/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ /* ==================================================================== * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. * * Portions of the attached software ("Contribution") are developed by * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project. * * The Contribution is licensed pursuant to the OpenSSL open source * license provided above. * * ECC cipher suite support in OpenSSL originally written by * Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories. * */ /* ==================================================================== * Copyright 2005 Nokia. All rights reserved. * * The portions of the attached software ("Contribution") is developed by * Nokia Corporation and is licensed pursuant to the OpenSSL open source * license. * * The Contribution, originally written by Mika Kousa and Pasi Eronen of * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites * support (see RFC 4279) to OpenSSL. * * No patent licenses or other rights except those expressly stated in * the OpenSSL open source license shall be deemed granted or received * expressly, by implication, estoppel, or otherwise. * * No assurances are provided by Nokia that the Contribution does not * infringe the patent or other intellectual property rights of any third * party or that the license provides you with all the necessary rights * to make use of the Contribution. * * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR * OTHERWISE. */ #define BORINGSSL_INTERNAL_CXX_TYPES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" #include "../crypto/internal.h" namespace bssl { static int ssl3_process_client_hello(SSL_HANDSHAKE *hs); static int ssl3_select_certificate(SSL_HANDSHAKE *hs); static int ssl3_select_parameters(SSL_HANDSHAKE *hs); static int ssl3_send_server_hello(SSL_HANDSHAKE *hs); static int ssl3_send_server_certificate(SSL_HANDSHAKE *hs); static int ssl3_send_server_key_exchange(SSL_HANDSHAKE *hs); static int ssl3_send_server_hello_done(SSL_HANDSHAKE *hs); static int ssl3_get_client_certificate(SSL_HANDSHAKE *hs); static int ssl3_get_client_key_exchange(SSL_HANDSHAKE *hs); static int ssl3_get_cert_verify(SSL_HANDSHAKE *hs); static int ssl3_get_next_proto(SSL_HANDSHAKE *hs); static int ssl3_get_channel_id(SSL_HANDSHAKE *hs); static int ssl3_send_server_finished(SSL_HANDSHAKE *hs); int ssl3_accept(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; int ret = -1; assert(ssl->handshake_func == ssl3_accept); assert(ssl->server); for (;;) { int state = hs->state; switch (hs->state) { case SSL_ST_INIT: ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_START, 1); hs->state = SSL3_ST_SR_CLNT_HELLO_A; break; case SSL3_ST_SR_CLNT_HELLO_A: ret = ssl->method->ssl_get_message(ssl); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SR_CLNT_HELLO_B; break; case SSL3_ST_SR_CLNT_HELLO_B: ret = ssl3_process_client_hello(hs); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SR_CLNT_HELLO_C; break; case SSL3_ST_SR_CLNT_HELLO_C: ret = ssl3_select_certificate(hs); if (ret <= 0) { goto end; } if (hs->state != SSL_ST_TLS13) { hs->state = SSL3_ST_SR_CLNT_HELLO_D; } break; case SSL3_ST_SR_CLNT_HELLO_D: ret = ssl3_select_parameters(hs); if (ret <= 0) { goto end; } ssl->method->received_flight(ssl); hs->state = SSL3_ST_SW_SRVR_HELLO_A; break; case SSL3_ST_SW_SRVR_HELLO_A: ret = ssl3_send_server_hello(hs); if (ret <= 0) { goto end; } if (ssl->session != NULL) { hs->state = SSL3_ST_SW_FINISHED_A; } else { hs->state = SSL3_ST_SW_CERT_A; } break; case SSL3_ST_SW_CERT_A: ret = ssl3_send_server_certificate(hs); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SW_KEY_EXCH_A; break; case SSL3_ST_SW_KEY_EXCH_A: if (hs->server_params_len > 0) { ret = ssl3_send_server_key_exchange(hs); if (ret <= 0) { goto end; } } hs->state = SSL3_ST_SW_SRVR_DONE_A; break; case SSL3_ST_SW_SRVR_DONE_A: ret = ssl3_send_server_hello_done(hs); if (ret <= 0) { goto end; } hs->next_state = SSL3_ST_SR_CERT_A; hs->state = SSL3_ST_SW_FLUSH; break; case SSL3_ST_SR_CERT_A: if (hs->cert_request) { ret = ssl3_get_client_certificate(hs); if (ret <= 0) { goto end; } } hs->state = SSL3_ST_VERIFY_CLIENT_CERT; break; case SSL3_ST_VERIFY_CLIENT_CERT: if (sk_CRYPTO_BUFFER_num(hs->new_session->certs) > 0) { switch (ssl_verify_peer_cert(hs)) { case ssl_verify_ok: break; case ssl_verify_invalid: ret = -1; goto end; case ssl_verify_retry: ssl->rwstate = SSL_CERTIFICATE_VERIFY; ret = -1; goto end; } } hs->state = SSL3_ST_SR_KEY_EXCH_A; break; case SSL3_ST_SR_KEY_EXCH_A: case SSL3_ST_SR_KEY_EXCH_B: ret = ssl3_get_client_key_exchange(hs); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SR_CERT_VRFY_A; break; case SSL3_ST_SR_CERT_VRFY_A: ret = ssl3_get_cert_verify(hs); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SR_CHANGE; break; case SSL3_ST_SR_CHANGE: ret = ssl->method->read_change_cipher_spec(ssl); if (ret <= 0) { goto end; } if (!tls1_change_cipher_state(hs, SSL3_CHANGE_CIPHER_SERVER_READ)) { ret = -1; goto end; } hs->state = SSL3_ST_SR_NEXT_PROTO_A; break; case SSL3_ST_SR_NEXT_PROTO_A: if (hs->next_proto_neg_seen) { ret = ssl3_get_next_proto(hs); if (ret <= 0) { goto end; } } hs->state = SSL3_ST_SR_CHANNEL_ID_A; break; case SSL3_ST_SR_CHANNEL_ID_A: if (ssl->s3->tlsext_channel_id_valid) { ret = ssl3_get_channel_id(hs); if (ret <= 0) { goto end; } } hs->state = SSL3_ST_SR_FINISHED_A; break; case SSL3_ST_SR_FINISHED_A: ret = ssl3_get_finished(hs); if (ret <= 0) { goto end; } ssl->method->received_flight(ssl); if (ssl->session != NULL) { hs->state = SSL_ST_OK; } else { hs->state = SSL3_ST_SW_FINISHED_A; } /* If this is a full handshake with ChannelID then record the handshake * hashes in |hs->new_session| in case we need them to verify a * ChannelID signature on a resumption of this session in the future. */ if (ssl->session == NULL && ssl->s3->tlsext_channel_id_valid) { ret = tls1_record_handshake_hashes_for_channel_id(hs); if (ret <= 0) { goto end; } } break; case SSL3_ST_SW_FINISHED_A: ret = ssl3_send_server_finished(hs); if (ret <= 0) { goto end; } hs->state = SSL3_ST_SW_FLUSH; if (ssl->session != NULL) { hs->next_state = SSL3_ST_SR_CHANGE; } else { hs->next_state = SSL_ST_OK; } break; case SSL3_ST_SW_FLUSH: ret = ssl->method->flush_flight(ssl); if (ret <= 0) { goto end; } hs->state = hs->next_state; if (hs->state != SSL_ST_OK) { ssl->method->expect_flight(ssl); } break; case SSL_ST_TLS13: { int early_return = 0; ret = tls13_handshake(hs, &early_return); if (ret <= 0) { goto end; } if (early_return) { ret = 1; goto end; } hs->state = SSL_ST_OK; break; } case SSL_ST_OK: ssl->method->release_current_message(ssl, 1 /* free_buffer */); /* If we aren't retaining peer certificates then we can discard it * now. */ if (hs->new_session != NULL && ssl->retain_only_sha256_of_client_certs) { sk_CRYPTO_BUFFER_pop_free(hs->new_session->certs, CRYPTO_BUFFER_free); hs->new_session->certs = NULL; ssl->ctx->x509_method->session_clear(hs->new_session); } SSL_SESSION_free(ssl->s3->established_session); if (ssl->session != NULL) { SSL_SESSION_up_ref(ssl->session); ssl->s3->established_session = ssl->session; } else { ssl->s3->established_session = hs->new_session; ssl->s3->established_session->not_resumable = 0; hs->new_session = NULL; } ssl->s3->initial_handshake_complete = 1; ssl_update_cache(hs, SSL_SESS_CACHE_SERVER); ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_DONE, 1); ret = 1; goto end; default: OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE); ret = -1; goto end; } if (hs->state != state) { ssl_do_info_callback(ssl, SSL_CB_ACCEPT_LOOP, 1); } } end: ssl_do_info_callback(ssl, SSL_CB_ACCEPT_EXIT, ret); return ret; } int ssl_client_cipher_list_contains_cipher(const SSL_CLIENT_HELLO *client_hello, uint16_t id) { CBS cipher_suites; CBS_init(&cipher_suites, client_hello->cipher_suites, client_hello->cipher_suites_len); while (CBS_len(&cipher_suites) > 0) { uint16_t got_id; if (!CBS_get_u16(&cipher_suites, &got_id)) { return 0; } if (got_id == id) { return 1; } } return 0; } static int negotiate_version(SSL_HANDSHAKE *hs, uint8_t *out_alert, const SSL_CLIENT_HELLO *client_hello) { SSL *const ssl = hs->ssl; assert(!ssl->s3->have_version); CBS supported_versions, versions; if (ssl_client_hello_get_extension(client_hello, &supported_versions, TLSEXT_TYPE_supported_versions)) { if (!CBS_get_u8_length_prefixed(&supported_versions, &versions) || CBS_len(&supported_versions) != 0 || CBS_len(&versions) == 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); *out_alert = SSL_AD_DECODE_ERROR; return 0; } } else { /* Convert the ClientHello version to an equivalent supported_versions * extension. */ static const uint8_t kTLSVersions[] = { 0x03, 0x03, /* TLS 1.2 */ 0x03, 0x02, /* TLS 1.1 */ 0x03, 0x01, /* TLS 1 */ 0x03, 0x00, /* SSL 3 */ }; static const uint8_t kDTLSVersions[] = { 0xfe, 0xfd, /* DTLS 1.2 */ 0xfe, 0xff, /* DTLS 1.0 */ }; size_t versions_len = 0; if (SSL_is_dtls(ssl)) { if (client_hello->version <= DTLS1_2_VERSION) { versions_len = 4; } else if (client_hello->version <= DTLS1_VERSION) { versions_len = 2; } CBS_init(&versions, kDTLSVersions + sizeof(kDTLSVersions) - versions_len, versions_len); } else { if (client_hello->version >= TLS1_2_VERSION) { versions_len = 8; } else if (client_hello->version >= TLS1_1_VERSION) { versions_len = 6; } else if (client_hello->version >= TLS1_VERSION) { versions_len = 4; } else if (client_hello->version >= SSL3_VERSION) { versions_len = 2; } CBS_init(&versions, kTLSVersions + sizeof(kTLSVersions) - versions_len, versions_len); } } if (!ssl_negotiate_version(hs, out_alert, &ssl->version, &versions)) { return 0; } /* At this point, the connection's version is known and |ssl->version| is * fixed. Begin enforcing the record-layer version. */ ssl->s3->have_version = 1; /* Handle FALLBACK_SCSV. */ if (ssl_client_cipher_list_contains_cipher(client_hello, SSL3_CK_FALLBACK_SCSV & 0xffff) && ssl3_protocol_version(ssl) < hs->max_version) { OPENSSL_PUT_ERROR(SSL, SSL_R_INAPPROPRIATE_FALLBACK); *out_alert = SSL3_AD_INAPPROPRIATE_FALLBACK; return 0; } return 1; } static STACK_OF(SSL_CIPHER) * ssl_parse_client_cipher_list(const SSL_CLIENT_HELLO *client_hello) { CBS cipher_suites; CBS_init(&cipher_suites, client_hello->cipher_suites, client_hello->cipher_suites_len); STACK_OF(SSL_CIPHER) *sk = sk_SSL_CIPHER_new_null(); if (sk == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } while (CBS_len(&cipher_suites) > 0) { uint16_t cipher_suite; if (!CBS_get_u16(&cipher_suites, &cipher_suite)) { OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST); goto err; } const SSL_CIPHER *c = SSL_get_cipher_by_value(cipher_suite); if (c != NULL && !sk_SSL_CIPHER_push(sk, c)) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } } return sk; err: sk_SSL_CIPHER_free(sk); return NULL; } /* ssl_get_compatible_server_ciphers determines the key exchange and * authentication cipher suite masks compatible with the server configuration * and current ClientHello parameters of |hs|. It sets |*out_mask_k| to the key * exchange mask and |*out_mask_a| to the authentication mask. */ static void ssl_get_compatible_server_ciphers(SSL_HANDSHAKE *hs, uint32_t *out_mask_k, uint32_t *out_mask_a) { SSL *const ssl = hs->ssl; uint32_t mask_k = 0; uint32_t mask_a = 0; if (ssl_has_certificate(ssl)) { mask_a |= ssl_cipher_auth_mask_for_key(hs->local_pubkey); if (EVP_PKEY_id(hs->local_pubkey) == EVP_PKEY_RSA) { mask_k |= SSL_kRSA; } } /* Check for a shared group to consider ECDHE ciphers. */ uint16_t unused; if (tls1_get_shared_group(hs, &unused)) { mask_k |= SSL_kECDHE; } /* PSK requires a server callback. */ if (ssl->psk_server_callback != NULL) { mask_k |= SSL_kPSK; mask_a |= SSL_aPSK; } *out_mask_k = mask_k; *out_mask_a = mask_a; } static const SSL_CIPHER *ssl3_choose_cipher( SSL_HANDSHAKE *hs, const SSL_CLIENT_HELLO *client_hello, const struct ssl_cipher_preference_list_st *server_pref) { SSL *const ssl = hs->ssl; STACK_OF(SSL_CIPHER) *prio, *allow; /* 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; STACK_OF(SSL_CIPHER) *client_pref = ssl_parse_client_cipher_list(client_hello); if (client_pref == NULL) { return NULL; } if (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE) { prio = server_pref->ciphers; in_group_flags = server_pref->in_group_flags; allow = client_pref; } else { prio = client_pref; in_group_flags = NULL; allow = server_pref->ciphers; } uint32_t mask_k, mask_a; ssl_get_compatible_server_ciphers(hs, &mask_k, &mask_a); const SSL_CIPHER *ret = NULL; for (size_t i = 0; i < sk_SSL_CIPHER_num(prio); i++) { const SSL_CIPHER *c = sk_SSL_CIPHER_value(prio, i); size_t cipher_index; if (/* Check if the cipher is supported for the current version. */ SSL_CIPHER_get_min_version(c) <= ssl3_protocol_version(ssl) && ssl3_protocol_version(ssl) <= SSL_CIPHER_get_max_version(c) && /* Check the cipher is supported for the server configuration. */ (c->algorithm_mkey & mask_k) && (c->algorithm_auth & mask_a) && /* Check the cipher is in the |allow| list. */ sk_SSL_CIPHER_find(allow, &cipher_index, c)) { 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 || (size_t)group_min > cipher_index) { group_min = cipher_index; } } else { if (group_min != -1 && (size_t)group_min < cipher_index) { cipher_index = group_min; } ret = sk_SSL_CIPHER_value(allow, cipher_index); break; } } if (in_group_flags != NULL && in_group_flags[i] == 0 && group_min != -1) { /* We are about to leave a group, but we found a match in it, so that's * our answer. */ ret = sk_SSL_CIPHER_value(allow, group_min); break; } } sk_SSL_CIPHER_free(client_pref); return ret; } static int ssl3_process_client_hello(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (!ssl_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) { return -1; } SSL_CLIENT_HELLO client_hello; if (!ssl_client_hello_init(ssl, &client_hello, ssl->init_msg, ssl->init_num)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } /* Run the early callback. */ if (ssl->ctx->select_certificate_cb != NULL) { switch (ssl->ctx->select_certificate_cb(&client_hello)) { case ssl_select_cert_retry: ssl->rwstate = SSL_CERTIFICATE_SELECTION_PENDING; return -1; case ssl_select_cert_error: /* Connection rejected. */ OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; default: /* fallthrough */; } } /* Freeze the version range after the early callback. */ if (!ssl_get_version_range(ssl, &hs->min_version, &hs->max_version)) { return -1; } uint8_t alert = SSL_AD_DECODE_ERROR; if (!negotiate_version(hs, &alert, &client_hello)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); return -1; } hs->client_version = client_hello.version; if (client_hello.random_len != SSL3_RANDOM_SIZE) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } OPENSSL_memcpy(ssl->s3->client_random, client_hello.random, client_hello.random_len); /* Only null compression is supported. TLS 1.3 further requires the peer * advertise no other compression. */ if (OPENSSL_memchr(client_hello.compression_methods, 0, client_hello.compression_methods_len) == NULL || (ssl3_protocol_version(ssl) >= TLS1_3_VERSION && client_hello.compression_methods_len != 1)) { OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMPRESSION_LIST); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); return -1; } /* TLS extensions. */ if (!ssl_parse_clienthello_tlsext(hs, &client_hello)) { OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT); return -1; } return 1; } static int ssl3_select_certificate(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; /* Call |cert_cb| to update server