package com.dhs.test;

import java.security.KeyFactory;

import java.security.KeyPair;

import java.security.KeyPairGenerator;

import java.security.NoSuchAlgorithmException;

import java.security.PrivateKey;

import java.security.PublicKey;

import java.security.Signature;

import java.security.interfaces.RSAPrivateKey;

import java.security.interfaces.RSAPublicKey;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

import org.bouncycastle.util.encoders.Hex;

public class RSATest {

public static final String SRC_STRING = "fdsfsfsfsfd";

public static void main(String[] args) {

try {

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

keyPairGenerator.initialize(512);

KeyPair keyPair = keyPairGenerator.generateKeyPair();

RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();// 私鑰

RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();// 公鑰

String sign = jdkRSASign(rsaPrivateKey, SRC_STRING);

System.out.println("sign:"+sign);

boolean bool = jdkRSACheck(rsaPublicKey, SRC_STRING, sign);

System.out.println(bool);

} catch (NoSuchAlgorithmException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

// 簽名方法

public static String jdkRSASign(RSAPrivateKey rsaPrivateKey, String src) {

String result = null;// 簽名結果

try {

// 2.執行簽名

PKCS8EncodedKeySpec pkcS8EncodedKeySpec = new PKCS8EncodedKeySpec(

rsaPrivateKey.getEncoded());

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

PrivateKey privateKey = keyFactory

.generatePrivate(pkcS8EncodedKeySpec);

Signature signature = Signature.getInstance("MD5withRSA");

signature.initSign(privateKey);

signature.update(src.getBytes("UTF-8"));

result = Hex.toHexString(signature.sign());

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

// 驗簽名方法

public static boolean jdkRSACheck(RSAPublicKey rsaPublicKey, String src, String sign) {

boolean result = false;

try {

// 2.驗證簽名

X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(

rsaPublicKey.getEncoded());

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);

Signature signature = Signature.getInstance("MD5withRSA");

signature.initVerify(publicKey);

signature.update(src.getBytes("UTF-8"));

result = signature.verify(Hex.decode(sign));

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

}