
1735 if (Ustrncmp(name, "auth", 4) == 0)
1736   {
1737   uschar *endptr;
1738   int n = Ustrtoul(name + 4, &endptr, 10);
1739   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1740     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1741   }
1742 else if (Ustrncmp(name, "regex", 5) == 0)
1743   {
1744   uschar *endptr;
1745   int n = Ustrtoul(name + 5, &endptr, 10);
1746   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1747     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1748   }
1749
1750 /* For all other variables, search the table */
1751
1752 if (!(vp = find_var_ent(name)))
1753   return NULL;          /* Unknown variable name */
1754
1755 /* Found an existing variable. If in skipping state, the value isn't needed,
1756 and we want to avoid processing (such as looking up the host name). */
1757
1758 if (skipping)
1759   return US"";
1760
1761 val = vp->value;
1762 switch (vp->type)
1763   {
1764   case vtype_filter_int:
1765     if (!filter_running) return NULL;
1766     /* Fall through */
1767     /* VVVVVVVVVVVV */
1768   case vtype_int:
1769     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1770     return var_buffer;
1771
1772   case vtype_ino:
1773     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1774     return var_buffer;
1775
1776   case vtype_gid:
1777     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1778     return var_buffer;
1779
1780   case vtype_uid:
1781     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1782     return var_buffer;
1783
1784   case vtype_bool:
1785     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1786     return var_buffer;
1787
1788   case vtype_stringptr:                      /* Pointer to string */
1789     return (s = *((uschar **)(val))) ? s : US"";
1790
1791   case vtype_pid:
1792     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1793     return var_buffer;
1794
1795   case vtype_load_avg:
1796     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1797     return var_buffer;
1798
1799   case vtype_host_lookup:                    /* Lookup if not done so */
1800     if (sender_host_name == NULL && sender_host_address != NULL &&
1801         !host_lookup_failed && host_name_lookup() == OK)
1802       host_build_sender_fullhost();
1803     return (sender_host_name == NULL)? US"" : sender_host_name;
1804
1805   case vtype_localpart:                      /* Get local part from address */
1806     s = *((uschar **)(val));
1807     if (s == NULL) return US"";
1808     domain = Ustrrchr(s, '@');
1809     if (domain == NULL) return s;
1810     if (domain - s > sizeof(var_buffer) - 1)
1811       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1812           " in string expansion", sizeof(var_buffer));
1813     Ustrncpy(var_buffer, s, domain - s);
1814     var_buffer[domain - s] = 0;
1815     return var_buffer;
1816
1817   case vtype_domain:                         /* Get domain from address */
1818     s = *((uschar **)(val));
1819     if (s == NULL) return US"";
1820     domain = Ustrrchr(s, '@');
1821     return (domain == NULL)? US"" : domain + 1;
1822
1823   case vtype_msgheaders:
1824     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1825
1826   case vtype_msgheaders_raw:
1827     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1828
1829   case vtype_msgbody:                        /* Pointer to msgbody string */
1830   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1831     ss = (uschar **)(val);
1832     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1833       {
1834       uschar *body;
1835       off_t start_offset = SPOOL_DATA_START_OFFSET;
1836       int len = message_body_visible;
1837       if (len > message_size) len = message_size;
1838       *ss = body = store_malloc(len+1);
1839       body[0] = 0;
1840       if (vp->type == vtype_msgbody_end)
1841         {
1842         struct stat statbuf;
1843         if (fstat(deliver_datafile, &statbuf) == 0)
1844           {
1845           start_offset = statbuf.st_size - len;
1846           if (start_offset < SPOOL_DATA_START_OFFSET)
1847             start_offset = SPOOL_DATA_START_OFFSET;
1848           }
1849         }
1850       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1851         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1852           strerror(errno));
1853       len = read(deliver_datafile, body, len);
1854       if (len > 0)
1855         {
1856         body[len] = 0;
1857         if (message_body_newlines)   /* Separate loops for efficiency */
1858           while (len > 0)
1859             { if (body[--len] == 0) body[len] = ' '; }
1860         else
1861           while (len > 0)
1862             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1863         }
1864       }
1865     return *ss ? *ss : US"";
1866
1867   case vtype_todbsdin:                       /* BSD inbox time of day */
1868     return tod_stamp(tod_bsdin);
1869
1870   case vtype_tode:                           /* Unix epoch time of day */
1871     return tod_stamp(tod_epoch);
1872
1873   case vtype_todel:                          /* Unix epoch/usec time of day */
1874     return tod_stamp(tod_epoch_l);
1875
1876   case vtype_todf:                           /* Full time of day */
1877     return tod_stamp(tod_full);
1878
1879   case vtype_todl:                           /* Log format time of day */
1880     return tod_stamp(tod_log_bare);            /* (without timezone) */
1881
1882   case vtype_todzone:                        /* Time zone offset only */
1883     return tod_stamp(tod_zone);
1884
1885   case vtype_todzulu:                        /* Zulu time */
1886     return tod_stamp(tod_zulu);
1887
1888   case vtype_todlf:                          /* Log file datestamp tod */
1889     return tod_stamp(tod_log_datestamp_daily);
1890
1891   case vtype_reply:                          /* Get reply address */
1892     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1893       headers_charset);
1894     if (s != NULL) while (isspace(*s)) s++;
1895     if (s == NULL || *s == 0)
1896       {
1897       *newsize = 0;                            /* For the *s==0 case */
1898       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1899       }
1900     if (s != NULL)
1901       {
1902       uschar *t;
1903       while (isspace(*s)) s++;
1904       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1905       while (t > s && isspace(t[-1])) t--;
1906       *t = 0;
1907       }
1908     return (s == NULL)? US"" : s;
1909
1910   case vtype_string_func:
1911     {
1912     uschar * (*fn)() = val;
1913     return fn();
1914     }
1915
1916   case vtype_pspace:
1917     {
1918     int inodes;
1919     sprintf(CS var_buffer, "%d",
1920       receive_statvfs(val == (void *)TRUE, &inodes));
1921     }
1922   return var_buffer;
1923
1924   case vtype_pinodes:
1925     {
1926     int inodes;
1927     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1928     sprintf(CS var_buffer, "%d", inodes);
1929     }
1930   return var_buffer;
1931
1932   case vtype_cert:
1933     return *(void **)val ? US"<cert>" : US"";
1934
1935 #ifndef DISABLE_DKIM
1936   case vtype_dkim:
1937     return dkim_exim_expand_query((int)(long)val);
1938 #endif
1939
1940   }
1941
1942 return NULL;  /* Unknown variable. Silences static checkers. */
1943 }
1944
1945
1946
1947
1948 void
1949 modify_variable(uschar *name, void * value)
1950 {
1951 var_entry * vp;
1952 if ((vp = find_var_ent(name))) vp->value = value;
1953 return;          /* Unknown variable name, fail silently */
1954 }
1955
1956
1957
1958
1959
1960
1961 /*************************************************
1962 *           Read and expand substrings           *
1963 *************************************************/
1964
1965 /* This function is called to read and expand argument substrings for various
1966 expansion items. Some have a minimum requirement that is less than the maximum;
1967 in these cases, the first non-present one is set to NULL.
1968
1969 Arguments:
1970   sub        points to vector of pointers to set
1971   n          maximum number of substrings
1972   m          minimum required
1973   sptr       points to current string pointer
1974   skipping   the skipping flag
1975   check_end  if TRUE, check for final '}'
1976   name       name of item, for error message
1977   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1978              the store.
1979
1980 Returns:     0 OK; string pointer updated
1981              1 curly bracketing error (too few arguments)
1982              2 too many arguments (only if check_end is set); message set
1983              3 other error (expansion failure)
1984 */
1985
1986 static int
1987 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1988   BOOL check_end, uschar *name, BOOL *resetok)
1989 {
1990 int i;
1991 const uschar *s = *sptr;
1992
1993 while (isspace(*s)) s++;
1994 for (i = 0; i < n; i++)
1995   {
1996   if (*s != '{')
1997     {
1998     if (i < m)
1999       {
2000       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2001         "(min is %d)", name, m);
2002       return 1;
2003       }
2004     sub[i] = NULL;
2005     break;
2006     }
2007   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2008     return 3;
2009   if (*s++ != '}') return 1;
2010   while (isspace(*s)) s++;
2011   }
2012 if (check_end && *s++ != '}')
2013   {
2014   if (s[-1] == '{')
2015     {
2016     expand_string_message = string_sprintf("Too many arguments for '%s' "
2017       "(max is %d)", name, n);
2018     return 2;
2019     }
2020   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2021   return 1;
2022   }
2023
2024 *sptr = s;
2025 return 0;
2026 }
2027
2028
2029
2030
2031 /*************************************************
2032 *     Elaborate message for bad variable         *
2033 *************************************************/
2034
2035 /* For the "unknown variable" message, take a look at the variable's name, and
2036 give additional information about possible ACL variables. The extra information
2037 is added on to expand_string_message.
2038
2039 Argument:   the name of the variable
2040 Returns:    nothing
2041 */
2042
2043 static void
2044 check_variable_error_message(uschar *name)
2045 {
2046 if (Ustrncmp(name, "acl_", 4) == 0)
2047   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2048     (name[4] == 'c' || name[4] == 'm')?
2049       (isalpha(name[5])?
2050         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2051         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2052       ) :
2053       US"user-defined ACL variables must start acl_c or acl_m");
2054 }
2055
2056
2057
2058 /*
2059 Load args from sub array to globals, and call acl_check().
2060 Sub array will be corrupted on return.
2061
2062 Returns:       OK         access is granted by an ACCEPT verb
2063                DISCARD    access is (apparently) granted by a DISCARD verb
2064                FAIL       access is denied
2065                FAIL_DROP  access is denied; drop the connection
2066                DEFER      can't tell at the moment
2067                ERROR      disaster
2068 */
2069 static int
2070 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2071 {
2072 int i;
2073 int sav_narg = acl_narg;
2074 int ret;
2075 uschar * dummy_logmsg;
2076 extern int acl_where;
2077
2078 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2079 for (i = 0; i < nsub && sub[i+1]; i++)
2080   {
2081   uschar * tmp = acl_arg[i];
2082   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2083   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2084   }
2085 acl_narg = i;
2086 while (i < nsub)
2087   {
2088   sub[i+1] = acl_arg[i];
2089   acl_arg[i++] = NULL;
2090   }
2091
2092 DEBUG(D_expand)
2093   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2094     sub[0],
2095     acl_narg>0 ? acl_arg[0] : US"<none>",
2096     acl_narg>1 ? " +more"   : "");
2097
2098 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2099
2100 for (i = 0; i < nsub; i++)
2101   acl_arg[i] = sub[i+1];        /* restore old args */
2102 acl_narg = sav_narg;
2103
2104 return ret;
2105 }
2106
2107
2108
2109
2110 /*************************************************
2111 *        Read and evaluate a condition           *
2112 *************************************************/
2113
2114 /*
2115 Arguments:
2116   s        points to the start of the condition text
2117   resetok  points to a BOOL which is written false if it is unsafe to
2118            free memory. Certain condition types (acl) may have side-effect
2119            allocation which must be preserved.
2120   yield    points to a BOOL to hold the result of the condition test;
2121            if NULL, we are just reading through a condition that is
2122            part of an "or" combination to check syntax, or in a state
2123            where the answer isn't required
2124
2125 Returns:   a pointer to the first character after the condition, or
2126            NULL after an error
2127 */
2128
2129 static const uschar *
2130 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2131 {
2132 BOOL testfor = TRUE;
2133 BOOL tempcond, combined_cond;
2134 BOOL *subcondptr;
2135 BOOL sub2_honour_dollar = TRUE;
2136 int i, rc, cond_type, roffset;
2137 int_eximarith_t num[2];
2138 struct stat statbuf;
2139 uschar name[256];
2140 const uschar *sub[10];
2141
2142 const pcre *re;
2143 const uschar *rerror;
2144
2145 for (;;)
2146   {
2147   while (isspace(*s)) s++;
2148   if (*s == '!') { testfor = !testfor; s++; } else break;
2149   }
2150
2151 /* Numeric comparisons are symbolic */
2152
2153 if (*s == '=' || *s == '>' || *s == '<')
2154   {
2155   int p = 0;
2156   name[p++] = *s++;
2157   if (*s == '=')
2158     {
2159     name[p++] = '=';
2160     s++;
2161     }
2162   name[p] = 0;
2163   }
2164
2165 /* All other conditions are named */
2166
2167 else s = read_name(name, 256, s, US"_");
2168
2169 /* If we haven't read a name, it means some non-alpha character is first. */
2170
2171 if (name[0] == 0)
2172   {
2173   expand_string_message = string_sprintf("condition name expected, "
2174     "but found \"%.16s\"", s);
2175   return NULL;
2176   }
2177
2178 /* Find which condition we are dealing with, and switch on it */
2179
2180 cond_type = chop_match(name, cond_table, nelem(cond_table));
2181 switch(cond_type)
2182   {
2183   /* def: tests for a non-empty variable, or for the existence of a header. If
2184   yield == NULL we are in a skipping state, and don't care about the answer. */
2185
2186   case ECOND_DEF:
2187   if (*s != ':')
2188     {
2189     expand_string_message = US"\":\" expected after \"def\"";
2190     return NULL;
2191     }
2192
2193   s = read_name(name, 256, s+1, US"_");
2194
2195   /* Test for a header's existence. If the name contains a closing brace
2196   character, this may be a user error where the terminating colon has been
2197   omitted. Set a flag to adjust a subsequent error message in this case. */
2198
2199   if (Ustrncmp(name, "h_", 2) == 0 ||
2200       Ustrncmp(name, "rh_", 3) == 0 ||
2201       Ustrncmp(name, "bh_", 3) == 0 ||
2202       Ustrncmp(name, "header_", 7) == 0 ||
2203       Ustrncmp(name, "rheader_", 8) == 0 ||
2204       Ustrncmp(name, "bheader_", 8) == 0)
2205     {
2206     s = read_header_name(name, 256, s);
2207     /* {-for-text-editors */
2208     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2209     if (yield != NULL) *yield =
2210       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2211     }
2212
2213   /* Test for a variable's having a non-empty value. A non-existent variable
2214   causes an expansion failure. */
2215
2216   else
2217     {
2218     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2219     if (value == NULL)
2220       {
2221       expand_string_message = (name[0] == 0)?
2222         string_sprintf("variable name omitted after \"def:\"") :
2223         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2224       check_variable_error_message(name);
2225       return NULL;
2226       }
2227     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2228     }
2229
2230   return s;
2231
2232
2233   /* first_delivery tests for first delivery attempt */
2234
2235   case ECOND_FIRST_DELIVERY:
2236   if (yield != NULL) *yield = deliver_firsttime == testfor;
2237   return s;
2238
2239
2240   /* queue_running tests for any process started by a queue runner */
2241
2242   case ECOND_QUEUE_RUNNING:
2243   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2244   return s;
2245
2246
2247   /* exists:  tests for file existence
2248        isip:  tests for any IP address
2249       isip4:  tests for an IPv4 address
2250       isip6:  tests for an IPv6 address
2251         pam:  does PAM authentication
2252      radius:  does RADIUS authentication
2253    ldapauth:  does LDAP authentication
2254     pwcheck:  does Cyrus SASL pwcheck authentication
2255   */
2256
2257   case ECOND_EXISTS:
2258   case ECOND_ISIP:
2259   case ECOND_ISIP4:
2260   case ECOND_ISIP6:
2261   case ECOND_PAM:
2262   case ECOND_RADIUS:
2263   case ECOND_LDAPAUTH:
2264   case ECOND_PWCHECK:
2265
2266   while (isspace(*s)) s++;
2267   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2268
2269   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2270   if (sub[0] == NULL) return NULL;
2271   /* {-for-text-editors */
2272   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2273
2274   if (yield == NULL) return s;   /* No need to run the test if skipping */
2275
2276   switch(cond_type)
2277     {
2278     case ECOND_EXISTS:
2279     if ((expand_forbid & RDO_EXISTS) != 0)
2280       {
2281       expand_string_message = US"File existence tests are not permitted";
2282       return NULL;
2283       }
2284     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2285     break;
2286
2287     case ECOND_ISIP:
2288     case ECOND_ISIP4:
2289     case ECOND_ISIP6:
2290     rc = string_is_ip_address(sub[0], NULL);
2291     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2292              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2293     break;
2294
2295     /* Various authentication tests - all optionally compiled */
2296
2297     case ECOND_PAM:
2298     #ifdef SUPPORT_PAM
2299     rc = auth_call_pam(sub[0], &expand_string_message);
2300     goto END_AUTH;
2301     #else
2302     goto COND_FAILED_NOT_COMPILED;
2303     #endif  /* SUPPORT_PAM */
2304
2305     case ECOND_RADIUS:
2306     #ifdef RADIUS_CONFIG_FILE
2307     rc = auth_call_radius(sub[0], &expand_string_message);
2308     goto END_AUTH;
2309     #else
2310     goto COND_FAILED_NOT_COMPILED;
2311     #endif  /* RADIUS_CONFIG_FILE */
2312
2313     case ECOND_LDAPAUTH:
2314     #ifdef LOOKUP_LDAP
2315       {
2316       /* Just to keep the interface the same */
2317       BOOL do_cache;
2318       int old_pool = store_pool;
2319       store_pool = POOL_SEARCH;
2320       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2321         &expand_string_message, &do_cache);
2322       store_pool = old_pool;
2323       }
2324     goto END_AUTH;
2325     #else
2326     goto COND_FAILED_NOT_COMPILED;
2327     #endif  /* LOOKUP_LDAP */
2328
2329     case ECOND_PWCHECK:
2330     #ifdef CYRUS_PWCHECK_SOCKET
2331     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2332     goto END_AUTH;
2333     #else
2334     goto COND_FAILED_NOT_COMPILED;
2335     #endif  /* CYRUS_PWCHECK_SOCKET */
2336
2337     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2338         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2339     END_AUTH:
2340     if (rc == ERROR || rc == DEFER) return NULL;
2341     *yield = (rc == OK) == testfor;
2342     #endif
2343     }
2344   return s;
2345
2346
2347   /* call ACL (in a conditional context).  Accept true, deny false.
2348   Defer is a forced-fail.  Anything set by message= goes to $value.
2349   Up to ten parameters are used; we use the braces round the name+args
2350   like the saslauthd condition does, to permit a variable number of args.
2351   See also the expansion-item version EITEM_ACL and the traditional
2352   acl modifier ACLC_ACL.
2353   Since the ACL may allocate new global variables, tell our caller to not
2354   reclaim memory.
2355   */
2356
2357   case ECOND_ACL:
2358     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2359     {
2360     uschar *sub[10];
2361     uschar *user_msg;
2362     BOOL cond = FALSE;
2363
2364     while (isspace(*s)) s++;
2365     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2366
2367     switch(read_subs(sub, nelem(sub), 1,
2368       &s, yield == NULL, TRUE, US"acl", resetok))
2369       {
2370       case 1: expand_string_message = US"too few arguments or bracketing "
2371         "error for acl";
2372       case 2:
2373       case 3: return NULL;
2374       }
2375
2376     if (yield != NULL)
2377       {
2378       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2379       switch(eval_acl(sub, nelem(sub), &user_msg))
2380         {
2381         case OK:
2382           cond = TRUE;
2383         case FAIL:
2384           lookup_value = NULL;
2385           if (user_msg)
2386             lookup_value = string_copy(user_msg);
2387           *yield = cond == testfor;
2388           break;
2389
2390         case DEFER:
2391           expand_string_forcedfail = TRUE;
2392           /*FALLTHROUGH*/
2393         default:
2394           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2395           return NULL;
2396         }
2397       }
2398     return s;
2399     }
2400
2401
2402   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2403
2404      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2405
2406   However, the last two are optional. That is why the whole set is enclosed
2407   in their own set of braces. */
2408
2409   case ECOND_SASLAUTHD:
2410 #ifndef CYRUS_SASLAUTHD_SOCKET
2411     goto COND_FAILED_NOT_COMPILED;
2412 #else
2413     {
2414     uschar *sub[4];
2415     while (isspace(*s)) s++;
2416     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2417     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2418                     resetok))
2419       {
2420       case 1: expand_string_message = US"too few arguments or bracketing "
2421         "error for saslauthd";
2422       case 2:
2423       case 3: return NULL;
2424       }
2425     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2426     if (yield != NULL)
2427       {
2428       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2429         &expand_string_message);
2430       if (rc == ERROR || rc == DEFER) return NULL;
2431       *yield = (rc == OK) == testfor;
2432       }
2433     return s;
2434     }
2435 #endif /* CYRUS_SASLAUTHD_SOCKET */
2436
2437
2438   /* symbolic operators for numeric and string comparison, and a number of
2439   other operators, all requiring two arguments.
