| /* |
| * 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.shiro.crypto; |
| |
| import javax.crypto.spec.GCMParameterSpec; |
| import java.security.spec.AlgorithmParameterSpec; |
| |
| /** |
| * {@code CipherService} using the {@code AES} cipher algorithm for all encryption, decryption, and key operations. |
| * <p/> |
| * The AES algorithm can support key sizes of {@code 128}, {@code 192} and {@code 256} bits<b>*</b>. This implementation |
| * defaults to 128 bits. |
| * <p/> |
| * Note that this class retains changes the parent class's default {@link OperationMode#CBC CBC} mode to {@link OperationMode#GCM GCM} of operation |
| * instead of the typical JDK default of {@link OperationMode#ECB ECB}. {@code ECB} should not be used in |
| * security-sensitive environments because {@code ECB} does not allow for initialization vectors, which are |
| * considered necessary for strong encryption. See the {@link DefaultBlockCipherService parent class}'s JavaDoc and the |
| * {@link JcaCipherService JcaCipherService} JavaDoc for more on why the JDK default should not be used and is not |
| * used in this implementation. |
| * <p/> |
| * <b>*</b> Generating and using AES key sizes greater than 128 require installation of the |
| * <a href="http://java.sun.com/javase/downloads/index.jsp">Java Cryptography Extension (JCE) Unlimited Strength |
| * Jurisdiction Policy files</a>. |
| * |
| * @since 1.0 |
| */ |
| public class AesCipherService extends DefaultBlockCipherService { |
| |
| private static final String ALGORITHM_NAME = "AES"; |
| |
| /** |
| * Creates a new {@link CipherService} instance using the {@code AES} cipher algorithm with the following |
| * important cipher default attributes: |
| * <table> |
| * <tr> |
| * <th>Attribute</th> |
| * <th>Value</th> |
| * </tr> |
| * <tr> |
| * <td>{@link #setKeySize keySize}</td> |
| * <td>{@code 128} bits</td> |
| * </tr> |
| * <tr> |
| * <td>{@link #setBlockSize blockSize}</td> |
| * <td>{@code 128} bits (required for {@code AES}</td> |
| * </tr> |
| * <tr> |
| * <td>{@link #setMode mode}</td> |
| * <td>{@link OperationMode#GCM GCM}<b>*</b></td> |
| * </tr> |
| * <tr> |
| * <td>{@link #setPaddingScheme paddingScheme}</td> |
| * <td>{@link PaddingScheme#PKCS5 PKCS5}</td> |
| * </tr> |
| * <tr> |
| * <td>{@link #setInitializationVectorSize(int) initializationVectorSize}</td> |
| * <td>{@code 128} bits</td> |
| * </tr> |
| * <tr> |
| * <td>{@link #setGenerateInitializationVectors(boolean) generateInitializationVectors}</td> |
| * <td>{@code true}<b>**</b></td> |
| * </tr> |
| * </table> |
| * <p/> |
| * <b>*</b> The {@link OperationMode#GCM GCM} operation mode is used instead of the JDK default {@code ECB} to |
| * ensure strong encryption. {@code ECB} should not be used in security-sensitive environments - see the |
| * {@link DefaultBlockCipherService DefaultBlockCipherService} class JavaDoc's "Operation Mode" section |
| * for more. |
| * <p/> |
| * <b>**</b>In conjunction with the default {@code GCM} operation mode, initialization vectors are generated by |
| * default to ensure strong encryption. See the {@link JcaCipherService JcaCipherService} class JavaDoc for more. |
| */ |
| public AesCipherService() { |
| super(ALGORITHM_NAME); |
| setMode(OperationMode.GCM); |
| setStreamingMode(OperationMode.GCM); |
| } |
| |
| @Override |
| protected AlgorithmParameterSpec createParameterSpec(byte[] iv, boolean streaming) { |
| |
| if ((streaming && OperationMode.GCM.name().equals(getStreamingModeName())) |
| || (!streaming && OperationMode.GCM.name().equals(getModeName()))) { |
| return new GCMParameterSpec(getKeySize(), iv); |
| } |
| |
| return super.createParameterSpec(iv, streaming); |
| } |
| } |