Merge pull request #4952 from xkqian/add_server_finished

Add server finished

include/mbedtls/ssl.h

@@ -605,6 +605,8 @@ union mbedtls_ssl_premaster_secret
 
 #define MBEDTLS_PREMASTER_SIZE     sizeof( union mbedtls_ssl_premaster_secret )
 
+#define MBEDTLS_TLS1_3_MD_MAX_SIZE         MBEDTLS_MD_MAX_SIZE
+
 /* Length in number of bytes of the TLS sequence number */
 #define MBEDTLS_SSL_SEQUENCE_NUMBER_LEN 8
 
@@ -1050,6 +1052,14 @@ typedef void mbedtls_ssl_async_cancel_t( mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED &&
           !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
+typedef struct
+{
+    unsigned char client_application_traffic_secret_N[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
+    unsigned char server_application_traffic_secret_N[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
+    unsigned char exporter_master_secret             [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
+    unsigned char resumption_master_secret           [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
+} mbedtls_ssl_tls1_3_application_secrets;
+
 #if defined(MBEDTLS_SSL_DTLS_SRTP)
 
 #define MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH             255
@@ -1140,6 +1150,10 @@ struct mbedtls_ssl_session
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
     int MBEDTLS_PRIVATE(encrypt_then_mac);       /*!< flag for EtM activation                */
 #endif
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+    mbedtls_ssl_tls1_3_application_secrets MBEDTLS_PRIVATE(app_secrets);
+#endif
 };
 
 /*

library/ssl_misc.h

@@ -307,8 +307,6 @@
       + ( MBEDTLS_SSL_CID_OUT_LEN_MAX ) )
 #endif
 
-#define MBEDTLS_TLS1_3_MD_MAX_SIZE         MBEDTLS_MD_MAX_SIZE
-
 #define MBEDTLS_CLIENT_HELLO_RANDOM_LEN 32
 #define MBEDTLS_SERVER_HELLO_RANDOM_LEN 32
 
@@ -522,14 +520,6 @@ typedef struct
     unsigned char server_handshake_traffic_secret[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
 } mbedtls_ssl_tls1_3_handshake_secrets;
 
-typedef struct
-{
-    unsigned char client_application_traffic_secret_N[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
-    unsigned char server_application_traffic_secret_N[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
-    unsigned char exporter_master_secret             [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
-    unsigned char resumption_master_secret           [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
-} mbedtls_ssl_tls1_3_application_secrets;
-
 /*
  * This structure contains the parameters only needed during handshake.
  */
@@ -719,6 +709,38 @@ struct mbedtls_ssl_handshake_params
                                 * but can be overwritten by the HRR. */
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 
+    /*
+     * State-local variables used during the processing
+     * of a specific handshake state.
+     */
+    union
+    {
+        /* Outgoing Finished message */
+        struct
+        {
+            uint8_t preparation_done;
+
+            /* Buffer holding digest of the handshake up to
+             * but excluding the outgoing finished message. */
+            unsigned char digest[MBEDTLS_TLS1_3_MD_MAX_SIZE];
+            size_t digest_len;
+        } finished_out;
+
+        /* Incoming Finished message */
+        struct
+        {
+            uint8_t preparation_done;
+
+            /* Buffer holding digest of the handshake up to but
+             * excluding the peer's incoming finished message. */
+            unsigned char digest[MBEDTLS_TLS1_3_MD_MAX_SIZE];
+            size_t digest_len;
+        } finished_in;
+
+    } state_local;
+
+    /* End of state-local variables. */
+
     mbedtls_ssl_ciphersuite_t const *ciphersuite_info;
 
     size_t pmslen;                      /*!<  premaster length        */
@@ -1162,6 +1184,8 @@ static inline int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
 int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush );
 int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
 
