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 },
 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_count_at_connection_start", vtype_int, &smtp_accept_count },
 684   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 685   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 686   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 687   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 688   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 689   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 690   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 691   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 692   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 693   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 694   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 695 #ifdef WITH_CONTENT_SCAN
 696   { "spam_action",         vtype_stringptr,   &spam_action },
 697   { "spam_bar",            vtype_stringptr,   &spam_bar },
 698   { "spam_report",         vtype_stringptr,   &spam_report },
 699   { "spam_score",          vtype_stringptr,   &spam_score },
 700   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 701 #endif
 702 #ifdef EXPERIMENTAL_SPF
 703   { "spf_guess",           vtype_stringptr,   &spf_guess },
 704   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 705   { "spf_received",        vtype_stringptr,   &spf_received },
 706   { "spf_result",          vtype_stringptr,   &spf_result },
 707   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 708 #endif
 709   { "spool_directory",     vtype_stringptr,   &spool_directory },
 710   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 711   { "spool_space",         vtype_pspace,      (void *)TRUE },
 712 #ifdef EXPERIMENTAL_SRS
 713   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 714   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 715   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 716   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 717   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 718   { "srs_status",          vtype_stringptr,   &srs_status },
 719 #endif
 720   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 721
 722   /* The non-(in,out) variables are now deprecated */
 723   { "tls_bits",            vtype_int,         &tls_in.bits },
 724   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 725   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 726
 727   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 728   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 729   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 730   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 731   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 732   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 733   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 734 #if defined(SUPPORT_TLS)
 735   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 736 #endif
 737   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 738   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 739   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 740 #ifdef EXPERIMENTAL_DANE
 741   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 742 #endif
 743   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 744   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 745   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 746   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 747 #if defined(SUPPORT_TLS)
 748   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 749 #endif
 750 #ifdef EXPERIMENTAL_DANE
 751   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 752 #endif
 753
 754   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 755 #if defined(SUPPORT_TLS)
 756   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 757 #endif
 758
 759   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 760   { "tod_epoch",           vtype_tode,        NULL },
 761   { "tod_epoch_l",         vtype_todel,       NULL },
 762   { "tod_full",            vtype_todf,        NULL },
 763   { "tod_log",             vtype_todl,        NULL },
 764   { "tod_logfile",         vtype_todlf,       NULL },
 765   { "tod_zone",            vtype_todzone,     NULL },
 766   { "tod_zulu",            vtype_todzulu,     NULL },
 767   { "transport_name",      vtype_stringptr,   &transport_name },
 768   { "value",               vtype_stringptr,   &lookup_value },
 769   { "verify_mode",         vtype_stringptr,   &verify_mode },
 770   { "version_number",      vtype_stringptr,   &version_string },
 771   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 772   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 773   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 774   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 775   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 776   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 777 };
 778
 779 static int var_table_size = nelem(var_table);
 780 static uschar var_buffer[256];
 781 static BOOL malformed_header;
 782
 783 /* For textual hashes */
 784
 785 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 786                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 787                                "0123456789";
 788
 789 enum { HMAC_MD5, HMAC_SHA1 };
 790
 791 /* For numeric hashes */
 792
 793 static unsigned int prime[] = {
 794   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 795  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 796  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 797
 798 /* For printing modes in symbolic form */
 799
 800 static uschar *mtable_normal[] =
 801   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 802
 803 static uschar *mtable_setid[] =
 804   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 805
 806 static uschar *mtable_sticky[] =
 807   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 808
 809
 810
 811 /*************************************************
 812 *           Tables for UTF-8 support             *
 813 *************************************************/
 814
 815 /* Table of the number of extra characters, indexed by the first character
 816 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 817 0x3d. */
 818
 819 static uschar utf8_table1[] = {
 820   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 821   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 822   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 823   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 824
 825 /* These are the masks for the data bits in the first byte of a character,
 826 indexed by the number of additional bytes. */
 827
 828 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 829
 830 /* Get the next UTF-8 character, advancing the pointer. */
 831
 832 #define GETUTF8INC(c, ptr) \
 833   c = *ptr++; \
 834   if ((c & 0xc0) == 0xc0) \
 835     { \
 836     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 837     int s = 6*a; \
 838     c = (c & utf8_table2[a]) << s; \
 839     while (a-- > 0) \
 840       { \
 841       s -= 6; \
 842       c |= (*ptr++ & 0x3f) << s; \
 843       } \
 844     }
 845
 846
 847
 848 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 849
 850 /*************************************************
 851 *           Binary chop search on a table        *
 852 *************************************************/
 853
 854 /* This is used for matching expansion items and operators.
 855
 856 Arguments:
 857   name        the name that is being sought
 858   table       the table to search
 859   table_size  the number of items in the table
 860
 861 Returns:      the offset in the table, or -1
 862 */
 863
 864 static int
 865 chop_match(uschar *name, uschar **table, int table_size)
 866 {
 867 uschar **bot = table;
 868 uschar **top = table + table_size;
 869
 870 while (top > bot)
 871   {
 872   uschar **mid = bot + (top - bot)/2;
 873   int c = Ustrcmp(name, *mid);
 874   if (c == 0) return mid - table;
 875   if (c > 0) bot = mid + 1; else top = mid;
 876   }
 877
 878 return -1;
 879 }
 880
 881
 882
 883 /*************************************************
 884 *          Check a condition string              *
 885 *************************************************/
 886
 887 /* This function is called to expand a string, and test the result for a "true"
 888 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 889 forced fail or lookup defer.
 890
 891 We used to release all store used, but this is not not safe due
 892 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 893 is reasonably careful to release what it can.
 894
 895 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 896
 897 Arguments:
 898   condition     the condition string
 899   m1            text to be incorporated in panic error
 900   m2            ditto
 901
 902 Returns:        TRUE if condition is met, FALSE if not
 903 */
 904
 905 BOOL
 906 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 907 {
 908 int rc;
 909 uschar *ss = expand_string(condition);
 910 if (ss == NULL)
 911   {
 912   if (!expand_string_forcedfail && !search_find_defer)
 913     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 914       "for %s %s: %s", condition, m1, m2, expand_string_message);
 915   return FALSE;
 916   }
 917 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 918   strcmpic(ss, US"false") != 0;
 919 return rc;
 920 }
 921
 922
 923
 924
 925 /*************************************************
 926 *        Pseudo-random number generation         *
 927 *************************************************/
 928
 929 /* Pseudo-random number generation.  The result is not "expected" to be
 930 cryptographically strong but not so weak that someone will shoot themselves
 931 in the foot using it as a nonce in some email header scheme or whatever
 932 weirdness they'll twist this into.  The result should ideally handle fork().
 933
 934 However, if we're stuck unable to provide this, then we'll fall back to
 935 appallingly bad randomness.
 936
 937 If SUPPORT_TLS is defined then this will not be used except as an emergency
 938 fallback.
 939
 940 Arguments:
 941   max       range maximum
 942 Returns     a random number in range [0, max-1]
 943 */
 944
 945 #ifdef SUPPORT_TLS
 946 # define vaguely_random_number vaguely_random_number_fallback
 947 #endif
 948 int
 949 vaguely_random_number(int max)
 950 {
 951 #ifdef SUPPORT_TLS
 952 # undef vaguely_random_number
 953 #endif
 954   static pid_t pid = 0;
 955   pid_t p2;
 956 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 957   struct timeval tv;
 958 #endif
 959
 960   p2 = getpid();
 961   if (p2 != pid)
 962     {
 963     if (pid != 0)
 964       {
 965
 966 #ifdef HAVE_ARC4RANDOM
 967       /* cryptographically strong randomness, common on *BSD platforms, not
 968       so much elsewhere.  Alas. */
 969 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 970       arc4random_stir();
 971 #endif
 972 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 973 #ifdef HAVE_SRANDOMDEV
 974       /* uses random(4) for seeding */
 975       srandomdev();
 976 #else
 977       gettimeofday(&tv, NULL);
 978       srandom(tv.tv_sec | tv.tv_usec | getpid());
 979 #endif
 980 #else
 981       /* Poor randomness and no seeding here */
 982 #endif
 983
 984       }
 985     pid = p2;
 986     }
 987
 988 #ifdef HAVE_ARC4RANDOM
 989   return arc4random() % max;
 990 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 991   return random() % max;
 992 #else
 993   /* This one returns a 16-bit number, definitely not crypto-strong */
 994   return random_number(max);
 995 #endif
 996 }
 997
 998
 999
1000
1001 /*************************************************
1002 *             Pick out a name from a string      *
1003 *************************************************/
1004
1005 /* If the name is too long, it is silently truncated.
1006
1007 Arguments:
1008   name      points to a buffer into which to put the name
1009   max       is the length of the buffer
1010   s         points to the first alphabetic character of the name
1011   extras    chars other than alphanumerics to permit
1012
1013 Returns:    pointer to the first character after the name
1014
1015 Note: The test for *s != 0 in the while loop is necessary because
1016 Ustrchr() yields non-NULL if the character is zero (which is not something
1017 I expected). */
1018
1019 static const uschar *
1020 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1021 {
1022 int ptr = 0;
1023 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1024   {
1025   if (ptr < max-1) name[ptr++] = *s;
1026   s++;
1027   }
1028 name[ptr] = 0;
1029 return s;
1030 }
1031
1032
1033
1034 /*************************************************
1035 *     Pick out the rest of a header name         *
1036 *************************************************/
1037
1038 /* A variable name starting $header_ (or just $h_ for those who like
1039 abbreviations) might not be the complete header name because headers can
1040 contain any printing characters in their names, except ':'. This function is
1041 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1042 on the end, if the name was terminated by white space.
1043
1044 Arguments:
1045   name      points to a buffer in which the name read so far exists
1046   max       is the length of the buffer
1047   s         points to the first character after the name so far, i.e. the
1048             first non-alphameric character after $header_xxxxx
1049
1050 Returns:    a pointer to the first character after the header name
1051 */
1052
1053 static const uschar *
1054 read_header_name(uschar *name, int max, const uschar *s)
1055 {
1056 int prelen = Ustrchr(name, '_') - name + 1;
1057 int ptr = Ustrlen(name) - prelen;
1058 if (ptr > 0) memmove(name, name+prelen, ptr);
1059 while (mac_isgraph(*s) && *s != ':')
1060   {
1061   if (ptr < max-1) name[ptr++] = *s;
1062   s++;
1063   }
1064 if (*s == ':') s++;
1065 name[ptr++] = ':';
1066 name[ptr] = 0;
1067 return s;
1068 }
1069
1070
1071
1072 /*************************************************
1073 *           Pick out a number from a string      *
1074 *************************************************/
1075
1076 /* Arguments:
1077   n     points to an integer into which to put the number
1078   s     points to the first digit of the number
1079
1080 Returns:  a pointer to the character after the last digit
1081 */
1082 /*XXX consider expanding to int_eximarith_t.  But the test for
1083 "overbig numbers" in 0002 still needs to overflow it. */
1084
1085 static uschar *
1086 read_number(int *n, uschar *s)
1087 {
1088 *n = 0;
1089 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1090 return s;
1091 }
1092
1093 static const uschar *
1094 read_cnumber(int *n, const uschar *s)
1095 {
1096 *n = 0;
1097 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1098 return s;
1099 }
1100
1101
1102
1103 /*************************************************
1104 *        Extract keyed subfield from a string    *
1105 *************************************************/
1106
1107 /* The yield is in dynamic store; NULL means that the key was not found.
1108
1109 Arguments:
1110   key       points to the name of the key
1111   s         points to the string from which to extract the subfield
1112
1113 Returns:    NULL if the subfield was not found, or
1114             a pointer to the subfield's data
1115 */
1116
1117 static uschar *
1118 expand_getkeyed(uschar *key, const uschar *s)
1119 {
1120 int length = Ustrlen(key);
1121 while (isspace(*s)) s++;
1122
1123 /* Loop to search for the key */
1124
1125 while (*s != 0)
1126   {
1127   int dkeylength;
1128   uschar *data;
1129   const uschar *dkey = s;
1130
1131   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1132   dkeylength = s - dkey;
1133   while (isspace(*s)) s++;
1134   if (*s == '=') while (isspace((*(++s))));
1135
1136   data = string_dequote(&s);
1137   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1138     return data;
1139
1140   while (isspace(*s)) s++;
1141   }
1142
1143 return NULL;
1144 }
1145
1146
1147
1148 static var_entry *
1149 find_var_ent(uschar * name)
1150 {
1151 int first = 0;
1152 int last = var_table_size;
1153
1154 while (last > first)
1155   {
1156   int middle = (first + last)/2;
1157   int c = Ustrcmp(name, var_table[middle].name);
1158
1159   if (c > 0) { first = middle + 1; continue; }
1160   if (c < 0) { last = middle; continue; }
1161   return &var_table[middle];
1162   }
1163 return NULL;
1164 }
1165
1166 /*************************************************
1167 *   Extract numbered subfield from string        *
1168 *************************************************/
1169
1170 /* Extracts a numbered field from a string that is divided by tokens - for
1171 example a line from /etc/passwd is divided by colon characters.  First field is
1172 numbered one.  Negative arguments count from the right. Zero returns the whole
1173 string. Returns NULL if there are insufficient tokens in the string
1174
1175 ***WARNING***
1176 Modifies final argument - this is a dynamically generated string, so that's OK.
1177
1178 Arguments:
1179   field       number of field to be extracted,
1180                 first field = 1, whole string = 0, last field = -1
1181   separators  characters that are used to break string into tokens
1182   s           points to the string from which to extract the subfield
1183
1184 Returns:      NULL if the field was not found,
1185               a pointer to the field's data inside s (modified to add 0)
1186 */
1187
1188 static uschar *
1189 expand_gettokened (int field, uschar *separators, uschar *s)
1190 {
1191 int sep = 1;
1192 int count;
1193 uschar *ss = s;
1194 uschar *fieldtext = NULL;
1195
1196 if (field == 0) return s;
1197
1198 /* Break the line up into fields in place; for field > 0 we stop when we have
1199 done the number of fields we want. For field < 0 we continue till the end of
1200 the string, counting the number of fields. */
1201
1202 count = (field > 0)? field : INT_MAX;
1203
1204 while (count-- > 0)
1205   {
1206   size_t len;
1207
1208   /* Previous field was the last one in the string. For a positive field
1209   number, this means there are not enough fields. For a negative field number,
1210   check that there are enough, and scan back to find the one that is wanted. */
1211
1212   if (sep == 0)
1213     {
1214     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1215     if ((-field) == (INT_MAX - count - 1)) return s;
1216     while (field++ < 0)
1217       {
1218       ss--;
1219       while (ss[-1] != 0) ss--;
1220       }
1221     fieldtext = ss;
1222     break;
1223     }
1224
1225   /* Previous field was not last in the string; save its start and put a
1226   zero at its end. */
1227
1228   fieldtext = ss;
1229   len = Ustrcspn(ss, separators);
1230   sep = ss[len];
1231   ss[len] = 0;
1232   ss += len + 1;
1233   }
1234
1235 return fieldtext;
1236 }
1237
1238
1239 static uschar *
1240 expand_getlistele(int field, const uschar * list)
1241 {
1242 const uschar * tlist= list;
1243 int sep= 0;
1244 uschar dummy;
1245
1246 if(field<0)
1247   {
1248   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1249   sep= 0;
1250   }
1251 if(field==0) return NULL;
1252 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1253 return string_nextinlist(&list, &sep, NULL, 0);
1254 }
1255
1256
1257 /* Certificate fields, by name.  Worry about by-OID later */
1258 /* Names are chosen to not have common prefixes */
1259
1260 #ifdef SUPPORT_TLS
1261 typedef struct
1262 {
1263 uschar * name;
1264 int      namelen;
1265 uschar * (*getfn)(void * cert, uschar * mod);
1266 } certfield;
1267 static certfield certfields[] =
1268 {                       /* linear search; no special order */
1269   { US"version",         7,  &tls_cert_version },
1270   { US"serial_number",   13, &tls_cert_serial_number },
1271   { US"subject",         7,  &tls_cert_subject },
1272   { US"notbefore",       9,  &tls_cert_not_before },
1273   { US"notafter",        8,  &tls_cert_not_after },
1274   { US"issuer",          6,  &tls_cert_issuer },
1275   { US"signature",       9,  &tls_cert_signature },
1276   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1277   { US"subj_altname",    12, &tls_cert_subject_altname },
1278   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1279   { US"crl_uri",         7,  &tls_cert_crl_uri },
1280 };
1281
1282 static uschar *
1283 expand_getcertele(uschar * field, uschar * certvar)
1284 {
1285 var_entry * vp;
1286 certfield * cp;
1287
1288 if (!(vp = find_var_ent(certvar)))
1289   {
1290   expand_string_message =
1291     string_sprintf("no variable named \"%s\"", certvar);
1292   return NULL;          /* Unknown variable name */
1293   }
1294 /* NB this stops us passing certs around in variable.  Might
1295 want to do that in future */
1296 if (vp->type != vtype_cert)
1297   {
1298   expand_string_message =
1299     string_sprintf("\"%s\" is not a certificate", certvar);
1300   return NULL;          /* Unknown variable name */
1301   }
1302 if (!*(void **)vp->value)
1303   return NULL;
1304
1305 if (*field >= '0' && *field <= '9')
1306   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1307
1308 for(cp = certfields;
1309     cp < certfields + nelem(certfields);
1310     cp++)
1311   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1312     {
1313     uschar * modifier = *(field += cp->namelen) == ','
1314       ? ++field : NULL;
1315     return (*cp->getfn)( *(void **)vp->value, modifier );
1316     }
1317
1318 expand_string_message =
1319   string_sprintf("bad field selector \"%s\" for certextract", field);
1320 return NULL;
1321 }
1322 #endif  /*SUPPORT_TLS*/
1323
1324 /*************************************************
1325 *        Extract a substring from a string       *
1326 *************************************************/
1327
1328 /* Perform the ${substr or ${length expansion operations.
1329
1330 Arguments:
1331   subject     the input string
1332   value1      the offset from the start of the input string to the start of
1333                 the output string; if negative, count from the right.
1334   value2      the length of the output string, or negative (-1) for unset
1335                 if value1 is positive, unset means "all after"
1336                 if value1 is negative, unset means "all before"
1337   len         set to the length of the returned string
1338
1339 Returns:      pointer to the output string, or NULL if there is an error
1340 */
1341
1342 static uschar *
1343 extract_substr(uschar *subject, int value1, int value2, int *len)
1344 {
1345 int sublen = Ustrlen(subject);
1346
1347 if (value1 < 0)    /* count from right */
1348   {
1349   value1 += sublen;
1350
1351   /* If the position is before the start, skip to the start, and adjust the
1352   length. If the length ends up negative, the substring is null because nothing
1353   can precede. This falls out naturally when the length is unset, meaning "all
1354   to the left". */
1355
1356   if (value1 < 0)
1357     {
1358     value2 += value1;
1359     if (value2 < 0) value2 = 0;
1360     value1 = 0;
1361     }
1362
1363   /* Otherwise an unset length => characters before value1 */
1364
1365   else if (value2 < 0)
1366     {
1367     value2 = value1;
1368     value1 = 0;
1369     }
1370   }
1371
1372 /* For a non-negative offset, if the starting position is past the end of the
1373 string, the result will be the null string. Otherwise, an unset length means
1374 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1375
1376 else
1377   {
1378   if (value1 > sublen)
1379     {
1380     value1 = sublen;
1381     value2 = 0;
1382     }
1383   else if (value2 < 0) value2 = sublen;
1384   }
1385
1386 /* Cut the length down to the maximum possible for the offset value, and get
1387 the required characters. */
1388
1389 if (value1 + value2 > sublen) value2 = sublen - value1;
1390 *len = value2;
1391 return subject + value1;
1392 }
1393
1394
1395
1396
1397 /*************************************************
1398 *            Old-style hash of a string          *
1399 *************************************************/
1400
1401 /* Perform the ${hash expansion operation.
1402
1403 Arguments:
1404   subject     the input string (an expanded substring)
1405   value1      the length of the output string; if greater or equal to the
1406                 length of the input string, the input string is returned
1407   value2      the number of hash characters to use, or 26 if negative
1408   len         set to the length of the returned string
1409
1410 Returns:      pointer to the output string, or NULL if there is an error
1411 */
1412
1413 static uschar *
1414 compute_hash(uschar *subject, int value1, int value2, int *len)
1415 {
1416 int sublen = Ustrlen(subject);
1417
1418 if (value2 < 0) value2 = 26;
1419 else if (value2 > Ustrlen(hashcodes))
1420   {
1421   expand_string_message =
1422     string_sprintf("hash count \"%d\" too big", value2);
1423   return NULL;
1424   }
1425
1426 /* Calculate the hash text. We know it is shorter than the original string, so
1427 can safely place it in subject[] (we know that subject is always itself an
1428 expanded substring). */
1429
1430 if (value1 < sublen)
1431   {
1432   int c;
1433   int i = 0;
1434   int j = value1;
1435   while ((c = (subject[j])) != 0)
1436     {
1437     int shift = (c + j++) & 7;
1438     subject[i] ^= (c << shift) | (c >> (8-shift));
1439     if (++i >= value1) i = 0;
1440     }
1441   for (i = 0; i < value1; i++)
1442     subject[i] = hashcodes[(subject[i]) % value2];
1443   }
1444 else value1 = sublen;
1445
1446 *len = value1;
1447 return subject;
1448 }
1449
1450
1451
1452
1453 /*************************************************
1454 *             Numeric hash of a string           *
1455 *************************************************/
1456
1457 /* Perform the ${nhash expansion operation. The first characters of the
1458 string are treated as most important, and get the highest prime numbers.
1459
1460 Arguments:
1461   subject     the input string
1462   value1      the maximum value of the first part of the result
1463   value2      the maximum value of the second part of the result,
1464                 or negative to produce only a one-part result
1465   len         set to the length of the returned string
1466
1467 Returns:  pointer to the output string, or NULL if there is an error.
1468 */
1469
1470 static uschar *
1471 compute_nhash (uschar *subject, int value1, int value2, int *len)
1472 {
1473 uschar *s = subject;
1474 int i = 0;
1475 unsigned long int total = 0; /* no overflow */
1476
1477 while (*s != 0)
1478   {
1479   if (i == 0) i = nelem(prime) - 1;
1480   total += prime[i--] * (unsigned int)(*s++);
1481   }
1482
1483 /* If value2 is unset, just compute one number */
1484
1485 if (value2 < 0)
1486   {
1487   s = string_sprintf("%d", total % value1);
1488   }
1489
1490 /* Otherwise do a div/mod hash */
1491
1492 else
1493   {
1494   total = total % (value1 * value2);
1495   s = string_sprintf("%d/%d", total/value2, total % value2);
1496   }
1497
1498 *len = Ustrlen(s);
1499 return s;
1500 }
1501
1502
1503
1504
1505
1506 /*************************************************
1507 *     Find the value of a header or headers      *
1508 *************************************************/
1509
1510 /* Multiple instances of the same header get concatenated, and this function
1511 can also return a concatenation of all the header lines. When concatenating
1512 specific headers that contain lists of addresses, a comma is inserted between
1513 them. Otherwise we use a straight concatenation. Because some messages can have
1514 pathologically large number of lines, there is a limit on the length that is
1515 returned. Also, to avoid massive store use which would result from using
1516 string_cat() as it copies and extends strings, we do a preliminary pass to find
1517 out exactly how much store will be needed. On "normal" messages this will be
1518 pretty trivial.
1519
1520 Arguments:
1521   name          the name of the header, without the leading $header_ or $h_,
1522                 or NULL if a concatenation of all headers is required
1523   exists_only   TRUE if called from a def: test; don't need to build a string;
1524                 just return a string that is not "" and not "0" if the header
1525                 exists
1526   newsize       return the size of memory block that was obtained; may be NULL
1527                 if exists_only is TRUE
1528   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1529                 other than concatenating, will be done on the header. Also used
1530                 for $message_headers_raw.
1531   charset       name of charset to translate MIME words to; used only if
1532                 want_raw is false; if NULL, no translation is done (this is
1533                 used for $bh_ and $bheader_)
1534
1535 Returns:        NULL if the header does not exist, else a pointer to a new
1536                 store block
1537 */
1538
1539 static uschar *
1540 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1541   uschar *charset)
1542 {
1543 BOOL found = name == NULL;
1544 int comma = 0;
1545 int len = found? 0 : Ustrlen(name);
1546 int i;
1547 uschar *yield = NULL;
1548 uschar *ptr = NULL;
1549
1550 /* Loop for two passes - saves code repetition */
1551
1552 for (i = 0; i < 2; i++)
1553   {
1554   int size = 0;
1555   header_line *h;
1556
1557   for (h = header_list; size < header_insert_maxlen && h != NULL; h = h->next)
1558     {
1559     if (h->type != htype_old && h->text != NULL)  /* NULL => Received: placeholder */
1560       {
1561       if (name == NULL || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1562         {
1563         int ilen;
1564         uschar *t;
1565
1566         if (exists_only) return US"1";      /* don't need actual string */
1567         found = TRUE;
1568         t = h->text + len;                  /* text to insert */
1569         if (!want_raw)                      /* unless wanted raw, */
1570           while (isspace(*t)) t++;          /* remove leading white space */
1571         ilen = h->slen - (t - h->text);     /* length to insert */
1572
1573         /* Unless wanted raw, remove trailing whitespace, including the
1574         newline. */
1575
1576         if (!want_raw)
1577           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1578
1579         /* Set comma = 1 if handling a single header and it's one of those
1580         that contains an address list, except when asked for raw headers. Only
1581         need to do this once. */
1582
1583         if (!want_raw && name != NULL && comma == 0 &&
1584             Ustrchr("BCFRST", h->type) != NULL)
1585           comma = 1;
1586
1587         /* First pass - compute total store needed; second pass - compute
1588         total store used, including this header. */
1589
1590         size += ilen + comma + 1;  /* +1 for the newline */
1591
1592         /* Second pass - concatenate the data, up to a maximum. Note that
1593         the loop stops when size hits the limit. */
1594
1595         if (i != 0)
1596           {
1597           if (size > header_insert_maxlen)
1598             {
1599             ilen -= size - header_insert_maxlen - 1;
1600             comma = 0;
1601             }
1602           Ustrncpy(ptr, t, ilen);
1603           ptr += ilen;
1604
1605           /* For a non-raw header, put in the comma if needed, then add
1606           back the newline we removed above, provided there was some text in
1607           the header. */
1608
1609           if (!want_raw && ilen > 0)
1610             {
1611             if (comma != 0) *ptr++ = ',';
1612             *ptr++ = '\n';
1613             }
1614           }
1615         }
1616       }
1617     }
1618
1619   /* At end of first pass, return NULL if no header found. Then truncate size
1620   if necessary, and get the buffer to hold the data, returning the buffer size.
1621   */
1622
1623   if (i == 0)
1624     {
1625     if (!found) return NULL;
1626     if (size > header_insert_maxlen) size = header_insert_maxlen;
1627     *newsize = size + 1;
1628     ptr = yield = store_get(*newsize);
1629     }
1630   }
1631
1632 /* That's all we do for raw header expansion. */
1633
1634 if (want_raw)
1635   {
1636   *ptr = 0;
1637   }
1638
1639 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1640 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1641 function can return an error with decoded data if the charset translation
1642 fails. If decoding fails, it returns NULL. */
1643
1644 else
1645   {
1646   uschar *decoded, *error;
1647   if (ptr > yield && ptr[-1] == '\n') ptr--;
1648   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1649   *ptr = 0;
1650   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1651     newsize, &error);
1652   if (error != NULL)
1653     {
1654     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1655       "    input was: %s\n", error, yield);
1656     }
1657   if (decoded != NULL) yield = decoded;
1658   }
1659
1660 return yield;
1661 }
1662
1663
1664
1665
1666 /*************************************************
1667 *               Return list of recipients        *
1668 *************************************************/
1669 /* A recipients list is available only during system message filtering,
1670 during ACL processing after DATA, and while expanding pipe commands
1671 generated from a system filter, but not elsewhere. */
1672
1673 static uschar *
1674 fn_recipients(void)
1675 {
1676 if (!enable_dollar_recipients) return NULL; else
1677   {
1678   int size = 128;
1679   int ptr = 0;
1680   int i;
1681   uschar * s = store_get(size);
1682   for (i = 0; i < recipients_count; i++)
1683     {
1684     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1685     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1686     }
1687   s[ptr] = 0;     /* string_cat() leaves room */
1688   return s;
1689   }
1690 }
1691
1692
1693 /*************************************************
1694 *               Find value of a variable         *
1695 *************************************************/
1696
1697 /* The table of variables is kept in alphabetic order, so we can search it
1698 using a binary chop. The "choplen" variable is nothing to do with the binary
1699 chop.
1700
1701 Arguments:
1702   name          the name of the variable being sought
1703   exists_only   TRUE if this is a def: test; passed on to find_header()
1704   skipping      TRUE => skip any processing evaluation; this is not the same as
1705                   exists_only because def: may test for values that are first
1706                   evaluated here
1707   newsize       pointer to an int which is initially zero; if the answer is in
1708                 a new memory buffer, *newsize is set to its size
1709
1710 Returns:        NULL if the variable does not exist, or
1711                 a pointer to the variable's contents, or
1712                 something non-NULL if exists_only is TRUE
1713 */
1714
1715 static uschar *
1716 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1717 {
1718 var_entry * vp;
1719 uschar *s, *domain;
1720 uschar **ss;
1721 void * val;
1722
1723 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1724 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1725 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1726 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1727 (this gave backwards compatibility at the changeover). There may be built-in
1728 variables whose names start acl_ but they should never start in this way. This
1729 slightly messy specification is a consequence of the history, needless to say.
1730
1731 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1732 set, in which case give an error. */
1733
1734 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1735      !isalpha(name[5]))
1736   {
1737   tree_node *node =
1738     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1739   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1740   }
1741
1742 /* Handle $auth<n> variables. */
1743
1744 if (Ustrncmp(name, "auth", 4) == 0)
1745   {
1746   uschar *endptr;
1747   int n = Ustrtoul(name + 4, &endptr, 10);
1748   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1749     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1750   }
1751 else if (Ustrncmp(name, "regex", 5) == 0)
1752   {
1753   uschar *endptr;
1754   int n = Ustrtoul(name + 5, &endptr, 10);
1755   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1756     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1757   }
1758
1759 /* For all other variables, search the table */
1760
1761 if (!(vp = find_var_ent(name)))
1762   return NULL;          /* Unknown variable name */
1763
1764 /* Found an existing variable. If in skipping state, the value isn't needed,
1765 and we want to avoid processing (such as looking up the host name). */
1766
1767 if (skipping)
1768   return US"";
1769
1770 val = vp->value;
1771 switch (vp->type)
1772   {
1773   case vtype_filter_int:
1774     if (!filter_running) return NULL;
1775     /* Fall through */
1776     /* VVVVVVVVVVVV */
1777   case vtype_int:
1778     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1779     return var_buffer;
1780
1781   case vtype_ino:
1782     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1783     return var_buffer;
1784
1785   case vtype_gid:
1786     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1787     return var_buffer;
1788
1789   case vtype_uid:
1790     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1791     return var_buffer;
1792
1793   case vtype_bool:
1794     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1795     return var_buffer;
1796
1797   case vtype_stringptr:                      /* Pointer to string */
1798     return (s = *((uschar **)(val))) ? s : US"";
1799
1800   case vtype_pid:
1801     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1802     return var_buffer;
1803
1804   case vtype_load_avg:
1805     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1806     return var_buffer;
1807
1808   case vtype_host_lookup:                    /* Lookup if not done so */
1809     if (sender_host_name == NULL && sender_host_address != NULL &&
1810         !host_lookup_failed && host_name_lookup() == OK)
1811       host_build_sender_fullhost();
1812     return (sender_host_name == NULL)? US"" : sender_host_name;
1813
1814   case vtype_localpart:                      /* Get local part from address */
1815     s = *((uschar **)(val));
1816     if (s == NULL) return US"";
1817     domain = Ustrrchr(s, '@');
1818     if (domain == NULL) return s;
1819     if (domain - s > sizeof(var_buffer) - 1)
1820       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1821           " in string expansion", sizeof(var_buffer));
1822     Ustrncpy(var_buffer, s, domain - s);
1823     var_buffer[domain - s] = 0;
1824     return var_buffer;
1825
1826   case vtype_domain:                         /* Get domain from address */
1827     s = *((uschar **)(val));
1828     if (s == NULL) return US"";
1829     domain = Ustrrchr(s, '@');
1830     return (domain == NULL)? US"" : domain + 1;
1831
1832   case vtype_msgheaders:
1833     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1834
1835   case vtype_msgheaders_raw:
1836     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1837
1838   case vtype_msgbody:                        /* Pointer to msgbody string */
1839   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1840     ss = (uschar **)(val);
1841     if (*ss == NULL && deliver_datafile >= 0)  /* Read body when needed */
1842       {
1843       uschar *body;
1844       off_t start_offset = SPOOL_DATA_START_OFFSET;
1845       int len = message_body_visible;
1846       if (len > message_size) len = message_size;
1847       *ss = body = store_malloc(len+1);
1848       body[0] = 0;
1849       if (vp->type == vtype_msgbody_end)
1850         {
1851         struct stat statbuf;
1852         if (fstat(deliver_datafile, &statbuf) == 0)
1853           {
1854           start_offset = statbuf.st_size - len;
1855           if (start_offset < SPOOL_DATA_START_OFFSET)
1856             start_offset = SPOOL_DATA_START_OFFSET;
1857           }
1858         }
1859       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1860         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1861           strerror(errno));
1862       len = read(deliver_datafile, body, len);
1863       if (len > 0)
1864         {
1865         body[len] = 0;
1866         if (message_body_newlines)   /* Separate loops for efficiency */
1867           while (len > 0)
1868             { if (body[--len] == 0) body[len] = ' '; }
1869         else
1870           while (len > 0)
1871             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1872         }
1873       }
1874     return (*ss == NULL)? US"" : *ss;
1875
1876   case vtype_todbsdin:                       /* BSD inbox time of day */
1877     return tod_stamp(tod_bsdin);
1878
1879   case vtype_tode:                           /* Unix epoch time of day */
1880     return tod_stamp(tod_epoch);
1881
1882   case vtype_todel:                          /* Unix epoch/usec time of day */
1883     return tod_stamp(tod_epoch_l);
1884
1885   case vtype_todf:                           /* Full time of day */
1886     return tod_stamp(tod_full);
1887
1888   case vtype_todl:                           /* Log format time of day */
1889     return tod_stamp(tod_log_bare);            /* (without timezone) */
1890
1891   case vtype_todzone:                        /* Time zone offset only */
1892     return tod_stamp(tod_zone);
1893
1894   case vtype_todzulu:                        /* Zulu time */
1895     return tod_stamp(tod_zulu);
1896
1897   case vtype_todlf:                          /* Log file datestamp tod */
1898     return tod_stamp(tod_log_datestamp_daily);
1899
1900   case vtype_reply:                          /* Get reply address */
1901     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1902       headers_charset);
1903     if (s != NULL) while (isspace(*s)) s++;
1904     if (s == NULL || *s == 0)
1905       {
1906       *newsize = 0;                            /* For the *s==0 case */
1907       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1908       }
1909     if (s != NULL)
1910       {
1911       uschar *t;
1912       while (isspace(*s)) s++;
1913       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1914       while (t > s && isspace(t[-1])) t--;
1915       *t = 0;
1916       }
1917     return (s == NULL)? US"" : s;
1918
1919   case vtype_string_func:
1920     {
1921     uschar * (*fn)() = val;
1922     return fn();
1923     }
1924
1925   case vtype_pspace:
1926     {
1927     int inodes;
1928     sprintf(CS var_buffer, "%d",
1929       receive_statvfs(val == (void *)TRUE, &inodes));
1930     }
1931   return var_buffer;
1932
1933   case vtype_pinodes:
1934     {
1935     int inodes;
1936     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1937     sprintf(CS var_buffer, "%d", inodes);
1938     }
1939   return var_buffer;
1940
1941   case vtype_cert:
1942     return *(void **)val ? US"<cert>" : US"";
1943
1944 #ifndef DISABLE_DKIM
1945   case vtype_dkim:
1946     return dkim_exim_expand_query((int)(long)val);
1947 #endif
1948
1949   }
1950
1951 return NULL;  /* Unknown variable. Silences static checkers. */
1952 }
1953
1954
1955
1956
1957 void
1958 modify_variable(uschar *name, void * value)
1959 {
1960 var_entry * vp;
1961 if ((vp = find_var_ent(name))) vp->value = value;
1962 return;          /* Unknown variable name, fail silently */
1963 }
1964
1965
1966
1967
1968
1969
1970 /*************************************************
1971 *           Read and expand substrings           *
1972 *************************************************/
1973
1974 /* This function is called to read and expand argument substrings for various
1975 expansion items. Some have a minimum requirement that is less than the maximum;
1976 in these cases, the first non-present one is set to NULL.
1977
1978 Arguments:
1979   sub        points to vector of pointers to set
1980   n          maximum number of substrings
1981   m          minimum required
1982   sptr       points to current string pointer
1983   skipping   the skipping flag
1984   check_end  if TRUE, check for final '}'
1985   name       name of item, for error message
1986   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1987              the store.
1988
1989 Returns:     0 OK; string pointer updated
1990              1 curly bracketing error (too few arguments)
1991              2 too many arguments (only if check_end is set); message set
1992              3 other error (expansion failure)
1993 */
1994
1995 static int
1996 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1997   BOOL check_end, uschar *name, BOOL *resetok)
1998 {
1999 int i;
2000 const uschar *s = *sptr;
2001
2002 while (isspace(*s)) s++;
2003 for (i = 0; i < n; i++)
2004   {
2005   if (*s != '{')
2006     {
2007     if (i < m)
2008       {
2009       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2010         "(min is %d)", name, m);
2011       return 1;
2012       }
2013     sub[i] = NULL;
2014     break;
2015     }
2016   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2017     return 3;
2018   if (*s++ != '}') return 1;
2019   while (isspace(*s)) s++;
2020   }
2021 if (check_end && *s++ != '}')
2022   {
2023   if (s[-1] == '{')
2024     {
2025     expand_string_message = string_sprintf("Too many arguments for '%s' "
2026       "(max is %d)", name, n);
2027     return 2;
2028     }
2029   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2030   return 1;
2031   }
2032
2033 *sptr = s;
2034 return 0;
2035 }
2036
2037
2038
2039
2040 /*************************************************
2041 *     Elaborate message for bad variable         *
2042 *************************************************/
2043
2044 /* For the "unknown variable" message, take a look at the variable's name, and
2045 give additional information about possible ACL variables. The extra information
2046 is added on to expand_string_message.
2047
2048 Argument:   the name of the variable
2049 Returns:    nothing
2050 */
2051
2052 static void
2053 check_variable_error_message(uschar *name)
2054 {
2055 if (Ustrncmp(name, "acl_", 4) == 0)
2056   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2057     (name[4] == 'c' || name[4] == 'm')?
2058       (isalpha(name[5])?
2059         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2060         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2061       ) :
2062       US"user-defined ACL variables must start acl_c or acl_m");
2063 }
2064
2065
2066
2067 /*
2068 Load args from sub array to globals, and call acl_check().
2069 Sub array will be corrupted on return.
2070
2071 Returns:       OK         access is granted by an ACCEPT verb
2072                DISCARD    access is (apparently) granted by a DISCARD verb
2073                FAIL       access is denied
2074                FAIL_DROP  access is denied; drop the connection
2075                DEFER      can't tell at the moment
2076                ERROR      disaster
2077 */
2078 static int
2079 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2080 {
2081 int i;
2082 int sav_narg = acl_narg;
2083 int ret;
2084 uschar * dummy_logmsg;
2085 extern int acl_where;
2086
2087 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2088 for (i = 0; i < nsub && sub[i+1]; i++)
2089   {
2090   uschar * tmp = acl_arg[i];
2091   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2092   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2093   }
2094 acl_narg = i;
2095 while (i < nsub)
2096   {
2097   sub[i+1] = acl_arg[i];
2098   acl_arg[i++] = NULL;
2099   }
2100
2101 DEBUG(D_expand)
2102   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2103     sub[0],
2104     acl_narg>0 ? acl_arg[0] : US"<none>",
2105     acl_narg>1 ? " +more"   : "");
2106
2107 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2108
2109 for (i = 0; i < nsub; i++)
2110   acl_arg[i] = sub[i+1];        /* restore old args */
2111 acl_narg = sav_narg;
2112
2113 return ret;
2114 }
2115
2116
2117
2118
2119 /*************************************************
2120 *        Read and evaluate a condition           *
2121 *************************************************/
2122
2123 /*
2124 Arguments:
2125   s        points to the start of the condition text
2126   resetok  points to a BOOL which is written false if it is unsafe to
2127            free memory. Certain condition types (acl) may have side-effect
2128            allocation which must be preserved.
2129   yield    points to a BOOL to hold the result of the condition test;
2130            if NULL, we are just reading through a condition that is
2131            part of an "or" combination to check syntax, or in a state
2132            where the answer isn't required
2133
2134 Returns:   a pointer to the first character after the condition, or
2135            NULL after an error
2136 */
2137
2138 static const uschar *
2139 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2140 {
2141 BOOL testfor = TRUE;
2142 BOOL tempcond, combined_cond;
2143 BOOL *subcondptr;
2144 BOOL sub2_honour_dollar = TRUE;
2145 int i, rc, cond_type, roffset;
2146 int_eximarith_t num[2];
2147 struct stat statbuf;
2148 uschar name[256];
2149 const uschar *sub[10];
2150
2151 const pcre *re;
2152 const uschar *rerror;
2153
2154 for (;;)
2155   {
2156   while (isspace(*s)) s++;
2157   if (*s == '!') { testfor = !testfor; s++; } else break;
2158   }
2159
2160 /* Numeric comparisons are symbolic */
2161
2162 if (*s == '=' || *s == '>' || *s == '<')
2163   {
2164   int p = 0;
2165   name[p++] = *s++;
2166   if (*s == '=')
2167     {
2168     name[p++] = '=';
2169     s++;
2170     }
2171   name[p] = 0;
2172   }
2173
2174 /* All other conditions are named */
2175
2176 else s = read_name(name, 256, s, US"_");
2177
2178 /* If we haven't read a name, it means some non-alpha character is first. */
2179
2180 if (name[0] == 0)
2181   {
2182   expand_string_message = string_sprintf("condition name expected, "
2183     "but found \"%.16s\"", s);
2184   return NULL;
2185   }
2186
2187 /* Find which condition we are dealing with, and switch on it */
2188
2189 cond_type = chop_match(name, cond_table, nelem(cond_table));
2190 switch(cond_type)
2191   {
2192   /* def: tests for a non-empty variable, or for the existence of a header. If
2193   yield == NULL we are in a skipping state, and don't care about the answer. */
2194
2195   case ECOND_DEF:
2196   if (*s != ':')
2197     {
2198     expand_string_message = US"\":\" expected after \"def\"";
2199     return NULL;
2200     }
2201
2202   s = read_name(name, 256, s+1, US"_");
2203
2204   /* Test for a header's existence. If the name contains a closing brace
2205   character, this may be a user error where the terminating colon has been
2206   omitted. Set a flag to adjust a subsequent error message in this case. */
2207
2208   if (Ustrncmp(name, "h_", 2) == 0 ||
2209       Ustrncmp(name, "rh_", 3) == 0 ||
2210       Ustrncmp(name, "bh_", 3) == 0 ||
2211       Ustrncmp(name, "header_", 7) == 0 ||
2212       Ustrncmp(name, "rheader_", 8) == 0 ||
2213       Ustrncmp(name, "bheader_", 8) == 0)
2214     {
2215     s = read_header_name(name, 256, s);
2216     /* {-for-text-editors */
2217     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2218     if (yield != NULL) *yield =
2219       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2220     }
2221
2222   /* Test for a variable's having a non-empty value. A non-existent variable
2223   causes an expansion failure. */
2224
2225   else
2226     {
2227     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2228     if (value == NULL)
2229       {
2230       expand_string_message = (name[0] == 0)?
2231         string_sprintf("variable name omitted after \"def:\"") :
2232         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2233       check_variable_error_message(name);
2234       return NULL;
2235       }
2236     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2237     }
2238
2239   return s;
2240
2241
2242   /* first_delivery tests for first delivery attempt */
2243
2244   case ECOND_FIRST_DELIVERY:
2245   if (yield != NULL) *yield = deliver_firsttime == testfor;
2246   return s;
2247
2248
2249   /* queue_running tests for any process started by a queue runner */
2250
2251   case ECOND_QUEUE_RUNNING:
2252   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2253   return s;
2254
2255
2256   /* exists:  tests for file existence
2257        isip:  tests for any IP address
2258       isip4:  tests for an IPv4 address
2259       isip6:  tests for an IPv6 address
2260         pam:  does PAM authentication
2261      radius:  does RADIUS authentication
2262    ldapauth:  does LDAP authentication
2263     pwcheck:  does Cyrus SASL pwcheck authentication
2264   */
2265
2266   case ECOND_EXISTS:
2267   case ECOND_ISIP:
2268   case ECOND_ISIP4:
2269   case ECOND_ISIP6:
2270   case ECOND_PAM:
2271   case ECOND_RADIUS:
2272   case ECOND_LDAPAUTH:
2273   case ECOND_PWCHECK:
2274
2275   while (isspace(*s)) s++;
2276   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2277
2278   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2279   if (sub[0] == NULL) return NULL;
2280   /* {-for-text-editors */
2281   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2282
2283   if (yield == NULL) return s;   /* No need to run the test if skipping */
2284
2285   switch(cond_type)
2286     {
2287     case ECOND_EXISTS:
2288     if ((expand_forbid & RDO_EXISTS) != 0)
2289       {
2290       expand_string_message = US"File existence tests are not permitted";
2291       return NULL;
2292       }
2293     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2294     break;
2295
2296     case ECOND_ISIP:
2297     case ECOND_ISIP4:
2298     case ECOND_ISIP6:
2299     rc = string_is_ip_address(sub[0], NULL);
2300     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2301              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2302     break;
2303
2304     /* Various authentication tests - all optionally compiled */
2305
2306     case ECOND_PAM:
2307     #ifdef SUPPORT_PAM
2308     rc = auth_call_pam(sub[0], &expand_string_message);
2309     goto END_AUTH;
2310     #else
2311     goto COND_FAILED_NOT_COMPILED;
2312     #endif  /* SUPPORT_PAM */
2313
2314     case ECOND_RADIUS:
2315     #ifdef RADIUS_CONFIG_FILE
2316     rc = auth_call_radius(sub[0], &expand_string_message);
2317     goto END_AUTH;
2318     #else
2319     goto COND_FAILED_NOT_COMPILED;
2320     #endif  /* RADIUS_CONFIG_FILE */
2321
2322     case ECOND_LDAPAUTH:
2323     #ifdef LOOKUP_LDAP
2324       {
2325       /* Just to keep the interface the same */
2326       BOOL do_cache;
2327       int old_pool = store_pool;
2328       store_pool = POOL_SEARCH;
2329       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2330         &expand_string_message, &do_cache);
2331       store_pool = old_pool;
2332       }
2333     goto END_AUTH;
2334     #else
2335     goto COND_FAILED_NOT_COMPILED;
2336     #endif  /* LOOKUP_LDAP */
2337
2338     case ECOND_PWCHECK:
2339     #ifdef CYRUS_PWCHECK_SOCKET
2340     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2341     goto END_AUTH;
2342     #else
2343     goto COND_FAILED_NOT_COMPILED;
2344     #endif  /* CYRUS_PWCHECK_SOCKET */
2345
2346     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2347         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2348     END_AUTH:
2349     if (rc == ERROR || rc == DEFER) return NULL;
2350     *yield = (rc == OK) == testfor;
2351     #endif
2352     }
2353   return s;
2354
2355
2356   /* call ACL (in a conditional context).  Accept true, deny false.
2357   Defer is a forced-fail.  Anything set by message= goes to $value.
2358   Up to ten parameters are used; we use the braces round the name+args
2359   like the saslauthd condition does, to permit a variable number of args.
2360   See also the expansion-item version EITEM_ACL and the traditional
2361   acl modifier ACLC_ACL.
2362   Since the ACL may allocate new global variables, tell our caller to not
2363   reclaim memory.
2364   */
2365
2366   case ECOND_ACL:
2367     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2368     {
2369     uschar *sub[10];
2370     uschar *user_msg;
2371     BOOL cond = FALSE;
2372     int size = 0;
2373     int ptr = 0;
2374
2375     while (isspace(*s)) s++;
2376     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2377
2378     switch(read_subs(sub, nelem(sub), 1,
2379       &s, yield == NULL, TRUE, US"acl", resetok))
2380       {
2381       case 1: expand_string_message = US"too few arguments or bracketing "
2382         "error for acl";
2383       case 2:
2384       case 3: return NULL;
2385       }
2386
2387     *resetok = FALSE;   /* eval_acl() might allocate; do not reclaim */
2388     if (yield != NULL) switch(eval_acl(sub, nelem(sub), &user_msg))
2389         {
2390         case OK:
2391           cond = TRUE;
2392         case FAIL:
2393           lookup_value = NULL;
2394           if (user_msg)
2395             {
2396             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2397             lookup_value[ptr] = '\0';
2398             }
2399           *yield = cond == testfor;
2400           break;
2401
2402         case DEFER:
2403           expand_string_forcedfail = TRUE;
2404           /*FALLTHROUGH*/
2405         default:
2406           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2407           return NULL;
2408         }
2409     return s;
2410     }
2411
2412
2413   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2414
2415      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2416
2417   However, the last two are optional. That is why the whole set is enclosed
2418   in their own set of braces. */
2419
2420   case ECOND_SASLAUTHD:
2421 #ifndef CYRUS_SASLAUTHD_SOCKET
2422     goto COND_FAILED_NOT_COMPILED;
2423 #else
2424     {
2425     uschar *sub[4];
2426     while (isspace(*s)) s++;
2427     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2428     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2429                     resetok))
2430       {
2431       case 1: expand_string_message = US"too few arguments or bracketing "
2432         "error for saslauthd";
2433       case 2:
2434       case 3: return NULL;
2435       }
2436     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2437     if (yield != NULL)
2438       {
2439       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2440         &expand_string_message);
2441       if (rc == ERROR || rc == DEFER) return NULL;
2442       *yield = (rc == OK) == testfor;
2443       }
2444     return s;
2445     }
2446 #endif /* CYRUS_SASLAUTHD_SOCKET */
2447
2448
2449   /* symbolic operators for numeric and string comparison, and a number of
2450   other operators, all requiring two arguments.
