boringssl/ssl/tls13_server.c
David Benjamin 6929f27ed5 Fix return values for TLS 1.3 state machine code.
This is a no-op because all affected codepaths are either unreachable or
are fine because ssl_hs_error (intentionally, since C doesn't help us
any) aligns with zero. Still, fix these.

Change-Id: Ieba4e3eec3881a56b5ddcd32abdd2c9dda875eda
Reviewed-on: https://boringssl-review.googlesource.com/12313
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2016-11-16 13:13:50 +00:00

768 lines
24 KiB
C

/* 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 <string.h>
#include <openssl/aead.h>
#include <openssl/bytestring.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include <openssl/stack.h>
#include "internal.h"
enum server_hs_state_t {
state_process_client_hello = 0,
state_select_parameters,
state_send_hello_retry_request,
state_flush_hello_retry_request,
state_process_second_client_hello,
state_send_server_hello,
state_send_encrypted_extensions,
state_send_certificate_request,
state_send_server_certificate,
state_send_server_certificate_verify,
state_complete_server_certificate_verify,
state_send_server_finished,
state_flush,
state_process_client_certificate,
state_process_client_certificate_verify,
state_process_channel_id,
state_process_client_finished,
state_send_new_session_ticket,
state_flush_new_session_tickets,
state_done,
};
static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
static int resolve_ecdhe_secret(SSL *ssl, int *out_need_retry,
struct ssl_early_callback_ctx *early_ctx) {
*out_need_retry = 0;
/* We only support connections that include an ECDHE key exchange. */
CBS key_share;
if (!ssl_early_callback_get_extension(early_ctx, &key_share,
TLSEXT_TYPE_key_share)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_KEY_SHARE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
return 0;
}
int found_key_share;
uint8_t *dhe_secret;
size_t dhe_secret_len;
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_ext_key_share_parse_clienthello(ssl, &found_key_share, &dhe_secret,
&dhe_secret_len, &alert,
&key_share)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return 0;
}
if (!found_key_share) {
*out_need_retry = 1;
return 0;
}
int ok = tls13_advance_key_schedule(ssl, dhe_secret, dhe_secret_len);
OPENSSL_free(dhe_secret);
return ok;
}
static enum ssl_hs_wait_t do_process_client_hello(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!tls13_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) {
return ssl_hs_error;
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
assert(ssl->s3->have_version);
/* Load the client random. */
if (client_hello.random_len != SSL3_RANDOM_SIZE) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
memcpy(ssl->s3->client_random, client_hello.random, client_hello.random_len);
uint8_t alert = SSL_AD_DECODE_ERROR;
CBS psk_key_exchange_modes;
if (ssl_early_callback_get_extension(&client_hello, &psk_key_exchange_modes,
TLSEXT_TYPE_psk_key_exchange_modes) &&
!ssl_ext_psk_key_exchange_modes_parse_clienthello(
ssl, &alert, &psk_key_exchange_modes)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
SSL_SESSION *session = NULL;
CBS binders;
if (hs->accept_psk_mode) {
CBS pre_shared_key;
if (ssl_early_callback_get_extension(&client_hello, &pre_shared_key,
TLSEXT_TYPE_pre_shared_key)) {
/* Verify that the pre_shared_key extension is the last extension in
* ClientHello. */
if (CBS_data(&pre_shared_key) + CBS_len(&pre_shared_key) !=
client_hello.extensions + client_hello.extensions_len) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PRE_SHARED_KEY_MUST_BE_LAST);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl_ext_pre_shared_key_parse_clienthello(ssl, &session, &binders,
&alert, &pre_shared_key)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
}
}
if (session != NULL &&
!ssl_session_is_resumable(ssl, session)) {
SSL_SESSION_free(session);
session = NULL;
}
if (session == NULL) {
