* What's this?
-EasyPG is yet another GnuPG interface for Emacs. It consists of two
-parts:
+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).
-- "The EasyPG Assistant"
- A GUI frontend of GnuPG
-- "The EasyPG Library"
- A library to interact with GnuPG
+* 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
+ Earlier versions are supported but not recommended.
* 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).
+
+** CVS version of Gnus
+
+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-cache-passphrase
+ mml2015-passphrase-cache-expiry
+ mml2015-verbose
+
+NOTE: You don't need pgg-epg.el in this case.
+
+** PGG based MUA
+
+PGG is outdated PGP library used by old Gnus (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
+
+As I noted "PGG is outdated PGP library" above, PGG has several
+limitations. For example
+
+- 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
+
+SEMI is the MIME library used by Wanderlust, cmail, T-gnus, etc.
+
+There is an EasyPG capable SEMI library called EMIKO-EasyPG. It can
+be downloaded from the same site of the EasyPG distribution point.
* 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.