certificates if required. */ if (ssl->cert->cert_cb != NULL) { int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg); if (rv == 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } if (rv < 0) { ssl->rwstate = SSL_X509_LOOKUP; return -1; } } if (!ssl_on_certificate_selected(hs)) { return -1; } if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) { /* Jump to the TLS 1.3 state machine. */ hs->state = SSL_ST_TLS13; hs->do_tls13_handshake = tls13_server_handshake; return 1; } SSL_CLIENT_HELLO client_hello; if (!ssl_client_hello_init(ssl, &client_hello, ssl->init_msg, ssl->init_num)) { return -1; } /* Negotiate the cipher suite. This must be done after |cert_cb| so the * certificate is finalized. */ hs->new_cipher = ssl3_choose_cipher(hs, &client_hello, ssl_get_cipher_preferences(ssl)); if (hs->new_cipher == NULL) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } return 1; } static int ssl3_select_parameters(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; SSL_CLIENT_HELLO client_hello; if (!ssl_client_hello_init(ssl, &client_hello, ssl->init_msg, ssl->init_num)) { return -1; } /* Determine whether we are doing session resumption. */ int tickets_supported = 0, renew_ticket = 0; /* TODO(davidben): Switch |ssl_get_prev_session| to take a |UniquePtr| * output and simplify this. */ SSL_SESSION *session_raw = nullptr; auto session_ret = ssl_get_prev_session(ssl, &session_raw, &tickets_supported, &renew_ticket, &client_hello); UniquePtr session(session_raw); switch (session_ret) { case ssl_session_success: break; case ssl_session_error: return -1; case ssl_session_retry: ssl->rwstate = SSL_PENDING_SESSION; return -1; case ssl_session_ticket_retry: ssl->rwstate = SSL_PENDING_TICKET; return -1; } if (session) { if (session->extended_master_secret && !hs->extended_master_secret) { /* A ClientHello without EMS that attempts to resume a session with EMS * is fatal to the connection. */ OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } if (!ssl_session_is_resumable(hs, session.get()) || /* If the client offers the EMS extension, but the previous session * didn't use it, then negotiate a new session. */ hs->extended_master_secret != session->extended_master_secret) { session.reset(); } } if (session) { /* Use the old session. */ hs->ticket_expected = renew_ticket; ssl->session = session.release(); ssl->s3->session_reused = 1; } else { hs->ticket_expected = tickets_supported; ssl_set_session(ssl, NULL); if (!ssl_get_new_session(hs, 1 /* server */)) { return -1; } /* Clear the session ID if we want the session to be single-use. */ if (!(ssl->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)) { hs->new_session->session_id_length = 0; } } if (ssl->ctx->dos_protection_cb != NULL && ssl->ctx->dos_protection_cb(&client_hello) == 0) { /* Connection rejected for DOS reasons. */ OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } if (ssl->session == NULL) { hs->new_session->cipher = hs->new_cipher; /* On new sessions, stash the SNI value in the session. */ if (hs->hostname != NULL) { OPENSSL_free(hs->new_session->tlsext_hostname); hs->new_session->tlsext_hostname = BUF_strdup(hs->hostname); if (hs->new_session->tlsext_hostname == NULL) { ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } } /* Determine whether to request a client certificate. */ hs->cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER); /* Only request a certificate if Channel ID isn't negotiated. */ if ((ssl->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) && ssl->s3->tlsext_channel_id_valid) { hs->cert_request = 0; } /* CertificateRequest may only be sent in certificate-based ciphers. */ if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) { hs->cert_request = 0; } if (!hs->cert_request) { /* OpenSSL returns X509_V_OK when no certificates are requested. This is * classed by them as a bug, but it's assumed by at least NGINX. */ hs->new_session->verify_result = X509_V_OK; } } /* HTTP/2 negotiation depends on the cipher suite, so ALPN negotiation was * deferred. Complete it now. */ uint8_t alert = SSL_AD_DECODE_ERROR; if (!ssl_negotiate_alpn(hs, &alert, &client_hello)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); return -1; } /* Now that all parameters are known, initialize the handshake hash and hash * the ClientHello. */ if (!SSL_TRANSCRIPT_init_hash(&hs->transcript, ssl3_protocol_version(ssl), hs->new_cipher->algorithm_prf) || !ssl_hash_current_message(hs)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } /* Release the handshake buffer if client authentication isn't required. */ if (!hs->cert_request) { SSL_TRANSCRIPT_free_buffer(&hs->transcript); } return 1; } static int ssl3_send_server_hello(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; /* We only accept ChannelIDs on connections with ECDHE in order to avoid a * known attack while we fix ChannelID itself. */ if (ssl->s3->tlsext_channel_id_valid && (hs->new_cipher->algorithm_mkey & SSL_kECDHE) == 0) { ssl->s3->tlsext_channel_id_valid = 0; } /* If this is a resumption and the original handshake didn't support * ChannelID then we didn't record the original handshake hashes in the * session and so cannot resume with