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boringssl / boringssl / 7c3252a67badce0854305403be6f51b1b298895a / . / ssl / handshake_client.cc
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/* 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 <algorithm>
#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_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_add_tls13_cipher(CBB *cbb, uint16_t cipher_id,
ssl_compliance_policy_t policy) {
if (ssl_tls13_cipher_meets_policy(cipher_id, policy)) {
return CBB_add_u16(cbb, cipher_id);
}
return true;
}
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) {
static const uint16_t kCiphersNoAESHardware[] = {
TLS1_3_CK_CHACHA20_POLY1305_SHA256 & 0xffff,
TLS1_3_CK_AES_128_GCM_SHA256 & 0xffff,
TLS1_3_CK_AES_256_GCM_SHA384 & 0xffff,
};
static const uint16_t kCiphersAESHardware[] = {
TLS1_3_CK_AES_128_GCM_SHA256 & 0xffff,
TLS1_3_CK_AES_256_GCM_SHA384 & 0xffff,
TLS1_3_CK_CHACHA20_POLY1305_SHA256 & 0xffff,
};
static const uint16_t kCiphersCNSA[] = {
TLS1_3_CK_AES_256_GCM_SHA384 & 0xffff,
TLS1_3_CK_AES_128_GCM_SHA256 & 0xffff,
TLS1_3_CK_CHACHA20_POLY1305_SHA256 & 0xffff,
};
const bool has_aes_hw = ssl->config->aes_hw_override
? ssl->config->aes_hw_override_value
: EVP_has_aes_hardware();
const bssl::Span<const uint16_t> ciphers =
ssl->config->tls13_cipher_policy == ssl_compliance_policy_cnsa_202407
? bssl::Span<const uint16_t>(kCiphersCNSA)
: (has_aes_hw ? bssl::Span<const uint16_t>(kCiphersAESHardware)
: bssl::Span<const uint16_t>(kCiphersNoAESHardware));
for (auto cipher : ciphers) {
if (!ssl_add_tls13_cipher(&child, cipher,
ssl->config->tls13_cipher_policy)) {
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.data(), hs->session_id.size())) {
return false;
}
if (SSL_is_dtls(ssl)) {
if (!CBB_add_u8_length_prefixed(cbb, &child) ||
!CBB_add_bytes(&child, hs->dtls_cookie.data(),
hs->dtls_cookie.size())) {
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)) ||
!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) {
uint16_t legacy_version = TLS1_2_VERSION;
if (SSL_is_dtls(hs->ssl)) {
legacy_version = DTLS1_2_VERSION;
}
// 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 != legacy_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 || SSL_is_dtls(ssl)) {
// We discard inapplicable sessions, so this is redundant with the session
// checks below, but reporting that TLS 1.3 was disabled is more useful.
//
// TODO(crbug.com/42290594): Support early data in DTLS 1.3.
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_outer.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.
SSLSessionType session_type = SSLSessionType::kNotResumable;
if (ssl->session != nullptr) {
session_type = ssl_session_get_type(ssl->session.get());
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) ||
session_type == SSLSessionType::kNotResumable ||
// Don't offer TLS 1.2 tickets if disabled.
(session_type == SSLSessionType::kTicket &&
(SSL_get_options(ssl) & SSL_OP_NO_TICKET)) ||
!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);
session_type = SSLSessionType::kNotResumable;
}
}
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;
}
// Compatibility mode sends a random session ID. Compatibility mode is
// enabled for TLS 1.3, but not when it's run over QUIC or DTLS.
const bool enable_compatibility_mode = hs->max_version >= TLS1_3_VERSION &&
ssl->quic_method == nullptr &&
!SSL_is_dtls(hs->ssl);
if (session_type == SSLSessionType::kID) {
hs->session_id = ssl->session->session_id;
} else if (session_type == SSLSessionType::kTicket ||
enable_compatibility_mode) {
// TLS 1.2 session tickets require a placeholder value to signal resumption.
