C#3DES加密了解一下

　　最近一个项目中，因为服务端是用的java开发的，客户端是用的C#，由于通信部分采用到了3DES加密，所以做个记录，以备以后需要的时候直接用。

　　这是对方（java）的加密算法，和网上流传的代码也差不多（主密钥直接写死了，方便测试）

 package org.zwork.market.mina.msg;

 import java.security.spec.KeySpec;

 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
 import javax.crypto.SecretKeyFactory;
 import javax.crypto.spec.DESKeySpec;
 import javax.crypto.spec.DESedeKeySpec;

 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.zwork.market.MktContants;

 public class ThreeEncryptDecrypt {

     private static final Logger LOGGER = LoggerFactory.getLogger(ThreeEncryptDecrypt.class);

     // 定义 加密算法,可用 DES,DESede,Blowfish
     public static final String Algorithm = "DESede";
     public static String DES = "DES/ECB/NoPadding";
     public static String TriDes = "DESede/ECB/NoPadding";

     // des加密
     public static byte[] des_crypt(byte key[], byte data[]) {
         try {
             KeySpec ks = new DESKeySpec(key);
             SecretKeyFactory kf = SecretKeyFactory.getInstance("DES");
             SecretKey ky = kf.generateSecret(ks);

             Cipher c = Cipher.getInstance(DES);
             c.init(Cipher.ENCRYPT_MODE, ky);
             return c.doFinal(data);
         } catch (Exception e) {
             LOGGER.error("des_crypt error:", e);
             return null;
         }
     }

     // des解密
     public static byte[] des_decrypt(byte key[], byte data[]) {

         try {
             KeySpec ks = new DESKeySpec(key);
             SecretKeyFactory kf = SecretKeyFactory.getInstance("DES");
             SecretKey ky = kf.generateSecret(ks);

             Cipher c = Cipher.getInstance(DES);
             c.init(Cipher.DECRYPT_MODE, ky);
             return c.doFinal(data);
         } catch (Exception e) {
             LOGGER.error("des_decrypt error:", e);
             return null;
         }
     }

     // 3DES加密
     public static byte[] trides_crypt(byte key[], byte data[]) {
         try {
             byte[] k = new byte[];

             int len = data.length;
             if (data.length %  != ) {
                 len = data.length - data.length %  + ;
             }
             byte[] needData = null;
             if (len != )
                 needData = new byte[len];

             for (int i = ; i < len; i++) {
                 needData[i] = 0x00;
             }

             System.arraycopy(data, , needData, , data.length);

             if (key.length == ) {
                 System.arraycopy(key, , k, , key.length);
                 System.arraycopy(key, , k, , );
             } else {
                 System.arraycopy(key, , k, , );
             }

             KeySpec ks = new DESedeKeySpec(k);
             SecretKeyFactory kf = SecretKeyFactory.getInstance("DESede");
             SecretKey ky = kf.generateSecret(ks);

             Cipher c = Cipher.getInstance(TriDes);
             c.init(Cipher.ENCRYPT_MODE, ky);
             return c.doFinal(needData);
         } catch (Exception e) {
             LOGGER.error("trides_crypt error:", e);
             return null;
         }

     }

     // 3DES解密
     public static byte[] trides_decrypt(byte key[], byte data[]) {
         try {
             byte[] k = new byte[];

             int len = data.length;
             if (data.length %  != ) {
                 len = data.length - data.length %  + ;
             }
             byte[] needData = null;
             if (len != )
                 needData = new byte[len];

             for (int i = ; i < len; i++) {
                 needData[i] = 0x00;
             }

             System.arraycopy(data, , needData, , data.length);

             if (key.length == ) {
                 System.arraycopy(key, , k, , key.length);
                 System.arraycopy(key, , k, , );
             } else {
                 System.arraycopy(key, , k, , );
             }
             KeySpec ks = new DESedeKeySpec(k);
             SecretKeyFactory kf = SecretKeyFactory.getInstance("DESede");
             SecretKey ky = kf.generateSecret(ks);

