Django 1.4 密码存储机制解析与自定义实现指南

PASSWORD_HASHERS = [
  'django.contrib.auth.hashers.PBKDF2PasswordHasher',
  'django.contrib.auth.hashers.PBKDF2SHA1PasswordHasher',
  'django.contrib.auth.hashers.Argon2PasswordHasher',
  'django.contrib.auth.hashers.BCryptSHA256PasswordHasher',
  'django.contrib.auth.hashers.BCryptPasswordHasher',
]

class BasePasswordHasher(object):
  """
  Abstract base class for password hashers
  When creating your own hasher, you need to override algorithm,
  verify(), encode() and safe_summary().
  PasswordHasher objects are immutable.
  """
  algorithm = None
  library = None
 
  def _load_library(self):
    if self.library is not None:
      if isinstance(self.library, (tuple, list)):
        name, mod_path = self.library
      else:
        name = mod_path = self.library
      try:
        module = importlib.import_module(mod_path)
      except ImportError:
        raise ValueError("Couldn't load %s password algorithm "
                 "library" % name)
      return module
    raise ValueError("Hasher '%s' doesn't specify a library attribute" %
             self.__class__)
 
  def salt(self):
    """
    Generates a cryptographically secure nonce salt in ascii
    """
    return get_random_string()
 
  def verify(self, password, encoded):
    """
    Checks if the given password is correct
    """
    raise NotImplementedError()
 
  def encode(self, password, salt):
    """
    Creates an encoded database value
    The result is normally formatted as "algorithm$salt$hash" and
    must be fewer than 128 characters.
    """
    raise NotImplementedError()
 
  def safe_summary(self, encoded):
    """
    Returns a summary of safe values
    The result is a dictionary and will be used where the password field
    must be displayed to construct a safe representation of the password.
    """
    raise NotImplementedError()
 
 
class PBKDF2PasswordHasher(BasePasswordHasher):
  """
  Secure password hashing using the PBKDF2 algorithm (recommended)
  Configured to use PBKDF2 + HMAC + SHA256.
  The result is a 64 byte binary string. Iterations may be changed
  safely but you must rename the algorithm if you change SHA256.
  """
  algorithm = "pbkdf2_sha256"
  iterations = 36000
  digest = hashlib.sha256
 
  def encode(self, password, salt, iterations=None):
    assert password is not None
    assert salt and '$' not in salt
    if not iterations:
      iterations = self.iterations
    hash = pbkdf2(password, salt, iterations, digest=self.digest)
    hash = base64.b64encode(hash).decode('ascii').strip()
    return "%s$%d$%s$%s" % (self.algorithm, iterations, salt, hash)
 
  def verify(self, password, encoded):
    algorithm, iterations, salt, hash = encoded.split('$', 3)
    assert algorithm == self.algorithm
    encoded_2 = self.encode(password, salt, int(iterations))
    return constant_time_compare(encoded, encoded_2)
 
  def safe_summary(self, encoded):
    algorithm, iterations, salt, hash = encoded.split('$', 3)
    assert algorithm == self.algorithm
    return OrderedDict([
      (_('algorithm'), algorithm),
      (_('iterations'), iterations),
      (_('salt'), mask_hash(salt)),
      (_('hash'), mask_hash(hash)),
    ])
 
  def must_update(self, encoded):
    algorithm, iterations, salt, hash = encoded.split('$', 3)
    return int(iterations) != self.iterations
 
  def harden_runtime(self, password, encoded):
    algorithm, iterations, salt, hash = encoded.split('$', 3)
    extra_iterations = self.iterations - int(iterations)
    if extra_iterations > 0:
      self.encode(password, salt, extra_iterations)

PASSWORD_HASHERS = [
  'myproject.hashers.MyMD5PasswordHasher', 
  'django.contrib.auth.hashers.PBKDF2PasswordHasher',
  'django.contrib.auth.hashers.PBKDF2SHA1PasswordHasher',
  'django.contrib.auth.hashers.Argon2PasswordHasher',
  'django.contrib.auth.hashers.BCryptSHA256PasswordHasher',
  'django.contrib.auth.hashers.BCryptPasswordHasher',
]

 from django.contrib.auth.hashers import BasePasswordHasher,MD5PasswordHasher
 from django.contrib.auth.hashers import mask_hash
 import hashlib
 
 class MyMD5PasswordHasher(MD5PasswordHasher):
   algorithm = "mymd5"
 
   def encode(self, password, salt):
     assert password is not None
     hash = hashlib.md5(password).hexdigest().upper()
     return hash
 
   def verify(self, password, encoded):
     encoded_2 = self.encode(password, '')
     return encoded.upper() == encoded_2.upper()
 
   def safe_summary(self, encoded):
     return OrderedDict([
         (_('algorithm'), algorithm),
         (_('salt'), ''),
         (_('hash'), mask_hash(hash)),
         ])

AUTHENTICATION_BACKENDS = (
  'framework.mybackend.MyBackend', #新加
  'django.contrib.auth.backends.ModelBackend',
  'guardian.backends.ObjectPermissionBackend',
)

framework.mybackend.py:

 import hashlib
 from pro import models
 from django.contrib.auth.backends import ModelBackend
 
 class MyBackend(ModelBackend):
   def authenticate(self, username=None, password=None):
     try:
       user = models.M_User.objects.get(username=username)
       print user
     except Exception:
       print 'no user'
       return None
     if hashlib.md5(password).hexdigest().upper() == user.password:
       return user
     return None
 
   def get_user(self, user_id):
     try:
       return models.M_User.objects.get(id=user_id)
     except Exception:
       return None