Source Code for Package django.contrib.auth

 1  import datetime 
 2  from django.core.exceptions import ImproperlyConfigured 
 3   
 4  SESSION_KEY = '_auth_user_id' 
 5  BACKEND_SESSION_KEY = '_auth_user_backend' 
 6  REDIRECT_FIELD_NAME = 'next' 
 7   
 8 -def load_backend(path): 
 9      i = path.rfind('.') 
10      module, attr = path[:i], path[i+1:] 
11      try: 
12          mod = __import__(module, {}, {}, [attr]) 
13      except ImportError, e: 
14          raise ImproperlyConfigured, 'Error importing authentication backend %s: "%s"' % (module, e) 
15      except ValueError, e: 
16          raise ImproperlyConfigured, 'Error importing authentication backends. Is AUTHENTICATION_BACKENDS a correctly defined list or tuple?' 
17      try: 
18          cls = getattr(mod, attr) 
19      except AttributeError: 
20          raise ImproperlyConfigured, 'Module "%s" does not define a "%s" authentication backend' % (module, attr) 
21      return cls() 
22   
23 -def get_backends(): 
24      from django.conf import settings 
25      backends = [] 
26      for backend_path in settings.AUTHENTICATION_BACKENDS: 
27          backends.append(load_backend(backend_path)) 
28      return backends 
29   
30 -def authenticate(**credentials): 
31      """ 
32      If the given credentials are valid, return a User object. 
33      """ 
34      for backend in get_backends(): 
35          try: 
36              user = backend.authenticate(**credentials) 
37          except TypeError: 
38              # This backend doesn't accept these credentials as arguments. Try the next one. 
39              continue 
40          if user is None: 
41              continue 
42          # Annotate the user object with the path of the backend. 
43          user.backend = "%s.%s" % (backend.__module__, backend.__class__.__name__) 
44          return user 
45   
46 -def login(request, user): 
47      """ 
48      Persist a user id and a backend in the request. This way a user doesn't 
49      have to reauthenticate on every request. 
50      """ 
51      if user is None: 
52          user = request.user 
53      # TODO: It would be nice to support different login methods, like signed cookies. 
54      user.last_login = datetime.datetime.now() 
55      user.save() 
56      request.session[SESSION_KEY] = user.id 
57      request.session[BACKEND_SESSION_KEY] = user.backend 
58      if hasattr(request, 'user'): 
59          request.user = user 
60   
61 -def logout(request): 
62      """ 
63      Remove the authenticated user's ID from the request. 
64      """ 
65      try: 
66          del request.session[SESSION_KEY] 
67      except KeyError: 
68          pass 
69      try: 
70          del request.session[BACKEND_SESSION_KEY] 
71      except KeyError: 
72          pass 
73      if hasattr(request, 'user'): 
74          from django.contrib.auth.models import AnonymousUser 
75          request.user = AnonymousUser() 
76   
77 -def get_user(request): 
78      from django.contrib.auth.models import AnonymousUser 
79      try: 
80          user_id = request.session[SESSION_KEY] 
81          backend_path = request.session[BACKEND_SESSION_KEY] 
82          backend = load_backend(backend_path) 
83          user = backend.get_user(user_id) or AnonymousUser() 
84      except KeyError: 
85          user = AnonymousUser() 
86      return user 
87