+int mbedtls_ssl_tls13_process_finished_message( mbedtls_ssl_context *ssl );
+
 int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );
 

library/ssl_tls13_client.c

@@ -1605,27 +1605,12 @@ static int ssl_tls1_3_process_certificate_verify( mbedtls_ssl_context *ssl )
  */
 static int ssl_tls1_3_process_server_finished( mbedtls_ssl_context *ssl )
 {
-    MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
+    int ret;
-    mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE );
-    return( 0 );
-}
 
-/*
+    ret = mbedtls_ssl_tls13_process_finished_message( ssl );
- * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE
+    if( ret != 0 )
- */
+        return( ret );
-static int ssl_tls1_3_write_client_certificate( mbedtls_ssl_context *ssl )
-{
-    MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
-    mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
-    return( 0 );
-}
 
-/*
- * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY
- */
-static int ssl_tls1_3_write_client_certificate_verify( mbedtls_ssl_context *ssl )
-{
-    MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
     return( 0 );
 }
@@ -1703,14 +1688,6 @@ int mbedtls_ssl_tls13_handshake_client_step( mbedtls_ssl_context *ssl )
             ret = ssl_tls1_3_process_server_finished( ssl );
             break;
 
-        case MBEDTLS_SSL_CLIENT_CERTIFICATE:
-            ret = ssl_tls1_3_write_client_certificate( ssl );
-            break;
-
-        case MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY:
-            ret = ssl_tls1_3_write_client_certificate_verify( ssl );
-            break;
-
         case MBEDTLS_SSL_CLIENT_FINISHED:
             ret = ssl_tls1_3_write_client_finished( ssl );
             break;

