(mime-edit-decrypt-application/pgp-encrypted): New function.
[elisp/semi.git] / mime-pgp.el
index c9a2637..508f279 100644 (file)
 ;;         by Kazuhiko Yamamoto <kazu@is.aist-nara.ac.jp> (1995/10;
 ;;         expired)
 
+;;     [OpenPGP/MIME] draft-yamamoto-openpgp-mime-00.txt: "MIME
+;;         Security with OpenPGP (OpenPGP/MIME)" by Kazuhiko YAMAMOTO
+;;         <kazu@iijlab.net> (1998/1)
+
 ;;; Code:
 
 (require 'std11)
 (require 'semi-def)
 (require 'mime-play)
 
+(defgroup mime-pgp nil
+  "Internal methods for either PGP or GnuPG."
+  :prefix "mime-pgp-"
+  :group 'mime)
 
 ;;; @ Internal method for multipart/signed
 ;;;
@@ -83,7 +91,8 @@
           (delete-region
            (point-min)
            (and
-            (re-search-forward "^-+BEGIN PGP SIGNED MESSAGE-+\n\n")
+            (re-search-forward "^-+BEGIN PGP SIGNED MESSAGE-+\n")
+            (search-forward "\n\n")
             (match-end 0)))
           (delete-region
            (and (re-search-forward "^-+BEGIN PGP SIGNATURE-+")
     (set-window-buffer p-win mime-preview-buffer)
     ))
 
-(defun mime-pgp-detect-version (entity)
-  "Detect PGP version from detached signature."
-  (with-temp-buffer
-    (mime-insert-entity-content entity)
-    (std11-narrow-to-header)
-    (let ((version (std11-fetch-field "Version")))
-      (cond ((not version)
-            pgp-version)
-           ((string-match "GnuPG" version)
-            'gpg)
-           ((string-match "5\\.0i" version)
-            'pgp50)
-           ((string-match "2\\.6" version)
-            'pgp)
-           (t
-            pgp-version)))))
-
 
 ;;; @ Internal method for application/pgp-signature
 ;;;
-;;; It is based on RFC 2015 (PGP/MIME).
+;;; It is based on RFC 2015 (PGP/MIME) and
+;;; draft-yamamoto-openpgp-mime-00.txt (OpenPGP/MIME).
 
 (defcustom mime-pgp-command-alist '((gpg   . "gpg")
                                    (pgp50 . "pgp")
 
 COMMAND for `pgp50' must *NOT* have a suffix, like neither \"pgpe\", \"pgpk\",
 \"pgps\" nor \"pgpv\"."
-  :group 'mime
+  :group 'mime-pgp
   :type '(repeat (cons :format "%v"
                       (choice (choice-item :tag "GnuPG" gpg)
                               (choice-item :tag "PGP 5.0i" pgp50)
@@ -159,7 +152,7 @@ COMMAND for `pgp50' must *NOT* have a suffix, like neither \"pgpe\", \"pgpk\",
   "Alist of the schemes and the symbol of languages.  It should be ISO 639
 2 letter language code such as en, ja, ...  Each element looks like
 \(SCHEME . SYMBOL).  See also `mime-pgp-command-alist' for valid SCHEMEs."
-  :group 'mime
+  :group 'mime-pgp
   :type '(repeat (cons :format "%v"
                       (choice (choice-item :tag "GnuPG" gpg)
                               (choice-item :tag "PGP 5.0i" pgp50)
@@ -182,7 +175,33 @@ detecting ``Good signature''.  The optional symbol of the post processing
 function for arranging the output message can be specified in each element.
 It will be called just after re-search is done successfully, and it is
 expected that the function returns a string for messaging."
-  :group 'mime
+  :group 'mime-pgp
+  :type '(repeat (cons :format "%v"
+                      (choice (choice-item :tag "GnuPG" gpg)
+                              (choice-item :tag "PGP 5.0i" pgp50)
+                              (choice-item :tag "PGP 2.6" pgp))
+                      (repeat (list :format "%v"
+                                    (symbol :tag "Language")
+                                    (regexp :tag "Regexp")
+                                    (function :tag "Post Function"))))))
+
+(defcustom mime-pgp-bad-signature-regexp-alist
+  '((gpg
+     (nil "BAD signature from.*$" nil)
+     )
+    (pgp50
+     (us "BAD signature made .* by key:$"
+        mime-pgp-bad-signature-post-function-pgp50-us)
+     )
+    (pgp
+     (en "Bad signature from user.*$" nil)
+     ))
+  "Alist of the schemes and alist of the languages and the regexps for
+detecting ``BAD signature''.  The optional symbol of the post processing
+function for arranging the output message can be specified in each element.
+It will be called just after re-search is done successfully, and it is
+expected that the function returns a string for messaging."
+  :group 'mime-pgp
   :type '(repeat (cons :format "%v"
                       (choice (choice-item :tag "GnuPG" gpg)
                               (choice-item :tag "PGP 5.0i" pgp50)
@@ -206,7 +225,7 @@ expected that the function returns a string for messaging."
      ))
   "Alist of the schemes and alist of the languages and regexps for detecting
 ``Key expected''."
-  :group 'mime
+  :group 'mime-pgp
   :type '(repeat (cons :format "%v"
                       (choice (choice-item :tag "GnuPG" gpg)
                               (choice-item :tag "PGP 5.0i" pgp50)
@@ -256,15 +275,62 @@ or \"v\" for choosing a command of PGP 5.0i."
         (cdr (assq pgp-version mime-pgp-good-signature-regexp-alist))
         )))
 
