Apache Geronimo Simple Encryption Password Decrypter

decrypt_geronimo.py

#!/usr/bin/python3
from Crypto.Cipher import AES #https://pycryptodome.readthedocs.io/en/latest/src/cipher/cipher.html
import javaobj #https://pypi.org/project/javaobj-py3/
import struct
import base64
import sys

if len(sys.argv) < 2:
    print("Usage:\n\tpython3 decrypt_geronimo.py [base64_{SIMPLE} Value]")

# hardcoded Apache Geronimo key: https://github.com/apache/geronimo/blob/trunk/framework/modules/geronimo-crypto/src/main/java/org/apache/geronimo/crypto/SimpleEncryption.java#L46
key = [-45, -15, 100, -34, 70, 83, 75, -100, -75, 61, 26, 114, -20, -58, 114, 77]
key = struct.pack('bbbbbbbbbbbbbbbb',*key)

# Geronimo {simple} and {standard} passwords will actually be a base64-encoded Java sealed object
# Example:
#"rO0ABXNyABlqYXZheC5jcnlwdG8uU2VhbGVkT2JqZWN0PjY9psO3VHACAARbAA1lbmNvZGVkUGFyYW1zdAACW0JbABBlbmNyeXB0ZWRDb250ZW50cQB+AAFMAAlwYXJhbXNBbGd0ABJMamF2YS9sYW5nL1N0cmluZztMAAdzZWFsQWxncQB+AAJ4cHB1cgACW0Ks8xf4BghU4AIAAHhwAAAAEHnh03EmiNu4VTuWH+xZiRBwdAADQUVT"
sealed_object = sys.argv[1] 
sealed_object = base64.b64decode(sealed_object)

# The sealed object contents can be accessed with some help from the javaobj python library which can parse serialized java object strings.
sealed_object = javaobj.loads(sealed_object)
ciphertext = sealed_object.encryptedContent._data
ciphertext = struct.pack('b'*len(ciphertext), *ciphertext)

# The simple encryption uses "AES" as the cipher, which by default in Java will be AES MODE_ECB.
ecb = AES.new(key, AES.MODE_ECB)
plaintext = ecb.decrypt(ciphertext)

# this will print out the raw serialized object, but the password will show up as plaintext.
print(plaintext)