1 ;;; gpg.el --- Interface to GNU Privacy Guard
3 ;; Copyright (C) 2000 RUS-CERT, University Of Stuttgart
5 ;; Author: Florian Weimer <Florian.Weimer@RUS.Uni-Stuttgart.DE>
6 ;; Maintainer: Florian Weimer <Florian.Weimer@RUS.Uni-Stuttgart.DE>
10 ;; $Id: gpg.el,v 1.2 2000/11/18 20:57:13 jas Exp $
12 ;; This file is NOT (yet?) part of GNU Emacs.
14 ;; GNU Emacs is free software; you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation; either version 2, or (at your option)
19 ;; GNU Emacs is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with GNU Emacs; see the file COPYING. If not, write to the
26 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
27 ;; Boston, MA 02111-1307, USA.
31 ;; ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA
32 ;; ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA
34 ;; This code is not well-tested. BE CAREFUL!
36 ;; ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA
37 ;; ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA ALPHA
39 ;; Implemented features which can be tested:
41 ;; * Customization for all flavors of PGP is possible.
42 ;; * The main operations (verify, decrypt, sign, encrypt, sign &
43 ;; encrypt) are implemented.
44 ;; * Gero Treuner's gpg-2comp script is supported, and data which is is
45 ;; compatible with PGP 2.6.3 is generated.
47 ;; Customizing external programs
48 ;; =============================
50 ;; The customization are very similar to those of others programs,
51 ;; only the C-ish "%" constructs have been replaced by more Lisp-like
54 ;; First, you have to adjust the default executable paths
55 ;; (`gpg-command-default-alist', customization group `gpg-options',
56 ;; "Controlling GnuPG invocation."). After that, you should
57 ;; change the configuration options which control how specific
58 ;; command line flags are built (`gpg-command-flag-sign-with-key',
59 ;; (`gpg-command-flag-recipient'). The elements of these lists are
60 ;; concatenated without spaces, and a new argument is only started
61 ;; where indicated. The `gpg-command-flag-recipient' list is special:
62 ;; it consists of two parts, the first one remains at the beginning
63 ;; of the argument, the second one is repeated for each recipient.
64 ;; Finally, `gpg-command-passphrase-env' has to be changed if there's
65 ;; no command line flag to force the external program to read the data
66 ;; from standard input before the message.
68 ;; In customization group `gpg-commands', "Controlling GnuPG
69 ;; invocation.", you have to supply the actual syntax for external
70 ;; program calls. Each variable consists of a pair of a program
71 ;; specification (if a Lisp symbol is given here, it is translated
72 ;; via `gpg-command-default-alist') and a list of program arguments
73 ;; with placeholders. Please read the documentation of each variable
74 ;; before making your adjustments and try to match the given
75 ;; requirements as closely as possible!
77 ;; The `gpg-commands-key' group, "GnuPG Key Management Commands.",
78 ;; specifies key management commands. The syntax of these variables
79 ;; is like those in the `gpg-commands' group. Note that the output
80 ;; format of some of these external programs has to match very close
81 ;; that of GnuPG. Additional tools (Thomas Roessler's "pgpring.c")
82 ;; are available if your favorite implementation of OpenPGP cannot
83 ;; output the this format.
85 ;; Security considerations
86 ;; =======================
88 ;; On a typical multiuser UNIX system, the memory image of the
89 ;; Emacs process is not locked, therefore it can be swapped to disk
90 ;; at any time. As a result, the passphrase might show up in the
91 ;; swap space (even if you don't use the passphrase cache, i.e. if
92 ;; `gpg-passphrase-timeout' is 0). If someone is able to run `gdb' or
93 ;; another debugger on your Emacs process, he might be able to recover
94 ;; the passphrase as well. Unfortunately, nothing can be done in
95 ;; order to prevent this at the moment.
97 ;; BE CAREFUL: If you use the passphrase cache feature, the passphrase
98 ;; is stored in the variable `gpg-passphrase' -- and it is NOT
99 ;; encrypted in any way. (This is a conceptual problem because the
100 ;; nature of the passphrase cache requires that Emacs is able to
101 ;; decrypt automatically, so only a very weak protection could be
104 ;; In addition, if you use an unpatched Emacs 20 (and earlier
105 ;; versions), passwords show up in the output of the `view-lossage'
106 ;; function (bound to `C-h l' by default).
116 (if (featurep 'xemacs)
117 (defalias 'line-end-position 'point-at-eol))
121 ;;; Customization: Groups:
124 "GNU Privacy Guard interface."
128 (defgroup gpg-options nil
129 "Controlling GnuPG invocation."
133 (defgroup gpg-commands nil
134 "Primary GnuPG Operations."
135 :tag "GnuPG Commands"
138 (defgroup gpg-commands-key nil
139 "Commands for GnuPG key management."
140 :tag "GnuPG Key Commands"
141 :group 'gpg-commands)
143 ;;; Customization: Widgets:
145 (define-widget 'gpg-command-alist 'alist
146 "An association list for GnuPG command names."
147 :key-type '(symbol :tag "Abbreviation")
148 :value-type '(string :tag "Program name")
149 :convert-widget 'widget-alist-convert-widget
152 (define-widget 'gpg-command-program 'choice
153 "Widget for entering the name of a program (mostly the GnuPG binary)."
155 :args '((const :tag "Default GnuPG program."
157 (const :tag "GnuPG compatibility wrapper."
159 (const :tag "Disabled"
161 (string :tag "Custom program" :format "%v")))
163 (define-widget 'gpg-command-sign-options 'cons
164 "Widget for entering signing options."
165 :args '(gpg-command-program
169 :format "%[Type%] %v"
170 (const :tag "Insert armor option here if necessary."