if (!ssl_get_new_session(ssl, 1 /* server */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
} else {
/* Check the PSK binder. */
if (!tls13_verify_psk_binder(ssl, session, &binders)) {
SSL_SESSION_free(session);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
return ssl_hs_error;
}
/* Only authentication information carries over in TLS 1.3. */
ssl->s3->new_session = SSL_SESSION_dup(session, SSL_SESSION_DUP_AUTH_ONLY);
if (ssl->s3->new_session == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
ssl->s3->session_reused = 1;
SSL_SESSION_free(session);
}
if (ssl->ctx->dos_protection_cb != NULL &&
ssl->ctx->dos_protection_cb(&client_hello) == 0) {
/* Connection rejected for DOS reasons. */
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
/* TLS 1.3 requires the peer only advertise the null compression. */
if (client_hello.compression_methods_len != 1 ||
client_hello.compression_methods[0] != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMPRESSION_LIST);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* TLS extensions. */
if (!ssl_parse_clienthello_tlsext(ssl, &client_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
hs->state = state_select_parameters;
return ssl_hs_ok;
}
static const SSL_CIPHER *choose_tls13_cipher(
const SSL *ssl, const struct ssl_early_callback_ctx *client_hello) {
if (client_hello->cipher_suites_len % 2 != 0) {
return NULL;
}
CBS cipher_suites;
CBS_init(&cipher_suites, client_hello->cipher_suites,
client_hello->cipher_suites_len);
const int aes_is_fine = EVP_has_aes_hardware();
const SSL_CIPHER *best = NULL;
while (CBS_len(&cipher_suites) > 0) {
uint16_t cipher_suite;
if (!CBS_get_u16(&cipher_suites, &cipher_suite)) {
return NULL;
}
const SSL_CIPHER *candidate = SSL_get_cipher_by_value(cipher_suite);
if (candidate == NULL || !ssl_is_valid_cipher(ssl, candidate)) {
continue;
}
/* TLS 1.3 removes legacy ciphers, so honor the client order, but prefer
* ChaCha20 if we do not have AES hardware. */
if (aes_is_fine) {
return candidate;
}
if (candidate->algorithm_enc == SSL_CHACHA20POLY1305) {
return candidate;
}
if (best == NULL) {
best = candidate;
}
}
return best;
}
static enum ssl_hs_wait_t do_select_parameters(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!ssl->s3->session_reused) {
/* Call |cert_cb| to update server certificates if required. */
if (ssl->cert->cert_cb != NULL) {
int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg);
if (rv == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
if (rv < 0) {
hs->state = state_select_parameters;
return ssl_hs_x509_lookup;
}
}
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (ssl->s3->session_reused) {
/* Clients may not offer sessions containing unsupported ciphers. */
if (!ssl_client_cipher_list_contains_cipher(
&client_hello,
(uint16_t)SSL_CIPHER_get_id(ssl->s3->new_session->cipher))) {
OPENSSL_PUT_ERROR(SSL, SSL_R_REQUIRED_CIPHER_MISSING);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
} else {
const SSL_CIPHER *cipher = choose_tls13_cipher(ssl, &client_hello);
if (cipher == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
ssl->s3->new_session->cipher = cipher;
}
ssl->s3->tmp.new_cipher = ssl->s3->new_session->cipher;
ssl->method->received_flight(ssl);
/* Resolve ALPN after the cipher suite is selected. HTTP/2 negotiation depends
* on the cipher suite. */
uint8_t alert;
if (!ssl_negotiate_alpn(ssl, &alert, &client_hello)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
/* The PRF hash is now known. */
size_t hash_len =
EVP_MD_size(ssl_get_handshake_digest(ssl_get_algorithm_prf(ssl)));
/* Derive resumption material. */
uint8_t psk_secret[EVP_MAX_MD_SIZE] = {0};
if (ssl->s3->session_reused) {
if (hash_len != (size_t) ssl->s3->new_session->master_key_length) {
return ssl_hs_error;
}
memcpy(psk_secret, ssl->s3->new_session->master_key, hash_len);
}
/* Set up the key schedule, hash in the ClientHello, and incorporate the PSK
