[FFmpeg-devel] [PATCH] add md5 muxer

[Michael Niedermayer]

On Sun, Sep 27, 2009 at 07:53:18PM +0200, Reimar D?ffinger wrote:
> On Sun, Sep 27, 2009 at 07:31:00PM +0200, Michael Niedermayer wrote:
> > On Sun, Sep 27, 2009 at 12:04:27PM +0200, Reimar D?ffinger wrote:
> > > we have -f crc, but IMO 32 bit crc are a bit little for a whole file and
> > > also we use md5sum in the regression tests, so I'd propose to add a -f
> > > md5 as in attached patch.
> > 
> > why md5 instead of sha1?
> 
> Because md5 makes more sense for the simple reasons that
> 1) we already use it in regression tests
> 2) a md5/md5sum binary is available anywhere, I do not know
>    something comparable for sha
> 3) for security-relevant stuff they are all "useless"
> 

> Which leaves me to ask: why sha1? I don't really see anything in
> its favour 

well, because someone could use it with source files under outside
control.
I would guess that in that case it can likely be used to return
misleading values ...
one could use it to detect files with duplicate content, for example
... <automatic app>ahh goatse.mkv contains the same as
bible_readings_for_children.mkv so lets skip the expensive human check
of content and allow it be uploaded as a new revission ...

now iam not a religious person and neither one of thouse who think
such content would seriously harm a child
(they plain wouldnt understand it or if they are older would find it
disgusting or funny but iam much more betting on disgusting here)
but it still feels kinda like a very annoying thing and sure better
if something like that didnt happen ...


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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