一、 非对称密钥加密算法RSA
非对称密钥算法需要一对密钥:公开密钥和私有密钥。利用公开密钥进行加密后的信息,只有用对应的私有密钥才能解密。因为加密和解密用的密钥是不一样的,因此,公开密钥是公开的,供所有人使用,并且不会威胁到传递信息和解密密钥的安全,不需要对密钥传递的额外保护。首先,提供RSA的密钥生成算法,生成公有密钥和私有密钥存入文件中:且看 RSAKeyCreater.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class RSAKeyCreater { 6. 7. /** 8. * @param args 9. * @throws Exception 10. */ 11. public static void main(String[] args) throws Exception { 12. RSAKeyCreater rSAKeyCreater = new RSAKeyCreater(); 13. rSAKeyCreater.createKeyFile(512, System.getProperty("user.dir")); 14. } 15. 16. public void createKeyFile(int in, String url) throws Exception { 17. KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA"); 18. kpg.initialize(in); 19. KeyPair kp = kpg.genKeyPair(); 20. PublicKey publicKey = kp.getPublic(); 21. PrivateKey privateKey = kp.getPrivate(); 22. 23. File file1 = new File(url + "/src/main/resources/public_key_file.rsa"); 24. FileOutputStream publicOut = new FileOutputStream(file1); 25. ObjectOutputStream publicObjectOutput = new ObjectOutputStream(publicOut); 26. publicObjectOutput.writeObject(publicKey); 27. publicObjectOutput.flush(); 28. publicObjectOutput.close(); 29. 30. File file2 = new File(url + "/src/main/resources/private_key_file.rsa"); 31. FileOutputStream privateOut = new FileOutputStream(file2); 32. ObjectOutputStream privateObjectOutput = new ObjectOutputStream(privateOut); 33. privateObjectOutput.writeObject(privateKey); 34. privateObjectOutput.flush(); 35. privateObjectOutput.close(); 36. } 37.}
RSAKeyCreater类中createKeyFile()方法生成公钥和私钥分别保存到public_key_file.rsa和private_key_file.rsa文件中,加密和解密时进行使用。
其次,提供加密解密算法,对byte[] 进行加密和解密:且看RSAEncryptionUtil.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class AESEncryptionUtil { 6. /** 7. * 加密 8. * @param bytes 9. * @param aesKey 10. * @return 11. */ 12. public static byte[] encryptMessage(byte[] bytes, String aesKey) { 13. try { 14. Object obj = KeyUtil.getKey(aesKey); 15. SecretKey key = (SecretKey) obj; 16. Cipher cipher = Cipher.getInstance("AES"); 17. cipher.init(Cipher.ENCRYPT_MODE, key); 18. byte[] decryptedBytes = cipher.doFinal(bytes); 19. return decryptedBytes; 20. } catch (Exception e) { 21. e.printStackTrace(); 22. return null; 23. } 24. } 25. 26. /** 27. * 解密 28. * @param encryptedBytes 29. * @param aesKey 30. * @return 31. */ 32. public static byte[] decryptMessage(byte[] encryptedBytes, String aesKey) { 33. try { 34. Object obj = KeyUtil.getKey(aesKey); 35. SecretKey key = (SecretKey) obj; 36. Cipher cipher = Cipher.getInstance("AES"); 37. cipher.init(Cipher.DECRYPT_MODE, key); 38. byte[] bytes = cipher.doFinal(encryptedBytes); 39. return bytes; 40. } catch (Exception e) { 41. e.printStackTrace(); 42. return null; 43. } 44. } 45.}
RSAEncryptionUtil的encryptWithPublicKey()方法对信息进行加
密,decryptWithPrivateKey()方法对加密后的信息进行解密,分别需要传入公有和私有密钥。
