enc_rsa.java

使用RSA对文件进行加解密

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{
   public static void main(String args[]) throws Exception{
        String s="Hello World!";
        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);
        String cs=c.toString( );
        BufferedWriter out= 
          new BufferedWriter(new OutputStreamWriter(
            new FileOutputStream("Enc_RSA.dat")));
        out.write(cs,0,cs.length( ));
        out.close( );
       
   }
}