| /* 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 <openssl/ssl.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <utility> |
| |
| #include <openssl/aead.h> |
| #include <openssl/bn.h> |
| #include <openssl/bytestring.h> |
| #include <openssl/ec_key.h> |
| #include <openssl/ecdsa.h> |
| #include <openssl/err.h> |
| #include <openssl/evp.h> |
| #include <openssl/hpke.h> |
| #include <openssl/md5.h> |
| #include <openssl/mem.h> |
| #include <openssl/rand.h> |
| #include <openssl/sha.h> |
| |
| #include "../crypto/internal.h" |
| #include "internal.h" |
| |
| |
| BSSL_NAMESPACE_BEGIN |
| |
| enum ssl_client_hs_state_t { |
| state_start_connect = 0, |
| state_enter_early_data, |
| state_early_reverify_server_certificate, |
| state_read_hello_verify_request, |
| state_read_server_hello, |
| state_tls13, |
| state_read_server_certificate, |
| state_read_certificate_status, |
| state_verify_server_certificate, |
| state_reverify_server_certificate, |
| state_read_server_key_exchange, |
| state_read_certificate_request, |
| state_read_server_hello_done, |
| state_send_client_certificate, |
| state_send_client_key_exchange, |
| state_send_client_certificate_verify, |
| state_send_client_finished, |
| state_finish_flight, |
| state_read_session_ticket, |
| state_process_change_cipher_spec, |
| state_read_server_finished, |
| state_finish_client_handshake, |
| state_done, |
| }; |
| |
| // ssl_get_client_disabled sets |*out_mask_a| and |*out_mask_k| to masks of |
| // disabled algorithms. |
| static void ssl_get_client_disabled(const SSL_HANDSHAKE *hs, |
| uint32_t *out_mask_a, |
| uint32_t *out_mask_k) { |
| *out_mask_a = 0; |
| *out_mask_k = 0; |
| |
| // PSK requires a client callback. |
| if (hs->config->psk_client_callback == NULL) { |
| *out_mask_a |= SSL_aPSK; |
| *out_mask_k |= SSL_kPSK; |
| } |
| } |
| |
| static bool ssl_write_client_cipher_list(const SSL_HANDSHAKE *hs, CBB *out, |
| ssl_client_hello_type_t type) { |
| const SSL *const ssl = hs->ssl; |
| uint32_t mask_a, mask_k; |
| ssl_get_client_disabled(hs, &mask_a, &mask_k); |
| |
| CBB child; |
| if (!CBB_add_u16_length_prefixed(out, &child)) { |
| return false; |
| } |
| |
| // Add a fake cipher suite. See RFC 8701. |
| if (ssl->ctx->grease_enabled && |
| !CBB_add_u16(&child, ssl_get_grease_value(hs, ssl_grease_cipher))) { |
| return false; |
| } |
| |
| // Add TLS 1.3 ciphers. Order ChaCha20-Poly1305 relative to AES-GCM based on |
| // hardware support. |
| if (hs->max_version >= TLS1_3_VERSION) { |
| if (!EVP_has_aes_hardware() && |
| !CBB_add_u16(&child, TLS1_CK_CHACHA20_POLY1305_SHA256 & 0xffff)) { |
| return false; |
| } |
| if (!CBB_add_u16(&child, TLS1_CK_AES_128_GCM_SHA256 & 0xffff) || |
| !CBB_add_u16(&child, TLS1_CK_AES_256_GCM_SHA384 & 0xffff)) { |
| return false; |
| } |
| if (EVP_has_aes_hardware() && |
| !CBB_add_u16(&child, TLS1_CK_CHACHA20_POLY1305_SHA256 & 0xffff)) { |
| return false; |
| } |
| } |
| |
| if (hs->min_version < TLS1_3_VERSION && type != ssl_client_hello_inner) { |
| bool any_enabled = false; |
| for (const SSL_CIPHER *cipher : SSL_get_ciphers(ssl)) { |
| // Skip disabled ciphers |
| if ((cipher->algorithm_mkey & mask_k) || |
| (cipher->algorithm_auth & mask_a)) { |
| continue; |
| } |
| if (SSL_CIPHER_get_min_version(cipher) > hs->max_version || |
| SSL_CIPHER_get_max_version(cipher) < hs->min_version) { |
| continue; |
| } |
| any_enabled = true; |
| if (!CBB_add_u16(&child, SSL_CIPHER_get_protocol_id(cipher))) { |
| return false; |
| } |
| } |
| |
| // If all ciphers were disabled, return the error to the caller. |
| if (!any_enabled && hs->max_version < TLS1_3_VERSION) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHERS_AVAILABLE); |
| return false; |
| } |
| } |
| |
| if (ssl->mode & SSL_MODE_SEND_FALLBACK_SCSV) { |
| if (!CBB_add_u16(&child, SSL3_CK_FALLBACK_SCSV & 0xffff)) { |
| return false; |
| } |
| } |
| |
| return CBB_flush(out); |
| } |
| |
| bool ssl_write_client_hello_without_extensions(const SSL_HANDSHAKE *hs, |
| CBB *cbb, |
| ssl_client_hello_type_t type, |
| bool empty_session_id) { |
| const SSL *const ssl = hs->ssl; |
| CBB child; |
| if (!CBB_add_u16(cbb, hs->client_version) || |
| !CBB_add_bytes(cbb, |
| type == ssl_client_hello_inner ? hs->inner_client_random |
| : ssl->s3->client_random, |
| SSL3_RANDOM_SIZE) || |
| !CBB_add_u8_length_prefixed(cbb, &child)) { |
| return false; |
| } |
| |
| // Do not send a session ID on renegotiation. |
| if (!ssl->s3->initial_handshake_complete && |
| !empty_session_id && |
| !CBB_add_bytes(&child, hs->session_id, hs->session_id_len)) { |
| return false; |
| } |
| |
| if (SSL_is_dtls(ssl)) { |
| if (!CBB_add_u8_length_prefixed(cbb, &child) || |
| !CBB_add_bytes(&child, ssl->d1->cookie, ssl->d1->cookie_len)) { |
| return false; |
| } |
| } |
| |
| if (!ssl_write_client_cipher_list(hs, cbb, type) || |
| !CBB_add_u8(cbb, 1 /* one compression method */) || |
| !CBB_add_u8(cbb, 0 /* null compression */)) { |
| return false; |
| } |
| return true; |
| } |
| |
| bool ssl_add_client_hello(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| ScopedCBB cbb; |
| CBB body; |
| ssl_client_hello_type_t type = hs->selected_ech_config |
| ? ssl_client_hello_outer |
| : ssl_client_hello_unencrypted; |
| bool needs_psk_binder; |
| Array<uint8_t> msg; |
| if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CLIENT_HELLO) || |
| !ssl_write_client_hello_without_extensions(hs, &body, type, |
| /*empty_session_id*/ false) || |
| !ssl_add_clienthello_tlsext(hs, &body, /*out_encoded=*/nullptr, |
| &needs_psk_binder, type, CBB_len(&body), |
| /*omit_ech_len=*/0) || |
| !ssl->method->finish_message(ssl, cbb.get(), &msg)) { |
| return false; |
| } |
| |
| // Now that the length prefixes have been computed, fill in the placeholder |
| // PSK binder. |
| if (needs_psk_binder) { |
| // ClientHelloOuter cannot have a PSK binder. Otherwise the |
| // ClientHellOuterAAD computation would break. |
| assert(type != ssl_client_hello_outer); |
| if (!tls13_write_psk_binder(hs, hs->transcript, MakeSpan(msg), |
| /*out_binder_len=*/0)) { |
| return false; |
| } |
| } |
| |
| return ssl->method->add_message(ssl, std::move(msg)); |
| } |
| |
| static bool parse_server_version(const SSL_HANDSHAKE *hs, uint16_t *out_version, |
| uint8_t *out_alert, |
| const ParsedServerHello &server_hello) { |
| // If the outer version is not TLS 1.2, use it. |
| // TODO(davidben): This function doesn't quite match the RFC8446 formulation. |
| if (server_hello.legacy_version != TLS1_2_VERSION) { |
| *out_version = server_hello.legacy_version; |
| return true; |
| } |
| |
| SSLExtension supported_versions(TLSEXT_TYPE_supported_versions); |
| CBS extensions = server_hello.extensions; |
| if (!ssl_parse_extensions(&extensions, out_alert, {&supported_versions}, |
| /*ignore_unknown=*/true)) { |
| return false; |
| } |
| |
| if (!supported_versions.present) { |
| *out_version = server_hello.legacy_version; |
| return true; |
| } |
| |
| if (!CBS_get_u16(&supported_versions.data, out_version) || |
| CBS_len(&supported_versions.data) != 0) { |
| *out_alert = SSL_AD_DECODE_ERROR; |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // should_offer_early_data returns |ssl_early_data_accepted| if |hs| should |
