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Apache POI - Java API To Access Microsoft Format Files
/* ====================================================================
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.usermodel;
import java.io.Closeable;
import java.io.IOException;
import java.io.OutputStream;
import java.security.GeneralSecurityException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.NavigableMap;
import java.util.TreeMap;
import org.apache.poi.EncryptedDocumentException;
import org.apache.poi.hslf.exceptions.CorruptPowerPointFileException;
import org.apache.poi.hslf.exceptions.EncryptedPowerPointFileException;
import org.apache.poi.hslf.record.DocumentEncryptionAtom;
import org.apache.poi.hslf.record.PersistPtrHolder;
import org.apache.poi.hslf.record.PositionDependentRecord;
import org.apache.poi.hslf.record.Record;
import org.apache.poi.hslf.record.UserEditAtom;
import org.apache.poi.hssf.record.crypto.Biff8EncryptionKey;
import org.apache.poi.poifs.crypt.ChunkedCipherInputStream;
import org.apache.poi.poifs.crypt.ChunkedCipherOutputStream;
import org.apache.poi.poifs.crypt.Decryptor;
import org.apache.poi.poifs.crypt.EncryptionInfo;
import org.apache.poi.poifs.crypt.Encryptor;
import org.apache.poi.util.BitField;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.Internal;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.LittleEndianByteArrayInputStream;
import org.apache.poi.util.LittleEndianByteArrayOutputStream;
/**
* This class provides helper functions for encrypted PowerPoint documents.
*/
@Internal
public class HSLFSlideShowEncrypted implements Closeable {
DocumentEncryptionAtom dea;
EncryptionInfo _encryptionInfo;
// Cipher cipher = null;
ChunkedCipherOutputStream cyos;
private static final BitField fieldRecInst = new BitField(0xFFF0);
private static final int[] BLIB_STORE_ENTRY_PARTS = {
1, // btWin32
1, // btMacOS
16, // rgbUid
2, // tag
4, // size
4, // cRef
4, // foDelay
1, // unused1
1, // cbName (@ index 33)
1, // unused2
1, // unused3
};
protected HSLFSlideShowEncrypted(DocumentEncryptionAtom dea) {
this.dea = dea;
}
protected HSLFSlideShowEncrypted(byte[] docstream, NavigableMap recordMap) {
// check for DocumentEncryptionAtom, which would be at the last offset
// need to ignore already set UserEdit and PersistAtoms
UserEditAtom userEditAtomWithEncryption = null;
for (Map.Entry me : recordMap.descendingMap().entrySet()) {
org.apache.poi.hslf.record.Record r = me.getValue();
if (!(r instanceof UserEditAtom)) {
continue;
}
UserEditAtom uea = (UserEditAtom)r;
if (uea.getEncryptSessionPersistIdRef() != -1) {
userEditAtomWithEncryption = uea;
break;
}
}
if (userEditAtomWithEncryption == null) {
dea = null;
return;
}
org.apache.poi.hslf.record.Record r = recordMap.get(userEditAtomWithEncryption.getPersistPointersOffset());
assert(r instanceof PersistPtrHolder);
PersistPtrHolder ptr = (PersistPtrHolder)r;
Integer encOffset = ptr.getSlideLocationsLookup().get(userEditAtomWithEncryption.getEncryptSessionPersistIdRef());
if (encOffset == null) {
// encryption info doesn't exist anymore
// SoftMaker Freeoffice produces such invalid files - check for "SMNativeObjData" ole stream
dea = null;
return;
}
r = recordMap.get(encOffset);
if (r == null) {
r = Record.buildRecordAtOffset(docstream, encOffset);
recordMap.put(encOffset, r);
}
assert(r instanceof DocumentEncryptionAtom);
this.dea = (DocumentEncryptionAtom)r;
