python /etc/kcpassword xor encode

# Python port of encoding routing found here:
#  http://www.brock-family.org/gavin/perl/kcpassword.html
def kcpassword_xor(passwd):
        ### The magic 11 bytes - these are just repeated
        # 0x7D 0x89 0x52 0x23 0xD2 0xBC 0xDD 0xEA 0xA3 0xB9 0x1F
        key = [125,137,82,35,210,188,221,234,163,185,31]
        key_len = len(key)

        passwd = [ord(x) for x in list(passwd)]
        # pad passwd length out to an even multiple of key length
        r = len(passwd) % key_len
        if (r > 0):
            passwd = passwd + [0] * (key_len - r)

        for n in range(0, len(passwd), len(key)):
           ki = 0
           for j in range(n, min(n+len(key), len(passwd))):
               passwd[j] = passwd[j] ^ key[ki]
               ki += 1

        passwd = [chr(x) for x in passwd]
        return "".join(passwd)