java rsa 加解密

参考 http://blog.csdn.net/a394268045/article/details/52232120

package rsa;

import org.apache.commons.codec.binary.Hex;

import javax.crypto.Cipher;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;

/**
 * Created by Administrator on 2018/3/12.
 */
public class Main {
    public static void main(String[] args) throws Exception {
        String source = "hhh测试";
        String cryptograph = encrypt(source);
        System.out.println("生成的密文-->" + cryptograph);

        String target = decrypt(cryptograph);
        System.out.println("解密密文-->" + target);
    }

    public static void generateKeyPair() throws Exception {
        SecureRandom sr = new SecureRandom();

        KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");

        kpg.initialize(512, sr);

        KeyPair kp = kpg.generateKeyPair();

        Key publicKey = kp.getPublic();
        Key privateKey = kp.getPrivate();

        ObjectOutputStream oos1 = new ObjectOutputStream(new FileOutputStream("e:/publicKey.keystore"));
        ObjectOutputStream oos2 = new ObjectOutputStream(new FileOutputStream("e:/privateKey.keystore"));
        oos1.writeObject(publicKey);
        oos2.writeObject(privateKey);

        oos1.close();
        oos2.close();
    }

    public static String encrypt(String source) throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("e:/publicKey.keystore"));
        Key key = (Key) ois.readObject();
        ois.close();

        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] b = source.getBytes("utf-8");

        byte[] b1 = cipher.doFinal(b);
//        return Base64.encodeBase64String(b1);
        return Hex.encodeHexString(b1);
    }

    public static String decrypt(String cryptograph) throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("e:/privateKey.keystore"));
        Key key = (Key) ois.readObject();

        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, key);

//        byte[] b1 = Base64.decodeBase64(cryptograph);
//
//        byte[] b = cipher.doFinal(b1);
//
//        return new String(b, "utf-8");

        byte[] b1 = Hex.decodeHex(cryptograph);

        byte[] b = cipher.doFinal(b1);

        return new String(b, "utf-8");
    }
}