diff --git a/doc/man1/ciphers.pod b/doc/man1/ciphers.pod index faf9e53814..428df515f1 100644 --- a/doc/man1/ciphers.pod +++ b/doc/man1/ciphers.pod @@ -400,6 +400,21 @@ permissible. =back +=head1 EQUAL PREFERENCE GROUPS + +If configuring a server, one may also configure equal-preference groups to +partially respect the client's preferences when +B is enabled. Ciphers in an equal-preference +group have equal priority and use the client order. This may be used to +enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305 +based on client preferences. An equal-preference is specified with square +brackets, combining multiple selectors separated by |. For example: + + [ECDHE-ECDSA-CHACHA20-POLY1305|ECDHE-ECDSA-AES128-GCM-SHA256] + + Once an equal-preference group is used, future directives must be + opcode-less. + =head1 CIPHER SUITE NAMES The following lists give the SSL or TLS cipher suites names from the diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h index 4b7757395f..8ff91f7570 100644 --- a/include/openssl/ssl.h +++ b/include/openssl/ssl.h @@ -173,12 +173,12 @@ extern "C" { # define SSL_DEFAULT_CIPHER_LIST "ALL:!COMPLEMENTOFDEFAULT:!eNULL" /* This is the default set of TLSv1.3 ciphersuites */ # if !defined(OPENSSL_NO_CHACHA) && !defined(OPENSSL_NO_POLY1305) -# define TLS_DEFAULT_CIPHERSUITES "TLS_AES_256_GCM_SHA384:" \ +# define TLS_DEFAULT_CIPHERSUITES "TLS_AES_128_GCM_SHA256:" \ "TLS_CHACHA20_POLY1305_SHA256:" \ - "TLS_AES_128_GCM_SHA256" + "TLS_AES_256_GCM_SHA384" # else -# define TLS_DEFAULT_CIPHERSUITES "TLS_AES_256_GCM_SHA384:" \ - "TLS_AES_128_GCM_SHA256" +# define TLS_DEFAULT_CIPHERSUITES "TLS_AES_128_GCM_SHA256:" \ + "TLS_AES_256_GCM_SHA384" #endif /* * As of OpenSSL 1.0.0, ssl_create_cipher_list() in ssl/ssl_ciph.c always diff --git a/include/openssl/sslerr.h b/include/openssl/sslerr.h index a50a075b42..e9abb98d4f 100644 --- a/include/openssl/sslerr.h +++ b/include/openssl/sslerr.h @@ -596,6 +596,8 @@ int ERR_load_SSL_strings(void); # define SSL_R_MISSING_SUPPORTED_GROUPS_EXTENSION 209 # define SSL_R_MISSING_TMP_DH_KEY 171 # define SSL_R_MISSING_TMP_ECDH_KEY 311 +# define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 101 +# define SSL_R_NESTED_GROUP 108 # define SSL_R_MIXED_HANDSHAKE_AND_NON_HANDSHAKE_DATA 293 # define SSL_R_NOT_ON_RECORD_BOUNDARY 182 # define SSL_R_NOT_REPLACING_CERTIFICATE 289 @@ -727,9 +729,11 @@ int ERR_load_SSL_strings(void); # define SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS 239 # define SSL_R_UNABLE_TO_LOAD_SSL3_MD5_ROUTINES 242 # define SSL_R_UNABLE_TO_LOAD_SSL3_SHA1_ROUTINES 243 +# define SSL_R_UNEXPECTED_GROUP_CLOSE 109 # define SSL_R_UNEXPECTED_CCS_MESSAGE 262 # define SSL_R_UNEXPECTED_END_OF_EARLY_DATA 178 # define SSL_R_UNEXPECTED_MESSAGE 244 +# define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 110 # define SSL_R_UNEXPECTED_RECORD 245 # define SSL_R_UNINITIALIZED 276 # define SSL_R_UNKNOWN_ALERT_TYPE 246 diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c index 99ae48199c..0c326fec0d 100644 --- a/ssl/s3_lib.c +++ b/ssl/s3_lib.c @@ -167,7 +167,7 @@ static SSL_CIPHER ssl3_ciphers[] = { SSL_aRSA, SSL_3DES, SSL_SHA1, - SSL3_VERSION, TLS1_2_VERSION, + SSL3_VERSION, TLS1_VERSION, DTLS1_BAD_VER, DTLS1_2_VERSION, SSL_NOT_DEFAULT | SSL_MEDIUM | SSL_FIPS, SSL_HANDSHAKE_MAC_DEFAULT | TLS1_PRF, @@ -232,7 +232,7 @@ static SSL_CIPHER ssl3_ciphers[] = { SSL_aRSA, SSL_AES128, SSL_SHA1, - SSL3_VERSION, TLS1_2_VERSION, + SSL3_VERSION, TLS1_VERSION, DTLS1_BAD_VER, DTLS1_2_VERSION, SSL_HIGH | SSL_FIPS, SSL_HANDSHAKE_MAC_DEFAULT | TLS1_PRF, @@ -296,7 +296,7 @@ static SSL_CIPHER ssl3_ciphers[] = { SSL_aRSA, SSL_AES256, SSL_SHA1, - SSL3_VERSION, TLS1_2_VERSION, + SSL3_VERSION, TLS1_VERSION, DTLS1_BAD_VER, DTLS1_2_VERSION, SSL_HIGH | SSL_FIPS, SSL_HANDSHAKE_MAC_DEFAULT | TLS1_PRF, @@ -4124,6 +4124,17 @@ int ssl3_put_cipher_by_char(const SSL_CIPHER *c, WPACKET *pkt, size_t *len) return 1; } +struct ssl_cipher_preference_list_st* ssl_get_cipher_preferences(SSL *s) +{ + if (s->cipher_list != NULL) + return (s->cipher_list); + + if ((s->ctx != NULL) && (s->ctx->cipher_list != NULL)) + return (s->ctx->cipher_list); + + return NULL; +} + /* * ssl3_choose_cipher - choose a cipher from those offered by the client * @s: SSL connection @@ -4133,16 +4144,24 @@ int ssl3_put_cipher_by_char(const SSL_CIPHER *c, WPACKET *pkt, size_t *len) * Returns the selected cipher or NULL when no common ciphers. */ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, - STACK_OF(SSL_CIPHER) *srvr) + struct