* 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
-(1) Restart emacs
+ $ ./configure
+ $ sudo make install
-(2) C-x C-f ~/test.gpg
+Add the following line to your ~/.emacs
-* Advantages over other competitors
+ (require 'epa-setup)
-There are many competitors of EasyPG such as Mailcrypt, PGG, gpg.el,
-etc. EasyPG has some advantages over them.
+Then you can do some cryptographic operations on dired.
-** EasyPG avoides potential security flaws of Emacs.
+ M-x dired
+ (mark some files)
+ : e (or M-x epg-dired-do-encrypt)
+ (select recipients and click [OK])
-*** `call-process-region' writes data in region to temporary files.
+* Security consideration
-`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
-*** There is no way to clear strings safely.
+`call-process-region' writes data in region to a temporary file.
+EasyPG does *not* use `call-process-region' to communicate with a gpg
+subprocess.
+
+** `(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!
-
-** Most GnuPG features are accessible from Emacs
+strings may be moved elsewhere in memory.
-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.
+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