Invisible signature annotation violates PDF/A

[Petras Petkus <pe...@mitsoft.lt>]

Hello,

 

Using PDFBox v2.0 snapshot I tried to sign PDF/A document with invisible
signature.

I noticed that invisible signature annotation dictionary, when signature are
created with this method PDDocument#addSignature(:PDSignature,
:SignatureInterface), is created with F key's NoView flag bit set to 1 in
Widget annotation dictionary (see: PDDocument.java#247):

if (options.getVisualSignature() == null)
{
 
signatureField.getWidget().setAnnotationFlags(PDAnnotationWidget.FLAG_NO_VIE
W);
}

 

The use of this flag is redundant for making signature field invisible. As
ISO 32000 states:

Signature fields that are not intended to be visible shall have an
annotation rectangle that has zero height and width. Conforming readers
shall treat such signatures as not visible.

 

Besides, the use of this flag violates PDF/A-1 (and PDF/A-2) requirements
for Annotation dictionary F key:

The F key's Print flag bit shall be set to 1 and its Hidden, Invisible and
NoView flag bits shall be set to 0.

 

 

With best regards,

Petras Petkus