The code in maybe_send_to_registration incorrectly used the
`get_realm_from_request` function to fetch the subdomain. This usage
was incorrect in a way that should have been irrelevant, because that
function only differs if there's a logged-in user, and in this code
path, a user is never logged in (it's the code path for logged-out
users trying to sign up).
This this bug could confuse unit tests that might run with a logged-in
client session. This made it possible for several of our GitHub auth
tests to have a totally invalid subdomain value (the root domain).
Fixing that bug in the tests, in turn, let us delete a code path in
the GitHub auth backend logic in `backends.py` that is impossible in
production, and had just been left around for these broken tests.
This is done mainly because this backend has the simplest code path
for calling login_or_register_remote_user, more than because we expect
this case to come up. It'll make it easier to write unit tests for
the `invalid_subdomain` corner case.
In this commit we start to support redirects to urls supplied as a
'next' param for the following two backends:
* GoogleOAuth2 based backend.
* GitHubAuthBackend.
This is necessary for mobile apps to do the right thing when only
RemoteUserBackend is enabled, namely, directly redirect to the
third-party SSO auth site as soon as the user enters the server URL
(no need to display a login form, since it'll be useless).
I probably should have just done this in the original implementation;
there's only a small downside in the form of an extra database query
when trying to authenticate a user who doesn't exist.
Structurally, the main change here is replacing the `clean_username`
function, which would get called when one accessed
self.cleaned_data['username'] with code in the main `clean` function.
This is important because only in `clean` do we have access to the
`realm` object.
Since I recently added full test coverage on this form, we know each
of the major cases have a test; the error messages are unchanged.
This deletes the old mock-covered test for this, which was mostly
useless. We have a much less messy test, which we extend to provide
the same test coverage the old one did.
While the result was the same before, this makes it more obvious.
We created this redundant pair of conditionals in a preceding commit,
in order to match the indentation of an `except` block so as to slice
the diffs extra finely as we're refactoring auth code.
This lets us delete some duplicate code, since common_get_active_user
handles an account in the wrong subdomain for us.
Also lets us delete the now-unused common_get_active_user_by_email.
This way, we don't attempt to evaluate whether the user's account is
active (etc.) until after we've checked the backend is enabled. This
won't change the result of actual auth, but feels more readable.
This is a behavior change, though we don't check the value in the
caller regardless. It just seems more logical for us to correctly
report to the caller whether the Google auth itself was valid
unconditionally.
This code path was only required because we had remote_user set as a
positional argument here, and thus we'd be running this auth backend's
code when actually using another auth backend (due to how Django auth
backends are selected based on argument signature).
This require some care to ensure we still provide the same nice error
messages for the case of a user who has an account, just not with this
organization.
Also, we fix the fact that the docstring was (and I think always has
been) at best confusing and perhaps even inaccurate.
Now we have moved the `do_auth` function to `SocialAuthMixin`. Instead
of overriding `do_auth`, derived class is now expected to override
`get_authenticated_user`.
`do_auth` now contains code which is expected by all backends.
Most of these have more to do with authentication in general than with
registering a new account. `create_preregistration_user` could go
either way; we move it to `auth` so we can make the imports go only in
one direction.