Merge pull request #5523 from ronald-cron-arm/one-flush-output-development
TLS 1.3: One flush output
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index be01eba..5d0331e 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1236,13 +1236,14 @@
int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want );
int mbedtls_ssl_write_handshake_msg_ext( mbedtls_ssl_context *ssl,
- int update_checksum );
+ int update_checksum,
+ int force_flush );
static inline int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
{
- return( mbedtls_ssl_write_handshake_msg_ext( ssl, 1 /* update checksum */ ) );
+ return( mbedtls_ssl_write_handshake_msg_ext( ssl, 1 /* update checksum */, 1 /* force flush */ ) );
}
-int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush );
+int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, int force_flush );
int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 5f80ed5..ffb1346 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -2157,7 +2157,7 @@
( cur->type == MBEDTLS_SSL_MSG_HANDSHAKE &&
cur->p[0] == MBEDTLS_SSL_HS_FINISHED );
- uint8_t const force_flush = ssl->disable_datagram_packing == 1 ?
+ int const force_flush = ssl->disable_datagram_packing == 1 ?
SSL_FORCE_FLUSH : SSL_DONT_FORCE_FLUSH;
/* Swap epochs before sending Finished: we can't do it after
@@ -2368,7 +2368,8 @@
* - ssl->out_msg: the record contents (handshake headers + content)
*/
int mbedtls_ssl_write_handshake_msg_ext( mbedtls_ssl_context *ssl,
- int update_checksum )
+ int update_checksum,
+ int force_flush )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
const size_t hs_len = ssl->out_msglen - 4;
@@ -2495,7 +2496,7 @@
else
#endif
{
- if( ( ret = mbedtls_ssl_write_record( ssl, SSL_FORCE_FLUSH ) ) != 0 )
+ if( ( ret = mbedtls_ssl_write_record( ssl, force_flush ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_record", ret );
return( ret );
@@ -2519,11 +2520,11 @@
* - ssl->out_msglen: length of the record content (excl headers)
* - ssl->out_msg: record content
*/
-int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush )
+int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, int force_flush )
{
int ret, done = 0;
size_t len = ssl->out_msglen;
- uint8_t flush = force_flush;
+ int flush = force_flush;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write record" ) );
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 2220721..6c7f84f 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2728,6 +2728,21 @@
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ /*
+ * We may have not been able to send to the peer all the handshake data
+ * that were written into the output buffer by the previous handshake step,
+ * if the write to the network callback returned with the
+ * #MBEDTLS_ERR_SSL_WANT_WRITE error code.
+ * We proceed to the next handshake step only when all data from the
+ * previous one have been sent to the peer, thus we make sure that this is
+ * the case here by calling `mbedtls_ssl_flush_output()`. The function may
+ * return with the #MBEDTLS_ERR_SSL_WANT_WRITE error code in which case
+ * we have to wait before to go ahead.
+ * In the case of TLS 1.3, handshake step handlers do not send data to the
+ * peer. Data are only sent here and through
+ * `mbedtls_ssl_handle_pending_alert` in case an error that triggered an
+ * alert occured.
+ */
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index cd1baa1..05b7941 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -919,12 +919,6 @@
return( 0 );
}
-static int ssl_tls13_finalize_client_hello( mbedtls_ssl_context *ssl )
-{
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_HELLO );
- return( 0 );
-}
-
static int ssl_tls13_prepare_client_hello( mbedtls_ssl_context *ssl )
{
int ret;
@@ -991,11 +985,12 @@
msg_len );
ssl->handshake->update_checksum( ssl, buf, msg_len );
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_client_hello( ssl ) );
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg( ssl,
buf_len,
msg_len ) );
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_HELLO );
+
cleanup:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
@@ -2049,52 +2044,62 @@
ssl,
MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED );
#else
-#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE );
-#else
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
-#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
-
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
return( 0 );
}
/*
- * Handler for MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED
- */
-#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
-static int ssl_tls13_write_change_cipher_spec( mbedtls_ssl_context *ssl )
-{
- int ret;
-
- ret = mbedtls_ssl_tls13_write_change_cipher_spec( ssl );
- if( ret != 0 )
- return( ret );
-
- return( 0 );