hs->session_id.ResizeForOverwrite(SSL_MAX_SSL_SESSION_ID_LENGTH);
if (!RAND_bytes(hs->session_id.data(), hs->session_id.size())) {
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 (!hs->early_data_offered) {
hs->state = state_read_server_hello;
return ssl_hs_ok;
}
// Stash the early data session and activate the early version. This must
// happen before |do_early_reverify_server_certificate|, so early connection
// properties are available to the callback. Note the early version may be
// overwritten later by the final version.
hs->early_session = UpRef(ssl->session);
ssl->s3->version = hs->early_session->ssl_version;
hs->is_early_version = true;
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) {
SSL *const ssl = hs->ssl;
if (ssl->ctx->reverify_on_resume) {
// Don't send an alert on error. The alert would be in the clear, which the
// server is not expecting anyway. Alerts in between ClientHello and
// ServerHello cannot usefully be delivered in TLS 1.3.
//
// 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;
}
}
if (!ssl->method->add_change_cipher_spec(ssl)) {
return ssl_hs_error;
}
// Defer releasing the 0-RTT key to after certificate reverification, so the
// QUIC implementation does not accidentally write data too early.
if (!tls13_init_early_key_schedule(hs, hs->early_session.get()) ||
!tls13_derive_early_secret(hs) ||
!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 bool handle_hello_verify_request(SSL_HANDSHAKE *hs,
const SSLMessage &msg) {
SSL *const ssl = hs->ssl;
assert(SSL_is_dtls(ssl));
assert(msg.type == DTLS1_MT_HELLO_VERIFY_REQUEST);
assert(!hs->received_hello_verify_request);
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(&hello_verify_request) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return false;
}
if (!hs->dtls_cookie.CopyFrom(cookie)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return false;
}
hs->received_hello_verify_request = true;
ssl->method->next_message(ssl);
// DTLS resets the handshake buffer after HelloVerifyRequest.
if (!hs->transcript.Init()) {
return false;
}
return ssl_add_client_hello(hs);
}
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;
}
out->raw = msg.raw;
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;
}
if (SSL_is_dtls(ssl) && !hs->received_hello_verify_request &&
msg.type == DTLS1_MT_HELLO_VERIFY_REQUEST) {
if (!handle_hello_verify_request(hs, msg)) {
return ssl_hs_error;
}
hs->received_hello_verify_request = true;
hs->state = state_read_server_hello;
return ssl_hs_flush;
}
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;
}
if (!ssl->s3->initial_handshake_complete) {
// |ssl->s3->version| may be set due to 0-RTT. If it was to a different
// value, the check below will fire.
assert(ssl->s3->version == 0 ||
(hs->is_early_version &&
ssl->s3->version == hs->early_session->ssl_version));
ssl->s3->version = server_version;
hs->is_early_version = false;
} else if (server_version != ssl->s3->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 the version did not match, stop sending 0-RTT data.
if (hs->early_data_offered &&
ssl->s3->version != hs->early_session->ssl_version) {
// This is currently only possible by reading a TLS 1.2 (or earlier)
// ServerHello in response to TLS 1.3. If there is ever a TLS 1.4, or
// another variant of TLS 1.3, the fatal error below will need to be a clean
// 0-RTT reject.
assert(ssl_protocol_version(ssl) < TLS1_3_VERSION);
assert(ssl_session_protocol_version(hs->early_session.get()) >=
TLS1_3_VERSION);
// A TLS 1.2 server would not know to skip the early data we offered, so
// there is no point in continuing the handshake. Report an error code as
// soon as we detect this. The caller may use this error code to implement
// the fallback described in RFC 8446 appendix D.3.
//
// 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?