library/ssl_tls13_generic.c

@@ -845,6 +845,176 @@ cleanup:
     return( ret );
 }
 
+/*
+ *
+ * STATE HANDLING: Incoming Finished message.
+ */
+/*
+ * Implementation
+ */
+
+static int ssl_tls13_preprocess_finished_message( mbedtls_ssl_context *ssl )
+{
+    int ret;
+
+    ret = mbedtls_ssl_tls13_calculate_verify_data( ssl,
+                    ssl->handshake->state_local.finished_in.digest,
+                    sizeof( ssl->handshake->state_local.finished_in.digest ),
+                    &ssl->handshake->state_local.finished_in.digest_len,
+                    ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ?
+                        MBEDTLS_SSL_IS_SERVER : MBEDTLS_SSL_IS_CLIENT );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_calculate_verify_data", ret );
+        return( ret );
+    }
+
+    return( 0 );
+}
+
+static int ssl_tls13_parse_finished_message( mbedtls_ssl_context *ssl,
+                                             const unsigned char *buf,
+                                             const unsigned char *end )
+{
+    /*
+     * struct {
+     *     opaque verify_data[Hash.length];
+     * } Finished;
+     */
+    const unsigned char *expected_verify_data =
+        ssl->handshake->state_local.finished_in.digest;
+    size_t expected_verify_data_len =
+        ssl->handshake->state_local.finished_in.digest_len;
+    /* Structural validation */
+    if( (size_t)( end - buf ) != expected_verify_data_len )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
+
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+                                      MBEDTLS_ERR_SSL_DECODE_ERROR );
+        return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+    }
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "verify_data (self-computed):",
+                           expected_verify_data,
+                           expected_verify_data_len );
+    MBEDTLS_SSL_DEBUG_BUF( 4, "verify_data (received message):", buf,
+                           expected_verify_data_len );
+
+    /* Semantic validation */
+    if( mbedtls_ssl_safer_memcmp( buf,
+                                  expected_verify_data,
+                                  expected_verify_data_len ) != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
+
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR,
+                                      MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+        return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+    }
+    return( 0 );
+}
+
+#if defined(MBEDTLS_SSL_CLI_C)
+static int ssl_tls13_postprocess_server_finished_message( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_key_set traffic_keys;
+    mbedtls_ssl_transform *transform_application = NULL;
+
+    ret = mbedtls_ssl_tls13_key_schedule_stage_application( ssl );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1,
+           "mbedtls_ssl_tls13_key_schedule_stage_application", ret );
+        goto cleanup;
+    }
+
+    ret = mbedtls_ssl_tls13_generate_application_keys( ssl, &traffic_keys );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1,
+            "mbedtls_ssl_tls13_generate_application_keys", ret );
+        goto cleanup;
+    }
+
+    transform_application =
+        mbedtls_calloc( 1, sizeof( mbedtls_ssl_transform ) );
+    if( transform_application == NULL )
+    {
+        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        goto cleanup;
+    }
+
+    ret = mbedtls_ssl_tls13_populate_transform(
+                                    transform_application,
+                                    ssl->conf->endpoint,
+                                    ssl->session_negotiate->ciphersuite,
+                                    &traffic_keys,
+                                    ssl );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_populate_transform", ret );
+        goto cleanup;
+    }
+
+    ssl->transform_application = transform_application;
+
+cleanup:
+
+    mbedtls_platform_zeroize( &traffic_keys, sizeof( traffic_keys ) );
+    if( ret != 0 )
+    {
+        mbedtls_free( transform_application );
+        MBEDTLS_SSL_PEND_FATAL_ALERT(
+                MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
+                MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+    }
+    return( ret );
+}
+#endif /* MBEDTLS_SSL_CLI_C */
+
+static int ssl_tls13_postprocess_finished_message( mbedtls_ssl_context* ssl )
+{
+
+#if defined(MBEDTLS_SSL_CLI_C)
+    if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
+    {
+        return( ssl_tls13_postprocess_server_finished_message( ssl ) );
+    }
+#else
+    ((void) ssl);
+#endif /* MBEDTLS_SSL_CLI_C */
+
+    return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+}
+
+int mbedtls_ssl_tls13_process_finished_message( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    unsigned char *buf;
+    size_t buflen;
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse finished message" ) );
+
+    /* Preprocessing step: Compute handshake digest */
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_preprocess_finished_message( ssl ) );
+
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls1_3_fetch_handshake_msg( ssl,
+                                              MBEDTLS_SSL_HS_FINISHED,
+                                              &buf, &buflen ) );
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_finished_message( ssl, buf, buf + buflen ) );
+    mbedtls_ssl_tls1_3_add_hs_msg_to_checksum(
+        ssl, MBEDTLS_SSL_HS_FINISHED, buf, buflen );
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_postprocess_finished_message( ssl ) );
+
+cleanup:
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse finished message" ) );
+    return( ret );
+}
+
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 
 #endif /* MBEDTLS_SSL_TLS_C */

library/ssl_tls13_keys.c

@@ -564,6 +564,35 @@ int mbedtls_ssl_tls1_3_derive_resumption_master_secret(
     return( 0 );
 }
 
+int mbedtls_ssl_tls13_key_schedule_stage_application( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+    mbedtls_md_type_t const md_type = handshake->ciphersuite_info->mac;
+#if defined(MBEDTLS_DEBUG_C)
+    mbedtls_md_info_t const * const md_info = mbedtls_md_info_from_type( md_type );
+    size_t const md_size = mbedtls_md_get_size( md_info );
+#endif /* MBEDTLS_DEBUG_C */
+
+    /*
+     * Compute MasterSecret
+     */
+    ret = mbedtls_ssl_tls1_3_evolve_secret( md_type,
+                    handshake->tls1_3_master_secrets.handshake,
+                    NULL, 0,
+                    handshake->tls1_3_master_secrets.app );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_evolve_secret", ret );
+        return( ret );
+    }
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "Master secret",
+             handshake->tls1_3_master_secrets.app, md_size );
+
+    return( 0 );
+}
+
 static int ssl_tls1_3_calc_finished_core( mbedtls_md_type_t md_type,
                                           unsigned char const *base_key,
                                           unsigned char const *transcript,
@@ -614,6 +643,57 @@ exit:
     return( ret );
 }
 
