apacsys-vaporrecoverymonitor-document/油机、传感器、远程协议/数据加密/des-java.txt

package learn;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.SecretKeySpec;


import java.util.Base64.Encoder;
import java.nio.charset.Charset;
import java.security.Key;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.Base64.Decoder;  //加解密的包


import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.io.*;
import java.security.spec.AlgorithmParameterSpec;



public class HelloWorld {
	
	public static final String ALGORITHM_DES = "DES/CBC/PKCS5Padding";
	public static final byte[] IV={8,3,2,0,2,3,8,0};
	public static final String DEFAULT_CHARSET="UTF-8";
	
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub

		
		
		String prefixString="QN=20160801042123;MN=010000A8900016F000169DC0;";
		//原始数据段字符串
		String dataString="ST=61;CN=2061;PW=123456;CP=&&DataTime=20160731001";
		//对数据段进行二次加密（不包含数据段结束标志符&&）
		String encodeString = encode("12345600", dataString, 1);
		
		System.out.println(encodeString);
		
		
		//加上校验前缀
		encodeString=prefixString+encodeString;
		//对加密后的数据段计算crc
		String crc = "";// = Crc16.crc16(encodeString).toUpperCase();
		//附上头部与长度段与加密标志位（加密为1），尾部追加crc校验码
		String originStr="##"+String.format("%04d", encodeString.length())+"1"+encodeString+crc;
		System.out.println("加密后的数据:");
		System.out.println(originStr);

		
		
		

	}

	

	
	public static String  encode(String key, String dataStr,int encodeCount) throws Exception 
	{
		try {
			SecureRandom random =SecureRandom.getInstance("SHA1PRNG");
			DESKeySpec dks = new DESKeySpec(key.getBytes());
			//将字符串数据转换成字节,使用UTF-8编码
			byte[] data = dataStr.getBytes(Charset.forName("UTF-8"));
			SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
			// key的长度不能够小于8位字节,使用PW段数据后补2个0
			Key secretKey = keyFactory.generateSecret(dks);
			Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
			IvParameterSpec iv = new IvParameterSpec(IV);
			AlgorithmParameterSpec paramSpec = iv;
			cipher.init(Cipher.ENCRYPT_MODE, secretKey, paramSpec,random);
			//进行多次加密操作，本文档要求为2
			byte[] temp=data;
			for(int i=0;i<encodeCount;i++){
				temp=cipher.doFinal(temp);
			}
			//将加密后的字节码使用不换行的base64编码成字符串,并去掉回车符（据RFC 822规定，每76个字符，还需要加上一个回车换行，但是我们本协议不需要）作为传输报文的数据段传输
			//return new String(Base64.encodeBase64(temp, false));
			
			
	        Encoder encoder = Base64.getEncoder();
	        String result = encoder.encodeToString(temp);
	        
	        return result;
		} 
		catch (Exception e) {
			throw new Exception(e);
		}
	}

	
	

}