| // offer early data, and some other reason code otherwise. |
| static ssl_early_data_reason_t should_offer_early_data( |
| const SSL_HANDSHAKE *hs) { |
| const SSL *const ssl = hs->ssl; |
| assert(!ssl->server); |
| if (!ssl->enable_early_data) { |
| return ssl_early_data_disabled; |
| } |
| |
| if (hs->max_version < TLS1_3_VERSION) { |
| // We discard inapplicable sessions, so this is redundant with the session |
| // checks below, but reporting that TLS 1.3 was disabled is more useful. |
| return ssl_early_data_protocol_version; |
| } |
| |
| if (ssl->session == nullptr) { |
| return ssl_early_data_no_session_offered; |
| } |
| |
| if (ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION || |
| ssl->session->ticket_max_early_data == 0) { |
| return ssl_early_data_unsupported_for_session; |
| } |
| |
| if (!ssl->session->early_alpn.empty()) { |
| if (!ssl_is_alpn_protocol_allowed(hs, ssl->session->early_alpn)) { |
| // Avoid reporting a confusing value in |SSL_get0_alpn_selected|. |
| return ssl_early_data_alpn_mismatch; |
| } |
| |
| // If the previous connection negotiated ALPS, only offer 0-RTT when the |
| // local are settings are consistent with what we'd offer for this |
| // connection. |
| if (ssl->session->has_application_settings) { |
| Span<const uint8_t> settings; |
| if (!ssl_get_local_application_settings(hs, &settings, |
| ssl->session->early_alpn) || |
| settings != ssl->session->local_application_settings) { |
| return ssl_early_data_alps_mismatch; |
| } |
| } |
| } |
| |
| // Early data has not yet been accepted, but we use it as a success code. |
| return ssl_early_data_accepted; |
| } |
| |
| void ssl_done_writing_client_hello(SSL_HANDSHAKE *hs) { |
| hs->ech_client_bytes.Reset(); |
| hs->cookie.Reset(); |
| hs->key_share_bytes.Reset(); |
| } |
| |
| static enum ssl_hs_wait_t do_start_connect(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_START, 1); |
| // |session_reused| must be reset in case this is a renegotiation. |
| ssl->s3->session_reused = false; |
| |
| // Freeze the version range. |
| if (!ssl_get_version_range(hs, &hs->min_version, &hs->max_version)) { |
| return ssl_hs_error; |
| } |
| |
| uint8_t ech_enc[EVP_HPKE_MAX_ENC_LENGTH]; |
| size_t ech_enc_len; |
| if (!ssl_select_ech_config(hs, ech_enc, &ech_enc_len)) { |
| return ssl_hs_error; |
| } |
| |
| // Always advertise the ClientHello version from the original maximum version, |
| // even on renegotiation. The static RSA key exchange uses this field, and |
| // some servers fail when it changes across handshakes. |
| if (SSL_is_dtls(hs->ssl)) { |
| hs->client_version = |
| hs->max_version >= TLS1_2_VERSION ? DTLS1_2_VERSION : DTLS1_VERSION; |
| } else { |
| hs->client_version = |
| hs->max_version >= TLS1_2_VERSION ? TLS1_2_VERSION : hs->max_version; |
| } |
| |
| // If the configured session has expired or is not usable, drop it. We also do |
| // not offer sessions on renegotiation. |
| if (ssl->session != nullptr) { |
| if (ssl->session->is_server || |
| !ssl_supports_version(hs, ssl->session->ssl_version) || |
| // Do not offer TLS 1.2 sessions with ECH. ClientHelloInner does not |
| // offer TLS 1.2, and the cleartext session ID may leak the server |
| // identity. |
| (hs->selected_ech_config && |
| ssl_session_protocol_version(ssl->session.get()) < TLS1_3_VERSION) || |
| !SSL_SESSION_is_resumable(ssl->session.get()) || |
| !ssl_session_is_time_valid(ssl, ssl->session.get()) || |
| (ssl->quic_method != nullptr) != ssl->session->is_quic || |
| ssl->s3->initial_handshake_complete) { |
| ssl_set_session(ssl, nullptr); |
| } |
| } |
| |
| if (!RAND_bytes(ssl->s3->client_random, sizeof(ssl->s3->client_random))) { |
| return ssl_hs_error; |
| } |
| if (hs->selected_ech_config && |
| !RAND_bytes(hs->inner_client_random, sizeof(hs->inner_client_random))) { |
| return ssl_hs_error; |
| } |
| |
| // Never send a session ID in QUIC. QUIC uses TLS 1.3 at a minimum and |
| // disables TLS 1.3 middlebox compatibility mode. |
| if (ssl->quic_method == nullptr) { |
| const bool has_id_session = ssl->session != nullptr && |
| ssl->session->session_id_length > 0 && |
| ssl->session->ticket.empty(); |
| const bool has_ticket_session = |
| ssl->session != nullptr && !ssl->session->ticket.empty(); |
| if (has_id_session) { |
| hs->session_id_len = ssl->session->session_id_length; |
| OPENSSL_memcpy(hs->session_id, ssl->session->session_id, |
| hs->session_id_len); |
| } else if (has_ticket_session || hs->max_version >= TLS1_3_VERSION) { |
| // Send a random session ID. TLS 1.3 always sends one, and TLS 1.2 session |
| // tickets require a placeholder value to signal resumption. |
| hs->session_id_len = sizeof(hs->session_id); |
| if (!RAND_bytes(hs->session_id, hs->session_id_len)) { |
| return ssl_hs_error; |
| } |
| } |
| } |
| |
| ssl_early_data_reason_t reason = should_offer_early_data(hs); |
| if (reason != ssl_early_data_accepted) { |
| ssl->s3->early_data_reason = reason; |
| } else { |
| hs->early_data_offered = true; |
| } |
| |
| if (!ssl_setup_key_shares(hs, /*override_group_id=*/0) || |
| !ssl_setup_extension_permutation(hs) || |
| !ssl_encrypt_client_hello(hs, MakeConstSpan(ech_enc, ech_enc_len)) || |
| !ssl_add_client_hello(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_enter_early_data; |
| return ssl_hs_flush; |
| } |
| |
| static enum ssl_hs_wait_t do_enter_early_data(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (SSL_is_dtls(ssl)) { |
| hs->state = state_read_hello_verify_request; |
| return ssl_hs_ok; |
| } |
| |
| if (!hs->early_data_offered) { |
| hs->state = state_read_server_hello; |
| return ssl_hs_ok; |
| } |
| |
| ssl->s3->aead_write_ctx->SetVersionIfNullCipher(ssl->session->ssl_version); |
| if (!ssl->method->add_change_cipher_spec(ssl)) { |
| return ssl_hs_error; |
| } |
| |
| if (!tls13_init_early_key_schedule(hs, ssl->session.get()) || |
| !tls13_derive_early_secret(hs)) { |
| return ssl_hs_error; |
| } |
| |
| // Stash the early data session, so connection properties may be queried out |
| // of it. |
| hs->early_session = UpRef(ssl->session); |
| hs->state = state_early_reverify_server_certificate; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_early_reverify_server_certificate(SSL_HANDSHAKE *hs) { |
| if (hs->ssl->ctx->reverify_on_resume) { |
| // Don't send an alert on error. The alert be in early data, which the |
| // server may not accept anyway. It would also be a mismatch between QUIC |
| // and TCP because the QUIC early keys are deferred below. |
| // |
| // TODO(davidben): The client behavior should be to verify the certificate |
| // before deciding whether to offer the session and, if invalid, decline to |
| // send the session. |
| switch (ssl_reverify_peer_cert(hs, /*send_alert=*/false)) { |
| case ssl_verify_ok: |
| break; |
| case ssl_verify_invalid: |
| return ssl_hs_error; |
| case ssl_verify_retry: |
| hs->state = state_early_reverify_server_certificate; |
| return ssl_hs_certificate_verify; |
| } |
| } |
| |
| // Defer releasing the 0-RTT key to after certificate reverification, so the |
| // QUIC implementation does not accidentally write data too early. |
| if (!tls13_set_traffic_key(hs->ssl, ssl_encryption_early_data, evp_aead_seal, |
