pdf-simple-sign

pdf-simple-sign is a simple PDF signer intended for documents produced by the Cairo library. As such, it currently comes with some restrictions:

the document may not have any forms or signatures already, as they will be overwitten
the document may not employ cross-reference streams, or must constitute a hybrid-reference file at least
the document may not be newer than PDF 1.6 already, or it will get downgraded to that version
the signature may take at most 4 kilobytes as a compile-time limit, which should be enough space even for one intermediate certificate

The signature is attached to the first page and has no appearance.

I don’t aim to extend the functionality any further. The project is fairly self-contained and it should be easy to grasp and change to suit to your needs.

Building

Build dependencies: Meson, a C++11 compiler, pkg-config
Runtime dependencies: libcrypto (OpenSSL 1.1 API)

$ git clone https://git.janouch.name/p/pdf-simple-sign.git
$ cd pdf-simple-sign
$ meson builddir
$ cd builddir
$ ninja

In addition to the C++ version, also included is a native Go port:

$ go get janouch.name/pdf-simple-sign/cmd/pdf-simple-sign

Usage

$ ./pdf-simple-sign document.pdf document.signed.pdf KeyAndCerts.p12 password

Contributing and Support

Use https://git.janouch.name/p/pdf-simple-sign to report bugs, request features, or submit pull requests. git send-email is tolerated. If you want to discuss the project, feel free to join me at ircs://irc.janouch.name, channel #dev.

Bitcoin donations are accepted at: 12r5uEWEgcHC46xd64tt3hHt9EUvYYDHe9

License

This software is released under the terms of the 0BSD license, the text of which is included within the package along with the list of authors.