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boringssl/ssl/tls13_client.cc
Steven Valdez cd8470f7fa Adding support for draft 21 as a TLS 1.3 variant. 
Change-Id: I46686aea9b68105cfe70a11db0e88052781e179c
Reviewed-on: https://boringssl-review.googlesource.com/22164
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
2017-11-01 21:32:36 +00:00

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/* Copyright (c) 2016, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/ssl.h>
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <utility>
#include <openssl/bytestring.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/stack.h>
#include "../crypto/internal.h"
#include "internal.h"
namespace bssl {
enum client_hs_state_t {
state_read_hello_retry_request = 0,
state_send_second_client_hello,
state_read_server_hello,
state_process_change_cipher_spec,
state_read_encrypted_extensions,
state_read_certificate_request,
state_read_server_certificate,
state_read_server_certificate_verify,
state_read_server_finished,
state_send_end_of_early_data,
state_send_client_certificate,
state_send_client_certificate_verify,
state_complete_second_flight,
state_done,
};
static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
static enum ssl_hs_wait_t do_read_hello_retry_request(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_HELLO_RETRY_REQUEST) {
hs->tls13_state = state_read_server_hello;
return ssl_hs_ok;
}
CBS body = msg.body, extensions;
uint16_t server_version, cipher_suite = 0;
if (!CBS_get_u16(&body, &server_version) ||
(ssl_is_draft21(ssl->version) &&
!CBS_get_u16(&body, &cipher_suite)) ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
// HelloRetryRequest may not be empty.
CBS_len(&extensions) == 0 ||
CBS_len(&body) != 0) {
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_is_draft21(ssl->version)) {
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
// Check if the cipher is a TLS 1.3 cipher.
if (cipher == NULL ||
SSL_CIPHER_get_min_version(cipher) > ssl_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl_protocol_version(ssl)) {
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->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher) ||
!hs->transcript.UpdateForHelloRetryRequest()) {
return ssl_hs_error;
}
}
bool have_cookie, have_key_share;
CBS cookie, key_share;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_key_share, &have_key_share, &key_share},
{TLSEXT_TYPE_cookie, &have_cookie, &cookie},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
0 /* reject unknown */)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (have_cookie) {
CBS cookie_value;
if (!CBS_get_u16_length_prefixed(&cookie, &cookie_value) ||
CBS_len(&cookie_value) == 0 ||
CBS_len(&cookie) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!hs->cookie.CopyFrom(cookie_value)) {
return ssl_hs_error;
}
}
if (have_key_share) {
uint16_t group_id;
if (!CBS_get_u16(&key_share, &group_id) || CBS_len(&key_share) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
// The group must be supported.
if (!tls1_check_group_id(ssl, group_id)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
return ssl_hs_error;
}
// Check that the HelloRetryRequest does not request the key share that
// was provided in the initial ClientHello.
if (hs->key_share->GroupID() == group_id) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
return ssl_hs_error;
}
hs->key_share.reset();
hs->retry_group = group_id;
}
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->received_hello_retry_request = true;
hs->tls13_state = state_send_second_client_hello;
// 0-RTT is rejected if we receive a HelloRetryRequest.
if (hs->in_early_data) {
return ssl_hs_early_data_rejected;
}
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_second_client_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// Restore the null cipher. We may have switched due to 0-RTT.
bssl::UniquePtr<SSLAEADContext> null_ctx =
SSLAEADContext::CreateNullCipher(SSL_is_dtls(ssl));
if (!null_ctx ||
!ssl->method->set_write_state(ssl, std::move(null_ctx))) {
return ssl_hs_error;
}
ssl->s3->aead_write_ctx->SetVersionIfNullCipher(ssl->version);
if (!ssl_write_client_hello(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_read_server_hello;
return ssl_hs_flush;
}
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_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS body = msg.body, server_random, session_id, extensions;
uint16_t server_version;
uint16_t cipher_suite;
uint8_t compression_method;
if (!CBS_get_u16(&body, &server_version) ||
!CBS_get_bytes(&body, &server_random, SSL3_RANDOM_SIZE) ||
(ssl_is_resumption_experiment(ssl->version) &&
!CBS_get_u8_length_prefixed(&body, &session_id)) ||
!CBS_get_u16(&body, &cipher_suite) ||
(ssl_is_resumption_experiment(ssl->version) &&
(!CBS_get_u8(&body, &compression_method) || compression_method != 0)) ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
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;
}
uint16_t expected_version = ssl_is_resumption_experiment(ssl->version)
? TLS1_2_VERSION
: ssl->version;
if (server_version != expected_version) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
return ssl_hs_error;
}
assert(ssl->s3->have_version);
OPENSSL_memcpy(ssl->s3->server_random, CBS_data(&server_random),
SSL3_RANDOM_SIZE);
// Check if the cipher is a TLS 1.3 cipher.
