Add TLS 1.3 1-RTT.
This adds the machinery for doing TLS 1.3 1RTT.
Change-Id: I736921ffe9dc6f6e64a08a836df6bb166d20f504
Reviewed-on: https://boringssl-review.googlesource.com/8720
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>
diff --git a/ssl/tls13_server.c b/ssl/tls13_server.c
new file mode 100644
index 0000000..ce65abf
--- /dev/null
+++ b/ssl/tls13_server.c
@@ -0,0 +1,483 @@
+/* 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/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_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_read_client_second_flight,
+ state_process_client_certificate,
+ state_process_client_certificate_verify,
+ state_process_client_finished,
+ state_done,
+};
+
+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 early_ctx;
+ uint16_t client_wire_version;
+ CBS client_random, session_id, cipher_suites, compression_methods;
+
+ memset(&early_ctx, 0, sizeof(early_ctx));
+ early_ctx.ssl = ssl;
+ early_ctx.client_hello = ssl->init_msg;
+ early_ctx.client_hello_len = ssl->init_num;
+ if (!ssl_early_callback_init(&early_ctx)) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+ return ssl_hs_error;
+ }
+
+ CBS cbs;
+ CBS_init(&cbs, ssl->init_msg, ssl->init_num);
+ if (!CBS_get_u16(&cbs, &client_wire_version) ||
+ !CBS_get_bytes(&cbs, &client_random, SSL3_RANDOM_SIZE) ||
+ !CBS_get_u8_length_prefixed(&cbs, &session_id) ||
+ CBS_len(&session_id) > SSL_MAX_SSL_SESSION_ID_LENGTH) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+ return ssl_hs_error;
+ }
+
+ uint16_t min_version, max_version;
+ if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ return ssl_hs_error;
+ }
+
+ assert(ssl->s3->have_version);
+
+ /* Load the client random. */
+ memcpy(ssl->s3->client_random, CBS_data(&client_random), SSL3_RANDOM_SIZE);
+
+ ssl->hit = 0;
+ if (!ssl_get_new_session(ssl, 1 /* server */)) {
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+ return ssl_hs_error;
+ }
+
+ if (ssl->ctx->dos_protection_cb != NULL &&
+ ssl->ctx->dos_protection_cb(&early_ctx) == 0) {
+ /* Connection rejected for DOS reasons. */
+ OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ACCESS_DENIED);
+ return ssl_hs_error;
+ }
+
+ if (!CBS_get_u16_length_prefixed(&cbs, &cipher_suites) ||
+ CBS_len(&cipher_suites) == 0 ||
+ CBS_len(&cipher_suites) % 2 != 0 ||
+ !CBS_get_u8_length_prefixed(&cbs, &compression_methods) ||
+ CBS_len(&compression_methods) == 0) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+ return ssl_hs_error;
+ }
+
+ /* TLS 1.3 requires the peer only advertise the null compression. */
+ if (CBS_len(&compression_methods) != 1 ||
+ CBS_data(&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, &cbs)) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
+ return ssl_hs_error;
+ }
+
+ /* There should be nothing left over in the message. */
+ if (CBS_len(&cbs) != 0) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_PACKET_LENGTH);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
+ return ssl_hs_error;
+ }
+
+ /* Let cert callback update server certificates if required.
+ *
+ * TODO(davidben): Can this get run earlier? */
+ 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_process_client_hello;
+ return ssl_hs_x509_lookup;
+ }
+ }
+
+ STACK_OF(SSL_CIPHER) *ciphers =
+ ssl_bytes_to_cipher_list(ssl, &cipher_suites, max_version);
+ if (ciphers == NULL) {
+ return ssl_hs_error;
+ }
+
+ const SSL_CIPHER *cipher =
+ ssl3_choose_cipher(ssl, ciphers, ssl_get_cipher_preferences(ssl));
+ sk_SSL_CIPHER_free(ciphers);
+ 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->session->cipher = cipher;
+ ssl->s3->tmp.new_cipher = cipher;
+
+ /* The PRF hash is now known. Set up the key schedule and hash the
+ * ClientHello. */
+ static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
+ size_t hash_len =
+ EVP_MD_size(ssl_get_handshake_digest(ssl_get_algorithm_prf(ssl)));
+ if (!tls13_init_key_schedule(ssl, kZeroes, hash_len)) {
+ return ssl_hs_error;
+ }
+
+ /* Resolve PSK and incorporate it into the secret. */
+ if (cipher->algorithm_auth == SSL_aPSK) {
+ /* TODO(davidben): Support PSK. */
+ OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
+ return ssl_hs_error;
+ } else if (!tls13_advance_key_schedule(ssl, kZeroes, hash_len)) {
+ return ssl_hs_error;
+ }
+
