C#AES解密码

我有使用AES算法进行字符串加密/解密的代码。加密工作正常，但我无法得到正确的纯文本时，我解密回来。解密代码中一定有错误

public static class EncryptionHelper
{
    private static int BlockSize = 16;

    private static byte[] Key
    {
        get
        {
            byte[] hash = SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes("BlahBlahBlah"));
            byte[] key = new byte[BlockSize];
            Array.Copy(hash, 0, key, 0, BlockSize);
            return key;
        }
    }

    private static byte[] IV
    {
        get
        {
            StringBuilder builder = new StringBuilder();
            Random random = new Random();
            for (int i = 0; i < BlockSize; i++)
            {
                char ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65)));
                builder.Append(ch);
            }
            return Encoding.UTF8.GetBytes(builder.ToString());
        }
    }

    public static string DecodeAndDecrypt(string cipherText)
    {
        string DecodeAndDecrypt = AesDecrypt(Convert.FromBase64String(HttpUtility.UrlDecode(cipherText)));
        return (DecodeAndDecrypt);
    }

    public static string EncryptAndEncode(string plaintext)
    {
        return HttpUtility.UrlEncode(Convert.ToBase64String(AesEncrypt(plaintext))); 
    }

    public static string AesDecrypt(Byte[] inputBytes)
    {
        Byte[] outputBytes = inputBytes;

        string plaintext = string.Empty;

        using (MemoryStream memoryStream = new MemoryStream(outputBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateDecryptor(Key, IV), CryptoStreamMode.Read))
            {
                using (StreamReader srDecrypt = new StreamReader(cryptoStream))
                {
                    plaintext = srDecrypt.ReadToEnd();
                }
            }
        }

        return plaintext;
    }

    public static byte[] AesEncrypt(string inputText)
    {
        byte[] inputBytes = UTF8Encoding.UTF8.GetBytes(inputText); 

        for (int i = 0; i < BlockSize; i++)
        {
            inputBytes[i] ^= IV[i];
        }

        byte[] result = null;
        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateEncryptor(Key, IV), CryptoStreamMode.Write))
            {
                cryptoStream.Write(inputBytes, 0, inputBytes.Length);
                cryptoStream.FlushFinalBlock();
                result = memoryStream.ToArray();
            }
        }
        return result;
    }

    private static RijndaelManaged GetCryptoAlgorithm()
    {
        RijndaelManaged algorithm = new RijndaelManaged();
        algorithm.Padding = PaddingMode.PKCS7;
        algorithm.Mode = CipherMode.CBC;
        algorithm.KeySize = 128;
        algorithm.BlockSize = 128;
        return algorithm;
    }
}

我已复制了下面的代码。
请帮忙。谢谢

下面是加密和解密代码

public static class EncryptionHelper
{
    private static int BlockSize = 16;

    private static byte[] Key
    {
        get
        {
            byte[] hash = SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes("BlahBlahBlah"));
            byte[] key = new byte[BlockSize];
            Array.Copy(hash, 0, key, 0, BlockSize);
            return key;
        }
    }

    private static byte[] IV
    {
        get
        {
            StringBuilder builder = new StringBuilder();
            Random random = new Random();
            for (int i = 0; i < BlockSize; i++)
            {
                char ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65)));
                builder.Append(ch);
            }
            return Encoding.UTF8.GetBytes(builder.ToString());
        }
    }

    public static string DecodeAndDecrypt(string cipherText)
    {
        string DecodeAndDecrypt = AesDecrypt(Convert.FromBase64String(HttpUtility.UrlDecode(cipherText)));
        return (DecodeAndDecrypt);
    }

    public static string EncryptAndEncode(string plaintext)
    {
        return HttpUtility.UrlEncode(Convert.ToBase64String(AesEncrypt(plaintext))); 
    }

    public static string AesDecrypt(Byte[] inputBytes)
    {
        Byte[] outputBytes = inputBytes;

        string plaintext = string.Empty;

        using (MemoryStream memoryStream = new MemoryStream(outputBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateDecryptor(Key, IV), CryptoStreamMode.Read))
            {
                using (StreamReader srDecrypt = new StreamReader(cryptoStream))
                {
                    plaintext = srDecrypt.ReadToEnd();
                }
            }
        }

        return plaintext;
    }

    public static byte[] AesEncrypt(string inputText)
    {
        byte[] inputBytes = UTF8Encoding.UTF8.GetBytes(inputText); 

        for (int i = 0; i < BlockSize; i++)
        {
            inputBytes[i] ^= IV[i];
        }

        byte[] result = null;
        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateEncryptor(Key, IV), CryptoStreamMode.Write))
            {
                cryptoStream.Write(inputBytes, 0, inputBytes.Length);
                cryptoStream.FlushFinalBlock();
                result = memoryStream.ToArray();
            }
        }
        return result;
    }

    private static RijndaelManaged GetCryptoAlgorithm()
    {
        RijndaelManaged algorithm = new RijndaelManaged();
        algorithm.Padding = PaddingMode.PKCS7;
        algorithm.Mode = CipherMode.CBC;
        algorithm.KeySize = 128;
        algorithm.BlockSize = 128;
        return algorithm;
    }
}