2451
2452   crypteq:           encrypts plaintext and compares against an encrypted text,
2453                        using crypt(), crypt16(), MD5 or SHA-1
2454   inlist/inlisti:    checks if first argument is in the list of the second
2455   match:             does a regular expression match and sets up the numerical
2456                        variables if it succeeds
2457   match_address:     matches in an address list
2458   match_domain:      matches in a domain list
2459   match_ip:          matches a host list that is restricted to IP addresses
2460   match_local_part:  matches in a local part list
2461   */
2462
2463   case ECOND_MATCH_ADDRESS:
2464   case ECOND_MATCH_DOMAIN:
2465   case ECOND_MATCH_IP:
2466   case ECOND_MATCH_LOCAL_PART:
2467 #ifndef EXPAND_LISTMATCH_RHS
2468     sub2_honour_dollar = FALSE;
2469 #endif
2470     /* FALLTHROUGH */
2471
2472   case ECOND_CRYPTEQ:
2473   case ECOND_INLIST:
2474   case ECOND_INLISTI:
2475   case ECOND_MATCH:
2476
2477   case ECOND_NUM_L:     /* Numerical comparisons */
2478   case ECOND_NUM_LE:
2479   case ECOND_NUM_E:
2480   case ECOND_NUM_EE:
2481   case ECOND_NUM_G:
2482   case ECOND_NUM_GE:
2483
2484   case ECOND_STR_LT:    /* String comparisons */
2485   case ECOND_STR_LTI:
2486   case ECOND_STR_LE:
2487   case ECOND_STR_LEI:
2488   case ECOND_STR_EQ:
2489   case ECOND_STR_EQI:
2490   case ECOND_STR_GT:
2491   case ECOND_STR_GTI:
2492   case ECOND_STR_GE:
2493   case ECOND_STR_GEI:
2494
2495   for (i = 0; i < 2; i++)
2496     {
2497     /* Sometimes, we don't expand substrings; too many insecure configurations
2498     created using match_address{}{} and friends, where the second param
2499     includes information from untrustworthy sources. */
2500     BOOL honour_dollar = TRUE;
2501     if ((i > 0) && !sub2_honour_dollar)
2502       honour_dollar = FALSE;
2503
2504     while (isspace(*s)) s++;
2505     if (*s != '{')
2506       {
2507       if (i == 0) goto COND_FAILED_CURLY_START;
2508       expand_string_message = string_sprintf("missing 2nd string in {} "
2509         "after \"%s\"", name);
2510       return NULL;
2511       }
2512     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2513         honour_dollar, resetok);
2514     if (sub[i] == NULL) return NULL;
2515     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2516
2517     /* Convert to numerical if required; we know that the names of all the
2518     conditions that compare numbers do not start with a letter. This just saves
2519     checking for them individually. */
2520
2521     if (!isalpha(name[0]) && yield != NULL)
2522       if (sub[i][0] == 0)
2523         {
2524         num[i] = 0;
2525         DEBUG(D_expand)
2526           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2527         }
2528       else
2529         {
2530         num[i] = expanded_string_integer(sub[i], FALSE);
2531         if (expand_string_message != NULL) return NULL;
2532         }
2533     }
2534
2535   /* Result not required */
2536
2537   if (yield == NULL) return s;
2538
2539   /* Do an appropriate comparison */
2540
2541   switch(cond_type)
2542     {
2543     case ECOND_NUM_E:
2544     case ECOND_NUM_EE:
2545     tempcond = (num[0] == num[1]);
2546     break;
2547
2548     case ECOND_NUM_G:
2549     tempcond = (num[0] > num[1]);
2550     break;
2551
2552     case ECOND_NUM_GE:
2553     tempcond = (num[0] >= num[1]);
2554     break;
2555
2556     case ECOND_NUM_L:
2557     tempcond = (num[0] < num[1]);
2558     break;
2559
2560     case ECOND_NUM_LE:
2561     tempcond = (num[0] <= num[1]);
2562     break;
2563
2564     case ECOND_STR_LT:
2565     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2566     break;
2567
2568     case ECOND_STR_LTI:
2569     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2570     break;
2571
2572     case ECOND_STR_LE:
2573     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2574     break;
2575
2576     case ECOND_STR_LEI:
2577     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2578     break;
2579
2580     case ECOND_STR_EQ:
2581     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2582     break;
2583
2584     case ECOND_STR_EQI:
2585     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2586     break;
2587
2588     case ECOND_STR_GT:
2589     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2590     break;
2591
2592     case ECOND_STR_GTI:
2593     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2594     break;
2595
2596     case ECOND_STR_GE:
2597     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2598     break;
2599
2600     case ECOND_STR_GEI:
2601     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2602     break;
2603
2604     case ECOND_MATCH:   /* Regular expression match */
2605     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2606       NULL);
2607     if (re == NULL)
2608       {
2609       expand_string_message = string_sprintf("regular expression error in "
2610         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2611       return NULL;
2612       }
2613     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2614     break;
2615
2616     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2617     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2618     goto MATCHED_SOMETHING;
2619
2620     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2621     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2622       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2623     goto MATCHED_SOMETHING;
2624
2625     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2626     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2627       {
2628       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2629         sub[0]);
2630       return NULL;
2631       }
2632     else
2633       {
2634       unsigned int *nullcache = NULL;
2635       check_host_block cb;
2636
2637       cb.host_name = US"";
2638       cb.host_address = sub[0];
2639
2640       /* If the host address starts off ::ffff: it is an IPv6 address in
2641       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2642       addresses. */
2643
2644       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2645         cb.host_address + 7 : cb.host_address;
2646
2647       rc = match_check_list(
2648              &sub[1],                   /* the list */
2649              0,                         /* separator character */
2650              &hostlist_anchor,          /* anchor pointer */
2651              &nullcache,                /* cache pointer */
2652              check_host,                /* function for testing */
2653              &cb,                       /* argument for function */
2654              MCL_HOST,                  /* type of check */
2655              sub[0],                    /* text for debugging */
2656              NULL);                     /* where to pass back data */
2657       }
2658     goto MATCHED_SOMETHING;
2659
2660     case ECOND_MATCH_LOCAL_PART:
2661     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2662       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2663     /* Fall through */
2664     /* VVVVVVVVVVVV */
2665     MATCHED_SOMETHING:
2666     switch(rc)
2667       {
2668       case OK:
2669       tempcond = TRUE;
2670       break;
2671
2672       case FAIL:
2673       tempcond = FALSE;
2674       break;
2675
2676       case DEFER:
2677       expand_string_message = string_sprintf("unable to complete match "
2678         "against \"%s\": %s", sub[1], search_error_message);
2679       return NULL;
2680       }
2681
2682     break;
2683
2684     /* Various "encrypted" comparisons. If the second string starts with
2685     "{" then an encryption type is given. Default to crypt() or crypt16()
2686     (build-time choice). */
2687     /* }-for-text-editors */
2688
2689     case ECOND_CRYPTEQ:
2690     #ifndef SUPPORT_CRYPTEQ
2691     goto COND_FAILED_NOT_COMPILED;
2692     #else
2693     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2694       {
2695       int sublen = Ustrlen(sub[1]+5);
2696       md5 base;
2697       uschar digest[16];
2698
2699       md5_start(&base);
2700       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2701
2702       /* If the length that we are comparing against is 24, the MD5 digest
2703       is expressed as a base64 string. This is the way LDAP does it. However,
2704       some other software uses a straightforward hex representation. We assume
2705       this if the length is 32. Other lengths fail. */
2706
2707       if (sublen == 24)
2708         {
2709         uschar *coded = b64encode(digest, 16);
2710         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2711           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2712         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2713         }
2714       else if (sublen == 32)
2715         {
2716         int i;
2717         uschar coded[36];
2718         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2719         coded[32] = 0;
2720         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2721           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2722         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2723         }
2724       else
2725         {
2726         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2727           "fail\n  crypted=%s\n", sub[1]+5);
2728         tempcond = FALSE;
2729         }
2730       }
2731
2732     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2733       {
2734       int sublen = Ustrlen(sub[1]+6);
2735       hctx h;
2736       uschar digest[20];
2737
2738       sha1_start(&h);
2739       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2740
2741       /* If the length that we are comparing against is 28, assume the SHA1
2742       digest is expressed as a base64 string. If the length is 40, assume a
2743       straightforward hex representation. Other lengths fail. */
2744
2745       if (sublen == 28)
2746         {
2747         uschar *coded = b64encode(digest, 20);
2748         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2749           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2750         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2751         }
2752       else if (sublen == 40)
2753         {
2754         int i;
2755         uschar coded[44];
2756         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2757         coded[40] = 0;
2758         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2759           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2760         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2761         }
2762       else
2763         {
2764         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2765           "fail\n  crypted=%s\n", sub[1]+6);
2766         tempcond = FALSE;
2767         }
2768       }
2769
2770     else   /* {crypt} or {crypt16} and non-{ at start */
2771            /* }-for-text-editors */
2772       {
2773       int which = 0;
2774       uschar *coded;
2775
2776       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2777         {
2778         sub[1] += 7;
2779         which = 1;
2780         }
2781       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2782         {
2783         sub[1] += 9;
2784         which = 2;
2785         }
2786       else if (sub[1][0] == '{')                /* }-for-text-editors */
2787         {
2788         expand_string_message = string_sprintf("unknown encryption mechanism "
2789           "in \"%s\"", sub[1]);
2790         return NULL;
2791         }
2792
2793       switch(which)
2794         {
2795         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2796         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2797         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2798         }
2799
2800       #define STR(s) # s
2801       #define XSTR(s) STR(s)
2802       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2803         "  subject=%s\n  crypted=%s\n",
2804         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2805         coded, sub[1]);
2806       #undef STR
2807       #undef XSTR
2808
2809       /* If the encrypted string contains fewer than two characters (for the
2810       salt), force failure. Otherwise we get false positives: with an empty
2811       string the yield of crypt() is an empty string! */
2812
2813       if (coded)
2814         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2815       else if (errno == EINVAL)
2816         tempcond = FALSE;
2817       else
2818         {
2819         expand_string_message = string_sprintf("crypt error: %s\n",
2820           US strerror(errno));
2821         return NULL;
2822         }
2823       }
2824     break;
2825     #endif  /* SUPPORT_CRYPTEQ */
2826
2827     case ECOND_INLIST:
2828     case ECOND_INLISTI:
2829       {
2830       const uschar * list = sub[1];
2831       int sep = 0;
2832       uschar *save_iterate_item = iterate_item;
2833       int (*compare)(const uschar *, const uschar *);
2834
2835       DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2836
2837       tempcond = FALSE;
2838       compare = cond_type == ECOND_INLISTI
2839         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2840
2841       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2842         if (compare(sub[0], iterate_item) == 0)
2843           {
2844           tempcond = TRUE;
2845           break;
2846           }
2847       iterate_item = save_iterate_item;
2848       }
2849
2850     }   /* Switch for comparison conditions */
2851
2852   *yield = tempcond == testfor;
2853   return s;    /* End of comparison conditions */
2854
2855
2856   /* and/or: computes logical and/or of several conditions */
2857
2858   case ECOND_AND:
2859   case ECOND_OR:
2860   subcondptr = (yield == NULL)? NULL : &tempcond;
2861   combined_cond = (cond_type == ECOND_AND);
2862
2863   while (isspace(*s)) s++;
2864   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2865
2866   for (;;)
2867     {
2868     while (isspace(*s)) s++;
2869     /* {-for-text-editors */
2870     if (*s == '}') break;
2871     if (*s != '{')                                      /* }-for-text-editors */
2872       {
2873       expand_string_message = string_sprintf("each subcondition "
2874         "inside an \"%s{...}\" condition must be in its own {}", name);
2875       return NULL;
2876       }
2877
2878     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2879       {
2880       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2881         expand_string_message, name);
2882       return NULL;
2883       }
2884     while (isspace(*s)) s++;
2885
2886     /* {-for-text-editors */
2887     if (*s++ != '}')
2888       {
2889       /* {-for-text-editors */
2890       expand_string_message = string_sprintf("missing } at end of condition "
2891         "inside \"%s\" group", name);
2892       return NULL;
2893       }
2894
2895     if (yield != NULL)
2896       {
2897       if (cond_type == ECOND_AND)
2898         {
2899         combined_cond &= tempcond;
2900         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2901         }                                       /* evaluate any more */
2902       else
2903         {
2904         combined_cond |= tempcond;
2905         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2906         }                                       /* evaluate any more */
2907       }
2908     }
2909
2910   if (yield != NULL) *yield = (combined_cond == testfor);
2911   return ++s;
2912
2913
2914   /* forall/forany: iterates a condition with different values */
2915
2916   case ECOND_FORALL:
2917   case ECOND_FORANY:
2918     {
2919     const uschar * list;
2920     int sep = 0;
2921     uschar *save_iterate_item = iterate_item;
2922
2923     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2924
2925     while (isspace(*s)) s++;
2926     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2927     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2928     if (sub[0] == NULL) return NULL;
2929     /* {-for-text-editors */
2930     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2931
2932     while (isspace(*s)) s++;
2933     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2934
2935     sub[1] = s;
2936
2937     /* Call eval_condition once, with result discarded (as if scanning a
2938     "false" part). This allows us to find the end of the condition, because if
2939     the list it empty, we won't actually evaluate the condition for real. */
2940
2941     if (!(s = eval_condition(sub[1], resetok, NULL)))
2942       {
2943       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2944         expand_string_message, name);
2945       return NULL;
2946       }
2947     while (isspace(*s)) s++;
2948
2949     /* {-for-text-editors */
2950     if (*s++ != '}')
2951       {
2952       /* {-for-text-editors */
2953       expand_string_message = string_sprintf("missing } at end of condition "
2954         "inside \"%s\"", name);
2955       return NULL;
2956       }
2957
2958     if (yield != NULL) *yield = !testfor;
2959     list = sub[0];
2960     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2961       {
2962       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2963       if (!eval_condition(sub[1], resetok, &tempcond))
2964         {
2965         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2966           expand_string_message, name);
2967         iterate_item = save_iterate_item;
2968         return NULL;
2969         }
2970       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2971         tempcond? "true":"false");
2972
2973       if (yield != NULL) *yield = (tempcond == testfor);
2974       if (tempcond == (cond_type == ECOND_FORANY)) break;
2975       }
2976
2977     iterate_item = save_iterate_item;
2978     return s;
2979     }
2980
2981
2982   /* The bool{} expansion condition maps a string to boolean.
2983   The values supported should match those supported by the ACL condition
2984   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2985   of true/false.  Note that Router "condition" rules have a different
2986   interpretation, where general data can be used and only a few values
2987   map to FALSE.
2988   Note that readconf.c boolean matching, for boolean configuration options,
2989   only matches true/yes/false/no.
2990   The bool_lax{} condition matches the Router logic, which is much more
2991   liberal. */
2992   case ECOND_BOOL:
2993   case ECOND_BOOL_LAX:
2994     {
2995     uschar *sub_arg[1];
2996     uschar *t, *t2;
2997     uschar *ourname;
2998     size_t len;
2999     BOOL boolvalue = FALSE;
3000     while (isspace(*s)) s++;
3001     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
3002     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
3003     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3004       {
3005       case 1: expand_string_message = string_sprintf(
3006                   "too few arguments or bracketing error for %s",
3007                   ourname);
3008       /*FALLTHROUGH*/
3009       case 2:
3010       case 3: return NULL;
3011       }
3012     t = sub_arg[0];
3013     while (isspace(*t)) t++;
3014     len = Ustrlen(t);
3015     if (len)
3016       {
3017       /* trailing whitespace: seems like a good idea to ignore it too */
3018       t2 = t + len - 1;
3019       while (isspace(*t2)) t2--;
3020       if (t2 != (t + len))
3021         {
3022         *++t2 = '\0';
3023         len = t2 - t;
3024         }
3025       }
3026     DEBUG(D_expand)
3027       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3028     /* logic for the lax case from expand_check_condition(), which also does
3029     expands, and the logic is both short and stable enough that there should
3030     be no maintenance burden from replicating it. */
3031     if (len == 0)
3032       boolvalue = FALSE;
3033     else if (*t == '-'
3034              ? Ustrspn(t+1, "0123456789") == len-1
3035              : Ustrspn(t,   "0123456789") == len)
3036       {
3037       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3038       /* expand_check_condition only does a literal string "0" check */
3039       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3040         boolvalue = TRUE;
3041       }
3042     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3043       boolvalue = TRUE;
3044     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3045       boolvalue = FALSE;
3046     else if (cond_type == ECOND_BOOL_LAX)
3047       boolvalue = TRUE;
3048     else
3049       {
3050       expand_string_message = string_sprintf("unrecognised boolean "
3051        "value \"%s\"", t);
3052       return NULL;
3053       }
3054     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3055         boolvalue? "true":"false");
3056     if (yield != NULL) *yield = (boolvalue == testfor);
3057     return s;
3058     }
3059
3060   /* Unknown condition */
3061
3062   default:
3063   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3064   return NULL;
3065   }   /* End switch on condition type */
3066
3067 /* Missing braces at start and end of data */
3068
3069 COND_FAILED_CURLY_START:
3070 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3071 return NULL;
3072
3073 COND_FAILED_CURLY_END:
3074 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3075   name);
3076 return NULL;
3077
3078 /* A condition requires code that is not compiled */
3079
3080 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3081     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3082     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3083 COND_FAILED_NOT_COMPILED:
3084 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3085   name);
3086 return NULL;
3087 #endif
3088 }
3089
3090
3091
3092
3093 /*************************************************
3094 *          Save numerical variables              *
3095 *************************************************/
3096
3097 /* This function is called from items such as "if" that want to preserve and
3098 restore the numbered variables.
3099
3100 Arguments:
3101   save_expand_string    points to an array of pointers to set
3102   save_expand_nlength   points to an array of ints for the lengths
3103
3104 Returns:                the value of expand max to save
3105 */
3106
3107 static int
3108 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3109 {
3110 int i;
3111 for (i = 0; i <= expand_nmax; i++)
3112   {
3113   save_expand_nstring[i] = expand_nstring[i];
3114   save_expand_nlength[i] = expand_nlength[i];
3115   }
3116 return expand_nmax;
3117 }
3118
3119
3120
3121 /*************************************************
3122 *           Restore numerical variables          *
3123 *************************************************/
3124
3125 /* This function restored saved values of numerical strings.
3126
3127 Arguments:
3128   save_expand_nmax      the number of strings to restore
3129   save_expand_string    points to an array of pointers
3130   save_expand_nlength   points to an array of ints
3131
3132 Returns:                nothing
3133 */
3134
3135 static void
3136 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3137   int *save_expand_nlength)
3138 {
3139 int i;
3140 expand_nmax = save_expand_nmax;
3141 for (i = 0; i <= expand_nmax; i++)
3142   {
3143   expand_nstring[i] = save_expand_nstring[i];
3144   expand_nlength[i] = save_expand_nlength[i];
3145   }
3146 }
3147
3148
3149
3150
3151
3152 /*************************************************
3153 *            Handle yes/no substrings            *
3154 *************************************************/
3155
3156 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3157 alternative substrings that depend on whether or not the condition was true,
3158 or the lookup or extraction succeeded. The substrings always have to be
3159 expanded, to check their syntax, but "skipping" is set when the result is not
3160 needed - this avoids unnecessary nested lookups.
3161
3162 Arguments:
3163   skipping       TRUE if we were skipping when this item was reached
3164   yes            TRUE if the first string is to be used, else use the second
3165   save_lookup    a value to put back into lookup_value before the 2nd expansion
3166   sptr           points to the input string pointer
3167   yieldptr       points to the output string pointer
3168   sizeptr        points to the output string size
3169   ptrptr         points to the output string pointer
3170   type           "lookup", "if", "extract", "run", "env", "listextract" or
3171                  "certextract" for error message
3172   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3173                 the store.
3174
3175 Returns:         0 OK; lookup_value has been reset to save_lookup
3176                  1 expansion failed
3177                  2 expansion failed because of bracketing error
3178 */
3179
3180 static int
3181 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3182   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3183 {
3184 int rc = 0;
3185 const uschar *s = *sptr;    /* Local value */
3186 uschar *sub1, *sub2;
3187 const uschar * errwhere;
3188
3189 /* If there are no following strings, we substitute the contents of $value for
3190 lookups and for extractions in the success case. For the ${if item, the string
3191 "true" is substituted. In the fail case, nothing is substituted for all three
3192 items. */
3193
3194 while (isspace(*s)) s++;
3195 if (*s == '}')
3196   {
3197   if (type[0] == 'i')
3198     {
3199     if (yes && !skipping)
3200       *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3201     }
3202   else
3203     {
3204     if (yes && lookup_value && !skipping)
3205       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3206     lookup_value = save_lookup;
3207     }
3208   s++;
3209   goto RETURN;
3210   }
3211
3212 /* The first following string must be braced. */
3213
3214 if (*s++ != '{')
3215   {
3216   errwhere = US"'yes' part did not start with '{'";
3217   goto FAILED_CURLY;
3218   }
3219
3220 /* Expand the first substring. Forced failures are noticed only if we actually
3221 want this string. Set skipping in the call in the fail case (this will always
3222 be the case if we were already skipping). */
3223
3224 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3225 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3226 expand_string_forcedfail = FALSE;
3227 if (*s++ != '}')
3228   {
3229   errwhere = US"'yes' part did not end with '}'";
3230   goto FAILED_CURLY;
3231   }
3232
3233 /* If we want the first string, add it to the output */
3234
3235 if (yes)
3236   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3237
3238 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3239 $value to what it was at the start of the item, so that it has this value
3240 during the second string expansion. For the call from "if" or "run" to this
3241 function, save_lookup is set to lookup_value, so that this statement does
3242 nothing. */
3243
3244 lookup_value = save_lookup;
3245
3246 /* There now follows either another substring, or "fail", or nothing. This
3247 time, forced failures are noticed only if we want the second string. We must
3248 set skipping in the nested call if we don't want this string, or if we were
3249 already skipping. */
3250
3251 while (isspace(*s)) s++;
3252 if (*s == '{')
3253   {
3254   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3255   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3256   expand_string_forcedfail = FALSE;
3257   if (*s++ != '}')
3258     {
3259     errwhere = US"'no' part did not start with '{'";
3260     goto FAILED_CURLY;
3261     }
3262
3263   /* If we want the second string, add it to the output */
3264
3265   if (!yes)
3266     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3267   }
3268
3269 /* If there is no second string, but the word "fail" is present when the use of
3270 the second string is wanted, set a flag indicating it was a forced failure
3271 rather than a syntactic error. Swallow the terminating } in case this is nested
3272 inside another lookup or if or extract. */
3273
3274 else if (*s != '}')
3275   {
3276   uschar name[256];
3277   /* deconst cast ok here as source is s anyway */
3278   s = US read_name(name, sizeof(name), s, US"_");
3279   if (Ustrcmp(name, "fail") == 0)
3280     {
3281     if (!yes && !skipping)
3282       {
3283       while (isspace(*s)) s++;
3284       if (*s++ != '}')
3285         {
3286         errwhere = US"did not close with '}' after forcedfail";
3287         goto FAILED_CURLY;
3288         }
3289       expand_string_message =
3290         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3291       expand_string_forcedfail = TRUE;
3292       goto FAILED;
3293       }
3294     }
3295   else
3296     {
3297     expand_string_message =
3298       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3299     goto FAILED;
3300     }
3301   }
3302
3303 /* All we have to do now is to check on the final closing brace. */
3304
3305 while (isspace(*s)) s++;
3306 if (*s++ != '}')
3307   {
3308   errwhere = US"did not close with '}'";
3309   goto FAILED_CURLY;
3310   }
3311
3312
3313 RETURN:
3314 /* Update the input pointer value before returning */
3315 *sptr = s;
3316 return rc;
3317
3318 FAILED_CURLY:
3319   /* Get here if there is a bracketing failure */
3320   expand_string_message = string_sprintf(
3321     "curly-bracket problem in conditional yes/no parsing: %s\n"
3322     " remaining string is '%s'", errwhere, --s);
3323   rc = 2;
3324   goto RETURN;
3325
3326 FAILED:
3327   /* Get here for other failures */
3328   rc = 1;
3329   goto RETURN;
3330 }
3331
3332
3333
3334
3335 /*************************************************
3336 *    Handle MD5 or SHA-1 computation for HMAC    *
3337 *************************************************/
3338
3339 /* These are some wrapping functions that enable the HMAC code to be a bit
3340 cleaner. A good compiler will spot the tail recursion.
3341
3342 Arguments:
3343   type         HMAC_MD5 or HMAC_SHA1
3344   remaining    are as for the cryptographic hash functions
3345
3346 Returns:       nothing
3347 */
3348
3349 static void
3350 chash_start(int type, void *base)
3351 {
3352 if (type == HMAC_MD5)
3353   md5_start((md5 *)base);
3354 else
3355   sha1_start((hctx *)base);
3356 }
3357
3358 static void
3359 chash_mid(int type, void *base, uschar *string)
3360 {
3361 if (type == HMAC_MD5)
3362   md5_mid((md5 *)base, string);
3363 else
3364   sha1_mid((hctx *)base, string);
3365 }
3366
3367 static void
3368 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3369 {
3370 if (type == HMAC_MD5)
3371   md5_end((md5 *)base, string, length, digest);
3372 else
3373   sha1_end((hctx *)base, string, length, digest);
3374 }
3375
3376
3377
3378
3379
3380 /********************************************************
3381 * prvs: Get last three digits of days since Jan 1, 1970 *
3382 ********************************************************/
3383
3384 /* This is needed to implement the "prvs" BATV reverse
3385    path signing scheme
3386
3387 Argument: integer "days" offset to add or substract to
3388           or from the current number of days.
