open-pdf-sign – Digitally Sign PDF Documents

open-pdf-sign is a command-line application for adding cryptographic electronic signatures to PDF documents.

It supports several PAdES profiles, visible or invisible signatures, timestamp services and long-term validation data. Besides its normal command-line operation, the program can run as a server for integration with document-processing applications and automated signing workflows.

This is free and open source software.

Key Features

• Applies standards-based electronic signatures to existing PDF documents.
• Supports PAdES baseline B, T, LT and LTA signature profiles.
• Creates invisible signatures or places a visible signature on a selected page.
• Lets users configure the visible signature’s position, width, text and graphical appearance.
• Supports custom signature images as well as an image-only presentation mode.
• Accepts certificates and private keys from files or supported keystores.
• Handles certificate chains needed to establish trust in a generated signature.
• Supports password-protected source documents, private keys and keystores.
• Adds trusted timestamps using one or more configurable timestamp authorities.
• Can fall back to another timestamp authority if the preferred service is unavailable.
• Supports timestamp-service authentication and operation through a proxy.
• Can incorporate validation information needed for long-term signature verification.
• Provides document-certification options through supported DocMDP permission levels.
• Lets users add details such as the signing reason, location, contact information and signature hint.
• Supports configurable labels, languages, locales and time zones for visible signatures.
• Can add a blank page when a document needs additional space for a visible signature.
• Reads reusable configuration settings from YAML files.
• Offers a server mode that accepts signing requests through a JSON-based HTTP interface.
• Can write the resulting binary document to standard output for use in shell pipelines.

Website: github.com/open-pdf-sign/open-pdf-sign
Support:
Developer: Thomas Schreiber and Philipp Omenitsch
License: Apache License 2.0

open-pdf-sign is written in Java. Learn Java with our recommended free books and free tutorials.

Related Software

Read our verdict in the software roundup.

Explore our carefully curated directory of recommended free and open source software, covering every major software category. The directory forms part of our extensive collection of articles for Linux enthusiasts. It includes hundreds of detailed reviews, together with free and open source alternatives to proprietary software from companies such as Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. LinuxLinks also covers interesting projects worth exploring, Linux-compatible hardware, free programming books and tutorials, and much more. Know a useful free and open source Linux application that we haven’t covered? Tell us about it using our submission form.