* into the running secret. */
if (!tls13_init_key_schedule(ssl) ||
!tls13_advance_key_schedule(ssl, psk_secret, hash_len)) {
return ssl_hs_error;
}
/* Resolve ECDHE and incorporate it into the secret. */
int need_retry;
if (!resolve_ecdhe_secret(ssl, &need_retry, &client_hello)) {
if (need_retry) {
hs->state = state_send_hello_retry_request;
return ssl_hs_ok;
}
return ssl_hs_error;
}
hs->state = state_send_server_hello;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_hello_retry_request(SSL *ssl,
SSL_HANDSHAKE *hs) {
CBB cbb, body, extensions;
uint16_t group_id;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_HELLO_RETRY_REQUEST) ||
!CBB_add_u16(&body, ssl->version) ||
!tls1_get_shared_group(ssl, &group_id) ||
!CBB_add_u16_length_prefixed(&body, &extensions) ||
!CBB_add_u16(&extensions, TLSEXT_TYPE_key_share) ||
!CBB_add_u16(&extensions, 2 /* length */) ||
!CBB_add_u16(&extensions, group_id) ||
!ssl_complete_message(ssl, &cbb)) {
CBB_cleanup(&cbb);
return ssl_hs_error;
}
hs->state = state_flush_hello_retry_request;
return ssl_hs_write_message;
}
static enum ssl_hs_wait_t do_flush_hello_retry_request(SSL *ssl,
SSL_HANDSHAKE *hs) {
hs->state = state_process_second_client_hello;
return ssl_hs_flush_and_read_message;
}
static enum ssl_hs_wait_t do_process_second_client_hello(SSL *ssl,
SSL_HANDSHAKE *hs) {
if (!tls13_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) {
return ssl_hs_error;
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
int need_retry;
if (!resolve_ecdhe_secret(ssl, &need_retry, &client_hello)) {
if (need_retry) {
/* Only send one HelloRetryRequest. */
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
}
return ssl_hs_error;
}
if (!ssl_hash_current_message(ssl)) {
return ssl_hs_error;
}
ssl->method->received_flight(ssl);
hs->state = state_send_server_hello;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_server_hello(SSL *ssl, SSL_HANDSHAKE *hs) {
CBB cbb, body, extensions;
if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_SERVER_HELLO) ||
!CBB_add_u16(&body, ssl->version) ||
!RAND_bytes(ssl->s3->server_random, sizeof(ssl->s3->server_random)) ||
!CBB_add_bytes(&body, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
!CBB_add_u16(&body, ssl_cipher_get_value(ssl->s3->tmp.new_cipher)) ||
!CBB_add_u16_length_prefixed(&body, &extensions) ||
!ssl_ext_pre_shared_key_add_serverhello(ssl, &extensions) ||
!ssl_ext_key_share_add_serverhello(ssl, &extensions) ||
!ssl_complete_message(ssl, &cbb)) {
goto err;
}
hs->state = state_send_encrypted_extensions;
return ssl_hs_write_message;
err:
CBB_cleanup(&cbb);
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_send_encrypted_extensions(SSL *ssl,
SSL_HANDSHAKE *hs) {
if (!tls13_set_handshake_traffic(ssl)) {
return ssl_hs_error;
}
CBB cbb, body;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_ENCRYPTED_EXTENSIONS) ||
!ssl_add_serverhello_tlsext(ssl, &body) ||
!ssl_complete_message(ssl, &cbb)) {
CBB_cleanup(&cbb);
return ssl_hs_error;
}
hs->state = state_send_certificate_request;
return ssl_hs_write_message;
}
static enum ssl_hs_wait_t do_send_certificate_request(SSL *ssl,
SSL_HANDSHAKE *hs) {
/* Determine whether to request a client certificate. */
ssl->s3->hs->cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER);
/* CertificateRequest may only be sent in non-resumption handshakes. */
if (ssl->s3->session_reused) {
ssl->s3->hs->cert_request = 0;
}
if (!ssl->s3->hs->cert_request) {
/* Skip this state. */
hs->state = state_send_server_certificate;
return ssl_hs_ok;
}
CBB cbb, body, sigalgs_cbb;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_CERTIFICATE_REQUEST) ||
!CBB_add_u8(&body, 0 /* no certificate_request_context. */)) {
goto err;
}
const uint16_t *sigalgs;
size_t num_sigalgs = tls12_get_verify_sigalgs(ssl, &sigalgs);
if (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb)) {
goto err;
}
for (size_t i = 0; i < num_sigalgs; i++) {
