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520e1220bb
boringssl/ssl/tls13_client.c
Steven Valdez 520e1220bb Implement experimental alternate encoding of TLS 1.3. 
TLS 1.3 deployment is currently blocked by buggy middleboxes
throughout the ecosystem. As an experiment to better understand these bugs
and the problems they are causing, implement TLS 1.3 variants with
alternate encodings. These are still the same protocol, only encoded
slightly differently. We will use what we learn from these experiments to
guide the TLS 1.3 deployment strategy and proposals to the IETF, if any.

These experiments only target the basic 1-RTT TLS 1.3 handshake. Based on
what we learn from this experiment, we may try future variations to
explore 0-RTT and HelloRetryRequest.

When enabled, the server supports all TLS 1.3 variants while the client
is configured to use a particular variant.

Change-Id: I532411d1abc41314dc76acce0246879b754b4c61
Reviewed-on: https://boringssl-review.googlesource.com/17327
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-07-10 18:15:08 +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 <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"
enum client_hs_state_t {
state_process_hello_retry_request = 0,
state_send_second_client_hello,
state_process_server_hello,
state_process_change_cipher_spec,
state_process_encrypted_extensions,
state_continue_second_server_flight,
state_process_certificate_request,
state_process_server_certificate,
state_process_server_certificate_verify,
state_process_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_process_hello_retry_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->s3->tmp.message_type != SSL3_MT_HELLO_RETRY_REQUEST) {
hs->tls13_state = state_process_server_hello;
return ssl_hs_ok;
}
CBS cbs, extensions;
uint16_t server_wire_version;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!CBS_get_u16(&cbs, &server_wire_version) ||
!CBS_get_u16_length_prefixed(&cbs, &extensions) ||
/* HelloRetryRequest may not be empty. */
CBS_len(&extensions) == 0 ||
CBS_len(&cbs) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
int 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 */)) {
ssl3_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);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!CBS_stow(&cookie_value, &hs->cookie, &hs->cookie_len)) {
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);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
/* The group must be supported. */
const uint16_t *groups;
size_t groups_len;
tls1_get_grouplist(ssl, &groups, &groups_len);
int found = 0;
for (size_t i = 0; i < groups_len; i++) {
if (groups[i] == group_id) {
found = 1;
break;
}
}
if (!found) {
ssl3_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 (SSL_ECDH_CTX_get_id(&hs->ecdh_ctx) == group_id) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
return ssl_hs_error;
}
SSL_ECDH_CTX_cleanup(&hs->ecdh_ctx);
hs->retry_group = group_id;
}
if (!ssl_hash_current_message(hs)) {
return ssl_hs_error;
}
hs->received_hello_retry_request = 1;
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;
if (!ssl->method->set_write_state(ssl, NULL) ||
!ssl_write_client_hello(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_process_server_hello;
return ssl_hs_flush_and_read_message;
}
static enum ssl_hs_wait_t do_process_server_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_check_message_type(ssl, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS cbs, server_random, session_id, extensions;
uint16_t server_wire_version;
uint16_t cipher_suite;
uint8_t compression_method;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!CBS_get_u16(&cbs, &server_wire_version) ||
!CBS_get_bytes(&cbs, &server_random, SSL3_RANDOM_SIZE) ||
(ssl->version == TLS1_3_EXPERIMENT_VERSION &&
!CBS_get_u8_length_prefixed(&cbs, &session_id)) ||
!CBS_get_u16(&cbs, &cipher_suite) ||
(ssl->version == TLS1_3_EXPERIMENT_VERSION &&
(!CBS_get_u8(&cbs, &compression_method) || compression_method != 0)) ||
!CBS_get_u16_length_prefixed(&cbs, &extensions) ||
CBS_len(&cbs) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (server_wire_version != ssl->version) {
ssl3_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);
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
if (cipher == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* Check if the cipher is a TLS 1.3 cipher. */
if (SSL_CIPHER_get_min_version(cipher) > ssl3_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl3_protocol_version(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* Parse out the extensions. */
int have_key_share = 0, have_pre_shared_key = 0;
CBS key_share, pre_shared_key;
