/*++ /* NAME /* tls_misc 3 /* SUMMARY /* miscellaneous TLS support routines /* SYNOPSIS /* #define TLS_INTERNAL /* #include /* /* char *var_tls_high_clist; /* char *var_tls_medium_clist; /* char *var_tls_low_clist; /* char *var_tls_export_clist; /* char *var_tls_null_clist; /* char *var_tls_eecdh_strong; /* char *var_tls_eecdh_ultra; /* char *var_tls_dane_agility; /* char *var_tls_dane_digests; /* int var_tls_daemon_rand_bytes; /* bool var_tls_append_def_CA; /* bool var_tls_dane_taa_dgst; /* bool var_tls_preempt_clist; /* bool var_tls_bc_pkey_fprint; /* bool var_tls_multi_wildcard; /* char *var_tls_mgr_service; /* /* TLS_APPL_STATE *tls_alloc_app_context(ssl_ctx, log_mask) /* SSL_CTX *ssl_ctx; /* int log_mask; /* /* void tls_free_app_context(app_ctx) /* void *app_ctx; /* /* TLS_SESS_STATE *tls_alloc_sess_context(log_mask, namaddr) /* int log_mask; /* const char *namaddr; /* /* void tls_free_context(TLScontext) /* TLS_SESS_STATE *TLScontext; /* /* void tls_check_version() /* /* long tls_bug_bits() /* /* void tls_param_init() /* /* int tls_protocol_mask(plist) /* const char *plist; /* /* int tls_cipher_grade(name) /* const char *name; /* /* const char *str_tls_cipher_grade(grade) /* int grade; /* /* const char *tls_set_ciphers(app_ctx, context, grade, exclusions) /* TLS_APPL_STATE *app_ctx; /* const char *context; /* int grade; /* const char *exclusions; /* /* void tls_print_errors() /* /* void tls_info_callback(ssl, where, ret) /* const SSL *ssl; /* unused */ /* int where; /* int ret; /* /* long tls_bio_dump_cb(bio, cmd, argp, argi, argl, ret) /* BIO *bio; /* int cmd; /* const char *argp; /* int argi; /* long argl; /* unused */ /* long ret; /* /* int tls_log_mask(log_param, log_level) /* const char *log_param; /* const char *log_level; /* /* void tls_update_app_logmask(app_ctx, log_mask) /* TLS_APPL_STATE *app_ctx; /* int log_mask; /* /* int tls_validate_digest(dgst) /* const char *dgst; /* DESCRIPTION /* This module implements routines that support the TLS client /* and server internals. /* /* tls_alloc_app_context() creates an application context that /* holds the SSL context for the application and related cached state. /* /* tls_free_app_context() deallocates the application context and its /* contents (the application context is stored outside the TLS library). /* /* tls_alloc_sess_context() creates an initialized TLS session context /* structure with the specified log mask and peer name[addr]. /* /* tls_free_context() destroys a TLScontext structure /* together with OpenSSL structures that are attached to it. /* /* tls_check_version() logs a warning when the run-time OpenSSL /* library differs in its major, minor or micro number from /* the compile-time OpenSSL headers. /* /* tls_bug_bits() returns the bug compatibility mask appropriate /* for the run-time library. Some of the bug work-arounds are /* not appropriate for some library versions. /* /* tls_param_init() loads main.cf parameters used internally in /* TLS library. Any errors are fatal. /* /* tls_protocol_mask() returns a bitmask of excluded protocols, given /* a list (plist) of protocols to include or (preceded by a '!') exclude. /* If "plist" contains invalid protocol names, TLS_PROTOCOL_INVALID is /* returned and no warning is logged. /* /* tls_cipher_grade() converts a case-insensitive cipher grade /* name (high, medium, low, export, null) to the corresponding /* TLS_CIPHER_ constant. When the input specifies an unrecognized /* grade, tls_cipher_grade() logs no warning, and returns /* TLS_CIPHER_NONE. /* /* str_tls_cipher_grade() converts a cipher grade to a name. /* When the input specifies an undefined grade, str_tls_cipher_grade() /* logs no warning, returns a null pointer. /* /* tls_set_ciphers() generates a cipher list from the specified /* grade, minus any ciphers specified via a list of exclusions. /* The cipherlist is applied to the supplied SSL context if it /* is different from the most recently applied value. The return /* value is the