Merge pull request #7058 from yuhaoth/pr/tls13-early-data-parsing-0-rtt-data
TLS 1.3 EarlyData SRV: Parsing 0-RTT data
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 3c2696f..043988f 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -687,7 +687,6 @@
MBEDTLS_SSL_SERVER_FINISHED,
MBEDTLS_SSL_FLUSH_BUFFERS,
MBEDTLS_SSL_HANDSHAKE_WRAPUP,
-
MBEDTLS_SSL_NEW_SESSION_TICKET,
MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT,
MBEDTLS_SSL_HELLO_RETRY_REQUEST,
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index d983a00..bfe805f 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1880,10 +1880,18 @@
#if defined(MBEDTLS_SSL_EARLY_DATA)
/* There is enough information, update early data state. */
ssl_tls13_update_early_data_status(ssl);
+
+ if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED) {
+ ret = mbedtls_ssl_tls13_compute_early_transform(ssl);
+ if (ret != 0) {
+ MBEDTLS_SSL_DEBUG_RET(
+ 1, "mbedtls_ssl_tls13_compute_early_transform", ret);
+ return ret;
+ }
+ }
#endif /* MBEDTLS_SSL_EARLY_DATA */
return 0;
-
}
/*
@@ -2749,6 +2757,59 @@
#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */
/*
+ * RFC 8446 section A.2
+ *
+ * | Send ServerHello
+ * | K_send = handshake
+ * | Send EncryptedExtensions
+ * | [Send CertificateRequest]
+ * Can send | [Send Certificate + CertificateVerify]
+ * app data | Send Finished
+ * after --> | K_send = application
+ * here +--------+--------+
+ * No 0-RTT | | 0-RTT
+ * | |
+ * K_recv = handshake | | K_recv = early data
+ * [Skip decrypt errors] | +------> WAIT_EOED -+
+ * | | Recv | | Recv EndOfEarlyData
+ * | | early data | | K_recv = handshake
+ * | +------------+ |
+ * | |
+ * +> WAIT_FLIGHT2 <--------+
+ * |
+ * +--------+--------+
+ * No auth | | Client auth
+ * | |
+ * | v
+ * | WAIT_CERT
+ * | Recv | | Recv Certificate
+ * | empty | v
+ * | Certificate | WAIT_CV
+ * | | | Recv
+ * | v | CertificateVerify
+ * +-> WAIT_FINISHED <---+
+ * | Recv Finished
+ *
+ *
+ * The following function handles the state changes after WAIT_FLIGHT2 in the
+ * above diagram. We are not going to receive early data related messages
+ * anymore, prepare to receive the first handshake message of the client
+ * second flight.
+ */
+static void ssl_tls13_prepare_for_handshake_second_flight(
+ mbedtls_ssl_context *ssl)
+{
+ if (ssl->handshake->certificate_request_sent) {
+ mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE);
+ } else {
+ MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate"));
+ MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate verify"));
+
+ mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_FINISHED);
+ }
+}
+
+/*
* Handler for MBEDTLS_SSL_SERVER_FINISHED
*/
MBEDTLS_CHECK_RETURN_CRITICAL
@@ -2769,20 +2830,200 @@
return ret;
}
- MBEDTLS_SSL_DEBUG_MSG(1, ("Switch to handshake keys for inbound traffic"));
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+ if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED) {
+ /* See RFC 8446 section A.2 for more information */
+ MBEDTLS_SSL_DEBUG_MSG(
+ 1, ("Switch to early keys for inbound traffic. "
+ "( K_recv = early data )"));
+ mbedtls_ssl_set_inbound_transform(
+ ssl, ssl->handshake->transform_earlydata);
+ mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_END_OF_EARLY_DATA);
+ return 0;
+ }
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+ MBEDTLS_SSL_DEBUG_MSG(
+ 1, ("Switch to handshake keys for inbound traffic "
+ "( K_recv = handshake )"));
mbedtls_ssl_set_inbound_transform(ssl, ssl->handshake->transform_handshake);
- if (ssl->handshake->certificate_request_sent) {
- mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE);
- } else {
- MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate"));
- MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate verify"));
- mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_FINISHED);
- }
+ ssl_tls13_prepare_for_handshake_second_flight(ssl);
return 0;
}
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+/*
+ * Handler for MBEDTLS_SSL_END_OF_EARLY_DATA
+ */
+#define SSL_GOT_END_OF_EARLY_DATA 0
+#define SSL_GOT_EARLY_DATA 1
+/* Coordination:
+ * Deals with the ambiguity of not knowing if the next message is an
+ * EndOfEarlyData message or an application message containing early data.
+ * Returns a negative code on failure, or
+ * - SSL_GOT_END_OF_EARLY_DATA
+ * - SSL_GOT_EARLY_DATA
+ * indicating which message is received.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_end_of_early_data_coordinate(mbedtls_ssl_context *ssl)
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ if ((ret = mbedtls_ssl_read_record(ssl, 0)) != 0) {
+ MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret);
+ return ret;
+ }
+ ssl->keep_current_message = 1;
+
+ if (ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+ ssl->in_msg[0] == MBEDTLS_SSL_HS_END_OF_EARLY_DATA) {
+ MBEDTLS_SSL_DEBUG_MSG(3, ("Received an end_of_early_data message."));
+ return SSL_GOT_END_OF_EARLY_DATA;
+ }
+
+ if (ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA) {
+ MBEDTLS_SSL_DEBUG_MSG(3, ("Received early data"));
+ return SSL_GOT_EARLY_DATA;
+ }
+
+ MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+ MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE);
+ return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE;
+}
+
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_parse_end_of_early_data(mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ const unsigned char *end)
+{
+ /* RFC 8446 section 4.5
+ *
+ * struct {} EndOfEarlyData;
+ */
+ if (buf != end) {
+ MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+ MBEDTLS_ERR_SSL_DECODE_ERROR);
+ return MBEDTLS_ERR_SSL_DECODE_ERROR;
+ }
+ return 0;
+}
+
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_process_early_application_data(mbedtls_ssl_context *ssl)
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ if ((ret = mbedtls_ssl_read_record(ssl, 0)) != 0) {
+ MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret);
+ return ret;
+ }
+
+ /*
+ * Output early data
+ *
+ * For the time being, we print received data via debug message.
