PBE with MD5 and DES

PBEdecrypt.py

from Crypto.Hash import MD5
from Crypto.Cipher import DES

d_password = "PBE.class"
d_salt = "\xC7\x73\x21\x8C\x7E\xC8\xEE\x99"

def unpad_pkcs7(text, blocklength=16):
    full_len = len(text)
    pad_val = ord(text[-1])
    pos = full_len - pad_val
    if pad_val == 0 or text[-pad_val:] != chr(pad_val) * pad_val:
        raise ValueError('bad padding')
    return text[:pos]

def compute_key_iv(password, salt, iterations=20):
    hasher = MD5.new()
    hasher.update(password)
    hasher.update(salt)
    result = hasher.digest()
    for i in xrange(1, iterations):
        hasher = MD5.new()
        hasher.update(result)
        result = hasher.digest()
    return result[:8], result[8:16]

def decrypt(plain, password, salt, iterations=20):
    key, iv = compute_key_iv(password, salt, iterations)
    decode = DES.new(key, DES.MODE_CBC, iv)
    decrypted = decode.decrypt(plain)
    decrypted = unpad_pkcs7(decrypted)
    print decrypted