JSignPdf is a Java application for adding digital signatures to PDF
documents. It provides a JavaFX graphical interface and a command-line
interface, PKCS#12 and PKCS#11 keystores, visible signatures,
timestamping,
and OpenPDF and DSS/PAdES signing engines.

This SlackBuild repackages the official full ZIP distribution. It uses
the bundled Java libraries and the Linux x86_64 JavaFX components, but
does not bundle a Java runtime or require Maven or network access while
building. Only x86_64 is supported.

Java 21 or newer is required. The launcher uses zulu-openjdk21 by
default.
To use another compatible Java installation, set JAVA_HOME explicitly.
JAVA_OPTS can be used to pass additional Java VM options, for example:

  JAVA_OPTS="-Djsignpdf.swing=true" jsignpdf

Run jsignpdf without arguments for the GUI, or jsignpdf --help for CLI
usage. The desktop entry uses --gui when opening PDF files.

Hardware tokens and smartcards need the manufacturer's PKCS#11 library
and, where applicable, PC/SC services. OpenSC is an optional provider:
https://github.com/OpenSC/OpenSC
Configure the library in JSignPdf's Preferences dialog. Software PKCS#12
certificates do not need these optional components.