| /* ==================================================================== |
| 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.hslf.record; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.Map; |
| |
| import org.apache.poi.poifs.crypt.CipherAlgorithm; |
| import org.apache.poi.poifs.crypt.EncryptionInfo; |
| import org.apache.poi.poifs.crypt.EncryptionMode; |
| import org.apache.poi.poifs.crypt.HashAlgorithm; |
| import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIEncryptionHeader; |
| import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIEncryptionVerifier; |
| import org.apache.poi.util.LittleEndian; |
| import org.apache.poi.util.LittleEndianByteArrayOutputStream; |
| import org.apache.poi.util.LittleEndianInputStream; |
| |
| /** |
| * A Document Encryption Atom (type 12052). Holds information |
| * on the Encryption of a Document |
| * |
| * @author Nick Burch |
| */ |
| public final class DocumentEncryptionAtom extends PositionDependentRecordAtom { |
| private static final long _type = 12052l; |
| private final byte[] _header; |
| private EncryptionInfo ei; |
| |
| /** |
| * For the Document Encryption Atom |
| */ |
| protected DocumentEncryptionAtom(byte[] source, int start, int len) throws IOException { |
| // Get the header |
| _header = new byte[8]; |
| System.arraycopy(source,start,_header,0,8); |
| |
| ByteArrayInputStream bis = new ByteArrayInputStream(source, start+8, len-8); |
| LittleEndianInputStream leis = new LittleEndianInputStream(bis); |
| ei = new EncryptionInfo(leis, EncryptionMode.cryptoAPI); |
| leis.close(); |
| } |
| |
| public DocumentEncryptionAtom() { |
| _header = new byte[8]; |
| LittleEndian.putShort(_header, 0, (short)0x000F); |
| LittleEndian.putShort(_header, 2, (short)_type); |
| // record length not yet known ... |
| |
| ei = new EncryptionInfo(EncryptionMode.cryptoAPI); |
| } |
| |
| /** |
| * Initializes the encryption settings |
| * |
| * @param keyBits see {@link CipherAlgorithm#rc4} for allowed values, use -1 for default size |
| */ |
| public void initializeEncryptionInfo(int keyBits) { |
| ei = new EncryptionInfo(EncryptionMode.cryptoAPI, CipherAlgorithm.rc4, HashAlgorithm.sha1, keyBits, -1, null); |
| } |
| |
| /** |
| * Return the length of the encryption key, in bits |
| */ |
| public int getKeyLength() { |
| return ei.getHeader().getKeySize(); |
| } |
| |
| /** |
| * Return the name of the encryption provider used |
| */ |
| public String getEncryptionProviderName() { |
| return ei.getHeader().getCspName(); |
| } |
| |
| /** |
| * @return the {@link EncryptionInfo} object for details about encryption settings |
| */ |
| public EncryptionInfo getEncryptionInfo() { |
| return ei; |
| } |
| |
| |
| /** |
| * We are of type 12052 |
| */ |
| public long getRecordType() { return _type; } |
| |
| /** |
| * Write the contents of the record back, so it can be written |
| * to disk |
| */ |
| public void writeOut(OutputStream out) throws IOException { |
| |
| // Data |
| byte data[] = new byte[1024]; |
| LittleEndianByteArrayOutputStream bos = new LittleEndianByteArrayOutputStream(data, 0); |
| bos.writeShort(ei.getVersionMajor()); |
| bos.writeShort(ei.getVersionMinor()); |
| bos.writeInt(ei.getEncryptionFlags()); |
| |
| ((CryptoAPIEncryptionHeader)ei.getHeader()).write(bos); |
| ((CryptoAPIEncryptionVerifier)ei.getVerifier()).write(bos); |
| |
| // Header |
| LittleEndian.putInt(_header, 4, bos.getWriteIndex()); |
| out.write(_header); |
| out.write(data, 0, bos.getWriteIndex()); |
| bos.close(); |
| } |
| |
| @Override |
| public void updateOtherRecordReferences(Map<Integer,Integer> oldToNewReferencesLookup) { |
| // nothing to update |
| } |
| } |