cipherlist used and is overwritten upon each call. /* When the input is invalid, tls_set_ciphers() logs a warning with /* the specified context, and returns a null pointer result. /* /* tls_print_errors() queries the OpenSSL error stack, /* logs the error messages, and clears the error stack. /* /* tls_info_callback() is a call-back routine for the /* SSL_CTX_set_info_callback() routine. It logs SSL events /* to the Postfix logfile. /* /* tls_bio_dump_cb() is a call-back routine for the /* BIO_set_callback() routine. It logs SSL content to the /* Postfix logfile. /* /* tls_log_mask() converts a TLS log_level value from string /* to mask. The main.cf parameter name is passed along for /* diagnostics. /* /* tls_update_app_logmask() changes the log mask of the /* application TLS context to the new setting. /* /* tls_validate_digest() returns non-zero if the named digest /* is usable and zero otherwise. /* LICENSE /* .ad /* .fi /* This software is free. You can do with it whatever you want. /* The original author kindly requests that you acknowledge /* the use of his software. /* AUTHOR(S) /* Originally written by: /* Lutz Jaenicke /* BTU Cottbus /* Allgemeine Elektrotechnik /* Universitaetsplatz 3-4 /* D-03044 Cottbus, Germany /* /* Updated by: /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /* /* Victor Duchovni /* Morgan Stanley /*--*/ /* System library. */ #include #include #include #ifdef USE_TLS /* Utility library. */ #include #include #include #include #include #include #include #include /* * Global library. */ #include #include /* * TLS library. */ #define TLS_INTERNAL #include /* Application-specific. */ /* * Tunable parameters. */ char *var_tls_high_clist; char *var_tls_medium_clist; char *var_tls_low_clist; char *var_tls_export_clist; char *var_tls_null_clist; int var_tls_daemon_rand_bytes; char *var_tls_eecdh_strong; char *var_tls_eecdh_ultra; char *var_tls_dane_agility; char *var_tls_dane_digests; bool var_tls_append_def_CA; char *var_tls_bug_tweaks; char *var_tls_ssl_options; bool var_tls_bc_pkey_fprint; bool var_tls_dane_taa_dgst; bool var_tls_multi_wildcard; char *var_tls_mgr_service; #ifdef VAR_TLS_PREEMPT_CLIST bool var_tls_preempt_clist; #endif /* * Index to attach TLScontext pointers to SSL objects, so that they can be * accessed by call-back routines. */ int TLScontext_index = -1; /* * Protocol name <=> mask conversion. */ static const NAME_CODE protocol_table[] = { SSL_TXT_SSLV2, TLS_PROTOCOL_SSLv2, SSL_TXT_SSLV3, TLS_PROTOCOL_SSLv3, SSL_TXT_TLSV1, TLS_PROTOCOL_TLSv1, #ifdef SSL_TXT_TLSV1_1 SSL_TXT_TLSV1_1, TLS_PROTOCOL_TLSv1_1, #endif #ifdef SSL_TXT_TLSV1_2 SSL_TXT_TLSV1_2, TLS_PROTOCOL_TLSv1_2, #endif 0, TLS_PROTOCOL_INVALID, }; /* * SSL_OP_MUMBLE bug work-around name <=> mask conversion. */ #define NAMEBUG(x) #x, SSL_OP_##x static const LONG_NAME_MASK ssl_bug_tweaks[] = { #ifndef SSL_OP_MICROSOFT_SESS_ID_BUG #define SSL_OP_MICROSOFT_SESS_ID_BUG 0 #endif NAMEBUG(MICROSOFT_SESS_ID_BUG), #ifndef SSL_OP_NETSCAPE_CHALLENGE_BUG #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0 #endif NAMEBUG(NETSCAPE_CHALLENGE_BUG), #ifndef SSL_OP_LEGACY_SERVER_CONNECT #define SSL_OP_LEGACY_SERVER_CONNECT 0 #endif NAMEBUG(LEGACY_SERVER_CONNECT), #ifndef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0 #endif NAMEBUG(NETSCAPE_REUSE_CIPHER_CHANGE_BUG), "CVE-2010-4180", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG, #ifndef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0 #endif NAMEBUG(SSLREF2_REUSE_CERT_TYPE_BUG), #ifndef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0 #endif NAMEBUG(MICROSOFT_BIG_SSLV3_BUFFER), #ifndef SSL_OP_MSIE_SSLV2_RSA_PADDING #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0 #endif NAMEBUG(MSIE_SSLV2_RSA_PADDING), "CVE-2005-2969", SSL_OP_MSIE_SSLV2_RSA_PADDING, #ifndef SSL_OP_SSLEAY_080_CLIENT_DH_BUG #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0 #endif NAMEBUG(SSLEAY_080_CLIENT_DH_BUG), #ifndef SSL_OP_TLS_D5_BUG #define SSL_OP_TLS_D5_BUG 0 #endif