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},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
0 /* reject unknown */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
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);
ssl3_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)) {
ssl3_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);
ssl3_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);
ssl3_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);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
ssl->s3->session_reused = 1;
/* 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 == NULL) {
ssl3_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,
ssl->session_ctx->session_psk_dhe_timeout);
} else if (!ssl_get_new_session(hs, 0)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->new_session->cipher = cipher;
hs->new_cipher = cipher;
/* The PRF hash is now known. Set up the key schedule. */
if (!tls13_init_key_schedule(hs)) {
return ssl_hs_error;
}
/* Incorporate the PSK into the running secret. */
if (ssl->s3->session_reused) {
if (!tls13_advance_key_schedule(hs, hs->new_session->master_key,
hs->new_session->master_key_length)) {
return ssl_hs_error;
}
} else if (!tls13_advance_key_schedule(hs, kZeroes, hs->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);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
return ssl_hs_error;
}
/* Resolve ECDHE and incorporate it into the secret. */
uint8_t *dhe_secret;
size_t dhe_secret_len;
alert = SSL_AD_DECODE_ERROR;
if (!ssl_ext_key_share_parse_serverhello(hs, &dhe_secret, &dhe_secret_len,
&alert, &key_share)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (!tls13_advance_key_schedule(hs, dhe_secret, dhe_secret_len)) {
OPENSSL_free(dhe_secret);
return ssl_hs_error;
}
OPENSSL_free(dhe_secret);
if (!ssl_hash_current_message(hs) ||
!tls13_derive_handshake_secrets(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_process_change_cipher_spec;
return ssl->version == TLS1_3_EXPERIMENT_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->version == TLS1_3_EXPERIMENT_VERSION &&
!ssl3_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_process_encrypted_extensions;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_encrypted_extensions(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_check_message_type(ssl, SSL3_MT_ENCRYPTED_EXTENSIONS)) {
return ssl_hs_error;
}
CBS cbs;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!ssl_parse_serverhello_tlsext(hs, &cbs)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
if (CBS_len(&cbs) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_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 != NULL) {
hs->new_session->early_alpn =
BUF_memdup(ssl->s3->alpn_selected, ssl->s3->alpn_selected_len);
if (hs->new_session->early_alpn == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->new_session->early_alpn_len = ssl->s3->alpn_selected_len;
}
if (ssl->early_data_accepted) {
if (hs->early_session->cipher != hs->new_session->cipher ||
hs->early_session->early_alpn_len != ssl->s3->alpn_selected_len ||
OPENSSL_memcmp(hs->early_session->early_alpn, ssl->s3->alpn_selected,
ssl->s3->alpn_selected_len) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_ALPN_MISMATCH_ON_EARLY_DATA);
return ssl_hs_error;
}
if (ssl->s3->tlsext_channel_id_valid) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_ON_EARLY_DATA);
return ssl_hs_error;
}
}
if (!ssl_hash_current_message(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_continue_second_server_flight;
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_continue_second_server_flight(SSL_HANDSHAKE *hs) {
hs->tls13_state = state_process_certificate_request;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_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_process_server_finished;
return ssl_hs_ok;
}
/* CertificateRequest is optional. */
if (ssl->s3->tmp.message_type != SSL3_MT_CERTIFICATE_REQUEST) {
hs->tls13_state = state_process_server_certificate;
return ssl_hs_ok;
}
CBS cbs, context, supported_signature_algorithms;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!CBS_get_u8_length_prefixed(&cbs, &context) ||
/* The request context is always empty during the handshake. */
CBS_len(&context) != 0 ||
!CBS_get_u16_length_prefixed(&cbs, &supported_signature_algorithms) ||
CBS_len(&supported_signature_algorithms) == 0 ||
!tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
ssl3_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;
STACK_OF(CRYPTO_BUFFER) *ca_names =
ssl_parse_client_CA_list(ssl, &alert, &cbs);
if (ca_names == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
/* Ignore extensions. */
CBS extensions;
