src/src/expand.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2016 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8
   9 /* Functions for handling string expansion. */
  10
  11
  12 #include "exim.h"
  13
  14 /* Recursively called function */
  15
  16 static uschar *expand_string_internal(const uschar *, BOOL, const uschar **, BOOL, BOOL, BOOL *);
  17 static int_eximarith_t expanded_string_integer(const uschar *, BOOL);
  18
  19 #ifdef STAND_ALONE
  20 #ifndef SUPPORT_CRYPTEQ
  21 #define SUPPORT_CRYPTEQ
  22 #endif
  23 #endif
  24
  25 #ifdef LOOKUP_LDAP
  26 #include "lookups/ldap.h"
  27 #endif
  28
  29 #ifdef SUPPORT_CRYPTEQ
  30 #ifdef CRYPT_H
  31 #include <crypt.h>
  32 #endif
  33 #ifndef HAVE_CRYPT16
  34 extern char* crypt16(char*, char*);
  35 #endif
  36 #endif
  37
  38 /* The handling of crypt16() is a mess. I will record below the analysis of the
  39 mess that was sent to me. We decided, however, to make changing this very low
  40 priority, because in practice people are moving away from the crypt()
  41 algorithms nowadays, so it doesn't seem worth it.
  42
  43 <quote>
  44 There is an algorithm named "crypt16" in Ultrix and Tru64.  It crypts
  45 the first 8 characters of the password using a 20-round version of crypt
  46 (standard crypt does 25 rounds).  It then crypts the next 8 characters,
  47 or an empty block if the password is less than 9 characters, using a
  48 20-round version of crypt and the same salt as was used for the first
  49 block.  Characters after the first 16 are ignored.  It always generates
  50 a 16-byte hash, which is expressed together with the salt as a string
  51 of 24 base 64 digits.  Here are some links to peruse:
  52
  53         http://cvs.pld.org.pl/pam/pamcrypt/crypt16.c?rev=1.2
  54         http://seclists.org/bugtraq/1999/Mar/0076.html
  55
  56 There's a different algorithm named "bigcrypt" in HP-UX, Digital Unix,
  57 and OSF/1.  This is the same as the standard crypt if given a password
  58 of 8 characters or less.  If given more, it first does the same as crypt
  59 using the first 8 characters, then crypts the next 8 (the 9th to 16th)
  60 using as salt the first two base 64 digits from the first hash block.
  61 If the password is more than 16 characters then it crypts the 17th to 24th
  62 characters using as salt the first two base 64 digits from the second hash
  63 block.  And so on: I've seen references to it cutting off the password at
  64 40 characters (5 blocks), 80 (10 blocks), or 128 (16 blocks).  Some links:
  65
  66         http://cvs.pld.org.pl/pam/pamcrypt/bigcrypt.c?rev=1.2
  67         http://seclists.org/bugtraq/1999/Mar/0109.html
  68         http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/HTML/AA-Q0R2D-
  69              TET1_html/sec.c222.html#no_id_208
  70
  71 Exim has something it calls "crypt16".  It will either use a native
  72 crypt16 or its own implementation.  A native crypt16 will presumably
  73 be the one that I called "crypt16" above.  The internal "crypt16"
  74 function, however, is a two-block-maximum implementation of what I called
  75 "bigcrypt".  The documentation matches the internal code.
  76
  77 I suspect that whoever did the "crypt16" stuff for Exim didn't realise
  78 that crypt16 and bigcrypt were different things.
  79
  80 Exim uses the LDAP-style scheme identifier "{crypt16}" to refer
  81 to whatever it is using under that name.  This unfortunately sets a
  82 precedent for using "{crypt16}" to identify two incompatible algorithms
  83 whose output can't be distinguished.  With "{crypt16}" thus rendered
  84 ambiguous, I suggest you deprecate it and invent two new identifiers
  85 for the two algorithms.
  86
  87 Both crypt16 and bigcrypt are very poor algorithms, btw.  Hashing parts
  88 of the password separately means they can be cracked separately, so
  89 the double-length hash only doubles the cracking effort instead of
  90 squaring it.  I recommend salted SHA-1 ({SSHA}), or the Blowfish-based
  91 bcrypt ({CRYPT}$2a$).
  92 </quote>
  93 */
  94
  95
  96
  97 /*************************************************
  98 *            Local statics and tables            *
  99 *************************************************/
 100
 101 /* Table of item names, and corresponding switch numbers. The names must be in
 102 alphabetical order. */
 103
 104 static uschar *item_table[] = {
 105   US"acl",
 106   US"certextract",
 107   US"dlfunc",
 108   US"env",
 109   US"extract",
 110   US"filter",
 111   US"hash",
 112   US"hmac",
 113   US"if",
 114 #ifdef SUPPORT_I18N
 115   US"imapfolder",
 116 #endif
 117   US"length",
 118   US"listextract",
 119   US"lookup",
 120   US"map",
 121   US"nhash",
 122   US"perl",
 123   US"prvs",
 124   US"prvscheck",
 125   US"readfile",
 126   US"readsocket",
 127   US"reduce",
 128   US"run",
 129   US"sg",
 130   US"sort",
 131   US"substr",
 132   US"tr" };
 133
 134 enum {
 135   EITEM_ACL,
 136   EITEM_CERTEXTRACT,
 137   EITEM_DLFUNC,
 138   EITEM_ENV,
 139   EITEM_EXTRACT,
 140   EITEM_FILTER,
 141   EITEM_HASH,
 142   EITEM_HMAC,
 143   EITEM_IF,
 144 #ifdef SUPPORT_I18N
 145   EITEM_IMAPFOLDER,
 146 #endif
 147   EITEM_LENGTH,
 148   EITEM_LISTEXTRACT,
 149   EITEM_LOOKUP,
 150   EITEM_MAP,
 151   EITEM_NHASH,
 152   EITEM_PERL,
 153   EITEM_PRVS,
 154   EITEM_PRVSCHECK,
 155   EITEM_READFILE,
 156   EITEM_READSOCK,
 157   EITEM_REDUCE,
 158   EITEM_RUN,
 159   EITEM_SG,
 160   EITEM_SORT,
 161   EITEM_SUBSTR,
 162   EITEM_TR };
 163
 164 /* Tables of operator names, and corresponding switch numbers. The names must be
 165 in alphabetical order. There are two tables, because underscore is used in some
 166 cases to introduce arguments, whereas for other it is part of the name. This is
 167 an historical mis-design. */
 168
 169 static uschar *op_table_underscore[] = {
 170   US"from_utf8",
 171   US"local_part",
 172   US"quote_local_part",
 173   US"reverse_ip",
 174   US"time_eval",
 175   US"time_interval"
 176 #ifdef SUPPORT_I18N
 177  ,US"utf8_domain_from_alabel",
 178   US"utf8_domain_to_alabel",
 179   US"utf8_localpart_from_alabel",
 180   US"utf8_localpart_to_alabel"
 181 #endif
 182   };
 183
 184 enum {
 185   EOP_FROM_UTF8,
 186   EOP_LOCAL_PART,
 187   EOP_QUOTE_LOCAL_PART,
 188   EOP_REVERSE_IP,
 189   EOP_TIME_EVAL,
 190   EOP_TIME_INTERVAL
 191 #ifdef SUPPORT_I18N
 192  ,EOP_UTF8_DOMAIN_FROM_ALABEL,
 193   EOP_UTF8_DOMAIN_TO_ALABEL,
 194   EOP_UTF8_LOCALPART_FROM_ALABEL,
 195   EOP_UTF8_LOCALPART_TO_ALABEL
 196 #endif
 197   };
 198
 199 static uschar *op_table_main[] = {
 200   US"address",
 201   US"addresses",
 202   US"base32",
 203   US"base32d",
 204   US"base62",
 205   US"base62d",
 206   US"base64",
 207   US"base64d",
 208   US"domain",
 209   US"escape",
 210   US"escape8bit",
 211   US"eval",
 212   US"eval10",
 213   US"expand",
 214   US"h",
 215   US"hash",
 216   US"hex2b64",
 217   US"hexquote",
 218   US"ipv6denorm",
 219   US"ipv6norm",
 220   US"l",
 221   US"lc",
 222   US"length",
 223   US"listcount",
 224   US"listnamed",
 225   US"mask",
 226   US"md5",
 227   US"nh",
 228   US"nhash",
 229   US"quote",
 230   US"randint",
 231   US"rfc2047",
 232   US"rfc2047d",
 233   US"rxquote",
 234   US"s",
 235   US"sha1",
 236   US"sha256",
 237   US"sha3",
 238   US"stat",
 239   US"str2b64",
 240   US"strlen",
 241   US"substr",
 242   US"uc",
 243   US"utf8clean" };
 244
 245 enum {
 246   EOP_ADDRESS =  nelem(op_table_underscore),
 247   EOP_ADDRESSES,
 248   EOP_BASE32,
 249   EOP_BASE32D,
 250   EOP_BASE62,
 251   EOP_BASE62D,
 252   EOP_BASE64,
 253   EOP_BASE64D,
 254   EOP_DOMAIN,
 255   EOP_ESCAPE,
 256   EOP_ESCAPE8BIT,
 257   EOP_EVAL,
 258   EOP_EVAL10,
 259   EOP_EXPAND,
 260   EOP_H,
 261   EOP_HASH,
 262   EOP_HEX2B64,
 263   EOP_HEXQUOTE,
 264   EOP_IPV6DENORM,
 265   EOP_IPV6NORM,
 266   EOP_L,
 267   EOP_LC,
 268   EOP_LENGTH,
 269   EOP_LISTCOUNT,
 270   EOP_LISTNAMED,
 271   EOP_MASK,
 272   EOP_MD5,
 273   EOP_NH,
 274   EOP_NHASH,
 275   EOP_QUOTE,
 276   EOP_RANDINT,
 277   EOP_RFC2047,
 278   EOP_RFC2047D,
 279   EOP_RXQUOTE,
 280   EOP_S,
 281   EOP_SHA1,
 282   EOP_SHA256,
 283   EOP_SHA3,
 284   EOP_STAT,
 285   EOP_STR2B64,
 286   EOP_STRLEN,
 287   EOP_SUBSTR,
 288   EOP_UC,
 289   EOP_UTF8CLEAN };
 290
 291
 292 /* Table of condition names, and corresponding switch numbers. The names must
 293 be in alphabetical order. */
 294
 295 static uschar *cond_table[] = {
 296   US"<",
 297   US"<=",
 298   US"=",
 299   US"==",     /* Backward compatibility */
 300   US">",
 301   US">=",
 302   US"acl",
 303   US"and",
 304   US"bool",
 305   US"bool_lax",
 306   US"crypteq",
 307   US"def",
 308   US"eq",
 309   US"eqi",
 310   US"exists",
 311   US"first_delivery",
 312   US"forall",
 313   US"forany",
 314   US"ge",
 315   US"gei",
 316   US"gt",
 317   US"gti",
 318   US"inlist",
 319   US"inlisti",
 320   US"isip",
 321   US"isip4",
 322   US"isip6",
 323   US"ldapauth",
 324   US"le",
 325   US"lei",
 326   US"lt",
 327   US"lti",
 328   US"match",
 329   US"match_address",
 330   US"match_domain",
 331   US"match_ip",
 332   US"match_local_part",
 333   US"or",
 334   US"pam",
 335   US"pwcheck",
 336   US"queue_running",
 337   US"radius",
 338   US"saslauthd"
 339 };
 340
 341 enum {
 342   ECOND_NUM_L,
 343   ECOND_NUM_LE,
 344   ECOND_NUM_E,
 345   ECOND_NUM_EE,
 346   ECOND_NUM_G,
 347   ECOND_NUM_GE,
 348   ECOND_ACL,
 349   ECOND_AND,
 350   ECOND_BOOL,
 351   ECOND_BOOL_LAX,
 352   ECOND_CRYPTEQ,
 353   ECOND_DEF,
 354   ECOND_STR_EQ,
 355   ECOND_STR_EQI,
 356   ECOND_EXISTS,
 357   ECOND_FIRST_DELIVERY,
 358   ECOND_FORALL,
 359   ECOND_FORANY,
 360   ECOND_STR_GE,
 361   ECOND_STR_GEI,
 362   ECOND_STR_GT,
 363   ECOND_STR_GTI,
 364   ECOND_INLIST,
 365   ECOND_INLISTI,
 366   ECOND_ISIP,
 367   ECOND_ISIP4,
 368   ECOND_ISIP6,
 369   ECOND_LDAPAUTH,
 370   ECOND_STR_LE,
 371   ECOND_STR_LEI,
 372   ECOND_STR_LT,
 373   ECOND_STR_LTI,
 374   ECOND_MATCH,
 375   ECOND_MATCH_ADDRESS,
 376   ECOND_MATCH_DOMAIN,
 377   ECOND_MATCH_IP,
 378   ECOND_MATCH_LOCAL_PART,
 379   ECOND_OR,
 380   ECOND_PAM,
 381   ECOND_PWCHECK,
 382   ECOND_QUEUE_RUNNING,
 383   ECOND_RADIUS,
 384   ECOND_SASLAUTHD
 385 };
 386
 387
 388 /* Types of table entry */
 389
 390 enum vtypes {
 391   vtype_int,            /* value is address of int */
 392   vtype_filter_int,     /* ditto, but recognized only when filtering */
 393   vtype_ino,            /* value is address of ino_t (not always an int) */
 394   vtype_uid,            /* value is address of uid_t (not always an int) */
 395   vtype_gid,            /* value is address of gid_t (not always an int) */
 396   vtype_bool,           /* value is address of bool */
 397   vtype_stringptr,      /* value is address of pointer to string */
 398   vtype_msgbody,        /* as stringptr, but read when first required */
 399   vtype_msgbody_end,    /* ditto, the end of the message */
 400   vtype_msgheaders,     /* the message's headers, processed */
 401   vtype_msgheaders_raw, /* the message's headers, unprocessed */
 402   vtype_localpart,      /* extract local part from string */
 403   vtype_domain,         /* extract domain from string */
 404   vtype_string_func,    /* value is string returned by given function */
 405   vtype_todbsdin,       /* value not used; generate BSD inbox tod */
 406   vtype_tode,           /* value not used; generate tod in epoch format */
 407   vtype_todel,          /* value not used; generate tod in epoch/usec format */
 408   vtype_todf,           /* value not used; generate full tod */
 409   vtype_todl,           /* value not used; generate log tod */
 410   vtype_todlf,          /* value not used; generate log file datestamp tod */
 411   vtype_todzone,        /* value not used; generate time zone only */
 412   vtype_todzulu,        /* value not used; generate zulu tod */
 413   vtype_reply,          /* value not used; get reply from headers */
 414   vtype_pid,            /* value not used; result is pid */
 415   vtype_host_lookup,    /* value not used; get host name */
 416   vtype_load_avg,       /* value not used; result is int from os_getloadavg */
 417   vtype_pspace,         /* partition space; value is T/F for spool/log */
 418   vtype_pinodes,        /* partition inodes; value is T/F for spool/log */
 419   vtype_cert            /* SSL certificate */
 420   #ifndef DISABLE_DKIM
 421   ,vtype_dkim           /* Lookup of value in DKIM signature */
 422   #endif
 423 };
 424
 425 /* Type for main variable table */
 426
 427 typedef struct {
 428   const char *name;
 429   enum vtypes type;
 430   void       *value;
 431 } var_entry;
 432
 433 /* Type for entries pointing to address/length pairs. Not currently
 434 in use. */
 435
 436 typedef struct {
 437   uschar **address;
 438   int  *length;
 439 } alblock;
 440
 441 static uschar * fn_recipients(void);
 442
 443 /* This table must be kept in alphabetical order. */
 444
 445 static var_entry var_table[] = {
 446   /* WARNING: Do not invent variables whose names start acl_c or acl_m because
 447      they will be confused with user-creatable ACL variables. */
 448   { "acl_arg1",            vtype_stringptr,   &acl_arg[0] },
 449   { "acl_arg2",            vtype_stringptr,   &acl_arg[1] },
 450   { "acl_arg3",            vtype_stringptr,   &acl_arg[2] },
 451   { "acl_arg4",            vtype_stringptr,   &acl_arg[3] },
 452   { "acl_arg5",            vtype_stringptr,   &acl_arg[4] },
 453   { "acl_arg6",            vtype_stringptr,   &acl_arg[5] },
 454   { "acl_arg7",            vtype_stringptr,   &acl_arg[6] },
 455   { "acl_arg8",            vtype_stringptr,   &acl_arg[7] },
 456   { "acl_arg9",            vtype_stringptr,   &acl_arg[8] },
 457   { "acl_narg",            vtype_int,         &acl_narg },
 458   { "acl_verify_message",  vtype_stringptr,   &acl_verify_message },
 459   { "address_data",        vtype_stringptr,   &deliver_address_data },
 460   { "address_file",        vtype_stringptr,   &address_file },
 461   { "address_pipe",        vtype_stringptr,   &address_pipe },
 462   { "authenticated_fail_id",vtype_stringptr,  &authenticated_fail_id },
 463   { "authenticated_id",    vtype_stringptr,   &authenticated_id },
 464   { "authenticated_sender",vtype_stringptr,   &authenticated_sender },
 465   { "authentication_failed",vtype_int,        &authentication_failed },
 466 #ifdef WITH_CONTENT_SCAN
 467   { "av_failed",           vtype_int,         &av_failed },
 468 #endif
 469 #ifdef EXPERIMENTAL_BRIGHTMAIL
 470   { "bmi_alt_location",    vtype_stringptr,   &bmi_alt_location },
 471   { "bmi_base64_tracker_verdict", vtype_stringptr, &bmi_base64_tracker_verdict },
 472   { "bmi_base64_verdict",  vtype_stringptr,   &bmi_base64_verdict },
 473   { "bmi_deliver",         vtype_int,         &bmi_deliver },
 474 #endif
 475   { "body_linecount",      vtype_int,         &body_linecount },
 476   { "body_zerocount",      vtype_int,         &body_zerocount },
 477   { "bounce_recipient",    vtype_stringptr,   &bounce_recipient },
 478   { "bounce_return_size_limit", vtype_int,    &bounce_return_size_limit },
 479   { "caller_gid",          vtype_gid,         &real_gid },
 480   { "caller_uid",          vtype_uid,         &real_uid },
 481   { "callout_address",     vtype_stringptr,   &callout_address },
 482   { "compile_date",        vtype_stringptr,   &version_date },
 483   { "compile_number",      vtype_stringptr,   &version_cnumber },
 484   { "config_dir",          vtype_stringptr,   &config_main_directory },
 485   { "config_file",         vtype_stringptr,   &config_main_filename },
 486   { "csa_status",          vtype_stringptr,   &csa_status },
 487 #ifdef EXPERIMENTAL_DCC
 488   { "dcc_header",          vtype_stringptr,   &dcc_header },
 489   { "dcc_result",          vtype_stringptr,   &dcc_result },
 490 #endif
 491 #ifndef DISABLE_DKIM
 492   { "dkim_algo",           vtype_dkim,        (void *)DKIM_ALGO },
 493   { "dkim_bodylength",     vtype_dkim,        (void *)DKIM_BODYLENGTH },
 494   { "dkim_canon_body",     vtype_dkim,        (void *)DKIM_CANON_BODY },
 495   { "dkim_canon_headers",  vtype_dkim,        (void *)DKIM_CANON_HEADERS },
 496   { "dkim_copiedheaders",  vtype_dkim,        (void *)DKIM_COPIEDHEADERS },
 497   { "dkim_created",        vtype_dkim,        (void *)DKIM_CREATED },
 498   { "dkim_cur_signer",     vtype_stringptr,   &dkim_cur_signer },
 499   { "dkim_domain",         vtype_stringptr,   &dkim_signing_domain },
 500   { "dkim_expires",        vtype_dkim,        (void *)DKIM_EXPIRES },
 501   { "dkim_headernames",    vtype_dkim,        (void *)DKIM_HEADERNAMES },
 502   { "dkim_identity",       vtype_dkim,        (void *)DKIM_IDENTITY },
 503   { "dkim_key_granularity",vtype_dkim,        (void *)DKIM_KEY_GRANULARITY },
 504   { "dkim_key_length",     vtype_int,         &dkim_key_length },
 505   { "dkim_key_nosubdomains",vtype_dkim,       (void *)DKIM_NOSUBDOMAINS },
 506   { "dkim_key_notes",      vtype_dkim,        (void *)DKIM_KEY_NOTES },
 507   { "dkim_key_srvtype",    vtype_dkim,        (void *)DKIM_KEY_SRVTYPE },
 508   { "dkim_key_testing",    vtype_dkim,        (void *)DKIM_KEY_TESTING },
 509   { "dkim_selector",       vtype_stringptr,   &dkim_signing_selector },
 510   { "dkim_signers",        vtype_stringptr,   &dkim_signers },
 511   { "dkim_verify_reason",  vtype_dkim,        (void *)DKIM_VERIFY_REASON },
 512   { "dkim_verify_status",  vtype_dkim,        (void *)DKIM_VERIFY_STATUS},
 513 #endif
 514 #ifdef EXPERIMENTAL_DMARC
 515   { "dmarc_ar_header",     vtype_stringptr,   &dmarc_ar_header },
 516   { "dmarc_domain_policy", vtype_stringptr,   &dmarc_domain_policy },
 517   { "dmarc_status",        vtype_stringptr,   &dmarc_status },
 518   { "dmarc_status_text",   vtype_stringptr,   &dmarc_status_text },
 519   { "dmarc_used_domain",   vtype_stringptr,   &dmarc_used_domain },
 520 #endif
 521   { "dnslist_domain",      vtype_stringptr,   &dnslist_domain },
 522   { "dnslist_matched",     vtype_stringptr,   &dnslist_matched },
 523   { "dnslist_text",        vtype_stringptr,   &dnslist_text },
 524   { "dnslist_value",       vtype_stringptr,   &dnslist_value },
 525   { "domain",              vtype_stringptr,   &deliver_domain },
 526   { "domain_data",         vtype_stringptr,   &deliver_domain_data },
 527 #ifndef DISABLE_EVENT
 528   { "event_data",          vtype_stringptr,   &event_data },
 529
 530   /*XXX want to use generic vars for as many of these as possible*/
 531   { "event_defer_errno",   vtype_int,         &event_defer_errno },
 532
 533   { "event_name",          vtype_stringptr,   &event_name },
 534 #endif
 535   { "exim_gid",            vtype_gid,         &exim_gid },
 536   { "exim_path",           vtype_stringptr,   &exim_path },
 537   { "exim_uid",            vtype_uid,         &exim_uid },
 538   { "exim_version",        vtype_stringptr,   &version_string },
 539   { "headers_added",       vtype_string_func, &fn_hdrs_added },
 540   { "home",                vtype_stringptr,   &deliver_home },
 541   { "host",                vtype_stringptr,   &deliver_host },
 542   { "host_address",        vtype_stringptr,   &deliver_host_address },
 543   { "host_data",           vtype_stringptr,   &host_data },
 544   { "host_lookup_deferred",vtype_int,         &host_lookup_deferred },
 545   { "host_lookup_failed",  vtype_int,         &host_lookup_failed },
 546   { "host_port",           vtype_int,         &deliver_host_port },
 547   { "initial_cwd",         vtype_stringptr,   &initial_cwd },
 548   { "inode",               vtype_ino,         &deliver_inode },
 549   { "interface_address",   vtype_stringptr,   &interface_address },
 550   { "interface_port",      vtype_int,         &interface_port },
 551   { "item",                vtype_stringptr,   &iterate_item },
 552   #ifdef LOOKUP_LDAP
 553   { "ldap_dn",             vtype_stringptr,   &eldap_dn },
 554   #endif
 555   { "load_average",        vtype_load_avg,    NULL },
 556   { "local_part",          vtype_stringptr,   &deliver_localpart },
 557   { "local_part_data",     vtype_stringptr,   &deliver_localpart_data },
 558   { "local_part_prefix",   vtype_stringptr,   &deliver_localpart_prefix },
 559   { "local_part_suffix",   vtype_stringptr,   &deliver_localpart_suffix },
 560   { "local_scan_data",     vtype_stringptr,   &local_scan_data },
 561   { "local_user_gid",      vtype_gid,         &local_user_gid },
 562   { "local_user_uid",      vtype_uid,         &local_user_uid },
 563   { "localhost_number",    vtype_int,         &host_number },
 564   { "log_inodes",          vtype_pinodes,     (void *)FALSE },
 565   { "log_space",           vtype_pspace,      (void *)FALSE },
 566   { "lookup_dnssec_authenticated",vtype_stringptr,&lookup_dnssec_authenticated},
 567   { "mailstore_basename",  vtype_stringptr,   &mailstore_basename },
 568 #ifdef WITH_CONTENT_SCAN
 569   { "malware_name",        vtype_stringptr,   &malware_name },
 570 #endif
 571   { "max_received_linelength", vtype_int,     &max_received_linelength },
 572   { "message_age",         vtype_int,         &message_age },
 573   { "message_body",        vtype_msgbody,     &message_body },
 574   { "message_body_end",    vtype_msgbody_end, &message_body_end },
 575   { "message_body_size",   vtype_int,         &message_body_size },
 576   { "message_exim_id",     vtype_stringptr,   &message_id },
 577   { "message_headers",     vtype_msgheaders,  NULL },
 578   { "message_headers_raw", vtype_msgheaders_raw, NULL },
 579   { "message_id",          vtype_stringptr,   &message_id },
 580   { "message_linecount",   vtype_int,         &message_linecount },
 581   { "message_size",        vtype_int,         &message_size },
 582 #ifdef SUPPORT_I18N
 583   { "message_smtputf8",    vtype_bool,        &message_smtputf8 },
 584 #endif
 585 #ifdef WITH_CONTENT_SCAN
 586   { "mime_anomaly_level",  vtype_int,         &mime_anomaly_level },
 587   { "mime_anomaly_text",   vtype_stringptr,   &mime_anomaly_text },
 588   { "mime_boundary",       vtype_stringptr,   &mime_boundary },
 589   { "mime_charset",        vtype_stringptr,   &mime_charset },
 590   { "mime_content_description", vtype_stringptr, &mime_content_description },
 591   { "mime_content_disposition", vtype_stringptr, &mime_content_disposition },
 592   { "mime_content_id",     vtype_stringptr,   &mime_content_id },
 593   { "mime_content_size",   vtype_int,         &mime_content_size },
 594   { "mime_content_transfer_encoding",vtype_stringptr, &mime_content_transfer_encoding },
 595   { "mime_content_type",   vtype_stringptr,   &mime_content_type },
 596   { "mime_decoded_filename", vtype_stringptr, &mime_decoded_filename },
 597   { "mime_filename",       vtype_stringptr,   &mime_filename },
 598   { "mime_is_coverletter", vtype_int,         &mime_is_coverletter },
 599   { "mime_is_multipart",   vtype_int,         &mime_is_multipart },
 600   { "mime_is_rfc822",      vtype_int,         &mime_is_rfc822 },
 601   { "mime_part_count",     vtype_int,         &mime_part_count },
 602 #endif
 603   { "n0",                  vtype_filter_int,  &filter_n[0] },
 604   { "n1",                  vtype_filter_int,  &filter_n[1] },
 605   { "n2",                  vtype_filter_int,  &filter_n[2] },
 606   { "n3",                  vtype_filter_int,  &filter_n[3] },
 607   { "n4",                  vtype_filter_int,  &filter_n[4] },
 608   { "n5",                  vtype_filter_int,  &filter_n[5] },
 609   { "n6",                  vtype_filter_int,  &filter_n[6] },
 610   { "n7",                  vtype_filter_int,  &filter_n[7] },
 611   { "n8",                  vtype_filter_int,  &filter_n[8] },
 612   { "n9",                  vtype_filter_int,  &filter_n[9] },
 613   { "original_domain",     vtype_stringptr,   &deliver_domain_orig },
 614   { "original_local_part", vtype_stringptr,   &deliver_localpart_orig },
 615   { "originator_gid",      vtype_gid,         &originator_gid },
 616   { "originator_uid",      vtype_uid,         &originator_uid },
 617   { "parent_domain",       vtype_stringptr,   &deliver_domain_parent },
 618   { "parent_local_part",   vtype_stringptr,   &deliver_localpart_parent },
 619   { "pid",                 vtype_pid,         NULL },
 620 #ifndef DISABLE_PRDR
 621   { "prdr_requested",      vtype_bool,        &prdr_requested },
 622 #endif
 623   { "primary_hostname",    vtype_stringptr,   &primary_hostname },
 624 #if defined(SUPPORT_PROXY) || defined(SUPPORT_SOCKS)
 625   { "proxy_external_address",vtype_stringptr, &proxy_external_address },
 626   { "proxy_external_port", vtype_int,         &proxy_external_port },
 627   { "proxy_local_address", vtype_stringptr,   &proxy_local_address },
 628   { "proxy_local_port",    vtype_int,         &proxy_local_port },
 629   { "proxy_session",       vtype_bool,        &proxy_session },
 630 #endif
 631   { "prvscheck_address",   vtype_stringptr,   &prvscheck_address },
 632   { "prvscheck_keynum",    vtype_stringptr,   &prvscheck_keynum },
 633   { "prvscheck_result",    vtype_stringptr,   &prvscheck_result },
 634   { "qualify_domain",      vtype_stringptr,   &qualify_domain_sender },
 635   { "qualify_recipient",   vtype_stringptr,   &qualify_domain_recipient },
 636   { "queue_name",          vtype_stringptr,   &queue_name },
 637   { "rcpt_count",          vtype_int,         &rcpt_count },
 638   { "rcpt_defer_count",    vtype_int,         &rcpt_defer_count },
 639   { "rcpt_fail_count",     vtype_int,         &rcpt_fail_count },
 640   { "received_count",      vtype_int,         &received_count },
 641   { "received_for",        vtype_stringptr,   &received_for },
 642   { "received_ip_address", vtype_stringptr,   &interface_address },
 643   { "received_port",       vtype_int,         &interface_port },
 644   { "received_protocol",   vtype_stringptr,   &received_protocol },
 645   { "received_time",       vtype_int,         &received_time.tv_sec },
 646   { "recipient_data",      vtype_stringptr,   &recipient_data },
 647   { "recipient_verify_failure",vtype_stringptr,&recipient_verify_failure },
 648   { "recipients",          vtype_string_func, &fn_recipients },
 649   { "recipients_count",    vtype_int,         &recipients_count },
 650 #ifdef WITH_CONTENT_SCAN
 651   { "regex_match_string",  vtype_stringptr,   &regex_match_string },
 652 #endif
 653   { "reply_address",       vtype_reply,       NULL },
 654   { "return_path",         vtype_stringptr,   &return_path },
 655   { "return_size_limit",   vtype_int,         &bounce_return_size_limit },
 656   { "router_name",         vtype_stringptr,   &router_name },
 657   { "runrc",               vtype_int,         &runrc },
 658   { "self_hostname",       vtype_stringptr,   &self_hostname },
 659   { "sender_address",      vtype_stringptr,   &sender_address },
 660   { "sender_address_data", vtype_stringptr,   &sender_address_data },
 661   { "sender_address_domain", vtype_domain,    &sender_address },
 662   { "sender_address_local_part", vtype_localpart, &sender_address },
 663   { "sender_data",         vtype_stringptr,   &sender_data },
 664   { "sender_fullhost",     vtype_stringptr,   &sender_fullhost },
 665   { "sender_helo_dnssec",  vtype_bool,        &sender_helo_dnssec },
 666   { "sender_helo_name",    vtype_stringptr,   &sender_helo_name },
 667   { "sender_host_address", vtype_stringptr,   &sender_host_address },
 668   { "sender_host_authenticated",vtype_stringptr, &sender_host_authenticated },
 669   { "sender_host_dnssec",  vtype_bool,        &sender_host_dnssec },
 670   { "sender_host_name",    vtype_host_lookup, NULL },
 671   { "sender_host_port",    vtype_int,         &sender_host_port },
 672   { "sender_ident",        vtype_stringptr,   &sender_ident },
 673   { "sender_rate",         vtype_stringptr,   &sender_rate },
 674   { "sender_rate_limit",   vtype_stringptr,   &sender_rate_limit },
 675   { "sender_rate_period",  vtype_stringptr,   &sender_rate_period },
 676   { "sender_rcvhost",      vtype_stringptr,   &sender_rcvhost },
 677   { "sender_verify_failure",vtype_stringptr,  &sender_verify_failure },
 678   { "sending_ip_address",  vtype_stringptr,   &sending_ip_address },
 679   { "sending_port",        vtype_int,         &sending_port },
 680   { "smtp_active_hostname", vtype_stringptr,  &smtp_active_hostname },
 681   { "smtp_command",        vtype_stringptr,   &smtp_cmd_buffer },
 682   { "smtp_command_argument", vtype_stringptr, &smtp_cmd_argument },
 683   { "smtp_command_history", vtype_string_func, &smtp_cmd_hist },
 684   { "smtp_count_at_connection_start", vtype_int, &smtp_accept_count },
 685   { "smtp_notquit_reason", vtype_stringptr,   &smtp_notquit_reason },
 686   { "sn0",                 vtype_filter_int,  &filter_sn[0] },
 687   { "sn1",                 vtype_filter_int,  &filter_sn[1] },
 688   { "sn2",                 vtype_filter_int,  &filter_sn[2] },
 689   { "sn3",                 vtype_filter_int,  &filter_sn[3] },
 690   { "sn4",                 vtype_filter_int,  &filter_sn[4] },
 691   { "sn5",                 vtype_filter_int,  &filter_sn[5] },
 692   { "sn6",                 vtype_filter_int,  &filter_sn[6] },
 693   { "sn7",                 vtype_filter_int,  &filter_sn[7] },
 694   { "sn8",                 vtype_filter_int,  &filter_sn[8] },
 695   { "sn9",                 vtype_filter_int,  &filter_sn[9] },
 696 #ifdef WITH_CONTENT_SCAN
 697   { "spam_action",         vtype_stringptr,   &spam_action },
 698   { "spam_bar",            vtype_stringptr,   &spam_bar },
 699   { "spam_report",         vtype_stringptr,   &spam_report },
 700   { "spam_score",          vtype_stringptr,   &spam_score },
 701   { "spam_score_int",      vtype_stringptr,   &spam_score_int },
 702 #endif
 703 #ifdef EXPERIMENTAL_SPF
 704   { "spf_guess",           vtype_stringptr,   &spf_guess },
 705   { "spf_header_comment",  vtype_stringptr,   &spf_header_comment },
 706   { "spf_received",        vtype_stringptr,   &spf_received },
 707   { "spf_result",          vtype_stringptr,   &spf_result },
 708   { "spf_smtp_comment",    vtype_stringptr,   &spf_smtp_comment },
 709 #endif
 710   { "spool_directory",     vtype_stringptr,   &spool_directory },
 711   { "spool_inodes",        vtype_pinodes,     (void *)TRUE },
 712   { "spool_space",         vtype_pspace,      (void *)TRUE },
 713 #ifdef EXPERIMENTAL_SRS
 714   { "srs_db_address",      vtype_stringptr,   &srs_db_address },
 715   { "srs_db_key",          vtype_stringptr,   &srs_db_key },
 716   { "srs_orig_recipient",  vtype_stringptr,   &srs_orig_recipient },
 717   { "srs_orig_sender",     vtype_stringptr,   &srs_orig_sender },
 718   { "srs_recipient",       vtype_stringptr,   &srs_recipient },
 719   { "srs_status",          vtype_stringptr,   &srs_status },
 720 #endif
 721   { "thisaddress",         vtype_stringptr,   &filter_thisaddress },
 722
 723   /* The non-(in,out) variables are now deprecated */
 724   { "tls_bits",            vtype_int,         &tls_in.bits },
 725   { "tls_certificate_verified", vtype_int,    &tls_in.certificate_verified },
 726   { "tls_cipher",          vtype_stringptr,   &tls_in.cipher },
 727
 728   { "tls_in_bits",         vtype_int,         &tls_in.bits },
 729   { "tls_in_certificate_verified", vtype_int, &tls_in.certificate_verified },
 730   { "tls_in_cipher",       vtype_stringptr,   &tls_in.cipher },
 731   { "tls_in_ocsp",         vtype_int,         &tls_in.ocsp },
 732   { "tls_in_ourcert",      vtype_cert,        &tls_in.ourcert },
 733   { "tls_in_peercert",     vtype_cert,        &tls_in.peercert },
 734   { "tls_in_peerdn",       vtype_stringptr,   &tls_in.peerdn },
 735 #if defined(SUPPORT_TLS)
 736   { "tls_in_sni",          vtype_stringptr,   &tls_in.sni },
 737 #endif
 738   { "tls_out_bits",        vtype_int,         &tls_out.bits },
 739   { "tls_out_certificate_verified", vtype_int,&tls_out.certificate_verified },
 740   { "tls_out_cipher",      vtype_stringptr,   &tls_out.cipher },
 741 #ifdef EXPERIMENTAL_DANE
 742   { "tls_out_dane",        vtype_bool,        &tls_out.dane_verified },
 743 #endif
 744   { "tls_out_ocsp",        vtype_int,         &tls_out.ocsp },
 745   { "tls_out_ourcert",     vtype_cert,        &tls_out.ourcert },
 746   { "tls_out_peercert",    vtype_cert,        &tls_out.peercert },
 747   { "tls_out_peerdn",      vtype_stringptr,   &tls_out.peerdn },
 748 #if defined(SUPPORT_TLS)
 749   { "tls_out_sni",         vtype_stringptr,   &tls_out.sni },
 750 #endif
 751 #ifdef EXPERIMENTAL_DANE
 752   { "tls_out_tlsa_usage",  vtype_int,         &tls_out.tlsa_usage },
 753 #endif
 754
 755   { "tls_peerdn",          vtype_stringptr,   &tls_in.peerdn }, /* mind the alphabetical order! */
 756 #if defined(SUPPORT_TLS)
 757   { "tls_sni",             vtype_stringptr,   &tls_in.sni },    /* mind the alphabetical order! */
 758 #endif
 759
 760   { "tod_bsdinbox",        vtype_todbsdin,    NULL },
 761   { "tod_epoch",           vtype_tode,        NULL },
 762   { "tod_epoch_l",         vtype_todel,       NULL },
 763   { "tod_full",            vtype_todf,        NULL },
 764   { "tod_log",             vtype_todl,        NULL },
 765   { "tod_logfile",         vtype_todlf,       NULL },
 766   { "tod_zone",            vtype_todzone,     NULL },
 767   { "tod_zulu",            vtype_todzulu,     NULL },
 768   { "transport_name",      vtype_stringptr,   &transport_name },
 769   { "value",               vtype_stringptr,   &lookup_value },
 770   { "verify_mode",         vtype_stringptr,   &verify_mode },
 771   { "version_number",      vtype_stringptr,   &version_string },
 772   { "warn_message_delay",  vtype_stringptr,   &warnmsg_delay },
 773   { "warn_message_recipient",vtype_stringptr, &warnmsg_recipients },
 774   { "warn_message_recipients",vtype_stringptr,&warnmsg_recipients },
 775   { "warnmsg_delay",       vtype_stringptr,   &warnmsg_delay },
 776   { "warnmsg_recipient",   vtype_stringptr,   &warnmsg_recipients },
 777   { "warnmsg_recipients",  vtype_stringptr,   &warnmsg_recipients }
 778 };
 779
 780 static int var_table_size = nelem(var_table);
 781 static uschar var_buffer[256];
 782 static BOOL malformed_header;
 783
 784 /* For textual hashes */
 785
 786 static const char *hashcodes = "abcdefghijklmnopqrtsuvwxyz"
 787                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 788                                "0123456789";
 789
 790 enum { HMAC_MD5, HMAC_SHA1 };
 791
 792 /* For numeric hashes */
 793
 794 static unsigned int prime[] = {
 795   2,   3,   5,   7,  11,  13,  17,  19,  23,  29,
 796  31,  37,  41,  43,  47,  53,  59,  61,  67,  71,
 797  73,  79,  83,  89,  97, 101, 103, 107, 109, 113};
 798
 799 /* For printing modes in symbolic form */
 800
 801 static uschar *mtable_normal[] =
 802   { US"---", US"--x", US"-w-", US"-wx", US"r--", US"r-x", US"rw-", US"rwx" };
 803
 804 static uschar *mtable_setid[] =
 805   { US"--S", US"--s", US"-wS", US"-ws", US"r-S", US"r-s", US"rwS", US"rws" };
 806
 807 static uschar *mtable_sticky[] =
 808   { US"--T", US"--t", US"-wT", US"-wt", US"r-T", US"r-t", US"rwT", US"rwt" };
 809
 810
 811
 812 /*************************************************
 813 *           Tables for UTF-8 support             *
 814 *************************************************/
 815
 816 /* Table of the number of extra characters, indexed by the first character
 817 masked with 0x3f. The highest number for a valid UTF-8 character is in fact
 818 0x3d. */
 819
 820 static uschar utf8_table1[] = {
 821   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 822   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
 823   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
 824   3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 };
 825
 826 /* These are the masks for the data bits in the first byte of a character,
 827 indexed by the number of additional bytes. */
 828
 829 static int utf8_table2[] = { 0xff, 0x1f, 0x0f, 0x07, 0x03, 0x01};
 830
 831 /* Get the next UTF-8 character, advancing the pointer. */
 832
 833 #define GETUTF8INC(c, ptr) \
 834   c = *ptr++; \
 835   if ((c & 0xc0) == 0xc0) \
 836     { \
 837     int a = utf8_table1[c & 0x3f];  /* Number of additional bytes */ \
 838     int s = 6*a; \
 839     c = (c & utf8_table2[a]) << s; \
 840     while (a-- > 0) \
 841       { \
 842       s -= 6; \
 843       c |= (*ptr++ & 0x3f) << s; \
 844       } \
 845     }
 846
 847
 848
 849 static uschar * base32_chars = US"abcdefghijklmnopqrstuvwxyz234567";
 850
 851 /*************************************************
 852 *           Binary chop search on a table        *
 853 *************************************************/
 854
 855 /* This is used for matching expansion items and operators.