3389
3390 Returns:  pointer to string containing the last three
3391           digits of the number of days since Jan 1, 1970,
3392           modified by the offset argument, NULL if there
3393           was an error in the conversion.
3394
3395 */
3396
3397 static uschar *
3398 prvs_daystamp(int day_offset)
3399 {
3400 uschar *days = store_get(32);                /* Need at least 24 for cases */
3401 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3402   (time(NULL) + day_offset*86400)/86400);
3403 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3404 }
3405
3406
3407
3408 /********************************************************
3409 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3410 ********************************************************/
3411
3412 /* This is needed to implement the "prvs" BATV reverse
3413    path signing scheme
3414
3415 Arguments:
3416   address RFC2821 Address to use
3417       key The key to use (must be less than 64 characters
3418           in size)
3419   key_num Single-digit key number to use. Defaults to
3420           '0' when NULL.
3421
3422 Returns:  pointer to string containing the first three
3423           bytes of the final hash in hex format, NULL if
3424           there was an error in the process.
3425 */
3426
3427 static uschar *
3428 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3429 {
3430 uschar *hash_source, *p;
3431 int size = 0,offset = 0,i;
3432 hctx h;
3433 uschar innerhash[20];
3434 uschar finalhash[20];
3435 uschar innerkey[64];
3436 uschar outerkey[64];
3437 uschar *finalhash_hex = store_get(40);
3438
3439 if (key_num == NULL)
3440   key_num = US"0";
3441
3442 if (Ustrlen(key) > 64)
3443   return NULL;
3444
3445 hash_source = string_catn(NULL, &size, &offset, key_num, 1);
3446 hash_source = string_catn(hash_source, &size, &offset, daystamp, 3);
3447 hash_source = string_cat(hash_source, &size, &offset, address);
3448 hash_source[offset] = '\0';
3449
3450 DEBUG(D_expand) debug_printf_indent("prvs: hash source is '%s'\n", hash_source);
3451
3452 memset(innerkey, 0x36, 64);
3453 memset(outerkey, 0x5c, 64);
3454
3455 for (i = 0; i < Ustrlen(key); i++)
3456   {
3457   innerkey[i] ^= key[i];
3458   outerkey[i] ^= key[i];
3459   }
3460
3461 chash_start(HMAC_SHA1, &h);
3462 chash_mid(HMAC_SHA1, &h, innerkey);
3463 chash_end(HMAC_SHA1, &h, hash_source, offset, innerhash);
3464
3465 chash_start(HMAC_SHA1, &h);
3466 chash_mid(HMAC_SHA1, &h, outerkey);
3467 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3468
3469 p = finalhash_hex;
3470 for (i = 0; i < 3; i++)
3471   {
3472   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3473   *p++ = hex_digits[finalhash[i] & 0x0f];
3474   }
3475 *p = '\0';
3476
3477 return finalhash_hex;
3478 }
3479
3480
3481
3482
3483 /*************************************************
3484 *        Join a file onto the output string      *
3485 *************************************************/
3486
3487 /* This is used for readfile/readsock and after a run expansion.
3488 It joins the contents of a file onto the output string, globally replacing
3489 newlines with a given string (optionally).
3490
3491 Arguments:
3492   f            the FILE
3493   yield        pointer to the expandable string
3494   sizep        pointer to the current size
3495   ptrp         pointer to the current position
3496   eol          newline replacement string, or NULL
3497
3498 Returns:       new value of string pointer
3499 */
3500
3501 static uschar *
3502 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3503 {
3504 uschar buffer[1024];
3505
3506 while (Ufgets(buffer, sizeof(buffer), f))
3507   {
3508   int len = Ustrlen(buffer);
3509   if (eol && buffer[len-1] == '\n') len--;
3510   yield = string_catn(yield, sizep, ptrp, buffer, len);
3511   if (eol && buffer[len])
3512     yield = string_cat(yield, sizep, ptrp, eol);
3513   }
3514
3515 if (yield) yield[*ptrp] = 0;
3516
3517 return yield;
3518 }
3519
3520
3521
3522
3523 /*************************************************
3524 *          Evaluate numeric expression           *
3525 *************************************************/
3526
3527 /* This is a set of mutually recursive functions that evaluate an arithmetic
3528 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3529 these functions that is called from elsewhere is eval_expr, whose interface is:
3530
3531 Arguments:
3532   sptr        pointer to the pointer to the string - gets updated
3533   decimal     TRUE if numbers are to be assumed decimal
3534   error       pointer to where to put an error message - must be NULL on input
3535   endket      TRUE if ')' must terminate - FALSE for external call
3536
3537 Returns:      on success: the value of the expression, with *error still NULL
3538               on failure: an undefined value, with *error = a message
3539 */
3540
3541 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3542
3543
3544 static int_eximarith_t
3545 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3546 {
3547 uschar *s = *sptr;
3548 int_eximarith_t x = eval_op_or(&s, decimal, error);
3549 if (*error == NULL)
3550   {
3551   if (endket)
3552     {
3553     if (*s != ')')
3554       *error = US"expecting closing parenthesis";
3555     else
3556       while (isspace(*(++s)));
3557     }
3558   else if (*s != 0) *error = US"expecting operator";
3559   }
3560 *sptr = s;
3561 return x;
3562 }
3563
3564
3565 static int_eximarith_t
3566 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3567 {
3568 register int c;
3569 int_eximarith_t n;
3570 uschar *s = *sptr;
3571 while (isspace(*s)) s++;
3572 c = *s;
3573 if (isdigit(c))
3574   {
3575   int count;
3576   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3577   s += count;
3578   switch (tolower(*s))
3579     {
3580     default: break;
3581     case 'k': n *= 1024; s++; break;
3582     case 'm': n *= 1024*1024; s++; break;
3583     case 'g': n *= 1024*1024*1024; s++; break;
3584     }
3585   while (isspace (*s)) s++;
3586   }
3587 else if (c == '(')
3588   {
3589   s++;
3590   n = eval_expr(&s, decimal, error, 1);
3591   }
3592 else
3593   {
3594   *error = US"expecting number or opening parenthesis";
3595   n = 0;
3596   }
3597 *sptr = s;
3598 return n;
3599 }
3600
3601
3602 static int_eximarith_t
3603 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3604 {
3605 uschar *s = *sptr;
3606 int_eximarith_t x;
3607 while (isspace(*s)) s++;
3608 if (*s == '+' || *s == '-' || *s == '~')
3609   {
3610   int op = *s++;
3611   x = eval_op_unary(&s, decimal, error);
3612   if (op == '-') x = -x;
3613     else if (op == '~') x = ~x;
3614   }
3615 else
3616   {
3617   x = eval_number(&s, decimal, error);
3618   }
3619 *sptr = s;
3620 return x;
3621 }
3622
3623
3624 static int_eximarith_t
3625 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3626 {
3627 uschar *s = *sptr;
3628 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3629 if (*error == NULL)
3630   {
3631   while (*s == '*' || *s == '/' || *s == '%')
3632     {
3633     int op = *s++;
3634     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3635     if (*error != NULL) break;
3636     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3637      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3638      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3639      * -N*M is INT_MIN will yield INT_MIN.
3640      * Since we don't support floating point, this is somewhat simpler.
3641      * Ideally, we'd return an error, but since we overflow for all other
3642      * arithmetic, consistency suggests otherwise, but what's the correct value
3643      * to use?  There is none.
3644      * The C standard guarantees overflow for unsigned arithmetic but signed
3645      * overflow invokes undefined behaviour; in practice, this is overflow
3646      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3647      * that long/longlong larger than int are available, or we could just work
3648      * with larger types.  We should consider whether to guarantee 32bit eval
3649      * and 64-bit working variables, with errors returned.  For now ...
3650      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3651      * can just let the other invalid results occur otherwise, as they have
3652      * until now.  For this one case, we can coerce.
3653      */
3654     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3655       {
3656       DEBUG(D_expand)
3657         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3658             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3659       x = EXIM_ARITH_MAX;
3660       continue;
3661       }
3662     if (op == '*')
3663       x *= y;
3664     else
3665       {
3666       if (y == 0)
3667         {
3668         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3669         x = 0;
3670         break;
3671         }
3672       if (op == '/')
3673         x /= y;
3674       else
3675         x %= y;
3676       }
3677     }
3678   }
3679 *sptr = s;
3680 return x;
3681 }
3682
3683
3684 static int_eximarith_t
3685 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3686 {
3687 uschar *s = *sptr;
3688 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3689 if (!*error)
3690   {
3691   while (*s == '+' || *s == '-')
3692     {
3693     int op = *s++;
3694     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3695     if (*error) break;
3696     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3697        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3698       {                 /* over-conservative check */
3699       *error = op == '+'
3700         ? US"overflow in sum" : US"overflow in difference";
3701       break;
3702       }
3703     if (op == '+') x += y; else x -= y;
3704     }
3705   }
3706 *sptr = s;
3707 return x;
3708 }
3709
3710
3711 static int_eximarith_t
3712 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3713 {
3714 uschar *s = *sptr;
3715 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3716 if (*error == NULL)
3717   {
3718   while ((*s == '<' || *s == '>') && s[1] == s[0])
3719     {
3720     int_eximarith_t y;
3721     int op = *s++;
3722     s++;
3723     y = eval_op_sum(&s, decimal, error);
3724     if (*error != NULL) break;
3725     if (op == '<') x <<= y; else x >>= y;
3726     }
3727   }
3728 *sptr = s;
3729 return x;
3730 }
3731
3732
3733 static int_eximarith_t
3734 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3735 {
3736 uschar *s = *sptr;
3737 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3738 if (*error == NULL)
3739   {
3740   while (*s == '&')
3741     {
3742     int_eximarith_t y;
3743     s++;
3744     y = eval_op_shift(&s, decimal, error);
3745     if (*error != NULL) break;
3746     x &= y;
3747     }
3748   }
3749 *sptr = s;
3750 return x;
3751 }
3752
3753
3754 static int_eximarith_t
3755 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3756 {
3757 uschar *s = *sptr;
3758 int_eximarith_t x = eval_op_and(&s, decimal, error);
3759 if (*error == NULL)
3760   {
3761   while (*s == '^')
3762     {
3763     int_eximarith_t y;
3764     s++;
3765     y = eval_op_and(&s, decimal, error);
3766     if (*error != NULL) break;
3767     x ^= y;
3768     }
3769   }
3770 *sptr = s;
3771 return x;
3772 }
3773
3774
3775 static int_eximarith_t
3776 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3777 {
3778 uschar *s = *sptr;
3779 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3780 if (*error == NULL)
3781   {
3782   while (*s == '|')
3783     {
3784     int_eximarith_t y;
3785     s++;
3786     y = eval_op_xor(&s, decimal, error);
3787     if (*error != NULL) break;
3788     x |= y;
3789     }
3790   }
3791 *sptr = s;
3792 return x;
3793 }
3794
3795
3796
3797 /*************************************************
3798 *                 Expand string                  *
3799 *************************************************/
3800
3801 /* Returns either an unchanged string, or the expanded string in stacking pool
3802 store. Interpreted sequences are:
3803
3804    \...                    normal escaping rules
3805    $name                   substitutes the variable
3806    ${name}                 ditto
3807    ${op:string}            operates on the expanded string value
3808    ${item{arg1}{arg2}...}  expands the args and then does the business
3809                              some literal args are not enclosed in {}
3810
3811 There are now far too many operators and item types to make it worth listing
3812 them here in detail any more.
3813
3814 We use an internal routine recursively to handle embedded substrings. The
3815 external function follows. The yield is NULL if the expansion failed, and there
3816 are two cases: if something collapsed syntactically, or if "fail" was given
3817 as the action on a lookup failure. These can be distinguished by looking at the
3818 variable expand_string_forcedfail, which is TRUE in the latter case.
3819
3820 The skipping flag is set true when expanding a substring that isn't actually
3821 going to be used (after "if" or "lookup") and it prevents lookups from
3822 happening lower down.
3823
3824 Store usage: At start, a store block of the length of the input plus 64
3825 is obtained. This is expanded as necessary by string_cat(), which might have to
3826 get a new block, or might be able to expand the original. At the end of the
3827 function we can release any store above that portion of the yield block that
3828 was actually used. In many cases this will be optimal.
3829
3830 However: if the first item in the expansion is a variable name or header name,
3831 we reset the store before processing it; if the result is in fresh store, we
3832 use that without copying. This is helpful for expanding strings like
3833 $message_headers which can get very long.
3834
3835 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3836 since resetting the store at the end of the expansion will free store that was
3837 allocated by the plugin code as well as the slop after the expanded string. So
3838 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3839 and, given the acl condition, ${if }. This is an unfortunate consequence of
3840 string expansion becoming too powerful.
3841
3842 Arguments:
3843   string         the string to be expanded
3844   ket_ends       true if expansion is to stop at }
3845   left           if not NULL, a pointer to the first character after the
3846                  expansion is placed here (typically used with ket_ends)
3847   skipping       TRUE for recursive calls when the value isn't actually going
3848                  to be used (to allow for optimisation)
3849   honour_dollar  TRUE if $ is to be expanded,
3850                  FALSE if it's just another character
3851   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3852                  the store.
3853
3854 Returns:         NULL if expansion fails:
3855                    expand_string_forcedfail is set TRUE if failure was forced
3856                    expand_string_message contains a textual error message
3857                  a pointer to the expanded string on success
3858 */
3859
3860 static uschar *
3861 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3862   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3863 {
3864 int ptr = 0;
3865 int size = Ustrlen(string)+ 64;
3866 uschar *yield = store_get(size);
3867 int item_type;
3868 const uschar *s = string;
3869 uschar *save_expand_nstring[EXPAND_MAXN+1];
3870 int save_expand_nlength[EXPAND_MAXN+1];
3871 BOOL resetok = TRUE;
3872
3873 expand_level++;
3874 DEBUG(D_expand)
3875   debug_printf_indent("/%s: %s\n", skipping ? "   scanning" : "considering", 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("|__condition: %.*s\n", (int)(next_s - s), s);
4123         debug_printf_indent("|_____result: %s\n", cond ? "true" : "false");
4124         }
4125
4126       s = next_s;
4127
4128       /* The handling of "yes" and "no" result strings is now in a separate
4129       function that is also used by ${lookup} and ${extract} and ${run}. */
4130
4131       switch(process_yesno(
4132                skipping,                     /* were previously skipping */
4133                cond,                         /* success/failure indicator */
4134                lookup_value,                 /* value to reset for string2 */
4135                &s,                           /* input pointer */
4136                &yield,                       /* output pointer */
4137                &size,                        /* output size */
4138                &ptr,                         /* output current point */
4139                US"if",                       /* condition type */
4140                &resetok))
4141         {
4142         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4143         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4144         }
4145
4146       /* Restore external setting of expansion variables for continuation
4147       at this level. */
4148
4149       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4150         save_expand_nlength);
4151       continue;
4152       }
4153
4154 #ifdef SUPPORT_I18N
4155     case EITEM_IMAPFOLDER:
4156       {                         /* ${imapfolder {name}{sep]{specials}} */
4157       uschar *sub_arg[3];
4158       uschar *encoded;
4159
4160       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4161                       &resetok))
4162         {
4163         case 1: goto EXPAND_FAILED_CURLY;
4164         case 2:
4165         case 3: goto EXPAND_FAILED;
4166         }
4167
4168       if (sub_arg[1] == NULL)           /* One argument */
4169         {
4170         sub_arg[1] = US"/";             /* default separator */
4171         sub_arg[2] = NULL;
4172         }
4173       else if (Ustrlen(sub_arg[1]) != 1)
4174         {
4175         expand_string_message =
4176           string_sprintf(
4177                 "IMAP folder separator must be one character, found \"%s\"",
4178                 sub_arg[1]);
4179         goto EXPAND_FAILED;
4180         }
4181
4182       if (!skipping)
4183         {
4184         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4185                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4186           goto EXPAND_FAILED;
4187         yield = string_cat(yield, &size, &ptr, encoded);
4188         }
4189       continue;
4190       }
4191 #endif
4192
4193     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4194     expanding an internal string that isn't actually going to be used. All we
4195     need to do is check the syntax, so don't do a lookup at all. Preserve the
4196     values of the numerical expansion variables in case they get changed by a
4197     partial lookup. If not, they retain their external settings. At the end
4198     of this "lookup" section, they get restored to their previous values. */
4199
4200     case EITEM_LOOKUP:
4201       {
4202       int stype, partial, affixlen, starflags;
4203       int expand_setup = 0;
4204       int nameptr = 0;
4205       uschar *key, *filename;
4206       const uschar *affix;
4207       uschar *save_lookup_value = lookup_value;
4208       int save_expand_nmax =
4209         save_expand_strings(save_expand_nstring, save_expand_nlength);
4210
4211       if ((expand_forbid & RDO_LOOKUP) != 0)
4212         {
4213         expand_string_message = US"lookup expansions are not permitted";
4214         goto EXPAND_FAILED;
4215         }
4216
4217       /* Get the key we are to look up for single-key+file style lookups.
4218       Otherwise set the key NULL pro-tem. */
4219
4220       while (isspace(*s)) s++;
4221       if (*s == '{')                                    /*}*/
4222         {
4223         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4224         if (!key) goto EXPAND_FAILED;                   /*{{*/
4225         if (*s++ != '}')
4226           {
4227           expand_string_message = US"missing '}' after lookup key";
4228           goto EXPAND_FAILED_CURLY;
4229           }
4230         while (isspace(*s)) s++;
4231         }
4232       else key = NULL;
4233
4234       /* Find out the type of database */
4235
4236       if (!isalpha(*s))
4237         {
4238         expand_string_message = US"missing lookup type";
4239         goto EXPAND_FAILED;
4240         }
4241
4242       /* The type is a string that may contain special characters of various
4243       kinds. Allow everything except space or { to appear; the actual content
4244       is checked by search_findtype_partial. */         /*}*/
4245
4246       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4247         {
4248         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4249         s++;
4250         }
4251       name[nameptr] = 0;
4252       while (isspace(*s)) s++;
4253
4254       /* Now check for the individual search type and any partial or default
4255       options. Only those types that are actually in the binary are valid. */
4256
4257       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4258         &starflags);
4259       if (stype < 0)
4260         {
4261         expand_string_message = search_error_message;
4262         goto EXPAND_FAILED;
4263         }
4264
4265       /* Check that a key was provided for those lookup types that need it,
4266       and was not supplied for those that use the query style. */
4267
4268       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4269         {
4270         if (key == NULL)
4271           {
4272           expand_string_message = string_sprintf("missing {key} for single-"
4273             "key \"%s\" lookup", name);
4274           goto EXPAND_FAILED;
4275           }
4276         }
4277       else
4278         {
4279         if (key != NULL)
4280           {
4281           expand_string_message = string_sprintf("a single key was given for "
4282             "lookup type \"%s\", which is not a single-key lookup type", name);
4283           goto EXPAND_FAILED;
4284           }
4285         }
4286
4287       /* Get the next string in brackets and expand it. It is the file name for
4288       single-key+file lookups, and the whole query otherwise. In the case of
4289       queries that also require a file name (e.g. sqlite), the file name comes
4290       first. */
4291
4292       if (*s != '{')
4293         {
4294         expand_string_message = US"missing '{' for lookup file-or-query arg";
4295         goto EXPAND_FAILED_CURLY;
4296         }
4297       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4298       if (filename == NULL) goto EXPAND_FAILED;
4299       if (*s++ != '}')
4300         {
4301         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4302         goto EXPAND_FAILED_CURLY;
4303         }
4304       while (isspace(*s)) s++;
4305
4306       /* If this isn't a single-key+file lookup, re-arrange the variables
4307       to be appropriate for the search_ functions. For query-style lookups,
4308       there is just a "key", and no file name. For the special query-style +
4309       file types, the query (i.e. "key") starts with a file name. */
4310
4311       if (!key)
4312         {
4313         while (isspace(*filename)) filename++;
4314         key = filename;
4315
4316         if (mac_islookup(stype, lookup_querystyle))
4317           filename = NULL;
4318         else
4319           {
4320           if (*filename != '/')
4321             {
4322             expand_string_message = string_sprintf(
4323               "absolute file name expected for \"%s\" lookup", name);
4324             goto EXPAND_FAILED;
4325             }
4326           while (*key != 0 && !isspace(*key)) key++;
4327           if (*key != 0) *key++ = 0;
4328           }
4329         }
4330
4331       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4332       the entry was not found. Note that there is no search_close() function.
4333       Files are left open in case of re-use. At suitable places in higher logic,
4334       search_tidyup() is called to tidy all open files. This can save opening
4335       the same file several times. However, files may also get closed when
4336       others are opened, if too many are open at once. The rule is that a
4337       handle should not be used after a second search_open().
4338
4339       Request that a partial search sets up $1 and maybe $2 by passing
4340       expand_setup containing zero. If its value changes, reset expand_nmax,
4341       since new variables will have been set. Note that at the end of this
4342       "lookup" section, the old numeric variables are restored. */
4343
4344       if (skipping)
4345         lookup_value = NULL;
4346       else
4347         {
4348         void *handle = search_open(filename, stype, 0, NULL, NULL);
4349         if (handle == NULL)
4350           {
4351           expand_string_message = search_error_message;
4352           goto EXPAND_FAILED;
4353           }
4354         lookup_value = search_find(handle, filename, key, partial, affix,
4355           affixlen, starflags, &expand_setup);
4356         if (search_find_defer)
4357           {
4358           expand_string_message =
4359             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4360               string_printing2(key, FALSE), search_error_message);
4361           goto EXPAND_FAILED;
4362           }
4363         if (expand_setup > 0) expand_nmax = expand_setup;
4364         }
4365
4366       /* The handling of "yes" and "no" result strings is now in a separate
4367       function that is also used by ${if} and ${extract}. */
4368
4369       switch(process_yesno(
4370                skipping,                     /* were previously skipping */
4371                lookup_value != NULL,         /* success/failure indicator */
4372                save_lookup_value,            /* value to reset for string2 */
4373                &s,                           /* input pointer */
4374                &yield,                       /* output pointer */
4375                &size,                        /* output size */
4376                &ptr,                         /* output current point */
4377                US"lookup",                   /* condition type */
4378                &resetok))
4379         {
4380         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4381         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4382         }
4383
4384       /* Restore external setting of expansion variables for carrying on
4385       at this level, and continue. */
4386
4387       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4388         save_expand_nlength);
4389       continue;
4390       }
4391
4392     /* If Perl support is configured, handle calling embedded perl subroutines,
4393     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4394     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4395     arguments (defined below). */
4396
4397     #define EXIM_PERL_MAX_ARGS 8
4398
4399     case EITEM_PERL:
4400     #ifndef EXIM_PERL
4401     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4402       "is not included in this binary";
4403     goto EXPAND_FAILED;
4404
4405     #else   /* EXIM_PERL */
4406       {
4407       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4408       uschar *new_yield;
4409
4410       if ((expand_forbid & RDO_PERL) != 0)
4411         {
4412         expand_string_message = US"Perl calls are not permitted";
4413         goto EXPAND_FAILED;
4414         }
4415
4416       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4417            US"perl", &resetok))
4418         {
4419         case 1: goto EXPAND_FAILED_CURLY;
4420         case 2:
4421         case 3: goto EXPAND_FAILED;
4422         }
4423
4424       /* If skipping, we don't actually do anything */
4425
4426       if (skipping) continue;
4427
4428       /* Start the interpreter if necessary */
4429
4430       if (!opt_perl_started)
4431         {
4432         uschar *initerror;
4433         if (opt_perl_startup == NULL)
4434           {
4435           expand_string_message = US"A setting of perl_startup is needed when "
4436             "using the Perl interpreter";
4437           goto EXPAND_FAILED;
4438           }
4439         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4440         initerror = init_perl(opt_perl_startup);
4441         if (initerror != NULL)
4442           {
4443           expand_string_message =
4444             string_sprintf("error in perl_startup code: %s\n", initerror);
4445           goto EXPAND_FAILED;
4446           }
4447         opt_perl_started = TRUE;
4448         }
4449
4450       /* Call the function */
4451
4452       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4453       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4454         sub_arg[0], sub_arg + 1);
4455
4456       /* NULL yield indicates failure; if the message pointer has been set to
4457       NULL, the yield was undef, indicating a forced failure. Otherwise the
4458       message will indicate some kind of Perl error. */
4459
4460       if (new_yield == NULL)
4461         {
4462         if (expand_string_message == NULL)
4463           {
4464           expand_string_message =
4465             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4466               "failure", sub_arg[0]);
4467           expand_string_forcedfail = TRUE;
4468           }
4469         goto EXPAND_FAILED;
4470         }
4471
4472       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4473       set during a callback from Perl. */
4474
4475       expand_string_forcedfail = FALSE;
4476       yield = new_yield;
4477       continue;
4478       }
4479     #endif /* EXIM_PERL */
4480
4481     /* Transform email address to "prvs" scheme to use
4482        as BATV-signed return path */
4483
4484     case EITEM_PRVS:
4485       {
4486       uschar *sub_arg[3];
4487       uschar *p,*domain;
4488
4489       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4490         {
4491         case 1: goto EXPAND_FAILED_CURLY;
4492         case 2:
4493         case 3: goto EXPAND_FAILED;
4494         }
4495
4496       /* If skipping, we don't actually do anything */
4497       if (skipping) continue;
4498
4499       /* sub_arg[0] is the address */
4500       domain = Ustrrchr(sub_arg[0],'@');
4501       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4502         {
4503         expand_string_message = US"prvs first argument must be a qualified email address";
4504         goto EXPAND_FAILED;
4505         }
4506
4507       /* Calculate the hash. The second argument must be a single-digit
4508       key number, or unset. */
4509
4510       if (sub_arg[2] != NULL &&
4511           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4512         {
4513         expand_string_message = US"prvs second argument must be a single digit";
4514         goto EXPAND_FAILED;
4515         }
4516
4517       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4518       if (p == NULL)
4519         {
4520         expand_string_message = US"prvs hmac-sha1 conversion failed";
4521         goto EXPAND_FAILED;
4522         }
4523
4524       /* Now separate the domain from the local part */
4525       *domain++ = '\0';
4526
4527       yield = string_catn(yield, &size, &ptr, US"prvs=", 5);
4528       yield = string_catn(yield, &size, &ptr, sub_arg[2] ? sub_arg[2] : US"0", 1);
4529       yield = string_catn(yield, &size, &ptr, prvs_daystamp(7), 3);
4530       yield = string_catn(yield, &size, &ptr, p, 6);
4531       yield = string_catn(yield, &size, &ptr, US"=", 1);
4532       yield = string_cat (yield, &size, &ptr, sub_arg[0]);
4533       yield = string_catn(yield, &size, &ptr, US"@", 1);
4534       yield = string_cat (yield, &size, &ptr, domain);
4535
4536       continue;
4537       }
4538
4539     /* Check a prvs-encoded address for validity */
4540
4541     case EITEM_PRVSCHECK:
4542       {
4543       uschar *sub_arg[3];
4544       int mysize = 0, myptr = 0;
4545       const pcre *re;
4546       uschar *p;
4547
4548       /* TF: Ugliness: We want to expand parameter 1 first, then set
4549          up expansion variables that are used in the expansion of
4550          parameter 2. So we clone the string for the first
4551          expansion, where we only expand parameter 1.
