ASP.NET常用加密解密方法

        public static string ToMd5(string clearString)
        {
            Byte[] clearBytes = System.Text.Encoding.Unicode.GetBytes(clearString);
            string hashedPwd = BitConverter.ToString(((HashAlgorithm)CryptoConfig.CreateFromName("MD5")).ComputeHash(clearBytes));
            return hashedPwd;
        }

        public static string GetMd5Base32(string sInput)
        {
            System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
            System.Security.Cryptography.MD5 md5;
            byte[] bytesSrc;
            byte[] result;
            StringBuilder sb = new StringBuilder();
            bytesSrc = encoding.GetBytes(sInput);
            md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            result = md5.ComputeHash(bytesSrc);
            for (int i = 0; i < result.Length; i++)
            {
                sb.AppendFormat("{0:x2}", result[i]);
            }
            return sb.ToString();
        }

DESEncrypt DES加密

DESDecrypt DES解密

    /// <summary>
    /// 有关base64编码算法的相关操作
    /// </summary>
    public class Base64
    {
        public Base64()
        {

        } 

        /// <summary>
        /// 将字符串使用base64算法加密
        /// </summary>
        /// <param name="sourceString">待加密的字符串</param>
        /// <param name="ens">System.Text.Encoding 对象，如创建中文编码集对象：System.Text.Encoding.GetEncoding(54936)</param>
        /// <returns>加码后的文本字符串</returns>
        public static string EncodingForString(string sourceString, System.Text.Encoding ens)
        {
            return Convert.ToBase64String(ens.GetBytes(sourceString));
        }


        /// <summary>
        /// 将字符串使用base64算法加密
        /// </summary>
        /// <param name="sourceString">待加密的字符串</param>
        /// <returns>加码后的文本字符串</returns>
        public static string EncodingForString(string sourceString)
        {
            return EncodingForString(sourceString, System.Text.Encoding.GetEncoding(54936));
        }


        /// <summary>
        /// 从base64编码的字符串中还原字符串，支持中文
        /// </summary>
        /// <param name="base64String">base64加密后的字符串</param>
        /// <param name="ens">System.Text.Encoding 对象，如创建中文编码集对象：System.Text.Encoding.GetEncoding(54936)</param>
        /// <returns>还原后的文本字符串</returns>
        public static string DecodingForString(string base64String, System.Text.Encoding ens)
        {
            /**
            * ***********************************************************
            * 
            * 从base64String中取得的字节值为字符的机内码（ansi字符编码）
            * 一般的，用机内码转换为汉字是公式：
            * (char)(第一字节的二进制值*256+第二字节值)
            * 而在c#中的char或string由于采用了unicode编码，就不能按照上面的公式计算了
            * ansi的字节编和unicode编码不兼容
            * 故利用.net类库提供的编码类实现从ansi编码到unicode代码的转换
            * 
            * GetEncoding 方法依赖于基础平台支持大部分代码页。但是，对于下列情况提供系统支持：默认编码，即在执行此方法的计算机的区域设置中指定的编码；Little- Endian Unicode (UTF-16LE)；Big-Endian Unicode (UTF-16BE)；Windows 操作系统 (windows-1252)；UTF-7；UTF-8；ASCII 以及 GB18030（简体中文）。
            *
            *指定下表 中列出的其中一个名称以获取具有对应代码页的系统支持的编码。
            *
            * 代码页 名称 
            * 1200 “UTF-16LE”、“utf-16”、“ucs-2”、“unicode”或“ISO-10646-UCS-2” 
            * 1201 “UTF-16BE”或“unicodeFFFE” 
            * 1252 “windows-1252” 
            * 65000 “utf-7”、“csUnicode11UTF7”、“unicode-1-1-utf-7”、“unicode-2-0-utf-7”、“x- unicode-1-1-utf-7”或“x-unicode-2-0-utf-7” 
            * 65001 “utf-8”、“unicode-1-1-utf-8”、“unicode-2-0-utf-8”、“x-unicode-1-1-utf-8”或 “x-unicode-2-0-utf-8” 
            * 20127 “us-ascii”、“us”、“ascii”、“ANSI_X3.4-1968”、“ANSI_X3.4-1986”、“cp367”、 “csASCII”、“IBM367”、“iso-ir-6”、“ISO646-US”或“ISO_646.irv:1991” 
            * 54936 “GB18030” 
            *
            * 某些平台可能不支持特定的代码页。例如，Windows 98 的美国版本可能不支持日语 Shift-jis 代码页（代码页 932）。这种情况下，GetEncoding 方法将在执行下面的 C# 代码时引发 NotSupportedException：
            *
            * Encoding enc = Encoding.GetEncoding("shift-jis"); 
            **************************************************************/
            // 从base64String中得到原始字符
            return ens.GetString(Convert.FromBase64String(base64String));
        }

