After a TSA URL is selected, the PDF signing code must send the required data to that URL via HTTP and retrieve a signed timestamp. This requires some calculation on the content of the previously generated PDF file.
After that, the PDF shall be signed and the result from the request to the TSA URL embedded in the signature field of the PDF.
The function should use the same HTTP settings that would be used otherwise (i.e. in other parts of LibreOffice that also connect to external HTTP servers), such as proxy settings etc.
This code depends on a TSA URL being available (as it would be after https://bugs.freedesktop.org/show_bug.cgi?id=88427, https://bugs.freedesktop.org/show_bug.cgi?id=88428, and https://bugs.freedesktop.org/show_bug.cgi?id=88429), but the functionality itself does not depend directly on those issues. Only a valid TSA URL is required.
Part of Bug 84881 - Add RFC 3161 timestamp when digitally signing PDF (tracker)
Status -> NEW
Severity -> enhancement
This will be in 4.5 (It's in nightly since about March 1st). Thanks for the excellent work!