ChannelIDs. */ if (ssl->session != NULL && ssl->session->original_handshake_hash_len == 0) { ssl->s3->tlsext_channel_id_valid = 0; } struct OPENSSL_timeval now; ssl_get_current_time(ssl, &now); ssl->s3->server_random[0] = now.tv_sec >> 24; ssl->s3->server_random[1] = now.tv_sec >> 16; ssl->s3->server_random[2] = now.tv_sec >> 8; ssl->s3->server_random[3] = now.tv_sec; if (!RAND_bytes(ssl->s3->server_random + 4, SSL3_RANDOM_SIZE - 4)) { return -1; } /* TODO(davidben): Implement the TLS 1.1 and 1.2 downgrade sentinels once TLS * 1.3 is finalized and we are not implementing a draft version. */ const SSL_SESSION *session = hs->new_session; if (ssl->session != NULL) { session = ssl->session; } ScopedCBB cbb; CBB body, session_id; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_HELLO) || !CBB_add_u16(&body, ssl->version) || !CBB_add_bytes(&body, ssl->s3->server_random, SSL3_RANDOM_SIZE) || !CBB_add_u8_length_prefixed(&body, &session_id) || !CBB_add_bytes(&session_id, session->session_id, session->session_id_length) || !CBB_add_u16(&body, ssl_cipher_get_value(hs->new_cipher)) || !CBB_add_u8(&body, 0 /* no compression */) || !ssl_add_serverhello_tlsext(hs, &body) || !ssl_add_message_cbb(ssl, cbb.get())) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } return 1; } static int ssl3_send_server_certificate(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; ScopedCBB cbb; if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) { if (!ssl_has_certificate(ssl)) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET); return -1; } if (!ssl3_output_cert_chain(ssl)) { return -1; } if (hs->certificate_status_expected) { CBB body, ocsp_response; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CERTIFICATE_STATUS) || !CBB_add_u8(&body, TLSEXT_STATUSTYPE_ocsp) || !CBB_add_u24_length_prefixed(&body, &ocsp_response) || !CBB_add_bytes(&ocsp_response, CRYPTO_BUFFER_data(ssl->cert->ocsp_response), CRYPTO_BUFFER_len(ssl->cert->ocsp_response)) || !ssl_add_message_cbb(ssl, cbb.get())) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } } } /* Assemble ServerKeyExchange parameters if needed. */ uint32_t alg_k = hs->new_cipher->algorithm_mkey; uint32_t alg_a = hs->new_cipher->algorithm_auth; if (ssl_cipher_requires_server_key_exchange(hs->new_cipher) || ((alg_a & SSL_aPSK) && ssl->psk_identity_hint)) { /* Pre-allocate enough room to comfortably fit an ECDHE public key. Prepend * the client and server randoms for the signing transcript. */ CBB child; if (!CBB_init(cbb.get(), SSL3_RANDOM_SIZE * 2 + 128) || !CBB_add_bytes(cbb.get(), ssl->s3->client_random, SSL3_RANDOM_SIZE) || !CBB_add_bytes(cbb.get(), ssl->s3->server_random, SSL3_RANDOM_SIZE)) { return -1; } /* PSK ciphers begin with an identity hint. */ if (alg_a & SSL_aPSK) { size_t len = (ssl->psk_identity_hint == NULL) ? 0 : strlen(ssl->psk_identity_hint); if (!CBB_add_u16_length_prefixed(cbb.get(), &child) || !CBB_add_bytes(&child, (const uint8_t *)ssl->psk_identity_hint, len)) { return -1; } } if (alg_k & SSL_kECDHE) { /* Determine the group to use. */ uint16_t group_id; if (!tls1_get_shared_group(hs, &group_id)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } hs->new_session->group_id = group_id; /* Set up ECDH, generate a key, and emit the public half. */ if (!SSL_ECDH_CTX_init(&hs->ecdh_ctx, group_id) || !CBB_add_u8(cbb.get(), NAMED_CURVE_TYPE) || !CBB_add_u16(cbb.get(), group_id) || !CBB_add_u8_length_prefixed(cbb.get(), &child) || !SSL_ECDH_CTX_offer(&hs->ecdh_ctx, &child)) { return -1; } } else { assert(alg_k & SSL_kPSK); } if (!CBB_finish(cbb.get(), &hs->server_params, &hs->server_params_len)) { return -1; } } return 1; } static int ssl3_send_server_key_exchange(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; ScopedCBB cbb; CBB body, child; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_KEY_EXCHANGE) || /* |hs->server_params| contains a prefix for signing. */ hs->server_params_len < 2 * SSL3_RANDOM_SIZE || !CBB_add_bytes(&body, hs->server_params + 2 * SSL3_RANDOM_SIZE, hs->server_params_len - 2 * SSL3_RANDOM_SIZE)) { return -1; } /* Add a signature. */ if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) { if (!ssl_has_private_key(ssl)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } /* Determine the signature algorithm. */ uint16_t signature_algorithm; if (!tls1_choose_signature_algorithm(hs, &signature_algorithm)) { return -1; } if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) { if (!CBB_add_u16(&body, signature_algorithm)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); return -1; } } /* Add space for the signature. */ const size_t max_sig_len = EVP_PKEY_size(hs->local_pubkey); uint8_t *ptr; if (!CBB_add_u16_length_prefixed(&body, &child) || !CBB_reserve(&child, &ptr, max_sig_len)) { return -1; } size_t sig_len; switch (ssl_private_key_sign(hs, ptr, &sig_len, max_sig_len, signature_algorithm, hs->server_params, hs->server_params_len)) { case ssl_private_key_success: if (!CBB_did_write(&child, sig_len)) { return -1; } break; case ssl_private_key_failure: return -1; case ssl_private_key_retry: ssl->rwstate = SSL_PRIVATE_KEY_OPERATION; return -1; } } if (!ssl_add_message_cbb(ssl, cbb.get())) { return -1; } OPENSSL_free(hs->server_params); hs->server_params = NULL; hs->server_params_len = 0; return 1; } static int ssl3_send_server_hello_done(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; ScopedCBB cbb; CBB body; if (hs->cert_request) { CBB cert_types, sigalgs_cbb; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CERTIFICATE_REQUEST) || !CBB_add_u8_length_prefixed(&body, &cert_types) || !CBB_add_u8(&cert_types, SSL3_CT_RSA_SIGN) || (ssl3_protocol_version(ssl) >= TLS1_VERSION && !CBB_add_u8(&cert_types, TLS_CT_ECDSA_SIGN)) || (ssl3_protocol_version(ssl) >= TLS1_2_VERSION && (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb) || !tls12_add_verify_sigalgs(ssl, &sigalgs_cbb))) || !ssl_add_client_CA_list(ssl, &body) || !ssl_add_message_cbb(ssl, cbb.get())) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } } if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_HELLO_DONE) || !ssl_add_message_cbb(ssl, cbb.get())) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } return 1; } static int ssl3_get_client_certificate(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; assert(hs->cert_request); int msg_ret = ssl->method->ssl_get_message(ssl); if (msg_ret <= 0) { return msg_ret; } if (ssl->s3->tmp.message_type != SSL3_MT_CERTIFICATE) { if (ssl->version == SSL3_VERSION && ssl->s3->tmp.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) { /* In SSL 3.0, the Certificate message is omitted to signal no * certificate. */ if (ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) { OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } /* OpenSSL returns X509_V_OK when no certificates are received. This is * classed by them as a bug, but it's assumed by at least NGINX. */ hs->new_session->verify_result = X509_V_OK; ssl->s3->tmp.reuse_message = 1; return 1; } OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); return -1; } if (!ssl_hash_current_message(hs)) { return -1; } CBS certificate_msg; CBS_init(&certificate_msg, ssl->init_msg, ssl->init_num); sk_CRYPTO_BUFFER_pop_free(hs->new_session->certs, CRYPTO_BUFFER_free); EVP_PKEY_free(hs->peer_pubkey); hs->peer_pubkey = NULL; uint8_t alert = SSL_AD_DECODE_ERROR; hs->new_session->certs = ssl_parse_cert_chain( &alert, &hs->peer_pubkey, ssl->retain_only_sha256_of_client_certs ? hs->new_session->peer_sha256 : NULL, &certificate_msg, ssl->ctx->pool); if (hs->new_session->certs == NULL) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); return -1; } if (CBS_len(&certificate_msg) != 0 || !ssl->ctx->x509_method->session_cache_objects(hs->new_session)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } if (sk_CRYPTO_BUFFER_num(hs->new_session->certs) == 0) { /* No client certificate so the handshake buffer may be discarded. */ SSL_TRANSCRIPT_free_buffer(&hs->transcript); /* In SSL 3.0, sending no certificate is signaled by omitting the * Certificate message. */ if (ssl->version == SSL3_VERSION) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATES_RETURNED); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } if (ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) { /* Fail for TLS only if we required a certificate */ OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); return -1; } /* OpenSSL returns X509_V_OK when no certificates are received. This is * classed by them as a bug, but it's assumed by at least NGINX. */ hs->new_session->verify_result = X509_V_OK; return 1; } /* The hash will have been filled in. */ if (ssl->retain_only_sha256_of_client_certs) { hs->new_session->peer_sha256_valid = 1; } return 1; } static int ssl3_get_client_key_exchange(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; CBS client_key_exchange; uint8_t *premaster_secret = NULL; size_t premaster_secret_len = 0; uint8_t *decrypt_buf = NULL; if (hs->state == SSL3_ST_SR_KEY_EXCH_A) { int ret = ssl->method->ssl_get_message(ssl); if (ret <= 0) { return ret; } } if (!ssl_check_message_type(ssl, SSL3_MT_CLIENT_KEY_EXCHANGE)) { return -1; } CBS_init(&client_key_exchange, ssl->init_msg, ssl->init_num); uint32_t alg_k = hs->new_cipher->algorithm_mkey; uint32_t alg_a = hs->new_cipher->algorithm_auth; /* If using a PSK key exchange, parse the PSK identity. */ if (alg_a & SSL_aPSK) { CBS psk_identity; /* If using PSK, the ClientKeyExchange contains a psk_identity. If PSK, * then this is the only field in the message. */ if (!CBS_get_u16_length_prefixed(&client_key_exchange, &psk_identity) || ((alg_k & SSL_kPSK) && CBS_len(&client_key_exchange) != 0)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); goto err; } if (CBS_len(&psk_identity) > PSK_MAX_IDENTITY_LEN || CBS_contains_zero_byte(&psk_identity)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); goto err; } if (!CBS_strdup(&psk_identity, &hs->new_session->psk_identity)) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); goto err; } } /* Depending on the key exchange method, compute |premaster_secret| and * |premaster_secret_len|. */ if (alg_k & SSL_kRSA) { CBS encrypted_premaster_secret; if (ssl->version > SSL3_VERSION) { if (!CBS_get_u16_length_prefixed(&client_key_exchange, &encrypted_premaster_secret) || CBS_len(&client_key_exchange) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); goto