SSO with Nextcloud

[erichrueger]

Hi,

no matter what I try I can't get SSO running with nextcloud. Is there a guide what to put in as oidc_provider?
I followed a guide from here:
matrix-org/synapse#8511
Have I misconfigured the oauth section in nextcloud? I don't know what to put in as redirection-uri
I tried the following:
https://matrix.example.de/_synapse/client/oidc/callback
After that, nextcloud displays the dialogue for granting access. But then I get the following error message:
There was an error
localpart is invalid:
Error code
mapping_error

The synapse server displays the following error message:
_File "/usr/local/lib/python3.8/site-packages/synapse/handlers/sso.py", line 606, in register_mapped_user
raise MappingException("localpart is invalid: %s" % (attributes.localpart,))

Can anyone help?
Best regards

Erich

[jonathanmmm]

This isn't a webapp problem, more a synapse or reverse proxy problem, do you use a reverse proxy?

If yes, follow the following to get it right:
https://matrix-org.github.io/synapse/develop/reverse_proxy.html

and here to get synapse homeserver.yaml and right
https://matrix-org.github.io/synapse/develop/openid.html

or both under here: https://github.com/matrix-org/synapse/blob/develop/docs/

[gymnae]

This made it work for me, but I'm still having issues with the CSRF when initially signing up:
matrix-org/synapse#8511 (comment)