 856
 857 Arguments:
 858   name        the name that is being sought
 859   table       the table to search
 860   table_size  the number of items in the table
 861
 862 Returns:      the offset in the table, or -1
 863 */
 864
 865 static int
 866 chop_match(uschar *name, uschar **table, int table_size)
 867 {
 868 uschar **bot = table;
 869 uschar **top = table + table_size;
 870
 871 while (top > bot)
 872   {
 873   uschar **mid = bot + (top - bot)/2;
 874   int c = Ustrcmp(name, *mid);
 875   if (c == 0) return mid - table;
 876   if (c > 0) bot = mid + 1; else top = mid;
 877   }
 878
 879 return -1;
 880 }
 881
 882
 883
 884 /*************************************************
 885 *          Check a condition string              *
 886 *************************************************/
 887
 888 /* This function is called to expand a string, and test the result for a "true"
 889 or "false" value. Failure of the expansion yields FALSE; logged unless it was a
 890 forced fail or lookup defer.
 891
 892 We used to release all store used, but this is not not safe due
 893 to ${dlfunc } and ${acl }.  In any case expand_string_internal()
 894 is reasonably careful to release what it can.
 895
 896 The actual false-value tests should be replicated for ECOND_BOOL_LAX.
 897
 898 Arguments:
 899   condition     the condition string
 900   m1            text to be incorporated in panic error
 901   m2            ditto
 902
 903 Returns:        TRUE if condition is met, FALSE if not
 904 */
 905
 906 BOOL
 907 expand_check_condition(uschar *condition, uschar *m1, uschar *m2)
 908 {
 909 int rc;
 910 uschar *ss = expand_string(condition);
 911 if (ss == NULL)
 912   {
 913   if (!expand_string_forcedfail && !search_find_defer)
 914     log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand condition \"%s\" "
 915       "for %s %s: %s", condition, m1, m2, expand_string_message);
 916   return FALSE;
 917   }
 918 rc = ss[0] != 0 && Ustrcmp(ss, "0") != 0 && strcmpic(ss, US"no") != 0 &&
 919   strcmpic(ss, US"false") != 0;
 920 return rc;
 921 }
 922
 923
 924
 925
 926 /*************************************************
 927 *        Pseudo-random number generation         *
 928 *************************************************/
 929
 930 /* Pseudo-random number generation.  The result is not "expected" to be
 931 cryptographically strong but not so weak that someone will shoot themselves
 932 in the foot using it as a nonce in some email header scheme or whatever
 933 weirdness they'll twist this into.  The result should ideally handle fork().
 934
 935 However, if we're stuck unable to provide this, then we'll fall back to
 936 appallingly bad randomness.
 937
 938 If SUPPORT_TLS is defined then this will not be used except as an emergency
 939 fallback.
 940
 941 Arguments:
 942   max       range maximum
 943 Returns     a random number in range [0, max-1]
 944 */
 945
 946 #ifdef SUPPORT_TLS
 947 # define vaguely_random_number vaguely_random_number_fallback
 948 #endif
 949 int
 950 vaguely_random_number(int max)
 951 {
 952 #ifdef SUPPORT_TLS
 953 # undef vaguely_random_number
 954 #endif
 955   static pid_t pid = 0;
 956   pid_t p2;
 957 #if defined(HAVE_SRANDOM) && !defined(HAVE_SRANDOMDEV)
 958   struct timeval tv;
 959 #endif
 960
 961   p2 = getpid();
 962   if (p2 != pid)
 963     {
 964     if (pid != 0)
 965       {
 966
 967 #ifdef HAVE_ARC4RANDOM
 968       /* cryptographically strong randomness, common on *BSD platforms, not
 969       so much elsewhere.  Alas. */
 970 #ifndef NOT_HAVE_ARC4RANDOM_STIR
 971       arc4random_stir();
 972 #endif
 973 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 974 #ifdef HAVE_SRANDOMDEV
 975       /* uses random(4) for seeding */
 976       srandomdev();
 977 #else
 978       gettimeofday(&tv, NULL);
 979       srandom(tv.tv_sec | tv.tv_usec | getpid());
 980 #endif
 981 #else
 982       /* Poor randomness and no seeding here */
 983 #endif
 984
 985       }
 986     pid = p2;
 987     }
 988
 989 #ifdef HAVE_ARC4RANDOM
 990   return arc4random() % max;
 991 #elif defined(HAVE_SRANDOM) || defined(HAVE_SRANDOMDEV)
 992   return random() % max;
 993 #else
 994   /* This one returns a 16-bit number, definitely not crypto-strong */
 995   return random_number(max);
 996 #endif
 997 }
 998
 999
1000
1001
1002 /*************************************************
1003 *             Pick out a name from a string      *
1004 *************************************************/
1005
1006 /* If the name is too long, it is silently truncated.
1007
1008 Arguments:
1009   name      points to a buffer into which to put the name
1010   max       is the length of the buffer
1011   s         points to the first alphabetic character of the name
1012   extras    chars other than alphanumerics to permit
1013
1014 Returns:    pointer to the first character after the name
1015
1016 Note: The test for *s != 0 in the while loop is necessary because
1017 Ustrchr() yields non-NULL if the character is zero (which is not something
1018 I expected). */
1019
1020 static const uschar *
1021 read_name(uschar *name, int max, const uschar *s, uschar *extras)
1022 {
1023 int ptr = 0;
1024 while (*s != 0 && (isalnum(*s) || Ustrchr(extras, *s) != NULL))
1025   {
1026   if (ptr < max-1) name[ptr++] = *s;
1027   s++;
1028   }
1029 name[ptr] = 0;
1030 return s;
1031 }
1032
1033
1034
1035 /*************************************************
1036 *     Pick out the rest of a header name         *
1037 *************************************************/
1038
1039 /* A variable name starting $header_ (or just $h_ for those who like
1040 abbreviations) might not be the complete header name because headers can
1041 contain any printing characters in their names, except ':'. This function is
1042 called to read the rest of the name, chop h[eader]_ off the front, and put ':'
1043 on the end, if the name was terminated by white space.
1044
1045 Arguments:
1046   name      points to a buffer in which the name read so far exists
1047   max       is the length of the buffer
1048   s         points to the first character after the name so far, i.e. the
1049             first non-alphameric character after $header_xxxxx
1050
1051 Returns:    a pointer to the first character after the header name
1052 */
1053
1054 static const uschar *
1055 read_header_name(uschar *name, int max, const uschar *s)
1056 {
1057 int prelen = Ustrchr(name, '_') - name + 1;
1058 int ptr = Ustrlen(name) - prelen;
1059 if (ptr > 0) memmove(name, name+prelen, ptr);
1060 while (mac_isgraph(*s) && *s != ':')
1061   {
1062   if (ptr < max-1) name[ptr++] = *s;
1063   s++;
1064   }
1065 if (*s == ':') s++;
1066 name[ptr++] = ':';
1067 name[ptr] = 0;
1068 return s;
1069 }
1070
1071
1072
1073 /*************************************************
1074 *           Pick out a number from a string      *
1075 *************************************************/
1076
1077 /* Arguments:
1078   n     points to an integer into which to put the number
1079   s     points to the first digit of the number
1080
1081 Returns:  a pointer to the character after the last digit
1082 */
1083 /*XXX consider expanding to int_eximarith_t.  But the test for
1084 "overbig numbers" in 0002 still needs to overflow it. */
1085
1086 static uschar *
1087 read_number(int *n, uschar *s)
1088 {
1089 *n = 0;
1090 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1091 return s;
1092 }
1093
1094 static const uschar *
1095 read_cnumber(int *n, const uschar *s)
1096 {
1097 *n = 0;
1098 while (isdigit(*s)) *n = *n * 10 + (*s++ - '0');
1099 return s;
1100 }
1101
1102
1103
1104 /*************************************************
1105 *        Extract keyed subfield from a string    *
1106 *************************************************/
1107
1108 /* The yield is in dynamic store; NULL means that the key was not found.
1109
1110 Arguments:
1111   key       points to the name of the key
1112   s         points to the string from which to extract the subfield
1113
1114 Returns:    NULL if the subfield was not found, or
1115             a pointer to the subfield's data
1116 */
1117
1118 static uschar *
1119 expand_getkeyed(uschar *key, const uschar *s)
1120 {
1121 int length = Ustrlen(key);
1122 while (isspace(*s)) s++;
1123
1124 /* Loop to search for the key */
1125
1126 while (*s != 0)
1127   {
1128   int dkeylength;
1129   uschar *data;
1130   const uschar *dkey = s;
1131
1132   while (*s != 0 && *s != '=' && !isspace(*s)) s++;
1133   dkeylength = s - dkey;
1134   while (isspace(*s)) s++;
1135   if (*s == '=') while (isspace((*(++s))));
1136
1137   data = string_dequote(&s);
1138   if (length == dkeylength && strncmpic(key, dkey, length) == 0)
1139     return data;
1140
1141   while (isspace(*s)) s++;
1142   }
1143
1144 return NULL;
1145 }
1146
1147
1148
1149 static var_entry *
1150 find_var_ent(uschar * name)
1151 {
1152 int first = 0;
1153 int last = var_table_size;
1154
1155 while (last > first)
1156   {
1157   int middle = (first + last)/2;
1158   int c = Ustrcmp(name, var_table[middle].name);
1159
1160   if (c > 0) { first = middle + 1; continue; }
1161   if (c < 0) { last = middle; continue; }
1162   return &var_table[middle];
1163   }
1164 return NULL;
1165 }
1166
1167 /*************************************************
1168 *   Extract numbered subfield from string        *
1169 *************************************************/
1170
1171 /* Extracts a numbered field from a string that is divided by tokens - for
1172 example a line from /etc/passwd is divided by colon characters.  First field is
1173 numbered one.  Negative arguments count from the right. Zero returns the whole
1174 string. Returns NULL if there are insufficient tokens in the string
1175
1176 ***WARNING***
1177 Modifies final argument - this is a dynamically generated string, so that's OK.
1178
1179 Arguments:
1180   field       number of field to be extracted,
1181                 first field = 1, whole string = 0, last field = -1
1182   separators  characters that are used to break string into tokens
1183   s           points to the string from which to extract the subfield
1184
1185 Returns:      NULL if the field was not found,
1186               a pointer to the field's data inside s (modified to add 0)
1187 */
1188
1189 static uschar *
1190 expand_gettokened (int field, uschar *separators, uschar *s)
1191 {
1192 int sep = 1;
1193 int count;
1194 uschar *ss = s;
1195 uschar *fieldtext = NULL;
1196
1197 if (field == 0) return s;
1198
1199 /* Break the line up into fields in place; for field > 0 we stop when we have
1200 done the number of fields we want. For field < 0 we continue till the end of
1201 the string, counting the number of fields. */
1202
1203 count = (field > 0)? field : INT_MAX;
1204
1205 while (count-- > 0)
1206   {
1207   size_t len;
1208
1209   /* Previous field was the last one in the string. For a positive field
1210   number, this means there are not enough fields. For a negative field number,
1211   check that there are enough, and scan back to find the one that is wanted. */
1212
1213   if (sep == 0)
1214     {
1215     if (field > 0 || (-field) > (INT_MAX - count - 1)) return NULL;
1216     if ((-field) == (INT_MAX - count - 1)) return s;
1217     while (field++ < 0)
1218       {
1219       ss--;
1220       while (ss[-1] != 0) ss--;
1221       }
1222     fieldtext = ss;
1223     break;
1224     }
1225
1226   /* Previous field was not last in the string; save its start and put a
1227   zero at its end. */
1228
1229   fieldtext = ss;
1230   len = Ustrcspn(ss, separators);
1231   sep = ss[len];
1232   ss[len] = 0;
1233   ss += len + 1;
1234   }
1235
1236 return fieldtext;
1237 }
1238
1239
1240 static uschar *
1241 expand_getlistele(int field, const uschar * list)
1242 {
1243 const uschar * tlist= list;
1244 int sep= 0;
1245 uschar dummy;
1246
1247 if(field<0)
1248   {
1249   for(field++; string_nextinlist(&tlist, &sep, &dummy, 1); ) field++;
1250   sep= 0;
1251   }
1252 if(field==0) return NULL;
1253 while(--field>0 && (string_nextinlist(&list, &sep, &dummy, 1))) ;
1254 return string_nextinlist(&list, &sep, NULL, 0);
1255 }
1256
1257
1258 /* Certificate fields, by name.  Worry about by-OID later */
1259 /* Names are chosen to not have common prefixes */
1260
1261 #ifdef SUPPORT_TLS
1262 typedef struct
1263 {
1264 uschar * name;
1265 int      namelen;
1266 uschar * (*getfn)(void * cert, uschar * mod);
1267 } certfield;
1268 static certfield certfields[] =
1269 {                       /* linear search; no special order */
1270   { US"version",         7,  &tls_cert_version },
1271   { US"serial_number",   13, &tls_cert_serial_number },
1272   { US"subject",         7,  &tls_cert_subject },
1273   { US"notbefore",       9,  &tls_cert_not_before },
1274   { US"notafter",        8,  &tls_cert_not_after },
1275   { US"issuer",          6,  &tls_cert_issuer },
1276   { US"signature",       9,  &tls_cert_signature },
1277   { US"sig_algorithm",   13, &tls_cert_signature_algorithm },
1278   { US"subj_altname",    12, &tls_cert_subject_altname },
1279   { US"ocsp_uri",        8,  &tls_cert_ocsp_uri },
1280   { US"crl_uri",         7,  &tls_cert_crl_uri },
1281 };
1282
1283 static uschar *
1284 expand_getcertele(uschar * field, uschar * certvar)
1285 {
1286 var_entry * vp;
1287 certfield * cp;
1288
1289 if (!(vp = find_var_ent(certvar)))
1290   {
1291   expand_string_message =
1292     string_sprintf("no variable named \"%s\"", certvar);
1293   return NULL;          /* Unknown variable name */
1294   }
1295 /* NB this stops us passing certs around in variable.  Might
1296 want to do that in future */
1297 if (vp->type != vtype_cert)
1298   {
1299   expand_string_message =
1300     string_sprintf("\"%s\" is not a certificate", certvar);
1301   return NULL;          /* Unknown variable name */
1302   }
1303 if (!*(void **)vp->value)
1304   return NULL;
1305
1306 if (*field >= '0' && *field <= '9')
1307   return tls_cert_ext_by_oid(*(void **)vp->value, field, 0);
1308
1309 for(cp = certfields;
1310     cp < certfields + nelem(certfields);
1311     cp++)
1312   if (Ustrncmp(cp->name, field, cp->namelen) == 0)
1313     {
1314     uschar * modifier = *(field += cp->namelen) == ','
1315       ? ++field : NULL;
1316     return (*cp->getfn)( *(void **)vp->value, modifier );
1317     }
1318
1319 expand_string_message =
1320   string_sprintf("bad field selector \"%s\" for certextract", field);
1321 return NULL;
1322 }
1323 #endif  /*SUPPORT_TLS*/
1324
1325 /*************************************************
1326 *        Extract a substring from a string       *
1327 *************************************************/
1328
1329 /* Perform the ${substr or ${length expansion operations.
1330
1331 Arguments:
1332   subject     the input string
1333   value1      the offset from the start of the input string to the start of
1334                 the output string; if negative, count from the right.
1335   value2      the length of the output string, or negative (-1) for unset
1336                 if value1 is positive, unset means "all after"
1337                 if value1 is negative, unset means "all before"
1338   len         set to the length of the returned string
1339
1340 Returns:      pointer to the output string, or NULL if there is an error
1341 */
1342
1343 static uschar *
1344 extract_substr(uschar *subject, int value1, int value2, int *len)
1345 {
1346 int sublen = Ustrlen(subject);
1347
1348 if (value1 < 0)    /* count from right */
1349   {
1350   value1 += sublen;
1351
1352   /* If the position is before the start, skip to the start, and adjust the
1353   length. If the length ends up negative, the substring is null because nothing
1354   can precede. This falls out naturally when the length is unset, meaning "all
1355   to the left". */
1356
1357   if (value1 < 0)
1358     {
1359     value2 += value1;
1360     if (value2 < 0) value2 = 0;
1361     value1 = 0;
1362     }
1363
1364   /* Otherwise an unset length => characters before value1 */
1365
1366   else if (value2 < 0)
1367     {
1368     value2 = value1;
1369     value1 = 0;
1370     }
1371   }
1372
1373 /* For a non-negative offset, if the starting position is past the end of the
1374 string, the result will be the null string. Otherwise, an unset length means
1375 "rest"; just set it to the maximum - it will be cut down below if necessary. */
1376
1377 else
1378   {
1379   if (value1 > sublen)
1380     {
1381     value1 = sublen;
1382     value2 = 0;
1383     }
1384   else if (value2 < 0) value2 = sublen;
1385   }
1386
1387 /* Cut the length down to the maximum possible for the offset value, and get
1388 the required characters. */
1389
1390 if (value1 + value2 > sublen) value2 = sublen - value1;
1391 *len = value2;
1392 return subject + value1;
1393 }
1394
1395
1396
1397
1398 /*************************************************
1399 *            Old-style hash of a string          *
1400 *************************************************/
1401
1402 /* Perform the ${hash expansion operation.
1403
1404 Arguments:
1405   subject     the input string (an expanded substring)
1406   value1      the length of the output string; if greater or equal to the
1407                 length of the input string, the input string is returned
1408   value2      the number of hash characters to use, or 26 if negative
1409   len         set to the length of the returned string
1410
1411 Returns:      pointer to the output string, or NULL if there is an error
1412 */
1413
1414 static uschar *
1415 compute_hash(uschar *subject, int value1, int value2, int *len)
1416 {
1417 int sublen = Ustrlen(subject);
1418
1419 if (value2 < 0) value2 = 26;
1420 else if (value2 > Ustrlen(hashcodes))
1421   {
1422   expand_string_message =
1423     string_sprintf("hash count \"%d\" too big", value2);
1424   return NULL;
1425   }
1426
1427 /* Calculate the hash text. We know it is shorter than the original string, so
1428 can safely place it in subject[] (we know that subject is always itself an
1429 expanded substring). */
1430
1431 if (value1 < sublen)
1432   {
1433   int c;
1434   int i = 0;
1435   int j = value1;
1436   while ((c = (subject[j])) != 0)
1437     {
1438     int shift = (c + j++) & 7;
1439     subject[i] ^= (c << shift) | (c >> (8-shift));
1440     if (++i >= value1) i = 0;
1441     }
1442   for (i = 0; i < value1; i++)
1443     subject[i] = hashcodes[(subject[i]) % value2];
1444   }
1445 else value1 = sublen;
1446
1447 *len = value1;
1448 return subject;
1449 }
1450
1451
1452
1453
1454 /*************************************************
1455 *             Numeric hash of a string           *
1456 *************************************************/
1457
1458 /* Perform the ${nhash expansion operation. The first characters of the
1459 string are treated as most important, and get the highest prime numbers.
1460
1461 Arguments:
1462   subject     the input string
1463   value1      the maximum value of the first part of the result
1464   value2      the maximum value of the second part of the result,
1465                 or negative to produce only a one-part result
1466   len         set to the length of the returned string
1467
1468 Returns:  pointer to the output string, or NULL if there is an error.
1469 */
1470
1471 static uschar *
1472 compute_nhash (uschar *subject, int value1, int value2, int *len)
1473 {
1474 uschar *s = subject;
1475 int i = 0;
1476 unsigned long int total = 0; /* no overflow */
1477
1478 while (*s != 0)
1479   {
1480   if (i == 0) i = nelem(prime) - 1;
1481   total += prime[i--] * (unsigned int)(*s++);
1482   }
1483
1484 /* If value2 is unset, just compute one number */
1485
1486 if (value2 < 0)
1487   s = string_sprintf("%d", total % value1);
1488
1489 /* Otherwise do a div/mod hash */
1490
1491 else
1492   {
1493   total = total % (value1 * value2);
1494   s = string_sprintf("%d/%d", total/value2, total % value2);
1495   }
1496
1497 *len = Ustrlen(s);
1498 return s;
1499 }
1500
1501
1502
1503
1504
1505 /*************************************************
1506 *     Find the value of a header or headers      *
1507 *************************************************/
1508
1509 /* Multiple instances of the same header get concatenated, and this function
1510 can also return a concatenation of all the header lines. When concatenating
1511 specific headers that contain lists of addresses, a comma is inserted between
1512 them. Otherwise we use a straight concatenation. Because some messages can have
1513 pathologically large number of lines, there is a limit on the length that is
1514 returned. Also, to avoid massive store use which would result from using
1515 string_cat() as it copies and extends strings, we do a preliminary pass to find
1516 out exactly how much store will be needed. On "normal" messages this will be
1517 pretty trivial.
1518
1519 Arguments:
1520   name          the name of the header, without the leading $header_ or $h_,
1521                 or NULL if a concatenation of all headers is required
1522   exists_only   TRUE if called from a def: test; don't need to build a string;
1523                 just return a string that is not "" and not "0" if the header
1524                 exists
1525   newsize       return the size of memory block that was obtained; may be NULL
1526                 if exists_only is TRUE
1527   want_raw      TRUE if called for $rh_ or $rheader_ variables; no processing,
1528                 other than concatenating, will be done on the header. Also used
1529                 for $message_headers_raw.
1530   charset       name of charset to translate MIME words to; used only if
1531                 want_raw is false; if NULL, no translation is done (this is
1532                 used for $bh_ and $bheader_)
1533
1534 Returns:        NULL if the header does not exist, else a pointer to a new
1535                 store block
1536 */
1537
1538 static uschar *
1539 find_header(uschar *name, BOOL exists_only, int *newsize, BOOL want_raw,
1540   uschar *charset)
1541 {
1542 BOOL found = name == NULL;
1543 int comma = 0;
1544 int len = found? 0 : Ustrlen(name);
1545 int i;
1546 uschar *yield = NULL;
1547 uschar *ptr = NULL;
1548
1549 /* Loop for two passes - saves code repetition */
1550
1551 for (i = 0; i < 2; i++)
1552   {
1553   int size = 0;
1554   header_line *h;
1555
1556   for (h = header_list; size < header_insert_maxlen && h; h = h->next)
1557     if (h->type != htype_old && h->text)  /* NULL => Received: placeholder */
1558       if (!name || (len <= h->slen && strncmpic(name, h->text, len) == 0))
1559         {
1560         int ilen;
1561         uschar *t;
1562
1563         if (exists_only) return US"1";      /* don't need actual string */
1564         found = TRUE;
1565         t = h->text + len;                  /* text to insert */
1566         if (!want_raw)                      /* unless wanted raw, */
1567           while (isspace(*t)) t++;          /* remove leading white space */
1568         ilen = h->slen - (t - h->text);     /* length to insert */
1569
1570         /* Unless wanted raw, remove trailing whitespace, including the
1571         newline. */
1572
1573         if (!want_raw)
1574           while (ilen > 0 && isspace(t[ilen-1])) ilen--;
1575
1576         /* Set comma = 1 if handling a single header and it's one of those
1577         that contains an address list, except when asked for raw headers. Only
1578         need to do this once. */
1579
1580         if (!want_raw && name && comma == 0 &&
1581             Ustrchr("BCFRST", h->type) != NULL)
1582           comma = 1;
1583
1584         /* First pass - compute total store needed; second pass - compute
1585         total store used, including this header. */
1586
1587         size += ilen + comma + 1;  /* +1 for the newline */
1588
1589         /* Second pass - concatenate the data, up to a maximum. Note that
1590         the loop stops when size hits the limit. */
1591
1592         if (i != 0)
1593           {
1594           if (size > header_insert_maxlen)
1595             {
1596             ilen -= size - header_insert_maxlen - 1;
1597             comma = 0;
1598             }
1599           Ustrncpy(ptr, t, ilen);
1600           ptr += ilen;
1601
1602           /* For a non-raw header, put in the comma if needed, then add
1603           back the newline we removed above, provided there was some text in
1604           the header. */
1605
1606           if (!want_raw && ilen > 0)
1607             {
1608             if (comma != 0) *ptr++ = ',';
1609             *ptr++ = '\n';
1610             }
1611           }
1612         }
1613
1614   /* At end of first pass, return NULL if no header found. Then truncate size
1615   if necessary, and get the buffer to hold the data, returning the buffer size.
1616   */
1617
1618   if (i == 0)
1619     {
1620     if (!found) return NULL;
1621     if (size > header_insert_maxlen) size = header_insert_maxlen;
1622     *newsize = size + 1;
1623     ptr = yield = store_get(*newsize);
1624     }
1625   }
1626
1627 /* That's all we do for raw header expansion. */
1628
1629 if (want_raw)
1630   *ptr = 0;
1631
1632 /* Otherwise, remove a final newline and a redundant added comma. Then we do
1633 RFC 2047 decoding, translating the charset if requested. The rfc2047_decode2()
1634 function can return an error with decoded data if the charset translation
1635 fails. If decoding fails, it returns NULL. */
1636
1637 else
1638   {
1639   uschar *decoded, *error;
1640   if (ptr > yield && ptr[-1] == '\n') ptr--;
1641   if (ptr > yield && comma != 0 && ptr[-1] == ',') ptr--;
1642   *ptr = 0;
1643   decoded = rfc2047_decode2(yield, check_rfc2047_length, charset, '?', NULL,
1644     newsize, &error);
1645   if (error != NULL)
1646     {
1647     DEBUG(D_any) debug_printf("*** error in RFC 2047 decoding: %s\n"
1648       "    input was: %s\n", error, yield);
1649     }
1650   if (decoded != NULL) yield = decoded;
1651   }
1652
1653 return yield;
1654 }
1655
1656
1657
1658
1659 /*************************************************
1660 *               Return list of recipients        *
1661 *************************************************/
1662 /* A recipients list is available only during system message filtering,
1663 during ACL processing after DATA, and while expanding pipe commands
1664 generated from a system filter, but not elsewhere. */
1665
1666 static uschar *
1667 fn_recipients(void)
1668 {
1669 if (!enable_dollar_recipients) return NULL; else
1670   {
1671   int size = 128;
1672   int ptr = 0;
1673   int i;
1674   uschar * s = store_get(size);
1675   for (i = 0; i < recipients_count; i++)
1676     {
1677     if (i != 0) s = string_catn(s, &size, &ptr, US", ", 2);
1678     s = string_cat(s, &size, &ptr, recipients_list[i].address);
1679     }
1680   s[ptr] = 0;     /* string_cat() leaves room */
1681   return s;
1682   }
1683 }
1684
1685
1686 /*************************************************
1687 *               Find value of a variable         *
1688 *************************************************/
1689
1690 /* The table of variables is kept in alphabetic order, so we can search it
1691 using a binary chop. The "choplen" variable is nothing to do with the binary
1692 chop.
1693
1694 Arguments:
1695   name          the name of the variable being sought
1696   exists_only   TRUE if this is a def: test; passed on to find_header()
1697   skipping      TRUE => skip any processing evaluation; this is not the same as
1698                   exists_only because def: may test for values that are first
1699                   evaluated here
1700   newsize       pointer to an int which is initially zero; if the answer is in
1701                 a new memory buffer, *newsize is set to its size
1702
1703 Returns:        NULL if the variable does not exist, or
1704                 a pointer to the variable's contents, or
1705                 something non-NULL if exists_only is TRUE
1706 */
1707
1708 static uschar *
1709 find_variable(uschar *name, BOOL exists_only, BOOL skipping, int *newsize)
1710 {
1711 var_entry * vp;
1712 uschar *s, *domain;
1713 uschar **ss;
1714 void * val;
1715
1716 /* Handle ACL variables, whose names are of the form acl_cxxx or acl_mxxx.
1717 Originally, xxx had to be a number in the range 0-9 (later 0-19), but from
1718 release 4.64 onwards arbitrary names are permitted, as long as the first 5
1719 characters are acl_c or acl_m and the sixth is either a digit or an underscore
1720 (this gave backwards compatibility at the changeover). There may be built-in
1721 variables whose names start acl_ but they should never start in this way. This
1722 slightly messy specification is a consequence of the history, needless to say.
