Подпись PDF

def generate_pdf_reference(request, template, data_dict):
    print('generate_pdf_reference')
 
    input_stream = open(template, "rb")
    pdf_reader = PyPDF2.PdfFileReader(input_stream, strict=False)
    if "/AcroForm" in pdf_reader.trailer["/Root"]:
        pdf_reader.trailer["/Root"]["/AcroForm"].update(
            {NameObject("/NeedAppearances"): BooleanObject(True)})
 
    pdf_writer = PyPDF2.PdfFileWriter()
    set_need_appearances_writer(pdf_writer)
    if "/AcroForm" in pdf_writer._root_object:
        pdf_writer._root_object["/AcroForm"].update(
            {NameObject("/NeedAppearances"): BooleanObject(True)})
 
    pdf_writer.addPage(pdf_reader.getPage(0))
    page = pdf_writer.getPage(0)
    pdf_writer.updatePageFormFieldValues(page, data_dict)
    for j in range(0, len(page['/Annots'])):
        writer_annot = page['/Annots'][j].getObject()
        for field in data_dict:
            if writer_annot.get('/T') == field:
              
                writer_annot.update({
                    NameObject("/Ff"): NumberObject(1)
                })
    output_stream = BytesIO()
    pdf_writer.write(output_stream)
 
    response = HttpResponse(output_stream.getvalue(), content_type='application/pdf')
    response['Content-Disposition'] = 'filename='+ os.path.basename(template)
    input_stream.close()
    return response

   help_what_is_being_trained = {
        'fio': padez(user.fio) + '\n',# дат падеж
        'class': user.klas + '\n',
        'birth': str(user.birth.strftime("%Y")) + '\n',
        'current_year_1': str(datetime.now().strftime("%Y-%m-%d")) + '\n',
        'current_year_2': str(
            (datetime.now() + timedelta(days=365))
                .strftime("%Y-%m-%d")) + '\n',
        'end_data': str(datetime.now().strftime("%Y-%m-%d")) + '\n',
        'end_data_year': str(datetime.now().strftime("%Y-%m-%d")) + '\n',
        'Signature' : b'static/cert/cert.cer',
    }
 
    response=generate_pdf_reference(
        request,
        'templates/tpl/help_what_is_being_trained.pdf',
        help_what_is_being_trained
        )