| hs->early_session.get(), |
| hs->early_traffic_secret())) { |
| return ssl_hs_error; |
| } |
| |
| hs->in_early_data = true; |
| hs->can_early_write = true; |
| hs->state = state_read_server_hello; |
| return ssl_hs_early_return; |
| } |
| |
| static enum ssl_hs_wait_t do_read_hello_verify_request(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| assert(SSL_is_dtls(ssl)); |
| |
| // When implementing DTLS 1.3, we need to handle the interactions between |
| // HelloVerifyRequest, DTLS 1.3's HelloVerifyRequest removal, and ECH. |
| assert(hs->max_version < TLS1_3_VERSION); |
| |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (msg.type != DTLS1_MT_HELLO_VERIFY_REQUEST) { |
| hs->state = state_read_server_hello; |
| return ssl_hs_ok; |
| } |
| |
| CBS hello_verify_request = msg.body, cookie; |
| uint16_t server_version; |
| if (!CBS_get_u16(&hello_verify_request, &server_version) || |
| !CBS_get_u8_length_prefixed(&hello_verify_request, &cookie) || |
| CBS_len(&cookie) > sizeof(ssl->d1->cookie) || |
| CBS_len(&hello_verify_request) != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| OPENSSL_memcpy(ssl->d1->cookie, CBS_data(&cookie), CBS_len(&cookie)); |
| ssl->d1->cookie_len = CBS_len(&cookie); |
| |
| ssl->method->next_message(ssl); |
| |
| // DTLS resets the handshake buffer after HelloVerifyRequest. |
| if (!hs->transcript.Init()) { |
| return ssl_hs_error; |
| } |
| |
| if (!ssl_add_client_hello(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_read_server_hello; |
| return ssl_hs_flush; |
| } |
| |
| bool ssl_parse_server_hello(ParsedServerHello *out, uint8_t *out_alert, |
| const SSLMessage &msg) { |
| if (msg.type != SSL3_MT_SERVER_HELLO) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); |
| *out_alert = SSL_AD_UNEXPECTED_MESSAGE; |
| return false; |
| } |
| CBS body = msg.body; |
| if (!CBS_get_u16(&body, &out->legacy_version) || |
| !CBS_get_bytes(&body, &out->random, SSL3_RANDOM_SIZE) || |
| !CBS_get_u8_length_prefixed(&body, &out->session_id) || |
| CBS_len(&out->session_id) > SSL3_SESSION_ID_SIZE || |
| !CBS_get_u16(&body, &out->cipher_suite) || |
| !CBS_get_u8(&body, &out->compression_method)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| *out_alert = SSL_AD_DECODE_ERROR; |
| return false; |
| } |
| // In TLS 1.2 and below, empty extensions blocks may be omitted. In TLS 1.3, |
| // ServerHellos always have extensions, so this can be applied generically. |
| CBS_init(&out->extensions, nullptr, 0); |
| if ((CBS_len(&body) != 0 && |
| !CBS_get_u16_length_prefixed(&body, &out->extensions)) || |
| CBS_len(&body) != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| *out_alert = SSL_AD_DECODE_ERROR; |
| return false; |
| } |
| return true; |
| } |
| |
| static enum ssl_hs_wait_t do_read_server_hello(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_server_hello; |
| } |
| |
| ParsedServerHello server_hello; |
| uint16_t server_version; |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| if (!ssl_parse_server_hello(&server_hello, &alert, msg) || |
| !parse_server_version(hs, &server_version, &alert, server_hello)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| |
| if (!ssl_supports_version(hs, server_version)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION); |
| return ssl_hs_error; |
| } |
| |
| assert(ssl->s3->have_version == ssl->s3->initial_handshake_complete); |
| if (!ssl->s3->have_version) { |
| ssl->version = server_version; |
| // At this point, the connection's version is known and ssl->version is |
| // fixed. Begin enforcing the record-layer version. |
| ssl->s3->have_version = true; |
| ssl->s3->aead_write_ctx->SetVersionIfNullCipher(ssl->version); |
| } else if (server_version != ssl->version) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SSL_VERSION); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION); |
| return ssl_hs_error; |
| } |
| |
| if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) { |
| hs->state = state_tls13; |
| return ssl_hs_ok; |
| } |
| |
| // Clear some TLS 1.3 state that no longer needs to be retained. |
| hs->key_shares[0].reset(); |
| hs->key_shares[1].reset(); |
| ssl_done_writing_client_hello(hs); |
| |
| // A TLS 1.2 server would not know to skip the early data we offered. Report |
| // an error code sooner. The caller may use this error code to implement the |
| // fallback described in RFC 8446 appendix D.3. |
| if (hs->early_data_offered) { |
| // Disconnect early writes. This ensures subsequent |SSL_write| calls query |
| // the handshake which, in turn, will replay the error code rather than fail |
| // at the |write_shutdown| check. See https://crbug.com/1078515. |
| // TODO(davidben): Should all handshake errors do this? What about record |
| // decryption failures? |
| hs->can_early_write = false; |
| OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_ON_EARLY_DATA); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION); |
| return ssl_hs_error; |
| } |
| |
| // TLS 1.2 handshakes cannot accept ECH. |
| if (hs->selected_ech_config) { |
| ssl->s3->ech_status = ssl_ech_rejected; |
| } |
| |
| // Copy over the server random. |
| OPENSSL_memcpy(ssl->s3->server_random, CBS_data(&server_hello.random), |
| SSL3_RANDOM_SIZE); |
| |
| // Enforce the TLS 1.3 anti-downgrade feature. |
| if (!ssl->s3->initial_handshake_complete && |
| ssl_supports_version(hs, TLS1_3_VERSION)) { |
| static_assert( |
| sizeof(kTLS12DowngradeRandom) == sizeof(kTLS13DowngradeRandom), |
| "downgrade signals have different size"); |
| static_assert( |
| sizeof(kJDK11DowngradeRandom) == sizeof(kTLS13DowngradeRandom), |
| "downgrade signals have different size"); |
| auto suffix = |
| MakeConstSpan(ssl->s3->server_random, sizeof(ssl->s3->server_random)) |
| .subspan(SSL3_RANDOM_SIZE - sizeof(kTLS13DowngradeRandom)); |
| if (suffix == kTLS12DowngradeRandom || suffix == kTLS13DowngradeRandom || |
| suffix == kJDK11DowngradeRandom) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_TLS13_DOWNGRADE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| } |
| |
| // The cipher must be allowed in the selected version and enabled. |
| const SSL_CIPHER *cipher = SSL_get_cipher_by_value(server_hello.cipher_suite); |
| uint32_t mask_a, mask_k; |
| ssl_get_client_disabled(hs, &mask_a, &mask_k); |
| if (cipher == nullptr || |
| (cipher->algorithm_mkey & mask_k) || |
| (cipher->algorithm_auth & mask_a) || |
| SSL_CIPHER_get_min_version(cipher) > ssl_protocol_version(ssl) || |
| SSL_CIPHER_get_max_version(cipher) < ssl_protocol_version(ssl) || |
| !sk_SSL_CIPHER_find(SSL_get_ciphers(ssl), nullptr, cipher)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| |
| hs->new_cipher = cipher; |
| |
| if (hs->session_id_len != 0 && |
| CBS_mem_equal(&server_hello.session_id, hs->session_id, |
| hs->session_id_len)) { |
| // Echoing the ClientHello session ID in TLS 1.2, whether from the session |
| // or a synthetic one, indicates resumption. If there was no session (or if |
| // the session was only offered in ECH ClientHelloInner), this was the |
| // TLS 1.3 compatibility mode session ID. As we know this is not a session |
| // the server knows about, any server resuming it is in error. Reject the |
