Warn if catalog type entry is invalid (fixes #810)

m-holger
1 parent 1e53da74
Showing 6 changed files with 116 additions and 4 deletions
include/qpdf/QPDF.hh
libqpdf/QPDF.cc
libqpdf/QPDFJob.cc
qpdf/qtest/invalid-objects.test
qpdf/qtest/qpdf/catalgg.out
qpdf/qtest/qpdf/catalgg.pdf
@@ -910,8 +910,7 @@ class QPDF
         }
     };
  
-    // The ParseGuard class allows QPDFObjectHandle to detect
-    // re-entrant parsing.
+    // The ParseGuard class allows QPDFParser to detect re-entrant parsing.
     class ParseGuard
     {
         friend class QPDFParser;
@@ -933,7 +932,7 @@ class QPDF
         QPDF* qpdf;
     };
  
-    // Pipe class is restricted to QPDF_Stream
+    // Pipe class is restricted to QPDF_Stream.
     class Pipe
     {
         friend class QPDF_Stream;
@@ -961,6 +960,20 @@ class QPDF
         }
     };
  
+    // JobSetter class is restricted to QPDFJob.
+    class JobSetter
+    {
+        friend class QPDFJob;
+
+      private:
+        // Enable enhanced warnings for pdf file checking.
+        static void
+        setCheckMode(QPDF& qpdf, bool val)
+        {
+            qpdf.m->check_mode = val;
+        }
+    };
+
     // For testing only -- do not add to DLL
     static bool test_json_validators();
  
@@ -1698,6 +1711,7 @@ class QPDF
         bool ignore_xref_streams{false};
         bool suppress_warnings{false};
         bool attempt_recovery{true};
+        bool check_mode{false};
         std::shared_ptr<EncryptionParameters> encp;
         std::string pdf_version;
         std::map<QPDFObjGen, QPDFXRefEntry> xref_table;
@@ -2461,6 +2461,13 @@ QPDF::getRoot()
     QPDFObjectHandle root = this->m->trailer.getKey("/Root");
     if (!root.isDictionary()) {
         throw damagedPDF("", 0, "unable to find /Root dictionary");
+    } else if (
+        // Check_mode is an interim solution to request #810 pending a more
+        // comprehensive review of the approach to more extensive checks and
+        // warning levels.
+        m->check_mode && !root.getKey("/Type").isNameAndEquals("/Catalog")) {
+        warn(damagedPDF("", 0, "catalog /Type entry missing or invalid"));
+        root.replaceKey("/Type", "/Catalog"_qpdf);
     }
     return root;
 }
@@ -798,6 +798,7 @@ QPDFJob::doCheck(QPDF&amp; pdf)
     bool okay = true;
     auto& cout = *this->m->log->getInfo();
     cout << "checking " << m->infilename.get() << "\n";
+    QPDF::JobSetter::setCheckMode(pdf, true);
     try {
         int extension_level = pdf.getExtensionLevel();
         cout << "PDF Version: " << pdf.getPDFVersion();
@@ -14,7 +14,7 @@ cleanup();
  
 my $td = new TestDriver('invalid-objects');
  
-my $n_tests = 3;
+my $n_tests = 4;
  
 $td->runtest("closed input source",
              {$td->COMMAND => "test_driver 73 minimal.pdf"},
@@ -33,5 +33,10 @@ $td-&gt;runtest(&quot;object with zero offset&quot;,
              {$td->FILE => "zero-offset.out", $td->EXIT_STATUS => 3},
              $td->NORMALIZE_NEWLINES);
  
+$td->runtest("catalog with invalid type entry",
+             {$td->COMMAND => "qpdf --check catalgg.pdf"},
+             {$td->FILE => "catalgg.out", $td->EXIT_STATUS => 3},
+             $td->NORMALIZE_NEWLINES);
+
 cleanup();
 $td->report($n_tests);
+checking catalgg.pdf
+WARNING: catalgg.pdf: catalog /Type entry missing or invalid
+PDF Version: 1.3
+File is not encrypted
+File is not linearized
+qpdf: operation succeeded with warnings
+%PDF-1.3
+1 0 obj
+<<
+  /Type /Catalgg
+  /Pages 2 0 R
+>>
+endobj
+
+2 0 obj
+<<
+  /Type /Pages
+  /Kids [
+    3 0 R
+  ]
+  /Count 1
+>>
+endobj
+
+3 0 obj
+<<
+  /Type /Page
+  /Parent 2 0 R
+  /MediaBox [0 0 612 792]
+  /Contents 4 0 R
+  /Resources <<
+    /ProcSet 5 0 R
+    /Font <<
+      /F1 6 0 R
+    >>
+  >>
+>>
+endobj
+
+4 0 obj
+<<
+  /Length 44
+>>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+
+5 0 obj
+[
+  /PDF
+  /Text
+]
+endobj
+
+6 0 obj
+<<
+  /Type /Font
+  /Subtype /Type1
+  /Name /F1
+  /BaseFont /Helvetica
+  /Encoding /WinAnsiEncoding
+>>
+endobj
+
+xref
+0 7
+0000000000 65535 f 
+0000000009 00000 n 
+0000000063 00000 n 
+0000000135 00000 n 
+0000000307 00000 n 
+0000000403 00000 n 
+0000000438 00000 n 
+trailer <<
+  /Size 7
+  /Root 1 0 R
+>>
+startxref
+556
+%%EOF