enc_rsa.java

RSA加密算法java代码

package src;
import java.security.*;


import java.security.spec.*;


import javax.crypto.*;


import javax.crypto.spec.*;


import javax.crypto.interfaces.*;


import java.security.interfaces.*;


import java.math.*;


import java.io.*;


public class Enc_RSA{
	
	//BigInteger e,n;
	RSAPublicKey  pbk;//=(RSAPublicKey)b.readObject( );
	
	public Enc_RSA(String RSAPublicKeyFileName) throws Exception
	{
        FileInputStream f=new FileInputStream(RSAPublicKeyFileName);
        ObjectInputStream b=new ObjectInputStream(f);
        pbk=(RSAPublicKey)b.readObject( );
        b.close();
        f.close();
	}
   public static void main(String args[]) throws Exception{


        String s="Hello World!  我是赵思奇";
        FileInputStream f=new FileInputStream("Skey_RSA_pub.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);
        
        byte ptext[]=s.getBytes("UTF8");
        BigInteger m=new BigInteger(ptext);
        BigInteger c=m.modPow(e,n);
        System.out.println("c= "+c.toString());
        String cs=c.toString( );
        BufferedWriter out= 
          new BufferedWriter(new OutputStreamWriter(
            new FileOutputStream("Enc_RSA.dat")));
        out.write(cs,0,cs.length( ));
        out.close( );
 }

   public String encrypt(String s) throws Exception
   {
	   BigInteger e=pbk.getPublicExponent();
       BigInteger n=pbk.getModulus();
       
	   byte ptext[]=s.getBytes("UTF8");
	   BigInteger m=new BigInteger(ptext);
	   BigInteger c=m.modPow(e,n);
	   
	   return c.toString();
	   
   }
   
   

}