err; } } else { encrypted_premaster_secret = client_key_exchange; } /* Allocate a buffer large enough for an RSA decryption. */ const size_t rsa_size = EVP_PKEY_size(hs->local_pubkey); decrypt_buf = (uint8_t *)OPENSSL_malloc(rsa_size); if (decrypt_buf == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } /* Decrypt with no padding. PKCS#1 padding will be removed as part of the * timing-sensitive code below. */ size_t decrypt_len; switch (ssl_private_key_decrypt(hs, decrypt_buf, &decrypt_len, rsa_size, CBS_data(&encrypted_premaster_secret), CBS_len(&encrypted_premaster_secret))) { case ssl_private_key_success: break; case ssl_private_key_failure: goto err; case ssl_private_key_retry: ssl->rwstate = SSL_PRIVATE_KEY_OPERATION; hs->state = SSL3_ST_SR_KEY_EXCH_B; goto err; } if (decrypt_len != rsa_size) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR); goto err; } /* Prepare a random premaster, to be used on invalid padding. See RFC 5246, * section 7.4.7.1. */ premaster_secret_len = SSL_MAX_MASTER_KEY_LENGTH; premaster_secret = (uint8_t *)OPENSSL_malloc(premaster_secret_len); if (premaster_secret == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } if (!RAND_bytes(premaster_secret, premaster_secret_len)) { goto err; } /* The smallest padded premaster is 11 bytes of overhead. Small keys are * publicly invalid. */ if (decrypt_len < 11 + premaster_secret_len) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR); goto err; } /* Check the padding. See RFC 3447, section 7.2.2. */ size_t padding_len = decrypt_len - premaster_secret_len; uint8_t good = constant_time_eq_int_8(decrypt_buf[0], 0) & constant_time_eq_int_8(decrypt_buf[1], 2); for (size_t i = 2; i < padding_len - 1; i++) { good &= ~constant_time_is_zero_8(decrypt_buf[i]); } good &= constant_time_is_zero_8(decrypt_buf[padding_len - 1]); /* The premaster secret must begin with |client_version|. This too must be * checked in constant time (http://eprint.iacr.org/2003/052/). */ good &= constant_time_eq_8(decrypt_buf[padding_len], (unsigned)(hs->client_version >> 8)); good &= constant_time_eq_8(decrypt_buf[padding_len + 1], (unsigned)(hs->client_version & 0xff)); /* Select, in constant time, either the decrypted premaster or the random * premaster based on |good|. */ for (size_t i = 0; i < premaster_secret_len; i++) { premaster_secret[i] = constant_time_select_8( good, decrypt_buf[padding_len + i], premaster_secret[i]); } OPENSSL_free(decrypt_buf); decrypt_buf = NULL; } else if (alg_k & SSL_kECDHE) { /* Parse the ClientKeyExchange. */ CBS peer_key; if (!CBS_get_u8_length_prefixed(&client_key_exchange, &peer_key) || CBS_len(&client_key_exchange) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); goto err; } /* Compute the premaster. */ uint8_t alert = SSL_AD_DECODE_ERROR; if (!SSL_ECDH_CTX_finish(&hs->ecdh_ctx, &premaster_secret, &premaster_secret_len, &alert, CBS_data(&peer_key), CBS_len(&peer_key))) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); goto err; } /* The key exchange state may now be discarded. */ SSL_ECDH_CTX_cleanup(&hs->ecdh_ctx); } else if (!(alg_k & SSL_kPSK)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); goto err; } /* For a PSK cipher suite, the actual pre-master secret is combined with the * pre-shared key. */ if (alg_a & SSL_aPSK) { if (ssl->psk_server_callback == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); goto err; } /* Look up the key for the identity. */ uint8_t psk[PSK_MAX_PSK_LEN]; unsigned psk_len = ssl->psk_server_callback( ssl, hs->new_session->psk_identity, psk, sizeof(psk)); if (psk_len > PSK_MAX_PSK_LEN) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); goto err; } else if (psk_len == 0) { /* PSK related to the given identity not found */ OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNKNOWN_PSK_IDENTITY); goto err; } if (alg_k & SSL_kPSK) { /* In plain PSK, other_secret is a block of 0s with the same length as the * pre-shared key. */ premaster_secret_len = psk_len; premaster_secret = (uint8_t *)OPENSSL_malloc(premaster_secret_len); if (premaster_secret == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } OPENSSL_memset(premaster_secret, 0, premaster_secret_len); } ScopedCBB new_premaster; CBB child; uint8_t *new_data; size_t new_len; if (!CBB_init(new_premaster.get(), 2 + psk_len + 2 + premaster_secret_len) || !CBB_add_u16_length_prefixed(new_premaster.get(), &child) || !CBB_add_bytes(&child, premaster_secret, premaster_secret_len) || !CBB_add_u16_length_prefixed(new_premaster.get(), &child) || !CBB_add_bytes(&child, psk, psk_len) || !CBB_finish(new_premaster.get(), &new_data, &new_len)) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } OPENSSL_cleanse(premaster_secret, premaster_secret_len); OPENSSL_free(premaster_secret); premaster_secret = new_data; premaster_secret_len = new_len; } if (!ssl_hash_current_message(hs)) { goto err; } /* Compute the master secret */ hs->new_session->master_key_length = tls1_generate_master_secret( hs, hs->new_session->master_key, premaster_secret, premaster_secret_len); if (hs->new_session->master_key_length == 0) { goto err; } hs->new_session->extended_master_secret = hs->extended_master_secret; OPENSSL_cleanse(premaster_secret, premaster_secret_len); OPENSSL_free(premaster_secret); return 1; err: if (premaster_secret != NULL) { OPENSSL_cleanse(premaster_secret, premaster_secret_len); OPENSSL_free(premaster_secret); } OPENSSL_free(decrypt_buf); return -1; } static int ssl3_get_cert_verify(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; CBS certificate_verify, signature; /* Only RSA and ECDSA client certificates are supported, so a * CertificateVerify is required if and only if there's a client certificate. * */ if (hs->peer_pubkey == NULL) { SSL_TRANSCRIPT_free_buffer(&hs->transcript); return 1; } int msg_ret = ssl->method->ssl_get_message(ssl); if (msg_ret <= 0) { return msg_ret; } if (!ssl_check_message_type(ssl, SSL3_MT_CERTIFICATE_VERIFY)) { return -1; } CBS_init(&certificate_verify, ssl->init_msg, ssl->init_num); /* Determine the digest type if needbe. */ uint16_t signature_algorithm = 0; if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) { if (!CBS_get_u16(&certificate_verify, &signature_algorithm)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } uint8_t alert = SSL_AD_DECODE_ERROR; if (!tls12_check_peer_sigalg(ssl, &alert, signature_algorithm)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); return -1; } hs->new_session->peer_signature_algorithm = signature_algorithm; } else if (!tls1_get_legacy_signature_algorithm(&signature_algorithm, hs->peer_pubkey)) { OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_CERTIFICATE); return -1; } /* Parse and verify the signature. */ if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) || CBS_len(&certificate_verify) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } int sig_ok; /* The SSL3 construction for CertificateVerify does not decompose into a * single final digest and signature, and must be special-cased. */ if (ssl3_protocol_version(ssl) == SSL3_VERSION) { uint8_t digest[EVP_MAX_MD_SIZE]; size_t digest_len; if (!SSL_TRANSCRIPT_ssl3_cert_verify_hash(&hs->transcript, digest, &digest_len, hs->new_session, signature_algorithm)) { return -1; } UniquePtr pctx(EVP_PKEY_CTX_new(hs->peer_pubkey, NULL)); sig_ok = pctx && EVP_PKEY_verify_init(pctx.get()) && EVP_PKEY_verify(pctx.get(), CBS_data(&signature), CBS_len(&signature), digest, digest_len); } else { sig_ok = ssl_public_key_verify( ssl, CBS_data(&signature), CBS_len(&signature), signature_algorithm, hs->peer_pubkey, (const uint8_t *)hs->transcript.buffer->data, hs->transcript.buffer->length); } #if defined(BORINGSSL_UNSAFE_FUZZER_MODE) sig_ok = 1; ERR_clear_error(); #endif if (!sig_ok) { OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR); return -1; } /* The handshake buffer is no longer necessary, and we may hash the current * message.*/ SSL_TRANSCRIPT_free_buffer(&hs->transcript); if (!ssl_hash_current_message(hs)) { return -1; } return 1; } /* ssl3_get_next_proto reads a Next Protocol Negotiation handshake message. It * sets the next_proto member in s if found */ static int ssl3_get_next_proto(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; int ret = ssl->method->ssl_get_message(ssl); if (ret <= 0) { return ret; } if (!ssl_check_message_type(ssl, SSL3_MT_NEXT_PROTO) || !ssl_hash_current_message(hs)) { return -1; } CBS next_protocol, selected_protocol, padding; CBS_init(&next_protocol, ssl->init_msg, ssl->init_num); if (!CBS_get_u8_length_prefixed(&next_protocol, &selected_protocol) || !CBS_get_u8_length_prefixed(&next_protocol, &padding) || CBS_len(&next_protocol) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return 0; } if (!CBS_stow(&selected_protocol, &ssl->s3->next_proto_negotiated, &ssl->s3->next_proto_negotiated_len)) { return 0; } return 1; } /* ssl3_get_channel_id reads and verifies a ClientID handshake message. */ static int ssl3_get_channel_id(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; int msg_ret = ssl->method->ssl_get_message(ssl); if (msg_ret <= 0) { return msg_ret; } if (!ssl_check_message_type(ssl, SSL3_MT_CHANNEL_ID) || !tls1_verify_channel_id(hs) || !ssl_hash_current_message(hs)) { return -1; } return 1; } static int ssl3_send_server_finished(SSL_HANDSHAKE *hs) { SSL *const ssl = hs->ssl; if (hs->ticket_expected) { const SSL_SESSION *session; UniquePtr session_copy; if (ssl->session == NULL) { /* Fix the timeout to measure from the ticket issuance time. */ ssl_session_rebase_time(ssl, hs->new_session); session = hs->new_session; } else { /* We are renewing an existing session. Duplicate the session to adjust * the timeout. */ session_copy.reset( SSL_SESSION_dup(ssl->session, SSL_SESSION_INCLUDE_NONAUTH)); if (!session_copy) { return -1; } ssl_session_rebase_time(ssl, session_copy.get()); session = session_copy.get(); } ScopedCBB cbb; CBB body, ticket; if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_NEW_SESSION_TICKET) || !CBB_add_u32(&body, session->timeout) || !CBB_add_u16_length_prefixed(&body, &ticket) || !ssl_encrypt_ticket(ssl, &ticket, session) || !ssl_add_message_cbb(ssl, cbb.get())) { return -1; } } if (!ssl->method->add_change_cipher_spec(ssl) || !tls1_change_cipher_state(hs, SSL3_CHANGE_CIPHER_SERVER_WRITE)) { return -1; } return ssl3_send_finished(hs); } } // namespace bssl