parcimonie.sh

This is a reimplementation of Parcimonie, written completely in a si{mp,ng}le Bash script.

What does it do?

parcimonie.sh refreshes individual keys in your GnuPG keyring at randomized intervals. Each key is refreshed over a unique, single-use Tor circuit.

Unlike the original Parcimonie, parcimonie.sh guarantees that each key refresh happens over a unique Tor circuit even when multiple refreshes happen at the same time (torsocks --isolate).

Why?

You can check the original Parcimonie design document if you are wondering why this is needed. This is the original file from the perl parcimonie and is only here to be archived.

The tl;dr version: gpg --refresh-keys discloses your entire list of PGP keys to the keyserver you are using, as well as whoever is wiretapping your connection if you are using an unencrypted protocol such as HKP (which is the default for most setups). That is a bad thing.

Known security issues

• On GnuPG 2.1+, key refreshes are not guaranteed to use unique Tor circuit (issue #15).
• On GnuPG 2.1+, if the user refreshes a key outside of parcimonie.sh prior to parcimonie.sh's first key refresh, Tor will not be used for key refreshes (also issue #15).

Installation

If on Arch, grab the parcimonie-sh-git package from the AUR.

On Fedora, install parcimonie.sh from the official repositories: dnf install parcimonie.sh.

Otherwise, just copy parcimonie.sh somewhere and make it run at boot with the right environment variables (see the "Usage" section).

Dependencies

• GnuPG: tested with GnuPG 2, probably works OK with 1.* as well
• torsocks 2.0
• Have Tor running

Usage

Just run parcimonie.sh. There are some optional environment variables that you can use to override the default values.

• TOR_ADDRESS: IP on which Tor is listening. If not set, uses 127.0.0.1.
• TOR_PORT: Port on which Tor is listening. If not set, uses 9050. Make sure this refers to a SOCKSPort entry of your torrc for which NoIsolateSOCKSAuth is not present. If you have no idea what that means, you have nothing to worry about.
• PARCIMONIE_USER: The user to run as. If not set, will run as whatever user is running the script. If set, will su to the specified user. You can also set it to the special value *, which will cause the script to multiple run instances of itself: one instance for each user who has a directory called .gnupg in their home directory. Useful for boot scripts, and for config files for the systemd service.
• MIN_WAIT_TIME: Minimum time to wait between key refreshes. Defaults to 900 seconds (15 minutes).
• TARGET_REFRESH_TIME: Rough expected time for refreshing every key in the keyring. Defaults to 604800 seconds (1 week). Note that this doesn't guarantee that every key will be refreshed in that time. The time intervals between refreshes and the actual keys to refresh are picked randomly every time. See the delay computation function for the exact formula.
• COMPUTER_ONLINE_FRACTION: Fraction of time that the computer is expected to be online, from 0.1 (online 10% of the time) to 1.0 (always online). Defaults to 1.0. This is used to scale TARGET_REFRESH_TIME accordingly in order to make it likely enough for keys to be regularly refreshed on a computer that is not online permanently. MIN_WAIT_TIME is still honored.
• USE_RANDOM: Whether or not to use /dev/random instead of /dev/urandom as source of randomness. By default, this is set to false, therefore /dev/urandom is used.
• GNUPG_BINARY: Path to gpg. If not set, will use gpg2 or gpg from the $PATH.
• DIRMNGR_PATH: Path to dirmngr, for GnuPG < 2.1. If not set, will try to find it in $PATH. If not found, GnuPG < 2.1 will be assumed.
• DIRMNGR_CLIENT_PATH: Path to dirmngr-client. If not set, will try to find it in $PATH. dirmngr-client is required if dirmngr is specified or found in $PATH.
• TORSOCKS_BINARY: Path to torsocks. If not set, will use torsocks from the $PATH.
• GNUPG_HOMEDIR: Value for the --homedir argument of gpg. Ignored when PARCIMONIE_USER=*. If not set, no --homedir argument is passed, which usually means ~/.gnupg will be used.
• GNUPG_KEYSERVER: Value for the --keyserver argument of gpg. If not set, no --keyserver argument is passed, which means your default keyserver will be used.
• GNUPG_KEYSERVER_OPTIONS: Value for the --keyserver-options argument of gpg. If not set, a single http-proxy= argument is passed. If you already use torify connections to keyservers with gpg's http-proxy keyserver-option in your gpg.conf while having other keyserver-options defined on top of that, you will need to re-specify those along with http-proxy= in GNUPG_KEYSERVER_OPTIONS in order to disable the proxying part. parcimonie.sh needs to run gpg with torsocks in order to ensure that all key grabs happen on different Tor circuits, and torsocks won't allow gpg to connect to its http-proxy on 127.0.0.1.
• PARCIMONIE_CONF: If set, this file will be sourced before running. Useful to set environment variables without polluting the environment too much.