+ *
+ * TODO: Remove it when `mbedtls_ssl_read_early_data` is ready.
+ */
+ ssl->in_msg[ssl->in_msglen] = 0;
+ MBEDTLS_SSL_DEBUG_MSG(3, ("\n%s", ssl->in_msg));
+
+ /* RFC 8446 section 4.6.1
+ *
+ * A server receiving more than max_early_data_size bytes of 0-RTT data
+ * SHOULD terminate the connection with an "unexpected_message" alert.
+ *
+ * TODO: Add received data size check here.
+ */
+
+ return 0;
+}
+
+/*
+ * RFC 8446 section A.2
+ *
+ * | Send ServerHello
+ * | K_send = handshake
+ * | Send EncryptedExtensions
+ * | [Send CertificateRequest]
+ * Can send | [Send Certificate + CertificateVerify]
+ * app data | Send Finished
+ * after --> | K_send = application
+ * here +--------+--------+
+ * No 0-RTT | | 0-RTT
+ * | |
+ * K_recv = handshake | | K_recv = early data
+ * [Skip decrypt errors] | +------> WAIT_EOED -+
+ * | | Recv | | Recv EndOfEarlyData
+ * | | early data | | K_recv = handshake
+ * | +------------+ |
+ * | |
+ * +> WAIT_FLIGHT2 <--------+
+ * |
+ * +--------+--------+
+ * No auth | | Client auth
+ * | |
+ * | v
+ * | WAIT_CERT
+ * | Recv | | Recv Certificate
+ * | empty | v
+ * | Certificate | WAIT_CV
+ * | | | Recv
+ * | v | CertificateVerify
+ * +-> WAIT_FINISHED <---+
+ * | Recv Finished
+ *
+ * The function handles actions and state changes from 0-RTT to WAIT_FLIGHT2 in
+ * the above diagram.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_process_end_of_early_data(mbedtls_ssl_context *ssl)
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ MBEDTLS_SSL_DEBUG_MSG(2, ("=> ssl_tls13_process_end_of_early_data"));
+
+ MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_end_of_early_data_coordinate(ssl));
+
+ if (ret == SSL_GOT_END_OF_EARLY_DATA) {
+ unsigned char *buf;
+ size_t buf_len;
+
+ MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg(
+ ssl, MBEDTLS_SSL_HS_END_OF_EARLY_DATA,
+ &buf, &buf_len));
+
+ MBEDTLS_SSL_PROC_CHK(ssl_tls13_parse_end_of_early_data(
+ ssl, buf, buf + buf_len));
+
+ MBEDTLS_SSL_DEBUG_MSG(
+ 1, ("Switch to handshake keys for inbound traffic"
+ "( K_recv = handshake )"));
+ mbedtls_ssl_set_inbound_transform(
+ ssl, ssl->handshake->transform_handshake);
+
+ MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum(
+ ssl, MBEDTLS_SSL_HS_END_OF_EARLY_DATA,
+ buf, buf_len));
+
+ ssl_tls13_prepare_for_handshake_second_flight(ssl);
+
+ } else if (ret == SSL_GOT_EARLY_DATA) {
+ MBEDTLS_SSL_PROC_CHK(ssl_tls13_process_early_application_data(ssl));
+ } else {
+ MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen"));
+ ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
+ goto cleanup;
+ }
+
+cleanup:
+ MBEDTLS_SSL_DEBUG_MSG(2, ("<= ssl_tls13_process_end_of_early_data"));
+ return ret;
+}
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
/*
* Handler for MBEDTLS_SSL_CLIENT_FINISHED
*/
@@ -3207,6 +3448,12 @@
ret = ssl_tls13_write_server_finished(ssl);
break;
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+ case MBEDTLS_SSL_END_OF_EARLY_DATA:
+ ret = ssl_tls13_process_end_of_early_data(ssl);
+ break;
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
case MBEDTLS_SSL_CLIENT_FINISHED:
ret = ssl_tls13_process_client_finished(ssl);
break;
diff --git a/tests/opt-testcases/tls13-misc.sh b/tests/opt-testcases/tls13-misc.sh
index f03a386..e4df1fe 100755
--- a/tests/opt-testcases/tls13-misc.sh
+++ b/tests/opt-testcases/tls13-misc.sh
@@ -513,12 +513,12 @@
MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
requires_any_configs_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED \
MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
-run_test "TLS 1.3 G->m: EarlyData: feature is enabled, fail." \
+run_test "TLS 1.3 G->m: EarlyData: feature is enabled, good." \
"$P_SRV force_version=tls13 debug_level=4 max_early_data_size=$EARLY_DATA_INPUT_LEN" \
"$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+GROUP-ALL:+KX-ALL \
-d 10 -r --earlydata $EARLY_DATA_INPUT " \
- 1 \
+ 0 \
-s "ClientHello: early_data(42) extension exists." \
-s "EncryptedExtensions: early_data(42) extension exists." \
-s "NewSessionTicket: early_data(42) extension does not exist." \
- -s "Last error was: -29056 - SSL - Verification of the message MAC failed"
+ -s "$( tail -1 $EARLY_DATA_INPUT )"