JAVA实现RSA加密,非对称加密算法

不念不忘少年蓝@ 2022-04-10 11:26 349阅读 0赞

RSA.java

package org.icesnow.jeasywx.util.security;
    
    import java.security.Key;
    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.SecureRandom;
    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 javax.crypto.Cipher;
    
    import org.apache.log4j.Logger;
    
    import sun.misc.BASE64Decoder;
    import sun.misc.BASE64Encoder;
    
    /**
     * @author: 782987839@qq.com
     * @date：2016-3-23下午12:25:07
     * @version: 1.0
     * @describe: JAVA实现RSA加密,非对称加密算法
     * 
     */
    public class RSA {
      private static Logger logger = Logger.getLogger(RSA.class);
    	
    	public static final String KEY_ALGORITHM = "RSA";
    	public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    
    	private static final String PUBLIC_KEY = "RSAPublicKey";
    	private static final String PRIVATE_KEY = "RSAPrivateKey";
    
    	/**
    	 * 初始化密钥
    	 * 
    	 * @return
    	 * @throws Exception
    	 */
    	public static Map<String, Object> initKey() throws Exception {
    		KeyPairGenerator keyPairGen = KeyPairGenerator
    				.getInstance(KEY_ALGORITHM);
    		keyPairGen.initialize(1024);
    		KeyPair keyPair = keyPairGen.generateKeyPair();
    
    		// 公钥
    		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
    //		logger.info("------" + publicKey);
    		// 私钥
    		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
    //		logger.info("------" + publicKey);
    		
    		Map<String, Object> keyMap = new HashMap<String, Object>(2);
    
    		keyMap.put(PUBLIC_KEY, publicKey);
    		keyMap.put(PRIVATE_KEY, privateKey);
    		return keyMap;
    	}
    
    	/**
    	 * 取得私钥
    	 * 
    	 * @param keyMap
    	 * @return
    	 * @throws Exception
    	 */
    	public static String getPrivateKey(Map<String, Object> keyMap)
    			throws Exception {
    		Key key = (Key) keyMap.get(PRIVATE_KEY);
    		return encryptBASE64(key.getEncoded());
    	}
    
    	/**
    	 * 取得公钥
    	 * 
    	 * @param keyMap
    	 * @return
    	 * @throws Exception
    	 */
    	public static String getPublicKey(Map<String, Object> keyMap)
    			throws Exception {
    		Key key = (Key) keyMap.get(PUBLIC_KEY);
    		return encryptBASE64(key.getEncoded());
    	}
    	
    	
    	/**
    	 * 解密<br>
    	 * 用私钥解密
    	 * 
    	 * @param data
    	 * @param key
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] decryptByPrivateKey(byte[] data, String key)
    			throws Exception {
    		// 对密钥解密
    		byte[] keyBytes = decryptBASE64(key);
    
    		// 取得私钥
    		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    		Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
    
    		// 对数据解密
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.DECRYPT_MODE, privateKey);
    
    		return cipher.doFinal(data);
    	}
    
    	/**
    	 * 解密<br>
    	 * 用公钥解密
    	 * 
    	 * @param data
    	 * @param key
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] decryptByPublicKey(byte[] data, String key)
    			throws Exception {
    		// 对密钥解密
    		byte[] keyBytes = decryptBASE64(key);
    
    		// 取得公钥
    		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    		Key publicKey = keyFactory.generatePublic(x509KeySpec);
    
    		// 对数据解密
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.DECRYPT_MODE, publicKey);
    
    		return cipher.doFinal(data);
    	}
    
    	/**
    	 * 加密<br>
    	 * 用公钥加密
    	 * 
    	 * @param data
    	 * @param key
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] encryptByPublicKey(byte[] data, String key)
    			throws Exception {
    		// 对公钥解密
    		byte[] keyBytes = decryptBASE64(key);
    
    		// 取得公钥
    		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    		Key publicKey = keyFactory.generatePublic(x509KeySpec);
    
    		// 对数据加密
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    
    		return cipher.doFinal(data);
    	}
    
    	/**
    	 * 加密<br>
    	 * 用私钥加密
    	 * 
    	 * @param data
    	 * @param key
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] encryptByPrivateKey(byte[] data, String key)
    			throws Exception {
    		// 对密钥解密
    		byte[] keyBytes = decryptBASE64(key);
    
    		// 取得私钥
    		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    		Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);
    
