/* 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" #include "../crypto/internal.h" static int ssl3_get_client_hello(SSL *ssl); static int ssl3_send_server_hello(SSL *ssl); static int ssl3_send_server_certificate(SSL *ssl); static int ssl3_send_certificate_status(SSL *ssl); static int ssl3_send_server_key_exchange(SSL *ssl); static int ssl3_send_certificate_request(SSL *ssl); static int ssl3_send_server_hello_done(SSL *ssl); static int ssl3_get_client_certificate(SSL *ssl); static int ssl3_get_client_key_exchange(SSL *ssl); static int ssl3_get_cert_verify(SSL *ssl); static int ssl3_get_next_proto(SSL *ssl); static int ssl3_get_channel_id(SSL *ssl); static int ssl3_send_new_session_ticket(SSL *ssl); int ssl3_accept(SSL *ssl) { uint32_t alg_a; int ret = -1; int state, skip = 0; assert(ssl->handshake_func == ssl3_accept); assert(ssl->server); for (;;) { state = ssl->state; switch (ssl->state) { case SSL_ST_INIT: ssl->state = SSL_ST_ACCEPT; skip = 1; break; case SSL_ST_ACCEPT: ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_START, 1); ssl->s3->hs = ssl_handshake_new(tls13_server_handshake); if (ssl->s3->hs == NULL) { ret = -1; goto end; } /* Enable a write buffer. This groups handshake messages within a flight * into a single write. */ if (!ssl_init_wbio_buffer(ssl)) { ret = -1; goto end; } if (!ssl3_init_handshake_buffer(ssl)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } ssl->state = SSL3_ST_SR_CLNT_HELLO_A; break; case SSL3_ST_SR_CLNT_HELLO_A: case SSL3_ST_SR_CLNT_HELLO_B: case SSL3_ST_SR_CLNT_HELLO_C: case SSL3_ST_SR_CLNT_HELLO_D: ret = ssl3_get_client_hello(ssl); if (ssl->state == SSL_ST_TLS13) { break; } if (ret <= 0) { goto end; } ssl->method->received_flight(ssl); ssl->state = SSL3_ST_SW_SRVR_HELLO_A; break; case SSL3_ST_SW_SRVR_HELLO_A: case SSL3_ST_SW_SRVR_HELLO_B: ret = ssl3_send_server_hello(ssl); if (ret <= 0) { goto end; } if (ssl->session != NULL) { ssl->state = SSL3_ST_SW_SESSION_TICKET_A; } else { ssl->state = SSL3_ST_SW_CERT_A; } break; case SSL3_ST_SW_CERT_A: case SSL3_ST_SW_CERT_B: if (ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) { ret = ssl3_send_server_certificate(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SW_CERT_STATUS_A; break; case SSL3_ST_SW_CERT_STATUS_A: case SSL3_ST_SW_CERT_STATUS_B: if (ssl->s3->tmp.certificate_status_expected) { ret = ssl3_send_certificate_status(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SW_KEY_EXCH_A; break; case SSL3_ST_SW_KEY_EXCH_A: case SSL3_ST_SW_KEY_EXCH_B: case SSL3_ST_SW_KEY_EXCH_C: alg_a = ssl->s3->tmp.new_cipher->algorithm_auth; /* PSK ciphers send ServerKeyExchange if there is an identity hint. */ if (ssl_cipher_requires_server_key_exchange(ssl->s3->tmp.new_cipher) || ((alg_a & SSL_aPSK) && ssl->psk_identity_hint)) { ret = ssl3_send_server_key_exchange(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SW_CERT_REQ_A; break; case SSL3_ST_SW_CERT_REQ_A: case SSL3_ST_SW_CERT_REQ_B: if (ssl->s3->tmp.cert_request) { ret = ssl3_send_certificate_request(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SW_SRVR_DONE_A; break; case SSL3_ST_SW_SRVR_DONE_A: case SSL3_ST_SW_SRVR_DONE_B: ret = ssl3_send_server_hello_done(ssl); if (ret <= 0) { goto end; } ssl->s3->tmp.next_state = SSL3_ST_SR_CERT_A; ssl->state = SSL3_ST_SW_FLUSH; break; case SSL3_ST_SR_CERT_A: if (ssl->s3->tmp.cert_request) { ret = ssl3_get_client_certificate(ssl); if (ret <= 0) { goto end; } } ssl->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(ssl); if (ret <= 0) { goto end; } ssl->state = SSL3_ST_SR_CERT_VRFY_A; break; case SSL3_ST_SR_CERT_VRFY_A: ret = ssl3_get_cert_verify(ssl); if (ret <= 0) { goto end; } ssl->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(ssl, SSL3_CHANGE_CIPHER_SERVER_READ)) { ret = -1; goto end; } ssl->state = SSL3_ST_SR_NEXT_PROTO_A; break; case SSL3_ST_SR_NEXT_PROTO_A: if (ssl->s3->next_proto_neg_seen) { ret = ssl3_get_next_proto(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->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(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SR_FINISHED_A; break; case SSL3_ST_SR_FINISHED_A: ret = ssl3_get_finished(ssl); if (ret <= 0) { goto end; } ssl->method->received_flight(ssl); if (ssl->session != NULL) { ssl->state = SSL_ST_OK; } else { ssl->state = SSL3_ST_SW_SESSION_TICKET_A; } /* If this is a full handshake with ChannelID then record the handshake * hashes in |ssl->s3->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(ssl); if (ret <= 0) { goto end; } } break; case SSL3_ST_SW_SESSION_TICKET_A: case SSL3_ST_SW_SESSION_TICKET_B: if (ssl->tlsext_ticket_expected) { ret = ssl3_send_new_session_ticket(ssl); if (ret <= 0) { goto end; } } else { skip = 1; } ssl->state = SSL3_ST_SW_CHANGE; break; case SSL3_ST_SW_CHANGE: ret = ssl->method->send_change_cipher_spec(ssl); if (ret <= 0) { goto end; } ssl->state = SSL3_ST_SW_FINISHED_A; if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_SERVER_WRITE)) { ret = -1; goto end; } break; case SSL3_ST_SW_FINISHED_A: case SSL3_ST_SW_FINISHED_B: ret = ssl3_send_finished(ssl, SSL3_ST_SW_FINISHED_A, SSL3_ST_SW_FINISHED_B); if (ret <= 0) { goto end; } ssl->state = SSL3_ST_SW_FLUSH; if (ssl->session != NULL) { ssl->s3->tmp.next_state = SSL3_ST_SR_CHANGE; } else { ssl->s3->tmp.next_state = SSL_ST_OK; } break; case SSL3_ST_SW_FLUSH: if (BIO_flush(ssl->wbio) <= 0) { ssl->rwstate = SSL_WRITING; ret = -1; goto end; } ssl->state = ssl->s3->tmp.next_state; if (ssl->state != SSL_ST_OK) { ssl->method->expect_flight(ssl); } break; case SSL_ST_TLS13: ret = tls13_handshake(ssl); if (ret <= 0) { goto end; } ssl->state = SSL_ST_OK; break; case SSL_ST_OK: /* Clean a few things up. */ ssl3_cleanup_key_block(ssl); ssl->method->release_current_message(ssl, 1 /* free_buffer */); /* If we aren't retaining peer certificates then we can discard it * now. */ if (ssl->s3->new_session != NULL && ssl->ctx->retain_only_sha256_of_client_certs) { X509_free(ssl->s3->new_session->peer); ssl->s3->new_session->peer = NULL; sk_X509_pop_free(ssl->s3->new_session->cert_chain, X509_free); ssl->s3->new_session->cert_chain = NULL; } 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 = ssl->s3->new_session; ssl->s3->established_session->not_resumable = 0; ssl->s3->new_session = NULL; } /* remove buffering on output */ ssl_free_wbio_buffer(ssl); ssl_handshake_free(ssl->s3->hs); ssl->s3->hs = NULL; ssl->s3->initial_handshake_complete = 1; ssl_update_cache(ssl, 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 (!ssl->s3->tmp.reuse_message && !skip && ssl->state != state) { int new_state = ssl->state; ssl->state = state; ssl_do_info_callback(ssl, SSL_CB_ACCEPT_LOOP, 1); ssl->state = new_state; } skip = 0; } end: ssl_do_info_callback(ssl, SSL_CB_ACCEPT_EXIT, ret); return ret; } int ssl_client_cipher_list_contains_cipher( const struct ssl_early_callback_ctx *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 *ssl, int *out_alert, const struct ssl_early_callback_ctx *client_hello) { uint16_t min_version, max_version; if (!ssl_get_version_range(ssl, &min_version, &max_version)) { *out_alert = SSL_AD_PROTOCOL_VERSION; return 0; } uint16_t version = 0; /* Check supported_versions extension if it is present. */ CBS supported_versions; if (ssl_early_callback_get_extension(client_hello, &supported_versions, TLSEXT_TYPE_supported_versions)) { CBS 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; } int found_version = 0; while (CBS_len(&versions) != 0) { uint16_t ext_version; if (!CBS_get_u16(&versions, &ext_version)) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); *out_alert = SSL_AD_DECODE_ERROR; return 0; } if (!ssl->method->version_from_wire(&ext_version, ext_version)) { continue; } if (min_version <= ext_version && ext_version <= max_version) { version = ext_version; found_version = 1; break; } } if (!found_version) { goto unsupported_protocol; } } else { /* Process ClientHello.version instead. Note that versions beyond (D)TLS 1.2 * do not use this mechanism. */ if (SSL_is_dtls(ssl)) { if (client_hello->version <= DTLS1_2_VERSION) { version = TLS1_2_VERSION; } else if (client_hello->version <= DTLS1_VERSION) { version = TLS1_1_VERSION; } else { goto unsupported_protocol; } } else { if (client_hello->version >= TLS1_2_VERSION) { version = TLS1_2_VERSION; } else if (client_hello->version >= TLS1_1_VERSION) { version = TLS1_1_VERSION; } else if (client_hello->version >= TLS1_VERSION) { version = TLS1_VERSION; } else if (client_hello->version >= SSL3_VERSION) { version = SSL3_VERSION; } else { goto unsupported_protocol; } } /* Apply our minimum and maximum version. */ if (version > max_version) { version = max_version; } if (version < min_version) { goto unsupported_protocol; } } /* Handle FALLBACK_SCSV. */ if (ssl_client_cipher_list_contains_cipher(client_hello, SSL3_CK_FALLBACK_SCSV & 0xffff) && version < max_version) { OPENSSL_PUT_ERROR(SSL, SSL_R_INAPPROPRIATE_FALLBACK); *out_alert = SSL3_AD_INAPPROPRIATE_FALLBACK; return 0; } ssl->client_version = client_hello->version; ssl->version = ssl->method->version_to_wire(version); ssl->s3->enc_method = ssl3_get_enc_method(version); assert(ssl->s3->enc_method != NULL); /* 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; return 1; unsupported_protocol: OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL); *out_alert = SSL_AD_PROTOCOL_VERSION; return 0; } static int ssl3_get_client_hello(SSL *ssl) { int al = SSL_AD_INTERNAL_ERROR, ret = -1; SSL_SESSION *session = NULL; if (ssl->state == SSL3_ST_SR_CLNT_HELLO_A) { /* The first time around, read the ClientHello. */ int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CLIENT_HELLO, ssl_hash_message); if (msg_ret <= 0) { return msg_ret; } ssl->state = SSL3_ST_SR_CLNT_HELLO_B; } struct ssl_early_callback_ctx client_hello; if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg, ssl->init_num)) { al = SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); goto f_err; } if (ssl->state == SSL3_ST_SR_CLNT_HELLO_B) { /* Unlike other callbacks, the early callback is not run a second time if * paused. */ ssl->state = SSL3_ST_SR_CLNT_HELLO_C; /* Run the early callback. */ if (ssl->ctx->select_certificate_cb != NULL) { switch (ssl->ctx->select_certificate_cb(&client_hello)) { case 0: ssl->rwstate = SSL_CERTIFICATE_SELECTION_PENDING; goto err; case -1: /* Connection rejected. */ al = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED); goto f_err; default: /* fallthrough */; } } } /* Negotiate the protocol version if we have not done so yet. */ if (!ssl->s3->have_version) { if (!negotiate_version(ssl, &al, &client_hello)) { goto f_err; } if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) { ssl->state = SSL_ST_TLS13; return 1; } } if (ssl->state == SSL3_ST_SR_CLNT_HELLO_C) { /* Load the client random. */ if (client_hello.random_len != SSL3_RANDOM_SIZE) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); return -1; } memcpy(ssl->s3->client_random, client_hello.random, client_hello.random_len); /* Determine whether we are doing session resumption. */ int send_new_ticket = 0; switch ( ssl_get_prev_session(ssl, &session, &send_new_ticket, &client_hello)) { case ssl_session_success: break; case ssl_session_error: goto err; case ssl_session_retry: ssl->rwstate = SSL_PENDING_SESSION; goto err; } ssl->tlsext_ticket_expected = send_new_ticket; /* The EMS state is needed when making the resumption decision, but * extensions are not normally parsed until later. This detects the EMS * extension for the resumption decision and it's checked against the result * of the normal parse later in this function. */ CBS ems; int have_extended_master_secret = ssl->version != SSL3_VERSION && ssl_early_callback_get_extension(&client_hello, &ems, TLSEXT_TYPE_extended_master_secret) && CBS_len(&ems) == 0; int has_session = 0; if (session != NULL) { if (session->extended_master_secret && !have_extended_master_secret) { /* A ClientHello without EMS that attempts to resume a session with EMS * is fatal to the connection. */ al = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION); goto f_err; } has_session = /* Only resume if the session's version matches the negotiated * version: most clients do not accept a mismatch. */ ssl->version == session->ssl_version && /* If the client offers the EMS extension, but the previous session * didn't use it, then negotiate a new session. */ have_extended_master_secret == session->extended_master_secret; } if (has_session) { /* Use the old session. */ ssl->session = session; session = NULL; ssl->s3->session_reused = 1; } else { ssl_set_session(ssl, NULL); if (!ssl_get_new_session(ssl, 1 /* server */)) { goto err; } /* Clear the session ID if we want the session to be single-use. */ if (!(ssl->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)) { ssl->s3->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. */ al = SSL_AD_INTERNAL_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED); goto f_err; } /* Only null compression is supported. */ if (memchr(client_hello.compression_methods, 0, client_hello.compression_methods_len) == NULL) { al = SSL_AD_ILLEGAL_PARAMETER; OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMPRESSION_SPECIFIED); goto f_err; } /* TLS extensions. */ if (!ssl_parse_clienthello_tlsext(ssl, &client_hello)) { OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT); goto err; } if (have_extended_master_secret != ssl->s3->tmp.extended_master_secret) { al = SSL_AD_INTERNAL_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_EMS_STATE_INCONSISTENT); goto f_err; } ssl->state = SSL3_ST_SR_CLNT_HELLO_D; } /* Determine the remaining connection parameters. This is a separate state so * |cert_cb| does not cause earlier logic to run multiple times. */ assert(ssl->state == SSL3_ST_SR_CLNT_HELLO_D); if (ssl->session != NULL) { /* Check that the cipher is in the list. */ if (!ssl_client_cipher_list_contains_cipher( &client_hello, (uint16_t)ssl->session->cipher->id)) { al = SSL_AD_ILLEGAL_PARAMETER; OPENSSL_PUT_ERROR(SSL, SSL_R_REQUIRED_CIPHER_MISSING); goto f_err; } ssl->s3->tmp.new_cipher = ssl->session->cipher; ssl->s3->tmp.cert_request = 0; } else { /* 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) { al = SSL_AD_INTERNAL_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR); goto f_err; } if (rv < 0) { ssl->rwstate = SSL_X509_LOOKUP; goto err; } } const SSL_CIPHER *c = ssl3_choose_cipher(ssl, &client_hello, ssl_get_cipher_preferences(ssl)); if (c == NULL) { al = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER); goto f_err; } ssl->s3->new_session->cipher = c; ssl->s3->tmp.new_cipher = c; /* Determine whether to request a client certificate. */ ssl->s3->tmp.