2440
2441   crypteq:           encrypts plaintext and compares against an encrypted text,
2442                        using crypt(), crypt16(), MD5 or SHA-1
2443   inlist/inlisti:    checks if first argument is in the list of the second
2444   match:             does a regular expression match and sets up the numerical
2445                        variables if it succeeds
2446   match_address:     matches in an address list
2447   match_domain:      matches in a domain list
2448   match_ip:          matches a host list that is restricted to IP addresses
2449   match_local_part:  matches in a local part list
2450   */
2451
2452   case ECOND_MATCH_ADDRESS:
2453   case ECOND_MATCH_DOMAIN:
2454   case ECOND_MATCH_IP:
2455   case ECOND_MATCH_LOCAL_PART:
2456 #ifndef EXPAND_LISTMATCH_RHS
2457     sub2_honour_dollar = FALSE;
2458 #endif
2459     /* FALLTHROUGH */
2460
2461   case ECOND_CRYPTEQ:
2462   case ECOND_INLIST:
2463   case ECOND_INLISTI:
2464   case ECOND_MATCH:
2465
2466   case ECOND_NUM_L:     /* Numerical comparisons */
2467   case ECOND_NUM_LE:
2468   case ECOND_NUM_E:
2469   case ECOND_NUM_EE:
2470   case ECOND_NUM_G:
2471   case ECOND_NUM_GE:
2472
2473   case ECOND_STR_LT:    /* String comparisons */
2474   case ECOND_STR_LTI:
2475   case ECOND_STR_LE:
2476   case ECOND_STR_LEI:
2477   case ECOND_STR_EQ:
2478   case ECOND_STR_EQI:
2479   case ECOND_STR_GT:
2480   case ECOND_STR_GTI:
2481   case ECOND_STR_GE:
2482   case ECOND_STR_GEI:
2483
2484   for (i = 0; i < 2; i++)
2485     {
2486     /* Sometimes, we don't expand substrings; too many insecure configurations
2487     created using match_address{}{} and friends, where the second param
2488     includes information from untrustworthy sources. */
2489     BOOL honour_dollar = TRUE;
2490     if ((i > 0) && !sub2_honour_dollar)
2491       honour_dollar = FALSE;
2492
2493     while (isspace(*s)) s++;
2494     if (*s != '{')
2495       {
2496       if (i == 0) goto COND_FAILED_CURLY_START;
2497       expand_string_message = string_sprintf("missing 2nd string in {} "
2498         "after \"%s\"", name);
2499       return NULL;
2500       }
2501     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2502         honour_dollar, resetok);
2503     if (sub[i] == NULL) return NULL;
2504     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2505
2506     /* Convert to numerical if required; we know that the names of all the
2507     conditions that compare numbers do not start with a letter. This just saves
2508     checking for them individually. */
2509
2510     if (!isalpha(name[0]) && yield != NULL)
2511       if (sub[i][0] == 0)
2512         {
2513         num[i] = 0;
2514         DEBUG(D_expand)
2515           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2516         }
2517       else
2518         {
2519         num[i] = expanded_string_integer(sub[i], FALSE);
2520         if (expand_string_message != NULL) return NULL;
2521         }
2522     }
2523
2524   /* Result not required */
2525
2526   if (yield == NULL) return s;
2527
2528   /* Do an appropriate comparison */
2529
2530   switch(cond_type)
2531     {
2532     case ECOND_NUM_E:
2533     case ECOND_NUM_EE:
2534     tempcond = (num[0] == num[1]);
2535     break;
2536
2537     case ECOND_NUM_G:
2538     tempcond = (num[0] > num[1]);
2539     break;
2540
2541     case ECOND_NUM_GE:
2542     tempcond = (num[0] >= num[1]);
2543     break;
2544
2545     case ECOND_NUM_L:
2546     tempcond = (num[0] < num[1]);
2547     break;
2548
2549     case ECOND_NUM_LE:
2550     tempcond = (num[0] <= num[1]);
2551     break;
2552
2553     case ECOND_STR_LT:
2554     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2555     break;
2556
2557     case ECOND_STR_LTI:
2558     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2559     break;
2560
2561     case ECOND_STR_LE:
2562     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2563     break;
2564
2565     case ECOND_STR_LEI:
2566     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2567     break;
2568
2569     case ECOND_STR_EQ:
2570     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2571     break;
2572
2573     case ECOND_STR_EQI:
2574     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2575     break;
2576
2577     case ECOND_STR_GT:
2578     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2579     break;
2580
2581     case ECOND_STR_GTI:
2582     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2583     break;
2584
2585     case ECOND_STR_GE:
2586     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2587     break;
2588
2589     case ECOND_STR_GEI:
2590     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2591     break;
2592
2593     case ECOND_MATCH:   /* Regular expression match */
2594     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2595       NULL);
2596     if (re == NULL)
2597       {
2598       expand_string_message = string_sprintf("regular expression error in "
2599         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2600       return NULL;
2601       }
2602     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2603     break;
2604
2605     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2606     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2607     goto MATCHED_SOMETHING;
2608
2609     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2610     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2611       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2612     goto MATCHED_SOMETHING;
2613
2614     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2615     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2616       {
2617       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2618         sub[0]);
2619       return NULL;
2620       }
2621     else
2622       {
2623       unsigned int *nullcache = NULL;
2624       check_host_block cb;
2625
2626       cb.host_name = US"";
2627       cb.host_address = sub[0];
2628
2629       /* If the host address starts off ::ffff: it is an IPv6 address in
2630       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2631       addresses. */
2632
2633       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2634         cb.host_address + 7 : cb.host_address;
2635
2636       rc = match_check_list(
2637              &sub[1],                   /* the list */
2638              0,                         /* separator character */
2639              &hostlist_anchor,          /* anchor pointer */
2640              &nullcache,                /* cache pointer */
2641              check_host,                /* function for testing */
2642              &cb,                       /* argument for function */
2643              MCL_HOST,                  /* type of check */
2644              sub[0],                    /* text for debugging */
2645              NULL);                     /* where to pass back data */
2646       }
2647     goto MATCHED_SOMETHING;
2648
2649     case ECOND_MATCH_LOCAL_PART:
2650     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2651       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2652     /* Fall through */
2653     /* VVVVVVVVVVVV */
2654     MATCHED_SOMETHING:
2655     switch(rc)
2656       {
2657       case OK:
2658       tempcond = TRUE;
2659       break;
2660
2661       case FAIL:
2662       tempcond = FALSE;
2663       break;
2664
2665       case DEFER:
2666       expand_string_message = string_sprintf("unable to complete match "
2667         "against \"%s\": %s", sub[1], search_error_message);
2668       return NULL;
2669       }
2670
2671     break;
2672
2673     /* Various "encrypted" comparisons. If the second string starts with
2674     "{" then an encryption type is given. Default to crypt() or crypt16()
2675     (build-time choice). */
2676     /* }-for-text-editors */
2677
2678     case ECOND_CRYPTEQ:
2679     #ifndef SUPPORT_CRYPTEQ
2680     goto COND_FAILED_NOT_COMPILED;
2681     #else
2682     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2683       {
2684       int sublen = Ustrlen(sub[1]+5);
2685       md5 base;
2686       uschar digest[16];
2687
2688       md5_start(&base);
2689       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2690
2691       /* If the length that we are comparing against is 24, the MD5 digest
2692       is expressed as a base64 string. This is the way LDAP does it. However,
2693       some other software uses a straightforward hex representation. We assume
2694       this if the length is 32. Other lengths fail. */
2695
2696       if (sublen == 24)
2697         {
2698         uschar *coded = b64encode(digest, 16);
2699         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2700           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2701         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2702         }
2703       else if (sublen == 32)
2704         {
2705         int i;
2706         uschar coded[36];
2707         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2708         coded[32] = 0;
2709         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2710           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2711         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2712         }
2713       else
2714         {
2715         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2716           "fail\n  crypted=%s\n", sub[1]+5);
2717         tempcond = FALSE;
2718         }
2719       }
2720
2721     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2722       {
2723       int sublen = Ustrlen(sub[1]+6);
2724       hctx h;
2725       uschar digest[20];
2726
2727       sha1_start(&h);
2728       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2729
2730       /* If the length that we are comparing against is 28, assume the SHA1
2731       digest is expressed as a base64 string. If the length is 40, assume a
2732       straightforward hex representation. Other lengths fail. */
2733
2734       if (sublen == 28)
2735         {
2736         uschar *coded = b64encode(digest, 20);
2737         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2738           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2739         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2740         }
2741       else if (sublen == 40)
2742         {
2743         int i;
2744         uschar coded[44];
2745         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2746         coded[40] = 0;
2747         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2748           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2749         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2750         }
2751       else
2752         {
2753         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2754           "fail\n  crypted=%s\n", sub[1]+6);
2755         tempcond = FALSE;
2756         }
2757       }
2758
2759     else   /* {crypt} or {crypt16} and non-{ at start */
2760            /* }-for-text-editors */
2761       {
2762       int which = 0;
2763       uschar *coded;
2764
2765       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2766         {
2767         sub[1] += 7;
2768         which = 1;
2769         }
2770       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2771         {
2772         sub[1] += 9;
2773         which = 2;
2774         }
2775       else if (sub[1][0] == '{')                /* }-for-text-editors */
2776         {
2777         expand_string_message = string_sprintf("unknown encryption mechanism "
2778           "in \"%s\"", sub[1]);
2779         return NULL;
2780         }
2781
2782       switch(which)
2783         {
2784         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2785         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2786         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2787         }
2788
2789       #define STR(s) # s
2790       #define XSTR(s) STR(s)
2791       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2792         "  subject=%s\n  crypted=%s\n",
2793         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2794         coded, sub[1]);
2795       #undef STR
2796       #undef XSTR
2797
2798       /* If the encrypted string contains fewer than two characters (for the
2799       salt), force failure. Otherwise we get false positives: with an empty
2800       string the yield of crypt() is an empty string! */
2801
2802       if (coded)
2803         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2804       else if (errno == EINVAL)
2805         tempcond = FALSE;
2806       else
2807         {
2808         expand_string_message = string_sprintf("crypt error: %s\n",
2809           US strerror(errno));
2810         return NULL;
2811         }
2812       }
2813     break;
2814     #endif  /* SUPPORT_CRYPTEQ */
2815
2816     case ECOND_INLIST:
2817     case ECOND_INLISTI:
2818       {
2819       const uschar * list = sub[1];
2820       int sep = 0;
2821       uschar *save_iterate_item = iterate_item;
2822       int (*compare)(const uschar *, const uschar *);
2823
2824       DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2825
2826       tempcond = FALSE;
2827       compare = cond_type == ECOND_INLISTI
2828         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2829
2830       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2831         if (compare(sub[0], iterate_item) == 0)
2832           {
2833           tempcond = TRUE;
2834           break;
2835           }
2836       iterate_item = save_iterate_item;
2837       }
2838
2839     }   /* Switch for comparison conditions */
2840
2841   *yield = tempcond == testfor;
2842   return s;    /* End of comparison conditions */
2843
2844
2845   /* and/or: computes logical and/or of several conditions */
2846
2847   case ECOND_AND:
2848   case ECOND_OR:
2849   subcondptr = (yield == NULL)? NULL : &tempcond;
2850   combined_cond = (cond_type == ECOND_AND);
2851
2852   while (isspace(*s)) s++;
2853   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2854
2855   for (;;)
2856     {
2857     while (isspace(*s)) s++;
2858     /* {-for-text-editors */
2859     if (*s == '}') break;
2860     if (*s != '{')                                      /* }-for-text-editors */
2861       {
2862       expand_string_message = string_sprintf("each subcondition "
2863         "inside an \"%s{...}\" condition must be in its own {}", name);
2864       return NULL;
2865       }
2866
2867     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2868       {
2869       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2870         expand_string_message, name);
2871       return NULL;
2872       }
2873     while (isspace(*s)) s++;
2874
2875     /* {-for-text-editors */
2876     if (*s++ != '}')
2877       {
2878       /* {-for-text-editors */
2879       expand_string_message = string_sprintf("missing } at end of condition "
2880         "inside \"%s\" group", name);
2881       return NULL;
2882       }
2883
2884     if (yield != NULL)
2885       {
2886       if (cond_type == ECOND_AND)
2887         {
2888         combined_cond &= tempcond;
2889         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2890         }                                       /* evaluate any more */
2891       else
2892         {
2893         combined_cond |= tempcond;
2894         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2895         }                                       /* evaluate any more */
2896       }
2897     }
2898
2899   if (yield != NULL) *yield = (combined_cond == testfor);
2900   return ++s;
2901
2902
2903   /* forall/forany: iterates a condition with different values */
2904
2905   case ECOND_FORALL:
2906   case ECOND_FORANY:
2907     {
2908     const uschar * list;
2909     int sep = 0;
2910     uschar *save_iterate_item = iterate_item;
2911
2912     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2913
2914     while (isspace(*s)) s++;
2915     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2916     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2917     if (sub[0] == NULL) return NULL;
2918     /* {-for-text-editors */
2919     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2920
2921     while (isspace(*s)) s++;
2922     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2923
2924     sub[1] = s;
2925
2926     /* Call eval_condition once, with result discarded (as if scanning a
2927     "false" part). This allows us to find the end of the condition, because if
2928     the list it empty, we won't actually evaluate the condition for real. */
2929
2930     if (!(s = eval_condition(sub[1], resetok, NULL)))
2931       {
2932       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2933         expand_string_message, name);
2934       return NULL;
2935       }
2936     while (isspace(*s)) s++;
2937
2938     /* {-for-text-editors */
2939     if (*s++ != '}')
2940       {
2941       /* {-for-text-editors */
2942       expand_string_message = string_sprintf("missing } at end of condition "
2943         "inside \"%s\"", name);
2944       return NULL;
2945       }
2946
2947     if (yield != NULL) *yield = !testfor;
2948     list = sub[0];
2949     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2950       {
2951       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2952       if (!eval_condition(sub[1], resetok, &tempcond))
2953         {
2954         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2955           expand_string_message, name);
2956         iterate_item = save_iterate_item;
2957         return NULL;
2958         }
2959       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2960         tempcond? "true":"false");
2961
2962       if (yield != NULL) *yield = (tempcond == testfor);
2963       if (tempcond == (cond_type == ECOND_FORANY)) break;
2964       }
2965
2966     iterate_item = save_iterate_item;
2967     return s;
2968     }
2969
2970
2971   /* The bool{} expansion condition maps a string to boolean.
2972   The values supported should match those supported by the ACL condition
2973   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2974   of true/false.  Note that Router "condition" rules have a different
2975   interpretation, where general data can be used and only a few values
2976   map to FALSE.
2977   Note that readconf.c boolean matching, for boolean configuration options,
2978   only matches true/yes/false/no.
2979   The bool_lax{} condition matches the Router logic, which is much more
2980   liberal. */
2981   case ECOND_BOOL:
2982   case ECOND_BOOL_LAX:
2983     {
2984     uschar *sub_arg[1];
2985     uschar *t, *t2;
2986     uschar *ourname;
2987     size_t len;
2988     BOOL boolvalue = FALSE;
2989     while (isspace(*s)) s++;
2990     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2991     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2992     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
2993       {
2994       case 1: expand_string_message = string_sprintf(
2995                   "too few arguments or bracketing error for %s",
2996                   ourname);
2997       /*FALLTHROUGH*/
2998       case 2:
2999       case 3: return NULL;
3000       }
3001     t = sub_arg[0];
3002     while (isspace(*t)) t++;
3003     len = Ustrlen(t);
3004     if (len)
3005       {
3006       /* trailing whitespace: seems like a good idea to ignore it too */
3007       t2 = t + len - 1;
3008       while (isspace(*t2)) t2--;
3009       if (t2 != (t + len))
3010         {
3011         *++t2 = '\0';
3012         len = t2 - t;
3013         }
3014       }
3015     DEBUG(D_expand)
3016       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3017     /* logic for the lax case from expand_check_condition(), which also does
3018     expands, and the logic is both short and stable enough that there should
3019     be no maintenance burden from replicating it. */
3020     if (len == 0)
3021       boolvalue = FALSE;
3022     else if (*t == '-'
3023              ? Ustrspn(t+1, "0123456789") == len-1
3024              : Ustrspn(t,   "0123456789") == len)
3025       {
3026       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3027       /* expand_check_condition only does a literal string "0" check */
3028       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3029         boolvalue = TRUE;
3030       }
3031     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3032       boolvalue = TRUE;
3033     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3034       boolvalue = FALSE;
3035     else if (cond_type == ECOND_BOOL_LAX)
3036       boolvalue = TRUE;
3037     else
3038       {
3039       expand_string_message = string_sprintf("unrecognised boolean "
3040        "value \"%s\"", t);
3041       return NULL;
3042       }
3043     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3044         boolvalue? "true":"false");
3045     if (yield != NULL) *yield = (boolvalue == testfor);
3046     return s;
3047     }
3048
3049   /* Unknown condition */
3050
3051   default:
3052   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3053   return NULL;
3054   }   /* End switch on condition type */
3055
3056 /* Missing braces at start and end of data */
3057
3058 COND_FAILED_CURLY_START:
3059 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3060 return NULL;
3061
3062 COND_FAILED_CURLY_END:
3063 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3064   name);
3065 return NULL;
3066
3067 /* A condition requires code that is not compiled */
3068
3069 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3070     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3071     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3072 COND_FAILED_NOT_COMPILED:
3073 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3074   name);
3075 return NULL;
3076 #endif
3077 }
3078
3079
3080
3081
3082 /*************************************************
3083 *          Save numerical variables              *
3084 *************************************************/
3085
3086 /* This function is called from items such as "if" that want to preserve and
3087 restore the numbered variables.
3088
3089 Arguments:
3090   save_expand_string    points to an array of pointers to set
3091   save_expand_nlength   points to an array of ints for the lengths
3092
3093 Returns:                the value of expand max to save
3094 */
3095
3096 static int
3097 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3098 {
3099 int i;
3100 for (i = 0; i <= expand_nmax; i++)
3101   {
3102   save_expand_nstring[i] = expand_nstring[i];
3103   save_expand_nlength[i] = expand_nlength[i];
3104   }
3105 return expand_nmax;
3106 }
3107
3108
3109
3110 /*************************************************
3111 *           Restore numerical variables          *
3112 *************************************************/
3113
3114 /* This function restored saved values of numerical strings.
3115
3116 Arguments:
3117   save_expand_nmax      the number of strings to restore
3118   save_expand_string    points to an array of pointers
3119   save_expand_nlength   points to an array of ints
3120
3121 Returns:                nothing
3122 */
3123
3124 static void
3125 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3126   int *save_expand_nlength)
3127 {
3128 int i;
3129 expand_nmax = save_expand_nmax;
3130 for (i = 0; i <= expand_nmax; i++)
3131   {
3132   expand_nstring[i] = save_expand_nstring[i];
3133   expand_nlength[i] = save_expand_nlength[i];
3134   }
3135 }
3136
3137
3138
3139
3140
3141 /*************************************************
3142 *            Handle yes/no substrings            *
3143 *************************************************/
3144
3145 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3146 alternative substrings that depend on whether or not the condition was true,
3147 or the lookup or extraction succeeded. The substrings always have to be
3148 expanded, to check their syntax, but "skipping" is set when the result is not
3149 needed - this avoids unnecessary nested lookups.
3150
3151 Arguments:
3152   skipping       TRUE if we were skipping when this item was reached
3153   yes            TRUE if the first string is to be used, else use the second
3154   save_lookup    a value to put back into lookup_value before the 2nd expansion
3155   sptr           points to the input string pointer
3156   yieldptr       points to the output growable-string pointer
3157   type           "lookup", "if", "extract", "run", "env", "listextract" or
3158                  "certextract" for error message
3159   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3160                 the store.
3161
3162 Returns:         0 OK; lookup_value has been reset to save_lookup
3163                  1 expansion failed
3164                  2 expansion failed because of bracketing error
3165 */
3166
3167 static int
3168 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3169   gstring ** yieldptr, uschar *type, BOOL *resetok)
3170 {
3171 int rc = 0;
3172 const uschar *s = *sptr;    /* Local value */
3173 uschar *sub1, *sub2;
3174 const uschar * errwhere;
3175
3176 /* If there are no following strings, we substitute the contents of $value for
3177 lookups and for extractions in the success case. For the ${if item, the string
3178 "true" is substituted. In the fail case, nothing is substituted for all three
3179 items. */
3180
3181 while (isspace(*s)) s++;
3182 if (*s == '}')
3183   {
3184   if (type[0] == 'i')
3185     {
3186     if (yes && !skipping)
3187       *yieldptr = string_catn(*yieldptr, US"true", 4);
3188     }
3189   else
3190     {
3191     if (yes && lookup_value && !skipping)
3192       *yieldptr = string_cat(*yieldptr, lookup_value);
3193     lookup_value = save_lookup;
3194     }
3195   s++;
3196   goto RETURN;
3197   }
3198
3199 /* The first following string must be braced. */
3200
3201 if (*s++ != '{')
3202   {
3203   errwhere = US"'yes' part did not start with '{'";
3204   goto FAILED_CURLY;
3205   }
3206
3207 /* Expand the first substring. Forced failures are noticed only if we actually
3208 want this string. Set skipping in the call in the fail case (this will always
3209 be the case if we were already skipping). */
3210
3211 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3212 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3213 expand_string_forcedfail = FALSE;
3214 if (*s++ != '}')
3215   {
3216   errwhere = US"'yes' part did not end with '}'";
3217   goto FAILED_CURLY;
3218   }
3219
3220 /* If we want the first string, add it to the output */
3221
3222 if (yes)
3223   *yieldptr = string_cat(*yieldptr, sub1);
3224
3225 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3226 $value to what it was at the start of the item, so that it has this value
3227 during the second string expansion. For the call from "if" or "run" to this
3228 function, save_lookup is set to lookup_value, so that this statement does
3229 nothing. */
3230
3231 lookup_value = save_lookup;
3232
3233 /* There now follows either another substring, or "fail", or nothing. This
3234 time, forced failures are noticed only if we want the second string. We must
3235 set skipping in the nested call if we don't want this string, or if we were
3236 already skipping. */
3237
3238 while (isspace(*s)) s++;
3239 if (*s == '{')
3240   {
3241   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3242   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3243   expand_string_forcedfail = FALSE;
3244   if (*s++ != '}')
3245     {
3246     errwhere = US"'no' part did not start with '{'";
3247     goto FAILED_CURLY;
3248     }
3249
3250   /* If we want the second string, add it to the output */
3251
3252   if (!yes)
3253     *yieldptr = string_cat(*yieldptr, sub2);
3254   }
3255
3256 /* If there is no second string, but the word "fail" is present when the use of
3257 the second string is wanted, set a flag indicating it was a forced failure
3258 rather than a syntactic error. Swallow the terminating } in case this is nested
3259 inside another lookup or if or extract. */
3260
3261 else if (*s != '}')
3262   {
3263   uschar name[256];
3264   /* deconst cast ok here as source is s anyway */
3265   s = US read_name(name, sizeof(name), s, US"_");
3266   if (Ustrcmp(name, "fail") == 0)
3267     {
3268     if (!yes && !skipping)
3269       {
3270       while (isspace(*s)) s++;
3271       if (*s++ != '}')
3272         {
3273         errwhere = US"did not close with '}' after forcedfail";
3274         goto FAILED_CURLY;
3275         }
3276       expand_string_message =
3277         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3278       expand_string_forcedfail = TRUE;
3279       goto FAILED;
3280       }
3281     }
3282   else
3283     {
3284     expand_string_message =
3285       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3286     goto FAILED;
3287     }
3288   }
3289
3290 /* All we have to do now is to check on the final closing brace. */
3291
3292 while (isspace(*s)) s++;
3293 if (*s++ != '}')
3294   {
3295   errwhere = US"did not close with '}'";
3296   goto FAILED_CURLY;
3297   }
3298
3299
3300 RETURN:
3301 /* Update the input pointer value before returning */
3302 *sptr = s;
3303 return rc;
3304
3305 FAILED_CURLY:
3306   /* Get here if there is a bracketing failure */
3307   expand_string_message = string_sprintf(
3308     "curly-bracket problem in conditional yes/no parsing: %s\n"
3309     " remaining string is '%s'", errwhere, --s);
3310   rc = 2;
3311   goto RETURN;
3312
3313 FAILED:
3314   /* Get here for other failures */
3315   rc = 1;
3316   goto RETURN;
3317 }
3318
3319
3320
3321
3322 /*************************************************
3323 *    Handle MD5 or SHA-1 computation for HMAC    *
3324 *************************************************/
3325
3326 /* These are some wrapping functions that enable the HMAC code to be a bit
3327 cleaner. A good compiler will spot the tail recursion.
