
PDFs downloaded using the Firefox PDF viewer change content and make the digital signature invalid version 136.0.2
There is an issue with PDFs downloaded using the Firefox PDF viewer. The PDF contains a valid digital signature. When I set the parameter pdfjs.disabled = true, everything works as expected, the PDF is downloaded correctly, and when I open it with Adobe Reader, the signature is valid. However, when I set this parameter to false (default value) and download the PDF using the built-in Firefox PDF viewer, the signature becomes invalid. I compared both PDF files using a text editor and a diff tool, and the only difference I found was a specific change in the content. 1)pdf- signature is valid Ψα Exif II* μ Ducky d α http://ns.adobe.com/xap/1.0/ <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.6-c138 79.159824, 2016/09/14-01:09:01 "> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description rdf:about="" xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/" xmlns:stRef="http://ns.adobe.com/xap/1.0/sType/ResourceRef#" xmlns:xmp="http://ns.adobe.com/xap/1.0/" xmpMM:DocumentID="xmp.did:FF61BC20787811E896E6E83BD502C18A" xmpMM:InstanceID="xmp.iid:FF61BC1F787811E896E6E83BD502C18A" xmp:CreatorTool="paint.net 4.0.16"> <xmpMM:DerivedFrom stRef:instanceID="452A56456B1E68A148301EBAD51349D5" stRef:documentID="452A56456B1E68A148301EBAD51349D5"/> </rdf:Description> </rdf:RDF> </x:xmpmeta> ξ Adobe dΐ Ϋ „ ΐ F F Δ • 2)invalid pdf Ψα Exif μ Ducky d α http://ns.adobe.com/xap/1.0/ <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.6-c138 79.159824, 2016/09/14-01:09:01 "> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description rdf:about="" xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/" xmlns:stRef="http://ns.adobe.com/xap/1.0/sType/ResourceRef#" xmlns:xmp="http://ns.adobe.com/xap/1.0/" xmpMM:DocumentID="xmp.did:FF61BC20787811E896E6E83BD502C18A" xmpMM:InstanceID="xmp.iid:FF61BC1F787811E896E6E83BD502C18A" xmp:CreatorTool="paint.net 4.0.16"> <xmpMM:DerivedFrom stRef:instanceID="452A56456B1E68A148301EBAD51349D5" stRef:documentID="452A56456B1E68A148301EBAD51349D5"/> </rdf:Description> </rdf:RDF> </x:xmpmeta> ξ Adobe dΐ Ϋ „ ΐ F F Δ • I cannot understand why the Firefox PDF viewer modifies the PDF content. This is happening only to version 136.0.2. I had no issue before this version. Could you please help me?
All Replies (1)
The characters after Exif are a bit different. Is it an image, or is it a coincidence that the string sounds like EXIF?
I thought, when you open a PDF in the viewer, and then use the viewer's download button, that Firefox just downloads the PDF from the cache in its original binary format. Unchanged. So this is strange.
While working with these signed files, you could switch Firefox to asking you what to do with PDFs, if it doesn't ruin your workflow too badly. See: Manage file types and download actions in Firefox.