Module: kamailio Branch: master Commit: 4fabe253a1eb0f9b494521cfa98365523a93adcf URL: https://github.com/kamailio/kamailio/commit/4fabe253a1eb0f9b494521cfa983655… Author: Armen Babikyan &lt;armen(a)firespotter.com&gt; Committer: Armen Babikyan &lt;armen(a)firespotter.com&gt; Date: 2018-01-25T17:43:33-08:00 websocket: check bounds before reading mask --- Modified: src/modules/websocket/ws_frame.c --- Diff: https://github.com/kamailio/kamailio/commit/4fabe253a1eb0f9b494521cfa983655… Patch: https://github.com/kamailio/kamailio/commit/4fabe253a1eb0f9b494521cfa983655… --- diff --git a/src/modules/websocket/ws_frame.c b/src/modules/websocket/ws_frame.c index 9bc3268601..32a1f4bf6a 100644 --- a/src/modules/websocket/ws_frame.c +++ b/src/modules/websocket/ws_frame.c @@ -470,13 +470,6 @@ static int decode_and_validate_ws_frame(ws_frame_t *frame, } else mask_start = 2; - /* Decode mask */ - frame->masking_key[0] = (buf[mask_start + 0] & 0xff); - frame->masking_key[1] = (buf[mask_start + 1] & 0xff); - frame->masking_key[2] = (buf[mask_start + 2] & 0xff); - frame->masking_key[3] = (buf[mask_start + 3] & 0xff); - - /* Decode and unmask payload */ if((unsigned long long)len != (unsigned long long)frame->payload_len + mask_start + 4) { LM_WARN("message not complete frame size %u but received %u\n", @@ -492,7 +485,15 @@ static int decode_and_validate_ws_frame(ws_frame_t *frame, *err_text = str_status_message_too_big; return -1; } + /* Decode mask */ + frame->masking_key[0] = (buf[mask_start + 0] & 0xff); + frame->masking_key[1] = (buf[mask_start + 1] & 0xff); + frame->masking_key[2] = (buf[mask_start + 2] & 0xff); + frame->masking_key[3] = (buf[mask_start + 3] & 0xff); + frame->payload_data = &buf[mask_start + 4]; + + /* Decode and unmask payload */ for(i = 0; i < frame->payload_len; i++) { j = i % 4; frame->payload_data[i] = frame->payload_data[i] ^ frame->masking_key[j];