172 (const :tag "Insert text mode option here if necessary."
174 (const :tag "Insert the sign with key option here if necessary."
175 :value sign-with-key)
176 (string :format "%v")))))
178 (define-widget 'gpg-command-key-options 'cons
179 "Widget for entering key command options."
180 :args '(gpg-command-program
184 :format "%[Type%] %v"
185 (const :tag "Insert key ID here."
187 (string :format "%v")))))
189 ;;; Customization: Variables:
191 ;;; Customization: Variables: Paths and Flags:
193 (defcustom gpg-passphrase-timeout
195 "Timeout (in seconds) for the passphrase cache.
196 The passphrase cache is cleared after is hasn't been used for this
197 many seconds. The values 0 means that the passphrase is not cached at
199 :tag "Passphrase Timeout"
203 (defcustom gpg-default-key-id
205 "Default key/user ID used for signatures."
206 :tag "Default Key ID"
208 (const :tag "Use GnuPG default." :value nil)
212 (defcustom gpg-temp-directory
213 (expand-file-name "~/tmp")
214 "Directory for temporary files.
215 If you are running Emacs 20, this directory must have mode 0700."
216 :tag "Temp directory"
220 (defcustom gpg-command-default-alist
222 (gpg-2comp . "gpg-2comp"))
223 "Default paths for some GnuPG-related programs.
224 Modify this variable if you have to change the paths to the
225 executables required by the GnuPG interface. You can enter \"gpg\"
226 for `gpg-2comp' if you don't have this script, but you'll lose PGP
227 2.6.x compatibility."
228 :tag "GnuPG programs"
229 :type 'gpg-command-alist
232 (defcustom gpg-command-flag-textmode "--textmode"
233 "The flag to indicate canonical text mode to GnuPG."
234 :tag "Text mode flag"
238 (defcustom gpg-command-flag-armor "--armor"
239 "The flag to request ASCII-armoring output from GnuPG."
244 (defcustom gpg-command-flag-sign-with-key '("--local-user=" sign-with-key)
245 "String to include to specify the signing key ID.
246 The elements are concatenated (without spaces) to form a command line
248 :tag "Sign with key flag"
249 :type '(repeat :tag "Argument parts"
250 (choice :format "%[Type%] %v"
251 (const :tag "Start next argument." :value next-argument)
252 (const :tag "Insert signing key ID here." :value sign-with-key)
256 (defcustom gpg-command-flag-recipient
257 '(nil . ("-r" next-argument recipient next-argument))
258 "Format of a recipient specification.
259 The elements are concatenated (without spaces) to form a command line
260 option. The second part is repeated for each recipient."
261 :tag "Recipients Flag"
263 (repeat :tag "Common prefix"
264 (choice :format "%[Type%] %v"
265 (const :tag "Start next argument." :value next-argument)
267 (repeat :tag "For each recipient"
268 (choice :format "%[Type%] %v"
269 (const :tag "Start next argument." :value next-argument)
270 (const :tag "Insert recipient key ID here." :value recipient)
274 (defcustom gpg-command-passphrase-env
276 "Environment variable to set when a passphrase is required, or nil.
277 If an operation is invoked which requires a passphrase, this
278 environment variable is set before calling the external program to
279 indicate that it should read the passphrase from standard input."
280 :tag "Passphrase environment"
282 (const :tag "Disabled" :value nil)
284 (string :tag "Variable")
285 (string :tag "Value")))
288 ;;; Customization: Variables: GnuPG Commands:
290 (defcustom gpg-command-verify
291 '(gpg . ("--batch" "--verbose" "--verify" signature-file message-file))
292 "Command to verify a detached signature.
293 The invoked program has to read the signed message and the signature
294 from the given files. It should write human-readable information to
295 standard output and/or standard error. The program shall not convert
296 charsets or line endings; the input data shall be treated as binary."
297 :tag "Verify Command"
303 :format "%[Type%] %v"
304 (const :tag "Insert name of file containing the message here."
306 (const :tag "Insert name of file containing the signature here."
307 :value signature-file)
308 (string :format "%v"))))
309 :group 'gpg-commands)
311 (defcustom gpg-command-verify-cleartext
312 '(gpg . ("--batch" "--verbose" "--verify" message-file))
313 "Command to verify a message.
314 The invoked program has to read the signed message from the given
315 file. It should write human-readable information to standard output
316 and/or standard error. The program shall not convert charsets or line
317 endings; the input data shall be treated as binary."
318 :tag "Cleartext Verify Command"
324 :format "%[Type%] %v"
325 (const :tag "Insert name of file containing the message here."
327 (string :format "%v"))))
328 :group 'gpg-commands)
330 (defcustom gpg-command-decrypt
331 '(gpg . ("--decrypt" "--batch" "--passphrase-fd=0"))
332 "Command to decrypt a message.
333 The invoked program has to read the passphrase from standard
334 input, followed by the encrypted message. It writes the decrypted
335 message to standard output, and human-readable diagnostic messages to
337 :tag "Decrypt Command"
343 :format "%[Type%] %v"
344 (const :tag "Insert name of file containing the message here."
346 (string :format "%v"))))
347 :group 'gpg-commands)
349 (defcustom gpg-command-sign-cleartext
350 '(gpg-2comp . ("--batch" "--passphrase-fd=0" "--output=-"
351 armor textmode "--clearsign"
353 "Command to create a create a \"clearsign\" text file.
