If we have integrations with multiple identity providers, when the user does a UI Auth, we need to redirect them to the right one.
There are a few steps to this. First of all we actually need to store the userid of the user we are trying to validate in the UIA session, since the /auth/sso/fallback/web request is unauthenticated.
Then, once we get the /auth/sso/fallback/web request, we can fish the user id out of the session, and use it to look up the external id mappings, and hence pick an SSO provider for them.
* Implement CasHandler.handle_redirect_request
... to make it match OidcHandler and SamlHandler
* Clean up interface for OidcHandler.handle_redirect_request
Make it accept `client_redirect_url=None`.
* Clean up interface for `SamlHandler.handle_redirect_request`
... bring it into line with CAS and OIDC by making it take a Request parameter,
move the magic for `client_redirect_url` for UIA into the handler, and fix the
return type to be a `str` rather than a `bytes`.
* Define a common protocol for SSO auth provider impls
* Give SsoIdentityProvider an ID and register them
* Combine the SSO Redirect servlets
Now that the SsoHandler knows about the identity providers, we can combine the
various *RedirectServlets into a single implementation which delegates to the
right IdP.
* changelog
This converts a few more of our inline HTML templates to Jinja. This is somewhat part of #7280 and should make it a bit easier to customize these in the future.
By persisting the user interactive authentication sessions to the database, this fixes
situations where a user hits different works throughout their auth session and also
allows sessions to persist through restarts of Synapse.
Broadly three things here:
* disable W504 which seems a bit whacko
* remove a bunch of `as e` expressions from exception handlers that don't use
them
* use `r""` for strings which include backslashes
Also, we don't use pep8 any more, so we can get rid of the duplicate config
there.
(instead of everywhere that writes a response. Or rather, the subset of places
which write responses where we haven't forgotten it).
This also means that we don't have to have the mysterious version_string
attribute in anything with a request handler.
Unfortunately it does mean that we have to pass the version string wherever we
instantiate a SynapseSite, which has been c&ped 150 times, but that is code
that ought to be cleaned up anyway really.
If you're a webapp running the fallback in an iframe, you can't set set a
window.onAuthDone function. Let's post a message back to window.opener instead.
* Now only the auth part goes to fallback, not the whole operation
* Auth fallback is a normal API endpoint, not a static page
* Params like the recaptcha pubkey can just live in the config
Involves a little engineering on JsonResource so its servlets aren't always forced to return JSON. I should document this more, in fact I'll do that now.
