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 Dec_RSA {
	public static void main(String args[]) throws Exception {
		//读取密文
		BufferedReader in =
			new BufferedReader(new InputStreamReader(
						new FileInputStream("Enc_RSA.dat")));
		String ctext = in.readLine();
		BigInteger c = new BigInteger(ctext);
		//读取私钥
		FileInputStream f = new FileInputStream("Skey_RSA_priv.dat");
		ObjectInputStream b = new ObjectInputStream(f);
		RSAPrivateKey prk = (RSAPrivateKey) b.readObject();
		BigInteger d = prk.getPrivateExponent();
		//获取私钥参数及解密
		BigInteger n = prk.getModulus();
		System.out.println("d= " + d);
		System.out.println("n= " + n);
		BigInteger m = c.modPow(d, n);
		//显示解密结果
		System.out.println("m= " + m);
		byte[] mt = m.toByteArray();
		System.out.println("PlainText is ");
		for (int i = 0; i < mt.length; i++) {
			System.out.print((char) mt[i]);
		}
	}
}