354 The invoked program has to read the passphrase from standard input,
355 followed by the message to sign. It should write the ASCII-amored
356 signed text message to standard output, and diagnostic messages to
358 :tag "Clearsign Command"
359 :type 'gpg-command-sign-options
360 :group 'gpg-commands)
362 (defcustom gpg-command-sign-detached
363 '(gpg-2comp . ("--batch" "--passphrase-fd=0" "--output=-"
364 armor textmode "--detach-sign"
366 "Command to create a create a detached signature.
367 The invoked program has to read the passphrase from standard input,
368 followed by the message to sign. It should write the ASCII-amored
369 detached signature to standard output, and diagnostic messages to
370 standard error. The program shall not convert charsets or line
371 endings; the input data shall be treated as binary."
372 :tag "Sign Detached Command"
373 :type 'gpg-command-sign-options
374 :group 'gpg-commands)
376 (defcustom gpg-command-sign-encrypt
377 '(gpg-2comp . ("--batch" "--passphrase-fd=0" "--output=-"
378 armor textmode "--always-trust" sign-with-key recipients
379 "--sign" "--encrypt" plaintext-file))
380 "Command to sign and encrypt a file.
381 The invoked program has to read the passphrase from standard input,
382 followed by the message to sign and encrypt if there is no
383 `plaintext-file' placeholder. It should write the ASCII-amored
384 encrypted message to standard output, and diagnostic messages to
386 :tag "Sign And Encrypt Command"
392 :format "%[Type%] %v"
393 (const :tag "Insert the `sign with key' option here if necessary."
394 :value sign-with-key)
395 (const :tag "Insert list of recipients here."
397 (const :tag "Insert here name of file with plaintext."
398 :value plaintext-file)
399 (string :format "%v"))))
400 :group 'gpg-commands)
402 (defcustom gpg-command-encrypt
403 '(gpg-2comp . ("--batch" "--output=-" armor textmode "--always-trust"
404 "--encrypt" recipients plaintext-file))
405 "Command to encrypt a file.
406 The invoked program has to read the message to encrypt from standard
407 input or from the plaintext file (if the `plaintext-file' placeholder
408 is present). It should write the ASCII-amored encrypted message to
409 standard output, and diagnostic messages to standard error."
415 :format "%[Type%] %v"
416 (const :tag "Insert list of recipients here."
418 (const :tag "Insert here name of file with plaintext."
419 :value plaintext-file)
420 (string :format "%v"))))
421 :group 'gpg-commands)
423 ;;; Customization: Variables: Key Management Commands:
425 (defcustom gpg-command-key-import
426 '(gpg . ("--import" "--verbose" message-file))
427 "Command to import a public key from a file."
428 :tag "Import Command"
434 :format "%[Type%] %v"
435 (const :tag "Insert name of file containing the key here."
437 (string :format "%v"))))
438 :group 'gpg-commands-key)
440 (defcustom gpg-command-key-export
441 '(gpg . ("--no-verbose" "--armor" "--export" key-id))
442 "Command to export a public key from the key ring.
443 The key should be written to standard output using ASCII armor."
444 :tag "Export Command"
445 :type 'gpg-command-key-options
446 :group 'gpg-commands-key)
448 (defcustom gpg-command-key-verify
449 '(gpg . ("--no-verbose" "--batch" "--fingerprint" "--check-sigs" key-id))
450 "Command to verify a public key."
451 :tag "Verification Command"
452 :type 'gpg-command-key-options
453 :group 'gpg-commands-key)
455 (defcustom gpg-command-key-public-ring
456 '(gpg . ("--no-verbose" "--batch" "--with-colons" "--list-keys" key-id))
457 "Command to list the contents of the public key ring."
458 :tag "List Public Key Ring Command"
459 :type 'gpg-command-key-options
460 :group 'gpg-commands-key)
462 (defcustom gpg-command-key-secret-ring
463 '(gpg . ("--no-verbose" "--batch" "--with-colons"
464 "--list-secret-keys" key-id))
465 "Command to list the contents of the secret key ring."
466 :tag "List Secret Key Ring Command"
467 :type 'gpg-command-key-options
468 :group 'gpg-commands-key)
470 (defcustom gpg-command-key-retrieve
471 '(gpg . ("--batch" "--recv-keys" key-id))
472 "Command to retrieve public keys."
473 :tag "Retrieve Keys Command"
474 :type 'gpg-command-key-options
475 :group 'gpg-commands-key)
478 ;;;; Helper functions for GnuPG invocation:
480 ;;; Build the GnuPG command line:
482 (defun gpg-build-argument (template substitutions &optional pass-start)
483 "Build command line argument(s) by substituting placeholders.
484 TEMPLATE is a list of strings and symbols. The placeholder symbols in
485 it are replaced by SUBSTITUTIONS, the elements between
486 `next-argument' symbols are concatenated without spaces and are
489 SUBSTITIONS is a list of (SYMBOL . SEXP) pairs, where SEXP is either
490 a string (which is inserted literally), a list of strings (which are
491 inserted as well), or nil, which means to insert nothing.
493 If PASS-START is t, `next-argument' is also inserted into the result,
494 and symbols without a proper substitution are retained in the output,
495 otherwise, an untranslated symbol results in an error.
497 This function does not handle empty arguments reliably."
498 (let ((current-arg "")
501 (let* ((templ (pop template))
502 (repl (assoc templ substitutions))
503 (new (if repl (cdr repl) templ)))
505 ((eq templ 'next-argument)
506 ;; If the current argument is not empty, start a new one.
507 (unless (equal current-arg "")
508 (setq arglist (nconc arglist
510 (list current-arg 'next-argument)
511 (list current-arg))))
512 (setq current-arg "")))
513 ((null new) nil) ; Drop it.
514 ((and (not (stringp templ)) (null repl))
515 ;; Retain an untranslated symbol in the output if
516 ;; `pass-start' is true.