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) { ssl->s3->tmp.cert_request = 0; } /* CertificateRequest may only be sent in certificate-based ciphers. */ if (!ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) { ssl->s3->tmp.cert_request = 0; } if (!ssl->s3->tmp.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. */ ssl->s3->new_session->verify_result = X509_V_OK; } } /* Now that the cipher is known, initialize the handshake hash. */ if (!ssl3_init_handshake_hash(ssl)) { goto f_err; } /* Release the handshake buffer if client authentication isn't required. */ if (!ssl->s3->tmp.cert_request) { ssl3_free_handshake_buffer(ssl); } ret = 1; if (0) { f_err: ssl3_send_alert(ssl, SSL3_AL_FATAL, al); } err: SSL_SESSION_free(session); return ret; } static int ssl3_send_server_hello(SSL *ssl) { if (ssl->state == SSL3_ST_SW_SRVR_HELLO_B) { return ssl->method->write_message(ssl); } assert(ssl->state == SSL3_ST_SW_SRVR_HELLO_A); /* 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 && (ssl->s3->tmp.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 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 = ssl->s3->new_session; if (ssl->session != NULL) { session = ssl->session; } CBB cbb, body, session_id; if (!ssl->method->init_message(ssl, &cbb, &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(ssl->s3->tmp.new_cipher)) || !CBB_add_u8(&body, 0 /* no compression */) || !ssl_add_serverhello_tlsext(ssl, &body) || !ssl->method->finish_message(ssl, &cbb)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); CBB_cleanup(&cbb); return -1; } ssl->state = SSL3_ST_SW_SRVR_HELLO_B; return ssl->method->write_message(ssl); } static int ssl3_send_server_certificate(SSL *ssl) { if (ssl->state == SSL3_ST_SW_CERT_B) { return ssl->method->write_message(ssl); } if (!ssl_has_certificate(ssl)) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET); return 0; } if (!ssl3_output_cert_chain(ssl)) { return 0; } ssl->state = SSL3_ST_SW_CERT_B; return ssl->method->write_message(ssl); } static int ssl3_send_certificate_status(SSL *ssl) { if (ssl->state == SSL3_ST_SW_CERT_STATUS_B) { return ssl->method->write_message(ssl); } CBB cbb, body, ocsp_response; if (!ssl->method->init_message(ssl, &cbb, &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, ssl->ctx->ocsp_response, ssl->ctx->ocsp_response_length) || !ssl->method->finish_message(ssl, &cbb)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); CBB_cleanup(&cbb); return -1; } ssl->state = SSL3_ST_SW_CERT_STATUS_B; return ssl->method->write_message(ssl); } static int ssl3_send_server_key_exchange(SSL *ssl) { if (ssl->state == SSL3_ST_SW_KEY_EXCH_C) { return ssl->method->write_message(ssl); } CBB cbb, child; CBB_zero(&cbb); /* Put together the parameters. */ if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) { uint32_t alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey; uint32_t alg_a = ssl->s3->tmp.new_cipher->algorithm_auth; /* Pre-allocate enough room to comfortably fit an ECDHE public key. */ if (!CBB_init(&cbb, 128)) { goto err; } /* 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, &child) || !CBB_add_bytes(&child, (const uint8_t *)ssl->psk_identity_hint, len)) { goto err; } } if (alg_k & SSL_kDHE) { /* Determine the group to use. */ DH *params = ssl->cert->dh_tmp; if (params == NULL && ssl->cert->dh_tmp_cb != NULL) { params = ssl->cert->dh_tmp_cb(ssl, 0, 1024); } if (params == NULL) { OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_DH_KEY); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); goto err; } ssl->s3->new_session->key_exchange_info = DH_num_bits(params); /* Set up DH, generate a key, and emit the public half. */ DH *dh = DHparams_dup(params); if (dh == NULL) { goto err; } SSL_ECDH_CTX_init_for_dhe(&ssl->s3->tmp.ecdh_ctx, dh); if (!CBB_add_u16_length_prefixed(&cbb, &child) || !BN_bn2cbb_padded(&child, BN_num_bytes(params->p), params->p) || !CBB_add_u16_length_prefixed(&cbb, &child) || !BN_bn2cbb_padded(&child, BN_num_bytes(params->g), params->g) || !CBB_add_u16_length_prefixed(&cbb, &child) || !SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) { goto err; } } else if (alg_k & SSL_kECDHE) { /* Determine the group to use. */ uint16_t group_id; if (!tls1_get_shared_group(ssl, &group_id)) { OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_ECDH_KEY); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); goto err; } ssl->s3->new_session->key_exchange_info = group_id; /* Set up ECDH, generate a key, and emit the public half. */ if (!SSL_ECDH_CTX_init(&ssl->s3->tmp.ecdh_ctx, group_id) || !CBB_add_u8(&cbb, NAMED_CURVE_TYPE) || !CBB_add_u16(&cbb, group_id) || !CBB_add_u8_length_prefixed(&cbb, &child) || !SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) { goto err; } } else if (alg_k & SSL_kCECPQ1) { SSL_ECDH_CTX_init_for_cecpq1(&ssl->s3->tmp.ecdh_ctx); if (!CBB_add_u16_length_prefixed(&cbb, &child) || !SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) { goto err; } } else { assert(alg_k & SSL_kPSK); } size_t len; if (!CBB_finish(&cbb, &ssl->s3->tmp.server_params, &len) || len > 0xffffffffu) { OPENSSL_free(ssl->s3->tmp.server_params); ssl->s3->tmp.server_params = NULL; goto err; } ssl->s3->tmp.server_params_len = (uint32_t)len; } /* Assemble the message. */ CBB body; if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_SERVER_KEY_EXCHANGE) || !CBB_add_bytes(&body, ssl->s3->tmp.server_params, ssl->s3->tmp.server_params_len)) { goto err; } /* Add a signature. */ if (ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) { if (!ssl_has_private_key(ssl)) { ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); goto err; } /* Determine the signature algorithm. */ uint16_t signature_algorithm; if (!tls1_choose_signature_algorithm(ssl, &signature_algorithm)) { goto err; } 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); goto err; } } /* Add space for the signature. */ const size_t max_sig_len = ssl_private_key_max_signature_len(ssl); uint8_t *ptr; if (!CBB_add_u16_length_prefixed(&body, &child) || !CBB_reserve(&child, &ptr, max_sig_len)) { goto err; } size_t sig_len; enum ssl_private_key_result_t sign_result; if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) { CBB transcript; uint8_t *transcript_data; size_t transcript_len; if (!CBB_init(&transcript, 2*SSL3_RANDOM_SIZE + ssl->s3->tmp.server_params_len) || !CBB_add_bytes(&transcript, ssl->s3->client_random, SSL3_RANDOM_SIZE) || !CBB_add_bytes(&transcript, ssl->s3->server_random, SSL3_RANDOM_SIZE) || !CBB_add_bytes(&transcript, ssl->s3->tmp.server_params, ssl->s3->tmp.server_params_len) || !CBB_finish(&transcript, &transcript_data, &transcript_len)) { CBB_cleanup(&transcript); OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); goto err; } sign_result = ssl_private_key_sign(ssl, ptr, &sig_len, max_sig_len, signature_algorithm, transcript_data, transcript_len); OPENSSL_free(transcript_data); } else { assert(ssl->state == SSL3_ST_SW_KEY_EXCH_B); sign_result = ssl_private_key_complete(ssl, ptr, &sig_len, max_sig_len); } switch (sign_result) { case ssl_private_key_success: if (!CBB_did_write(&child, sig_len)) { goto err; } break; case ssl_private_key_failure: goto err; case ssl_private_key_retry: ssl->rwstate = SSL_PRIVATE_KEY_OPERATION; ssl->state = SSL3_ST_SW_KEY_EXCH_B; goto err; } } if (!ssl->method->finish_message(ssl, &cbb)) { goto err; } OPENSSL_free(ssl->s3->tmp.server_params); ssl->s3->tmp.server_params = NULL; ssl->s3->tmp.server_params_len = 0; ssl->state = SSL3_ST_SW_KEY_EXCH_C; return ssl->method->write_message(ssl); err: CBB_cleanup(&cbb); return -1; } static int add_cert_types(SSL *ssl, CBB *cbb) { /* Get configured signature algorithms. */ int have_rsa_sign = 0; int have_ecdsa_sign = 0; const uint16_t *sig_algs; size_t sig_algs_len = tls12_get_psigalgs(ssl, &sig_algs); for (size_t i = 0; i < sig_algs_len; i++) { switch (sig_algs[i]) { case SSL_SIGN_RSA_PKCS1_SHA512: case SSL_SIGN_RSA_PKCS1_SHA384: case SSL_SIGN_RSA_PKCS1_SHA256: case SSL_SIGN_RSA_PKCS1_SHA1: have_rsa_sign = 1; break; case SSL_SIGN_ECDSA_SECP521R1_SHA512: case SSL_SIGN_ECDSA_SECP384R1_SHA384: case SSL_SIGN_ECDSA_SECP256R1_SHA256: case SSL_SIGN_ECDSA_SHA1: have_ecdsa_sign = 1; break; } } if (have_rsa_sign && !CBB_add_u8(cbb, SSL3_CT_RSA_SIGN)) { return 0; } /* ECDSA certs can be used with RSA cipher suites as well so we don't need to * check for SSL_kECDH or SSL_kECDHE. */ if (ssl->version >= TLS1_VERSION && have_ecdsa_sign && !CBB_add_u8(cbb, TLS_CT_ECDSA_SIGN)) { return 0; } return 1; } static int ssl3_send_certificate_request(SSL *ssl) { if (ssl->state == SSL3_ST_SW_CERT_REQ_B) { return ssl->method->write_message(ssl); } CBB cbb, body, cert_types, sigalgs_cbb; if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_CERTIFICATE_REQUEST) || !CBB_add_u8_length_prefixed(&body, &cert_types) || !add_cert_types(ssl, &cert_types)) { goto err; } if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) { const uint16_t *sigalgs; size_t num_sigalgs = tls12_get_psigalgs(ssl, &sigalgs); if (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb)) { goto err; } for (size_t i = 0; i < num_sigalgs; i++) { if (!CBB_add_u16(&sigalgs_cbb, sigalgs[i])) { goto err; } } } if (!ssl_add_client_CA_list(ssl, &body) || !ssl->method->finish_message(ssl, &cbb)) { goto err; } ssl->state = SSL3_ST_SW_CERT_REQ_B; return ssl->method->write_message(ssl); err: OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); CBB_cleanup(&cbb); return -1; } static int ssl3_send_server_hello_done(SSL *ssl) { if (ssl->state == SSL3_ST_SW_SRVR_DONE_B) { return ssl->method->write_message(ssl); } CBB cbb, body; if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_SERVER_HELLO_DONE) || !ssl->method->finish_message(ssl, &cbb)) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); CBB_cleanup(&cbb); return -1; } ssl->state = SSL3_ST_SW_SRVR_DONE_B; return ssl->method->write_message(ssl); } static int ssl3_get_client_certificate(SSL *ssl) { assert(ssl->s3->tmp.cert_request); int msg_ret = ssl->method->ssl_get_message(ssl, -1, ssl_hash_message); 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. */ ssl->s3->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; } CBS certificate_msg; CBS_init(&certificate_msg, ssl->init_msg, ssl->init_num); uint8_t alert; STACK_OF(X509) *chain = ssl_parse_cert_chain( ssl, &alert, ssl->ctx->retain_only_sha256_of_client_certs ? ssl->s3->new_session->peer_sha256 : NULL, &certificate_msg); if (chain == NULL) { ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); goto err; } if (CBS_len(&certificate_msg) != 0) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); goto err; } if (sk_X509_num(chain) == 0) { /* No client certificate so the handshake buffer may be discarded. */ ssl3_free_handshake_buffer(ssl); /* 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); goto err; } 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); goto err; } /* 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. */ ssl->s3->new_session->verify_result = X509_V_OK; } else { /* The hash would have been filled in. */ if (ssl->ctx->retain_only_sha256_of_client_certs) { ssl->s3->new_session->peer_sha256_valid = 1; } if (!ssl_verify_cert_chain(ssl, &ssl->s3->new_session->verify_result, chain)) { goto err; } } X509_free(ssl->s3->new_session->peer); ssl->s3->new_session->peer = sk_X509_shift(chain); sk_X509_pop_free(ssl->s3->new_session->cert_chain, X509_free); ssl->s3->new_session->cert_chain = chain; /* Inconsistency alert: cert_chain does *not* include the peer's own * certificate, while we do include it in s3_clnt.c */ return 1; err: sk_X509_pop_free(chain, X509_free); return -1; } static int ssl3_get_client_key_exchange(SSL *ssl) { int al; CBS client_key_exchange; uint32_t alg_k; uint32_t alg_a; uint8_t *premaster_secret = NULL; size_t premaster_secret_len = 0; uint8_t *decrypt_buf = NULL; unsigned psk_len = 0; uint8_t psk[PSK_MAX_PSK_LEN]; if (ssl->state == SSL3_ST_SR_KEY_EXCH_A) { int ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CLIENT_KEY_EXCHANGE, ssl_hash_message); if (ret <= 0) { return ret; } } CBS_init(&client_key_exchange, ssl->init_msg, ssl->init_num); alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey; alg_a = ssl->s3->tmp.new_cipher->algorithm_auth; /* If using a PSK key exchange, prepare the pre-shared key. */ 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); al = SSL_AD_DECODE_ERROR; goto f_err; } if (ssl->psk_server_callback == NULL) { OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_NO_SERVER_CB); al = SSL_AD_INTERNAL_ERROR; goto f_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); al = SSL_AD_ILLEGAL_PARAMETER; goto f_err; } if (!CBS_strdup(&psk_identity, &ssl->s3->new_session->psk_identity)) { al = SSL_AD_INTERNAL_ERROR; OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto f_err; } /* Look up the key for the identity. */ psk_len = ssl->psk_server_callback(ssl, ssl->s3->new_session->psk_identity, psk, sizeof(psk)); if (psk_len > PSK_MAX_PSK_LEN) { OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); al = SSL_AD_INTERNAL_ERROR; goto f_err; } else if (psk_len == 0) { /* PSK related to the given identity not found */ OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND); al = SSL_AD_UNKNOWN_PSK_IDENTITY; goto f_err; } } /* Depending on the key exchange method, compute |premaster_secret| and * |premaster_secret_len|. */ if (alg_k & SSL_kRSA) { /* Allocate a buffer large enough for an RSA decryption. */ const size_t rsa_size = ssl_private_key_max_signature_len(ssl); decrypt_buf = OPENSSL_malloc(rsa_size); if (decrypt_buf == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } enum ssl_private_key_result_t decrypt_result; size_t decrypt_len; if (ssl->state == SSL3_ST_SR_KEY_EXCH_A) { if (!ssl_has_private_key(ssl) || ssl_private_key_type(ssl) != NID_rsaEncryption) { al = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_RSA_CERTIFICATE); goto f_err; } 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) { al = SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG); goto f_err; } } else { encrypted_premaster_secret = client_key_exchange; } /* Decrypt with no padding. PKCS#1 padding will be removed as