| // first connection deterministicly, rather than installing an invalid |
| // session into the session cache. https://crbug.com/796910 |
| if (ssl->session == nullptr || ssl->s3->ech_status == ssl_ech_rejected) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_SERVER_ECHOED_INVALID_SESSION_ID); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| if (ssl->session->ssl_version != ssl->version) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_VERSION_NOT_RETURNED); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| if (ssl->session->cipher != hs->new_cipher) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| if (!ssl_session_is_context_valid(hs, ssl->session.get())) { |
| // This is actually a client application bug. |
| OPENSSL_PUT_ERROR(SSL, |
| SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| // We never offer sessions on renegotiation. |
| assert(!ssl->s3->initial_handshake_complete); |
| ssl->s3->session_reused = true; |
| } else { |
| // The session wasn't resumed. Create a fresh SSL_SESSION to fill out. |
| ssl_set_session(ssl, NULL); |
| if (!ssl_get_new_session(hs)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| // Note: session_id could be empty. |
| hs->new_session->session_id_length = CBS_len(&server_hello.session_id); |
| OPENSSL_memcpy(hs->new_session->session_id, |
| CBS_data(&server_hello.session_id), |
| CBS_len(&server_hello.session_id)); |
| hs->new_session->cipher = hs->new_cipher; |
| } |
| |
| // Now that the cipher is known, initialize the handshake hash and hash the |
| // ServerHello. |
| if (!hs->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher) || |
| !ssl_hash_message(hs, msg)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| // If doing a full handshake, the server may request a client certificate |
| // which requires hashing the handshake transcript. Otherwise, the handshake |
| // buffer may be released. |
| if (ssl->session != NULL || |
| !ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| hs->transcript.FreeBuffer(); |
| } |
| |
| // Only the NULL compression algorithm is supported. |
| if (server_hello.compression_method != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| |
| if (!ssl_parse_serverhello_tlsext(hs, &server_hello.extensions)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT); |
| return ssl_hs_error; |
| } |
| |
| if (ssl->session != NULL && |
| hs->extended_master_secret != ssl->session->extended_master_secret) { |
| if (ssl->session->extended_master_secret) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION); |
| } else { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION); |
| } |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); |
| return ssl_hs_error; |
| } |
| |
| ssl->method->next_message(ssl); |
| |
| if (ssl->session != NULL) { |
| if (ssl->ctx->reverify_on_resume && |
| ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| hs->state = state_reverify_server_certificate; |
| } else { |
| hs->state = state_read_session_ticket; |
| } |
| return ssl_hs_ok; |
| } |
| |
| hs->state = state_read_server_certificate; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_tls13(SSL_HANDSHAKE *hs) { |
| enum ssl_hs_wait_t wait = tls13_client_handshake(hs); |
| if (wait == ssl_hs_ok) { |
| hs->state = state_finish_client_handshake; |
| return ssl_hs_ok; |
| } |
| |
| return wait; |
| } |
| |
| static enum ssl_hs_wait_t do_read_server_certificate(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| hs->state = state_read_certificate_status; |
| return ssl_hs_ok; |
| } |
| |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE) || |
| !ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| CBS body = msg.body; |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| if (!ssl_parse_cert_chain(&alert, &hs->new_session->certs, &hs->peer_pubkey, |
| NULL, &body, ssl->ctx->pool)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| |
| if (sk_CRYPTO_BUFFER_num(hs->new_session->certs.get()) == 0 || |
| CBS_len(&body) != 0 || |
| !ssl->ctx->x509_method->session_cache_objects(hs->new_session.get())) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| if (!ssl_check_leaf_certificate( |
| hs, hs->peer_pubkey.get(), |
| sk_CRYPTO_BUFFER_value(hs->new_session->certs.get(), 0))) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| |
| ssl->method->next_message(ssl); |
| |
| hs->state = state_read_certificate_status; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_certificate_status(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (!hs->certificate_status_expected) { |
| hs->state = state_verify_server_certificate; |
| return ssl_hs_ok; |
| } |
| |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (msg.type != SSL3_MT_CERTIFICATE_STATUS) { |
| // A server may send status_request in ServerHello and then change its mind |
| // about sending CertificateStatus. |
| hs->state = state_verify_server_certificate; |
| return ssl_hs_ok; |
| } |
| |
| if (!ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| CBS certificate_status = msg.body, ocsp_response; |
| uint8_t status_type; |
| if (!CBS_get_u8(&certificate_status, &status_type) || |
| status_type != TLSEXT_STATUSTYPE_ocsp || |
| !CBS_get_u24_length_prefixed(&certificate_status, &ocsp_response) || |
| CBS_len(&ocsp_response) == 0 || |
| CBS_len(&certificate_status) != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| hs->new_session->ocsp_response.reset( |
| CRYPTO_BUFFER_new_from_CBS(&ocsp_response, ssl->ctx->pool)); |
| if (hs->new_session->ocsp_response == nullptr) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| ssl->method->next_message(ssl); |
| |
| hs->state = state_verify_server_certificate; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_verify_server_certificate(SSL_HANDSHAKE *hs) { |
| if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| hs->state = state_read_server_key_exchange; |
| return ssl_hs_ok; |
| } |
| |
| switch (ssl_verify_peer_cert(hs)) { |
| case ssl_verify_ok: |
| break; |
| case ssl_verify_invalid: |
| return ssl_hs_error; |
| case ssl_verify_retry: |
| hs->state = state_verify_server_certificate; |
| return ssl_hs_certificate_verify; |
| } |
| |
| hs->state = state_read_server_key_exchange; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_reverify_server_certificate(SSL_HANDSHAKE *hs) { |
| assert(hs->ssl->ctx->reverify_on_resume); |
| |
| switch (ssl_reverify_peer_cert(hs, /*send_alert=*/true)) { |
| case ssl_verify_ok: |
| break; |
| case ssl_verify_invalid: |
| return ssl_hs_error; |
| case ssl_verify_retry: |
| hs->state = state_reverify_server_certificate; |
| return ssl_hs_certificate_verify; |
| } |
| |
| hs->state = state_read_session_ticket; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_server_key_exchange(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (msg.type != SSL3_MT_SERVER_KEY_EXCHANGE) { |
| // Some ciphers (pure PSK) have an optional ServerKeyExchange message. |
| if (ssl_cipher_requires_server_key_exchange(hs->new_cipher)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_read_certificate_request; |
| return ssl_hs_ok; |
| } |
| |
| if (!ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| uint32_t alg_k = hs->new_cipher->algorithm_mkey; |