+(defmacro mime-pgp-bad-signature-regexp ()
+  "Return a regexp to detect ``BAD signature''."
+  '(nth 1
+       (assq
+        (mime-pgp-default-language)
+        (cdr (assq pgp-version mime-pgp-bad-signature-regexp-alist))
+        )))
+
+(defmacro mime-pgp-bad-signature-post-function ()
+  "Return a post processing function for arranging the message for
+``BAD signature''."
+  '(nth 2
+       (assq
+        (mime-pgp-default-language)
+        (cdr (assq pgp-version mime-pgp-bad-signature-regexp-alist))
+        )))
+
 (defmacro mime-pgp-key-expected-regexp ()
   "Return a regexp to detect ``Key expected''."
   '(cdr (assq (mime-pgp-default-language)
              (cdr (assq pgp-version mime-pgp-key-expected-regexp-alist))
              )))
 
-(defun mime-pgp-check-signature (output-buffer orig-file)
-  (save-excursion
-    (set-buffer output-buffer)
+(defun mime-pgp-detect-version ()
+  "Detect PGP version in the buffer.  The buffer is expected to be narrowed
+to just an ascii armor.  However, a few leading garbage lines are allowed."
+  (let ((version (save-restriction
+                  (goto-char (point-min))
+                  (if (re-search-forward "^-+BEGIN PGP " nil t)
+                      (progn
+                        (forward-line 1)
+                        (narrow-to-region (point) (point-max))
+                        (std11-narrow-to-header)
+                        (std11-fetch-field "Version")
+                        )))))
+    (cond ((not version)
+          pgp-version)
+         ((string-match "GnuPG" version)
+          'gpg)
+         ((string-match "5\\.0i" version)
+          'pgp50)
+         ((string-match "2\\.6" version)
+          'pgp)
+         (t
+          pgp-version))))
+
+(defun mime-entity-detect-pgp-version (entity)
+  "Detect PGP version from entity content."
+  (with-temp-buffer
+    (mime-insert-entity-content entity)
+    (mime-pgp-detect-version)
+    ))
+
+(defun mime-pgp-check-signature (output-buffer orig-file
+                                              &optional hide-lines)
+  (with-current-buffer output-buffer
     (erase-buffer)
     (setq truncate-lines t))
   (let* ((lang (mime-pgp-default-language))
@@ -281,57 +347,106 @@ or \"v\" for choosing a command of PGP 5.0i."
                     ((eq 'pgp pgp-version)
                      (list (format "+language=%s" lang) orig-file))
                     ))
-        (regexp (mime-pgp-good-signature-regexp))
-        (post-function (mime-pgp-good-signature-post-function))
-        pgp-id)
-    (if (zerop (apply 'call-process-region
-                     (point-min) (point-max) command nil output-buffer nil
-                     args))
-       (save-excursion
-         (set-buffer output-buffer)
-         (goto-char (point-min))
-         (cond
-          ((not (stringp regexp))
-           (message "Please specify right regexp for specified language")
-           )
-          ((re-search-forward regexp nil t)
-           (message (if post-function
-                        (funcall post-function)
-                      (buffer-substring (match-beginning 0) (match-end 0))))
-           (goto-char (point-min))
-           )
-          ;; PGP 5.0i always returns 0, so we should attempt to fetch.
-          ((eq 'pgp50 pgp-version)
-           (if (not (stringp (setq regexp (mime-pgp-key-expected-regexp))))
-               (message "Please specify right regexp for specified language")
-             (if (re-search-forward regexp nil t)
-                 (progn
-                   (setq pgp-id
-                         (concat "0x" (buffer-substring-no-properties
-                                       (match-beginning 1)
-                                       (match-end 1))))
-                   (if (and
-                        pgp-id
-                        (y-or-n-p
-                         (format "Key %s not found; attempt to fetch? "
-                                 pgp-id)
-                         ))
-                       (progn
-                         (funcall (pgp-function 'fetch-key) (cons nil pgp-id))
-                         (mime-pgp-check-signature mime-echo-buffer-name
-                                                   orig-file)