518 (error "No replacement for `%s'" templ))
519 (setq arglist (nconc arglist (list current-arg templ)))
520 (setq current-arg ""))
523 (setq new (list new)))
524 (setq current-arg (concat current-arg
525 (apply 'concat new)))))))
526 (unless (equal current-arg "")
527 (setq arglist (nconc arglist (list current-arg))))
530 (defun gpg-build-arg-list (template substitutions)
531 "Build command line by substituting placeholders.
532 TEMPLATE is a list of strings and symbols. The placeholder symbols in
533 it are replaced by SUBSTITUTIONS.
535 SUBSTITIONS is a list of (SYMBOL . SEXP) pairs, where SEXP is either a
536 string (which is inserted literally), a list of strings (which are
537 inserted as well), or nil, which means to insert nothing."
540 (let* ((templ (pop template))
541 (repl (assoc templ substitutions))
542 (new (if repl (cdr repl) templ)))
544 ((and (symbolp templ) (null repl))
545 (error "No replacement for `%s'" templ))
546 ((null new) nil) ; Drop it.
549 (setq new (list new)))
550 (setq arglist (nconc arglist new))))))
553 (defun gpg-build-flag-recipients-one (recipient)
554 "Build argument for one RECIPIENT."
555 (gpg-build-argument (cdr gpg-command-flag-recipient)
556 `((recipient . ,recipient)) t))
558 (defun gpg-build-flag-recipients (recipients)
559 "Build list of RECIPIENTS using `gpg-command-flag-recipient'."
561 (apply 'append (car gpg-command-flag-recipient)
562 (mapcar 'gpg-build-flag-recipients-one
566 (defun gpg-read-recipients ()
567 "Query the user for several recipients."
571 (setq r (read-string "Enter recipient ID [RET when no more]: "))
574 (setq recipients (nconc recipients (list r)))))
577 (defun gpg-build-flag-sign-with-key (key)
578 "Build sign with key flag using `gpg-command-flag-sign-with-key'."
580 (if gpg-default-key-id gpg-default-key-id
583 (gpg-build-argument gpg-command-flag-sign-with-key
584 (list (cons 'sign-with-key k)))
587 (defmacro gpg-with-passphrase-env (&rest body)
588 "Adjust the process environment and evaluate BODY.
589 During the evaluation of the body forms, the process environment is
590 adjust according to `gpg-command-passphrase-env'."
591 (let ((env-value (make-symbol "env-value")))
595 (when gpg-command-passphrase-env
596 (setq ,env-value (getenv (car gpg-command-passphrase-env)))
597 (setenv (car gpg-command-passphrase-env)
598 (cdr gpg-command-passphrase-env)))
600 (when gpg-command-passphrase-env
601 ;; This will clear the variable if it wasn't set before.
602 (setenv (car gpg-command-passphrase-env) ,env-value))))))
606 (defun gpg-make-temp-file ()
607 "Create a temporary file in a safe way"
608 (let ((name (concat gpg-temp-directory "/gnupg")))
609 (if (fboundp 'make-temp-file)
610 ;; If we've got make-temp-file, we are on the save side.
611 (make-temp-file name)
612 ;; make-temp-name doesn't create the file, and an ordinary
613 ;; write-file operation is prone to nasty symlink attacks if the
614 ;; temporary file resides in a world-writable directory.
615 (unless (eq (file-modes gpg-temp-directory) 448) ; mode 0700
616 (error "Directory for temporary files must have mode 0700."))
617 (setq name (make-temp-name name))
618 (let ((mode (default-file-modes)))
621 (set-default-file-modes 384) ; mode 0600
622 (with-temp-file name))
623 (set-default-file-modes mode)))
626 (defvar gpg-temp-files nil
627 "List of temporary files used by the GnuPG interface.
628 Do not set this variable. Call `gpg-with-temp-files' if you need
631 (defun gpg-with-temp-files-create (count)
632 "Do not call this function. Used internally by `gpg-with-temp-files'."
634 (setq gpg-temp-files (cons (gpg-make-temp-file) gpg-temp-files))
635 (setq count (1- count))))
637 (defun gpg-with-temp-files-delete ()
638 "Do not call this function. Used internally by `gpg-with-temp-files'."
639 (while gpg-temp-files
640 (let ((file (pop gpg-temp-files)))
645 (defmacro gpg-with-temp-files (count &rest body)
646 "Create COUNT temporary files, USE them, and delete them.
647 The function USE is called with the names of all temporary files as
649 `(let ((gpg-temp-files))
652 ;; Create the temporary files.
653 (gpg-with-temp-files-create ,count)
655 (gpg-with-temp-files-delete))))
657 ;;; Making subprocesses:
659 (defun gpg-exec-path (option)
660 "Return the program name for OPTION.
661 OPTION is of the form (PROGRAM . ARGLIST). This functions returns
662 PROGRAM, but takes default values into account."
663 (let* ((prg (car option))
664 (path (assq prg gpg-command-default-alist)))
666 (path (if (null (cdr path))
667 (error "Command `%s' is not available" prg)
669 ((null prg) (error "Command is disabled"))
672 (defun gpg-call-process (cmd args stdin stdout stderr &optional passphrase)
673 "Invoke external program CMD with ARGS on buffer STDIN.
674 Standard output is insert before point in STDOUT, standard error in
675 STDERR. If PASSPHRASE is given, send it before STDIN. PASSPHRASE
676 should not end with a line feed (\"\\n\").