| uint32_t alg_a = hs->new_cipher->algorithm_auth; |
| CBS server_key_exchange = msg.body; |
| if (alg_a & SSL_aPSK) { |
| CBS psk_identity_hint; |
| |
| // Each of the PSK key exchanges begins with a psk_identity_hint. |
| if (!CBS_get_u16_length_prefixed(&server_key_exchange, |
| &psk_identity_hint)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| // Store the PSK identity hint for the ClientKeyExchange. Assume that the |
| // maximum length of a PSK identity hint can be as long as the maximum |
| // length of a PSK identity. Also do not allow NULL characters; identities |
| // are saved as C strings. |
| // |
| // TODO(davidben): Should invalid hints be ignored? It's a hint rather than |
| // a specific identity. |
| if (CBS_len(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN || |
| CBS_contains_zero_byte(&psk_identity_hint)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); |
| return ssl_hs_error; |
| } |
| |
| // Save non-empty identity hints as a C string. Empty identity hints we |
| // treat as missing. Plain PSK makes it possible to send either no hint |
| // (omit ServerKeyExchange) or an empty hint, while ECDHE_PSK can only spell |
| // empty hint. Having different capabilities is odd, so we interpret empty |
| // and missing as identical. |
| char *raw = nullptr; |
| if (CBS_len(&psk_identity_hint) != 0 && |
| !CBS_strdup(&psk_identity_hint, &raw)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| hs->peer_psk_identity_hint.reset(raw); |
| } |
| |
| if (alg_k & SSL_kECDHE) { |
| // Parse the server parameters. |
| uint8_t group_type; |
| uint16_t group_id; |
| CBS point; |
| if (!CBS_get_u8(&server_key_exchange, &group_type) || |
| group_type != NAMED_CURVE_TYPE || |
| !CBS_get_u16(&server_key_exchange, &group_id) || |
| !CBS_get_u8_length_prefixed(&server_key_exchange, &point)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| hs->new_session->group_id = group_id; |
| |
| // Ensure the group is consistent with preferences. |
| if (!tls1_check_group_id(hs, group_id)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); |
| return ssl_hs_error; |
| } |
| |
| // Initialize ECDH and save the peer public key for later. |
| hs->key_shares[0] = SSLKeyShare::Create(group_id); |
| if (!hs->key_shares[0] || |
| !hs->peer_key.CopyFrom(point)) { |
| return ssl_hs_error; |
| } |
| } else if (!(alg_k & SSL_kPSK)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); |
| return ssl_hs_error; |
| } |
| |
| // At this point, |server_key_exchange| contains the signature, if any, while |
| // |msg.body| contains the entire message. From that, derive a CBS containing |
| // just the parameter. |
| CBS parameter; |
| CBS_init(¶meter, CBS_data(&msg.body), |
| CBS_len(&msg.body) - CBS_len(&server_key_exchange)); |
| |
| // ServerKeyExchange should be signed by the server's public key. |
| if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| uint16_t signature_algorithm = 0; |
| if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) { |
| if (!CBS_get_u16(&server_key_exchange, &signature_algorithm)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| if (!tls12_check_peer_sigalg(hs, &alert, signature_algorithm)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| hs->new_session->peer_signature_algorithm = signature_algorithm; |
| } else if (!tls1_get_legacy_signature_algorithm(&signature_algorithm, |
| hs->peer_pubkey.get())) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_CERTIFICATE); |
| return ssl_hs_error; |
| } |
| |
| // The last field in |server_key_exchange| is the signature. |
| CBS signature; |
| if (!CBS_get_u16_length_prefixed(&server_key_exchange, &signature) || |
| CBS_len(&server_key_exchange) != 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| ScopedCBB transcript; |
| Array<uint8_t> transcript_data; |
| if (!CBB_init(transcript.get(), |
| 2 * SSL3_RANDOM_SIZE + CBS_len(¶meter)) || |
| !CBB_add_bytes(transcript.get(), ssl->s3->client_random, |
| SSL3_RANDOM_SIZE) || |
| !CBB_add_bytes(transcript.get(), ssl->s3->server_random, |
| SSL3_RANDOM_SIZE) || |
| !CBB_add_bytes(transcript.get(), CBS_data(¶meter), |
| CBS_len(¶meter)) || |
| !CBBFinishArray(transcript.get(), &transcript_data)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| if (!ssl_public_key_verify(ssl, signature, signature_algorithm, |
| hs->peer_pubkey.get(), transcript_data)) { |
| // bad signature |
| OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR); |
| return ssl_hs_error; |
| } |
| } else { |
| // PSK ciphers are the only supported certificate-less ciphers. |
| assert(alg_a == SSL_aPSK); |
| |
| if (CBS_len(&server_key_exchange) > 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_EXTRA_DATA_IN_MESSAGE); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| } |
| |
| ssl->method->next_message(ssl); |
| hs->state = state_read_certificate_request; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_certificate_request(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| hs->state = state_read_server_hello_done; |
| return ssl_hs_ok; |
| } |
| |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (msg.type == SSL3_MT_SERVER_HELLO_DONE) { |
| // If we get here we don't need the handshake buffer as we won't be doing |
| // client auth. |
| hs->transcript.FreeBuffer(); |
| hs->state = state_read_server_hello_done; |
| return ssl_hs_ok; |
| } |
| |
| if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_REQUEST) || |
| !ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| // Get the certificate types. |
| CBS body = msg.body, certificate_types; |
| if (!CBS_get_u8_length_prefixed(&body, &certificate_types)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| if (!hs->certificate_types.CopyFrom(certificate_types)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) { |
| CBS supported_signature_algorithms; |
| if (!CBS_get_u16_length_prefixed(&body, &supported_signature_algorithms) || |
| !tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| } |
| |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| UniquePtr<STACK_OF(CRYPTO_BUFFER)> ca_names = |
| ssl_parse_client_CA_list(ssl, &alert, &body); |
| if (!ca_names) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| |
| if (CBS_len(&body) != 0) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| hs->cert_request = true; |
| hs->ca_names = std::move(ca_names); |
| ssl->ctx->x509_method->hs_flush_cached_ca_names(hs); |
| |
| ssl->method->next_message(ssl); |
| hs->state = state_read_server_hello_done; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_server_hello_done(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO_DONE) || |
| !ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| // ServerHelloDone is empty. |
| if (CBS_len(&msg.body) != 0) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| // ServerHelloDone should be the end of the flight. |
| if (ssl->method->has_unprocessed_handshake_data(ssl)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESS_HANDSHAKE_DATA); |
| return ssl_hs_error; |
| } |
| |
| ssl->method->next_message(ssl); |
| hs->state = state_send_client_certificate; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_send_client_certificate(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| // The peer didn't request a certificate. |
