asp.net实现的DES加密解密操作示例

//加密方法private string encrypt(string strToEncrypt){    if (strToEncrypt == null || strToEncrypt == "") return strToEncrypt;    DESCryptoServiceProvider des = new DESCryptoServiceProvider();    //把字符串放到byte数组中，主意编码方式    byte[] inputByteArray = Encoding.Default.GetBytes(strToEncrypt);    //建立加密对象的密钥和偏移量    des.Key = new byte[] { 1, 3, 5, 7, 2, 4, 6, 8 };    des.Mode = CipherMode.ECB;    MemoryStream ms = new MemoryStream();    CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);    cs.Write(inputByteArray, 0, inputByteArray.Length);    cs.FlushFinalBlock();    StringBuilder ret = new StringBuilder();    foreach (byte b in ms.ToArray())    {      ret.AppendFormat("{0:X2}", b);    }    return ret.ToString();}//解密方法private string Decrypt(string pToDecrypt){    if (pToDecrypt == null || pToDecrypt == "") return pToDecrypt;    try    {      DESCryptoServiceProvider des = new DESCryptoServiceProvider();      //Put the input string into the byte array      byte[] inputByteArray = new byte[pToDecrypt.Length / 2];      for (int x = 0; x < pToDecrypt.Length / 2; x++)      {        int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));        inputByteArray[x] = (byte)i;      }      //key      des.Key = new byte[] { 1, 3, 5, 7, 2, 4, 6, 8 }; ;      //des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);      des.Mode = CipherMode.ECB;      MemoryStream ms = new MemoryStream();      CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);      cs.Write(inputByteArray, 0, inputByteArray.Length);      cs.FlushFinalBlock();      //建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象      StringBuilder ret = new StringBuilder();      return System.Text.Encoding.Default.GetString(ms.ToArray());    }    catch (Exception Exp)    {      return String.Empty;    }}