String pass = Biff8EncryptionKey.getCurrentUserPassword();
EncryptionInfo ei = getEncryptionInfo();
try {
if(!ei.getDecryptor().verifyPassword(pass != null ? pass : Decryptor.DEFAULT_PASSWORD)) {
throw new EncryptedPowerPointFileException("PowerPoint file is encrypted. The correct password needs to be set via Biff8EncryptionKey.setCurrentUserPassword()");
}
} catch (GeneralSecurityException e) {
throw new EncryptedPowerPointFileException(e);
}
}
public DocumentEncryptionAtom getDocumentEncryptionAtom() {
return dea;
}
protected EncryptionInfo getEncryptionInfo() {
return (dea != null) ? dea.getEncryptionInfo() : null;
}
protected OutputStream encryptRecord(OutputStream plainStream, int persistId, org.apache.poi.hslf.record.Record record) {
boolean isPlain = (dea == null
|| record instanceof UserEditAtom
|| record instanceof PersistPtrHolder
|| record instanceof DocumentEncryptionAtom
);
try {
if (isPlain) {
if (cyos != null) {
// write cached data to stream
cyos.flush();
}
return plainStream;
}
if (cyos == null) {
Encryptor enc = getEncryptionInfo().getEncryptor();
enc.setChunkSize(-1);
cyos = enc.getDataStream(plainStream, 0);
}
cyos.initCipherForBlock(persistId, false);
} catch (Exception e) {
throw new EncryptedPowerPointFileException(e);
}
return cyos;
}
private static void readFully(ChunkedCipherInputStream ccis, byte[] docstream, int offset, int len) throws IOException {
if (IOUtils.readFully(ccis, docstream, offset, len) == -1) {
throw new EncryptedPowerPointFileException("unexpected EOF");
}
}
protected void decryptRecord(byte[] docstream, int persistId, int offset) {
if (dea == null) {
return;
}
Decryptor dec = getEncryptionInfo().getDecryptor();
dec.setChunkSize(-1);
try (LittleEndianByteArrayInputStream lei = new LittleEndianByteArrayInputStream(docstream, offset);
ChunkedCipherInputStream ccis = (ChunkedCipherInputStream)dec.getDataStream(lei, docstream.length-offset, 0)) {
ccis.initCipherForBlock(persistId);
// decrypt header and read length to be decrypted
readFully(ccis, docstream, offset, 8);
// decrypt the rest of the record
int rlen = (int)LittleEndian.getUInt(docstream, offset+4);
readFully(ccis, docstream, offset+8, rlen);
} catch (Exception e) {
throw new EncryptedPowerPointFileException(e);
}
}
private void decryptPicBytes(byte[] pictstream, int offset, int len)
throws IOException, GeneralSecurityException {
// when reading the picture elements, each time a segment is read, the cipher needs
// to be reset (usually done when calling Cipher.doFinal)
LittleEndianByteArrayInputStream lei = new LittleEndianByteArrayInputStream(pictstream, offset);
Decryptor dec = getEncryptionInfo().getDecryptor();
ChunkedCipherInputStream ccis = (ChunkedCipherInputStream)dec.getDataStream(lei, len, 0);
readFully(ccis, pictstream, offset, len);
ccis.close();
lei.close();
}
protected void decryptPicture(byte[] pictstream, int offset) {
if (dea == null) {
return;
}
try {
// decrypt header and read length to be decrypted
decryptPicBytes(pictstream, offset, 8);
int recInst = fieldRecInst.getValue(LittleEndian.getUShort(pictstream, offset));
int recType = LittleEndian.getUShort(pictstream, offset+2);
int rlen = (int)LittleEndian.getUInt(pictstream, offset+4);
offset += 8;
int endOffset = offset + rlen;
if (recType == 0xF007) {
// TOOD: get a real example file ... to actual test the FBSE entry
// not sure where the foDelay block is
// File BLIP Store Entry (FBSE)
for (int part : BLIB_STORE_ENTRY_PARTS) {
decryptPicBytes(pictstream, offset, part);
}
offset += 36;
int cbName = LittleEndian.getUShort(pictstream, offset-3);
if (cbName > 0) {
// read nameData
decryptPicBytes(pictstream, offset, cbName);
offset += cbName;
}
if (offset == endOffset) {
return; // no embedded blip
}
// fall through, read embedded blip now
// update header data
decryptPicBytes(pictstream, offset, 8);
recInst = fieldRecInst.getValue(LittleEndian.getUShort(pictstream, offset));
recType = LittleEndian.getUShort(pictstream, offset+2);
// rlen = (int)LittleEndian.getUInt(pictstream, offset+4);
offset += 8;
}
int rgbUidCnt = (recInst == 0x217 || recInst == 0x3D5 || recInst == 0x46B || recInst == 0x543 ||
recInst == 0x6E1 || recInst == 0x6E3 || recInst == 0x6E5 || recInst == 0x7A9) ? 2 : 1;
// rgbUid 1/2
for (int i=0; i 0) {
ccos.write(pictstream, offset, cbName);
ccos.flush();
offset += cbName;
}
if (offset == endOffset) {
return; // no embedded blip
}
// fall through, read embedded blip now
// update header data
recInst = fieldRecInst.getValue(LittleEndian.getUShort(pictstream, offset));
recType = LittleEndian.getUShort(pictstream, offset+2);
ccos.write(pictstream, offset, 8);
ccos.flush();
offset += 8;
}
int rgbUidCnt = (recInst == 0x217 || recInst == 0x3D5 || recInst == 0x46B || recInst == 0x543 ||
recInst == 0x6E1 || recInst == 0x6E3 || recInst == 0x6E5 || recInst == 0x7A9) ? 2 : 1;
for (int i=0; i done
return records;
} else {
// need to remove password data
dea = null;
return removeEncryptionRecord(records);
}
} else {
// create password record
if (dea == null) {
dea = new DocumentEncryptionAtom();
}
EncryptionInfo ei = dea.getEncryptionInfo();
byte[] salt = ei.getVerifier().getSalt();
Encryptor enc = getEncryptionInfo().getEncryptor();
if (salt == null) {
enc.confirmPassword(password);
} else {
byte[] verifier = ei.getDecryptor().getVerifier();
enc.confirmPassword(password, null, null, verifier, salt, null);
}
// move EncryptionRecord to last slide position
records = normalizeRecords(records);
return addEncryptionRecord(records, dea);
}
}
/**
* remove duplicated UserEditAtoms and merge PersistPtrHolder.
* Before this method is called, make sure that the offsets are correct,
* i.e. call {@link HSLFSlideShowImpl#updateAndWriteDependantRecords(OutputStream, Map)}
*/
protected static org.apache.poi.hslf.record.Record[] normalizeRecords(org.apache.poi.hslf.record.Record[] records) {
// http://msdn.microsoft.com/en-us/library/office/gg615594(v=office.14).aspx
// repeated slideIds can be overwritten, i.e. ignored
UserEditAtom uea = null;
PersistPtrHolder pph = null;
TreeMap slideLocations = new TreeMap<>();
TreeMap recordMap = new TreeMap<>();
List obsoleteOffsets = new ArrayList<>();
int duplicatedCount = 0;
for (org.apache.poi.hslf.record.Record r : records) {
assert(r instanceof PositionDependentRecord);
PositionDependentRecord pdr = (PositionDependentRecord)r;
if (pdr instanceof UserEditAtom) {
uea = (UserEditAtom)pdr;
continue;
}
if (pdr instanceof PersistPtrHolder) {
if (pph != null) {
duplicatedCount++;
}
pph = (PersistPtrHolder)pdr;
for (Map.Entry me : pph.getSlideLocationsLookup().entrySet()) {
Integer oldOffset = slideLocations.put(me.getKey(), me.getValue());
if (oldOffset != null) {
obsoleteOffsets.add(oldOffset);
}
}
continue;
}
recordMap.put(pdr.getLastOnDiskOffset(), r);
}
if (uea == null || pph == null || uea.getPersistPointersOffset() != pph.getLastOnDiskOffset()) {
