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