ssl_cipher_preference_list_st + *server_pref) { const SSL_CIPHER *c, *ret = NULL; - STACK_OF(SSL_CIPHER) *prio, *allow; - int i, ii, ok, prefer_sha256 = 0; + STACK_OF(SSL_CIPHER) *srvr = server_pref->ciphers, *prio, *allow; + int i, ii, ok, prefer_sha256 = 0, safari_ec = 0; unsigned long alg_k = 0, alg_a = 0, mask_k = 0, mask_a = 0; const EVP_MD *mdsha256 = EVP_sha256(); -#ifndef OPENSSL_NO_CHACHA - STACK_OF(SSL_CIPHER) *prio_chacha = NULL; -#endif + + /* in_group_flags will either be NULL, or will point to an array of + * bytes which indicate equal-preference groups in the |prio| stack. + * See the comment about |in_group_flags| in the + * |ssl_cipher_preference_list_st| struct. */ + const uint8_t *in_group_flags; + + /* group_min contains the minimal index so far found in a group, or -1 + * if no such value exists yet. */ + int group_min = -1; /* Let's see which ciphers we can support */ @@ -4169,54 +4188,13 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, #endif /* SUITE-B takes precedence over server preference and ChaCha priortiy */ - if (tls1_suiteb(s)) { + if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || tls1_suiteb(s)) { prio = srvr; + in_group_flags = server_pref->in_group_flags; allow = clnt; - } else if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) { - prio = srvr; - allow = clnt; -#ifndef OPENSSL_NO_CHACHA - /* If ChaCha20 is at the top of the client preference list, - and there are ChaCha20 ciphers in the server list, then - temporarily prioritize all ChaCha20 ciphers in the servers list. */ - if (s->options & SSL_OP_PRIORITIZE_CHACHA && sk_SSL_CIPHER_num(clnt) > 0) { - c = sk_SSL_CIPHER_value(clnt, 0); - if (c->algorithm_enc == SSL_CHACHA20POLY1305) { - /* ChaCha20 is client preferred, check server... */ - int num = sk_SSL_CIPHER_num(srvr); - int found = 0; - for (i = 0; i < num; i++) { - c = sk_SSL_CIPHER_value(srvr, i); - if (c->algorithm_enc == SSL_CHACHA20POLY1305) { - found = 1; - break; - } - } - if (found) { - prio_chacha = sk_SSL_CIPHER_new_reserve(NULL, num); - /* if reserve fails, then there's likely a memory issue */ - if (prio_chacha != NULL) { - /* Put all ChaCha20 at the top, starting with the one we just found */ - sk_SSL_CIPHER_push(prio_chacha, c); - for (i++; i < num; i++) { - c = sk_SSL_CIPHER_value(srvr, i); - if (c->algorithm_enc == SSL_CHACHA20POLY1305) - sk_SSL_CIPHER_push(prio_chacha, c); - } - /* Pull in the rest */ - for (i = 0; i < num; i++) { - c = sk_SSL_CIPHER_value(srvr, i); - if (c->algorithm_enc != SSL_CHACHA20POLY1305) - sk_SSL_CIPHER_push(prio_chacha, c); - } - prio = prio_chacha; - } - } - } - } -# endif } else { prio = clnt; + in_group_flags = NULL; allow = srvr; } @@ -4247,14 +4225,16 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, for (i = 0; i < sk_SSL_CIPHER_num(prio); i++) { c = sk_SSL_CIPHER_value(prio, i); + ok = 1; + /* Skip ciphers not supported by the protocol version */ if (!SSL_IS_DTLS(s) && ((s->version < c->min_tls) || (s->version > c->max_tls))) - continue; + ok = 0; if (SSL_IS_DTLS(s) && (DTLS_VERSION_LT(s->version, c->min_dtls) || DTLS_VERSION_GT(s->version, c->max_dtls))) - continue; + ok = 0; /* * Since TLS 1.3 ciphersuites can be used with any auth or @@ -4276,10 +4256,10 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, #ifndef OPENSSL_NO_PSK /* with PSK there must be server callback set */ if ((alg_k & SSL_PSK) && s->psk_server_callback == NULL) - continue; + ok = 0; #endif /* OPENSSL_NO_PSK */ - ok = (alg_k & mask_k) && (alg_a & mask_a); + ok = ok && (alg_k & mask_k) && (alg_a & mask_a); #ifdef CIPHER_DEBUG fprintf(stderr, "%d:[%08lX:%08lX:%08lX:%08lX]%p:%s\n", ok, alg_k, alg_a, mask_k, mask_a, (void *)c, c->name); @@ -4296,6 +4276,14 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, if (!ok) continue; + + safari_ec = 0; +#if !defined(OPENSSL_NO_EC) + if ((alg_k & SSL_kECDHE) && (alg_a & SSL_aECDSA)) { + if (s->s3->is_probably_safari) + safari_ec = 1; + } +#endif } ii = sk_SSL_CIPHER_find(allow, c); if (ii >= 0) { @@ -4303,14 +4291,7 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, if (!ssl_security(s, SSL_SECOP_CIPHER_SHARED, c->strength_bits, 0, (void *)c)) continue; -#if !defined(OPENSSL_NO_EC) - if ((alg_k & SSL_kECDHE) && (alg_a & SSL_aECDSA) - && s->s3->is_probably_safari) { - if (!ret) - ret = sk_SSL_CIPHER_value(allow, ii); - continue; - } -#endif + if (prefer_sha256) { const SSL_CIPHER *tmp = sk_SSL_CIPHER_value(allow, ii); @@ -4322,13 +4303,38 @@ const SSL_CIPHER *ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt, ret = tmp; continue; } - ret = sk_SSL_CIPHER_value(allow, ii); + + if (in_group_flags != NULL && in_group_flags[i] == 1) { + /* This element of |prio| is in a group. Update + * the minimum index found so far and continue + * looking. */ + if (group_min == -1 || group_min > ii) + group_min = ii; + } else { + if (group_min != -1 && group_min < ii) + ii = group_min; + if (safari_ec) { + if (!ret) + ret = sk_SSL_CIPHER_value(allow, ii); + continue; + } + ret = sk_SSL_CIPHER_value(allow, ii); + break; + } + } + + if (in_group_flags != NULL && !in_group_flags[i] && group_min != -1) { + /* We are about to leave a group, but we found a match + * in it, so that's our answer. */ + if (safari_ec) { + if (!ret) + ret = sk_SSL_CIPHER_value(allow, group_min); + continue; + } + ret = sk_SSL_CIPHER_value(allow, group_min); break; } } -#ifndef OPENSSL_NO_CHACHA - sk_SSL_CIPHER_free(prio_chacha); -#endif return ret; } diff --git a/ssl/ssl_ciph.c b/ssl/ssl_ciph.c index 044dd3af92..f9dbd0b2ad 100644 --- a/ssl/ssl_ciph.c +++ b/ssl/ssl_ciph.c @@ -192,6 +192,7 @@ typedef struct cipher_order_st { const SSL_CIPHER *cipher; int active; int dead; + int in_group; struct cipher_order_st *next, *prev; } CIPHER_ORDER; @@ -681,6 +682,7 @@ static void ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method, co_list[co_list_num].next = NULL; co_list[co_list_num].prev = NULL; co_list[co_list_num].active = 0; + co_list[co_list_num].in_group = 0; co_list_num++; } @@ -774,8 +776,8 @@ static void ssl_cipher_apply_rule(uint32_t cipher_id, uint32_t alg_mkey, uint32_t alg_auth, uint32_t alg_enc, uint32_t alg_mac, int min_tls, uint32_t algo_strength, int rule, - int32_t strength_bits, CIPHER_ORDER **head_p, - CIPHER_ORDER **tail_p) + int32_t strength_bits, int in_group, + CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p) { CIPHER_ORDER *head, *tail, *curr, *next, *last; const SSL_CIPHER *cp; @@ -783,9 +785,9 @@ static void ssl_cipher_apply_rule(uint32_t cipher_id, uint32_t alg_mkey, #ifdef CIPHER_DEBUG fprintf(stderr, - "Applying rule %d with %08x/%08x/%08x/%08x/%08x %08x (%d)\n", + "Applying rule %d with %08x/%08x/%08x/%08x/%08x %08x (%d) g:%d\n", rule, alg_mkey, alg_auth, alg_enc, alg_mac, min_tls, - algo_strength, strength_bits); + algo_strength, strength_bits, in_group); #endif if (rule == CIPHER_DEL || rule == CIPHER_BUMP) @@ -862,6 +864,7 @@ static void ssl_cipher_apply_rule(uint32_t cipher_id, uint32_t alg_mkey, if (!curr->active) { ll_append_tail(&head, curr, &tail); curr->active = 1; + curr->in_group = in_group; } } /* Move the added cipher to this location */ @@ -869,6 +872,7 @@ static void ssl_cipher_apply_rule(uint32_t cipher_id, uint32_t alg_mkey, /* reverse == 0 */ if (curr->active) { ll_append_tail(&head, curr, &tail); + curr->in_group = 0; } } else if (rule == CIPHER_DEL) { /* reverse == 1 */ @@ -880,6 +884,7 @@ static void ssl_cipher_apply_rule(uint32_t cipher_id, uint32_t alg_mkey, */ ll_append_head(&head, curr, &tail); curr->active = 0; + curr->in_group = 0; } } else if (rule == CIPHER_BUMP) { if (curr->active) @@ -947,8 +952,8 @@ static int ssl_cipher_strength_sort(CIPHER_ORDER **head_p, */ for (i = max_strength_bits; i >= 0; i--) if (number_uses[i] > 0) - ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ORD, i, head_p, - tail_p); + ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ORD, i, 0, + head_p, tail_p); OPENSSL_free(number_uses); return 1; @@ -962,7 +967,7 @@ static int ssl_cipher_process_rulestr(const char *rule_str, uint32_t alg_mkey, alg_auth, alg_enc, alg_mac, algo_strength; int min_tls; const char *l, *buf; - int j, multi, found, rule, retval, ok, buflen; + int j, multi, found, rule, retval, ok, buflen, in_group = 0, has_group = 0; uint32_t cipher_id = 0; char ch; @@ -973,18 +978,66 @@ static int ssl_cipher_process_rulestr(const char *rule_str, if (ch == '\0') break; /* done */ - if (ch == '-') { + if (in_group) { + if (ch == ']') { + if (!in_group) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, + SSL_R_UNEXPECTED_GROUP_CLOSE); + retval = found = in_group = 0; + break; + } + if (*tail_p) + (*tail_p)->in_group = 0; + in_group = 0; + l++; + continue; + } + if (ch == '|') { + rule = CIPHER_ADD; + l++; + continue; + } else if (!(ch >= 'a' && ch <= 'z') + && !(ch >= 'A' && ch <= 'Z') + && !