if (!CBS_get_u16_length_prefixed(&cbs, &extensions) ||
CBS_len(&cbs) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
sk_CRYPTO_BUFFER_pop_free(ca_names, CRYPTO_BUFFER_free);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
hs->cert_request = 1;
sk_CRYPTO_BUFFER_pop_free(hs->ca_names, CRYPTO_BUFFER_free);
hs->ca_names = ca_names;
ssl->ctx->x509_method->hs_flush_cached_ca_names(hs);
if (!ssl_hash_current_message(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_process_server_certificate;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_server_certificate(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_check_message_type(ssl, SSL3_MT_CERTIFICATE) ||
!tls13_process_certificate(hs, 0 /* certificate required */) ||
!ssl_hash_current_message(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_process_server_certificate_verify;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_server_certificate_verify(
SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_check_message_type(ssl, SSL3_MT_CERTIFICATE_VERIFY) ||
!tls13_process_certificate_verify(hs) ||
!ssl_hash_current_message(hs)) {
return ssl_hs_error;
}
hs->tls13_state = state_process_server_finished;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_server_finished(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_check_message_type(ssl, SSL3_MT_FINISHED) ||
!tls13_process_finished(hs, 0 /* don't use saved value */) ||
!ssl_hash_current_message(hs) ||
/* 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->received_flight(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 = 0;
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->version == TLS1_3_EXPERIMENT_VERSION &&
!ssl3_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) {
ssl3_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;
}
CBB cbb, body;
if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_CHANNEL_ID) ||
!tls1_write_channel_id(hs, &body) ||
!ssl_add_message_cbb(ssl, &cbb)) {
CBB_cleanup(&cbb);
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 = hs->tls13_state;
switch (state) {
case state_process_hello_retry_request:
ret = do_process_hello_retry_request(hs);
break;
case state_send_second_client_hello:
ret = do_send_second_client_hello(hs);
break;
case state_process_server_hello:
ret = do_process_server_hello(hs);
break;
case state_process_change_cipher_spec:
ret = do_process_change_cipher_spec(hs);
break;
case state_process_encrypted_extensions:
ret = do_process_encrypted_extensions(hs);
break;
case state_continue_second_server_flight:
ret = do_continue_second_server_flight(hs);
break;
case state_process_certificate_request:
ret = do_process_certificate_request(hs);
break;
case state_process_server_certificate:
ret = do_process_server_certificate(hs);
break;
case state_process_server_certificate_verify:
ret = do_process_server_certificate_verify(hs);
break;
case state_process_server_finished:
ret = do_process_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 (ret != ssl_hs_ok) {
return ret;
}
}
return ssl_hs_ok;
}
int tls13_process_new_session_ticket(SSL *ssl) {
int ret = 0;
SSL_SESSION *session = SSL_SESSION_dup(ssl->s3->established_session,
SSL_SESSION_INCLUDE_NONAUTH);
if (session == NULL) {
return 0;
}
ssl_session_rebase_time(ssl, session);
uint32_t server_timeout;
CBS cbs, ticket, extensions;
CBS_init(&cbs, ssl->init_msg, ssl->init_num);
if (!CBS_get_u32(&cbs, &server_timeout) ||
!CBS_get_u32(&cbs, &session->ticket_age_add) ||
!CBS_get_u16_length_prefixed(&cbs, &ticket) ||
!CBS_stow(&ticket, &session->tlsext_tick, &session->tlsext_ticklen) ||
!CBS_get_u16_length_prefixed(&cbs, &extensions) ||
CBS_len(&cbs) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto err;
}
/* 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;
}
/* Parse out the extensions. */
int have_early_data_info = 0;
CBS early_data_info;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_ticket_early_data_info, &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 */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
goto err;
}
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) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto err;
}
}
session->ticket_age_add_valid = 1;
session->not_resumable = 0;
if (ssl->ctx->new_session_cb != NULL &&
ssl->ctx->new_session_cb(ssl, session)) {
/* |new_session_cb|'s return value signals that it took ownership. */
session = NULL;
}
ret = 1;
err:
SSL_SESSION_free(session);
return ret;
}
void ssl_clear_tls13_state(SSL_HANDSHAKE *hs) {
SSL_ECDH_CTX_cleanup(&hs->ecdh_ctx);
OPENSSL_free(hs->key_share_bytes);
hs->key_share_bytes = NULL;
hs->key_share_bytes_len = 0;
}
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