1723
1724 If an ACL variable does not exist, treat it as empty, unless strict_acl_vars is
1725 set, in which case give an error. */
1726
1727 if ((Ustrncmp(name, "acl_c", 5) == 0 || Ustrncmp(name, "acl_m", 5) == 0) &&
1728      !isalpha(name[5]))
1729   {
1730   tree_node *node =
1731     tree_search((name[4] == 'c')? acl_var_c : acl_var_m, name + 4);
1732   return node ? node->data.ptr : strict_acl_vars ? NULL : US"";
1733   }
1734
1735 /* Handle $auth<n> variables. */
1736
1737 if (Ustrncmp(name, "auth", 4) == 0)
1738   {
1739   uschar *endptr;
1740   int n = Ustrtoul(name + 4, &endptr, 10);
1741   if (*endptr == 0 && n != 0 && n <= AUTH_VARS)
1742     return !auth_vars[n-1] ? US"" : auth_vars[n-1];
1743   }
1744 else if (Ustrncmp(name, "regex", 5) == 0)
1745   {
1746   uschar *endptr;
1747   int n = Ustrtoul(name + 5, &endptr, 10);
1748   if (*endptr == 0 && n != 0 && n <= REGEX_VARS)
1749     return !regex_vars[n-1] ? US"" : regex_vars[n-1];
1750   }
1751
1752 /* For all other variables, search the table */
1753
1754 if (!(vp = find_var_ent(name)))
1755   return NULL;          /* Unknown variable name */
1756
1757 /* Found an existing variable. If in skipping state, the value isn't needed,
1758 and we want to avoid processing (such as looking up the host name). */
1759
1760 if (skipping)
1761   return US"";
1762
1763 val = vp->value;
1764 switch (vp->type)
1765   {
1766   case vtype_filter_int:
1767     if (!filter_running) return NULL;
1768     /* Fall through */
1769     /* VVVVVVVVVVVV */
1770   case vtype_int:
1771     sprintf(CS var_buffer, "%d", *(int *)(val)); /* Integer */
1772     return var_buffer;
1773
1774   case vtype_ino:
1775     sprintf(CS var_buffer, "%ld", (long int)(*(ino_t *)(val))); /* Inode */
1776     return var_buffer;
1777
1778   case vtype_gid:
1779     sprintf(CS var_buffer, "%ld", (long int)(*(gid_t *)(val))); /* gid */
1780     return var_buffer;
1781
1782   case vtype_uid:
1783     sprintf(CS var_buffer, "%ld", (long int)(*(uid_t *)(val))); /* uid */
1784     return var_buffer;
1785
1786   case vtype_bool:
1787     sprintf(CS var_buffer, "%s", *(BOOL *)(val) ? "yes" : "no"); /* bool */
1788     return var_buffer;
1789
1790   case vtype_stringptr:                      /* Pointer to string */
1791     return (s = *((uschar **)(val))) ? s : US"";
1792
1793   case vtype_pid:
1794     sprintf(CS var_buffer, "%d", (int)getpid()); /* pid */
1795     return var_buffer;
1796
1797   case vtype_load_avg:
1798     sprintf(CS var_buffer, "%d", OS_GETLOADAVG()); /* load_average */
1799     return var_buffer;
1800
1801   case vtype_host_lookup:                    /* Lookup if not done so */
1802     if (sender_host_name == NULL && sender_host_address != NULL &&
1803         !host_lookup_failed && host_name_lookup() == OK)
1804       host_build_sender_fullhost();
1805     return (sender_host_name == NULL)? US"" : sender_host_name;
1806
1807   case vtype_localpart:                      /* Get local part from address */
1808     s = *((uschar **)(val));
1809     if (s == NULL) return US"";
1810     domain = Ustrrchr(s, '@');
1811     if (domain == NULL) return s;
1812     if (domain - s > sizeof(var_buffer) - 1)
1813       log_write(0, LOG_MAIN|LOG_PANIC_DIE, "local part longer than " SIZE_T_FMT
1814           " in string expansion", sizeof(var_buffer));
1815     Ustrncpy(var_buffer, s, domain - s);
1816     var_buffer[domain - s] = 0;
1817     return var_buffer;
1818
1819   case vtype_domain:                         /* Get domain from address */
1820     s = *((uschar **)(val));
1821     if (s == NULL) return US"";
1822     domain = Ustrrchr(s, '@');
1823     return (domain == NULL)? US"" : domain + 1;
1824
1825   case vtype_msgheaders:
1826     return find_header(NULL, exists_only, newsize, FALSE, NULL);
1827
1828   case vtype_msgheaders_raw:
1829     return find_header(NULL, exists_only, newsize, TRUE, NULL);
1830
1831   case vtype_msgbody:                        /* Pointer to msgbody string */
1832   case vtype_msgbody_end:                    /* Ditto, the end of the msg */
1833     ss = (uschar **)(val);
1834     if (!*ss && deliver_datafile >= 0)  /* Read body when needed */
1835       {
1836       uschar *body;
1837       off_t start_offset = SPOOL_DATA_START_OFFSET;
1838       int len = message_body_visible;
1839       if (len > message_size) len = message_size;
1840       *ss = body = store_malloc(len+1);
1841       body[0] = 0;
1842       if (vp->type == vtype_msgbody_end)
1843         {
1844         struct stat statbuf;
1845         if (fstat(deliver_datafile, &statbuf) == 0)
1846           {
1847           start_offset = statbuf.st_size - len;
1848           if (start_offset < SPOOL_DATA_START_OFFSET)
1849             start_offset = SPOOL_DATA_START_OFFSET;
1850           }
1851         }
1852       if (lseek(deliver_datafile, start_offset, SEEK_SET) < 0)
1853         log_write(0, LOG_MAIN|LOG_PANIC_DIE, "deliver_datafile lseek: %s",
1854           strerror(errno));
1855       len = read(deliver_datafile, body, len);
1856       if (len > 0)
1857         {
1858         body[len] = 0;
1859         if (message_body_newlines)   /* Separate loops for efficiency */
1860           while (len > 0)
1861             { if (body[--len] == 0) body[len] = ' '; }
1862         else
1863           while (len > 0)
1864             { if (body[--len] == '\n' || body[len] == 0) body[len] = ' '; }
1865         }
1866       }
1867     return *ss ? *ss : US"";
1868
1869   case vtype_todbsdin:                       /* BSD inbox time of day */
1870     return tod_stamp(tod_bsdin);
1871
1872   case vtype_tode:                           /* Unix epoch time of day */
1873     return tod_stamp(tod_epoch);
1874
1875   case vtype_todel:                          /* Unix epoch/usec time of day */
1876     return tod_stamp(tod_epoch_l);
1877
1878   case vtype_todf:                           /* Full time of day */
1879     return tod_stamp(tod_full);
1880
1881   case vtype_todl:                           /* Log format time of day */
1882     return tod_stamp(tod_log_bare);            /* (without timezone) */
1883
1884   case vtype_todzone:                        /* Time zone offset only */
1885     return tod_stamp(tod_zone);
1886
1887   case vtype_todzulu:                        /* Zulu time */
1888     return tod_stamp(tod_zulu);
1889
1890   case vtype_todlf:                          /* Log file datestamp tod */
1891     return tod_stamp(tod_log_datestamp_daily);
1892
1893   case vtype_reply:                          /* Get reply address */
1894     s = find_header(US"reply-to:", exists_only, newsize, TRUE,
1895       headers_charset);
1896     if (s != NULL) while (isspace(*s)) s++;
1897     if (s == NULL || *s == 0)
1898       {
1899       *newsize = 0;                            /* For the *s==0 case */
1900       s = find_header(US"from:", exists_only, newsize, TRUE, headers_charset);
1901       }
1902     if (s != NULL)
1903       {
1904       uschar *t;
1905       while (isspace(*s)) s++;
1906       for (t = s; *t != 0; t++) if (*t == '\n') *t = ' ';
1907       while (t > s && isspace(t[-1])) t--;
1908       *t = 0;
1909       }
1910     return (s == NULL)? US"" : s;
1911
1912   case vtype_string_func:
1913     {
1914     uschar * (*fn)() = val;
1915     return fn();
1916     }
1917
1918   case vtype_pspace:
1919     {
1920     int inodes;
1921     sprintf(CS var_buffer, "%d",
1922       receive_statvfs(val == (void *)TRUE, &inodes));
1923     }
1924   return var_buffer;
1925
1926   case vtype_pinodes:
1927     {
1928     int inodes;
1929     (void) receive_statvfs(val == (void *)TRUE, &inodes);
1930     sprintf(CS var_buffer, "%d", inodes);
1931     }
1932   return var_buffer;
1933
1934   case vtype_cert:
1935     return *(void **)val ? US"<cert>" : US"";
1936
1937 #ifndef DISABLE_DKIM
1938   case vtype_dkim:
1939     return dkim_exim_expand_query((int)(long)val);
1940 #endif
1941
1942   }
1943
1944 return NULL;  /* Unknown variable. Silences static checkers. */
1945 }
1946
1947
1948
1949
1950 void
1951 modify_variable(uschar *name, void * value)
1952 {
1953 var_entry * vp;
1954 if ((vp = find_var_ent(name))) vp->value = value;
1955 return;          /* Unknown variable name, fail silently */
1956 }
1957
1958
1959
1960
1961
1962
1963 /*************************************************
1964 *           Read and expand substrings           *
1965 *************************************************/
1966
1967 /* This function is called to read and expand argument substrings for various
1968 expansion items. Some have a minimum requirement that is less than the maximum;
1969 in these cases, the first non-present one is set to NULL.
1970
1971 Arguments:
1972   sub        points to vector of pointers to set
1973   n          maximum number of substrings
1974   m          minimum required
1975   sptr       points to current string pointer
1976   skipping   the skipping flag
1977   check_end  if TRUE, check for final '}'
1978   name       name of item, for error message
1979   resetok    if not NULL, pointer to flag - write FALSE if unsafe to reset
1980              the store.
1981
1982 Returns:     0 OK; string pointer updated
1983              1 curly bracketing error (too few arguments)
1984              2 too many arguments (only if check_end is set); message set
1985              3 other error (expansion failure)
1986 */
1987
1988 static int
1989 read_subs(uschar **sub, int n, int m, const uschar **sptr, BOOL skipping,
1990   BOOL check_end, uschar *name, BOOL *resetok)
1991 {
1992 int i;
1993 const uschar *s = *sptr;
1994
1995 while (isspace(*s)) s++;
1996 for (i = 0; i < n; i++)
1997   {
1998   if (*s != '{')
1999     {
2000     if (i < m)
2001       {
2002       expand_string_message = string_sprintf("Not enough arguments for '%s' "
2003         "(min is %d)", name, m);
2004       return 1;
2005       }
2006     sub[i] = NULL;
2007     break;
2008     }
2009   if (!(sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, resetok)))
2010     return 3;
2011   if (*s++ != '}') return 1;
2012   while (isspace(*s)) s++;
2013   }
2014 if (check_end && *s++ != '}')
2015   {
2016   if (s[-1] == '{')
2017     {
2018     expand_string_message = string_sprintf("Too many arguments for '%s' "
2019       "(max is %d)", name, n);
2020     return 2;
2021     }
2022   expand_string_message = string_sprintf("missing '}' after '%s'", name);
2023   return 1;
2024   }
2025
2026 *sptr = s;
2027 return 0;
2028 }
2029
2030
2031
2032
2033 /*************************************************
2034 *     Elaborate message for bad variable         *
2035 *************************************************/
2036
2037 /* For the "unknown variable" message, take a look at the variable's name, and
2038 give additional information about possible ACL variables. The extra information
2039 is added on to expand_string_message.
2040
2041 Argument:   the name of the variable
2042 Returns:    nothing
2043 */
2044
2045 static void
2046 check_variable_error_message(uschar *name)
2047 {
2048 if (Ustrncmp(name, "acl_", 4) == 0)
2049   expand_string_message = string_sprintf("%s (%s)", expand_string_message,
2050     (name[4] == 'c' || name[4] == 'm')?
2051       (isalpha(name[5])?
2052         US"6th character of a user-defined ACL variable must be a digit or underscore" :
2053         US"strict_acl_vars is set"    /* Syntax is OK, it has to be this */
2054       ) :
2055       US"user-defined ACL variables must start acl_c or acl_m");
2056 }
2057
2058
2059
2060 /*
2061 Load args from sub array to globals, and call acl_check().
2062 Sub array will be corrupted on return.
2063
2064 Returns:       OK         access is granted by an ACCEPT verb
2065                DISCARD    access is (apparently) granted by a DISCARD verb
2066                FAIL       access is denied
2067                FAIL_DROP  access is denied; drop the connection
2068                DEFER      can't tell at the moment
2069                ERROR      disaster
2070 */
2071 static int
2072 eval_acl(uschar ** sub, int nsub, uschar ** user_msgp)
2073 {
2074 int i;
2075 int sav_narg = acl_narg;
2076 int ret;
2077 uschar * dummy_logmsg;
2078 extern int acl_where;
2079
2080 if(--nsub > nelem(acl_arg)) nsub = nelem(acl_arg);
2081 for (i = 0; i < nsub && sub[i+1]; i++)
2082   {
2083   uschar * tmp = acl_arg[i];
2084   acl_arg[i] = sub[i+1];        /* place callers args in the globals */
2085   sub[i+1] = tmp;               /* stash the old args using our caller's storage */
2086   }
2087 acl_narg = i;
2088 while (i < nsub)
2089   {
2090   sub[i+1] = acl_arg[i];
2091   acl_arg[i++] = NULL;
2092   }
2093
2094 DEBUG(D_expand)
2095   debug_printf_indent("expanding: acl: %s  arg: %s%s\n",
2096     sub[0],
2097     acl_narg>0 ? acl_arg[0] : US"<none>",
2098     acl_narg>1 ? " +more"   : "");
2099
2100 ret = acl_eval(acl_where, sub[0], user_msgp, &dummy_logmsg);
2101
2102 for (i = 0; i < nsub; i++)
2103   acl_arg[i] = sub[i+1];        /* restore old args */
2104 acl_narg = sav_narg;
2105
2106 return ret;
2107 }
2108
2109
2110
2111
2112 /*************************************************
2113 *        Read and evaluate a condition           *
2114 *************************************************/
2115
2116 /*
2117 Arguments:
2118   s        points to the start of the condition text
2119   resetok  points to a BOOL which is written false if it is unsafe to
2120            free memory. Certain condition types (acl) may have side-effect
2121            allocation which must be preserved.
2122   yield    points to a BOOL to hold the result of the condition test;
2123            if NULL, we are just reading through a condition that is
2124            part of an "or" combination to check syntax, or in a state
2125            where the answer isn't required
2126
2127 Returns:   a pointer to the first character after the condition, or
2128            NULL after an error
2129 */
2130
2131 static const uschar *
2132 eval_condition(const uschar *s, BOOL *resetok, BOOL *yield)
2133 {
2134 BOOL testfor = TRUE;
2135 BOOL tempcond, combined_cond;
2136 BOOL *subcondptr;
2137 BOOL sub2_honour_dollar = TRUE;
2138 int i, rc, cond_type, roffset;
2139 int_eximarith_t num[2];
2140 struct stat statbuf;
2141 uschar name[256];
2142 const uschar *sub[10];
2143
2144 const pcre *re;
2145 const uschar *rerror;
2146
2147 for (;;)
2148   {
2149   while (isspace(*s)) s++;
2150   if (*s == '!') { testfor = !testfor; s++; } else break;
2151   }
2152
2153 /* Numeric comparisons are symbolic */
2154
2155 if (*s == '=' || *s == '>' || *s == '<')
2156   {
2157   int p = 0;
2158   name[p++] = *s++;
2159   if (*s == '=')
2160     {
2161     name[p++] = '=';
2162     s++;
2163     }
2164   name[p] = 0;
2165   }
2166
2167 /* All other conditions are named */
2168
2169 else s = read_name(name, 256, s, US"_");
2170
2171 /* If we haven't read a name, it means some non-alpha character is first. */
2172
2173 if (name[0] == 0)
2174   {
2175   expand_string_message = string_sprintf("condition name expected, "
2176     "but found \"%.16s\"", s);
2177   return NULL;
2178   }
2179
2180 /* Find which condition we are dealing with, and switch on it */
2181
2182 cond_type = chop_match(name, cond_table, nelem(cond_table));
2183 switch(cond_type)
2184   {
2185   /* def: tests for a non-empty variable, or for the existence of a header. If
2186   yield == NULL we are in a skipping state, and don't care about the answer. */
2187
2188   case ECOND_DEF:
2189   if (*s != ':')
2190     {
2191     expand_string_message = US"\":\" expected after \"def\"";
2192     return NULL;
2193     }
2194
2195   s = read_name(name, 256, s+1, US"_");
2196
2197   /* Test for a header's existence. If the name contains a closing brace
2198   character, this may be a user error where the terminating colon has been
2199   omitted. Set a flag to adjust a subsequent error message in this case. */
2200
2201   if (Ustrncmp(name, "h_", 2) == 0 ||
2202       Ustrncmp(name, "rh_", 3) == 0 ||
2203       Ustrncmp(name, "bh_", 3) == 0 ||
2204       Ustrncmp(name, "header_", 7) == 0 ||
2205       Ustrncmp(name, "rheader_", 8) == 0 ||
2206       Ustrncmp(name, "bheader_", 8) == 0)
2207     {
2208     s = read_header_name(name, 256, s);
2209     /* {-for-text-editors */
2210     if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
2211     if (yield != NULL) *yield =
2212       (find_header(name, TRUE, NULL, FALSE, NULL) != NULL) == testfor;
2213     }
2214
2215   /* Test for a variable's having a non-empty value. A non-existent variable
2216   causes an expansion failure. */
2217
2218   else
2219     {
2220     uschar *value = find_variable(name, TRUE, yield == NULL, NULL);
2221     if (value == NULL)
2222       {
2223       expand_string_message = (name[0] == 0)?
2224         string_sprintf("variable name omitted after \"def:\"") :
2225         string_sprintf("unknown variable \"%s\" after \"def:\"", name);
2226       check_variable_error_message(name);
2227       return NULL;
2228       }
2229     if (yield != NULL) *yield = (value[0] != 0) == testfor;
2230     }
2231
2232   return s;
2233
2234
2235   /* first_delivery tests for first delivery attempt */
2236
2237   case ECOND_FIRST_DELIVERY:
2238   if (yield != NULL) *yield = deliver_firsttime == testfor;
2239   return s;
2240
2241
2242   /* queue_running tests for any process started by a queue runner */
2243
2244   case ECOND_QUEUE_RUNNING:
2245   if (yield != NULL) *yield = (queue_run_pid != (pid_t)0) == testfor;
2246   return s;
2247
2248
2249   /* exists:  tests for file existence
2250        isip:  tests for any IP address
2251       isip4:  tests for an IPv4 address
2252       isip6:  tests for an IPv6 address
2253         pam:  does PAM authentication
2254      radius:  does RADIUS authentication
2255    ldapauth:  does LDAP authentication
2256     pwcheck:  does Cyrus SASL pwcheck authentication
2257   */
2258
2259   case ECOND_EXISTS:
2260   case ECOND_ISIP:
2261   case ECOND_ISIP4:
2262   case ECOND_ISIP6:
2263   case ECOND_PAM:
2264   case ECOND_RADIUS:
2265   case ECOND_LDAPAUTH:
2266   case ECOND_PWCHECK:
2267
2268   while (isspace(*s)) s++;
2269   if (*s != '{') goto COND_FAILED_CURLY_START;          /* }-for-text-editors */
2270
2271   sub[0] = expand_string_internal(s+1, TRUE, &s, yield == NULL, TRUE, resetok);
2272   if (sub[0] == NULL) return NULL;
2273   /* {-for-text-editors */
2274   if (*s++ != '}') goto COND_FAILED_CURLY_END;
2275
2276   if (yield == NULL) return s;   /* No need to run the test if skipping */
2277
2278   switch(cond_type)
2279     {
2280     case ECOND_EXISTS:
2281     if ((expand_forbid & RDO_EXISTS) != 0)
2282       {
2283       expand_string_message = US"File existence tests are not permitted";
2284       return NULL;
2285       }
2286     *yield = (Ustat(sub[0], &statbuf) == 0) == testfor;
2287     break;
2288
2289     case ECOND_ISIP:
2290     case ECOND_ISIP4:
2291     case ECOND_ISIP6:
2292     rc = string_is_ip_address(sub[0], NULL);
2293     *yield = ((cond_type == ECOND_ISIP)? (rc != 0) :
2294              (cond_type == ECOND_ISIP4)? (rc == 4) : (rc == 6)) == testfor;
2295     break;
2296
2297     /* Various authentication tests - all optionally compiled */
2298
2299     case ECOND_PAM:
2300     #ifdef SUPPORT_PAM
2301     rc = auth_call_pam(sub[0], &expand_string_message);
2302     goto END_AUTH;
2303     #else
2304     goto COND_FAILED_NOT_COMPILED;
2305     #endif  /* SUPPORT_PAM */
2306
2307     case ECOND_RADIUS:
2308     #ifdef RADIUS_CONFIG_FILE
2309     rc = auth_call_radius(sub[0], &expand_string_message);
2310     goto END_AUTH;
2311     #else
2312     goto COND_FAILED_NOT_COMPILED;
2313     #endif  /* RADIUS_CONFIG_FILE */
2314
2315     case ECOND_LDAPAUTH:
2316     #ifdef LOOKUP_LDAP
2317       {
2318       /* Just to keep the interface the same */
2319       BOOL do_cache;
2320       int old_pool = store_pool;
2321       store_pool = POOL_SEARCH;
2322       rc = eldapauth_find((void *)(-1), NULL, sub[0], Ustrlen(sub[0]), NULL,
2323         &expand_string_message, &do_cache);
2324       store_pool = old_pool;
2325       }
2326     goto END_AUTH;
2327     #else
2328     goto COND_FAILED_NOT_COMPILED;
2329     #endif  /* LOOKUP_LDAP */
2330
2331     case ECOND_PWCHECK:
2332     #ifdef CYRUS_PWCHECK_SOCKET
2333     rc = auth_call_pwcheck(sub[0], &expand_string_message);
2334     goto END_AUTH;
2335     #else
2336     goto COND_FAILED_NOT_COMPILED;
2337     #endif  /* CYRUS_PWCHECK_SOCKET */
2338
2339     #if defined(SUPPORT_PAM) || defined(RADIUS_CONFIG_FILE) || \
2340         defined(LOOKUP_LDAP) || defined(CYRUS_PWCHECK_SOCKET)
2341     END_AUTH:
2342     if (rc == ERROR || rc == DEFER) return NULL;
2343     *yield = (rc == OK) == testfor;
2344     #endif
2345     }
2346   return s;
2347
2348
2349   /* call ACL (in a conditional context).  Accept true, deny false.
2350   Defer is a forced-fail.  Anything set by message= goes to $value.
2351   Up to ten parameters are used; we use the braces round the name+args
2352   like the saslauthd condition does, to permit a variable number of args.
2353   See also the expansion-item version EITEM_ACL and the traditional
2354   acl modifier ACLC_ACL.
2355   Since the ACL may allocate new global variables, tell our caller to not
2356   reclaim memory.
2357   */
2358
2359   case ECOND_ACL:
2360     /* ${if acl {{name}{arg1}{arg2}...}  {yes}{no}} */
2361     {
2362     uschar *sub[10];
2363     uschar *user_msg;
2364     BOOL cond = FALSE;
2365     int size = 0;
2366     int ptr = 0;
2367
2368     while (isspace(*s)) s++;
2369     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /*}*/
2370
2371     switch(read_subs(sub, nelem(sub), 1,
2372       &s, yield == NULL, TRUE, US"acl", resetok))
2373       {
2374       case 1: expand_string_message = US"too few arguments or bracketing "
2375         "error for acl";
2376       case 2:
2377       case 3: return NULL;
2378       }
2379
2380     if (yield != NULL)
2381       {
2382       *resetok = FALSE; /* eval_acl() might allocate; do not reclaim */
2383       switch(eval_acl(sub, nelem(sub), &user_msg))
2384         {
2385         case OK:
2386           cond = TRUE;
2387         case FAIL:
2388           lookup_value = NULL;
2389           if (user_msg)
2390             {
2391             lookup_value = string_cat(NULL, &size, &ptr, user_msg);
2392             lookup_value[ptr] = '\0';
2393             }
2394           *yield = cond == testfor;
2395           break;
2396
2397         case DEFER:
2398           expand_string_forcedfail = TRUE;
2399           /*FALLTHROUGH*/
2400         default:
2401           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
2402           return NULL;
2403         }
2404       }
2405     return s;
2406     }
2407
2408
2409   /* saslauthd: does Cyrus saslauthd authentication. Four parameters are used:
2410
2411      ${if saslauthd {{username}{password}{service}{realm}}  {yes}{no}}
2412
2413   However, the last two are optional. That is why the whole set is enclosed
2414   in their own set of braces. */
2415
2416   case ECOND_SASLAUTHD:
2417 #ifndef CYRUS_SASLAUTHD_SOCKET
2418     goto COND_FAILED_NOT_COMPILED;
2419 #else
2420     {
2421     uschar *sub[4];
2422     while (isspace(*s)) s++;
2423     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2424     switch(read_subs(sub, nelem(sub), 2, &s, yield == NULL, TRUE, US"saslauthd",
2425                     resetok))
2426       {
2427       case 1: expand_string_message = US"too few arguments or bracketing "
2428         "error for saslauthd";
2429       case 2:
2430       case 3: return NULL;
2431       }
2432     if (sub[2] == NULL) sub[3] = NULL;  /* realm if no service */
2433     if (yield != NULL)
2434       {
2435       int rc = auth_call_saslauthd(sub[0], sub[1], sub[2], sub[3],
2436         &expand_string_message);
2437       if (rc == ERROR || rc == DEFER) return NULL;
2438       *yield = (rc == OK) == testfor;
2439       }
2440     return s;
2441     }
2442 #endif /* CYRUS_SASLAUTHD_SOCKET */
2443
2444
2445   /* symbolic operators for numeric and string comparison, and a number of
2446   other operators, all requiring two arguments.
2447
2448   crypteq:           encrypts plaintext and compares against an encrypted text,
2449                        using crypt(), crypt16(), MD5 or SHA-1
2450   inlist/inlisti:    checks if first argument is in the list of the second
2451   match:             does a regular expression match and sets up the numerical
2452                        variables if it succeeds
2453   match_address:     matches in an address list
2454   match_domain:      matches in a domain list
2455   match_ip:          matches a host list that is restricted to IP addresses
2456   match_local_part:  matches in a local part list
2457   */
2458
2459   case ECOND_MATCH_ADDRESS:
2460   case ECOND_MATCH_DOMAIN:
2461   case ECOND_MATCH_IP:
2462   case ECOND_MATCH_LOCAL_PART:
2463 #ifndef EXPAND_LISTMATCH_RHS
2464     sub2_honour_dollar = FALSE;
2465 #endif
2466     /* FALLTHROUGH */
2467
2468   case ECOND_CRYPTEQ:
2469   case ECOND_INLIST:
2470   case ECOND_INLISTI:
2471   case ECOND_MATCH:
2472
2473   case ECOND_NUM_L:     /* Numerical comparisons */
2474   case ECOND_NUM_LE:
2475   case ECOND_NUM_E:
2476   case ECOND_NUM_EE:
2477   case ECOND_NUM_G:
2478   case ECOND_NUM_GE:
2479
2480   case ECOND_STR_LT:    /* String comparisons */
2481   case ECOND_STR_LTI:
2482   case ECOND_STR_LE:
2483   case ECOND_STR_LEI:
2484   case ECOND_STR_EQ:
2485   case ECOND_STR_EQI:
2486   case ECOND_STR_GT:
2487   case ECOND_STR_GTI:
2488   case ECOND_STR_GE:
2489   case ECOND_STR_GEI:
2490
2491   for (i = 0; i < 2; i++)
2492     {
2493     /* Sometimes, we don't expand substrings; too many insecure configurations
2494     created using match_address{}{} and friends, where the second param
2495     includes information from untrustworthy sources. */
2496     BOOL honour_dollar = TRUE;
2497     if ((i > 0) && !sub2_honour_dollar)
2498       honour_dollar = FALSE;
2499
2500     while (isspace(*s)) s++;
2501     if (*s != '{')
2502       {
2503       if (i == 0) goto COND_FAILED_CURLY_START;
2504       expand_string_message = string_sprintf("missing 2nd string in {} "
2505         "after \"%s\"", name);
2506       return NULL;
2507       }
2508     sub[i] = expand_string_internal(s+1, TRUE, &s, yield == NULL,
2509         honour_dollar, resetok);
2510     if (sub[i] == NULL) return NULL;
2511     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2512
2513     /* Convert to numerical if required; we know that the names of all the
2514     conditions that compare numbers do not start with a letter. This just saves
2515     checking for them individually. */
2516
2517     if (!isalpha(name[0]) && yield != NULL)
2518       if (sub[i][0] == 0)
2519         {
2520         num[i] = 0;
2521         DEBUG(D_expand)
2522           debug_printf_indent("empty string cast to zero for numerical comparison\n");
2523         }
2524       else
2525         {
2526         num[i] = expanded_string_integer(sub[i], FALSE);
2527         if (expand_string_message != NULL) return NULL;
2528         }
2529     }
2530
2531   /* Result not required */
2532
2533   if (yield == NULL) return s;
2534
2535   /* Do an appropriate comparison */
2536
2537   switch(cond_type)
2538     {
2539     case ECOND_NUM_E:
2540     case ECOND_NUM_EE:
2541     tempcond = (num[0] == num[1]);
2542     break;
2543
2544     case ECOND_NUM_G:
2545     tempcond = (num[0] > num[1]);
2546     break;
2547
2548     case ECOND_NUM_GE:
2549     tempcond = (num[0] >= num[1]);
2550     break;
2551
2552     case ECOND_NUM_L:
2553     tempcond = (num[0] < num[1]);
2554     break;
2555
2556     case ECOND_NUM_LE:
2557     tempcond = (num[0] <= num[1]);
2558     break;
2559
2560     case ECOND_STR_LT:
2561     tempcond = (Ustrcmp(sub[0], sub[1]) < 0);
2562     break;
2563
2564     case ECOND_STR_LTI:
2565     tempcond = (strcmpic(sub[0], sub[1]) < 0);
2566     break;
2567
2568     case ECOND_STR_LE:
2569     tempcond = (Ustrcmp(sub[0], sub[1]) <= 0);
2570     break;
2571
2572     case ECOND_STR_LEI:
2573     tempcond = (strcmpic(sub[0], sub[1]) <= 0);
2574     break;
2575
2576     case ECOND_STR_EQ:
2577     tempcond = (Ustrcmp(sub[0], sub[1]) == 0);
2578     break;
2579
2580     case ECOND_STR_EQI:
2581     tempcond = (strcmpic(sub[0], sub[1]) == 0);
2582     break;
2583
2584     case ECOND_STR_GT:
2585     tempcond = (Ustrcmp(sub[0], sub[1]) > 0);
2586     break;
2587
2588     case ECOND_STR_GTI:
2589     tempcond = (strcmpic(sub[0], sub[1]) > 0);
2590     break;
2591
2592     case ECOND_STR_GE:
2593     tempcond = (Ustrcmp(sub[0], sub[1]) >= 0);
2594     break;
2595
2596     case ECOND_STR_GEI:
2597     tempcond = (strcmpic(sub[0], sub[1]) >= 0);
2598     break;
2599
2600     case ECOND_MATCH:   /* Regular expression match */
2601     re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
2602       NULL);
2603     if (re == NULL)
2604       {
2605       expand_string_message = string_sprintf("regular expression error in "
2606         "\"%s\": %s at offset %d", sub[1], rerror, roffset);
2607       return NULL;
2608       }
2609     tempcond = regex_match_and_setup(re, sub[0], 0, -1);
2610     break;
2611
2612     case ECOND_MATCH_ADDRESS:  /* Match in an address list */
2613     rc = match_address_list(sub[0], TRUE, FALSE, &(sub[1]), NULL, -1, 0, NULL);
2614     goto MATCHED_SOMETHING;
2615
2616     case ECOND_MATCH_DOMAIN:   /* Match in a domain list */
2617     rc = match_isinlist(sub[0], &(sub[1]), 0, &domainlist_anchor, NULL,
2618       MCL_DOMAIN + MCL_NOEXPAND, TRUE, NULL);
2619     goto MATCHED_SOMETHING;
2620
2621     case ECOND_MATCH_IP:       /* Match IP address in a host list */
2622     if (sub[0][0] != 0 && string_is_ip_address(sub[0], NULL) == 0)
2623       {
2624       expand_string_message = string_sprintf("\"%s\" is not an IP address",
2625         sub[0]);
2626       return NULL;
2627       }
2628     else
2629       {
2630       unsigned int *nullcache = NULL;
2631       check_host_block cb;
2632
2633       cb.host_name = US"";
2634       cb.host_address = sub[0];
2635
2636       /* If the host address starts off ::ffff: it is an IPv6 address in
2637       IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2638       addresses. */
2639
2640       cb.host_ipv4 = (Ustrncmp(cb.host_address, "::ffff:", 7) == 0)?
