RSA加解密工具类

我会带着你远行 2021-11-04 15:50 380阅读 0赞

package com.fh.util;
    
    import javax.crypto.Cipher;
    
    import Decoder.BASE64Decoder;
    import Decoder.BASE64Encoder;
    
    import java.io.ByteArrayOutputStream;
    import java.security.*;
    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;
    
    /**
     * RSA加密工具类 使用PKCS1_PADDING填充，密钥长度1024
     * 加解密结果在这里测试通过：http://tool.chacuo.net/cryptrsaprikey 注意加密内容的编码要一致，统一UTF-8比较好
     *
     * @author daxi
     */
    public class RSAUtil {
    
    	public static final String KEY_ALGORTHM = "RSA";
    	public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    
    	public static final String PUBLIC_KEY = "RSAPublicKey";// 公钥
    	public static final String PRIVATE_KEY = "RSAPrivateKey";// 私钥
    
    	/**
    	 * RSA最大加密明文大小
    	 */
    	private static final int MAX_ENCRYPT_BLOCK = 117;
    	/** */
    	/**
    	 * RSA最大解密密文大小
    	 */
    	private static final int MAX_DECRYPT_BLOCK = 128;
    
    	/**
    	 * 初始化密钥 RSA加密解密的实现，需要有一对公私密钥，公私密钥的初始化如下 非对称加密一般都用于加密对称加密算法的密钥，而不是直接加密内容
    	 *
    	 * @return
    	 * @throws Exception
    	 */
    	public static Map<String, Object> initKey() throws Exception {
    		KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORTHM);
    		keyPairGenerator.initialize(1024);
    		KeyPair keyPair = keyPairGenerator.generateKeyPair();
    
    		// 公钥
    		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
    		// 私钥
    		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
    
    		Map<String, Object> keyMap = new HashMap<String, Object>(2);
    		keyMap.put(PUBLIC_KEY, publicKey);
    		keyMap.put(PRIVATE_KEY, privateKey);
    
    		return keyMap;
    	}
    
    	/**
    	 * 取得公钥，并转化为String类型
    	 *
    	 * @param keyMap
    	 * @throws Exception
    	 * @return-
    	 */
    	public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
    		Key key = (Key) keyMap.get(PUBLIC_KEY);
    		return Coder.encryptBASE64(key.getEncoded());
    	}
    
    	/**
    	 * 取得私钥，并转化为String类型
    	 *
    	 * @param keyMap
    	 * @return
    	 * @throws Exception
    	 */
    	public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
    		Key key = (Key) keyMap.get(PRIVATE_KEY);
    		return Coder.encryptBASE64(key.getEncoded());
    	}
    
    	/**
    	 * 用私钥加密
    	 *
    	 * @param data 加密数据
    	 * @param key  密钥
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] encryptByPrivateKey(byte[] data, String key) throws Exception {
    
    		byte[] keyBytes = Coder.decryptBASE64(key);
    		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.ENCRYPT_MODE, privateK);
    		int inputLen = data.length;
    		ByteArrayOutputStream out = new ByteArrayOutputStream();
    		int offSet = 0;
    		byte[] cache;
    		int i = 0;
    		// 对数据分段加密
    		while (inputLen - offSet > 0) {
    			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
    				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
    			} else {
    				cache = cipher.doFinal(data, offSet, inputLen - offSet);
    			}
    			out.write(cache, 0, cache.length);
    			i++;
    			offSet = i * MAX_ENCRYPT_BLOCK;
    		}
    		byte[] encryptedData = out.toByteArray();
    		out.close();
    		return encryptedData;
    
    	}
    
    	/**
    	 * 用私钥解密 * @param data 加密数据
    	 *
    	 * @param key 密钥
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception {
    		byte[] keyBytes = Coder.decryptBASE64(key);
    		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.DECRYPT_MODE, privateK);
    		int inputLen = data.length;
    		ByteArrayOutputStream out = new ByteArrayOutputStream();
    		int offSet = 0;
    		byte[] cache;
    		int i = 0;
    		// 对数据分段解密
    		while (inputLen - offSet > 0) {
    			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
    				cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
    			} else {
    				cache = cipher.doFinal(data, offSet, inputLen - offSet);
    			}
    			out.write(cache, 0, cache.length);
    			i++;
    			offSet = i * MAX_DECRYPT_BLOCK;
    		}
    		byte[] decryptedData = out.toByteArray();
    		out.close();
    		return decryptedData;
    