    		// 对数据加密
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.ENCRYPT_MODE, privateKey);
    
    		return cipher.doFinal(data);
    	}
    	
    	/**
    	 * 用私钥对信息生成数字签名
    	 * 
    	 * @param data
    	 *            加密数据
    	 * @param privateKey
    	 *            私钥
    	 * 
    	 * @return
    	 * @throws Exception
    	 */
    	public static String sign(byte[] data, String privateKey) throws Exception {
    		// 解密由base64编码的私钥
    		byte[] keyBytes = decryptBASE64(privateKey);
    
    		// 构造PKCS8EncodedKeySpec对象
    		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    
    		// KEY_ALGORITHM 指定的加密算法
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    
    		// 取私钥匙对象
    		PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);
    
    		// 用私钥对信息生成数字签名
    		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
    		signature.initSign(priKey);
    		signature.update(data);
    
    		return encryptBASE64(signature.sign());
    	}
    
    	/**
    	 * 校验数字签名
    	 * 
    	 * @param data
    	 *            加密数据
    	 * @param publicKey
    	 *            公钥
    	 * @param sign
    	 *            数字签名
    	 * 
    	 * @return 校验成功返回true 失败返回false
    	 * @throws Exception
    	 * 
    	 */
    	public static boolean verify(byte[] data, String publicKey, String sign)
    			throws Exception {
    
    		// 解密由base64编码的公钥
    		byte[] keyBytes = decryptBASE64(publicKey);
    
    		// 构造X509EncodedKeySpec对象
    		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
    
    		// KEY_ALGORITHM 指定的加密算法
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
    
    		// 取公钥匙对象
    		PublicKey pubKey = keyFactory.generatePublic(keySpec);
    
    		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
    		signature.initVerify(pubKey);
    		signature.update(data);
    
    		// 验证签名是否正常
    		return signature.verify(decryptBASE64(sign));
    	}
    
    	private static byte[] decryptBASE64(String key) throws Exception {
    		return (new BASE64Decoder()).decodeBuffer(key);
    	}
    
    	private static String encryptBASE64(byte[] key) throws Exception {
    		return (new BASE64Encoder()).encodeBuffer(key);
    	}
    	
    	public static void main(String[] args) {
    		Map<String, Object> keyMap;
    		try {
    			//取得公钥和么私钥
    			keyMap = initKey();
    			String publicKey = getPublicKey(keyMap);
    			logger.info("字符类型公钥:" + publicKey);
    
    			String privateKey = getPrivateKey(keyMap);
    			logger.info("字符类型私钥:" + privateKey);
    
    			
    			System.err.println("公钥加密——私钥解密");
    	        String source = "这是一行没有任何意义的文字，你看完了等于没看，不是吗？";
    	        System.out.println("\r加密前文字：\r\n" + source);
    	        byte[] data = source.getBytes();
    	        byte[] encodedData = encryptByPublicKey(data, publicKey);
    	        System.out.println("加密后文字：\r\n" + encryptBASE64(encodedData));
    	        byte[] decodedData = decryptByPrivateKey(encodedData, privateKey);
    	        String target = new String(decodedData);
    	        System.out.println("解密后文字: \r\n" + target);
    	        
    	        System.err.println("私钥加密——公钥解密");
    	        String source1 = "这是一行测试RSA数字签名的无意义文字";
    	        System.out.println("原文字：\r\n" + source1);
    	        byte[] data1 = source1.getBytes();
    	        byte[] encodedData1 = encryptByPrivateKey(data1, privateKey);
    	        System.out.println("加密后：\r\n" + new String(encodedData1));
    	        byte[] decodedData1 = decryptByPublicKey(encodedData1, publicKey);
    	        String target1 = new String(decodedData1);
    	        System.out.println("解密后: \r\n" + target1);
    	        System.err.println("私钥签名——公钥验证签名");
    	        String sign = sign(encodedData, privateKey);
    	        System.err.println("签名:\r" + sign);
    	        boolean status = verify(encodedData, publicKey, sign);
    	        System.err.println("验证结果:\r" + status);
    //			//对内容进行加密和解密
    			String str = "this is test RSA";
    			byte[] strByte = str.getBytes();
    //			//私钥加密 
    			byte[] encode = encryptByPrivateKey(strByte,privateKey);
    			logger.info("私钥加密结果:" + encryptBASE64(encode));
    			//公钥解密
    			byte[] decode = decryptByPublicKey(encode,publicKey);
    			logger.info("公钥解密结果:" + new String(decode));
    			
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    
    }