(ch >= '0' && ch <= '9')) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, + SSL_R_UNEXPECTED_OPERATOR_IN_GROUP); + retval = found = in_group = 0; + break; + } else { + rule = CIPHER_ADD; + } + } else if (ch == '-') { rule = CIPHER_DEL; l++; } else if (ch == '+') { rule = CIPHER_ORD; l++; + } else if (ch == '!' && has_group) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, + SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS); + retval = found = in_group = 0; + break; } else if (ch == '!') { rule = CIPHER_KILL; l++; + } else if (ch == '@' && has_group) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, + SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS); + retval = found = in_group = 0; + break; } else if (ch == '@') { rule = CIPHER_SPECIAL; l++; + } else if (ch == '[') { + if (in_group) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, SSL_R_NESTED_GROUP); + retval = found = in_group = 0; + break; + } + in_group = 1; + has_group = 1; + l++; + continue; } else { rule = CIPHER_ADD; } @@ -1026,7 +1079,7 @@ static int ssl_cipher_process_rulestr(const char *rule_str, * alphanumeric, so we call this an error. */ SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, SSL_R_INVALID_COMMAND); - retval = found = 0; + retval = found = in_group = 0; l++; break; } @@ -1205,8 +1258,8 @@ static int ssl_cipher_process_rulestr(const char *rule_str, } else if (found) { ssl_cipher_apply_rule(cipher_id, alg_mkey, alg_auth, alg_enc, alg_mac, - min_tls, algo_strength, rule, -1, head_p, - tail_p); + min_tls, algo_strength, rule, -1, in_group, + head_p, tail_p); } else { while ((*l != '\0') && !ITEM_SEP(*l)) l++; @@ -1215,6 +1268,11 @@ static int ssl_cipher_process_rulestr(const char *rule_str, break; /* done */ } + if (in_group) { + SSLerr(SSL_F_SSL_CIPHER_PROCESS_RULESTR, SSL_R_INVALID_COMMAND); + retval = 0; + } + return retval; } @@ -1379,7 +1437,7 @@ int SSL_CTX_set_ciphersuites(SSL_CTX *ctx, const char *str) if (ret && ctx->cipher_list != NULL) { /* We already have a cipher_list, so we need to update it */ - return update_cipher_list(&ctx->cipher_list, &ctx->cipher_list_by_id, + return update_cipher_list(&ctx->cipher_list->ciphers, &ctx->cipher_list_by_id, ctx->tls13_ciphersuites); } @@ -1392,7 +1450,7 @@ int SSL_set_ciphersuites(SSL *s, const char *str) if (ret && s->cipher_list != NULL) { /* We already have a cipher_list, so we need to update it */ - return update_cipher_list(&s->cipher_list, &s->cipher_list_by_id, + return update_cipher_list(&s->cipher_list->ciphers, &s->cipher_list_by_id, s->tls13_ciphersuites); } @@ -1401,17 +1459,20 @@ int SSL_set_ciphersuites(SSL *s, const char *str) STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, STACK_OF(SSL_CIPHER) *tls13_ciphersuites, - STACK_OF(SSL_CIPHER) **cipher_list, + struct ssl_cipher_preference_list_st **cipher_list, STACK_OF(SSL_CIPHER) **cipher_list_by_id, const char *rule_str, CERT *c) { - int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases, i; + int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases, i, tls13_len; uint32_t disabled_mkey, disabled_auth, disabled_enc, disabled_mac; - STACK_OF(SSL_CIPHER) *cipherstack; + STACK_OF(SSL_CIPHER) *cipherstack = NULL; const char *rule_p; CIPHER_ORDER *co_list = NULL, *head = NULL, *tail = NULL, *curr; - const SSL_CIPHER **ca_list = NULL; + const SSL_CIPHER **ca_list = NULL, *tmp = NULL; + uint8_t *in_group_flags = NULL; + unsigned int num_in_group_flags = 0; + struct ssl_cipher_preference_list_st *pref_list = NULL; /* * Return with error if nothing to do. @@ -1460,16 +1521,16 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, * preference). */ ssl_cipher_apply_rule(0, SSL_kECDHE, SSL_aECDSA, 0, 0, 0, 0, CIPHER_ADD, - -1, &head, &tail); - ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, - &tail); - ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, - &tail); + -1, 0, &head, &tail); + ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_ADD, -1, 0, + &head, &tail); + ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_DEL, -1, 0, + &head, &tail); /* Within each strength group, we prefer GCM over CHACHA... */ - ssl_cipher_apply_rule(0, 0, 0, SSL_AESGCM, 0, 0, 0, CIPHER_ADD, -1, + ssl_cipher_apply_rule(0, 0, 0, SSL_AESGCM, 0, 0, 0, CIPHER_ADD, -1, 0, &head, &tail); - ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20, 0, 0, 0, CIPHER_ADD, -1, + ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20, 0, 0, 0, CIPHER_ADD, -1, 0, &head, &tail); /* @@ -1478,13 +1539,13 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, * strength. */ ssl_cipher_apply_rule(0, 0, 0, SSL_AES ^ SSL_AESGCM, 0, 0, 0, CIPHER_ADD, - -1, &head, &tail); + -1, 0, &head, &tail); /* Temporarily enable everything else for sorting */ - ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, &tail); + ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ADD, -1, 0, &head, &tail); /* Low priority for MD5 */ - ssl_cipher_apply_rule(0, 0, 0, 0, SSL_MD5, 0, 0, CIPHER_ORD, -1, &head, + ssl_cipher_apply_rule(0, 0, 0, 0, SSL_MD5, 0, 0, CIPHER_ORD, -1, 0, &head, &tail); /* @@ -1492,16 +1553,16 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, * disabled. (For applications that allow them, they aren't too bad, but * we prefer authenticated ciphers.) */ - ssl_cipher_apply_rule(0, 0, SSL_aNULL, 0, 0, 0, 0, CIPHER_ORD, -1, &head, + ssl_cipher_apply_rule(0, 0, SSL_aNULL, 0, 0, 0, 0, CIPHER_ORD, -1, 0, &head, &tail); - ssl_cipher_apply_rule(0, SSL_kRSA, 0, 0, 0, 0, 0, CIPHER_ORD, -1, &head, + ssl_cipher_apply_rule(0, SSL_kRSA, 0, 0, 0, 0, 0, CIPHER_ORD, -1, 0, &head, &tail); - ssl_cipher_apply_rule(0, SSL_kPSK, 0, 0, 0, 0, 0, CIPHER_ORD, -1, &head, + ssl_cipher_apply_rule(0, SSL_kPSK, 0, 0, 0, 0, 0, CIPHER_ORD, -1, 0, &head, &tail); /* RC4 is sort-of broken -- move to the end */ - ssl_cipher_apply_rule(0, 0, 0, SSL_RC4, 0, 0, 0, CIPHER_ORD, -1, &head, + ssl_cipher_apply_rule(0, 0, 0, SSL_RC4, 0, 0, 0, CIPHER_ORD, -1, 0, &head, &tail); /* @@ -1517,7 +1578,7 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, * Partially overrule strength sort to prefer TLS 1.2 ciphers/PRFs. * TODO(openssl-team): is there an easier way to accomplish all this? */ - ssl_cipher_apply_rule(0, 0, 0, 0, 0, TLS1_2_VERSION, 0, CIPHER_BUMP, -1, + ssl_cipher_apply_rule(0, 0, 0, 0, 0, TLS1_2_VERSION, 0, CIPHER_BUMP, -1, 0, &head, &tail); /* @@ -1533,15 +1594,15 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, * Because we now bump ciphers to the top of the list, we proceed in * reverse order of preference. */ - ssl_cipher_apply_rule(0, 0, 0, 0, SSL_AEAD, 0, 0, CIPHER_BUMP, -1, + ssl_cipher_apply_rule(0, 0, 0, 0, SSL_AEAD, 0, 0, CIPHER_BUMP, -1, 0, &head, &tail); ssl_cipher_apply_rule(0, SSL_kDHE | SSL_kECDHE, 0, 0, 0, 0, 0, - CIPHER_BUMP, -1, &head, &tail); + CIPHER_BUMP, -1, 0, &head, &tail); ssl_cipher_apply_rule(0, SSL_kDHE | SSL_kECDHE, 0, 0, SSL_AEAD, 0, 0, - CIPHER_BUMP, -1, &head, &tail); + CIPHER_BUMP, -1, 0, &head, &tail); /* Now disable everything (maintaining the ordering!) */ - ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, &tail); + ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_DEL, -1, 0, &head, &tail); /* * We also need cipher aliases for selecting based on the rule_str. @@ -1555,9 +1616,8 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, num_of_alias_max = num_of_ciphers + num_of_group_aliases + 1; ca_list = OPENSSL_malloc(sizeof(*ca_list) * num_of_alias_max); if (ca_list == NULL) { - OPENSSL_free(co_list); SSLerr(SSL_F_SSL_CREATE_CIPHER_LIST, ERR_R_MALLOC_FAILURE); - return NULL; /* Failure */ + goto err; /* Failure */ } ssl_cipher_collect_aliases(ca_list, num_of_group_aliases, disabled_mkey, disabled_auth, disabled_enc, @@ -1582,27 +1642,35 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, OPENSSL_free(ca_list); /* Not needed anymore */ - if (!ok) { /* Rule processing failure */ - OPENSSL_free(co_list); - return NULL; - } + if (!ok) + goto err; /* Rule processing failure */ /* * Allocate new "cipherstack" for the result, return with error * if we cannot get one. */ - if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL) { - OPENSSL_free(co_list); - return NULL; - } + if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL) + goto err; + + in_group_flags = OPENSSL_malloc(num_of_ciphers); + if (!in_group_flags) + goto err; /* Add TLSv1.3 ciphers first - we always prefer those if possible */ - for (i = 0; i < sk_SSL_CIPHER_num(tls13_ciphersuites); i++) { + tls13_len = sk_SSL_CIPHER_num(tls13_ciphersuites); + for (i = 0; i < tls13_len; i++) { + tmp = sk_SSL_CIPHER_value(tls13_ciphersuites, i); if (!sk_SSL_CIPHER_push(cipherstack, - sk_SSL_CIPHER_value(tls13_ciphersuites, i))) { - sk_SSL_CIPHER_free(cipherstack); - return NULL; + tmp)) + goto err; + /* Temporary - AES128, CHACHA20 priority adjustment of TLS 1.3. */ + if (tmp->algorithm_enc == SSL_AES128GCM && + tls13_len > (i + 1)) { + tmp = sk_SSL_CIPHER_value(tls13_ciphersuites, i + 1); + in_group_flags[num_in_group_flags++] = (tmp->algorithm_enc == SSL_CHACHA20POLY1305) ? 