introduce sent/recv extensions field
And remove `extensions_present`
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 5eac1f1..7b66be1 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -448,7 +448,6 @@
{
size_t cert_data_len, extensions_len;
const unsigned char *extensions_end;
- uint32_t extensions_present;
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, 3 );
cert_data_len = MBEDTLS_GET_UINT24_BE( p, 0 );
@@ -508,7 +507,7 @@
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, extensions_len );
extensions_end = p + extensions_len;
- extensions_present = MBEDTLS_SSL_EXT_NONE;
+ ssl->handshake->received_extensions = MBEDTLS_SSL_EXT_NONE;
while( p < extensions_end )
{
@@ -528,26 +527,12 @@
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
- /* RFC 8446 page 35
- *
- * If an implementation receives an extension which it recognizes and
- * which is not specified for the message in which it appears, it MUST
- * abort the handshake with an "illegal_parameter" alert.
- */
- extensions_present |= mbedtls_tls13_get_extension_mask( extension_type );
- MBEDTLS_SSL_DEBUG_MSG( 3,
- ( "encrypted extensions : received %s(%u) extension",
- mbedtls_tls13_get_extension_name( extension_type ),
- extension_type ) );
- if( ( extensions_present & MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CT ) == 0 )
- {
- MBEDTLS_SSL_DEBUG_MSG(
- 3, ( "forbidden extension received." ) );
- MBEDTLS_SSL_PEND_FATAL_ALERT(
- MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
- MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
- return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
- }
+ ret = mbedtls_tls13_check_received_extensions(
+ ssl, MBEDTLS_SSL_HS_CERTIFICATE, extension_type,
+ MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CT );
+ if( ret != 0 )
+ return( ret );
+
switch( extension_type )
{
default:
@@ -561,7 +546,8 @@
p += extension_data_len;
}
- MBEDTLS_SSL_TLS1_3_PRINT_EXTS( 3, "Certificate", extensions_present );
+ MBEDTLS_SSL_TLS1_3_PRINT_EXTS(
+ 3, MBEDTLS_SSL_HS_CERTIFICATE, ssl->handshake->received_extensions );
}
exit:
@@ -1691,9 +1677,31 @@
return( "unknown" );
}
+static const char *ssl_tls13_get_hs_msg_name( int hs_msg_type )
+{
+ switch( hs_msg_type )
+ {
+ case MBEDTLS_SSL_HS_CLIENT_HELLO:
+ return( "ClientHello" );
+ case MBEDTLS_SSL_HS_SERVER_HELLO:
+ return( "ServerHello" );
+ case -MBEDTLS_SSL_HS_SERVER_HELLO: // HRR does not have IANA value.
+ return( "HelloRetryRequest" );
+ case MBEDTLS_SSL_HS_NEW_SESSION_TICKET:
+ return( "NewSessionTicket" );
+ case MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS:
+ return( "EncryptedExtensions" );
+ case MBEDTLS_SSL_HS_CERTIFICATE:
+ return( "Certificate" );
+ case MBEDTLS_SSL_HS_CERTIFICATE_REQUEST:
+ return( "CertificateRequest" );
+ }
+ return( NULL );
+}
+
void mbedtls_ssl_tls13_print_extensions( const mbedtls_ssl_context *ssl,
int level, const char *file, int line,
- const char *hs_msg_name,
+ int hs_msg_type,
uint32_t extensions_present )
{
static const struct{
@@ -1724,7 +1732,8 @@
{ MBEDTLS_SSL_EXT_KEY_SHARE, "key_share" } };
mbedtls_debug_print_msg( ssl, level, file, line,
- "extension list of %s:", hs_msg_name );
+ "extension list of %s:",
+ ssl_tls13_get_hs_msg_name( hs_msg_type ) );
for( unsigned i = 0;
i < sizeof( mask_to_str_table ) / sizeof( mask_to_str_table[0] );
@@ -1742,4 +1751,63 @@
#endif /* MBEDTLS_DEBUG_C */
+/* RFC 8446 section 4.2
+ *
+ * If an implementation receives an extension which it recognizes and which is
+ * not specified for the message in which it appears, it MUST abort the handshake
+ * with an "illegal_parameter" alert.
+ *
+ */
+
+int mbedtls_tls13_check_received_extensions( mbedtls_ssl_context *ssl,
+ int hs_msg_type,
+ uint32_t extension_type,
+ uint32_t allowed_mask )
+{
+ uint32_t extension_mask;
+
+#if defined(MBEDTLS_DEBUG_C)
+ const char *hs_msg_name = ssl_tls13_get_hs_msg_name( hs_msg_type );
+#endif
+
+ extension_mask = mbedtls_tls13_get_extension_mask( extension_type );
+
+ MBEDTLS_SSL_DEBUG_MSG( 3,
+ ( "%s : received %s(%x) extension",
+ hs_msg_name,
+ mbedtls_tls13_get_extension_name( extension_type ),
+ (unsigned int)extension_type ) );
+
+ if( ( extension_mask & allowed_mask ) == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG(
+ 3, ( "%s : forbidden extension received.", hs_msg_name ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT(
+ MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+ MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ }
+
+ ssl->handshake->received_extensions |= extension_mask;
+ switch( hs_msg_type )
+ {
+ case MBEDTLS_SSL_HS_SERVER_HELLO:
+ case -MBEDTLS_SSL_HS_SERVER_HELLO: // HRR does not have IANA value.
+ case MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS:
+ case MBEDTLS_SSL_HS_CERTIFICATE:
+ if( ( ~ssl->handshake->sent_extensions & extension_mask ) == 0 )
+ return( 0 );
+ break;
+ default:
+ return( 0 );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG(
+ 3, ( "%s : forbidden extension received.", hs_msg_name ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT(
+ MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
+ MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+}
+
#endif /* MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_PROTO_TLS1_3 */