4552
4553          PH: Actually, that isn't necessary. The read_subs() function is
4554          designed to work this way for the ${if and ${lookup expansions. I've
4555          tidied the code.
4556       */
4557
4558       /* Reset expansion variables */
4559       prvscheck_result = NULL;
4560       prvscheck_address = NULL;
4561       prvscheck_keynum = NULL;
4562
4563       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4564         {
4565         case 1: goto EXPAND_FAILED_CURLY;
4566         case 2:
4567         case 3: goto EXPAND_FAILED;
4568         }
4569
4570       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4571                               TRUE,FALSE);
4572
4573       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4574         {
4575         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4576         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4577         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4578         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4579         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4580
4581         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4582         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4583         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4584         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4585         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4586
4587         /* Set up expansion variables */
4588         prvscheck_address = string_cat (NULL, &mysize, &myptr, local_part);
4589         prvscheck_address = string_catn(prvscheck_address, &mysize, &myptr, US"@", 1);
4590         prvscheck_address = string_cat (prvscheck_address, &mysize, &myptr, domain);
4591         prvscheck_address[myptr] = '\0';
4592         prvscheck_keynum = string_copy(key_num);
4593
4594         /* Now expand the second argument */
4595         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4596           {
4597           case 1: goto EXPAND_FAILED_CURLY;
4598           case 2:
4599           case 3: goto EXPAND_FAILED;
4600           }
4601
4602         /* Now we have the key and can check the address. */
4603
4604         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4605           daystamp);
4606
4607         if (p == NULL)
4608           {
4609           expand_string_message = US"hmac-sha1 conversion failed";
4610           goto EXPAND_FAILED;
4611           }
4612
4613         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4614         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4615
4616         if (Ustrcmp(p,hash) == 0)
4617           {
4618           /* Success, valid BATV address. Now check the expiry date. */
4619           uschar *now = prvs_daystamp(0);
4620           unsigned int inow = 0,iexpire = 1;
4621
4622           (void)sscanf(CS now,"%u",&inow);
4623           (void)sscanf(CS daystamp,"%u",&iexpire);
4624
4625           /* When "iexpire" is < 7, a "flip" has occured.
4626              Adjust "inow" accordingly. */
4627           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4628
4629           if (iexpire >= inow)
4630             {
4631             prvscheck_result = US"1";
4632             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4633             }
4634             else
4635             {
4636             prvscheck_result = NULL;
4637             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4638             }
4639           }
4640         else
4641           {
4642           prvscheck_result = NULL;
4643           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4644           }
4645
4646         /* Now expand the final argument. We leave this till now so that
4647         it can include $prvscheck_result. */
4648
4649         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4650           {
4651           case 1: goto EXPAND_FAILED_CURLY;
4652           case 2:
4653           case 3: goto EXPAND_FAILED;
4654           }
4655
4656         yield = string_cat(yield, &size, &ptr,
4657           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4658
4659         /* Reset the "internal" variables afterwards, because they are in
4660         dynamic store that will be reclaimed if the expansion succeeded. */
4661
4662         prvscheck_address = NULL;
4663         prvscheck_keynum = NULL;
4664         }
4665       else
4666         /* Does not look like a prvs encoded address, return the empty string.
4667            We need to make sure all subs are expanded first, so as to skip over
4668            the entire item. */
4669
4670         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4671           {
4672           case 1: goto EXPAND_FAILED_CURLY;
4673           case 2:
4674           case 3: goto EXPAND_FAILED;
4675           }
4676
4677       continue;
4678       }
4679
4680     /* Handle "readfile" to insert an entire file */
4681
4682     case EITEM_READFILE:
4683       {
4684       FILE *f;
4685       uschar *sub_arg[2];
4686
4687       if ((expand_forbid & RDO_READFILE) != 0)
4688         {
4689         expand_string_message = US"file insertions are not permitted";
4690         goto EXPAND_FAILED;
4691         }
4692
4693       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4694         {
4695         case 1: goto EXPAND_FAILED_CURLY;
4696         case 2:
4697         case 3: goto EXPAND_FAILED;
4698         }
4699
4700       /* If skipping, we don't actually do anything */
4701
4702       if (skipping) continue;
4703
4704       /* Open the file and read it */
4705
4706       f = Ufopen(sub_arg[0], "rb");
4707       if (f == NULL)
4708         {
4709         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4710         goto EXPAND_FAILED;
4711         }
4712
4713       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4714       (void)fclose(f);
4715       continue;
4716       }
4717
4718     /* Handle "readsocket" to insert data from a Unix domain socket */
4719
4720     case EITEM_READSOCK:
4721       {
4722       int fd;
4723       int timeout = 5;
4724       int save_ptr = ptr;
4725       FILE *f;
4726       struct sockaddr_un sockun;         /* don't call this "sun" ! */
4727       uschar *arg;
4728       uschar *sub_arg[4];
4729       BOOL do_shutdown = TRUE;
4730
4731       if (expand_forbid & RDO_READSOCK)
4732         {
4733         expand_string_message = US"socket insertions are not permitted";
4734         goto EXPAND_FAILED;
4735         }
4736
4737       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4738       because there may be a string for expansion on failure. */
4739
4740       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4741         {
4742         case 1: goto EXPAND_FAILED_CURLY;
4743         case 2:                             /* Won't occur: no end check */
4744         case 3: goto EXPAND_FAILED;
4745         }
4746
4747       /* Sort out timeout, if given.  The second arg is a list with the first element
4748       being a time value.  Any more are options of form "name=value".  Currently the
4749       only option recognised is "shutdown". */
4750
4751       if (sub_arg[2])
4752         {
4753         const uschar * list = sub_arg[2];
4754         uschar * item;
4755         int sep = 0;
4756
4757         item = string_nextinlist(&list, &sep, NULL, 0);
4758         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4759           {
4760           expand_string_message = string_sprintf("bad time value %s", item);
4761           goto EXPAND_FAILED;
4762           }
4763
4764         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4765           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4766             if (Ustrcmp(item + 9, US"no") == 0)
4767               do_shutdown = FALSE;
4768         }
4769       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4770
4771       /* If skipping, we don't actually do anything. Otherwise, arrange to
4772       connect to either an IP or a Unix socket. */
4773
4774       if (!skipping)
4775         {
4776         /* Handle an IP (internet) domain */
4777
4778         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4779           {
4780           int port;
4781           uschar *server_name = sub_arg[0] + 5;
4782           uschar *port_name = Ustrrchr(server_name, ':');
4783
4784           /* Sort out the port */
4785
4786           if (port_name == NULL)
4787             {
4788             expand_string_message =
4789               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4790             goto EXPAND_FAILED;
4791             }
4792           *port_name++ = 0;           /* Terminate server name */
4793
4794           if (isdigit(*port_name))
4795             {
4796             uschar *end;
4797             port = Ustrtol(port_name, &end, 0);
4798             if (end != port_name + Ustrlen(port_name))
4799               {
4800               expand_string_message =
4801                 string_sprintf("invalid port number %s", port_name);
4802               goto EXPAND_FAILED;
4803               }
4804             }
4805           else
4806             {
4807             struct servent *service_info = getservbyname(CS port_name, "tcp");
4808             if (service_info == NULL)
4809               {
4810               expand_string_message = string_sprintf("unknown port \"%s\"",
4811                 port_name);
4812               goto EXPAND_FAILED;
4813               }
4814             port = ntohs(service_info->s_port);
4815             }
4816
4817           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4818                   timeout, NULL, &expand_string_message);
4819           callout_address = NULL;
4820           if (fd < 0)
4821               goto SOCK_FAIL;
4822           }
4823
4824         /* Handle a Unix domain socket */
4825
4826         else
4827           {
4828           int rc;
4829           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4830             {
4831             expand_string_message = string_sprintf("failed to create socket: %s",
4832               strerror(errno));
4833             goto SOCK_FAIL;
4834             }
4835
4836           sockun.sun_family = AF_UNIX;
4837           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4838             sub_arg[0]);
4839
4840           sigalrm_seen = FALSE;
4841           alarm(timeout);
4842           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4843           alarm(0);
4844           if (sigalrm_seen)
4845             {
4846             expand_string_message = US "socket connect timed out";
4847             goto SOCK_FAIL;
4848             }
4849           if (rc < 0)
4850             {
4851             expand_string_message = string_sprintf("failed to connect to socket "
4852               "%s: %s", sub_arg[0], strerror(errno));
4853             goto SOCK_FAIL;
4854             }
4855           }
4856
4857         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4858
4859         /* Allow sequencing of test actions */
4860         if (running_in_test_harness) millisleep(100);
4861
4862         /* Write the request string, if not empty */
4863
4864         if (sub_arg[1][0] != 0)
4865           {
4866           int len = Ustrlen(sub_arg[1]);
4867           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4868             sub_arg[1]);
4869           if (write(fd, sub_arg[1], len) != len)
4870             {
4871             expand_string_message = string_sprintf("request write to socket "
4872               "failed: %s", strerror(errno));
4873             goto SOCK_FAIL;
4874             }
4875           }
4876
4877         /* Shut down the sending side of the socket. This helps some servers to
4878         recognise that it is their turn to do some work. Just in case some
4879         system doesn't have this function, make it conditional. */
4880
4881 #ifdef SHUT_WR
4882         if (do_shutdown) shutdown(fd, SHUT_WR);
4883 #endif
4884
4885         if (running_in_test_harness) millisleep(100);
4886
4887         /* Now we need to read from the socket, under a timeout. The function
4888         that reads a file can be used. */
4889
4890         f = fdopen(fd, "rb");
4891         sigalrm_seen = FALSE;
4892         alarm(timeout);
4893         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4894         alarm(0);
4895         (void)fclose(f);
4896
4897         /* After a timeout, we restore the pointer in the result, that is,
4898         make sure we add nothing from the socket. */
4899
4900         if (sigalrm_seen)
4901           {
4902           ptr = save_ptr;
4903           expand_string_message = US "socket read timed out";
4904           goto SOCK_FAIL;
4905           }
4906         }
4907
4908       /* The whole thing has worked (or we were skipping). If there is a
4909       failure string following, we need to skip it. */
4910
4911       if (*s == '{')
4912         {
4913         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4914           goto EXPAND_FAILED;
4915         if (*s++ != '}')
4916           {
4917           expand_string_message = US"missing '}' closing failstring for readsocket";
4918           goto EXPAND_FAILED_CURLY;
4919           }
4920         while (isspace(*s)) s++;
4921         }
4922
4923     READSOCK_DONE:
4924       if (*s++ != '}')
4925         {
4926         expand_string_message = US"missing '}' closing readsocket";
4927         goto EXPAND_FAILED_CURLY;
4928         }
4929       continue;
4930
4931       /* Come here on failure to create socket, connect socket, write to the
4932       socket, or timeout on reading. If another substring follows, expand and
4933       use it. Otherwise, those conditions give expand errors. */
4934
4935     SOCK_FAIL:
4936       if (*s != '{') goto EXPAND_FAILED;
4937       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4938       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4939         goto EXPAND_FAILED;
4940       yield = string_cat(yield, &size, &ptr, arg);
4941       if (*s++ != '}')
4942         {
4943         expand_string_message = US"missing '}' closing failstring for readsocket";
4944         goto EXPAND_FAILED_CURLY;
4945         }
4946       while (isspace(*s)) s++;
4947       goto READSOCK_DONE;
4948       }
4949
4950     /* Handle "run" to execute a program. */
4951
4952     case EITEM_RUN:
4953       {
4954       FILE *f;
4955       uschar *arg;
4956       const uschar **argv;
4957       pid_t pid;
4958       int fd_in, fd_out;
4959       int lsize = 0, lptr = 0;
4960
4961       if ((expand_forbid & RDO_RUN) != 0)
4962         {
4963         expand_string_message = US"running a command is not permitted";
4964         goto EXPAND_FAILED;
4965         }
4966
4967       while (isspace(*s)) s++;
4968       if (*s != '{')
4969         {
4970         expand_string_message = US"missing '{' for command arg of run";
4971         goto EXPAND_FAILED_CURLY;
4972         }
4973       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4974       if (arg == NULL) goto EXPAND_FAILED;
4975       while (isspace(*s)) s++;
4976       if (*s++ != '}')
4977         {
4978         expand_string_message = US"missing '}' closing command arg of run";
4979         goto EXPAND_FAILED_CURLY;
4980         }
4981
4982       if (skipping)   /* Just pretend it worked when we're skipping */
4983         {
4984         runrc = 0;
4985         lookup_value = NULL;
4986         }
4987       else
4988         {
4989         if (!transport_set_up_command(&argv,    /* anchor for arg list */
4990             arg,                                /* raw command */
4991             FALSE,                              /* don't expand the arguments */
4992             0,                                  /* not relevant when... */
4993             NULL,                               /* no transporting address */
4994             US"${run} expansion",               /* for error messages */
4995             &expand_string_message))            /* where to put error message */
4996           goto EXPAND_FAILED;
4997
4998         /* Create the child process, making it a group leader. */
4999
5000         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5001           {
5002           expand_string_message =
5003             string_sprintf("couldn't create child process: %s", strerror(errno));
5004           goto EXPAND_FAILED;
5005           }
5006
5007         /* Nothing is written to the standard input. */
5008
5009         (void)close(fd_in);
5010
5011         /* Read the pipe to get the command's output into $value (which is kept
5012         in lookup_value). Read during execution, so that if the output exceeds
5013         the OS pipe buffer limit, we don't block forever. Remember to not release
5014         memory just allocated for $value. */
5015
5016         resetok = FALSE;
5017         f = fdopen(fd_out, "rb");
5018         sigalrm_seen = FALSE;
5019         alarm(60);
5020         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
5021         alarm(0);
5022         (void)fclose(f);
5023
5024         /* Wait for the process to finish, applying the timeout, and inspect its
5025         return code for serious disasters. Simple non-zero returns are passed on.
5026         */
5027
5028         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5029           {
5030           if (sigalrm_seen || runrc == -256)
5031             {
5032             expand_string_message = string_sprintf("command timed out");
5033             killpg(pid, SIGKILL);       /* Kill the whole process group */
5034             }
5035
5036           else if (runrc == -257)
5037             expand_string_message = string_sprintf("wait() failed: %s",
5038               strerror(errno));
5039
5040           else
5041             expand_string_message = string_sprintf("command killed by signal %d",
5042               -runrc);
5043
5044           goto EXPAND_FAILED;
5045           }
5046         }
5047
5048       /* Process the yes/no strings; $value may be useful in both cases */
5049
5050       switch(process_yesno(
5051                skipping,                     /* were previously skipping */
5052                runrc == 0,                   /* success/failure indicator */
5053                lookup_value,                 /* value to reset for string2 */
5054                &s,                           /* input pointer */
5055                &yield,                       /* output pointer */
5056                &size,                        /* output size */
5057                &ptr,                         /* output current point */
5058                US"run",                      /* condition type */
5059                &resetok))
5060         {
5061         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5062         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5063         }
5064
5065       continue;
5066       }
5067
5068     /* Handle character translation for "tr" */
5069
5070     case EITEM_TR:
5071       {
5072       int oldptr = ptr;
5073       int o2m;
5074       uschar *sub[3];
5075
5076       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5077         {
5078         case 1: goto EXPAND_FAILED_CURLY;
5079         case 2:
5080         case 3: goto EXPAND_FAILED;
5081         }
5082
5083       yield = string_cat(yield, &size, &ptr, sub[0]);
5084       o2m = Ustrlen(sub[2]) - 1;
5085
5086       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
5087         {
5088         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
5089         if (m != NULL)
5090           {
5091           int o = m - sub[1];
5092           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5093           }
5094         }
5095
5096       continue;
5097       }
5098
5099     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5100     expanded arguments. */
5101
5102     case EITEM_HASH:
5103     case EITEM_LENGTH:
5104     case EITEM_NHASH:
5105     case EITEM_SUBSTR:
5106       {
5107       int i;
5108       int len;
5109       uschar *ret;
5110       int val[2] = { 0, -1 };
5111       uschar *sub[3];
5112
5113       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5114       Ensure that sub[2] is set in the ${length } case. */
5115
5116       sub[2] = NULL;
5117       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5118              TRUE, name, &resetok))
5119         {
5120         case 1: goto EXPAND_FAILED_CURLY;
5121         case 2:
5122         case 3: goto EXPAND_FAILED;
5123         }
5124
5125       /* Juggle the arguments if there are only two of them: always move the
5126       string to the last position and make ${length{n}{str}} equivalent to
5127       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5128
5129       if (sub[2] == NULL)
5130         {
5131         sub[2] = sub[1];
5132         sub[1] = NULL;
5133         if (item_type == EITEM_LENGTH)
5134           {
5135           sub[1] = sub[0];
5136           sub[0] = NULL;
5137           }
5138         }
5139
5140       for (i = 0; i < 2; i++)
5141         {
5142         if (sub[i] == NULL) continue;
5143         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5144         if (*ret != 0 || (i != 0 && val[i] < 0))
5145           {
5146           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5147             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5148           goto EXPAND_FAILED;
5149           }
5150         }
5151
5152       ret =
5153         (item_type == EITEM_HASH)?
5154           compute_hash(sub[2], val[0], val[1], &len) :
5155         (item_type == EITEM_NHASH)?
5156           compute_nhash(sub[2], val[0], val[1], &len) :
5157           extract_substr(sub[2], val[0], val[1], &len);
5158
5159       if (ret == NULL) goto EXPAND_FAILED;
5160       yield = string_catn(yield, &size, &ptr, ret, len);
5161       continue;
5162       }
5163
5164     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5165     This code originally contributed by Steve Haslam. It currently supports
5166     the use of MD5 and SHA-1 hashes.
5167
5168     We need some workspace that is large enough to handle all the supported
5169     hash types. Use macros to set the sizes rather than be too elaborate. */
5170
5171     #define MAX_HASHLEN      20
5172     #define MAX_HASHBLOCKLEN 64
5173
5174     case EITEM_HMAC:
5175       {
5176       uschar *sub[3];
5177       md5 md5_base;
5178       hctx sha1_ctx;
5179       void *use_base;
5180       int type, i;
5181       int hashlen;      /* Number of octets for the hash algorithm's output */
5182       int hashblocklen; /* Number of octets the hash algorithm processes */
5183       uschar *keyptr, *p;
5184       unsigned int keylen;
5185
5186       uschar keyhash[MAX_HASHLEN];
5187       uschar innerhash[MAX_HASHLEN];
5188       uschar finalhash[MAX_HASHLEN];
5189       uschar finalhash_hex[2*MAX_HASHLEN];
5190       uschar innerkey[MAX_HASHBLOCKLEN];
5191       uschar outerkey[MAX_HASHBLOCKLEN];
5192
5193       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5194         {
5195         case 1: goto EXPAND_FAILED_CURLY;
5196         case 2:
5197         case 3: goto EXPAND_FAILED;
5198         }
5199
5200       if (!skipping)
5201         {
5202         if (Ustrcmp(sub[0], "md5") == 0)
5203           {
5204           type = HMAC_MD5;
5205           use_base = &md5_base;
5206           hashlen = 16;
5207           hashblocklen = 64;
5208           }
5209         else if (Ustrcmp(sub[0], "sha1") == 0)
5210           {
5211           type = HMAC_SHA1;
5212           use_base = &sha1_ctx;
5213           hashlen = 20;
5214           hashblocklen = 64;
5215           }
5216         else
5217           {
5218           expand_string_message =
5219             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5220           goto EXPAND_FAILED;
5221           }
5222
5223         keyptr = sub[1];
5224         keylen = Ustrlen(keyptr);
5225
5226         /* If the key is longer than the hash block length, then hash the key
5227         first */
5228
5229         if (keylen > hashblocklen)
5230           {
5231           chash_start(type, use_base);
5232           chash_end(type, use_base, keyptr, keylen, keyhash);
5233           keyptr = keyhash;
5234           keylen = hashlen;
5235           }
5236
5237         /* Now make the inner and outer key values */
5238
5239         memset(innerkey, 0x36, hashblocklen);
5240         memset(outerkey, 0x5c, hashblocklen);
5241
5242         for (i = 0; i < keylen; i++)
5243           {
5244           innerkey[i] ^= keyptr[i];
5245           outerkey[i] ^= keyptr[i];
5246           }
5247
5248         /* Now do the hashes */
5249
5250         chash_start(type, use_base);
5251         chash_mid(type, use_base, innerkey);
5252         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5253
5254         chash_start(type, use_base);
5255         chash_mid(type, use_base, outerkey);
5256         chash_end(type, use_base, innerhash, hashlen, finalhash);
5257
5258         /* Encode the final hash as a hex string */
5259
5260         p = finalhash_hex;
5261         for (i = 0; i < hashlen; i++)
5262           {
5263           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5264           *p++ = hex_digits[finalhash[i] & 0x0f];
5265           }
5266
5267         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5268           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5269
5270         yield = string_catn(yield, &size, &ptr, finalhash_hex, hashlen*2);
5271         }
5272       continue;
5273       }
5274
5275     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5276     We have to save the numerical variables and restore them afterwards. */
5277
5278     case EITEM_SG:
5279       {
5280       const pcre *re;
5281       int moffset, moffsetextra, slen;
5282       int roffset;
5283       int emptyopt;
5284       const uschar *rerror;
5285       uschar *subject;
5286       uschar *sub[3];
5287       int save_expand_nmax =
5288         save_expand_strings(save_expand_nstring, save_expand_nlength);
5289
5290       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5291         {
5292         case 1: goto EXPAND_FAILED_CURLY;
5293         case 2:
5294         case 3: goto EXPAND_FAILED;
5295         }
5296
5297       /* Compile the regular expression */
5298
5299       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5300         NULL);
5301
5302       if (re == NULL)
5303         {
5304         expand_string_message = string_sprintf("regular expression error in "
5305           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5306         goto EXPAND_FAILED;
5307         }
5308
5309       /* Now run a loop to do the substitutions as often as necessary. It ends
5310       when there are no more matches. Take care over matches of the null string;
5311       do the same thing as Perl does. */
5312
5313       subject = sub[0];
5314       slen = Ustrlen(sub[0]);
5315       moffset = moffsetextra = 0;
5316       emptyopt = 0;
5317
5318       for (;;)
5319         {
5320         int ovector[3*(EXPAND_MAXN+1)];
5321         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5322           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5323         int nn;
5324         uschar *insert;
5325
5326         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5327         is not necessarily the end. We want to repeat the match from one
5328         character further along, but leaving the basic offset the same (for
5329         copying below). We can't be at the end of the string - that was checked
5330         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5331         finished; copy the remaining string and end the loop. */
5332
5333         if (n < 0)
5334           {
5335           if (emptyopt != 0)
5336             {
5337             moffsetextra = 1;
5338             emptyopt = 0;
5339             continue;
5340             }
5341           yield = string_catn(yield, &size, &ptr, subject+moffset, slen-moffset);
5342           break;
5343           }
5344
5345         /* Match - set up for expanding the replacement. */
5346
5347         if (n == 0) n = EXPAND_MAXN + 1;
5348         expand_nmax = 0;
5349         for (nn = 0; nn < n*2; nn += 2)
5350           {
5351           expand_nstring[expand_nmax] = subject + ovector[nn];
5352           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5353           }
5354         expand_nmax--;
5355
5356         /* Copy the characters before the match, plus the expanded insertion. */
5357
5358         yield = string_catn(yield, &size, &ptr, subject + moffset,
5359           ovector[0] - moffset);
5360         insert = expand_string(sub[2]);
5361         if (insert == NULL) goto EXPAND_FAILED;
5362         yield = string_cat(yield, &size, &ptr, insert);
5363
5364         moffset = ovector[1];
5365         moffsetextra = 0;
5366         emptyopt = 0;
5367
5368         /* If we have matched an empty string, first check to see if we are at
5369         the end of the subject. If so, the loop is over. Otherwise, mimic
5370         what Perl's /g options does. This turns out to be rather cunning. First
5371         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5372         string at the same point. If this fails (picked up above) we advance to
5373         the next character. */
5374
5375         if (ovector[0] == ovector[1])
5376           {
5377           if (ovector[0] == slen) break;
5378           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5379           }
5380         }
5381
5382       /* All done - restore numerical variables. */
5383
5384       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5385         save_expand_nlength);
5386       continue;
5387       }
5388
5389     /* Handle keyed and numbered substring extraction. If the first argument
5390     consists entirely of digits, then a numerical extraction is assumed. */
5391
5392     case EITEM_EXTRACT:
5393       {
5394       int i;
5395       int j;
5396       int field_number = 1;
5397       BOOL field_number_set = FALSE;
5398       uschar *save_lookup_value = lookup_value;
5399       uschar *sub[3];
5400       int save_expand_nmax =
5401         save_expand_strings(save_expand_nstring, save_expand_nlength);
5402
5403       /* While skipping we cannot rely on the data for expansions being
5404       available (eg. $item) hence cannot decide on numeric vs. keyed.