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
if (cipher == nullptr ||
SSL_CIPHER_get_min_version(cipher) > ssl_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl_protocol_version(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
// Check that the cipher matches the one in the HelloRetryRequest.
if (ssl_is_draft21(ssl->version) &&
hs->received_hello_retry_request &&
hs->new_cipher != 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;
}
// Parse out the extensions.
bool have_key_share = false, have_pre_shared_key = false,
have_supported_versions = false;
CBS key_share, pre_shared_key, supported_versions;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_key_share, &have_key_share, &key_share},
{TLSEXT_TYPE_pre_shared_key, &have_pre_shared_key, &pre_shared_key},
{TLSEXT_TYPE_supported_versions, &have_supported_versions,
&supported_versions},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
0 /* reject unknown */)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
// supported_versions is parsed in handshake_client to select the experimental
// TLS 1.3 version.
if (have_supported_versions && !ssl_is_resumption_experiment(ssl->version)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
alert = SSL_AD_DECODE_ERROR;
if (have_pre_shared_key) {
if (ssl->session == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_EXTENSION);
return ssl_hs_error;
}
if (!ssl_ext_pre_shared_key_parse_serverhello(hs, &alert,
&pre_shared_key)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
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->algorithm_prf != cipher->algorithm_prf) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_PRF_HASH_MISMATCH);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl_session_is_context_valid(ssl, ssl->session)) {
// 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;
}
ssl->s3->session_reused = true;
// Only authentication information carries over in TLS 1.3.
hs->new_session = SSL_SESSION_dup(ssl->session, SSL_SESSION_DUP_AUTH_ONLY);
if (!hs->new_session) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
ssl_set_session(ssl, NULL);
// Resumption incorporates fresh key material, so refresh the timeout.
ssl_session_renew_timeout(ssl, hs->new_session.get(),
ssl->session_ctx->session_psk_dhe_timeout);
} else if (!ssl_get_new_session(hs, 0)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->new_session->cipher = cipher;
hs->new_cipher = cipher;
size_t hash_len =
EVP_MD_size(ssl_get_handshake_digest(ssl_protocol_version(ssl), cipher));
// Set up the key schedule and incorporate the PSK into the running secret.
if (ssl->s3->session_reused) {
if (!tls13_init_key_schedule(hs, hs->new_session->master_key,
hs->new_session->master_key_length)) {
return ssl_hs_error;
}
} else if (!tls13_init_key_schedule(hs, kZeroes, hash_len)) {
return ssl_hs_error;
}
if (!have_key_share) {
// We do not support psk_ke and thus always require a key share.
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_KEY_SHARE);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
return ssl_hs_error;
}
// Resolve ECDHE and incorporate it into the secret.
Array<uint8_t> dhe_secret;
alert = SSL_AD_DECODE_ERROR;
if (!ssl_ext_key_share_parse_serverhello(hs, &dhe_secret, &alert,
&key_share)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (!tls13_advance_key_schedule(hs, dhe_secret.data(), dhe_secret.size()) ||
!ssl_hash_message(hs, msg) ||
!tls13_derive_handshake_secrets(hs)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_process_change_cipher_spec;
return ssl_is_resumption_experiment(ssl->version)
? ssl_hs_read_change_cipher_spec
: ssl_hs_ok;
}
static enum ssl_hs_wait_t do_process_change_cipher_spec(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!tls13_set_traffic_key(ssl, evp_aead_open, hs->server_handshake_secret,
hs->hash_len)) {
return ssl_hs_error;
}
if (!hs->early_data_offered) {
// If not sending early data, set client traffic keys now so that alerts are
// encrypted.
