JAVA 非对称加密算法RSA
非对称加密算法 RSA过程 ： 以甲乙双方为例
1、初始化密钥 构建密钥对,生成公钥、私钥保存到keymap中
KeyPairGenerator ---> KeyPair --> RSAPublicKey、RSAPrivateKey
2、甲方使用私钥加密, 加密后在用私钥对加密数据进行数据签名，然后发送给乙方
RSACoder.encryptByPrivateKey(data, privateKey);
RSACoder.sign(encodedData, privateKey);
3、乙方则通过公钥验证签名的加密数据，如果验证正确则在通过公钥对加密数据进行解密
RSACoder.verify(encodedData, publicKey, sign);
RSACoder.decryptByPublicKey(encodedData, publicKey);
4、乙方在通过公钥加密发送给甲方
RSACoder.encryptByPublicKey(decodedData, publicKey);
5、甲方通过私钥解密该数据
RSACoder.decryptPrivateKey(encodedData, privateKey);
流程图如下：
java代码实现如下：
package com.bank.utils; import java.security.MessageDigest; import javax.crypto.KeyGenerator; import javax.crypto.Mac; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public abstract class Coder { public static final String KEY_SHA = "SHA"; public static final String KEY_MD5 = "MD5"; /** * MAC算法可选以下多种算法 * * <pre> * HmacMD5 * HmacSHA1 * HmacSHA256 * HmacSHA384 * HmacSHA512 * </pre> */ public static final String KEY_MAC = "HmacMD5"; /** * 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); } /** * MD5 加密 * @param data * @return * @throws Exception */ public static byte[] encryptMD5( byte[] data) throws Exception { MessageDigest md5 = MessageDigest.getInstance(KEY_MD5); md5.update(data); return md5.digest(); } /** * SHA 加密 * @param data * @return * @throws Exception */ public static byte[] encryptSHA( byte[] data) throws Exception { MessageDigest sha = MessageDigest.getInstance(KEY_SHA); sha.update(data); return sha.digest(); } /** * 初始化HMAC密钥 * * @return * @throws Exception */ public static String initMacKey() throws Exception{ KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC); SecretKey secretKey = keyGenerator.generateKey(); return encryptBASE64(secretKey.getEncoded()); } /** * HMAC 加密 * @param data * @param key * @return * @throws Exception */ public static byte[] encryptHMAC( byte[] data, String key) throws Exception{ SecretKey secretKey = new SecretKeySpec(decryptBASE64(key), KEY_MAC); Mac mac = Mac.getInstance(secretKey.getAlgorithm()); mac.init(secretKey); return mac.doFinal(data); } }
package com.bank.utils; import java.security.Key; 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 javax.crypto.Cipher; public abstract class RSACoder extends Coder{ 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"; /** * 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); PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //取私钥对象 PrivateKey pKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec); //用私钥生成数字签名 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initSign(pKey); 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 * @throws Exception */ public static boolean verify(byte[] data, String publicKey, String sign) throws Exception{ //解密有base64编码的公钥 byte[] keyBytes = decryptBASE64(publicKey); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); //取公钥对象 PublicKey pKey = keyFactory.generatePublic(keySpec); Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initVerify(pKey); signature.update(data); //验证签名是否正常 return signature.verify(decryptBASE64(sign)); } /** * 解密 * 用私钥解密 * @param data 加密数据 * @param key * @return * @throws Exception */ public static byte[] decryptPrivateKey(byte[] data, String key) throws Exception{ byte[] keyBytes = decryptBASE64(key); //取得私钥 PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory factory = KeyFactory.getInstance(KEY_ALGORITHM); Key pKey = factory.generatePrivate(encodedKeySpec); //对数据解密 Cipher cipher = Cipher.getInstance(factory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, pKey); return cipher.doFinal(data); } /** * 用公钥解密 * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPublicKey( byte[] data, String key) throws Exception{ //解密 byte[] keyBytes = decryptBASE64(key); //取得公钥 X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key pKey = keyFactory.generatePublic(keySpec); //对数据解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, pKey); return cipher.doFinal(data); } /** * 