PHP和.net中des加解密的实现方法(2)

sealed public class CryptoHelper
 {
     /// <summary>
     /// Encrypts the specified input.
     /// </summary>
     /// <param>The input.</param>
     /// <param>key</param>
     /// <param>iv</param>
     /// <returns></returns>
     public static string EncryptDes(string input, byte[] key, byte[] iv)
     {
         if (input == null || input.Length == 0)
             return String.Empty;

         DESCryptoServiceProvider des = new DESCryptoServiceProvider();
         MemoryStream ms = null;
         CryptoStream encStream = null;
         StreamWriter sw = null;
         string result = String.Empty;

         try
         {
             ms = new MemoryStream();

             // Create a CryptoStream using the memory stream and the
             // CSP DES key. 
             //des.Mode = CipherMode.CBC;
             //des.Padding = PaddingMode.PKCS7; 
             encStream = new CryptoStream(ms, des.CreateEncryptor(key, iv), CryptoStreamMode.Write);

             // Create a StreamWriter to write a string
             // to the stream.
             sw = new StreamWriter(encStream);

             // Write the plaintext to the stream.
             sw.Write(input);

             sw.Flush();
             encStream.FlushFinalBlock();
             ms.Flush();

 
             result = Convert.ToBase64String(ms.GetBuffer(), 0, Convert.ToInt32(ms.Length, CultureInfo.InvariantCulture));
         }
         finally
         {
             //close objects
             if (sw != null)
                 sw.Close();
             if (encStream != null)
                 encStream.Close();
             if (ms != null)
                 ms.Close();
         }

         // Return the encrypted string
         return result;
     }
     /// <summary>
     /// Decrypts the specified input.
     /// </summary>
     /// <param>the input.</param>
     /// <param>key</param>
     /// <param>iv</param>
     /// <returns></returns>
     public static string DecryptDes(string input, byte[] key, byte[] iv)
     {
         byte[] buffer;
         try { buffer = Convert.FromBase64String(input); }
         catch (System.ArgumentNullException) { return String.Empty; }
         // length is zero, or not an even multiple of four (plus a few other cases)
         catch (System.FormatException) { return String.Empty; }

         DESCryptoServiceProvider des = new DESCryptoServiceProvider();
         MemoryStream ms = null;
         CryptoStream encStream = null;
         StreamReader sr = null;
         string result = String.Empty;

         try
         {
             ms = new MemoryStream(buffer);

             // Create a CryptoStream using the memory stream and the
             // CSP DES key.
             encStream = new CryptoStream(ms, des.CreateDecryptor(key, iv), CryptoStreamMode.Read);

             // Create a StreamReader for reading the stream.
             sr = new StreamReader(encStream);

             // Read the stream as a string.
             result = sr.ReadToEnd();
         }
         finally
         {
             //close objects
             if (sr != null)
                 sr.Close();
             if (encStream != null)
                 encStream.Close();
             if (ms != null)
                 ms.Close();
         }

         return result;
     }
 }

 
 //调用

 string key = "abcdefgh";
 string iv = "abcdefgh";
 string msg="test string";
 string rs1 = CryptoHelper.EncryptDes(msg, System.Text.Encoding.ASCII.GetBytes(key), System.Text.Encoding.ASCII.GetBytes(iv));
 string rs2 = CryptoHelper.DecryptDes(rs1, System.Text.Encoding.ASCII.GetBytes(key), System.Text.Encoding.ASCII.GetBytes(iv));