diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 058173c4a..4b64fe623 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -4476,6 +4476,7 @@ static int ssl_buffer_message( mbedtls_ssl_context *ssl ) { case MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC: MBEDTLS_SSL_DEBUG_MSG( 2, ( "Remember CCS message" ) ); + hs->buffering.seen_ccs = 1; break; @@ -4986,23 +4987,38 @@ int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl ) } } -#if defined(MBEDTLS_SSL_PROTO_DTLS) - /* Drop unexpected ChangeCipherSpec messages */ - if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && - ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC && - ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC && - ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) + if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { - if( ssl->handshake == NULL ) + if( ssl->in_msglen != 1 ) { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) ); - return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); + MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, len: %d", + ssl->in_msglen ) ); + return( MBEDTLS_ERR_SSL_INVALID_RECORD ); } - MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) ); - return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); - } + if( ssl->in_msg[0] != 1 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid CCS message, content: %02x", + ssl->in_msg[0] ) ); + return( MBEDTLS_ERR_SSL_INVALID_RECORD ); + } + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && + ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC && + ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC ) + { + if( ssl->handshake == NULL ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping ChangeCipherSpec outside handshake" ) ); + return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD ); + } + + MBEDTLS_SSL_DEBUG_MSG( 1, ( "received out-of-order ChangeCipherSpec - remember" ) ); + return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); + } #endif + } if( ssl->in_msgtype == MBEDTLS_SSL_MSG_ALERT ) { @@ -5718,13 +5734,8 @@ int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl ) return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE ); } - if( ssl->in_msglen != 1 || ssl->in_msg[0] != 1 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); - mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, - MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR ); - return( MBEDTLS_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC ); - } + /* CCS records are only accepted if they have length 1 and content '1', + * so we don't need to check this here. */ /* * Switch to our negotiated transform and session parameters for inbound