2641         cb.host_address + 7 : cb.host_address;
2642
2643       rc = match_check_list(
2644              &sub[1],                   /* the list */
2645              0,                         /* separator character */
2646              &hostlist_anchor,          /* anchor pointer */
2647              &nullcache,                /* cache pointer */
2648              check_host,                /* function for testing */
2649              &cb,                       /* argument for function */
2650              MCL_HOST,                  /* type of check */
2651              sub[0],                    /* text for debugging */
2652              NULL);                     /* where to pass back data */
2653       }
2654     goto MATCHED_SOMETHING;
2655
2656     case ECOND_MATCH_LOCAL_PART:
2657     rc = match_isinlist(sub[0], &(sub[1]), 0, &localpartlist_anchor, NULL,
2658       MCL_LOCALPART + MCL_NOEXPAND, TRUE, NULL);
2659     /* Fall through */
2660     /* VVVVVVVVVVVV */
2661     MATCHED_SOMETHING:
2662     switch(rc)
2663       {
2664       case OK:
2665       tempcond = TRUE;
2666       break;
2667
2668       case FAIL:
2669       tempcond = FALSE;
2670       break;
2671
2672       case DEFER:
2673       expand_string_message = string_sprintf("unable to complete match "
2674         "against \"%s\": %s", sub[1], search_error_message);
2675       return NULL;
2676       }
2677
2678     break;
2679
2680     /* Various "encrypted" comparisons. If the second string starts with
2681     "{" then an encryption type is given. Default to crypt() or crypt16()
2682     (build-time choice). */
2683     /* }-for-text-editors */
2684
2685     case ECOND_CRYPTEQ:
2686     #ifndef SUPPORT_CRYPTEQ
2687     goto COND_FAILED_NOT_COMPILED;
2688     #else
2689     if (strncmpic(sub[1], US"{md5}", 5) == 0)
2690       {
2691       int sublen = Ustrlen(sub[1]+5);
2692       md5 base;
2693       uschar digest[16];
2694
2695       md5_start(&base);
2696       md5_end(&base, sub[0], Ustrlen(sub[0]), digest);
2697
2698       /* If the length that we are comparing against is 24, the MD5 digest
2699       is expressed as a base64 string. This is the way LDAP does it. However,
2700       some other software uses a straightforward hex representation. We assume
2701       this if the length is 32. Other lengths fail. */
2702
2703       if (sublen == 24)
2704         {
2705         uschar *coded = b64encode(digest, 16);
2706         DEBUG(D_auth) debug_printf("crypteq: using MD5+B64 hashing\n"
2707           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2708         tempcond = (Ustrcmp(coded, sub[1]+5) == 0);
2709         }
2710       else if (sublen == 32)
2711         {
2712         int i;
2713         uschar coded[36];
2714         for (i = 0; i < 16; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2715         coded[32] = 0;
2716         DEBUG(D_auth) debug_printf("crypteq: using MD5+hex hashing\n"
2717           "  subject=%s\n  crypted=%s\n", coded, sub[1]+5);
2718         tempcond = (strcmpic(coded, sub[1]+5) == 0);
2719         }
2720       else
2721         {
2722         DEBUG(D_auth) debug_printf("crypteq: length for MD5 not 24 or 32: "
2723           "fail\n  crypted=%s\n", sub[1]+5);
2724         tempcond = FALSE;
2725         }
2726       }
2727
2728     else if (strncmpic(sub[1], US"{sha1}", 6) == 0)
2729       {
2730       int sublen = Ustrlen(sub[1]+6);
2731       hctx h;
2732       uschar digest[20];
2733
2734       sha1_start(&h);
2735       sha1_end(&h, sub[0], Ustrlen(sub[0]), digest);
2736
2737       /* If the length that we are comparing against is 28, assume the SHA1
2738       digest is expressed as a base64 string. If the length is 40, assume a
2739       straightforward hex representation. Other lengths fail. */
2740
2741       if (sublen == 28)
2742         {
2743         uschar *coded = b64encode(digest, 20);
2744         DEBUG(D_auth) debug_printf("crypteq: using SHA1+B64 hashing\n"
2745           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2746         tempcond = (Ustrcmp(coded, sub[1]+6) == 0);
2747         }
2748       else if (sublen == 40)
2749         {
2750         int i;
2751         uschar coded[44];
2752         for (i = 0; i < 20; i++) sprintf(CS (coded+2*i), "%02X", digest[i]);
2753         coded[40] = 0;
2754         DEBUG(D_auth) debug_printf("crypteq: using SHA1+hex hashing\n"
2755           "  subject=%s\n  crypted=%s\n", coded, sub[1]+6);
2756         tempcond = (strcmpic(coded, sub[1]+6) == 0);
2757         }
2758       else
2759         {
2760         DEBUG(D_auth) debug_printf("crypteq: length for SHA-1 not 28 or 40: "
2761           "fail\n  crypted=%s\n", sub[1]+6);
2762         tempcond = FALSE;
2763         }
2764       }
2765
2766     else   /* {crypt} or {crypt16} and non-{ at start */
2767            /* }-for-text-editors */
2768       {
2769       int which = 0;
2770       uschar *coded;
2771
2772       if (strncmpic(sub[1], US"{crypt}", 7) == 0)
2773         {
2774         sub[1] += 7;
2775         which = 1;
2776         }
2777       else if (strncmpic(sub[1], US"{crypt16}", 9) == 0)
2778         {
2779         sub[1] += 9;
2780         which = 2;
2781         }
2782       else if (sub[1][0] == '{')                /* }-for-text-editors */
2783         {
2784         expand_string_message = string_sprintf("unknown encryption mechanism "
2785           "in \"%s\"", sub[1]);
2786         return NULL;
2787         }
2788
2789       switch(which)
2790         {
2791         case 0:  coded = US DEFAULT_CRYPT(CS sub[0], CS sub[1]); break;
2792         case 1:  coded = US crypt(CS sub[0], CS sub[1]); break;
2793         default: coded = US crypt16(CS sub[0], CS sub[1]); break;
2794         }
2795
2796       #define STR(s) # s
2797       #define XSTR(s) STR(s)
2798       DEBUG(D_auth) debug_printf("crypteq: using %s()\n"
2799         "  subject=%s\n  crypted=%s\n",
2800         which == 0 ? XSTR(DEFAULT_CRYPT) : which == 1 ? "crypt" : "crypt16",
2801         coded, sub[1]);
2802       #undef STR
2803       #undef XSTR
2804
2805       /* If the encrypted string contains fewer than two characters (for the
2806       salt), force failure. Otherwise we get false positives: with an empty
2807       string the yield of crypt() is an empty string! */
2808
2809       if (coded)
2810         tempcond = Ustrlen(sub[1]) < 2 ? FALSE : Ustrcmp(coded, sub[1]) == 0;
2811       else if (errno == EINVAL)
2812         tempcond = FALSE;
2813       else
2814         {
2815         expand_string_message = string_sprintf("crypt error: %s\n",
2816           US strerror(errno));
2817         return NULL;
2818         }
2819       }
2820     break;
2821     #endif  /* SUPPORT_CRYPTEQ */
2822
2823     case ECOND_INLIST:
2824     case ECOND_INLISTI:
2825       {
2826       const uschar * list = sub[1];
2827       int sep = 0;
2828       uschar *save_iterate_item = iterate_item;
2829       int (*compare)(const uschar *, const uschar *);
2830
2831       DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2832
2833       tempcond = FALSE;
2834       compare = cond_type == ECOND_INLISTI
2835         ? strcmpic : (int (*)(const uschar *, const uschar *)) strcmp;
2836
2837       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
2838         if (compare(sub[0], iterate_item) == 0)
2839           {
2840           tempcond = TRUE;
2841           break;
2842           }
2843       iterate_item = save_iterate_item;
2844       }
2845
2846     }   /* Switch for comparison conditions */
2847
2848   *yield = tempcond == testfor;
2849   return s;    /* End of comparison conditions */
2850
2851
2852   /* and/or: computes logical and/or of several conditions */
2853
2854   case ECOND_AND:
2855   case ECOND_OR:
2856   subcondptr = (yield == NULL)? NULL : &tempcond;
2857   combined_cond = (cond_type == ECOND_AND);
2858
2859   while (isspace(*s)) s++;
2860   if (*s++ != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2861
2862   for (;;)
2863     {
2864     while (isspace(*s)) s++;
2865     /* {-for-text-editors */
2866     if (*s == '}') break;
2867     if (*s != '{')                                      /* }-for-text-editors */
2868       {
2869       expand_string_message = string_sprintf("each subcondition "
2870         "inside an \"%s{...}\" condition must be in its own {}", name);
2871       return NULL;
2872       }
2873
2874     if (!(s = eval_condition(s+1, resetok, subcondptr)))
2875       {
2876       expand_string_message = string_sprintf("%s inside \"%s{...}\" condition",
2877         expand_string_message, name);
2878       return NULL;
2879       }
2880     while (isspace(*s)) s++;
2881
2882     /* {-for-text-editors */
2883     if (*s++ != '}')
2884       {
2885       /* {-for-text-editors */
2886       expand_string_message = string_sprintf("missing } at end of condition "
2887         "inside \"%s\" group", name);
2888       return NULL;
2889       }
2890
2891     if (yield != NULL)
2892       {
2893       if (cond_type == ECOND_AND)
2894         {
2895         combined_cond &= tempcond;
2896         if (!combined_cond) subcondptr = NULL;  /* once false, don't */
2897         }                                       /* evaluate any more */
2898       else
2899         {
2900         combined_cond |= tempcond;
2901         if (combined_cond) subcondptr = NULL;   /* once true, don't */
2902         }                                       /* evaluate any more */
2903       }
2904     }
2905
2906   if (yield != NULL) *yield = (combined_cond == testfor);
2907   return ++s;
2908
2909
2910   /* forall/forany: iterates a condition with different values */
2911
2912   case ECOND_FORALL:
2913   case ECOND_FORANY:
2914     {
2915     const uschar * list;
2916     int sep = 0;
2917     uschar *save_iterate_item = iterate_item;
2918
2919     DEBUG(D_expand) debug_printf_indent("condition: %s\n", name);
2920
2921     while (isspace(*s)) s++;
2922     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2923     sub[0] = expand_string_internal(s, TRUE, &s, (yield == NULL), TRUE, resetok);
2924     if (sub[0] == NULL) return NULL;
2925     /* {-for-text-editors */
2926     if (*s++ != '}') goto COND_FAILED_CURLY_END;
2927
2928     while (isspace(*s)) s++;
2929     if (*s++ != '{') goto COND_FAILED_CURLY_START;      /* }-for-text-editors */
2930
2931     sub[1] = s;
2932
2933     /* Call eval_condition once, with result discarded (as if scanning a
2934     "false" part). This allows us to find the end of the condition, because if
2935     the list it empty, we won't actually evaluate the condition for real. */
2936
2937     if (!(s = eval_condition(sub[1], resetok, NULL)))
2938       {
2939       expand_string_message = string_sprintf("%s inside \"%s\" condition",
2940         expand_string_message, name);
2941       return NULL;
2942       }
2943     while (isspace(*s)) s++;
2944
2945     /* {-for-text-editors */
2946     if (*s++ != '}')
2947       {
2948       /* {-for-text-editors */
2949       expand_string_message = string_sprintf("missing } at end of condition "
2950         "inside \"%s\"", name);
2951       return NULL;
2952       }
2953
2954     if (yield != NULL) *yield = !testfor;
2955     list = sub[0];
2956     while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)) != NULL)
2957       {
2958       DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, iterate_item);
2959       if (!eval_condition(sub[1], resetok, &tempcond))
2960         {
2961         expand_string_message = string_sprintf("%s inside \"%s\" condition",
2962           expand_string_message, name);
2963         iterate_item = save_iterate_item;
2964         return NULL;
2965         }
2966       DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", name,
2967         tempcond? "true":"false");
2968
2969       if (yield != NULL) *yield = (tempcond == testfor);
2970       if (tempcond == (cond_type == ECOND_FORANY)) break;
2971       }
2972
2973     iterate_item = save_iterate_item;
2974     return s;
2975     }
2976
2977
2978   /* The bool{} expansion condition maps a string to boolean.
2979   The values supported should match those supported by the ACL condition
2980   (acl.c, ACLC_CONDITION) so that we keep to a minimum the different ideas
2981   of true/false.  Note that Router "condition" rules have a different
2982   interpretation, where general data can be used and only a few values
2983   map to FALSE.
2984   Note that readconf.c boolean matching, for boolean configuration options,
2985   only matches true/yes/false/no.
2986   The bool_lax{} condition matches the Router logic, which is much more
2987   liberal. */
2988   case ECOND_BOOL:
2989   case ECOND_BOOL_LAX:
2990     {
2991     uschar *sub_arg[1];
2992     uschar *t, *t2;
2993     uschar *ourname;
2994     size_t len;
2995     BOOL boolvalue = FALSE;
2996     while (isspace(*s)) s++;
2997     if (*s != '{') goto COND_FAILED_CURLY_START;        /* }-for-text-editors */
2998     ourname = cond_type == ECOND_BOOL_LAX ? US"bool_lax" : US"bool";
2999     switch(read_subs(sub_arg, 1, 1, &s, yield == NULL, FALSE, ourname, resetok))
3000       {
3001       case 1: expand_string_message = string_sprintf(
3002                   "too few arguments or bracketing error for %s",
3003                   ourname);
3004       /*FALLTHROUGH*/
3005       case 2:
3006       case 3: return NULL;
3007       }
3008     t = sub_arg[0];
3009     while (isspace(*t)) t++;
3010     len = Ustrlen(t);
3011     if (len)
3012       {
3013       /* trailing whitespace: seems like a good idea to ignore it too */
3014       t2 = t + len - 1;
3015       while (isspace(*t2)) t2--;
3016       if (t2 != (t + len))
3017         {
3018         *++t2 = '\0';
3019         len = t2 - t;
3020         }
3021       }
3022     DEBUG(D_expand)
3023       debug_printf_indent("considering %s: %s\n", ourname, len ? t : US"<empty>");
3024     /* logic for the lax case from expand_check_condition(), which also does
3025     expands, and the logic is both short and stable enough that there should
3026     be no maintenance burden from replicating it. */
3027     if (len == 0)
3028       boolvalue = FALSE;
3029     else if (*t == '-'
3030              ? Ustrspn(t+1, "0123456789") == len-1
3031              : Ustrspn(t,   "0123456789") == len)
3032       {
3033       boolvalue = (Uatoi(t) == 0) ? FALSE : TRUE;
3034       /* expand_check_condition only does a literal string "0" check */
3035       if ((cond_type == ECOND_BOOL_LAX) && (len > 1))
3036         boolvalue = TRUE;
3037       }
3038     else if (strcmpic(t, US"true") == 0 || strcmpic(t, US"yes") == 0)
3039       boolvalue = TRUE;
3040     else if (strcmpic(t, US"false") == 0 || strcmpic(t, US"no") == 0)
3041       boolvalue = FALSE;
3042     else if (cond_type == ECOND_BOOL_LAX)
3043       boolvalue = TRUE;
3044     else
3045       {
3046       expand_string_message = string_sprintf("unrecognised boolean "
3047        "value \"%s\"", t);
3048       return NULL;
3049       }
3050     DEBUG(D_expand) debug_printf_indent("%s: condition evaluated to %s\n", ourname,
3051         boolvalue? "true":"false");
3052     if (yield != NULL) *yield = (boolvalue == testfor);
3053     return s;
3054     }
3055
3056   /* Unknown condition */
3057
3058   default:
3059   expand_string_message = string_sprintf("unknown condition \"%s\"", name);
3060   return NULL;
3061   }   /* End switch on condition type */
3062
3063 /* Missing braces at start and end of data */
3064
3065 COND_FAILED_CURLY_START:
3066 expand_string_message = string_sprintf("missing { after \"%s\"", name);
3067 return NULL;
3068
3069 COND_FAILED_CURLY_END:
3070 expand_string_message = string_sprintf("missing } at end of \"%s\" condition",
3071   name);
3072 return NULL;
3073
3074 /* A condition requires code that is not compiled */
3075
3076 #if !defined(SUPPORT_PAM) || !defined(RADIUS_CONFIG_FILE) || \
3077     !defined(LOOKUP_LDAP) || !defined(CYRUS_PWCHECK_SOCKET) || \
3078     !defined(SUPPORT_CRYPTEQ) || !defined(CYRUS_SASLAUTHD_SOCKET)
3079 COND_FAILED_NOT_COMPILED:
3080 expand_string_message = string_sprintf("support for \"%s\" not compiled",
3081   name);
3082 return NULL;
3083 #endif
3084 }
3085
3086
3087
3088
3089 /*************************************************
3090 *          Save numerical variables              *
3091 *************************************************/
3092
3093 /* This function is called from items such as "if" that want to preserve and
3094 restore the numbered variables.
3095
3096 Arguments:
3097   save_expand_string    points to an array of pointers to set
3098   save_expand_nlength   points to an array of ints for the lengths
3099
3100 Returns:                the value of expand max to save
3101 */
3102
3103 static int
3104 save_expand_strings(uschar **save_expand_nstring, int *save_expand_nlength)
3105 {
3106 int i;
3107 for (i = 0; i <= expand_nmax; i++)
3108   {
3109   save_expand_nstring[i] = expand_nstring[i];
3110   save_expand_nlength[i] = expand_nlength[i];
3111   }
3112 return expand_nmax;
3113 }
3114
3115
3116
3117 /*************************************************
3118 *           Restore numerical variables          *
3119 *************************************************/
3120
3121 /* This function restored saved values of numerical strings.
3122
3123 Arguments:
3124   save_expand_nmax      the number of strings to restore
3125   save_expand_string    points to an array of pointers
3126   save_expand_nlength   points to an array of ints
3127
3128 Returns:                nothing
3129 */
3130
3131 static void
3132 restore_expand_strings(int save_expand_nmax, uschar **save_expand_nstring,
3133   int *save_expand_nlength)
3134 {
3135 int i;
3136 expand_nmax = save_expand_nmax;
3137 for (i = 0; i <= expand_nmax; i++)
3138   {
3139   expand_nstring[i] = save_expand_nstring[i];
3140   expand_nlength[i] = save_expand_nlength[i];
3141   }
3142 }
3143
3144
3145
3146
3147
3148 /*************************************************
3149 *            Handle yes/no substrings            *
3150 *************************************************/
3151
3152 /* This function is used by ${if}, ${lookup} and ${extract} to handle the
3153 alternative substrings that depend on whether or not the condition was true,
3154 or the lookup or extraction succeeded. The substrings always have to be
3155 expanded, to check their syntax, but "skipping" is set when the result is not
3156 needed - this avoids unnecessary nested lookups.
3157
3158 Arguments:
3159   skipping       TRUE if we were skipping when this item was reached
3160   yes            TRUE if the first string is to be used, else use the second
3161   save_lookup    a value to put back into lookup_value before the 2nd expansion
3162   sptr           points to the input string pointer
3163   yieldptr       points to the output string pointer
3164   sizeptr        points to the output string size
3165   ptrptr         points to the output string pointer
3166   type           "lookup", "if", "extract", "run", "env", "listextract" or
3167                  "certextract" for error message
3168   resetok        if not NULL, pointer to flag - write FALSE if unsafe to reset
3169                 the store.
3170
3171 Returns:         0 OK; lookup_value has been reset to save_lookup
3172                  1 expansion failed
3173                  2 expansion failed because of bracketing error
3174 */
3175
3176 static int
3177 process_yesno(BOOL skipping, BOOL yes, uschar *save_lookup, const uschar **sptr,
3178   uschar **yieldptr, int *sizeptr, int *ptrptr, uschar *type, BOOL *resetok)
3179 {
3180 int rc = 0;
3181 const uschar *s = *sptr;    /* Local value */
3182 uschar *sub1, *sub2;
3183 const uschar * errwhere;
3184
3185 /* If there are no following strings, we substitute the contents of $value for
3186 lookups and for extractions in the success case. For the ${if item, the string
3187 "true" is substituted. In the fail case, nothing is substituted for all three
3188 items. */
3189
3190 while (isspace(*s)) s++;
3191 if (*s == '}')
3192   {
3193   if (type[0] == 'i')
3194     {
3195     if (yes && !skipping)
3196       *yieldptr = string_catn(*yieldptr, sizeptr, ptrptr, US"true", 4);
3197     }
3198   else
3199     {
3200     if (yes && lookup_value && !skipping)
3201       *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, lookup_value);
3202     lookup_value = save_lookup;
3203     }
3204   s++;
3205   goto RETURN;
3206   }
3207
3208 /* The first following string must be braced. */
3209
3210 if (*s++ != '{')
3211   {
3212   errwhere = US"'yes' part did not start with '{'";
3213   goto FAILED_CURLY;
3214   }
3215
3216 /* Expand the first substring. Forced failures are noticed only if we actually
3217 want this string. Set skipping in the call in the fail case (this will always
3218 be the case if we were already skipping). */
3219
3220 sub1 = expand_string_internal(s, TRUE, &s, !yes, TRUE, resetok);
3221 if (sub1 == NULL && (yes || !expand_string_forcedfail)) goto FAILED;
3222 expand_string_forcedfail = FALSE;
3223 if (*s++ != '}')
3224   {
3225   errwhere = US"'yes' part did not end with '}'";
3226   goto FAILED_CURLY;
3227   }
3228
3229 /* If we want the first string, add it to the output */
3230
3231 if (yes)
3232   *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub1);
3233
3234 /* If this is called from a lookup/env or a (cert)extract, we want to restore
3235 $value to what it was at the start of the item, so that it has this value
3236 during the second string expansion. For the call from "if" or "run" to this
3237 function, save_lookup is set to lookup_value, so that this statement does
3238 nothing. */
3239
3240 lookup_value = save_lookup;
3241
3242 /* There now follows either another substring, or "fail", or nothing. This
3243 time, forced failures are noticed only if we want the second string. We must
3244 set skipping in the nested call if we don't want this string, or if we were
3245 already skipping. */
3246
3247 while (isspace(*s)) s++;
3248 if (*s == '{')
3249   {
3250   sub2 = expand_string_internal(s+1, TRUE, &s, yes || skipping, TRUE, resetok);
3251   if (sub2 == NULL && (!yes || !expand_string_forcedfail)) goto FAILED;
3252   expand_string_forcedfail = FALSE;
3253   if (*s++ != '}')
3254     {
3255     errwhere = US"'no' part did not start with '{'";
3256     goto FAILED_CURLY;
3257     }
3258
3259   /* If we want the second string, add it to the output */
3260
3261   if (!yes)
3262     *yieldptr = string_cat(*yieldptr, sizeptr, ptrptr, sub2);
3263   }
3264
3265 /* If there is no second string, but the word "fail" is present when the use of
3266 the second string is wanted, set a flag indicating it was a forced failure
3267 rather than a syntactic error. Swallow the terminating } in case this is nested
3268 inside another lookup or if or extract. */
3269
3270 else if (*s != '}')
3271   {
3272   uschar name[256];
3273   /* deconst cast ok here as source is s anyway */
3274   s = US read_name(name, sizeof(name), s, US"_");
3275   if (Ustrcmp(name, "fail") == 0)
3276     {
3277     if (!yes && !skipping)
3278       {
3279       while (isspace(*s)) s++;
3280       if (*s++ != '}')
3281         {
3282         errwhere = US"did not close with '}' after forcedfail";
3283         goto FAILED_CURLY;
3284         }
3285       expand_string_message =
3286         string_sprintf("\"%s\" failed and \"fail\" requested", type);
3287       expand_string_forcedfail = TRUE;
3288       goto FAILED;
3289       }
3290     }
3291   else
3292     {
3293     expand_string_message =
3294       string_sprintf("syntax error in \"%s\" item - \"fail\" expected", type);
3295     goto FAILED;
3296     }
3297   }
3298
3299 /* All we have to do now is to check on the final closing brace. */
3300
3301 while (isspace(*s)) s++;
3302 if (*s++ != '}')
3303   {
3304   errwhere = US"did not close with '}'";
3305   goto FAILED_CURLY;
3306   }
3307
3308
3309 RETURN:
3310 /* Update the input pointer value before returning */
3311 *sptr = s;
3312 return rc;
3313
3314 FAILED_CURLY:
3315   /* Get here if there is a bracketing failure */
3316   expand_string_message = string_sprintf(
3317     "curly-bracket problem in conditional yes/no parsing: %s\n"
3318     " remaining string is '%s'", errwhere, --s);
3319   rc = 2;
3320   goto RETURN;
3321
3322 FAILED:
3323   /* Get here for other failures */
3324   rc = 1;
3325   goto RETURN;
3326 }
3327
3328
3329
3330
3331 /*************************************************
3332 *    Handle MD5 or SHA-1 computation for HMAC    *
3333 *************************************************/
3334
3335 /* These are some wrapping functions that enable the HMAC code to be a bit
3336 cleaner. A good compiler will spot the tail recursion.
3337
3338 Arguments:
3339   type         HMAC_MD5 or HMAC_SHA1
3340   remaining    are as for the cryptographic hash functions
3341
3342 Returns:       nothing
3343 */
3344
3345 static void
3346 chash_start(int type, void *base)
3347 {
3348 if (type == HMAC_MD5)
3349   md5_start((md5 *)base);
3350 else
3351   sha1_start((hctx *)base);
3352 }
3353
3354 static void
3355 chash_mid(int type, void *base, uschar *string)
3356 {
3357 if (type == HMAC_MD5)
3358   md5_mid((md5 *)base, string);
3359 else
3360   sha1_mid((hctx *)base, string);
3361 }
3362
3363 static void
3364 chash_end(int type, void *base, uschar *string, int length, uschar *digest)
3365 {
3366 if (type == HMAC_MD5)
3367   md5_end((md5 *)base, string, length, digest);
3368 else
3369   sha1_end((hctx *)base, string, length, digest);
3370 }
3371
3372
3373
3374
3375
3376 /********************************************************
3377 * prvs: Get last three digits of days since Jan 1, 1970 *
3378 ********************************************************/
3379
3380 /* This is needed to implement the "prvs" BATV reverse
3381    path signing scheme
3382
3383 Argument: integer "days" offset to add or substract to
3384           or from the current number of days.
3385
3386 Returns:  pointer to string containing the last three
3387           digits of the number of days since Jan 1, 1970,
3388           modified by the offset argument, NULL if there
3389           was an error in the conversion.
3390
3391 */
3392
3393 static uschar *
3394 prvs_daystamp(int day_offset)
3395 {
3396 uschar *days = store_get(32);                /* Need at least 24 for cases */
3397 (void)string_format(days, 32, TIME_T_FMT,    /* where TIME_T_FMT is %lld */
3398   (time(NULL) + day_offset*86400)/86400);
3399 return (Ustrlen(days) >= 3) ? &days[Ustrlen(days)-3] : US"100";
3400 }
3401
3402
3403
3404 /********************************************************
3405 *   prvs: perform HMAC-SHA1 computation of prvs bits    *
3406 ********************************************************/
3407
3408 /* This is needed to implement the "prvs" BATV reverse
3409    path signing scheme
3410
3411 Arguments:
3412   address RFC2821 Address to use
3413       key The key to use (must be less than 64 characters
3414           in size)
3415   key_num Single-digit key number to use. Defaults to
3416           '0' when NULL.
3417
3418 Returns:  pointer to string containing the first three
3419           bytes of the final hash in hex format, NULL if
3420           there was an error in the process.
3421 */
3422
3423 static uschar *
3424 prvs_hmac_sha1(uschar *address, uschar *key, uschar *key_num, uschar *daystamp)
3425 {
3426 uschar *hash_source, *p;
3427 int size = 0,offset = 0,i;
3428 hctx h;
3429 uschar innerhash[20];
3430 uschar finalhash[20];
3431 uschar innerkey[64];
3432 uschar outerkey[64];
3433 uschar *finalhash_hex = store_get(40);
3434
3435 if (key_num == NULL)
3436   key_num = US"0";
3437
3438 if (Ustrlen(key) > 64)
3439   return NULL;
3440
3441 hash_source = string_catn(NULL, &size, &offset, key_num, 1);
3442 hash_source = string_catn(hash_source, &size, &offset, daystamp, 3);
3443 hash_source = string_cat(hash_source, &size, &offset, address);
3444 hash_source[offset] = '\0';
3445
3446 DEBUG(D_expand) debug_printf_indent("prvs: hash source is '%s'\n", hash_source);
3447
3448 memset(innerkey, 0x36, 64);
3449 memset(outerkey, 0x5c, 64);
3450
3451 for (i = 0; i < Ustrlen(key); i++)
3452   {
3453   innerkey[i] ^= key[i];
3454   outerkey[i] ^= key[i];
3455   }
3456
3457 chash_start(HMAC_SHA1, &h);
3458 chash_mid(HMAC_SHA1, &h, innerkey);
3459 chash_end(HMAC_SHA1, &h, hash_source, offset, innerhash);
3460
3461 chash_start(HMAC_SHA1, &h);
3462 chash_mid(HMAC_SHA1, &h, outerkey);
3463 chash_end(HMAC_SHA1, &h, innerhash, 20, finalhash);
3464
3465 p = finalhash_hex;
3466 for (i = 0; i < 3; i++)
3467   {
3468   *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
3469   *p++ = hex_digits[finalhash[i] & 0x0f];
3470   }
3471 *p = '\0';
3472
3473 return finalhash_hex;
3474 }
3475
3476
3477
3478
3479 /*************************************************
3480 *        Join a file onto the output string      *
3481 *************************************************/
3482
3483 /* This is used for readfile/readsock and after a run expansion.
3484 It joins the contents of a file onto the output string, globally replacing
3485 newlines with a given string (optionally).
3486
3487 Arguments:
3488   f            the FILE
3489   yield        pointer to the expandable string
3490   sizep        pointer to the current size
3491   ptrp         pointer to the current position
3492   eol          newline replacement string, or NULL
3493
3494 Returns:       new value of string pointer
3495 */
3496
3497 static uschar *
3498 cat_file(FILE *f, uschar *yield, int *sizep, int *ptrp, uschar *eol)
3499 {
3500 uschar buffer[1024];
3501
3502 while (Ufgets(buffer, sizeof(buffer), f))
3503   {
3504   int len = Ustrlen(buffer);
3505   if (eol && buffer[len-1] == '\n') len--;
3506   yield = string_catn(yield, sizep, ptrp, buffer, len);
3507   if (eol && buffer[len])
3508     yield = string_cat(yield, sizep, ptrp, eol);
3509   }
3510
3511 if (yield) yield[*ptrp] = 0;
3512
3513 return yield;
3514 }
3515
3516
3517
3518
3519 /*************************************************
3520 *          Evaluate numeric expression           *
3521 *************************************************/
3522
3523 /* This is a set of mutually recursive functions that evaluate an arithmetic
3524 expression involving + - * / % & | ^ ~ << >> and parentheses. The only one of
3525 these functions that is called from elsewhere is eval_expr, whose interface is:
3526
3527 Arguments:
3528   sptr        pointer to the pointer to the string - gets updated
3529   decimal     TRUE if numbers are to be assumed decimal
3530   error       pointer to where to put an error message - must be NULL on input
3531   endket      TRUE if ')' must terminate - FALSE for external call
3532
3533 Returns:      on success: the value of the expression, with *error still NULL
3534               on failure: an undefined value, with *error = a message
3535 */
3536
3537 static int_eximarith_t eval_op_or(uschar **, BOOL, uschar **);
3538
3539
3540 static int_eximarith_t
3541 eval_expr(uschar **sptr, BOOL decimal, uschar **error, BOOL endket)
3542 {
3543 uschar *s = *sptr;
3544 int_eximarith_t x = eval_op_or(&s, decimal, error);
3545 if (*error == NULL)
3546   {
3547   if (endket)
3548     {
3549     if (*s != ')')
3550       *error = US"expecting closing parenthesis";
3551     else
3552       while (isspace(*(++s)));
3553     }
3554   else if (*s != 0) *error = US"expecting operator";
3555   }
3556 *sptr = s;
3557 return x;
3558 }
3559
3560
3561 static int_eximarith_t
3562 eval_number(uschar **sptr, BOOL decimal, uschar **error)
3563 {
3564 register int c;
3565 int_eximarith_t n;
3566 uschar *s = *sptr;
3567 while (isspace(*s)) s++;
3568 c = *s;
3569 if (isdigit(c))
3570   {
3571   int count;
3572   (void)sscanf(CS s, (decimal? SC_EXIM_DEC "%n" : SC_EXIM_ARITH "%n"), &n, &count);
3573   s += count;
3574   switch (tolower(*s))
3575     {
3576     default: break;
3577     case 'k': n *= 1024; s++; break;
3578     case 'm': n *= 1024*1024; s++; break;
3579     case 'g': n *= 1024*1024*1024; s++; break;
3580     }
3581   while (isspace (*s)) s++;
3582   }
3583 else if (c == '(')
3584   {
3585   s++;
3586   n = eval_expr(&s, decimal, error, 1);
3587   }
3588 else
3589   {
3590   *error = US"expecting number or opening parenthesis";
3591   n = 0;
3592   }
3593 *sptr = s;
3594 return n;
3595 }
3596
3597
3598 static int_eximarith_t
3599 eval_op_unary(uschar **sptr, BOOL decimal, uschar **error)
3600 {
3601 uschar *s = *sptr;
3602 int_eximarith_t x;
3603 while (isspace(*s)) s++;
3604 if (*s == '+' || *s == '-' || *s == '~')
3605   {
3606   int op = *s++;
3607   x = eval_op_unary(&s, decimal, error);
3608   if (op == '-') x = -x;
3609     else if (op == '~') x = ~x;
3610   }
3611 else
3612   {
3613   x = eval_number(&s, decimal, error);
3614   }
3615 *sptr = s;
3616 return x;
3617 }
3618
3619
3620 static int_eximarith_t
3621 eval_op_mult(uschar **sptr, BOOL decimal, uschar **error)
3622 {
3623 uschar *s = *sptr;
3624 int_eximarith_t x = eval_op_unary(&s, decimal, error);
3625 if (*error == NULL)
3626   {
3627   while (*s == '*' || *s == '/' || *s == '%')
3628     {
3629     int op = *s++;
3630     int_eximarith_t y = eval_op_unary(&s, decimal, error);
3631     if (*error != NULL) break;
3632     /* SIGFPE both on div/mod by zero and on INT_MIN / -1, which would give
3633      * a value of INT_MAX+1. Note that INT_MIN * -1 gives INT_MIN for me, which
3634      * is a bug somewhere in [gcc 4.2.1, FreeBSD, amd64].  In fact, -N*-M where
3635      * -N*M is INT_MIN will yield INT_MIN.
3636      * Since we don't support floating point, this is somewhat simpler.
3637      * Ideally, we'd return an error, but since we overflow for all other
3638      * arithmetic, consistency suggests otherwise, but what's the correct value
3639      * to use?  There is none.
3640      * The C standard guarantees overflow for unsigned arithmetic but signed
3641      * overflow invokes undefined behaviour; in practice, this is overflow
3642      * except for converting INT_MIN to INT_MAX+1.  We also can't guarantee
3643      * that long/longlong larger than int are available, or we could just work
3644      * with larger types.  We should consider whether to guarantee 32bit eval
3645      * and 64-bit working variables, with errors returned.  For now ...
3646      * So, the only SIGFPEs occur with a non-shrinking div/mod, thus -1; we
3647      * can just let the other invalid results occur otherwise, as they have
3648      * until now.  For this one case, we can coerce.
3649      */
3650     if (y == -1 && x == EXIM_ARITH_MIN && op != '*')
3651       {
3652       DEBUG(D_expand)
3653         debug_printf("Integer exception dodging: " PR_EXIM_ARITH "%c-1 coerced to " PR_EXIM_ARITH "\n",
3654             EXIM_ARITH_MIN, op, EXIM_ARITH_MAX);
3655       x = EXIM_ARITH_MAX;
3656       continue;
3657       }
3658     if (op == '*')
3659       x *= y;
3660     else
3661       {
3662       if (y == 0)
3663         {
3664         *error = (op == '/') ? US"divide by zero" : US"modulo by zero";
3665         x = 0;
3666         break;
3667         }
3668       if (op == '/')
3669         x /= y;
3670       else
3671         x %= y;
3672       }
3673     }
3674   }
3675 *sptr = s;
3676 return x;
3677 }
3678
3679
3680 static int_eximarith_t
3681 eval_op_sum(uschar **sptr, BOOL decimal, uschar **error)
3682 {
3683 uschar *s = *sptr;
3684 int_eximarith_t x = eval_op_mult(&s, decimal, error);
3685 if (!*error)
3686   {
3687   while (*s == '+' || *s == '-')
3688     {
3689     int op = *s++;
3690     int_eximarith_t y = eval_op_mult(&s, decimal, error);
3691     if (*error) break;
3692     if (  (x >=   EXIM_ARITH_MAX/2  && x >=   EXIM_ARITH_MAX/2)
3693        || (x <= -(EXIM_ARITH_MAX/2) && y <= -(EXIM_ARITH_MAX/2)))
3694       {                 /* over-conservative check */
3695       *error = op == '+'
3696         ? US"overflow in sum" : US"overflow in difference";
3697       break;
3698       }
3699     if (op == '+') x += y; else x -= y;
3700     }
3701   }
3702 *sptr = s;
3703 return x;
3704 }
3705
3706
3707 static int_eximarith_t
3708 eval_op_shift(uschar **sptr, BOOL decimal, uschar **error)
3709 {
3710 uschar *s = *sptr;
3711 int_eximarith_t x = eval_op_sum(&s, decimal, error);
3712 if (*error == NULL)
3713   {
3714   while ((*s == '<' || *s == '>') && s[1] == s[0])
3715     {
3716     int_eximarith_t y;
3717     int op = *s++;
3718     s++;
3719     y = eval_op_sum(&s, decimal, error);
3720     if (*error != NULL) break;
3721     if (op == '<') x <<= y; else x >>= y;
3722     }
3723   }
3724 *sptr = s;
3725 return x;
3726 }
3727
3728
3729 static int_eximarith_t
3730 eval_op_and(uschar **sptr, BOOL decimal, uschar **error)
3731 {
3732 uschar *s = *sptr;
3733 int_eximarith_t x = eval_op_shift(&s, decimal, error);
3734 if (*error == NULL)
3735   {
3736   while (*s == '&')
3737     {
3738     int_eximarith_t y;
3739     s++;
3740     y = eval_op_shift(&s, decimal, error);
3741     if (*error != NULL) break;
3742     x &= y;
3743     }
3744   }
3745 *sptr = s;
3746 return x;
3747 }
3748
3749
3750 static int_eximarith_t
3751 eval_op_xor(uschar **sptr, BOOL decimal, uschar **error)
3752 {
3753 uschar *s = *sptr;
3754 int_eximarith_t x = eval_op_and(&s, decimal, error);
3755 if (*error == NULL)
3756   {
3757   while (*s == '^')
3758     {
3759     int_eximarith_t y;
3760     s++;
3761     y = eval_op_and(&s, decimal, error);
3762     if (*error != NULL) break;
3763     x ^= y;
3764     }
3765   }
3766 *sptr = s;
3767 return x;
3768 }
3769
3770
3771 static int_eximarith_t
3772 eval_op_or(uschar **sptr, BOOL decimal, uschar **error)
3773 {
3774 uschar *s = *sptr;
3775 int_eximarith_t x = eval_op_xor(&s, decimal, error);
3776 if (*error == NULL)
3777   {
3778   while (*s == '|')
3779     {
3780     int_eximarith_t y;
3781     s++;
3782     y = eval_op_xor(&s, decimal, error);
3783     if (*error != NULL) break;
3784     x |= y;
3785     }
3786   }
3787 *sptr = s;
3788 return x;
3789 }
3790
3791
3792
3793 /*************************************************
3794 *                 Expand string                  *
3795 *************************************************/
3796
3797 /* Returns either an unchanged string, or the expanded string in stacking pool
3798 store. Interpreted sequences are:
3799
3800    \...                    normal escaping rules
3801    $name                   substitutes the variable
3802    ${name}                 ditto
3803    ${op:string}            operates on the expanded string value
3804    ${item{arg1}{arg2}...}  expands the args and then does the business
3805                              some literal args are not enclosed in {}
3806
3807 There are now far too many operators and item types to make it worth listing
3808 them here in detail any more.
3809
3810 We use an internal routine recursively to handle embedded substrings. The
3811 external function follows. The yield is NULL if the expansion failed, and there
3812 are two cases: if something collapsed syntactically, or if "fail" was given
3813 as the action on a lookup failure. These can be distinguished by looking at the
3814 variable expand_string_forcedfail, which is TRUE in the latter case.
3815
3816 The skipping flag is set true when expanding a substring that isn't actually
3817 going to be used (after "if" or "lookup") and it prevents lookups from
3818 happening lower down.
3819
3820 Store usage: At start, a store block of the length of the input plus 64
3821 is obtained. This is expanded as necessary by string_cat(), which might have to
3822 get a new block, or might be able to expand the original. At the end of the
3823 function we can release any store above that portion of the yield block that
3824 was actually used. In many cases this will be optimal.
3825
3826 However: if the first item in the expansion is a variable name or header name,
3827 we reset the store before processing it; if the result is in fresh store, we
3828 use that without copying. This is helpful for expanding strings like
3829 $message_headers which can get very long.
3830
3831 There's a problem if a ${dlfunc item has side-effects that cause allocation,
3832 since resetting the store at the end of the expansion will free store that was
3833 allocated by the plugin code as well as the slop after the expanded string. So
3834 we skip any resets if ${dlfunc } has been used. The same applies for ${acl }
3835 and, given the acl condition, ${if }. This is an unfortunate consequence of
3836 string expansion becoming too powerful.
3837
3838 Arguments:
3839   string         the string to be expanded
3840   ket_ends       true if expansion is to stop at }
3841   left           if not NULL, a pointer to the first character after the
3842                  expansion is placed here (typically used with ket_ends)
3843   skipping       TRUE for recursive calls when the value isn't actually going
3844                  to be used (to allow for optimisation)
3845   honour_dollar  TRUE if $ is to be expanded,
3846                  FALSE if it's just another character
3847   resetok_p      if not NULL, pointer to flag - write FALSE if unsafe to reset
3848                  the store.