由于提供的算法是对byte[]数组进行加密和解密返回新的byte[],因此我们需要提供一个普通object对象到byte[]之间转化的工具:且看SerializationUtil.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class SerializationUtil { 6. 7. public static byte[] serialize(Object obj) { 8. try { 9. if (obj == null) 10. throw new NullPointerException(); 11. 12. ByteArrayOutputStream os = new ByteArrayOutputStream(); 13. ObjectOutputStream out = new ObjectOutputStream(os); 14. out.writeObject(obj); 15. out.flush(); 16. out.close(); 17. return os.toByteArray(); 18. } catch (Exception e) { 19. e.printStackTrace(); 20. return null; 21. } 22. } 23. 24. public static Object deserialize(byte[] by) { 25. try { 26. if (by == null) 27. throw new NullPointerException(); 28. 29. ByteArrayInputStream is = new ByteArrayInputStream(by); 30. ObjectInputStream in = new ObjectInputStream(is); 31. Object obj = in.readObject(); 32. in.close(); 33. return obj; 34. } catch (Exception e) { 35. e.printStackTrace(); 36. return null; 37. } 38. } 39.}
SerializationUtil类中的serialize()方法将普通java对象序列化成byte[],deserialize()方法将byte[]反序列化成原来的对象。
RSA加密算法有个特点,就是对加密明文和密文的长度有限制,当我们加密的明文过长时,我们需要对明文分块进行加密,因此那种长度较短的信息进行加密适合使用RSA算法。一般来说,我们进行加密的对象序列化成byte[]数组之后长度都超过了RSA加密算法的要求,因此我们可以选用另一种加密算法:AES。
二、 对称密钥加密算法AES
对称密钥算法中,信息的加密和解密都是使用相同的密钥,使用起来简单,速度快,但在使用之前,需要通过额外安全的途径交换加密密钥。首先,提供AES密钥生成算法,生成密钥保存在文件中,且看AESKeyCreater.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class AESKeyCreater { 6. 7. /** 8. * @param args 9. */ 10. public static void main(String[] args) throws Exception{ 11. String url = System.getProperty("user.dir"); 12. AESKeyCreater aESKeyCreater = new AESKeyCreater(); 13. aESKeyCreater.createKeyFile(url); 14. } 15. 16. public void createKeyFile(String url) throws Exception{ 17. Security.addProvider(new SunJCE()); 18. KeyGenerator keygen = KeyGenerator.getInstance("AES"); 19. SecretKey key = keygen.generateKey(); 20. File file = new File(url + "/src/main/resources/AES_Secret_Key_File.aes"); 21. FileOutputStream out = new FileOutputStream(file); 22. ObjectOutputStream objectOutput = new ObjectOutputStream(out); 23. objectOutput.writeObject(key); 24. objectOutput.flush(); 25. objectOutput.close(); 26. } 27.}
AESKeyCreater类中createKeyFile()方法生成AES算法的密钥,保存在AES_Secret_Key_File.aes文件中,供加密和解密时使用。
其次,提供加密解密算法,对byte[] 进行加密和解密:且看AESEncryptionUtil.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class AESEncryptionUtil { 6. /** 7. * 加密 8. * @param bytes 9. * @param aesKey 10. * @return 11. */ 12. public static byte[] encryptMessage(byte[] bytes, String aesKey) { 13. try { 14. Object obj = KeyUtil.getKey(aesKey); 15. SecretKey key = (SecretKey) obj; 16. Cipher cipher = Cipher.getInstance("AES"); 17. cipher.init(Cipher.ENCRYPT_MODE, key); 18. byte[] decryptedBytes = cipher.doFinal(bytes); 19. return decryptedBytes; 20. } catch (Exception e) { 21. e.printStackTrace(); 22. return null; 23. } 24. } 25. 26. /** 27. * 解密 28. * @param encryptedBytes 29. * @param aesKey 30. * @return 31. */ 32. public static byte[] decryptMessage(byte[] encryptedBytes, String aesKey) { 33. try { 34. Object obj = KeyUtil.getKey(aesKey); 35. SecretKey key = (SecretKey) obj; 36. Cipher cipher = Cipher.getInstance("AES"); 37. cipher.init(Cipher.DECRYPT_MODE, key); 38. byte[] bytes = cipher.doFinal(encryptedBytes); 39. return bytes; 40. } catch (Exception e) { 41. e.printStackTrace(); 42. return null; 43. } 44. } 45.}