3328
3329 Arguments:
3330   type         HMAC_MD5 or HMAC_SHA1
3331   remaining    are as for the cryptographic hash functions
3332
3333 Returns:       nothing
3334 */
3335
3336 static void
3337 chash_start(int type, void *base)
3338 {
3339 if (type == HMAC_MD5)
3340   md5_start((md5 *)base);
3341 else
3342   sha1_start((hctx *)base);
3343 }
3344
3345 static void
3346 chash_mid(int type, void *base, uschar *string)
3347 {
3348 if (type == HMAC_MD5)
3349   md5_mid((md5 *)base, string);
3350 else
3351   sha1_mid((hctx *)base, string);
3352 }
3353
3354 static void
3355 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3356 {
3357 if (type == HMAC_MD5)
3358   md5_end((md5 *)base, string, length, digest);
3359 else
3360   sha1_end((hctx *)base, string, length, digest);
3361 }
3362
3363
3364
3365
3366
3367 /********************************************************
3368 * prvs: Get last three digits of days since Jan 1, 1970 *
3369 ********************************************************/
3370
3371 /* This is needed to implement the "prvs" BATV reverse
3372    path signing scheme
3373
3374 Argument: integer "days" offset to add or substract to
3375           or from the current number of days.
3376
3377 Returns:  pointer to string containing the last three
3378           digits of the number of days since Jan 1, 1970,
3379           modified by the offset argument, NULL if there
3380           was an error in the conversion.
3381
3382 */
3383
3384 static uschar *
3385 prvs_daystamp(int day_offset)
3386 {
3387 uschar *days = store_get(32);                /* Need at least 24 for cases */
3388 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3389   (time(NULL) + day_offset*86400)/86400);
3390 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3391 }
3392
3393
3394
3395 /********************************************************
3396 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3397 ********************************************************/
3398
3399 /* This is needed to implement the "prvs" BATV reverse
3400    path signing scheme
3401
3402 Arguments:
3403   address RFC2821 Address to use
3404       key The key to use (must be less than 64 characters
3405           in size)
3406   key_num Single-digit key number to use. Defaults to
3407           '0' when NULL.
3408
3409 Returns:  pointer to string containing the first three
3410           bytes of the final hash in hex format, NULL if
3411           there was an error in the process.
3412 */
3413
3414 static uschar *
3415 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3416 {
3417 gstring * hash_source;
3418 uschar * p;
3419 int i;
3420 hctx h;
3421 uschar innerhash[20];
3422 uschar finalhash[20];
3423 uschar innerkey[64];
3424 uschar outerkey[64];
3425 uschar *finalhash_hex = store_get(40);
3426
3427 if (key_num == NULL)
3428   key_num = US"0";
3429
3430 if (Ustrlen(key) > 64)
3431   return NULL;
3432
3433 hash_source = string_catn(NULL, key_num, 1);
3434 hash_source = string_catn(hash_source, daystamp, 3);
3435 hash_source = string_cat(hash_source, address);
3436 (void) string_from_gstring(hash_source);
3437
3438 DEBUG(D_expand)
3439   debug_printf_indent("prvs: hash source is '%s'\n", hash_source->s);
3440
3441 memset(innerkey, 0x36, 64);
3442 memset(outerkey, 0x5c, 64);
3443
3444 for (i = 0; i < Ustrlen(key); i++)
3445   {
3446   innerkey[i] ^= key[i];
3447   outerkey[i] ^= key[i];
3448   }
3449
3450 chash_start(HMAC_SHA1, &h);
3451 chash_mid(HMAC_SHA1, &h, innerkey);
3452 chash_end(HMAC_SHA1, &h, hash_source->s, hash_source->ptr, innerhash);
3453
3454 chash_start(HMAC_SHA1, &h);
3455 chash_mid(HMAC_SHA1, &h, outerkey);
3456 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3457
3458 p = finalhash_hex;
3459 for (i = 0; i < 3; i++)
3460   {
3461   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3462   *p++ = hex_digits[finalhash[i] & 0x0f];
3463   }
3464 *p = '\0';
3465
3466 return finalhash_hex;
3467 }
3468
3469
3470
3471
3472 /*************************************************
3473 *        Join a file onto the output string      *
3474 *************************************************/
3475
3476 /* This is used for readfile/readsock and after a run expansion.
3477 It joins the contents of a file onto the output string, globally replacing
3478 newlines with a given string (optionally).
3479
3480 Arguments:
3481   f            the FILE
3482   yield        pointer to the expandable string struct
3483   eol          newline replacement string, or NULL
3484
3485 Returns:       new pointer for expandable string, terminated if non-null
3486 */
3487
3488 static gstring *
3489 cat_file(FILE *f, gstring *yield, uschar *eol)
3490 {
3491 uschar buffer[1024];
3492
3493 while (Ufgets(buffer, sizeof(buffer), f))
3494   {
3495   int len = Ustrlen(buffer);
3496   if (eol && buffer[len-1] == '\n') len--;
3497   yield = string_catn(yield, buffer, len);
3498   if (eol && buffer[len])
3499     yield = string_cat(yield, eol);
3500   }
3501
3502 (void) string_from_gstring(yield);
3503 return yield;
3504 }
3505
3506
3507
3508
3509 /*************************************************
3510 *          Evaluate numeric expression           *
3511 *************************************************/
3512
3513 /* This is a set of mutually recursive functions that evaluate an arithmetic
3514 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3515 these functions that is called from elsewhere is eval_expr, whose interface is:
3516
3517 Arguments:
3518   sptr        pointer to the pointer to the string - gets updated
3519   decimal     TRUE if numbers are to be assumed decimal
3520   error       pointer to where to put an error message - must be NULL on input
3521   endket      TRUE if ')' must terminate - FALSE for external call
3522
3523 Returns:      on success: the value of the expression, with *error still NULL
3524               on failure: an undefined value, with *error = a message
3525 */
3526
3527 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3528
3529
3530 static int_eximarith_t
3531 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3532 {
3533 uschar *s = *sptr;
3534 int_eximarith_t x = eval_op_or(&s, decimal, error);
3535 if (*error == NULL)
3536   {
3537   if (endket)
3538     {
3539     if (*s != ')')
3540       *error = US"expecting closing parenthesis";
3541     else
3542       while (isspace(*(++s)));
3543     }
3544   else if (*s != 0) *error = US"expecting operator";
3545   }
3546 *sptr = s;
3547 return x;
3548 }
3549
3550
3551 static int_eximarith_t
3552 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3553 {
3554 register int c;
3555 int_eximarith_t n;
3556 uschar *s = *sptr;
3557 while (isspace(*s)) s++;
3558 c = *s;
3559 if (isdigit(c))
3560   {
3561   int count;
3562   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3563   s += count;
3564   switch (tolower(*s))
3565     {
3566     default: break;
3567     case 'k': n *= 1024; s++; break;
3568     case 'm': n *= 1024*1024; s++; break;
3569     case 'g': n *= 1024*1024*1024; s++; break;
3570     }
3571   while (isspace (*s)) s++;
3572   }
3573 else if (c == '(')
3574   {
3575   s++;
3576   n = eval_expr(&s, decimal, error, 1);
3577   }
3578 else
3579   {
3580   *error = US"expecting number or opening parenthesis";
3581   n = 0;
3582   }
3583 *sptr = s;
3584 return n;
3585 }
3586
3587
3588 static int_eximarith_t
3589 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3590 {
3591 uschar *s = *sptr;
3592 int_eximarith_t x;
3593 while (isspace(*s)) s++;
3594 if (*s == '+' || *s == '-' || *s == '~')
3595   {
3596   int op = *s++;
3597   x = eval_op_unary(&s, decimal, error);
3598   if (op == '-') x = -x;
3599     else if (op == '~') x = ~x;
3600   }
3601 else
3602   {
3603   x = eval_number(&s, decimal, error);
3604   }
3605 *sptr = s;
3606 return x;
3607 }
3608
3609
3610 static int_eximarith_t
3611 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3612 {
3613 uschar *s = *sptr;
3614 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3615 if (*error == NULL)
3616   {
3617   while (*s == '*' || *s == '/' || *s == '%')
3618     {
3619     int op = *s++;
3620     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3621     if (*error != NULL) break;
3622     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3623      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3624      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3625      * -N*M is INT_MIN will yield INT_MIN.
3626      * Since we don't support floating point, this is somewhat simpler.
3627      * Ideally, we'd return an error, but since we overflow for all other
3628      * arithmetic, consistency suggests otherwise, but what's the correct value
3629      * to use?  There is none.
3630      * The C standard guarantees overflow for unsigned arithmetic but signed
3631      * overflow invokes undefined behaviour; in practice, this is overflow
3632      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3633      * that long/longlong larger than int are available, or we could just work
3634      * with larger types.  We should consider whether to guarantee 32bit eval
3635      * and 64-bit working variables, with errors returned.  For now ...
3636      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3637      * can just let the other invalid results occur otherwise, as they have
3638      * until now.  For this one case, we can coerce.
3639      */
3640     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3641       {
3642       DEBUG(D_expand)
3643         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3644             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3645       x = EXIM_ARITH_MAX;
3646       continue;
3647       }
3648     if (op == '*')
3649       x *= y;
3650     else
3651       {
3652       if (y == 0)
3653         {
3654         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3655         x = 0;
3656         break;
3657         }
3658       if (op == '/')
3659         x /= y;
3660       else
3661         x %= y;
3662       }
3663     }
3664   }
3665 *sptr = s;
3666 return x;
3667 }
3668
3669
3670 static int_eximarith_t
3671 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3672 {
3673 uschar *s = *sptr;
3674 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3675 if (!*error)
3676   {
3677   while (*s == '+' || *s == '-')
3678     {
3679     int op = *s++;
3680     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3681     if (*error) break;
3682     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3683        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3684       {                 /* over-conservative check */
3685       *error = op == '+'
3686         ? US"overflow in sum" : US"overflow in difference";
3687       break;
3688       }
3689     if (op == '+') x += y; else x -= y;
3690     }
3691   }
3692 *sptr = s;
3693 return x;
3694 }
3695
3696
3697 static int_eximarith_t
3698 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3699 {
3700 uschar *s = *sptr;
3701 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3702 if (*error == NULL)
3703   {
3704   while ((*s == '<' || *s == '>') && s[1] == s[0])
3705     {
3706     int_eximarith_t y;
3707     int op = *s++;
3708     s++;
3709     y = eval_op_sum(&s, decimal, error);
3710     if (*error != NULL) break;
3711     if (op == '<') x <<= y; else x >>= y;
3712     }
3713   }
3714 *sptr = s;
3715 return x;
3716 }
3717
3718
3719 static int_eximarith_t
3720 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3721 {
3722 uschar *s = *sptr;
3723 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3724 if (*error == NULL)
3725   {
3726   while (*s == '&')
3727     {
3728     int_eximarith_t y;
3729     s++;
3730     y = eval_op_shift(&s, decimal, error);
3731     if (*error != NULL) break;
3732     x &= y;
3733     }
3734   }
3735 *sptr = s;
3736 return x;
3737 }
3738
3739
3740 static int_eximarith_t
3741 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3742 {
3743 uschar *s = *sptr;
3744 int_eximarith_t x = eval_op_and(&s, decimal, error);
3745 if (*error == NULL)
3746   {
3747   while (*s == '^')
3748     {
3749     int_eximarith_t y;
3750     s++;
3751     y = eval_op_and(&s, decimal, error);
3752     if (*error != NULL) break;
3753     x ^= y;
3754     }
3755   }
3756 *sptr = s;
3757 return x;
3758 }
3759
3760
3761 static int_eximarith_t
3762 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3763 {
3764 uschar *s = *sptr;
3765 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3766 if (*error == NULL)
3767   {
3768   while (*s == '|')
3769     {
3770     int_eximarith_t y;
3771     s++;
3772     y = eval_op_xor(&s, decimal, error);
3773     if (*error != NULL) break;
3774     x |= y;
3775     }
3776   }
3777 *sptr = s;
3778 return x;
3779 }
3780
3781
3782
3783 /*************************************************
3784 *                 Expand string                  *
3785 *************************************************/
3786
3787 /* Returns either an unchanged string, or the expanded string in stacking pool
3788 store. Interpreted sequences are:
3789
3790    \...                    normal escaping rules
3791    $name                   substitutes the variable
3792    ${name}                 ditto
3793    ${op:string}            operates on the expanded string value
3794    ${item{arg1}{arg2}...}  expands the args and then does the business
3795                              some literal args are not enclosed in {}
3796
3797 There are now far too many operators and item types to make it worth listing
3798 them here in detail any more.
3799
3800 We use an internal routine recursively to handle embedded substrings. The
3801 external function follows. The yield is NULL if the expansion failed, and there
3802 are two cases: if something collapsed syntactically, or if "fail" was given
3803 as the action on a lookup failure. These can be distinguished by looking at the
3804 variable expand_string_forcedfail, which is TRUE in the latter case.
3805
3806 The skipping flag is set true when expanding a substring that isn't actually
3807 going to be used (after "if" or "lookup") and it prevents lookups from
3808 happening lower down.
3809
3810 Store usage: At start, a store block of the length of the input plus 64
3811 is obtained. This is expanded as necessary by string_cat(), which might have to
3812 get a new block, or might be able to expand the original. At the end of the
3813 function we can release any store above that portion of the yield block that
3814 was actually used. In many cases this will be optimal.
3815
3816 However: if the first item in the expansion is a variable name or header name,
3817 we reset the store before processing it; if the result is in fresh store, we
3818 use that without copying. This is helpful for expanding strings like
3819 $message_headers which can get very long.
3820
3821 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3822 since resetting the store at the end of the expansion will free store that was
3823 allocated by the plugin code as well as the slop after the expanded string. So
3824 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3825 and, given the acl condition, ${if }. This is an unfortunate consequence of
3826 string expansion becoming too powerful.
3827
3828 Arguments:
3829   string         the string to be expanded
3830   ket_ends       true if expansion is to stop at }
3831   left           if not NULL, a pointer to the first character after the
3832                  expansion is placed here (typically used with ket_ends)
3833   skipping       TRUE for recursive calls when the value isn't actually going
3834                  to be used (to allow for optimisation)
3835   honour_dollar  TRUE if $ is to be expanded,
3836                  FALSE if it's just another character
3837   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3838                  the store.
3839
3840 Returns:         NULL if expansion fails:
3841                    expand_string_forcedfail is set TRUE if failure was forced
3842                    expand_string_message contains a textual error message
3843                  a pointer to the expanded string on success
3844 */
3845
3846 static uschar *
3847 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3848   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3849 {
3850 gstring * yield = string_get(Ustrlen(string) + 64);
3851 int item_type;
3852 const uschar *s = string;
3853 uschar *save_expand_nstring[EXPAND_MAXN+1];
3854 int save_expand_nlength[EXPAND_MAXN+1];
3855 BOOL resetok = TRUE;
3856
3857 expand_level++;
3858 DEBUG(D_expand)
3859   debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
3860     skipping
3861     ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
3862     : "considering",
3863     string);
3864
3865 expand_string_forcedfail = FALSE;
3866 expand_string_message = US"";
3867
3868 while (*s != 0)
3869   {
3870   uschar *value;
3871   uschar name[256];
3872
3873   /* \ escapes the next character, which must exist, or else
3874   the expansion fails. There's a special escape, \N, which causes
3875   copying of the subject verbatim up to the next \N. Otherwise,
3876   the escapes are the standard set. */
3877
3878   if (*s == '\\')
3879     {
3880     if (s[1] == 0)
3881       {
3882       expand_string_message = US"\\ at end of string";
3883       goto EXPAND_FAILED;
3884       }
3885
3886     if (s[1] == 'N')
3887       {
3888       const uschar * t = s + 2;
3889       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3890       yield = string_catn(yield, t, s - t);
3891       if (*s != 0) s += 2;
3892       }
3893
3894     else
3895       {
3896       uschar ch[1];
3897       ch[0] = string_interpret_escape(&s);
3898       s++;
3899       yield = string_catn(yield, ch, 1);
3900       }
3901
3902     continue;
3903     }
3904
3905   /*{*/
3906   /* Anything other than $ is just copied verbatim, unless we are
3907   looking for a terminating } character. */
3908
3909   /*{*/
3910   if (ket_ends && *s == '}') break;
3911
3912   if (*s != '$' || !honour_dollar)
3913     {
3914     yield = string_catn(yield, s++, 1);
3915     continue;
3916     }
3917
3918   /* No { after the $ - must be a plain name or a number for string
3919   match variable. There has to be a fudge for variables that are the
3920   names of header fields preceded by "$header_" because header field
3921   names can contain any printing characters except space and colon.
3922   For those that don't like typing this much, "$h_" is a synonym for
3923   "$header_". A non-existent header yields a NULL value; nothing is
3924   inserted. */  /*}*/
3925
3926   if (isalpha((*(++s))))
3927     {
3928     int len;
3929     int newsize = 0;
3930     gstring * g;
3931
3932     s = read_name(name, sizeof(name), s, US"_");
3933
3934     /* If this is the first thing to be expanded, release the pre-allocated
3935     buffer. */
3936
3937     if (yield && yield->ptr == 0)
3938       {
3939       if (resetok) store_reset(yield);
3940       yield = NULL;
3941       g = store_get(sizeof(gstring));
3942       }
3943
3944     /* Header */
3945
3946     if (Ustrncmp(name, "h_", 2) == 0 ||
3947         Ustrncmp(name, "rh_", 3) == 0 ||
3948         Ustrncmp(name, "bh_", 3) == 0 ||
3949         Ustrncmp(name, "header_", 7) == 0 ||
3950         Ustrncmp(name, "rheader_", 8) == 0 ||
3951         Ustrncmp(name, "bheader_", 8) == 0)
3952       {
3953       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3954       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3955       s = read_header_name(name, sizeof(name), s);
3956       value = find_header(name, FALSE, &newsize, want_raw, charset);
3957
3958       /* If we didn't find the header, and the header contains a closing brace
3959       character, this may be a user error where the terminating colon
3960       has been omitted. Set a flag to adjust the error message in this case.
3961       But there is no error here - nothing gets inserted. */
3962
3963       if (!value)
3964         {
3965         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3966         continue;
3967         }
3968       }
3969
3970     /* Variable */
3971
3972     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3973       {
3974       expand_string_message =
3975         string_sprintf("unknown variable name \"%s\"", name);
3976         check_variable_error_message(name);
3977       goto EXPAND_FAILED;
3978       }
3979
3980     /* If the data is known to be in a new buffer, newsize will be set to the
3981     size of that buffer. If this is the first thing in an expansion string,
3982     yield will be NULL; just point it at the new store instead of copying. Many
3983     expansion strings contain just one reference, so this is a useful
3984     optimization, especially for humungous headers.  We need to use a gstring
3985     structure that is not allocated after that new-buffer, else a later store
3986     reset in the middle of the buffer will make it inaccessible. */
3987
3988     len = Ustrlen(value);
3989     if (!yield && newsize != 0)
3990       {
3991       yield = g;
3992       yield->size = newsize;
3993       yield->ptr = len;
3994       yield->s = value;
3995       }
3996     else yield = string_catn(yield, value, len);
3997
3998     continue;
3999     }
4000
4001   if (isdigit(*s))
4002     {
4003     int n;
4004     s = read_cnumber(&n, s);
4005     if (n >= 0 && n <= expand_nmax)
4006       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4007     continue;
4008     }
4009
4010   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4011
4012   if (*s != '{')                                                        /*}*/
4013     {
4014     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4015     goto EXPAND_FAILED;
4016     }
4017
4018   /* After { there can be various things, but they all start with
4019   an initial word, except for a number for a string match variable. */
4020
4021   if (isdigit((*(++s))))
4022     {
4023     int n;
4024     s = read_cnumber(&n, s);            /*{*/
4025     if (*s++ != '}')
4026       {                                 /*{*/
4027       expand_string_message = US"} expected after number";
4028       goto EXPAND_FAILED;
4029       }
4030     if (n >= 0 && n <= expand_nmax)
4031       yield = string_catn(yield, expand_nstring[n], expand_nlength[n]);
4032     continue;
4033     }
4034
4035   if (!isalpha(*s))
4036     {
4037     expand_string_message = US"letter or digit expected after ${";      /*}*/
4038     goto EXPAND_FAILED;
4039     }
4040
4041   /* Allow "-" in names to cater for substrings with negative
4042   arguments. Since we are checking for known names after { this is
4043   OK. */
4044
4045   s = read_name(name, sizeof(name), s, US"_-");
4046   item_type = chop_match(name, item_table, nelem(item_table));
4047
4048   switch(item_type)
4049     {
4050     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4051     If the ACL returns accept or reject we return content set by "message ="
4052     There is currently no limit on recursion; this would have us call
4053     acl_check_internal() directly and get a current level from somewhere.
4054     See also the acl expansion condition ECOND_ACL and the traditional
4055     acl modifier ACLC_ACL.
