TripleDES类 3des加密算法实现

可以加密字符串，也可以加密字节数组。

采用3-des加密算法，加密键只能是16byte(128位)或者是24byte(192位)的，指定的键不仅有长度上的要求，还不能是个弱键
 （ 注：DES 算法使用 56 位（7 字节）的密钥）

//调用方法

// 指定加密键
string key = "yygmldcsjmdsthcg"; //16byte
CryptionData cd = new CryptionData(key);
string testStr = "SpNumber + “$”+ UserNumber + “$”+ ServiceTag + “$”+ AccessTime";
string result = cd.EncryptionStringData(testStr); // result 已经经过base64编码
string encodingStr = HttpUtility.UrlEncode(result, System.Text.Encoding.GetEncoding("GB2312"));

//TripleDES类代码

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


public class CryptionData
{
  // The length of Encryptionstring should be 24 byte and not be a weak key
  private string EncryptionString;

  // The length of initialization vector should be 8 byte
  private static Byte[] EncryptionIV = Encoding.Default.GetBytes("abcdefgh");

  /// <summary>
  /// Constructor
  /// </summary>
  public CryptionData()
  {
  }

  /// <summary>
  /// Constructor
  /// </summary>
  /// <param name="EncryptionString">SecureKey</param>
  public CryptionData(string EncryptionString)
  {
    this.EncryptionString = EncryptionString;
  }

  /// <summary>
  /// Encryption method for byte array
  /// </summary>
  /// <param name="SourceData">source data</param>
  /// <returns>byte array</returns>
  public byte[] EncryptionByteData(byte[] SourceData)
  {
    byte[] returnData = null;
    try
    {
      // Create TripleDESCryptoServiceProvider object
      TripleDESCryptoServiceProvider desProvider = new TripleDESCryptoServiceProvider();

      // Set SecureKey and IV of desProvider
      byte[] byteKey = Encoding.Default.GetBytes(EncryptionString);
      desProvider.Key = byteKey;
      desProvider.IV = EncryptionIV;

      // A MemoryStream object
      MemoryStream ms = new MemoryStream();

      // Create Encryptor
      ICryptoTransform encrypto = desProvider.CreateEncryptor();

      // Create CryptoStream object
      CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);

      // Encrypt SourceData
      cs.Write(SourceData,0,SourceData.Length);
      cs.FlushFinalBlock();

      // Get Encryption result
      returnData = ms.ToArray();
    }
    catch(Exception ex)
    {
      throw ex;
    }

    return returnData;

  }

  /// <summary>
  /// Decryption method for byte array
  /// </summary>
  /// <param name="SourceData">source data</param>
  /// <returns>byte array</returns>
  public byte[] DecryptionByteData(byte[] SourceData)
  {
    byte[] returnData = null;
    try
    {
      // Create TripleDESCryptoServiceProvider object
      TripleDESCryptoServiceProvider desProvider = new TripleDESCryptoServiceProvider();

      // Set SecureKey and IV of desProvider
      byte[] byteKey = Encoding.Default.GetBytes(EncryptionString);
      desProvider.Key = byteKey;
      desProvider.IV = EncryptionIV;

      // A MemoryStream object
      MemoryStream ms = new MemoryStream();

      // Create Decryptor
      ICryptoTransform encrypto = desProvider.CreateDecryptor();

      // Create CryptoStream object
      CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);

      // Decrypt SourceData
      cs.Write(SourceData, 0, SourceData.Length);
      cs.FlushFinalBlock();

      // Get Decryption result
      returnData = ms.ToArray();
    }
    catch(Exception ex)
    {
      throw ex;
    }
    return returnData;

  }

  /// <summary>
  /// Encryption method for string
  /// </summary>
  /// <param name="SourceData">source data</param>
  /// <returns>string</returns>
  public string EncryptionStringData(string SourceData)
  {
    try
    {
      // Convert source data from string to byte array
      byte[] SourData = Encoding.Default.GetBytes(SourceData);

      // Encrypt byte array
      byte[] retData = EncryptionByteData(SourData);

      // Convert encryption result from byte array to Base64String
      return Convert.ToBase64String(retData, 0, retData.Length);
    }
    catch(Exception ex)
    {
      throw ex;
    }
  }

  /// <summary>
  /// Decryption method for string
  /// </summary>
  /// <param name="SourceData">source data</param>
  /// <returns>string</returns>
  public string DecryptionStringdata(string SourceData)
  {
    try
    {
      // Convert source data from Base64String to byte array
      byte[] SourData = Convert.FromBase64String(SourceData);

      // Decrypt byte array
      byte[] retData = DecryptionByteData(SourData);

      // Convert Decryption result from byte array to string
      return Encoding.Default.GetString(retData, 0, retData.Length);
    }
    catch(Exception ex)
    {
      throw ex;
    }
  }
}