5405       Read a maximum of 5 arguments (including the yes/no) */
5406
5407       if (skipping)
5408         {
5409         while (isspace(*s)) s++;
5410         for (j = 5; j > 0 && *s == '{'; j--)
5411           {
5412           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5413             goto EXPAND_FAILED;                                 /*{*/
5414           if (*s++ != '}')
5415             {
5416             expand_string_message = US"missing '{' for arg of extract";
5417             goto EXPAND_FAILED_CURLY;
5418             }
5419           while (isspace(*s)) s++;
5420           }
5421         if (  Ustrncmp(s, "fail", 4) == 0
5422            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5423            )
5424           {
5425           s += 4;
5426           while (isspace(*s)) s++;
5427           }
5428         if (*s != '}')
5429           {
5430           expand_string_message = US"missing '}' closing extract";
5431           goto EXPAND_FAILED_CURLY;
5432           }
5433         }
5434
5435       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5436         {
5437         while (isspace(*s)) s++;
5438         if (*s == '{')                                          /*}*/
5439           {
5440           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5441           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5442           if (*s++ != '}')
5443             {
5444             expand_string_message = string_sprintf(
5445               "missing '}' closing arg %d of extract", i+1);
5446             goto EXPAND_FAILED_CURLY;
5447             }
5448
5449           /* After removal of leading and trailing white space, the first
5450           argument must not be empty; if it consists entirely of digits
5451           (optionally preceded by a minus sign), this is a numerical
5452           extraction, and we expect 3 arguments. */
5453
5454           if (i == 0)
5455             {
5456             int len;
5457             int x = 0;
5458             uschar *p = sub[0];
5459
5460             while (isspace(*p)) p++;
5461             sub[0] = p;
5462
5463             len = Ustrlen(p);
5464             while (len > 0 && isspace(p[len-1])) len--;
5465             p[len] = 0;
5466
5467             if (*p == 0)
5468               {
5469               expand_string_message = US"first argument of \"extract\" must "
5470                 "not be empty";
5471               goto EXPAND_FAILED;
5472               }
5473
5474             if (*p == '-')
5475               {
5476               field_number = -1;
5477               p++;
5478               }
5479             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5480             if (*p == 0)
5481               {
5482               field_number *= x;
5483               j = 3;               /* Need 3 args */
5484               field_number_set = TRUE;
5485               }
5486             }
5487           }
5488         else
5489           {
5490           expand_string_message = string_sprintf(
5491             "missing '{' for arg %d of extract", i+1);
5492           goto EXPAND_FAILED_CURLY;
5493           }
5494         }
5495
5496       /* Extract either the numbered or the keyed substring into $value. If
5497       skipping, just pretend the extraction failed. */
5498
5499       lookup_value = skipping? NULL : field_number_set?
5500         expand_gettokened(field_number, sub[1], sub[2]) :
5501         expand_getkeyed(sub[0], sub[1]);
5502
5503       /* If no string follows, $value gets substituted; otherwise there can
5504       be yes/no strings, as for lookup or if. */
5505
5506       switch(process_yesno(
5507                skipping,                     /* were previously skipping */
5508                lookup_value != NULL,         /* success/failure indicator */
5509                save_lookup_value,            /* value to reset for string2 */
5510                &s,                           /* input pointer */
5511                &yield,                       /* output pointer */
5512                &size,                        /* output size */
5513                &ptr,                         /* output current point */
5514                US"extract",                  /* condition type */
5515                &resetok))
5516         {
5517         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5518         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5519         }
5520
5521       /* All done - restore numerical variables. */
5522
5523       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5524         save_expand_nlength);
5525
5526       continue;
5527       }
5528
5529     /* return the Nth item from a list */
5530
5531     case EITEM_LISTEXTRACT:
5532       {
5533       int i;
5534       int field_number = 1;
5535       uschar *save_lookup_value = lookup_value;
5536       uschar *sub[2];
5537       int save_expand_nmax =
5538         save_expand_strings(save_expand_nstring, save_expand_nlength);
5539
5540       /* Read the field & list arguments */
5541
5542       for (i = 0; i < 2; i++)
5543         {
5544         while (isspace(*s)) s++;
5545         if (*s != '{')                                  /*}*/
5546           {
5547           expand_string_message = string_sprintf(
5548             "missing '{' for arg %d of listextract", i+1);
5549           goto EXPAND_FAILED_CURLY;
5550           }
5551
5552         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5553         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5554         if (*s++ != '}')
5555           {
5556           expand_string_message = string_sprintf(
5557             "missing '}' closing arg %d of listextract", i+1);
5558           goto EXPAND_FAILED_CURLY;
5559           }
5560
5561         /* After removal of leading and trailing white space, the first
5562         argument must be numeric and nonempty. */
5563
5564         if (i == 0)
5565           {
5566           int len;
5567           int x = 0;
5568           uschar *p = sub[0];
5569
5570           while (isspace(*p)) p++;
5571           sub[0] = p;
5572
5573           len = Ustrlen(p);
5574           while (len > 0 && isspace(p[len-1])) len--;
5575           p[len] = 0;
5576
5577           if (!*p && !skipping)
5578             {
5579             expand_string_message = US"first argument of \"listextract\" must "
5580               "not be empty";
5581             goto EXPAND_FAILED;
5582             }
5583
5584           if (*p == '-')
5585             {
5586             field_number = -1;
5587             p++;
5588             }
5589           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5590           if (*p)
5591             {
5592             expand_string_message = US"first argument of \"listextract\" must "
5593               "be numeric";
5594             goto EXPAND_FAILED;
5595             }
5596           field_number *= x;
5597           }
5598         }
5599
5600       /* Extract the numbered element into $value. If
5601       skipping, just pretend the extraction failed. */
5602
5603       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5604
5605       /* If no string follows, $value gets substituted; otherwise there can
5606       be yes/no strings, as for lookup or if. */
5607
5608       switch(process_yesno(
5609                skipping,                     /* were previously skipping */
5610                lookup_value != NULL,         /* success/failure indicator */
5611                save_lookup_value,            /* value to reset for string2 */
5612                &s,                           /* input pointer */
5613                &yield,                       /* output pointer */
5614                &size,                        /* output size */
5615                &ptr,                         /* output current point */
5616                US"listextract",              /* condition type */
5617                &resetok))
5618         {
5619         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5620         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5621         }
5622
5623       /* All done - restore numerical variables. */
5624
5625       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5626         save_expand_nlength);
5627
5628       continue;
5629       }
5630
5631 #ifdef SUPPORT_TLS
5632     case EITEM_CERTEXTRACT:
5633       {
5634       uschar *save_lookup_value = lookup_value;
5635       uschar *sub[2];
5636       int save_expand_nmax =
5637         save_expand_strings(save_expand_nstring, save_expand_nlength);
5638
5639       /* Read the field argument */
5640       while (isspace(*s)) s++;
5641       if (*s != '{')                                    /*}*/
5642         {
5643         expand_string_message = US"missing '{' for field arg of certextract";
5644         goto EXPAND_FAILED_CURLY;
5645         }
5646       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5647       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5648       if (*s++ != '}')
5649         {
5650         expand_string_message = US"missing '}' closing field arg of certextract";
5651         goto EXPAND_FAILED_CURLY;
5652         }
5653       /* strip spaces fore & aft */
5654       {
5655       int len;
5656       uschar *p = sub[0];
5657
5658       while (isspace(*p)) p++;
5659       sub[0] = p;
5660
5661       len = Ustrlen(p);
5662       while (len > 0 && isspace(p[len-1])) len--;
5663       p[len] = 0;
5664       }
5665
5666       /* inspect the cert argument */
5667       while (isspace(*s)) s++;
5668       if (*s != '{')                                    /*}*/
5669         {
5670         expand_string_message = US"missing '{' for cert variable arg of certextract";
5671         goto EXPAND_FAILED_CURLY;
5672         }
5673       if (*++s != '$')
5674         {
5675         expand_string_message = US"second argument of \"certextract\" must "
5676           "be a certificate variable";
5677         goto EXPAND_FAILED;
5678         }
5679       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5680       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5681       if (*s++ != '}')
5682         {
5683         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5684         goto EXPAND_FAILED_CURLY;
5685         }
5686
5687       if (skipping)
5688         lookup_value = NULL;
5689       else
5690         {
5691         lookup_value = expand_getcertele(sub[0], sub[1]);
5692         if (*expand_string_message) goto EXPAND_FAILED;
5693         }
5694       switch(process_yesno(
5695                skipping,                     /* were previously skipping */
5696                lookup_value != NULL,         /* success/failure indicator */
5697                save_lookup_value,            /* value to reset for string2 */
5698                &s,                           /* input pointer */
5699                &yield,                       /* output pointer */
5700                &size,                        /* output size */
5701                &ptr,                         /* output current point */
5702                US"certextract",              /* condition type */
5703                &resetok))
5704         {
5705         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5706         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5707         }
5708
5709       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5710         save_expand_nlength);
5711       continue;
5712       }
5713 #endif  /*SUPPORT_TLS*/
5714
5715     /* Handle list operations */
5716
5717     case EITEM_FILTER:
5718     case EITEM_MAP:
5719     case EITEM_REDUCE:
5720       {
5721       int sep = 0;
5722       int save_ptr = ptr;
5723       uschar outsep[2] = { '\0', '\0' };
5724       const uschar *list, *expr, *temp;
5725       uschar *save_iterate_item = iterate_item;
5726       uschar *save_lookup_value = lookup_value;
5727
5728       while (isspace(*s)) s++;
5729       if (*s++ != '{')
5730         {
5731         expand_string_message =
5732           string_sprintf("missing '{' for first arg of %s", name);
5733         goto EXPAND_FAILED_CURLY;
5734         }
5735
5736       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5737       if (list == NULL) goto EXPAND_FAILED;
5738       if (*s++ != '}')
5739         {
5740         expand_string_message =
5741           string_sprintf("missing '}' closing first arg of %s", name);
5742         goto EXPAND_FAILED_CURLY;
5743         }
5744
5745       if (item_type == EITEM_REDUCE)
5746         {
5747         uschar * t;
5748         while (isspace(*s)) s++;
5749         if (*s++ != '{')
5750           {
5751           expand_string_message = US"missing '{' for second arg of reduce";
5752           goto EXPAND_FAILED_CURLY;
5753           }
5754         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5755         if (!t) goto EXPAND_FAILED;
5756         lookup_value = t;
5757         if (*s++ != '}')
5758           {
5759           expand_string_message = US"missing '}' closing second arg of reduce";
5760           goto EXPAND_FAILED_CURLY;
5761           }
5762         }
5763
5764       while (isspace(*s)) s++;
5765       if (*s++ != '{')
5766         {
5767         expand_string_message =
5768           string_sprintf("missing '{' for last arg of %s", name);
5769         goto EXPAND_FAILED_CURLY;
5770         }
5771
5772       expr = s;
5773
5774       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5775       if scanning a "false" part). This allows us to find the end of the
5776       condition, because if the list is empty, we won't actually evaluate the
5777       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5778       the normal internal expansion function. */
5779
5780       if (item_type == EITEM_FILTER)
5781         {
5782         temp = eval_condition(expr, &resetok, NULL);
5783         if (temp != NULL) s = temp;
5784         }
5785       else
5786         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5787
5788       if (temp == NULL)
5789         {
5790         expand_string_message = string_sprintf("%s inside \"%s\" item",
5791           expand_string_message, name);
5792         goto EXPAND_FAILED;
5793         }
5794
5795       while (isspace(*s)) s++;
5796       if (*s++ != '}')
5797         {                                               /*{*/
5798         expand_string_message = string_sprintf("missing } at end of condition "
5799           "or expression inside \"%s\"", name);
5800         goto EXPAND_FAILED;
5801         }
5802
5803       while (isspace(*s)) s++;                          /*{*/
5804       if (*s++ != '}')
5805         {                                               /*{*/
5806         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5807           name);
5808         goto EXPAND_FAILED;
5809         }
5810
5811       /* If we are skipping, we can now just move on to the next item. When
5812       processing for real, we perform the iteration. */
5813
5814       if (skipping) continue;
5815       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5816         {
5817         *outsep = (uschar)sep;      /* Separator as a string */
5818
5819         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5820                           name, iterate_item, lookup_value);
5821
5822         if (item_type == EITEM_FILTER)
5823           {
5824           BOOL condresult;
5825           if (eval_condition(expr, &resetok, &condresult) == NULL)
5826             {
5827             iterate_item = save_iterate_item;
5828             lookup_value = save_lookup_value;
5829             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5830               expand_string_message, name);
5831             goto EXPAND_FAILED;
5832             }
5833           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5834             condresult? "true":"false");
5835           if (condresult)
5836             temp = iterate_item;    /* TRUE => include this item */
5837           else
5838             continue;               /* FALSE => skip this item */
5839           }
5840
5841         /* EITEM_MAP and EITEM_REDUCE */
5842
5843         else
5844           {
5845           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5846           temp = t;
5847           if (temp == NULL)
5848             {
5849             iterate_item = save_iterate_item;
5850             expand_string_message = string_sprintf("%s inside \"%s\" item",
5851               expand_string_message, name);
5852             goto EXPAND_FAILED;
5853             }
5854           if (item_type == EITEM_REDUCE)
5855             {
5856             lookup_value = t;         /* Update the value of $value */
5857             continue;                 /* and continue the iteration */
5858             }
5859           }
5860
5861         /* We reach here for FILTER if the condition is true, always for MAP,
5862         and never for REDUCE. The value in "temp" is to be added to the output
5863         list that is being created, ensuring that any occurrences of the
5864         separator character are doubled. Unless we are dealing with the first
5865         item of the output list, add in a space if the new item begins with the
5866         separator character, or is an empty string. */
5867
5868         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5869           yield = string_catn(yield, &size, &ptr, US" ", 1);
5870
5871         /* Add the string in "temp" to the output list that we are building,
5872         This is done in chunks by searching for the separator character. */
5873
5874         for (;;)
5875           {
5876           size_t seglen = Ustrcspn(temp, outsep);
5877
5878           yield = string_catn(yield, &size, &ptr, temp, seglen + 1);
5879
5880           /* If we got to the end of the string we output one character
5881           too many; backup and end the loop. Otherwise arrange to double the
5882           separator. */
5883
5884           if (temp[seglen] == '\0') { ptr--; break; }
5885           yield = string_catn(yield, &size, &ptr, outsep, 1);
5886           temp += seglen + 1;
5887           }
5888
5889         /* Output a separator after the string: we will remove the redundant
5890         final one at the end. */
5891
5892         yield = string_catn(yield, &size, &ptr, outsep, 1);
5893         }   /* End of iteration over the list loop */
5894
5895       /* REDUCE has generated no output above: output the final value of
5896       $value. */
5897
5898       if (item_type == EITEM_REDUCE)
5899         {
5900         yield = string_cat(yield, &size, &ptr, lookup_value);
5901         lookup_value = save_lookup_value;  /* Restore $value */
5902         }
5903
5904       /* FILTER and MAP generate lists: if they have generated anything, remove
5905       the redundant final separator. Even though an empty item at the end of a
5906       list does not count, this is tidier. */
5907
5908       else if (ptr != save_ptr) ptr--;
5909
5910       /* Restore preserved $item */
5911
5912       iterate_item = save_iterate_item;
5913       continue;
5914       }
5915
5916     case EITEM_SORT:
5917       {
5918       int sep = 0;
5919       const uschar *srclist, *cmp, *xtract;
5920       uschar *srcitem;
5921       const uschar *dstlist = NULL, *dstkeylist = NULL;
5922       uschar * tmp;
5923       uschar *save_iterate_item = iterate_item;
5924
5925       while (isspace(*s)) s++;
5926       if (*s++ != '{')
5927         {
5928         expand_string_message = US"missing '{' for list arg of sort";
5929         goto EXPAND_FAILED_CURLY;
5930         }
5931
5932       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5933       if (!srclist) goto EXPAND_FAILED;
5934       if (*s++ != '}')
5935         {
5936         expand_string_message = US"missing '}' closing list arg of sort";
5937         goto EXPAND_FAILED_CURLY;
5938         }
5939
5940       while (isspace(*s)) s++;
5941       if (*s++ != '{')
5942         {
5943         expand_string_message = US"missing '{' for comparator arg of sort";
5944         goto EXPAND_FAILED_CURLY;
5945         }
5946
5947       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5948       if (!cmp) goto EXPAND_FAILED;
5949       if (*s++ != '}')
5950         {
5951         expand_string_message = US"missing '}' closing comparator arg of sort";
5952         goto EXPAND_FAILED_CURLY;
5953         }
5954
5955       while (isspace(*s)) s++;
5956       if (*s++ != '{')
5957         {
5958         expand_string_message = US"missing '{' for extractor arg of sort";
5959         goto EXPAND_FAILED_CURLY;
5960         }
5961
5962       xtract = s;
5963       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5964       if (!tmp) goto EXPAND_FAILED;
5965       xtract = string_copyn(xtract, s - xtract);
5966
5967       if (*s++ != '}')
5968         {
5969         expand_string_message = US"missing '}' closing extractor arg of sort";
5970         goto EXPAND_FAILED_CURLY;
5971         }
5972                                                         /*{*/
5973       if (*s++ != '}')
5974         {                                               /*{*/
5975         expand_string_message = US"missing } at end of \"sort\"";
5976         goto EXPAND_FAILED;
5977         }
5978
5979       if (skipping) continue;
5980
5981       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5982         {
5983         uschar * dstitem;
5984         uschar * newlist = NULL;
5985         uschar * newkeylist = NULL;
5986         uschar * srcfield;
5987
5988         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
5989
5990         /* extract field for comparisons */
5991         iterate_item = srcitem;
5992         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
5993                                           TRUE, &resetok))
5994            || !*srcfield)
5995           {
5996           expand_string_message = string_sprintf(
5997               "field-extract in sort: \"%s\"", xtract);
5998           goto EXPAND_FAILED;
5999           }
6000
6001         /* Insertion sort */
6002
6003         /* copy output list until new-item < list-item */
6004         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6005           {
6006           uschar * dstfield;
6007           uschar * expr;
6008           BOOL before;
6009
6010           /* field for comparison */
6011           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6012             goto sort_mismatch;
6013
6014           /* build and run condition string */
6015           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6016
6017           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6018           if (!eval_condition(expr, &resetok, &before))
6019             {
6020             expand_string_message = string_sprintf("comparison in sort: %s",
6021                 expr);
6022             goto EXPAND_FAILED;
6023             }
6024
6025           if (before)
6026             {
6027             /* New-item sorts before this dst-item.  Append new-item,
6028             then dst-item, then remainder of dst list. */
6029
6030             newlist = string_append_listele(newlist, sep, srcitem);
6031             newkeylist = string_append_listele(newkeylist, sep, srcfield);
6032             srcitem = NULL;
6033
6034             newlist = string_append_listele(newlist, sep, dstitem);
6035             newkeylist = string_append_listele(newkeylist, sep, dstfield);
6036
6037             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6038               {
6039               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6040                 goto sort_mismatch;
6041               newlist = string_append_listele(newlist, sep, dstitem);
6042               newkeylist = string_append_listele(newkeylist, sep, dstfield);
6043               }
6044
6045             break;
6046             }
6047
6048           newlist = string_append_listele(newlist, sep, dstitem);
6049           newkeylist = string_append_listele(newkeylist, sep, dstfield);
6050           }
6051
6052         /* If we ran out of dstlist without consuming srcitem, append it */
6053         if (srcitem)
6054           {
6055           newlist = string_append_listele(newlist, sep, srcitem);
6056           newkeylist = string_append_listele(newkeylist, sep, srcfield);
6057           }
6058
6059         dstlist = newlist;
6060         dstkeylist = newkeylist;
6061
6062         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6063         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6064         }
6065
6066       if (dstlist)
6067         yield = string_cat(yield, &size, &ptr, dstlist);
6068
6069       /* Restore preserved $item */
6070       iterate_item = save_iterate_item;
6071       continue;
6072
6073       sort_mismatch:
6074         expand_string_message = US"Internal error in sort (list mismatch)";
6075         goto EXPAND_FAILED;
6076       }
6077
6078
6079     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6080     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6081     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6082     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6083
6084     #define EXPAND_DLFUNC_MAX_ARGS 8
6085
6086     case EITEM_DLFUNC:
6087 #ifndef EXPAND_DLFUNC
6088       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6089         "is not included in this binary";
6090       goto EXPAND_FAILED;
6091
6092 #else   /* EXPAND_DLFUNC */
6093       {
6094       tree_node *t;
6095       exim_dlfunc_t *func;
6096       uschar *result;
6097       int status, argc;
6098       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6099
6100       if ((expand_forbid & RDO_DLFUNC) != 0)
6101         {
6102         expand_string_message =
6103           US"dynamically-loaded functions are not permitted";
6104         goto EXPAND_FAILED;
6105         }
6106
6107       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6108            TRUE, US"dlfunc", &resetok))
6109         {
6110         case 1: goto EXPAND_FAILED_CURLY;
6111         case 2:
6112         case 3: goto EXPAND_FAILED;
6113         }
6114
6115       /* If skipping, we don't actually do anything */
6116
6117       if (skipping) continue;
6118
6119       /* Look up the dynamically loaded object handle in the tree. If it isn't
6120       found, dlopen() the file and put the handle in the tree for next time. */
6121
6122       t = tree_search(dlobj_anchor, argv[0]);
6123       if (t == NULL)
6124         {
6125         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6126         if (handle == NULL)
6127           {
6128           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6129             argv[0], dlerror());
6130           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6131           goto EXPAND_FAILED;
6132           }
6133         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6134         Ustrcpy(t->name, argv[0]);
6135         t->data.ptr = handle;
6136         (void)tree_insertnode(&dlobj_anchor, t);
6137         }
6138
6139       /* Having obtained the dynamically loaded object handle, look up the
6140       function pointer. */
6141
6142       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6143       if (func == NULL)
6144         {
6145         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6146           "%s", argv[1], argv[0], dlerror());
6147         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6148         goto EXPAND_FAILED;
6149         }
6150
6151       /* Call the function and work out what to do with the result. If it
6152       returns OK, we have a replacement string; if it returns DEFER then
6153       expansion has failed in a non-forced manner; if it returns FAIL then
6154       failure was forced; if it returns ERROR or any other value there's a
6155       problem, so panic slightly. In any case, assume that the function has
6156       side-effects on the store that must be preserved. */
6157
6158       resetok = FALSE;
6159       result = NULL;
6160       for (argc = 0; argv[argc] != NULL; argc++);
6161       status = func(&result, argc - 2, &argv[2]);
6162       if(status == OK)
6163         {
6164         if (result == NULL) result = US"";
6165         yield = string_cat(yield, &size, &ptr, result);
6166         continue;
6167         }
6168       else
6169         {
6170         expand_string_message = result == NULL ? US"(no message)" : result;
6171         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6172           else if(status != FAIL)
6173             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6174               argv[0], argv[1], status, expand_string_message);
6175         goto EXPAND_FAILED;
6176         }
6177       }
6178 #endif /* EXPAND_DLFUNC */
6179
6180     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6181       {
6182       uschar * key;
6183       uschar *save_lookup_value = lookup_value;
6184
6185       while (isspace(*s)) s++;
6186       if (*s != '{')                                    /*}*/
6187         goto EXPAND_FAILED;
6188
6189       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6190       if (!key) goto EXPAND_FAILED;                     /*{*/
6191       if (*s++ != '}')
6192         {
6193         expand_string_message = US"missing '{' for name arg of env";
6194         goto EXPAND_FAILED_CURLY;
6195         }
6196
6197       lookup_value = US getenv(CS key);
6198
6199       switch(process_yesno(
6200                skipping,                     /* were previously skipping */
6201                lookup_value != NULL,         /* success/failure indicator */
6202                save_lookup_value,            /* value to reset for string2 */
6203                &s,                           /* input pointer */
6204                &yield,                       /* output pointer */
6205                &size,                        /* output size */
6206                &ptr,                         /* output current point */
6207                US"env",                      /* condition type */
6208                &resetok))
6209         {
6210         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6211         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6212         }
6213       continue;
6214       }
6215     }   /* EITEM_* switch */
6216
6217   /* Control reaches here if the name is not recognized as one of the more
6218   complicated expansion items. Check for the "operator" syntax (name terminated
6219   by a colon). Some of the operators have arguments, separated by _ from the
6220   name. */
6221
6222   if (*s == ':')
6223     {
6224     int c;
6225     uschar *arg = NULL;
6226     uschar *sub;
6227     var_entry *vp = NULL;
6228
6229     /* Owing to an historical mis-design, an underscore may be part of the
6230     operator name, or it may introduce arguments.  We therefore first scan the
6231     table of names that contain underscores. If there is no match, we cut off
6232     the arguments and then scan the main table. */
6233
6234     if ((c = chop_match(name, op_table_underscore,
6235                         nelem(op_table_underscore))) < 0)
6236       {
6237       arg = Ustrchr(name, '_');
6238       if (arg != NULL) *arg = 0;
6239       c = chop_match(name, op_table_main, nelem(op_table_main));
6240       if (c >= 0) c += nelem(op_table_underscore);
6241       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6242       }
6243
6244     /* Deal specially with operators that might take a certificate variable
6245     as we do not want to do the usual expansion. For most, expand the string.*/
6246     switch(c)
6247       {
6248 #ifdef SUPPORT_TLS
6249       case EOP_MD5:
6250       case EOP_SHA1:
6251       case EOP_SHA256:
6252       case EOP_BASE64:
6253         if (s[1] == '$')
6254           {
6255           const uschar * s1 = s;
6256           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6257                   FALSE, &resetok);
6258           if (!sub)       goto EXPAND_FAILED;           /*{*/
6259           if (*s1 != '}')
6260             {
6261             expand_string_message =
6262               string_sprintf("missing '}' closing cert arg of %s", name);
6263             goto EXPAND_FAILED_CURLY;
6264             }
6265           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6266             {
6267             s = s1+1;
6268             break;
6269             }
6270           vp = NULL;
6271           }
6272         /*FALLTHROUGH*/
6273 #endif
6274       default:
6275         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6276         if (!sub) goto EXPAND_FAILED;
6277         s++;
6278         break;
6279       }
6280
6281     /* If we are skipping, we don't need to perform the operation at all.