1 : 0; } + else + in_group_flags[num_in_group_flags++] = 0; } /* @@ -1611,26 +1679,50 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, */ for (curr = head; curr != NULL; curr = curr->next) { if (curr->active) { - if (!sk_SSL_CIPHER_push(cipherstack, curr->cipher)) { - OPENSSL_free(co_list); - sk_SSL_CIPHER_free(cipherstack); - return NULL; - } + if (!sk_SSL_CIPHER_push(cipherstack, curr->cipher)) + goto err; + in_group_flags[num_in_group_flags++] = curr->in_group; #ifdef CIPHER_DEBUG fprintf(stderr, "<%s>\n", curr->cipher->name); #endif } } - OPENSSL_free(co_list); /* Not needed any longer */ - if (!update_cipher_list_by_id(cipher_list_by_id, cipherstack)) { - sk_SSL_CIPHER_free(cipherstack); - return NULL; - } - sk_SSL_CIPHER_free(*cipher_list); - *cipher_list = cipherstack; + OPENSSL_free(co_list); /* Not needed any longer */ + co_list = NULL; + + if (!update_cipher_list_by_id(cipher_list_by_id, cipherstack)) + goto err; + + pref_list = OPENSSL_malloc(sizeof(struct ssl_cipher_preference_list_st)); + if (!pref_list) + goto err; + pref_list->ciphers = cipherstack; + pref_list->in_group_flags = OPENSSL_malloc(num_in_group_flags); + if (!pref_list->in_group_flags) + goto err; + memcpy(pref_list->in_group_flags, in_group_flags, num_in_group_flags); + OPENSSL_free(in_group_flags); + in_group_flags = NULL; + if (*cipher_list != NULL) + ssl_cipher_preference_list_free(*cipher_list); + *cipher_list = pref_list; + pref_list = NULL; return cipherstack; + +err: + if (co_list) + OPENSSL_free(co_list); + if (in_group_flags) + OPENSSL_free(in_group_flags); + if (cipherstack) + sk_SSL_CIPHER_free(cipherstack); + if (pref_list && pref_list->in_group_flags) + OPENSSL_free(pref_list->in_group_flags); + if (pref_list) + OPENSSL_free(pref_list); + return NULL; } char *SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int len) diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c index 4b12ed1485..cd1a95d1d2 100644 --- a/ssl/ssl_err.c +++ b/ssl/ssl_err.c @@ -965,6 +965,9 @@ static const ERR_STRING_DATA SSL_str_reasons[] = { {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_MISSING_TMP_DH_KEY), "missing tmp dh key"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_MISSING_TMP_ECDH_KEY), "missing tmp ecdh key"}, + {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS), + "mixed special operator with groups"}, + {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_NESTED_GROUP), "nested group"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_MIXED_HANDSHAKE_AND_NON_HANDSHAKE_DATA), "mixed handshake and non handshake data"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_NOT_ON_RECORD_BOUNDARY), @@ -1201,11 +1204,14 @@ static const ERR_STRING_DATA SSL_str_reasons[] = { "unable to load ssl3 md5 routines"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNABLE_TO_LOAD_SSL3_SHA1_ROUTINES), "unable to load ssl3 sha1 routines"}, + {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_GROUP_CLOSE), "unexpected group close"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_CCS_MESSAGE), "unexpected ccs message"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_END_OF_EARLY_DATA), "unexpected end of early data"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_MESSAGE), "unexpected message"}, + {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_OPERATOR_IN_GROUP), + "unexpected operator in group"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNEXPECTED_RECORD), "unexpected record"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNINITIALIZED), "uninitialized"}, {ERR_PACK(ERR_LIB_SSL, 0, SSL_R_UNKNOWN_ALERT_TYPE), "unknown alert type"}, diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index 5bd2fcf5d5..91623b5612 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -1117,6 +1117,71 @@ int SSL_set1_param(SSL *ssl, X509_VERIFY_PARAM *vpm) return X509_VERIFY_PARAM_set1(ssl->param, vpm); } +void ssl_cipher_preference_list_free(struct ssl_cipher_preference_list_st + *cipher_list) +{ + sk_SSL_CIPHER_free(cipher_list->ciphers); + OPENSSL_free(cipher_list->in_group_flags); + OPENSSL_free(cipher_list); +} + +struct ssl_cipher_preference_list_st* +ssl_cipher_preference_list_dup(struct ssl_cipher_preference_list_st + *cipher_list) +{ + struct ssl_cipher_preference_list_st* ret = NULL; + size_t n = sk_SSL_CIPHER_num(cipher_list->ciphers); + + ret = OPENSSL_malloc(sizeof(struct ssl_cipher_preference_list_st)); + if (!ret) + goto err; + ret->ciphers = NULL; + ret->in_group_flags = NULL; + ret->ciphers = sk_SSL_CIPHER_dup(cipher_list->ciphers); + if (!ret->ciphers) + goto err; + ret->in_group_flags = OPENSSL_malloc(n); + if (!ret->in_group_flags) + goto err; + memcpy(ret->in_group_flags, cipher_list->in_group_flags, n); + return ret; + +err: + if (ret->ciphers) + sk_SSL_CIPHER_free(ret->ciphers); + if (ret) + OPENSSL_free(ret); + return NULL; +} + +struct ssl_cipher_preference_list_st* +ssl_cipher_preference_list_from_ciphers(STACK_OF(SSL_CIPHER) *ciphers) +{ + struct ssl_cipher_preference_list_st* ret = NULL; + size_t n = sk_SSL_CIPHER_num(ciphers); + + ret = OPENSSL_malloc(sizeof(struct ssl_cipher_preference_list_st)); + if (!ret) + goto err; + ret->ciphers = NULL; + ret->in_group_flags = NULL; + ret->ciphers = sk_SSL_CIPHER_dup(ciphers); + if (!ret->ciphers) + goto err; + ret->in_group_flags = OPENSSL_malloc(n); + if (!ret->in_group_flags) + goto err; + memset(ret->in_group_flags, 0, n); + return ret; + +err: + if (ret->ciphers) + sk_SSL_CIPHER_free(ret->ciphers); + if (ret) + OPENSSL_free(ret); + return NULL; +} + X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx) { return ctx->param; @@ -1157,7 +1222,8 @@ void SSL_free(SSL *s) BUF_MEM_free(s->init_buf); /* add extra stuff */ - sk_SSL_CIPHER_free(s->cipher_list); + if (s->cipher_list != NULL) + ssl_cipher_preference_list_free(s->cipher_list); sk_SSL_CIPHER_free(s->cipher_list_by_id); sk_SSL_CIPHER_free(s->tls13_ciphersuites); @@ -2427,9 +2493,9 @@ STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *s) { if (s != NULL) { if (s->cipher_list != NULL) { - return s->cipher_list; + return (s->cipher_list->ciphers); } else if ((s->ctx != NULL) && (s->ctx->cipher_list != NULL)) { - return s->ctx->cipher_list; + return (s->ctx->cipher_list->ciphers); } } return NULL; @@ -2503,8 +2569,8 @@ const char *SSL_get_cipher_list(const SSL *s, int n) * preference */ STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx) { - if (ctx != NULL) - return ctx->cipher_list; + if (ctx != NULL && ctx->cipher_list != NULL) + return ctx->cipher_list->ciphers; return NULL; } @@ -2955,7 +3021,7 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth) ret->tls13_ciphersuites, &ret->cipher_list, &ret->cipher_list_by_id, SSL_DEFAULT_CIPHER_LIST, ret->cert) - || sk_SSL_CIPHER_num(ret->cipher_list) <= 0) { + || sk_SSL_CIPHER_num(ret->cipher_list->ciphers) <= 0) { SSLerr(SSL_F_SSL_CTX_NEW, SSL_R_LIBRARY_HAS_NO_CIPHERS); goto err2; } @@ -3131,7 +3197,7 @@ void SSL_CTX_free(SSL_CTX *a) #ifndef OPENSSL_NO_CT CTLOG_STORE_free(a->ctlog_store); #endif - sk_SSL_CIPHER_free(a->cipher_list); + ssl_cipher_preference_list_free(a->cipher_list); sk_SSL_CIPHER_free(a->cipher_list_by_id); sk_SSL_CIPHER_free(a->tls13_ciphersuites); ssl_cert_free(a->cert); @@ -3809,13 +3875,15 @@ SSL *SSL_dup(SSL *s) /* dup the cipher_list and cipher_list_by_id stacks */ if (s->cipher_list != NULL) { - if ((ret->cipher_list = sk_SSL_CIPHER_dup(s->cipher_list)) == NULL) + ret->cipher_list = ssl_cipher_preference_list_dup(s->cipher_list); + if (ret->cipher_list == NULL) goto err; } - if (s->cipher_list_by_id != NULL) - if ((ret->cipher_list_by_id = sk_SSL_CIPHER_dup(s->cipher_list_by_id)) - == NULL) + if (s->cipher_list_by_id != NULL) { + ret->cipher_list_by_id = sk_SSL_CIPHER_dup(s->cipher_list_by_id); + if (ret->cipher_list_by_id == NULL) goto err; + } /* Dup the client_CA list */ if (!dup_ca_names(&ret->ca_names, s->ca_names) diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h index 6559012f30..1e0cddfa7b 100644 --- a/ssl/ssl_locl.h +++ b/ssl/ssl_locl.h @@ -741,9 +741,46 @@ typedef struct ssl_ctx_ext_secure_st { unsigned char tick_aes_key[TLSEXT_TICK_KEY_LENGTH]; } SSL_CTX_EXT_SECURE; +/* ssl_cipher_preference_list_st contains a list of SSL_CIPHERs with + * equal-preference groups. For TLS clients, the groups are moot because the + * server picks the cipher and groups cannot be expressed on the wire. However, + * for servers, the equal-preference groups allow the client's preferences to + * be partially respected. (This only has an effect with + * SSL_OP_CIPHER_SERVER_PREFERENCE). + * + * The equal-preference groups are expressed by grouping SSL_CIPHERs together. + * All elements of a group have the same priority: no ordering is expressed + * within a group. + * + * The values in |ciphers| are in one-to-one correspondence with + * |in_group_flags|. (That is, sk_SSL_CIPHER_num(ciphers) is the number of + * bytes in |in_group_flags|.) The bytes in |in_group_flags| are