[FFmpeg-devel] [PATCH] ipfsgateway: Remove default gateway

[Timo Rothenpieler]

On 11.08.2022 18:26, Mark Gaiser wrote:
> Hi all,
> 
> On the IPFS side we do have a solution for that with CAR files, you can
> read more about that here [1].
> Within the scope of this ipfs gateway protocol handler there isn't a
> solution yet to use CAR files, it is on our radar but still in the
> discussion phase.
> 
> On the cURL side we had this same discussion with 2 possible solutions [2].
> For completeness, i'll list them here in full too:
> 
> 1. An error message that gives no example but instead points the user to
> documentation on how to get it working.
> === cURL example
> $ curl ipfs://bafkreicysg23kiwv34eg2d7qweipxwosdo2py4ldv42nbauguluen5v6am
> Error: local gateway not found and/or IPFS_GATEWAY is not set
> Learn how to run one: https://docs.ipfs.tech/install/command-line/
> ===
> 
> 2. An error message that makes the user aware of IPFS and provides a
> solution to get it working immediately.
> === cURL example
> $ curl ipfs://bafkreicysg23kiwv34eg2d7qweipxwosdo2py4ldv42nbauguluen5v6am
> Error: local gateway not found and/or IPFS_GATEWAY is not set.
> Try: IPFS_GATEWAY=https://ipfs.io
> or run your own: https://docs.ipfs.tech/install/command-line/
> ===
> 
> Within the cURL implementation we're going for point 1.
> The same idea can very well apply to ffmpeg too. Different texts that match
> the different context, but in the same spirit.
> 
> Now ffmpeg is a bit different here. First and foremost because it predates
> the curl.
> But also because the default fallback gateway was an explicitly requested
> feature from the ffmpeg side to give an "it always works" feeling.
> ffmpeg therefore has a fourth option: Do nothing and keep it as-is.

I'm not sure who requested that, but I doubt "tunnel all user traffic 
through some random third parties server" was the idea there.

Releases with that hardcoded server in will be in distributions for 
years, potentially over a decade long.
Nobody can guarantee that it doesn't turn malicious in the future.
And nobody can fully guarantee what the owner does with all the data today.

This is simply unacceptable and it has to be fixed ASAP.
The approach taken by this patch seems the correct way to deal with it 
to me.
It prints a message informing the user on what to do, akin to what curl 
seems to do.