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Diffstat (limited to 'oox/source/crypto/DocumentDecryption.cxx')
| -rw-r--r-- | oox/source/crypto/DocumentDecryption.cxx | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/oox/source/crypto/DocumentDecryption.cxx b/oox/source/crypto/DocumentDecryption.cxx new file mode 100644 index 0000000000..858558433c --- /dev/null +++ b/oox/source/crypto/DocumentDecryption.cxx @@ -0,0 +1,223 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + */ + +#include <oox/crypto/DocumentDecryption.hxx> + +#include <comphelper/sequenceashashmap.hxx> + +#include <com/sun/star/beans/NamedValue.hpp> +#include <com/sun/star/io/XSeekable.hpp> +#include <com/sun/star/io/XStream.hpp> +#include <com/sun/star/io/IOException.hpp> +#include <com/sun/star/uno/XComponentContext.hpp> +#include <com/sun/star/packages/XPackageEncryption.hpp> +#include <oox/ole/olestorage.hxx> +#include <oox/helper/binaryinputstream.hxx> + +#include <sal/log.hxx> +#include <utility> + +namespace +{ +void lcl_getListOfStreams(oox::StorageBase* pStorage, std::vector<OUString>& rElementNames) +{ + std::vector<OUString> oElementNames; + pStorage->getElementNames(oElementNames); + for (const auto& sName : oElementNames) + { + oox::StorageRef rSubStorage = pStorage->openSubStorage(sName, false); + if (rSubStorage && rSubStorage->isStorage()) + { + lcl_getListOfStreams(rSubStorage.get(), rElementNames); + } + else + { + if (pStorage->isRootStorage()) + rElementNames.push_back(sName); + else + rElementNames.push_back(pStorage->getPath() + "/" + sName); + } + } +} +} + +namespace oox::crypto +{ +using namespace css; + +DocumentDecryption::DocumentDecryption(css::uno::Reference<css::uno::XComponentContext> xContext, + oox::ole::OleStorage& rOleStorage) + : mxContext(std::move(xContext)) + , mrOleStorage(rOleStorage) +{ + // Get OLE streams into sequences for later use in CryptoEngine + std::vector<OUString> aStreamNames; + lcl_getListOfStreams(&mrOleStorage, aStreamNames); + + comphelper::SequenceAsHashMap aStreamsData; + for (const auto& sStreamName : aStreamNames) + { + uno::Reference<io::XInputStream> xStream = mrOleStorage.openInputStream(sStreamName); + if (!xStream.is()) + throw io::IOException("Cannot open OLE input stream for " + sStreamName + "!"); + + BinaryXInputStream aBinaryInputStream(xStream, true); + + css::uno::Sequence<sal_Int8> oData; + sal_Int32 nStreamSize = aBinaryInputStream.size(); + sal_Int32 nReadBytes = aBinaryInputStream.readData(oData, nStreamSize); + + if (nStreamSize != nReadBytes) + { + SAL_WARN("oox", "OLE stream invalid content"); + throw io::IOException("OLE stream invalid content for " + sStreamName + "!"); + } + + aStreamsData[sStreamName] <<= oData; + } + maStreamsSequence = aStreamsData.getAsConstNamedValueList(); +} + +bool DocumentDecryption::generateEncryptionKey(const OUString& rPassword) +{ + if (mxPackageEncryption.is()) + return mxPackageEncryption->generateEncryptionKey(rPassword); + return false; +} + +bool DocumentDecryption::readEncryptionInfo() +{ + if (!mrOleStorage.isStorage()) + return false; + + // Read 0x6DataSpaces/DataSpaceMap + uno::Reference<io::XInputStream> xDataSpaceMap + = mrOleStorage.openInputStream("\006DataSpaces/DataSpaceMap"); + OUString sDataSpaceName; + + if (xDataSpaceMap.is()) + { + bool bBroken = false; + + BinaryXInputStream aDataSpaceStream(xDataSpaceMap, true); + sal_uInt32 aHeaderLength = aDataSpaceStream.readuInt32(); + SAL_WARN_IF(aHeaderLength != 8, "oox", + "DataSpaceMap length != 8 is not supported. Some