xmlsecurity: detect unsigned incremental update between signatures

(cherry picked from commit 7468d5df5ec79783eae84b62bdc5ecf12f0ca255)

Conflicts:
	vcl/source/filter/ipdf/pdfdocument.cxx
	xmlsecurity/source/pdfio/pdfdocument.cxx

Change-Id: I269ed858852ee7d1275adf340c8cc1565fc30693
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/99480
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

2 files changed, 16 insertions, 3 deletions

diff --git a/xmlsecurity/qa/unit/pdfsigning/data/partial-in-between.pdf b/xmlsecurity/qa/unit/pdfsigning/data/partial-in-between.pdf
new file mode 100644
index 000000000000..211a111cb394
--- /dev/null
+++ b/xmlsecurity/qa/unit/pdfsigning/data/partial-in-between.pdf
diff --git a/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx b/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
index 442323deb6ad..ea6a67f4e64f 100644
--- a/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
+++ b/xmlsecurity/qa/unit/pdfsigning/pdfsigning.cxx
@@ -75,6 +75,7 @@ public:
     void testPDFPAdESGood();
     /// Test a valid signature that does not cover the whole file.
     void testPartial();
+    void testPartialInBetween();
     /// Test writing a PAdES signature.
     void testSigningCertificateAttribute();
     /// Test that we accept files which are supposed to be good.
@@ -96,6 +97,7 @@ public:
     CPPUNIT_TEST(testPDF14LOWin);
     CPPUNIT_TEST(testPDFPAdESGood);
     CPPUNIT_TEST(testPartial);
+    CPPUNIT_TEST(testPartialInBetween);
     CPPUNIT_TEST(testSigningCertificateAttribute);
     CPPUNIT_TEST(testGood);
     CPPUNIT_TEST(testTokenize);
@@ -142,9 +144,8 @@ std::vector<SignatureInformation> PDFSigningTest::verify(const OUString& rURL, s
     for (size_t i = 0; i < aSignatures.size(); ++i)
     {
         SignatureInformation aInfo(i);
-        bool bLast = i == aSignatures.size() - 1;
         CPPUNIT_ASSERT(
-            xmlsecurity::pdfio::ValidateSignature(aStream, aSignatures[i], aInfo, bLast));
+            xmlsecurity::pdfio::ValidateSignature(aStream, aSignatures[i], aInfo, aVerifyDocument));
         aRet.push_back(aInfo);
 
         if (!rExpectedSubFilter.isEmpty())
@@ -286,7 +287,7 @@ void PDFSigningTest::testPDFRemove()
         CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(1), aSignatures.size());
         SignatureInformation aInfo(0);
         CPPUNIT_ASSERT(
-            xmlsecurity::pdfio::ValidateSignature(aStream, aSignatures[0], aInfo, /*bLast=*/true));
+            xmlsecurity::pdfio::ValidateSignature(aStream, aSignatures[0], aInfo, aDocument));
     }
 
     // Remove the signature and write out the result as remove.pdf.
@@ -526,6 +527,18 @@ void PDFSigningTest::testUnknownSubFilter()
     CPPUNIT_ASSERT_EQUAL(static_cast<std::size_t>(2), rInformations.size());
 }
 
+void PDFSigningTest::testPartialInBetween()
+{
+    std::vector<SignatureInformation> aInfos
+        = verify(m_directories.getURLFromSrc(DATA_DIRECTORY) + "partial-in-between.pdf", 2,
+                 /*rExpectedSubFilter=*/OString());
+    CPPUNIT_ASSERT(!aInfos.empty());
+    SignatureInformation& rInformation = aInfos[0];
+    // Without the accompanying fix in place, this test would have failed, as unsigned incremental
+    // update between two signatures were not detected.
+    CPPUNIT_ASSERT(rInformation.bPartialDocumentSignature);
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(PDFSigningTest);
 
 CPPUNIT_PLUGIN_IMPLEMENT();