NAMEBUG(TLS_D5_BUG), #ifndef SSL_OP_TLS_BLOCK_PADDING_BUG #define SSL_OP_TLS_BLOCK_PADDING_BUG 0 #endif NAMEBUG(TLS_BLOCK_PADDING_BUG), #ifndef SSL_OP_TLS_ROLLBACK_BUG #define SSL_OP_TLS_ROLLBACK_BUG 0 #endif NAMEBUG(TLS_ROLLBACK_BUG), #ifndef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0 #endif NAMEBUG(DONT_INSERT_EMPTY_FRAGMENTS), #ifndef SSL_OP_CRYPTOPRO_TLSEXT_BUG #define SSL_OP_CRYPTOPRO_TLSEXT_BUG 0 #endif NAMEBUG(CRYPTOPRO_TLSEXT_BUG), 0, 0, }; /* * SSL_OP_MUMBLE option name <=> mask conversion for options that are not * (or may in the future not be) in SSL_OP_ALL. These enable optional * behavior, rather than bug interoperability work-arounds. */ #define NAME_SSL_OP(x) #x, SSL_OP_##x static const LONG_NAME_MASK ssl_op_tweaks[] = { #ifndef SSL_OP_LEGACY_SERVER_CONNECT #define SSL_OP_LEGACY_SERVER_CONNECT 0 #endif NAME_SSL_OP(LEGACY_SERVER_CONNECT), #ifndef SSL_OP_NO_TICKET #define SSL_OP_NO_TICKET 0 #endif NAME_SSL_OP(NO_TICKET), #ifndef SSL_OP_NO_COMPRESSION #define SSL_OP_NO_COMPRESSION 0 #endif NAME_SSL_OP(NO_COMPRESSION), 0, 0, }; /* * Ciphersuite name <=> code conversion. */ const NAME_CODE tls_cipher_grade_table[] = { "high", TLS_CIPHER_HIGH, "medium", TLS_CIPHER_MEDIUM, "low", TLS_CIPHER_LOW, "export", TLS_CIPHER_EXPORT, "null", TLS_CIPHER_NULL, "invalid", TLS_CIPHER_NONE, 0, TLS_CIPHER_NONE, }; /* * Log keyword <=> mask conversion. */ #define TLS_LOG_0 TLS_LOG_NONE #define TLS_LOG_1 TLS_LOG_SUMMARY #define TLS_LOG_2 (TLS_LOG_1 | TLS_LOG_VERBOSE | TLS_LOG_CACHE | TLS_LOG_DEBUG) #define TLS_LOG_3 (TLS_LOG_2 | TLS_LOG_TLSPKTS) #define TLS_LOG_4 (TLS_LOG_3 | TLS_LOG_ALLPKTS) static const NAME_MASK tls_log_table[] = { "0", TLS_LOG_0, "none", TLS_LOG_NONE, "1", TLS_LOG_1, "routine", TLS_LOG_1, "2", TLS_LOG_2, "debug", TLS_LOG_2, "3", TLS_LOG_3, "ssl-expert", TLS_LOG_3, "4", TLS_LOG_4, "ssl-developer", TLS_LOG_4, "5", TLS_LOG_4, /* for good measure */ "6", TLS_LOG_4, /* for good measure */ "7", TLS_LOG_4, /* for good measure */ "8", TLS_LOG_4, /* for good measure */ "9", TLS_LOG_4, /* for good measure */ "summary", TLS_LOG_SUMMARY, "untrusted", TLS_LOG_UNTRUSTED, "peercert", TLS_LOG_PEERCERT, "certmatch", TLS_LOG_CERTMATCH, "verbose", TLS_LOG_VERBOSE, /* Postfix TLS library verbose */ "cache", TLS_LOG_CACHE, "ssl-debug", TLS_LOG_DEBUG, /* SSL library debug/verbose */ "ssl-handshake-packet-dump", TLS_LOG_TLSPKTS, "ssl-session-packet-dump", TLS_LOG_TLSPKTS | TLS_LOG_ALLPKTS, 0, 0, }; /* * Parsed OpenSSL version number. */ typedef struct { int major; int minor; int micro; int patch; int status; } TLS_VINFO; /* * OpenSSL adopted the cipher selection patch, so we don't expect any more * broken ciphers other than AES and CAMELLIA. */ typedef struct { const char *ssl_name; const int alg_bits; const char *evp_name; } cipher_probe_t; static const cipher_probe_t cipher_probes[] = { "AES", 256, "AES-256-CBC", "CAMELLIA", 256, "CAMELLIA-256-CBC", 0, 0, 0, }; /* tls_log_mask - Convert user TLS loglevel to internal log feature mask */ int tls_log_mask(const char *log_param, const char *log_level) { int mask; mask = name_mask_opt(log_param, tls_log_table, log_level, NAME_MASK_ANY_CASE | NAME_MASK_RETURN); return (mask); } /* tls_update_app_logmask - update log level after init */ void tls_update_app_logmask(TLS_APPL_STATE *app_ctx, int log_mask) { app_ctx->log_mask = log_mask; } /* tls_exclude_missing - Append exclusions for missing ciphers */ static const char *tls_exclude_missing(SSL_CTX *ctx, VSTRING *buf) { const char *myname = "tls_exclude_missing"; static ARGV *exclude; /* Cached */ SSL *s = 0; ssl_cipher_stack_t *ciphers; SSL_CIPHER *c; const cipher_probe_t *probe; int alg_bits; int num; int i; /* * Process a list of probes which specify: * * An SSL cipher-suite name for a family of ciphers that use the same * symmetric algorithm at two or more key sizes, typically 128/256 bits. * * The key size (typically 256) that OpenSSL fails to check, and assumes * available when another key size (typically 128) is usable. * * The