Each login facility must provide this hook. The hook should
succeed if-and-only-if the user is logged in using this facility
and the hook must bind UserInfo with a dict that contains the
following fields:
- user:User
- User name (id) if the logged in user.
- name:Name
- Common name of the logged in user.
- email:Email
- Email address of the logged in user.
- picture:URL
- If present, URL is used to indicate the currently logged in
user.
- auth_method:Method
- Authentication method used. Currently one of
basic, digest
or oauth2.
- logout_url:URL
- URL that must be used to logout. Needed if
auth_method is
not one of the HTTP authentication methods (basic or
digest).
If this hook fails the user is not logged in.