3849
3850 Returns:         NULL if expansion fails:
3851                    expand_string_forcedfail is set TRUE if failure was forced
3852                    expand_string_message contains a textual error message
3853                  a pointer to the expanded string on success
3854 */
3855
3856 static uschar *
3857 expand_string_internal(const uschar *string, BOOL ket_ends, const uschar **left,
3858   BOOL skipping, BOOL honour_dollar, BOOL *resetok_p)
3859 {
3860 int ptr = 0;
3861 int size = Ustrlen(string)+ 64;
3862 uschar *yield = store_get(size);
3863 int item_type;
3864 const uschar *s = string;
3865 uschar *save_expand_nstring[EXPAND_MAXN+1];
3866 int save_expand_nlength[EXPAND_MAXN+1];
3867 BOOL resetok = TRUE;
3868
3869 expand_level++;
3870 DEBUG(D_expand)
3871   debug_printf_indent(UTF8_DOWN_RIGHT "%s: %s\n",
3872     skipping
3873     ? UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ "scanning"
3874     : "considering",
3875     string);
3876
3877 expand_string_forcedfail = FALSE;
3878 expand_string_message = US"";
3879
3880 while (*s != 0)
3881   {
3882   uschar *value;
3883   uschar name[256];
3884
3885   /* \ escapes the next character, which must exist, or else
3886   the expansion fails. There's a special escape, \N, which causes
3887   copying of the subject verbatim up to the next \N. Otherwise,
3888   the escapes are the standard set. */
3889
3890   if (*s == '\\')
3891     {
3892     if (s[1] == 0)
3893       {
3894       expand_string_message = US"\\ at end of string";
3895       goto EXPAND_FAILED;
3896       }
3897
3898     if (s[1] == 'N')
3899       {
3900       const uschar * t = s + 2;
3901       for (s = t; *s != 0; s++) if (*s == '\\' && s[1] == 'N') break;
3902       yield = string_catn(yield, &size, &ptr, t, s - t);
3903       if (*s != 0) s += 2;
3904       }
3905
3906     else
3907       {
3908       uschar ch[1];
3909       ch[0] = string_interpret_escape(&s);
3910       s++;
3911       yield = string_catn(yield, &size, &ptr, ch, 1);
3912       }
3913
3914     continue;
3915     }
3916
3917   /*{*/
3918   /* Anything other than $ is just copied verbatim, unless we are
3919   looking for a terminating } character. */
3920
3921   /*{*/
3922   if (ket_ends && *s == '}') break;
3923
3924   if (*s != '$' || !honour_dollar)
3925     {
3926     yield = string_catn(yield, &size, &ptr, s++, 1);
3927     continue;
3928     }
3929
3930   /* No { after the $ - must be a plain name or a number for string
3931   match variable. There has to be a fudge for variables that are the
3932   names of header fields preceded by "$header_" because header field
3933   names can contain any printing characters except space and colon.
3934   For those that don't like typing this much, "$h_" is a synonym for
3935   "$header_". A non-existent header yields a NULL value; nothing is
3936   inserted. */  /*}*/
3937
3938   if (isalpha((*(++s))))
3939     {
3940     int len;
3941     int newsize = 0;
3942
3943     s = read_name(name, sizeof(name), s, US"_");
3944
3945     /* If this is the first thing to be expanded, release the pre-allocated
3946     buffer. */
3947
3948     if (ptr == 0 && yield != NULL)
3949       {
3950       if (resetok) store_reset(yield);
3951       yield = NULL;
3952       size = 0;
3953       }
3954
3955     /* Header */
3956
3957     if (Ustrncmp(name, "h_", 2) == 0 ||
3958         Ustrncmp(name, "rh_", 3) == 0 ||
3959         Ustrncmp(name, "bh_", 3) == 0 ||
3960         Ustrncmp(name, "header_", 7) == 0 ||
3961         Ustrncmp(name, "rheader_", 8) == 0 ||
3962         Ustrncmp(name, "bheader_", 8) == 0)
3963       {
3964       BOOL want_raw = (name[0] == 'r')? TRUE : FALSE;
3965       uschar *charset = (name[0] == 'b')? NULL : headers_charset;
3966       s = read_header_name(name, sizeof(name), s);
3967       value = find_header(name, FALSE, &newsize, want_raw, charset);
3968
3969       /* If we didn't find the header, and the header contains a closing brace
3970       character, this may be a user error where the terminating colon
3971       has been omitted. Set a flag to adjust the error message in this case.
3972       But there is no error here - nothing gets inserted. */
3973
3974       if (value == NULL)
3975         {
3976         if (Ustrchr(name, '}') != NULL) malformed_header = TRUE;
3977         continue;
3978         }
3979       }
3980
3981     /* Variable */
3982
3983     else if (!(value = find_variable(name, FALSE, skipping, &newsize)))
3984       {
3985       expand_string_message =
3986         string_sprintf("unknown variable name \"%s\"", name);
3987         check_variable_error_message(name);
3988       goto EXPAND_FAILED;
3989       }
3990
3991     /* If the data is known to be in a new buffer, newsize will be set to the
3992     size of that buffer. If this is the first thing in an expansion string,
3993     yield will be NULL; just point it at the new store instead of copying. Many
3994     expansion strings contain just one reference, so this is a useful
3995     optimization, especially for humungous headers. */
3996
3997     len = Ustrlen(value);
3998     if (yield == NULL && newsize != 0)
3999       {
4000       yield = value;
4001       size = newsize;
4002       ptr = len;
4003       }
4004     else yield = string_catn(yield, &size, &ptr, value, len);
4005
4006     continue;
4007     }
4008
4009   if (isdigit(*s))
4010     {
4011     int n;
4012     s = read_cnumber(&n, s);
4013     if (n >= 0 && n <= expand_nmax)
4014       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4015         expand_nlength[n]);
4016     continue;
4017     }
4018
4019   /* Otherwise, if there's no '{' after $ it's an error. */             /*}*/
4020
4021   if (*s != '{')                                                        /*}*/
4022     {
4023     expand_string_message = US"$ not followed by letter, digit, or {";  /*}*/
4024     goto EXPAND_FAILED;
4025     }
4026
4027   /* After { there can be various things, but they all start with
4028   an initial word, except for a number for a string match variable. */
4029
4030   if (isdigit((*(++s))))
4031     {
4032     int n;
4033     s = read_cnumber(&n, s);            /*{*/
4034     if (*s++ != '}')
4035       {                                 /*{*/
4036       expand_string_message = US"} expected after number";
4037       goto EXPAND_FAILED;
4038       }
4039     if (n >= 0 && n <= expand_nmax)
4040       yield = string_catn(yield, &size, &ptr, expand_nstring[n],
4041         expand_nlength[n]);
4042     continue;
4043     }
4044
4045   if (!isalpha(*s))
4046     {
4047     expand_string_message = US"letter or digit expected after ${";      /*}*/
4048     goto EXPAND_FAILED;
4049     }
4050
4051   /* Allow "-" in names to cater for substrings with negative
4052   arguments. Since we are checking for known names after { this is
4053   OK. */
4054
4055   s = read_name(name, sizeof(name), s, US"_-");
4056   item_type = chop_match(name, item_table, nelem(item_table));
4057
4058   switch(item_type)
4059     {
4060     /* Call an ACL from an expansion.  We feed data in via $acl_arg1 - $acl_arg9.
4061     If the ACL returns accept or reject we return content set by "message ="
4062     There is currently no limit on recursion; this would have us call
4063     acl_check_internal() directly and get a current level from somewhere.
4064     See also the acl expansion condition ECOND_ACL and the traditional
4065     acl modifier ACLC_ACL.
4066     Assume that the function has side-effects on the store that must be preserved.
4067     */
4068
4069     case EITEM_ACL:
4070       /* ${acl {name} {arg1}{arg2}...} */
4071       {
4072       uschar *sub[10];  /* name + arg1-arg9 (which must match number of acl_arg[]) */
4073       uschar *user_msg;
4074
4075       switch(read_subs(sub, nelem(sub), 1, &s, skipping, TRUE, US"acl",
4076                       &resetok))
4077         {
4078         case 1: goto EXPAND_FAILED_CURLY;
4079         case 2:
4080         case 3: goto EXPAND_FAILED;
4081         }
4082       if (skipping) continue;
4083
4084       resetok = FALSE;
4085       switch(eval_acl(sub, nelem(sub), &user_msg))
4086         {
4087         case OK:
4088         case FAIL:
4089           DEBUG(D_expand)
4090             debug_printf_indent("acl expansion yield: %s\n", user_msg);
4091           if (user_msg)
4092             yield = string_cat(yield, &size, &ptr, user_msg);
4093           continue;
4094
4095         case DEFER:
4096           expand_string_forcedfail = TRUE;
4097           /*FALLTHROUGH*/
4098         default:
4099           expand_string_message = string_sprintf("error from acl \"%s\"", sub[0]);
4100           goto EXPAND_FAILED;
4101         }
4102       }
4103
4104     /* Handle conditionals - preserve the values of the numerical expansion
4105     variables in case they get changed by a regular expression match in the
4106     condition. If not, they retain their external settings. At the end
4107     of this "if" section, they get restored to their previous values. */
4108
4109     case EITEM_IF:
4110       {
4111       BOOL cond = FALSE;
4112       const uschar *next_s;
4113       int save_expand_nmax =
4114         save_expand_strings(save_expand_nstring, save_expand_nlength);
4115
4116       while (isspace(*s)) s++;
4117       next_s = eval_condition(s, &resetok, skipping ? NULL : &cond);
4118       if (next_s == NULL) goto EXPAND_FAILED;  /* message already set */
4119
4120       DEBUG(D_expand)
4121         {
4122         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4123           "condition: %.*s\n",
4124           (int)(next_s - s), s);
4125         debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
4126           UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
4127           "result: %s\n",
4128           cond ? "true" : "false");
4129         }
4130
4131       s = next_s;
4132
4133       /* The handling of "yes" and "no" result strings is now in a separate
4134       function that is also used by ${lookup} and ${extract} and ${run}. */
4135
4136       switch(process_yesno(
4137                skipping,                     /* were previously skipping */
4138                cond,                         /* success/failure indicator */
4139                lookup_value,                 /* value to reset for string2 */
4140                &s,                           /* input pointer */
4141                &yield,                       /* output pointer */
4142                &size,                        /* output size */
4143                &ptr,                         /* output current point */
4144                US"if",                       /* condition type */
4145                &resetok))
4146         {
4147         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4148         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4149         }
4150
4151       /* Restore external setting of expansion variables for continuation
4152       at this level. */
4153
4154       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4155         save_expand_nlength);
4156       continue;
4157       }
4158
4159 #ifdef SUPPORT_I18N
4160     case EITEM_IMAPFOLDER:
4161       {                         /* ${imapfolder {name}{sep]{specials}} */
4162       uschar *sub_arg[3];
4163       uschar *encoded;
4164
4165       switch(read_subs(sub_arg, nelem(sub_arg), 1, &s, skipping, TRUE, name,
4166                       &resetok))
4167         {
4168         case 1: goto EXPAND_FAILED_CURLY;
4169         case 2:
4170         case 3: goto EXPAND_FAILED;
4171         }
4172
4173       if (sub_arg[1] == NULL)           /* One argument */
4174         {
4175         sub_arg[1] = US"/";             /* default separator */
4176         sub_arg[2] = NULL;
4177         }
4178       else if (Ustrlen(sub_arg[1]) != 1)
4179         {
4180         expand_string_message =
4181           string_sprintf(
4182                 "IMAP folder separator must be one character, found \"%s\"",
4183                 sub_arg[1]);
4184         goto EXPAND_FAILED;
4185         }
4186
4187       if (!skipping)
4188         {
4189         if (!(encoded = imap_utf7_encode(sub_arg[0], headers_charset,
4190                             sub_arg[1][0], sub_arg[2], &expand_string_message)))
4191           goto EXPAND_FAILED;
4192         yield = string_cat(yield, &size, &ptr, encoded);
4193         }
4194       continue;
4195       }
4196 #endif
4197
4198     /* Handle database lookups unless locked out. If "skipping" is TRUE, we are
4199     expanding an internal string that isn't actually going to be used. All we
4200     need to do is check the syntax, so don't do a lookup at all. Preserve the
4201     values of the numerical expansion variables in case they get changed by a
4202     partial lookup. If not, they retain their external settings. At the end
4203     of this "lookup" section, they get restored to their previous values. */
4204
4205     case EITEM_LOOKUP:
4206       {
4207       int stype, partial, affixlen, starflags;
4208       int expand_setup = 0;
4209       int nameptr = 0;
4210       uschar *key, *filename;
4211       const uschar *affix;
4212       uschar *save_lookup_value = lookup_value;
4213       int save_expand_nmax =
4214         save_expand_strings(save_expand_nstring, save_expand_nlength);
4215
4216       if ((expand_forbid & RDO_LOOKUP) != 0)
4217         {
4218         expand_string_message = US"lookup expansions are not permitted";
4219         goto EXPAND_FAILED;
4220         }
4221
4222       /* Get the key we are to look up for single-key+file style lookups.
4223       Otherwise set the key NULL pro-tem. */
4224
4225       while (isspace(*s)) s++;
4226       if (*s == '{')                                    /*}*/
4227         {
4228         key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4229         if (!key) goto EXPAND_FAILED;                   /*{{*/
4230         if (*s++ != '}')
4231           {
4232           expand_string_message = US"missing '}' after lookup key";
4233           goto EXPAND_FAILED_CURLY;
4234           }
4235         while (isspace(*s)) s++;
4236         }
4237       else key = NULL;
4238
4239       /* Find out the type of database */
4240
4241       if (!isalpha(*s))
4242         {
4243         expand_string_message = US"missing lookup type";
4244         goto EXPAND_FAILED;
4245         }
4246
4247       /* The type is a string that may contain special characters of various
4248       kinds. Allow everything except space or { to appear; the actual content
4249       is checked by search_findtype_partial. */         /*}*/
4250
4251       while (*s != 0 && *s != '{' && !isspace(*s))      /*}*/
4252         {
4253         if (nameptr < sizeof(name) - 1) name[nameptr++] = *s;
4254         s++;
4255         }
4256       name[nameptr] = 0;
4257       while (isspace(*s)) s++;
4258
4259       /* Now check for the individual search type and any partial or default
4260       options. Only those types that are actually in the binary are valid. */
4261
4262       stype = search_findtype_partial(name, &partial, &affix, &affixlen,
4263         &starflags);
4264       if (stype < 0)
4265         {
4266         expand_string_message = search_error_message;
4267         goto EXPAND_FAILED;
4268         }
4269
4270       /* Check that a key was provided for those lookup types that need it,
4271       and was not supplied for those that use the query style. */
4272
4273       if (!mac_islookup(stype, lookup_querystyle|lookup_absfilequery))
4274         {
4275         if (key == NULL)
4276           {
4277           expand_string_message = string_sprintf("missing {key} for single-"
4278             "key \"%s\" lookup", name);
4279           goto EXPAND_FAILED;
4280           }
4281         }
4282       else
4283         {
4284         if (key != NULL)
4285           {
4286           expand_string_message = string_sprintf("a single key was given for "
4287             "lookup type \"%s\", which is not a single-key lookup type", name);
4288           goto EXPAND_FAILED;
4289           }
4290         }
4291
4292       /* Get the next string in brackets and expand it. It is the file name for
4293       single-key+file lookups, and the whole query otherwise. In the case of
4294       queries that also require a file name (e.g. sqlite), the file name comes
4295       first. */
4296
4297       if (*s != '{')
4298         {
4299         expand_string_message = US"missing '{' for lookup file-or-query arg";
4300         goto EXPAND_FAILED_CURLY;
4301         }
4302       filename = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4303       if (filename == NULL) goto EXPAND_FAILED;
4304       if (*s++ != '}')
4305         {
4306         expand_string_message = US"missing '}' closing lookup file-or-query arg";
4307         goto EXPAND_FAILED_CURLY;
4308         }
4309       while (isspace(*s)) s++;
4310
4311       /* If this isn't a single-key+file lookup, re-arrange the variables
4312       to be appropriate for the search_ functions. For query-style lookups,
4313       there is just a "key", and no file name. For the special query-style +
4314       file types, the query (i.e. "key") starts with a file name. */
4315
4316       if (!key)
4317         {
4318         while (isspace(*filename)) filename++;
4319         key = filename;
4320
4321         if (mac_islookup(stype, lookup_querystyle))
4322           filename = NULL;
4323         else
4324           {
4325           if (*filename != '/')
4326             {
4327             expand_string_message = string_sprintf(
4328               "absolute file name expected for \"%s\" lookup", name);
4329             goto EXPAND_FAILED;
4330             }
4331           while (*key != 0 && !isspace(*key)) key++;
4332           if (*key != 0) *key++ = 0;
4333           }
4334         }
4335
4336       /* If skipping, don't do the next bit - just lookup_value == NULL, as if
4337       the entry was not found. Note that there is no search_close() function.
4338       Files are left open in case of re-use. At suitable places in higher logic,
4339       search_tidyup() is called to tidy all open files. This can save opening
4340       the same file several times. However, files may also get closed when
4341       others are opened, if too many are open at once. The rule is that a
4342       handle should not be used after a second search_open().
4343
4344       Request that a partial search sets up $1 and maybe $2 by passing
4345       expand_setup containing zero. If its value changes, reset expand_nmax,
4346       since new variables will have been set. Note that at the end of this
4347       "lookup" section, the old numeric variables are restored. */
4348
4349       if (skipping)
4350         lookup_value = NULL;
4351       else
4352         {
4353         void *handle = search_open(filename, stype, 0, NULL, NULL);
4354         if (handle == NULL)
4355           {
4356           expand_string_message = search_error_message;
4357           goto EXPAND_FAILED;
4358           }
4359         lookup_value = search_find(handle, filename, key, partial, affix,
4360           affixlen, starflags, &expand_setup);
4361         if (search_find_defer)
4362           {
4363           expand_string_message =
4364             string_sprintf("lookup of \"%s\" gave DEFER: %s",
4365               string_printing2(key, FALSE), search_error_message);
4366           goto EXPAND_FAILED;
4367           }
4368         if (expand_setup > 0) expand_nmax = expand_setup;
4369         }
4370
4371       /* The handling of "yes" and "no" result strings is now in a separate
4372       function that is also used by ${if} and ${extract}. */
4373
4374       switch(process_yesno(
4375                skipping,                     /* were previously skipping */
4376                lookup_value != NULL,         /* success/failure indicator */
4377                save_lookup_value,            /* value to reset for string2 */
4378                &s,                           /* input pointer */
4379                &yield,                       /* output pointer */
4380                &size,                        /* output size */
4381                &ptr,                         /* output current point */
4382                US"lookup",                   /* condition type */
4383                &resetok))
4384         {
4385         case 1: goto EXPAND_FAILED;          /* when all is well, the */
4386         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
4387         }
4388
4389       /* Restore external setting of expansion variables for carrying on
4390       at this level, and continue. */
4391
4392       restore_expand_strings(save_expand_nmax, save_expand_nstring,
4393         save_expand_nlength);
4394       continue;
4395       }
4396
4397     /* If Perl support is configured, handle calling embedded perl subroutines,
4398     unless locked out at this time. Syntax is ${perl{sub}} or ${perl{sub}{arg}}
4399     or ${perl{sub}{arg1}{arg2}} or up to a maximum of EXIM_PERL_MAX_ARGS
4400     arguments (defined below). */
4401
4402     #define EXIM_PERL_MAX_ARGS 8
4403
4404     case EITEM_PERL:
4405     #ifndef EXIM_PERL
4406     expand_string_message = US"\"${perl\" encountered, but this facility "      /*}*/
4407       "is not included in this binary";
4408     goto EXPAND_FAILED;
4409
4410     #else   /* EXIM_PERL */
4411       {
4412       uschar *sub_arg[EXIM_PERL_MAX_ARGS + 2];
4413       uschar *new_yield;
4414
4415       if ((expand_forbid & RDO_PERL) != 0)
4416         {
4417         expand_string_message = US"Perl calls are not permitted";
4418         goto EXPAND_FAILED;
4419         }
4420
4421       switch(read_subs(sub_arg, EXIM_PERL_MAX_ARGS + 1, 1, &s, skipping, TRUE,
4422            US"perl", &resetok))
4423         {
4424         case 1: goto EXPAND_FAILED_CURLY;
4425         case 2:
4426         case 3: goto EXPAND_FAILED;
4427         }
4428
4429       /* If skipping, we don't actually do anything */
4430
4431       if (skipping) continue;
4432
4433       /* Start the interpreter if necessary */
4434
4435       if (!opt_perl_started)
4436         {
4437         uschar *initerror;
4438         if (opt_perl_startup == NULL)
4439           {
4440           expand_string_message = US"A setting of perl_startup is needed when "
4441             "using the Perl interpreter";
4442           goto EXPAND_FAILED;
4443           }
4444         DEBUG(D_any) debug_printf("Starting Perl interpreter\n");
4445         initerror = init_perl(opt_perl_startup);
4446         if (initerror != NULL)
4447           {
4448           expand_string_message =
4449             string_sprintf("error in perl_startup code: %s\n", initerror);
4450           goto EXPAND_FAILED;
4451           }
4452         opt_perl_started = TRUE;
4453         }
4454
4455       /* Call the function */
4456
4457       sub_arg[EXIM_PERL_MAX_ARGS + 1] = NULL;
4458       new_yield = call_perl_cat(yield, &size, &ptr, &expand_string_message,
4459         sub_arg[0], sub_arg + 1);
4460
4461       /* NULL yield indicates failure; if the message pointer has been set to
4462       NULL, the yield was undef, indicating a forced failure. Otherwise the
4463       message will indicate some kind of Perl error. */
4464
4465       if (new_yield == NULL)
4466         {
4467         if (expand_string_message == NULL)
4468           {
4469           expand_string_message =
4470             string_sprintf("Perl subroutine \"%s\" returned undef to force "
4471               "failure", sub_arg[0]);
4472           expand_string_forcedfail = TRUE;
4473           }
4474         goto EXPAND_FAILED;
4475         }
4476
4477       /* Yield succeeded. Ensure forcedfail is unset, just in case it got
4478       set during a callback from Perl. */
4479
4480       expand_string_forcedfail = FALSE;
4481       yield = new_yield;
4482       continue;
4483       }
4484     #endif /* EXIM_PERL */
4485
4486     /* Transform email address to "prvs" scheme to use
4487        as BATV-signed return path */
4488
4489     case EITEM_PRVS:
4490       {
4491       uschar *sub_arg[3];
4492       uschar *p,*domain;
4493
4494       switch(read_subs(sub_arg, 3, 2, &s, skipping, TRUE, US"prvs", &resetok))
4495         {
4496         case 1: goto EXPAND_FAILED_CURLY;
4497         case 2:
4498         case 3: goto EXPAND_FAILED;
4499         }
4500
4501       /* If skipping, we don't actually do anything */
4502       if (skipping) continue;
4503
4504       /* sub_arg[0] is the address */
4505       domain = Ustrrchr(sub_arg[0],'@');
4506       if ( (domain == NULL) || (domain == sub_arg[0]) || (Ustrlen(domain) == 1) )
4507         {
4508         expand_string_message = US"prvs first argument must be a qualified email address";
4509         goto EXPAND_FAILED;
4510         }
4511
4512       /* Calculate the hash. The second argument must be a single-digit
4513       key number, or unset. */
4514
4515       if (sub_arg[2] != NULL &&
4516           (!isdigit(sub_arg[2][0]) || sub_arg[2][1] != 0))
4517         {
4518         expand_string_message = US"prvs second argument must be a single digit";
4519         goto EXPAND_FAILED;
4520         }
4521
4522       p = prvs_hmac_sha1(sub_arg[0],sub_arg[1],sub_arg[2],prvs_daystamp(7));
4523       if (p == NULL)
4524         {
4525         expand_string_message = US"prvs hmac-sha1 conversion failed";
4526         goto EXPAND_FAILED;
4527         }
4528
4529       /* Now separate the domain from the local part */
4530       *domain++ = '\0';
4531
4532       yield = string_catn(yield, &size, &ptr, US"prvs=", 5);
4533       yield = string_catn(yield, &size, &ptr, sub_arg[2] ? sub_arg[2] : US"0", 1);
4534       yield = string_catn(yield, &size, &ptr, prvs_daystamp(7), 3);
4535       yield = string_catn(yield, &size, &ptr, p, 6);
4536       yield = string_catn(yield, &size, &ptr, US"=", 1);
4537       yield = string_cat (yield, &size, &ptr, sub_arg[0]);
4538       yield = string_catn(yield, &size, &ptr, US"@", 1);
4539       yield = string_cat (yield, &size, &ptr, domain);
4540
4541       continue;
4542       }
4543
4544     /* Check a prvs-encoded address for validity */
4545
4546     case EITEM_PRVSCHECK:
4547       {
4548       uschar *sub_arg[3];
4549       int mysize = 0, myptr = 0;
4550       const pcre *re;
4551       uschar *p;
4552
4553       /* TF: Ugliness: We want to expand parameter 1 first, then set
4554          up expansion variables that are used in the expansion of
4555          parameter 2. So we clone the string for the first
4556          expansion, where we only expand parameter 1.
4557
4558          PH: Actually, that isn't necessary. The read_subs() function is
4559          designed to work this way for the ${if and ${lookup expansions. I've
4560          tidied the code.
4561       */
4562
4563       /* Reset expansion variables */
4564       prvscheck_result = NULL;
4565       prvscheck_address = NULL;
4566       prvscheck_keynum = NULL;
4567
4568       switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4569         {
4570         case 1: goto EXPAND_FAILED_CURLY;
4571         case 2:
4572         case 3: goto EXPAND_FAILED;
4573         }
4574
4575       re = regex_must_compile(US"^prvs\\=([0-9])([0-9]{3})([A-F0-9]{6})\\=(.+)\\@(.+)$",
4576                               TRUE,FALSE);
4577
4578       if (regex_match_and_setup(re,sub_arg[0],0,-1))
4579         {
4580         uschar *local_part = string_copyn(expand_nstring[4],expand_nlength[4]);
4581         uschar *key_num = string_copyn(expand_nstring[1],expand_nlength[1]);
4582         uschar *daystamp = string_copyn(expand_nstring[2],expand_nlength[2]);
4583         uschar *hash = string_copyn(expand_nstring[3],expand_nlength[3]);
4584         uschar *domain = string_copyn(expand_nstring[5],expand_nlength[5]);
4585
4586         DEBUG(D_expand) debug_printf_indent("prvscheck localpart: %s\n", local_part);
4587         DEBUG(D_expand) debug_printf_indent("prvscheck key number: %s\n", key_num);
4588         DEBUG(D_expand) debug_printf_indent("prvscheck daystamp: %s\n", daystamp);
4589         DEBUG(D_expand) debug_printf_indent("prvscheck hash: %s\n", hash);
4590         DEBUG(D_expand) debug_printf_indent("prvscheck domain: %s\n", domain);
4591
4592         /* Set up expansion variables */
4593         prvscheck_address = string_cat (NULL, &mysize, &myptr, local_part);
4594         prvscheck_address = string_catn(prvscheck_address, &mysize, &myptr, US"@", 1);
4595         prvscheck_address = string_cat (prvscheck_address, &mysize, &myptr, domain);
4596         prvscheck_address[myptr] = '\0';
4597         prvscheck_keynum = string_copy(key_num);
4598
4599         /* Now expand the second argument */
4600         switch(read_subs(sub_arg, 1, 1, &s, skipping, FALSE, US"prvs", &resetok))
4601           {
4602           case 1: goto EXPAND_FAILED_CURLY;
4603           case 2:
4604           case 3: goto EXPAND_FAILED;
4605           }
4606
4607         /* Now we have the key and can check the address. */
4608
4609         p = prvs_hmac_sha1(prvscheck_address, sub_arg[0], prvscheck_keynum,
4610           daystamp);
4611
4612         if (p == NULL)
4613           {
4614           expand_string_message = US"hmac-sha1 conversion failed";
4615           goto EXPAND_FAILED;
4616           }
4617
4618         DEBUG(D_expand) debug_printf_indent("prvscheck: received hash is %s\n", hash);
4619         DEBUG(D_expand) debug_printf_indent("prvscheck:      own hash is %s\n", p);
4620
4621         if (Ustrcmp(p,hash) == 0)
4622           {
4623           /* Success, valid BATV address. Now check the expiry date. */
4624           uschar *now = prvs_daystamp(0);
4625           unsigned int inow = 0,iexpire = 1;
4626
4627           (void)sscanf(CS now,"%u",&inow);
4628           (void)sscanf(CS daystamp,"%u",&iexpire);
4629
4630           /* When "iexpire" is < 7, a "flip" has occured.
4631              Adjust "inow" accordingly. */
4632           if ( (iexpire < 7) && (inow >= 993) ) inow = 0;
4633
4634           if (iexpire >= inow)
4635             {
4636             prvscheck_result = US"1";
4637             DEBUG(D_expand) debug_printf_indent("prvscheck: success, $pvrs_result set to 1\n");
4638             }
4639             else
4640             {
4641             prvscheck_result = NULL;
4642             DEBUG(D_expand) debug_printf_indent("prvscheck: signature expired, $pvrs_result unset\n");
4643             }
4644           }
4645         else
4646           {
4647           prvscheck_result = NULL;
4648           DEBUG(D_expand) debug_printf_indent("prvscheck: hash failure, $pvrs_result unset\n");
4649           }
4650
4651         /* Now expand the final argument. We leave this till now so that
4652         it can include $prvscheck_result. */
4653
4654         switch(read_subs(sub_arg, 1, 0, &s, skipping, TRUE, US"prvs", &resetok))
4655           {
4656           case 1: goto EXPAND_FAILED_CURLY;
4657           case 2:
4658           case 3: goto EXPAND_FAILED;
4659           }
4660
4661         yield = string_cat(yield, &size, &ptr,
4662           !sub_arg[0] || !*sub_arg[0] ? prvscheck_address : sub_arg[0]);
4663
4664         /* Reset the "internal" variables afterwards, because they are in
4665         dynamic store that will be reclaimed if the expansion succeeded. */
4666
4667         prvscheck_address = NULL;
4668         prvscheck_keynum = NULL;
4669         }
4670       else
4671         /* Does not look like a prvs encoded address, return the empty string.
