学习http://docs.djangoproject.com/en/dev/topics/auth/?from=olddocs#writing-an-authentication-backend记录authetication backend是一个类，实现了两个方法：get_user(user_id)与authenticate(**credentials).get_user函数有一个参数user_id,它可以是username,database ID或其他，返回一个User对象实例。authenticate方法有一个名为credentials的关键字参数。一般情况，它如下：class MyBackend:  def authenticate(self,username=None,password=None):    #检测username与password，然后返回一个User实例但也可以是身份验证令牌，如下：class MyBackend:  def authenticate(self,token=None):    #检测token返回一个User实例下面的例子实现功能为：username与password是在自己的settings.py文件中定义的，利用这个信息实现登录，返回一个Django　User.from django.conf import settingsfrom django.contrib.auth.models import User,check_passwordclass SettingsBackend:    """    Authenticate against the settings ADMIN_LOGIN and ADMIN_PASSWORD.    Use the login name, and a hash of the password. For example:    ADMIN_LOGIN = 'admin'    ADMIN_PASSWORD = 'sha1$4e987$afbcf42e21bd417fb71db8c66b321e9fc33051de'    """    def authenticate(self, username=None, password=None):        login_valid = (settings.ADMIN_LOGIN == username)        pwd_valid = check_password(password, settings.ADMIN_PASSWORD)        if login_valid and pwd_valid:            try:                user = User.objects.get(username=username)            except User.DoesNotExist:                # Create a new user. Note that we can set password                # to anything, because it won't be checked; the password                # from settings.py will.                user = User(username=username, password='get from settings.py')                user.is_staff = True                user.is_superuser = True                user.save()            return user        return None    def get_user(self, user_id):        try:            return User.objects.get(pk=user_id)        except User.DoesNotExist:            return None在自定义backend中处理授权自定义认证后台提供了自己的权限。user model将通过委托实现了（get_group_permissions(),get_all_permission(),has_perm()与has_module_perms())这些函数authentication backend处理权限查询。代码如下：class SettingsBackend:  ...  def has_perm(self.user_obj,perm):    if user_obj.username == settings.ADMIN_LOGIN:      return True    else:      return False

原文：http://plq168.blog.163.com/blog/static/53101462201092711170704/