| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.ki.crypto; |
| |
| import java.security.InvalidKeyException; |
| import java.security.Key; |
| import java.security.NoSuchAlgorithmException; |
| import java.util.Arrays; |
| import javax.crypto.KeyGenerator; |
| import javax.crypto.spec.SecretKeySpec; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.ki.codec.Base64; |
| import org.apache.ki.codec.CodecSupport; |
| |
| |
| /** |
| * Ki's default symmetric block Cipher using the Blowfish algorithm. As it is a symmetric Cipher, it uses the |
| * same <tt>Key</tt> to both encrypt and decrypt data. If one is not provided via the {@link #setKey setKey} method, |
| * a default one will be used, BUT NOTE: |
| * |
| * <p>Because Ki is an open-source project, if anyone knew that you were using Ki's default |
| * <code>Key</code>, they could download/view the source, and with enough effort, reconstruct the <code>Key</code> |
| * and decode encrypted data at will. |
| * |
| * <p>Ki only really uses Ciphers to encrypt user ids and session ids, so if that information is not critical |
| * to you and you think the default key still makes things 'sufficiently difficult', then you can ignore this issue. |
| * |
| * <p>However, if you do feel this constitutes sensitive information, it is recommended that you provide your own |
| * <tt>Key</tt> via the {@link #setKey setKey} method to a Key known only to your application, |
| * guaranteeing that no third party can decrypt your data. If you want to know how to do this, you can browse this |
| * class's source code for the {@link #generateNewKey()} method to see how we created our default. Then you can |
| * duplicate the same in your environment and set the result on an instance of this class via the |
| * <code>setKey</code> method. |
| * |
| * @author Les Hazlewood |
| * @author Jeremy Haile |
| * @since 0.9 |
| */ |
| public class BlowfishCipher implements Cipher { |
| |
| /** |
| * The JDK Crypto Cipher algorithm to use for this class, equal to "Blowfish". |
| */ |
| private static final String ALGORITHM = "Blowfish"; |
| |
| /** |
| * The JDK Crypto Transformation string to use for this class, equal to {@link #ALGORITHM ALGORITHM} + "/ECB/PKCS5Padding"; |
| */ |
| private static final String TRANSFORMATION_STRING = ALGORITHM + "/ECB/PKCS5Padding"; |
| |
| //The following KEY_BYTES String was created by running |
| //System.out.println( Base64.encode( generateNewKey().getEncoded() ) ); and copying-n-pasting the output here. |
| //You should run the same and set the resulting output as a property of this class instead of using |
| //Ki's default Key for proper security. |
| private static final byte[] KEY_BYTES = Base64.decode("jJ9Kg1BAevbvhSg3vBfwfQ=="); |
| private static final Key DEFAULT_CIPHER_KEY = new SecretKeySpec(KEY_BYTES, ALGORITHM); |
| |
| /** |
| * Internal private log instance. |
| */ |
| private static final Logger log = LoggerFactory.getLogger(BlowfishCipher.class); |
| |
| /** |
| * The key to use by default, can be overridden by calling {@link #setKey(java.security.Key)}. |
| */ |
| private Key key = DEFAULT_CIPHER_KEY; |
| |
| /** |
| * Default no argument constructor that uses an internal default {@link #getKey() key} to use during |
| * encryption and decryption. For propery security, you should definitely supply your own key by using the |
| * {@link #setKey(java.security.Key) setKey(Key)} method. |
| */ |
| public BlowfishCipher() { |
| } |
| |
| /** |
| * Returns the default {@link Key Key} to use for symmetric encryption and decryption if one is not specified during |
| * encryption/decryption. For truly secure applications, |
