Adobe Acrobat DC — Fixing up Form Fields?

A Chilkat customer signed a PDF using the Chilkat API. There were no errors, and the output PDF seemed to be signed. Using the Chilkat API to verify the signed PDF was also successful. Chilkat could see the signature and validated it successfully. However, the signature in the signed PDF could not be seen in Adobe Acrobat DC. When the […]

Possible Solution for Failure to Produce LTV Enabled PDF Signature

This blog post describes the case where your application asks Chilkat to produce an LTV-enabled PDF signature by specifying “ltvOcsp” in the signing attributes, yet the signed PDF as viewed in Adobe Acrobat does not show the signature as being LTV enabled. For example, in Adobe Acrobat, an LTV enabled signature looks like this: You can see the message “Signature […]

How to Know a PDF is Corrupt

Open a PDF in Adobe Acrobat DC.  Then without doing anything else, close the PDF. Does Acrobat ask to save changes even though you made no changes? If so, then it means that Acrobat auto-fixed a corrupt PDF.

Validating PDF Signatures with https://ec.europa.eu/cefdigital/DSS/webapp-demo/validation

A Chilkat customer is signing PDFs and then validating using the online tool at https://ec.europa.eu/cefdigital/DSS/webapp-demo/validation A few errors/warnings were encountered: 1) “The signature is not intact”.   <b>This error only happens if the “ltvOcsp” option was set</b> to create an LTV-enabled signature.  The source of the “Signature is not intact” error can be found here:  https://github.com/esig/dss/blob/master/validation-policy/src/main/java/eu/europa/esig/dss/validation/process/bbb/cv/checks/SignatureIntactCheck.java When “ltvOcsp” is specified (i.e. […]