Inside Bitcoin

1#!/usr/bin/env python3
2# Copyright (c) 2015-present The Bitcoin Core developers
3# Distributed under the MIT software license, see the accompanying
4# file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6from argparse import ArgumentParser
7from getpass import getpass
8from secrets import token_hex, token_urlsafe
9import hmac
10import json
11
12def generate_salt(size):
13    """Create size byte hex salt"""
14    return token_hex(size)
15
16def generate_password():
17    """Create 32 byte b64 password"""
18    return token_urlsafe(32)
19
20def password_to_hmac(salt, password):
21    m = hmac.new(salt.encode('utf-8'), password.encode('utf-8'), 'SHA256')
22    return m.hexdigest()
23
24def main():
25    parser = ArgumentParser(description='Create login credentials for a JSON-RPC user')
26    parser.add_argument('username', help='the username for authentication')
27    parser.add_argument('password', help='leave empty to generate a random password or specify "-" to prompt for password', nargs='?')
28    parser.add_argument("-j", "--json", help="output to json instead of plain-text", action='store_true')
29    args = parser.parse_args()
30
31    if not args.password:
32        args.password = generate_password()
33    elif args.password == '-':
34        args.password = getpass()
35
36    # Create 16 byte hex salt
37    salt = generate_salt(16)
38    password_hmac = password_to_hmac(salt, args.password)
39
40    if args.json:
41        odict={'username':args.username, 'password':args.password, 'rpcauth':f'{args.username}:{salt}${password_hmac}'}
42        print(json.dumps(odict))
43    else:
44        print('String to be appended to bitcoin.conf:')
45        print(f'rpcauth={args.username}:{salt}${password_hmac}')
46        print(f'Your password:\n{args.password}')
47
48if __name__ == '__main__':
49    main()
50