4056     Assume that the function has side-effects on the store that must be preserved.
4057     */
4058
4059     case EITEM_ACL:
4060       /* ${acl {name} {arg1}{arg2}...} */
4061       {
4062       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4063       uschar *user_msg;
4064
4065       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4066                       &resetok))
4067         {
4068         case 1: goto EXPAND_FAILED_CURLY;
4069         case 2:
4070         case 3: goto EXPAND_FAILED;
4071         }
4072       if (skipping) continue;
4073
4074       resetok = FALSE;
4075       switch(eval_acl(sub, nelem(sub), &user_msg))
4076         {
4077         case OK:
4078         case FAIL:
4079           DEBUG(D_expand)
4080             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4081           if (user_msg)
4082             yield = string_cat(yield, user_msg);
4083           continue;
4084
4085         case DEFER:
4086           expand_string_forcedfail = TRUE;
4087           /*FALLTHROUGH*/
4088         default:
4089           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4090           goto EXPAND_FAILED;
4091         }
4092       }
4093
4094     /* Handle conditionals - preserve the values of the numerical expansion
4095     variables in case they get changed by a regular expression match in the
4096     condition. If not, they retain their external settings. At the end
4097     of this "if" section, they get restored to their previous values. */
4098
4099     case EITEM_IF:
4100       {
4101       BOOL cond = FALSE;
4102       const uschar *next_s;
4103       int save_expand_nmax =
4104         save_expand_strings(save_expand_nstring, save_expand_nlength);
4105
4106       while (isspace(*s)) s++;
4107       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4108       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4109
4110       DEBUG(D_expand)
4111         {
4112         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4113           "condition: %.*s\n",
4114           (int)(next_s - s), s);
4115         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4116           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4117           "result: %s\n",
4118           cond ? "true" : "false");
4119         }
4120
4121       s = next_s;
4122
4123       /* The handling of "yes" and "no" result strings is now in a separate
4124       function that is also used by ${lookup} and ${extract} and ${run}. */
4125
4126       switch(process_yesno(
4127                skipping,                     /* were previously skipping */
4128                cond,                         /* success/failure indicator */
4129                lookup_value,                 /* value to reset for string2 */
4130                &s,                           /* input pointer */
4131                &yield,                       /* output pointer */
4132                US"if",                       /* condition type */
4133                &resetok))
4134         {
4135         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4136         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4137         }
4138
4139       /* Restore external setting of expansion variables for continuation
4140       at this level. */
4141
4142       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4143         save_expand_nlength);
4144       continue;
4145       }
4146
4147 #ifdef SUPPORT_I18N
4148     case EITEM_IMAPFOLDER:
4149       {                         /* ${imapfolder {name}{sep]{specials}} */
4150       uschar *sub_arg[3];
4151       uschar *encoded;
4152
4153       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4154                       &resetok))
4155         {
4156         case 1: goto EXPAND_FAILED_CURLY;
4157         case 2:
4158         case 3: goto EXPAND_FAILED;
4159         }
4160
4161       if (sub_arg[1] == NULL)           /* One argument */
4162         {
4163         sub_arg[1] = US"/";             /* default separator */
4164         sub_arg[2] = NULL;
4165         }
4166       else if (Ustrlen(sub_arg[1]) != 1)
4167         {
4168         expand_string_message =
4169           string_sprintf(
4170                 "IMAP folder separator must be one character, found \"%s\"",
4171                 sub_arg[1]);
4172         goto EXPAND_FAILED;
4173         }
4174
4175       if (!skipping)
4176         {
4177         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4178                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4179           goto EXPAND_FAILED;
4180         yield = string_cat(yield, encoded);
4181         }
4182       continue;
4183       }
4184 #endif
4185
4186     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4187     expanding an internal string that isn't actually going to be used. All we
4188     need to do is check the syntax, so don't do a lookup at all. Preserve the
4189     values of the numerical expansion variables in case they get changed by a
4190     partial lookup. If not, they retain their external settings. At the end
4191     of this "lookup" section, they get restored to their previous values. */
4192
4193     case EITEM_LOOKUP:
4194       {
4195       int stype, partial, affixlen, starflags;
4196       int expand_setup = 0;
4197       int nameptr = 0;
4198       uschar *key, *filename;
4199       const uschar *affix;
4200       uschar *save_lookup_value = lookup_value;
4201       int save_expand_nmax =
4202         save_expand_strings(save_expand_nstring, save_expand_nlength);
4203
4204       if ((expand_forbid & RDO_LOOKUP) != 0)
4205         {
4206         expand_string_message = US"lookup expansions are not permitted";
4207         goto EXPAND_FAILED;
4208         }
4209
4210       /* Get the key we are to look up for single-key+file style lookups.
4211       Otherwise set the key NULL pro-tem. */
4212
4213       while (isspace(*s)) s++;
4214       if (*s == '{')                                    /*}*/
4215         {
4216         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4217         if (!key) goto EXPAND_FAILED;                   /*{{*/
4218         if (*s++ != '}')
4219           {
4220           expand_string_message = US"missing '}' after lookup key";
4221           goto EXPAND_FAILED_CURLY;
4222           }
4223         while (isspace(*s)) s++;
4224         }
4225       else key = NULL;
4226
4227       /* Find out the type of database */
4228
4229       if (!isalpha(*s))
4230         {
4231         expand_string_message = US"missing lookup type";
4232         goto EXPAND_FAILED;
4233         }
4234
4235       /* The type is a string that may contain special characters of various
4236       kinds. Allow everything except space or { to appear; the actual content
4237       is checked by search_findtype_partial. */         /*}*/
4238
4239       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4240         {
4241         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4242         s++;
4243         }
4244       name[nameptr] = 0;
4245       while (isspace(*s)) s++;
4246
4247       /* Now check for the individual search type and any partial or default
4248       options. Only those types that are actually in the binary are valid. */
4249
4250       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4251         &starflags);
4252       if (stype < 0)
4253         {
4254         expand_string_message = search_error_message;
4255         goto EXPAND_FAILED;
4256         }
4257
4258       /* Check that a key was provided for those lookup types that need it,
4259       and was not supplied for those that use the query style. */
4260
4261       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4262         {
4263         if (key == NULL)
4264           {
4265           expand_string_message = string_sprintf("missing {key} for single-"
4266             "key \"%s\" lookup", name);
4267           goto EXPAND_FAILED;
4268           }
4269         }
4270       else
4271         {
4272         if (key != NULL)
4273           {
4274           expand_string_message = string_sprintf("a single key was given for "
4275             "lookup type \"%s\", which is not a single-key lookup type", name);
4276           goto EXPAND_FAILED;
4277           }
4278         }
4279
4280       /* Get the next string in brackets and expand it. It is the file name for
4281       single-key+file lookups, and the whole query otherwise. In the case of
4282       queries that also require a file name (e.g. sqlite), the file name comes
4283       first. */
4284
4285       if (*s != '{')
4286         {
4287         expand_string_message = US"missing '{' for lookup file-or-query arg";
4288         goto EXPAND_FAILED_CURLY;
4289         }
4290       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4291       if (filename == NULL) goto EXPAND_FAILED;
4292       if (*s++ != '}')
4293         {
4294         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4295         goto EXPAND_FAILED_CURLY;
4296         }
4297       while (isspace(*s)) s++;
4298
4299       /* If this isn't a single-key+file lookup, re-arrange the variables
4300       to be appropriate for the search_ functions. For query-style lookups,
4301       there is just a "key", and no file name. For the special query-style +
4302       file types, the query (i.e. "key") starts with a file name. */
4303
4304       if (!key)
4305         {
4306         while (isspace(*filename)) filename++;
4307         key = filename;
4308
4309         if (mac_islookup(stype, lookup_querystyle))
4310           filename = NULL;
4311         else
4312           {
4313           if (*filename != '/')
4314             {
4315             expand_string_message = string_sprintf(
4316               "absolute file name expected for \"%s\" lookup", name);
4317             goto EXPAND_FAILED;
4318             }
4319           while (*key != 0 && !isspace(*key)) key++;
4320           if (*key != 0) *key++ = 0;
4321           }
4322         }
4323
4324       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4325       the entry was not found. Note that there is no search_close() function.
4326       Files are left open in case of re-use. At suitable places in higher logic,
4327       search_tidyup() is called to tidy all open files. This can save opening
4328       the same file several times. However, files may also get closed when
4329       others are opened, if too many are open at once. The rule is that a
4330       handle should not be used after a second search_open().
4331
4332       Request that a partial search sets up $1 and maybe $2 by passing
4333       expand_setup containing zero. If its value changes, reset expand_nmax,
4334       since new variables will have been set. Note that at the end of this
4335       "lookup" section, the old numeric variables are restored. */
4336
4337       if (skipping)
4338         lookup_value = NULL;
4339       else
4340         {
4341         void *handle = search_open(filename, stype, 0, NULL, NULL);
4342         if (handle == NULL)
4343           {
4344           expand_string_message = search_error_message;
4345           goto EXPAND_FAILED;
4346           }
4347         lookup_value = search_find(handle, filename, key, partial, affix,
4348           affixlen, starflags, &expand_setup);
4349         if (search_find_defer)
4350           {
4351           expand_string_message =
4352             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4353               string_printing2(key, FALSE), search_error_message);
4354           goto EXPAND_FAILED;
4355           }
4356         if (expand_setup > 0) expand_nmax = expand_setup;
4357         }
4358
4359       /* The handling of "yes" and "no" result strings is now in a separate
4360       function that is also used by ${if} and ${extract}. */
4361
4362       switch(process_yesno(
4363                skipping,                     /* were previously skipping */
4364                lookup_value != NULL,         /* success/failure indicator */
4365                save_lookup_value,            /* value to reset for string2 */
4366                &s,                           /* input pointer */
4367                &yield,                       /* output pointer */
4368                US"lookup",                   /* condition type */
4369                &resetok))
4370         {
4371         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4372         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4373         }
4374
4375       /* Restore external setting of expansion variables for carrying on
4376       at this level, and continue. */
4377
4378       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4379         save_expand_nlength);
4380       continue;
4381       }
4382
4383     /* If Perl support is configured, handle calling embedded perl subroutines,
4384     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4385     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4386     arguments (defined below). */
4387
4388     #define EXIM_PERL_MAX_ARGS 8
4389
4390     case EITEM_PERL:
4391     #ifndef EXIM_PERL
4392     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4393       "is not included in this binary";
4394     goto EXPAND_FAILED;
4395
4396     #else   /* EXIM_PERL */
4397       {
4398       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4399       gstring *new_yield;
4400
4401       if ((expand_forbid & RDO_PERL) != 0)
4402         {
4403         expand_string_message = US"Perl calls are not permitted";
4404         goto EXPAND_FAILED;
4405         }
4406
4407       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4408            US"perl", &resetok))
4409         {
4410         case 1: goto EXPAND_FAILED_CURLY;
4411         case 2:
4412         case 3: goto EXPAND_FAILED;
4413         }
4414
4415       /* If skipping, we don't actually do anything */
4416
4417       if (skipping) continue;
4418
4419       /* Start the interpreter if necessary */
4420
4421       if (!opt_perl_started)
4422         {
4423         uschar *initerror;
4424         if (opt_perl_startup == NULL)
4425           {
4426           expand_string_message = US"A setting of perl_startup is needed when "
4427             "using the Perl interpreter";
4428           goto EXPAND_FAILED;
4429           }
4430         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4431         initerror = init_perl(opt_perl_startup);
4432         if (initerror != NULL)
4433           {
4434           expand_string_message =
4435             string_sprintf("error in perl_startup code: %s\n", initerror);
4436           goto EXPAND_FAILED;
4437           }
4438         opt_perl_started = TRUE;
4439         }
4440
4441       /* Call the function */
4442
4443       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4444       new_yield = call_perl_cat(yield, &expand_string_message,
4445         sub_arg[0], sub_arg + 1);
4446
4447       /* NULL yield indicates failure; if the message pointer has been set to
4448       NULL, the yield was undef, indicating a forced failure. Otherwise the
4449       message will indicate some kind of Perl error. */
4450
4451       if (new_yield == NULL)
4452         {
4453         if (expand_string_message == NULL)
4454           {
4455           expand_string_message =
4456             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4457               "failure", sub_arg[0]);
4458           expand_string_forcedfail = TRUE;
4459           }
4460         goto EXPAND_FAILED;
4461         }
4462
4463       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4464       set during a callback from Perl. */
4465
4466       expand_string_forcedfail = FALSE;
4467       yield = new_yield;
4468       continue;
4469       }
4470     #endif /* EXIM_PERL */
4471
4472     /* Transform email address to "prvs" scheme to use
4473        as BATV-signed return path */
4474
4475     case EITEM_PRVS:
4476       {
4477       uschar *sub_arg[3];
4478       uschar *p,*domain;
4479
4480       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4481         {
4482         case 1: goto EXPAND_FAILED_CURLY;
4483         case 2:
4484         case 3: goto EXPAND_FAILED;
4485         }
4486
4487       /* If skipping, we don't actually do anything */
4488       if (skipping) continue;
4489
4490       /* sub_arg[0] is the address */
4491       domain = Ustrrchr(sub_arg[0],'@');
4492       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4493         {
4494         expand_string_message = US"prvs first argument must be a qualified email address";
4495         goto EXPAND_FAILED;
4496         }
4497
4498       /* Calculate the hash. The second argument must be a single-digit
4499       key number, or unset. */
4500
4501       if (sub_arg[2] != NULL &&
4502           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4503         {
4504         expand_string_message = US"prvs second argument must be a single digit";
4505         goto EXPAND_FAILED;
4506         }
4507
4508       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4509       if (p == NULL)
4510         {
4511         expand_string_message = US"prvs hmac-sha1 conversion failed";
4512         goto EXPAND_FAILED;
4513         }
4514
4515       /* Now separate the domain from the local part */
4516       *domain++ = '\0';
4517
4518       yield = string_catn(yield, US"prvs=", 5);
4519       yield = string_catn(yield, sub_arg[2] ? sub_arg[2] : US"0", 1);
4520       yield = string_catn(yield, prvs_daystamp(7), 3);
4521       yield = string_catn(yield, p, 6);
4522       yield = string_catn(yield, US"=", 1);
4523       yield = string_cat (yield, sub_arg[0]);
4524       yield = string_catn(yield, US"@", 1);
4525       yield = string_cat (yield, domain);
4526
4527       continue;
4528       }
4529
4530     /* Check a prvs-encoded address for validity */
4531
4532     case EITEM_PRVSCHECK:
4533       {
4534       uschar *sub_arg[3];
4535       gstring * g;
4536       const pcre *re;
4537       uschar *p;
4538
4539       /* TF: Ugliness: We want to expand parameter 1 first, then set
4540          up expansion variables that are used in the expansion of
4541          parameter 2. So we clone the string for the first
4542          expansion, where we only expand parameter 1.
4543
4544          PH: Actually, that isn't necessary. The read_subs() function is
4545          designed to work this way for the ${if and ${lookup expansions. I've
4546          tidied the code.
4547       */
4548
4549       /* Reset expansion variables */
4550       prvscheck_result = NULL;
4551       prvscheck_address = NULL;
4552       prvscheck_keynum = NULL;
4553
4554       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4555         {
4556         case 1: goto EXPAND_FAILED_CURLY;
4557         case 2:
4558         case 3: goto EXPAND_FAILED;
4559         }
4560
4561       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4562                               TRUE,FALSE);
4563
4564       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4565         {
4566         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4567         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4568         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4569         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4570         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4571
4572         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4573         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4574         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4575         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4576         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4577
4578         /* Set up expansion variables */
4579         g = string_cat (NULL, local_part);
4580         g = string_catn(g, US"@", 1);
4581         g = string_cat (g, domain);
4582         prvscheck_address = string_from_gstring(g);
4583         prvscheck_keynum = string_copy(key_num);
4584
4585         /* Now expand the second argument */
4586         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4587           {
4588           case 1: goto EXPAND_FAILED_CURLY;
4589           case 2:
4590           case 3: goto EXPAND_FAILED;
4591           }
4592
4593         /* Now we have the key and can check the address. */
4594
4595         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4596           daystamp);
4597
4598         if (!p)
4599           {
4600           expand_string_message = US"hmac-sha1 conversion failed";
4601           goto EXPAND_FAILED;
4602           }
4603
4604         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4605         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4606
4607         if (Ustrcmp(p,hash) == 0)
4608           {
4609           /* Success, valid BATV address. Now check the expiry date. */
4610           uschar *now = prvs_daystamp(0);
4611           unsigned int inow = 0,iexpire = 1;
4612
4613           (void)sscanf(CS now,"%u",&inow);
4614           (void)sscanf(CS daystamp,"%u",&iexpire);
4615
4616           /* When "iexpire" is < 7, a "flip" has occured.
4617              Adjust "inow" accordingly. */
4618           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4619
4620           if (iexpire >= inow)
4621             {
4622             prvscheck_result = US"1";
4623             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4624             }
4625             else
4626             {
4627             prvscheck_result = NULL;
4628             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4629             }
4630           }
4631         else
4632           {
4633           prvscheck_result = NULL;
4634           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4635           }
4636
4637         /* Now expand the final argument. We leave this till now so that
4638         it can include $prvscheck_result. */
4639
4640         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4641           {
4642           case 1: goto EXPAND_FAILED_CURLY;
4643           case 2:
4644           case 3: goto EXPAND_FAILED;
4645           }
4646
4647         yield = string_cat(yield,
4648           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4649
4650         /* Reset the "internal" variables afterwards, because they are in
4651         dynamic store that will be reclaimed if the expansion succeeded. */
4652
4653         prvscheck_address = NULL;
4654         prvscheck_keynum = NULL;
4655         }
4656       else
4657         /* Does not look like a prvs encoded address, return the empty string.
4658            We need to make sure all subs are expanded first, so as to skip over
4659            the entire item. */
4660
4661         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4662           {
4663           case 1: goto EXPAND_FAILED_CURLY;
4664           case 2:
4665           case 3: goto EXPAND_FAILED;
4666           }
4667
4668       continue;
4669       }
4670
4671     /* Handle "readfile" to insert an entire file */
4672
4673     case EITEM_READFILE:
4674       {
4675       FILE *f;
4676       uschar *sub_arg[2];
4677
4678       if ((expand_forbid & RDO_READFILE) != 0)
4679         {
4680         expand_string_message = US"file insertions are not permitted";
4681         goto EXPAND_FAILED;
4682         }
4683
4684       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4685         {
4686         case 1: goto EXPAND_FAILED_CURLY;
4687         case 2:
4688         case 3: goto EXPAND_FAILED;
4689         }
4690
4691       /* If skipping, we don't actually do anything */
4692
4693       if (skipping) continue;
4694
4695       /* Open the file and read it */
4696
4697       if (!(f = Ufopen(sub_arg[0], "rb")))
4698         {
4699         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4700         goto EXPAND_FAILED;
4701         }
4702
4703       yield = cat_file(f, yield, sub_arg[1]);
4704       (void)fclose(f);
4705       continue;
4706       }
4707
4708     /* Handle "readsocket" to insert data from a socket, either
4709     Inet or Unix domain */
4710
4711     case EITEM_READSOCK:
4712       {
4713       int fd;
4714       int timeout = 5;
4715       int save_ptr = yield->ptr;
4716       FILE *f;
4717       uschar *arg;
4718       uschar *sub_arg[4];
4719       BOOL do_shutdown = TRUE;
4720       blob reqstr;
4721
4722       if (expand_forbid & RDO_READSOCK)
4723         {
4724         expand_string_message = US"socket insertions are not permitted";
4725         goto EXPAND_FAILED;
4726         }
4727
4728       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4729       because there may be a string for expansion on failure. */
4730
4731       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4732         {
4733         case 1: goto EXPAND_FAILED_CURLY;
4734         case 2:                             /* Won't occur: no end check */
4735         case 3: goto EXPAND_FAILED;
4736         }
4737
4738       /* Grab the request string, if any */
4739
4740       reqstr.data = sub_arg[1];
4741       reqstr.len = Ustrlen(sub_arg[1]);
4742
4743       /* Sort out timeout, if given.  The second arg is a list with the first element
4744       being a time value.  Any more are options of form "name=value".  Currently the
4745       only option recognised is "shutdown". */
4746
4747       if (sub_arg[2])
4748         {
4749         const uschar * list = sub_arg[2];
4750         uschar * item;
4751         int sep = 0;
4752
4753         item = string_nextinlist(&list, &sep, NULL, 0);
4754         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4755           {
4756           expand_string_message = string_sprintf("bad time value %s", item);
4757           goto EXPAND_FAILED;
4758           }
4759
4760         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4761           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4762             if (Ustrcmp(item + 9, US"no") == 0)
4763               do_shutdown = FALSE;
4764         }
4765       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4766
4767       /* If skipping, we don't actually do anything. Otherwise, arrange to
4768       connect to either an IP or a Unix socket. */
4769
4770       if (!skipping)
4771         {
4772         /* Handle an IP (internet) domain */
4773
4774         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4775           {
4776           int port;
4777           uschar * server_name = sub_arg[0] + 5;
4778           uschar * port_name = Ustrrchr(server_name, ':');
4779
4780           /* Sort out the port */
4781
4782           if (!port_name)
4783             {
4784             expand_string_message =
4785               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4786             goto EXPAND_FAILED;
4787             }
4788           *port_name++ = 0;           /* Terminate server name */
4789
4790           if (isdigit(*port_name))
4791             {
4792             uschar *end;
4793             port = Ustrtol(port_name, &end, 0);
4794             if (end != port_name + Ustrlen(port_name))
4795               {
4796               expand_string_message =
4797                 string_sprintf("invalid port number %s", port_name);
4798               goto EXPAND_FAILED;
4799               }
4800             }
4801           else
4802             {
4803             struct servent *service_info = getservbyname(CS port_name, "tcp");
4804             if (!service_info)
4805               {
4806               expand_string_message = string_sprintf("unknown port \"%s\"",
4807                 port_name);
4808               goto EXPAND_FAILED;
4809               }
4810             port = ntohs(service_info->s_port);
4811             }
4812
4813           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4814                   timeout, NULL, &expand_string_message, &reqstr);
4815           callout_address = NULL;
4816           if (fd < 0)
4817               goto SOCK_FAIL;
4818           reqstr.len = 0;
4819           }
4820
4821         /* Handle a Unix domain socket */
4822
4823         else
4824           {
4825           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4826           int rc;
4827
4828           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4829             {
4830             expand_string_message = string_sprintf("failed to create socket: %s",
4831               strerror(errno));
4832             goto SOCK_FAIL;
4833             }
4834
4835           sockun.sun_family = AF_UNIX;
4836           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4837             sub_arg[0]);
4838
4839           sigalrm_seen = FALSE;
4840           alarm(timeout);
4841           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4842           alarm(0);
4843           if (sigalrm_seen)
4844             {
4845             expand_string_message = US "socket connect timed out";
4846             goto SOCK_FAIL;
4847             }
4848           if (rc < 0)
4849             {
4850             expand_string_message = string_sprintf("failed to connect to socket "
4851               "%s: %s", sub_arg[0], strerror(errno));
4852             goto SOCK_FAIL;
4853             }
4854           }
4855
4856         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4857
4858         /* Allow sequencing of test actions */
4859         if (running_in_test_harness) millisleep(100);
4860
4861         /* Write the request string, if not empty or already done */
4862
4863         if (reqstr.len)
4864           {
4865           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4866             reqstr.data);
4867           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4868             {
4869             expand_string_message = string_sprintf("request write to socket "
4870               "failed: %s", strerror(errno));
4871             goto SOCK_FAIL;
4872             }
4873           }
4874
4875         /* Shut down the sending side of the socket. This helps some servers to
4876         recognise that it is their turn to do some work. Just in case some
4877         system doesn't have this function, make it conditional. */
4878
4879 #ifdef SHUT_WR
4880         if (do_shutdown) shutdown(fd, SHUT_WR);
4881 #endif
4882
4883         if (running_in_test_harness) millisleep(100);
4884
4885         /* Now we need to read from the socket, under a timeout. The function
4886         that reads a file can be used. */
4887
4888         f = fdopen(fd, "rb");
4889         sigalrm_seen = FALSE;
4890         alarm(timeout);
4891         yield = cat_file(f, yield, sub_arg[3]);
4892         alarm(0);
4893         (void)fclose(f);
4894
4895         /* After a timeout, we restore the pointer in the result, that is,
4896         make sure we add nothing from the socket. */
4897
4898         if (sigalrm_seen)
4899           {
4900           yield->ptr = save_ptr;
4901           expand_string_message = US "socket read timed out";
4902           goto SOCK_FAIL;
4903           }
4904         }
4905
4906       /* The whole thing has worked (or we were skipping). If there is a
4907       failure string following, we need to skip it. */
4908
4909       if (*s == '{')
4910         {
4911         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4912           goto EXPAND_FAILED;
4913         if (*s++ != '}')
4914           {
4915           expand_string_message = US"missing '}' closing failstring for readsocket";
4916           goto EXPAND_FAILED_CURLY;
4917           }
4918         while (isspace(*s)) s++;
4919         }
4920
4921     READSOCK_DONE:
4922       if (*s++ != '}')
4923         {
4924         expand_string_message = US"missing '}' closing readsocket";
4925         goto EXPAND_FAILED_CURLY;
4926         }
4927       continue;
4928
4929       /* Come here on failure to create socket, connect socket, write to the
4930       socket, or timeout on reading. If another substring follows, expand and
4931       use it. Otherwise, those conditions give expand errors. */
4932
4933     SOCK_FAIL:
4934       if (*s != '{') goto EXPAND_FAILED;
4935       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4936       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4937         goto EXPAND_FAILED;
4938       yield = string_cat(yield, arg);
4939       if (*s++ != '}')
4940         {
4941         expand_string_message = US"missing '}' closing failstring for readsocket";
4942         goto EXPAND_FAILED_CURLY;
4943         }
4944       while (isspace(*s)) s++;
4945       goto READSOCK_DONE;
4946       }
4947
4948     /* Handle "run" to execute a program. */
4949
4950     case EITEM_RUN:
4951       {
4952       FILE *f;
4953       uschar *arg;
4954       const uschar **argv;
4955       pid_t pid;
4956       int fd_in, fd_out;
4957
4958       if ((expand_forbid & RDO_RUN) != 0)
4959         {
4960         expand_string_message = US"running a command is not permitted";
4961         goto EXPAND_FAILED;
4962         }
4963
4964       while (isspace(*s)) s++;
4965       if (*s != '{')
4966         {
4967         expand_string_message = US"missing '{' for command arg of run";
4968         goto EXPAND_FAILED_CURLY;
4969         }
4970       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4971       if (arg == NULL) goto EXPAND_FAILED;
4972       while (isspace(*s)) s++;
4973       if (*s++ != '}')
4974         {
4975         expand_string_message = US"missing '}' closing command arg of run";
4976         goto EXPAND_FAILED_CURLY;
4977         }
4978
4979       if (skipping)   /* Just pretend it worked when we're skipping */
4980         {
4981         runrc = 0;
4982         lookup_value = NULL;
4983         }
4984       else
4985         {
4986         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4987             arg,                                /* raw command */
4988             FALSE,                              /* don't expand the arguments */
4989             0,                                  /* not relevant when... */
4990             NULL,                               /* no transporting address */
4991             US"${run} expansion",               /* for error messages */
4992             &expand_string_message))            /* where to put error message */
4993           goto EXPAND_FAILED;
4994
4995         /* Create the child process, making it a group leader. */
4996
4997         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
4998           {
4999           expand_string_message =
5000             string_sprintf("couldn't create child process: %s", strerror(errno));
5001           goto EXPAND_FAILED;
5002           }
5003
5004         /* Nothing is written to the standard input. */
5005
5006         (void)close(fd_in);
5007
5008         /* Read the pipe to get the command's output into $value (which is kept
5009         in lookup_value). Read during execution, so that if the output exceeds
5010         the OS pipe buffer limit, we don't block forever. Remember to not release
5011         memory just allocated for $value. */
5012
5013         resetok = FALSE;
5014         f = fdopen(fd_out, "rb");
5015         sigalrm_seen = FALSE;
5016         alarm(60);
5017         lookup_value = string_from_gstring(cat_file(f, NULL, NULL));
5018         alarm(0);
5019         (void)fclose(f);
5020
5021         /* Wait for the process to finish, applying the timeout, and inspect its
5022         return code for serious disasters. Simple non-zero returns are passed on.
