[FFmpeg-devel] [PATCH 3/4] avformat/concat: Add concat_enable option that is disable by default

[Andreas Cadhalpun]

On 20.01.2016 18:51, Michael Niedermayer wrote:
> On Wed, Jan 20, 2016 at 05:06:37PM +0100, Nicolas George wrote:
>> If people start to care about playlist-based security issues (Reimar used to
>> warn about it long ago), a cross-protocol solution needs to be found.
> 
> thats true for git-master, and i can look into implementing whitelists
> similar to the format&codec whitelists we have

I think introducing protocol_whitelist could be a general solution.
It could have sensible defaults, e.g. if it is not passed as option
to avio_open2/ffurl_connect it could default to only local protocols
unless the protocol to open is a network protocol, in which case
it could default to only network protocols.

So when opening 'file:', 'concat:' or other local protocol, the
protocol_whitelist would default to local protocols.
When opening 'http:', 'https:' or other network protocols, the
protocol_whitelist would default to network protocols.

That should prevent mixing of local and remote data, unless
specifically requested by the API/CLI user.

So if e.g. a local playlist 'file:' would contain 'http:' URLs a
protocol_whitelist allowing this combination would be required
for playback.

> but ATM my concern is
> more about the past releases
> 
> do you object to this patch being applied to the past releases ?

I think this patch and the similar one for subfile would at least
be better than removing these protocols from released versions.

Best regards,
Andreas