systemd service

If you installed the Arch package or the Fedora package, you have a parameterized systemd service called parcimonie.sh@. The parameter refers to an environment file in /etc/parcimonie.sh.d; for example, the parcimonie.sh@hello service reads the environment variables from /etc/parcimonie.sh.d/hello.conf, and runs parcimonie.sh with it.

A ready-to-use configuration file is provided at /etc/parcimonie.sh.d/all-users.conf; it is set to start parcimonie.sh for all users on the system who have a ~/.gnupg directory. If that sounds like what you want, you can enable it right away using the parcimonie.sh@all-users service. If not, another sample configuration file is provided at /etc/parcimonie.sh.d/sample-configuration.conf.sample (Arch package) or at /usr/share/doc/parcimonie.sh/sample-configuration.conf.sample (Fedora package).

You can also use the systemd user service called parcimonie.sh, which uses the configuration file ~/.config/parcimonie.sh.conf.

Why a reimplementation?

Oh gee, let me think.

$ pactree parcimonie-git                       $ pactree -d 1 parcimonie-sh-git
parcimonie-git                                 parcimonie-sh-git
perl-any-moose                               bash
 perl-moose                                 torsocks
  perl-class-load                          tor
   perl-module-runtime                    gnupg
    perl-params-classify
   perl-data-optlist
    perl-params-util
    perl provides perl-scalar-list-utils
    perl-sub-install
   perl-package-stash
    perl-dist-checkconflicts
     perl-list-moreutils
     perl provides perl-exporter
    perl-package-deprecationmanager
     perl-list-moreutils
     perl-params-util
     perl-sub-install
    perl provides perl-scalar-list-utils
    perl-package-stash-xs
   perl-try-tiny
   perl-test-fatal
    perl-try-tiny
   perl-module-implementation
     perl-module-runtime
  perl-class-load-xs
   perl-class-load
  perl-data-optlist
  perl-devel-globaldestruction
   perl-sub-exporter
    perl
    perl-data-optlist
    perl-params-util
    perl-sub-install
   perl-sub-exporter-progressive
  perl-dist-checkconflicts
  perl-eval-closure
   perl provides perl-test-simple
   perl-test-requires
   perl-test-fatal
   perl-try-tiny
   perl-sub-exporter
  perl-list-moreutils
  perl-mro-compat
  perl-package-deprecationmanager
  perl-package-stash
  perl-package-stash-xs
  perl-params-util
  perl-sub-exporter
  perl-sub-name
  perl-task-weaken
  perl-try-tiny
 perl-mouse
perl-namespace-autoclean
 perl-b-hooks-endofscope
  perl-module-implementation
  perl-module-runtime
  perl-sub-exporter
  perl-sub-exporter-progressive
  perl-try-tiny
  perl-variable-magic
 perl-namespace-clean
   perl-b-hooks-endofscope
   perl-package-stash
perl-gnupg-interface
 perl-any-moose
perl-clone
perl-config-general
perl-file-homedir
 perl-file-which
perl-path-class
perl-net-dbus
 dbus
  expat
   glibc
  coreutils
  filesystem
  shadow
    bash
    pam
    acl
 perl-xml-twig
   perl-xml-parser
    expat
   perl-text-iconv
perl-tie-cache
perl-time-duration-parse
 perl-exporter-lite
perl-moosex-types-path-class
 perl-moose
 perl-moosex-types
  perl-carp-clan
  perl-namespace-clean
  perl-sub-install
  perl-sub-name
 perl-path-class
perl-moosex-getopt
 perl-getopt-long-descriptive
  perl-params-validate
   perl-module-implementation
  perl-sub-exporter
 perl-moose
 perl-moosex-role-parameterized
perl

Licensing

parcimonie.sh is licensed under the WTFPL.