RSA加密算法

RSA是非对称加密算法，客户端生成一对密匙秘钥，公钥用于加密，私钥用于解密
package RSA;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;

public class RS1 {

    
    String string="admin";
    byte ptext[];
    public RS1(String ss ) throws IOException, ClassNotFoundException, NoSuchAlgorithmException, InvalidKeySpecException {
        
        //
        /*
        
        KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");  
        kpg.initialize(2048);  
        KeyPair kp = kpg.genKeyPair();  
        PublicKey pbkey = kp.getPublic();  
        PrivateKey prkey = kp.getPrivate(); 
        System.out.println(pbkey);
        */
        


      KeyPairGenerator keyPair = KeyPairGenerator.getInstance("RSA");   
       keyPair.initialize(1024);   
       KeyPair kp = keyPair.generateKeyPair();   
       X509EncodedKeySpec keySpec=new X509EncodedKeySpec(kp.getPublic().getEncoded());    
        KeyFactory keyFactory=KeyFactory.getInstance("RSA");    
        PublicKey publickey=keyFactory.generatePublic(keySpec);
        
        System.out.println(publickey);
        
        System.out.println("###################################");
        
        
        // TODO Auto-generated constructor stub
        FileOutputStream f1 = new FileOutputStream("D:"+File.separator+"search"+File.separator+"bb"+File.separator+"pubkey.dat");  
        ObjectOutputStream b1 = new ObjectOutputStream(f1);  
        b1.writeObject(publickey);  
        b1.close();
        FileInputStream f = new FileInputStream("D:"+File.separator+"search"+File.separator+"bb"+File.separator+"pubkey.dat");  
        ObjectInputStream b = new ObjectInputStream(f);  
        RSAPublicKey pbk = (RSAPublicKey) b.readObject();  
        
        
        
        BigInteger e = pbk.getPublicExponent();  
        BigInteger n = pbk.getModulus();  
        System.out.println("e= " + e);  
        System.out.println("n= " + n); 
        
        try {
            ptext = string.getBytes("UTF-8");
        } catch (UnsupportedEncodingException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }  
        BigInteger m = new BigInteger(ptext);  
        // 计算密文c  
        BigInteger c = m.modPow(e, n);  
        System.out.println("c= " + c);  
        // 保存密文  
        String cs = c.toString(); 
        
        System.out.print(cs);
        b.close();
    }

    public static void main(String[] args) throws ClassNotFoundException, IOException, NoSuchAlgorithmException, InvalidKeySpecException {
        // TODO Auto-generated method stub
        RS1 rs=new RS1("C02A0C475D31142C25BC1EB8000462B502447FBE76FC48F3609BF7D714116AA08AF117F53FDEBF6E06AB8FCB74BBB892CCAF28A13B7EA83718DA44B3648107007D4609C684F67028D4F9E170126544A3281CDA4C6941E4ADB112497D0C739A9296DA3A6FC849C15116B3CFEFFF0B1F515530CCA3A0E9296B2F02ADEB207B4451");
    }
    
    public  void encrypt() throws UnsupportedEncodingException{
        
        
    }
    

}