Reputation: 199
I've been banging my head against the wall for a couple of days now and was hoping someone could point out the obvious. I am trying to match the RijndaelManaged encryption of C# with that of Python using Crypto.Cipher.
Problem: Despite everything being equal I am receiving two different encrypted outputs.
These are the values passed:
Python 3:
import os
import base64
from Crypto.Cipher import AES
iv = 'wdp0hP2WRKWsuP8B'
def fix_binary_data_length(binary_value):
block_length = 16
binary_value_length = len(binary_value)
length_with_padding = (
binary_value_length + (block_length - binary_value_length) % block_length
)
return binary_value.ljust(length_with_padding, b'=')
def encrypt(value: str, key: str):
binary_iv = iv.encode('UTF-8')
binary_value = value.encode('UTF-8')
binary_value = fix_binary_data_length(binary_value)
binary_key = key.encode('UTF-8')
cipher = AES.new(binary_key, AES.MODE_CBC, binary_iv)
encrypted_value = cipher.encrypt(binary_value)
return encrypted_value
C#
using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
public class Crypt {
public static string encrypt(string _sValue, string _sKey){
string _sIv = "wdp0hP2WRKWsuP8B";
if (_sKey.Length != 32) { return string.Empty; }
using (RijndaelManaged _Rijndael = new RijndaelManaged(){
Mode = CipherMode.CBC,
KeySize = 256,
BlockSize = 128
}){
byte[] _chEncrypt = Encoding.UTF8.GetBytes(_sValue);
using (ICryptoTransform _Encryptor = _Rijndael.CreateEncryptor(Encoding.UTF8.GetBytes(_sKey), Encoding.UTF8.GetBytes(_sIv)))
using (MemoryStream _Stream = new MemoryStream())
using (CryptoStream _CryptoStream = new CryptoStream(_Stream, _Encryptor, CryptoStreamMode.Write)){
_CryptoStream.Write(_chEncrypt, 0, _chEncrypt.Length);
_CryptoStream.FlushFinalBlock();
return Convert.ToBase64String(_Stream.ToArray());
}
}
return string.Empty;
}
}
Upvotes: 2
Views: 709
Reputation: 199
Credits to @Topaco for pointing out the obvious ;)
Seems like I did not fully grasp the concept of padding. This is how I got it to work:
import os
import base64
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
iv = 'wdp0hP2WRKWsuP8B'
def encrypt(value: str, key: str):
binary_iv = iv.encode('UTF-8')
binary_value = value.encode('UTF-8')
binary_key = key.encode('UTF-8')
cipher = AES.new(binary_key, AES.MODE_CBC, binary_iv)
encrypted_value = cipher.encrypt(pad(binary_value, AES.block_size))
encrypted_value = base64.b64encode(encrypted_value)
return encrypted_value
Upvotes: 1