+ /* Resolve ECDHE and incorporate it into the secret. */
+ if (cipher->algorithm_mkey == SSL_kECDHE) {
+ const uint8_t *key_share_buf = NULL;
+ size_t key_share_len = 0;
+ CBS key_share;
+ if (!SSL_early_callback_ctx_extension_get(&early_ctx, TLSEXT_TYPE_key_share,
+ &key_share_buf, &key_share_len)) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_KEY_SHARE);
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_MISSING_EXTENSION);
+ return ssl_hs_error;
+ }
+
+ CBS_init(&key_share, key_share_buf, key_share_len);
+ uint8_t *dhe_secret;
+ size_t dhe_secret_len;
+ uint8_t alert;
+ if (!ext_key_share_parse_clienthello(ssl, &dhe_secret, &dhe_secret_len,
+ &alert, &key_share)) {
+ ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
+ return ssl_hs_error;
+ }
+
+ int ok = tls13_advance_key_schedule(ssl, dhe_secret, dhe_secret_len);
+ OPENSSL_free(dhe_secret);
+ if (!ok) {
+ return ssl_hs_error;
+ }
+ } else if (!tls13_advance_key_schedule(ssl, kZeroes, hash_len)) {
+ return ssl_hs_error;
+ }
+
+ 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) ||
+ !ext_key_share_add_serverhello(ssl, &extensions) ||
+ !ssl->method->finish_message(ssl, &cbb)) {
+ CBB_cleanup(&cbb);
+ return ssl_hs_error;
+ }
+
+ hs->state = state_send_encrypted_extensions;
+ return ssl_hs_write_message;
+}
+
+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->method->finish_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->tmp.cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER);
+ /* CertificateRequest may only be sent in certificate-based ciphers. */
+ if (!ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
+ ssl->s3->tmp.cert_request = 0;
+ }
+
+ if (!ssl->s3->tmp.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 sigalgs_len = tls12_get_psigalgs(ssl, &sigalgs);
+ if (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb)) {
+ goto err;
+ }
+
+ for (size_t i = 0; i < sigalgs_len; 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->method->finish_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_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
+ 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) {
+ hs->state = state_read_client_second_flight;
+ return ssl_hs_flush;
+}
+
+static enum ssl_hs_wait_t do_read_client_second_flight(SSL *ssl,
+ SSL_HANDSHAKE *hs) {
+ /* Update the secret to the master secret and derive traffic keys. */
+ static const uint8_t kZeroes[EVP_MAX_MD_SIZE] = {0};
+ if (!tls13_advance_key_schedule(ssl, kZeroes, hs->hash_len) ||
+ !tls13_derive_traffic_secret_0(ssl) ||
+ !tls13_set_traffic_key(ssl, type_data, evp_aead_seal,
+ hs->traffic_secret_0, hs->hash_len)) {
+ return ssl_hs_error;
+ }
+
+ hs->state = state_process_client_certificate;
+ return ssl_hs_read_message;
+}
+
+static enum ssl_hs_wait_t do_process_client_certificate(SSL *ssl,
+ SSL_HANDSHAKE *hs) {
+ if (!ssl->s3->tmp.cert_request) {
+ /* Skip this state. */
+ hs->state = state_process_client_certificate_verify;
+ return ssl_hs_ok;
+ }
+
+ if (!tls13_check_message_type(ssl, SSL3_MT_CERTIFICATE) ||
+ !tls13_process_certificate(ssl) ||
+ !ssl->method->hash_current_message(ssl)) {
+ return ssl_hs_error;
+ }
+
+ 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->session->peer == NULL) {
+ /* Skip this state. */
+ hs->state = state_process_client_finished;
+ return ssl_hs_ok;
+ }
+
+ if (!tls13_check_message_type(ssl, SSL3_MT_CERTIFICATE_VERIFY) ||
+ !tls13_process_certificate_verify(ssl) ||
+ !ssl->method->hash_current_message(ssl)) {
+ return 0;
+ }
+
+ 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->method->hash_current_message(ssl) ||
+ /* evp_aead_seal keys have already been switched. */
+ !tls13_set_traffic_key(ssl, type_data, evp_aead_open,
+ hs->traffic_secret_0, hs->hash_len) ||
+ !tls13_finalize_keys(ssl)) {
+ return ssl_hs_error;
+ }
+
+ hs->state = state_done;
+ return ssl_hs_ok;
+}
+
+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_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_read_client_second_flight:
+ ret = do_read_client_second_flight(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_client_finished:
+ ret = do_process_client_finished(ssl, hs);
+ break;
+ case state_done:
+ ret = ssl_hs_ok;
+ break;
+ }
+
+ if (ret != ssl_hs_ok) {
+ return ret;
+ }
+ }
+
+ return ssl_hs_ok;
+}