X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2Ftls-openssl.c;h=e9628ba29a1e50488a836b20b9ab4d3e0da8fb08;hp=146cb6293c09e82edc496562a2a8789556b2c1f8;hb=754a0503134b184183f64c04ed30a3524fc3860b;hpb=c91535f35c1f54bb30e5611791c93e78f2efd5d0 diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c index 146cb6293..e9628ba29 100644 --- a/src/src/tls-openssl.c +++ b/src/src/tls-openssl.c @@ -1,10 +1,10 @@ -/* $Cambridge: exim/src/src/tls-openssl.c,v 1.7 2006/02/14 14:12:07 ph10 Exp $ */ +/* $Cambridge: exim/src/src/tls-openssl.c,v 1.28 2010/06/12 17:56:32 jetmore Exp $ */ /************************************************* * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2006 */ +/* Copyright (c) University of Cambridge 1995 - 2009 */ /* See the file NOTICE for conditions of use and distribution. */ /* This module provides the TLS (aka SSL) support for Exim using the OpenSSL @@ -26,8 +26,8 @@ functions from the OpenSSL library. */ /* Structure for collecting random data for seeding. */ typedef struct randstuff { - time_t t; - pid_t p; + struct timeval tv; + pid_t p; } randstuff; /* Local static variables */ @@ -62,25 +62,33 @@ Argument: prefix text to include in the logged error host NULL if setting up a server; the connected host if setting up a client + msg error message or NULL if we should ask OpenSSL Returns: OK/DEFER/FAIL */ static int -tls_error(uschar *prefix, host_item *host) +tls_error(uschar *prefix, host_item *host, uschar *msg) { -ERR_error_string(ERR_get_error(), ssl_errstring); +if (msg == NULL) + { + ERR_error_string(ERR_get_error(), ssl_errstring); + msg = (uschar *)ssl_errstring; + } + if (host == NULL) { - log_write(0, LOG_MAIN, "TLS error on connection from %s (%s): %s", - (sender_fullhost != NULL)? sender_fullhost : US"local process", - prefix, ssl_errstring); + uschar *conn_info = smtp_get_connection_info(); + if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) + conn_info += 5; + log_write(0, LOG_MAIN, "TLS error on %s (%s): %s", + conn_info, prefix, msg); return DEFER; } else { log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s", - host->name, host->address, prefix, ssl_errstring); + host->name, host->address, prefix, msg); return FAIL; } } @@ -224,12 +232,13 @@ DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); Arguments: dhparam DH parameter file + host connected host, if client; NULL if server Returns: TRUE if OK (nothing to set up, or setup worked) */ static BOOL -init_dh(uschar *dhparam) +init_dh(uschar *dhparam, host_item *host) { BOOL yield = TRUE; BIO *bio; @@ -243,16 +252,16 @@ if (dhexpanded == NULL) return TRUE; if ((bio = BIO_new_file(CS dhexpanded, "r")) == NULL) { - log_write(0, LOG_MAIN, "DH: could not read %s: %s", dhexpanded, - strerror(errno)); + tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), + host, (uschar *)strerror(errno)); yield = FALSE; } else { if ((dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)) == NULL) { - log_write(0, LOG_MAIN, "DH: could not load params from %s", - dhexpanded); + tls_error(string_sprintf("could not read dhparams file %s", dhexpanded), + host, NULL); yield = FALSE; } else @@ -293,15 +302,24 @@ static int tls_init(host_item *host, uschar *dhparam, uschar *certificate, uschar *privatekey, address_item *addr) { +long init_options; +BOOL okay; + SSL_load_error_strings(); /* basic set up */ OpenSSL_add_ssl_algorithms(); +#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) +/* SHA256 is becoming ever more popular. This makes sure it gets added to the +list of available digests. */ +EVP_add_digest(EVP_sha256()); +#endif + /* Create a context */ ctx = SSL_CTX_new((host == NULL)? SSLv23_server_method() : SSLv23_client_method()); -if (ctx == NULL) return tls_error(US"SSL_CTX_new", host); +if (ctx == NULL) return tls_error(US"SSL_CTX_new", host, NULL); /* It turns out that we need to seed the random number generator this early in order to get the full complement of ciphers to work. It took me roughly a day @@ -314,7 +332,7 @@ afterwards. */ if (!RAND_status()) { randstuff r; - r.t = time(NULL); + gettimeofday(&r.tv, NULL); r.p = getpid(); RAND_seed((uschar *)(&r), sizeof(r)); @@ -322,49 +340,41 @@ if (!RAND_status()) if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr)); if (!RAND_status()) - { - if (host == NULL) - { - log_write(0, LOG_MAIN, "TLS error on connection from %s: " - "unable to seed random number generator", - (sender_fullhost != NULL)? sender_fullhost : US"local process"); - return DEFER; - } - else - { - log_write(0, LOG_MAIN, "TLS error on connection to %s [%s]: " - "unable to seed random number generator", - host->name, host->address); - return FAIL; - } - } + return tls_error(US"RAND_status", host, + US"unable to seed random number generator"); } /* Set up the information callback, which outputs if debugging is at a suitable level. */ -if (!