6282     This matters for operations like "mask", because the data may not be
6283     in the correct format when skipping. For example, the expression may test
6284     for the existence of $sender_host_address before trying to mask it. For
6285     other operations, doing them may not fail, but it is a waste of time. */
6286
6287     if (skipping && c >= 0) continue;
6288
6289     /* Otherwise, switch on the operator type */
6290
6291     switch(c)
6292       {
6293       case EOP_BASE32:
6294         {
6295         uschar *t;
6296         unsigned long int n = Ustrtoul(sub, &t, 10);
6297         uschar * s = NULL;
6298         int sz = 0, i = 0;
6299
6300         if (*t != 0)
6301           {
6302           expand_string_message = string_sprintf("argument for base32 "
6303             "operator is \"%s\", which is not a decimal number", sub);
6304           goto EXPAND_FAILED;
6305           }
6306         for ( ; n; n >>= 5)
6307           s = string_catn(s, &sz, &i, &base32_chars[n & 0x1f], 1);
6308
6309         while (i > 0) yield = string_catn(yield, &size, &ptr, &s[--i], 1);
6310         continue;
6311         }
6312
6313       case EOP_BASE32D:
6314         {
6315         uschar *tt = sub;
6316         unsigned long int n = 0;
6317         uschar * s;
6318         while (*tt)
6319           {
6320           uschar * t = Ustrchr(base32_chars, *tt++);
6321           if (t == NULL)
6322             {
6323             expand_string_message = string_sprintf("argument for base32d "
6324               "operator is \"%s\", which is not a base 32 number", sub);
6325             goto EXPAND_FAILED;
6326             }
6327           n = n * 32 + (t - base32_chars);
6328           }
6329         s = string_sprintf("%ld", n);
6330         yield = string_cat(yield, &size, &ptr, s);
6331         continue;
6332         }
6333
6334       case EOP_BASE62:
6335         {
6336         uschar *t;
6337         unsigned long int n = Ustrtoul(sub, &t, 10);
6338         if (*t != 0)
6339           {
6340           expand_string_message = string_sprintf("argument for base62 "
6341             "operator is \"%s\", which is not a decimal number", sub);
6342           goto EXPAND_FAILED;
6343           }
6344         t = string_base62(n);
6345         yield = string_cat(yield, &size, &ptr, t);
6346         continue;
6347         }
6348
6349       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6350
6351       case EOP_BASE62D:
6352         {
6353         uschar buf[16];
6354         uschar *tt = sub;
6355         unsigned long int n = 0;
6356         while (*tt != 0)
6357           {
6358           uschar *t = Ustrchr(base62_chars, *tt++);
6359           if (t == NULL)
6360             {
6361             expand_string_message = string_sprintf("argument for base62d "
6362               "operator is \"%s\", which is not a base %d number", sub,
6363               BASE_62);
6364             goto EXPAND_FAILED;
6365             }
6366           n = n * BASE_62 + (t - base62_chars);
6367           }
6368         (void)sprintf(CS buf, "%ld", n);
6369         yield = string_cat(yield, &size, &ptr, buf);
6370         continue;
6371         }
6372
6373       case EOP_EXPAND:
6374         {
6375         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6376         if (expanded == NULL)
6377           {
6378           expand_string_message =
6379             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6380               expand_string_message);
6381           goto EXPAND_FAILED;
6382           }
6383         yield = string_cat(yield, &size, &ptr, expanded);
6384         continue;
6385         }
6386
6387       case EOP_LC:
6388         {
6389         int count = 0;
6390         uschar *t = sub - 1;
6391         while (*(++t) != 0) { *t = tolower(*t); count++; }
6392         yield = string_catn(yield, &size, &ptr, sub, count);
6393         continue;
6394         }
6395
6396       case EOP_UC:
6397         {
6398         int count = 0;
6399         uschar *t = sub - 1;
6400         while (*(++t) != 0) { *t = toupper(*t); count++; }
6401         yield = string_catn(yield, &size, &ptr, sub, count);
6402         continue;
6403         }
6404
6405       case EOP_MD5:
6406 #ifdef SUPPORT_TLS
6407         if (vp && *(void **)vp->value)
6408           {
6409           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6410           yield = string_cat(yield, &size, &ptr, cp);
6411           }
6412         else
6413 #endif
6414           {
6415           md5 base;
6416           uschar digest[16];
6417           int j;
6418           char st[33];
6419           md5_start(&base);
6420           md5_end(&base, sub, Ustrlen(sub), digest);
6421           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6422           yield = string_cat(yield, &size, &ptr, US st);
6423           }
6424         continue;
6425
6426       case EOP_SHA1:
6427 #ifdef SUPPORT_TLS
6428         if (vp && *(void **)vp->value)
6429           {
6430           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6431           yield = string_cat(yield, &size, &ptr, cp);
6432           }
6433         else
6434 #endif
6435           {
6436           hctx h;
6437           uschar digest[20];
6438           int j;
6439           char st[41];
6440           sha1_start(&h);
6441           sha1_end(&h, sub, Ustrlen(sub), digest);
6442           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6443           yield = string_catn(yield, &size, &ptr, US st, 40);
6444           }
6445         continue;
6446
6447       case EOP_SHA256:
6448 #ifdef EXIM_HAVE_SHA2
6449         if (vp && *(void **)vp->value)
6450           {
6451           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6452           yield = string_cat(yield, &size, &ptr, cp);
6453           }
6454         else
6455           {
6456           hctx h;
6457           blob b;
6458           char st[3];
6459
6460           if (!exim_sha_init(&h, HASH_SHA256))
6461             {
6462             expand_string_message = US"unrecognised sha256 variant";
6463             goto EXPAND_FAILED;
6464             }
6465           exim_sha_update(&h, sub, Ustrlen(sub));
6466           exim_sha_finish(&h, &b);
6467           while (b.len-- > 0)
6468             {
6469             sprintf(st, "%02X", *b.data++);
6470             yield = string_catn(yield, &size, &ptr, US st, 2);
6471             }
6472           }
6473 #else
6474           expand_string_message = US"sha256 only supported with TLS";
6475 #endif
6476         continue;
6477
6478       case EOP_SHA3:
6479 #ifdef EXIM_HAVE_SHA3
6480         {
6481         hctx h;
6482         blob b;
6483         char st[3];
6484         hashmethod m = !arg ? HASH_SHA3_256
6485           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6486           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6487           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6488           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6489           : HASH_BADTYPE;
6490
6491         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6492           {
6493           expand_string_message = US"unrecognised sha3 variant";
6494           goto EXPAND_FAILED;
6495           }
6496
6497         exim_sha_update(&h, sub, Ustrlen(sub));
6498         exim_sha_finish(&h, &b);
6499         while (b.len-- > 0)
6500           {
6501           sprintf(st, "%02X", *b.data++);
6502           yield = string_catn(yield, &size, &ptr, US st, 2);
6503           }
6504         }
6505         continue;
6506 #else
6507         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6508         goto EXPAND_FAILED;
6509 #endif
6510
6511       /* Convert hex encoding to base64 encoding */
6512
6513       case EOP_HEX2B64:
6514         {
6515         int c = 0;
6516         int b = -1;
6517         uschar *in = sub;
6518         uschar *out = sub;
6519         uschar *enc;
6520
6521         for (enc = sub; *enc != 0; enc++)
6522           {
6523           if (!isxdigit(*enc))
6524             {
6525             expand_string_message = string_sprintf("\"%s\" is not a hex "
6526               "string", sub);
6527             goto EXPAND_FAILED;
6528             }
6529           c++;
6530           }
6531
6532         if ((c & 1) != 0)
6533           {
6534           expand_string_message = string_sprintf("\"%s\" contains an odd "
6535             "number of characters", sub);
6536           goto EXPAND_FAILED;
6537           }
6538
6539         while ((c = *in++) != 0)
6540           {
6541           if (isdigit(c)) c -= '0';
6542           else c = toupper(c) - 'A' + 10;
6543           if (b == -1)
6544             {
6545             b = c << 4;
6546             }
6547           else
6548             {
6549             *out++ = b | c;
6550             b = -1;
6551             }
6552           }
6553
6554         enc = b64encode(sub, out - sub);
6555         yield = string_cat(yield, &size, &ptr, enc);
6556         continue;
6557         }
6558
6559       /* Convert octets outside 0x21..0x7E to \xXX form */
6560
6561       case EOP_HEXQUOTE:
6562         {
6563         uschar *t = sub - 1;
6564         while (*(++t) != 0)
6565           {
6566           if (*t < 0x21 || 0x7E < *t)
6567             yield = string_catn(yield, &size, &ptr,
6568               string_sprintf("\\x%02x", *t), 4);
6569           else
6570             yield = string_catn(yield, &size, &ptr, t, 1);
6571           }
6572         continue;
6573         }
6574
6575       /* count the number of list elements */
6576
6577       case EOP_LISTCOUNT:
6578         {
6579         int cnt = 0;
6580         int sep = 0;
6581         uschar * cp;
6582         uschar buffer[256];
6583
6584         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6585         cp = string_sprintf("%d", cnt);
6586         yield = string_cat(yield, &size, &ptr, cp);
6587         continue;
6588         }
6589
6590       /* expand a named list given the name */
6591       /* handles nested named lists; requotes as colon-sep list */
6592
6593       case EOP_LISTNAMED:
6594         {
6595         tree_node *t = NULL;
6596         const uschar * list;
6597         int sep = 0;
6598         uschar * item;
6599         uschar * suffix = US"";
6600         BOOL needsep = FALSE;
6601         uschar buffer[256];
6602
6603         if (*sub == '+') sub++;
6604         if (arg == NULL)        /* no-argument version */
6605           {
6606           if (!(t = tree_search(addresslist_anchor, sub)) &&
6607               !(t = tree_search(domainlist_anchor,  sub)) &&
6608               !(t = tree_search(hostlist_anchor,    sub)))
6609             t = tree_search(localpartlist_anchor, sub);
6610           }
6611         else switch(*arg)       /* specific list-type version */
6612           {
6613           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6614           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6615           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6616           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6617           default:
6618             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6619             goto EXPAND_FAILED;
6620           }
6621
6622         if(!t)
6623           {
6624           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6625             sub, !arg?""
6626               : *arg=='a'?"address "
6627               : *arg=='d'?"domain "
6628               : *arg=='h'?"host "
6629               : *arg=='l'?"localpart "
6630               : 0);
6631           goto EXPAND_FAILED;
6632           }
6633
6634         list = ((namedlist_block *)(t->data.ptr))->string;
6635
6636         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6637           {
6638           uschar * buf = US" : ";
6639           if (needsep)
6640             yield = string_catn(yield, &size, &ptr, buf, 3);
6641           else
6642             needsep = TRUE;
6643
6644           if (*item == '+')     /* list item is itself a named list */
6645             {
6646             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6647             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6648             }
6649           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6650             {
6651             char * cp;
6652             char tok[3];
6653             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6654             while ((cp= strpbrk((const char *)item, tok)))
6655               {
6656               yield = string_catn(yield, &size, &ptr, item, cp-(char *)item);
6657               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6658                 {
6659                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6660                 item = (uschar *)cp;
6661                 }
6662               else              /* sep in item; should already be doubled; emit once */
6663                 {
6664                 yield = string_catn(yield, &size, &ptr, (uschar *)tok, 1);
6665                 if (*cp == sep) cp++;
6666                 item = (uschar *)cp;
6667                 }
6668               }
6669             }
6670           yield = string_cat(yield, &size, &ptr, item);
6671           }
6672         continue;
6673         }
6674
6675       /* mask applies a mask to an IP address; for example the result of
6676       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6677
6678       case EOP_MASK:
6679         {
6680         int count;
6681         uschar *endptr;
6682         int binary[4];
6683         int mask, maskoffset;
6684         int type = string_is_ip_address(sub, &maskoffset);
6685         uschar buffer[64];
6686
6687         if (type == 0)
6688           {
6689           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6690            sub);
6691           goto EXPAND_FAILED;
6692           }
6693
6694         if (maskoffset == 0)
6695           {
6696           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6697             sub);
6698           goto EXPAND_FAILED;
6699           }
6700
6701         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6702
6703         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6704           {
6705           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6706             sub);
6707           goto EXPAND_FAILED;
6708           }
6709
6710         /* Convert the address to binary integer(s) and apply the mask */
6711
6712         sub[maskoffset] = 0;
6713         count = host_aton(sub, binary);
6714         host_mask(count, binary, mask);
6715
6716         /* Convert to masked textual format and add to output. */
6717
6718         yield = string_catn(yield, &size, &ptr, buffer,
6719           host_nmtoa(count, binary, mask, buffer, '.'));
6720         continue;
6721         }
6722
6723       case EOP_IPV6NORM:
6724       case EOP_IPV6DENORM:
6725         {
6726         int type = string_is_ip_address(sub, NULL);
6727         int binary[4];
6728         uschar buffer[44];
6729
6730         switch (type)
6731           {
6732           case 6:
6733             (void) host_aton(sub, binary);
6734             break;
6735
6736           case 4:       /* convert to IPv4-mapped IPv6 */
6737             binary[0] = binary[1] = 0;
6738             binary[2] = 0x0000ffff;
6739             (void) host_aton(sub, binary+3);
6740             break;
6741
6742           case 0:
6743             expand_string_message =
6744               string_sprintf("\"%s\" is not an IP address", sub);
6745             goto EXPAND_FAILED;
6746           }
6747
6748         yield = string_catn(yield, &size, &ptr, buffer,
6749                   c == EOP_IPV6NORM
6750                     ? ipv6_nmtoa(binary, buffer)
6751                     : host_nmtoa(4, binary, -1, buffer, ':')
6752                   );
6753         continue;
6754         }
6755
6756       case EOP_ADDRESS:
6757       case EOP_LOCAL_PART:
6758       case EOP_DOMAIN:
6759         {
6760         uschar * error;
6761         int start, end, domain;
6762         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6763           FALSE);
6764         if (t)
6765           if (c != EOP_DOMAIN)
6766             {
6767             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6768             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6769             }
6770           else if (domain != 0)
6771             {
6772             domain += start;
6773             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6774             }
6775         continue;
6776         }
6777
6778       case EOP_ADDRESSES:
6779         {
6780         uschar outsep[2] = { ':', '\0' };
6781         uschar *address, *error;
6782         int save_ptr = ptr;
6783         int start, end, domain;  /* Not really used */
6784
6785         while (isspace(*sub)) sub++;
6786         if (*sub == '>') { *outsep = *++sub; ++sub; }
6787         parse_allow_group = TRUE;
6788
6789         for (;;)
6790           {
6791           uschar *p = parse_find_address_end(sub, FALSE);
6792           uschar saveend = *p;
6793           *p = '\0';
6794           address = parse_extract_address(sub, &error, &start, &end, &domain,
6795             FALSE);
6796           *p = saveend;
6797
6798           /* Add the address to the output list that we are building. This is
6799           done in chunks by searching for the separator character. At the
6800           start, unless we are dealing with the first address of the output
6801           list, add in a space if the new address begins with the separator
6802           character, or is an empty string. */
6803
6804           if (address != NULL)
6805             {
6806             if (ptr != save_ptr && address[0] == *outsep)
6807               yield = string_catn(yield, &size, &ptr, US" ", 1);
6808
6809             for (;;)
6810               {
6811               size_t seglen = Ustrcspn(address, outsep);
6812               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6813
6814               /* If we got to the end of the string we output one character
6815               too many. */
6816
6817               if (address[seglen] == '\0') { ptr--; break; }
6818               yield = string_catn(yield, &size, &ptr, outsep, 1);
6819               address += seglen + 1;
6820               }
6821
6822             /* Output a separator after the string: we will remove the
6823             redundant final one at the end. */
6824
6825             yield = string_catn(yield, &size, &ptr, outsep, 1);
6826             }
6827
6828           if (saveend == '\0') break;
6829           sub = p + 1;
6830           }
6831
6832         /* If we have generated anything, remove the redundant final
6833         separator. */
6834
6835         if (ptr != save_ptr) ptr--;
6836         parse_allow_group = FALSE;
6837         continue;
6838         }
6839
6840
6841       /* quote puts a string in quotes if it is empty or contains anything
6842       other than alphamerics, underscore, dot, or hyphen.
6843
6844       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6845       be quoted in order to be a valid local part.
6846
6847       In both cases, newlines and carriage returns are converted into \n and \r
6848       respectively */
6849
6850       case EOP_QUOTE:
6851       case EOP_QUOTE_LOCAL_PART:
6852       if (arg == NULL)
6853         {
6854         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6855         uschar *t = sub - 1;
6856
6857         if (c == EOP_QUOTE)
6858           {
6859           while (!needs_quote && *(++t) != 0)
6860             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6861           }
6862         else  /* EOP_QUOTE_LOCAL_PART */
6863           {
6864           while (!needs_quote && *(++t) != 0)
6865             needs_quote = !isalnum(*t) &&
6866               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6867               (*t != '.' || t == sub || t[1] == 0);
6868           }
6869
6870         if (needs_quote)
6871           {
6872           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6873           t = sub - 1;
6874           while (*(++t) != 0)
6875             {
6876             if (*t == '\n')
6877               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6878             else if (*t == '\r')
6879               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6880             else
6881               {
6882               if (*t == '\\' || *t == '"')
6883                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6884               yield = string_catn(yield, &size, &ptr, t, 1);
6885               }
6886             }
6887           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6888           }
6889         else yield = string_cat(yield, &size, &ptr, sub);
6890         continue;
6891         }
6892
6893       /* quote_lookuptype does lookup-specific quoting */
6894
6895       else
6896         {
6897         int n;
6898         uschar *opt = Ustrchr(arg, '_');
6899
6900         if (opt != NULL) *opt++ = 0;
6901
6902         n = search_findtype(arg, Ustrlen(arg));
6903         if (n < 0)
6904           {
6905           expand_string_message = search_error_message;
6906           goto EXPAND_FAILED;
6907           }
6908
6909         if (lookup_list[n]->quote != NULL)
6910           sub = (lookup_list[n]->quote)(sub, opt);
6911         else if (opt != NULL) sub = NULL;
6912
6913         if (sub == NULL)
6914           {
6915           expand_string_message = string_sprintf(
6916             "\"%s\" unrecognized after \"${quote_%s\"",
6917             opt, arg);
6918           goto EXPAND_FAILED;
6919           }
6920
6921         yield = string_cat(yield, &size, &ptr, sub);
6922         continue;
6923         }
6924
6925       /* rx quote sticks in \ before any non-alphameric character so that
6926       the insertion works in a regular expression. */
6927
6928       case EOP_RXQUOTE:
6929         {
6930         uschar *t = sub - 1;
6931         while (*(++t) != 0)
6932           {
6933           if (!isalnum(*t))
6934             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6935           yield = string_catn(yield, &size, &ptr, t, 1);
6936           }
6937         continue;
6938         }
6939
6940       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6941       prescribed by the RFC, if there are characters that need to be encoded */
6942
6943       case EOP_RFC2047:
6944         {
6945         uschar buffer[2048];
6946         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6947           buffer, sizeof(buffer), FALSE);
6948         yield = string_cat(yield, &size, &ptr, string);
6949         continue;
6950         }
6951
6952       /* RFC 2047 decode */
6953
6954       case EOP_RFC2047D:
6955         {
6956         int len;
6957         uschar *error;
6958         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6959           headers_charset, '?', &len, &error);
6960         if (error != NULL)
6961           {
6962           expand_string_message = error;
6963           goto EXPAND_FAILED;
6964           }
6965         yield = string_catn(yield, &size, &ptr, decoded, len);
6966         continue;
6967         }
6968
6969       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6970       underscores */
6971
6972       case EOP_FROM_UTF8:
6973         {
6974         while (*sub != 0)
6975           {
6976           int c;
6977           uschar buff[4];
6978           GETUTF8INC(c, sub);
6979           if (c > 255) c = '_';
6980           buff[0] = c;
6981           yield = string_catn(yield, &size, &ptr, buff, 1);
6982           }
6983         continue;
6984         }
6985
6986           /* replace illegal UTF-8 sequences by replacement character  */
6987
6988       #define UTF8_REPLACEMENT_CHAR US"?"
