* epg.el (epg-status-GET_BOOL): New function.

[elisp/epg.git] / README

diff --git a/README b/README
index b3bca39..e231330 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@
 
 EasyPG is yet another GnuPG interface for Emacs.  It consists of three
 parts: transparent file encryption utility, Gnus/PGG backend, and
-easy-to-use elisp library to interact with GnuPG.
+elisp library to interact with GnuPG.
 
 * Requirements
 
@@ -16,43 +16,51 @@ easy-to-use elisp library to interact with GnuPG.
 
 * Quick start
 
-** Transparent file encryption
+** Installation
 
-EasyPG provides transparent file encryption similar to crypt++,
-alpaca.el, hedgehog.  To try this feature, put (require 'epg-file)
-in your ~/.emacs.el and C-x C-f ~/test.txt.gpg.
+$ ./configure
+$ sudo make install
 
-** Using with Gnus/PGG
+** 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 'epg-file)
+
+** 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
+add the following line to your ~/.gnus.
 
 (setq pgg-scheme 'epg)
 
 * Advantages over other competitors
 
-There are many competitors of EasyPG such as Mailcrypt, PGG, gpg.el,
-etc.  EasyPG has some advantages over them.
+There are many competitors of EasyPG such as Mailcrypt, Gnus/PGG,
+gpg.el, etc.  EasyPG has some advantages over them.
 
-** EasyPG avoides potential security flaws of Emacs.
+** EasyPG avoides potential security flaws of Emacs
 
-*** `call-process-region' writes data in region to temporary files.
+*** `call-process-region' writes data in region to temporary files
 
-`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 temporary files.
+EasyPG do _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!
+strings may be moved elsewhere in memory.
+
+Fortunately, there is gpg-agent to cache passphrases in more secure
+way, so EasyPG dares _not_ to cache passphrase.  Elisp programs can
+set `epg-context-passphrase-callback' to cache user's passphrases.
 
 ** GnuPG features are directly accessible from Emacs