package text.java;
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!";
        // 获取公钥及参数e,n
        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);
        // 明文 m
        byte ptext[]=s.getBytes("UTF8");
        BigInteger m=new BigInteger(ptext);
        // 计算密文c,打印
        BigInteger c=m.modPow(e,n);
        System.out.println("c= "+c);
        // 保存密文
        String cs=c.toString( );
        BufferedWriter out=
                new BufferedWriter(new OutputStreamWriter(
                        new FileOutputStream("Enc_RSA.dat")));
        out.write(cs,0,cs.length( ));
        out.close( );

    }
}