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[24];

            int len = data.length;
            if (data.length % 8 != 0) {
                len = data.length - data.length % 8 + 8;
            }
            byte[] needData = null;
            if (len != 0)
                needData = new byte[len];

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

            System.arraycopy(data, 0, needData, 0, data.length);

            if (key.length == 16) {
                System.arraycopy(key, 0, k, 0, key.length);
                System.arraycopy(key, 0, k, 16, 8);
            } else {
                System.arraycopy(key, 0, k, 0, 24);
            }

            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[24];

            int len = data.length;
            if (data.length % 8 != 0) {
                len = data.length - data.length % 8 + 8;
            }
            byte[] needData = null;
            if (len != 0)
                needData = new byte[len];

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

            System.arraycopy(data, 0, needData, 0, data.length);

            if (key.length == 16) {
                System.arraycopy(key, 0, k, 0, key.length);
                System.arraycopy(key, 0, k, 16, 8);
            } else {
                System.arraycopy(key, 0, k, 0, 24);
            }
            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(2, 8);
    }

    public static String byte2hex(byte[] data) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
            String temp = Integer.toHexString(((int) data[i]) & 0xFF);
            for (int t = temp.length(); t < 2; t++) {
                sb.append("0");
            }
            sb.append(temp);
        }
        return sb.toString();
    }

    public static byte[] hexToBytes(String str) {
        if (str == null) {
            return null;
        } else if (str.length() < 2) {
            return null;
        } else {
            int len = str.length() / 2;
            byte[] buffer = new byte[len];
            for (int i = 0; i < len; i++) {
                buffer[i] = (byte) Integer.parseInt(str.substring(i * 2, i * 2 + 2), 16);
            }
            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 < 2)
            {
                return null;
            }
            else
            {
                int len = str.Length / 2;
                byte[] buffer = new byte[len];
                for (int i = 0; i < len; i++)
                {
                    var temp = str.Substring(i * 2, 2);
                    buffer[i] = (byte)Convert.ToInt32(temp, 16);
                }
                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[24];
            int len = data.Length;
            if (data.Length % 8 != 0)
            {
                len = data.Length - data.Length % 8 + 8;
            }
            byte[] needData = null;
            if (len != 0)
                needData = new byte[len];

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

            Buffer.BlockCopy(data, 0, needData, 0, data.Length);

            if (key.Length == 16)
            {
                Buffer.BlockCopy(key, 0, k, 0, key.Length);
                Buffer.BlockCopy(key, 0, k, 16, 8);
            }
            else
            {
                Buffer.BlockCopy(key, 0, k, 0, 24);
            }

            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, 0, 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 = 0; i < data.Length; i++)
            {
                String temp = string.Format("{0:X}", ((int)data[i]) & 0xFF);
                for (int t = temp.Length; t < 2; t++)
                {
                    sb.Append("0");
                }
                sb.Append(temp);
            }
            return sb.ToString();
        }
    }