DES/MD5加解密方法

    private const string Key = "自定义秘钥";

    /// <summary>
    /// DES+Base64加密
    /// <para>采用ECB、PKCS7</para>
    /// </summary>
    /// <param name="encryptString">加密字符串</param>
    /// <param name="key">秘钥</param>
    /// <returns></returns>
    public static string Encrypt(string encryptString, string key = null)
    {
        return Encrypt(encryptString, key, false, true);
    }

    /// <summary>
    /// DES+Base64解密
    /// <para>采用ECB、PKCS7</para>
    /// </summary>
    /// <param name="decryptString">解密字符串</param>
    /// <param name="key">秘钥</param>
    /// <returns></returns>
    public static string Decrypt(string decryptString, string key = null)
    {
        return Decrypt(decryptString, key, false);
    }

    /// <summary>
    /// DES+16进制加密
    /// <para>采用ECB、PKCS7</para>
    /// </summary>
    /// <param name="encryptString">加密字符串</param>
    /// <param name="key">秘钥</param>
    /// <param name="lowerCase">是否小写</param>
    /// <returns></returns>
    public static string Encrypt4Hex(string encryptString, string key = null, bool lowerCase = false)
    {
        return Encrypt(encryptString, key, true, lowerCase);
    }

    /// <summary>
    /// DES+16进制解密
    /// <para>采用ECB、PKCS7</para>
    /// </summary>
    /// <param name="decryptString">解密字符串</param>
    /// <param name="key">秘钥</param>
    /// <returns></returns>
    public static string Decrypt4Hex(string decryptString, string key = null)
    {
        return Decrypt(decryptString, key, true);
    }

    /// <summary>
    /// DES加密
    /// </summary>
    /// <param name="encryptString"></param>
    /// <param name="key"></param>
    /// <param name="hex"></param>
    /// <param name="lowerCase"></param>
    /// <returns></returns>
    private static string Encrypt(string encryptString, string key, bool hex, bool lowerCase = false)
    {
        if (encryptString.IsNull())
            return null;
        if (key.IsNull())
            key = Key;
        if (key.Length < 8)
            throw new ArgumentException("秘钥长度为8位", nameof(key));

        var keyBytes = Encoding.UTF8.GetBytes(key[..8]);
        var inputByteArray = Encoding.UTF8.GetBytes(encryptString);

        var des = DES.Create();
        des.Mode = CipherMode.ECB;
        des.Key = keyBytes;
        des.Padding = PaddingMode.PKCS7;

        using var stream = new MemoryStream();
        var cStream = new CryptoStream(stream, des.CreateEncryptor(), CryptoStreamMode.Write);
        cStream.Write(inputByteArray, 0, inputByteArray.Length);
        cStream.FlushFinalBlock();

        var bytes = stream.ToArray();
        return hex ? bytes.ToHex(lowerCase) : bytes.ToBase64();
    }

    /// <summary>
    /// DES解密
    /// </summary>
    /// <param name="decryptString"></param>
    /// <param name="key"></param>
    /// <param name="hex"></param>
    /// <returns></returns>
    private static string Decrypt(string decryptString, string key, bool hex)
    {
        if (decryptString.IsNull())
            return null;
        if (key.IsNull())
            key = Key;
        if (key.Length < 8)
            throw new ArgumentException("秘钥长度为8位", nameof(key));

        var keyBytes = Encoding.UTF8.GetBytes(key[..8]);
        var inputByteArray = hex ? decryptString.HexToBytes() : Convert.FromBase64String(decryptString);

        var des = DES.Create();
        des.Mode = CipherMode.ECB;
        des.Key = keyBytes;
        des.Padding = PaddingMode.PKCS7;

        using var mStream = new MemoryStream();
        var cStream = new CryptoStream(mStream, des.CreateDecryptor(), CryptoStreamMode.Write);
        cStream.Write(inputByteArray, 0, inputByteArray.Length);
        cStream.FlushFinalBlock();
        return Encoding.UTF8.GetString(mStream.ToArray());
    }



    /// <summary>
    /// 16位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <param name="lowerCase"></param>
    /// <returns></returns>
    public static string Encrypt16(string password, bool lowerCase = false)
    {
        if (password.IsNull())
            return null;

        using var md5 = MD5.Create();
        return md5.ComputeHash(Encoding.UTF8.GetBytes(password)).ToHex(lowerCase);
    }

    /// <summary>
    /// 32位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <param name="lowerCase"></param>
    /// <returns></returns>
    public static string Encrypt32(string password = "", bool lowerCase = false)
    {
        if (password.IsNull())
            return null;

        using var md5 = MD5.Create();
        string pwd = string.Empty;
        byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(password));
        var format = lowerCase ? "x2" : "X2";
        foreach (var item in s)
        {
            pwd = string.Concat(pwd, item.ToString(format));
        }
        return pwd;
    }

    /// <summary>
    /// 64位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <returns></returns>
    public static string Encrypt64(string password)
    {
        if (password.IsNull())
            return null;

        using var md5 = MD5.Create();
        byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(password));
        return s.ToBase64();
    }

    public static string GetHash(Stream stream)
    {
        StringBuilder sb = new();
        using var md5 = MD5.Create();
        byte[] hashBytes = md5.ComputeHash(stream);
        foreach (byte bt in hashBytes)
        {
            sb.Append(bt.ToString("x2"));
        }

        return sb.ToString();
    }