if ((ssl_is_resumption_client_ccs_experiment(ssl->version) &&
!ssl->method->add_change_cipher_spec(ssl)) ||
!tls13_set_traffic_key(ssl, evp_aead_seal, hs->client_handshake_secret,
hs->hash_len)) {
return ssl_hs_error;
}
}
hs->tls13_state = state_read_encrypted_extensions;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_encrypted_extensions(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_ENCRYPTED_EXTENSIONS)) {
return ssl_hs_error;
}
CBS body = msg.body;
if (!ssl_parse_serverhello_tlsext(hs, &body)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
if (CBS_len(&body) != 0) {
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 negotiated ALPN in the session.
if (!ssl->s3->alpn_selected.empty()) {
hs->new_session->early_alpn = (uint8_t *)BUF_memdup(
ssl->s3->alpn_selected.data(), ssl->s3->alpn_selected.size());
if (hs->new_session->early_alpn == NULL) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->new_session->early_alpn_len = ssl->s3->alpn_selected.size();
}
if (ssl->early_data_accepted) {
if (hs->early_session->cipher != hs->new_session->cipher ||
MakeConstSpan(hs->early_session->early_alpn,
hs->early_session->early_alpn_len) !=
ssl->s3->alpn_selected) {
OPENSSL_PUT_ERROR(SSL, SSL_R_ALPN_MISMATCH_ON_EARLY_DATA);
return ssl_hs_error;
}
if (ssl->s3->tlsext_channel_id_valid || hs->received_custom_extension) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION_ON_EARLY_DATA);
return ssl_hs_error;
}
}
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_certificate_request;
if (hs->in_early_data && !ssl->early_data_accepted) {
return ssl_hs_early_data_rejected;
}
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_certificate_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// CertificateRequest may only be sent in non-resumption handshakes.
if (ssl->s3->session_reused) {
hs->tls13_state = state_read_server_finished;
return ssl_hs_ok;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
// CertificateRequest is optional.
if (msg.type != SSL3_MT_CERTIFICATE_REQUEST) {
hs->tls13_state = state_read_server_certificate;
return ssl_hs_ok;
}
if (ssl_is_draft21(ssl->version)) {
bool have_sigalgs = false, have_ca = false;
CBS sigalgs, ca;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_signature_algorithms, &have_sigalgs, &sigalgs},
{TLSEXT_TYPE_certificate_authorities, &have_ca, &ca},
};
CBS body = msg.body, context, extensions, supported_signature_algorithms;
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!CBS_get_u8_length_prefixed(&body, &context) ||
// The request context is always empty during the handshake.
CBS_len(&context) != 0 ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
CBS_len(&body) != 0 ||
!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
1 /* accept unknown */) ||
(have_ca && CBS_len(&ca) == 0) ||
!have_sigalgs ||
!CBS_get_u16_length_prefixed(&sigalgs,
&supported_signature_algorithms) ||
CBS_len(&supported_signature_algorithms) == 0 ||
!tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (have_ca) {
hs->ca_names = ssl_parse_client_CA_list(ssl, &alert, &ca);
if (!hs->ca_names) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
} else {
hs->ca_names.reset(sk_CRYPTO_BUFFER_new_null());
if (!hs->ca_names) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
}
} else {
CBS body = msg.body, context, supported_signature_algorithms;
if (!CBS_get_u8_length_prefixed(&body, &context) ||
// The request context is always empty during the handshake.
CBS_len(&context) != 0 ||
!CBS_get_u16_length_prefixed(&body, &supported_signature_algorithms) ||
CBS_len(&supported_signature_algorithms) == 0 ||
!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;
hs->ca_names = ssl_parse_client_CA_list(ssl, &alert, &body);
if (!hs->ca_names) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
// Ignore extensions.
CBS extensions;
if (!CBS_get_u16_length_prefixed(&body, &extensions) ||
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;
ssl->ctx->x509_method->hs_flush_cached_ca_names(hs);
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_server_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_certificate(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_CERTIFICATE) ||
!tls13_process_certificate(hs, msg, 0 /* certificate required */) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_read_server_certificate_verify;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_certificate_verify(
SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
switch (ssl_verify_peer_cert(hs)) {
case ssl_verify_ok:
break;
case ssl_verify_invalid:
return ssl_hs_error;
case ssl_verify_retry:
hs->tls13_state = state_read_server_certificate_verify;
return ssl_hs_certificate_verify;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_VERIFY) ||
!tls13_process_certificate_verify(hs, msg) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_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;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_FINISHED) ||
!tls13_process_finished(hs, msg, 0 /* don't use saved value */) ||
!ssl_hash_message(hs, msg) ||
// Update the secret to the master secret and derive traffic keys.