4672            We need to make sure all subs are expanded first, so as to skip over
4673            the entire item. */
4674
4675         switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"prvs", &resetok))
4676           {
4677           case 1: goto EXPAND_FAILED_CURLY;
4678           case 2:
4679           case 3: goto EXPAND_FAILED;
4680           }
4681
4682       continue;
4683       }
4684
4685     /* Handle "readfile" to insert an entire file */
4686
4687     case EITEM_READFILE:
4688       {
4689       FILE *f;
4690       uschar *sub_arg[2];
4691
4692       if ((expand_forbid & RDO_READFILE) != 0)
4693         {
4694         expand_string_message = US"file insertions are not permitted";
4695         goto EXPAND_FAILED;
4696         }
4697
4698       switch(read_subs(sub_arg, 2, 1, &s, skipping, TRUE, US"readfile", &resetok))
4699         {
4700         case 1: goto EXPAND_FAILED_CURLY;
4701         case 2:
4702         case 3: goto EXPAND_FAILED;
4703         }
4704
4705       /* If skipping, we don't actually do anything */
4706
4707       if (skipping) continue;
4708
4709       /* Open the file and read it */
4710
4711       if (!(f = Ufopen(sub_arg[0], "rb")))
4712         {
4713         expand_string_message = string_open_failed(errno, "%s", sub_arg[0]);
4714         goto EXPAND_FAILED;
4715         }
4716
4717       yield = cat_file(f, yield, &size, &ptr, sub_arg[1]);
4718       (void)fclose(f);
4719       continue;
4720       }
4721
4722     /* Handle "readsocket" to insert data from a socket, either
4723     Inet or Unix domain */
4724
4725     case EITEM_READSOCK:
4726       {
4727       int fd;
4728       int timeout = 5;
4729       int save_ptr = ptr;
4730       FILE *f;
4731       uschar *arg;
4732       uschar *sub_arg[4];
4733       BOOL do_shutdown = TRUE;
4734       blob reqstr;
4735
4736       if (expand_forbid & RDO_READSOCK)
4737         {
4738         expand_string_message = US"socket insertions are not permitted";
4739         goto EXPAND_FAILED;
4740         }
4741
4742       /* Read up to 4 arguments, but don't do the end of item check afterwards,
4743       because there may be a string for expansion on failure. */
4744
4745       switch(read_subs(sub_arg, 4, 2, &s, skipping, FALSE, US"readsocket", &resetok))
4746         {
4747         case 1: goto EXPAND_FAILED_CURLY;
4748         case 2:                             /* Won't occur: no end check */
4749         case 3: goto EXPAND_FAILED;
4750         }
4751
4752       /* Grab the request string, if any */
4753
4754       reqstr.data = sub_arg[1];
4755       reqstr.len = Ustrlen(sub_arg[1]);
4756
4757       /* Sort out timeout, if given.  The second arg is a list with the first element
4758       being a time value.  Any more are options of form "name=value".  Currently the
4759       only option recognised is "shutdown". */
4760
4761       if (sub_arg[2])
4762         {
4763         const uschar * list = sub_arg[2];
4764         uschar * item;
4765         int sep = 0;
4766
4767         item = string_nextinlist(&list, &sep, NULL, 0);
4768         if ((timeout = readconf_readtime(item, 0, FALSE)) < 0)
4769           {
4770           expand_string_message = string_sprintf("bad time value %s", item);
4771           goto EXPAND_FAILED;
4772           }
4773
4774         while ((item = string_nextinlist(&list, &sep, NULL, 0)))
4775           if (Ustrncmp(item, US"shutdown=", 9) == 0)
4776             if (Ustrcmp(item + 9, US"no") == 0)
4777               do_shutdown = FALSE;
4778         }
4779       else sub_arg[3] = NULL;                     /* No eol if no timeout */
4780
4781       /* If skipping, we don't actually do anything. Otherwise, arrange to
4782       connect to either an IP or a Unix socket. */
4783
4784       if (!skipping)
4785         {
4786         /* Handle an IP (internet) domain */
4787
4788         if (Ustrncmp(sub_arg[0], "inet:", 5) == 0)
4789           {
4790           int port;
4791           uschar * server_name = sub_arg[0] + 5;
4792           uschar * port_name = Ustrrchr(server_name, ':');
4793
4794           /* Sort out the port */
4795
4796           if (!port_name)
4797             {
4798             expand_string_message =
4799               string_sprintf("missing port for readsocket %s", sub_arg[0]);
4800             goto EXPAND_FAILED;
4801             }
4802           *port_name++ = 0;           /* Terminate server name */
4803
4804           if (isdigit(*port_name))
4805             {
4806             uschar *end;
4807             port = Ustrtol(port_name, &end, 0);
4808             if (end != port_name + Ustrlen(port_name))
4809               {
4810               expand_string_message =
4811                 string_sprintf("invalid port number %s", port_name);
4812               goto EXPAND_FAILED;
4813               }
4814             }
4815           else
4816             {
4817             struct servent *service_info = getservbyname(CS port_name, "tcp");
4818             if (!service_info)
4819               {
4820               expand_string_message = string_sprintf("unknown port \"%s\"",
4821                 port_name);
4822               goto EXPAND_FAILED;
4823               }
4824             port = ntohs(service_info->s_port);
4825             }
4826
4827           fd = ip_connectedsocket(SOCK_STREAM, server_name, port, port,
4828                   timeout, NULL, &expand_string_message, &reqstr);
4829           callout_address = NULL;
4830           if (fd < 0)
4831               goto SOCK_FAIL;
4832           reqstr.len = 0;
4833           }
4834
4835         /* Handle a Unix domain socket */
4836
4837         else
4838           {
4839           struct sockaddr_un sockun;         /* don't call this "sun" ! */
4840           int rc;
4841
4842           if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
4843             {
4844             expand_string_message = string_sprintf("failed to create socket: %s",
4845               strerror(errno));
4846             goto SOCK_FAIL;
4847             }
4848
4849           sockun.sun_family = AF_UNIX;
4850           sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1),
4851             sub_arg[0]);
4852
4853           sigalrm_seen = FALSE;
4854           alarm(timeout);
4855           rc = connect(fd, (struct sockaddr *)(&sockun), sizeof(sockun));
4856           alarm(0);
4857           if (sigalrm_seen)
4858             {
4859             expand_string_message = US "socket connect timed out";
4860             goto SOCK_FAIL;
4861             }
4862           if (rc < 0)
4863             {
4864             expand_string_message = string_sprintf("failed to connect to socket "
4865               "%s: %s", sub_arg[0], strerror(errno));
4866             goto SOCK_FAIL;
4867             }
4868           }
4869
4870         DEBUG(D_expand) debug_printf_indent("connected to socket %s\n", sub_arg[0]);
4871
4872         /* Allow sequencing of test actions */
4873         if (running_in_test_harness) millisleep(100);
4874
4875         /* Write the request string, if not empty or already done */
4876
4877         if (reqstr.len)
4878           {
4879           DEBUG(D_expand) debug_printf_indent("writing \"%s\" to socket\n",
4880             reqstr.data);
4881           if (write(fd, reqstr.data, reqstr.len) != reqstr.len)
4882             {
4883             expand_string_message = string_sprintf("request write to socket "
4884               "failed: %s", strerror(errno));
4885             goto SOCK_FAIL;
4886             }
4887           }
4888
4889         /* Shut down the sending side of the socket. This helps some servers to
4890         recognise that it is their turn to do some work. Just in case some
4891         system doesn't have this function, make it conditional. */
4892
4893 #ifdef SHUT_WR
4894         if (do_shutdown) shutdown(fd, SHUT_WR);
4895 #endif
4896
4897         if (running_in_test_harness) millisleep(100);
4898
4899         /* Now we need to read from the socket, under a timeout. The function
4900         that reads a file can be used. */
4901
4902         f = fdopen(fd, "rb");
4903         sigalrm_seen = FALSE;
4904         alarm(timeout);
4905         yield = cat_file(f, yield, &size, &ptr, sub_arg[3]);
4906         alarm(0);
4907         (void)fclose(f);
4908
4909         /* After a timeout, we restore the pointer in the result, that is,
4910         make sure we add nothing from the socket. */
4911
4912         if (sigalrm_seen)
4913           {
4914           ptr = save_ptr;
4915           expand_string_message = US "socket read timed out";
4916           goto SOCK_FAIL;
4917           }
4918         }
4919
4920       /* The whole thing has worked (or we were skipping). If there is a
4921       failure string following, we need to skip it. */
4922
4923       if (*s == '{')
4924         {
4925         if (expand_string_internal(s+1, TRUE, &s, TRUE, TRUE, &resetok) == NULL)
4926           goto EXPAND_FAILED;
4927         if (*s++ != '}')
4928           {
4929           expand_string_message = US"missing '}' closing failstring for readsocket";
4930           goto EXPAND_FAILED_CURLY;
4931           }
4932         while (isspace(*s)) s++;
4933         }
4934
4935     READSOCK_DONE:
4936       if (*s++ != '}')
4937         {
4938         expand_string_message = US"missing '}' closing readsocket";
4939         goto EXPAND_FAILED_CURLY;
4940         }
4941       continue;
4942
4943       /* Come here on failure to create socket, connect socket, write to the
4944       socket, or timeout on reading. If another substring follows, expand and
4945       use it. Otherwise, those conditions give expand errors. */
4946
4947     SOCK_FAIL:
4948       if (*s != '{') goto EXPAND_FAILED;
4949       DEBUG(D_any) debug_printf("%s\n", expand_string_message);
4950       if (!(arg = expand_string_internal(s+1, TRUE, &s, FALSE, TRUE, &resetok)))
4951         goto EXPAND_FAILED;
4952       yield = string_cat(yield, &size, &ptr, arg);
4953       if (*s++ != '}')
4954         {
4955         expand_string_message = US"missing '}' closing failstring for readsocket";
4956         goto EXPAND_FAILED_CURLY;
4957         }
4958       while (isspace(*s)) s++;
4959       goto READSOCK_DONE;
4960       }
4961
4962     /* Handle "run" to execute a program. */
4963
4964     case EITEM_RUN:
4965       {
4966       FILE *f;
4967       uschar *arg;
4968       const uschar **argv;
4969       pid_t pid;
4970       int fd_in, fd_out;
4971       int lsize = 0, lptr = 0;
4972
4973       if ((expand_forbid & RDO_RUN) != 0)
4974         {
4975         expand_string_message = US"running a command is not permitted";
4976         goto EXPAND_FAILED;
4977         }
4978
4979       while (isspace(*s)) s++;
4980       if (*s != '{')
4981         {
4982         expand_string_message = US"missing '{' for command arg of run";
4983         goto EXPAND_FAILED_CURLY;
4984         }
4985       arg = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
4986       if (arg == NULL) goto EXPAND_FAILED;
4987       while (isspace(*s)) s++;
4988       if (*s++ != '}')
4989         {
4990         expand_string_message = US"missing '}' closing command arg of run";
4991         goto EXPAND_FAILED_CURLY;
4992         }
4993
4994       if (skipping)   /* Just pretend it worked when we're skipping */
4995         {
4996         runrc = 0;
4997         lookup_value = NULL;
4998         }
4999       else
5000         {
5001         if (!transport_set_up_command(&argv,    /* anchor for arg list */
5002             arg,                                /* raw command */
5003             FALSE,                              /* don't expand the arguments */
5004             0,                                  /* not relevant when... */
5005             NULL,                               /* no transporting address */
5006             US"${run} expansion",               /* for error messages */
5007             &expand_string_message))            /* where to put error message */
5008           goto EXPAND_FAILED;
5009
5010         /* Create the child process, making it a group leader. */
5011
5012         if ((pid = child_open(USS argv, NULL, 0077, &fd_in, &fd_out, TRUE)) < 0)
5013           {
5014           expand_string_message =
5015             string_sprintf("couldn't create child process: %s", strerror(errno));
5016           goto EXPAND_FAILED;
5017           }
5018
5019         /* Nothing is written to the standard input. */
5020
5021         (void)close(fd_in);
5022
5023         /* Read the pipe to get the command's output into $value (which is kept
5024         in lookup_value). Read during execution, so that if the output exceeds
5025         the OS pipe buffer limit, we don't block forever. Remember to not release
5026         memory just allocated for $value. */
5027
5028         resetok = FALSE;
5029         f = fdopen(fd_out, "rb");
5030         sigalrm_seen = FALSE;
5031         alarm(60);
5032         lookup_value = cat_file(f, NULL, &lsize, &lptr, NULL);
5033         alarm(0);
5034         (void)fclose(f);
5035
5036         /* Wait for the process to finish, applying the timeout, and inspect its
5037         return code for serious disasters. Simple non-zero returns are passed on.
5038         */
5039
5040         if (sigalrm_seen || (runrc = child_close(pid, 30)) < 0)
5041           {
5042           if (sigalrm_seen || runrc == -256)
5043             {
5044             expand_string_message = string_sprintf("command timed out");
5045             killpg(pid, SIGKILL);       /* Kill the whole process group */
5046             }
5047
5048           else if (runrc == -257)
5049             expand_string_message = string_sprintf("wait() failed: %s",
5050               strerror(errno));
5051
5052           else
5053             expand_string_message = string_sprintf("command killed by signal %d",
5054               -runrc);
5055
5056           goto EXPAND_FAILED;
5057           }
5058         }
5059
5060       /* Process the yes/no strings; $value may be useful in both cases */
5061
5062       switch(process_yesno(
5063                skipping,                     /* were previously skipping */
5064                runrc == 0,                   /* success/failure indicator */
5065                lookup_value,                 /* value to reset for string2 */
5066                &s,                           /* input pointer */
5067                &yield,                       /* output pointer */
5068                &size,                        /* output size */
5069                &ptr,                         /* output current point */
5070                US"run",                      /* condition type */
5071                &resetok))
5072         {
5073         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5074         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5075         }
5076
5077       continue;
5078       }
5079
5080     /* Handle character translation for "tr" */
5081
5082     case EITEM_TR:
5083       {
5084       int oldptr = ptr;
5085       int o2m;
5086       uschar *sub[3];
5087
5088       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"tr", &resetok))
5089         {
5090         case 1: goto EXPAND_FAILED_CURLY;
5091         case 2:
5092         case 3: goto EXPAND_FAILED;
5093         }
5094
5095       yield = string_cat(yield, &size, &ptr, sub[0]);
5096       o2m = Ustrlen(sub[2]) - 1;
5097
5098       if (o2m >= 0) for (; oldptr < ptr; oldptr++)
5099         {
5100         uschar *m = Ustrrchr(sub[1], yield[oldptr]);
5101         if (m != NULL)
5102           {
5103           int o = m - sub[1];
5104           yield[oldptr] = sub[2][(o < o2m)? o : o2m];
5105           }
5106         }
5107
5108       continue;
5109       }
5110
5111     /* Handle "hash", "length", "nhash", and "substr" when they are given with
5112     expanded arguments. */
5113
5114     case EITEM_HASH:
5115     case EITEM_LENGTH:
5116     case EITEM_NHASH:
5117     case EITEM_SUBSTR:
5118       {
5119       int i;
5120       int len;
5121       uschar *ret;
5122       int val[2] = { 0, -1 };
5123       uschar *sub[3];
5124
5125       /* "length" takes only 2 arguments whereas the others take 2 or 3.
5126       Ensure that sub[2] is set in the ${length } case. */
5127
5128       sub[2] = NULL;
5129       switch(read_subs(sub, (item_type == EITEM_LENGTH)? 2:3, 2, &s, skipping,
5130              TRUE, name, &resetok))
5131         {
5132         case 1: goto EXPAND_FAILED_CURLY;
5133         case 2:
5134         case 3: goto EXPAND_FAILED;
5135         }
5136
5137       /* Juggle the arguments if there are only two of them: always move the
5138       string to the last position and make ${length{n}{str}} equivalent to
5139       ${substr{0}{n}{str}}. See the defaults for val[] above. */
5140
5141       if (sub[2] == NULL)
5142         {
5143         sub[2] = sub[1];
5144         sub[1] = NULL;
5145         if (item_type == EITEM_LENGTH)
5146           {
5147           sub[1] = sub[0];
5148           sub[0] = NULL;
5149           }
5150         }
5151
5152       for (i = 0; i < 2; i++)
5153         {
5154         if (sub[i] == NULL) continue;
5155         val[i] = (int)Ustrtol(sub[i], &ret, 10);
5156         if (*ret != 0 || (i != 0 && val[i] < 0))
5157           {
5158           expand_string_message = string_sprintf("\"%s\" is not a%s number "
5159             "(in \"%s\" expansion)", sub[i], (i != 0)? " positive" : "", name);
5160           goto EXPAND_FAILED;
5161           }
5162         }
5163
5164       ret =
5165         (item_type == EITEM_HASH)?
5166           compute_hash(sub[2], val[0], val[1], &len) :
5167         (item_type == EITEM_NHASH)?
5168           compute_nhash(sub[2], val[0], val[1], &len) :
5169           extract_substr(sub[2], val[0], val[1], &len);
5170
5171       if (ret == NULL) goto EXPAND_FAILED;
5172       yield = string_catn(yield, &size, &ptr, ret, len);
5173       continue;
5174       }
5175
5176     /* Handle HMAC computation: ${hmac{<algorithm>}{<secret>}{<text>}}
5177     This code originally contributed by Steve Haslam. It currently supports
5178     the use of MD5 and SHA-1 hashes.
5179
5180     We need some workspace that is large enough to handle all the supported
5181     hash types. Use macros to set the sizes rather than be too elaborate. */
5182
5183     #define MAX_HASHLEN      20
5184     #define MAX_HASHBLOCKLEN 64
5185
5186     case EITEM_HMAC:
5187       {
5188       uschar *sub[3];
5189       md5 md5_base;
5190       hctx sha1_ctx;
5191       void *use_base;
5192       int type, i;
5193       int hashlen;      /* Number of octets for the hash algorithm's output */
5194       int hashblocklen; /* Number of octets the hash algorithm processes */
5195       uschar *keyptr, *p;
5196       unsigned int keylen;
5197
5198       uschar keyhash[MAX_HASHLEN];
5199       uschar innerhash[MAX_HASHLEN];
5200       uschar finalhash[MAX_HASHLEN];
5201       uschar finalhash_hex[2*MAX_HASHLEN];
5202       uschar innerkey[MAX_HASHBLOCKLEN];
5203       uschar outerkey[MAX_HASHBLOCKLEN];
5204
5205       switch (read_subs(sub, 3, 3, &s, skipping, TRUE, name, &resetok))
5206         {
5207         case 1: goto EXPAND_FAILED_CURLY;
5208         case 2:
5209         case 3: goto EXPAND_FAILED;
5210         }
5211
5212       if (!skipping)
5213         {
5214         if (Ustrcmp(sub[0], "md5") == 0)
5215           {
5216           type = HMAC_MD5;
5217           use_base = &md5_base;
5218           hashlen = 16;
5219           hashblocklen = 64;
5220           }
5221         else if (Ustrcmp(sub[0], "sha1") == 0)
5222           {
5223           type = HMAC_SHA1;
5224           use_base = &sha1_ctx;
5225           hashlen = 20;
5226           hashblocklen = 64;
5227           }
5228         else
5229           {
5230           expand_string_message =
5231             string_sprintf("hmac algorithm \"%s\" is not recognised", sub[0]);
5232           goto EXPAND_FAILED;
5233           }
5234
5235         keyptr = sub[1];
5236         keylen = Ustrlen(keyptr);
5237
5238         /* If the key is longer than the hash block length, then hash the key
5239         first */
5240
5241         if (keylen > hashblocklen)
5242           {
5243           chash_start(type, use_base);
5244           chash_end(type, use_base, keyptr, keylen, keyhash);
5245           keyptr = keyhash;
5246           keylen = hashlen;
5247           }
5248
5249         /* Now make the inner and outer key values */
5250
5251         memset(innerkey, 0x36, hashblocklen);
5252         memset(outerkey, 0x5c, hashblocklen);
5253
5254         for (i = 0; i < keylen; i++)
5255           {
5256           innerkey[i] ^= keyptr[i];
5257           outerkey[i] ^= keyptr[i];
5258           }
5259
5260         /* Now do the hashes */
5261
5262         chash_start(type, use_base);
5263         chash_mid(type, use_base, innerkey);
5264         chash_end(type, use_base, sub[2], Ustrlen(sub[2]), innerhash);
5265
5266         chash_start(type, use_base);
5267         chash_mid(type, use_base, outerkey);
5268         chash_end(type, use_base, innerhash, hashlen, finalhash);
5269
5270         /* Encode the final hash as a hex string */
5271
5272         p = finalhash_hex;
5273         for (i = 0; i < hashlen; i++)
5274           {
5275           *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
5276           *p++ = hex_digits[finalhash[i] & 0x0f];
5277           }
5278
5279         DEBUG(D_any) debug_printf("HMAC[%s](%.*s,%s)=%.*s\n",
5280           sub[0], (int)keylen, keyptr, sub[2], hashlen*2, finalhash_hex);
5281
5282         yield = string_catn(yield, &size, &ptr, finalhash_hex, hashlen*2);
5283         }
5284       continue;
5285       }
5286
5287     /* Handle global substitution for "sg" - like Perl's s/xxx/yyy/g operator.
5288     We have to save the numerical variables and restore them afterwards. */
5289
5290     case EITEM_SG:
5291       {
5292       const pcre *re;
5293       int moffset, moffsetextra, slen;
5294       int roffset;
5295       int emptyopt;
5296       const uschar *rerror;
5297       uschar *subject;
5298       uschar *sub[3];
5299       int save_expand_nmax =
5300         save_expand_strings(save_expand_nstring, save_expand_nlength);
5301
5302       switch(read_subs(sub, 3, 3, &s, skipping, TRUE, US"sg", &resetok))
5303         {
5304         case 1: goto EXPAND_FAILED_CURLY;
5305         case 2:
5306         case 3: goto EXPAND_FAILED;
5307         }
5308
5309       /* Compile the regular expression */
5310
5311       re = pcre_compile(CS sub[1], PCRE_COPT, (const char **)&rerror, &roffset,
5312         NULL);
5313
5314       if (re == NULL)
5315         {
5316         expand_string_message = string_sprintf("regular expression error in "
5317           "\"%s\": %s at offset %d", sub[1], rerror, roffset);
5318         goto EXPAND_FAILED;
5319         }
5320
5321       /* Now run a loop to do the substitutions as often as necessary. It ends
5322       when there are no more matches. Take care over matches of the null string;
5323       do the same thing as Perl does. */
5324
5325       subject = sub[0];
5326       slen = Ustrlen(sub[0]);
5327       moffset = moffsetextra = 0;
5328       emptyopt = 0;
5329
5330       for (;;)
5331         {
5332         int ovector[3*(EXPAND_MAXN+1)];
5333         int n = pcre_exec(re, NULL, CS subject, slen, moffset + moffsetextra,
5334           PCRE_EOPT | emptyopt, ovector, nelem(ovector));
5335         int nn;
5336         uschar *insert;
5337
5338         /* No match - if we previously set PCRE_NOTEMPTY after a null match, this
5339         is not necessarily the end. We want to repeat the match from one
5340         character further along, but leaving the basic offset the same (for
5341         copying below). We can't be at the end of the string - that was checked
5342         before setting PCRE_NOTEMPTY. If PCRE_NOTEMPTY is not set, we are
5343         finished; copy the remaining string and end the loop. */
5344
5345         if (n < 0)
5346           {
5347           if (emptyopt != 0)
5348             {
5349             moffsetextra = 1;
5350             emptyopt = 0;
5351             continue;
5352             }
5353           yield = string_catn(yield, &size, &ptr, subject+moffset, slen-moffset);
5354           break;
5355           }
5356
5357         /* Match - set up for expanding the replacement. */
5358
5359         if (n == 0) n = EXPAND_MAXN + 1;
5360         expand_nmax = 0;
5361         for (nn = 0; nn < n*2; nn += 2)
5362           {
5363           expand_nstring[expand_nmax] = subject + ovector[nn];
5364           expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
5365           }
5366         expand_nmax--;
5367
5368         /* Copy the characters before the match, plus the expanded insertion. */
5369
5370         yield = string_catn(yield, &size, &ptr, subject + moffset,
5371           ovector[0] - moffset);
5372         insert = expand_string(sub[2]);
5373         if (insert == NULL) goto EXPAND_FAILED;
5374         yield = string_cat(yield, &size, &ptr, insert);
5375
5376         moffset = ovector[1];
5377         moffsetextra = 0;
5378         emptyopt = 0;
5379
5380         /* If we have matched an empty string, first check to see if we are at
5381         the end of the subject. If so, the loop is over. Otherwise, mimic
5382         what Perl's /g options does. This turns out to be rather cunning. First
5383         we set PCRE_NOTEMPTY and PCRE_ANCHORED and try the match a non-empty
5384         string at the same point. If this fails (picked up above) we advance to
5385         the next character. */
5386
5387         if (ovector[0] == ovector[1])
5388           {
5389           if (ovector[0] == slen) break;
5390           emptyopt = PCRE_NOTEMPTY | PCRE_ANCHORED;
5391           }
5392         }
5393
5394       /* All done - restore numerical variables. */
5395
5396       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5397         save_expand_nlength);
5398       continue;
5399       }
5400
5401     /* Handle keyed and numbered substring extraction. If the first argument
5402     consists entirely of digits, then a numerical extraction is assumed. */
5403
5404     case EITEM_EXTRACT:
5405       {
5406       int i;
5407       int j;
5408       int field_number = 1;
5409       BOOL field_number_set = FALSE;
5410       uschar *save_lookup_value = lookup_value;
5411       uschar *sub[3];
5412       int save_expand_nmax =
5413         save_expand_strings(save_expand_nstring, save_expand_nlength);
5414
5415       /* While skipping we cannot rely on the data for expansions being
5416       available (eg. $item) hence cannot decide on numeric vs. keyed.
5417       Read a maximum of 5 arguments (including the yes/no) */
5418
5419       if (skipping)
5420         {
5421         while (isspace(*s)) s++;
5422         for (j = 5; j > 0 && *s == '{'; j--)
5423           {
5424           if (!expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok))
5425             goto EXPAND_FAILED;                                 /*{*/
5426           if (*s++ != '}')
5427             {
5428             expand_string_message = US"missing '{' for arg of extract";
5429             goto EXPAND_FAILED_CURLY;
5430             }
5431           while (isspace(*s)) s++;
5432           }
5433         if (  Ustrncmp(s, "fail", 4) == 0
5434            && (s[4] == '}' || s[4] == ' ' || s[4] == '\t' || !s[4])
5435            )
5436           {
5437           s += 4;
5438           while (isspace(*s)) s++;
5439           }
5440         if (*s != '}')
5441           {
5442           expand_string_message = US"missing '}' closing extract";
5443           goto EXPAND_FAILED_CURLY;
5444           }
5445         }
5446
5447       else for (i = 0, j = 2; i < j; i++) /* Read the proper number of arguments */
5448         {
5449         while (isspace(*s)) s++;
5450         if (*s == '{')                                          /*}*/
5451           {
5452           sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5453           if (sub[i] == NULL) goto EXPAND_FAILED;               /*{*/
5454           if (*s++ != '}')
5455             {
5456             expand_string_message = string_sprintf(
5457               "missing '}' closing arg %d of extract", i+1);
5458             goto EXPAND_FAILED_CURLY;
5459             }
5460
5461           /* After removal of leading and trailing white space, the first
5462           argument must not be empty; if it consists entirely of digits
5463           (optionally preceded by a minus sign), this is a numerical
5464           extraction, and we expect 3 arguments. */
5465
5466           if (i == 0)
5467             {
5468             int len;
5469             int x = 0;
5470             uschar *p = sub[0];
5471
5472             while (isspace(*p)) p++;
5473             sub[0] = p;
5474
5475             len = Ustrlen(p);
5476             while (len > 0 && isspace(p[len-1])) len--;
5477             p[len] = 0;
5478
5479             if (*p == 0)
5480               {
5481               expand_string_message = US"first argument of \"extract\" must "
5482                 "not be empty";
5483               goto EXPAND_FAILED;
5484               }
5485
5486             if (*p == '-')
5487               {
5488               field_number = -1;
5489               p++;
5490               }
5491             while (*p != 0 && isdigit(*p)) x = x * 10 + *p++ - '0';
5492             if (*p == 0)
5493               {
5494               field_number *= x;
5495               j = 3;               /* Need 3 args */
5496               field_number_set = TRUE;
5497               }
5498             }
5499           }
5500         else
5501           {
5502           expand_string_message = string_sprintf(
5503             "missing '{' for arg %d of extract", i+1);
5504           goto EXPAND_FAILED_CURLY;
5505           }
5506         }
5507
5508       /* Extract either the numbered or the keyed substring into $value. If
5509       skipping, just pretend the extraction failed. */
5510
5511       lookup_value = skipping? NULL : field_number_set?
5512         expand_gettokened(field_number, sub[1], sub[2]) :
5513         expand_getkeyed(sub[0], sub[1]);
5514
5515       /* If no string follows, $value gets substituted; otherwise there can
5516       be yes/no strings, as for lookup or if. */
5517
5518       switch(process_yesno(
5519                skipping,                     /* were previously skipping */
5520                lookup_value != NULL,         /* success/failure indicator */
5521                save_lookup_value,            /* value to reset for string2 */
5522                &s,                           /* input pointer */
5523                &yield,                       /* output pointer */
5524                &size,                        /* output size */
5525                &ptr,                         /* output current point */
5526                US"extract",                  /* condition type */
5527                &resetok))
5528         {
5529         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5530         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5531         }
5532
5533       /* All done - restore numerical variables. */
5534
5535       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5536         save_expand_nlength);
5537
5538       continue;
5539       }
5540
5541     /* return the Nth item from a list */
5542
5543     case EITEM_LISTEXTRACT:
5544       {
5545       int i;
5546       int field_number = 1;
5547       uschar *save_lookup_value = lookup_value;
5548       uschar *sub[2];
5549       int save_expand_nmax =
5550         save_expand_strings(save_expand_nstring, save_expand_nlength);
5551
5552       /* Read the field & list arguments */
5553
5554       for (i = 0; i < 2; i++)
5555         {
5556         while (isspace(*s)) s++;
5557         if (*s != '{')                                  /*}*/
5558           {
5559           expand_string_message = string_sprintf(
5560             "missing '{' for arg %d of listextract", i+1);
5561           goto EXPAND_FAILED_CURLY;
5562           }
5563
5564         sub[i] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5565         if (!sub[i])     goto EXPAND_FAILED;            /*{*/
5566         if (*s++ != '}')
5567           {
5568           expand_string_message = string_sprintf(
5569             "missing '}' closing arg %d of listextract", i+1);
5570           goto EXPAND_FAILED_CURLY;
5571           }
5572
5573         /* After removal of leading and trailing white space, the first
5574         argument must be numeric and nonempty. */
5575
5576         if (i == 0)
5577           {
5578           int len;
5579           int x = 0;
5580           uschar *p = sub[0];
5581
5582           while (isspace(*p)) p++;
5583           sub[0] = p;
5584
5585           len = Ustrlen(p);
5586           while (len > 0 && isspace(p[len-1])) len--;
5587           p[len] = 0;
5588
5589           if (!*p && !skipping)
5590             {
5591             expand_string_message = US"first argument of \"listextract\" must "
5592               "not be empty";
5593             goto EXPAND_FAILED;
5594             }
5595
5596           if (*p == '-')
5597             {
5598             field_number = -1;
5599             p++;
5600             }
5601           while (*p && isdigit(*p)) x = x * 10 + *p++ - '0';
5602           if (*p)
5603             {
5604             expand_string_message = US"first argument of \"listextract\" must "
5605               "be numeric";
5606             goto EXPAND_FAILED;
5607             }
5608           field_number *= x;
5609           }
5610         }
5611
5612       /* Extract the numbered element into $value. If
5613       skipping, just pretend the extraction failed. */
5614
5615       lookup_value = skipping? NULL : expand_getlistele(field_number, sub[1]);
5616
5617       /* If no string follows, $value gets substituted; otherwise there can
5618       be yes/no strings, as for lookup or if. */
5619
5620       switch(process_yesno(
5621                skipping,                     /* were previously skipping */
5622                lookup_value != NULL,         /* success/failure indicator */
5623                save_lookup_value,            /* value to reset for string2 */
5624                &s,                           /* input pointer */
5625                &yield,                       /* output pointer */
5626                &size,                        /* output size */
5627                &ptr,                         /* output current point */
5628                US"listextract",              /* condition type */
5629                &resetok))
5630         {
5631         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5632         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5633         }
5634
5635       /* All done - restore numerical variables. */
5636
5637       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5638         save_expand_nlength);
5639
5640       continue;
5641       }
5642
5643 #ifdef SUPPORT_TLS
5644     case EITEM_CERTEXTRACT:
5645       {
5646       uschar *save_lookup_value = lookup_value;
5647       uschar *sub[2];
5648       int save_expand_nmax =
5649         save_expand_strings(save_expand_nstring, save_expand_nlength);
5650
5651       /* Read the field argument */
5652       while (isspace(*s)) s++;
5653       if (*s != '{')                                    /*}*/
5654         {
5655         expand_string_message = US"missing '{' for field arg of certextract";
5656         goto EXPAND_FAILED_CURLY;
5657         }
5658       sub[0] = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
5659       if (!sub[0])     goto EXPAND_FAILED;              /*{*/
5660       if (*s++ != '}')
5661         {
5662         expand_string_message = US"missing '}' closing field arg of certextract";
5663         goto EXPAND_FAILED_CURLY;
5664         }
5665       /* strip spaces fore & aft */
5666       {
5667       int len;
5668       uschar *p = sub[0];
5669
5670       while (isspace(*p)) p++;
5671       sub[0] = p;
5672
5673       len = Ustrlen(p);
5674       while (len > 0 && isspace(p[len-1])) len--;
5675       p[len] = 0;
5676       }
5677
5678       /* inspect the cert argument */
5679       while (isspace(*s)) s++;
5680       if (*s != '{')                                    /*}*/
5681         {
5682         expand_string_message = US"missing '{' for cert variable arg of certextract";
5683         goto EXPAND_FAILED_CURLY;
5684         }
5685       if (*++s != '$')
5686         {
5687         expand_string_message = US"second argument of \"certextract\" must "
5688           "be a certificate variable";
5689         goto EXPAND_FAILED;
5690         }
5691       sub[1] = expand_string_internal(s+1, TRUE, &s, skipping, FALSE, &resetok);
5692       if (!sub[1])     goto EXPAND_FAILED;              /*{*/
5693       if (*s++ != '}')
5694         {
5695         expand_string_message = US"missing '}' closing cert variable arg of certextract";
5696         goto EXPAND_FAILED_CURLY;
5697         }
5698
5699       if (skipping)
5700         lookup_value = NULL;
5701       else
5702         {
5703         lookup_value = expand_getcertele(sub[0], sub[1]);
5704         if (*expand_string_message) goto EXPAND_FAILED;
5705         }
5706       switch(process_yesno(
5707                skipping,                     /* were previously skipping */
5708                lookup_value != NULL,         /* success/failure indicator */
5709                save_lookup_value,            /* value to reset for string2 */
5710                &s,                           /* input pointer */
5711                &yield,                       /* output pointer */
5712                &size,                        /* output size */
5713                &ptr,                         /* output current point */
5714                US"certextract",              /* condition type */
5715                &resetok))
5716         {
5717         case 1: goto EXPAND_FAILED;          /* when all is well, the */
5718         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
5719         }
5720
5721       restore_expand_strings(save_expand_nmax, save_expand_nstring,
5722         save_expand_nlength);
5723       continue;
5724       }
5725 #endif  /*SUPPORT_TLS*/
5726
5727     /* Handle list operations */
5728
5729     case EITEM_FILTER:
5730     case EITEM_MAP:
5731     case EITEM_REDUCE:
5732       {
5733       int sep = 0;
5734       int save_ptr = ptr;
5735       uschar outsep[2] = { '\0', '\0' };
5736       const uschar *list, *expr, *temp;
5737       uschar *save_iterate_item = iterate_item;
5738       uschar *save_lookup_value = lookup_value;
5739
5740       while (isspace(*s)) s++;
5741       if (*s++ != '{')
5742         {
5743         expand_string_message =
5744           string_sprintf("missing '{' for first arg of %s", name);
5745         goto EXPAND_FAILED_CURLY;
5746         }
5747
5748       list = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5749       if (list == NULL) goto EXPAND_FAILED;
5750       if (*s++ != '}')
5751         {
5752         expand_string_message =
5753           string_sprintf("missing '}' closing first arg of %s", name);
5754         goto EXPAND_FAILED_CURLY;
5755         }
5756
5757       if (item_type == EITEM_REDUCE)
5758         {
5759         uschar * t;
5760         while (isspace(*s)) s++;
5761         if (*s++ != '{')
5762           {
5763           expand_string_message = US"missing '{' for second arg of reduce";
5764           goto EXPAND_FAILED_CURLY;
5765           }
5766         t = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5767         if (!t) goto EXPAND_FAILED;
5768         lookup_value = t;
5769         if (*s++ != '}')
5770           {
5771           expand_string_message = US"missing '}' closing second arg of reduce";
5772           goto EXPAND_FAILED_CURLY;
5773           }
5774         }
5775
5776       while (isspace(*s)) s++;
5777       if (*s++ != '{')
5778         {
5779         expand_string_message =
5780           string_sprintf("missing '{' for last arg of %s", name);
5781         goto EXPAND_FAILED_CURLY;
5782         }
5783
5784       expr = s;
5785
5786       /* For EITEM_FILTER, call eval_condition once, with result discarded (as
5787       if scanning a "false" part). This allows us to find the end of the
5788       condition, because if the list is empty, we won't actually evaluate the
5789       condition for real. For EITEM_MAP and EITEM_REDUCE, do the same, using
5790       the normal internal expansion function. */
5791
5792       if (item_type == EITEM_FILTER)
5793         {
5794         temp = eval_condition(expr, &resetok, NULL);
5795         if (temp != NULL) s = temp;
5796         }
5797       else
5798         temp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5799
5800       if (temp == NULL)
5801         {
5802         expand_string_message = string_sprintf("%s inside \"%s\" item",
5803           expand_string_message, name);
5804         goto EXPAND_FAILED;
5805         }
5806
5807       while (isspace(*s)) s++;
5808       if (*s++ != '}')
5809         {                                               /*{*/
5810         expand_string_message = string_sprintf("missing } at end of condition "
5811           "or expression inside \"%s\"", name);
5812         goto EXPAND_FAILED;
5813         }
5814
5815       while (isspace(*s)) s++;                          /*{*/
5816       if (*s++ != '}')
5817         {                                               /*{*/
5818         expand_string_message = string_sprintf("missing } at end of \"%s\"",
5819           name);
5820         goto EXPAND_FAILED;
5821         }
5822
5823       /* If we are skipping, we can now just move on to the next item. When
5824       processing for real, we perform the iteration. */
5825
5826       if (skipping) continue;
5827       while ((iterate_item = string_nextinlist(&list, &sep, NULL, 0)))
5828         {
5829         *outsep = (uschar)sep;      /* Separator as a string */
5830
5831         DEBUG(D_expand) debug_printf_indent("%s: $item = '%s'  $value = '%s'\n",
5832                           name, iterate_item, lookup_value);
5833
5834         if (item_type == EITEM_FILTER)
5835           {
5836           BOOL condresult;
5837           if (eval_condition(expr, &resetok, &condresult) == NULL)
5838             {
5839             iterate_item = save_iterate_item;
5840             lookup_value = save_lookup_value;