OpenSSL name of the symmetric algorithm associated with the SSL * cipher-suite. Typically, this is MUMBLE-256-CBC, where "MUMBLE" is the * name of the SSL cipher-suite that use the MUMBLE symmetric algorithm. * On systems that support the required encryption algorithm, the name is * listed in the output of "openssl list-cipher-algorithms". * * When an encryption algorithm is not available at the given key size but * the corresponding OpenSSL cipher-suite contains ciphers that have have * this key size, the problem ciphers are explicitly disabled in Postfix. * The list is cached in the static "exclude" array. */ if (exclude == 0) { exclude = argv_alloc(1); /* * Iterate over the probe list */ for (probe = cipher_probes; probe->ssl_name; ++probe) { /* No exclusions if evp_name is a valid algorithm */ if (EVP_get_cipherbyname(probe->evp_name)) continue; /* * Sadly there is no SSL_CTX_get_ciphers() interface, so we are * forced to allocate and free an SSL object. Fatal error if we * can't allocate the SSL object. */ ERR_clear_error(); if (s == 0 && (s = SSL_new(ctx)) == 0) { tls_print_errors(); msg_fatal("%s: error allocating SSL object", myname); } /* * Cipher is not supported by libcrypto, nothing to do if also * not supported by libssl. Flush the OpenSSL error stack. * * XXX: There may be additional places in pre-existing code where * SSL errors are generated and ignored, that require a similar * "flush". Better yet, is to always flush before calls that run * tls_print_errors() on failure. * * Contrary to documentation, on SunOS 5.10 SSL_set_cipher_list() * returns success with no ciphers selected, when this happens * SSL_get_ciphers() produces a stack with 0 elements! */ if (SSL_set_cipher_list(s, probe->ssl_name) == 0 || (ciphers = SSL_get_ciphers(s)) == 0 || (num = sk_SSL_CIPHER_num(ciphers)) == 0) { ERR_clear_error(); /* flush any generated errors */ continue; } for (i = 0; i < num; ++i) { c = sk_SSL_CIPHER_value(ciphers, i); (void) SSL_CIPHER_get_bits(c, &alg_bits); if (alg_bits == probe->alg_bits) argv_add(exclude, SSL_CIPHER_get_name(c), ARGV_END); } } if (s != 0) SSL_free(s); } for (i = 0; i < exclude->argc; ++i) vstring_sprintf_append(buf, ":!%s", exclude->argv[i]); return (vstring_str(buf)); } /* tls_apply_cipher_list - update SSL_CTX cipher list */ static const char *tls_apply_cipher_list(TLS_APPL_STATE *app_ctx, const char *context, VSTRING *spec) { const char *new = tls_exclude_missing(app_ctx->ssl_ctx, spec); ERR_clear_error(); if (SSL_CTX_set_cipher_list(app_ctx->ssl_ctx, new) == 0) { tls_print_errors(); vstring_sprintf(app_ctx->why, "invalid %s cipher list: \"%s\"", context, new); return (0); } return (new); } /* tls_protocol_mask - Bitmask of protocols to exclude */ int tls_protocol_mask(const char *plist) { char *save; char *tok; char *cp; int code; int exclude = 0; int include = 0; #define FREE_AND_RETURN(ptr, res) do { \ myfree(ptr); \ return (res); \ } while (0) save = cp = mystrdup(plist); while ((tok = mystrtok(&cp, "\t\n\r ,:")) != 0) { if (*tok == '!') exclude |= code = name_code(protocol_table, NAME_CODE_FLAG_NONE, ++tok); else include |= code = name_code(protocol_table, NAME_CODE_FLAG_NONE, tok); if (code == TLS_PROTOCOL_INVALID) FREE_AND_RETURN(save, TLS_PROTOCOL_INVALID); } /* * When the include list is empty, use only the explicit exclusions. * Otherwise, also exclude the complement of the include list from the * built-in list of known protocols. There is no way to exclude protocols * we don't know about at compile time, and this is unavoidable because * the OpenSSL API works with compile-time *exclusion* bit-masks. */ FREE_AND_RETURN(save, (include ? (exclude | (TLS_KNOWN_PROTOCOLS & ~include)) : exclude)); } /* tls_param_init - Load TLS related config parameters */ void tls_param_init(void) { static const CONFIG_STR_TABLE str_table[] = { VAR_TLS_HIGH_CLIST, DEF_TLS_HIGH_CLIST, &var_tls_high_clist, 1, 0, VAR_TLS_MEDIUM_CLIST, DEF_TLS_MEDIUM_CLIST, &var_tls_medium_clist, 1, 