5023         */
5024
5025         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5026           {
5027           if (sigalrm_seen || runrc == -256)
5028             {
5029             expand_string_message = string_sprintf("command timed out");
5030             killpg(pid, SIGKILL);       /* Kill the whole process group */
5031             }
5032
5033           else if (runrc == -257)
5034             expand_string_message = string_sprintf("wait() failed: %s",
5035               strerror(errno));
5036
5037           else
5038             expand_string_message = string_sprintf("command killed by signal %d",
5039               -runrc);
5040
5041           goto EXPAND_FAILED;
5042           }
5043         }
5044
5045       /* Process the yes/no strings; $value may be useful in both cases */
5046
5047       switch(process_yesno(
5048                skipping,                     /* were previously skipping */
5049                runrc == 0,                   /* success/failure indicator */
5050                lookup_value,                 /* value to reset for string2 */
5051                &s,                           /* input pointer */
5052                &yield,                       /* output pointer */
5053                US"run",                      /* condition type */
5054                &resetok))
5055         {
5056         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5057         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5058         }
5059
5060       continue;
5061       }
5062
5063     /* Handle character translation for "tr" */
5064
5065     case EITEM_TR:
5066       {
5067       int oldptr = yield->ptr;
5068       int o2m;
5069       uschar *sub[3];
5070
5071       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5072         {
5073         case 1: goto EXPAND_FAILED_CURLY;
5074         case 2:
5075         case 3: goto EXPAND_FAILED;
5076         }
5077
5078       yield = string_cat(yield, sub[0]);
5079       o2m = Ustrlen(sub[2]) - 1;
5080
5081       if (o2m >= 0) for (; oldptr < yield->ptr; oldptr++)
5082         {
5083         uschar *m = Ustrrchr(sub[1], yield->s[oldptr]);
5084         if (m != NULL)
5085           {
5086           int o = m - sub[1];
5087           yield->s[oldptr] = sub[2][(o < o2m)? o : o2m];
5088           }
5089         }
5090
5091       continue;
5092       }
5093
5094     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5095     expanded arguments. */
5096
5097     case EITEM_HASH:
5098     case EITEM_LENGTH:
5099     case EITEM_NHASH:
5100     case EITEM_SUBSTR:
5101       {
5102       int i;
5103       int len;
5104       uschar *ret;
5105       int val[2] = { 0, -1 };
5106       uschar *sub[3];
5107
5108       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5109       Ensure that sub[2] is set in the ${length } case. */
5110
5111       sub[2] = NULL;
5112       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5113              TRUE, name, &resetok))
5114         {
5115         case 1: goto EXPAND_FAILED_CURLY;
5116         case 2:
5117         case 3: goto EXPAND_FAILED;
5118         }
5119
5120       /* Juggle the arguments if there are only two of them: always move the
5121       string to the last position and make ${length{n}{str}} equivalent to
5122       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5123
5124       if (sub[2] == NULL)
5125         {
5126         sub[2] = sub[1];
5127         sub[1] = NULL;
5128         if (item_type == EITEM_LENGTH)
5129           {
5130           sub[1] = sub[0];
5131           sub[0] = NULL;
5132           }
5133         }
5134
5135       for (i = 0; i < 2; i++)
5136         {
5137         if (sub[i] == NULL) continue;
5138         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5139         if (*ret != 0 || (i != 0 && val[i] < 0))
5140           {
5141           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5142             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5143           goto EXPAND_FAILED;
5144           }
5145         }
5146
5147       ret =
5148         (item_type == EITEM_HASH)?
5149           compute_hash(sub[2], val[0], val[1], &len) :
5150         (item_type == EITEM_NHASH)?
5151           compute_nhash(sub[2], val[0], val[1], &len) :
5152           extract_substr(sub[2], val[0], val[1], &len);
5153
5154       if (ret == NULL) goto EXPAND_FAILED;
5155       yield = string_catn(yield, ret, len);
5156       continue;
5157       }
5158
5159     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5160     This code originally contributed by Steve Haslam. It currently supports
5161     the use of MD5 and SHA-1 hashes.
5162
5163     We need some workspace that is large enough to handle all the supported
5164     hash types. Use macros to set the sizes rather than be too elaborate. */
5165
5166     #define MAX_HASHLEN      20
5167     #define MAX_HASHBLOCKLEN 64
5168
5169     case EITEM_HMAC:
5170       {
5171       uschar *sub[3];
5172       md5 md5_base;
5173       hctx sha1_ctx;
5174       void *use_base;
5175       int type, i;
5176       int hashlen;      /* Number of octets for the hash algorithm's output */
5177       int hashblocklen; /* Number of octets the hash algorithm processes */
5178       uschar *keyptr, *p;
5179       unsigned int keylen;
5180
5181       uschar keyhash[MAX_HASHLEN];
5182       uschar innerhash[MAX_HASHLEN];
5183       uschar finalhash[MAX_HASHLEN];
5184       uschar finalhash_hex[2*MAX_HASHLEN];
5185       uschar innerkey[MAX_HASHBLOCKLEN];
5186       uschar outerkey[MAX_HASHBLOCKLEN];
5187
5188       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5189         {
5190         case 1: goto EXPAND_FAILED_CURLY;
5191         case 2:
5192         case 3: goto EXPAND_FAILED;
5193         }
5194
5195       if (!skipping)
5196         {
5197         if (Ustrcmp(sub[0], "md5") == 0)
5198           {
5199           type = HMAC_MD5;
5200           use_base = &md5_base;
5201           hashlen = 16;
5202           hashblocklen = 64;
5203           }
5204         else if (Ustrcmp(sub[0], "sha1") == 0)
5205           {
5206           type = HMAC_SHA1;
5207           use_base = &sha1_ctx;
5208           hashlen = 20;
5209           hashblocklen = 64;
5210           }
5211         else
5212           {
5213           expand_string_message =
5214             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5215           goto EXPAND_FAILED;
5216           }
5217
5218         keyptr = sub[1];
5219         keylen = Ustrlen(keyptr);
5220
5221         /* If the key is longer than the hash block length, then hash the key
5222         first */
5223
5224         if (keylen > hashblocklen)
5225           {
5226           chash_start(type, use_base);
5227           chash_end(type, use_base, keyptr, keylen, keyhash);
5228           keyptr = keyhash;
5229           keylen = hashlen;
5230           }
5231
5232         /* Now make the inner and outer key values */
5233
5234         memset(innerkey, 0x36, hashblocklen);
5235         memset(outerkey, 0x5c, hashblocklen);
5236
5237         for (i = 0; i < keylen; i++)
5238           {
5239           innerkey[i] ^= keyptr[i];
5240           outerkey[i] ^= keyptr[i];
5241           }
5242
5243         /* Now do the hashes */
5244
5245         chash_start(type, use_base);
5246         chash_mid(type, use_base, innerkey);
5247         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5248
5249         chash_start(type, use_base);
5250         chash_mid(type, use_base, outerkey);
5251         chash_end(type, use_base, innerhash, hashlen, finalhash);
5252
5253         /* Encode the final hash as a hex string */
5254
5255         p = finalhash_hex;
5256         for (i = 0; i < hashlen; i++)
5257           {
5258           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5259           *p++ = hex_digits[finalhash[i] & 0x0f];
5260           }
5261
5262         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5263           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5264
5265         yield = string_catn(yield, finalhash_hex, hashlen*2);
5266         }
5267       continue;
5268       }
5269
5270     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5271     We have to save the numerical variables and restore them afterwards. */
5272
5273     case EITEM_SG:
5274       {
5275       const pcre *re;
5276       int moffset, moffsetextra, slen;
5277       int roffset;
5278       int emptyopt;
5279       const uschar *rerror;
5280       uschar *subject;
5281       uschar *sub[3];
5282       int save_expand_nmax =
5283         save_expand_strings(save_expand_nstring, save_expand_nlength);
5284
5285       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5286         {
5287         case 1: goto EXPAND_FAILED_CURLY;
5288         case 2:
5289         case 3: goto EXPAND_FAILED;
5290         }
5291
5292       /* Compile the regular expression */
5293
5294       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5295         NULL);
5296
5297       if (re == NULL)
5298         {
5299         expand_string_message = string_sprintf("regular expression error in "
5300           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5301         goto EXPAND_FAILED;
5302         }
5303
5304       /* Now run a loop to do the substitutions as often as necessary. It ends
5305       when there are no more matches. Take care over matches of the null string;
5306       do the same thing as Perl does. */
5307
5308       subject = sub[0];
5309       slen = Ustrlen(sub[0]);
5310       moffset = moffsetextra = 0;
5311       emptyopt = 0;
5312
5313       for (;;)
5314         {
5315         int ovector[3*(EXPAND_MAXN+1)];
5316         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5317           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5318         int nn;
5319         uschar *insert;
5320
5321         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5322         is not necessarily the end. We want to repeat the match from one
5323         character further along, but leaving the basic offset the same (for
5324         copying below). We can't be at the end of the string - that was checked
5325         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5326         finished; copy the remaining string and end the loop. */
5327
5328         if (n < 0)
5329           {
5330           if (emptyopt != 0)
5331             {
5332             moffsetextra = 1;
5333             emptyopt = 0;
5334             continue;
5335             }
5336           yield = string_catn(yield, subject+moffset, slen-moffset);
5337           break;
5338           }
5339
5340         /* Match - set up for expanding the replacement. */
5341
5342         if (n == 0) n = EXPAND_MAXN + 1;
5343         expand_nmax = 0;
5344         for (nn = 0; nn < n*2; nn += 2)
5345           {
5346           expand_nstring[expand_nmax] = subject + ovector[nn];
5347           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5348           }
5349         expand_nmax--;
5350
5351         /* Copy the characters before the match, plus the expanded insertion. */
5352
5353         yield = string_catn(yield, subject + moffset, ovector[0] - moffset);
5354         insert = expand_string(sub[2]);
5355         if (insert == NULL) goto EXPAND_FAILED;
5356         yield = string_cat(yield, insert);
5357
5358         moffset = ovector[1];
5359         moffsetextra = 0;
5360         emptyopt = 0;
5361
5362         /* If we have matched an empty string, first check to see if we are at
5363         the end of the subject. If so, the loop is over. Otherwise, mimic
5364         what Perl's /g options does. This turns out to be rather cunning. First
5365         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5366         string at the same point. If this fails (picked up above) we advance to
5367         the next character. */
5368
5369         if (ovector[0] == ovector[1])
5370           {
5371           if (ovector[0] == slen) break;
5372           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5373           }
5374         }
5375
5376       /* All done - restore numerical variables. */
5377
5378       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5379         save_expand_nlength);
5380       continue;
5381       }
5382
5383     /* Handle keyed and numbered substring extraction. If the first argument
5384     consists entirely of digits, then a numerical extraction is assumed. */
5385
5386     case EITEM_EXTRACT:
5387       {
5388       int i;
5389       int j;
5390       int field_number = 1;
5391       BOOL field_number_set = FALSE;
5392       uschar *save_lookup_value = lookup_value;
5393       uschar *sub[3];
5394       int save_expand_nmax =
5395         save_expand_strings(save_expand_nstring, save_expand_nlength);
5396
5397       /* While skipping we cannot rely on the data for expansions being
5398       available (eg. $item) hence cannot decide on numeric vs. keyed.
5399       Read a maximum of 5 arguments (including the yes/no) */
5400
5401       if (skipping)
5402         {
5403         while (isspace(*s)) s++;
5404         for (j = 5; j > 0 && *s == '{'; j--)
5405           {
5406           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5407             goto EXPAND_FAILED;                                 /*{*/
5408           if (*s++ != '}')
5409             {
5410             expand_string_message = US"missing '{' for arg of extract";
5411             goto EXPAND_FAILED_CURLY;
5412             }
5413           while (isspace(*s)) s++;
5414           }
5415         if (  Ustrncmp(s, "fail", 4) == 0
5416            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5417            )
5418           {
5419           s += 4;
5420           while (isspace(*s)) s++;
5421           }
5422         if (*s != '}')
5423           {
5424           expand_string_message = US"missing '}' closing extract";
5425           goto EXPAND_FAILED_CURLY;
5426           }
5427         }
5428
5429       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5430         {
5431         while (isspace(*s)) s++;
5432         if (*s == '{')                                          /*}*/
5433           {
5434           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5435           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5436           if (*s++ != '}')
5437             {
5438             expand_string_message = string_sprintf(
5439               "missing '}' closing arg %d of extract", i+1);
5440             goto EXPAND_FAILED_CURLY;
5441             }
5442
5443           /* After removal of leading and trailing white space, the first
5444           argument must not be empty; if it consists entirely of digits
5445           (optionally preceded by a minus sign), this is a numerical
5446           extraction, and we expect 3 arguments. */
5447
5448           if (i == 0)
5449             {
5450             int len;
5451             int x = 0;
5452             uschar *p = sub[0];
5453
5454             while (isspace(*p)) p++;
5455             sub[0] = p;
5456
5457             len = Ustrlen(p);
5458             while (len > 0 && isspace(p[len-1])) len--;
5459             p[len] = 0;
5460
5461             if (*p == 0)
5462               {
5463               expand_string_message = US"first argument of \"extract\" must "
5464                 "not be empty";
5465               goto EXPAND_FAILED;
5466               }
5467
5468             if (*p == '-')
5469               {
5470               field_number = -1;
5471               p++;
5472               }
5473             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5474             if (*p == 0)
5475               {
5476               field_number *= x;
5477               j = 3;               /* Need 3 args */
5478               field_number_set = TRUE;
5479               }
5480             }
5481           }
5482         else
5483           {
5484           expand_string_message = string_sprintf(
5485             "missing '{' for arg %d of extract", i+1);
5486           goto EXPAND_FAILED_CURLY;
5487           }
5488         }
5489
5490       /* Extract either the numbered or the keyed substring into $value. If
5491       skipping, just pretend the extraction failed. */
5492
5493       lookup_value = skipping? NULL : field_number_set?