-                         )
-                     (message "Bad signature")
-                     ))
-               (message "Bad signature")
-               ))
-           )
-          (t
-           (message "Bad signature")
-           ))
+        (good-regexp (mime-pgp-good-signature-regexp))
+        (good-post-function (mime-pgp-good-signature-post-function))
+        (bad-regexp (mime-pgp-bad-signature-regexp))
+        (bad-post-function (mime-pgp-bad-signature-post-function))
+        status start lines
+        )
+    (setq status (apply 'call-process-region (point-min) (point-max)
+                       command nil output-buffer nil args)
          )
-      (message "Bad signature")
-      nil)))
+    (with-current-buffer output-buffer
+      (goto-char (point-min))
+      (forward-line (or hide-lines 0))
+      (setq start (point)
+           lines (count-lines start (point-max)))
+      (cond ((not (stringp good-regexp))
+            (message "Please specify right regexp for specified language")
+            (cons start lines)
+            )
+           ((and (zerop status)
+                 (progn
+                   (goto-char (point-min))
+                   (re-search-forward good-regexp nil t)
+                   ))
+            (message (if good-post-function
+                         (funcall good-post-function)
+                       (buffer-substring (match-beginning 0)
+                                         (match-end 0))))
+            (cons start lines)
+            )
+           ((not (stringp bad-regexp))
+            (message "Please specify right regexp for specified language")
+            (cons start lines)
+            )
+           ((progn
+              (goto-char (point-min))
+              (re-search-forward bad-regexp nil t)
+              )
+            (message (if bad-post-function
+                         (funcall bad-post-function)
+                       (buffer-substring (match-beginning 0)
+                                         (match-end 0))))
+            (cons start lines)
+            )
+           (t
+            ;; Returns nil in order for attempt to fetch key.
+            nil
+            )))))
+
+(defmacro mime-pgp-parse-verify-error (output-buffer &rest forms)
+  (` (let ((regexp (mime-pgp-key-expected-regexp))
+          keyid)
+       (with-current-buffer (, output-buffer)
+        (goto-char (point-min))
+        (if (stringp regexp)
+            (if (re-search-forward regexp nil t)
+                (progn
+                  (setq keyid (concat
+                               "0x"
+                               (buffer-substring-no-properties
+                                (match-beginning 1) (match-end 1))))
+                  (goto-char (point-min))
+                  ))
+          (message "Please specify right regexp for specified language")
+          )
+        (,@ forms)
+        (list keyid (point) (count-lines (point) (point-max)))
+        ))))
+
+(defun mime-pgp-parse-verify-error-for-gpg (output-buffer)
+  "Subroutine used for parsing verify error with GnuPG.  Returns the
+list of expected key-ID, start position and lines to be shown a result."
+  (mime-pgp-parse-verify-error output-buffer)
+  )
+
+(defun mime-pgp-parse-verify-error-for-pgp50 (output-buffer)
+  "Subroutine used for parsing verify error with PGP 5.0i.  Returns the
+list of expected key-ID, start position and lines to be shown a result."
+  (mime-pgp-parse-verify-error output-buffer (forward-line 1))
+  )
+
+(defun mime-pgp-parse-verify-error-for-pgp (output-buffer)
+  "Subroutine used for parsing verify error with PGP 2.6.  Returns the
+list of expected key-ID, start position and lines to be shown a result."
+  (mime-pgp-parse-verify-error
+   output-buffer
+   (if (search-forward "\C-g" nil t)
+       (goto-char (match-beginning 0))
+     (forward-line 7))
+   ))
+
+(defmacro mime-pgp-show-echo-buffer (start lines)
+  (` (let ((mime-echo-window-height
+           (min (+ 2 (, lines))
+                (max window-min-height
+                     (- (window-height) window-min-height)
+                     ))))
+       (set-window-start
+       (car (save-current-buffer (mime-show-echo-buffer)))
+       (, start))
+       )))
 