| * you should always specify your own key via the {@link #setKey(java.security.Key) setKey} method. |
| * |
| * @return the {@link Key Key} to use for symmetric encryption and decryption. |
| * @see #encrypt(byte[], byte[]) |
| * @see #decrypt(byte[], byte[]) |
| */ |
| public Key getKey() { |
| return key; |
| } |
| |
| /** |
| * Sets the internal default {@link Key Key} to use for symmetric encryption and decryption if one is not |
| * specified during encryption/decryption. For truly secure applications, you should always specify your own |
| * key via this method. |
| * |
| * @param key the key to use for symmetric encryption and decryption. |
| * @see #encrypt(byte[], byte[]) |
| * @see #decrypt(byte[], byte[]) |
| */ |
| public void setKey(Key key) { |
| this.key = key; |
| } |
| |
| /** |
| * Encrypts the specified raw byte array. If the <code>key</code> argument is null, the internal default |
| * {@link #getKey() key} will be used to encrypt the byte array. |
| */ |
| public byte[] encrypt(byte[] raw, byte[] key) { |
| byte[] encrypted = crypt(raw, javax.crypto.Cipher.ENCRYPT_MODE, key); |
| if (log.isTraceEnabled()) { |
| log.trace("Incoming byte array of size " + (raw != null ? raw.length : 0) + ". Encrypted " + |
| "byte array is size " + (encrypted != null ? encrypted.length : 0)); |
| } |
| return encrypted; |
| } |
| |
| /** |
| * Decrypts the specified already-encrypted byte array. If the <code>key</code> argument is null, the internal default |
| * {@link #getKey() key} will be used to encrypt the byte array. |
| */ |
| public byte[] decrypt(byte[] encrypted, byte[] key) { |
| if (log.isTraceEnabled()) { |
| log.trace("Attempting to decrypt incoming byte array of length " + |
| (encrypted != null ? encrypted.length : 0)); |
| } |
| return crypt(encrypted, javax.crypto.Cipher.DECRYPT_MODE, key); |
| } |
| |
| /** |
| * Returns a new {@link javax.crypto.Cipher Cipher} instance to use for encryption/decryption operations, based on |
| * the {@link #TRANSFORMATION_STRING TRANSFORMATION_STRING} constant. |
| * |
| * @return a new Cipher instance. |
| * @throws IllegalStateException if a new Cipher instance cannot be constructed based on the |
| * {@link #TRANSFORMATION_STRING TRANSFORMATION_STRING} constant. |
| */ |
| protected javax.crypto.Cipher newCipherInstance() throws IllegalStateException { |
| try { |
| return javax.crypto.Cipher.getInstance(TRANSFORMATION_STRING); |
| } catch (Exception e) { |
| String msg = "Unable to acquire a Java JCE Cipher instance using " + |
| javax.crypto.Cipher.class.getName() + ".getInstance( \"" + TRANSFORMATION_STRING + "\" ). " + |
| "Blowfish under this configuration is required for the " + |
| getClass().getName() + " instance to function."; |
| throw new IllegalStateException(msg, e); |
| } |
| } |
| |
| /** |
| * Initializes the JDK Cipher with the specified mode and key. This is primarily a utility method to catch any |
| * potential {@link InvalidKeyException InvalidKeyException} that might arise. |
| * |
| * @param cipher the JDK Cipher to {@link javax.crypto.Cipher#init(int, java.security.Key) init}. |
| * @param mode the Cipher mode |
| * @param key the Cipher's Key |
| */ |
| protected void init(javax.crypto.Cipher cipher, int mode, java.security.Key key) { |
| try { |
| cipher.init(mode, key); |
| } catch (InvalidKeyException e) { |
| String msg = "Unable to init cipher."; |
| throw new IllegalStateException(msg, e); |
| } |
| } |
| |
| /** |
| * Calls the {@link javax.crypto.Cipher#doFinal(byte[]) doFinal(bytes)} method, propagating any exception that |
| * might arise in an {@link IllegalStateException IllegalStateException} |
| * |