//
// TODO(crbug.com/42290594): Although missing from the spec, a DTLS 1.2
// server will already naturally skip 0-RTT data. If we implement DTLS 1.3
// 0-RTT, we may want a clean reject.
assert(!SSL_is_dtls(ssl));
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;
}
if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
if (hs->received_hello_verify_request) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_MESSAGE);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION);
return ssl_hs_error;
}
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);
// 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.empty() &&
Span<const uint8_t>(server_hello.session_id) == hs->session_id) {
// 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->s3->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;
}
// Save the session ID from the server. This may be empty if the session
// isn't resumable, or if we'll receive a session ticket later. The
// ServerHello parser ensures |server_hello.session_id| is within bounds.
hs->new_session->session_id.CopyFrom(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)) {
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;
}
// 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;
}
// Save the group and peer public key for later.
hs->new_session->group_id = group_id;
if (!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(&parameter, 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,
hs->peer_pubkey.get())) {
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(&parameter)) ||
!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(&parameter),
CBS_len(&parameter)) ||
!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_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 bool check_credential(SSL_HANDSHAKE *hs, const SSL_CREDENTIAL *cred,
uint16_t *out_sigalg) {
if (cred->type != SSLCredentialType::kX509) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
return false;
}
if (hs->config->check_client_certificate_type) {
// Check the certificate types advertised by the peer.
uint8_t cert_type;
switch (EVP_PKEY_id(cred->pubkey.get())) {
case EVP_PKEY_RSA:
cert_type = SSL3_CT_RSA_SIGN;
break;
case EVP_PKEY_EC:
case EVP_PKEY_ED25519:
cert_type = TLS_CT_ECDSA_SIGN;
break;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
return false;
}
if (std::find(hs->certificate_types.begin(), hs->certificate_types.end(),
cert_type) == hs->certificate_types.end()) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
return false;
}
}
// All currently supported credentials require a signature. Note this does not
// check the ECDSA curve. Prior to TLS 1.3, there is no way to determine which
// ECDSA curves are supported by the peer, so we must assume all curves are
// supported.
return tls1_choose_signature_algorithm(hs, cred, out_sigalg);
}
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;
}
}
Array<SSL_CREDENTIAL *> creds;
if (!ssl_get_credential_list(hs, &creds)) {
return ssl_hs_error;
}
if (creds.empty()) {
// If there were no credentials, proceed without a client certificate. In
// this case, the handshake buffer may be released early.
hs->transcript.FreeBuffer();
} else {
// Select the credential to use.
for (SSL_CREDENTIAL *cred : creds) {
ERR_clear_error();
uint16_t sigalg;
if (check_credential(hs, cred, &sigalg)) {
hs->credential = UpRef(cred);
hs->signature_algorithm = sigalg;
break;
}
}
if (hs->credential == nullptr) {
// The error from the last attempt is in the error queue.
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
}
if (!ssl_send_tls12_certificate(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 (!ssl_cert_check_key_usage(&leaf_cbs, intended_use)) {
if (hs->config->enforce_rsa_key_usage ||
EVP_PKEY_id(hs->peer_pubkey.get()) != EVP_PKEY_RSA) {
return ssl_hs_error;
}
ERR_clear_error();
ssl->s3->was_key_usage_invalid = true;
}
}
// 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) {
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) {
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;
}
if (!pms.InitForOverwrite(SSL_MAX_MASTER_KEY_LENGTH)) {
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) {
CBB child;
if (!CBB_add_u8_length_prefixed(&body, &child)) {
return ssl_hs_error;
}
// Generate a premaster secret and encapsulate it.
bssl::UniquePtr<SSLKeyShare> kem =
SSLKeyShare::Create(hs->new_session->group_id);
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!kem || !kem->Encap(&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 peer key can now be discarded.
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;
}
} 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)) {
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.ResizeForOverwrite(SSL3_MASTER_SECRET_SIZE);
if (!tls1_generate_master_secret(hs, MakeSpan(hs->new_session->secret),
pms)) {
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 || hs->credential == nullptr) {
hs->state = state_send_client_finished;
return ssl_hs_ok;
}
ScopedCBB cbb;
CBB body, child;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_CERTIFICATE_VERIFY)) {
return ssl_hs_error;
}
assert(hs->signature_algorithm != 0);
if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) {
// Write out the digest type in TLS 1.2.
if (!CBB_add_u16(&body, hs->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->credential->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,
hs->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.
hs->new_session->session_id.ResizeForOverwrite(SHA256_DIGEST_LENGTH);
SHA256(CBS_data(&ticket), CBS_len(&ticket),
hs->new_session->session_id.data());
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_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_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