 (defun mime-verify-application/pgp-signature (entity situation)
   "Internal method to check PGP/MIME signature."
@@ -345,69 +460,60 @@ or \"v\" for choosing a command of PGP 5.0i."
         (basename (expand-file-name "tm" temporary-file-directory))
         (orig-file (make-temp-name basename))
         (sig-file (concat orig-file ".sig"))
-        (pgp-version (mime-pgp-detect-version entity))
-        )
+        (pgp-version (mime-entity-detect-pgp-version entity))
+        (output-buffer (get-buffer-create mime-echo-buffer-name))
+        (hide-lines (cdr (assq pgp-version
+                               '((gpg . nil) (pgp50 . 1) (pgp . 10)))))
+        (parser (intern (format "mime-pgp-parse-verify-error-for-%s"
+                                pgp-version)))
+        done return pgp-id)
     (mime-write-entity orig-entity orig-file)
-    (save-excursion (mime-show-echo-buffer))
     (mime-write-entity-content entity sig-file)
-    (if (mime-pgp-check-signature mime-echo-buffer-name orig-file)
-       (let ((other-window-scroll-buffer mime-echo-buffer-name))
-         (scroll-other-window
-          (cdr (assq pgp-version '((gpg . 0) (pgp50 . 1) (pgp . 10))))
-          ))
-      (if (eq 'pgp pgp-version)
-         (save-excursion
-           (set-buffer mime-echo-buffer-name)
-           (goto-char (point-min))
-           (if (search-forward "\C-g" nil t)
-               (goto-char (match-beginning 0))
-             (forward-line 7))
-           (set-window-start
-            (get-buffer-window mime-echo-buffer-name)
-            (point))
-           )
-       (let ((other-window-scroll-buffer mime-echo-buffer-name))
-         (scroll-other-window
-          (cdr (assq pgp-version '((gpg . 0) (pgp50 . 1))))
-          )))
-      (let (pgp-id)
-       (save-excursion
-         (set-buffer mime-echo-buffer-name)
-         (goto-char (point-min))
-         (let ((regexp (mime-pgp-key-expected-regexp)))
-           (cond
-            ((not (stringp regexp))
-             (message "Please specify right regexp for specified language")
-             )
-            ((re-search-forward regexp nil t)
-             (setq pgp-id (concat "0x" (buffer-substring-no-properties
-                                        (match-beginning 1)
-                                        (match-end 1))))
-             ))))
-       (if (and pgp-id
-                (prog1
-                    (y-or-n-p
-                     (format "Key %s not found; attempt to fetch? " pgp-id))
-                  (message ""))
+    (message "Checking signature...")
+    (unwind-protect
+       (while (not done)
+         (if (setq return (mime-pgp-check-signature
+                           output-buffer orig-file hide-lines))
+             (progn
+               (mime-pgp-show-echo-buffer (car return) (cdr return))
+               (setq done t)
+               )
+           (if (and
+                (not pgp-id)
+                (progn
+                  (setq return (funcall parser output-buffer))
+                  (mime-pgp-show-echo-buffer (nth 1 return)
+                                             (nth 2 return))
+                  (setq pgp-id (car return))
+                  )
+                (y-or-n-p (format "Key %s not found; attempt to fetch? "
+                                  pgp-id))
                 )
-           (progn
-             (funcall (pgp-function 'fetch-key) (cons nil pgp-id))
-             (mime-pgp-check-signature mime-echo-buffer-name orig-file)
-             )
-         )))
-    (delete-file orig-file)
-    (delete-file sig-file)
-    ))
+               (funcall (pgp-function 'fetch-key) (cons nil pgp-id))
+             (setq return (funcall parser output-buffer))
+             (mime-pgp-show-echo-buffer (nth 1 return) (nth 2 return))
+             (setq done t)
+             (message "Can't check signature")
+             )))
+      (delete-file orig-file)
+      (delete-file sig-file)
+      )))
 