| * @param cipher the JDK Cipher to finalize (perform the actual cryption) |
| * @param bytes the bytes to crypt |
| * @return the resulting crypted byte array. |
| */ |
| protected byte[] crypt(javax.crypto.Cipher cipher, byte[] bytes) { |
| try { |
| return cipher.doFinal(bytes); |
| } catch (Exception e) { |
| String msg = "Unable to crypt bytes with cipher [" + cipher + "]."; |
| throw new IllegalStateException(msg, e); |
| } |
| } |
| |
| /** |
| * Calls the {@link #init(javax.crypto.Cipher, int, java.security.Key)} and then |
| * {@link #crypt(javax.crypto.Cipher, byte[])}. Ensures that the key is never null by using the |
| * {@link #getKey() default key} if the method argument key is <code>null</code>. |
| * |
| * @param bytes the bytes to crypt |
| * @param mode the JDK Cipher mode |
| * @param key the key to use to do the cryption. If <code>null</code> the {@link #getKey() default key} will be used. |
| * @return the resulting crypted byte array |
| */ |
| protected byte[] crypt(byte[] bytes, int mode, byte[] key) { |
| javax.crypto.Cipher cipher = newCipherInstance(); |
| |
| java.security.Key jdkKey; |
| if (key == null) { |
| jdkKey = getKey(); |
| } else { |
| jdkKey = new SecretKeySpec(key, ALGORITHM); |
| } |
| |
| init(cipher, mode, jdkKey); |
| return crypt(cipher, bytes); |
| } |
| |
| /** |
| * Generates a new {@link Key Key} suitable for this Cipher by calling |
| * {@link #generateNewKey(int) generateNewKey(128)} (uses a 128 bit size by default). |
| * |
| * @return a new {@link Key Key}, 128 bits in length. |
| */ |
| public static Key generateNewKey() { |
| return generateNewKey(128); |
| } |
| |
| /** |
| * Generates a new {@link Key Key} of the specified size suitable for this Cipher |
| * (based on the {@link #ALGORITHM ALGORITHM} using the JDK {@link KeyGenerator KeyGenerator}. |
| * |
| * @param keyBitSize the bit size of the key to create |
| * @return the created key suitable for use with this Cipher. |
| */ |
| public static Key generateNewKey(int keyBitSize) { |
| KeyGenerator kg; |
| try { |
| kg = KeyGenerator.getInstance(ALGORITHM); |
| } catch (NoSuchAlgorithmException e) { |
| String msg = "Unable to acquire " + ALGORITHM + " algorithm. This is required to function."; |
| throw new IllegalStateException(msg, e); |
| } |
| kg.init(keyBitSize); |
| return kg.generateKey(); |
| } |
| |
| /** |
| * Simple test main method to ensure functionality is correct. Should really be moved to a proper test case. |
| * |
| * @param unused ignored |
| * @throws Exception if anything unexpected happens. |
| */ |
| public static void main(String[] unused) throws Exception { |
| |
| Cipher cipher = new BlowfishCipher(); |
| |
| String[] cleartext = new String[]{ |
| "Hello, this is a test.", |
| "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua." |
| }; |
| |
| for (String clear : cleartext) { |
| byte[] cleartextBytes = CodecSupport.toBytes(clear); |
| System.out.println("Clear text: [" + clear + "]"); |
| System.out.println("Clear text base64: [" + Base64.encodeToString(cleartextBytes) + "]"); |
| |
| byte[] encrypted = cipher.encrypt(cleartextBytes, null); |
| String encryptedBase64 = Base64.encodeToString(encrypted); |
| System.out.println("Encrypted base64: [" + encryptedBase64 + "]"); |
| |
| byte[] decrypted = cipher.decrypt(Base64.decode(encryptedBase64), null); |
| String decryptedString = CodecSupport.toString(decrypted); |
| |
| System.out.println("Arrays equal? " + Arrays.equals(cleartextBytes, decrypted)); |
| |
| System.out.println("Decrypted text: [" + decryptedString + "]"); |
| System.out.println("Decrypted text base64: [" + Base64.encodeToString(decrypted) + "]"); |
| } |
| } |
| } |