This changes the way django_to_ldap_username works to make sure the ldap
username it returns actually has a corresponding ldap entry and raise an
exception if that's not possible. It seems to be a more sound approach
than just having it return its best guess - which was the case so far.
Now there is a guarantee that what it returns is the username of an
actual ldap user.
This allows communicating to the registration flow when the email being
registered doesn't belong to ldap, which then will proceed to register
it via the normal email backend flow - finally fixing the bug where you
couldn't register a non-ldap email even with the email backend enabled.
These changes to the behavior of django_to_ldap_username require small
refactorings in a couple of other functions that call it, as well as
adapting some tests to these changes. Finally, additional tests are
added for the above-mentioned registration flow behavior and some
related corner-cases.
Fixes#11878
Instead of a confusing mix of django_auth_backed applying
ldap_to_django_username in its internals for one part of the
translation, and then custom logic for grabbing it from the email
attribute of the ldapuser in ZulipLDAPAuthBackend.get_or_build_user
for the second part of the translation,
we put all the logic in a single function user_email_from_ldapuser
which will be used by get_or_build of both ZulipLDAPUserPopulator and
ZulipLDAPAuthBackend.
This, building on the previous commits with the email search feature,
fixes the ldap sync bug from issue #11878.
If we can get upstream django-auth-ldap to merge
https://github.com/django-auth-ldap/django-auth-ldap/pull/154, we'll
be able to go back to using the version of ldap_to_django_username
that accepts a _LDAPUser object.
With this, django_to_ldap_username can take an email and find the ldap
username of the ldap user who has this email - if email search is
configured.
This allows successful authenticate() with ldap email and ldap password,
instead of ldap username. This is especially useful because when
a user wants to fetch their api key, the server attempts authenticate
with user_profile.email - and this used to fail if the user was an ldap
user (because the ldap username was required to authenticate
succesfully). See issue #9277.
Mateusz Mandera