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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.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 javax.crypto.Cipher;
import javax.crypto.CipherOutputStream;
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.Decryptor;
import org.apache.poi.poifs.crypt.EncryptionInfo;
import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIDecryptor;
import org.apache.poi.poifs.crypt.cryptoapi.CryptoAPIEncryptor;
import org.apache.poi.util.BitField;
import org.apache.poi.util.Internal;
import org.apache.poi.util.LittleEndian;
/**
* This class provides helper functions for encrypted PowerPoint documents.
*/
@Internal
public class HSLFSlideShowEncrypted {
DocumentEncryptionAtom dea;
CryptoAPIEncryptor enc = null;
CryptoAPIDecryptor dec = null;
Cipher cipher = null;
CipherOutputStream cyos = null;
private static final BitField fieldRecInst = new BitField(0xFFF0);
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()) {
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;
}
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;
decryptInit();
String pass = Biff8EncryptionKey.getCurrentUserPassword();
if(!dec.verifyPassword(pass != null ? pass : Decryptor.DEFAULT_PASSWORD)) {
throw new EncryptedPowerPointFileException("PowerPoint file is encrypted. The correct password needs to be set via Biff8EncryptionKey.setCurrentUserPassword()");
}
}
public DocumentEncryptionAtom getDocumentEncryptionAtom() {
return dea;
}
protected void setPersistId(int persistId) {
if (enc != null && dec != null) {
throw new EncryptedPowerPointFileException("Use instance either for en- or decryption");
}
try {
if (enc != null) cipher = enc.initCipherForBlock(cipher, persistId);
if (dec != null) cipher = dec.initCipherForBlock(cipher, persistId);
} catch (GeneralSecurityException e) {
throw new EncryptedPowerPointFileException(e);
}
}
protected void decryptInit() {
if (dec != null) return;
EncryptionInfo ei = dea.getEncryptionInfo();
dec = (CryptoAPIDecryptor)ei.getDecryptor();
}
protected void encryptInit() {
if (enc != null) return;
EncryptionInfo ei = dea.getEncryptionInfo();
enc = (CryptoAPIEncryptor)ei.getEncryptor();
}
protected OutputStream encryptRecord(OutputStream plainStream, int persistId, Record record) {
boolean isPlain = (dea == null
|| record instanceof UserEditAtom
|| record instanceof PersistPtrHolder
|| record instanceof DocumentEncryptionAtom
);
if (isPlain) return plainStream;
encryptInit();
setPersistId(persistId);
if (cyos == null) {
cyos = new CipherOutputStream(plainStream, cipher);
}
return cyos;
}
protected void decryptRecord(byte[] docstream, int persistId, int offset) {
if (dea == null) return;
decryptInit();
setPersistId(persistId);
try {
// decrypt header and read length to be decrypted
cipher.update(docstream, offset, 8, docstream, offset);
// decrypt the rest of the record
int rlen = (int)LittleEndian.getUInt(docstream, offset+4);
cipher.update(docstream, offset+8, rlen, docstream, offset+8);
} catch (GeneralSecurityException e) {
throw new CorruptPowerPointFileException(e);
}
}
protected void decryptPicture(byte[] pictstream, int offset) {
if (dea == null) return;
decryptInit();
setPersistId(0);
try {
// decrypt header and read length to be decrypted
cipher.doFinal(pictstream, offset, 8, pictstream, offset);
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)
cipher.doFinal(pictstream, offset, 1, pictstream, offset); // btWin32
offset++;
cipher.doFinal(pictstream, offset, 1, pictstream, offset); // btMacOS
offset++;
cipher.doFinal(pictstream, offset, 16, pictstream, offset); // rgbUid
offset += 16;
cipher.doFinal(pictstream, offset, 2, pictstream, offset); // tag
offset += 2;
cipher.doFinal(pictstream, offset, 4, pictstream, offset); // size
offset += 4;
cipher.doFinal(pictstream, offset, 4, pictstream, offset); // cRef
offset += 4;
cipher.doFinal(pictstream, offset, 4, pictstream, offset); // foDelay
offset += 4;
cipher.doFinal(pictstream, offset+0, 1, pictstream, offset+0); // unused1
cipher.doFinal(pictstream, offset+1, 1, pictstream, offset+1); // cbName
cipher.doFinal(pictstream, offset+2, 1, pictstream, offset+2); // unused2
cipher.doFinal(pictstream, offset+3, 1, pictstream, offset+3); // unused3
int cbName = LittleEndian.getUShort(pictstream, offset+1);
offset += 4;
if (cbName > 0) {
cipher.doFinal(pictstream, offset, cbName, pictstream, offset); // nameData
offset += cbName;
}
if (offset == endOffset) {
return; // no embedded blip
}
// fall through, read embedded blip now
// update header data
cipher.doFinal(pictstream, offset, 8, pictstream, offset);
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;
for (int i=0; i 0) {
cipher.doFinal(pictstream, offset, cbName, pictstream, offset); // nameData
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);
// rlen = (int) LittleEndian.getUInt(pictstream, offset+4);
cipher.doFinal(pictstream, offset, 8, pictstream, offset);
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();
enc = null;
}
encryptInit();
EncryptionInfo ei = dea.getEncryptionInfo();
byte salt[] = ei.getVerifier().getSalt();
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 Record[] normalizeRecords(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 (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);
}
assert(uea != null && pph != null && uea.getPersistPointersOffset() == pph.getLastOnDiskOffset());
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 Record[recordMap.size()]);
}
protected static Record[] removeEncryptionRecord(Record records[]) {
int deaSlideId = -1;
int deaOffset = -1;
PersistPtrHolder ptr = null;
UserEditAtom uea = null;
List recordList = new ArrayList();
for (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);
}
assert(ptr != null);
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 Record[recordList.size()]);
return records;
}
protected static Record[] addEncryptionRecord(Record records[], DocumentEncryptionAtom dea) {
assert(dea != null);
int ueaIdx = -1, ptrIdx = -1, deaIdx = -1, idx = -1;
for (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);
Record newRecords[] = new 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;
}
}
}