5841             expand_string_message = string_sprintf("%s inside \"%s\" condition",
5842               expand_string_message, name);
5843             goto EXPAND_FAILED;
5844             }
5845           DEBUG(D_expand) debug_printf_indent("%s: condition is %s\n", name,
5846             condresult? "true":"false");
5847           if (condresult)
5848             temp = iterate_item;    /* TRUE => include this item */
5849           else
5850             continue;               /* FALSE => skip this item */
5851           }
5852
5853         /* EITEM_MAP and EITEM_REDUCE */
5854
5855         else
5856           {
5857           uschar * t = expand_string_internal(expr, TRUE, NULL, skipping, TRUE, &resetok);
5858           temp = t;
5859           if (temp == NULL)
5860             {
5861             iterate_item = save_iterate_item;
5862             expand_string_message = string_sprintf("%s inside \"%s\" item",
5863               expand_string_message, name);
5864             goto EXPAND_FAILED;
5865             }
5866           if (item_type == EITEM_REDUCE)
5867             {
5868             lookup_value = t;         /* Update the value of $value */
5869             continue;                 /* and continue the iteration */
5870             }
5871           }
5872
5873         /* We reach here for FILTER if the condition is true, always for MAP,
5874         and never for REDUCE. The value in "temp" is to be added to the output
5875         list that is being created, ensuring that any occurrences of the
5876         separator character are doubled. Unless we are dealing with the first
5877         item of the output list, add in a space if the new item begins with the
5878         separator character, or is an empty string. */
5879
5880         if (ptr != save_ptr && (temp[0] == *outsep || temp[0] == 0))
5881           yield = string_catn(yield, &size, &ptr, US" ", 1);
5882
5883         /* Add the string in "temp" to the output list that we are building,
5884         This is done in chunks by searching for the separator character. */
5885
5886         for (;;)
5887           {
5888           size_t seglen = Ustrcspn(temp, outsep);
5889
5890           yield = string_catn(yield, &size, &ptr, temp, seglen + 1);
5891
5892           /* If we got to the end of the string we output one character
5893           too many; backup and end the loop. Otherwise arrange to double the
5894           separator. */
5895
5896           if (temp[seglen] == '\0') { ptr--; break; }
5897           yield = string_catn(yield, &size, &ptr, outsep, 1);
5898           temp += seglen + 1;
5899           }
5900
5901         /* Output a separator after the string: we will remove the redundant
5902         final one at the end. */
5903
5904         yield = string_catn(yield, &size, &ptr, outsep, 1);
5905         }   /* End of iteration over the list loop */
5906
5907       /* REDUCE has generated no output above: output the final value of
5908       $value. */
5909
5910       if (item_type == EITEM_REDUCE)
5911         {
5912         yield = string_cat(yield, &size, &ptr, lookup_value);
5913         lookup_value = save_lookup_value;  /* Restore $value */
5914         }
5915
5916       /* FILTER and MAP generate lists: if they have generated anything, remove
5917       the redundant final separator. Even though an empty item at the end of a
5918       list does not count, this is tidier. */
5919
5920       else if (ptr != save_ptr) ptr--;
5921
5922       /* Restore preserved $item */
5923
5924       iterate_item = save_iterate_item;
5925       continue;
5926       }
5927
5928     case EITEM_SORT:
5929       {
5930       int sep = 0;
5931       const uschar *srclist, *cmp, *xtract;
5932       uschar *srcitem;
5933       const uschar *dstlist = NULL, *dstkeylist = NULL;
5934       uschar * tmp;
5935       uschar *save_iterate_item = iterate_item;
5936
5937       while (isspace(*s)) s++;
5938       if (*s++ != '{')
5939         {
5940         expand_string_message = US"missing '{' for list arg of sort";
5941         goto EXPAND_FAILED_CURLY;
5942         }
5943
5944       srclist = expand_string_internal(s, TRUE, &s, skipping, TRUE, &resetok);
5945       if (!srclist) goto EXPAND_FAILED;
5946       if (*s++ != '}')
5947         {
5948         expand_string_message = US"missing '}' closing list arg of sort";
5949         goto EXPAND_FAILED_CURLY;
5950         }
5951
5952       while (isspace(*s)) s++;
5953       if (*s++ != '{')
5954         {
5955         expand_string_message = US"missing '{' for comparator arg of sort";
5956         goto EXPAND_FAILED_CURLY;
5957         }
5958
5959       cmp = expand_string_internal(s, TRUE, &s, skipping, FALSE, &resetok);
5960       if (!cmp) goto EXPAND_FAILED;
5961       if (*s++ != '}')
5962         {
5963         expand_string_message = US"missing '}' closing comparator arg of sort";
5964         goto EXPAND_FAILED_CURLY;
5965         }
5966
5967       while (isspace(*s)) s++;
5968       if (*s++ != '{')
5969         {
5970         expand_string_message = US"missing '{' for extractor arg of sort";
5971         goto EXPAND_FAILED_CURLY;
5972         }
5973
5974       xtract = s;
5975       tmp = expand_string_internal(s, TRUE, &s, TRUE, TRUE, &resetok);
5976       if (!tmp) goto EXPAND_FAILED;
5977       xtract = string_copyn(xtract, s - xtract);
5978
5979       if (*s++ != '}')
5980         {
5981         expand_string_message = US"missing '}' closing extractor arg of sort";
5982         goto EXPAND_FAILED_CURLY;
5983         }
5984                                                         /*{*/
5985       if (*s++ != '}')
5986         {                                               /*{*/
5987         expand_string_message = US"missing } at end of \"sort\"";
5988         goto EXPAND_FAILED;
5989         }
5990
5991       if (skipping) continue;
5992
5993       while ((srcitem = string_nextinlist(&srclist, &sep, NULL, 0)))
5994         {
5995         uschar * dstitem;
5996         uschar * newlist = NULL;
5997         int size = 0, len = 0;
5998         uschar * newkeylist = NULL;
5999         int ksize = 0, klen = 0;
6000         uschar * srcfield;
6001
6002         DEBUG(D_expand) debug_printf_indent("%s: $item = \"%s\"\n", name, srcitem);
6003
6004         /* extract field for comparisons */
6005         iterate_item = srcitem;
6006         if (  !(srcfield = expand_string_internal(xtract, FALSE, NULL, FALSE,
6007                                           TRUE, &resetok))
6008            || !*srcfield)
6009           {
6010           expand_string_message = string_sprintf(
6011               "field-extract in sort: \"%s\"", xtract);
6012           goto EXPAND_FAILED;
6013           }
6014
6015         /* Insertion sort */
6016
6017         /* copy output list until new-item < list-item */
6018         while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6019           {
6020           uschar * dstfield;
6021           uschar * expr;
6022           BOOL before;
6023
6024           /* field for comparison */
6025           if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6026             goto sort_mismatch;
6027
6028           /* build and run condition string */
6029           expr = string_sprintf("%s{%s}{%s}", cmp, srcfield, dstfield);
6030
6031           DEBUG(D_expand) debug_printf_indent("%s: cond = \"%s\"\n", name, expr);
6032           if (!eval_condition(expr, &resetok, &before))
6033             {
6034             expand_string_message = string_sprintf("comparison in sort: %s",
6035                 expr);
6036             goto EXPAND_FAILED;
6037             }
6038
6039           if (before)
6040             {
6041             /* New-item sorts before this dst-item.  Append new-item,
6042             then dst-item, then remainder of dst list. */
6043
6044             newlist = string_append_listele(newlist, &size, &len, sep, srcitem);
6045             newkeylist = string_append_listele(newkeylist, &ksize, &klen, sep, srcfield);
6046             srcitem = NULL;
6047
6048             newlist = string_append_listele(newlist, &size, &len, sep, dstitem);
6049             newkeylist = string_append_listele(newkeylist, &ksize, &klen, sep, dstfield);
6050
6051             while ((dstitem = string_nextinlist(&dstlist, &sep, NULL, 0)))
6052               {
6053               if (!(dstfield = string_nextinlist(&dstkeylist, &sep, NULL, 0)))
6054                 goto sort_mismatch;
6055               newlist = string_append_listele(newlist, &size, &len, sep, dstitem);
6056               newkeylist = string_append_listele(newkeylist, &ksize, &klen, sep, dstfield);
6057               }
6058
6059             break;
6060             }
6061
6062           newlist = string_append_listele(newlist, &size, &len, sep, dstitem);
6063           newkeylist = string_append_listele(newkeylist, &ksize, &klen, sep, dstfield);
6064           }
6065
6066         /* If we ran out of dstlist without consuming srcitem, append it */
6067         if (srcitem)
6068           {
6069           newlist = string_append_listele(newlist, &size, &len, sep, srcitem);
6070           newkeylist = string_append_listele(newkeylist, &ksize, &klen, sep, srcfield);
6071           }
6072
6073         dstlist = newlist;
6074         dstkeylist = newkeylist;
6075
6076         DEBUG(D_expand) debug_printf_indent("%s: dstlist = \"%s\"\n", name, dstlist);
6077         DEBUG(D_expand) debug_printf_indent("%s: dstkeylist = \"%s\"\n", name, dstkeylist);
6078         }
6079
6080       if (dstlist)
6081         yield = string_cat(yield, &size, &ptr, dstlist);
6082
6083       /* Restore preserved $item */
6084       iterate_item = save_iterate_item;
6085       continue;
6086
6087       sort_mismatch:
6088         expand_string_message = US"Internal error in sort (list mismatch)";
6089         goto EXPAND_FAILED;
6090       }
6091
6092
6093     /* If ${dlfunc } support is configured, handle calling dynamically-loaded
6094     functions, unless locked out at this time. Syntax is ${dlfunc{file}{func}}
6095     or ${dlfunc{file}{func}{arg}} or ${dlfunc{file}{func}{arg1}{arg2}} or up to
6096     a maximum of EXPAND_DLFUNC_MAX_ARGS arguments (defined below). */
6097
6098     #define EXPAND_DLFUNC_MAX_ARGS 8
6099
6100     case EITEM_DLFUNC:
6101 #ifndef EXPAND_DLFUNC
6102       expand_string_message = US"\"${dlfunc\" encountered, but this facility "  /*}*/
6103         "is not included in this binary";
6104       goto EXPAND_FAILED;
6105
6106 #else   /* EXPAND_DLFUNC */
6107       {
6108       tree_node *t;
6109       exim_dlfunc_t *func;
6110       uschar *result;
6111       int status, argc;
6112       uschar *argv[EXPAND_DLFUNC_MAX_ARGS + 3];
6113
6114       if ((expand_forbid & RDO_DLFUNC) != 0)
6115         {
6116         expand_string_message =
6117           US"dynamically-loaded functions are not permitted";
6118         goto EXPAND_FAILED;
6119         }
6120
6121       switch(read_subs(argv, EXPAND_DLFUNC_MAX_ARGS + 2, 2, &s, skipping,
6122            TRUE, US"dlfunc", &resetok))
6123         {
6124         case 1: goto EXPAND_FAILED_CURLY;
6125         case 2:
6126         case 3: goto EXPAND_FAILED;
6127         }
6128
6129       /* If skipping, we don't actually do anything */
6130
6131       if (skipping) continue;
6132
6133       /* Look up the dynamically loaded object handle in the tree. If it isn't
6134       found, dlopen() the file and put the handle in the tree for next time. */
6135
6136       t = tree_search(dlobj_anchor, argv[0]);
6137       if (t == NULL)
6138         {
6139         void *handle = dlopen(CS argv[0], RTLD_LAZY);
6140         if (handle == NULL)
6141           {
6142           expand_string_message = string_sprintf("dlopen \"%s\" failed: %s",
6143             argv[0], dlerror());
6144           log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6145           goto EXPAND_FAILED;
6146           }
6147         t = store_get_perm(sizeof(tree_node) + Ustrlen(argv[0]));
6148         Ustrcpy(t->name, argv[0]);
6149         t->data.ptr = handle;
6150         (void)tree_insertnode(&dlobj_anchor, t);
6151         }
6152
6153       /* Having obtained the dynamically loaded object handle, look up the
6154       function pointer. */
6155
6156       func = (exim_dlfunc_t *)dlsym(t->data.ptr, CS argv[1]);
6157       if (func == NULL)
6158         {
6159         expand_string_message = string_sprintf("dlsym \"%s\" in \"%s\" failed: "
6160           "%s", argv[1], argv[0], dlerror());
6161         log_write(0, LOG_MAIN|LOG_PANIC, "%s", expand_string_message);
6162         goto EXPAND_FAILED;
6163         }
6164
6165       /* Call the function and work out what to do with the result. If it
6166       returns OK, we have a replacement string; if it returns DEFER then
6167       expansion has failed in a non-forced manner; if it returns FAIL then
6168       failure was forced; if it returns ERROR or any other value there's a
6169       problem, so panic slightly. In any case, assume that the function has
6170       side-effects on the store that must be preserved. */
6171
6172       resetok = FALSE;
6173       result = NULL;
6174       for (argc = 0; argv[argc] != NULL; argc++);
6175       status = func(&result, argc - 2, &argv[2]);
6176       if(status == OK)
6177         {
6178         if (result == NULL) result = US"";
6179         yield = string_cat(yield, &size, &ptr, result);
6180         continue;
6181         }
6182       else
6183         {
6184         expand_string_message = result == NULL ? US"(no message)" : result;
6185         if(status == FAIL_FORCED) expand_string_forcedfail = TRUE;
6186           else if(status != FAIL)
6187             log_write(0, LOG_MAIN|LOG_PANIC, "dlfunc{%s}{%s} failed (%d): %s",
6188               argv[0], argv[1], status, expand_string_message);
6189         goto EXPAND_FAILED;
6190         }
6191       }
6192 #endif /* EXPAND_DLFUNC */
6193
6194     case EITEM_ENV:     /* ${env {name} {val_if_found} {val_if_unfound}} */
6195       {
6196       uschar * key;
6197       uschar *save_lookup_value = lookup_value;
6198
6199       while (isspace(*s)) s++;
6200       if (*s != '{')                                    /*}*/
6201         goto EXPAND_FAILED;
6202
6203       key = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6204       if (!key) goto EXPAND_FAILED;                     /*{*/
6205       if (*s++ != '}')
6206         {
6207         expand_string_message = US"missing '{' for name arg of env";
6208         goto EXPAND_FAILED_CURLY;
6209         }
6210
6211       lookup_value = US getenv(CS key);
6212
6213       switch(process_yesno(
6214                skipping,                     /* were previously skipping */
6215                lookup_value != NULL,         /* success/failure indicator */
6216                save_lookup_value,            /* value to reset for string2 */
6217                &s,                           /* input pointer */
6218                &yield,                       /* output pointer */
6219                &size,                        /* output size */
6220                &ptr,                         /* output current point */
6221                US"env",                      /* condition type */
6222                &resetok))
6223         {
6224         case 1: goto EXPAND_FAILED;          /* when all is well, the */
6225         case 2: goto EXPAND_FAILED_CURLY;    /* returned value is 0 */
6226         }
6227       continue;
6228       }
6229     }   /* EITEM_* switch */
6230
6231   /* Control reaches here if the name is not recognized as one of the more
6232   complicated expansion items. Check for the "operator" syntax (name terminated
6233   by a colon). Some of the operators have arguments, separated by _ from the
6234   name. */
6235
6236   if (*s == ':')
6237     {
6238     int c;
6239     uschar *arg = NULL;
6240     uschar *sub;
6241     var_entry *vp = NULL;
6242
6243     /* Owing to an historical mis-design, an underscore may be part of the
6244     operator name, or it may introduce arguments.  We therefore first scan the
6245     table of names that contain underscores. If there is no match, we cut off
6246     the arguments and then scan the main table. */
6247
6248     if ((c = chop_match(name, op_table_underscore,
6249                         nelem(op_table_underscore))) < 0)
6250       {
6251       arg = Ustrchr(name, '_');
6252       if (arg != NULL) *arg = 0;
6253       c = chop_match(name, op_table_main, nelem(op_table_main));
6254       if (c >= 0) c += nelem(op_table_underscore);
6255       if (arg != NULL) *arg++ = '_';   /* Put back for error messages */
6256       }
6257
6258     /* Deal specially with operators that might take a certificate variable
6259     as we do not want to do the usual expansion. For most, expand the string.*/
6260     switch(c)
6261       {
6262 #ifdef SUPPORT_TLS
6263       case EOP_MD5:
6264       case EOP_SHA1:
6265       case EOP_SHA256:
6266       case EOP_BASE64:
6267         if (s[1] == '$')
6268           {
6269           const uschar * s1 = s;
6270           sub = expand_string_internal(s+2, TRUE, &s1, skipping,
6271                   FALSE, &resetok);
6272           if (!sub)       goto EXPAND_FAILED;           /*{*/
6273           if (*s1 != '}')
6274             {
6275             expand_string_message =
6276               string_sprintf("missing '}' closing cert arg of %s", name);
6277             goto EXPAND_FAILED_CURLY;
6278             }
6279           if ((vp = find_var_ent(sub)) && vp->type == vtype_cert)
6280             {
6281             s = s1+1;
6282             break;
6283             }
6284           vp = NULL;
6285           }
6286         /*FALLTHROUGH*/
6287 #endif
6288       default:
6289         sub = expand_string_internal(s+1, TRUE, &s, skipping, TRUE, &resetok);
6290         if (!sub) goto EXPAND_FAILED;
6291         s++;
6292         break;
6293       }
6294
6295     /* If we are skipping, we don't need to perform the operation at all.
6296     This matters for operations like "mask", because the data may not be
6297     in the correct format when skipping. For example, the expression may test
6298     for the existence of $sender_host_address before trying to mask it. For
6299     other operations, doing them may not fail, but it is a waste of time. */
6300
6301     if (skipping && c >= 0) continue;
6302
6303     /* Otherwise, switch on the operator type */
6304
6305     switch(c)
6306       {
6307       case EOP_BASE32:
6308         {
6309         uschar *t;
6310         unsigned long int n = Ustrtoul(sub, &t, 10);
6311         uschar * s = NULL;
6312         int sz = 0, i = 0;
6313
6314         if (*t != 0)
6315           {
6316           expand_string_message = string_sprintf("argument for base32 "
6317             "operator is \"%s\", which is not a decimal number", sub);
6318           goto EXPAND_FAILED;
6319           }
6320         for ( ; n; n >>= 5)
6321           s = string_catn(s, &sz, &i, &base32_chars[n & 0x1f], 1);
6322
6323         while (i > 0) yield = string_catn(yield, &size, &ptr, &s[--i], 1);
6324         continue;
6325         }
6326
6327       case EOP_BASE32D:
6328         {
6329         uschar *tt = sub;
6330         unsigned long int n = 0;
6331         uschar * s;
6332         while (*tt)
6333           {
6334           uschar * t = Ustrchr(base32_chars, *tt++);
6335           if (t == NULL)
6336             {
6337             expand_string_message = string_sprintf("argument for base32d "
6338               "operator is \"%s\", which is not a base 32 number", sub);
6339             goto EXPAND_FAILED;
6340             }
6341           n = n * 32 + (t - base32_chars);
6342           }
6343         s = string_sprintf("%ld", n);
6344         yield = string_cat(yield, &size, &ptr, s);
6345         continue;
6346         }
6347
6348       case EOP_BASE62:
6349         {
6350         uschar *t;
6351         unsigned long int n = Ustrtoul(sub, &t, 10);
6352         if (*t != 0)
6353           {
6354           expand_string_message = string_sprintf("argument for base62 "
6355             "operator is \"%s\", which is not a decimal number", sub);
6356           goto EXPAND_FAILED;
6357           }
6358         t = string_base62(n);
6359         yield = string_cat(yield, &size, &ptr, t);
6360         continue;
6361         }
6362
6363       /* Note that for Darwin and Cygwin, BASE_62 actually has the value 36 */
6364
6365       case EOP_BASE62D:
6366         {
6367         uschar buf[16];
6368         uschar *tt = sub;
6369         unsigned long int n = 0;
6370         while (*tt != 0)
6371           {
6372           uschar *t = Ustrchr(base62_chars, *tt++);
6373           if (t == NULL)
6374             {
6375             expand_string_message = string_sprintf("argument for base62d "
6376               "operator is \"%s\", which is not a base %d number", sub,
6377               BASE_62);
6378             goto EXPAND_FAILED;
6379             }
6380           n = n * BASE_62 + (t - base62_chars);
6381           }
6382         (void)sprintf(CS buf, "%ld", n);
6383         yield = string_cat(yield, &size, &ptr, buf);
6384         continue;
6385         }
6386
6387       case EOP_EXPAND:
6388         {
6389         uschar *expanded = expand_string_internal(sub, FALSE, NULL, skipping, TRUE, &resetok);
6390         if (expanded == NULL)
6391           {
6392           expand_string_message =
6393             string_sprintf("internal expansion of \"%s\" failed: %s", sub,
6394               expand_string_message);
6395           goto EXPAND_FAILED;
6396           }
6397         yield = string_cat(yield, &size, &ptr, expanded);
6398         continue;
6399         }
6400
6401       case EOP_LC:
6402         {
6403         int count = 0;
6404         uschar *t = sub - 1;
6405         while (*(++t) != 0) { *t = tolower(*t); count++; }
6406         yield = string_catn(yield, &size, &ptr, sub, count);
6407         continue;
6408         }
6409
6410       case EOP_UC:
6411         {
6412         int count = 0;
6413         uschar *t = sub - 1;
6414         while (*(++t) != 0) { *t = toupper(*t); count++; }
6415         yield = string_catn(yield, &size, &ptr, sub, count);
6416         continue;
6417         }
6418
6419       case EOP_MD5:
6420 #ifdef SUPPORT_TLS
6421         if (vp && *(void **)vp->value)
6422           {
6423           uschar * cp = tls_cert_fprt_md5(*(void **)vp->value);
6424           yield = string_cat(yield, &size, &ptr, cp);
6425           }
6426         else
6427 #endif
6428           {
6429           md5 base;
6430           uschar digest[16];
6431           int j;
6432           char st[33];
6433           md5_start(&base);
6434           md5_end(&base, sub, Ustrlen(sub), digest);
6435           for(j = 0; j < 16; j++) sprintf(st+2*j, "%02x", digest[j]);
6436           yield = string_cat(yield, &size, &ptr, US st);
6437           }
6438         continue;
6439
6440       case EOP_SHA1:
6441 #ifdef SUPPORT_TLS
6442         if (vp && *(void **)vp->value)
6443           {
6444           uschar * cp = tls_cert_fprt_sha1(*(void **)vp->value);
6445           yield = string_cat(yield, &size, &ptr, cp);
6446           }
6447         else
6448 #endif
6449           {
6450           hctx h;
6451           uschar digest[20];
6452           int j;
6453           char st[41];
6454           sha1_start(&h);
6455           sha1_end(&h, sub, Ustrlen(sub), digest);
6456           for(j = 0; j < 20; j++) sprintf(st+2*j, "%02X", digest[j]);
6457           yield = string_catn(yield, &size, &ptr, US st, 40);
6458           }
6459         continue;
6460
6461       case EOP_SHA256:
6462 #ifdef EXIM_HAVE_SHA2
6463         if (vp && *(void **)vp->value)
6464           {
6465           uschar * cp = tls_cert_fprt_sha256(*(void **)vp->value);
6466           yield = string_cat(yield, &size, &ptr, cp);
6467           }
6468         else
6469           {
6470           hctx h;
6471           blob b;
6472           char st[3];
6473
6474           if (!exim_sha_init(&h, HASH_SHA2_256))
6475             {
6476             expand_string_message = US"unrecognised sha256 variant";
6477             goto EXPAND_FAILED;
6478             }
6479           exim_sha_update(&h, sub, Ustrlen(sub));
6480           exim_sha_finish(&h, &b);
6481           while (b.len-- > 0)
6482             {
6483             sprintf(st, "%02X", *b.data++);
6484             yield = string_catn(yield, &size, &ptr, US st, 2);
6485             }
6486           }
6487 #else
6488           expand_string_message = US"sha256 only supported with TLS";
6489 #endif
6490         continue;
6491
6492       case EOP_SHA3:
6493 #ifdef EXIM_HAVE_SHA3
6494         {
6495         hctx h;
6496         blob b;
6497         char st[3];
6498         hashmethod m = !arg ? HASH_SHA3_256
6499           : Ustrcmp(arg, "224") == 0 ? HASH_SHA3_224
6500           : Ustrcmp(arg, "256") == 0 ? HASH_SHA3_256
6501           : Ustrcmp(arg, "384") == 0 ? HASH_SHA3_384
6502           : Ustrcmp(arg, "512") == 0 ? HASH_SHA3_512
6503           : HASH_BADTYPE;
6504
6505         if (m == HASH_BADTYPE || !exim_sha_init(&h, m))
6506           {
6507           expand_string_message = US"unrecognised sha3 variant";
6508           goto EXPAND_FAILED;
6509           }
6510
6511         exim_sha_update(&h, sub, Ustrlen(sub));
6512         exim_sha_finish(&h, &b);
6513         while (b.len-- > 0)
6514           {
6515           sprintf(st, "%02X", *b.data++);
6516           yield = string_catn(yield, &size, &ptr, US st, 2);
6517           }
6518         }
6519         continue;
6520 #else
6521         expand_string_message = US"sha3 only supported with GnuTLS 3.5.0 +";
6522         goto EXPAND_FAILED;
6523 #endif
6524
6525       /* Convert hex encoding to base64 encoding */
6526
6527       case EOP_HEX2B64:
6528         {
6529         int c = 0;
6530         int b = -1;
6531         uschar *in = sub;
6532         uschar *out = sub;
6533         uschar *enc;
6534
6535         for (enc = sub; *enc != 0; enc++)
6536           {
6537           if (!isxdigit(*enc))
6538             {
6539             expand_string_message = string_sprintf("\"%s\" is not a hex "
6540               "string", sub);
6541             goto EXPAND_FAILED;
6542             }
6543           c++;
6544           }
6545
6546         if ((c & 1) != 0)
6547           {
6548           expand_string_message = string_sprintf("\"%s\" contains an odd "
6549             "number of characters", sub);
6550           goto EXPAND_FAILED;
6551           }
6552
6553         while ((c = *in++) != 0)
6554           {
6555           if (isdigit(c)) c -= '0';
6556           else c = toupper(c) - 'A' + 10;
6557           if (b == -1)
6558             {
6559             b = c << 4;
6560             }
6561           else
6562             {
6563             *out++ = b | c;
6564             b = -1;
6565             }
6566           }
6567
6568         enc = b64encode(sub, out - sub);
6569         yield = string_cat(yield, &size, &ptr, enc);
6570         continue;
6571         }
6572
6573       /* Convert octets outside 0x21..0x7E to \xXX form */
6574
6575       case EOP_HEXQUOTE:
6576         {
6577         uschar *t = sub - 1;
6578         while (*(++t) != 0)
6579           {
6580           if (*t < 0x21 || 0x7E < *t)
6581             yield = string_catn(yield, &size, &ptr,
6582               string_sprintf("\\x%02x", *t), 4);
6583           else
6584             yield = string_catn(yield, &size, &ptr, t, 1);
6585           }
6586         continue;
6587         }
6588
6589       /* count the number of list elements */
6590
6591       case EOP_LISTCOUNT:
6592         {
6593         int cnt = 0;
6594         int sep = 0;
6595         uschar * cp;
6596         uschar buffer[256];
6597
6598         while (string_nextinlist(CUSS &sub, &sep, buffer, sizeof(buffer)) != NULL) cnt++;
6599         cp = string_sprintf("%d", cnt);
6600         yield = string_cat(yield, &size, &ptr, cp);
6601         continue;
6602         }
6603
6604       /* expand a named list given the name */
6605       /* handles nested named lists; requotes as colon-sep list */
6606
6607       case EOP_LISTNAMED:
6608         {
6609         tree_node *t = NULL;
6610         const uschar * list;
6611         int sep = 0;
6612         uschar * item;
6613         uschar * suffix = US"";
6614         BOOL needsep = FALSE;
6615         uschar buffer[256];
6616
6617         if (*sub == '+') sub++;
6618         if (arg == NULL)        /* no-argument version */
6619           {
6620           if (!(t = tree_search(addresslist_anchor, sub)) &&
6621               !(t = tree_search(domainlist_anchor,  sub)) &&
6622               !(t = tree_search(hostlist_anchor,    sub)))
6623             t = tree_search(localpartlist_anchor, sub);
6624           }
6625         else switch(*arg)       /* specific list-type version */
6626           {
6627           case 'a': t = tree_search(addresslist_anchor,   sub); suffix = US"_a"; break;
6628           case 'd': t = tree_search(domainlist_anchor,    sub); suffix = US"_d"; break;
6629           case 'h': t = tree_search(hostlist_anchor,      sub); suffix = US"_h"; break;
6630           case 'l': t = tree_search(localpartlist_anchor, sub); suffix = US"_l"; break;
6631           default:
6632             expand_string_message = string_sprintf("bad suffix on \"list\" operator");
6633             goto EXPAND_FAILED;
6634           }
6635
6636         if(!t)
6637           {
6638           expand_string_message = string_sprintf("\"%s\" is not a %snamed list",
6639             sub, !arg?""
6640               : *arg=='a'?"address "
6641               : *arg=='d'?"domain "
6642               : *arg=='h'?"host "
6643               : *arg=='l'?"localpart "
6644               : 0);
6645           goto EXPAND_FAILED;
6646           }
6647
6648         list = ((namedlist_block *)(t->data.ptr))->string;
6649
6650         while ((item = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
6651           {
6652           uschar * buf = US" : ";
6653           if (needsep)
6654             yield = string_catn(yield, &size, &ptr, buf, 3);
6655           else
6656             needsep = TRUE;
6657
6658           if (*item == '+')     /* list item is itself a named list */
6659             {
6660             uschar * sub = string_sprintf("${listnamed%s:%s}", suffix, item);
6661             item = expand_string_internal(sub, FALSE, NULL, FALSE, TRUE, &resetok);
6662             }
6663           else if (sep != ':')  /* item from non-colon-sep list, re-quote for colon list-separator */
6664             {
6665             char * cp;
6666             char tok[3];
6667             tok[0] = sep; tok[1] = ':'; tok[2] = 0;
6668             while ((cp= strpbrk(CCS item, tok)))
6669               {
6670               yield = string_catn(yield, &size, &ptr, item, cp-CS item);
6671               if (*cp++ == ':') /* colon in a non-colon-sep list item, needs doubling */
6672                 {
6673                 yield = string_catn(yield, &size, &ptr, US"::", 2);
6674                 item = US cp;
6675                 }
6676               else              /* sep in item; should already be doubled; emit once */
6677                 {
6678                 yield = string_catn(yield, &size, &ptr, US tok, 1);
6679                 if (*cp == sep) cp++;
6680                 item = US cp;
6681                 }
6682               }
6683             }
6684           yield = string_cat(yield, &size, &ptr, item);
6685           }
6686         continue;
6687         }
6688
6689       /* mask applies a mask to an IP address; for example the result of
6690       ${mask:131.111.10.206/28} is 131.111.10.192/28. */
6691
6692       case EOP_MASK:
6693         {
6694         int count;
6695         uschar *endptr;
6696         int binary[4];
6697         int mask, maskoffset;
6698         int type = string_is_ip_address(sub, &maskoffset);
6699         uschar buffer[64];
6700
6701         if (type == 0)
6702           {
6703           expand_string_message = string_sprintf("\"%s\" is not an IP address",
6704            sub);
6705           goto EXPAND_FAILED;
6706           }
6707
6708         if (maskoffset == 0)
6709           {
6710           expand_string_message = string_sprintf("missing mask value in \"%s\"",
6711             sub);
6712           goto EXPAND_FAILED;
6713           }
6714
6715         mask = Ustrtol(sub + maskoffset + 1, &endptr, 10);
6716
6717         if (*endptr != 0 || mask < 0 || mask > ((type == 4)? 32 : 128))
6718           {
6719           expand_string_message = string_sprintf("mask value too big in \"%s\"",
6720             sub);
6721           goto EXPAND_FAILED;
6722           }
6723
6724         /* Convert the address to binary integer(s) and apply the mask */
6725
6726         sub[maskoffset] = 0;
6727         count = host_aton(sub, binary);
6728         host_mask(count, binary, mask);
6729
6730         /* Convert to masked textual format and add to output. */
6731
6732         yield = string_catn(yield, &size, &ptr, buffer,
6733           host_nmtoa(count, binary, mask, buffer, '.'));
6734         continue;
6735         }
6736
6737       case EOP_IPV6NORM:
6738       case EOP_IPV6DENORM:
6739         {
6740         int type = string_is_ip_address(sub, NULL);
6741         int binary[4];
6742         uschar buffer[44];
6743
6744         switch (type)
6745           {
6746           case 6:
6747             (void) host_aton(sub, binary);
6748             break;
6749
6750           case 4:       /* convert to IPv4-mapped IPv6 */
6751             binary[0] = binary[1] = 0;
6752             binary[2] = 0x0000ffff;
6753             (void) host_aton(sub, binary+3);
6754             break;
6755
6756           case 0:
6757             expand_string_message =
6758               string_sprintf("\"%s\" is not an IP address", sub);
6759             goto EXPAND_FAILED;
6760           }
6761
6762         yield = string_catn(yield, &size, &ptr, buffer,
6763                   c == EOP_IPV6NORM
6764                     ? ipv6_nmtoa(binary, buffer)
6765                     : host_nmtoa(4, binary, -1, buffer, ':')
6766                   );
6767         continue;
6768         }
6769
6770       case EOP_ADDRESS:
6771       case EOP_LOCAL_PART:
6772       case EOP_DOMAIN:
6773         {
6774         uschar * error;
6775         int start, end, domain;
6776         uschar * t = parse_extract_address(sub, &error, &start, &end, &domain,
6777           FALSE);
6778         if (t)
6779           if (c != EOP_DOMAIN)
6780             {
6781             if (c == EOP_LOCAL_PART && domain != 0) end = start + domain - 1;
6782             yield = string_catn(yield, &size, &ptr, sub+start, end-start);
6783             }
6784           else if (domain != 0)
6785             {
6786             domain += start;
6787             yield = string_catn(yield, &size, &ptr, sub+domain, end-domain);
6788             }
6789         continue;
6790         }
6791
6792       case EOP_ADDRESSES:
6793         {
6794         uschar outsep[2] = { ':', '\0' };
6795         uschar *address, *error;
6796         int save_ptr = ptr;
6797         int start, end, domain;  /* Not really used */
6798
6799         while (isspace(*sub)) sub++;
6800         if (*sub == '>')
6801           if (*outsep = *++sub) ++sub;
6802           else {
6803             expand_string_message = string_sprintf("output separator "
6804               "missing in expanding ${addresses:%s}", --sub);
6805             goto EXPAND_FAILED;
6806           }
6807         parse_allow_group = TRUE;
6808
6809         for (;;)
6810           {
6811           uschar *p = parse_find_address_end(sub, FALSE);
6812           uschar saveend = *p;
6813           *p = '\0';
6814           address = parse_extract_address(sub, &error, &start, &end, &domain,
6815             FALSE);
6816           *p = saveend;
6817
6818           /* Add the address to the output list that we are building. This is
6819           done in chunks by searching for the separator character. At the
6820           start, unless we are dealing with the first address of the output
6821           list, add in a space if the new address begins with the separator
6822           character, or is an empty string. */
6823
6824           if (address != NULL)
6825             {
6826             if (ptr != save_ptr && address[0] == *outsep)
6827               yield = string_catn(yield, &size, &ptr, US" ", 1);
6828
6829             for (;;)
6830               {
6831               size_t seglen = Ustrcspn(address, outsep);
6832               yield = string_catn(yield, &size, &ptr, address, seglen + 1);
6833
6834               /* If we got to the end of the string we output one character
6835               too many. */
6836
6837               if (address[seglen] == '\0') { ptr--; break; }
6838               yield = string_catn(yield, &size, &ptr, outsep, 1);
6839               address += seglen + 1;
6840               }
6841
6842             /* Output a separator after the string: we will remove the
6843             redundant final one at the end. */
6844
6845             yield = string_catn(yield, &size, &ptr, outsep, 1);
6846             }
6847
6848           if (saveend == '\0') break;
6849           sub = p + 1;
6850           }
6851
6852         /* If we have generated anything, remove the redundant final
6853         separator. */
6854
6855         if (ptr != save_ptr) ptr--;
6856         parse_allow_group = FALSE;
6857         continue;
6858         }
6859
6860
6861       /* quote puts a string in quotes if it is empty or contains anything
6862       other than alphamerics, underscore, dot, or hyphen.
6863
6864       quote_local_part puts a string in quotes if RFC 2821/2822 requires it to
6865       be quoted in order to be a valid local part.
6866
6867       In both cases, newlines and carriage returns are converted into \n and \r
6868       respectively */
6869
6870       case EOP_QUOTE:
6871       case EOP_QUOTE_LOCAL_PART:
6872       if (arg == NULL)
6873         {
6874         BOOL needs_quote = (*sub == 0);      /* TRUE for empty string */
6875         uschar *t = sub - 1;
6876
6877         if (c == EOP_QUOTE)
6878           {
6879           while (!needs_quote && *(++t) != 0)
6880             needs_quote = !isalnum(*t) && !strchr("_-.", *t);
6881           }
6882         else  /* EOP_QUOTE_LOCAL_PART */
6883           {
6884           while (!needs_quote && *(++t) != 0)
6885             needs_quote = !isalnum(*t) &&
6886               strchr("!#$%&'*+-/=?^_`{|}~", *t) == NULL &&
6887               (*t != '.' || t == sub || t[1] == 0);
6888           }
6889
6890         if (needs_quote)
6891           {
6892           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6893           t = sub - 1;
6894           while (*(++t) != 0)
6895             {
6896             if (*t == '\n')
6897               yield = string_catn(yield, &size, &ptr, US"\\n", 2);
6898             else if (*t == '\r')
6899               yield = string_catn(yield, &size, &ptr, US"\\r", 2);
6900             else
6901               {
6902               if (*t == '\\' || *t == '"')
6903                 yield = string_catn(yield, &size, &ptr, US"\\", 1);
6904               yield = string_catn(yield, &size, &ptr, t, 1);
6905               }
6906             }
6907           yield = string_catn(yield, &size, &ptr, US"\"", 1);
6908           }
6909         else yield = string_cat(yield, &size, &ptr, sub);
6910         continue;
6911         }
6912
6913       /* quote_lookuptype does lookup-specific quoting */
6914
6915       else
6916         {
6917         int n;
6918         uschar *opt = Ustrchr(arg, '_');
6919
6920         if (opt != NULL) *opt++ = 0;
6921
6922         n = search_findtype(arg, Ustrlen(arg));
6923         if (n < 0)
6924           {
6925           expand_string_message = search_error_message;
6926           goto EXPAND_FAILED;
6927           }
6928
6929         if (lookup_list[n]->quote != NULL)
6930           sub = (lookup_list[n]->quote)(sub, opt);
6931         else if (opt != NULL) sub = NULL;
6932
6933         if (sub == NULL)
6934           {
6935           expand_string_message = string_sprintf(
6936             "\"%s\" unrecognized after \"${quote_%s\"",
6937             opt, arg);
6938           goto EXPAND_FAILED;
6939           }
6940
6941         yield = string_cat(yield, &size, &ptr, sub);
6942         continue;
6943         }
6944
6945       /* rx quote sticks in \ before any non-alphameric character so that
6946       the insertion works in a regular expression. */
6947
6948       case EOP_RXQUOTE:
6949         {
6950         uschar *t = sub - 1;
6951         while (*(++t) != 0)
6952           {
6953           if (!isalnum(*t))
6954             yield = string_catn(yield, &size, &ptr, US"\\", 1);
6955           yield = string_catn(yield, &size, &ptr, t, 1);
6956           }
6957         continue;
6958         }
6959
6960       /* RFC 2047 encodes, assuming headers_charset (default ISO 8859-1) as
6961       prescribed by the RFC, if there are characters that need to be encoded */
6962
6963       case EOP_RFC2047:
6964         {
6965         uschar buffer[2048];
6966         const uschar *string = parse_quote_2047(sub, Ustrlen(sub), headers_charset,
6967           buffer, sizeof(buffer), FALSE);
6968         yield = string_cat(yield, &size, &ptr, string);
6969         continue;
6970         }
6971
6972       /* RFC 2047 decode */
6973
6974       case EOP_RFC2047D:
6975         {
6976         int len;
6977         uschar *error;
6978         uschar *decoded = rfc2047_decode(sub, check_rfc2047_length,
6979           headers_charset, '?', &len, &error);
6980         if (error != NULL)
6981           {
6982           expand_string_message = error;
6983           goto EXPAND_FAILED;
6984           }
6985         yield = string_catn(yield, &size, &ptr, decoded, len);
6986         continue;
6987         }
6988
6989       /* from_utf8 converts UTF-8 to 8859-1, turning non-existent chars into
6990       underscores */
6991
6992       case EOP_FROM_UTF8:
6993         {
6994         while (*sub != 0)
6995           {
6996           int c;
6997           uschar buff[4];
6998           GETUTF8INC(c, sub);
6999           if (c > 255) c = '_';
7000           buff[0] = c;
7001           yield = string_catn(yield, &size, &ptr, buff, 1);
7002           }
7003         continue;
7004         }
7005
7006           /* replace illegal UTF-8 sequences by replacement character  */
7007
7008       #define UTF8_REPLACEMENT_CHAR US"?"
