| /* 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 "../crypto/internal.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_HANDSHAKE *hs, int *out_need_retry, |
| SSL_CLIENT_HELLO *client_hello) { |
| SSL *const ssl = hs->ssl; |
| *out_need_retry = 0; |
| |
| /* We only support connections that include an ECDHE key exchange. */ |
| CBS key_share; |
| if (!ssl_client_hello_get_extension(client_hello, &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(hs, &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(hs, dhe_secret, dhe_secret_len); |
| OPENSSL_free(dhe_secret); |
| return ok; |
| } |
| |
| static enum ssl_hs_wait_t do_process_client_hello(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!tls13_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) { |
| return ssl_hs_error; |
| } |
| |
| SSL_CLIENT_HELLO client_hello; |
| if (!ssl_client_hello_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; |
| } |
| OPENSSL_memcpy(ssl->s3->client_random, client_hello.random, |
| client_hello.random_len); |
| |
| /* 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(hs, &client_hello)) { |
| OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT); |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_select_parameters; |
| return ssl_hs_ok; |
| } |
| |
| static const SSL_CIPHER *choose_tls13_cipher( |
| const SSL *ssl, const SSL_CLIENT_HELLO *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 uint16_t version = ssl3_protocol_version(ssl); |
| |
| 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; |
| } |
| |
| /* Limit to TLS 1.3 ciphers we know about. */ |
| const SSL_CIPHER *candidate = SSL_get_cipher_by_value(cipher_suite); |
| if (candidate == NULL || |
| SSL_CIPHER_get_min_version(candidate) > version || |
| SSL_CIPHER_get_max_version(candidate) < version) { |
| 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_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| /* 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->tls13_state = state_select_parameters; |
| return ssl_hs_x509_lookup; |
| } |
| } |
| |
| SSL_CLIENT_HELLO client_hello; |
| if (!ssl_client_hello_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; |
| } |
| |
| /* Negotiate the cipher suite. */ |
| ssl->s3->tmp.new_cipher = choose_tls13_cipher(ssl, &client_hello); |
| if (ssl->s3->tmp.new_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; |
| } |
| |
| /* Decode the ticket if we agree on a PSK key exchange mode. */ |
| uint8_t alert = SSL_AD_DECODE_ERROR; |
| SSL_SESSION *session = NULL; |
| CBS pre_shared_key, binders; |
| if (hs->accept_psk_mode && |
| ssl_client_hello_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(hs, &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; |
| } |
| |
| /* Set up the new session, either using the original one as a template or |
| * creating a fresh one. */ |
| if (session == NULL) { |
| if (!ssl_get_new_session(hs, 1 /* server */)) { |
| ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR); |
| return ssl_hs_error; |
| } |
| |
| ssl->s3->new_session->cipher = ssl->s3->tmp.new_cipher; |
| |
| /* On new sessions, stash the SNI value in the session. */ |
| if (hs->hostname != NULL) { |
| ssl->s3->new_session->tlsext_hostname = BUF_strdup(hs->hostname); |
| if (ssl->s3->new_session->tlsext_hostname == NULL) { |
| 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; |
| } |
| |
| /* HTTP/2 negotiation depends on the cipher suite, so ALPN negotiation was |
| * deferred. Complete it now. */ |
| if (!ssl_negotiate_alpn(hs, &alert, &client_hello)) { |
| ssl3_send_alert(ssl, SSL3_AL_FATAL, alert); |
| return ssl_hs_error; |
| } |
| |
| /* The PRF hash is now known. Set up the key schedule. */ |
| size_t hash_len = |
| EVP_MD_size(ssl_get_handshake_digest(ssl_get_algorithm_prf(ssl))); |
| 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, ssl->s3->new_session->master_key, |
| ssl->s3->new_session->master_key_length)) { |
| return ssl_hs_error; |
| } |
| } else if (!tls13_advance_key_schedule(hs, kZeroes, hash_len)) { |
| return ssl_hs_error; |
| } |
| |
| ssl->method->received_flight(ssl); |
| |
| /* Resolve ECDHE and incorporate it into the secret. */ |
