age.el: age encryption support for Emacs
age.el provides transparent Age file encryption and decryption in Emacs. It is based on the Emacs EasyPG code and offers similar Emacs file handling for Age encrypted files.
Using age.el you can, for example, maintain .org.age encrypted Org files,
provide Age encrypted authentication information out of .authinfo.age, and
open/edit/save Age encrypted files via TRAMP.
Usage
Age is available on melpa and you can install it from there:
(use-package age
:ensure t
:demand t
:config
(age-file-enable))Alternatively, put age.el in your load-path and:
(require 'age)
(age-file-enable)You can now open, edit, and save Age encryted files from Emacs as
long as they end with the .age file extension. You can also find-file
new Age files and they will be encrypted to the age-default-recipient on
first save.
Identities (private keys) and recipients (public keys) are maintained via the
customizable age-default-identity and age-default-recipient variables. By
default they are set to ~/.ssh/id_rsa and ~/.ssh/id_rsa.pub respectively.
age.el tries to remain composable with the core philosophy of age itself and as such does not try to provide a kitchen sink worth of features.
Example configuration
You can find my current configuration for age.el below. I am using age-yubikey-plugin to supply an age identity off of a yubikey PIV slot. The slot is configured to require a touch (with a 15 second cache) for every age client query against the identity stored in that slot.
This means that every age.el decrypt requires a physical touch for confirmation. The cache makes it such that e.g. decrypting a series of age encrypted org files in sequence only requires a single touch confirmation.
This limits the amount of actively accessible encrypted data inside Emacs to only the things I physically confirm, and only for 15 second windows, but without having to type a passphrase at any point. This excludes any open buffers that have decrypted data in memory of course.
The key scheme I employ encrypts against the public keys of two main identities. My aforementioned yubikey identity as well as a disaster recovery identity, who’s private key is passphrase encrypted and kept in cold storage.
You’ll note that I’ve set age-default-identity and age-default-recipient
to be lists. These two variables can be file paths, key strings, or lists that
contain a mix of both. This allows you to easily encrypt to a series of
identities in whatever way you choose to store and manage them.
Note that I’m using rage as opposed to age as my age client. This is due the aforementioned lack of pinentry support in the reference age implemention, which rage does support.
(use-package age
:quelpa (age :fetcher github :repo "anticomputer/age.el")
:ensure t
:demand t
:custom
(age-program "rage")
(age-default-identity "~/.ssh/age_yubikey")
(age-default-recipient
'("~/.ssh/age_yubikey.pub"
"~/.ssh/age_recovery.pub"))
:config
(age-file-enable))I use the above configuration in combination with a version of org-roam that
has the following patches applied:
https://patch-diff.githubusercontent.com/raw/org-roam/org-roam/pull/2302.patch
This patch enables .org.age discoverability in org-roam and beyond that
everything just works the same as you’re used to with .org.gpg files. This
patch was merged into org-roam main on Dec 31, 2022, so any org-roam release
post that date should provide you with age support out of the box.
Other fun examples
Encrypting a file to a given GitHub username’s ssh keys
(defun my/age-github-keys-for (username)
"Turn GitHub USERNAME into a list of ssh public keys."
(let* ((res (shell-command-to-string
(format "curl -s https://api.github.com/users/%s/keys"
(shell-quote-argument username))))
(json (json-parse-string res :object-type 'alist)))
(cl-assert (arrayp json))
(cl-loop for alist across json
for key = (cdr (assoc 'key alist))
when (and (stringp key)
(string-match-p "^\\(ssh-rsa\\|ssh-ed25519\\) AAAA" key))
collect key)))
(defun my/age-save-with-github-recipient (username)
"Encrypt an age file to the public keys of GitHub USERNAME."
(interactive "MGitHub username: ")
(cl-letf (((symbol-value 'age-default-recipient)
(append (if (listp age-default-recipient)
age-default-recipient
(list age-default-recipient))
(my/age-github-keys-for username))))
(save-buffer)))Visual indicators of encryption and decryption in progress
Since I use a yubikey touch controlled age identity I find it useful to have a
visual indication of when age.el is performing operations that might require
me to touch the yubikey. The following advice adds visual notifications to
age-start-decrypt and age-start-encrypt.
I’m also using this as a way to get a good feel for just how much Emacs is interacting with my encrypted data.
(require 'notifications)
(defun my/age-notify (msg &optional simple)
(cond (simple
(message (format "%s" msg)))
((eq system-type 'gnu/linux)
(notifications-notify
:title "age.el"
:body (format "%s" msg)
:urgency 'low
:timeout 800))
((eq system-type 'darwin)
(do-applescript
(format "display notification \"%s\" with title \"age.el\"" msg)))
(t
(message (format "%s" msg)))))
(defun my/age-notify-decrypt (&rest args)
(cl-destructuring-bind (context cipher) args
(my/age-notify (format "Decrypting %s" (age-data-file cipher)) t)))
(defun my/age-notify-encrypt (&rest args)
(cl-destructuring-bind (context plain recipients) args
(my/age-notify (format "Encrypting %s" (age-data-file plain)) t)))
(defun my/age-toggle-decrypt-notifications ()
(interactive)
(cond ((advice-member-p #'my/age-notify-decrypt #'age-start-decrypt)
(advice-remove #'age-start-decrypt #'my/age-notify-decrypt)
(message "Disabled age decrypt notifications."))
(t
(advice-add #'age-start-decrypt :before #'my/age-notify-decrypt)
(message "Enabled age decrypt notifications."))))
(defun my/age-toggle-encrypt-notifications ()
(interactive)
(cond ((advice-member-p #'my/age-notify-encrypt #'age-start-encrypt)
(advice-remove #'age-start-encrypt #'my/age-notify-encrypt)
(message "Disabled age encrypt notifications."))
