* 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
+epa.el - EasyPG Assistant, a basic GUI of GnuPG
+epg.el - the EasyPG library which interacts with GnuPG
-** GNU Emacs 21.4 or later
+NOTE: EasyPG is not a fork or a re-implementation of Gnus/PGG.
-** XEmacs 21.4 or later
+* Requirements
-** GnuPG 1.4.3 or later
+** GNU Emacs 21.4 or later, XEmacs 21.4 or later
-** Gnus 5.10.8 or later (optional)
+** GnuPG 1.4.3 or later
* Quick start
-** Transparent file encryption utility
+** Installation
-EasyPG provides transparent file encryption utility similar to
-crypt++, alpaca.el, hedgehog. To try this feature, add the following
-line to your ~/.emacs and C-x C-f ~/test.txt.gpg.
+$ ./configure
+$ sudo make install
-(require 'epg-file)
+Add the following line to your ~/.emacs
-** Gnus/PGG backend
+(require 'epa-setup)
-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.
+* Advantages over other competitors
-(setq pgg-scheme 'epg)
+There are many competitors of EasyPG such as Mailcrypt, Gnus/PGG,
+gpg.el, etc. EasyPG has some advantages over them.
-* Advantages over other competitors
+** EasyPG avoides potential security flaws of Emacs
-There are many competitors of EasyPG such as Mailcrypt, PGG, gpg.el,
-etc. EasyPG has some advantages over them.
+See "Security consideration" section.
-** EasyPG avoides potential security flaws of Emacs.
+** GnuPG features are directly accessible from Emacs
-*** `call-process-region' writes data in region to temporary files.
+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 consideration
+
+** `call-process-region' writes data in region to a temporary file
-`call-process-region' writes data in region to temporary files. PGG
-and gpg.el use `call-process-region' to communicate with a gpg
-subprocess. Your passphrases leak to the filesystem!
+`call-process-region' writes data in region to a temporary file.
+EasyPG does *not* use `call-process-region' to communicate with a gpg
+subprocess.
-*** There is no way to clear strings safely.
+** `(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. It is recommended that as
-soon as you are done with passphrase you should clear it manually.
-However, PGG and gpg.el can keep passphrase strings in cache for a
-while and this behavior is their default!
-
-** GnuPG features are directly accessible from Emacs
+strings may be moved elsewhere in memory.
-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.
+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.
projects / elisp / epg.git / blobdiff