How to detect signature in a form pdf?

[manish59]

FDA-1572_508_R6_FINAL.pdf
FDA-1572_508_R6_FINAL (2).pdf

I have a form pdf which has signature embedded and I want to detect wether the pdf is signed or not?

[JorjMcKie]

This is currently (up to version 1.14.18) not supported unfortunately.
I need to straighten out that version anyway b/o some screw ups. So I may insert a Document method which inquires this state. The key PDF object property is called /SigFlags in the AcroForm object. This is an integer with 2 significant bit positions (see p. 674 of the manual):

• bit 0 "If set, the document contains at least one signature field."
• bit 1 "If set, the document contains signatures that may be invalidated if the file is saved (written) in a way that alters its previous contents, as opposed to an incremental update."

So what I will probably do in version 1.14.19 is defining a document method isSigned which returns this integer /Sigflags. Or maybe I call it getSigFlags. If not positive, the PDF has no signature fields. A value of 3 would mean True in the sense of your question.

Support for signature widgets themselves will have to wait until version 1.15.x I am afraid.

[JorjMcKie]

just uploaded v1.14.19 to PyPI.
As announced, there is a new method doc.getSigFlags(), which returns

• -1 for no (Form) PDF / no signature fields
• 1 if there is at least one signature field
• 3 if signatures would be invalidated upon a non-incremental save / write. I.e. this value should indicate the status "signed".

[manish59]

You are an amazing person buddy. Thanks a lot

…

On Fri, Jul 19, 2019 at 2:49 AM Jorj X. McKie ***@***.***> wrote: just uploaded v1.14.19 to PyPI. As announced, there is a new method doc.getSigFlags(), which returns - -1 for no (Form) PDF / no signature fields - 1 if there is at least one signature field - 3 if signatures would be invalidated upon a non-incremental save / write. I.e. this value should indicate the status "signed". — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#326?email_source=notifications&email_token=AD2AH5FYDENWJJJM7KIJONTQAGE2JA5CNFSM4IFAGAYKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD2LFI3Q#issuecomment-513168494>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AD2AH5BG2ULT4DQ7WDOPZPTQAGE2JANCNFSM4IFAGAYA> .

[JorjMcKie]

thanks a lot, very flattering.
But it wasn't difficult, just a 10-liner in C. Your examples were a big help to focus right on spot!