Creating a salt in python

Question

How would I create a random, 16-character base-62 salt in python? I need it for a protocol and I'm not sure where to start. Thanks.

Answer 1

>>> import random >>> ALPHABET = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" >>> chars=[] >>> for i in range(16):     chars.append(random.choice(ALPHABET))  >>> "".join(chars) 'wE9mg9pu2KSmp5lh' 

This should work.

Answer 2

You shouldn't use UUIDs, they are unique, not random: Is using a CreateUUID() function as salt a good idea?

Your salts should use a cryptographically secure random numbers, in python 2.4+, os.urandom is the source of these (if you have a good timing source).

# for some given b62encode function  salt = b62encode(os.urandom(16)) 

you could also use a generator from bcrypt or other awesome crypto/hashing library that is well known and vetted by the people much more expert than I am.

import bcrypt salt = bcrypt.gensalt() # will be 29 chars you can then encode it however you want.