678 If `stdin-file' is present in ARGS, it is replaced by the name of a
679 temporary file. Before invoking CMD, the contents of STDIN is written
681 (gpg-with-temp-files 2
682 (let* ((coding-system-for-read 'no-conversion)
683 (coding-system-for-write 'no-conversion)
684 (have-stdin-file (memq 'stdin-file args))
685 (stdin-file (nth 0 gpg-temp-files))
686 (stderr-file (nth 1 gpg-temp-files))
689 (,stdout ,stderr-file)
691 ;; Replace `stdin-file'.
692 ,@(gpg-build-arg-list
693 args (list (cons 'stdin-file stdin-file)))))
695 (when have-stdin-file
696 (with-temp-file stdin-file
697 (buffer-disable-undo)
698 (insert-buffer-substring stdin)))
702 (buffer-disable-undo)
703 (insert passphrase "\n")
704 (unless have-stdin-file
705 (apply 'insert-buffer-substring
706 (if (listp stdin) stdin (list stdin))))
707 (apply 'call-process-region (point-min) (point-max) cpr-args)
708 ;; Wipe out passphrase.
709 (goto-char (point-min))
710 (translate-region (point) (line-end-position)
711 (make-string 256 ? )))
713 (with-current-buffer (car stdin)
714 (apply 'call-process-region
716 (if have-stdin-file (cadr stdin) (caddr stdin))
718 (with-current-buffer stdin
719 (apply 'call-process-region
721 (if have-stdin-file (point-min) (point-max))
723 (with-current-buffer stderr
724 (insert-file-contents-literally stderr-file))
725 (if (or (stringp res) (> res 0))
726 ;; Signal or abnormal exit.
727 (with-current-buffer stderr
728 (goto-char (point-max))
729 (insert (format "\nCommand exit status: %s\n" res))
733 (defvar gpg-result-buffer nil
734 "The result of a GnuPG operation is stored in this buffer.
735 Never set this variable directly, use `gpg-show-result' instead.")
737 (defun gpg-show-result-buffer (always-show result)
738 "Called by `gpg-show-results' to actually show the buffer."
739 (with-current-buffer gpg-result-buffer
740 ;; Only proceed if the buffer is non-empty.
741 (when (and (/= (point-min) (point-max))
742 (or always-show (not result)))
743 (save-window-excursion
744 (display-buffer (current-buffer))
745 (unless (y-or-n-p "Continue? ")
746 (error "GnuPG operation aborted."))))))
748 (defmacro gpg-show-result (always-show &rest body)
749 "Show GnuPG result to user for confirmation.
750 This macro binds `gpg-result-buffer' to a temporary buffer and
751 evaluates BODY, like `progn'. If BODY evaluates to `nil' (or
752 `always-show' is not nil), the user is asked for confirmation."
753 `(let ((gpg-result-buffer (get-buffer-create
754 (generate-new-buffer-name "*GnuPG Output*"))))
756 (gpg-show-result-buffer ,always-show (progn ,@body))
757 (kill-buffer gpg-result-buffer))))
759 ;;; Passphrase handling:
761 (defvar gpg-passphrase-timer
763 "This timer will clear the passphrase cache periodically.")
765 (defvar gpg-passphrase
767 "The (unencrypted) passphrase cache.")
769 (defun gpg-passphrase-clear-string (str)
770 "Erases STR by overwriting all characters."
778 (defun gpg-passphrase-forget ()
779 "Forget stored passphrase."
781 (cancel-timer gpg-passphrase-timer)
782 (gpg-passphrase-clear-string gpg-passphrase)
783 (setq gpg-passphrase nil))
785 (defun gpg-passphrase-store (passphrase)
786 "Store PASSPHRASE in cache.
787 Updates the timeout for clearing the cache to `gpg-passphrase-timeout'."
788 (unless (equal gpg-passphrase-timeout 0)
789 (timer-set-time gpg-passphrase-timer
790 (timer-relative-time (current-time)
791 gpg-passphrase-timeout))
792 (timer-set-function gpg-passphrase-timer 'gpg-passphrase-forget)
793 (timer-activate gpg-passphrase-timer)
794 (setq gpg-passphrase passphrase))
797 (defun gpg-passphrase-read ()
798 "Read a passphrase and remember it for some time."
801 ;; This reinitializes the timer.
802 (gpg-passphrase-store gpg-passphrase)
803 (let ((pp (read-passwd "Enter passphrase: ")))
804 (gpg-passphrase-store pp))))
807 ;;;; Main operations:
810 (defun gpg-verify (message signature result)
811 "Verify buffer MESSAGE against detached SIGNATURE buffer.
812 Returns t if everything worked out well, nil otherwise. Consult
813 buffer RESULT for details."
814 (interactive "bBuffer containing message: \nbBuffer containing signature: \nbBuffor for result: ")
815 (gpg-with-temp-files 2
816 (let* ((sig-file (nth 0 gpg-temp-files))
817 (msg-file (nth 1 gpg-temp-files))
818 (cmd (gpg-exec-path gpg-command-verify))
819 (args (gpg-build-arg-list (cdr gpg-command-verify)
820 `((signature-file . ,sig-file)
821 (message-file . ,msg-file))))
823 (with-temp-file sig-file
824 (buffer-disable-undo)
825 (apply 'insert-buffer-substring (if (listp signature)
828 (with-temp-file msg-file
829 (buffer-disable-undo)
830 (apply 'insert-buffer-substring (if (listp message)
833 (setq res (apply 'call-process-region
834 (point-min) (point-min) ; no data
840 (if (or (stringp res) (> res 0))
841 ;; Signal or abnormal exit.
842 (with-current-buffer result
843 (insert (format "\nCommand exit status: %s\n" res))
848 (defun gpg-verify-cleartext (message result)
849 "Verify message in buffer MESSAGE.
