poi/src/java/org/apache/poi/hssf/record/FilePassRecord.java

/* ====================================================================
   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.hssf.record;

import java.io.IOException;

import org.apache.poi.EncryptedDocumentException;
import org.apache.poi.poifs.crypt.EncryptionInfo;
import org.apache.poi.poifs.crypt.EncryptionMode;
import org.apache.poi.poifs.crypt.binaryrc4.BinaryRC4EncryptionHeader;
import org.apache.poi.poifs.crypt.binaryrc4.BinaryRC4EncryptionVerifier;
import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIEncryptionHeader;
import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIEncryptionVerifier;
import org.apache.poi.poifs.crypt.xor.XOREncryptionHeader;
import org.apache.poi.poifs.crypt.xor.XOREncryptionVerifier;
import org.apache.poi.util.HexDump;
import org.apache.poi.util.LittleEndianByteArrayOutputStream;
import org.apache.poi.util.LittleEndianOutput;

/**
 * Title: File Pass Record (0x002F) <p>
 *
 * Description: Indicates that the record after this record are encrypted.
 */
public final class FilePassRecord extends StandardRecord implements Cloneable {
	public static final short sid = 0x002F;
    private static final int ENCRYPTION_XOR = 0;
    private static final int ENCRYPTION_OTHER = 1;
	
	private int encryptionType;
    private EncryptionInfo encryptionInfo;
    private int dataLength;
	
	private FilePassRecord(FilePassRecord other) {
	    dataLength = other.dataLength;
	    encryptionType = other.encryptionType;
        try {
            encryptionInfo = other.encryptionInfo.clone();
        } catch (CloneNotSupportedException e) {
            throw new EncryptedDocumentException(e);
        }
	}
	
	public FilePassRecord(RecordInputStream in) {
        dataLength = in.remaining();
		encryptionType = in.readUShort();
		
		EncryptionMode preferredMode;
        switch (encryptionType) {
            case ENCRYPTION_XOR:
                preferredMode = EncryptionMode.xor;
                break;
            case ENCRYPTION_OTHER:
                preferredMode = EncryptionMode.cryptoAPI;
                break;
            default:
                throw new EncryptedDocumentException("invalid encryption type");
        }
		
		try {
            encryptionInfo = new EncryptionInfo(in, preferredMode);
        } catch (IOException e) {
            throw new EncryptedDocumentException(e);
        }
	}

	public void serialize(LittleEndianOutput out) {
        out.writeShort(encryptionType);

        byte data[] = new byte[1024];
        LittleEndianByteArrayOutputStream bos = new LittleEndianByteArrayOutputStream(data, 0);

        switch (encryptionInfo.getEncryptionMode()) {
            case xor:
                ((XOREncryptionHeader)encryptionInfo.getHeader()).write(bos);
                ((XOREncryptionVerifier)encryptionInfo.getVerifier()).write(bos);
                break;
            case binaryRC4:
                out.writeShort(encryptionInfo.getVersionMajor());
                out.writeShort(encryptionInfo.getVersionMinor());
                ((BinaryRC4EncryptionHeader)encryptionInfo.getHeader()).write(bos);
                ((BinaryRC4EncryptionVerifier)encryptionInfo.getVerifier()).write(bos);
                break;
            case cryptoAPI:
                out.writeShort(encryptionInfo.getVersionMajor());
                out.writeShort(encryptionInfo.getVersionMinor());
                ((CryptoAPIEncryptionHeader)encryptionInfo.getHeader()).write(bos);
                ((CryptoAPIEncryptionVerifier)encryptionInfo.getVerifier()).write(bos);
                break;
            default:
                throw new RuntimeException("not supported");
        }

        out.write(data, 0, bos.getWriteIndex());
	}

	protected int getDataSize() {
	    return dataLength;
	}

	public EncryptionInfo getEncryptionInfo() {
        return encryptionInfo;
    }

    public short getSid() {
		return sid;
	}
	
	@Override
	public FilePassRecord clone() {
		return new FilePassRecord(this);
	}

	public String toString() {
		StringBuffer buffer = new StringBuffer();

		buffer.append("[FILEPASS]\n");
		buffer.append("    .type = ").append(HexDump.shortToHex(encryptionType)).append("\n");
        String prefix = "     ."+encryptionInfo.getEncryptionMode();
        buffer.append(prefix+".info = ").append(HexDump.shortToHex(encryptionInfo.getVersionMajor())).append("\n");
        buffer.append(prefix+".ver  = ").append(HexDump.shortToHex(encryptionInfo.getVersionMinor())).append("\n");
        buffer.append(prefix+".salt = ").append(HexDump.toHex(encryptionInfo.getVerifier().getSalt())).append("\n");
        buffer.append(prefix+".verifier = ").append(HexDump.toHex(encryptionInfo.getVerifier().getEncryptedVerifier())).append("\n");
        buffer.append(prefix+".verifierHash = ").append(HexDump.toHex(encryptionInfo.getVerifier().getEncryptedVerifierHash())).append("\n");
		buffer.append("[/FILEPASS]\n");
		return buffer.toString();
	}
}