From b41f8207c4cfebf9bb6b66a9f354c8bbba3036b5 Mon Sep 17 00:00:00 2001 From: Jack Lau Date: Thu, 4 Sep 2025 07:49:41 +0800 Subject: [PATCH] avformat/whip: fix SDP ICE candidates parsing fix issue #20407 Refer to RFC 5245 15.1, the foundation may be any string up to 32 chars. The old code could misread foundations as transport("udp"). This patch fully parse all these attr to avoid parsing error. Signed-off-by: Jack Lau --- libavformat/whip.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/libavformat/whip.c b/libavformat/whip.c index e6b03b6a4b..587b6f8d41 100644 --- a/libavformat/whip.c +++ b/libavformat/whip.c @@ -865,12 +865,12 @@ static int parse_answer(AVFormatContext *s) goto end; } } else if (av_strstart(line, "a=candidate:", &ptr) && !whip->ice_protocol) { - ptr = av_stristr(ptr, "udp"); if (ptr && av_stristr(ptr, "host")) { - char protocol[17], host[129]; - int priority, port; - ret = sscanf(ptr, "%16s %d %128s %d typ host", protocol, &priority, host, &port); - if (ret != 4) { + /* Refer to RFC 5245 15.1 */ + char foundation[33], protocol[17], host[129]; + int component_id, priority, port; + ret = sscanf(ptr, "%32s %d %16s %d %128s %d typ host", foundation, &component_id, protocol, &priority, host, &port); + if (ret != 6) { av_log(whip, AV_LOG_ERROR, "Failed %d to parse line %d %s from %s\n", ret, i, line, whip->sdp_answer); ret = AVERROR(EIO);