content may be skipped"); + sal_uInt32 aEntryCount = aDataSpaceStream.readuInt32(); + SAL_WARN_IF(aEntryCount != 1, "oox", + "DataSpaceMap contains more than one entry. Some content may be skipped"); + + // Read each DataSpaceMapEntry (MS-OFFCRYPTO 2.1.6.1) + for (sal_uInt32 i = 0; i < aEntryCount && !bBroken; i++) + { + // entryLen unused for the moment + aDataSpaceStream.skip(sizeof(sal_uInt32)); + + // Read each DataSpaceReferenceComponent (MS-OFFCRYPTO 2.1.6.2) + sal_uInt32 aReferenceComponentCount = aDataSpaceStream.readuInt32(); + for (sal_uInt32 j = 0; j < aReferenceComponentCount && !bBroken; j++) + { + // Read next reference component + // refComponentType unused for the moment + aDataSpaceStream.skip(sizeof(sal_uInt32)); + sal_uInt32 aReferenceComponentNameLength = aDataSpaceStream.readuInt32(); + // sReferenceComponentName unused for the moment + if (aDataSpaceStream.getRemaining() < aReferenceComponentNameLength) + { + bBroken = true; + break; + } + aDataSpaceStream.readUnicodeArray(aReferenceComponentNameLength / 2); + aDataSpaceStream.skip((4 - (aReferenceComponentNameLength & 3)) + & 3); // Skip padding + + bBroken |= aDataSpaceStream.isEof(); + } + + sal_uInt32 aDataSpaceNameLength = aDataSpaceStream.readuInt32(); + if (aDataSpaceStream.getRemaining() < aDataSpaceNameLength) + { + bBroken = true; + break; + } + sDataSpaceName = aDataSpaceStream.readUnicodeArray(aDataSpaceNameLength / 2); + aDataSpaceStream.skip((4 - (aDataSpaceNameLength & 3)) & 3); // Skip padding + + bBroken |= aDataSpaceStream.isEof(); + } + + if (bBroken) + { + SAL_WARN("oox", "EOF on parsing DataSpaceMapEntry table"); + return false; + } + } + else + { + // Fallback for documents generated by LO: they sometimes do not have all + // required by MS-OFFCRYPTO specification streams (0x6DataSpaces/DataSpaceMap and others) + SAL_WARN("oox", "Encrypted package does not contain DataSpaceMap"); + sDataSpaceName = "StrongEncryptionDataSpace"; + } + + uno::Sequence<uno::Any> aArguments; + mxPackageEncryption.set( + mxContext->getServiceManager()->createInstanceWithArgumentsAndContext( + "com.sun.star.comp.oox.crypto." + sDataSpaceName, aArguments, mxContext), + css::uno::UNO_QUERY); + + if (!mxPackageEncryption.is()) + { + // we do not know how to decrypt this document + return false; + } + + return mxPackageEncryption->readEncryptionInfo(maStreamsSequence); +} + +uno::Sequence<beans::NamedValue> DocumentDecryption::createEncryptionData(const OUString& rPassword) +{ + if (!mxPackageEncryption.is()) + return uno::Sequence<beans::NamedValue>(); + + return mxPackageEncryption->createEncryptionData(rPassword); +} + +bool DocumentDecryption::decrypt(const uno::Reference<io::XStream>& xDocumentStream) +{ + bool bResult = false; + + if (!mrOleStorage.isStorage()) + return false; + + if (!mxPackageEncryption.is()) + return false; + + // open the required input streams in the encrypted package + uno::Reference<io::XInputStream> xEncryptedPackage + = mrOleStorage.openInputStream("EncryptedPackage"); + + // create temporary file for unencrypted package + uno::Reference<io::XOutputStream> xDecryptedPackage = xDocumentStream->getOutputStream(); + + bResult = mxPackageEncryption->decrypt(xEncryptedPackage, xDecryptedPackage); + + css::uno::Reference<io::XSeekable> xSeekable(xDecryptedPackage, css::uno::UNO_QUERY); + xSeekable->seek(0); + + if (bResult) + return mxPackageEncryption->checkDataIntegrity(); + + return bResult; +} + +} // namespace oox::crypto + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |