Decrypts passwords stored in rclone configuration files

rcd.py

import sys
import base64
from Crypto.Cipher import AES

# Constant key rclone uses
key = bytearray.fromhex('9c935b48730a554d6bfd7c63c886a92bd390198eb8128afbf4de162b8b95f638')

enc_pwd = sys.argv[1]
enc_pwd += '=' * (-len(enc_pwd) % 4) # add padding, else some passwords will fail

ciphertext = base64.urlsafe_b64decode(enc_pwd)

buffer = ciphertext[16:]
iv = ciphertext[:16]

dec = AES.new(key, AES.MODE_CTR, initial_value=iv, nonce=b'')

print(f'\nPlaintext password: {dec.decrypt(buffer).decode()}')