             Cipher c = Cipher.getInstance(TriDes);
             c.init(Cipher.DECRYPT_MODE, ky);
             return c.doFinal(needData);
         } catch (Exception e) {
             LOGGER.error("trides_decrypt error:", e);
             return null;
         }
     }

     public static String getPass(String source) {
         byte[] data= hexToBytes(source);
         byte[] key ="111111111111111111111111111a1.1.".getBytes();
         String result = byte2hex(trides_decrypt(key, data)).toUpperCase();
         return result.substring(, );
     }

     public static String byte2hex(byte[] data) {
         StringBuffer sb = new StringBuffer();
         for (int i = ; i < data.length; i++) {
             String temp = Integer.toHexString(((int) data[i]) & 0xFF);
             for (int t = temp.length(); t < ; t++) {
                 sb.append("");
             }
             sb.append(temp);
         }
         return sb.toString();
     }

     public static byte[] hexToBytes(String str) {
         if (str == null) {
             return null;
         } else if (str.length() < ) {
             return null;
         } else {
             int len = str.length() / ;
             byte[] buffer = new byte[len];
             for (int i = ; i < len; i++) {
                 buffer[i] = (byte) Integer.parseInt(str.substring(i * , i *  + ), );
             }
             return buffer;
         }
     }
 }

　　因为客户端只负责数据加密，所以我这里只写了加密的部分。由于java和C#语言很相似，所以我就仿这他们给的java代码改成C#的，当然也在网上参考了一些代码，不过中间还是出现了些问题，比如C#不支持弱密钥（把密钥弄复杂点）,因为没注意大小写造成加密结果不一致等等。编程这东西一个点都能让整个系统崩溃，所以小细节很重要！！！

     public class DESHelper
     {
         /// <summary>
         /// 将密码转成直接数组
         /// </summary>
         /// <param name="str"></param>
         /// <returns></returns>
         public static byte[] HexToBytes(String str)
         {
             if (str == null)
             {
                 return null;
             }
             else if (str.Length < )
             {
                 return null;
             }
             else
             {
                 int len = str.Length / ;
                 byte[] buffer = new byte[len];
                 for (int i = ; i < len; i++)
                 {
                     var temp = str.Substring(i * , );
                     buffer[i] = (byte)Convert.ToInt32(temp, );
                 }
                 return buffer;
             }
         }
         /// <summary>
         /// 3DES加密
         /// </summary>
         /// <param name="key"></param>
         /// <param name="data"></param>
         /// <returns></returns>
         public static byte[] GetDes3EncryptedText(byte[] key, byte[] data)
         {
             byte[] k = new byte[];
             int len = data.Length;
             if (data.Length %  != )
             {
                 len = data.Length - data.Length %  + ;
             }
             byte[] needData = null;
             if (len != )
                 needData = new byte[len];

             for (int i = ; i < len; i++)
             {
                 needData[i] = 0x00;
             }

             Buffer.BlockCopy(data, , needData, , data.Length);

             if (key.Length == )
             {
                 Buffer.BlockCopy(key, , k, , key.Length);
                 Buffer.BlockCopy(key, , k, , );
             }
             else
             {
                 Buffer.BlockCopy(key, , k, , );
             }

             var des3 = new TripleDESCryptoServiceProvider();
             des3.Key = k;
             des3.Mode = CipherMode.ECB;
             des3.Padding = PaddingMode.Zeros;

             using (MemoryStream ms = new MemoryStream())
             using (CryptoStream cs = new CryptoStream(ms, des3.CreateEncryptor(), CryptoStreamMode.Write))
             {
                 cs.Write(data, , data.Length);
                 cs.FlushFinalBlock();
                 return ms.ToArray();
             }
         }

         /// <summary>
         /// 将加密结果转成字符串
         /// </summary>
         /// <param name="data"></param>
         /// <returns></returns>
         public static String GetByte2Hex(byte[] data)
         {
             StringBuilder sb = new StringBuilder();
             for (int i = ; i < data.Length; i++)
             {
                 String temp = string.Format("{0:X}", ((int)data[i]) & 0xFF);
                 for (int t = temp.Length; t < ; t++)
                 {
                     sb.Append("");
                 }
                 sb.Append(temp);
             }
             return sb.ToString();
         }
     }