6989
6990       case EOP_UTF8CLEAN:
6991         {
6992         int seq_len = 0, index = 0;
6993         int bytes_left = 0;
6994         long codepoint = -1;
6995         uschar seq_buff[4];                     /* accumulate utf-8 here */
6996
6997         while (*sub != 0)
6998           {
6999           int complete = 0;
7000           uschar c = *sub++;
7001
7002           if (bytes_left)
7003             {
7004             if ((c & 0xc0) != 0x80)
7005                     /* wrong continuation byte; invalidate all bytes */
7006               complete = 1; /* error */
7007             else
7008               {
7009               codepoint = (codepoint << 6) | (c & 0x3f);
7010               seq_buff[index++] = c;
7011               if (--bytes_left == 0)            /* codepoint complete */
7012                 if(codepoint > 0x10FFFF)        /* is it too large? */
7013                   complete = -1;        /* error (RFC3629 limit) */
7014                 else
7015                   {             /* finished; output utf-8 sequence */
7016                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
7017                   index = 0;
7018                   }
7019               }
7020             }
7021           else  /* no bytes left: new sequence */
7022             {
7023             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7024               {
7025               yield = string_catn(yield, &size, &ptr, &c, 1);
7026               continue;
7027               }
7028             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7029               {
7030               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7031                 complete = -1;
7032               else
7033                 {
7034                   bytes_left = 1;
7035                   codepoint = c & 0x1f;
7036                 }
7037               }
7038             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7039               {
7040               bytes_left = 2;
7041               codepoint = c & 0x0f;
7042               }
7043             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7044               {
7045               bytes_left = 3;
7046               codepoint = c & 0x07;
7047               }
7048             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7049               complete = -1;
7050
7051             seq_buff[index++] = c;
7052             seq_len = bytes_left + 1;
7053             }           /* if(bytes_left) */
7054
7055           if (complete != 0)
7056             {
7057             bytes_left = index = 0;
7058             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
7059             }
7060           if ((complete == 1) && ((c & 0x80) == 0))
7061                         /* ASCII character follows incomplete sequence */
7062               yield = string_catn(yield, &size, &ptr, &c, 1);
7063           }
7064         continue;
7065         }
7066
7067 #ifdef SUPPORT_I18N
7068       case EOP_UTF8_DOMAIN_TO_ALABEL:
7069         {
7070         uschar * error = NULL;
7071         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7072         if (error)
7073           {
7074           expand_string_message = string_sprintf(
7075             "error converting utf8 (%s) to alabel: %s",
7076             string_printing(sub), error);
7077           goto EXPAND_FAILED;
7078           }
7079         yield = string_cat(yield, &size, &ptr, s);
7080         continue;
7081         }
7082
7083       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7084         {
7085         uschar * error = NULL;
7086         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7087         if (error)
7088           {
7089           expand_string_message = string_sprintf(
7090             "error converting alabel (%s) to utf8: %s",
7091             string_printing(sub), error);
7092           goto EXPAND_FAILED;
7093           }
7094         yield = string_cat(yield, &size, &ptr, s);
7095         continue;
7096         }
7097
7098       case EOP_UTF8_LOCALPART_TO_ALABEL:
7099         {
7100         uschar * error = NULL;
7101         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7102         if (error)
7103           {
7104           expand_string_message = string_sprintf(
7105             "error converting utf8 (%s) to alabel: %s",
7106             string_printing(sub), error);
7107           goto EXPAND_FAILED;
7108           }
7109         yield = string_cat(yield, &size, &ptr, s);
7110         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield);
7111         continue;
7112         }
7113
7114       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7115         {
7116         uschar * error = NULL;
7117         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7118         if (error)
7119           {
7120           expand_string_message = string_sprintf(
7121             "error converting alabel (%s) to utf8: %s",
7122             string_printing(sub), error);
7123           goto EXPAND_FAILED;
7124           }
7125         yield = string_cat(yield, &size, &ptr, s);
7126         continue;
7127         }
7128 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7129
7130       /* escape turns all non-printing characters into escape sequences. */
7131
7132       case EOP_ESCAPE:
7133         {
7134         const uschar * t = string_printing(sub);
7135         yield = string_cat(yield, &size, &ptr, t);
7136         continue;
7137         }
7138
7139       case EOP_ESCAPE8BIT:
7140         {
7141         const uschar * s = sub;
7142         uschar c;
7143
7144         for (s = sub; (c = *s); s++)
7145           yield = c < 127 && c != '\\'
7146             ? string_catn(yield, &size, &ptr, s, 1)
7147             : string_catn(yield, &size, &ptr, string_sprintf("\\%03o", c), 4);
7148         continue;
7149         }
7150
7151       /* Handle numeric expression evaluation */
7152
7153       case EOP_EVAL:
7154       case EOP_EVAL10:
7155         {
7156         uschar *save_sub = sub;
7157         uschar *error = NULL;
7158         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7159         if (error != NULL)
7160           {
7161           expand_string_message = string_sprintf("error in expression "
7162             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7163               save_sub);
7164           goto EXPAND_FAILED;
7165           }
7166         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7167         yield = string_cat(yield, &size, &ptr, var_buffer);
7168         continue;
7169         }
7170
7171       /* Handle time period formating */
7172
7173       case EOP_TIME_EVAL:
7174         {
7175         int n = readconf_readtime(sub, 0, FALSE);
7176         if (n < 0)
7177           {
7178           expand_string_message = string_sprintf("string \"%s\" is not an "
7179             "Exim time interval in \"%s\" operator", sub, name);
7180           goto EXPAND_FAILED;
7181           }
7182         sprintf(CS var_buffer, "%d", n);
7183         yield = string_cat(yield, &size, &ptr, var_buffer);
7184         continue;
7185         }
7186
7187       case EOP_TIME_INTERVAL:
7188         {
7189         int n;
7190         uschar *t = read_number(&n, sub);
7191         if (*t != 0) /* Not A Number*/
7192           {
7193           expand_string_message = string_sprintf("string \"%s\" is not a "
7194             "positive number in \"%s\" operator", sub, name);
7195           goto EXPAND_FAILED;
7196           }
7197         t = readconf_printtime(n);
7198         yield = string_cat(yield, &size, &ptr, t);
7199         continue;
7200         }
7201
7202       /* Convert string to base64 encoding */
7203
7204       case EOP_STR2B64:
7205       case EOP_BASE64:
7206         {
7207 #ifdef SUPPORT_TLS
7208         uschar * s = vp && *(void **)vp->value
7209           ? tls_cert_der_b64(*(void **)vp->value)
7210           : b64encode(sub, Ustrlen(sub));
7211 #else
7212         uschar * s = b64encode(sub, Ustrlen(sub));
7213 #endif
7214         yield = string_cat(yield, &size, &ptr, s);
7215         continue;
7216         }
7217
7218       case EOP_BASE64D:
7219         {
7220         uschar * s;
7221         int len = b64decode(sub, &s);
7222         if (len < 0)
7223           {
7224           expand_string_message = string_sprintf("string \"%s\" is not "
7225             "well-formed for \"%s\" operator", sub, name);
7226           goto EXPAND_FAILED;
7227           }
7228         yield = string_cat(yield, &size, &ptr, s);
7229         continue;
7230         }
7231
7232       /* strlen returns the length of the string */
7233
7234       case EOP_STRLEN:
7235         {
7236         uschar buff[24];
7237         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7238         yield = string_cat(yield, &size, &ptr, buff);
7239         continue;
7240         }
7241
7242       /* length_n or l_n takes just the first n characters or the whole string,
7243       whichever is the shorter;
7244
7245       substr_m_n, and s_m_n take n characters from offset m; negative m take
7246       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7247       takes the rest, either to the right or to the left.
7248
7249       hash_n or h_n makes a hash of length n from the string, yielding n
7250       characters from the set a-z; hash_n_m makes a hash of length n, but
7251       uses m characters from the set a-zA-Z0-9.
7252
7253       nhash_n returns a single number between 0 and n-1 (in text form), while
7254       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7255       between 0 and n-1 and the second between 0 and m-1. */
7256
7257       case EOP_LENGTH:
7258       case EOP_L:
7259       case EOP_SUBSTR:
7260       case EOP_S:
7261       case EOP_HASH:
7262       case EOP_H:
7263       case EOP_NHASH:
7264       case EOP_NH:
7265         {
7266         int sign = 1;
7267         int value1 = 0;
7268         int value2 = -1;
7269         int *pn;
7270         int len;
7271         uschar *ret;
7272
7273         if (arg == NULL)
7274           {
7275           expand_string_message = string_sprintf("missing values after %s",
7276             name);
7277           goto EXPAND_FAILED;
7278           }
7279
7280         /* "length" has only one argument, effectively being synonymous with
7281         substr_0_n. */
7282
7283         if (c == EOP_LENGTH || c == EOP_L)
7284           {
7285           pn = &value2;
7286           value2 = 0;
7287           }
7288
7289         /* The others have one or two arguments; for "substr" the first may be
7290         negative. The second being negative means "not supplied". */
7291
7292         else
7293           {
7294           pn = &value1;
7295           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7296           }
7297
7298         /* Read up to two numbers, separated by underscores */
7299
7300         ret = arg;
7301         while (*arg != 0)
7302           {
7303           if (arg != ret && *arg == '_' && pn == &value1)
7304             {
7305             pn = &value2;
7306             value2 = 0;
7307             if (arg[1] != 0) arg++;
7308             }
7309           else if (!isdigit(*arg))
7310             {
7311             expand_string_message =
7312               string_sprintf("non-digit after underscore in \"%s\"", name);
7313             goto EXPAND_FAILED;
7314             }
7315           else *pn = (*pn)*10 + *arg++ - '0';
7316           }
7317         value1 *= sign;
7318
7319         /* Perform the required operation */
7320
7321         ret =
7322           (c == EOP_HASH || c == EOP_H)?
7323              compute_hash(sub, value1, value2, &len) :
7324           (c == EOP_NHASH || c == EOP_NH)?
7325              compute_nhash(sub, value1, value2, &len) :
7326              extract_substr(sub, value1, value2, &len);
7327
7328         if (ret == NULL) goto EXPAND_FAILED;
7329         yield = string_catn(yield, &size, &ptr, ret, len);
7330         continue;
7331         }
7332
7333       /* Stat a path */
7334
7335       case EOP_STAT:
7336         {
7337         uschar *s;
7338         uschar smode[12];
7339         uschar **modetable[3];
7340         int i;
7341         mode_t mode;
7342         struct stat st;
7343
7344         if ((expand_forbid & RDO_EXISTS) != 0)
7345           {
7346           expand_string_message = US"Use of the stat() expansion is not permitted";
7347           goto EXPAND_FAILED;
7348           }
7349
7350         if (stat(CS sub, &st) < 0)
7351           {
7352           expand_string_message = string_sprintf("stat(%s) failed: %s",
7353             sub, strerror(errno));
7354           goto EXPAND_FAILED;
7355           }
7356         mode = st.st_mode;
7357         switch (mode & S_IFMT)
7358           {
7359           case S_IFIFO: smode[0] = 'p'; break;
7360           case S_IFCHR: smode[0] = 'c'; break;
7361           case S_IFDIR: smode[0] = 'd'; break;
7362           case S_IFBLK: smode[0] = 'b'; break;
7363           case S_IFREG: smode[0] = '-'; break;
7364           default: smode[0] = '?'; break;
7365           }
7366
7367         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7368         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7369         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7370
7371         for (i = 0; i < 3; i++)
7372           {
7373           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7374           mode >>= 3;
7375           }
7376
7377         smode[10] = 0;
7378         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7379           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7380           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7381           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7382           (long)st.st_gid, st.st_size, (long)st.st_atime,
7383           (long)st.st_mtime, (long)st.st_ctime);
7384         yield = string_cat(yield, &size, &ptr, s);
7385         continue;
7386         }
7387
7388       /* vaguely random number less than N */
7389
7390       case EOP_RANDINT:
7391         {
7392         int_eximarith_t max;
7393         uschar *s;
7394
7395         max = expanded_string_integer(sub, TRUE);
7396         if (expand_string_message != NULL)
7397           goto EXPAND_FAILED;
7398         s = string_sprintf("%d", vaguely_random_number((int)max));
7399         yield = string_cat(yield, &size, &ptr, s);
7400         continue;
7401         }
7402
7403       /* Reverse IP, including IPv6 to dotted-nibble */
7404
7405       case EOP_REVERSE_IP:
7406         {
7407         int family, maskptr;
7408         uschar reversed[128];
7409
7410         family = string_is_ip_address(sub, &maskptr);
7411         if (family == 0)
7412           {
7413           expand_string_message = string_sprintf(
7414               "reverse_ip() not given an IP address [%s]", sub);
7415           goto EXPAND_FAILED;
7416           }
7417         invert_address(reversed, sub);
7418         yield = string_cat(yield, &size, &ptr, reversed);
7419         continue;
7420         }
7421
7422       /* Unknown operator */
7423
7424       default:
7425       expand_string_message =
7426         string_sprintf("unknown expansion operator \"%s\"", name);
7427       goto EXPAND_FAILED;
7428       }
7429     }
7430
7431   /* Handle a plain name. If this is the first thing in the expansion, release
7432   the pre-allocated buffer. If the result data is known to be in a new buffer,
7433   newsize will be set to the size of that buffer, and we can just point at that
7434   store instead of copying. Many expansion strings contain just one reference,
7435   so this is a useful optimization, especially for humungous headers
7436   ($message_headers). */
7437                                                 /*{*/
7438   if (*s++ == '}')
7439     {
7440     int len;
7441     int newsize = 0;
7442     if (ptr == 0)
7443       {
7444       if (resetok) store_reset(yield);
7445       yield = NULL;
7446       size = 0;
7447       }
7448     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7449       {
7450       expand_string_message =
7451         string_sprintf("unknown variable in \"${%s}\"", name);
7452       check_variable_error_message(name);
7453       goto EXPAND_FAILED;
7454       }
7455     len = Ustrlen(value);
7456     if (!yield && newsize)
7457       {
7458       yield = value;
7459       size = newsize;
7460       ptr = len;
7461       }
7462     else
7463       yield = string_catn(yield, &size, &ptr, value, len);
7464     continue;
7465     }
7466
7467   /* Else there's something wrong */
7468
7469   expand_string_message =
7470     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7471     "in a variable reference)", name);
7472   goto EXPAND_FAILED;
7473   }
7474
7475 /* If we hit the end of the string when ket_ends is set, there is a missing
7476 terminating brace. */
7477
7478 if (ket_ends && *s == 0)
7479   {
7480   expand_string_message = malformed_header?
7481     US"missing } at end of string - could be header name not terminated by colon"
7482     :
7483     US"missing } at end of string";
7484   goto EXPAND_FAILED;
7485   }
7486
7487 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7488 added to the string. If so, set up an empty string. Add a terminating zero. If
7489 left != NULL, return a pointer to the terminator. */
7490
7491 if (yield == NULL) yield = store_get(1);
7492 yield[ptr] = 0;
7493 if (left != NULL) *left = s;
7494
7495 /* Any stacking store that was used above the final string is no longer needed.
7496 In many cases the final string will be the first one that was got and so there
7497 will be optimal store usage. */
7498
7499 if (resetok) store_reset(yield + ptr + 1);
7500 else if (resetok_p) *resetok_p = FALSE;
7501
7502 DEBUG(D_expand)
7503   {
7504   debug_printf_indent("|__expanding: %.*s\n", (int)(s - string), string);
7505   debug_printf_indent("%s_____result: %s\n", skipping ? "|" : "\\", yield);
7506   if (skipping) debug_printf_indent("\\___skipping: result is not used\n");
7507   }
7508 expand_level--;
7509 return yield;
7510
7511 /* This is the failure exit: easiest to program with a goto. We still need
7512 to update the pointer to the terminator, for cases of nested calls with "fail".
7513 */
7514
7515 EXPAND_FAILED_CURLY:
7516 if (malformed_header)
7517   expand_string_message =
7518     US"missing or misplaced { or } - could be header name not terminated by colon";
7519
7520 else if (!expand_string_message || !*expand_string_message)
7521   expand_string_message = US"missing or misplaced { or }";
7522
7523 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7524 that is a bad idea, because expand_string_message is in dynamic store. */
7525
7526 EXPAND_FAILED:
7527 if (left != NULL) *left = s;
7528 DEBUG(D_expand)
7529   {
7530   debug_printf_indent("|failed to expand: %s\n", string);
7531   debug_printf_indent("%s___error message: %s\n",
7532     expand_string_forcedfail ? "|" : "\\", expand_string_message);
7533   if (expand_string_forcedfail) debug_printf_indent("\\failure was forced\n");
7534   }
7535 if (resetok_p) *resetok_p = resetok;
7536 expand_level--;
7537 return NULL;
7538 }
7539
7540
7541 /* This is the external function call. Do a quick check for any expansion
7542 metacharacters, and if there are none, just return the input string.
7543
7544 Argument: the string to be expanded
7545 Returns:  the expanded string, or NULL if expansion failed; if failure was
7546           due to a lookup deferring, search_find_defer will be TRUE
7547 */
7548
7549 uschar *
7550 expand_string(uschar *string)
7551 {
7552 search_find_defer = FALSE;
7553 malformed_header = FALSE;
7554 return (Ustrpbrk(string, "$\\") == NULL)? string :
7555   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7556 }
7557
7558
7559
7560 const uschar *
7561 expand_cstring(const uschar *string)
7562 {
7563 search_find_defer = FALSE;
7564 malformed_header = FALSE;
7565 return (Ustrpbrk(string, "$\\") == NULL)? string :
7566   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7567 }
7568
7569
7570
7571 /*************************************************
7572 *              Expand and copy                   *
7573 *************************************************/
7574
7575 /* Now and again we want to expand a string and be sure that the result is in a
7576 new bit of store. This function does that.
7577 Since we know it has been copied, the de-const cast is safe.
7578
7579 Argument: the string to be expanded
7580 Returns:  the expanded string, always in a new bit of store, or NULL
7581 */
7582
7583 uschar *
7584 expand_string_copy(const uschar *string)
7585 {
7586 const uschar *yield = expand_cstring(string);
7587 if (yield == string) yield = string_copy(string);
7588 return US yield;
7589 }
7590
7591
7592
7593 /*************************************************
7594 *        Expand and interpret as an integer      *
7595 *************************************************/
7596
7597 /* Expand a string, and convert the result into an integer.
7598
7599 Arguments:
7600   string  the string to be expanded
7601   isplus  TRUE if a non-negative number is expected
7602
7603 Returns:  the integer value, or
7604           -1 for an expansion error               ) in both cases, message in
7605           -2 for an integer interpretation error  ) expand_string_message
7606           expand_string_message is set NULL for an OK integer
7607 */
7608
7609 int_eximarith_t
7610 expand_string_integer(uschar *string, BOOL isplus)
7611 {
7612 return expanded_string_integer(expand_string(string), isplus);
7613 }
7614
7615
7616 /*************************************************
7617  *         Interpret string as an integer        *
7618  *************************************************/
7619
7620 /* Convert a string (that has already been expanded) into an integer.
7621
7622 This function is used inside the expansion code.
7623
7624 Arguments:
7625   s       the string to be expanded
7626   isplus  TRUE if a non-negative number is expected
7627
7628 Returns:  the integer value, or
7629           -1 if string is NULL (which implies an expansion error)
7630           -2 for an integer interpretation error
7631           expand_string_message is set NULL for an OK integer
7632 */
7633
7634 static int_eximarith_t
7635 expanded_string_integer(const uschar *s, BOOL isplus)
7636 {
7637 int_eximarith_t value;
7638 uschar *msg = US"invalid integer \"%s\"";
7639 uschar *endptr;
7640
7641 /* If expansion failed, expand_string_message will be set. */
7642
7643 if (s == NULL) return -1;
7644
7645 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7646 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7647 systems, so we set it zero ourselves. */
7648
7649 errno = 0;
7650 expand_string_message = NULL;               /* Indicates no error */
7651
7652 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7653 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7654 the behaviour explicitly.  Stripping leading whitespace is a harmless
7655 noop change since strtol skips it anyway (provided that there is a number
7656 to find at all). */
7657 if (isspace(*s))
7658   {
7659   while (isspace(*s)) ++s;
7660   if (*s == '\0')
7661     {
7662       DEBUG(D_expand)
7663        debug_printf_indent("treating blank string as number 0\n");
7664       return 0;
7665     }
7666   }
7667
7668 value = strtoll(CS s, CSS &endptr, 10);
7669
7670 if (endptr == s)
7671   {
7672   msg = US"integer expected but \"%s\" found";
7673   }
7674 else if (value < 0 && isplus)
7675   {
7676   msg = US"non-negative integer expected but \"%s\" found";
7677   }
7678 else
7679   {
7680   switch (tolower(*endptr))
7681     {
7682     default:
7683       break;
7684     case 'k':
7685       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7686       else value *= 1024;
7687       endptr++;
7688       break;
7689     case 'm':
7690       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7691       else value *= 1024*1024;
7692       endptr++;
7693       break;
7694     case 'g':
7695       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7696       else value *= 1024*1024*1024;
7697       endptr++;
7698       break;
7699     }
7700   if (errno == ERANGE)
7701     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7702   else
7703     {
7704     while (isspace(*endptr)) endptr++;
7705     if (*endptr == 0) return value;
7706     }
7707   }
7708
7709 expand_string_message = string_sprintf(CS msg, s);
7710 return -2;
7711 }
7712
7713
7714 /* These values are usually fixed boolean values, but they are permitted to be
7715 expanded strings.
7716
7717 Arguments:
7718   addr       address being routed
7719   mtype      the module type
7720   mname      the module name
7721   dbg_opt    debug selectors
7722   oname      the option name
7723   bvalue     the router's boolean value
7724   svalue     the router's string value
7725   rvalue     where to put the returned value
7726
7727 Returns:     OK     value placed in rvalue
7728              DEFER  expansion failed
7729 */
7730
7731 int
7732 exp_bool(address_item *addr,
7733   uschar *mtype, uschar *mname, unsigned dbg_opt,
7734   uschar *oname, BOOL bvalue,
7735   uschar *svalue, BOOL *rvalue)
7736 {
7737 uschar *expanded;
7738 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7739
7740 expanded = expand_string(svalue);
7741 if (expanded == NULL)
7742   {
7743   if (expand_string_forcedfail)
7744     {
7745     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7746     *rvalue = bvalue;
7747     return OK;
7748     }
7749   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7750       oname, mname, mtype, expand_string_message);
7751   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7752   return DEFER;
7753   }
7754
7755 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7756   expanded);
7757
7758 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7759   *rvalue = TRUE;
7760 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7761   *rvalue = FALSE;
7762 else
7763   {
7764   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7765     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7766   return DEFER;
7767   }
7768
7769 return OK;
7770 }
7771
7772
7773
7774 /* Avoid potentially exposing a password in a string about to be logged */
7775
7776 uschar *
7777 expand_hide_passwords(uschar * s)
7778 {
7779 return (  (  Ustrstr(s, "failed to expand") != NULL
7780           || Ustrstr(s, "expansion of ")    != NULL
7781           )
7782        && (  Ustrstr(s, "mysql")   != NULL
7783           || Ustrstr(s, "pgsql")   != NULL
7784           || Ustrstr(s, "redis")   != NULL
7785           || Ustrstr(s, "sqlite")  != NULL
7786           || Ustrstr(s, "ldap:")   != NULL
7787           || Ustrstr(s, "ldaps:")  != NULL
7788           || Ustrstr(s, "ldapi:")  != NULL
7789           || Ustrstr(s, "ldapdn:") != NULL
7790           || Ustrstr(s, "ldapm:")  != NULL
7791        )  )
7792   ? US"Temporary internal error" : s;
7793 }
7794
7795
7796
7797 /*************************************************
7798 * Error-checking for testsuite                   *
7799 *************************************************/
7800 typedef struct {
7801   const char *  filename;
7802   int           linenumber;
7803   uschar *      region_start;
7804   uschar *      region_end;
7805   const uschar *var_name;
7806   const uschar *var_data;
7807 } err_ctx;
7808
7809 static void
7810 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7811 {
7812 err_ctx * e = ctx;
7813 if (var_data >= e->region_start  &&  var_data < e->region_end)
7814   {
7815   e->var_name = CUS var_name;
7816   e->var_data = CUS var_data;
7817   }
7818 }
7819
7820 void
7821 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7822 {
7823 err_ctx e = {filename, linenumber, ptr, US ptr + len, NULL };
7824 int i;
7825 var_entry * v;
7826
7827 /* check acl_ variables */
7828 tree_walk(acl_var_c, assert_variable_notin, &e);
7829 tree_walk(acl_var_m, assert_variable_notin, &e);
7830
7831 /* check auth<n> variables */
7832 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7833   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7834
7835 /* check regex<n> variables */
7836 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7837   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7838
7839 /* check known-name variables */
7840 for (v = var_table; v < var_table + var_table_size; v++)
7841   if (v->type == vtype_stringptr)
7842     assert_variable_notin(US v->name, *(USS v->value), &e);
7843
7844 if (e.var_name)
7845   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7846     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7847     e.var_name, e.filename, e.linenumber, e.var_data);
7848 }
7849
7850
7851
7852 /*************************************************
7853 **************************************************
7854 *             Stand-alone test program           *
7855 **************************************************
7856 *************************************************/
7857
7858 #ifdef STAND_ALONE
7859
7860
7861 BOOL
7862 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7863 {
7864 int ovector[3*(EXPAND_MAXN+1)];
7865 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7866   ovector, nelem(ovector));
7867 BOOL yield = n >= 0;
7868 if (n == 0) n = EXPAND_MAXN + 1;
7869 if (yield)
7870   {
7871   int nn;
7872   expand_nmax = (setup < 0)? 0 : setup + 1;
7873   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7874     {
7875     expand_nstring[expand_nmax] = subject + ovector[nn];
7876     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7877     }
7878   expand_nmax--;
7879   }
7880 return yield;
7881 }
7882
7883
7884 int main(int argc, uschar **argv)
7885 {
7886 int i;
7887 uschar buffer[1024];
7888
7889 debug_selector = D_v;
7890 debug_file = stderr;
7891 debug_fd = fileno(debug_file);
7892 big_buffer = malloc(big_buffer_size);
7893
7894 for (i = 1; i < argc; i++)
7895   {
7896   if (argv[i][0] == '+')
7897     {
7898     debug_trace_memory = 2;
7899     argv[i]++;
7900     }
7901   if (isdigit(argv[i][0]))
7902     debug_selector = Ustrtol(argv[i], NULL, 0);
7903   else
7904     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7905         Ustrlen(argv[i]))
7906       {
7907 #ifdef LOOKUP_LDAP
7908       eldap_default_servers = argv[i];
7909 #endif
7910 #ifdef LOOKUP_MYSQL
7911       mysql_servers = argv[i];
7912 #endif
7913 #ifdef LOOKUP_PGSQL
7914       pgsql_servers = argv[i];
7915 #endif
7916 #ifdef LOOKUP_REDIS
7917       redis_servers = argv[i];
7918 #endif
7919       }
7920 #ifdef EXIM_PERL
7921   else opt_perl_startup = argv[i];
7922 #endif
7923   }
7924
7925 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7926
7927 expand_nstring[1] = US"string 1....";
7928 expand_nlength[1] = 8;
7929 expand_nmax = 1;
7930
7931 #ifdef EXIM_PERL
7932 if (opt_perl_startup != NULL)
7933   {
7934   uschar *errstr;
7935   printf("Starting Perl interpreter\n");
7936   errstr = init_perl(opt_perl_startup);
7937   if (errstr != NULL)
7938     {
7939     printf("** error in perl_startup code: %s\n", errstr);
7940     return EXIT_FAILURE;
7941     }
7942   }
7943 #endif /* EXIM_PERL */
7944
7945 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7946   {
7947   void *reset_point = store_get(0);
7948   uschar *yield = expand_string(buffer);
7949   if (yield != NULL)
7950     {
7951     printf("%s\n", yield);
7952     store_reset(reset_point);
7953     }
7954   else
7955     {
7956     if (search_find_defer) printf("search_find deferred\n");
7957     printf("Failed: %s\n", expand_string_message);
7958     if (expand_string_forcedfail) printf("Forced failure\n");
7959     printf("\n");
7960     }
7961   }
7962
7963 search_tidyup();
7964
7965 return 0;
7966 }
7967
7968 #endif
7969
7970 /* vi: aw ai sw=2
7971 */
7972 /* End of expand.c */