if (!CBB_add_u16(&sigalgs_cbb, sigalgs[i])) {
goto err;
}
}
if (!ssl_add_client_CA_list(ssl, &body) ||
!CBB_add_u16(&body, 0 /* empty certificate_extensions. */) ||
!ssl_complete_message(ssl, &cbb)) {
goto err;
}
hs->state = state_send_server_certificate;
return ssl_hs_write_message;
err:
CBB_cleanup(&cbb);
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_send_server_certificate(SSL *ssl,
SSL_HANDSHAKE *hs) {
if (ssl->s3->session_reused) {
hs->state = state_send_server_finished;
return ssl_hs_ok;
}
if (!ssl_has_certificate(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
return ssl_hs_error;
}
if (!tls13_prepare_certificate(ssl)) {
return ssl_hs_error;
}
hs->state = state_send_server_certificate_verify;
return ssl_hs_write_message;
}
static enum ssl_hs_wait_t do_send_server_certificate_verify(SSL *ssl,
SSL_HANDSHAKE *hs,
int is_first_run) {
switch (tls13_prepare_certificate_verify(ssl, is_first_run)) {
case ssl_private_key_success:
hs->state = state_send_server_finished;
return ssl_hs_write_message;
case ssl_private_key_retry:
hs->state = state_complete_server_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_send_server_finished(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!tls13_prepare_finished(ssl)) {
return ssl_hs_error;
}
hs->state = state_flush;
return ssl_hs_write_message;
}
static enum ssl_hs_wait_t do_flush(SSL *ssl, SSL_HANDSHAKE *hs) {
/* Update the secret to the master secret and derive traffic keys. */
if (!tls13_advance_key_schedule(ssl, kZeroes, hs->hash_len) ||
!tls13_derive_application_secrets(ssl) ||
!tls13_set_traffic_key(ssl, evp_aead_seal, hs->server_traffic_secret_0,
hs->hash_len)) {
return ssl_hs_error;
}
hs->state = state_process_client_certificate;
return ssl_hs_flush_and_read_message;
}
static enum ssl_hs_wait_t do_process_client_certificate(SSL *ssl,
SSL_HANDSHAKE *hs) {
if (!ssl->s3->hs->cert_request) {
/* OpenSSL returns X509_V_OK when no certificates are requested. This is
* classed by them as a bug, but it's assumed by at least NGINX. */
ssl->s3->new_session->verify_result = X509_V_OK;
/* Skip this state. */
hs->state = state_process_channel_id;
return ssl_hs_ok;
}
const int allow_anonymous =
(ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) == 0;
if (!tls13_check_message_type(ssl, SSL3_MT_CERTIFICATE) ||
!tls13_process_certificate(ssl, allow_anonymous) ||
!ssl_hash_current_message(ssl)) {
return ssl_hs_error;
}
/* For historical reasons, the server's copy of the chain does not include the
* leaf while the client's does. */
if (sk_X509_num(ssl->s3->new_session->x509_chain) > 0) {
X509_free(sk_X509_shift(ssl->s3->new_session->x509_chain));
}
hs->state = state_process_client_certificate_verify;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_client_certificate_verify(
SSL *ssl, SSL_HANDSHAKE *hs) {
if (ssl->s3->new_session->x509_peer == NULL) {
/* Skip this state. */
hs->state = state_process_channel_id;
return ssl_hs_ok;
}
if (!tls13_check_message_type(ssl, SSL3_MT_CERTIFICATE_VERIFY) ||
!tls13_process_certificate_verify(ssl) ||
!ssl_hash_current_message(ssl)) {
return ssl_hs_error;
}
hs->state = state_process_channel_id;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_channel_id(SSL *ssl, SSL_HANDSHAKE *hs) {
if (!ssl->s3->tlsext_channel_id_valid) {
hs->state = state_process_client_finished;
return ssl_hs_ok;
}
if (!tls13_check_message_type(ssl, SSL3_MT_CHANNEL_ID) ||
!tls1_verify_channel_id(ssl) ||
!ssl_hash_current_message(ssl)) {
return ssl_hs_error;
}
hs->state = state_process_client_finished;
return ssl_hs_read_message;
}
static enum ssl_hs_wait_t do_process_client_finished(SSL *ssl,
SSL_HANDSHAKE *hs) {
if (!tls13_check_message_type(ssl, SSL3_MT_FINISHED) ||
!tls13_process_finished(ssl) ||
!ssl_hash_current_message(ssl) ||
/* evp_aead_seal keys have already been switched. */
!tls13_set_traffic_key(ssl, evp_aead_open, hs->client_traffic_secret_0,
hs->hash_len) ||
!tls13_derive_resumption_secret(ssl)) {
return ssl_hs_error;
}
ssl->method->received_flight(ssl);
/* Refresh the session timestamp so that it is measured from ticket
* issuance. */
ssl_session_refresh_time(ssl, ssl->s3->new_session);
hs->state = state_send_new_session_ticket;
return ssl_hs_ok;
}
/* TLS 1.3 recommends single-use tickets, so issue multiple tickets in case the
* client makes several connections before getting a renewal. */
static const int kNumTickets = 2;
static enum ssl_hs_wait_t do_send_new_session_ticket(SSL *ssl,
SSL_HANDSHAKE *hs) {
/* If the client doesn't accept resumption with PSK_DHE_KE, don't send a
* session ticket. */
if (!hs->accept_psk_mode) {
hs->state = state_done;
return ssl_hs_ok;
}
SSL_SESSION *session = ssl->s3->new_session;
if (!RAND_bytes((uint8_t *)&session->ticket_age_add, 4)) {
goto err;
}
/* TODO(svaldez): Add support for sending 0RTT through TicketEarlyDataInfo
* extension. */
CBB cbb, body, ticket, extensions;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_NEW_SESSION_TICKET) ||
!CBB_add_u32(&body, session->timeout) ||
!CBB_add_u32(&body, session->ticket_age_add) ||
!CBB_add_u16_length_prefixed(&body, &ticket) ||
!ssl_encrypt_ticket(ssl, &ticket, session) ||
!CBB_add_u16_length_prefixed(&body, &extensions)) {
goto err;
}
/* Add a fake extension. See draft-davidben-tls-grease-01. */
if (!CBB_add_u16(&extensions,
ssl_get_grease_value(ssl, ssl_grease_ticket_extension)) ||
!CBB_add_u16(&extensions, 0 /* empty */)) {
goto err;
}
if (!ssl_complete_message(ssl, &cbb)) {
goto err;
}
hs->session_tickets_sent++;
if (hs->session_tickets_sent >= kNumTickets) {
hs->state = state_flush_new_session_tickets;
} else {
hs->state = state_send_new_session_ticket;
}
return ssl_hs_write_message;
err:
CBB_cleanup(&cbb);
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_flush_new_session_tickets(SSL *ssl,
SSL_HANDSHAKE *hs) {
hs->state = state_done;
return ssl_hs_flush;
}
enum ssl_hs_wait_t tls13_server_handshake(SSL *ssl) {
SSL_HANDSHAKE *hs = ssl->s3->hs;
while (hs->state != state_done) {
enum ssl_hs_wait_t ret = ssl_hs_error;
enum server_hs_state_t state = hs->state;
switch (state) {
case state_process_client_hello:
ret = do_process_client_hello(ssl, hs);
break;
case state_select_parameters:
ret = do_select_parameters(ssl, hs);
break;
case state_send_hello_retry_request:
ret = do_send_hello_retry_request(ssl, hs);
break;
case state_flush_hello_retry_request:
ret = do_flush_hello_retry_request(ssl, hs);
break;
case state_process_second_client_hello:
ret = do_process_second_client_hello(ssl, hs);
break;
case state_send_server_hello:
ret = do_send_server_hello(ssl, hs);
break;
case state_send_encrypted_extensions:
ret = do_send_encrypted_extensions(ssl, hs);
break;
case state_send_certificate_request:
ret = do_send_certificate_request(ssl, hs);
break;
case state_send_server_certificate:
ret = do_send_server_certificate(ssl, hs);
break;
case state_send_server_certificate_verify:
ret = do_send_server_certificate_verify(ssl, hs, 1 /* first run */);
break;
case state_complete_server_certificate_verify:
ret = do_send_server_certificate_verify(ssl, hs, 0 /* complete */);
break;
case state_send_server_finished:
ret = do_send_server_finished(ssl, hs);
break;
case state_flush:
ret = do_flush(ssl, hs);
break;
case state_process_client_certificate:
ret = do_process_client_certificate(ssl, hs);
break;
case state_process_client_certificate_verify:
ret = do_process_client_certificate_verify(ssl, hs);
break;
case state_process_channel_id:
ret = do_process_channel_id(ssl, hs);
break;
case state_process_client_finished:
ret = do_process_client_finished(ssl, hs);
break;
case state_send_new_session_ticket:
ret = do_send_new_session_ticket(ssl, hs);
break;
case state_flush_new_session_tickets:
ret = do_flush_new_session_tickets(ssl, hs);
break;
case state_done:
ret = ssl_hs_ok;
break;
}
if (ret != ssl_hs_ok) {
return ret;
}
}
return ssl_hs_ok;
}