850 Returns t if everything worked out well, nil otherwise. Consult
851 buffer RESULT for details.
853 NOTE: Use of this function is deprecated."
854 (interactive "bBuffer containing message: \nbBuffor for result: ")
855 (gpg-with-temp-files 1
856 (let* ((msg-file (nth 0 gpg-temp-files))
857 (cmd (gpg-exec-path gpg-command-verify-cleartext))
858 (args (gpg-build-arg-list (cdr gpg-command-verify-cleartext)
859 `((message-file . ,msg-file))))
861 (with-temp-file msg-file
862 (buffer-disable-undo)
863 (apply 'insert-buffer-substring (if (listp message)
866 (setq res (apply 'call-process-region
867 (point-min) (point-min) ; no data
873 (if (or (stringp res) (> res 0))
874 ;; Signal or abnormal exit.
875 (with-current-buffer result
876 (insert (format "\nCommand exit status: %s\n" res))
881 (defun gpg-decrypt (ciphertext plaintext result &optional passphrase)
882 "Decrypt buffer CIPHERTEXT to buffer PLAINTEXT.
883 Returns t if everything worked out well, nil otherwise. Consult
884 buffer RESULT for details. Reads a missing PASSPHRASE using
885 `gpg-passphrase-read'."
886 (interactive "bBuffer containing ciphertext: \nbBuffer for plaintext: \nbBuffor for decryption status: ")
887 (gpg-call-process (gpg-exec-path gpg-command-decrypt)
888 (gpg-build-arg-list (cdr gpg-command-decrypt) nil)
889 ciphertext plaintext result
890 (if passphrase passphrase (gpg-passphrase-read)))
892 (gpg-passphrase-clear-string passphrase)))
895 (defun gpg-sign-cleartext
896 (plaintext signed-text result &optional passphrase sign-with-key)
897 "Sign buffer PLAINTEXT, and store PLAINTEXT with signature in
899 Reads a missing PASSPHRASE using `gpg-passphrase-read'. Uses key ID
900 SIGN-WITH-KEY if given, otherwise the default key ID. Returns t if
901 everything worked out well, nil otherwise. Consult buffer RESULT for
904 NOTE: Use of this function is deprecated."
905 (interactive "bBuffer containing plaintext: \nbBuffer for text with signature: \nbBuffer for status information: ")
906 (let ((subst (list (cons 'sign-with-key
907 (gpg-build-flag-sign-with-key sign-with-key))
908 (cons 'armor gpg-command-flag-armor)
909 (cons 'textmode gpg-command-flag-textmode))))
910 (gpg-call-process (gpg-exec-path gpg-command-sign-cleartext)
911 (gpg-build-arg-list (cdr gpg-command-sign-cleartext)
913 plaintext signed-text result
914 (if passphrase passphrase (gpg-passphrase-read))))
916 (gpg-passphrase-clear-string passphrase)))
919 (defun gpg-sign-detached
920 (plaintext signature result &optional passphrase sign-with-key
922 "Sign buffer PLAINTEXT, and store SIGNATURE in that buffer.
923 Reads a missing PASSPHRASE using `gpg-passphrase-read'. Uses key ID
924 SIGN-WITH-KEY if given, otherwise the default key ID. Returns t if
925 everything worked out well, nil otherwise. Consult buffer RESULT for
926 details. ARMOR the result and activate canonical TEXTMODE if
928 (interactive "bBuffer containing plaintext: \nbBuffer for text with signature: \nbBuffer for status information: ")
929 (let ((subst (list (cons 'sign-with-key
930 (gpg-build-flag-sign-with-key sign-with-key))
931 (cons 'armor (if armor gpg-command-flag-armor))
932 (cons 'textmode (if armor gpg-command-flag-textmode)))))
933 (gpg-call-process (gpg-exec-path gpg-command-sign-detached)
934 (gpg-build-arg-list (cdr gpg-command-sign-detached)
936 plaintext signature result
937 (if passphrase passphrase (gpg-passphrase-read))))
939 (gpg-passphrase-clear-string passphrase)))
943 (defun gpg-sign-encrypt
944 (plaintext ciphertext result recipients &optional passphrase sign-with-key
946 "Sign buffer PLAINTEXT, and store SIGNATURE in that buffer.
947 RECIPIENTS is a list of key IDs used for encryption. This function
948 reads a missing PASSPHRASE using `gpg-passphrase-read', and uses key
949 ID SIGN-WITH-KEY for the signature if given, otherwise the default key
950 ID. Returns t if everything worked out well, nil otherwise. Consult
951 buffer RESULT for details. ARMOR the result and activate canonical
952 TEXTMODE if requested."
954 (read-buffer "Buffer containing plaintext: " nil t)
955 (read-buffer "Buffer for ciphertext: " nil t)
956 (read-buffer "Buffer for status informationt: " nil t)
957 (gpg-read-recipients)))
958 (let ((subst `((sign-with-key . ,(gpg-build-flag-sign-with-key
960 (plaintext-file . stdin-file)
961 (recipients . ,(gpg-build-flag-recipients recipients))
962 (armor ,(if armor gpg-command-flag-armor))
963 (textmode ,(if armor gpg-command-flag-textmode)))))
964 (gpg-call-process (gpg-exec-path gpg-command-sign-encrypt)
965 (gpg-build-arg-list (cdr gpg-command-sign-encrypt)
967 plaintext ciphertext result
968 (if passphrase passphrase (gpg-passphrase-read))))
970 (gpg-passphrase-clear-string passphrase)))
975 (plaintext ciphertext result recipients &optional passphrase armor textmode)
976 "Encrypt buffer PLAINTEXT, and store CIPHERTEXT in that buffer.
