* What's this?

EasyPG is yet another GnuPG interface for Emacs.  It consists of two parts:

- "The EasyPG Assistant" which provides basic GUI of GnuPG
- "The EasyPG Library" which enables use of various features of GnuPG

NOTE: EasyPG is not a fork or a re-implementation of Gnus/PGG.

* Requirements

** GNU Emacs 21.4 or later, XEmacs 21.4 or later

** GnuPG 1.4.3 or later

* Quick start

** Installation

  $ ./configure
  $ sudo make install

Add the following line to your ~/.emacs

  (require 'epa-setup)

Then you can do some cryptographic operations on dired.

  M-x dired
  (mark some files)
  : e (or M-x epg-dired-do-encrypt)
  (select recipients and click [OK])

* Security consideration

** `call-process-region' writes data in region to a temporary file

`call-process-region' writes data in region to a temporary file.
EasyPG does *not* use `call-process-region' to communicate with a gpg
subprocess.

** `(fillarray string 0)' is not enough to clear passphrases

If Emacs crashed and dumps core, passphrase strings in memory are also
dumped within the core file.  `read-passwd' function clears passphrase
strings by `(fillarray string 0)'.  However, Emacs performs compaction
in gc_sweep phase.  If GC happens before `fillarray', passphrase
strings may be moved elsewhere in memory.

Fortunately, there is gpg-agent to cache passphrases in more secure
way, so the EasyPG Library dares *not* to cache passphrase by itself.
Elisp programs can set `epg-context-passphrase-callback' to cache
user's passphrases.