* What's this?
-EasyPG is a GnuPG interface for Emacs. It has two aspects: convenient
-tools to use GnuPG from Emacs (The EasyPG Assistant), and a fully
-functional library to interact with GnuPG (The EasyPG Library.)
+EasyPG is an all-in-one GnuPG interface for Emacs. It has two
+aspects: convenient tools which allow to use GnuPG from Emacs (EasyPG
+Assistant), and a fully functional interface library to GnuPG (EasyPG
+Library).
+
+* Features
+
+The EasyPG Assistant provides the following features:
+
+- Keyring browser.
+- Cryptographic operations on regions.
+- Cryptographic operations on files.
+- Dired integration.
+- Encryption/decryption of *.gpg files.
+
+The EasyPG Library provides the following features:
+
+- The API covers most functions of GnuPG like GPGME.
+- S/MIME support using gpgsm.
+- Designed to avoid potential security pitfalls around Emacs
* Requirements
-** GNU Emacs 21.4 or XEmacs 21.4
+** GNU Emacs 21.4, XEmacs 21.4, or later
-** GnuPG 1.4.3
+** GnuPG 1.4.3 or later
+ If you are using earlier versions, you will need to specify
+ --disable-gpg-test when ./configure.
* Quick start
(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.
+Restart emacs and type `M-x epa- TAB', and you will see a lot of
+commands available. For example,
+
+- To browse your keyring, type `M-x epa-list-keys'
+- To create a cleartext signature of the region, type `M-x epa-sign-region'
+
+You can also do some cryptographic operations from dired.
M-x dired
(mark some files)
: e (or M-x epa-dired-do-encrypt)
- (select recipients and click [OK])
+ (select recipients by 'm' and click [OK])
* MUA Integration
The EasyPG Library can be used in combination with various MUA (Mail
-User Agents.)
+User Agents).
** CVS version of Gnus
-CVS version of Gnus has the native EasyPG binding, simply put the
-following line into your ~/.emacs.
-
- (setq mml2015-use 'epg)
-
-Other options which affect on the binding are
+CVS version of Gnus uses EasyPG by default. To make sure of that,
+check mml2015-use set to 'epg. Other options which affect on the
+EasyPG are
mml2015-signers
mml2015-encrypt-to-self
mml2015-passphrase-cache-expiry
mml2015-verbose
-NOTE: You need not to install pgg-epg.el in this case.
+NOTE: You don't need pgg-epg.el in this case.
** PGG based MUA
-PGG is somewhat outdated PGP library used by old Gnus, MH-E, etc.
+PGG is outdated PGP library used by old Gnus (<= v5.11), MH-E, etc.
+
+There is a PGG backend written using EasyPG called pgg-epg.el.
+However, EasyPG API is a superset of PGG and pgg-epg.el provides
+nothing but compatibility with PGG.
+
+*** Limitations of PGG
-There is a PGG backend using EasyPG called pgg-epg.el. However,
-EasyPG API is a superset of PGG, so pgg-epg.el just emulate the old
-behavior of pgg.el. Major features which PGG lacks are
+As I noted "PGG is outdated PGP library" above, PGG has several
+limitations. For example
-- Key selection interface
-- Web of trust support
-- A mechanism to investigate the verify result
-- S/MIME support using gpgsm
+- PGG can't handle a message signed with multiple keys.
+- PGG can't prompt a user which key is being used.
+- PGG can't create a binary PGP messages.
+- PGG doesn't provide a way to select keys per cryptographic operation.
+- PGG ignores GnuPG's trust metrics.
** SEMI based MUA
* Security
-There are security pitfalls around Emacs.
+There are security pitfalls around Emacs. EasyPG is written with
+avoiding them.
** Passphrase may leak to a temporary file.