Generate user credentials for Solr BasicAuthentication

generate_user_credentials.py

#!/usr/bin/env python3

# Copyright 2020 Sebastian Gassner <sebastian.gassner@gmail.com>
# License: MIT
# Based on java.org.apache.solr.security.Sha256AuthenticationProvider
#
# Usage: generate_user_credentials.py USER PASS
#
# Then add the output into security.json under 'credentials'.

import hashlib
import os
import base64
import sys
import json

os.path.basename(__file__)
if len(sys.argv) != 3:
    print(f"Usage: {os.path.basename(__file__)} USER PASSWORD")
    sys.exit(2)
user = sys.argv[1]
password = sys.argv[2]

# Generate 32 random bytes for salt;
# then, the hashed_password is sha256(sha256(salt+password));
# return base64(hashed_password) base64(salt).
m = hashlib.sha256()
salt = os.urandom(32)
m.update(salt)
m.update(password.encode('utf-8'))
tmp = m.digest()
m = hashlib.sha256()
m.update(tmp)
hashed = m.digest()

result = {}
print('"{}" : "{} {}"'.format(
    user,
    base64.standard_b64encode(hashed).decode('utf-8'),
    base64.standard_b64encode(salt).decode('utf-8')))