RSA加密算法--Java實現詳細案例:
阿新 • • 發佈：2017-07-05
數據 turn 是否 exce x509 ase algorithm 實現 date
import org.apache.commons.codec.binary.Base64; import java.security.*; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.HashMap; import java.util.Map; import javax.crypto.Cipher; /** * Created by humf.需要依賴 commons-codec 包 */ public classRSACoder { 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); } /** * 用私鑰對信息生成數字簽名 * * @param data 加密數據 * @param privateKey 私鑰 * @return * @throws Exception */ publicstatic String sign(byte[] data, String privateKey) throws Exception { // 解密由base64編碼的私鑰 byte[] keyBytes = decryptBASE64(privateKey); // 構造PKCS8EncodedKeySpec對象 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); // KEY_ALGORITHM 指定的加密算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 取私鑰匙對象 PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec); // 用私鑰對信息生成數字簽名 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); signature.initSign(priKey); signature.update(data); return encryptBASE64(signature.sign()); } /** * 校驗數字簽名 * * @param data 加密數據 * @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對象 X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); // KEY_ALGORITHM 指定的加密算法 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); // 取公鑰匙對象 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)); } public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception{ // 對密鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得私鑰 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec); // 對數據解密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.DECRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 解密<br> * 用私鑰解密 * * @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> * 用公鑰解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decryptByPublicKey(byte[] data, String key) throws Exception { // 對密鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得公鑰 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicKey = keyFactory.generatePublic(x509KeySpec); // 對數據解密 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(String 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); // 對數據加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, publicKey); return cipher.doFinal(data.getBytes()); } /** * 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 { // 對密鑰解密 byte[] keyBytes = decryptBASE64(key); // 取得私鑰 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec); // 對數據加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); cipher.init(Cipher.ENCRYPT_MODE, privateKey); return cipher.doFinal(data); } /** * 取得私鑰 * * @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()); } /** * 取得公鑰 * * @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()); } /** * 初始化密鑰 * * @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());// 公鑰 keyMap.put(PRIVATE_KEY, keyPair.getPrivate());// 私鑰 return keyMap; } public static void main(String[] args) throws Exception { Map<String, Key> keyMap = initKey(); String publicKey = getPublicKey(keyMap); String privateKey = getPrivateKey(keyMap); System.out.println(keyMap); System.out.println("-----------------------------------"); System.out.println(publicKey); System.out.println("-----------------------------------"); System.out.println(privateKey); System.out.println("-----------------------------------"); byte[] encryptByPrivateKey = encryptByPrivateKey("123456".getBytes(),privateKey); byte[] encryptByPublicKey = encryptByPublicKey("123456",publicKey); System.out.println(new String(encryptByPrivateKey)); System.out.println("-----------------------------------"); System.out.println(new String(encryptByPublicKey)); System.out.println("-----------------------------------"); String sign = sign(encryptByPrivateKey,privateKey); System.out.println(sign); System.out.println("-----------------------------------"); boolean verify = verify(encryptByPrivateKey,publicKey,sign); System.out.println(verify); System.out.println("-----------------------------------"); byte[] decryptByPublicKey = decryptByPublicKey(encryptByPrivateKey,publicKey); byte[] decryptByPrivateKey = decryptByPrivateKey(encryptByPublicKey,privateKey); System.out.println(new String(decryptByPublicKey)); System.out.println("-----------------------------------"); System.out.println(new String(decryptByPrivateKey)); } }
RSA加密算法--Java實現詳細案例: