| 12 | | == Authenticating == |
| 13 | | |
| 14 | | Here's a code sample that authenticates a user. This would be used to process login forms. Like before, you'd check {{{request.user.is_anonymous()}}} if you want to test if user is logged in. |
| 15 | | |
| 16 | | {{{ |
| 17 | | #!python |
| 18 | | |
| 19 | | from django.contrib.auth import AuthUtil |
| 20 | | |
| 21 | | def login(self, request): |
| 22 | | authutil = AuthUtil() |
| 23 | | user = authutil.authenticate(request) |
| 24 | | if user is None: |
| 25 | | # do whatever for invalid logins |
| 26 | | else: |
| 27 | | # the user is valid, persist their id (username, email, token, etc.) in a session var or whatever. |
| 28 | | # do whatever else this view is supposed to do. |
| 29 | | }}} |
| 30 | | |
| 31 | | Note that the view is in charge of "logging in" a user, that is, the view must persist the id of the user somehow. A session variable is the easiest place, but a signed cookie would be desireable for those who don't want to use the session middleware. It would be nice if this were more convenient. It shouldn't be hard to do. Also, in practice, all of this would probably happen in a decorator. Adding that much boilerplate code to every view would be a little ridiculous. |
| 32 | | |
| 33 | | For extra points, there should be ways of tying this all in with WSGI ;) |
| 34 | | |
| 35 | | |
| 36 | | == Credentials == |
| 37 | | |
| 38 | | Credentials are extracted from the request by plugins. These plugins are just functions that take the request as their only argument and return a dict or string containing the credentials. You can have multiple ordered credential plugins by changing {{{CREDENTIAL_PLUGINS}}} in your settings file. |
| 39 | | |
| 40 | | {{{ |
| 41 | | #!python |
| 42 | | |
| 43 | | CREDENTIAL_PLUGINS = ( |
| 44 | | 'django.contrib.auth.credentials.username_password_form', |
| 45 | | 'django.contrib.auth.credentials.token', |
| 46 | | ) |
| 47 | | |
| 48 | | }}} |
| 49 | | |
| 50 | | AuthUtil will use the first plugin and hand the credentials to {{{AUTHENTICATION_BACKEND}}}. If {{{AUTHENTICATION_BACKEND}}} returns None for the first set of credentials, the next plugin will be tried, and so on. |
| 51 | | |
| 52 | | {{{CREDENTIAL_PLUGINS}}} defaults to {{{('django.contrib.auth.credentials.username_password_form',)}}} |
| 53 | | |
| 54 | | |
| 55 | | == Using Multiple Backends == |
| 56 | | |
| 57 | | To use multiple authentication backends, set AUTHENTICATION_BACKEND to {{{django.contrib.auth.backends. MultiAuthBackend}}} in your settings file.You must also set AUTHENTICATION_BACKEND to a tuple of the backends you wish to use, in order. |
| 58 | | |
| 59 | | For example: |
| 60 | | |
| 61 | | {{{ |
| 62 | | #!python |
| 63 | | |
| 64 | | AUTHENTICATION_BACKEND = 'django.contrib.auth.backends.MultiAuthBackend' |
| 65 | | |
| 66 | | MULTIAUTH_BACKENDS = ( |
| 67 | | 'django.contrib.auth.backends.LDAPBackend', |
| 68 | | 'django.contrib.auth.backends.ModelBackend', |
| 69 | | ) |
| 70 | | }}} |
| 71 | | |
| 72 | | When you call {{{authenticate}}} or {{{get_user}}} on {{{MultiAuthBackend}}}, it will in turn call the same method on each backend in {{{MULTIAUTH_BACKENDS}}} in order. |
| 73 | | |
| | 14 | ''Note: For those paying attention to this proposal, credential plugins have been completely removed. While useful for some applications, the added complexity just wasn't worth it.'' |
| 96 | | |
| 97 | | |
| 98 | | == Writing Backends == |
| 99 | | |
| 100 | | Authentication backends are pretty simple. They just need to implement 2 |
| 101 | | methods, {{{authenticate}}} and {{{get_user}}}. |
| 102 | | |
| 103 | | === backend.authenticate(self, credentials) === |
| 104 | | If the credentials match a user in this backend it returns a user object. If not, it returns None. Keep in mind that credentials could be a dict, a string, pretty much anything. You'll have to make sure that {{{authenticate}}} does the appropriate checking and returns None for credentials that it can't handle. |
| 105 | | |
| 106 | | The user object will generally be an instance of {{{django.contrib.auth.models.User}}}, but really, it could be anything. You will need to at least fake the interface for {{{django.contrib.auth.models.User}}} if you want to use the admin system however. Your backend can create and save an instance of {{{django.contrib.auth.models.User}}} when a user logs in for the first time. You could also add them to a default set of groups at that time. |
| 107 | | |
| 108 | | === backend.get_user(self, user_id) === |
| 109 | | |
| 110 | | {{{backend.get_user}}} simply takes a user id and returns the user that matches that id. The user id is not neccessarily numeric, and in most cases it won't be. It could be a username, an email address, whatever. The important part is that it uniquely identifies a user. |