 (defun mime-pgp-good-signature-post-function-pgp50-us ()
   (forward-line 2)
   (looking-at "\\s +\\(.+\\)$")
   (format "Good signature from %s" (match-string 1)))
 
+(defun mime-pgp-bad-signature-post-function-pgp50-us ()
+  (forward-line 2)
+  (looking-at "\\s +\\(.+\\)$")
+  (format "BAD signature from %s" (match-string 1)))
+
 
 ;;; @ Internal method for application/pgp-encrypted
 ;;;
-;;; It is based on RFC 2015 (PGP/MIME).
+;;; It is based on RFC 2015 (PGP/MIME) and
+;;; draft-yamamoto-openpgp-mime-00.txt (OpenPGP/MIME).
 
 (defun mime-decrypt-application/pgp-encrypted (entity situation)
   (let* ((entity-node-id (mime-entity-node-id entity))
@@ -417,36 +523,266 @@ or \"v\" for choosing a command of PGP 5.0i."
                   (1- knum)
                 (1+ knum)))
         (orig-entity (nth onum (mime-entity-children mother)))
-        (pgp-version (mime-pgp-detect-version orig-entity)))
+        (pgp-version (mime-entity-detect-pgp-version orig-entity))
+        )
     (mime-view-application/pgp orig-entity situation)
     ))
 
+(defun mime-edit-decrypt-application/pgp-encrypted ()
+  "Decrypt the encrypted part for the function `mime-edit-again'."
+  (let ((pgp-version (mime-pgp-detect-version)))
+    ;; The following process should returns a pair (SUCCEEDED . VERIFIED)
+    ;; where SUCCEEDED is t if the decryption succeeded and VERIFIED is t
+    ;; if there was a valid signature.
+    (as-binary-process (funcall (pgp-function 'decrypt)))
+    ))
+
 
 ;;; @ Internal method for application/pgp-keys
 ;;;
-;;; It is based on RFC 2015 (PGP/MIME).
-
-(defun mime-add-application/pgp-keys (entity situation)
-  (let* ((start (mime-entity-point-min entity))
-        (end (mime-entity-point-max entity))
-        (entity-number (mime-raw-point-to-entity-number start))
-        (new-name (format "%s-%s" (buffer-name) entity-number))
-        (encoding (cdr (assq 'encoding situation)))
-        str)
-    (setq str (buffer-substring start end))
-    (switch-to-buffer new-name)
-    (setq buffer-read-only nil)
-    (erase-buffer)
-    (insert str)
-    (goto-char (point-min))
-    (if (re-search-forward "^\n" nil t)
-       (delete-region (point-min) (match-end 0))
+;;; It is based on RFC 2015 (PGP/MIME) and
+;;; draft-yamamoto-openpgp-mime-00.txt (OpenPGP/MIME).
+
+(defun mime-add-application/pgp-keys (entity &optional situation)
+  (with-temp-buffer
+    (mime-insert-entity-content entity)
+    (let ((pgp-version (mime-pgp-detect-version)))
+      (funcall (pgp-function 'snarf-keys))
+      )))
+
+
+;;; @ Internal method for fetching a public key
+;;;
+
+(defcustom mime-pgp-keyserver-url-template "/pks/lookup?op=get&search=%s"
+  "The URL to pass to the keyserver."
+  :group 'mime-pgp
+  :type 'string)
+
+(defcustom mime-pgp-keyserver-address "pgp.nic.ad.jp"
+  "Host name of keyserver."
+  :group 'mime-pgp
+  :type 'string)
+
+(defcustom mime-pgp-keyserver-port 11371
+  "Port on which the keyserver's HKP daemon lives."
+  :group 'mime-pgp
+  :type 'integer)
+
+(defcustom mime-pgp-http-proxy-url-template
+  "/cgi-bin/pgpsearchkey.pl?op=get&search=%s"
+  "The URL to pass to the keyserver via HTTP proxy."
+  :group 'mime-pgp
+  :type 'string)
+
+(defcustom mime-pgp-http-proxy-server-address nil
+  "Host name of HTTP proxy server.  If you are behind firewalls, set the
+values of this variable and `mime-pgp-http-proxy-server-port' appropriately."
+  :group 'mime-pgp
+  :type 'string)
+
+(defcustom mime-pgp-http-proxy-server-port 8080
+  "Port on which the proxy server's HTTP daemon lives."
+  :group 'mime-pgp
+  :type 'integer)
+
+(defcustom mime-pgp-fetch-timeout 20
+  "Timeout, in seconds, for any particular key fetch operation."
+  :group 'mime-pgp
+  :type 'integer)
+
+(defmacro mime-pgp-show-fetched-key (key scroll &rest args)
+  (` (let ((current-window (selected-window))
+          keys start hide return window)
+       (with-temp-buffer
+        (insert (, key))
+        (as-binary-process
+         (call-process-region
+          (point-min) (point-max) (mime-pgp-command 'v) t t (,@ args))
+         )
+        (goto-char (point-min))
+        (forward-line (, scroll))
+        (setq keys (buffer-string)
+              start (point)
+              hide (count-lines (point) (point-max)))
+        )
+       (setq return (mime-show-echo-buffer "%s" keys)
+            window (car return)
+            start (1- (+ start (car (cdr return))))
+            hide (- (window-height window) hide 2))
+       (if (>= (+ (window-height current-window) hide) window-min-height)
+          (progn
+            (select-window window)
+            (shrink-window hide)
+            (select-window current-window)
+            ))
+       (set-window-start window start)
+       )))
+
+(defun mime-pgp-show-fetched-key-for-gpg (key)
+  "Extract KEY and show."
+  (mime-pgp-show-fetched-key key 0)
+  )
+
+(defun mime-pgp-show-fetched-key-for-pgp50 (key)
+  "Extract KEY and show."
+  (let ((current-window (selected-window))
+       (process-environment process-environment)
+       process-connection-type process keys start hide return window)
+    (setenv "PGPPASSFD" nil)
+    (with-temp-buffer
+      (setq process
+           (start-process "*show fetched keys*"
+                          (current-buffer) (mime-pgp-command 'v)
+                          "-f" "+batchmode=0" "+language=us")
+           )
+      (set-process-coding-system process 'binary 'binary)
+      (process-send-string process key)
+      (process-send-eof process)
+      (while
+         (progn
+           (accept-process-output process 1)
+           (goto-char (point-min))
+           (not
+            (re-search-forward
+             "^Add these keys to your keyring\\? \\[Y/n\\] "
+             nil t))
+           ))
+      (setq start (match-beginning 0))
+      (delete-process process)
+      (delete-region start (point-max))
+      (goto-char (point-min))
+      (forward-line 10)
+      (setq keys (buffer-string)
+           start (point)
+           hide (count-lines (point) start))
       )
-    (mime-decode-region (point-min)(point-max) encoding)
-    (funcall (pgp-function 'snarf-keys))
-    (kill-buffer (current-buffer))
+    (setq return (mime-show-echo-buffer "%s" keys)
+         window (car return)
+         start (1- (+ start (car (cdr return))))
+         hide (- (window-height window) hide 2))
+    (if (>= (+ (window-height current-window) hide) window-min-height)
+       (progn
+         (select-window window)
+         (shrink-window hide)
+         (select-window current-window)
+         ))
+    (set-window-start window start)
     ))
 