0, VAR_TLS_LOW_CLIST, DEF_TLS_LOW_CLIST, &var_tls_low_clist, 1, 0, VAR_TLS_EXPORT_CLIST, DEF_TLS_EXPORT_CLIST, &var_tls_export_clist, 1, 0, VAR_TLS_NULL_CLIST, DEF_TLS_NULL_CLIST, &var_tls_null_clist, 1, 0, VAR_TLS_EECDH_STRONG, DEF_TLS_EECDH_STRONG, &var_tls_eecdh_strong, 1, 0, VAR_TLS_EECDH_ULTRA, DEF_TLS_EECDH_ULTRA, &var_tls_eecdh_ultra, 1, 0, VAR_TLS_BUG_TWEAKS, DEF_TLS_BUG_TWEAKS, &var_tls_bug_tweaks, 0, 0, VAR_TLS_SSL_OPTIONS, DEF_TLS_SSL_OPTIONS, &var_tls_ssl_options, 0, 0, VAR_TLS_DANE_AGILITY, DEF_TLS_DANE_AGILITY, &var_tls_dane_agility, 1, 0, VAR_TLS_DANE_DIGESTS, DEF_TLS_DANE_DIGESTS, &var_tls_dane_digests, 1, 0, VAR_TLS_MGR_SERVICE, DEF_TLS_MGR_SERVICE, &var_tls_mgr_service, 1, 0, 0, }; static const CONFIG_INT_TABLE int_table[] = { VAR_TLS_DAEMON_RAND_BYTES, DEF_TLS_DAEMON_RAND_BYTES, &var_tls_daemon_rand_bytes, 1, 0, 0, }; static const CONFIG_BOOL_TABLE bool_table[] = { VAR_TLS_APPEND_DEF_CA, DEF_TLS_APPEND_DEF_CA, &var_tls_append_def_CA, VAR_TLS_BC_PKEY_FPRINT, DEF_TLS_BC_PKEY_FPRINT, &var_tls_bc_pkey_fprint, VAR_TLS_DANE_TAA_DGST, DEF_TLS_DANE_TAA_DGST, &var_tls_dane_taa_dgst, VAR_TLS_PREEMPT_CLIST, DEF_TLS_PREEMPT_CLIST, &var_tls_preempt_clist, VAR_TLS_MULTI_WILDCARD, DEF_TLS_MULTI_WILDCARD, &var_tls_multi_wildcard, 0, }; static int init_done; if (init_done) return; init_done = 1; get_mail_conf_str_table(str_table); get_mail_conf_int_table(int_table); get_mail_conf_bool_table(bool_table); } /* tls_set_ciphers - Set SSL context cipher list */ const char *tls_set_ciphers(TLS_APPL_STATE *app_ctx, const char *context, const char *grade, const char *exclusions) { const char *myname = "tls_set_ciphers"; static VSTRING *buf; int new_grade; char *save; char *cp; char *tok; const char *new_list; new_grade = tls_cipher_grade(grade); if (new_grade == TLS_CIPHER_NONE) { vstring_sprintf(app_ctx->why, "invalid %s cipher grade: \"%s\"", context, grade); return (0); } if (buf == 0) buf = vstring_alloc(10); VSTRING_RESET(buf); /* * Given cached state and identical input, we return the same result. */ if (app_ctx->cipher_list) { if (new_grade == app_ctx->cipher_grade && strcmp(app_ctx->cipher_exclusions, exclusions) == 0) return (app_ctx->cipher_list); /* Change required, flush cached state */ app_ctx->cipher_grade = TLS_CIPHER_NONE; myfree(app_ctx->cipher_exclusions); app_ctx->cipher_exclusions = 0; myfree(app_ctx->cipher_list); app_ctx->cipher_list = 0; } switch (new_grade) { case TLS_CIPHER_HIGH: vstring_strcpy(buf, var_tls_high_clist); break; case TLS_CIPHER_MEDIUM: vstring_strcpy(buf, var_tls_medium_clist); break; case TLS_CIPHER_LOW: vstring_strcpy(buf, var_tls_low_clist); break; case TLS_CIPHER_EXPORT: vstring_strcpy(buf, var_tls_export_clist); break; case TLS_CIPHER_NULL: vstring_strcpy(buf, var_tls_null_clist); break; default: /* * The caller MUST provide a valid cipher grade */ msg_panic("invalid %s cipher grade: %d", context, new_grade); } /* * The base lists for each grade can't be empty. */ if (VSTRING_LEN(buf) == 0) msg_panic("%s: empty \"%s\" cipherlist", myname, grade); /* * Apply locally-specified exclusions. */ #define CIPHER_SEP "\t\n\r ,:" if (exclusions != 0) { cp = save = mystrdup(exclusions); while ((tok = mystrtok(&cp, CIPHER_SEP)) != 0) { /* * Can't exclude ciphers that start with modifiers. */ if (strchr("!+-@", *tok)) { vstring_sprintf(app_ctx->why, "invalid unary '!+-@' in %s cipher " "exclusion: \"%s\"", context, tok); return (0); } vstring_sprintf_append(buf, ":!