XtsAes256.cs

using System;
using System.Security.Cryptography;

namespace XTSSharp;

public class XtsAes256 : Xts
{
    private const int KEY_LENGTH = 256;
    private const int KEY_BYTE_LENGTH = 32;

    protected XtsAes256(Func<SymmetricAlgorithm> create, byte[] key1, byte[] key2)
        : base(create, VerifyKey(256, key1), VerifyKey(256, key2))
    {
    }

    public static Xts Create(byte[] key1, byte[] key2)
    {
        VerifyKey(256, key1);
        VerifyKey(256, key2);
        return new XtsAes256(Aes.Create, key1, key2);
    }

    public static Xts Create(byte[] key)
    {
        VerifyKey(512, key);
        byte[] array = new byte[32];
        byte[] array2 = new byte[32];
        Buffer.BlockCopy(key, 0, array, 0, 32);
        Buffer.BlockCopy(key, 32, array2, 0, 32);
        return new XtsAes256(Aes.Create, array, array2);
    }
}