977 RECIPIENTS is a list of key IDs used for encryption. Returns t if
978 everything worked out well, nil otherwise. Consult buffer RESULT for
979 details. ARMOR the result and activate canonical
980 TEXTMODE if requested."
982 (read-buffer "Buffer containing plaintext: " nil t)
983 (read-buffer "Buffer for ciphertext: " nil t)
984 (read-buffer "Buffer for status informationt: " nil t)
985 (gpg-read-recipients)))
986 (let ((subst `((plaintext-file . stdin-file)
987 (recipients . ,(gpg-build-flag-recipients recipients))
988 (armor ,(if armor gpg-command-flag-armor))
989 (textmode ,(if armor gpg-command-flag-textmode)))))
990 (gpg-call-process (gpg-exec-path gpg-command-encrypt)
991 (gpg-build-arg-list (cdr gpg-command-encrypt) subst)
992 plaintext ciphertext result nil))
994 (gpg-passphrase-clear-string passphrase)))
1001 (defun gpg-key-make (user-id key-id unique-id length algorithm
1002 creation-date expire-date validity trust)
1003 "Create a new key object (for internal use only)."
1006 user-id key-id unique-id length algorithm
1008 creation-date expire-date validity trust))
1011 (defun gpg-key-p (key)
1012 "Return t if KEY is a key specification."
1013 (and (arrayp key) (equal (length key) 9) key))
1015 (defmacro gpg-key-primary-user-id (key)
1016 "The primary user ID for KEY (human-readable).
1017 DO NOT USE this ID for selecting recipients. It is probably not
1019 (list 'car (list 'aref key 0)))
1021 (defmacro gpg-key-user-ids (key)
1022 "A list of additional user IDs for KEY (human-readable).
1023 DO NOT USE these IDs for selecting recipients. They are probably not
1025 (list 'cdr (list 'aref key 0)))
1027 (defmacro gpg-key-id (key)
1029 DO NOT USE this ID for selecting recipients. It is not guaranteed to
1033 (defun gpg-short-key-id (key)
1034 "The short key ID of KEY."
1035 (let* ((id (gpg-key-id key))
1038 (substring id (- len 8))
1041 (defmacro gpg-key-unique-id (key)
1042 "A non-standard ID of KEY which is only valid locally.
1043 This ID can be used to specify recipients in a safe manner. Note,
1044 even this ID might not be unique unless GnuPG is used."
1047 (defmacro gpg-key-unique-id-list (key-list)
1048 "Like `gpg-key-unique-id', but operate on a list."
1049 `(mapcar (lambda (key) (gpg-key-unique-id key))
1052 (defmacro gpg-key-length (key)
1053 "Returns the key length."
1056 (defmacro gpg-key-algorithm (key)
1057 "The encryption algorithm used by KEY.
1058 One of the symbols `rsa', `rsa-encrypt', `rsa-sign', `elgamal',
1059 `elgamal-encrypt', `dsa'."
1062 (defmacro gpg-key-creation-date (key)
1063 "A string with the creation date of KEY in ISO format."
1066 (defmacro gpg-key-expire-date (key)
1067 "A string with the expiration date of KEY in ISO format."
1070 (defmacro gpg-key-validity (key)
1071 "The calculated validity of KEY.
1072 One of the symbols `not-known', `disabled', `revoked', `expired',
1073 `undefined', `trust-none', `trust-marginal', `trust-full',
1074 `trust-ultimate' (see the GnuPG documentation for details)."
1077 (defmacro gpg-key-trust (key)
1078 "The assigned trust for KEY.
1079 One of the symbols `not-known', `undefined', `trust-none',
1080 `trust-marginal', `trust-full' (see the GnuPG
1081 documentation for details)."
1084 (defun gpg-key-lessp (a b)
1085 "Returns t if primary user ID of A is less than B."
1086 (string-lessp (gpg-key-primary-user-id a) (gpg-key-primary-user-id b) ))
1088 ;;; Accessing the key database:
1090 ;; Internal functions:
1092 (defmacro gpg-key-list-keys-skip-field ()
1093 '(search-forward ":" eol 'move))
1095 (defmacro gpg-key-list-keys-get-field ()
1096 '(buffer-substring (point) (if (gpg-key-list-keys-skip-field)
1099 (defmacro gpg-key-list-keys-string-field ()
1100 '(gpg-key-list-keys-get-field))
1102 (defmacro gpg-key-list-keys-read-field ()
1103 (let ((field (make-symbol "field")))
1104 `(let ((,field (gpg-key-list-keys-get-field)))
1105 (if (equal (length ,field) 0)
1109 (defun gpg-key-list-keys-parse-line ()
1110 "Parse the line in the current buffer and return a vector of fields."
1111 (let* ((eol (line-end-position))
1115 (gpg-key-list-keys-read-field) ; type
1116 (gpg-key-list-keys-get-field) ; trust
1117 (gpg-key-list-keys-read-field) ; key length
1118 (gpg-key-list-keys-read-field) ; algorithm
1119 (gpg-key-list-keys-get-field) ; key ID
1120 (gpg-key-list-keys-get-field) ; creation data
1121 (gpg-key-list-keys-get-field) ; expire
1122 (gpg-key-list-keys-get-field) ; unique (local) ID
1123 (gpg-key-list-keys-get-field) ; ownertrust
1124 (gpg-key-list-keys-string-field) ; user ID
1129 (error "Too many fields in GnuPG key database"))
1132 (defconst gpg-pubkey-algo-alist
1134 (2 . rsa-encrypt-only)
1136 (16 . elgamal-encrypt-only)
1139 "Alist mapping OpenPGP public key algorithm numbers to symbols.")
1141 (defconst gpg-trust-alist
1147 (?q . trust-undefined)
1149 (?m . trust-marginal)
1151 (?u . trust-ultimate))
1152 "Alist mapping GnuPG trust value short forms to long symbols.")
1154 (defmacro gpg-key-list-keys-in-buffer-store ()
1155 '(when primary-user-id
1156 (sort user-id 'string-lessp)
1157 (push (gpg-key-make (cons primary-user-id user-id)
1158 key-id unique-id key-length
1159 algorithm creation-date
1160 expire-date validity trust)
1163 (defun gpg-key-list-keys-in-buffer (&optional buffer)
1164 "Return a list of keys for BUFFER.
1165 If BUFFER is omitted, use current buffer."
1166 (with-current-buffer (if buffer buffer (current-buffer))
1167 (goto-char (point-min))
1168 ;; Skip key ring filename written by GnuPG.
1169 (search-forward "\n---------------------------\n" nil t)
1170 ;; Loop over all lines in buffer and analyze them.
1171 (let (primary-user-id user-id key-id unique-id ; current key components
1172 key-length algorithm creation-date expire-date validity trust
1173 line ; fields in current line
1174 key-list) ; keys gather so far
1176 (while (setq line (gpg-key-list-keys-parse-line))
1178 ;; Public or secret key.
1179 ((memq (aref line 0) '(pub sec))
1180 ;; Store previous key, if any.
1181 (gpg-key-list-keys-in-buffer-store)
1182 ;; Record field values.
1183 (setq primary-user-id (aref line 9))
1185 (setq key-id (aref line 4))
1186 ;; We use the key ID if no unique ID is available.
1187 (setq unique-id (if (> (length (aref line 7)) 0)
1188 (concat "#" (aref line 7))
1189 (concat "0x" key-id)))
1190 (setq key-length (aref line 2))
1191 (setq algorithm (assq (aref line 3) gpg-pubkey-algo-alist))
1193 (setq algorithm (cdr algorithm))
1194 (error "Unknown algorithm %s" (aref line 3)))
1195 (setq creation-date (if (> (length (aref line 5)) 0)
1197 (setq expire-date (if (> (length (aref line 6)) 0)
1199 (setq validity (assq (aref (aref line 1) 0) gpg-trust-alist))
1201 (setq validity (cdr validity))
1202 (error "Unknown validity specification %S" (aref line 1)))
1203 (setq trust (assq (aref (aref line 8) 0) gpg-trust-alist))
1205 (setq trust (cdr trust))
1206 (error "Unknown trust specification %S" (aref line 8))))
1208 ;; Additional user ID
1209 ((eq 'uid (aref line 0))
1210 (setq user-id (cons (aref line 9) user-id)))
1212 ;; Subkeys are ignored for now.
1213 ((memq (aref line 0) '(sub ssb))
1215 (t (error "Unknown record type %S" (aref line 0)))))
1217 ;; Store the key retrieved last.
1218 (gpg-key-list-keys-in-buffer-store)
1219 ;; Sort the keys according to the primary user ID.
1220 (sort key-list 'gpg-key-lessp))))
1222 (defun gpg-key-list-keyspec (command &optional keyspec stderr ignore-error)
1223 "Insert the output of COMMAND before point in current buffer."
1224 (let* ((cmd (gpg-exec-path command))
1225 (key (if (equal keyspec "") nil keyspec))
1226 (args (gpg-build-arg-list (cdr command) `((key-id . ,key))))
1229 (apply 'call-process-region
1230 (point-min) (point-min) ; no data
1233 (if stderr t '(t nil))
1236 (unless (or ignore-error (equal exit-status 0))
1237 (error "GnuPG command exited unsuccessfully"))))
1240 (defun gpg-key-list-keyspec-parse (command &optional keyspec)
1241 "Return a list of keys matching KEYSPEC.
1242 COMMAND is used to obtain the key list. The usual substring search
1243 for keys is performed."
1245 (buffer-disable-undo)
1246 (gpg-key-list-keyspec command keyspec)
1247 (gpg-key-list-keys-in-buffer)))
1250 (defun gpg-key-list-keys (&optional keyspec)
1251 "A list of public keys matching KEYSPEC.
1252 The usual substring search for keys is performed."
1253 (gpg-key-list-keyspec-parse gpg-command-key-public-ring keyspec))
1256 (defun gpg-key-list-secret-keys (&optional keyspec)
1257 "A list of secret keys matching KEYSPEC.
1258 The usual substring search for keys is performed."
1259 (gpg-key-list-keyspec-parse gpg-command-key-secret-ring keyspec))
1262 (defun gpg-key-insert-public-key (key)
1263 "Inserts the public key(s) matching KEYSPEC.
1264 The ASCII-armored key is inserted before point into current buffer."
1265 (gpg-key-list-keyspec gpg-command-key-export key))
1268 (defun gpg-key-insert-information (key)
1269 "Insert human-readable information (including fingerprint) on KEY.
1270 Insertion takes place in current buffer before point."
1271 (gpg-key-list-keyspec gpg-command-key-verify key))
1274 (defun gpg-key-retrieve (key)
1275 "Fetch KEY from default key server.
1276 KEY is a key ID or a list of key IDs. Status information about this
1277 operation is inserted into the current buffer before point."
1278 (gpg-key-list-keyspec gpg-command-key-retrieve key t t))
1281 (defun gpg-key-add-to-ring (key result)
1282 "Adds key in buffer KEY to the GnuPG key ring.
1283 Human-readable information on the RESULT is stored in buffer RESULT
1288 ;;; gpg.el ends here