gistfile1.py

import base64
import hashlib

from django.contrib.auth.hashers import BasePasswordHasher, mask_hash
from django.utils.crypto import constant_time_compare
from django.utils.datastructures import SortedDict
from django.utils.translation import ugettext_lazy as _


class SymfonyPasswordHasher(BasePasswordHasher):
    algorithm = 'symf'
    iterations = 5000
    digest = hashlib.sha512

    def encode(self, password, salt, iterations=None):
        assert password
        assert salt and '$' not in salt
        if not iterations:
            iterations = self.iterations
        password = password.encode('utf-8')
        salted = '%s{%s}' % (password, salt)
        salted = salted.encode('utf-8')
        hash =  self.digest(salted).digest()
        for i in range(iterations - 1):
            hash = self.digest('%s%s' % (hash, salted)).digest()
        hash = base64.b64encode(hash)  # .decode('ascii').strip()
        return '%s$%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 migrate(self, enc_password, salt):
        return '%s$%d$%s$%s' % (self.algorithm, self.iterations, salt, enc_password)

    def safe_summary(self, encoded):
        algorithm, iterations, salt, hash = encoded.split('$', 3)
        assert algorithm == self.algorithm
        return SortedDict([
            (_('algorithm'), algorithm),
            (_('iterations'), iterations),
            (_('salt'), mask_hash(salt)),
            (_('hash'), mask_hash(hash)),
        ])