(t
(advice-add #'age-start-encrypt :before #'my/age-notify-encrypt)
(message "Enabled age encrypt notifications."))))
;; we only care about decrypt notifications really
(my/age-toggle-decrypt-notifications)
(my/age-toggle-encrypt-notifications)Known issues
Lack of pinentry support in age reference implementation
The age reference implementation does not support pinentry by design. Users are encouraged to use identity (private) keys and recipient (public) keys, and manage those secrets accordingly.
Workaround: pinentry support through rage
You can work around this by using rage instead of age, which is a Rust based implementation of the Age spec which does support pinentry by default. age.el will work with rage as well. An example rage config may look like:
(use-package age
:ensure t
:demand t
:custom
(age-program "rage")
:config
(age-file-enable))You will now be able to use passphrase protected Age identities and files.
Tip: configuring pinentry-emacs for minibuffer passphrase entry
If you’d like to keep your pinentry support inside of emacs entirely for
whatever reason, you can use pinentry-emacs for a pinentry program that
will prompt you inside of Emacs. Most distributions have a package for
pinentry-emacs available, which provides a GNU pinentry executable with the
Emacs flavor enabled.
If your distribution does not provide an Emacs enabled build of GNU pinentry, you can find the GNU pinentry collection, which contains the Emacs flavor of pinentry as well here.
Warning: don’t confuse GNU pinentry with this pinentry-emacs shellscript they are not the same thing.
Note: if you’re saying file not found errors when trying to use pinentry
you’ll also want to ensure the Emacs pinentry socket actually exists and is
running by using the GNU ELPA pinentry package:
(use-package pinentry
:config
(pinentry-start))With both of those requirements satisfied, rage will use pinentry-emacs to
prompt you for passphrases in the minibuffer.
Note: this will attempt to use Emacs as your pinentry for all commandline use of the rage client as well.
Direct use of passphrase encrypted age files
This again requires you to use rage, or another age-spec compliant client that supports pinentry and follows the rage or age argument and error reporting conventions.
By default, age.el will be able to open and save passphrase encrypted age files. It will detect the scrypt stanza in the age file and set the age.el handling context for passphrase mode accordingly.
You can also programmatically force age.el into passphrase mode by binding
age-default-identity and age-default-recipient to nil temporarily, e.g.:
(defun my/age-open-with-passphrase (file)
(interactive "fPassphrase encrypted age file: ")
(cl-letf (((symbol-value 'age-default-identity) nil)
((symbol-value 'age-default-recipient) nil))
(find-file file)))
(defun my/age-save-with-passphrase ()
(interactive)
(cl-letf (((symbol-value 'age-default-identity) nil)
((symbol-value 'age-default-recipient) nil))
(save-buffer)))org-roam support for age encrypted org files
Org-roam has merged org-roam/org-roam#2302 which
provides .org.age discoverability support for org-roam, so if you update to
the latest release from e.g. MELPA or the main branch, org-roam will function
with .age encrypted org files.
pass (https://passwordstore.org) and its Emacs packages depend on gpg
Please see https://github.com/anticomputer/passage.el for an age based drop-in replacement for pass and its associated Emacs packages.
I use the following configuration that also rebinds the pass function to
passage for convenience:
(use-package passage
:quelpa (passage :fetcher github :repo "anticomputer/passage.el")
:ensure t
:demand t
:config
;; rebind function value for pass to passage
(fset #'pass (lambda () (interactive) (passage))))Disclaimer
This is experimental software and subject to heavy feature iterations.
Why age over gpg?
This is, apparently, a heated topic and folks more qualified than me have commented on this in great detail over many years. The following blog post I think provides a good summary of the state of the debate regarding the OpenPGP specification:
Thanks to reddit’s /u/a-huge-waste-of-time for linking that reference.
In true megalomaniac fashion I’ll quote myself out of the age.el /r/emacs
announcement thread when asked why I was looking to limit my use of gpg for my
local file encryption needs inside Emacs.
I wanted to reduce the amount of key management in my life to the bare minimum. I don’t use gpg for its intended purpose (maintaining a web of trust with folks that you communicate with), but rather only use it for Emacs file encryption and things like password-store (which I’m replacing with https://github.com/FiloSottile/passage and will also port the Emacs pass frontend to work with).
Age functions with ssh keys as well as its own key formats, so it hugely simplifies the amount of key material I have to maintain. Especially when managing key material on e.g. YubiKeys, maintaining Encryption, Authentication, and Signing subkeys and juggling what is essentially a personal PKI (not to mention bringing it along on every system) surrounding gpg’s key trust relationship maintainance.
I use e2e encrypted email and messaging services for encrypted communications and ssh keys to sign git commits.
So with age I can also just use my ssh public key to encrypt and my ssh private key to decrypt my files. If I want to get fancy, I can use something like https://github.com/str4d/age-plugin-yubikey to provide the key material for my age operations (which should compose with age.el quite well also, i.e. you can have every decrypt operation have a touch requirement in Emacs that way).
TL;DR: gpg is overly complex for my use case and I’m currently shoehorning gpg into a role it was never designed or intended to play. Complexity of use and secure use of cryptography don’t compose well for most folks, so now that gpg no longer serves any real purpose in my environment, it’s time to retire it from my dependency stack.
Having said that, age.el is not intended to encourage you to abandon gpg. However, if you’ve been looking for a lighter weight alternative for Emacs encryption, it might be a good fit for you.
License
GPLv3
This code was ported from the EasyPG Emacs code and the original author is Daiki Ueno <ueno@unixuser.org> who has assigned their copyright to the FSF.