在.net核中用TripleDES加密

Question

public static string Encrypt(string toEncrypt, string secretKey)
    {
        byte[] keyArray;
        byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

        var md5Serv = System.Security.Cryptography.MD5.Create();
        keyArray = md5Serv.ComputeHash(UTF8Encoding.UTF8.GetBytes(secretKey));
        md5Serv.Dispose();


        var tdes = System.Security.Cryptography.TripleDES.Create();


        //set the secret key for the tripleDES algorithm
        tdes.Key = keyArray;
        //mode of operation. there are other 4 modes.
        //We choose ECB(Electronic code Book)
        tdes.Mode = CipherMode.ECB;
        //padding mode(if any extra byte added)

        tdes.Padding = PaddingMode.PKCS7;

        ICryptoTransform cTransform = tdes.CreateEncryptor();
        //transform the specified region of bytes array to resultArray
        byte[] resultArray =
          cTransform.TransformFinalBlock(toEncryptArray, 0,
          toEncryptArray.Length);
        //Release resources held by TripleDes Encryptor
        tdes.Dispose();
        //Return the encrypted data into unreadable string format
        return Convert.ToBase64String(resultArray, 0, resultArray.Length);
    }

秘密键=字符串的16个字符

在这一行：

tdes.Key = keyArray;

我得到了这个错误: Message =“指定的键对于这个算法来说不是一个有效的大小”。

错误信息屏幕截图

如何在asp.net内核1.1.0中解决这个问题？如何将byte16转换为byte24

更新后

谢谢你的帮助:)但是！

我在.Net Framework4.6.2中使用这段代码进行加密：

public static string Encrypt(string toEncrypt, string secretKey)
{
    byte[] keyArray;
    byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

    System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();


        MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
        keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(secretKey));

        hashmd5.Clear();



    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
    //set the secret key for the tripleDES algorithm
    tdes.Key = keyArray;
    //mode of operation. there are other 4 modes.
    //We choose ECB(Electronic code Book)
    tdes.Mode = CipherMode.ECB;
    //padding mode(if any extra byte added)

    tdes.Padding = PaddingMode.PKCS7;

    ICryptoTransform cTransform = tdes.CreateEncryptor();
    //transform the specified region of bytes array to resultArray
    byte[] resultArray =
      cTransform.TransformFinalBlock(toEncryptArray, 0,
      toEncryptArray.Length);
    //Release resources held by TripleDes Encryptor
    tdes.Clear();
    //Return the encrypted data into unreadable string format
    return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}

并在.Net Core1.1中使用此方法：

public static string Encrypt(string toEncrypt, string secretKey)
{
    byte[] keyArray;
    byte[] resultArray;
    byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);

    using (var md5Serv = System.Security.Cryptography.MD5.Create())
    {
        keyArray = md5Serv.ComputeHash(UTF8Encoding.Unicode.GetBytes(secretKey));
        if(keyArray.Length==16)
        {
            byte[] tmp = new byte[24];
            Buffer.BlockCopy(keyArray, 0, tmp, 0, keyArray.Length);
            Buffer.BlockCopy(keyArray, 0, tmp, keyArray.Length, 8);
            keyArray = tmp;
        }
    }

    using (var tdes = System.Security.Cryptography.TripleDES.Create())
    {
        //set the secret key for the tripleDES algorithm
        tdes.Key = keyArray;
        //mode of operation. there are other 4 modes.
        //We choose ECB(Electronic code Book)
        tdes.Mode = CipherMode.ECB;
        //padding mode(if any extra byte added)

        tdes.Padding = PaddingMode.PKCS7;

        ICryptoTransform cTransform = tdes.CreateEncryptor();
        //transform the specified region of bytes array to resultArray
        resultArray =
          cTransform.TransformFinalBlock(toEncryptArray, 0,
          toEncryptArray.Length);
    }

    //Return the encrypted data into unreadable string format
    return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}

，但我不知道为什么这种方法给我不同的结果？！

Answer 1

if (key.Length == 16)
{
    byte[] tmp = new byte[24];
    Buffer.BlockCopy(key, 0, tmp, 0, key.Length);
    Buffer.BlockCopy(key, 0, tmp, key.Length, 8);
    key = tmp;
}

这将将您的2 3DES键(k1、k2)转换为3 3DES键(k1、k2、k1)。FWIW，.NET Core2.0 (https://github.com/dotnet/corefx/issues/9966)已经修复了这个问题。

所以，现在您的代码将再次工作。不过，正如其他人在评论中指出的那样，在您的代码中有很多事情是不符合现代标准的密码的。您应该强烈考虑将此作为增强加密的机会。(如果你不能“因为它不能处理已经存在的数据”，那么你应该利用这个机会，在你的数据中增加密码灵活性，允许你在一段时间内使用不同的密钥方案和/或算法。)