(SSL_CTX_set_info_callback(ctx, (void (*)())info_callback))) - return tls_error(US"SSL_CTX_set_info_callback", host); +SSL_CTX_set_info_callback(ctx, (void (*)())info_callback); -/* The following patch was supplied by Robert Roselius */ +/* Apply administrator-supplied work-arounds. +Historically we applied just one requested option, +SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, but when bug 994 requested a second, we +moved to an administrator-controlled list of options to specify and +grandfathered in the first one as the default value for "openssl_options". -#if OPENSSL_VERSION_NUMBER > 0x00906040L -/* Enable client-bug workaround. - Versions of OpenSSL as of 0.9.6d include a "CBC countermeasure" feature, - which causes problems with some clients (such as the Certicom SSL Plus - library used by Eudora). This option, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS, - disables the coutermeasure allowing Eudora to connect. - Some poppers and MTAs use SSL_OP_ALL, which enables all such bug - workarounds. */ -/* XXX (Silently?) ignore failure here? XXX*/ +No OpenSSL version number checks: the options we accept depend upon the +availability of the option value macros from OpenSSL. */ -if (!(SSL_CTX_set_options(ctx, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))) - return tls_error(US"SSL_CTX_set_option", host); -#endif +okay = tls_openssl_options_parse(openssl_options, &init_options); +if (!okay) + return tls_error(US"openssl_options parsing failed", host, NULL); + +if (init_options) + { + DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options); + if (!(SSL_CTX_set_options(ctx, init_options))) + return tls_error(string_sprintf( + "SSL_CTX_set_option(%#lx)", init_options), host, NULL); + } +else + DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); /* Initialize with DH parameters if supplied */ -if (!init_dh(dhparam)) return DEFER; +if (!init_dh(dhparam, host)) return DEFER; /* Set up certificate and key */ @@ -379,7 +389,7 @@ if (certificate != NULL) DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); if (!SSL_CTX_use_certificate_chain_file(ctx, CS expanded)) return tls_error(string_sprintf( - "SSL_CTX_use_certificate_chain_file file=%s", expanded), host); + "SSL_CTX_use_certificate_chain_file file=%s", expanded), host, NULL); } if (privatekey != NULL && @@ -395,7 +405,7 @@ if (certificate != NULL) DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); if (!SSL_CTX_use_PrivateKey_file(ctx, CS expanded, SSL_FILETYPE_PEM)) return tls_error(string_sprintf( - "SSL_CTX_use_PrivateKey_file file=%s", expanded), host); + "SSL_CTX_use_PrivateKey_file file=%s", expanded), host, NULL); } } @@ -428,7 +438,10 @@ static void construct_cipher_name(SSL *ssl) { static uschar cipherbuf[256]; -SSL_CIPHER *c; +/* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't +yet reflect that. It should be a safe change anyway, even 0.9.8 versions have +the accessor functions use const in the prototype. */ +const SSL_CIPHER *c; uschar *ver; int bits; @@ -450,7 +463,7 @@ switch (ssl->session->ssl_version) ver = US"UNKNOWN"; } -c = SSL_get_current_cipher(ssl); +c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl); SSL_CIPHER_get_bits(c, &bits); string_format(cipherbuf, sizeof(cipherbuf), "%s:%s:%u", ver, @@ -492,7 +505,7 @@ if (expcerts != NULL) { struct stat statbuf; if (!SSL_CTX_set_default_verify_paths(ctx)) - return tls_error(US"SSL_CTX_set_default_verify_paths", host); + return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); if (Ustat(expcerts, &statbuf) < 0) { @@ -515,7 +528,7 @@ if (expcerts != NULL) if ((file == NULL || statbuf.st_size > 0) && !SSL_CTX_load_verify_locations(ctx, CS file, CS dir)) - return tls_error(US"SSL_CTX_load_verify_locations", host); + return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); if (file != NULL) { @@ -565,7 +578,7 @@ if (expcerts != NULL) DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file); } if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0) - return tls_error(US"X509_STORE_load_locations", host); + return tls_error(US"X509_STORE_load_locations", host, NULL); /* setting the flags to check against the complete crl chain */ @@ -598,6 +611,11 @@ a TLS session. Arguments: require_ciphers allowed ciphers + ------------------------------------------------------ + require_mac list of allowed MACs ) Not used + require_kx list of allowed key_exchange methods ) for + require_proto list of allowed protocols ) OpenSSL + ------------------------------------------------------ Returns: OK on success DEFER for errors before the start of the negotiation @@ -606,7 +624,8 @@ Returns: OK on success */ int -tls_server_start(uschar *require_ciphers) +tls_server_start(uschar *require_ciphers, uschar *require_mac, + uschar *require_kx, uschar *require_proto) { int rc; uschar *expciphers; @@ -615,9 +634,7 @@ uschar *expciphers; if (tls_active >= 0) { - log_write(0, LOG_MAIN, "STARTTLS received in already encrypted " - "connection from %s", - (sender_fullhost != NULL)? sender_fullhost : US"local process"); + tls_error(US"STARTTLS received after TLS started", NULL, US""); smtp_printf("554 Already in TLS\r\n"); return FAIL; } @@ -641,7 +658,7 @@ if (expciphers != NULL) while (*s != 0) { if (*s == '_') *s = '-'; s++; } DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) - return tls_error(US"SSL_CTX_set_cipher_list", NULL); + return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL); } /* If this is a host for which certificate verification is mandatory or @@ -665,7 +682,7 @@ else if (verify_check_host(&tls_try_verify_hosts) == OK) /* Prepare for new connection */ -if ((ssl = SSL_new(ctx)) == NULL) return tls_error(US"SSL_new", NULL); +if ((ssl = SSL_new(ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); SSL_clear(ssl); /* Set context and tell client to go ahead, except in the case of TLS startup @@ -684,7 +701,8 @@ if (!tls_on_connect) /* Now negotiate the TLS session. We put our own timer on it, since it seems that the OpenSSL library doesn't. */ -SSL_set_fd(ssl, fileno(smtp_out)); +SSL_set_wfd(ssl, fileno(smtp_out)); +SSL_set_rfd(ssl, fileno(smtp_in)); SSL_set_accept_state(ssl); DEBUG(D_tls) debug_printf("Calling SSL_accept\n"); @@ -696,11 +714,10 @@ alarm(0); if (rc <= 0) { - if (sigalrm_seen) Ustrcpy(ssl_errstring, "timed out"); - else ERR_error_string(ERR_get_error(), ssl_errstring); - log_write(0, LOG_MAIN, "TLS error on connection from %s (SSL_accept): %s", - (sender_fullhost != NULL)? sender_fullhost : US"local process", - ssl_errstring); + tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL); + if (ERR_get_error() == 0) + log_write(0, LOG_MAIN, + "TLS client disconnected cleanly (rejected our certificate?)"); return FAIL; } @@ -727,6 +744,7 @@ receive_getc = tls_getc; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; +receive_smtp_buffered = tls_smtp_buffered; tls_active = fileno(smtp_out); return OK; @@ -745,12 +763,19 @@ return OK; Argument: fd the fd of the connection host connected host (for messages) + addr the first address dhparam DH parameter file certificate certificate file privatekey private key file verify_certs file for certificate verify crl file containing CRL require_ciphers list of allowed ciphers + ------------------------------------------------------ + require_mac list of allowed MACs ) Not used + require_kx list of allowed key_exchange methods ) for + require_proto list of allowed protocols ) OpenSSL + ------------------------------------------------------ + timeout startup timeout Returns: OK on success FAIL otherwise - note that tls_error() will not give DEFER @@ -760,7 +785,8 @@ Returns: OK on success int tls_client_start(int fd, host_item *host, address_item *addr, uschar *dhparam, uschar *certificate, uschar *privatekey, uschar *verify_certs, uschar *crl, - uschar *require_ciphers, int timeout) + uschar *require_ciphers, uschar *require_mac, uschar *require_kx, + uschar *require_proto, int timeout) { static uschar txt[256]; uschar *expciphers; @@ -786,13 +812,13 @@ if (expciphers != NULL) while (*s != 0) { if (*s == '_') *s = '-'; s++; } DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); if (!SSL_CTX_set_cipher_list(ctx, CS expciphers)) - return tls_error(US"SSL_CTX_set_cipher_list", host); + return tls_error(US"SSL_CTX_set_cipher_list", host, NULL); } rc = setup_certs(verify_certs, crl, host, FALSE); if (rc != OK) return rc; -if ((ssl = SSL_new(ctx)) == NULL) return tls_error(US"SSL_new", host); +if ((ssl = SSL_new(ctx)) == NULL) return tls_error(US"SSL_new", host, NULL); SSL_set_session_id_context(ssl, sid_ctx, Ustrlen(sid_ctx)); SSL_set_fd(ssl, fd); SSL_set_connect_state(ssl); @@ -806,22 +832,20 @@ rc = SSL_connect(ssl); alarm(0); if (rc <= 0) - { - if (sigalrm_seen) - { - log_write(0, LOG_MAIN, "TLS error on connection to %s [%s]: " - "SSL_connect timed out", host->name, host->address); - return FAIL; - } - else return