JAVA實現RSA加密,非對稱加密演算法
阿新 • • 發佈：2019-01-05
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:[email protected] * @date：2016-3-23下午12:25:07 * @version: 1.0 * @describe: JAVA實現RSA加密,非對稱加密演算法 * */ 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"; /** * 初始化金鑰 * * @return * @throws Exception */ public static Map<String, Object> initKey() throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator .getInstance(KEY_ALGORITHM); keyPairGen.initialize(1024); KeyPair keyPair = keyPairGen.generateKeyPair(); // 公鑰 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); // logger.info("------" + publicKey); // 私鑰 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; } /** * 取得私鑰 * * @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()); } /** * 取得公鑰 * * @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> * 用私鑰解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception { // 對金鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得私鑰 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec); // 對資料解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 解密<br> * 用公鑰解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPublicKey(byte[] data, String key) throws Exception { // 對金鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得公鑰 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicKey = keyFactory.generatePublic(x509KeySpec); // 對資料解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, publicKey); return cipher.doFinal(data); } /** * 加密<br> * 用公鑰加密 * * @param data * @param key * @return * @throws Exception */ public static byte[] encryptByPublicKey(byte[] data, String key) throws Exception { // 對公鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得公鑰 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicKey = keyFactory.generatePublic(x509KeySpec); // 對資料加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, publicKey); return cipher.doFinal(data); } /** * 加密<br> * 用私鑰加密 * * @param data * @param key * @return * @throws Exception */ public static byte[] encryptByPrivateKey(byte[] data, String key) throws Exception { // 對金鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得私鑰 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec); // 對資料加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 用私鑰對資訊生成數字簽名 * * @param data * 加密資料 * @param privateKey * 私鑰 * * @return * @throws Exception */ public static String sign(byte[] data, String privateKey) throws Exception { // 解密由base64編碼的私鑰 byte[] keyBytes = decryptBASE64(privateKey); // 構造PKCS8EncodedKeySpec物件 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); // KEY_ALGORITHM 指定的加密演算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 取私鑰匙物件 PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec); // 用私鑰對資訊生成數字簽名 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initSign(priKey); signature.update(data); return encryptBASE64(signature.sign()); } /** * 校驗數字簽名 * * @param data * 加密資料 * @param publicKey * 公鑰 * @param sign * 數字簽名 * * @return 校驗成功返回true 失敗返回false * @throws Exception * */ public static boolean verify(byte[] data, String publicKey, String sign) throws Exception { // 解密由base64編碼的公鑰 byte[] keyBytes = decryptBASE64(publicKey); // 構造X509EncodedKeySpec物件 X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); // KEY_ALGORITHM 指定的加密演算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 取公鑰匙物件 PublicKey pubKey = keyFactory.generatePublic(keySpec); Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initVerify(pubKey); signature.update(data); // 驗證簽名是否正常 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 { //取得公鑰和麼私鑰 keyMap = initKey(); String publicKey = getPublicKey(keyMap); logger.info("字元型別公鑰:" + publicKey); String privateKey = getPrivateKey(keyMap); logger.info("字元型別私鑰:" + privateKey); System.err.println("公鑰加密——私鑰解密"); String source = "這是一行沒有任何意義的文字，你看完了等於沒看，不是嗎？"; System.out.println("\r加密前文字：\r\n" + source); byte[] data = source.getBytes(); byte[] encodedData = encryptByPublicKey(data, publicKey); System.out.println("加密後文字：\r\n" + encryptBASE64(encodedData)); byte[] decodedData = decryptByPrivateKey(encodedData, privateKey); String target = new String(decodedData); System.out.println("解密後文字: \r\n" + target); System.err.println("私鑰加密——公鑰解密"); String source1 = "這是一行測試RSA數字簽名的無意義文字"; System.out.println("原文字：\r\n" + source1); byte[] data1 = source1.getBytes(); byte[] encodedData1 = encryptByPrivateKey(data1, privateKey); System.out.println("加密後：\r\n" + new String(encodedData1)); byte[] decodedData1 = decryptByPublicKey(encodedData1, publicKey); String target1 = new String(decodedData1); System.out.println("解密後: \r\n" + target1); System.err.println("私鑰簽名——公鑰驗證簽名"); String sign = sign(encodedData, privateKey); System.err.println("簽名:\r" + sign); boolean status = verify(encodedData, publicKey, sign); System.err.println("驗證結果:\r" + status); // //對內容進行加密和解密 String str = "this is test RSA"; byte[] strByte = str.getBytes(); // //私鑰加密 byte[] encode = encryptByPrivateKey(strByte,privateKey); logger.info("私鑰加密結果:" + encryptBASE64(encode)); //公鑰解密 byte[] decode = decryptByPublicKey(encode,publicKey); logger.info("公鑰解密結果:" + new String(decode)); } catch (Exception e) { e.printStackTrace(); } } }