Pure Python implementation of FNV64 and a custom hash suitable for urls. The hash prepends a salt in from of the data, then computes the FNV64 hash and encode the data in base64. Remember however that the FNV64 is not a cryptographic hash.

fnv64basedhash.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
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#  Copyright 2014 Cilyan Olowen <[email protected]>
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import base64
import struct

def fnv64(data):
    hash_ = 0xcbf29ce484222325
    for b in data:
        hash_ *= 0x100000001b3
        hash_ &= 0xffffffffffffffff
        hash_ ^= b
    return hash_

def hash_dn(dn, salt):
    # Turn dn into bytes with a salt, dn is expected to be ascii data
    data = salt.encode("ascii") + dn.encode("ascii")
    # Hash data
    hash_ = fnv64(data)
    # Pack hash (int) into bytes
    bhash = struct.pack("<Q", hash_)
    # Encode in base64. There is always a padding "=" at the end, because the
    # hash is always 64bits long. We don't need it.
    return base64.urlsafe_b64encode(bhash)[:-1].decode("ascii")