    	}
    
    	/**
    	 * 用公钥加密
    	 *
    	 * @param data 加密数据
    	 * @param key  密钥
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] encryptByPublicKey(byte[] data, String key) throws Exception {
    		byte[] keyBytes = Coder.decryptBASE64(key);
    		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		Key publicK = keyFactory.generatePublic(x509KeySpec);
    		// 对数据加密
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.ENCRYPT_MODE, publicK);
    		int inputLen = data.length;
    		ByteArrayOutputStream out = new ByteArrayOutputStream();
    		int offSet = 0;
    		byte[] cache;
    		int i = 0;
    		// 对数据分段加密
    		while (inputLen - offSet > 0) {
    			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
    				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
    			} else {
    				cache = cipher.doFinal(data, offSet, inputLen - offSet);
    			}
    			out.write(cache, 0, cache.length);
    			i++;
    			offSet = i * MAX_ENCRYPT_BLOCK;
    		}
    		byte[] encryptedData = out.toByteArray();
    		out.close();
    		return encryptedData;
    	}
    
    	/**
    	 * 用公钥解密
    	 *
    	 * @param data 加密数据
    	 * @param key  密钥
    	 * @return
    	 * @throws Exception
    	 */
    	public static byte[] decryptByPublicKey(byte[] data, String key) throws Exception {
    		byte[] keyBytes = Coder.decryptBASE64(key);
    		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		Key publicK = keyFactory.generatePublic(x509KeySpec);
    		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
    		cipher.init(Cipher.DECRYPT_MODE, publicK);
    		int inputLen = data.length;
    		ByteArrayOutputStream out = new ByteArrayOutputStream();
    		int offSet = 0;
    		byte[] cache;
    		int i = 0;
    		// 对数据分段解密
    		while (inputLen - offSet > 0) {
    			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
    				cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
    			} else {
    				cache = cipher.doFinal(data, offSet, inputLen - offSet);
    			}
    			out.write(cache, 0, cache.length);
    			i++;
    			offSet = i * MAX_DECRYPT_BLOCK;
    		}
    		byte[] decryptedData = out.toByteArray();
    		out.close();
    		return decryptedData;
    	}
    
    	/**************************************************************************
    	 * 通过RSA加密解密算法，我们可以实现数字签名的功能。我们可以用私钥对信息生 成数字签名，再用公钥来校验数字签名，当然也可以反过来公钥签名，私钥校验。
    	 *************************************************************************/
    
    	/**
    	 * 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 {
    		// 解密私钥
    		byte[] keyBytes = Coder.decryptBASE64(privateKey);
    		// 构造PKCS8EncodedKeySpec对象
    		PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes);
    		// 指定加密算法
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		// 取私钥匙对象
    		PrivateKey privateKey2 = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
    		// 用私钥对信息生成数字签名
    		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
    		signature.initSign(privateKey2);
    		signature.update(data);
    
    		return Coder.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
    	 * @throws Exception
    	 */
    	public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {
    		// 解密公钥
    		byte[] keyBytes = Coder.decryptBASE64(publicKey);
    		// 构造X509EncodedKeySpec对象
    		X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(keyBytes);
    		// 指定加密算法
    		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORTHM);
    		// 取公钥匙对象
    		PublicKey publicKey2 = keyFactory.generatePublic(x509EncodedKeySpec);
    
    		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
    		signature.initVerify(publicKey2);
    		signature.update(data);
    		// 验证签名是否正常
    		return signature.verify(Coder.decryptBASE64(sign));
    
    	}
    
    	public static void main(String[] args) throws Exception {
    		// 生产密钥
    		Map<String, Object> keys = initKey();
    		String privatekey = RSAUtil.getPrivateKey(keys);
    		String publickey = RSAUtil.getPublicKey(keys);
    
    		// 打印私钥
    		//System.out.println("-----BEGIN PRIVATE KEY-----");
    		//System.out.println(privatekey);
    		//System.out.println("-----END PRIVATE KEY-----");
    
    		//System.out.println();
    
    		// 打印公钥
    		//System.out.println("-----BEGIN PUBLIC KEY-----");
    		//System.out.println(publickey);
    		//System.out.println("-----END PUBLIC KEY-----");
    
    		// RSA公钥加密
    		/*
    		 * String message = "hello"; byte[] publicEncrypt =
    		 * encryptByPublicKey(message.getBytes("UTF-8"),publickey.replace(" ",""));
    		 * String publicBase = Coder.encryptBASE64(publicEncrypt);
    		 * System.out.println("公钥加密：" + publicBase);
    		 * 
    		 * //RSA私钥解密 byte[] messages = Coder.decryptBASE64(publicBase); String
    		 * decryptedNaughty = new String(decryptByPrivateKey(messages,
    		 * privatekey.replace(" ",""))); System.out.println("私钥解密"+decryptedNaughty);
    		 * 
    		 * //RSA私钥加密 byte[] privateEncrypt =
    		 * encryptByPrivateKey(message.getBytes("UTF-8"),privatekey.replace(" ",""));
    		 * String privateBase = Coder.encryptBASE64(privateEncrypt);
    		 * System.out.println("私钥加密"+privateBase);
    		 * 
    		 * //RSA公钥解密 byte[] messages1 = Coder.decryptBASE64(privateBase); String
    		 * decryptedNaughty1 = new String(decryptByPublicKey(messages1,
    		 * publickey.replace(" ",""))); System.out.println("公钥解密"+decryptedNaughty1);
    		 */
    		syjm();
    	}
    
