import java.security.Provider;
  import java.security.*;
 import java.security.spec.*;
 import java.io.*;
 import javax.crypto.*;
 import javax.crypto.Cipher;
 
 public class ClientSend extends Thread{
 
 public static void main(String[] args){
   ClientSend my=new ClientSend();
   String file="info.dat";
    my.run(file);
  }
  
  //生成一對文件myprikey.dat和mypubkey.dat---私鑰和公鑰,
  //公鑰要用戶發(fā)送(文件,網(wǎng)絡(luò)等方法)給其它用戶,私鑰保存在本地
  public boolean generatekey()
  {
    try {
    KeyPairGenerator  keygen=KeyPairGenerator.getInstance("RSA");
    keygen.initialize(1024);  //密鑰大小
   // KeyPair keys=keygen.genKeyPair();
    KeyPair keys=keygen.generateKeyPair(); //生成密鑰組
    PublicKey pubkey=keys.getPublic();
    PrivateKey prikey=keys.getPrivate();

    ObjectOutputStream out=new ObjectOutputStream(new FileOutputStream("MyPrikey.dat"));
    out.writeObject(prikey);
    out.close();
    System.out.println("寫入對象 prikeys ok");
    
   /* 將公鑰pubKey保存在文件pubKey.dat文件中,供接收方使用*/ 
    out=new ObjectOutputStream(new FileOutputStream("MyPubkey.dat"));
    out.writeObject(pubkey);
    out.close();
    System.out.println("寫入對象 pubkeys ok");
    
    System.out.println("生成密鑰對成功");
    return true;
   }
   catch (java.lang.Exception e) {
   e.printStackTrace();
   System.out.println("生成密鑰對失敗");
   return false;
   }
   
  }
  
   public String byte2hex(byte[] b)
    {
     String hs="";
     String stmp="";
     for (int n=0;n<b.length;n++)
      {
       stmp=(Integer.toHexString(b[n] & 0XFF));
       if (stmp.length()==1) hs=hs+"0"+stmp;
       else hs=hs+stmp;
       if (n<b.length-1)  hs=hs+":";
      }
     return hs.toUpperCase();
    }
    
 
  
  public void run(String filename)
  { 
     Security.addProvider(new com.sun.crypto.provider.SunJCE());
  	 //第一步生成密鑰對,如果已經(jīng)生成過,本過程就可以跳過,對用戶來講myprikey.dat要保存在本地
  //而mypubkey.dat給發(fā)布給其它用戶
     if ((new File("MyPrikey.dat")).exists()==false) {
        if (generatekey()==false) {
           System.out.println("生成密鑰對失敗");
           return;
          }
        }
        
     try {
     		
     //從文件中讀取私要進(jìn)行簽名
     ObjectInputStream in=new ObjectInputStream(new FileInputStream("MyPrikey.dat"));
     PrivateKey priKey=(PrivateKey)in.readObject();
     in.close();   
      System.out.println("讀私鑰");
     
    
     /*生成DES算法的密鑰Key*/
    
     KeyGenerator SinglekeyGen = KeyGenerator.getInstance("DES");
     SinglekeyGen.init(56);
     Key SingleKey = SinglekeyGen.generateKey();
	 System.out.println("生成DES對稱密鑰");
     
  	  /*從文件info.dat讀出需要傳輸?shù)脑紨?shù)據(jù)并保存在數(shù)組info_Plain[]中*/
     RandomAccessFile fin=new RandomAccessFile(filename,"rw");//以只讀形式打開文件
     long f1=fin.length();   //文件的長度
     int  f2=(int)f1; 
     byte[] info_Plain=new byte[f2];   //建一個字節(jié)數(shù)組b存放文件
     fin.read(info_Plain,0,f2); 
     fin.close();
    
     System.out.println("原文件信息:"+new String(info_Plain));
  //  System.out.println("原文件二進(jìn)制信息："+byte2hex(info_Plain));
     
     
     /* 將待傳輸?shù)男畔⒂肈ES加密，并將加密后的數(shù)據(jù)保存在數(shù)組Des_info[]中*/
     Cipher cipher = Cipher.getInstance("DES");
     cipher.init(Cipher.ENCRYPT_MODE,SingleKey);
     byte[] Des_info= cipher.doFinal(info_Plain);
     System.out.println("加密成功");
    // System.out.println("明文加密后得到的信息:"+byte2hex(Des_info));
     
     /*將待傳輸?shù)脑夹畔⑸上⒄狹D_1*/
     MessageDigest messageDigest = MessageDigest.getInstance("MD5");
     messageDigest.update(info_Plain);
	 byte[] MD_1 = messageDigest.digest();   //得到消息的摘要MD_1里
	 System.out.println("消息摘要生成成功");
	// System.out.println("經(jīng)過MD5消息摘要是:"+byte2hex(MD_1));
     
	 
	 //把對稱密鑰加到摘要md_1后形成新的字節(jié)數(shù)組MD_Key;
	 byte[] MD_Key=JOIN(MD_1,SingleKey);

	// System.out.println("合并摘要和加密密鑰后的二進(jìn)制信息為："+byte2hex(MD_Key));
     
	 
    /* 將消息摘要MD_1[]和對稱密鑰SingleKey合并到字節(jié)數(shù)組MD_Key[]中，并用RSA算法中的私鑰對該數(shù)組加密并保存在數(shù)組Rsa_sign[]中形成了數(shù)字簽名*/
    /*  合并數(shù)組的算法略（主要就是通過循環(huán)將對稱密鑰添加到消息摘要數(shù)組的后面，形成一個新的數(shù)組MD_Key[],對稱密鑰要通過強(qiáng)制類型轉(zhuǎn)化為byte類型）*/
     
     Cipher cipher1 = Cipher.getInstance("RSA/ECB/PKCS1Padding","SUN");
     System.out.println(cipher.getProvider().getInfo());
     cipher1.init(Cipher.ENCRYPT_MODE, priKey);
     byte[] Rsa_sign = cipher1.doFinal(MD_Key);
     System.out.println("公鑰生成數(shù)字簽名成功！");
  
   //System.out.println("RSA加密后的:"+byte2hex(Rsa_sign));
     
  
  /*將需要傳輸?shù)脑牡拿芪暮蛿?shù)字簽名寫到文件En_info.dat中，En_info.dat即為在網(wǎng)上傳輸?shù)男畔?/
   ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("En_info.dat"));
   out.writeObject(Des_info);
   out.writeObject(Rsa_sign);
   out.close();
   System.out.println("原文件加密的密文和數(shù)字簽名寫到En_info.dat成功＃!");
   }catch (Exception e) {
    e.printStackTrace();
    System.out.println(e.toString());
   
  }

  	
  }
  
  public byte[] JOIN(byte[] A,Key deskey)
 { System.out.println("開始合并!"); 
  byte[] B=deskey.toString().getBytes();
  System.out.println("密鑰在字符數(shù)組B中"+byte2hex(B));
   int alen=A.length;
   
   int blen=B.length;
   int length=alen+blen;
   
   System.out.println("總長"+alen+blen+(alen+blen));
   byte[] C=new byte[length];
   int i;
   int j=0;
   for( i=0;i<length;i++)
   { 
     if(i<alen)
     { C[i]=A[i];
     // System.out.println(C[i]);
      }
    else
    { 
      if(j<blen)
      {
     	C[i]=B[j];
     	j++;
      //  System.out.println(C[i]);
      }
    }
    }
   System.out.println("合并消息摘要和對稱密鑰成功!");
  return C;
 }
 
 }