#Autocrypt for Emacs

Autocrypt is cryptography protocol, for distributing and automatically encrypting emails. This package generically implements the protocol, for various Emacs MUAs (Mail User Agent).

Currently, it supports:

• Rmail, as a viewer
• Gnus, as a viewer
• mu4e, as a viewer
• message, as a composer

As of writing, this package doesn't fully implement the autocrypt protocol. It is currently still missing:

• Composing the setup message
• Parsing the setup message
• Key-Gossip Parsing (although the logic has been implemented)

I will attempt to on these issues in time, but any contributions, both in terms of extending the support of the protocol, but also MUA integration is welcomed.

#How to use

This package is distributed on GNU ELPA.

One might configure autocrypt.el to read headers using Rmail and inject headers using message-mode as follows:

(add-hook 'rmail-mode-hook #'autocrypt-mode)
(add-hook 'message-mode-hook #'autocrypt-mode)

Autocrypt recommends using a new or separate key pair for signing and encrypting. If you wish to do so, call the autocrypt-create-account command. In case you want to manually configure your setup, customise the autocrypt-accounts option. Note that configuring a key is necessary for autocrypt.el to function properly.

Bug reports and patches should be sent to my public inbox.

#Extending autocrypt.el

Autocrypt.el uses a custom extension mechanism, comparable to vc-mode. Each time a "generic" function is invoked, either autocrypt-backend-function is used to return the right function or autocrypt-backends is used to find a function.

Support for additional MUAs can be added to this package, but should preferably be part of the MUAs. An external MUA should either set autocrypt-backend-function in every buffer it handles, or modify autocrypt-backends to define a backend.

A backend is designated by a symbol. This is used together with a generic command to check for a function. For example, given the backend gnus and the command get-header, autocrypt would check if any of the following functions are defined:

• autocrypt-gnus--get-header
• gnus-autocrypt--get-header
• gnus--autocrypt-get-header

and call the first one it finds. All a backend has to do is to define these functions and ensure that they are visible (e.g. by autoloading when necessary).

#Copying

autocrypt.el is distributed under the CC0 1.0 Universal (CC0 1.0) Public Domain Dedication license.