__init__.py 文件源码

def encode(the_id, sub_key):
    assert 0 <= the_id < 2 ** 64

    crc = binascii.crc32(bytes(the_id)) & 0xffffffff

    message = struct.pack(b"<IQxxxx", crc, the_id)
    assert len(message) == 16

    key = settings.SECRET_KEY
    iv = hashlib.sha256((key + sub_key).encode('ascii')).digest()[:16]
    cypher = AES.new(key[:32], AES.MODE_CBC, iv)

    eid = base64.urlsafe_b64encode(cypher.encrypt(message)).replace(b"=", b"")
    return eid.decode('utf-8')