5494         expand_gettokened(field_number, sub[1], sub[2]) :
5495         expand_getkeyed(sub[0], sub[1]);
5496
5497       /* If no string follows, $value gets substituted; otherwise there can
5498       be yes/no strings, as for lookup or if. */
5499
5500       switch(process_yesno(
5501                skipping,                     /* were previously skipping */
5502                lookup_value != NULL,         /* success/failure indicator */
5503                save_lookup_value,            /* value to reset for string2 */
5504                &s,                           /* input pointer */
5505                &yield,                       /* output pointer */
5506                US"extract",                  /* condition type */
5507                &resetok))
5508         {
5509         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5510         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5511         }
5512
5513       /* All done - restore numerical variables. */
5514
5515       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5516         save_expand_nlength);
5517
5518       continue;
5519       }
5520
5521     /* return the Nth item from a list */
5522
5523     case EITEM_LISTEXTRACT:
5524       {
5525       int i;
5526       int field_number = 1;
5527       uschar *save_lookup_value = lookup_value;
5528       uschar *sub[2];
5529       int save_expand_nmax =
5530         save_expand_strings(save_expand_nstring, save_expand_nlength);
5531
5532       /* Read the field & list arguments */
5533
5534       for (i = 0; i < 2; i++)
5535         {
5536         while (isspace(*s)) s++;
5537         if (*s != '{')                                  /*}*/
5538           {
5539           expand_string_message = string_sprintf(
5540             "missing '{' for arg %d of listextract", i+1);
5541           goto EXPAND_FAILED_CURLY;
5542           }
5543
5544         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5545         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5546         if (*s++ != '}')
5547           {
5548           expand_string_message = string_sprintf(
5549             "missing '}' closing arg %d of listextract", i+1);
5550           goto EXPAND_FAILED_CURLY;
5551           }
5552
5553         /* After removal of leading and trailing white space, the first
5554         argument must be numeric and nonempty. */
5555
5556         if (i == 0)
5557           {
5558           int len;
5559           int x = 0;
5560           uschar *p = sub[0];
5561
5562           while (isspace(*p)) p++;
5563           sub[0] = p;
5564
5565           len = Ustrlen(p);
5566           while (len > 0 && isspace(p[len-1])) len--;
5567           p[len] = 0;
5568
5569           if (!*p && !skipping)
5570             {
5571             expand_string_message = US"first argument of \"listextract\" must "
5572               "not be empty";
5573             goto EXPAND_FAILED;
5574             }
5575
5576           if (*p == '-')
5577             {
5578             field_number = -1;
5579             p++;
5580             }
5581           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5582           if (*p)
5583             {
5584             expand_string_message = US"first argument of \"listextract\" must "
5585               "be numeric";
5586             goto EXPAND_FAILED;
5587             }
5588           field_number *= x;
5589           }
5590         }
5591
5592       /* Extract the numbered element into $value. If
5593       skipping, just pretend the extraction failed. */
5594
5595       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5596
5597       /* If no string follows, $value gets substituted; otherwise there can
5598       be yes/no strings, as for lookup or if. */
5599
5600       switch(process_yesno(
5601                skipping,                     /* were previously skipping */
5602                lookup_value != NULL,         /* success/failure indicator */
5603                save_lookup_value,            /* value to reset for string2 */
5604                &s,                           /* input pointer */
5605                &yield,                       /* output pointer */
5606                US"listextract",              /* condition type */
5607                &resetok))
5608         {
5609         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5610         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5611         }
5612
5613       /* All done - restore numerical variables. */
5614
5615       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5616         save_expand_nlength);
5617
5618       continue;
5619       }
5620
5621 #ifdef SUPPORT_TLS
5622     case EITEM_CERTEXTRACT:
5623       {
5624       uschar *save_lookup_value = lookup_value;
5625       uschar *sub[2];
5626       int save_expand_nmax =
5627         save_expand_strings(save_expand_nstring, save_expand_nlength);
5628
5629       /* Read the field argument */
5630       while (isspace(*s)) s++;
5631       if (*s != '{')                                    /*}*/
5632         {
5633         expand_string_message = US"missing '{' for field arg of certextract";
5634         goto EXPAND_FAILED_CURLY;
5635         }
5636       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5637       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5638       if (*s++ != '}')
5639         {
5640         expand_string_message = US"missing '}' closing field arg of certextract";
5641         goto EXPAND_FAILED_CURLY;
5642         }
5643       /* strip spaces fore & aft */
5644       {
5645       int len;
5646       uschar *p = sub[0];
5647
5648       while (isspace(*p)) p++;
5649       sub[0] = p;
5650
5651       len = Ustrlen(p);
5652       while (len > 0 && isspace(p[len-1])) len--;
5653       p[len] = 0;
5654       }
5655
5656       /* inspect the cert argument */
5657       while (isspace(*s)) s++;
5658       if (*s != '{')                                    /*}*/
5659         {
5660         expand_string_message = US"missing '{' for cert variable arg of certextract";
5661         goto EXPAND_FAILED_CURLY;
5662         }
5663       if (*++s != '$')
5664         {
5665         expand_string_message = US"second argument of \"certextract\" must "
5666           "be a certificate variable";
5667         goto EXPAND_FAILED;
5668         }
5669       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5670       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5671       if (*s++ != '}')
5672         {
5673         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5674         goto EXPAND_FAILED_CURLY;
5675         }
5676
5677       if (skipping)
5678         lookup_value = NULL;
5679       else
5680         {
5681         lookup_value = expand_getcertele(sub[0], sub[1]);
5682         if (*expand_string_message) goto EXPAND_FAILED;
5683         }
5684       switch(process_yesno(
5685                skipping,                     /* were previously skipping */
5686                lookup_value != NULL,         /* success/failure indicator */
5687                save_lookup_value,            /* value to reset for string2 */
5688                &s,                           /* input pointer */
5689                &yield,                       /* output pointer */
5690                US"certextract",              /* condition type */
5691                &resetok))
5692         {
5693         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5694         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5695         }
5696
5697       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5698         save_expand_nlength);
5699       continue;
5700       }
5701 #endif  /*SUPPORT_TLS*/
5702
5703     /* Handle list operations */
5704
5705     case EITEM_FILTER:
5706     case EITEM_MAP:
5707     case EITEM_REDUCE:
5708       {
5709       int sep = 0;
5710       int save_ptr = yield->ptr;
5711       uschar outsep[2] = { '\0', '\0' };
5712       const uschar *list, *expr, *temp;
5713       uschar *save_iterate_item = iterate_item;
5714       uschar *save_lookup_value = lookup_value;
5715
5716       while (isspace(*s)) s++;
5717       if (*s++ != '{')
5718         {
5719         expand_string_message =
5720           string_sprintf("missing '{' for first arg of %s", name);
5721         goto EXPAND_FAILED_CURLY;
5722         }
5723
5724       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5725       if (list == NULL) goto EXPAND_FAILED;
5726       if (*s++ != '}')
5727         {
5728         expand_string_message =
5729           string_sprintf("missing '}' closing first arg of %s", name);
5730         goto EXPAND_FAILED_CURLY;
5731         }
5732
5733       if (item_type == EITEM_REDUCE)
5734         {
5735         uschar * t;
5736         while (isspace(*s)) s++;
5737         if (*s++ != '{')
5738           {
5739           expand_string_message = US"missing '{' for second arg of reduce";
5740           goto EXPAND_FAILED_CURLY;
5741           }
5742         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5743         if (!t) goto EXPAND_FAILED;
5744         lookup_value = t;
5745         if (*s++ != '}')
5746           {
5747           expand_string_message = US"missing '}' closing second arg of reduce";
5748           goto EXPAND_FAILED_CURLY;
5749           }
5750         }
5751
5752       while (isspace(*s)) s++;
5753       if (*s++ != '{')
5754         {
5755         expand_string_message =
5756           string_sprintf("missing '{' for last arg of %s", name);
5757         goto EXPAND_FAILED_CURLY;
5758         }
5759
5760       expr = s;
5761
5762       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5763       if scanning a "false" part). This allows us to find the end of the
5764       condition, because if the list is empty, we won't actually evaluate the
5765       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5766       the normal internal expansion function. */
5767
5768       if (item_type == EITEM_FILTER)
5769         {
5770         temp = eval_condition(expr, &resetok, NULL);
5771         if (temp != NULL) s = temp;
5772         }
5773       else
5774         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5775
5776       if (temp == NULL)
5777         {
5778         expand_string_message = string_sprintf("%s inside \"%s\" item",
5779           expand_string_message, name);
5780         goto EXPAND_FAILED;
5781         }
5782
5783       while (isspace(*s)) s++;
5784       if (*s++ != '}')
5785         {                                               /*{*/
5786         expand_string_message = string_sprintf("missing } at end of condition "
5787           "or expression inside \"%s\"", name);
5788         goto EXPAND_FAILED;
5789         }
5790
5791       while (isspace(*s)) s++;                          /*{*/
5792       if (*s++ != '}')
5793         {                                               /*{*/
5794         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5795           name);
5796         goto EXPAND_FAILED;
5797         }
5798
5799       /* If we are skipping, we can now just move on to the next item. When
5800       processing for real, we perform the iteration. */
5801
5802       if (skipping) continue;
5803       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5804         {
5805         *outsep = (uschar)sep;      /* Separator as a string */
5806
5807         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5808                           name, iterate_item, lookup_value);
5809
5810         if (item_type == EITEM_FILTER)
5811           {
5812           BOOL condresult;
5813           if (eval_condition(expr, &resetok, &condresult) == NULL)
5814             {
5815             iterate_item = save_iterate_item;
5816             lookup_value = save_lookup_value;
5817             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5818               expand_string_message, name);
5819             goto EXPAND_FAILED;
5820             }
5821           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5822             condresult? "true":"false");
5823           if (condresult)
5824             temp = iterate_item;    /* TRUE => include this item */
5825           else
5826             continue;               /* FALSE => skip this item */
5827           }
5828
5829         /* EITEM_MAP and EITEM_REDUCE */
5830
5831         else
5832           {
5833           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5834           temp = t;
5835           if (temp == NULL)
5836             {
5837             iterate_item = save_iterate_item;
5838             expand_string_message = string_sprintf("%s inside \"%s\" item",
5839               expand_string_message, name);
5840             goto EXPAND_FAILED;
5841             }
5842           if (item_type == EITEM_REDUCE)
5843             {
5844             lookup_value = t;         /* Update the value of $value */
5845             continue;                 /* and continue the iteration */
5846             }
5847           }
5848
5849         /* We reach here for FILTER if the condition is true, always for MAP,
5850         and never for REDUCE. The value in "temp" is to be added to the output
5851         list that is being created, ensuring that any occurrences of the
5852         separator character are doubled. Unless we are dealing with the first
5853         item of the output list, add in a space if the new item begins with the
5854         separator character, or is an empty string. */
5855
5856         if (yield->ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5857           yield = string_catn(yield, US" ", 1);
5858
5859         /* Add the string in "temp" to the output list that we are building,
5860         This is done in chunks by searching for the separator character. */
5861
5862         for (;;)
5863           {
5864           size_t seglen = Ustrcspn(temp, outsep);
5865
5866           yield = string_catn(yield, temp, seglen + 1);
5867
5868           /* If we got to the end of the string we output one character
5869           too many; backup and end the loop. Otherwise arrange to double the
5870           separator. */
5871
5872           if (temp[seglen] == '\0') { yield->ptr--; break; }
5873           yield = string_catn(yield, outsep, 1);
5874           temp += seglen + 1;
5875           }
5876
5877         /* Output a separator after the string: we will remove the redundant
5878         final one at the end. */
5879
5880         yield = string_catn(yield, outsep, 1);
5881         }   /* End of iteration over the list loop */
5882
5883       /* REDUCE has generated no output above: output the final value of
5884       $value. */
5885
5886       if (item_type == EITEM_REDUCE)
5887         {
5888         yield = string_cat(yield, lookup_value);
5889         lookup_value = save_lookup_value;  /* Restore $value */
5890         }
5891
5892       /* FILTER and MAP generate lists: if they have generated anything, remove
5893       the redundant final separator. Even though an empty item at the end of a
5894       list does not count, this is tidier. */
5895
5896       else if (yield->ptr != save_ptr) yield->ptr--;
5897
5898       /* Restore preserved $item */
5899
5900       iterate_item = save_iterate_item;
5901       continue;
5902       }
5903
5904     case EITEM_SORT:
5905       {
5906       int sep = 0;
5907       const uschar *srclist, *cmp, *xtract;
5908       uschar *srcitem;
5909       const uschar *dstlist = NULL, *dstkeylist = NULL;
5910       uschar * tmp;
5911       uschar *save_iterate_item = iterate_item;
5912
5913       while (isspace(*s)) s++;
5914       if (*s++ != '{')
5915         {
5916         expand_string_message = US"missing '{' for list arg of sort";
5917         goto EXPAND_FAILED_CURLY;
5918         }
5919
5920       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5921       if (!srclist) goto EXPAND_FAILED;
5922       if (*s++ != '}')
5923         {
5924         expand_string_message = US"missing '}' closing list arg of sort";
5925         goto EXPAND_FAILED_CURLY;
5926         }
5927
5928       while (isspace(*s)) s++;
5929       if (*s++ != '{')
5930         {
5931         expand_string_message = US"missing '{' for comparator arg of sort";
5932         goto EXPAND_FAILED_CURLY;
5933         }
5934
5935       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5936       if (!cmp) goto EXPAND_FAILED;
5937       if (*s++ != '}')
5938         {
5939         expand_string_message = US"missing '}' closing comparator arg of sort";
5940         goto EXPAND_FAILED_CURLY;
5941         }
5942
5943       while (isspace(*s)) s++;
5944       if (*s++ != '{')
5945         {
5946         expand_string_message = US"missing '{' for extractor arg of sort";
5947         goto EXPAND_FAILED_CURLY;
5948         }
5949
5950       xtract = s;
5951       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5952       if (!tmp) goto EXPAND_FAILED;
5953       xtract = string_copyn(xtract, s - xtract);
5954
5955       if (*s++ != '}')
5956         {
5957         expand_string_message = US"missing '}' closing extractor arg of sort";
5958         goto EXPAND_FAILED_CURLY;
5959         }
5960                                                         /*{*/
5961       if (*s++ != '}')
5962         {                                               /*{*/
5963         expand_string_message = US"missing } at end of \"sort\"";
5964         goto EXPAND_FAILED;
5965         }
5966
5967       if (skipping) continue;
5968
5969       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5970         {
5971         uschar * dstitem;
5972         gstring * newlist = NULL;
5973         gstring * newkeylist = NULL;
5974         uschar * srcfield;
5975
5976         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
5977
5978         /* extract field for comparisons */
5979         iterate_item = srcitem;
5980         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5981                                           TRUE, &resetok))
5982            || !*srcfield)
5983           {
5984           expand_string_message = string_sprintf(
5985               "field-extract in sort: \"%s\"", xtract);
5986           goto EXPAND_FAILED;
5987           }
5988
5989         /* Insertion sort */
5990
5991         /* copy output list until new-item < list-item */
5992         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
5993           {
5994           uschar * dstfield;
5995           uschar * expr;
5996           BOOL before;
5997
5998           /* field for comparison */
5999           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6000             goto sort_mismatch;
6001
6002           /* build and run condition string */
6003           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6004
6005           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6006           if (!eval_condition(expr, &resetok, &before))
6007             {
6008             expand_string_message = string_sprintf("comparison in sort: %s",
6009                 expr);
6010             goto EXPAND_FAILED;
6011             }
6012
6013           if (before)
6014             {
6015             /* New-item sorts before this dst-item.  Append new-item,
6016             then dst-item, then remainder of dst list. */
6017
6018             newlist = string_append_listele(newlist, sep, srcitem);
6019             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6020             srcitem = NULL;
6021
6022             newlist = string_append_listele(newlist, sep, dstitem);
6023             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6024
6025             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6026               {
6027               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6028                 goto sort_mismatch;
6029               newlist = string_append_listele(newlist, sep, dstitem);
6030               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6031               }
6032
6033             break;
6034             }
6035
6036           newlist = string_append_listele(newlist, sep, dstitem);
6037           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6038           }
6039
6040         /* If we ran out of dstlist without consuming srcitem, append it */
6041         if (srcitem)
6042           {
6043           newlist = string_append_listele(newlist, sep, srcitem);
6044           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6045           }
6046
6047         dstlist = newlist->s;
6048         dstkeylist = newkeylist->s;
6049
6050         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6051         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6052         }
6053
6054       if (dstlist)
6055         yield = string_cat(yield, dstlist);
6056
6057       /* Restore preserved $item */
6058       iterate_item = save_iterate_item;
6059       continue;
6060
6061       sort_mismatch:
6062         expand_string_message = US"Internal error in sort (list mismatch)";
6063         goto EXPAND_FAILED;
6064       }
6065
6066
6067     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6068     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6069     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6070     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6071
6072     #define EXPAND_DLFUNC_MAX_ARGS 8
6073
6074     case EITEM_DLFUNC:
6075 #ifndef EXPAND_DLFUNC
6076       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6077         "is not included in this binary";
6078       goto EXPAND_FAILED;
6079
6080 #else   /* EXPAND_DLFUNC */
6081       {
6082       tree_node *t;
6083       exim_dlfunc_t *func;
6084       uschar *result;
6085       int status, argc;
6086       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6087
6088       if ((expand_forbid & RDO_DLFUNC) != 0)
6089         {
6090         expand_string_message =
6091           US"dynamically-loaded functions are not permitted";
6092         goto EXPAND_FAILED;
6093         }
6094
6095       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6096            TRUE, US"dlfunc", &resetok))
6097         {
6098         case 1: goto EXPAND_FAILED_CURLY;
6099         case 2:
6100         case 3: goto EXPAND_FAILED;
6101         }
6102
6103       /* If skipping, we don't actually do anything */
6104
6105       if (skipping) continue;
6106
6107       /* Look up the dynamically loaded object handle in the tree. If it isn't
6108       found, dlopen() the file and put the handle in the tree for next time. */
6109
6110       t = tree_search(dlobj_anchor, argv[0]);
6111       if (t == NULL)
6112         {
6113         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6114         if (handle == NULL)
6115           {
6116           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6117             argv[0], dlerror());
6118           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6119           goto EXPAND_FAILED;
6120           }
6121         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6122         Ustrcpy(t->name, argv[0]);
6123         t->data.ptr = handle;
6124         (void)tree_insertnode(&dlobj_anchor, t);
6125         }
6126
6127       /* Having obtained the dynamically loaded object handle, look up the
6128       function pointer. */
6129
6130       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6131       if (func == NULL)
6132         {
6133         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6134           "%s", argv[1], argv[0], dlerror());
6135         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6136         goto EXPAND_FAILED;
6137         }
6138
6139       /* Call the function and work out what to do with the result. If it
6140       returns OK, we have a replacement string; if it returns DEFER then
6141       expansion has failed in a non-forced manner; if it returns FAIL then
6142       failure was forced; if it returns ERROR or any other value there's a
6143       problem, so panic slightly. In any case, assume that the function has
6144       side-effects on the store that must be preserved. */
6145
6146       resetok = FALSE;
6147       result = NULL;
6148       for (argc = 0; argv[argc] != NULL; argc++);
6149       status = func(&result, argc - 2, &argv[2]);
6150       if(status == OK)
6151         {
6152         if (result == NULL) result = US"";
6153         yield = string_cat(yield, result);
6154         continue;
6155         }
6156       else
6157         {
6158         expand_string_message = result == NULL ? US"(no message)" : result;
6159         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6160           else if(status != FAIL)
6161             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6162               argv[0], argv[1], status, expand_string_message);
6163         goto EXPAND_FAILED;
6164         }
6165       }
6166 #endif /* EXPAND_DLFUNC */
6167
6168     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6169       {
6170       uschar * key;
6171       uschar *save_lookup_value = lookup_value;
6172
6173       while (isspace(*s)) s++;
6174       if (*s != '{')                                    /*}*/
6175         goto EXPAND_FAILED;
6176
6177       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6178       if (!key) goto EXPAND_FAILED;                     /*{*/
6179       if (*s++ != '}')
6180         {
6181         expand_string_message = US"missing '{' for name arg of env";
6182         goto EXPAND_FAILED_CURLY;
6183         }
6184
6185       lookup_value = US getenv(CS key);
6186
6187       switch(process_yesno(
6188                skipping,                     /* were previously skipping */
6189                lookup_value != NULL,         /* success/failure indicator */
6190                save_lookup_value,            /* value to reset for string2 */
6191                &s,                           /* input pointer */
6192                &yield,                       /* output pointer */
6193                US"env",                      /* condition type */
6194                &resetok))
6195         {
6196         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6197         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6198         }
6199       continue;
6200       }
6201     }   /* EITEM_* switch */
6202
6203   /* Control reaches here if the name is not recognized as one of the more
6204   complicated expansion items. Check for the "operator" syntax (name terminated
6205   by a colon). Some of the operators have arguments, separated by _ from the
6206   name. */
6207
6208   if (*s == ':')
6209     {
6210     int c;
6211     uschar *arg = NULL;
6212     uschar *sub;
6213     var_entry *vp = NULL;
6214
6215     /* Owing to an historical mis-design, an underscore may be part of the
6216     operator name, or it may introduce arguments.  We therefore first scan the
6217     table of names that contain underscores. If there is no match, we cut off
6218     the arguments and then scan the main table. */
6219
6220     if ((c = chop_match(name, op_table_underscore,
6221                         nelem(op_table_underscore))) < 0)
6222       {
6223       arg = Ustrchr(name, '_');
6224       if (arg != NULL) *arg = 0;
6225       c = chop_match(name, op_table_main, nelem(op_table_main));
6226       if (c >= 0) c += nelem(op_table_underscore);
6227       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6228       }
6229
6230     /* Deal specially with operators that might take a certificate variable
6231     as we do not want to do the usual expansion. For most, expand the string.*/
6232     switch(c)
6233       {
6234 #ifdef SUPPORT_TLS
6235       case EOP_MD5:
6236       case EOP_SHA1:
6237       case EOP_SHA256:
6238       case EOP_BASE64:
6239         if (s[1] == '$')
6240           {
6241           const uschar * s1 = s;
6242           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6243                   FALSE, &resetok);
6244           if (!sub)       goto EXPAND_FAILED;           /*{*/
6245           if (*s1 != '}')
6246             {
6247             expand_string_message =
6248               string_sprintf("missing '}' closing cert arg of %s", name);
6249             goto EXPAND_FAILED_CURLY;
6250             }
6251           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6252             {
6253             s = s1+1;
6254             break;
6255             }
6256           vp = NULL;
6257           }
6258         /*FALLTHROUGH*/
6259 #endif
6260       default:
6261         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6262         if (!sub) goto EXPAND_FAILED;
6263         s++;
6264         break;
6265       }
6266
6267     /* If we are skipping, we don't need to perform the operation at all.
