신한 InsideBankNew

using System;
using System.Text;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;

class Program
{
    static void Main()
    {
        string plainText = "Hello, ARIA 256!";
        string keyHex = "00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF"; // 256-bit 키 (32바이트)

        byte[] key = HexStringToByteArray(keyHex);
        byte[] encrypted = AriaEncrypt(plainText, key);
        string encryptedHex = BitConverter.ToString(encrypted).Replace("-", "");

        Console.WriteLine($"Encrypted: {encryptedHex}");

        byte[] decrypted = AriaDecrypt(encrypted, key);
        string decryptedText = Encoding.UTF8.GetString(decrypted);

        Console.WriteLine($"Decrypted: {decryptedText}");
    }

    static byte[] AriaEncrypt(string plainText, byte[] key)
    {
        IBlockCipher engine = new AriaEngine();
        PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
        KeyParameter keyParam = new KeyParameter(key);

        cipher.Init(true, keyParam);
        byte[] inputBytes = Encoding.UTF8.GetBytes(plainText);
        return ProcessCipher(cipher, inputBytes);
    }

    static byte[] AriaDecrypt(byte[] cipherText, byte[] key)
    {
        IBlockCipher engine = new AriaEngine();
        PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(engine);
        KeyParameter keyParam = new KeyParameter(key);

        cipher.Init(false, keyParam);
        return ProcessCipher(cipher, cipherText);
    }

    static byte[] ProcessCipher(PaddedBufferedBlockCipher cipher, byte[] input)
    {
        byte[] output = new byte[cipher.GetOutputSize(input.Length)];
        int length = cipher.ProcessBytes(input, 0, input.Length, output, 0);
        length += cipher.DoFinal(output, length);
        Array.Resize(ref output, length);
        return output;
    }

    static byte[] HexStringToByteArray(string hex)
    {
        int length = hex.Length / 2;
        byte[] bytes = new byte[length];
        for (int i = 0; i < length; i++)
        {
            bytes[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
        }
        return bytes;
    }
}