diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h index a34d38521..fbf3e70e8 100644 --- a/include/mbedtls/ssl_internal.h +++ b/include/mbedtls/ssl_internal.h @@ -297,8 +297,6 @@ struct mbedtls_ssl_handshake_params unsigned char verify_cookie_len; /*!< Cli: cookie length Srv: flag for sending a cookie */ - unsigned char *hs_msg; /*!< Reassembled handshake message */ - uint32_t retransmit_timeout; /*!< Current value of timeout */ unsigned char retransmit_state; /*!< Retransmission state */ mbedtls_ssl_flight_item *flight; /*!< Current outgoing flight */ diff --git a/library/ssl_tls.c b/library/ssl_tls.c index a321eaf42..ed4168631 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -3558,141 +3558,6 @@ static int ssl_prepare_reassembly_buffer( mbedtls_ssl_context *ssl, /* debug */ return( 0 ); } -/* - * Reassemble fragmented DTLS handshake messages. - * - * Use a temporary buffer for reassembly, divided in two parts: - * - the first holds the reassembled message (including handshake header), - * - the second holds a bitmask indicating which parts of the message - * (excluding headers) have been received so far. - */ -static int ssl_reassemble_dtls_handshake( mbedtls_ssl_context *ssl ) -{ - unsigned char *msg, *bitmask; - size_t frag_len, frag_off; - size_t msg_len = ssl->in_hslen - 12; /* Without headers */ - - if( ssl->handshake == NULL ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "not supported outside handshake (for now)" ) ); - return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); - } - - /* - * For first fragment, check size and allocate buffer - */ - if( ssl->handshake->hs_msg == NULL ) - { - ret = ssl_prepare_reassembly_buffer( msg_len, 1, - &ssl->handshake->hs_msg ); - if( ret != 0 ) - return( ret ); - - /* Prepare final header: copy msg_type, length and message_seq, - * then add standardised fragment_offset and fragment_length */ - memcpy( ssl->handshake->hs_msg, ssl->in_msg, 6 ); - memset( ssl->handshake->hs_msg + 6, 0, 3 ); - memcpy( ssl->handshake->hs_msg + 9, - ssl->handshake->hs_msg + 1, 3 ); - } - else - { - /* Make sure msg_type and length are consistent */ - if( memcmp( ssl->handshake->hs_msg, ssl->in_msg, 4 ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "fragment header mismatch" ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - } - - msg = ssl->handshake->hs_msg + 12; - bitmask = msg + msg_len; - - /* - * Check and copy current fragment - */ - frag_off = ( ssl->in_msg[6] << 16 ) | - ( ssl->in_msg[7] << 8 ) | - ssl->in_msg[8]; - frag_len = ( ssl->in_msg[9] << 16 ) | - ( ssl->in_msg[10] << 8 ) | - ssl->in_msg[11]; - - if( frag_off + frag_len > msg_len ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid fragment offset/len: %d + %d > %d", - frag_off, frag_len, msg_len ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - if( frag_len + 12 > ssl->in_msglen ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid fragment length: %d + 12 > %d", - frag_len, ssl->in_msglen ) ); - return( MBEDTLS_ERR_SSL_INVALID_RECORD ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %d, length = %d", - frag_off, frag_len ) ); - - memcpy( msg + frag_off, ssl->in_msg + 12, frag_len ); - ssl_bitmask_set( bitmask, frag_off, frag_len ); - - /* - * Do we have the complete message by now? - * If yes, finalize it, else ask to read the next record. - */ - if( ssl_bitmask_check( bitmask, msg_len ) != 0 ) - { - MBEDTLS_SSL_DEBUG_MSG( 2, ( "message is not complete yet" ) ); - return( MBEDTLS_ERR_SSL_CONTINUE_PROCESSING ); - } - - MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake message completed" ) ); - - if( frag_len + 12 < ssl->in_msglen ) - { - /* - * We'got more handshake messages in the same record. - * This case is not handled now because no know implementation does - * that and it's hard to test, so we prefer to fail cleanly for now. - */ - MBEDTLS_SSL_DEBUG_MSG( 1, ( "last fragment not alone in its record" ) ); - return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); - } - - if( ssl->in_left > ssl->next_record_offset ) - { - /* - * We've got more data in the buffer after the current record, - * that we don't want to overwrite. Move it before writing the - * reassembled message, and adjust in_left and next_record_offset. - */ - unsigned char *cur_remain = ssl->in_hdr + ssl->next_record_offset; - unsigned char *new_remain = ssl->in_msg + ssl->in_hslen; - size_t remain_len = ssl->in_left - ssl->next_record_offset; - - /* First compute and check new lengths */ - ssl->next_record_offset = new_remain - ssl->in_hdr; - ssl->in_left = ssl->next_record_offset + remain_len; - - if( ssl->in_left > MBEDTLS_SSL_IN_BUFFER_LEN - - (size_t)( ssl->in_hdr - ssl->in_buf ) ) - { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "reassembled message too large for buffer" ) ); - return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL ); - } - - memmove( new_remain, cur_remain, remain_len ); - } - - memcpy( ssl->in_msg, ssl->handshake->hs_msg, ssl->in_hslen ); - - MBEDTLS_SSL_DEBUG_BUF( 3, "reassembled handshake message", - ssl->in_msg, ssl->in_hslen ); - - return( 0 ); -} #endif /* MBEDTLS_SSL_PROTO_DTLS */ static uint32_t ssl_get_hs_total_len( mbedtls_ssl_context *ssl ) @@ -3772,15 +3637,14 @@ int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl ) } /* Wait until message completion to increment in_msg_seq */ + /* Message reassembly is handled alongside buffering of future + * messages; the commonality is that both handshake fragments and + * future messages cannot be forwarded immediately to the handshake + * handshake logic layer. */ if( ssl_hs_is_proper_fragment( ssl ) == 1 ) { MBEDTLS_SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) ); - - if( ( ret = ssl_reassemble_dtls_handshake( ssl ) ) != 0 ) - { - MBEDTLS_SSL_DEBUG_RET( 1, "ssl_reassemble_dtls_handshake", ret ); - return( ret ); - } + return( MBEDTLS_ERR_SSL_EARLY_MESSAGE ); } } else @@ -3812,13 +3676,6 @@ void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl ) unsigned offset; mbedtls_ssl_hs_buffer *hs_buf; - /* Clear up handshake reassembly structure, if any. */ - if( ssl->handshake->hs_msg != NULL ) - { - mbedtls_free( ssl->handshake->hs_msg ); - ssl->handshake->hs_msg = NULL; - } - /* Increment handshake sequence number */ hs->in_msg_seq++; @@ -4554,7 +4411,7 @@ static int ssl_buffer_message( mbedtls_ssl_context *ssl ) break; case MBEDTLS_SSL_MSG_HANDSHAKE: - /* No support for buffering handshake messages so far. */ + /* TODO: Implement buffering and reassembly here. */ break; default: @@ -8461,7 +8318,6 @@ void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl ) #if defined(MBEDTLS_SSL_PROTO_DTLS) mbedtls_free( handshake->verify_cookie ); - mbedtls_free( handshake->hs_msg ); ssl_flight_free( handshake->flight ); ssl_buffering_free( ssl ); #endif