Kirk Strauser <kirk@strauser.com> writes:

> I use gpg-agent.  How can I prevent Gnus from prompting for my
> passphrase so that the agent always handles the entry?

For a while I have been using the appended patch. It introduces a
defcustom of type boolean `pgg-gpg-use-agent-if-available', and a
defconst `pgg-gpg-agent-available' that is t if GPG_AGENT_INFO is set.

A function pgg-gpg-use-agent then is used at various places to avoid
the passphrase being read by Gnus.

-- 
Michael

Index: pgg-gpg.el
===================================================================
RCS file: /usr/local/cvsroot/gnus/lisp/pgg-gpg.el,v
retrieving revision 6.13
diff -u -p -r6.13 pgg-gpg.el
--- pgg-gpg.el	6 Apr 2003 00:18:33 -0000	6.13
+++ pgg-gpg.el	17 Apr 2003 12:14:01 -0000
@@ -36,6 +36,14 @@
   :group 'pgg-gpg
   :type 'string)
 
+(defcustom pgg-gpg-use-agent-if-available nil 
+  "Whether to use gpg-agent if it can be located via environment."
+  :group 'pgg-gpg
+  :type 'boolean)
+
+(defconst pgg-gpg-agent-available (if (getenv "GPG_AGENT_INFO") t)
+  "If gpg-agent can be located, this constant is t.")
+
 (defcustom pgg-gpg-extra-args nil
   "Extra arguments for every GnuPG invocation."
   :group 'pgg-gpg
@@ -46,6 +54,13 @@
 (defvar pgg-gpg-user-id nil
   "GnuPG ID of your default identity.")
 
+(defun pgg-gpg-use-agent ()
+  "If it returns t, gpg will be told to use gpg-agent for secret key
+management, otherwise PGG will ask you for passphrase(s). Depends on
+the value of `pgg-gpg-use-agent-if-available', and whether the agent
+can be located."
+  (and pgg-gpg-agent-available pgg-gpg-use-agent-if-available))
+
 (defun pgg-gpg-process-region (start end passphrase program args)
   (let* ((output-file-name
 	  (expand-file-name (make-temp-name "pgg-output") 
@@ -53,7 +68,8 @@
 	 (args
 	  `("--status-fd" "2"
 	    ,@(if passphrase '("--passphrase-fd" "0"))
+	    ,@(if (pgg-gpg-use-agent) '("--use-agent"))
 	    "--yes" ; overwrite
 	    "--output" ,output-file-name
 	    ,@pgg-gpg-extra-args ,@args))
 	 (output-buffer pgg-output-buffer)
@@ -96,8 +112,8 @@
 	     (re-search-forward "^\\[GNUPG:] GOOD_PASSPHRASE\\>" nil t)))
       (pgg-add-passphrase-cache
        (progn
-	 (goto-char (point-min))
-	 (if (re-search-forward
+	 (goto-char (point-max))
+	 (if (re-search-backward
 	      "^\\[GNUPG:] NEED_PASSPHRASE \\w+ ?\\w*" nil t)
 	     (substring (match-string 0) -8)))
        passphrase)))
@@ -123,9 +139,10 @@ If optional argument SIGN is non-nil, do
   (let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
 	 (passphrase
 	  (when sign
-	    (pgg-read-passphrase
-	     (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
-	     (pgg-gpg-lookup-key pgg-gpg-user-id 'encrypt))))
+	    (unless (pgg-gpg-use-agent)
+	      (pgg-read-passphrase
+	       (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
+	       (pgg-gpg-lookup-key pgg-gpg-user-id 'encrypt)))))
 	 (args
 	  (append
 	   (list "--batch" "--armor" "--always-trust" "--encrypt")
@@ -148,9 +165,10 @@ If optional argument SIGN is non-nil, do
   "Decrypt the current region between START and END."
   (let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
 	 (passphrase
-	  (pgg-read-passphrase
-	   (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
-	   (pgg-gpg-lookup-key pgg-gpg-user-id 'encrypt)))
+	  (unless (pgg-gpg-use-agent)
+	    (pgg-read-passphrase
+	     (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
+	     (pgg-gpg-lookup-key pgg-gpg-user-id 'encrypt))))
 	 (args '("--batch" "--decrypt")))
     (pgg-gpg-process-region start end passphrase pgg-gpg-program args)
     (with-current-buffer pgg-errors-buffer
@@ -162,9 +180,10 @@ If optional argument SIGN is non-nil, do
   "Make detached signature from text between START and END."
   (let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
 	 (passphrase
-	  (pgg-read-passphrase
-	   (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
-	   (pgg-gpg-lookup-key pgg-gpg-user-id 'sign)))
+	  (unless (pgg-gpg-use-agent)
+	    (pgg-read-passphrase
+	     (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
+	     (pgg-gpg-lookup-key pgg-gpg-user-id 'sign))))
 	 (args
 	  (list (if cleartext "--clearsign" "--detach-sign")
 		"--armor" "--batch" "--verbose"