| if (!hs->cert_request) { |
| hs->state = state_send_client_key_exchange; |
| return ssl_hs_ok; |
| } |
| |
| if (ssl->s3->ech_status == ssl_ech_rejected) { |
| // Do not send client certificates on ECH reject. We have not authenticated |
| // the server for the name that can learn the certificate. |
| SSL_certs_clear(ssl); |
| } else if (hs->config->cert->cert_cb != nullptr) { |
| // Call cert_cb to update the certificate. |
| int rv = hs->config->cert->cert_cb(ssl, hs->config->cert->cert_cb_arg); |
| if (rv == 0) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR); |
| return ssl_hs_error; |
| } |
| if (rv < 0) { |
| hs->state = state_send_client_certificate; |
| return ssl_hs_x509_lookup; |
| } |
| } |
| |
| if (!ssl_has_certificate(hs)) { |
| // Without a client certificate, the handshake buffer may be released. |
| hs->transcript.FreeBuffer(); |
| } |
| |
| if (!ssl_on_certificate_selected(hs) || |
| !ssl_output_cert_chain(hs)) { |
| return ssl_hs_error; |
| } |
| |
| |
| hs->state = state_send_client_key_exchange; |
| return ssl_hs_ok; |
| } |
| |
| static_assert(sizeof(size_t) >= sizeof(unsigned), |
| "size_t is smaller than unsigned"); |
| |
| static enum ssl_hs_wait_t do_send_client_key_exchange(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| ScopedCBB cbb; |
| CBB body; |
| if (!ssl->method->init_message(ssl, cbb.get(), &body, |
| SSL3_MT_CLIENT_KEY_EXCHANGE)) { |
| return ssl_hs_error; |
| } |
| |
| Array<uint8_t> pms; |
| uint32_t alg_k = hs->new_cipher->algorithm_mkey; |
| uint32_t alg_a = hs->new_cipher->algorithm_auth; |
| if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) { |
| const CRYPTO_BUFFER *leaf = |
| sk_CRYPTO_BUFFER_value(hs->new_session->certs.get(), 0); |
| CBS leaf_cbs; |
| CRYPTO_BUFFER_init_CBS(leaf, &leaf_cbs); |
| |
| // Check the key usage matches the cipher suite. We do this unconditionally |
| // for non-RSA certificates. In particular, it's needed to distinguish ECDH |
| // certificates, which we do not support, from ECDSA certificates. |
| // Historically, we have not checked RSA key usages, so it is controlled by |
| // a flag for now. See https://crbug.com/795089. |
| ssl_key_usage_t intended_use = (alg_k & SSL_kRSA) |
| ? key_usage_encipherment |
| : key_usage_digital_signature; |
| if (hs->config->enforce_rsa_key_usage || |
| EVP_PKEY_id(hs->peer_pubkey.get()) != EVP_PKEY_RSA) { |
| if (!ssl_cert_check_key_usage(&leaf_cbs, intended_use)) { |
| return ssl_hs_error; |
| } |
| } |
| } |
| |
| // If using a PSK key exchange, prepare the pre-shared key. |
| unsigned psk_len = 0; |
| uint8_t psk[PSK_MAX_PSK_LEN]; |
| if (alg_a & SSL_aPSK) { |
| if (hs->config->psk_client_callback == NULL) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_NO_CLIENT_CB); |
| return ssl_hs_error; |
| } |
| |
| char identity[PSK_MAX_IDENTITY_LEN + 1]; |
| OPENSSL_memset(identity, 0, sizeof(identity)); |
| psk_len = hs->config->psk_client_callback( |
| ssl, hs->peer_psk_identity_hint.get(), identity, sizeof(identity), psk, |
| sizeof(psk)); |
| if (psk_len == 0) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND); |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); |
| return ssl_hs_error; |
| } |
| assert(psk_len <= PSK_MAX_PSK_LEN); |
| |
| hs->new_session->psk_identity.reset(OPENSSL_strdup(identity)); |
| if (hs->new_session->psk_identity == nullptr) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| return ssl_hs_error; |
| } |
| |
| // Write out psk_identity. |
| CBB child; |
| if (!CBB_add_u16_length_prefixed(&body, &child) || |
| !CBB_add_bytes(&child, (const uint8_t *)identity, |
| OPENSSL_strnlen(identity, sizeof(identity))) || |
| !CBB_flush(&body)) { |
| return ssl_hs_error; |
| } |
| } |
| |
| // Depending on the key exchange method, compute |pms|. |
| if (alg_k & SSL_kRSA) { |
| if (!pms.Init(SSL_MAX_MASTER_KEY_LENGTH)) { |
| return ssl_hs_error; |
| } |
| |
| RSA *rsa = EVP_PKEY_get0_RSA(hs->peer_pubkey.get()); |
| if (rsa == NULL) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| pms[0] = hs->client_version >> 8; |
| pms[1] = hs->client_version & 0xff; |
| if (!RAND_bytes(&pms[2], SSL_MAX_MASTER_KEY_LENGTH - 2)) { |
| return ssl_hs_error; |
| } |
| |
| CBB enc_pms; |
| uint8_t *ptr; |
| size_t enc_pms_len; |
| if (!CBB_add_u16_length_prefixed(&body, &enc_pms) || |
| !CBB_reserve(&enc_pms, &ptr, RSA_size(rsa)) || |
| !RSA_encrypt(rsa, &enc_pms_len, ptr, RSA_size(rsa), pms.data(), |
| pms.size(), RSA_PKCS1_PADDING) || |
| !CBB_did_write(&enc_pms, enc_pms_len) || |
| !CBB_flush(&body)) { |
| return ssl_hs_error; |
| } |
| } else if (alg_k & SSL_kECDHE) { |
| // Generate a keypair and serialize the public half. |
| CBB child; |
| if (!CBB_add_u8_length_prefixed(&body, &child)) { |
| return ssl_hs_error; |
| } |
| |
| // Compute the premaster. |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| if (!hs->key_shares[0]->Accept(&child, &pms, &alert, hs->peer_key)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| if (!CBB_flush(&body)) { |
| return ssl_hs_error; |
| } |
| |
| // The key exchange state may now be discarded. |
| hs->key_shares[0].reset(); |
| hs->key_shares[1].reset(); |
| hs->peer_key.Reset(); |
| } 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. |
| if (!pms.Init(psk_len)) { |
| return ssl_hs_error; |
| } |
| OPENSSL_memset(pms.data(), 0, pms.size()); |
| } else { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| // For a PSK cipher suite, other_secret is combined with the pre-shared |
| // key. |
| if (alg_a & SSL_aPSK) { |
| ScopedCBB pms_cbb; |
| CBB child; |
| if (!CBB_init(pms_cbb.get(), 2 + psk_len + 2 + pms.size()) || |
| !CBB_add_u16_length_prefixed(pms_cbb.get(), &child) || |
| !CBB_add_bytes(&child, pms.data(), pms.size()) || |
| !CBB_add_u16_length_prefixed(pms_cbb.get(), &child) || |
| !CBB_add_bytes(&child, psk, psk_len) || |
| !CBBFinishArray(pms_cbb.get(), &pms)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); |
| return ssl_hs_error; |
| } |
| } |
| |
| // The message must be added to the finished hash before calculating the |
| // master secret. |
| if (!ssl_add_message_cbb(ssl, cbb.get())) { |
| return ssl_hs_error; |
| } |
| |
| hs->new_session->secret_length = |
| tls1_generate_master_secret(hs, hs->new_session->secret, pms); |
| if (hs->new_session->secret_length == 0) { |
| return ssl_hs_error; |
| } |
| hs->new_session->extended_master_secret = hs->extended_master_secret; |
| |
| hs->state = state_send_client_certificate_verify; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_send_client_certificate_verify(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (!hs->cert_request || !ssl_has_certificate(hs)) { |
| hs->state = state_send_client_finished; |
| return ssl_hs_ok; |
| } |
| |
| assert(ssl_has_private_key(hs)); |
| ScopedCBB cbb; |
| CBB body, child; |
| if (!ssl->method->init_message(ssl, cbb.get(), &body, |
| SSL3_MT_CERTIFICATE_VERIFY)) { |
| return ssl_hs_error; |
| } |
| |
| uint16_t signature_algorithm; |
| if (!tls1_choose_signature_algorithm(hs, &signature_algorithm)) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE); |
| return ssl_hs_error; |
| } |
