;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2023 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu home services gnupg)
#:use-module (guix gexp)
#:use-module ((guix records) #:select (match-record))
#:use-module (gnu services)
#:use-module (gnu services configuration)
#:use-module (gnu home services)
#:use-module (gnu home services shepherd)
#:autoload (gnu packages gnupg) (gnupg pinentry)
#:export (home-gpg-agent-configuration
home-gpg-agent-configuration?
home-gpg-agent-configuration-gnupg
home-gpg-agent-configuration-pinentry-program
home-gpg-agent-configuration-ssh-support?
home-gpg-agent-configuration-default-cache-ttl
home-gpg-agent-configuration-max-cache-ttl
home-gpg-agent-configuration-max-cache-ttl-ssh
home-gpg-agent-configuration-extra-content
home-gpg-agent-service-type))
(define raw-configuration-string? string?)
;; Configuration of 'gpg-agent'.
(define-configuration/no-serialization home-gpg-agent-configuration
(gnupg
(file-like gnupg)
"The GnuPG package to use.")
(pinentry-program
(file-like (file-append pinentry "/bin/pinentry-curses"))
"Pinentry program to use. Pinentry is a small user interface that
@command{gpg-agent} delegates to anytime it needs user input for a passphrase
or @acronym{PIN, personal identification number} (@pxref{Top,,, pinentry,
Using the PIN-Entry}).")
(ssh-support?
(boolean #f)
"Whether to enable @acronym{SSH, secure shell} support. When true,
@command{gpg-agent} acts as a drop-in replacement for OpenSSH's
@command{ssh-agent} program, taking care of OpenSSH secret keys and directing
passphrase requests to the chosen Pinentry program.")
(default-cache-ttl
(integer 600)
"Time a cache entry is valid, in seconds.")
(max-cache-ttl
(integer 7200)
"Maximum time a cache entry is valid, in seconds. After this time a cache
entry will be expired even if it has been accessed recently.")
(default-cache-ttl-ssh
(integer 1800)
"Time a cache entry for SSH keys is valid, in seconds.")
(max-cache-ttl-ssh
(integer 7200)
"Maximum time a cache entry for SSH keys is valid, in seconds.")
(extra-content
(raw-configuration-string "")
"Raw content to add to the end of @file{~/.gnupg/gpg-agent.conf}."))
(define (home-gpg-agent-configuration-file config)
"Return the @file{gpg-agent.conf} file for @var{config}."
(match-record config <home-gpg-agent-configuration>
(pinentry-program default-cache-ttl max-cache-ttl
default-cache-ttl-ssh max-cache-ttl-ssh
extra-content)
(mixed-text-file "gpg-agent.conf"
"pinentry-program " pinentry-program "\n"
"default-cache-ttl "
(number->string default-cache-ttl) "\n"
"max-cache-ttl "
(number->string max-cache-ttl) "\n"
"default-cache-ttl-ssh "
(number->string default-cache-ttl-ssh) "\n"
"max-cache-ttl-ssh "
(number->string max-cache-ttl-ssh) "\n"
extra-content)))
(define (home-gpg-agent-shepherd-services config)
"Return the possibly-empty list of Shepherd services for @var{config}."
(match-record config <home-gpg-agent-configuration>
(gnupg ssh-support?)
;; 'gpg-agent' is started on demand by GnuPG's programs, but it has to be
;; started explicitly when OpenSSH support is enabled (info "(gnupg) Agent
;; Options").
(if ssh-support?
(let ((endpoint (lambda (name socket)
#~(endpoint
(make-socket-address
AF_UNIX
(string-append %user-runtime-dir
"/gnupg/" #$socket))
#:name #$name
#:socket-directory-permissions #o700))))
(list (shepherd-service
(provision '(gpg-agent ssh-agent))
(modules '((shepherd support))) ;for '%user-runtime-dir'
(start #~(make-systemd-constructor
(list #$(file-append gnupg "/bin/gpg-agent")
"--supervised" "--enable-ssh-support")
(list #$(endpoint "ssh" "S.gpg-agent.ssh")
#$(endpoint "browser" "S.gpg-agent.browser")
#$(endpoint "extra" "S.gpg-agent.extra")
;; #$(endpoint "scdaemon" "S.scdaemon")
#$(endpoint "std" "S.gpg-agent"))))
(stop #~(make-systemd-destructor))
(documentation "Start 'gpg-agent', the GnuPG passphrase
agent, with support for handling OpenSSH material."))))
'())))
(define (home-gpg-agent-files config)
`((".gnupg/gpg-agent.conf" ,(home-gpg-agent-configuration-file config))))
(define (home-gpg-agent-environment-variables config)
"Return GnuPG environment variables needed for @var{config}."
(if (home-gpg-agent-configuration-ssh-support? config)
`(("SSH_AUTH_SOCK"
. "$XDG_RUNTIME_DIR/gnupg/S.gpg-agent.ssh"))
'()))
(define home-gpg-agent-service-type
(service-type
(name 'home-gpg-agent)
(extensions
(list (service-extension home-files-service-type
home-gpg-agent-files)
(service-extension home-shepherd-service-type
home-gpg-agent-shepherd-services)
(service-extension home-environment-variables-service-type
home-gpg-agent-environment-variables)))
(default-value (home-gpg-agent-configuration))
(description
"Configure GnuPG's agent, @command{gpg-agent}, which is responsible for
managing OpenPGP and optionally SSH private keys. When SSH support is
enabled, @command{gpg-agent} acts as a drop-in replacement for OpenSSH's
@command{ssh-agent}.")))