4、MD5不可逆加密

   4.1、32位加密

    /// <summary>
    /// 与ASP兼容的MD5加密算法
    /// </summary>
    public string GetMD5(string s, string _input_charset)
    {
        MD5 md5 = new MD5CryptoServiceProvider();
        byte[] t = md5.ComputeHash(Encoding.GetEncoding(_input_charset).GetBytes(s));
        StringBuilder sb = new StringBuilder(32);
        for (int i = 0; i < t.Length; i++)
            sb.Append(t[i].ToString("x").PadLeft(2, '0'));
        return sb.ToString();
    }

  4.2、16位加密

    public static string GetMd5Str(string ConvertString)
    {
        MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
        string t2 =BitConverter.ToString(
            md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString))
            , 4
            , 8);
        t2 = t2.Replace("-", "");
        return t2;
    }