part of the * timing-sensitive code below. */ decrypt_result = ssl_private_key_decrypt( ssl, decrypt_buf, &decrypt_len, rsa_size, CBS_data(&encrypted_premaster_secret), CBS_len(&encrypted_premaster_secret)); } else { assert(ssl->state == SSL3_ST_SR_KEY_EXCH_B); /* Complete async decrypt. */ decrypt_result = ssl_private_key_complete(ssl, decrypt_buf, &decrypt_len, rsa_size); } switch (decrypt_result) { case ssl_private_key_success: break; case ssl_private_key_failure: goto err; case ssl_private_key_retry: ssl->rwstate = SSL_PRIVATE_KEY_OPERATION; ssl->state = SSL3_ST_SR_KEY_EXCH_B; goto err; } if (decrypt_len != rsa_size) { al = SSL_AD_DECRYPT_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED); goto f_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 = 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) { al = SSL_AD_DECRYPT_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED); goto f_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)(ssl->client_version >> 8)); good &= constant_time_eq_8(decrypt_buf[padding_len + 1], (unsigned)(ssl->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|SSL_kDHE|SSL_kCECPQ1)) { /* Parse the ClientKeyExchange. */ CBS peer_key; if (!SSL_ECDH_CTX_get_key(&ssl->s3->tmp.ecdh_ctx, &client_key_exchange, &peer_key) || CBS_len(&client_key_exchange) != 0) { al = SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); goto f_err; } /* Compute the premaster. */ uint8_t alert; if (!SSL_ECDH_CTX_finish(&ssl->s3->tmp.ecdh_ctx, &premaster_secret, &premaster_secret_len, &alert, CBS_data(&peer_key), CBS_len(&peer_key))) { al = alert; goto f_err; } /* The key exchange state may now be discarded. */ SSL_ECDH_CTX_cleanup(&ssl->s3->tmp.ecdh_ctx); } else if (alg_k & SSL_kPSK) { /* For 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 = OPENSSL_malloc(premaster_secret_len); if (premaster_secret == NULL) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); goto err; } memset(premaster_secret, 0, premaster_secret_len); } else { al = SSL_AD_HANDSHAKE_FAILURE; OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_TYPE); goto f_err; } /* For a PSK cipher suite, the actual pre-master secret is combined with the * pre-shared key. */ if (alg_a & SSL_aPSK) { CBB new_premaster, child; uint8_t *new_data; size_t new_len; CBB_zero(&new_premaster); if (!CBB_init(&new_premaster, 2 + psk_len + 2 + premaster_secret_len) || !CBB_add_u16_length_prefixed(&new_premaster, &child) || !CBB_add_bytes(&child, premaster_secret, premaster_secret_len) || !CBB_add_u16_length_prefixed(&new_premaster, &child) || !CBB_add_bytes(&child, psk, psk_len) || !CBB_finish(&new_premaster, &new_data, &new_len)) { OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); CBB_cleanup(&new_premaster); goto err; } OPENSSL_cleanse(premaster_secret, premaster_secret_len); OPENSSL_free(premaster_secret); premaster_secret = new_data; premaster_secret_len = new_len; } /* Compute the master secret */ ssl->s3->new_session->master_key_length = tls1_generate_master_secret( ssl, ssl->s3->new_session->master_key, premaster_secret, premaster_secret_len); if (ssl->s3->new_session->master_key_length == 0) { goto err; } ssl->s3->new_session->extended_master_secret = ssl->s3->tmp.extended_master_secret; OPENSSL_cleanse(premaster_secret, premaster_secret_len); OPENSSL_free(premaster_secret); return 1; f_err: ssl3_send_alert(ssl, SSL3_AL_FATAL, al); 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 *ssl) { int al, ret = 0; CBS certificate_verify, signature; X509 *peer = ssl->s3->new_session->peer; EVP_PKEY *pkey = NULL; /* Only RSA and ECDSA client certificates are supported, so a * CertificateVerify is required if and only if there's a client certificate. * */ if (peer == NULL) { ssl3_free_handshake_buffer(ssl); return 1; } int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CERTIFICATE_VERIFY, ssl_dont_hash_message); if (msg_ret <= 0) { return msg_ret; } /* Filter out unsupported certificate types. */ pkey = X509_get_pubkey(peer); if (pkey == NULL) { goto err; } 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)) { al = SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); goto f_err; } if (!tls12_check_peer_sigalg(ssl, &al, signature_algorithm)) { goto f_err; } ssl->s3->tmp.peer_signature_algorithm = signature_algorithm; } else if (pkey->type == EVP_PKEY_RSA) { signature_algorithm = SSL_SIGN_RSA_PKCS1_MD5_SHA1; } else if (pkey->type == EVP_PKEY_EC) { signature_algorithm = SSL_SIGN_ECDSA_SHA1; } else { al = SSL_AD_UNSUPPORTED_CERTIFICATE; OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE); goto f_err; } /* Parse and verify the signature. */ if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) || CBS_len(&certificate_verify) != 0) { al = SSL_AD_DECODE_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); goto