How do I create a PDF file containing a Signature Field, using python?
Question:
In order to be able to sign a PDF document using a token based DSC, I need a so-called signature field in my PDF.
This is a rectangular field you can fill with a digital signature using e.g. Adobe Reader or Adobe Acrobat.
I want to create this signable PDF in Python.
I’m starting from plain text, or a rich-text document (Image & Text) in .docx format.
How do I generate a PDF file with this field, in Python?
Answers:
Unfortunately, I couldn’t find any (free) solutions. Just Python programs that sign PDF documents.
But there is a Python PDF SDK called PDFTron that has a free trial. Here’s a link to a specific article showing how to “add a certification signature field to a PDF document and sign it”.
# Open an existing PDF
doc = PDFDoc(docpath)
page1 = doc.GetPage(1)
# Create a text field that we can lock using the field permissions feature.
annot1 = TextWidget.Create(doc.GetSDFDoc(), Rect(50, 550, 350, 600), "asdf_test_field")
page1.AnnotPushBack(annot1)
# Create a new signature form field in the PDFDoc. The name argument is optional;
# leaving it empty causes it to be auto-generated. However, you may need the name for later.
# Acrobat doesn't show digsigfield in side panel if it's without a widget. Using a
# Rect with 0 width and 0 height, or setting the NoPrint/Invisible flags makes it invisible.
certification_sig_field = doc.CreateDigitalSignatureField(cert_field_name)
widgetAnnot = SignatureWidget.Create(doc, Rect(0, 100, 200, 150), certification_sig_field)
page1.AnnotPushBack(widgetAnnot)
...
# Save the PDFDoc. Once the method below is called, PDFNet will also sign the document using the information provided.
doc.Save(outpath, 0)
I use signpdf library of python to sign pdf.
Read this document for better understanding https://github.com/yourcelf/signpdf
pip install signpdf
Demo:
Sign the first page of "contract.pdf" with the signature "sig.png": ->
signpdf contract.pdf sig.png --coords 1x100x100x150x40
Understand Co-ordinates: Github link
you can use https://github.com/mstamy2/PyPDF2 for PDF generation with python code.
and then use open source Java-Digital-Signature: Java command line tool for digital signature with PKCS#11 token: https://github.com/AlessioScarfone/Java-Digital-Signature
and call on your python code:
import subprocess
subprocess.call(['java', '-jar', 'signer.jar', 'pades', 'test.pdf'])
Check out pyHanko. You can add, edit and digitally sign PDFs using Python.
https://github.com/MatthiasValvekens/pyHanko
It’s totally free. And if you have any problems, Matthias is very helpful and responsive.
In order to be able to sign a PDF document using a token based DSC, I need a so-called signature field in my PDF.
This is a rectangular field you can fill with a digital signature using e.g. Adobe Reader or Adobe Acrobat.
I want to create this signable PDF in Python.
I’m starting from plain text, or a rich-text document (Image & Text) in .docx format.
How do I generate a PDF file with this field, in Python?
Unfortunately, I couldn’t find any (free) solutions. Just Python programs that sign PDF documents.
But there is a Python PDF SDK called PDFTron that has a free trial. Here’s a link to a specific article showing how to “add a certification signature field to a PDF document and sign it”.
# Open an existing PDF
doc = PDFDoc(docpath)
page1 = doc.GetPage(1)
# Create a text field that we can lock using the field permissions feature.
annot1 = TextWidget.Create(doc.GetSDFDoc(), Rect(50, 550, 350, 600), "asdf_test_field")
page1.AnnotPushBack(annot1)
# Create a new signature form field in the PDFDoc. The name argument is optional;
# leaving it empty causes it to be auto-generated. However, you may need the name for later.
# Acrobat doesn't show digsigfield in side panel if it's without a widget. Using a
# Rect with 0 width and 0 height, or setting the NoPrint/Invisible flags makes it invisible.
certification_sig_field = doc.CreateDigitalSignatureField(cert_field_name)
widgetAnnot = SignatureWidget.Create(doc, Rect(0, 100, 200, 150), certification_sig_field)
page1.AnnotPushBack(widgetAnnot)
...
# Save the PDFDoc. Once the method below is called, PDFNet will also sign the document using the information provided.
doc.Save(outpath, 0)
I use signpdf library of python to sign pdf.
Read this document for better understanding https://github.com/yourcelf/signpdf
pip install signpdf
Demo:
Sign the first page of "contract.pdf" with the signature "sig.png": ->
signpdf contract.pdf sig.png --coords 1x100x100x150x40
Understand Co-ordinates: Github link
you can use https://github.com/mstamy2/PyPDF2 for PDF generation with python code.
and then use open source Java-Digital-Signature: Java command line tool for digital signature with PKCS#11 token: https://github.com/AlessioScarfone/Java-Digital-Signature
and call on your python code:
import subprocess
subprocess.call(['java', '-jar', 'signer.jar', 'pades', 'test.pdf'])
Check out pyHanko. You can add, edit and digitally sign PDFs using Python.
https://github.com/MatthiasValvekens/pyHanko
It’s totally free. And if you have any problems, Matthias is very helpful and responsive.