+(defun mime-pgp-show-fetched-key-for-pgp (key)
+  "Extract KEY and show."
+  (mime-pgp-show-fetched-key key 7 "-f" "+language=en")
+  )
+
+(defun mime-pgp-fetch-key (&optional id)
+  "Attempt to fetch a key for addition to PGP or GnuPG keyring.
+Interactively, prompt for string matching key to fetch.
+
+Non-interactively, ID must be a pair.  The CAR must be a bare Email
+address and the CDR a keyID (with \"0x\" prefix).  Either, but not
+both, may be nil.
+
+Return t if we think we were successful; nil otherwise.  Note that nil
+is not necessarily an error, since we may have merely fired off an Email
+request for the key.
+
+If you want to use this function for verifying a message of PGP/MIME,
+for example, please put the following lines in your startup file:
+
+  (eval-after-load \"semi-def\"
+    '(progn (require 'alist)
+           (set-alist 'pgp-function-alist 'fetch-key
+                      '(mime-pgp-fetch-key \"mime-pgp\"))
+           (autoload 'mime-pgp-fetch-key \"mime-pgp\" nil t)
+           ))
+
+In addition, if you are behind firewalls, please set the values of
+`mime-pgp-http-proxy-server-address' and `mime-pgp-http-proxy-server-port'
+appropriately."
+  (interactive)
+  (let ((server (or mime-pgp-http-proxy-server-address
+                   mime-pgp-keyserver-address))
+       (port (or mime-pgp-http-proxy-server-port
+                 mime-pgp-keyserver-port))
+       (url-template
+        (if mime-pgp-http-proxy-server-address
+            (concat "http://"
+                    mime-pgp-keyserver-address
+                    mime-pgp-http-proxy-url-template
+                    " HTTP/1.0\r\n")
+          mime-pgp-keyserver-url-template))
+       (show-function (intern (format "mime-pgp-show-fetched-key-for-%s"
+                                      pgp-version)))
+       (snarf-function (pgp-function 'snarf-keys))
+       armor case-fold-search process-connection-type process start)
+    (if (cond ((interactive-p)
+              (setq id (read-string "Fetch key for: "))
+              (cond ((string-equal "" id)
+                     (message "Aborted")
+                     nil)
+                    ((string-match "^0[Xx]" id)
+                     (setq id (cons nil id)))
+                    (t
+                     (setq id (cons id nil)))))
+             ((or (null id)
+                  (not (or (stringp (car id)) (stringp (cdr id)))))
+              (message "Aborted")
+              nil)
+             (t t))
+       (progn
+         (with-temp-buffer
+           (catch 'mime-pgp-fetch-key-done
+             (message "Fetching %s via HTTP to %s..."
+                      (or (cdr id) (car id))
+                      mime-pgp-keyserver-address)
+             (condition-case err
+                 (setq process (open-network-stream-as-binary
+                                "*key fetch*" (current-buffer) server port))
+               (error
+                (message "%s" err)
+                (throw 'mime-pgp-fetch-key-done nil)
+                ))
+             (if (not process)
+                 (progn
+                   (message "Can't connect to %s%s."
+                            mime-pgp-keyserver-address
+                            (if mime-pgp-http-proxy-server-address
+                                (concat "via "
+                                        mime-pgp-http-proxy-server-address)
+                              ""))
+                   (throw 'mime-pgp-fetch-key-done nil)
+                   )
+               (process-send-string
+                process
+                (concat "GET " (format url-template
+                                       (or (cdr id) (car id))) "\r\n")
+                )
+               (while (and (eq 'open (process-status process))
+                           (accept-process-output process
+                                                  mime-pgp-fetch-timeout)
+                           ))
+               (delete-process process)
+               (goto-char (point-min))
+               (if (and (re-search-forward
+                         "^-----BEGIN PGP PUBLIC KEY BLOCK-----\r?$" nil t)
+                        (setq start (match-beginning 0))
+                        (re-search-forward
+                         "^-----END PGP PUBLIC KEY BLOCK-----\r?$" nil t)
+                        )
+                   (setq armor (buffer-substring start (1+ (point))))
+                 ))))
+         (if armor
+             (save-window-excursion
+               (funcall show-function armor)
+               (if (y-or-n-p "Add this key to keyring? ")
+                   (with-temp-buffer
+                     (insert armor)
+                     (funcall snarf-function)))
+               t)
+           (message "Key not found.")
+           nil)))))
+
 
 ;;; @ end
 ;;;