Dear list, I’m experiencing an issue with some signature fields that, after signed with `pdfsig`, “Acrobat” cannot recognize (and asks to save, disabling the signature in the output document).
After inspecting the contents of the PDF document with the signature field (before any signing [file attached]), these are the three objects that may be wrong: 2 0 obj [ 4 0 R ] 3 0 obj << /DA (/rmtf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG) /DV () /F 4 /FT /Sig /Ff 0 /Kids 2 0 R /MaxLen 1024 /Q 0 /Subtype /Widget /T (Signature) /V () >> endobj 4 0 obj << /Type /Annot /DA (/rmtf 11.9552 Tf 1.1955 Ts 0 0 0 rg 0 0 0 RG) /F 4 /Parent 3 0 R /Q 0 /Subtype /Widget /Rect [ 51.630315 26.737366 367.897241 270.900429 ] >> endobj `pdfsig` adds the reference to a duplicated object 4 (right after %%EOF, in an incremental update), instead of object 3 (the actual signature field). But before reporting this at GitLab, I need to know whether signature/widget is fine with two objects. In particular: 1. Can the signature field define the annotation as a child or must signature field and widget annotation be only one object? (I know that “Acrobat Reader” merges these two objects into a single one, but I don’t know whether this is strictly required.) 2. If object 3 is already a widget, may object 4 (which mainly contains the annotation values) also be a widget itself? 3. Is there anything else I may be missing for these signature field? I have checked the relevant parts of the PDF-1.7 spec (since this is a PDF-1.7 document) and this is all that comes to my mind. I haven’t writt the TeX (ConTeXt, not LaTeX) code that generates these signature fields. I’m going to report back the required changes to ConTeXt. Leonard, could you give us a hint on what may be wrong with the described signature field? Many thanks for your help, Pablo
nocompression-signature-field.pdf
Description: Adobe PDF document
