[PDFBOX-5381] Catalog object twice in signed file

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0 PDFBox
• Fix Version/s: 3.0.0 PDFBox
• Component/s: Signing
• Labels: regression
• Assignee: Andreas Lehmkühler
• Reporter: Tilman Hausherr
• Created: 27/Feb/22 10:27
• Updated: 18/Aug/23 05:46
• Resolved: 22/Mar/22 06:57

Description

The catalog object is twice in the signed file

1 0 obj
<<
/Type /Catalog
/Version /1.4
/Pages 2 0 R
/Metadata 3 0 R
/OutputIntents [4 0 R]
/Perms 18 0 R
/AcroForm <<
/Fields [22 0 R]
/SigFlags 3
>>
>>
endobj
1 0 obj
<<
/Type /Catalog
/Version /1.4
/Pages 2 0 R
/Metadata 3 0 R
/OutputIntents [4 0 R]
/Perms 18 0 R
/AcroForm <<
/Fields [22 0 R]
/SigFlags 3
>>
>>
endobj

here's a failing test, to be added at the end of CreatePDFATest.java (and probably elsewhere)

// Check that no object numbers are double
File signedFile = new File(signedPdfaFilename);
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(signedFile)));
String line;
boolean isIncrementalArea = false;
Set<String> set = new HashSet<>();
int linePos = 0;
while ((line = br.readLine()) != null)
{
    ++linePos;
    if (line.equals("%%EOF"))
    {
        isIncrementalArea = true;
    }
    if (line.equals("%%EOF"))
    {
        isIncrementalArea = true;
        set.clear(); // for cases with several revisions
    }
    if (line.matches("^\\d+ 0 obj$"))
    {
        int pos = line.indexOf(" 0 obj");
        line = line.substring(0, pos);
        assertFalse(set.contains(line), "object '" + line + " 0 obj' twice in incremental part of PDF at line " +linePos);
        set.add(line);
    }
}
br.close();

I don't know why it happens (although I remember I had such a thing years ago when trying different strategies while working on incremental saving in PDFBOX-45)