        /// <summary>
        /// 从base64编码的字符串中还原字符串，支持中文
        /// </summary>
        /// <param name="base64String">base64加密后的字符串</param>
        /// <returns>还原后的文本字符串</returns>
        public static string DecodingForString(string base64String)
        {
            return DecodingForString(base64String, System.Text.Encoding.GetEncoding(54936));
        }


        //--------------------------------------------------------------------------------------

        /// <summary>
        /// 对任意类型的文件进行base64加码
        /// </summary>
        /// <param name="fileName">文件的路径和文件名</param>
        /// <returns>对文件进行base64编码后的字符串</returns>
        public static string EncodingForFile(string fileName)
        {
            System.IO.FileStream fs = System.IO.File.OpenRead(fileName);
            System.IO.BinaryReader br = new System.IO.BinaryReader(fs);

            /*System.Byte[] b=new System.Byte[fs.Length];
        fs.Read(b,0,Convert.ToInt32(fs.Length));*/


            string base64String = Convert.ToBase64String(br.ReadBytes((int)fs.Length));


            br.Close();
            fs.Close();
            return base64String;
        }

        /// <summary>
        /// 把经过base64编码的字符串保存为文件
        /// </summary>
        /// <param name="base64String">经base64加码后的字符串</param>
        /// <param name="fileName">保存文件的路径和文件名</param>
        /// <returns>保存文件是否成功</returns>
        public static bool SaveDecodingToFile(string base64String, string fileName)
        {
            System.IO.FileStream fs = new System.IO.FileStream(fileName, System.IO.FileMode.Create);
            System.IO.BinaryWriter bw = new System.IO.BinaryWriter(fs);
            bw.Write(Convert.FromBase64String(base64String));
            bw.Close();
            fs.Close();
            return true;
        }


        //-------------------------------------------------------------------------------

        /// <summary>
        /// 从网络地址一取得文件并转化为base64编码
        /// </summary>
        /// <param name="url">文件的url地址,一个绝对的url地址</param>
        /// <param name="objWebClient">System.Net.WebClient 对象</param>
        /// <returns></returns>
        public static string EncodingFileFromUrl(string url, System.Net.WebClient objWebClient)
        {
            return Convert.ToBase64String(objWebClient.DownloadData(url));
        }


        /// <summary>
        /// 从网络地址一取得文件并转化为base64编码
        /// </summary>
        /// <param name="url">文件的url地址,一个绝对的url地址</param>
        /// <returns>将文件转化后的base64字符串</returns>
        public static string EncodingFileFromUrl(string url)
        {
            //System.Net.WebClient myWebClient = new System.Net.WebClient();
            return EncodingFileFromUrl(url, new System.Net.WebClient());
        }
    }

private string getSHA(string code) 
{ 
  if (!String.IsNullOrEmpty(code)) 
  {
      return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(code, "SHA1").ToLower(); 
  } 
  else
    {

      return string.Empty; 
  }   
}

/// <summary>
    /// AES加密解密
    /// </summary>
    public class AES
    {
        /// <summary>
        /// 获取密钥
        /// </summary>
        private static string Key
        {
            get { return @")O[NB]6,YF}+efcaj{+oESb9d8>Z‘e9M"; }
        }

        /// <summary>
        /// 获取向量
        /// </summary>
        private static string IV
        {
            get { return @"L+/~f4,Ir)b$=pkf"; }
        }

        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <returns>密文</returns>
        public static string AESEncrypt(string plainStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

            string encrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        encrypt = Convert.ToBase64String(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();

            return encrypt;
        }

        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <param name="returnNull">加密失败时是否返回 null，false 返回 String.Empty</param>
        /// <returns>密文</returns>
        public static string AESEncrypt(string plainStr, bool returnNull)
        {
            string encrypt = AESEncrypt(plainStr);
            return returnNull ? encrypt : (encrypt == null ? String.Empty : encrypt);
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <returns>明文</returns>
        public static string AESDecrypt(string encryptStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Convert.FromBase64String(encryptStr);

            string decrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        decrypt = Encoding.UTF8.GetString(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();

            return decrypt;
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <param name="returnNull">解密失败时是否返回 null，false 返回 String.Empty</param>
        /// <returns>明文</returns>
        public static string AESDecrypt(string encryptStr, bool returnNull)
        {
            string decrypt = AESDecrypt(encryptStr);
            return returnNull ? decrypt : (decrypt == null ? String.Empty : decrypt);
        }
    }