* What's this?
-EasyPG is yet another GnuPG interface for Emacs. It consists of three
-parts: transparent file encryption utility, Gnus/PGG backend, and
-elisp library to interact with GnuPG.
+EasyPG is yet another GnuPG interface for Emacs. It consists of two parts:
-* Requirements
+- "The EasyPG Assistant"
+ A GUI frontend of GnuPG
+- "The EasyPG Library"
+ A library to interact with GnuPG
+
+NOTE: EasyPG is neither a fork nor a re-implementation of PGG.
-** GNU Emacs 21.4 or later, XEmacs 21.4 or later
+* Requirements
-** GnuPG 1.4.3 or later
+** GNU Emacs 21.4 or XEmacs 21.4
-** Gnus 5.10.8 or later (optional)
+** GnuPG 1.4.3
* Quick start
** Installation
-$ ./configure
-$ sudo make install
-
-** Transparent file encryption utility
-
-EasyPG provides transparent file encryption utility similar to
-crypt++, alpaca.el, hedgehog. To try this, add the following line to
-your ~/.emacs and C-x C-f ~/test.txt.gpg.
-
-(require 'epf)
-
-** Gnus/PGG backend
-
-EasyPG provides an implementation of the backend interface of
-Gnus/PGG. To use EasyPG instead of pgg-gpg, install pgg-epg.el and
-add the following line to your ~/.gnus.
-
-(setq pgg-scheme 'epg)
-
-* Advantages over other competitors
+ $ ./configure
+ $ sudo make install
-There are many competitors of EasyPG such as Mailcrypt, Gnus/PGG,
-gpg.el, etc. EasyPG has some advantages over them.
+Add the following line to your ~/.emacs
-** EasyPG avoides potential security flaws of Emacs
+ (require 'epa-setup)
-See "Security consideration" section.
+Then you can browse your keyring by `M-x epa-list-keys'. In addition,
+you can do some cryptographic operations on dired.
-** GnuPG features are directly accessible from Emacs
+ M-x dired
+ (mark some files)
+ : e (or M-x epa-dired-do-encrypt)
+ (select recipients and click [OK])
-Other competitors provide only specific features of GnuPG since they
-still support PGP 2.*, 5.*, 6.*. As the name indicates, EasyPG is
-inspired by GPGME (GnuPG Made Easy), and the library interface is
-close to GPGME. With EasyPG you can benefit from a lot of features of
-GnuPG.
+* Security
-* Security consideration
+There are security pitfalls around Emacs.
-** `call-process-region' writes data in region to a temporary file
+** Passphrase may leak 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
+The EasyPG Library does not use `call-process-region' to communicate with a gpg
subprocess.
-** `(fillarray string 0)' is not enough to clear passphrases
+** Passphrase may be stolen from a core file.
-If Emacs crashed and dumps core, passphrase strings in memory are also
+If Emacs crashes and dumps core, Lisp 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.
+strings may be moved elsewhere in memory. Therefore, passphrase
+caching in elisp is generally a bad idea.
-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.
+The EasyPG Library dares to disable passphrase caching. Fortunately,
+there is more secure way to cache passphrases - use gpg-agent. Elisp
+programs can set `epg-context-passphrase-callback' to cache user's
+passphrases, it is not recommended though.