%s", tok); } myfree(save); } if ((new_list = tls_apply_cipher_list(app_ctx, context, buf)) == 0) return (0); /* Cache new state */ app_ctx->cipher_grade = new_grade; app_ctx->cipher_exclusions = mystrdup(exclusions); return (app_ctx->cipher_list = mystrdup(new_list)); } /* tls_alloc_app_context - allocate TLS application context */ TLS_APPL_STATE *tls_alloc_app_context(SSL_CTX *ssl_ctx, int log_mask) { TLS_APPL_STATE *app_ctx; app_ctx = (TLS_APPL_STATE *) mymalloc(sizeof(*app_ctx)); /* See portability note below with other memset() call. */ memset((char *) app_ctx, 0, sizeof(*app_ctx)); app_ctx->ssl_ctx = ssl_ctx; app_ctx->log_mask = log_mask; /* See also: cache purging code in tls_set_ciphers(). */ app_ctx->cipher_grade = TLS_CIPHER_NONE; app_ctx->cipher_exclusions = 0; app_ctx->cipher_list = 0; app_ctx->cache_type = 0; app_ctx->why = vstring_alloc(1); return (app_ctx); } /* tls_free_app_context - Free TLS application context */ void tls_free_app_context(TLS_APPL_STATE *app_ctx) { if (app_ctx->ssl_ctx) SSL_CTX_free(app_ctx->ssl_ctx); if (app_ctx->cache_type) myfree(app_ctx->cache_type); /* See also: cache purging code in tls_set_ciphers(). */ if (app_ctx->cipher_exclusions) myfree(app_ctx->cipher_exclusions); if (app_ctx->cipher_list) myfree(app_ctx->cipher_list); if (app_ctx->why) vstring_free(app_ctx->why); myfree((char *) app_ctx); } /* tls_alloc_sess_context - allocate TLS session context */ TLS_SESS_STATE *tls_alloc_sess_context(int log_mask, const char *namaddr) { TLS_SESS_STATE *TLScontext; /* * PORTABILITY: Do not assume that null pointers are all-zero bits. Use * explicit assignments to initialize pointers. * * See the C language FAQ item 5.17, or if you have time to burn, * http://www.google.com/search?q=zero+bit+null+pointer * * However, it's OK to use memset() to zero integer values. */ TLScontext = (TLS_SESS_STATE *) mymalloc(sizeof(TLS_SESS_STATE)); memset((char *) TLScontext, 0, sizeof(*TLScontext)); TLScontext->con = 0; TLScontext->cache_type = 0; TLScontext->serverid = 0; TLScontext->peer_CN = 0; TLScontext->issuer_CN = 0; TLScontext->peer_cert_fprint = 0; TLScontext->peer_pkey_fprint = 0; TLScontext->protocol = 0; TLScontext->cipher_name = 0; TLScontext->log_mask = log_mask; TLScontext->namaddr = lowercase(mystrdup(namaddr)); TLScontext->mdalg = 0; /* Alias for props->mdalg */ TLScontext->dane = 0; /* Alias for props->dane */ TLScontext->errordepth = -1; TLScontext->tadepth = -1; TLScontext->errorcode = X509_V_OK; TLScontext->errorcert = 0; TLScontext->untrusted = 0; TLScontext->trusted = 0; return (TLScontext); } /* tls_free_context - deallocate TLScontext and members */ void tls_free_context(TLS_SESS_STATE *TLScontext) { /* * Free the SSL structure and the BIOs. Warning: the internal_bio is * connected to the SSL structure and is automatically freed with it. Do * not free it again (core dump)!! Only free the network_bio. */ if (TLScontext->con != 0) SSL_free(TLScontext->con); if (TLScontext->namaddr) myfree(TLScontext->namaddr); if (TLScontext->serverid) myfree(TLScontext->serverid); if (TLScontext->peer_CN) myfree(TLScontext->peer_CN); if (TLScontext->issuer_CN) myfree(TLScontext->issuer_CN); if (TLScontext->peer_cert_fprint) myfree(TLScontext->peer_cert_fprint); if (TLScontext->peer_pkey_fprint) myfree(TLScontext->peer_pkey_fprint); if (TLScontext->errorcert) X509_free(TLScontext->errorcert); if (TLScontext->untrusted) sk_X509_pop_free(TLScontext->untrusted, X509_free); if (TLScontext->trusted) sk_X509_pop_free(TLScontext->trusted, X509_free); myfree((char *) TLScontext); } /* tls_version_split - Split OpenSSL version number into major, minor, ... */ static void tls_version_split(long version, TLS_VINFO *info) { /* * OPENSSL_VERSION_NUMBER(3): * * OPENSSL_VERSION_NUMBER is a numeric release version identifier: * * MMNNFFPPS: major minor fix patch status * * The status nibble has one of the values 0 for development, 1 to e for * betas 1 to 14, and f for release. Parsed OpenSSL version number. for * example * * 0x000906000 == 0.9.6 dev 0x000906023 == 0.9.6b beta 3 0x00090605f == * 0.9.6e release * * Versions prior to 0.9.3 have identifiers < 0x0930. Versions between * 0.9.3 and 0.9.5 had a version identifier with this interpretation: * * MMNNFFRBB major minor fix final beta/patch * * for example * * 0x000904100 == 0.9.4 release 0x000905000 == 0.9.5 dev * * Version 0.9.5a had an interim interpretation that is like the current * one, except the patch level got the highest bit set, to keep continu- * ity. The number was therefore 0x0090581f. */ if (version < 0x0930) { info->status = 0; info->patch = version & 0x0f; version >>= 4; info->micro = version & 0x0f; version >>= 4; info->minor = version & 0x0f; version >>= 4; info->major = version & 0x0f; } else if (version < 0x00905800L) { info->patch = version & 0xff; version >>= 8; info->status = version & 0xf; version >>= 4; info->micro = version & 0xff; version >>= 8; info->minor = version & 0xff; version >>= 8; info->major = version & 0xff; } else { info->status = version & 0xf; version >>= 4; info->patch = version & 0xff; version >>= 8; info->micro = version & 0xff; version >>= 8; info->minor = version & 0xff; version >>= 8; info->major = version & 0xff; if (version < 0x00906000L) info->patch &= ~0x80; } } /* tls_check_version - Detect mismatch between headers and library. */ void tls_check_version(void) { TLS_VINFO hdr_info; TLS_VINFO lib_info; tls_version_split(OPENSSL_VERSION_NUMBER, &hdr_info); tls_version_split(SSLeay(), &lib_info); if (lib_info.major != hdr_info.major || lib_info.minor != hdr_info.minor || lib_info.micro != hdr_info.micro) msg_warn("run-time library vs. compile-time header version mismatch: " "OpenSSL %d.%d.%d may not be compatible with OpenSSL %d.%d.%d", lib_info.major, lib_info.minor, lib_info.micro, hdr_info.major, hdr_info.minor, hdr_info.micro); } /* tls_bug_bits - SSL bug compatibility bits for this OpenSSL version */ long tls_bug_bits(void) { long bits = SSL_OP_ALL; /* Work around all known bugs */ #if OPENSSL_VERSION_NUMBER >= 0x00908000L && \ OPENSSL_VERSION_NUMBER < 0x10000000L long lib_version = SSLeay(); /* * In OpenSSL 0.9.8[ab], enabling zlib compression breaks the padding bug * work-around, leading to false positives and failed connections. We may * not interoperate with systems with the bug, but this is better than * breaking on all 0.9.8[ab] systems that have zlib support enabled. */ if (lib_version >= 0x00908000L && lib_version <= 0x0090802fL) { ssl_comp_stack_t *comp_methods = SSL_COMP_get_compression_methods(); comp_methods = SSL_COMP_get_compression_methods(); if (comp_methods != 0 && sk_SSL_COMP_num(comp_methods) > 0) bits &= ~SSL_OP_TLS_BLOCK_PADDING_BUG; } #endif /* * Silently ignore any strings that don't appear in the tweaks table, or * hex bits that are not in SSL_OP_ALL. */ if (*var_tls_bug_tweaks) { bits &= ~long_name_mask_opt(VAR_TLS_BUG_TWEAKS, ssl_bug_tweaks, var_tls_bug_tweaks, NAME_MASK_ANY_CASE | NAME_MASK_NUMBER | NAME_MASK_WARN); #ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG /* Not relevant to SMTP */ bits &= ~SSL_OP_SAFARI_ECDHE_ECDSA_BUG; #endif } /* * Allow users to set options not in SSL_OP_ALL, and not already managed * via other Postfix parameters. */ if (*var_tls_ssl_options) { long enable; enable = long_name_mask_opt(VAR_TLS_SSL_OPTIONS, ssl_op_tweaks, var_tls_ssl_options, NAME_MASK_ANY_CASE | NAME_MASK_NUMBER | NAME_MASK_WARN); enable &= ~(SSL_OP_ALL | TLS_SSL_OP_MANAGED_BITS); bits |= enable; } return (bits); } /* tls_print_errors - print and clear the error stack */ void tls_print_errors(void) { unsigned long err; char buffer[1024]; /* XXX */ const char *file; const char *data; int line; int flags; while ((err = ERR_get_error_line_data(&file, &line, &data, &flags)) != 0) { ERR_error_string_n(err, buffer, sizeof(buffer)); if (flags & ERR_TXT_STRING) msg_warn("TLS library problem: %s:%s:%d:%s:", buffer, file, line, data); else msg_warn("TLS library problem: %s:%s:%d:", buffer, file, line); } } /* tls_info_callback - callback for logging SSL events via Postfix */ void tls_info_callback(const SSL *s, int where, int ret) { char *str; int w; /* Adapted from OpenSSL apps/s_cb.c. */ w = where & ~SSL_ST_MASK; if (w & SSL_ST_CONNECT) str = "SSL_connect"; else if (w & SSL_ST_ACCEPT) str = "SSL_accept"; else str = "unknown"; if (where & SSL_CB_LOOP) { msg_info("%s:%s", str, SSL_state_string_long((SSL *) s)); } else if (where & SSL_CB_ALERT) { str = (where & SSL_CB_READ) ? "read" : "write"; if ((ret & 0xff) != SSL3_AD_CLOSE_NOTIFY) msg_info("SSL3 