!tls13_advance_key_schedule(hs, kZeroes, hs->hash_len) ||
!tls13_derive_application_secrets(hs)) {
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->tls13_state = state_send_end_of_early_data;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_end_of_early_data(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->early_data_accepted) {
hs->can_early_write = false;
if (ssl_is_draft21(ssl->version)) {
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_END_OF_EARLY_DATA) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
return ssl_hs_error;
}
} else {
if (!ssl->method->add_alert(ssl, SSL3_AL_WARNING,
TLS1_AD_END_OF_EARLY_DATA)) {
return ssl_hs_error;
}
}
}
if (hs->early_data_offered) {
if ((ssl_is_resumption_client_ccs_experiment(ssl->version) &&
!ssl->method->add_change_cipher_spec(ssl)) ||
!tls13_set_traffic_key(ssl, evp_aead_seal, hs->client_handshake_secret,
hs->hash_len)) {
return ssl_hs_error;
}
}
hs->tls13_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->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
}
// Call cert_cb to update the certificate.
if (ssl->cert->cert_cb != NULL) {
int rv = ssl->cert->cert_cb(ssl, ssl->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->tls13_state = state_send_client_certificate;
return ssl_hs_x509_lookup;
}
}
if (!ssl_on_certificate_selected(hs) ||
!tls13_add_certificate(hs)) {
return ssl_hs_error;
}
hs->tls13_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;
// Don't send CertificateVerify if there is no certificate.
if (!ssl_has_certificate(ssl)) {
hs->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
}
switch (tls13_add_certificate_verify(hs)) {
case ssl_private_key_success:
hs->tls13_state = state_complete_second_flight;
return ssl_hs_ok;
case ssl_private_key_retry:
hs->tls13_state = state_send_client_certificate_verify;
return ssl_hs_private_key_operation;
case ssl_private_key_failure:
return ssl_hs_error;
}
assert(0);
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_complete_second_flight(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
// Send a Channel ID assertion if necessary.
if (ssl->s3->tlsext_channel_id_valid) {
if (!ssl_do_channel_id_callback(ssl)) {
hs->tls13_state = state_complete_second_flight;
return ssl_hs_error;
}
if (ssl->tlsext_channel_id_private == NULL) {
return ssl_hs_channel_id_lookup;
}
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())) {
return ssl_hs_error;
}
}
// Send a Finished message.
if (!tls13_add_finished(hs)) {
return ssl_hs_error;
}
// Derive the final keys and enable them.
if (!tls13_set_traffic_key(ssl, evp_aead_open, hs->server_traffic_secret_0,
hs->hash_len) ||
!tls13_set_traffic_key(ssl, evp_aead_seal, hs->client_traffic_secret_0,
hs->hash_len) ||
!tls13_derive_resumption_secret(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_done;
return ssl_hs_flush;
}
enum ssl_hs_wait_t tls13_client_handshake(SSL_HANDSHAKE *hs) {
while (hs->tls13_state != state_done) {
enum ssl_hs_wait_t ret = ssl_hs_error;
enum client_hs_state_t state =
static_cast<enum client_hs_state_t>(hs->tls13_state);
switch (state) {
case state_read_hello_retry_request:
ret = do_read_hello_retry_request(hs);
break;
case state_send_second_client_hello:
ret = do_send_second_client_hello(hs);
break;
case state_read_server_hello:
ret = do_read_server_hello(hs);
break;
case state_process_change_cipher_spec:
ret = do_process_change_cipher_spec(hs);
break;
case state_read_encrypted_extensions:
ret = do_read_encrypted_extensions(hs);
break;
case state_read_certificate_request:
ret = do_read_certificate_request(hs);
break;
case state_read_server_certificate:
ret = do_read_server_certificate(hs);
break;
case state_read_server_certificate_verify:
ret = do_read_server_certificate_verify(hs);
break;
case state_read_server_finished:
ret = do_read_server_finished(hs);
break;
case state_send_end_of_early_data:
ret = do_send_end_of_early_data(hs);
break;
case state_send_client_certificate:
ret = do_send_client_certificate(hs);
break;
case state_send_client_certificate_verify:
ret = do_send_client_certificate_verify(hs);
break;
case state_complete_second_flight:
ret = do_complete_second_flight(hs);
break;
case state_done:
ret = ssl_hs_ok;
break;
}
if (hs->tls13_state != state) {
ssl_do_info_callback(hs->ssl, SSL_CB_CONNECT_LOOP, 1);
}
if (ret != ssl_hs_ok) {
return ret;
}
}
return ssl_hs_ok;
}
const char *tls13_client_handshake_state(SSL_HANDSHAKE *hs) {
enum client_hs_state_t state =
static_cast<enum client_hs_state_t>(hs->tls13_state);
switch (state) {
case state_read_hello_retry_request:
return "TLS 1.3 client read_hello_retry_request";
case state_send_second_client_hello:
return "TLS 1.3 client send_second_client_hello";
case state_read_server_hello:
return "TLS 1.3 client read_server_hello";
case state_process_change_cipher_spec:
return "TLS 1.3 client process_change_cipher_spec";
case state_read_encrypted_extensions:
return "TLS 1.3 client read_encrypted_extensions";
case state_read_certificate_request:
return "TLS 1.3 client read_certificate_request";
case state_read_server_certificate:
return "TLS 1.3 client read_server_certificate";
case state_read_server_certificate_verify:
return "TLS 1.3 client read_server_certificate_verify";
case state_read_server_finished:
return "TLS 1.3 client read_server_finished";
case state_send_end_of_early_data:
return "TLS 1.3 client send_end_of_early_data";
case state_send_client_certificate:
return "TLS 1.3 client send_client_certificate";
case state_send_client_certificate_verify:
return "TLS 1.3 client send_client_certificate_verify";
case state_complete_second_flight:
return "TLS 1.3 client complete_second_flight";
case state_done:
return "TLS 1.3 client done";
}
return "TLS 1.3 client unknown";
}
int tls13_process_new_session_ticket(SSL *ssl, const SSLMessage &msg) {
if (ssl->s3->write_shutdown != ssl_shutdown_none) {
// Ignore tickets on shutdown. Callers tend to indiscriminately call
// |SSL_shutdown| before destroying an |SSL|, at which point calling the new
// session callback may be confusing.
return 1;
}
UniquePtr<SSL_SESSION> session = SSL_SESSION_dup(
ssl->s3->established_session.get(), SSL_SESSION_INCLUDE_NONAUTH);
if (!session) {
return 0;
}
ssl_session_rebase_time(ssl, session.get());
uint32_t server_timeout;
CBS body = msg.body, ticket_nonce, ticket, extensions;
if (!CBS_get_u32(&body, &server_timeout) ||
!CBS_get_u32(&body, &session->ticket_age_add) ||
(ssl_is_draft21(ssl->version) &&
!CBS_get_u8_length_prefixed(&body, &ticket_nonce)) ||
!CBS_get_u16_length_prefixed(&body, &ticket) ||
!CBS_stow(&ticket, &session->tlsext_tick, &session->tlsext_ticklen) ||
!CBS_get_u16_length_prefixed(&body, &extensions) ||
CBS_len(&body) != 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return 0;
}
// Cap the renewable lifetime by the server advertised value. This avoids
// wasting bandwidth on 0-RTT when we know the server will reject it.
if (session->timeout > server_timeout) {
session->timeout = server_timeout;
}
if (!tls13_derive_session_psk(session.get(), ticket_nonce)) {
return 0;
}
// Parse out the extensions.
bool have_early_data_info = false;
CBS early_data_info;
uint16_t ext_id = ssl_is_draft21(ssl->version)
? TLSEXT_TYPE_early_data
: TLSEXT_TYPE_ticket_early_data_info;
const SSL_EXTENSION_TYPE ext_types[] = {
{ext_id, &have_early_data_info, &early_data_info},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
1 /* ignore unknown */)) {
ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
return 0;
}
if (have_early_data_info && ssl->cert->enable_early_data) {
if (!CBS_get_u32(&early_data_info, &session->ticket_max_early_data) ||
CBS_len(&early_data_info) != 0) {
ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return 0;
}
}
session->ticket_age_add_valid = 1;
session->not_resumable = 0;
if ((ssl->ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) &&
ssl->ctx->new_session_cb != NULL &&
ssl->ctx->new_session_cb(ssl, session.get())) {
// |new_session_cb|'s return value signals that it took ownership.
session.release();
}
return 1;
}
} // namespace bssl
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