X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=README;h=610523f68d58f07c8cf9b8b4375e96744ae04734;hb=5312c05cb5a923991a4d5ab8de4b9fc53d21f0d2;hp=187db0d370eea27466b7151c501fe4d7a01fdecf;hpb=31d97193bafb50321267222e8e7db2489c4c43b0;p=elisp%2Fepg.git

diff --git a/README b/README
index 187db0d..610523f 100644
--- a/README
+++ b/README
@@ -1,30 +1,54 @@
 * What's this?
 
-EasyPG is yet another GnuPG interface for Emacs.  It consists of a
-transparent file encryption application and easy-to-use elisp library
-to interact with GnuPG.
+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 neither a fork nor a re-implementation of Gnus/PGG.
+
+* Requirements
+
+** GNU Emacs 21.4 or XEmacs 21.4
+
+** GnuPG 1.4.3
 
 * Quick start
 
-(0) Put (require 'epg-file) in your ~/.emacs.el
+** Installation
+
+  $ ./configure
+  $ sudo make install
+
+Add the following line to your ~/.emacs
+
+  (require 'epa-setup)
+
+Then you can browse your keyring by M-x epa-list-keys.  In addition,
+you can do some cryptographic operations on dired.
 
-(1) Restart emacs
+  M-x dired
+  (mark some files)
+  : e (or M-x epg-dired-do-encrypt)
+  (select recipients and click [OK])
 
-(2) C-x C-f ~/test.gpg
+* Security consideration
 
-* Advantages over other competitors
+** `call-process-region' writes data in region to a temporary file
 
-** EasyPG avoides potential security flaws of Emacs.
+`call-process-region' writes data in region to a temporary file.
+EasyPG does *not* use `call-process-region' to communicate with a gpg
+subprocess.
 
-*** `call-process-region' writes data in region to a temporary file.
-PGG and gpg.el use `call-process-region' to communicate with a
-subprocess "gpg".  So, your passphrases may leak to the filesystem.
+** `(fillarray string 0)' is not enough to clear passphrases
 
-*** There is no way to clear strings safely.
-To prevent passphrases from been stealing from cores, `read-passwd'
-function clears passphrase strings by `(fillarray string 0)'.
-However, it is not enough.  In GC sweep phase, Emacs does compaction
-on small strings.  If GC happens before `fillarray', passphrase
-strings may be copied elsewhere in the memory.
+If Emacs crashes 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.
 
-PGG and gpg.el enables passphrase caching by default.
+Fortunately, there is gpg-agent to cache passphrases in more secure
+way, so the EasyPG Library dares to disable passphrase caching.  Elisp
+programs can set `epg-context-passphrase-callback' to cache user's
+passphrases.