either 1, to + * indicate that the corresponding SSL_CIPHER is not the last element of a + * group, or 0 to indicate that it is. + * + * For example, if |in_group_flags| contains all zeros then that indicates a + * traditional, fully-ordered preference. Every SSL_CIPHER is the last element + * of the group (i.e. they are all in a one-element group). + * + * For a more complex example, consider: + * ciphers: A B C D E F + * in_group_flags: 1 1 0 0 1 0 + * + * That would express the following, order: + * + * A E + * B -> D -> F + * C + */ +struct ssl_cipher_preference_list_st { + STACK_OF(SSL_CIPHER) *ciphers; + uint8_t *in_group_flags; +}; + + struct ssl_ctx_st { const SSL_METHOD *method; - STACK_OF(SSL_CIPHER) *cipher_list; + struct ssl_cipher_preference_list_st *cipher_list; /* same as above but sorted for lookup */ STACK_OF(SSL_CIPHER) *cipher_list_by_id; /* TLSv1.3 specific ciphersuites */ @@ -1138,7 +1175,7 @@ struct ssl_st { /* Per connection DANE state */ SSL_DANE dane; /* crypto */ - STACK_OF(SSL_CIPHER) *cipher_list; + struct ssl_cipher_preference_list_st *cipher_list; STACK_OF(SSL_CIPHER) *cipher_list_by_id; /* TLSv1.3 specific ciphersuites */ STACK_OF(SSL_CIPHER) *tls13_ciphersuites; @@ -2263,7 +2300,7 @@ __owur int ssl_cipher_ptr_id_cmp(const SSL_CIPHER *const *ap, const SSL_CIPHER *const *bp); __owur STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method, STACK_OF(SSL_CIPHER) *tls13_ciphersuites, - STACK_OF(SSL_CIPHER) **cipher_list, + struct ssl_cipher_preference_list_st **cipher_list, STACK_OF(SSL_CIPHER) **cipher_list_by_id, const char *rule_str, CERT *c); @@ -2273,6 +2310,13 @@ __owur int bytes_to_cipher_list(SSL *s, PACKET *cipher_suites, STACK_OF(SSL_CIPHER) **scsvs, int sslv2format, int fatal); void ssl_update_cache(SSL *s, int mode); +struct ssl_cipher_preference_list_st* ssl_cipher_preference_list_dup( + struct ssl_cipher_preference_list_st *cipher_list); +void ssl_cipher_preference_list_free( + struct ssl_cipher_preference_list_st *cipher_list); +struct ssl_cipher_preference_list_st* ssl_cipher_preference_list_from_ciphers( + STACK_OF(SSL_CIPHER) *ciphers); +struct ssl_cipher_preference_list_st* ssl_get_cipher_preferences(SSL *s); __owur int ssl_cipher_get_evp(const SSL_SESSION *s, const EVP_CIPHER **enc, const EVP_MD **md, int *mac_pkey_type, size_t *mac_secret_size, SSL_COMP **comp, @@ -2356,7 +2400,7 @@ __owur unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk); __owur const SSL_CIPHER *ssl3_choose_cipher(SSL *ssl, STACK_OF(SSL_CIPHER) *clnt, - STACK_OF(SSL_CIPHER) *srvr); + struct ssl_cipher_preference_list_st *srvr); __owur int ssl3_digest_cached_records(SSL *s, int keep); __owur int ssl3_new(SSL *s); void ssl3_free(SSL *s); diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c index 0eab35c5c8..21f3dd707e 100644 --- a/ssl/statem/statem_srvr.c +++ b/ssl/statem/statem_srvr.c @@ -1750,7 +1750,7 @@ static int tls_early_post_process_client_hello(SSL *s) /* For TLSv1.3 we must select the ciphersuite *before* session resumption */ if (SSL_IS_TLS13(s)) { const SSL_CIPHER *cipher = - ssl3_choose_cipher(s, ciphers, SSL_get_ciphers(s)); + ssl3_choose_cipher(s, ciphers, ssl_get_cipher_preferences(s)); if (cipher == NULL) { SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, @@ -1931,7 +1931,7 @@ static int tls_early_post_process_client_hello(SSL *s) /* check if some cipher was preferred by call back */ if (pref_cipher == NULL) pref_cipher = ssl3_choose_cipher(s, s->session->ciphers, - SSL_get_ciphers(s)); + ssl_get_cipher_preferences(s)); if (pref_cipher == NULL) { SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO, @@ -1940,8 +1940,9 @@ static int tls_early_post_process_client_hello(SSL *s) } s->session->cipher = pref_cipher; - sk_SSL_CIPHER_free(s->cipher_list); - s->cipher_list = sk_SSL_CIPHER_dup(s->session->ciphers); + ssl_cipher_preference_list_free(s->cipher_list); + s->cipher_list = ssl_cipher_preference_list_from_ciphers( + s->session->ciphers); sk_SSL_CIPHER_free(s->cipher_list_by_id); s->cipher_list_by_id = sk_SSL_CIPHER_dup(s->session->ciphers); } @@ -2255,7 +2256,7 @@ WORK_STATE tls_post_process_client_hello(SSL *s, WORK_STATE wst) /* In TLSv1.3 we selected the ciphersuite before resumption */ if (!SSL_IS_TLS13(s)) { cipher = - ssl3_choose_cipher(s, s->session->ciphers, SSL_get_ciphers(s)); + ssl3_choose_cipher(s, s->session->ciphers, ssl_get_cipher_preferences(s)); if (cipher == NULL) { SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,