throw new EncryptedDocumentException("UserEditAtom and PersistPtrHolder must exist and their offset need to match.");
}
recordMap.put(pph.getLastOnDiskOffset(), pph);
recordMap.put(uea.getLastOnDiskOffset(), uea);
if (duplicatedCount == 0 && obsoleteOffsets.isEmpty()) {
return records;
}
uea.setLastUserEditAtomOffset(0);
pph.clear();
for (Map.Entry me : slideLocations.entrySet()) {
pph.addSlideLookup(me.getKey(), me.getValue());
}
for (Integer oldOffset : obsoleteOffsets) {
recordMap.remove(oldOffset);
}
return recordMap.values().toArray(new org.apache.poi.hslf.record.Record[0]);
}
protected static org.apache.poi.hslf.record.Record[] removeEncryptionRecord(org.apache.poi.hslf.record.Record[] records) {
int deaSlideId = -1;
int deaOffset = -1;
PersistPtrHolder ptr = null;
UserEditAtom uea = null;
List recordList = new ArrayList<>();
for (org.apache.poi.hslf.record.Record r : records) {
if (r instanceof DocumentEncryptionAtom) {
deaOffset = ((DocumentEncryptionAtom)r).getLastOnDiskOffset();
continue;
} else if (r instanceof UserEditAtom) {
uea = (UserEditAtom)r;
deaSlideId = uea.getEncryptSessionPersistIdRef();
uea.setEncryptSessionPersistIdRef(-1);
} else if (r instanceof PersistPtrHolder) {
ptr = (PersistPtrHolder)r;
}
recordList.add(r);
}
if (ptr == null || uea == null) {
throw new EncryptedDocumentException("UserEditAtom or PersistPtrholder not found.");
}
if (deaSlideId == -1 && deaOffset == -1) {
return records;
}
TreeMap tm = new TreeMap<>(ptr.getSlideLocationsLookup());
ptr.clear();
int maxSlideId = -1;
for (Map.Entry me : tm.entrySet()) {
if (me.getKey() == deaSlideId || me.getValue() == deaOffset) {
continue;
}
ptr.addSlideLookup(me.getKey(), me.getValue());
maxSlideId = Math.max(me.getKey(), maxSlideId);
}
uea.setMaxPersistWritten(maxSlideId);
records = recordList.toArray(new org.apache.poi.hslf.record.Record[0]);
return records;
}
protected static org.apache.poi.hslf.record.Record[] addEncryptionRecord(org.apache.poi.hslf.record.Record[] records, DocumentEncryptionAtom dea) {
assert(dea != null);
int ueaIdx = -1, ptrIdx = -1, deaIdx = -1, idx = -1;
for (org.apache.poi.hslf.record.Record r : records) {
idx++;
if (r instanceof UserEditAtom) {
ueaIdx = idx;
} else if (r instanceof PersistPtrHolder) {
ptrIdx = idx;
} else if (r instanceof DocumentEncryptionAtom) {
deaIdx = idx;
}
}
assert(ueaIdx != -1 && ptrIdx != -1 && ptrIdx < ueaIdx);
if (deaIdx != -1) {
DocumentEncryptionAtom deaOld = (DocumentEncryptionAtom)records[deaIdx];
dea.setLastOnDiskOffset(deaOld.getLastOnDiskOffset());
records[deaIdx] = dea;
return records;
} else {
PersistPtrHolder ptr = (PersistPtrHolder)records[ptrIdx];
UserEditAtom uea = ((UserEditAtom)records[ueaIdx]);
dea.setLastOnDiskOffset(ptr.getLastOnDiskOffset()-1);
int nextSlideId = uea.getMaxPersistWritten()+1;
ptr.addSlideLookup(nextSlideId, ptr.getLastOnDiskOffset()-1);
uea.setEncryptSessionPersistIdRef(nextSlideId);
uea.setMaxPersistWritten(nextSlideId);
org.apache.poi.hslf.record.Record[] newRecords = new org.apache.poi.hslf.record.Record[records.length + 1];
if (ptrIdx > 0) {
System.arraycopy(records, 0, newRecords, 0, ptrIdx);
}
if (ptrIdx < records.length-1) {
System.arraycopy(records, ptrIdx, newRecords, ptrIdx+1, records.length-ptrIdx);
}
newRecords[ptrIdx] = dea;
return newRecords;
}
}
@Override
public void close() throws IOException {
if (cyos != null) {
cyos.close();
}
}
}