xmlsecurity OOXML export: remove signature relation with the last signature

The signature relation refers to _xmlsignatures/origin.sigs, but
that's not written when all signatures are removed.

Change-Id: I5ee1c8849962cba4b338e6f43243bcf89aedad36
(cherry picked from commit 57e6b9f3f4861f6283841e24a189eae3c02db9e8)

3 files changed, 35 insertions, 11 deletions

diff --git a/xmlsecurity/inc/xmlsecurity/xmlsignaturehelper.hxx b/xmlsecurity/inc/xmlsecurity/xmlsignaturehelper.hxx
index 9cea31fe321c..1ad2e41e6257 100644
--- a/xmlsecurity/inc/xmlsecurity/xmlsignaturehelper.hxx
+++ b/xmlsecurity/inc/xmlsecurity/xmlsignaturehelper.hxx
@@ -182,8 +182,8 @@ public:
     bool ReadAndVerifySignatureStorage(const css::uno::Reference<css::embed::XStorage>& xStorage, bool bCacheLastSignature = true);
     /// Read and verify a single OOXML signature.
     bool ReadAndVerifySignatureStorageStream(const css::uno::Reference<css::io::XInputStream>& xInputStream);
-    /// Adds an OOXML digital signature relation to _rels/.rels if there wasn't any before.
-    void EnsureSignaturesRelation(css::uno::Reference<css::embed::XStorage> xStorage);
+    /// Adds or removes an OOXML digital signature relation to _rels/.rels if there wasn't any before.
+    void EnsureSignaturesRelation(css::uno::Reference<css::embed::XStorage> xStorage, bool bAdd);
     /// Given that xStorage is an OOXML _xmlsignatures storage, create origin.sigs and its relations.
     void ExportSignatureRelations(css::uno::Reference<css::embed::XStorage> xStorage, int nSignatureCount);
     /// Given that xSignatureStorage is an OOXML _xmlsignatures storage, create and write a new signature.
diff --git a/xmlsecurity/source/helper/documentsignaturemanager.cxx b/xmlsecurity/source/helper/documentsignaturemanager.cxx
index 218bb6025aaf..8a568bd107d4 100644
--- a/xmlsecurity/source/helper/documentsignaturemanager.cxx
+++ b/xmlsecurity/source/helper/documentsignaturemanager.cxx
@@ -264,7 +264,7 @@ bool DocumentSignatureManager::add(const uno::Reference<security::XCertificate>&
         // OOXML
 
         // Handle relations.
-        maSignatureHelper.EnsureSignaturesRelation(mxStore);
+        maSignatureHelper.EnsureSignaturesRelation(mxStore, /*bAdd=*/true);
         // Old signatures + the new one.
         int nSignatureCount = maCurrentSignatureInformations.size() + 1;
         maSignatureHelper.ExportSignatureRelations(aStreamHelper.xSignatureStorage, nSignatureCount);
@@ -379,6 +379,11 @@ void DocumentSignatureManager::write()
             maSignatureHelper.ExportSignatureContentTypes(mxStore, nSignatureCount);
             maSignatureHelper.ExportSignatureRelations(aStreamHelper.xSignatureStorage, nSignatureCount);
         }
+        else
+        {
+            // Removing all signatures: then need to remove the signature relation as well.
+            maSignatureHelper.EnsureSignaturesRelation(mxStore, /*bAdd=*/false);
+        }
 
         for (size_t i = 0; i < nSignatureCount; ++i)
             maSignatureHelper.ExportOOXMLSignature(mxStore, aStreamHelper.xSignatureStorage, maCurrentSignatureInformations[i], i + 1);
diff --git a/xmlsecurity/source/helper/xmlsignaturehelper.cxx b/xmlsecurity/source/helper/xmlsignaturehelper.cxx
index d9cd0fd99372..f180f09314fb 100644
--- a/xmlsecurity/source/helper/xmlsignaturehelper.cxx
+++ b/xmlsecurity/source/helper/xmlsignaturehelper.cxx
@@ -487,7 +487,7 @@ bool XMLSignatureHelper::ReadAndVerifySignatureStorageStream(const css::uno::Ref
     return !mbError;
 }
 
-void XMLSignatureHelper::EnsureSignaturesRelation(css::uno::Reference<css::embed::XStorage> xStorage)
+void XMLSignatureHelper::EnsureSignaturesRelation(css::uno::Reference<css::embed::XStorage> xStorage, bool bAdd)
 {
     sal_Int32 nOpenMode = embed::ElementModes::READWRITE;
     uno::Reference<embed::XStorage> xSubStorage = xStorage->openStorageElement("_rels", nOpenMode);
@@ -496,21 +496,40 @@ void XMLSignatureHelper::EnsureSignaturesRelation(css::uno::Reference<css::embed
     aRelationsInfo = comphelper::sequenceToContainer< std::vector< uno::Sequence<beans::StringPair> > >(comphelper::OFOPXMLHelper::ReadRelationsInfoSequence(xRelStream, ".rels", mxCtx));
 
     // Do we have a relation already?
+    bool bHaveRelation = false;
     int nCount = 0;
     for (const uno::Sequence<beans::StringPair>& rRelation : aRelationsInfo)
     {
         auto aRelation = comphelper::sequenceToContainer< std::vector<beans::StringPair> >(rRelation);
         if (std::find_if(aRelation.begin(), aRelation.end(), lcl_isSignatureOriginType) != aRelation.end())
-            return;
+        {
+            bHaveRelation = true;
+            break;
+        }
         ++nCount;
     }
 
-    // No, then add one.
-    std::vector<beans::StringPair> aRelation;
-    aRelation.push_back(beans::StringPair("Id", "rId" + OUString::number(++nCount)));
-    aRelation.push_back(beans::StringPair("Type", OOXML_SIGNATURE_ORIGIN));
-    aRelation.push_back(beans::StringPair("Target", "_xmlsignatures/origin.sigs"));
-    aRelationsInfo.push_back(comphelper::containerToSequence(aRelation));
+    if (!bHaveRelation && bAdd)
+    {
+        // No, and have to add one.
+        std::vector<beans::StringPair> aRelation;
+        aRelation.push_back(beans::StringPair("Id", "rId" + OUString::number(++nCount)));
+        aRelation.push_back(beans::StringPair("Type", OOXML_SIGNATURE_ORIGIN));
+        aRelation.push_back(beans::StringPair("Target", "_xmlsignatures/origin.sigs"));
+        aRelationsInfo.push_back(comphelper::containerToSequence(aRelation));
+    }
+    else if (bHaveRelation && !bAdd)
+    {
+        // Yes, and need to remove it.
+        for (std::vector< uno::Sequence<beans::StringPair> >::iterator it = aRelationsInfo.begin(); it != aRelationsInfo.end();)
+        {
+            auto aRelation = comphelper::sequenceToContainer< std::vector<beans::StringPair> >(*it);
+            if (std::find_if(aRelation.begin(), aRelation.end(), lcl_isSignatureOriginType) != aRelation.end())
+                it = aRelationsInfo.erase(it);
+            else
+                ++it;
+        }
+    }
 
     // Write it back.
     uno::Reference<io::XTruncate> xTruncate(xRelStream, uno::UNO_QUERY);