xmlsecurity: export OOXML signature relations to persistent storage

With this, _xmlsignatures/_rels/origin.sigs.rels and
_xmlsignatures/origin.sigs is written to the destination file.

Change-Id: I8d63a182e7cf05ed20195f88c90fba2a9a05379e

xmlsecurity/source/dialogs/digitalsignaturesdialog.cxx

@@ -411,13 +411,20 @@ IMPL_LINK_NOARG_TYPED(DigitalSignaturesDialog, OKButtonHdl, Button*, void)
 
         XMLSignatureHelper::CloseDocumentHandler( xDocumentHandler);
 
-        // If stream was not provided, we are responsible for committing it....
-        if ( !mxSignatureStream.is() )
-        {
-            uno::Reference< embed::XTransactedObject > xTrans(
-                aStreamHelper.xSignatureStorage, uno::UNO_QUERY );
-            xTrans->commit();
-        }
+    }
+    else if (aStreamHelper.xSignatureStorage.is() && aStreamHelper.nStorageFormat == embed::StorageFormats::OFOPXML)
+    {
+        // OOXML
+        size_t nSignatureCount = maCurrentSignatureInformations.size();
+        maSignatureHelper.ExportSignatureRelations(aStreamHelper.xSignatureStorage, nSignatureCount);
+    }
+
+    // If stream was not provided, we are responsible for committing it....
+    if ( !mxSignatureStream.is() )
+    {
+        uno::Reference< embed::XTransactedObject > xTrans(
+            aStreamHelper.xSignatureStorage, uno::UNO_QUERY );
+        xTrans->commit();
     }
 
     EndDialog(RET_OK);

xmlsecurity/source/helper/xmlsignaturehelper.cxx

@@ -377,6 +377,13 @@ bool XMLSignatureHelper::ReadAndVerifySignatureStorage(const uno::Reference<embe
             std::vector<beans::StringPair>::iterator it = std::find_if(aRelation.begin(), aRelation.end(), [](const beans::StringPair& rPair) { return rPair.First == "Target"; });
             if (it != aRelation.end())
             {
+                uno::Reference<container::XNameAccess> xNameAccess(xStorage, uno::UNO_QUERY);
+                if (xNameAccess.is() && !xNameAccess->hasByName(it->Second))
+                {
+                    SAL_WARN("xmlsecurity.helper", "expected stream, but not found: " << it->Second);
+                    continue;
+                }
+
                 uno::Reference<io::XInputStream> xInputStream(xStorage->openStreamElement(it->Second, nOpenMode), uno::UNO_QUERY);
                 if (!ReadAndVerifySignatureStorageStream(xInputStream))
                     return false;