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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-29 11:02:01 +00:00
emacs/lisp/pgg-gpg.el
Eli Zaretskii df570e6fe2 (pgg-gpg-select-matching-key): Fixed: look at the right part of the
decoded armor to find the key-identifier.
(pgg-gpg-lookup-key-owner): New function to return the
human-readable identifier of a key owner.
(pgg-gpg-lookup-id-from-key-owner): Make it easy to identify the
key itself.
(pgg-gpg-decrypt-region): Prompt with the key owner (rather
than the key value) if we have a key and can match it against a
secret key.  Also, added an XXX note pointing out fact that the
prompt only indicates the first matching key.
(pgg-pgp-encrypt-region)
(pgg-pgp-encrypt-symmetric-region, pgg-pgp-encrypt-symmetric)
(pgg-pgp-encrypt, pgg-pgp-decrypt-region, pgg-pgp-decrypt)
(pgg-pgp-sign-region, pgg-pgp-sign): Add optional 'passphrase'
argument to all these routines, so the passphrase can be managed
externally and passed in to the system.
(pgg-gpg-possibly-cache-passphrase): Add optional
'notruncate' argument, so the passphrase cache can be used
reliably with identifiers besides a pgp packet's key id.
(pgg-gpg-encrypt-symmetric-region): New function for
symmetric encryption.
(pgg-gpg-symmetric-key-p): New function to check for an symmetric
encrypted session key.
(pgg-gpg-decrypt-region): When decrypting a symmetric encrypted
message ask for the passphrase in a proper way.
2005-10-29 11:31:08 +00:00

350 lines
13 KiB
EmacsLisp

;;; pgg-gpg.el --- GnuPG support for PGG.
;; Copyright (C) 1999, 2000, 2002, 2003, 2004,
;; 2005 Free Software Foundation, Inc.
;; Author: Daiki Ueno <ueno@unixuser.org>
;; Symmetric encryption added by: Sascha Wilde <wilde@sha-bang.de>
;; Created: 1999/10/28
;; Keywords: PGP, OpenPGP, GnuPG
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
;;; Code:
(eval-when-compile
(require 'cl) ; for gpg macros
(require 'pgg))
(defgroup pgg-gpg ()
"GnuPG interface."
:group 'pgg)
(defcustom pgg-gpg-program "gpg"
"The GnuPG executable."
:group 'pgg-gpg
:type 'string)
(defcustom pgg-gpg-extra-args nil
"Extra arguments for every GnuPG invocation."
:group 'pgg-gpg
:type '(repeat (string :tag "Argument")))
(defcustom pgg-gpg-recipient-argument "--recipient"
"GnuPG option to specify recipient."
:group 'pgg-gpg
:type '(choice (const :tag "New `--recipient' option" "--recipient")
(const :tag "Old `--remote-user' option" "--remote-user")))
(defvar pgg-gpg-user-id nil
"GnuPG ID of your default identity.")
(defun pgg-gpg-process-region (start end passphrase program args)
(let* ((output-file-name (pgg-make-temp-file "pgg-output"))
(args
`("--status-fd" "2"
,@(if passphrase '("--passphrase-fd" "0"))
"--yes" ; overwrite
"--output" ,output-file-name
,@pgg-gpg-extra-args ,@args))
(output-buffer pgg-output-buffer)
(errors-buffer pgg-errors-buffer)
(orig-mode (default-file-modes))
(process-connection-type nil)
exit-status)
(with-current-buffer (get-buffer-create errors-buffer)
(buffer-disable-undo)
(erase-buffer))
(unwind-protect
(progn
(set-default-file-modes 448)
(let ((coding-system-for-write 'binary)
(input (buffer-substring-no-properties start end))
(default-enable-multibyte-characters nil))
(with-temp-buffer
(when passphrase
(insert passphrase "\n"))
(insert input)
(setq exit-status
(apply #'call-process-region (point-min) (point-max) program
nil errors-buffer nil args))))
(with-current-buffer (get-buffer-create output-buffer)
(buffer-disable-undo)
(erase-buffer)
(if (file-exists-p output-file-name)
(let ((coding-system-for-read 'raw-text-dos))
(insert-file-contents output-file-name)))
(set-buffer errors-buffer)
(if (not (equal exit-status 0))
(insert (format "\n%s exited abnormally: '%s'\n"
program exit-status)))))
(if (file-exists-p output-file-name)
(delete-file output-file-name))
(set-default-file-modes orig-mode))))
(defun pgg-gpg-possibly-cache-passphrase (passphrase &optional key notruncate)
(if (and pgg-cache-passphrase
(progn
(goto-char (point-min))
(re-search-forward "^\\[GNUPG:] \\(GOOD_PASSPHRASE\\>\\)\\|\\(SIG_CREATED\\)" nil t)))
(pgg-add-passphrase-to-cache
(or key
(progn
(goto-char (point-min))
(if (re-search-forward
"^\\[GNUPG:] NEED_PASSPHRASE\\(_PIN\\)? \\w+ ?\\w*" nil t)
(substring (match-string 0) -8))))
passphrase
notruncate)))
(defvar pgg-gpg-all-secret-keys 'unknown)
(defun pgg-gpg-lookup-all-secret-keys ()
"Return all secret keys present in secret key ring."
(when (eq pgg-gpg-all-secret-keys 'unknown)
(setq pgg-gpg-all-secret-keys '())
(let ((args (list "--with-colons" "--no-greeting" "--batch"
"--list-secret-keys")))
(with-temp-buffer
(apply #'call-process pgg-gpg-program nil t nil args)
(goto-char (point-min))
(while (re-search-forward
"^\\(sec\\|pub\\):[^:]*:[^:]*:[^:]*:\\([^:]*\\)" nil t)
(push (substring (match-string 2) 8)
pgg-gpg-all-secret-keys)))))
pgg-gpg-all-secret-keys)
(defun pgg-gpg-lookup-key (string &optional type)
"Search keys associated with STRING."
(let ((args (list "--with-colons" "--no-greeting" "--batch"
(if type "--list-secret-keys" "--list-keys")
string)))
(with-temp-buffer
(apply #'call-process pgg-gpg-program nil t nil args)
(goto-char (point-min))
(if (re-search-forward "^\\(sec\\|pub\\):[^:]*:[^:]*:[^:]*:\\([^:]*\\)"
nil t)
(substring (match-string 2) 8)))))
(defun pgg-gpg-lookup-key-owner (string &optional all)
"Search keys associated with STRING and return owner of identified key.
The value may be just the bare key id, or it may be a combination of the
user name associated with the key and the key id, with the key id enclosed
in \"<...>\" angle brackets.
Optional ALL non-nil means search all keys, including secret keys."
(let ((args (list "--with-colons" "--no-greeting" "--batch"
(if all "--list-secret-keys" "--list-keys")
string))
(key-regexp (concat "^\\(sec\\|pub\\)"
":[^:]*:[^:]*:[^:]*:\\([^:]*\\):[^:]*"
":[^:]*:[^:]*:[^:]*:\\([^:]*\\):"))
)
(with-temp-buffer
(apply #'call-process pgg-gpg-program nil t nil args)
(goto-char (point-min))
(if (re-search-forward key-regexp
nil t)
(match-string 3)))))
(defun pgg-gpg-key-id-from-key-owner (key-owner)
(cond ((not key-owner) nil)
;; Extract bare key id from outermost paired angle brackets, if any:
((string-match "[^<]*<\\(.+\\)>[^>]*" key-owner)
(substring key-owner (match-beginning 1)(match-end 1)))
(key-owner))
)
(defun pgg-gpg-encrypt-region (start end recipients &optional sign passphrase)
"Encrypt the current region between START and END.
If optional argument SIGN is non-nil, do a combined sign and encrypt.
If optional PASSPHRASE is not specified, it will be obtained from the
passphrase cache or user."
(let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
(passphrase (or passphrase
(when sign
(pgg-read-passphrase
(format "GnuPG passphrase for %s: "
pgg-gpg-user-id)
pgg-gpg-user-id))))
(args
(append
(list "--batch" "--textmode" "--armor" "--always-trust" "--encrypt")
(if sign (list "--sign" "--local-user" pgg-gpg-user-id))
(if recipients
(apply #'nconc
(mapcar (lambda (rcpt)
(list pgg-gpg-recipient-argument rcpt))
(append recipients
(if pgg-encrypt-for-me
(list pgg-gpg-user-id)))))))))
(pgg-as-lbt start end 'CRLF
(pgg-gpg-process-region start end passphrase pgg-gpg-program args))
(when sign
(with-current-buffer pgg-errors-buffer
;; Possibly cache passphrase under, e.g. "jas", for future sign.
(pgg-gpg-possibly-cache-passphrase passphrase pgg-gpg-user-id)
;; Possibly cache passphrase under, e.g. B565716F, for future decrypt.
