java数字签名算法之RSA

© 版权声明：本文为博主原创文章，转载请注明出处

实例

1.项目结构

2.pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  	<modelVersion>4.0.0</modelVersion>

	<groupId>org.security</groupId>

	<artifactId>DigitalSignature</artifactId>

	<version>0.0.1-SNAPSHOT</version>

	<packaging>jar</packaging>

	<properties>

		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

	</properties>

	<dependencies>

		<!-- junit -->

		<dependency>

			<groupId>junit</groupId>

			<artifactId>junit</artifactId>

			<version>4.12</version>

			<scope>test</scope>

		</dependency>

		<!-- commons-codec -->

		<dependency>

		    <groupId>commons-codec</groupId>

		    <artifactId>commons-codec</artifactId>

		    <version>1.10</version>

		</dependency>

	</dependencies>

</project>

3.RSA.java

package org.security.rsa;

import java.security.KeyFactory;

import java.security.KeyPair;

import java.security.KeyPairGenerator;

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 java.util.HashMap;

import java.util.Map;

import org.apache.commons.codec.binary.Base64;

public class RSA {

	private static final String str = "Digital signature algorithm RSA MD5WithRSA";

	private static final String SECURITY = "RSA";// 加密方式

	private static final String ALGORITHM = "MD5withRSA";// 加密算法

	private static final String PUBLIC_KEY = "RSAPublicKey";// 公钥

	private static final String PRIVATE_KEY = "RSAPrivateKey";// 秘钥

	public static void main(String[] args) {

		System.out.println("==========初始化密钥信息==========");

		Map<String, Object> map = RSA.init();

		System.out.println("=========密钥信息初始化成功=========");

		byte[] private_key = RSA.getPrivateKey(map);

		System.out.println("=============私钥为=============\n" + Base64.encodeBase64String(private_key));

		byte[] public_key = RSA.getPublicKey(map);

		System.out.println("=============公钥为=============\n" + Base64.encodeBase64String(public_key));

		byte[] bs = RSA.sign(private_key);

		System.out.println("=============签名为=============\n" + Base64.encodeBase64String(bs));

		boolean result = RSA.verify(public_key, bs);

		System.out.println("===========签名验证结果===========\n" + result);

	}

	/**

	 * 初始化密钥

	 *

	 * @return

	 */

	private static Map<String, Object> init() {

		Map<String, Object> map = null;

		try {

			// 生成实现指定算法的KeyPairGenerator对象，用于生成密钥对

			KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(SECURITY);

			keyPairGenerator.initialize(1024);// 初始化密钥长度

			KeyPair keyPair = keyPairGenerator.generateKeyPair();// 生成密钥对

			RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();// 获取公钥

			RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();// 获取私钥

			// 保存到map中

			map = new HashMap<String, Object>();

			map.put(PUBLIC_KEY, rsaPublicKey);

			map.put(PRIVATE_KEY, rsaPrivateKey);

		} catch (Exception e) {

			e.printStackTrace();

		}

		return map;

	}

	/**

	 * 用私钥生成签名

	 *

	 * @param privateKey

	 * 						私钥字节数组

	 * @return

	 */

	private static byte[] sign(byte[] privateKey) {

		byte[] signByte = null;

		try {

			// 根据给定的编码密钥创建一个新的PKCS8EncodedKeySpec对象，指定PKCS#8标准为密钥规范管理的编码格式

			PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey);

			// 实例化密钥工厂对象，将密钥转换成密钥规范

			KeyFactory keyFactory = KeyFactory.getInstance(SECURITY);

			// 根据提供的密钥规范生成私钥对象

			PrivateKey key = keyFactory.generatePrivate(pkcs8EncodedKeySpec);

			// 实例化实现指定签名算法的Signature对象

			Signature signature = Signature.getInstance(ALGORITHM);

			// 根据私钥对象初始化签名对象

			signature.initSign(key);

			// 使用指定的byte数组更新要签名或验证的数据

			signature.update(str.getBytes());

			// 返回所有已更新数据的签名字节

			signByte = signature.sign();

		} catch (Exception e) {

			e.printStackTrace();

		}

		return signByte;

	}

	/**

	 * 用公钥验证签名

	 *

	 * @param publicKey

	 * 					公钥字节数组

	 * @param signByte

	 * 					签名字节数组

	 * @return

	 */

	public static boolean verify(byte[] publicKey, byte[] signByte) {

		boolean result = false;

		try {

			// 根据给定的编码密钥创建一个新的X509EncodedKeySpec对象

			X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey);

			// 实例化密钥工厂对象，将密钥转换成密钥规范

			KeyFactory keyFactory = KeyFactory.getInstance(SECURITY);

			// 根据提供的密钥规范生成公钥对象

			PublicKey key = keyFactory.generatePublic(x509EncodedKeySpec);

			// 实例化实现指定签名算法的Signature对象

			Signature signature = Signature.getInstance(ALGORITHM);

			// 根据公钥对象初始化用于验证的对象

			signature.initVerify(key);

			// 使用指定的byte数组更新要签名或验证的数据

			signature.update(str.getBytes());

			// 验证传入的签名

			result = signature.verify(signByte);

		} catch (Exception e) {

			e.printStackTrace();

		}

		return result;

	}

	/**

	 * 获取私钥

	 *

	 * @param map

	 * 				密钥map集合

	 * @return

	 */

	public static byte[] getPrivateKey(Map<String, Object> map) {

		RSAPrivateKey key = (RSAPrivateKey) map.get(PRIVATE_KEY);

		return key.getEncoded();

	}

	/**

	 * 获取私钥

	 *

	 * @param map

	 * 				密钥map集合

	 * @return

	 */

	public static byte[] getPublicKey(Map<String, Object> map) {

		RSAPublicKey key = (RSAPublicKey) map.get(PUBLIC_KEY);

		return key.getEncoded();

	}

}

4.效果预览

==========初始化密钥信息==========

=========密钥信息初始化成功=========

=============私钥为=============

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

=============公钥为=============

MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCLG6V1r9Yyf/LCzTwvXVqgZl4csezBU918MsWPbjtZiya9W4i9ocrWPqxXhi/hAocZZwkkuB/DNe31T+54eSpORT+7E6qd4XsKfTy6ShbMrT+U97q0GG0OULSrx+KGlJOFLvCCdQXNHEzb8XkrpbzDM8ZPsLlRHcXzt7QS1Fpo3QIDAQAB

=============签名为=============

ODGCnrrBV/1SXfB65SHYWbdgNAuY8QbfAzWGeRscMhGCudfQk9cnLzHVQkhlC9eXruTvjQqQSmBNLmGdegUlAh+bPi/EkqReidD0efsLSy4FQSJIdmFVW6Xl3FuAqzIqidPLPFk0rFDK/DJzGVQtUYm5rKDap0zKMxe/P3/6bbs=

===========签名验证结果===========

true

参考：http://www.imooc.com/video/6154