gpg4libre: Wrap PGPOwner in own namespace

as recommended by W3C: https://www.w3.org/TR/xmldsig-core/#sec-PGPData

Change-Id: I2cc0ae24eefc9137d2e3432da1d65e44245c7616
Reviewed-on: https://gerrit.libreoffice.org/40058Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

xmlsecurity/inc/xmlsignaturehelper.hxx

@@ -96,6 +96,7 @@ private:
     rtl::Reference<XSecController> mpXSecController;
     bool                        mbError;
     bool mbODFPre1_2;
+    bool mbHasGpgSignatures;
     Link<LinkParamNone*,bool>   maStartVerifySignatureHdl;
 
 private:

xmlsecurity/source/helper/xmlsignaturehelper.cxx

@@ -51,6 +51,7 @@
 
 #define NS_DOCUMENTSIGNATURES   "http://openoffice.org/2004/documentsignatures"
 #define NS_DOCUMENTSIGNATURES_ODF_1_2 "urn:oasis:names:tc:opendocument:xmlns:digitalsignature:1.0"
+#define NS_DOCUMENTSIGNATURES_LOEXT "urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0"
 #define OOXML_SIGNATURE_ORIGIN "http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/origin"
 #define OOXML_SIGNATURE_SIGNATURE "http://schemas.openxmlformats.org/package/2006/relationships/digital-signature/signature"
 
@@ -58,7 +59,7 @@ using namespace ::com::sun::star;
 using namespace ::com::sun::star::uno;
 
 XMLSignatureHelper::XMLSignatureHelper( const uno::Reference< uno::XComponentContext >& rxCtx)
-    : mxCtx(rxCtx), mbODFPre1_2(false)
+    : mxCtx(rxCtx), mbODFPre1_2(false), mbHasGpgSignatures(false)
 {
     mpXSecController = new XSecController(rxCtx);
     mbError = false;
@@ -128,6 +129,7 @@ void XMLSignatureHelper::SetGpgCertificate(sal_Int32 nSecurityId,
                                            const OUString& ouGpgCert,
                                            const OUString& ouGpgOwner)
 {
+    mbHasGpgSignatures = true;
     mpXSecController->setGpgCertificate(
         nSecurityId,
         ouGpgCertDigest,
@@ -179,6 +181,9 @@ uno::Reference<xml::sax::XWriter> XMLSignatureHelper::CreateDocumentHandlerWithH
         "xmlns",
         sNamespace);
 
+    if (mbHasGpgSignatures)
+        pAttributeList->AddAttribute("xmlns:loext", NS_DOCUMENTSIGNATURES_LOEXT);
+
     xSaxWriter->startDocument();
     xSaxWriter->startElement(
         "document-signatures",

xmlsecurity/source/helper/xsecctl.cxx

@@ -749,9 +749,11 @@ void XSecController::exportSignature(
                     }
 
                     /* Write PGPOwner element */
+                    pAttributeList = new SvXMLAttributeList();
+                    pAttributeList->AddAttribute("namespace", "loext");
                     xDocumentHandler->startElement(
                         "PGPOwner",
-                        cssu::Reference< cssxs::XAttributeList > (new SvXMLAttributeList()));
+                        cssu::Reference< cssxs::XAttributeList >(pAttributeList));
                     xDocumentHandler->characters( signatureInfo.ouGpgOwner );
                     xDocumentHandler->endElement( "PGPOwner" );
                 }