android_decode_text.py

'''
 Project: curinga
 Time: 27/02/2020 04:45
 '''
import base64
import hashlib

from Crypto import Random
from Crypto.Cipher import AES

block_size = 16
pad = lambda s: s + (block_size - len(s) % block_size) * chr(block_size - len(s) % block_size)
unpad = lambda s: s[0:-ord(s[-1:])]
iv = Random.new().read(AES.block_size) # Random IV

def get_private_key(secret_key, salt):
	return hashlib.pbkdf2_hmac('SHA256', secret_key.encode(), salt.encode(), 65536, 32)

def encrypt_with_AES(message, secret_key, salt):
	private_key = get_private_key(secret_key, salt)
	message = pad(message).encode()
	cipher = AES.new(private_key, AES.MODE_CBC, iv)
	cipher_bytes = base64.b64encode(iv + cipher.encrypt(message))
	return bytes.decode(cipher_bytes)


def decrypt_with_AES(encoded, secret_key, salt):
	private_key = get_private_key(secret_key, salt)
	cipher_text = base64.b64decode(encoded)
	iv = cipher_text[:AES.block_size]
	cipher = AES.new(private_key, AES.MODE_CBC, iv)
	plain_bytes = unpad(cipher.decrypt(cipher_text[block_size:]));
	return bytes.decode(plain_bytes)

secret_key = "123"
salt = "anySaltYouCanUseOfOn"
plain_text = "9999"

cipher = encrypt_with_AES(plain_text, secret_key, salt)
print("Cipher: " + cipher)

#cipher = "xrNbcYkfIlbXIeU6LJscBkz8DV2ivOq80Lxk2zj3LX4="

decrypted = decrypt_with_AES(cipher, secret_key, salt)
print("Decrypted " + decrypted)