+int mbedtls_ssl_tls13_calculate_verify_data( mbedtls_ssl_context* ssl,
+                                             unsigned char* dst,
+                                             size_t dst_len,
+                                             size_t *actual_len,
+                                             int from )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+    unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
+    size_t transcript_len;
+
+    unsigned char const *base_key = NULL;
+
+    mbedtls_md_type_t const md_type = ssl->handshake->ciphersuite_info->mac;
+    const mbedtls_md_info_t* const md = mbedtls_md_info_from_type( md_type );
+    size_t const md_size = mbedtls_md_get_size( md );
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_tls13_calculate_verify_data" ) );
+
+    if( dst_len < md_size )
+        return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+
+    ret = mbedtls_ssl_get_handshake_transcript( ssl, md_type,
+                                                transcript, sizeof( transcript ),
+                                                &transcript_len );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_get_handshake_transcript", ret );
+        goto exit;
+    }
+    MBEDTLS_SSL_DEBUG_BUF( 4, "handshake hash", transcript, transcript_len );
+
+    if( from == MBEDTLS_SSL_IS_CLIENT )
+        base_key = ssl->handshake->tls13_hs_secrets.client_handshake_traffic_secret;
+    else
+        base_key = ssl->handshake->tls13_hs_secrets.server_handshake_traffic_secret;
+
+    ret = ssl_tls1_3_calc_finished_core( md_type, base_key, transcript, dst );
+    if( ret != 0 )
+        goto exit;
+    *actual_len = md_size;
+
+    MBEDTLS_SSL_DEBUG_BUF( 3, "verify_data for finished message", dst, md_size );
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= mbedtls_ssl_tls13_calculate_verify_data" ) );
+
+exit:
+
+    mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
+    return( ret );
+}
+
 int mbedtls_ssl_tls1_3_create_psk_binder( mbedtls_ssl_context *ssl,
                                const mbedtls_md_type_t md_type,
                                unsigned char const *psk, size_t psk_len,
@@ -1028,4 +1108,125 @@ int mbedtls_ssl_tls13_key_schedule_stage_handshake( mbedtls_ssl_context *ssl )
     return( 0 );
 }
 
+/* Generate application traffic keys since any records following a 1-RTT Finished message
+ * MUST be encrypted under the application traffic key.
+ */
+int mbedtls_ssl_tls13_generate_application_keys(
+                                        mbedtls_ssl_context *ssl,
+                                        mbedtls_ssl_key_set *traffic_keys )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+
+    /* Address at which to store the application secrets */
+    mbedtls_ssl_tls1_3_application_secrets * const app_secrets =
+        &ssl->session_negotiate->app_secrets;
+
+    /* Holding the transcript up to and including the ServerFinished */
+    unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
+    size_t transcript_len;
+
+    /* Variables relating to the hash for the chosen ciphersuite. */
+    mbedtls_md_type_t md_type;
+    mbedtls_md_info_t const *md_info;
+    size_t md_size;
+
+    /* Variables relating to the cipher for the chosen ciphersuite. */
+    mbedtls_cipher_info_t const *cipher_info;
+    size_t keylen, ivlen;
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive application traffic keys" ) );
+
+    /* Extract basic information about hash and ciphersuite */
+
+    cipher_info = mbedtls_cipher_info_from_type(
+                                  handshake->ciphersuite_info->cipher );
+    keylen = cipher_info->key_bitlen / 8;
+    ivlen = cipher_info->iv_size;
+
+    md_type = handshake->ciphersuite_info->mac;
+    md_info = mbedtls_md_info_from_type( md_type );
+    md_size = mbedtls_md_get_size( md_info );
+
+    /* Compute current handshake transcript. It's the caller's responsiblity
+     * to call this at the right time, that is, after the ServerFinished. */
+
+    ret = mbedtls_ssl_get_handshake_transcript( ssl, md_type,
+                                      transcript, sizeof( transcript ),
+                                      &transcript_len );
+    if( ret != 0 )
+        goto cleanup;
+
+    /* Compute application secrets from master secret and transcript hash. */
+
+    ret = mbedtls_ssl_tls1_3_derive_application_secrets( md_type,
+                                   handshake->tls1_3_master_secrets.app,
+                                   transcript, transcript_len,
+                                   app_secrets );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1,
+                     "mbedtls_ssl_tls1_3_derive_application_secrets", ret );
+        goto cleanup;
+    }
+
+    /* Derive first epoch of IV + Key for application traffic. */
+
+    ret = mbedtls_ssl_tls1_3_make_traffic_keys( md_type,
+                             app_secrets->client_application_traffic_secret_N,
+                             app_secrets->server_application_traffic_secret_N,
+                             md_size, keylen, ivlen, traffic_keys );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_make_traffic_keys", ret );
+        goto cleanup;
+    }
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "Client application traffic secret",
+                           app_secrets->client_application_traffic_secret_N,
+                           md_size );
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "Server application traffic secret",
+                           app_secrets->server_application_traffic_secret_N,
+                           md_size );
+
+    /*
+     * Export client/server application traffic secret 0
+     */
+    if( ssl->f_export_keys != NULL )
+    {
+        ssl->f_export_keys( ssl->p_export_keys,
+                MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_APPLICATION_TRAFFIC_SECRET,
+                app_secrets->client_application_traffic_secret_N, md_size,
+                handshake->randbytes + 32,
+                handshake->randbytes,
+                MBEDTLS_SSL_TLS_PRF_NONE /* TODO: this should be replaced by
+                                            a new constant for TLS 1.3! */ );
+
+        ssl->f_export_keys( ssl->p_export_keys,
+                MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_APPLICATION_TRAFFIC_SECRET,
+                app_secrets->server_application_traffic_secret_N, md_size,
+                handshake->randbytes + 32,
+                handshake->randbytes,
+                MBEDTLS_SSL_TLS_PRF_NONE /* TODO: this should be replaced by
+                                            a new constant for TLS 1.3! */ );
+    }
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "client application_write_key:",
+                              traffic_keys->client_write_key, keylen );
+    MBEDTLS_SSL_DEBUG_BUF( 4, "server application write key",
+                              traffic_keys->server_write_key, keylen );
+    MBEDTLS_SSL_DEBUG_BUF( 4, "client application write IV",
+                              traffic_keys->client_write_iv, ivlen );
+    MBEDTLS_SSL_DEBUG_BUF( 4, "server application write IV",
+                              traffic_keys->server_write_iv, ivlen );
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= derive application traffic keys" ) );
+
+ cleanup:
+
+    mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
+    return( ret );
+}
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */

library/ssl_tls13_keys.h

@@ -570,4 +570,65 @@ int mbedtls_ssl_tls13_key_schedule_stage_handshake( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_tls13_generate_handshake_keys( mbedtls_ssl_context *ssl,
                                                mbedtls_ssl_key_set *traffic_keys );
 
