JAVA 中解密RSA算法JS加密实例详解
有这样一个需求，前端登录的用户名密码，密码必需加密，但不可使用MD5，因为后台要检测密码的复杂度，那么在保证安全的前提下将密码传到后台呢，答案就是使用RSA非对称加密算法解决 。
java代码
需要依赖 commons-codec 包
RSACoder.Java
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import org.apache.commons.codec.binary.Base64;import javax.crypto.Cipher;import java.security.*;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;/** * Created by lake on 17-4-12. */public class RSACoder { 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"; public static byte[] decryptBASE64(String key) { return Base64.decodeBase64(key); } public static String encryptBASE64(byte[] bytes) { return Base64.encodeBase64String(bytes); } /** * 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)); } 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> * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPrivateKey(String data, String key) throws Exception { return decryptByPrivateKey(decryptBASE64(data),key); } /** * 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(String 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.getBytes()); } /** * 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); } /** * 取得私钥 * * @param keyMap * @return * @throws Exception */ public static String getPrivateKey(Map<String, Key> 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, Key> keyMap) throws Exception { Key key = keyMap.get(PUBLIC_KEY); return encryptBASE64(key.getEncoded()); } /** * 初始化密钥 * * @return * @throws Exception */ public static Map<String, Key> initKey() throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator .getInstance(KEY_ALGORITHM); keyPairGen.initialize(1024); KeyPair keyPair = keyPairGen.generateKeyPair(); Map<String, Key> keyMap = new HashMap(2); keyMap.put(PUBLIC_KEY, keyPair.getPublic());// 公钥 keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私钥 return keyMap; }} |
测试类
RSACoderTest.java
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import org.junit.Before;import org.junit.Test;import java.security.Key;import java.util.Map;import static org.junit.Assert.assertEquals;import static org.junit.Assert.assertTrue;/** * Created by lake on 17-4-12. */public class RSACoderTest { private String publicKey; private String privateKey; @Before public void setUp() throws Exception { Map<String, Key> keyMap = RSACoder.initKey(); publicKey = RSACoder.getPublicKey(keyMap); privateKey = RSACoder.getPrivateKey(keyMap); System.err.println("公钥: \n\r" + publicKey); System.err.println("私钥： \n\r" + privateKey); } @Test public void test() throws Exception { System.err.println("公钥加密——私钥解密"); String inputStr = "abc"; byte[] encodedData = RSACoder.encryptByPublicKey(inputStr, publicKey); byte[] decodedData = RSACoder.decryptByPrivateKey(encodedData, privateKey); String outputStr = new String(decodedData); System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr); assertEquals(inputStr, outputStr); } @Test public void testSign() throws Exception { System.err.println("私钥加密——公钥解密"); String inputStr = "sign"; byte[] data = inputStr.getBytes(); byte[] encodedData = RSACoder.encryptByPrivateKey(data, privateKey); byte[] decodedData = RSACoder.decryptByPublicKey(encodedData, publicKey); String outputStr = new String(decodedData); System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr); assertEquals(inputStr, outputStr); System.err.println("私钥签名——公钥验证签名"); // 产生签名 String sign = RSACoder.sign(encodedData, privateKey); System.err.println("签名:" + sign); // 验证签名 boolean status = RSACoder.verify(encodedData, publicKey, sign); System.err.println("状态:" + status); assertTrue(status); }} |
前端代码
依赖 jsencrypt 项目
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<script src="bin/jsencrypt.min.js"></script><script type="text/javascript"> var encrypt = new JSEncrypt(); encrypt.setPublicKey('java生成的公钥'); var encrypted = encrypt.encrypt('加密的字符串');</script> |
说明
前端生成加密的字符串encrypted，传到后台，java使用私钥进行解密即可。
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