-}
-#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
-
-#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
-/*
* Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE
*/
static int ssl_tls13_write_client_certificate( mbedtls_ssl_context *ssl )
{
+ int non_empty_certificate_msg = 0;
+
MBEDTLS_SSL_DEBUG_MSG( 1,
( "Switch to handshake traffic keys for outbound traffic" ) );
mbedtls_ssl_set_outbound_transform( ssl, ssl->handshake->transform_handshake );
- return( mbedtls_ssl_tls13_write_certificate( ssl ) );
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+ if( ssl->handshake->client_auth )
+ {
+ int ret = mbedtls_ssl_tls13_write_certificate( ssl );
+ if( ret != 0 )
+ return( ret );
+
+ if( mbedtls_ssl_own_cert( ssl ) != NULL )
+ non_empty_certificate_msg = 1;
+ }
+ else
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "No certificate message to send." ) );
+ }
+#endif
+
+ if( non_empty_certificate_msg )
+ {
+ mbedtls_ssl_handshake_set_state( ssl,
+ MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
+ }
+ else
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
+
+ return( 0 );
}
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
/*
* Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY
*/
static int ssl_tls13_write_client_certificate_verify( mbedtls_ssl_context *ssl )
{
- return( mbedtls_ssl_tls13_write_certificate_verify( ssl ) );
+ int ret = mbedtls_ssl_tls13_write_certificate_verify( ssl );
+
+ if( ret == 0 )
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
+
+ return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
@@ -2105,13 +2110,6 @@
{
int ret;
- if( !ssl->handshake->client_auth )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1,
- ( "Switch to handshake traffic keys for outbound traffic" ) );
- mbedtls_ssl_set_outbound_transform( ssl,
- ssl->handshake->transform_handshake );
- }
ret = mbedtls_ssl_tls13_write_finished_message( ssl );
if( ret != 0 )
return( ret );
@@ -2192,11 +2190,11 @@
ret = ssl_tls13_process_server_finished( ssl );
break;
-#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
case MBEDTLS_SSL_CLIENT_CERTIFICATE:
ret = ssl_tls13_write_client_certificate( ssl );
break;
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
case MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY:
ret = ssl_tls13_write_client_certificate_verify( ssl );
break;
@@ -2218,9 +2216,16 @@
* Injection of dummy-CCS's for middlebox compatibility
*/
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
- case MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED:
case MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO:
- ret = ssl_tls13_write_change_cipher_spec( ssl );
+ ret = mbedtls_ssl_tls13_write_change_cipher_spec( ssl );
+ if( ret == 0 )
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_HELLO );
+ break;
+
+ case MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED:
+ ret = mbedtls_ssl_tls13_write_change_cipher_spec( ssl );
+ if( ret == 0 )
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE );
break;
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index f006438..24a3d9d 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -103,7 +103,7 @@
/* Add reserved 4 bytes for handshake header */
msg_with_header_len = msg_len + 4;
ssl->out_msglen = msg_with_header_len;
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_handshake_msg_ext( ssl, 0 ) );
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_handshake_msg_ext( ssl, 0, 0 ) );
cleanup:
return( ret );
@@ -847,54 +847,6 @@
return( ret );
}
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
-
-/*
- * STATE HANDLING: Output Certificate
- */
-/* Check if a certificate should be written, and if yes,
- * if it is available.
- * Returns a negative error code on failure ( such as no certificate
- * being available on the server ), and otherwise
- * SSL_WRITE_CERTIFICATE_SEND or
- * SSL_WRITE_CERTIFICATE_SKIP
- * indicating that a Certificate message should be written based
- * on the configured certificate, or whether it should be silently skipped.
- */
-#define SSL_WRITE_CERTIFICATE_SEND 0
-#define SSL_WRITE_CERTIFICATE_SKIP 1
-
-static int ssl_tls13_write_certificate_coordinate( mbedtls_ssl_context *ssl )
-{
-
- /* For PSK and ECDHE-PSK ciphersuites there is no certificate to exchange. */
- if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
- {
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
- return( SSL_WRITE_CERTIFICATE_SKIP );
- }
-
-#if defined(MBEDTLS_SSL_CLI_C)
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
- {
- /* The client MUST send a Certificate message if and only
- * if the server has requested client authentication via a
- * CertificateRequest message.
- *
- * client_auth indicates whether the server had requested
- * client authentication.
