Changes of displayname from auth providers are not reflected in synapse

[tgurr]

Description:

I'm using mxisd with matrix-synapse-rest-auth as password provider to sync users from LDAP/AD.

in mxisd.yaml I have:

ldap:
  enabled: true
  connection:
    host: 'xxx'
    port: 389
    bindDn: 'CN=xxx,OU=xxx,DC=xxx,DC=xxx'
    bindPassword: 'xxx'
    baseDNs:
      - 'OU=xxx,DC=xxx,DC=xxx'
  attribute:
    name: 'cn'

and in homserver.yaml

password_providers:
  - module: "rest_auth_provider.RestAuthProvider"
    config:
      endpoint: "http://localhost:8090"
      policy:
        registration:
          profile:
            name: true
        login:
          profile:
            name: true

When logging in with riot-web I can see the name correctly changing on every login in the top left corner whether I set the name: attribute in myisd.yaml to either 'cn' or 'displayName'.

Also curl https://matrix.domain.local/_matrix/client/r0/profile/%40matrixid%3Adomain.local shows the correct "displayname".

However in the riot-web/matrix profile the "Display Name" is not applied and/or changing accordingly, so in the rooms I already joined I still appear with the matrixid:server.xxx instead of the correct name: transferred by mxisd via LDAP.

In our organization it's quite common for names to change, e.g. because of marriage and thus it would be nice to have an option for synapse to force syncing the displayname to all rooms so users don't need to worry about, don't need to be instructed about and more importantly not making a support request about their old name still being shown.

For reference: kamax-matrix/matrix-synapse-rest-password-provider#6

[dklimpel]

see also: #6572 and #7023

[n3rdybyn47ur3]

Anything new?
We had to downgrade our server to synapse 1.18 because the rest auth provider seems to stop working with the following versions. After that we noticed that displayNames dont change correctly (as mentioned above). Maybe the case in newer versions too, but we had no reason to test it. Since we have to deal with a lot of name changes, this is an absolute requirement and an release stopper.

[clokep]

I don't believe this has ever been supported in Synapse, it probably wouldn't be too terrible, but would require adding a new API method and then updating the auth providers to call it.