# Copyright (c) 2015-2018 The Bitcoin Core developers
# Distributed under the MIT software license, see the accompanying
# file COPYING or http://www.opensource.org/licenses/mit-license.php.

# SPDX-FileCopyrightText: 2015-2018 The Bitcoin Core developers
#
# SPDX-License-Identifier: GPL-3.0-or-later

from argparse import ArgumentParser
from base64 import urlsafe_b64encode
from binascii import hexlify
from getpass import getpass
from os import urandom

import hmac

def generate_salt(size):
    """Create size byte hex salt"""
    return hexlify(urandom(size)).decode()

def generate_password():
    """Create 32 byte b64 password"""
    return urlsafe_b64encode(urandom(32)).decode('utf-8')

def password_to_hmac(salt, password):
    m = hmac.new(bytearray(salt, 'utf-8'), bytearray(password, 'utf-8'), 'SHA256')
    return m.hexdigest()

def get_data(username: str, password=None):
    # If no password is given, then get it from generate_password()
    if password is None:
        password = generate_password()

    # Create 16 byte hex salt
    salt = generate_salt(16)
    password_hmac = password_to_hmac(salt, password)

    return {
        'conf_data': 'rpcauth={0}:{1}${2}'.format(username, salt, password_hmac),
        'auth': '{0}:{1}${2}'.format(username, salt, password_hmac),
        'password': password
    }