tls_error(US"SSL_connect", host); - } + return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL); DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); +/* Beware anonymous ciphers which lead to server_cert being NULL */ server_cert = SSL_get_peer_certificate (ssl); -tls_peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), - CS txt, sizeof(txt)); -tls_peerdn = txt; +if (server_cert) + { + tls_peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), + CS txt, sizeof(txt)); + tls_peerdn = txt; + } +else + tls_peerdn = NULL; construct_cipher_name(ssl); /* Sets tls_cipher */ @@ -872,6 +896,7 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; + receive_smtp_buffered = smtp_buffered; SSL_free(ssl); ssl = NULL; @@ -884,13 +909,23 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) /* Handle genuine errors */ + else if (error == SSL_ERROR_SSL) + { + ERR_error_string(ERR_get_error(), ssl_errstring); + log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring); + ssl_xfer_error = 1; + return EOF; + } + else if (error != SSL_ERROR_NONE) { DEBUG(D_tls) debug_printf("Got SSL error %d\n", error); ssl_xfer_error = 1; return EOF; } - +#ifndef DISABLE_DKIM + dkim_exim_verify_feed(ssl_xfer_buffer, inbytes); +#endif ssl_xfer_buffer_hwm = inbytes; ssl_xfer_buffer_lwm = 0; } @@ -1026,4 +1061,282 @@ ssl = NULL; tls_active = -1; } + + + +/************************************************* +* Report the library versions. * +*************************************************/ + +/* There have historically been some issues with binary compatibility in +OpenSSL libraries; if Exim (like many other applications) is built against +one version of OpenSSL but the run-time linker picks up another version, +it can result in serious failures, including crashing with a SIGSEGV. So +report the version found by the compiler and the run-time version. + +Arguments: a FILE* to print the results to +Returns: nothing +*/ + +void +tls_version_report(FILE *f) +{ +fprintf(f, "Library version: OpenSSL: Compile: %s\n" + " Runtime: %s\n", + OPENSSL_VERSION_TEXT, + SSLeay_version(SSLEAY_VERSION)); +} + + + + +/************************************************* +* Pseudo-random number generation * +*************************************************/ + +/* Pseudo-random number generation. The result is not expected to be +cryptographically strong but not so weak that someone will shoot themselves +in the foot using it as a nonce in input in some email header scheme or +whatever weirdness they'll twist this into. The result should handle fork() +and avoid repeating sequences. OpenSSL handles that for us. + +Arguments: + max range maximum +Returns a random number in range [0, max-1] +*/ + +int +pseudo_random_number(int max) +{ +unsigned int r; +int i, needed_len; +uschar *p; +uschar smallbuf[sizeof(r)]; + +if (max <= 1) + return 0; + +/* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */ +if (!RAND_status()) + { + randstuff r; + gettimeofday(&r.tv, NULL); + r.p = getpid(); + + RAND_seed((uschar *)(&r), sizeof(r)); + } +/* We're after pseudo-random, not random; if we still don't have enough data +in the internal PRNG then our options are limited. We could sleep and hope +for entropy to come along (prayer technique) but if the system is so depleted +in the first place then something is likely to just keep taking it. Instead, +we'll just take whatever little bit of pseudo-random we can still manage to +get. */ + +needed_len = sizeof(r); +/* Don't take 8 times more entropy than needed if int is 8 octets and we were +asked for a number less than 10. */ +for (r = max, i = 0; r; ++i) + r >>= 1; +i = (i + 7) / 8; +if (i < needed_len) + needed_len = i; + +/* We do not care if crypto-strong */ +(void) RAND_pseudo_bytes(smallbuf, needed_len); +r = 0; +for (p = smallbuf; needed_len; --needed_len, ++p) + { + r *= 256; + r += *p; + } + +/* We don't particularly care about weighted results; if someone wants +smooth distribution and cares enough then they should submit a patch then. */ +return r % max; +} + + + + +/************************************************* +* OpenSSL option parse * +*************************************************/ + +/* Parse one option for tls_openssl_options_parse below + +Arguments: + name one option name + value place to store a value for it +Returns success or failure in parsing +*/ + +struct exim_openssl_option { + uschar *name; + long value; +}; +/* We could use a macro to expand, but we need the ifdef and not all the +options document which version they were introduced in. Policylet: include +all options unless explicitly for