- */
- if( ssl->handshake->client_auth == 0 )
- {
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
- return( SSL_WRITE_CERTIFICATE_SKIP );
- }
- }
-#endif /* MBEDTLS_SSL_CLI_C */
-
- return( SSL_WRITE_CERTIFICATE_SEND );
-
-}
-
/*
* enum {
* X509(0),
@@ -982,63 +934,29 @@
return( 0 );
}
-static int ssl_tls13_finalize_write_certificate( mbedtls_ssl_context *ssl )
-{
-#if defined(MBEDTLS_SSL_CLI_C)
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
- {
- const mbedtls_x509_crt *crt = mbedtls_ssl_own_cert( ssl );
- if( ssl->handshake->client_auth && crt != NULL )
- {
- mbedtls_ssl_handshake_set_state( ssl,
- MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
- }
- else
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
- return( 0 );
- }
- else
-#endif /* MBEDTLS_SSL_CLI_C */
- ((void) ssl);
- return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
-}
-
int mbedtls_ssl_tls13_write_certificate( mbedtls_ssl_context *ssl )
{
int ret;
+ unsigned char *buf;
+ size_t buf_len, msg_len;
+
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
- /* Coordination: Check if we need to send a certificate. */
- MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_write_certificate_coordinate( ssl ) );
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
+ MBEDTLS_SSL_HS_CERTIFICATE, &buf, &buf_len ) );
- if( ret == SSL_WRITE_CERTIFICATE_SEND )
- {
- unsigned char *buf;
- size_t buf_len, msg_len;
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate_body( ssl,
+ buf,
+ buf + buf_len,
+ &msg_len ) );
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
- MBEDTLS_SSL_HS_CERTIFICATE, &buf, &buf_len ) );
+ mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
+ MBEDTLS_SSL_HS_CERTIFICATE,
+ buf,
+ msg_len );
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate_body( ssl,
- buf,
- buf + buf_len,
- &msg_len ) );
-
- mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
- MBEDTLS_SSL_HS_CERTIFICATE,
- buf,
- msg_len );
-
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_write_certificate( ssl ) );
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
- ssl, buf_len, msg_len ) );
- }
- else
- {
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_write_certificate( ssl ) );
- }
-
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
+ ssl, buf_len, msg_len ) );
cleanup:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate" ) );
@@ -1188,22 +1106,6 @@
return( ret );
}
-static int ssl_tls13_finalize_certificate_verify( mbedtls_ssl_context *ssl )
-{
-#if defined(MBEDTLS_SSL_CLI_C)
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
- {
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
- }
- else
-#endif /* MBEDTLS_SSL_CLI_C */
- {
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
- }
-
- return( 0 );
-}
-
int mbedtls_ssl_tls13_write_certificate_verify( mbedtls_ssl_context *ssl )
{
int ret = 0;
@@ -1220,8 +1122,6 @@
mbedtls_ssl_tls13_add_hs_msg_to_checksum(
ssl, MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, buf, msg_len );
- /* Update state */
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_certificate_verify( ssl ) );
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
ssl, buf_len, msg_len ) );
@@ -1483,7 +1383,6 @@
MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_finished_message( ssl ) );
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg( ssl,
buf_len, msg_len ) );
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_flush_output( ssl ) );
cleanup:
@@ -1516,40 +1415,6 @@
*
*/
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
-
-static int ssl_tls13_finalize_change_cipher_spec( mbedtls_ssl_context* ssl )
-{
-
-#if defined(MBEDTLS_SSL_CLI_C)
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
- {
- switch( ssl->state )
- {
- case MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO:
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_HELLO );
- break;
- case MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED:
-#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
- mbedtls_ssl_handshake_set_state( ssl,
- MBEDTLS_SSL_CLIENT_CERTIFICATE );
-#else
- mbedtls_ssl_handshake_set_state( ssl,
- MBEDTLS_SSL_CLIENT_FINISHED );
-#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
-
- break;
- default:
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
- return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
- }
- }
-#else
- ((void) ssl);
-#endif /* MBEDTLS_SSL_CLI_C */
-
- return( 0 );
-}
-
static int ssl_tls13_write_change_cipher_spec_body( mbedtls_ssl_context *ssl,
unsigned char *buf,
unsigned char *end,
@@ -1570,8 +1435,6 @@
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) );
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_flush_output( ssl ) );
-
/* Write CCS message */
MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_change_cipher_spec_body(
ssl, ssl->out_msg,
@@ -1580,11 +1443,8 @@
ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
- /* Update state */
- MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_change_cipher_spec( ssl ) );
-
/* Dispatch message */
- MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_record( ssl, 1 ) );
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_record( ssl, 0 ) );
cleanup: