I haven't used external authentication backends for any projects, but I still think the concept of dynamically changing how the password change form/views work based on which backend you authenticated with is too much complexity. This scheme feels very brittle and I'm not sure that making this change in Django offers much benefit (in reduced code, for example) in the end.
On Thursday, December 11, 2014 2:05:22 PM UTC-5, Roman Akopov wrote: > > I've researched a little more, and looks like there is BACKEND_SESSION_KEY > so it is possible to annotate user with backend on subsequent requests. > > https://github.com/django/django/blob/master/django/contrib/auth/__init__.py#L169 > Look like it should be a one line fix for this like > user.backend = backend > I think this will not break any existing code. > > At non-request situations for non-authenticated User model, i.e. > instantiated from database, or just created and saved, we can simply > fallback to old behavior. Actually, I think this is correct, because a user > can have valid credentials in various backends simultaneously. Imagine we > have three backends: Model, LDAP, SMTP. So if you authenticate with > credentials valid for SMTP backend, you can't change password because SMTP > does not support this at all. It should be something like methods throwing > NotImplementedError. If you authenticate with credentials valid for LDAP > backend you can change password and that change will be performed against > LDAP. If you authenticate with credentials valid for Model backend you can > change password in model database. This looks like consistent behavior, > since you change password you just used to authenticate, not some other > password you probably even do not know about. And if no custom backend is > registered or no backend information is available, we fallback to default > one. Of course there is a question, how to reset LDAP password from admin > interface. The answer will be "you cannot". This looks sane for me, because > end-users are happy using just one software for all their tasks and LDAP > administrator should use LDAP tools for administrative tasks anyway, and > password reset is just a small one, there will be permission management, > group membership and all of these tools should not be doubled in Django > admin. > > On Thursday, December 11, 2014 7:49:05 PM UTC+4, Tim Graham wrote: >> >> User is only annotated with backend when calling authenticate(). On >> subsequent requests, or in non-request situations like the Python shell, >> how will you know which backend to delegate to? >> >> How do existing LDAP backends deal with this problem? (or do they just >> ignore it?) >> >> On Thursday, December 11, 2014 4:40:09 AM UTC-5, Roman Akopov wrote: >>> >>> Hello, >>> >>> This is my fist post, so I'm not fully aware of any posting policies you >>> have, but at least I'll try to present my ideas in clear way. >>> >>> *Very brief description of what I suggest:* >>> >>> Optionally delegate password change and password reset to authentication >>> backend. >>> >>> *Motivation:* >>> >>> Django framework is very popular and widely used not only for public, >>> but for private projects too. To make it clear, by private I mean not only >>> personal, but mostly corporate intranet projects. >>> >>> One of the important part of any corporate project is some kind of >>> single sing on (SSO) or, at least, integration with external authentication >>> backend. From my experience it may be any service able to validate >>> credentials. LDAP is most often used for authentication purposes, however, >>> it is not the only available choice. I had projects with authentication >>> delegated to custom HTTP web-services, SMTP, POP3 and IMAP servers, and so >>> on. Corporate intranet you have to deal with may be a zoo of unbelievably >>> non-standard software. Also, even if we’ll talk about LDAP, it may be a >>> few, more than one, LDAP servers you have to try authentication against, >>> like Active Directory and OpenLDAP. >>> >>> Current implementation of User model as well as standard forms, >>> delegates to backend authentication only, but not password reset or change. >>> This forces to reimplementation of user model and/or reimplementation of >>> standard forms for very common tasks, high coupling and bad architecture. >>> Also, if left as is, behavior is very inconsistent, since user is >>> authenticated against one password database (LDAP), but changes or resets >>> password in another (relational model database). And while LDAP may be >>> administered externally by standard web tools, this is not a good option >>> too, since means inconsistent user experience. And custom HTTP services >>> cannot be administered by standard tools at all. >>> >>> *Implementation:* >>> >>> As far as I can see User model is already annotated with backend field >>> >>> https://github.com/django/django/blob/master/django/contrib/auth/__init__.py#L75 >>> >>> so it is possible, and looks simple, to delegate password change and >>> reset to backend, if backend support these operations, which means >>> AbstractBaseUser.set_password method >>> >>> https://github.com/django/django/blob/master/django/contrib/auth/models.py#L226 >>> >>> >>> should be refactored to two methods: reset_password and change_password >>> instead of one set_password, and these two method should delegate operation >>> to backend if supported. (set_password may be left as alias of >>> reset_password). Signatures will be >>> >>> def reset_password(self, new_password) >>> def change_password(self, old_password, new_password) >>> >>> Also authentication forms >>> >>> https://github.com/django/django/blob/master/django/contrib/auth/models.py#L226 >>> >>> >>> should be refactored to use these new reset_password and change_password >>> methods. There must be two methods, as change_password and reset_password >>> may not be both available, also change_password requires old password as >>> backend may require it. Returning to LDAP, there may be various policies >>> which should be respected, like not to change password too often, but reset >>> whenever you want, so we need two separate methods. >>> >>> *Backward compatibility:* >>> >>> As far as I can see change is backwards compatible. Authentication >>> backends not providing extra operations will behave old way without any >>> change. >>> >>> *Patch:* >>> >>> I wanted my design to be reviewed before I’ll try to provide any patch. >>> I'mm pretty sure I've missed something, so discussion is welcome. Also, >>> this will be my first code for Django project, so I'll probably break some >>> rules and will need some help. >>> With best regards, >>> Roman >>> ... >> >> -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-developers. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/8c8177e1-e29a-4b99-a469-8430913d50ad%40googlegroups.com. 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