New 100 char display name length limit is too restrictive

[ulope]

Description:

With d16c637 a display name length limit of 100 characters was introduced.

Unfortunately this breaks our (Raiden Network) (admittedly unorthodox) use of the display name field as a way to publish ECDSA (recoverable) signatures.

Hex encoded those take up 132 chars.

We could switch to base64 encoding (which would just fit) or (mis-)use the avatar_url field but both of those would be backwards incompatible changes at our protocol level which we would like to avoid if possible.

So the question is: Is there a possibility of having this length restriction increased (to say 256) or better yet be made configurable?

[turt2live]

It sounds like you want https://github.com/matrix-org/matrix-doc/issues/489 or matrix-org/matrix-spec-proposals#1769 instead

[aaronraimist]

It probably should still be configurable though

[t3chguy]

How would configurability work with federation?

[ara4n]

i suspect we should just bump it to 256

[aaronraimist]

@t3chguy I haven’t really looked at how it worked but I had assumed it was only limiting display names on your server’s own users, nothing to do with federation but maybe I’m wrong. Anyway even if it did affect all user’s display names, that number doesn’t come from the spec AFAIK so server implementations would be free to use any number or not limit it

[Half-Shot]

Currently it's a local limit, not over federation.

[neilisfragile]

We can bump to 256

The reason that 100 was chosen (over any other finite number) was to give enough space for what we thought would be most profiles, but short enough to make it harder to spread abusive content via profile names (which used to be a thing ...)

[richvdh]

fixed by #5906

[ulope]

Great! Thanks for the quick turnaround.

Do you have a notion when a new release that includes this change could happen?

[richvdh]

releases normally happen every couple of weeks.