Quoting Michael Niedermayer (2023-05-09 00:35:08) > On Mon, May 08, 2023 at 04:05:40PM +0200, Tobias Rapp wrote: > > On 08/05/2023 14:00, James Almer wrote: > > > > > On 5/6/2023 10:25 AM, Michael Niedermayer wrote: > > > > Its unexpected that a .avi or other "standard" file turns into a > > > > playlist. > > > > The goal of this patch is to avoid this unexpected behavior and possible > > > > privacy or security differences. > > > > > > > > This is similar to the same change to hls > > > > > > > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > > > > --- > > > > libavformat/dashdec.c | 11 +++++++---- > > > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > > > > > diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c > > > > index 29d4680c68..294e14150d 100644 > > > > --- a/libavformat/dashdec.c > > > > +++ b/libavformat/dashdec.c > > > > @@ -2336,10 +2336,13 @@ static int dash_probe(const AVProbeData *p) > > > > av_stristr(p->buf, "dash:profile:isoff-live:2011") || > > > > av_stristr(p->buf, "dash:profile:isoff-live:2012") || > > > > av_stristr(p->buf, "dash:profile:isoff-main:2011") || > > > > - av_stristr(p->buf, "3GPP:PSS:profile:DASH1")) { > > > > - return AVPROBE_SCORE_MAX; > > > > - } > > > > - if (av_stristr(p->buf, "dash:profile")) { > > > > + av_stristr(p->buf, "3GPP:PSS:profile:DASH1") || > > > > + av_stristr(p->buf, "dash:profile")) { > > > > + if (!av_match_ext(p->filename, "mpd")) { > > > > + av_log(NULL, AV_LOG_ERROR, "Not detecting dash with non > > > > standard extension\n"); > > > > + return 0; > > > > + } > > > > + > > > > return AVPROBE_SCORE_MAX; > > > > } > > > > > > Failing because it didn't match an extensions sort of goes against the > > > point of probing, which even has a low score return value that's > > > basically "it matched extension" as a sort of last resort. > > > > > > I'd say wrap this in a FF_COMPLIANCE_STRICT check (since i assume the > > > spec does state mpd must be the extension), but i think we have no > > > access to the AVFormatContext here? > > > > DASH is usually transferred over HTTP where file extensions are of minor > > interest, the relevant type information is in the Mime-Type header. > > would anyone be opposed to return 0 from dash_probe() when > both the mime_type and the extension are wrong ?
I would. probe() is for probing, not implementing security policies. IMO trying to fix security issues at the wrong layer will only lead to more confusion, more complexity, and LESS security. -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".