Dotnetencryption256havinganissue786305

使用BouncyCastle库中的AES-256算法进行加密和解密。

代码示例：

using System;
using System.IO;
using System.Security.Cryptography;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;

public static class AesUtility
{
    public static byte[] Encrypt(byte[] data, byte[] key, byte[] iv)
    {
        using var aes = new RijndaelManaged { KeySize = 256, BlockSize = 128, Padding = PaddingMode.PKCS7 };
        var encryptor = aes.CreateEncryptor(key, iv);

        using var memoryStream = new MemoryStream();
        using var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
        cryptoStream.Write(data, 0, data.Length);
        cryptoStream.FlushFinalBlock();

        return memoryStream.ToArray();
    }

    public static byte[] Decrypt(byte[] data, byte[] key, byte[] iv)
    {
        using var aes = new RijndaelManaged { KeySize = 256, BlockSize = 128, Padding = PaddingMode.PKCS7 };
        var decryptor = aes.CreateDecryptor(key, iv);

        using var memoryStream = new MemoryStream(data);
        using var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);

        var buffer = new byte[data.Length];
        var count = cryptoStream.Read(buffer, 0, buffer.Length);

        return buffer[..count];
    }

    public static byte[] GenerateRandomKey()
    {
        var aes = new RijndaelManaged { KeySize = 256 };
        aes.GenerateKey();
        return aes.Key;
    }

    public static byte[] GenerateRandomIv()
    {
        var aes = new RijndaelManaged { BlockSize = 128 };
        aes.GenerateIV();
        return aes.IV;
    }

    public static byte[] EncryptUsingBouncyCastle(byte[] data, byte[] key, byte[] iv)
    {
        var cipher = CipherUtilities.GetCipher("AES/CBC/PKCS7Padding");
        var keyParameter = new KeyParameter(key);
        var ivParameter = new ParametersWithIV(keyParameter, iv);
        cipher.Init(true, ivParameter);

        return cipher.DoFinal(data);
    }

    public static byte[] DecryptUsingBouncyCastle(byte[] data, byte[] key, byte[] iv)
    {
        var cipher = CipherUtilities.GetCipher("AES/CBC/PKCS7Padding");
        var keyParameter = new KeyParameter(key);
        var ivParameter = new ParametersWithIV(keyParameter, iv);
        cipher.Init(false, ivParameter);

        return cipher.DoFinal(data);
    }
}

使用BouncyCastle库中的AES-256算法进行加密和解密，解决了Dotnet 256位加密存在的问题。