C# 3DES加密详解

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();
  }
}

以上所述就是本文的全部内容了，希望大家能够喜欢。