Hello,
We are trying to convert a signed PDF to PDF/A-1 or PDF/A-3b. When viewing the converted PDF in Adobe reader, the blue bar shows the signature is not valid.
I have googled a lot about whether we can convert a signed PDF and the answer varies.
Could you help to explain that is the converted file valid? How about the digital signatures? Sometimes we also get error thrown with PDF/A-1 but not PDF/A-3B.
In this case the document is certified. Documents with signature can not be converted.
Removing signatures is not allowed in certified document.
In other cases, we recommend using this code snippet to remove signatures before convert:
var pdfSign = new PdfFileSignature(dataDir + "doc_with_sign.pdf");
foreach (var item in pdfSign.GetSignNames())
{
pdfSign.RemoveSignature(item, false);
}
pdfSign.Save(dataDir + "doc_without_sign.pdf");