MSC3860: Add media download redirect proposal

[Fizzadar]

Rendered.

Tiny one here, may not even need any implementation work. Confirmed working on:

• [x] element desktop
• [x] element iOS
• [x] element Android
• [ ] Federation / between servers
• [x] Fluffychat

Given working implementations this MSC is merely to clarify that redirects are allowed responses to media endpoints in the spec.

Signed off by Nick @ Beeper (@fizzadar) [email protected].

[turt2live]

For sign off: We will need an email address, or the form completed with [email protected]

[Fizzadar]

~~Ok this is now confirmed working on all platforms, so implementation is done?~~ See description!

[turt2live]

@matrix-org/spec-core-team the author believes this is ready for FCP, though I'm not seeing a whole lot of technical review on this. Please review the MSC, and if it looks ready for FCP, send it :)

[spaetz]

May I just add one more argument for this MSC which has not been mentioned so far? The logic focuses mostly on efficiency and CDNs now, but there is also a legal aspect. Right now, I can make any matrix server download, cache and proxy any matrix mid that I want, including potentially very bad and illegal stuff. Allowing for a 307 redirect (which specific server implementations could allow on a configurable basis) would permit cautious server operators to not store and provide any media that floats in the matrixverse, but just refer to the "original" media.

On the other hand, it would allow for replacing media after the fact, which comes with its own sets of problems (circumventing moderation tools by replacing media after upload and moderation checks comes to my mind).

Not sure if these arguments somehow also belong into the MSC?

[spaetz]

The proposed allow_redirect param would make redirects optional though which would directly circumvent the legal aspect outlined in my comment above. So I am not sure if that param should really be introduced just to remain backward compatible or if breakage of clients who do not follow redirects is acceptable...

[richvdh]

@spaetz please make comments on the diff view. They are liable to get lost here.

[richvdh]

@mscbot fcp merge

[mscbot]

Team member @richvdh has proposed to merge this. The next step is review by the rest of the tagged people:

• [x] @dbkr
• [x] @uhoreg
• [x] @turt2live
• [ ] @ara4n
• [x] @anoadragon453
• [x] @richvdh
• [x] @erikjohnston
• [ ] @KitsuneRal

Once at least 75% of reviewers approve (and there are no outstanding concerns), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for information about what commands tagged team members can give me.

[Fizzadar]

lgtm assuming these comments can get folded into the MSC before it's formally accepted (blocks FCP completing, not starting):

https://github.com/matrix-org/matrix-spec-proposals/pull/3860/files#r1170042073 https://github.com/matrix-org/matrix-spec-proposals/pull/3860/files#r1170051233 https://github.com/matrix-org/matrix-spec-proposals/pull/3860/files#r1171840795

Should all now be addressed!

[mscbot]

:bell: This is now entering its final comment period, as per the review above. :bell:

[mscbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

[turt2live]

Spec PR: https://github.com/matrix-org/matrix-spec/pull/1529

[turt2live]

Merged 🎉