    	/***
    	 * 测试加密
    	 */
    	public static void syjm() throws Exception {
    		String privatekey = "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAJKpBM8FQknWV4W+0uJrEkbR4pZS\r\n" + 
    				"qBfxCDApe0NA2SAW7ZWL8OM0LWXP5XhYQCStnUGT5GLrqxUZzTxm/HfHpv7loKrW8RNwZBCOq2lS\r\n" + 
    				"ekTGHSpytTgV7B9JdE1PNIlNmN4CM3wEwJfEWp3dFmXm6EEyn/pe009F+zEbDY6dQSQrAgMBAAEC\r\n" + 
    				"gYBAoEglLY0TWmdA4WCuMz5fhLdTRGMcAbN4/Z56eUX0VQYmgv8IL4LdvWnBySmiv/pu3kuip3TB\r\n" + 
    				"HJiKyFryMUFNn7c4wwe3bE7qTbxlI12HVNi2TM5juSwkcOnQoCSO36GUQnpTfircp1hUudmAudpE\r\n" + 
    				"H3iB5q7KYvs9mOaVJQ892QJBANU5W1R+4bWjSvz06Yd9MrWobgTmk8dmwQ1gb5dryxvzpT7lLQtQ\r\n" + 
    				"W+17mwByPWbdU4To1mvdESo6HqD5D9AnRt0CQQCwFR0xJ1i+BWMRs8dk6nv3TEbfCYG62ymxoOEB\r\n" + 
    				"zTy1Gl43GT7T3gFd5X2U2FR5Yq3Wl9zoHUgVRMSb9XgKafKnAkBRJ7OLRX/DEpPIE6+O0igq3CCD\r\n" + 
    				"3P8CNinkXYAbsftseB+9AJ1UYRGcIh+s285jCHpxa+2wwEN4PwbJXgKWx1xBAkBtxev6DdaUOFWH\r\n" + 
    				"3rVrI4f/Jy1ztMCM1j8K/wnnjqTPHs4nuXRirx/ZAs4ksi0Ps8Y+Z1SP3Flo8QNFW2Xn0B83AkB4\r\n" + 
    				"6voviQRiKWwUjX1xPikrLEWNmLw94MUvAcUb4kH2vvpsRBJzaWAP5/ZaF9QOMCokyYtWTF5Y88/w\r\n" + 
    				"1PfezMdT";
    
    		String publickey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCSqQTPBUJJ1leFvtLiaxJG0eKWUqgX8QgwKXtD\r\n" + 
    				"QNkgFu2Vi/DjNC1lz+V4WEAkrZ1Bk+Ri66sVGc08Zvx3x6b+5aCq1vETcGQQjqtpUnpExh0qcrU4\r\n" + 
    				"FewfSXRNTzSJTZjeAjN8BMCXxFqd3RZl5uhBMp/6XtNPRfsxGw2OnUEkKwIDAQAB";
    
    		// 公钥加密\
    		String message = "123";
    		byte[] publicEncrypt = encryptByPublicKey(message.getBytes("UTF-8"), publickey.replace(" ", ""));
    		String publicBase = Coder.encryptBASE64(publicEncrypt);
    		System.out.println("公钥加密：" + publicBase);
    
    		// RSA私钥解密
    		byte[] messages = Coder.decryptBASE64(publicBase);
    		String decryptedNaughty = new String(decryptByPrivateKey(messages, privatekey.replace(" ", "")));
    		System.out.println("私钥解密" + decryptedNaughty);
    
    		// RSA私钥加密
    		byte[] privateEncrypt = encryptByPrivateKey(message.getBytes("UTF-8"), privatekey.replace(" ", ""));
    		String privateBase = Coder.encryptBASE64(privateEncrypt);
    		System.out.println("私钥加密" + privateBase);
    
    		// RSA公钥解密
    		byte[] messages1 = Coder.decryptBASE64(privateBase);
    		String decryptedNaughty1 = new String(decryptByPublicKey(messages1, publickey.replace(" ", "")));
    		System.out.println("公钥解密" + decryptedNaughty1);
    	}
    }
    
    class Coder {
    	/** 
    	 * BASE64解密 
    	 *  
    	 * @param key 
    	 * @return 
    	 * @throws Exception 
    	 */  
    	public static byte[] decryptBASE64(String key) throws Exception {  
    	    return (new BASE64Decoder()).decodeBuffer(key);  
    	}  
    	  
    	/** 
    	 * BASE64加密 
    	 *  
    	 * @param key 
    	 * @return 
    	 * @throws Exception 
    	 */  
    	public static String encryptBASE64(byte[] key) throws Exception {  
    	    return (new BASE64Encoder()).encodeBuffer(key);  
    	}  
    }