用公钥加密 * @param data * @param key * @return * @throws Exception */ public static byte[] encryptByPublicKey( byte[] data, String key) throws Exception{ byte[] keyBytes = decryptBASE64(key); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key pKey = keyFactory.generatePublic(keySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, pKey); return cipher.doFinal(data); } /** * 用私钥加密 * @param data * @param key * @return * @throws Exception */ public static byte[] encryptByPrivateKey(byte[] data, String key) throws Exception{ byte[] keyBytes = decryptBASE64(key); PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateKey = keyFactory.generatePrivate(keySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 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()); } /** * 初始化密钥 * @return * @throws Exception */ public static Map<String, Object> initKey() throws Exception{ KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(KEY_ALGORITHM); 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(PRIVATE_KEY, privateKey); keyMap.put(PUBLIC_KEY, publicKey); return keyMap; } }
package com.bank.test; import java.util.Map; import org.junit.Assert; import org.junit.Before; import org.junit.Test; import com.bank.utils.RSACoder; public class RSACoderTest { private String publicKey; private String privateKey; /* * 非对称加密算法 RSA过程 ： 以甲乙双方为例 * 1、初始化密钥 构建密钥对,生成公钥、私钥保存到keymap中 * KeyPairGenerator ---> KeyPair --> RSAPublicKey、RSAPrivateKey * 2、甲方使用私钥加密, 加密后在用私钥对加密数据进行数据签名，然后发送给乙方 * RSACoder.encryptByPrivateKey(data, privateKey); * RSACoder.sign(encodedData, privateKey); * 3、乙方则通过公钥验证签名的加密数据，如果验证正确则在通过公钥对加密数据进行解密 * RSACoder.verify(encodedData, publicKey, sign); * RSACoder.decryptByPublicKey(encodedData, publicKey); * * 4、乙方在通过公钥加密发送给甲方 * RSACoder.encryptByPublicKey(decodedData, publicKey); * 5、甲方通过私钥解密该数据 * RSACoder.decryptPrivateKey(encodedData, privateKey); */ @Before public void setUp() throws Exception { Map<String , Object> keyMap = RSACoder.initKey(); publicKey = RSACoder.getPublicKey(keyMap); privateKey = RSACoder.getPrivateKey(keyMap); System.out.println("公钥：\n" + publicKey); System.out.println("私钥：\n" + privateKey); } @Test public void test() throws Exception{ String inputStr = "abc"; byte[] data = inputStr.getBytes();//每次的得到的字节数组是不一样的。 //第二步 私钥加密 byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey); //私钥进行数据签名 String sign = RSACoder.sign(encodedData, privateKey); //第三步 公钥验证数字签名 boolean flag = RSACoder.verify(encodedData, publicKey, sign); System.out.println("flag:" + flag); //用公钥对数据解密 byte[] decodedData = RSACoder.decryptByPublicKey(encodedData, publicKey); System.out.println("data:" + data + "加密数据：" + encodedData + " 解密数据：" + decodedData); System.out.println("加密前数据-：" + new String(data) + " 解密后数据： " + new String(decodedData)); //第四步使用公钥加密数据 encodedData = RSACoder.encryptByPublicKey(decodedData, publicKey); //第五步 使用私钥解密数据 decodedData = RSACoder.decryptPrivateKey(encodedData, privateKey); System.out.println("data:" + data + "加密数据：" + encodedData + " 解密数据：" + decodedData); System.out.println("加密前数据：" + inputStr + " 解密后数据： " + new String(decodedData)); } @Test public void test1() throws Exception{ System.out.println("私钥加密-----公钥解密"); String inputStr = "abc"; byte[] data = inputStr.getBytes(); System.out.println("data:" + data); byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey); byte[] decodedData = RSACoder.decryptByPublicKey(encodedData, publicKey); String outputStr = new String( decodedData ); System.out.println("加密前：" + inputStr +"\n 解密后：" + outputStr); Assert.assertEquals(inputStr, outputStr); System.out.println("私钥签名---公钥验证签名"); //产生签名 String sign = RSACoder.sign(encodedData, privateKey); System.out.println("签名：\r" + sign); //验证签名 boolean flag = RSACoder.verify(encodedData, publicKey, sign); System.out.println("状态：\r" + flag); Assert.assertTrue(flag); } }
</div>
本文由用户 jopen 自行上传分享，仅供网友学习交流。所有权归原作者，若您的权利被侵害，请联系管理员。
转载本站原创文章，请注明出处，并保留原始链接、图片水印。
本站是一个以用户分享为主的开源技术平台，欢迎各类分享！