公共静态类EncryptionHelper
{
私有静态int BlockSize=16；
专用静态字节[]密钥
{
得到
{
byte[]hash=SHA1.Create（）.ComputeHash（Encoding.UTF8.GetBytes（“BlahBlahBlah”）；
字节[]键=新字节[块大小]；
复制（散列，0，键，0，块大小）；
返回键；
}
}
专用静态字节[]IV
{
得到
{
StringBuilder=新的StringBuilder（）；
随机=新随机（）；
对于（int i=0；i

我做了一些更改，并将在下面发布一些源代码。要使其工作，只需在Form1上放置3个文本框，并将此代码用于Form1.cs。我在上面提到过，我认为一个主要问题是如何在不指定编码的情况下以字符串形式从StreamReader中读取数据。我的更改使用BinaryReader作为字节数组进行读取，然后在读取后转换为UTF-8字符串。我还删除了XOR循环。我认为您试图自己实现CBC（CBC是一种XOR的反馈循环），但它不是必需的——当您指定CBC模式时，.NET为您实现CBC模式。为了使我的版本尽可能接近你的版本，我没有做更多的更改。但请记住上面的一些评论。例如，当.NET提供DeriveBytes函数时，不要使用简单的哈希。像对待纸巾一样对待静脉注射——使用一次，也只能使用一次，永远不要。等等无论如何，如果不是“最佳实践”，功能代码如下：

编辑：对不起，我忘了提到我还将纯文本类型更改为常规字符串，删除了与HTTP相关的代码。这只是为了让我的工作更简单。不过，它对HTTP方法的作用应该与对常规字符串的作用一样好

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Windows.Forms;

namespace StackOverflow
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox3_TextChanged(object sender, EventArgs e)
        {
            textBox1.Text = EncryptionHelper.EncryptAndEncode(textBox3.Text);
            textBox2.Text = EncryptionHelper.DecodeAndDecrypt(textBox1.Text);
        }
    }

    public static class EncryptionHelper
    {
        private static int BlockSize = 16;

        private static byte[] Key
        {
            get
            {
                byte[] hash = SHA1.Create().ComputeHash(Encoding.UTF8.GetBytes("BlahBlahBlah"));
                byte[] key = new byte[BlockSize];
                Array.Copy(hash, 0, key, 0, BlockSize);
                return key;
            }
        }

        private static byte[] IV
        {
            get
            {
                StringBuilder builder = new StringBuilder();
                Random random = new Random();
                for (int i = 0; i < BlockSize; i++)
                {
                    char ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65)));
                    builder.Append(ch);
                }
                return Encoding.UTF8.GetBytes(builder.ToString());
            }
        }

        public static string DecodeAndDecrypt(string cipherText)
        {
            byte[] cipherBytes = Convert.FromBase64String(cipherText);
            string decodeAndDecrypt = AesDecrypt(cipherBytes);
            return decodeAndDecrypt;
        }

        public static string EncryptAndEncode(string plaintext)
        {
            return Convert.ToBase64String(AesEncrypt(plaintext));
        }

        public static string AesDecrypt(Byte[] inputBytes)
        {
            Byte[] outputBytes = inputBytes;

            string plaintext = string.Empty;

            using (MemoryStream memoryStream = new MemoryStream(outputBytes))
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateDecryptor(Key, IV), CryptoStreamMode.Read))
                {
                    using (BinaryReader srDecrypt = new BinaryReader(cryptoStream))
                    {
                        outputBytes = srDecrypt.ReadBytes(inputBytes.Length);
                        plaintext = Encoding.UTF8.GetString(outputBytes);
                    }
                }
            }
            return plaintext;
        }

        public static byte[] AesEncrypt(string inputText)
        {
            byte[] inputBytes = UTF8Encoding.UTF8.GetBytes(inputText);
            byte[] result = null;
            using (MemoryStream memoryStream = new MemoryStream())
            {
                using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateEncryptor(Key, IV), CryptoStreamMode.Write))
                {
                    cryptoStream.Write(inputBytes, 0, inputBytes.Length);
                    cryptoStream.FlushFinalBlock();
                    result = memoryStream.ToArray();
                }
            }
            return result;
        }

        private static RijndaelManaged GetCryptoAlgorithm()
        {
            RijndaelManaged algorithm = new RijndaelManaged();
            algorithm.Padding = PaddingMode.PKCS7;
            algorithm.Mode = CipherMode.CBC;
            algorithm.KeySize = 128;
            algorithm.BlockSize = 128;
            return algorithm;
        }
    }
}

使用系统；
使用System.IO；
使用System.Security.Cryptography；
使用系统文本；
使用System.Windows.Forms；
命名空间堆栈溢出
{
公共部分类Form1:Form
{
公共表格1（）
{
初始化组件（）；
}
私有void textBox3\u TextChanged（对象发送方，事件参数e）
{
textBox1.Text=EncryptionHelper.EncryptAndEncode（textBox3.Text）；
textBox2.Text=EncryptionHelper.DecodeAndDecrypt（textBox1.Text）；
}
}
公共静态类EncryptionHelper
{
私有静态int BlockSize=16；
专用静态字节[]密钥
{
得到
{
byte[]hash=SHA1.Create（）.ComputeHash（Encoding.UTF8.GetBytes（“BlahBlahBlah”）；
字节[]键=新字节[块大小]；
复制（散列，0，键，0，块大小）；
返回键；
}
}
专用静态字节[]IV
{
得到
{
StringBuilder=新的StringBuilder（）；
随机=新随机（）；
对于（int i=0；i