6268     This matters for operations like "mask", because the data may not be
6269     in the correct format when skipping. For example, the expression may test
6270     for the existence of $sender_host_address before trying to mask it. For
6271     other operations, doing them may not fail, but it is a waste of time. */
6272
6273     if (skipping && c >= 0) continue;
6274
6275     /* Otherwise, switch on the operator type */
6276
6277     switch(c)
6278       {
6279       case EOP_BASE32:
6280         {
6281         uschar *t;
6282         unsigned long int n = Ustrtoul(sub, &t, 10);
6283         gstring * g = NULL;
6284
6285         if (*t != 0)
6286           {
6287           expand_string_message = string_sprintf("argument for base32 "
6288             "operator is \"%s\", which is not a decimal number", sub);
6289           goto EXPAND_FAILED;
6290           }
6291         for ( ; n; n >>= 5)
6292           g = string_catn(g, &base32_chars[n & 0x1f], 1);
6293
6294         if (g) while (g->ptr > 0) yield = string_catn(yield, &g->s[--g->ptr], 1);
6295         continue;
6296         }
6297
6298       case EOP_BASE32D:
6299         {
6300         uschar *tt = sub;
6301         unsigned long int n = 0;
6302         uschar * s;
6303         while (*tt)
6304           {
6305           uschar * t = Ustrchr(base32_chars, *tt++);
6306           if (t == NULL)
6307             {
6308             expand_string_message = string_sprintf("argument for base32d "
6309               "operator is \"%s\", which is not a base 32 number", sub);
6310             goto EXPAND_FAILED;
6311             }
6312           n = n * 32 + (t - base32_chars);
6313           }
6314         s = string_sprintf("%ld", n);
6315         yield = string_cat(yield, s);
6316         continue;
6317         }
6318
6319       case EOP_BASE62:
6320         {
6321         uschar *t;
6322         unsigned long int n = Ustrtoul(sub, &t, 10);
6323         if (*t != 0)
6324           {
6325           expand_string_message = string_sprintf("argument for base62 "
6326             "operator is \"%s\", which is not a decimal number", sub);
6327           goto EXPAND_FAILED;
6328           }
6329         t = string_base62(n);
6330         yield = string_cat(yield, t);
6331         continue;
6332         }
6333
6334       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6335
6336       case EOP_BASE62D:
6337         {
6338         uschar buf[16];
6339         uschar *tt = sub;
6340         unsigned long int n = 0;
6341         while (*tt != 0)
6342           {
6343           uschar *t = Ustrchr(base62_chars, *tt++);
6344           if (t == NULL)
6345             {
6346             expand_string_message = string_sprintf("argument for base62d "
6347               "operator is \"%s\", which is not a base %d number", sub,
6348               BASE_62);
6349             goto EXPAND_FAILED;
6350             }
6351           n = n * BASE_62 + (t - base62_chars);
6352           }
6353         (void)sprintf(CS buf, "%ld", n);
6354         yield = string_cat(yield, buf);
6355         continue;
6356         }
6357
6358       case EOP_EXPAND:
6359         {
6360         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6361         if (expanded == NULL)
6362           {
6363           expand_string_message =
6364             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6365               expand_string_message);
6366           goto EXPAND_FAILED;
6367           }
6368         yield = string_cat(yield, expanded);
6369         continue;
6370         }
6371
6372       case EOP_LC:
6373         {
6374         int count = 0;
6375         uschar *t = sub - 1;
6376         while (*(++t) != 0) { *t = tolower(*t); count++; }
6377         yield = string_catn(yield, sub, count);
6378         continue;
6379         }
6380
6381       case EOP_UC:
6382         {
6383         int count = 0;
6384         uschar *t = sub - 1;
6385         while (*(++t) != 0) { *t = toupper(*t); count++; }
6386         yield = string_catn(yield, sub, count);
6387         continue;
6388         }
6389
6390       case EOP_MD5:
6391 #ifdef SUPPORT_TLS
6392         if (vp && *(void **)vp->value)
6393           {
6394           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6395           yield = string_cat(yield, cp);
6396           }
6397         else
6398 #endif
6399           {
6400           md5 base;
6401           uschar digest[16];
6402           int j;
6403           char st[33];
6404           md5_start(&base);
6405           md5_end(&base, sub, Ustrlen(sub), digest);
6406           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6407           yield = string_cat(yield, US st);
6408           }
6409         continue;
6410
6411       case EOP_SHA1:
6412 #ifdef SUPPORT_TLS
6413         if (vp && *(void **)vp->value)
6414           {
6415           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6416           yield = string_cat(yield, cp);
6417           }
6418         else
6419 #endif
6420           {
6421           hctx h;
6422           uschar digest[20];
6423           int j;
6424           char st[41];
6425           sha1_start(&h);
6426           sha1_end(&h, sub, Ustrlen(sub), digest);
6427           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6428           yield = string_catn(yield, US st, 40);
6429           }
6430         continue;
6431
6432       case EOP_SHA256:
6433 #ifdef EXIM_HAVE_SHA2
6434         if (vp && *(void **)vp->value)
6435           {
6436           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6437           yield = string_cat(yield, cp);
6438           }
6439         else
6440           {
6441           hctx h;
6442           blob b;
6443           char st[3];
6444
6445           if (!exim_sha_init(&h, HASH_SHA2_256))
6446             {
6447             expand_string_message = US"unrecognised sha256 variant";
6448             goto EXPAND_FAILED;
6449             }
6450           exim_sha_update(&h, sub, Ustrlen(sub));
6451           exim_sha_finish(&h, &b);
6452           while (b.len-- > 0)
6453             {
6454             sprintf(st, "%02X", *b.data++);
6455             yield = string_catn(yield, US st, 2);
6456             }
6457           }
6458 #else
6459           expand_string_message = US"sha256 only supported with TLS";
6460 #endif
6461         continue;
6462
6463       case EOP_SHA3:
6464 #ifdef EXIM_HAVE_SHA3
6465         {
6466         hctx h;
6467         blob b;
6468         char st[3];
6469         hashmethod m = !arg ? HASH_SHA3_256
6470           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6471           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6472           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6473           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6474           : HASH_BADTYPE;
6475
6476         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6477           {
6478           expand_string_message = US"unrecognised sha3 variant";
6479           goto EXPAND_FAILED;
6480           }
6481
6482         exim_sha_update(&h, sub, Ustrlen(sub));
6483         exim_sha_finish(&h, &b);
6484         while (b.len-- > 0)
6485           {
6486           sprintf(st, "%02X", *b.data++);
6487           yield = string_catn(yield, US st, 2);
6488           }
6489         }
6490         continue;
6491 #else
6492         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6493         goto EXPAND_FAILED;
6494 #endif
6495
6496       /* Convert hex encoding to base64 encoding */
6497
6498       case EOP_HEX2B64:
6499         {
6500         int c = 0;
6501         int b = -1;
6502         uschar *in = sub;
6503         uschar *out = sub;
6504         uschar *enc;
6505
6506         for (enc = sub; *enc != 0; enc++)
6507           {
6508           if (!isxdigit(*enc))
6509             {
6510             expand_string_message = string_sprintf("\"%s\" is not a hex "
6511               "string", sub);
6512             goto EXPAND_FAILED;
6513             }
6514           c++;
6515           }
6516
6517         if ((c & 1) != 0)
6518           {
6519           expand_string_message = string_sprintf("\"%s\" contains an odd "
6520             "number of characters", sub);
6521           goto EXPAND_FAILED;
6522           }
6523
6524         while ((c = *in++) != 0)
6525           {
6526           if (isdigit(c)) c -= '0';
6527           else c = toupper(c) - 'A' + 10;
6528           if (b == -1)
6529             {
6530             b = c << 4;
6531             }
6532           else
6533             {
6534             *out++ = b | c;
6535             b = -1;
6536             }
6537           }
6538
6539         enc = b64encode(sub, out - sub);
6540         yield = string_cat(yield, enc);
6541         continue;
6542         }
6543
6544       /* Convert octets outside 0x21..0x7E to \xXX form */
6545
6546       case EOP_HEXQUOTE:
6547         {
6548         uschar *t = sub - 1;
6549         while (*(++t) != 0)
6550           {
6551           if (*t < 0x21 || 0x7E < *t)
6552             yield = string_catn(yield, string_sprintf("\\x%02x", *t), 4);
6553           else
6554             yield = string_catn(yield, t, 1);
6555           }
6556         continue;
6557         }
6558
6559       /* count the number of list elements */
6560
6561       case EOP_LISTCOUNT:
6562         {
6563         int cnt = 0;
6564         int sep = 0;
6565         uschar * cp;
6566         uschar buffer[256];
6567
6568         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6569         cp = string_sprintf("%d", cnt);
6570         yield = string_cat(yield, cp);
6571         continue;
6572         }
6573
6574       /* expand a named list given the name */
6575       /* handles nested named lists; requotes as colon-sep list */
6576
6577       case EOP_LISTNAMED:
6578         {
6579         tree_node *t = NULL;
6580         const uschar * list;
6581         int sep = 0;
6582         uschar * item;
6583         uschar * suffix = US"";
6584         BOOL needsep = FALSE;
6585         uschar buffer[256];
6586
6587         if (*sub == '+') sub++;
6588         if (arg == NULL)        /* no-argument version */
6589           {
6590           if (!(t = tree_search(addresslist_anchor, sub)) &&
6591               !(t = tree_search(domainlist_anchor,  sub)) &&
6592               !(t = tree_search(hostlist_anchor,    sub)))
6593             t = tree_search(localpartlist_anchor, sub);
6594           }
6595         else switch(*arg)       /* specific list-type version */
6596           {
6597           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6598           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6599           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6600           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6601           default:
6602             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6603             goto EXPAND_FAILED;
6604           }
6605
6606         if(!t)
6607           {
6608           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6609             sub, !arg?""
6610               : *arg=='a'?"address "
6611               : *arg=='d'?"domain "
6612               : *arg=='h'?"host "
6613               : *arg=='l'?"localpart "
6614               : 0);
6615           goto EXPAND_FAILED;
6616           }
6617
6618         list = ((namedlist_block *)(t->data.ptr))->string;
6619
6620         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))))
6621           {
6622           uschar * buf = US" : ";
6623           if (needsep)
6624             yield = string_catn(yield, buf, 3);
6625           else
6626             needsep = TRUE;
6627
6628           if (*item == '+')     /* list item is itself a named list */
6629             {
6630             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6631             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6632             }
6633           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6634             {
6635             char * cp;
6636             char tok[3];
6637             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6638             while ((cp= strpbrk(CCS item, tok)))
6639               {
6640               yield = string_catn(yield, item, cp - CS item);
6641               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6642                 {
6643                 yield = string_catn(yield, US"::", 2);
6644                 item = US cp;
6645                 }
6646               else              /* sep in item; should already be doubled; emit once */
6647                 {
6648                 yield = string_catn(yield, US tok, 1);
6649                 if (*cp == sep) cp++;
6650                 item = US cp;
6651                 }
6652               }
6653             }
6654           yield = string_cat(yield, item);
6655           }
6656         continue;
6657         }
6658
6659       /* mask applies a mask to an IP address; for example the result of
6660       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6661
6662       case EOP_MASK:
6663         {
6664         int count;
6665         uschar *endptr;
6666         int binary[4];
6667         int mask, maskoffset;
6668         int type = string_is_ip_address(sub, &maskoffset);
6669         uschar buffer[64];
6670
6671         if (type == 0)
6672           {
6673           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6674            sub);
6675           goto EXPAND_FAILED;
6676           }
6677
6678         if (maskoffset == 0)
6679           {
6680           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6681             sub);
6682           goto EXPAND_FAILED;
6683           }
6684
6685         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6686
6687         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6688           {
6689           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6690             sub);
6691           goto EXPAND_FAILED;
6692           }
6693
6694         /* Convert the address to binary integer(s) and apply the mask */
6695
6696         sub[maskoffset] = 0;
6697         count = host_aton(sub, binary);
6698         host_mask(count, binary, mask);
6699
6700         /* Convert to masked textual format and add to output. */
6701
6702         yield = string_catn(yield, buffer,
6703           host_nmtoa(count, binary, mask, buffer, '.'));
6704         continue;
6705         }
6706
6707       case EOP_IPV6NORM:
6708       case EOP_IPV6DENORM:
6709         {
6710         int type = string_is_ip_address(sub, NULL);
6711         int binary[4];
6712         uschar buffer[44];
6713
6714         switch (type)
6715           {
6716           case 6:
6717             (void) host_aton(sub, binary);
6718             break;
6719
6720           case 4:       /* convert to IPv4-mapped IPv6 */
6721             binary[0] = binary[1] = 0;
6722             binary[2] = 0x0000ffff;
6723             (void) host_aton(sub, binary+3);
6724             break;
6725
6726           case 0:
6727             expand_string_message =
6728               string_sprintf("\"%s\" is not an IP address", sub);
6729             goto EXPAND_FAILED;
6730           }
6731
6732         yield = string_catn(yield, buffer, c == EOP_IPV6NORM
6733                     ? ipv6_nmtoa(binary, buffer)
6734                     : host_nmtoa(4, binary, -1, buffer, ':')
6735                   );
6736         continue;
6737         }
6738
6739       case EOP_ADDRESS:
6740       case EOP_LOCAL_PART:
6741       case EOP_DOMAIN:
6742         {
6743         uschar * error;
6744         int start, end, domain;
6745         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6746           FALSE);
6747         if (t)
6748           if (c != EOP_DOMAIN)
6749             {
6750             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6751             yield = string_catn(yield, sub+start, end-start);
6752             }
6753           else if (domain != 0)
6754             {
6755             domain += start;
6756             yield = string_catn(yield, sub+domain, end-domain);
6757             }
6758         continue;
6759         }
6760
6761       case EOP_ADDRESSES:
6762         {
6763         uschar outsep[2] = { ':', '\0' };
6764         uschar *address, *error;
6765         int save_ptr = yield->ptr;
6766         int start, end, domain;  /* Not really used */
6767
6768         while (isspace(*sub)) sub++;
6769         if (*sub == '>') { *outsep = *++sub; ++sub; }
6770         parse_allow_group = TRUE;
6771
6772         for (;;)
6773           {
6774           uschar *p = parse_find_address_end(sub, FALSE);
6775           uschar saveend = *p;
6776           *p = '\0';
6777           address = parse_extract_address(sub, &error, &start, &end, &domain,
6778             FALSE);
6779           *p = saveend;
6780
6781           /* Add the address to the output list that we are building. This is
6782           done in chunks by searching for the separator character. At the
6783           start, unless we are dealing with the first address of the output
6784           list, add in a space if the new address begins with the separator
6785           character, or is an empty string. */
6786
6787           if (address != NULL)
6788             {
6789             if (yield->ptr != save_ptr && address[0] == *outsep)
6790               yield = string_catn(yield, US" ", 1);
6791
6792             for (;;)
6793               {
6794               size_t seglen = Ustrcspn(address, outsep);
6795               yield = string_catn(yield, address, seglen + 1);
6796
6797               /* If we got to the end of the string we output one character
6798               too many. */
6799
6800               if (address[seglen] == '\0') { yield->ptr--; break; }
6801               yield = string_catn(yield, outsep, 1);
6802               address += seglen + 1;
6803               }
6804
6805             /* Output a separator after the string: we will remove the
6806             redundant final one at the end. */
6807
6808             yield = string_catn(yield, outsep, 1);
6809             }
6810
6811           if (saveend == '\0') break;
6812           sub = p + 1;
6813           }
6814
6815         /* If we have generated anything, remove the redundant final
6816         separator. */
6817
6818         if (yield->ptr != save_ptr) yield->ptr--;
6819         parse_allow_group = FALSE;
6820         continue;
6821         }
6822
6823
6824       /* quote puts a string in quotes if it is empty or contains anything
6825       other than alphamerics, underscore, dot, or hyphen.
6826
6827       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6828       be quoted in order to be a valid local part.
6829
6830       In both cases, newlines and carriage returns are converted into \n and \r
6831       respectively */
6832
6833       case EOP_QUOTE:
6834       case EOP_QUOTE_LOCAL_PART:
6835       if (arg == NULL)
6836         {
6837         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6838         uschar *t = sub - 1;
6839
6840         if (c == EOP_QUOTE)
6841           {
6842           while (!needs_quote && *(++t) != 0)
6843             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6844           }
6845         else  /* EOP_QUOTE_LOCAL_PART */
6846           {
6847           while (!needs_quote && *(++t) != 0)
6848             needs_quote = !isalnum(*t) &&
6849               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6850               (*t != '.' || t == sub || t[1] == 0);
6851           }
6852
6853         if (needs_quote)
6854           {
6855           yield = string_catn(yield, US"\"", 1);
6856           t = sub - 1;
6857           while (*(++t) != 0)
6858             {
6859             if (*t == '\n')
6860               yield = string_catn(yield, US"\\n", 2);
6861             else if (*t == '\r')
6862               yield = string_catn(yield, US"\\r", 2);
6863             else
6864               {
6865               if (*t == '\\' || *t == '"')
6866                 yield = string_catn(yield, US"\\", 1);
6867               yield = string_catn(yield, t, 1);
6868               }
6869             }
6870           yield = string_catn(yield, US"\"", 1);
6871           }
6872         else yield = string_cat(yield, sub);
6873         continue;
6874         }
6875
6876       /* quote_lookuptype does lookup-specific quoting */
6877
6878       else
6879         {
6880         int n;
6881         uschar *opt = Ustrchr(arg, '_');
6882
6883         if (opt != NULL) *opt++ = 0;
6884
6885         n = search_findtype(arg, Ustrlen(arg));
6886         if (n < 0)
6887           {
6888           expand_string_message = search_error_message;
6889           goto EXPAND_FAILED;
6890           }
6891
6892         if (lookup_list[n]->quote != NULL)
6893           sub = (lookup_list[n]->quote)(sub, opt);
6894         else if (opt != NULL) sub = NULL;
6895
6896         if (sub == NULL)
6897           {
6898           expand_string_message = string_sprintf(
6899             "\"%s\" unrecognized after \"${quote_%s\"",
6900             opt, arg);
6901           goto EXPAND_FAILED;
6902           }
6903
6904         yield = string_cat(yield, sub);
6905         continue;
6906         }
6907
6908       /* rx quote sticks in \ before any non-alphameric character so that
6909       the insertion works in a regular expression. */
6910
6911       case EOP_RXQUOTE:
6912         {
6913         uschar *t = sub - 1;
6914         while (*(++t) != 0)
6915           {
6916           if (!isalnum(*t))
6917             yield = string_catn(yield, US"\\", 1);
6918           yield = string_catn(yield, t, 1);
6919           }
6920         continue;
6921         }
6922
6923       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6924       prescribed by the RFC, if there are characters that need to be encoded */
6925
6926       case EOP_RFC2047:
6927         {
6928         uschar buffer[2048];
6929         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6930           buffer, sizeof(buffer), FALSE);
6931         yield = string_cat(yield, string);
6932         continue;
6933         }
6934
6935       /* RFC 2047 decode */
6936
6937       case EOP_RFC2047D:
6938         {
6939         int len;
6940         uschar *error;
6941         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6942           headers_charset, '?', &len, &error);
6943         if (error != NULL)
6944           {
6945           expand_string_message = error;
6946           goto EXPAND_FAILED;
6947           }
6948         yield = string_catn(yield, decoded, len);
6949         continue;
6950         }
6951
6952       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6953       underscores */
6954
6955       case EOP_FROM_UTF8:
6956         {
6957         while (*sub != 0)
6958           {
6959           int c;
6960           uschar buff[4];
6961           GETUTF8INC(c, sub);
6962           if (c > 255) c = '_';
6963           buff[0] = c;
6964           yield = string_catn(yield, buff, 1);
6965           }
6966         continue;
6967         }
6968
6969           /* replace illegal UTF-8 sequences by replacement character  */
6970
6971       #define UTF8_REPLACEMENT_CHAR US"?"
6972
6973       case EOP_UTF8CLEAN:
6974         {
6975         int seq_len = 0, index = 0;
6976         int bytes_left = 0;
6977         long codepoint = -1;
6978         uschar seq_buff[4];                     /* accumulate utf-8 here */
6979
6980         while (*sub != 0)
6981           {
6982           int complete = 0;
6983           uschar c = *sub++;
6984
6985           if (bytes_left)
6986             {
6987             if ((c & 0xc0) != 0x80)
6988                     /* wrong continuation byte; invalidate all bytes */
6989               complete = 1; /* error */
6990             else
6991               {
6992               codepoint = (codepoint << 6) | (c & 0x3f);
6993               seq_buff[index++] = c;
6994               if (--bytes_left == 0)            /* codepoint complete */
6995                 if(codepoint > 0x10FFFF)        /* is it too large? */
6996                   complete = -1;        /* error (RFC3629 limit) */
6997                 else
6998                   {             /* finished; output utf-8 sequence */
6999                   yield = string_catn(yield, seq_buff, seq_len);
7000                   index = 0;
7001                   }
7002               }
7003             }
7004           else  /* no bytes left: new sequence */
7005             {
7006             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7007               {
7008               yield = string_catn(yield, &c, 1);
7009               continue;
7010               }
7011             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7012               {
7013               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7014                 complete = -1;
7015               else
7016                 {
7017                   bytes_left = 1;
7018                   codepoint = c & 0x1f;
7019                 }
7020               }
7021             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7022               {
7023               bytes_left = 2;
7024               codepoint = c & 0x0f;
7025               }
7026             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7027               {
7028               bytes_left = 3;
7029               codepoint = c & 0x07;
7030               }
7031             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7032               complete = -1;
7033
7034             seq_buff[index++] = c;
7035             seq_len = bytes_left + 1;
7036             }           /* if(bytes_left) */
7037
7038           if (complete != 0)
7039             {
7040             bytes_left = index = 0;
7041             yield = string_catn(yield, UTF8_REPLACEMENT_CHAR, 1);
7042             }
7043           if ((complete == 1) && ((c & 0x80) == 0))
7044                         /* ASCII character follows incomplete sequence */
7045               yield = string_catn(yield, &c, 1);
7046           }
7047         continue;
7048         }
7049
7050 #ifdef SUPPORT_I18N
7051       case EOP_UTF8_DOMAIN_TO_ALABEL:
7052         {
7053         uschar * error = NULL;
7054         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7055         if (error)
7056           {
7057           expand_string_message = string_sprintf(
7058             "error converting utf8 (%s) to alabel: %s",
7059             string_printing(sub), error);
7060           goto EXPAND_FAILED;
7061           }
7062         yield = string_cat(yield, s);
7063         continue;
7064         }
7065
7066       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7067         {
7068         uschar * error = NULL;
7069         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7070         if (error)
7071           {
7072           expand_string_message = string_sprintf(
7073             "error converting alabel (%s) to utf8: %s",
7074             string_printing(sub), error);
7075           goto EXPAND_FAILED;
7076           }
7077         yield = string_cat(yield, s);
7078         continue;
7079         }
7080
7081       case EOP_UTF8_LOCALPART_TO_ALABEL:
7082         {
7083         uschar * error = NULL;
7084         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7085         if (error)
7086           {
7087           expand_string_message = string_sprintf(
7088             "error converting utf8 (%s) to alabel: %s",
7089             string_printing(sub), error);
7090           goto EXPAND_FAILED;
7091           }
7092         yield = string_cat(yield, s);
7093         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield->s);
7094         continue;
7095         }
7096
7097       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7098         {
7099         uschar * error = NULL;
7100         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7101         if (error)
7102           {
7103           expand_string_message = string_sprintf(
7104             "error converting alabel (%s) to utf8: %s",
7105             string_printing(sub), error);
7106           goto EXPAND_FAILED;
7107           }
7108         yield = string_cat(yield, s);
7109         continue;
7110         }
7111 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7112
7113       /* escape turns all non-printing characters into escape sequences. */
7114
7115       case EOP_ESCAPE:
7116         {
7117         const uschar * t = string_printing(sub);
7118         yield = string_cat(yield, t);
7119         continue;
7120         }
7121
7122       case EOP_ESCAPE8BIT:
7123         {
7124         const uschar * s = sub;
7125         uschar c;
7126
7127         for (s = sub; (c = *s); s++)
7128           yield = c < 127 && c != '\\'
7129             ? string_catn(yield, s, 1)
7130             : string_catn(yield, string_sprintf("\\%03o", c), 4);
7131         continue;
7132         }
7133
7134       /* Handle numeric expression evaluation */
7135
7136       case EOP_EVAL:
7137       case EOP_EVAL10:
7138         {
7139         uschar *save_sub = sub;
7140         uschar *error = NULL;
7141         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7142         if (error != NULL)
7143           {
7144           expand_string_message = string_sprintf("error in expression "
7145             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7146               save_sub);
7147           goto EXPAND_FAILED;
7148           }
7149         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7150         yield = string_cat(yield, var_buffer);
7151         continue;
7152         }
7153
7154       /* Handle time period formating */
7155
7156       case EOP_TIME_EVAL:
7157         {
7158         int n = readconf_readtime(sub, 0, FALSE);
7159         if (n < 0)
7160           {
7161           expand_string_message = string_sprintf("string \"%s\" is not an "
7162             "Exim time interval in \"%s\" operator", sub, name);
7163           goto EXPAND_FAILED;
7164           }
7165         sprintf(CS var_buffer, "%d", n);
7166         yield = string_cat(yield, var_buffer);
7167         continue;
7168         }
7169
7170       case EOP_TIME_INTERVAL:
7171         {
7172         int n;
7173         uschar *t = read_number(&n, sub);
7174         if (*t != 0) /* Not A Number*/
7175           {
7176           expand_string_message = string_sprintf("string \"%s\" is not a "
7177             "positive number in \"%s\" operator", sub, name);
7178           goto EXPAND_FAILED;
7179           }
7180         t = readconf_printtime(n);
7181         yield = string_cat(yield, t);
7182         continue;
7183         }
7184
7185       /* Convert string to base64 encoding */
7186
7187       case EOP_STR2B64:
7188       case EOP_BASE64:
7189         {
7190 #ifdef SUPPORT_TLS
7191         uschar * s = vp && *(void **)vp->value
7192           ? tls_cert_der_b64(*(void **)vp->value)
7193           : b64encode(sub, Ustrlen(sub));
7194 #else
7195         uschar * s = b64encode(sub, Ustrlen(sub));
7196 #endif
7197         yield = string_cat(yield, s);
7198         continue;
7199         }
7200
7201       case EOP_BASE64D:
7202         {
7203         uschar * s;
7204         int len = b64decode(sub, &s);
7205         if (len < 0)
7206           {
7207           expand_string_message = string_sprintf("string \"%s\" is not "
7208             "well-formed for \"%s\" operator", sub, name);
7209           goto EXPAND_FAILED;
7210           }
7211         yield = string_cat(yield, s);
7212         continue;
7213         }
7214
7215       /* strlen returns the length of the string */
7216
7217       case EOP_STRLEN:
7218         {
7219         uschar buff[24];
7220         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7221         yield = string_cat(yield, buff);
7222         continue;
7223         }
7224
7225       /* length_n or l_n takes just the first n characters or the whole string,
7226       whichever is the shorter;
7227
7228       substr_m_n, and s_m_n take n characters from offset m; negative m take
7229       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7230       takes the rest, either to the right or to the left.