| if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) { |
| // Write out the digest type in TLS 1.2. |
| if (!CBB_add_u16(&body, signature_algorithm)) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| } |
| |
| // Set aside space for the signature. |
| const size_t max_sig_len = EVP_PKEY_size(hs->local_pubkey.get()); |
| uint8_t *ptr; |
| if (!CBB_add_u16_length_prefixed(&body, &child) || |
| !CBB_reserve(&child, &ptr, max_sig_len)) { |
| return ssl_hs_error; |
| } |
| |
| size_t sig_len = max_sig_len; |
| switch (ssl_private_key_sign(hs, ptr, &sig_len, max_sig_len, |
| signature_algorithm, |
| hs->transcript.buffer())) { |
| case ssl_private_key_success: |
| break; |
| case ssl_private_key_failure: |
| return ssl_hs_error; |
| case ssl_private_key_retry: |
| hs->state = state_send_client_certificate_verify; |
| return ssl_hs_private_key_operation; |
| } |
| |
| if (!CBB_did_write(&child, sig_len) || |
| !ssl_add_message_cbb(ssl, cbb.get())) { |
| return ssl_hs_error; |
| } |
| |
| // The handshake buffer is no longer necessary. |
| hs->transcript.FreeBuffer(); |
| |
| hs->state = state_send_client_finished; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_send_client_finished(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| hs->can_release_private_key = true; |
| if (!ssl->method->add_change_cipher_spec(ssl) || |
| !tls1_change_cipher_state(hs, evp_aead_seal)) { |
| return ssl_hs_error; |
| } |
| |
| if (hs->next_proto_neg_seen) { |
| static const uint8_t kZero[32] = {0}; |
| size_t padding_len = |
| 32 - ((ssl->s3->next_proto_negotiated.size() + 2) % 32); |
| |
| ScopedCBB cbb; |
| CBB body, child; |
| if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_NEXT_PROTO) || |
| !CBB_add_u8_length_prefixed(&body, &child) || |
| !CBB_add_bytes(&child, ssl->s3->next_proto_negotiated.data(), |
| ssl->s3->next_proto_negotiated.size()) || |
| !CBB_add_u8_length_prefixed(&body, &child) || |
| !CBB_add_bytes(&child, kZero, padding_len) || |
| !ssl_add_message_cbb(ssl, cbb.get())) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| } |
| |
| if (hs->channel_id_negotiated) { |
| ScopedCBB cbb; |
| CBB body; |
| if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CHANNEL_ID) || |
| !tls1_write_channel_id(hs, &body) || |
| !ssl_add_message_cbb(ssl, cbb.get())) { |
| OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| } |
| |
| if (!ssl_send_finished(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_finish_flight; |
| return ssl_hs_flush; |
| } |
| |
| static bool can_false_start(const SSL_HANDSHAKE *hs) { |
| const SSL *const ssl = hs->ssl; |
| |
| // False Start bypasses the Finished check's downgrade protection. This can |
| // enable attacks where we send data under weaker settings than supported |
| // (e.g. the Logjam attack). Thus we require TLS 1.2 with an ECDHE+AEAD |
| // cipher, our strongest settings before TLS 1.3. |
| // |
| // Now that TLS 1.3 exists, we would like to avoid similar attacks between |
| // TLS 1.2 and TLS 1.3, but there are too many TLS 1.2 deployments to |
| // sacrifice False Start on them. Instead, we rely on the ServerHello.random |
| // downgrade signal, which we unconditionally enforce. |
| if (SSL_is_dtls(ssl) || |
| SSL_version(ssl) != TLS1_2_VERSION || |
| hs->new_cipher->algorithm_mkey != SSL_kECDHE || |
| hs->new_cipher->algorithm_mac != SSL_AEAD) { |
| return false; |
| } |
| |
| // If ECH was rejected, disable False Start. We run the handshake to |
| // completion, including the Finished downgrade check, to authenticate the |
| // recovery flow. |
| if (ssl->s3->ech_status == ssl_ech_rejected) { |
| return false; |
| } |
| |
| // Additionally require ALPN or NPN by default. |
| // |
| // TODO(davidben): Can this constraint be relaxed globally now that cipher |
| // suite requirements have been tightened? |
| if (!ssl->ctx->false_start_allowed_without_alpn && |
| ssl->s3->alpn_selected.empty() && |
| ssl->s3->next_proto_negotiated.empty()) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static enum ssl_hs_wait_t do_finish_flight(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (ssl->session != NULL) { |
| hs->state = state_finish_client_handshake; |
| return ssl_hs_ok; |
| } |
| |
| // This is a full handshake. If it involves ChannelID, then record the |
| // handshake hashes at this point in the session so that any resumption of |
| // this session with ChannelID can sign those hashes. |
| if (!tls1_record_handshake_hashes_for_channel_id(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_read_session_ticket; |
| |
| if ((SSL_get_mode(ssl) & SSL_MODE_ENABLE_FALSE_START) && |
| can_false_start(hs) && |
| // No False Start on renegotiation (would complicate the state machine). |
| !ssl->s3->initial_handshake_complete) { |
| hs->in_false_start = true; |
| hs->can_early_write = true; |
| return ssl_hs_early_return; |
| } |
| |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_session_ticket(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| |
| if (!hs->ticket_expected) { |
| hs->state = state_process_change_cipher_spec; |
| return ssl_hs_read_change_cipher_spec; |
| } |
| |
| SSLMessage msg; |
| if (!ssl->method->get_message(ssl, &msg)) { |
| return ssl_hs_read_message; |
| } |
| |
| if (!ssl_check_message_type(ssl, msg, SSL3_MT_NEW_SESSION_TICKET) || |
| !ssl_hash_message(hs, msg)) { |
| return ssl_hs_error; |
| } |
| |
| CBS new_session_ticket = msg.body, ticket; |
| uint32_t ticket_lifetime_hint; |
| if (!CBS_get_u32(&new_session_ticket, &ticket_lifetime_hint) || |
| !CBS_get_u16_length_prefixed(&new_session_ticket, &ticket) || |
| CBS_len(&new_session_ticket) != 0) { |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR); |
| return ssl_hs_error; |
| } |
| |
| if (CBS_len(&ticket) == 0) { |
| // RFC 5077 allows a server to change its mind and send no ticket after |
| // negotiating the extension. The value of |ticket_expected| is checked in |
| // |ssl_update_cache| so is cleared here to avoid an unnecessary update. |
| hs->ticket_expected = false; |
| ssl->method->next_message(ssl); |
| hs->state = state_process_change_cipher_spec; |
| return ssl_hs_read_change_cipher_spec; |
| } |
| |
| if (ssl->session != nullptr) { |
| // The server is sending a new ticket for an existing session. Sessions are |
| // immutable once established, so duplicate all but the ticket of the |
| // existing session. |
| assert(!hs->new_session); |
| hs->new_session = |
| SSL_SESSION_dup(ssl->session.get(), SSL_SESSION_INCLUDE_NONAUTH); |
| if (!hs->new_session) { |
| return ssl_hs_error; |
| } |
| } |
| |
| // |ticket_lifetime_hint| is measured from when the ticket was issued. |
| ssl_session_rebase_time(ssl, hs->new_session.get()); |
| |
| if (!hs->new_session->ticket.CopyFrom(ticket)) { |
| return ssl_hs_error; |
| } |
| hs->new_session->ticket_lifetime_hint = ticket_lifetime_hint; |
| |
| // Historically, OpenSSL filled in fake session IDs for ticket-based sessions. |
| // TODO(davidben): Are external callers relying on this? Try removing this. |
| SHA256(CBS_data(&ticket), CBS_len(&ticket), hs->new_session->session_id); |
| hs->new_session->session_id_length = SHA256_DIGEST_LENGTH; |
| |
| ssl->method->next_message(ssl); |