7009
7010       case EOP_UTF8CLEAN:
7011         {
7012         int seq_len = 0, index = 0;
7013         int bytes_left = 0;
7014         long codepoint = -1;
7015         uschar seq_buff[4];                     /* accumulate utf-8 here */
7016
7017         while (*sub != 0)
7018           {
7019           int complete = 0;
7020           uschar c = *sub++;
7021
7022           if (bytes_left)
7023             {
7024             if ((c & 0xc0) != 0x80)
7025                     /* wrong continuation byte; invalidate all bytes */
7026               complete = 1; /* error */
7027             else
7028               {
7029               codepoint = (codepoint << 6) | (c & 0x3f);
7030               seq_buff[index++] = c;
7031               if (--bytes_left == 0)            /* codepoint complete */
7032                 if(codepoint > 0x10FFFF)        /* is it too large? */
7033                   complete = -1;        /* error (RFC3629 limit) */
7034                 else
7035                   {             /* finished; output utf-8 sequence */
7036                   yield = string_catn(yield, &size, &ptr, seq_buff, seq_len);
7037                   index = 0;
7038                   }
7039               }
7040             }
7041           else  /* no bytes left: new sequence */
7042             {
7043             if((c & 0x80) == 0) /* 1-byte sequence, US-ASCII, keep it */
7044               {
7045               yield = string_catn(yield, &size, &ptr, &c, 1);
7046               continue;
7047               }
7048             if((c & 0xe0) == 0xc0)              /* 2-byte sequence */
7049               {
7050               if(c == 0xc0 || c == 0xc1)        /* 0xc0 and 0xc1 are illegal */
7051                 complete = -1;
7052               else
7053                 {
7054                   bytes_left = 1;
7055                   codepoint = c & 0x1f;
7056                 }
7057               }
7058             else if((c & 0xf0) == 0xe0)         /* 3-byte sequence */
7059               {
7060               bytes_left = 2;
7061               codepoint = c & 0x0f;
7062               }
7063             else if((c & 0xf8) == 0xf0)         /* 4-byte sequence */
7064               {
7065               bytes_left = 3;
7066               codepoint = c & 0x07;
7067               }
7068             else        /* invalid or too long (RFC3629 allows only 4 bytes) */
7069               complete = -1;
7070
7071             seq_buff[index++] = c;
7072             seq_len = bytes_left + 1;
7073             }           /* if(bytes_left) */
7074
7075           if (complete != 0)
7076             {
7077             bytes_left = index = 0;
7078             yield = string_catn(yield, &size, &ptr, UTF8_REPLACEMENT_CHAR, 1);
7079             }
7080           if ((complete == 1) && ((c & 0x80) == 0))
7081                         /* ASCII character follows incomplete sequence */
7082               yield = string_catn(yield, &size, &ptr, &c, 1);
7083           }
7084         continue;
7085         }
7086
7087 #ifdef SUPPORT_I18N
7088       case EOP_UTF8_DOMAIN_TO_ALABEL:
7089         {
7090         uschar * error = NULL;
7091         uschar * s = string_domain_utf8_to_alabel(sub, &error);
7092         if (error)
7093           {
7094           expand_string_message = string_sprintf(
7095             "error converting utf8 (%s) to alabel: %s",
7096             string_printing(sub), error);
7097           goto EXPAND_FAILED;
7098           }
7099         yield = string_cat(yield, &size, &ptr, s);
7100         continue;
7101         }
7102
7103       case EOP_UTF8_DOMAIN_FROM_ALABEL:
7104         {
7105         uschar * error = NULL;
7106         uschar * s = string_domain_alabel_to_utf8(sub, &error);
7107         if (error)
7108           {
7109           expand_string_message = string_sprintf(
7110             "error converting alabel (%s) to utf8: %s",
7111             string_printing(sub), error);
7112           goto EXPAND_FAILED;
7113           }
7114         yield = string_cat(yield, &size, &ptr, s);
7115         continue;
7116         }
7117
7118       case EOP_UTF8_LOCALPART_TO_ALABEL:
7119         {
7120         uschar * error = NULL;
7121         uschar * s = string_localpart_utf8_to_alabel(sub, &error);
7122         if (error)
7123           {
7124           expand_string_message = string_sprintf(
7125             "error converting utf8 (%s) to alabel: %s",
7126             string_printing(sub), error);
7127           goto EXPAND_FAILED;
7128           }
7129         yield = string_cat(yield, &size, &ptr, s);
7130         DEBUG(D_expand) debug_printf_indent("yield: '%s'\n", yield);
7131         continue;
7132         }
7133
7134       case EOP_UTF8_LOCALPART_FROM_ALABEL:
7135         {
7136         uschar * error = NULL;
7137         uschar * s = string_localpart_alabel_to_utf8(sub, &error);
7138         if (error)
7139           {
7140           expand_string_message = string_sprintf(
7141             "error converting alabel (%s) to utf8: %s",
7142             string_printing(sub), error);
7143           goto EXPAND_FAILED;
7144           }
7145         yield = string_cat(yield, &size, &ptr, s);
7146         continue;
7147         }
7148 #endif  /* EXPERIMENTAL_INTERNATIONAL */
7149
7150       /* escape turns all non-printing characters into escape sequences. */
7151
7152       case EOP_ESCAPE:
7153         {
7154         const uschar * t = string_printing(sub);
7155         yield = string_cat(yield, &size, &ptr, t);
7156         continue;
7157         }
7158
7159       case EOP_ESCAPE8BIT:
7160         {
7161         const uschar * s = sub;
7162         uschar c;
7163
7164         for (s = sub; (c = *s); s++)
7165           yield = c < 127 && c != '\\'
7166             ? string_catn(yield, &size, &ptr, s, 1)
7167             : string_catn(yield, &size, &ptr, string_sprintf("\\%03o", c), 4);
7168         continue;
7169         }
7170
7171       /* Handle numeric expression evaluation */
7172
7173       case EOP_EVAL:
7174       case EOP_EVAL10:
7175         {
7176         uschar *save_sub = sub;
7177         uschar *error = NULL;
7178         int_eximarith_t n = eval_expr(&sub, (c == EOP_EVAL10), &error, FALSE);
7179         if (error != NULL)
7180           {
7181           expand_string_message = string_sprintf("error in expression "
7182             "evaluation: %s (after processing \"%.*s\")", error, sub-save_sub,
7183               save_sub);
7184           goto EXPAND_FAILED;
7185           }
7186         sprintf(CS var_buffer, PR_EXIM_ARITH, n);
7187         yield = string_cat(yield, &size, &ptr, var_buffer);
7188         continue;
7189         }
7190
7191       /* Handle time period formating */
7192
7193       case EOP_TIME_EVAL:
7194         {
7195         int n = readconf_readtime(sub, 0, FALSE);
7196         if (n < 0)
7197           {
7198           expand_string_message = string_sprintf("string \"%s\" is not an "
7199             "Exim time interval in \"%s\" operator", sub, name);
7200           goto EXPAND_FAILED;
7201           }
7202         sprintf(CS var_buffer, "%d", n);
7203         yield = string_cat(yield, &size, &ptr, var_buffer);
7204         continue;
7205         }
7206
7207       case EOP_TIME_INTERVAL:
7208         {
7209         int n;
7210         uschar *t = read_number(&n, sub);
7211         if (*t != 0) /* Not A Number*/
7212           {
7213           expand_string_message = string_sprintf("string \"%s\" is not a "
7214             "positive number in \"%s\" operator", sub, name);
7215           goto EXPAND_FAILED;
7216           }
7217         t = readconf_printtime(n);
7218         yield = string_cat(yield, &size, &ptr, t);
7219         continue;
7220         }
7221
7222       /* Convert string to base64 encoding */
7223
7224       case EOP_STR2B64:
7225       case EOP_BASE64:
7226         {
7227 #ifdef SUPPORT_TLS
7228         uschar * s = vp && *(void **)vp->value
7229           ? tls_cert_der_b64(*(void **)vp->value)
7230           : b64encode(sub, Ustrlen(sub));
7231 #else
7232         uschar * s = b64encode(sub, Ustrlen(sub));
7233 #endif
7234         yield = string_cat(yield, &size, &ptr, s);
7235         continue;
7236         }
7237
7238       case EOP_BASE64D:
7239         {
7240         uschar * s;
7241         int len = b64decode(sub, &s);
7242         if (len < 0)
7243           {
7244           expand_string_message = string_sprintf("string \"%s\" is not "
7245             "well-formed for \"%s\" operator", sub, name);
7246           goto EXPAND_FAILED;
7247           }
7248         yield = string_cat(yield, &size, &ptr, s);
7249         continue;
7250         }
7251
7252       /* strlen returns the length of the string */
7253
7254       case EOP_STRLEN:
7255         {
7256         uschar buff[24];
7257         (void)sprintf(CS buff, "%d", Ustrlen(sub));
7258         yield = string_cat(yield, &size, &ptr, buff);
7259         continue;
7260         }
7261
7262       /* length_n or l_n takes just the first n characters or the whole string,
7263       whichever is the shorter;
7264
7265       substr_m_n, and s_m_n take n characters from offset m; negative m take
7266       from the end; l_n is synonymous with s_0_n. If n is omitted in substr it
7267       takes the rest, either to the right or to the left.
7268
7269       hash_n or h_n makes a hash of length n from the string, yielding n
7270       characters from the set a-z; hash_n_m makes a hash of length n, but
7271       uses m characters from the set a-zA-Z0-9.
7272
7273       nhash_n returns a single number between 0 and n-1 (in text form), while
7274       nhash_n_m returns a div/mod hash as two numbers "a/b". The first lies
7275       between 0 and n-1 and the second between 0 and m-1. */
7276
7277       case EOP_LENGTH:
7278       case EOP_L:
7279       case EOP_SUBSTR:
7280       case EOP_S:
7281       case EOP_HASH:
7282       case EOP_H:
7283       case EOP_NHASH:
7284       case EOP_NH:
7285         {
7286         int sign = 1;
7287         int value1 = 0;
7288         int value2 = -1;
7289         int *pn;
7290         int len;
7291         uschar *ret;
7292
7293         if (arg == NULL)
7294           {
7295           expand_string_message = string_sprintf("missing values after %s",
7296             name);
7297           goto EXPAND_FAILED;
7298           }
7299
7300         /* "length" has only one argument, effectively being synonymous with
7301         substr_0_n. */
7302
7303         if (c == EOP_LENGTH || c == EOP_L)
7304           {
7305           pn = &value2;
7306           value2 = 0;
7307           }
7308
7309         /* The others have one or two arguments; for "substr" the first may be
7310         negative. The second being negative means "not supplied". */
7311
7312         else
7313           {
7314           pn = &value1;
7315           if (name[0] == 's' && *arg == '-') { sign = -1; arg++; }
7316           }
7317
7318         /* Read up to two numbers, separated by underscores */
7319
7320         ret = arg;
7321         while (*arg != 0)
7322           {
7323           if (arg != ret && *arg == '_' && pn == &value1)
7324             {
7325             pn = &value2;
7326             value2 = 0;
7327             if (arg[1] != 0) arg++;
7328             }
7329           else if (!isdigit(*arg))
7330             {
7331             expand_string_message =
7332               string_sprintf("non-digit after underscore in \"%s\"", name);
7333             goto EXPAND_FAILED;
7334             }
7335           else *pn = (*pn)*10 + *arg++ - '0';
7336           }
7337         value1 *= sign;
7338
7339         /* Perform the required operation */
7340
7341         ret =
7342           (c == EOP_HASH || c == EOP_H)?
7343              compute_hash(sub, value1, value2, &len) :
7344           (c == EOP_NHASH || c == EOP_NH)?
7345              compute_nhash(sub, value1, value2, &len) :
7346              extract_substr(sub, value1, value2, &len);
7347
7348         if (ret == NULL) goto EXPAND_FAILED;
7349         yield = string_catn(yield, &size, &ptr, ret, len);
7350         continue;
7351         }
7352
7353       /* Stat a path */
7354
7355       case EOP_STAT:
7356         {
7357         uschar *s;
7358         uschar smode[12];
7359         uschar **modetable[3];
7360         int i;
7361         mode_t mode;
7362         struct stat st;
7363
7364         if ((expand_forbid & RDO_EXISTS) != 0)
7365           {
7366           expand_string_message = US"Use of the stat() expansion is not permitted";
7367           goto EXPAND_FAILED;
7368           }
7369
7370         if (stat(CS sub, &st) < 0)
7371           {
7372           expand_string_message = string_sprintf("stat(%s) failed: %s",
7373             sub, strerror(errno));
7374           goto EXPAND_FAILED;
7375           }
7376         mode = st.st_mode;
7377         switch (mode & S_IFMT)
7378           {
7379           case S_IFIFO: smode[0] = 'p'; break;
7380           case S_IFCHR: smode[0] = 'c'; break;
7381           case S_IFDIR: smode[0] = 'd'; break;
7382           case S_IFBLK: smode[0] = 'b'; break;
7383           case S_IFREG: smode[0] = '-'; break;
7384           default: smode[0] = '?'; break;
7385           }
7386
7387         modetable[0] = ((mode & 01000) == 0)? mtable_normal : mtable_sticky;
7388         modetable[1] = ((mode & 02000) == 0)? mtable_normal : mtable_setid;
7389         modetable[2] = ((mode & 04000) == 0)? mtable_normal : mtable_setid;
7390
7391         for (i = 0; i < 3; i++)
7392           {
7393           memcpy(CS(smode + 7 - i*3), CS(modetable[i][mode & 7]), 3);
7394           mode >>= 3;
7395           }
7396
7397         smode[10] = 0;
7398         s = string_sprintf("mode=%04lo smode=%s inode=%ld device=%ld links=%ld "
7399           "uid=%ld gid=%ld size=" OFF_T_FMT " atime=%ld mtime=%ld ctime=%ld",
7400           (long)(st.st_mode & 077777), smode, (long)st.st_ino,
7401           (long)st.st_dev, (long)st.st_nlink, (long)st.st_uid,
7402           (long)st.st_gid, st.st_size, (long)st.st_atime,
7403           (long)st.st_mtime, (long)st.st_ctime);
7404         yield = string_cat(yield, &size, &ptr, s);
7405         continue;
7406         }
7407
7408       /* vaguely random number less than N */
7409
7410       case EOP_RANDINT:
7411         {
7412         int_eximarith_t max;
7413         uschar *s;
7414
7415         max = expanded_string_integer(sub, TRUE);
7416         if (expand_string_message != NULL)
7417           goto EXPAND_FAILED;
7418         s = string_sprintf("%d", vaguely_random_number((int)max));
7419         yield = string_cat(yield, &size, &ptr, s);
7420         continue;
7421         }
7422
7423       /* Reverse IP, including IPv6 to dotted-nibble */
7424
7425       case EOP_REVERSE_IP:
7426         {
7427         int family, maskptr;
7428         uschar reversed[128];
7429
7430         family = string_is_ip_address(sub, &maskptr);
7431         if (family == 0)
7432           {
7433           expand_string_message = string_sprintf(
7434               "reverse_ip() not given an IP address [%s]", sub);
7435           goto EXPAND_FAILED;
7436           }
7437         invert_address(reversed, sub);
7438         yield = string_cat(yield, &size, &ptr, reversed);
7439         continue;
7440         }
7441
7442       /* Unknown operator */
7443
7444       default:
7445       expand_string_message =
7446         string_sprintf("unknown expansion operator \"%s\"", name);
7447       goto EXPAND_FAILED;
7448       }
7449     }
7450
7451   /* Handle a plain name. If this is the first thing in the expansion, release
7452   the pre-allocated buffer. If the result data is known to be in a new buffer,
7453   newsize will be set to the size of that buffer, and we can just point at that
7454   store instead of copying. Many expansion strings contain just one reference,
7455   so this is a useful optimization, especially for humungous headers
7456   ($message_headers). */
7457                                                 /*{*/
7458   if (*s++ == '}')
7459     {
7460     int len;
7461     int newsize = 0;
7462     if (ptr == 0)
7463       {
7464       if (resetok) store_reset(yield);
7465       yield = NULL;
7466       size = 0;
7467       }
7468     if (!(value = find_variable(name, FALSE, skipping, &newsize)))
7469       {
7470       expand_string_message =
7471         string_sprintf("unknown variable in \"${%s}\"", name);
7472       check_variable_error_message(name);
7473       goto EXPAND_FAILED;
7474       }
7475     len = Ustrlen(value);
7476     if (!yield && newsize)
7477       {
7478       yield = value;
7479       size = newsize;
7480       ptr = len;
7481       }
7482     else
7483       yield = string_catn(yield, &size, &ptr, value, len);
7484     continue;
7485     }
7486
7487   /* Else there's something wrong */
7488
7489   expand_string_message =
7490     string_sprintf("\"${%s\" is not a known operator (or a } is missing "
7491     "in a variable reference)", name);
7492   goto EXPAND_FAILED;
7493   }
7494
7495 /* If we hit the end of the string when ket_ends is set, there is a missing
7496 terminating brace. */
7497
7498 if (ket_ends && *s == 0)
7499   {
7500   expand_string_message = malformed_header?
7501     US"missing } at end of string - could be header name not terminated by colon"
7502     :
7503     US"missing } at end of string";
7504   goto EXPAND_FAILED;
7505   }
7506
7507 /* Expansion succeeded; yield may still be NULL here if nothing was actually
7508 added to the string. If so, set up an empty string. Add a terminating zero. If
7509 left != NULL, return a pointer to the terminator. */
7510
7511 if (yield == NULL) yield = store_get(1);
7512 yield[ptr] = 0;
7513 if (left != NULL) *left = s;
7514
7515 /* Any stacking store that was used above the final string is no longer needed.
7516 In many cases the final string will be the first one that was got and so there
7517 will be optimal store usage. */
7518
7519 if (resetok) store_reset(yield + ptr + 1);
7520 else if (resetok_p) *resetok_p = FALSE;
7521
7522 DEBUG(D_expand)
7523   {
7524   debug_printf_indent(UTF8_VERT_RIGHT UTF8_HORIZ UTF8_HORIZ
7525     "expanding: %.*s\n",
7526     (int)(s - string), string);
7527   debug_printf_indent("%s"
7528     UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7529     "result: %s\n",
7530     skipping ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7531     yield);
7532   if (skipping)
7533     debug_printf_indent(UTF8_UP_RIGHT UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7534       "skipping: result is not used\n");
7535   }
7536 expand_level--;
7537 return yield;
7538
7539 /* This is the failure exit: easiest to program with a goto. We still need
7540 to update the pointer to the terminator, for cases of nested calls with "fail".
7541 */
7542
7543 EXPAND_FAILED_CURLY:
7544 if (malformed_header)
7545   expand_string_message =
7546     US"missing or misplaced { or } - could be header name not terminated by colon";
7547
7548 else if (!expand_string_message || !*expand_string_message)
7549   expand_string_message = US"missing or misplaced { or }";
7550
7551 /* At one point, Exim reset the store to yield (if yield was not NULL), but
7552 that is a bad idea, because expand_string_message is in dynamic store. */
7553
7554 EXPAND_FAILED:
7555 if (left != NULL) *left = s;
7556 DEBUG(D_expand)
7557   {
7558   debug_printf_indent(UTF8_VERT_RIGHT "failed to expand: %s\n",
7559     string);
7560   debug_printf_indent("%s" UTF8_HORIZ UTF8_HORIZ UTF8_HORIZ
7561     "error message: %s\n",
7562     expand_string_forcedfail ? UTF8_VERT_RIGHT : UTF8_UP_RIGHT,
7563     expand_string_message);
7564   if (expand_string_forcedfail)
7565     debug_printf_indent(UTF8_UP_RIGHT "failure was forced\n");
7566   }
7567 if (resetok_p) *resetok_p = resetok;
7568 expand_level--;
7569 return NULL;
7570 }
7571
7572
7573 /* This is the external function call. Do a quick check for any expansion
7574 metacharacters, and if there are none, just return the input string.
7575
7576 Argument: the string to be expanded
7577 Returns:  the expanded string, or NULL if expansion failed; if failure was
7578           due to a lookup deferring, search_find_defer will be TRUE
7579 */
7580
7581 uschar *
7582 expand_string(uschar *string)
7583 {
7584 search_find_defer = FALSE;
7585 malformed_header = FALSE;
7586 return (Ustrpbrk(string, "$\\") == NULL)? string :
7587   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7588 }
7589
7590
7591
7592 const uschar *
7593 expand_cstring(const uschar *string)
7594 {
7595 search_find_defer = FALSE;
7596 malformed_header = FALSE;
7597 return (Ustrpbrk(string, "$\\") == NULL)? string :
7598   expand_string_internal(string, FALSE, NULL, FALSE, TRUE, NULL);
7599 }
7600
7601
7602
7603 /*************************************************
7604 *              Expand and copy                   *
7605 *************************************************/
7606
7607 /* Now and again we want to expand a string and be sure that the result is in a
7608 new bit of store. This function does that.
7609 Since we know it has been copied, the de-const cast is safe.
7610
7611 Argument: the string to be expanded
7612 Returns:  the expanded string, always in a new bit of store, or NULL
7613 */
7614
7615 uschar *
7616 expand_string_copy(const uschar *string)
7617 {
7618 const uschar *yield = expand_cstring(string);
7619 if (yield == string) yield = string_copy(string);
7620 return US yield;
7621 }
7622
7623
7624
7625 /*************************************************
7626 *        Expand and interpret as an integer      *
7627 *************************************************/
7628
7629 /* Expand a string, and convert the result into an integer.
7630
7631 Arguments:
7632   string  the string to be expanded
7633   isplus  TRUE if a non-negative number is expected
7634
7635 Returns:  the integer value, or
7636           -1 for an expansion error               ) in both cases, message in
7637           -2 for an integer interpretation error  ) expand_string_message
7638           expand_string_message is set NULL for an OK integer
7639 */
7640
7641 int_eximarith_t
7642 expand_string_integer(uschar *string, BOOL isplus)
7643 {
7644 return expanded_string_integer(expand_string(string), isplus);
7645 }
7646
7647
7648 /*************************************************
7649  *         Interpret string as an integer        *
7650  *************************************************/
7651
7652 /* Convert a string (that has already been expanded) into an integer.
7653
7654 This function is used inside the expansion code.
7655
7656 Arguments:
7657   s       the string to be expanded
7658   isplus  TRUE if a non-negative number is expected
7659
7660 Returns:  the integer value, or
7661           -1 if string is NULL (which implies an expansion error)
7662           -2 for an integer interpretation error
7663           expand_string_message is set NULL for an OK integer
7664 */
7665
7666 static int_eximarith_t
7667 expanded_string_integer(const uschar *s, BOOL isplus)
7668 {
7669 int_eximarith_t value;
7670 uschar *msg = US"invalid integer \"%s\"";
7671 uschar *endptr;
7672
7673 /* If expansion failed, expand_string_message will be set. */
7674
7675 if (s == NULL) return -1;
7676
7677 /* On an overflow, strtol() returns LONG_MAX or LONG_MIN, and sets errno
7678 to ERANGE. When there isn't an overflow, errno is not changed, at least on some
7679 systems, so we set it zero ourselves. */
7680
7681 errno = 0;
7682 expand_string_message = NULL;               /* Indicates no error */
7683
7684 /* Before Exim 4.64, strings consisting entirely of whitespace compared
7685 equal to 0.  Unfortunately, people actually relied upon that, so preserve
7686 the behaviour explicitly.  Stripping leading whitespace is a harmless
7687 noop change since strtol skips it anyway (provided that there is a number
7688 to find at all). */
7689 if (isspace(*s))
7690   {
7691   while (isspace(*s)) ++s;
7692   if (*s == '\0')
7693     {
7694       DEBUG(D_expand)
7695        debug_printf_indent("treating blank string as number 0\n");
7696       return 0;
7697     }
7698   }
7699
7700 value = strtoll(CS s, CSS &endptr, 10);
7701
7702 if (endptr == s)
7703   {
7704   msg = US"integer expected but \"%s\" found";
7705   }
7706 else if (value < 0 && isplus)
7707   {
7708   msg = US"non-negative integer expected but \"%s\" found";
7709   }
7710 else
7711   {
7712   switch (tolower(*endptr))
7713     {
7714     default:
7715       break;
7716     case 'k':
7717       if (value > EXIM_ARITH_MAX/1024 || value < EXIM_ARITH_MIN/1024) errno = ERANGE;
7718       else value *= 1024;
7719       endptr++;
7720       break;
7721     case 'm':
7722       if (value > EXIM_ARITH_MAX/(1024*1024) || value < EXIM_ARITH_MIN/(1024*1024)) errno = ERANGE;
7723       else value *= 1024*1024;
7724       endptr++;
7725       break;
7726     case 'g':
7727       if (value > EXIM_ARITH_MAX/(1024*1024*1024) || value < EXIM_ARITH_MIN/(1024*1024*1024)) errno = ERANGE;
7728       else value *= 1024*1024*1024;
7729       endptr++;
7730       break;
7731     }
7732   if (errno == ERANGE)
7733     msg = US"absolute value of integer \"%s\" is too large (overflow)";
7734   else
7735     {
7736     while (isspace(*endptr)) endptr++;
7737     if (*endptr == 0) return value;
7738     }
7739   }
7740
7741 expand_string_message = string_sprintf(CS msg, s);
7742 return -2;
7743 }
7744
7745
7746 /* These values are usually fixed boolean values, but they are permitted to be
7747 expanded strings.
7748
7749 Arguments:
7750   addr       address being routed
7751   mtype      the module type
7752   mname      the module name
7753   dbg_opt    debug selectors
7754   oname      the option name
7755   bvalue     the router's boolean value
7756   svalue     the router's string value
7757   rvalue     where to put the returned value
7758
7759 Returns:     OK     value placed in rvalue
7760              DEFER  expansion failed
7761 */
7762
7763 int
7764 exp_bool(address_item *addr,
7765   uschar *mtype, uschar *mname, unsigned dbg_opt,
7766   uschar *oname, BOOL bvalue,
7767   uschar *svalue, BOOL *rvalue)
7768 {
7769 uschar *expanded;
7770 if (svalue == NULL) { *rvalue = bvalue; return OK; }
7771
7772 expanded = expand_string(svalue);
7773 if (expanded == NULL)
7774   {
7775   if (expand_string_forcedfail)
7776     {
7777     DEBUG(dbg_opt) debug_printf("expansion of \"%s\" forced failure\n", oname);
7778     *rvalue = bvalue;
7779     return OK;
7780     }
7781   addr->message = string_sprintf("failed to expand \"%s\" in %s %s: %s",
7782       oname, mname, mtype, expand_string_message);
7783   DEBUG(dbg_opt) debug_printf("%s\n", addr->message);
7784   return DEFER;
7785   }
7786
7787 DEBUG(dbg_opt) debug_printf("expansion of \"%s\" yields \"%s\"\n", oname,
7788   expanded);
7789
7790 if (strcmpic(expanded, US"true") == 0 || strcmpic(expanded, US"yes") == 0)
7791   *rvalue = TRUE;
7792 else if (strcmpic(expanded, US"false") == 0 || strcmpic(expanded, US"no") == 0)
7793   *rvalue = FALSE;
7794 else
7795   {
7796   addr->message = string_sprintf("\"%s\" is not a valid value for the "
7797     "\"%s\" option in the %s %s", expanded, oname, mname, mtype);
7798   return DEFER;
7799   }
7800
7801 return OK;
7802 }
7803
7804
7805
7806 /* Avoid potentially exposing a password in a string about to be logged */
7807
7808 uschar *
7809 expand_hide_passwords(uschar * s)
7810 {
7811 return (  (  Ustrstr(s, "failed to expand") != NULL
7812           || Ustrstr(s, "expansion of ")    != NULL
7813           )
7814        && (  Ustrstr(s, "mysql")   != NULL
7815           || Ustrstr(s, "pgsql")   != NULL
7816           || Ustrstr(s, "redis")   != NULL
7817           || Ustrstr(s, "sqlite")  != NULL
7818           || Ustrstr(s, "ldap:")   != NULL
7819           || Ustrstr(s, "ldaps:")  != NULL
7820           || Ustrstr(s, "ldapi:")  != NULL
7821           || Ustrstr(s, "ldapdn:") != NULL
7822           || Ustrstr(s, "ldapm:")  != NULL
7823        )  )
7824   ? US"Temporary internal error" : s;
7825 }
7826
7827
7828
7829 /*************************************************
7830 * Error-checking for testsuite                   *
7831 *************************************************/
7832 typedef struct {
7833   const char *  filename;
7834   int           linenumber;
7835   uschar *      region_start;
7836   uschar *      region_end;
7837   const uschar *var_name;
7838   const uschar *var_data;
7839 } err_ctx;
7840
7841 static void
7842 assert_variable_notin(uschar * var_name, uschar * var_data, void * ctx)
7843 {
7844 err_ctx * e = ctx;
7845 if (var_data >= e->region_start  &&  var_data < e->region_end)
7846   {
7847   e->var_name = CUS var_name;
7848   e->var_data = CUS var_data;
7849   }
7850 }
7851
7852 void
7853 assert_no_variables(void * ptr, int len, const char * filename, int linenumber)
7854 {
7855 err_ctx e = {filename, linenumber, ptr, US ptr + len, NULL };
7856 int i;
7857 var_entry * v;
7858
7859 /* check acl_ variables */
7860 tree_walk(acl_var_c, assert_variable_notin, &e);
7861 tree_walk(acl_var_m, assert_variable_notin, &e);
7862
7863 /* check auth<n> variables */
7864 for (i = 0; i < AUTH_VARS; i++) if (auth_vars[i])
7865   assert_variable_notin(US"auth<n>", auth_vars[i], &e);
7866
7867 /* check regex<n> variables */
7868 for (i = 0; i < REGEX_VARS; i++) if (regex_vars[i])
7869   assert_variable_notin(US"regex<n>", regex_vars[i], &e);
7870
7871 /* check known-name variables */
7872 for (v = var_table; v < var_table + var_table_size; v++)
7873   if (v->type == vtype_stringptr)
7874     assert_variable_notin(US v->name, *(USS v->value), &e);
7875
7876 if (e.var_name)
7877   log_write(0, LOG_MAIN|LOG_PANIC_DIE,
7878     "live variable '%s' destroyed by reset_store at %s:%d\n- value '%.64s'",
7879     e.var_name, e.filename, e.linenumber, e.var_data);
7880 }
7881
7882
7883
7884 /*************************************************
7885 **************************************************
7886 *             Stand-alone test program           *
7887 **************************************************
7888 *************************************************/
7889
7890 #ifdef STAND_ALONE
7891
7892
7893 BOOL
7894 regex_match_and_setup(const pcre *re, uschar *subject, int options, int setup)
7895 {
7896 int ovector[3*(EXPAND_MAXN+1)];
7897 int n = pcre_exec(re, NULL, subject, Ustrlen(subject), 0, PCRE_EOPT|options,
7898   ovector, nelem(ovector));
7899 BOOL yield = n >= 0;
7900 if (n == 0) n = EXPAND_MAXN + 1;
7901 if (yield)
7902   {
7903   int nn;
7904   expand_nmax = (setup < 0)? 0 : setup + 1;
7905   for (nn = (setup < 0)? 0 : 2; nn < n*2; nn += 2)
7906     {
7907     expand_nstring[expand_nmax] = subject + ovector[nn];
7908     expand_nlength[expand_nmax++] = ovector[nn+1] - ovector[nn];
7909     }
7910   expand_nmax--;
7911   }
7912 return yield;
7913 }
7914
7915
7916 int main(int argc, uschar **argv)
7917 {
7918 int i;
7919 uschar buffer[1024];
7920
7921 debug_selector = D_v;
7922 debug_file = stderr;
7923 debug_fd = fileno(debug_file);
7924 big_buffer = malloc(big_buffer_size);
7925
7926 for (i = 1; i < argc; i++)
7927   {
7928   if (argv[i][0] == '+')
7929     {
7930     debug_trace_memory = 2;
7931     argv[i]++;
7932     }
7933   if (isdigit(argv[i][0]))
7934     debug_selector = Ustrtol(argv[i], NULL, 0);
7935   else
7936     if (Ustrspn(argv[i], "abcdefghijklmnopqrtsuvwxyz0123456789-.:/") ==
7937         Ustrlen(argv[i]))
7938       {
7939 #ifdef LOOKUP_LDAP
7940       eldap_default_servers = argv[i];
7941 #endif
7942 #ifdef LOOKUP_MYSQL
7943       mysql_servers = argv[i];
7944 #endif
7945 #ifdef LOOKUP_PGSQL
7946       pgsql_servers = argv[i];
7947 #endif
7948 #ifdef LOOKUP_REDIS
7949       redis_servers = argv[i];
7950 #endif
7951       }
7952 #ifdef EXIM_PERL
7953   else opt_perl_startup = argv[i];
7954 #endif
7955   }
7956
7957 printf("Testing string expansion: debug_level = %d\n\n", debug_level);
7958
7959 expand_nstring[1] = US"string 1....";
7960 expand_nlength[1] = 8;
7961 expand_nmax = 1;
7962
7963 #ifdef EXIM_PERL
7964 if (opt_perl_startup != NULL)
7965   {
7966   uschar *errstr;
7967   printf("Starting Perl interpreter\n");
7968   errstr = init_perl(opt_perl_startup);
7969   if (errstr != NULL)
7970     {
7971     printf("** error in perl_startup code: %s\n", errstr);
7972     return EXIT_FAILURE;
7973     }
7974   }
7975 #endif /* EXIM_PERL */
7976
7977 while (fgets(buffer, sizeof(buffer), stdin) != NULL)
7978   {
7979   void *reset_point = store_get(0);
7980   uschar *yield = expand_string(buffer);
7981   if (yield != NULL)
7982     {
7983     printf("%s\n", yield);
7984     store_reset(reset_point);
7985     }
7986   else
7987     {
7988     if (search_find_defer) printf("search_find deferred\n");
7989     printf("Failed: %s\n", expand_string_message);
7990     if (expand_string_forcedfail) printf("Forced failure\n");
7991     printf("\n");
7992     }
7993   }
7994
7995 search_tidyup();
7996
7997 return 0;
7998 }
7999
8000 #endif
8001
8002 /* vi: aw ai sw=2
8003 */
8004 /* End of expand.c */