7231
7232       hash_n or h_n makes a hash of length n from the string, yielding n
7233       characters from the set a-z; hash_n_m makes a hash of length n, but
7234       uses m characters from the set a-zA-Z0-9.
7235
7236       nhash_n returns a single number between 0 and n-1 (in text form), while
7237       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7238       between 0 and n-1 and the second between 0 and m-1. */
7239
7240       case EOP_LENGTH:
7241       case EOP_L:
7242       case EOP_SUBSTR:
7243       case EOP_S:
7244       case EOP_HASH:
7245       case EOP_H:
7246       case EOP_NHASH:
7247       case EOP_NH:
7248         {
7249         int sign = 1;
7250         int value1 = 0;
7251         int value2 = -1;
7252         int *pn;
7253         int len;
7254         uschar *ret;
7255
7256         if (arg == NULL)
7257           {
7258           expand_string_message = string_sprintf("missing values after %s",
7259             name);
7260           goto EXPAND_FAILED;
7261           }
7262
7263         /* "length" has only one argument, effectively being synonymous with
7264         substr_0_n. */
7265
7266         if (c == EOP_LENGTH || c == EOP_L)
7267           {
7268           pn = &value2;
7269           value2 = 0;
7270           }
7271
7272         /* The others have one or two arguments; for "substr" the first may be
7273         negative. The second being negative means "not supplied". */
7274
7275         else
7276           {
7277           pn = &value1;
7278           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7279           }
7280
7281         /* Read up to two numbers, separated by underscores */
7282
7283         ret = arg;
7284         while (*arg != 0)
7285           {
7286           if (arg != ret && *arg == '_' && pn == &value1)
7287             {
7288             pn = &value2;
7289             value2 = 0;
7290             if (arg[1] != 0) arg++;
7291             }
7292           else if (!isdigit(*arg))
7293             {
7294             expand_string_message =
7295               string_sprintf("non-digit after underscore in \"%s\"", name);
7296             goto EXPAND_FAILED;
7297             }
7298           else *pn = (*pn)*10 + *arg++ - '0';
7299           }
7300         value1 *= sign;
7301
7302         /* Perform the required operation */
7303
7304         ret =
7305           (c == EOP_HASH || c == EOP_H)?
7306              compute_hash(sub, value1, value2, &len) :
7307           (c == EOP_NHASH || c == EOP_NH)?
7308              compute_nhash(sub, value1, value2, &len) :
7309              extract_substr(sub, value1, value2, &len);
7310
7311         if (ret == NULL) goto EXPAND_FAILED;
7312         yield = string_catn(yield, ret, len);
7313         continue;
7314         }
7315
7316       /* Stat a path */
7317
7318       case EOP_STAT:
7319         {
7320         uschar *s;
7321         uschar smode[12];
7322         uschar **modetable[3];
7323         int i;
7324         mode_t mode;
7325         struct stat st;
7326
7327         if ((expand_forbid & RDO_EXISTS) != 0)
7328           {
7329           expand_string_message = US"Use of the stat() expansion is not permitted";
7330           goto EXPAND_FAILED;
7331           }
7332
7333         if (stat(CS sub, &st) < 0)
7334           {
7335           expand_string_message = string_sprintf("stat(%s) failed: %s",
7336             sub, strerror(errno));
7337           goto EXPAND_FAILED;
7338           }
7339         mode = st.st_mode;
7340         switch (mode & S_IFMT)
7341           {
7342           case S_IFIFO: smode[0] = 'p'; break;
7343           case S_IFCHR: smode[0] = 'c'; break;
7344           case S_IFDIR: smode[0] = 'd'; break;
7345           case S_IFBLK: smode[0] = 'b'; break;
7346           case S_IFREG: smode[0] = '-'; break;
7347           default: smode[0] = '?'; break;
7348           }
7349
7350         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7351         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7352         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7353
7354         for (i = 0; i < 3; i++)
7355           {
7356           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7357           mode >>= 3;
7358           }
7359
7360         smode[10] = 0;
7361         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7362           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7363           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7364           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7365           (long)st.st_gid, st.st_size, (long)st.st_atime,
7366           (long)st.st_mtime, (long)st.st_ctime);
7367         yield = string_cat(yield, s);
7368         continue;
7369         }
7370
7371       /* vaguely random number less than N */
7372
7373       case EOP_RANDINT:
7374         {
7375         int_eximarith_t max;
7376         uschar *s;
7377
7378         max = expanded_string_integer(sub, TRUE);
7379         if (expand_string_message != NULL)
7380           goto EXPAND_FAILED;
7381         s = string_sprintf("%d", vaguely_random_number((int)max));
7382         yield = string_cat(yield, s);
7383         continue;
7384         }
7385
7386       /* Reverse IP, including IPv6 to dotted-nibble */
7387
7388       case EOP_REVERSE_IP:
7389         {
7390         int family, maskptr;
7391         uschar reversed[128];
7392
7393         family = string_is_ip_address(sub, &maskptr);
7394         if (family == 0)
7395           {
7396           expand_string_message = string_sprintf(
7397               "reverse_ip() not given an IP address [%s]", sub);
7398           goto EXPAND_FAILED;
7399           }
7400         invert_address(reversed, sub);
7401         yield = string_cat(yield, reversed);
7402         continue;
7403         }
7404
7405       /* Unknown operator */
7406
7407       default:
7408       expand_string_message =
7409         string_sprintf("unknown expansion operator \"%s\"", name);
7410       goto EXPAND_FAILED;
7411       }
7412     }
7413
7414   /* Handle a plain name. If this is the first thing in the expansion, release
7415   the pre-allocated buffer. If the result data is known to be in a new buffer,
7416   newsize will be set to the size of that buffer, and we can just point at that
7417   store instead of copying. Many expansion strings contain just one reference,
7418   so this is a useful optimization, especially for humungous headers
7419   ($message_headers). */
7420                                                 /*{*/
7421   if (*s++ == '}')
7422     {
7423     int len;
7424     int newsize = 0;
7425     gstring * g;
7426
7427     if (yield && yield->ptr == 0)
7428       {
7429       if (resetok) store_reset(yield);
7430       yield = NULL;
7431       g = store_get(sizeof(gstring));
7432       }
7433     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7434       {
7435       expand_string_message =
7436         string_sprintf("unknown variable in \"${%s}\"", name);
7437       check_variable_error_message(name);
7438       goto EXPAND_FAILED;
7439       }
7440     len = Ustrlen(value);
7441     if (!yield && newsize)
7442       {
7443       yield = g;
7444       yield->size = newsize;
7445       yield->ptr = len;
7446       yield->s = value;
7447       }
7448     else
7449       yield = string_catn(yield, value, len);
7450     continue;
7451     }
7452
7453   /* Else there's something wrong */
7454
7455   expand_string_message =
7456     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7457     "in a variable reference)", name);
7458   goto EXPAND_FAILED;
7459   }
7460
7461 /* If we hit the end of the string when ket_ends is set, there is a missing
7462 terminating brace. */
7463
7464 if (ket_ends && *s == 0)
7465   {
7466   expand_string_message = malformed_header?
7467     US"missing } at end of string - could be header name not terminated by colon"
7468     :
7469     US"missing } at end of string";
7470   goto EXPAND_FAILED;
7471   }
7472
7473 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7474 added to the string. If so, set up an empty string. Add a terminating zero. If
7475 left != NULL, return a pointer to the terminator. */
7476
7477 if (!yield)
7478   yield = string_get(1);
7479 (void) string_from_gstring(yield);
7480 if (left) *left = s;
7481
7482 /* Any stacking store that was used above the final string is no longer needed.
7483 In many cases the final string will be the first one that was got and so there
7484 will be optimal store usage. */
7485
7486 if (resetok) store_reset(yield->s + (yield->size = yield->ptr + 1));
7487 else if (resetok_p) *resetok_p = FALSE;
7488
7489 DEBUG(D_expand)
7490   {
7491   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7492     "expanding: %.*s\n",
7493     (int)(s - string), string);
7494   debug_printf_indent("%s"
7495     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7496     "result: %s\n",
7497     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7498     yield->s);
7499   if (skipping)
7500     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7501       "skipping: result is not used\n");
7502   }
7503 expand_level--;
7504 return yield->s;
7505
7506 /* This is the failure exit: easiest to program with a goto. We still need
7507 to update the pointer to the terminator, for cases of nested calls with "fail".
7508 */
7509
7510 EXPAND_FAILED_CURLY:
7511 if (malformed_header)
7512   expand_string_message =
7513     US"missing or misplaced { or } - could be header name not terminated by colon";
7514
7515 else if (!expand_string_message || !*expand_string_message)
7516   expand_string_message = US"missing or misplaced { or }";
7517
7518 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7519 that is a bad idea, because expand_string_message is in dynamic store. */
7520
7521 EXPAND_FAILED:
7522 if (left) *left = s;
7523 DEBUG(D_expand)
7524   {
7525   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7526     string);
7527   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7528     "error message: %s\n",
7529     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7530     expand_string_message);
7531   if (expand_string_forcedfail)
7532     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7533   }
7534 if (resetok_p) *resetok_p = resetok;
7535 expand_level--;
7536 return NULL;
7537 }
7538
7539
7540 /* This is the external function call. Do a quick check for any expansion
7541 metacharacters, and if there are none, just return the input string.
7542
7543 Argument: the string to be expanded
7544 Returns:  the expanded string, or NULL if expansion failed; if failure was
7545           due to a lookup deferring, search_find_defer will be TRUE
7546 */
7547
7548 uschar *
7549 expand_string(uschar *string)
7550 {
7551 search_find_defer = FALSE;
7552 malformed_header = FALSE;
7553 return (Ustrpbrk(string, "$\\") == NULL)? string :
7554   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7555 }
7556
7557
7558
7559 const uschar *
7560 expand_cstring(const uschar *string)
7561 {
7562 search_find_defer = FALSE;
7563 malformed_header = FALSE;
7564 return (Ustrpbrk(string, "$\\") == NULL)? string :
7565   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7566 }
7567
7568
7569
7570 /*************************************************
7571 *              Expand and copy                   *
7572 *************************************************/
7573
7574 /* Now and again we want to expand a string and be sure that the result is in a
7575 new bit of store. This function does that.
7576 Since we know it has been copied, the de-const cast is safe.
7577
7578 Argument: the string to be expanded
7579 Returns:  the expanded string, always in a new bit of store, or NULL
7580 */
7581
7582 uschar *
7583 expand_string_copy(const uschar *string)
7584 {
7585 const uschar *yield = expand_cstring(string);
7586 if (yield == string) yield = string_copy(string);
7587 return US yield;
7588 }
7589
7590
7591
7592 /*************************************************
7593 *        Expand and interpret as an integer      *
7594 *************************************************/
7595
7596 /* Expand a string, and convert the result into an integer.
7597
7598 Arguments:
7599   string  the string to be expanded
7600   isplus  TRUE if a non-negative number is expected
7601
7602 Returns:  the integer value, or
7603           -1 for an expansion error               ) in both cases, message in
7604           -2 for an integer interpretation error  ) expand_string_message
7605           expand_string_message is set NULL for an OK integer
7606 */
7607
7608 int_eximarith_t
7609 expand_string_integer(uschar *string, BOOL isplus)
7610 {
7611 return expanded_string_integer(expand_string(string), isplus);
7612 }
7613
7614
7615 /*************************************************
7616  *         Interpret string as an integer        *
7617  *************************************************/
7618
7619 /* Convert a string (that has already been expanded) into an integer.
7620
7621 This function is used inside the expansion code.
7622
7623 Arguments:
7624   s       the string to be expanded
7625   isplus  TRUE if a non-negative number is expected
7626
7627 Returns:  the integer value, or
7628           -1 if string is NULL (which implies an expansion error)
7629           -2 for an integer interpretation error
7630           expand_string_message is set NULL for an OK integer
7631 */
7632
7633 static int_eximarith_t
7634 expanded_string_integer(const uschar *s, BOOL isplus)
7635 {
7636 int_eximarith_t value;
7637 uschar *msg = US"invalid integer \"%s\"";
7638 uschar *endptr;
7639
7640 /* If expansion failed, expand_string_message will be set. */
7641
7642 if (s == NULL) return -1;
7643
7644 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7645 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7646 systems, so we set it zero ourselves. */
7647
7648 errno = 0;
7649 expand_string_message = NULL;               /* Indicates no error */
7650
7651 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7652 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7653 the behaviour explicitly.  Stripping leading whitespace is a harmless
7654 noop change since strtol skips it anyway (provided that there is a number
7655 to find at all). */
7656 if (isspace(*s))
7657   {
7658   while (isspace(*s)) ++s;
7659   if (*s == '\0')
7660     {
7661       DEBUG(D_expand)
7662        debug_printf_indent("treating blank string as number 0\n");
7663       return 0;
7664     }
7665   }
7666
7667 value = strtoll(CS s, CSS &endptr, 10);
7668
7669 if (endptr == s)
7670   {
7671   msg = US"integer expected but \"%s\" found";
7672   }
7673 else if (value < 0 && isplus)
7674   {
7675   msg = US"non-negative integer expected but \"%s\" found";
7676   }
7677 else
7678   {
7679   switch (tolower(*endptr))
7680     {
7681     default:
7682       break;
7683     case 'k':
7684       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7685       else value *= 1024;
7686       endptr++;
7687       break;
7688     case 'm':
7689       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7690       else value *= 1024*1024;
7691       endptr++;
7692       break;
7693     case 'g':
7694       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7695       else value *= 1024*1024*1024;
7696       endptr++;
7697       break;
7698     }
7699   if (errno == ERANGE)
7700     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7701   else
7702     {
7703     while (isspace(*endptr)) endptr++;
7704     if (*endptr == 0) return value;
7705     }
7706   }
7707
7708 expand_string_message = string_sprintf(CS msg, s);
7709 return -2;
7710 }
7711
7712
7713 /* These values are usually fixed boolean values, but they are permitted to be
7714 expanded strings.
7715
7716 Arguments:
7717   addr       address being routed
7718   mtype      the module type
7719   mname      the module name
7720   dbg_opt    debug selectors
7721   oname      the option name
7722   bvalue     the router's boolean value
7723   svalue     the router's string value
7724   rvalue     where to put the returned value
7725
7726 Returns:     OK     value placed in rvalue
7727              DEFER  expansion failed
7728 */
7729
7730 int
7731 exp_bool(address_item *addr,
7732   uschar *mtype, uschar *mname, unsigned dbg_opt,
7733   uschar *oname, BOOL bvalue,
7734   uschar *svalue, BOOL *rvalue)
7735 {
7736 uschar *expanded;
7737 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7738
7739 expanded = expand_string(svalue);
7740 if (expanded == NULL)
7741   {
7742   if (expand_string_forcedfail)
7743     {
7744     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7745     *rvalue = bvalue;
7746     return OK;
7747     }
7748   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7749       oname, mname, mtype, expand_string_message);
7750   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7751   return DEFER;
7752   }
7753
7754 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7755   expanded);
7756
7757 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7758   *rvalue = TRUE;
7759 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7760   *rvalue = FALSE;
7761 else
7762   {
7763   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7764     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7765   return DEFER;
7766   }
7767
7768 return OK;
7769 }
7770
7771
7772
7773 /* Avoid potentially exposing a password in a string about to be logged */
7774
7775 uschar *
7776 expand_hide_passwords(uschar * s)
7777 {
7778 return (  (  Ustrstr(s, "failed to expand") != NULL
7779           || Ustrstr(s, "expansion of ")    != NULL
7780           )
7781        && (  Ustrstr(s, "mysql")   != NULL
7782           || Ustrstr(s, "pgsql")   != NULL
7783           || Ustrstr(s, "redis")   != NULL
7784           || Ustrstr(s, "sqlite")  != NULL
7785           || Ustrstr(s, "ldap:")   != NULL
7786           || Ustrstr(s, "ldaps:")  != NULL
7787           || Ustrstr(s, "ldapi:")  != NULL
7788           || Ustrstr(s, "ldapdn:") != NULL
7789           || Ustrstr(s, "ldapm:")  != NULL
7790        )  )
7791   ? US"Temporary internal error" : s;
7792 }
7793
7794
7795
7796 /*************************************************
7797 * Error-checking for testsuite                   *
7798 *************************************************/
7799 typedef struct {
7800   const char *  filename;
7801   int           linenumber;
7802   uschar *      region_start;
7803   uschar *      region_end;
7804   const uschar *var_name;
7805   const uschar *var_data;
7806 } err_ctx;
7807
7808 static void
7809 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7810 {
7811 err_ctx * e = ctx;
7812 if (var_data >= e->region_start  &&  var_data < e->region_end)
7813   {
7814   e->var_name = CUS var_name;
7815   e->var_data = CUS var_data;
7816   }
7817 }
7818
7819 void
7820 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7821 {
7822 err_ctx e = {filename, linenumber, ptr, US ptr + len, NULL };
7823 int i;
7824 var_entry * v;
7825
7826 /* check acl_ variables */
7827 tree_walk(acl_var_c, assert_variable_notin, &e);
7828 tree_walk(acl_var_m, assert_variable_notin, &e);
7829
7830 /* check auth<n> variables */
7831 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7832   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7833
7834 /* check regex<n> variables */
7835 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7836   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7837
7838 /* check known-name variables */
7839 for (v = var_table; v < var_table + var_table_size; v++)
7840   if (v->type == vtype_stringptr)
7841     assert_variable_notin(US v->name, *(USS v->value), &e);
7842
7843 if (e.var_name)
7844   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7845     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7846     e.var_name, e.filename, e.linenumber, e.var_data);
7847 }
7848
7849
7850
7851 /*************************************************
7852 **************************************************
7853 *             Stand-alone test program           *
7854 **************************************************
7855 *************************************************/
7856
7857 #ifdef STAND_ALONE
7858
7859
7860 BOOL
7861 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7862 {
7863 int ovector[3*(EXPAND_MAXN+1)];
7864 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7865   ovector, nelem(ovector));
7866 BOOL yield = n >= 0;
7867 if (n == 0) n = EXPAND_MAXN + 1;
7868 if (yield)
7869   {
7870   int nn;
7871   expand_nmax = (setup < 0)? 0 : setup + 1;
7872   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7873     {
7874     expand_nstring[expand_nmax] = subject + ovector[nn];
7875     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7876     }
7877   expand_nmax--;
7878   }
7879 return yield;
7880 }
7881
7882
7883 int main(int argc, uschar **argv)
7884 {
7885 int i;
7886 uschar buffer[1024];
7887
7888 debug_selector = D_v;
7889 debug_file = stderr;
7890 debug_fd = fileno(debug_file);
7891 big_buffer = malloc(big_buffer_size);
7892
7893 for (i = 1; i < argc; i++)
7894   {
7895   if (argv[i][0] == '+')
7896     {
7897     debug_trace_memory = 2;
7898     argv[i]++;
7899     }
7900   if (isdigit(argv[i][0]))
7901     debug_selector = Ustrtol(argv[i], NULL, 0);
7902   else
7903     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7904         Ustrlen(argv[i]))
7905       {
7906 #ifdef LOOKUP_LDAP
7907       eldap_default_servers = argv[i];
7908 #endif
7909 #ifdef LOOKUP_MYSQL
7910       mysql_servers = argv[i];
7911 #endif
7912 #ifdef LOOKUP_PGSQL
7913       pgsql_servers = argv[i];
7914 #endif
7915 #ifdef LOOKUP_REDIS
7916       redis_servers = argv[i];
7917 #endif
7918       }
7919 #ifdef EXIM_PERL
7920   else opt_perl_startup = argv[i];
7921 #endif
7922   }
7923
7924 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7925
7926 expand_nstring[1] = US"string 1....";
7927 expand_nlength[1] = 8;
7928 expand_nmax = 1;
7929
7930 #ifdef EXIM_PERL
7931 if (opt_perl_startup != NULL)
7932   {
7933   uschar *errstr;
7934   printf("Starting Perl interpreter\n");
7935   errstr = init_perl(opt_perl_startup);
7936   if (errstr != NULL)
7937     {
7938     printf("** error in perl_startup code: %s\n", errstr);
7939     return EXIT_FAILURE;
7940     }
7941   }
7942 #endif /* EXIM_PERL */
7943
7944 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7945   {
7946   void *reset_point = store_get(0);
7947   uschar *yield = expand_string(buffer);
7948   if (yield != NULL)
7949     {
7950     printf("%s\n", yield);
7951     store_reset(reset_point);
7952     }
7953   else
7954     {
7955     if (search_find_defer) printf("search_find deferred\n");
7956     printf("Failed: %s\n", expand_string_message);
7957     if (expand_string_forcedfail) printf("Forced failure\n");
7958     printf("\n");
7959     }
7960   }
7961
7962 search_tidyup();
7963
7964 return 0;
7965 }
7966
7967 #endif
7968
7969 /* vi: aw ai sw=2
7970 */
7971 /* End of expand.c */