| hs->state = state_process_change_cipher_spec; |
| return ssl_hs_read_change_cipher_spec; |
| } |
| |
| static enum ssl_hs_wait_t do_process_change_cipher_spec(SSL_HANDSHAKE *hs) { |
| if (!tls1_change_cipher_state(hs, evp_aead_open)) { |
| return ssl_hs_error; |
| } |
| |
| hs->state = state_read_server_finished; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_read_server_finished(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| enum ssl_hs_wait_t wait = ssl_get_finished(hs); |
| if (wait != ssl_hs_ok) { |
| return wait; |
| } |
| |
| if (ssl->session != NULL) { |
| hs->state = state_send_client_finished; |
| return ssl_hs_ok; |
| } |
| |
| hs->state = state_finish_client_handshake; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_finish_client_handshake(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (ssl->s3->ech_status == ssl_ech_rejected) { |
| // Release the retry configs. |
| hs->ech_authenticated_reject = true; |
| ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ECH_REQUIRED); |
| OPENSSL_PUT_ERROR(SSL, SSL_R_ECH_REJECTED); |
| return ssl_hs_error; |
| } |
| |
| ssl->method->on_handshake_complete(ssl); |
| |
| // Note TLS 1.2 resumptions with ticket renewal have both |ssl->session| (the |
| // resumed session) and |hs->new_session| (the session with the new ticket). |
| bool has_new_session = hs->new_session != nullptr; |
| if (has_new_session) { |
| // When False Start is enabled, the handshake reports completion early. The |
| // caller may then have passed the (then unresuable) |hs->new_session| to |
| // another thread via |SSL_get0_session| for resumption. To avoid potential |
| // race conditions in such callers, we duplicate the session before |
| // clearing |not_resumable|. |
| ssl->s3->established_session = |
| SSL_SESSION_dup(hs->new_session.get(), SSL_SESSION_DUP_ALL); |
| if (!ssl->s3->established_session) { |
| return ssl_hs_error; |
| } |
| // Renegotiations do not participate in session resumption. |
| if (!ssl->s3->initial_handshake_complete) { |
| ssl->s3->established_session->not_resumable = false; |
| } |
| |
| hs->new_session.reset(); |
| } else { |
| assert(ssl->session != nullptr); |
| ssl->s3->established_session = UpRef(ssl->session); |
| } |
| |
| hs->handshake_finalized = true; |
| ssl->s3->initial_handshake_complete = true; |
| if (has_new_session) { |
| ssl_update_cache(ssl); |
| } |
| |
| hs->state = state_done; |
| return ssl_hs_ok; |
| } |
| |
| enum ssl_hs_wait_t ssl_client_handshake(SSL_HANDSHAKE *hs) { |
| while (hs->state != state_done) { |
| enum ssl_hs_wait_t ret = ssl_hs_error; |
| enum ssl_client_hs_state_t state = |
| static_cast<enum ssl_client_hs_state_t>(hs->state); |
| switch (state) { |
| case state_start_connect: |
| ret = do_start_connect(hs); |
| break; |
| case state_enter_early_data: |
| ret = do_enter_early_data(hs); |
| break; |
| case state_early_reverify_server_certificate: |
| ret = do_early_reverify_server_certificate(hs); |
| break; |
| case state_read_hello_verify_request: |
| ret = do_read_hello_verify_request(hs); |
| break; |
| case state_read_server_hello: |
| ret = do_read_server_hello(hs); |
| break; |
| case state_tls13: |
| ret = do_tls13(hs); |
| break; |
| case state_read_server_certificate: |
| ret = do_read_server_certificate(hs); |
| break; |
| case state_read_certificate_status: |
| ret = do_read_certificate_status(hs); |
| break; |
| case state_verify_server_certificate: |
| ret = do_verify_server_certificate(hs); |
| break; |
| case state_reverify_server_certificate: |
| ret = do_reverify_server_certificate(hs); |
| break; |
| case state_read_server_key_exchange: |
| ret = do_read_server_key_exchange(hs); |
| break; |
| case state_read_certificate_request: |
| ret = do_read_certificate_request(hs); |
| break; |
| case state_read_server_hello_done: |
| ret = do_read_server_hello_done(hs); |
| break; |
| case state_send_client_certificate: |
| ret = do_send_client_certificate(hs); |
| break; |
| case state_send_client_key_exchange: |
| ret = do_send_client_key_exchange(hs); |
| break; |
| case state_send_client_certificate_verify: |
| ret = do_send_client_certificate_verify(hs); |
| break; |
| case state_send_client_finished: |
| ret = do_send_client_finished(hs); |
| break; |
| case state_finish_flight: |
| ret = do_finish_flight(hs); |
| break; |
| case state_read_session_ticket: |
| ret = do_read_session_ticket(hs); |
| break; |
| case state_process_change_cipher_spec: |
| ret = do_process_change_cipher_spec(hs); |
| break; |
| case state_read_server_finished: |
| ret = do_read_server_finished(hs); |
| break; |
| case state_finish_client_handshake: |
| ret = do_finish_client_handshake(hs); |
| break; |
| case state_done: |
| ret = ssl_hs_ok; |
| break; |
| } |
| |
| if (hs->state != state) { |
| ssl_do_info_callback(hs->ssl, SSL_CB_CONNECT_LOOP, 1); |
| } |
| |
| if (ret != ssl_hs_ok) { |
| return ret; |
| } |
| } |
| |
| ssl_do_info_callback(hs->ssl, SSL_CB_HANDSHAKE_DONE, 1); |
| return ssl_hs_ok; |
| } |
| |
| const char *ssl_client_handshake_state(SSL_HANDSHAKE *hs) { |
| enum ssl_client_hs_state_t state = |
| static_cast<enum ssl_client_hs_state_t>(hs->state); |
| switch (state) { |
| case state_start_connect: |
| return "TLS client start_connect"; |
| case state_enter_early_data: |
| return "TLS client enter_early_data"; |
| case state_early_reverify_server_certificate: |
| return "TLS client early_reverify_server_certificate"; |
| case state_read_hello_verify_request: |
| return "TLS client read_hello_verify_request"; |
| case state_read_server_hello: |
| return "TLS client read_server_hello"; |
| case state_tls13: |
| return tls13_client_handshake_state(hs); |
| case state_read_server_certificate: |
| return "TLS client read_server_certificate"; |
| case state_read_certificate_status: |
| return "TLS client read_certificate_status"; |
| case state_verify_server_certificate: |
| return "TLS client verify_server_certificate"; |
| case state_reverify_server_certificate: |
| return "TLS client reverify_server_certificate"; |
| case state_read_server_key_exchange: |
| return "TLS client read_server_key_exchange"; |
| case state_read_certificate_request: |
| return "TLS client read_certificate_request"; |
| case state_read_server_hello_done: |
| return "TLS client read_server_hello_done"; |
| case state_send_client_certificate: |
| return "TLS client send_client_certificate"; |
| case state_send_client_key_exchange: |
| return "TLS client send_client_key_exchange"; |
| case state_send_client_certificate_verify: |
| return "TLS client send_client_certificate_verify"; |
| case state_send_client_finished: |
| return "TLS client send_client_finished"; |
| case state_finish_flight: |
| return "TLS client finish_flight"; |
| case state_read_session_ticket: |
| return "TLS client read_session_ticket"; |
| case state_process_change_cipher_spec: |
| return "TLS client process_change_cipher_spec"; |
| case state_read_server_finished: |
| return "TLS client read_server_finished"; |
| case state_finish_client_handshake: |
| return "TLS client finish_client_handshake"; |
| case state_done: |
| return "TLS client done"; |
| } |
| |
| return "TLS client unknown"; |
| } |
| |
| BSSL_NAMESPACE_END |