X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=README;h=b438bd3330e83010f5e01ce59e33527d0b1ba665;hb=359180decf50389e8a5313a3fb04c88a6a93f69e;hp=2a780486ad6409bbfa8138707b4c76b5d4477677;hpb=80e5c7246f6205ed05c6f77deaa736d7e00eede1;p=elisp%2Fepg.git diff --git a/README b/README index 2a78048..b438bd3 100644 --- a/README +++ b/README @@ -1,52 +1,57 @@ * 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 neither a fork nor a re-implementation of Gnus/PGG. -** GNU Emacs 21.4 or later +* Requirements -** XEmacs 21.4 or later +** GNU Emacs 21.4 or XEmacs 21.4 -** GnuPG 1.4.3 or later +** GnuPG 1.4.3 * Quick start -(0) Put (require 'epg-file) in your ~/.emacs.el +** Installation + + $ ./configure + $ sudo make install -(1) Restart emacs +Add the following line to your ~/.emacs -(2) C-x C-f ~/test.gpg + (require 'epa-setup) -* Advantages over other competitors +Then you can browse your keyring by M-x epa-list-keys. In addition, +you can do some cryptographic operations on dired. -There are many competitors of EasyPG such as Mailcrypt, PGG, gpg.el, -etc. EasyPG has some advantages over them. + 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 temporary files. +** `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 +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. 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. Therefore, passphrase +caching in Elisp is generally a bad idea. The EasyPG Library dares to +disable passphrase caching. -** Most GnuPG features are accessible from Emacs +Fortunately, there is more secure way to cache passphrases - use +gpg-agent. -Other competitors provide only specific features of GnuPG. As the -name indicates, EasyPG is inspired by GPGME (GnuPG Made Easy), and the -library interface is close to GPGME. With EasyPG you can handle -binary messages, sign/encrypt combined messages, etc. +Elisp programs can set `epg-context-passphrase-callback' to cache +user's passphrases, it is not recommended though.