AESEncryptionUtil类中encryptMessage()方法对信息进行加密,decryptMessage()方法对信息进行解密,都需要传入AES密钥文件。由于都是对byte[]数组进行加密和解密,因此也需要RSA算法中提供的普通Object对象和byte[]之间的映射工具。
下面给出AES算法对hessian进行加密和解密传输,思路:客户端通过Hessian工厂获取到Hessian服务之后,将传入参数对象序列化成byte[],然后对byte[]进行加密,然后调用hessian服务的方法,服务端获取到客户端传过来的加密之后的byte[]参数,首先进行AES解密,然后将byte[]反序列化成参数对象,再调用相应的业务逻辑,再然后将返回结果进行序列化成byte[],然后进行AES加密,然后客户端获得返回结果之后进行AES解密,然后反序列化成结果对象,至此一轮调用完成。且看hessian服务接口:EncryptionService.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public interface EncryptionService { 6. 7. public static final String publicKeyFile = EncryptionService.class.getResource("/").getPath() + "/public_key_file.rsa"; 8. public static final String privateKeyFile = EncryptionService.class.getResource("/").getPath() + "/private_key_file.rsa"; 9. public static final String aesKeyFile = EncryptionService.class.getResource("/").getPath() + "AES_Secret_Key_File.aes"; 10. 11. public byte[] testHessianEncrypt(byte[] encryptedBytes); 12. 13.}
由于hessian是一个二进制协议,非常适合传输二进制数据,以byte[]作为参数和返回结果是非常合适的,将来这部分完全可以做在框架之中。且看hessian服务实现类:EncryptionServiceImpl.java
1./** 2. * @author zhangwei 3. * 4. */ 5.public class EncryptionServiceImpl implements EncryptionService{ 6. 7. public byte[] testHessianEncrypt(byte[] encryptedBytes) { 8. //解密参数 9. byte[] decryptedBytes = AESEncryptionUtil.decryptMessage(encryptedBytes, aesKeyFile); 10. //将参数反序列化 11. Secret secret = (Secret)SerializationUtil.deserialize(decryptedBytes); 12. //业务逻辑 13. System.out.println(secret.getMessage()); 14. secret.setMessage("I love you too!"); 15. System.out.println(secret.getMessage()); 16. //将结果序列化 17. byte[] returnBytes = SerializationUtil.serialize(secret); 18. //加密返回结果 19. byte[] encryptedReturnBytes = AESEncryptionUtil.encryptMessage(returnBytes,aesKeyFile); 20. return encryptedReturnBytes; 21. } 22.}
代码一目了然,没啥好说的。且看客户端调用:TestClient.java
1./**
2. * @author zhangwei
3. *
4. */
5.public class TestClient {
6. 7. /** 8. * @param args 9. * @throws MalformedURLException 10. */ 11. public static void main(String[] args) throws MalformedURLException { 12. String hessianServiceUrl = "http://localhost:8089/HessianEncryption/hessianService"; 13. String aesKeyFile = System.getProperty("user.dir") + "/lib/AES_Secret_Key_File.aes"; 14. 15. HessianProxyFactory factory = new HessianProxyFactory(); 16. EncryptionService service = (EncryptionService)factory.create(EncryptionService.class, hessianServiceUrl); 17. Secret secret = new Secret(); 18. secret.setMessage("I love you!"); 19. System.out.println(secret.getMessage()); 20. //序列化參數 21. byte[] paramBytes = SerializationUtil.serialize(secret); 22. //加密參數 23. byte[] encryptedParamBytes = AESEncryptionUtil.encryptMessage(paramBytes, aesKeyFile); 24. //調用方法 25. byte[] encryptedReturnBytes = service.testHessianEncrypt(encryptedParamBytes); 26. //解密返回結果 27. byte[] decryptedReturnBytes = AESEncryptionUtil.decryptMessage(encryptedReturnBytes, aesKeyFile); 28. //反序列化結果 29. Secret returnResult = (Secret)SerializationUtil.deserialize(decryptedReturnBytes); 30. System.out.println(returnResult.getMessage()); 31. } 32. 33.}
【转载地址】http://zwustudy.iteye.com/blog/1679850