alert %s:%s:%s", str, SSL_alert_type_string_long(ret), SSL_alert_desc_string_long(ret)); } else if (where & SSL_CB_EXIT) { if (ret == 0) msg_info("%s:failed in %s", str, SSL_state_string_long((SSL *) s)); else if (ret < 0) { #ifndef LOG_NON_ERROR_STATES switch (SSL_get_error((SSL *) s, ret)) { case SSL_ERROR_WANT_READ: case SSL_ERROR_WANT_WRITE: /* Don't log non-error states. */ break; default: #endif msg_info("%s:error in %s", str, SSL_state_string_long((SSL *) s)); #ifndef LOG_NON_ERROR_STATES } #endif } } } /* * taken from OpenSSL crypto/bio/b_dump.c. * * Modified to save a lot of strcpy and strcat by Matti Aarnio. * * Rewritten by Wietse to elimate fixed-size stack buffer, array index * multiplication and division, sprintf() and strcpy(), and lots of strlen() * calls. We could make it a little faster by using a fixed-size stack-based * buffer. * * 200412 - use %lx to print pointers, after casting them to unsigned long. */ #define TRUNCATE_SPACE_NULL #define DUMP_WIDTH 16 #define VERT_SPLIT 7 static void tls_dump_buffer(const unsigned char *start, int len) { VSTRING *buf = vstring_alloc(100); const unsigned char *last = start + len - 1; const unsigned char *row; const unsigned char *col; int ch; #ifdef TRUNCATE_SPACE_NULL while (last >= start && (*last == ' ' || *last == 0)) last--; #endif for (row = start; row <= last; row += DUMP_WIDTH) { VSTRING_RESET(buf); vstring_sprintf(buf, "%04lx ", (unsigned long) (row - start)); for (col = row; col < row + DUMP_WIDTH; col++) { if (col > last) { vstring_strcat(buf, " "); } else { ch = *col; vstring_sprintf_append(buf, "%02x%c", ch, col - row == VERT_SPLIT ? '|' : ' '); } } VSTRING_ADDCH(buf, ' '); for (col = row; col < row + DUMP_WIDTH; col++) { if (col > last) break; ch = *col; if (!ISPRINT(ch)) ch = '.'; VSTRING_ADDCH(buf, ch); if (col - row == VERT_SPLIT) VSTRING_ADDCH(buf, ' '); } VSTRING_TERMINATE(buf); msg_info("%s", vstring_str(buf)); } #ifdef TRUNCATE_SPACE_NULL if ((last + 1) - start < len) msg_info("%04lx - ", (unsigned long) ((last + 1) - start)); #endif vstring_free(buf); } /* taken from OpenSSL apps/s_cb.c */ long tls_bio_dump_cb(BIO *bio, int cmd, const char *argp, int argi, long unused_argl, long ret) { if (cmd == (BIO_CB_READ | BIO_CB_RETURN)) { msg_info("read from %08lX [%08lX] (%d bytes => %ld (0x%lX))", (unsigned long) bio, (unsigned long) argp, argi, ret, (unsigned long) ret); tls_dump_buffer((unsigned char *) argp, (int) ret); } else if (cmd == (BIO_CB_WRITE | BIO_CB_RETURN)) { msg_info("write to %08lX [%08lX] (%d bytes => %ld (0x%lX))", (unsigned long) bio, (unsigned long) argp, argi, ret, (unsigned long) ret); tls_dump_buffer((unsigned char *) argp, (int) ret); } return (ret); } int tls_validate_digest(const char *dgst) { const EVP_MD *md_alg; unsigned int md_len; /* * Register SHA-2 digests, if implemented and not already registered. * Improves interoperability with clients and servers that prematurely * deploy SHA-2 certificates. Also facilitates DANE and TA support. */ #if defined(LN_sha256) && defined(NID_sha256) && !defined(OPENSSL_NO_SHA256) if (!EVP_get_digestbyname(LN_sha224)) EVP_add_digest(EVP_sha224()); if (!EVP_get_digestbyname(LN_sha256)) EVP_add_digest(EVP_sha256()); #endif #if defined(LN_sha512) && defined(NID_sha512) && !defined(OPENSSL_NO_SHA512) if (!EVP_get_digestbyname(LN_sha384)) EVP_add_digest(EVP_sha384()); if (!EVP_get_digestbyname(LN_sha512)) EVP_add_digest(EVP_sha512()); #endif /* * If the administrator specifies an unsupported digest algorithm, fail * now, rather than in the middle of a TLS handshake. */ if ((md_alg = EVP_get_digestbyname(dgst)) == 0) { msg_warn("Digest algorithm \"%s\" not found", dgst); return (0); } /* * Sanity check: Newer shared libraries may use larger digests. */ if ((md_len = EVP_MD_size(md_alg)) > EVP_MAX_MD_SIZE) { msg_warn("Digest algorithm \"%s\" output size %u too large", dgst, md_len); return (0); } return (1); } #else /* * Broken linker workaround. */ int tls_dummy_for_broken_linkers; #endif