| /* |
| * ==================================================================== |
| * 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.poi.poifs.crypt.temp; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.security.SecureRandom; |
| |
| import javax.crypto.Cipher; |
| import javax.crypto.CipherInputStream; |
| import javax.crypto.CipherOutputStream; |
| import javax.crypto.spec.SecretKeySpec; |
| |
| import org.apache.poi.poifs.crypt.ChainingMode; |
| import org.apache.poi.poifs.crypt.CipherAlgorithm; |
| import org.apache.poi.poifs.crypt.CryptoFunctions; |
| import org.apache.poi.util.Beta; |
| import org.apache.poi.util.Internal; |
| import org.apache.poi.util.POILogFactory; |
| import org.apache.poi.util.POILogger; |
| import org.apache.poi.util.TempFile; |
| |
| /** |
| * EncryptedTempData can be used to buffer binary data in a secure way, by using encrypted temp files. |
| */ |
| @Beta |
| public class EncryptedTempData { |
| private static POILogger LOG = POILogFactory.getLogger(EncryptedTempData.class); |
| |
| private final static CipherAlgorithm cipherAlgorithm = CipherAlgorithm.aes128; |
| private final SecretKeySpec skeySpec; |
| private final byte[] ivBytes; |
| private final File tempFile; |
| |
| public EncryptedTempData() throws IOException { |
| SecureRandom sr = new SecureRandom(); |
| ivBytes = new byte[16]; |
| byte[] keyBytes = new byte[16]; |
| sr.nextBytes(ivBytes); |
| sr.nextBytes(keyBytes); |
| skeySpec = new SecretKeySpec(keyBytes, cipherAlgorithm.jceId); |
| tempFile = TempFile.createTempFile("poi-temp-data", ".tmp"); |
| } |
| |
| public OutputStream getOutputStream() throws IOException { |
| Cipher ciEnc = CryptoFunctions.getCipher(skeySpec, cipherAlgorithm, ChainingMode.cbc, ivBytes, Cipher.ENCRYPT_MODE, null); |
| return new CipherOutputStream(new FileOutputStream(tempFile), ciEnc); |
| } |
| |
| public InputStream getInputStream() throws IOException { |
| Cipher ciDec = CryptoFunctions.getCipher(skeySpec, cipherAlgorithm, ChainingMode.cbc, ivBytes, Cipher.DECRYPT_MODE, null); |
| return new CipherInputStream(new FileInputStream(tempFile), ciDec); |
| } |
| |
| public void dispose() { |
| if (!tempFile.delete()) { |
| LOG.log(POILogger.WARN, tempFile.getAbsolutePath()+" can't be removed (or was already removed."); |
| } |
| } |
| } |