calc: support for reading DRM encrypted xls files

DRM encryption is implemented as an optional service, so
just use it when available.

Change-Id: Ie580e5c12c48ccf99f9a932b1c66eb35866b7ef4

1 files changed, 105 insertions, 0 deletions

diff --git a/sc/source/filter/excel/excel.cxx b/sc/source/filter/excel/excel.cxx
index ca87efc2988c..56adce29a061 100644
--- a/sc/source/filter/excel/excel.cxx
+++ b/sc/source/filter/excel/excel.cxx
@@ -24,7 +24,9 @@
 #include <sot/exchange.hxx>
 #include <filter/msfilter/classids.hxx>
 #include <tools/globname.hxx>
+#include <com/sun/star/packages/XPAckageEncryption.hpp>
 #include <com/sun/star/ucb/ContentCreationException.hpp>
+#include <com/sun/star/uno/XComponentContext.hpp>
 #include <unotools/streamwrap.hxx>
 #include <osl/diagnose.h>
 #include <filter.hxx>
@@ -32,6 +34,8 @@
 #include <xistream.hxx>
 #include <xltools.hxx>
 #include <docoptio.hxx>
+#include <comphelper/sequenceashashmap.hxx>
+#include <comphelper/processfactory.hxx>
 
 #include <docsh.hxx>
 #include <scerrors.hxx>
@@ -42,6 +46,99 @@
 
 #include <memory>
 
+using namespace css;
+
+static void lcl_getListOfStreams(SotStorage * pStorage, comphelper::SequenceAsHashMap& aStreamsData, const OUString& sPrefix)
+{
+    SvStorageInfoList aElements;
+    pStorage->FillInfoList(&aElements);
+    for (const auto & aElement : aElements)
+    {
+        OUString sStreamFullName = sPrefix.getLength() ? sPrefix + "/" + aElement.GetName() : aElement.GetName();
+        if (aElement.IsStorage())
+        {
+            SotStorage * pSubStorage = pStorage->OpenSotStorage(aElement.GetName(), StreamMode::STD_READ | StreamMode::SHARE_DENYALL);
+            lcl_getListOfStreams(pSubStorage, aStreamsData, sStreamFullName);
+        }
+        else
+        {
+            // Read stream
+            tools::SvRef<SotStorageStream> rStream = pStorage->OpenSotStream(aElement.GetName(), StreamMode::READ | StreamMode::SHARE_DENYALL);
+            assert(rStream.is());
+
+            sal_Int32 nStreamSize = rStream->GetSize();
+            uno::Sequence< sal_Int8 > oData;
+            oData.realloc(nStreamSize);
+            sal_Int32 nReadBytes = rStream->ReadBytes(oData.getArray(), nStreamSize);
+            assert(nStreamSize == nReadBytes);
+            aStreamsData[sStreamFullName] <<= oData;
+        }
+    }
+}
+
+static tools::SvRef<SotStorage> lcl_DRMDecrypt(SfxMedium& rMedium, tools::SvRef<SotStorage>& rStorage, std::shared_ptr<SvStream>& rNewStorageStrm)
+{
+    tools::SvRef<SotStorage> aNewStorage;
+
+    // We have DRM encrypted storage. We should try to decrypt it first, if we can
+    uno::Sequence< uno::Any > aArguments;
+    uno::Reference<uno::XComponentContext> xComponentContext(comphelper::getProcessComponentContext());
+    uno::Reference< packages::XPackageEncryption > xPackageEncryption(
+        xComponentContext->getServiceManager()->createInstanceWithArgumentsAndContext(
+            "com.sun.star.comp.oox.crypto.DRMDataSpace", aArguments, xComponentContext), uno::UNO_QUERY);
+
+    if (!xPackageEncryption.is())
+    {
+        // We do not know how to decrypt this
+        return aNewStorage;
+    }
+
+    std::vector<OUString> aStreamsList;
+    comphelper::SequenceAsHashMap aStreamsData;
+    lcl_getListOfStreams(rStorage.get(), aStreamsData, OUString(""));
+
+    try {
+        uno::Sequence<beans::NamedValue> aStreams = aStreamsData.getAsConstNamedValueList();
+        if (!xPackageEncryption->readEncryptionInfo(aStreams))
+        {
+            // We failed with decryption
+            return aNewStorage;
+        }
+
+        tools::SvRef<SotStorageStream> rContentStream = rStorage->OpenSotStream("\011DRMContent", StreamMode::READ | StreamMode::SHARE_DENYALL);
+        if (!rContentStream.is())
+        {
+            return aNewStorage;
+        }
+
+        rNewStorageStrm.reset(new SvMemoryStream());
+
+        uno::Reference<io::XInputStream > xInputStream(new utl::OSeekableInputStreamWrapper(rContentStream.get(), false));
+        uno::Reference<io::XOutputStream > xDecryptedStream(new utl::OSeekableOutputStreamWrapper(*rNewStorageStrm.get()));
+
+        if (!xPackageEncryption->decrypt(xInputStream, xDecryptedStream))
+        {
+            // We failed with decryption
+            return aNewStorage;
+        }
+
+        rNewStorageStrm->Seek(0);
+
+        // Further reading is done from new document
+        aNewStorage = new SotStorage(*rNewStorageStrm);
+
+        // Set the media descriptor data
+        uno::Sequence<beans::NamedValue> aEncryptionData = xPackageEncryption->createEncryptionData("");
+        rMedium.GetItemSet()->Put(SfxUnoAnyItem(SID_ENCRYPTIONDATA, uno::makeAny(aEncryptionData)));
+    }
+    catch (const std::exception&)
+    {
+        return aNewStorage;
+    }
+
+    return aNewStorage;
+}
+
 ErrCode ScFormatFilterPluginImpl::ScImportExcel( SfxMedium& rMedium, ScDocument* pDocument, const EXCIMPFORMAT eFormat )
 {
     // check the passed Calc document
@@ -67,6 +164,7 @@ ErrCode ScFormatFilterPluginImpl::ScImportExcel( SfxMedium& rMedium, ScDocument*
     // try to open an OLE storage
     tools::SvRef<SotStorage> xRootStrg;
     tools::SvRef<SotStorageStream> xStrgStrm;
+    std::shared_ptr<SvStream> aNewStorageStrm;
     if( SotStorage::IsStorageFile( pMedStrm ) )
     {
         xRootStrg = new SotStorage( pMedStrm, false );
@@ -77,6 +175,13 @@ ErrCode ScFormatFilterPluginImpl::ScImportExcel( SfxMedium& rMedium, ScDocument*
     // try to open "Book" or "Workbook" stream in OLE storage
     if( xRootStrg.is() )
     {
+        // Check if there is DRM encryption in storage
+        tools::SvRef<SotStorageStream> xDRMStrm = ScfTools::OpenStorageStreamRead(xRootStrg, "\011DRMContent");
+        if (xDRMStrm.is())
+        {
+            xRootStrg = lcl_DRMDecrypt(rMedium, xRootStrg, aNewStorageStrm);
+        }
+
         // try to open the "Book" stream
         tools::SvRef<SotStorageStream> xBookStrm = ScfTools::OpenStorageStreamRead( xRootStrg, EXC_STREAM_BOOK );
         XclBiff eBookBiff = xBookStrm.is() ?  XclImpStream::DetectBiffVersion( *xBookStrm ) : EXC_BIFF_UNKNOWN;