| int need_retry; |
| if (!resolve_ecdhe_secret(hs, &need_retry, &client_hello)) { |
| if (need_retry) { |
| hs->tls13_state = state_send_hello_retry_request; |
| return ssl_hs_ok; |
| } |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_send_server_hello; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_send_hello_retry_request(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| 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(hs, &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->tls13_state = state_flush_hello_retry_request; |
| return ssl_hs_write_message; |
| } |
| |
| static enum ssl_hs_wait_t do_flush_hello_retry_request(SSL_HANDSHAKE *hs) { |
| hs->tls13_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_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!tls13_check_message_type(ssl, SSL3_MT_CLIENT_HELLO)) { |
| return ssl_hs_error; |
| } |
| |
| SSL_CLIENT_HELLO client_hello; |
| if (!ssl_client_hello_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(hs, &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->tls13_state = state_send_server_hello; |
| return ssl_hs_ok; |
| } |
| |
| static enum ssl_hs_wait_t do_send_server_hello(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| 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(hs, &extensions) || |
| !ssl_ext_key_share_add_serverhello(hs, &extensions) || |
| !ssl_complete_message(ssl, &cbb)) { |
| goto err; |
| } |
| |
| hs->tls13_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_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!tls13_derive_handshake_secrets(hs) || |
| !tls13_set_traffic_key(ssl, evp_aead_open, hs->client_handshake_secret, |
| hs->hash_len) || |
| !tls13_set_traffic_key(ssl, evp_aead_seal, hs->server_handshake_secret, |
| hs->hash_len)) { |
| return ssl_hs_error; |
| } |
| |
| CBB cbb, body; |
| if (!ssl->method->init_message(ssl, &cbb, &body, |
| SSL3_MT_ENCRYPTED_EXTENSIONS) || |
| !ssl_add_serverhello_tlsext(hs, &body) || |
| !ssl_complete_message(ssl, &cbb)) { |
| CBB_cleanup(&cbb); |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_send_certificate_request; |
| return ssl_hs_write_message; |
| } |
| |
| static enum ssl_hs_wait_t do_send_certificate_request(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| /* Determine whether to request a client certificate. */ |
| hs->cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER); |
| /* CertificateRequest may only be sent in non-resumption handshakes. */ |
| if (ssl->s3->session_reused) { |
| hs->cert_request = 0; |
| } |
| |
| if (!hs->cert_request) { |
| /* Skip this state. */ |
| hs->tls13_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->tls13_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_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (ssl->s3->session_reused) { |
| hs->tls13_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(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_send_server_certificate_verify; |
| return ssl_hs_write_message; |
| } |
| |
| static enum ssl_hs_wait_t do_send_server_certificate_verify(SSL_HANDSHAKE *hs, |
| int is_first_run) { |
| switch (tls13_prepare_certificate_verify(hs, is_first_run)) { |
| case ssl_private_key_success: |
| hs->tls13_state = state_send_server_finished; |
| return ssl_hs_write_message; |
| |
| case ssl_private_key_retry: |
| hs->tls13_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_HANDSHAKE *hs) { |
| if (!tls13_prepare_finished(hs)) { |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_flush; |
| return ssl_hs_write_message; |
| } |
| |
| static enum ssl_hs_wait_t do_flush(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| /* Update the secret to the master secret and derive traffic keys. */ |
| if (!tls13_advance_key_schedule(hs, kZeroes, hs->hash_len) || |
| !tls13_derive_application_secrets(hs) || |
| !tls13_set_traffic_key(ssl, evp_aead_seal, hs->server_traffic_secret_0, |
| hs->hash_len)) { |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_process_client_certificate; |
| return ssl_hs_flush_and_read_message; |
| } |
| |
| static enum ssl_hs_wait_t do_process_client_certificate(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!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->tls13_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(hs, allow_anonymous) || |
| !ssl_hash_current_message(ssl)) { |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_process_client_certificate_verify; |
| return ssl_hs_read_message; |
| } |
| |
| static enum ssl_hs_wait_t do_process_client_certificate_verify( |
| SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (ssl->s3->new_session->x509_peer == NULL) { |
| /* Skip this state. */ |
| hs->tls13_state = state_process_channel_id; |
| return ssl_hs_ok; |
| } |
| |
| if (!tls13_check_message_type(ssl, SSL3_MT_CERTIFICATE_VERIFY) || |
| !tls13_process_certificate_verify(hs) || |
| !ssl_hash_current_message(ssl)) { |
| return ssl_hs_error; |
| } |
| |
| hs->tls13_state = state_process_channel_id; |
| return ssl_hs_read_message; |
| } |
| |
| static enum ssl_hs_wait_t do_process_channel_id(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!ssl->s3->tlsext_channel_id_valid) { |
| hs->tls13_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->tls13_state = state_process_client_finished; |
| return ssl_hs_read_message; |
| } |
| |
| static enum ssl_hs_wait_t do_process_client_finished(SSL_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| if (!tls13_check_message_type(ssl, SSL3_MT_FINISHED) || |
| !tls13_process_finished(hs) || |
| !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(hs)) { |
| 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->tls13_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_HANDSHAKE *hs) { |
| SSL *const ssl = hs->ssl; |
| /* If the client doesn't accept resumption with PSK_DHE_KE, don't send a |
| * session ticket. */ |
| if (!hs->accept_psk_mode) { |
| hs->tls13_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->tls13_state = state_flush_new_session_tickets; |
| } else { |
| hs->tls13_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_HANDSHAKE *hs) { |
| hs->tls13_state = state_done; |
| return ssl_hs_flush; |
| } |
| |
| enum ssl_hs_wait_t tls13_server_handshake(SSL_HANDSHAKE *hs) { |
| while (hs->tls13_state != state_done) { |
| enum ssl_hs_wait_t ret = ssl_hs_error; |
| enum server_hs_state_t state = hs->tls13_state; |
| switch (state) { |
| case state_process_client_hello: |
| ret = do_process_client_hello(hs); |
| break; |
| case state_select_parameters: |
| ret = do_select_parameters(hs); |
| break; |
| case state_send_hello_retry_request: |
| ret = do_send_hello_retry_request(hs); |
| break; |
| case state_flush_hello_retry_request: |
| ret = do_flush_hello_retry_request(hs); |
| break; |
| case state_process_second_client_hello: |
| ret = do_process_second_client_hello(hs); |
| break; |
| case state_send_server_hello: |
| ret = do_send_server_hello(hs); |
| break; |
| case state_send_encrypted_extensions: |
| ret = do_send_encrypted_extensions(hs); |
| break; |
| case state_send_certificate_request: |
| ret = do_send_certificate_request(hs); |
| break; |
| case state_send_server_certificate: |
| ret = do_send_server_certificate(hs); |
| break; |
| case state_send_server_certificate_verify: |
| ret = do_send_server_certificate_verify(hs, 1 /* first run */); |
| break; |
| case state_complete_server_certificate_verify: |
| ret = do_send_server_certificate_verify(hs, 0 /* complete */); |
| break; |
| case state_send_server_finished: |
| ret = do_send_server_finished(hs); |
| break; |
| case state_flush: |
| ret = do_flush(hs); |
| break; |
| case state_process_client_certificate: |
| ret = do_process_client_certificate(hs); |
| break; |
| case state_process_client_certificate_verify: |
| ret = do_process_client_certificate_verify(hs); |
| break; |
| case state_process_channel_id: |
| ret = do_process_channel_id(hs); |
| break; |
| case state_process_client_finished: |
| ret = do_process_client_finished(hs); |
| break; |
| case state_send_new_session_ticket: |
| ret = do_send_new_session_ticket(hs); |
| break; |
| case state_flush_new_session_tickets: |
| ret = do_flush_new_session_tickets(hs); |
| break; |
| case state_done: |
| ret = ssl_hs_ok; |
| break; |
| } |
| |
| if (ret != ssl_hs_ok) { |
| return ret; |
| } |
| } |
| |
| return ssl_hs_ok; |
| } |