DTLS, let the administrator choose which +to apply. + +This list is current as of: + ==> 0.9.8n <== */ +static struct exim_openssl_option exim_openssl_options[] = { +/* KEEP SORTED ALPHABETICALLY! */ +#ifdef SSL_OP_ALL + { US"all", SSL_OP_ALL }, +#endif +#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION + { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION }, +#endif +#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE + { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE }, +#endif +#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS + { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS }, +#endif +#ifdef SSL_OP_EPHEMERAL_RSA + { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA }, +#endif +#ifdef SSL_OP_LEGACY_SERVER_CONNECT + { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT }, +#endif +#ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER + { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER }, +#endif +#ifdef SSL_OP_MICROSOFT_SESS_ID_BUG + { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG }, +#endif +#ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING + { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING }, +#endif +#ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG + { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG }, +#endif +#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG + { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG }, +#endif +#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION + { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION }, +#endif +#ifdef SSL_OP_SINGLE_DH_USE + { US"single_dh_use", SSL_OP_SINGLE_DH_USE }, +#endif +#ifdef SSL_OP_SINGLE_ECDH_USE + { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE }, +#endif +#ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG + { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG }, +#endif +#ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG + { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG }, +#endif +#ifdef SSL_OP_TLS_BLOCK_PADDING_BUG + { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG }, +#endif +#ifdef SSL_OP_TLS_D5_BUG + { US"tls_d5_bug", SSL_OP_TLS_D5_BUG }, +#endif +#ifdef SSL_OP_TLS_ROLLBACK_BUG + { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG }, +#endif +}; +static int exim_openssl_options_size = + sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option); + +static BOOL +tls_openssl_one_option_parse(uschar *name, long *value) +{ +int first = 0; +int last = exim_openssl_options_size; +while (last > first) + { + int middle = (first + last)/2; + int c = Ustrcmp(name, exim_openssl_options[middle].name); + if (c == 0) + { + *value = exim_openssl_options[middle].value; + return TRUE; + } + else if (c > 0) + first = middle + 1; + else + last = middle; + } +return FALSE; +} + + + + +/************************************************* +* OpenSSL option parsing logic * +*************************************************/ + +/* OpenSSL has a number of compatibility options which an administrator might +reasonably wish to set. Interpret a list similarly to decode_bits(), so that +we look like log_selector. + +Arguments: + option_spec the administrator-supplied string of options + results ptr to long storage for the options bitmap +Returns success or failure +*/ + +BOOL +tls_openssl_options_parse(uschar *option_spec, long *results) +{ +long result, item; +uschar *s, *end; +uschar keep_c; +BOOL adding, item_parsed; + +/* We grandfather in as default the one option which we used to set always. */ +#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS +result = SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; +#else +result = 0L; +#endif + +if (option_spec == NULL) + { + *results = result; + return TRUE; + } + +for (s=option_spec; *s != '\0'; /**/) + { + while (isspace(*s)) ++s; + if (*s == '\0') + break; + if (*s != '+' && *s != '-') + { + DEBUG(D_tls) debug_printf("malformed openssl option setting: " + "+ or - expected but found \"%s\"", s); + return FALSE; + } + adding = *s++ == '+'; + for (end = s; (*end != '\0') && !isspace(*end); ++end) /**/ ; + keep_c = *end; + *end = '\0'; + item_parsed = tls_openssl_one_option_parse(s, &item); + if (!item_parsed) + { + DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"", s); + return FALSE; + } + DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n", + adding ? "adding" : "removing", result, item, s); + if (adding) + result |= item; + else + result &= ~item; + *end = keep_c; + s = end; + } + +*results = result; +return TRUE; +} + /* End of tls-openssl.c */