+/**
+ * \brief Transition into application stage of TLS 1.3 key schedule.
+ *
+ *        The TLS 1.3 key schedule can be viewed as a simple state machine
+ *        with states Initial -> Early -> Handshake -> Application, and
+ *        this function represents the Handshake -> Application transition.
+ *
+ *        In the handshake stage, mbedtls_ssl_tls13_generate_application_keys()
+ *        can be used to derive the handshake traffic keys.
+ *
+ * \param ssl  The SSL context to operate on. This must be in key schedule
+ *             stage \c Handshake.
+ *
+ * \returns    \c 0 on success.
+ * \returns    A negative error code on failure.
+ */
+int mbedtls_ssl_tls13_key_schedule_stage_application( mbedtls_ssl_context *ssl );
+
+/**
+ * \brief Compute TLS 1.3 application traffic keys.
+ *
+ * \param ssl  The SSL context to operate on. This must be in
+ *             key schedule stage \c Application, see
+ *             mbedtls_ssl_tls13_key_schedule_stage_application().
+ * \param traffic_keys The address at which to store the application traffic key
+ *                     keys. This must be writable but may be uninitialized.
+ *
+ * \returns    \c 0 on success.
+ * \returns    A negative error code on failure.
+ */
+int mbedtls_ssl_tls13_generate_application_keys(
+    mbedtls_ssl_context* ssl, mbedtls_ssl_key_set *traffic_keys );
+
+/**
+ * \brief Calculate the verify_data value for the client or server TLS 1.3
+ * Finished message.
+ *
+ * \param ssl  The SSL context to operate on. This must be in
+ *             key schedule stage \c Handshake, see
+ *             mbedtls_ssl_tls13_key_schedule_stage_application().
+ * \param dst        The address at which to write the verify_data value.
+ * \param dst_len    The size of \p dst in bytes.
+ * \param actual_len The address at which to store the amount of data
+ *                   actually written to \p dst upon success.
+ * \param which      The message to calculate the `verify_data` for:
+ *                   - #MBEDTLS_SSL_IS_CLIENT for the Client's Finished message
+ *                   - #MBEDTLS_SSL_IS_SERVER for the Server's Finished message
+ *
+ * \note       Both client and server call this function twice, once to
+ *             generate their own Finished message, and once to verify the
+ *             peer's Finished message.
+
+ * \returns    \c 0 on success.
+ * \returns    A negative error code on failure.
+ */
+int mbedtls_ssl_tls13_calculate_verify_data( mbedtls_ssl_context *ssl,
+                                             unsigned char *dst,
+                                             size_t dst_len,
+                                             size_t *actual_len,
+                                             int which );
+
 #endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */

tests/ssl-opt.sh

@@ -8822,8 +8822,6 @@ run_test    "TLS1.3: Test client hello msg work - openssl" \
             -c "tls1_3 client state: 3"     \
             -c "tls1_3 client state: 9"     \
             -c "tls1_3 client state: 13"    \
-            -c "tls1_3 client state: 7"     \
-            -c "tls1_3 client state: 20"    \
             -c "tls1_3 client state: 11"    \
             -c "tls1_3 client state: 14"    \
             -c "tls1_3 client state: 15"    \
@@ -8835,7 +8833,8 @@ run_test    "TLS1.3: Test client hello msg work - openssl" \
             -c "Certificate verification flags clear" \
             -c "=> parse certificate verify"          \
             -c "<= parse certificate verify"          \
-            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0"
+            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0" \
+            -c "<= parse finished message"
 
 requires_gnutls_tls1_3
 requires_gnutls_next_no_ticket
@@ -8855,8 +8854,6 @@ run_test    "TLS1.3: Test client hello msg work - gnutls" \
             -c "tls1_3 client state: 3"     \
             -c "tls1_3 client state: 9"     \
             -c "tls1_3 client state: 13"    \
-            -c "tls1_3 client state: 7"     \
-            -c "tls1_3 client state: 20"    \
             -c "tls1_3 client state: 11"    \
             -c "tls1_3 client state: 14"    \
             -c "tls1_3 client state: 15"    \
@@ -8868,7 +8865,9 @@ run_test    "TLS1.3: Test client hello msg work - gnutls" \
             -c "Certificate verification flags clear" \
             -c "=> parse certificate verify"          \
             -c "<= parse certificate verify"          \
-            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0"
+            -c "mbedtls_ssl_tls13_process_certificate_verify() returned 0" \
+            -c "<= parse finished message"
+
 
 # Test heap memory usage after handshake
 requires_config_enabled MBEDTLS_MEMORY_DEBUG