f_err; } 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) { const EVP_MD *md; uint8_t digest[EVP_MAX_MD_SIZE]; size_t digest_len; if (!ssl3_cert_verify_hash(ssl, &md, digest, &digest_len, signature_algorithm)) { goto err; } EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pkey, NULL); sig_ok = pctx != NULL && EVP_PKEY_verify_init(pctx) && EVP_PKEY_CTX_set_signature_md(pctx, md) && EVP_PKEY_verify(pctx, CBS_data(&signature), CBS_len(&signature), digest, digest_len); EVP_PKEY_CTX_free(pctx); } else { sig_ok = ssl_public_key_verify( ssl, CBS_data(&signature), CBS_len(&signature), signature_algorithm, pkey, (const uint8_t *)ssl->s3->handshake_buffer->data, ssl->s3->handshake_buffer->length); } #if defined(BORINGSSL_UNSAFE_FUZZER_MODE) sig_ok = 1; ERR_clear_error(); #endif if (!sig_ok) { al = SSL_AD_DECRYPT_ERROR; OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE); goto f_err; } /* The handshake buffer is no longer necessary, and we may hash the current * message.*/ ssl3_free_handshake_buffer(ssl); if (!ssl->method->hash_current_message(ssl)) { goto err; } ret = 1; if (0) { f_err: ssl3_send_alert(ssl, SSL3_AL_FATAL, al); } err: EVP_PKEY_free(pkey); return ret; } /* 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 *ssl) { int ret = ssl->method->ssl_get_message(ssl, SSL3_MT_NEXT_PROTO, ssl_hash_message); if (ret <= 0) { return ret; } 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 *ssl) { int ret = -1; uint8_t channel_id_hash[EVP_MAX_MD_SIZE]; size_t channel_id_hash_len; const uint8_t *p; uint16_t extension_type; EC_GROUP *p256 = NULL; EC_KEY *key = NULL; EC_POINT *point = NULL; ECDSA_SIG sig; BIGNUM x, y; CBS encrypted_extensions, extension; int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CHANNEL_ID, ssl_dont_hash_message); if (msg_ret <= 0) { return msg_ret; } /* Before incorporating the EncryptedExtensions message to the handshake * hash, compute the hash that should have been signed. */ if (!tls1_channel_id_hash(ssl, channel_id_hash, &channel_id_hash_len)) { return -1; } assert(channel_id_hash_len == SHA256_DIGEST_LENGTH); if (!ssl->method->hash_current_message(ssl)) { return -1; } CBS_init(&encrypted_extensions, ssl->init_msg, ssl->init_num); /* EncryptedExtensions could include multiple extensions, but the only * extension that could be negotiated is Channel ID, so there can only be one * entry. */ if (!CBS_get_u16(&encrypted_extensions, &extension_type) || !CBS_get_u16_length_prefixed(&encrypted_extensions, &extension) || CBS_len(&encrypted_extensions) != 0 || extension_type != TLSEXT_TYPE_channel_id || CBS_len(&extension) != TLSEXT_CHANNEL_ID_SIZE) { OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); return -1; } p256 = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1); if (!p256) { OPENSSL_PUT_ERROR(SSL, SSL_R_NO_P256_SUPPORT); return -1; } BN_init(&x); BN_init(&y); sig.r = BN_new(); sig.s = BN_new(); if (sig.r == NULL || sig.s == NULL) { goto err; } p = CBS_data(&extension); if (BN_bin2bn(p + 0, 32, &x) == NULL || BN_bin2bn(p + 32, 32, &y) == NULL || BN_bin2bn(p + 64, 32, sig.r) == NULL || BN_bin2bn(p + 96, 32, sig.s) == NULL) { goto err; } point = EC_POINT_new(p256); if (!point || !EC_POINT_set_affine_coordinates_GFp(p256, point, &x, &y, NULL)) { goto err; } key = EC_KEY_new(); if (!key || !EC_KEY_set_group(key, p256) || !EC_KEY_set_public_key(key, point)) { goto err; } /* We stored the handshake hash in |tlsext_channel_id| the first time that we * were called. */ int sig_ok = ECDSA_do_verify(channel_id_hash, channel_id_hash_len, &sig, key); #if defined(BORINGSSL_UNSAFE_FUZZER_MODE) sig_ok = 1; #endif if (!sig_ok) { OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_SIGNATURE_INVALID); ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR); ssl->s3->tlsext_channel_id_valid = 0; goto err; } memcpy(ssl->s3->tlsext_channel_id, p, 64); ret = 1; err: BN_free(&x); BN_free(&y); BN_free(sig.r); BN_free(sig.s); EC_KEY_free(key); EC_POINT_free(point); EC_GROUP_free(p256); return ret; } static int ssl3_send_new_session_ticket(SSL *ssl) { if (ssl->state == SSL3_ST_SW_SESSION_TICKET_B) { return ssl->method->write_message(ssl); } CBB cbb, body, ticket; if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_NEW_SESSION_TICKET) || /* Ticket lifetime hint (advisory only): We leave this unspecified for * resumed session (for simplicity), and guess that tickets for new * sessions will live as long as their sessions. */ !CBB_add_u32(&body, ssl->session != NULL ? 0 : ssl->s3->new_session->timeout) || !CBB_add_u16_length_prefixed(&body, &ticket) || !ssl_encrypt_ticket(ssl, &ticket, ssl->session != NULL ? ssl->session : ssl->s3->new_session) || !ssl->method->finish_message(ssl, &cbb)) { return 0; } ssl->state = SSL3_ST_SW_SESSION_TICKET_B; return ssl->method->write_message(ssl); }