X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=README;h=81a94abea80d0851b38e0fabbb30586e43f8ca74;hb=3c0243c9e94a1185749b53a334b3358fa0d5bd8f;hp=c370ac87003b607c1d56a6f7ad97f73f012a892d;hpb=afe1a4421ada9e44c87787257aad124648973e11;p=elisp%2Fepg.git diff --git a/README b/README index c370ac8..81a94ab 100644 --- a/README +++ b/README @@ -1,46 +1,53 @@ * What's this? -EasyPG is yet another GnuPG interface for Emacs. It consists of two -parts: transparent file encryption utility and easy-to-use elisp -library to interact with GnuPG. +EasyPG is yet another GnuPG interface for Emacs. It consists of two parts: -* Requirements +- "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. -** GNU Emacs 21.4 or later +* Requirements -** XEmacs 21.4 or later +** GNU Emacs 21.4 or later, XEmacs 21.4 or later ** GnuPG 1.4.3 or later * Quick start -(0) Put (require 'epg-file) in your ~/.emacs.el +** Installation + + $ ./configure + $ sudo make install + +Add the following line to your ~/.emacs -(1) Restart emacs + (require 'epa-setup) -(2) C-x C-f ~/test.gpg +Then you can do some cryptographic operations on dired. -* Advantages over other competitors + M-x dired + (mark some files) + : e (or M-x epg-dired-do-encrypt) + (select recipients and click [OK]) -** EasyPG avoides potential security flaws of Emacs. +* Security consideration -*** `call-process-region' writes data in region to a temporary file. +** `call-process-region' writes data in region to a temporary file -PGG and gpg.el use `call-process-region' to communicate with a gpg -subprocess. Your passphrases may 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 with the core file. `read-passwd' function clears passphrase -strings by `(fillarray string 0)'. However, it is not perfect. Emacs -does compaction of small strings in gc_sweep phase. If GC happens -before `fillarray', passphrase strings may be copied elsewhere in -memory. So, it is recommended that if you are done with passphrase -you should clear it manually. However, PGG and gpg.el enables -passphrase caching by default. - -** Most GnuPG features are accessible from Emacs - -As the name indicates, EasyPG is inspired by GPGME (GnuPG Made Easy), -and the library interface is close to GPGME. +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.