(pgg-gpg-possibly-cache-passphrase passphrase)))
(pgg-process-when-success)))
(defun pgg-gpg-encrypt-symmetric-region (start end &optional passphrase)
"Encrypt the current region between START and END with symmetric cipher.
If optional PASSPHRASE is not specified, it will be obtained from the
passphrase cache or user."
(let* ((passphrase (or passphrase
(pgg-read-passphrase
"GnuPG passphrase for symmetric encryption: ")))
(args
(append (list "--batch" "--textmode" "--armor" "--symmetric" ))))
(pgg-as-lbt start end 'CRLF
(pgg-gpg-process-region start end passphrase pgg-gpg-program args))
(pgg-process-when-success)))
(defun pgg-gpg-decrypt-region (start end &optional passphrase)
"Decrypt the current region between START and END.
If optional PASSPHRASE is not specified, it will be obtained from the
passphrase cache or user."
(let* ((current-buffer (current-buffer))
(message-keys (with-temp-buffer
(insert-buffer-substring current-buffer)
(pgg-decode-armor-region (point-min) (point-max))))
(secret-keys (pgg-gpg-lookup-all-secret-keys))
;; XXX the user is stuck if they need to use the passphrase for
;; any but the first secret key for which the message is
;; encrypted. ideally, we would incrementally give them a
;; chance with subsequent keys each time they fail with one.
(key (pgg-gpg-select-matching-key message-keys secret-keys))
(key-owner (and key (pgg-gpg-lookup-key-owner key t)))
(key-id (pgg-gpg-key-id-from-key-owner key-owner))
(pgg-gpg-user-id (or key-id key
pgg-gpg-user-id pgg-default-user-id))
(passphrase (or passphrase
(pgg-read-passphrase
(format (if (pgg-gpg-symmetric-key-p message-keys)
"Passphrase for symmetric decryption: "
"GnuPG passphrase for %s: ")
(or key-owner "??"))
pgg-gpg-user-id)))
(args '("--batch" "--decrypt")))
(pgg-gpg-process-region start end passphrase pgg-gpg-program args)
(with-current-buffer pgg-errors-buffer
(pgg-gpg-possibly-cache-passphrase passphrase pgg-gpg-user-id)
(goto-char (point-min))
(re-search-forward "^\\[GNUPG:] DECRYPTION_OKAY\\>" nil t))))
;;;###autoload
(defun pgg-gpg-symmetric-key-p (message-keys)
"True if decoded armor MESSAGE-KEYS has symmetric encryption indicator."
(let (result)
(dolist (key message-keys result)
(when (and (eq (car key) 3)
(member '(symmetric-key-algorithm) key))
(setq result key)))))
(defun pgg-gpg-select-matching-key (message-keys secret-keys)
"Choose a key from MESSAGE-KEYS that matches one of the keys in SECRET-KEYS."
(loop for message-key in message-keys
for message-key-id = (and (equal (car message-key) 1)
(cdr (assq 'key-identifier
(cdr message-key))))
for key = (and message-key-id (pgg-lookup-key message-key-id 'encrypt))
when (and key (member key secret-keys)) return key))
(defun pgg-gpg-sign-region (start end &optional cleartext passphrase)
"Make detached signature from text between START and END."
(let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
(passphrase (or passphrase
(pgg-read-passphrase
(format "GnuPG passphrase for %s: " pgg-gpg-user-id)
pgg-gpg-user-id)))
(args
(list (if cleartext "--clearsign" "--detach-sign")
"--armor" "--batch" "--verbose"
"--local-user" pgg-gpg-user-id))
(inhibit-read-only t)
buffer-read-only)
(pgg-as-lbt start end 'CRLF
(pgg-gpg-process-region start end passphrase pgg-gpg-program args))
(with-current-buffer pgg-errors-buffer
;; Possibly cache passphrase under, e.g. "jas", for future sign.
(pgg-gpg-possibly-cache-passphrase passphrase pgg-gpg-user-id)
;; Possibly cache passphrase under, e.g. B565716F, for future decrypt.
(pgg-gpg-possibly-cache-passphrase passphrase))
(pgg-process-when-success)))
(defun pgg-gpg-verify-region (start end &optional signature)
"Verify region between START and END as the detached signature SIGNATURE."
(let ((args '("--batch" "--verify")))
(when (stringp signature)
(setq args (append args (list signature))))
(setq args (append args '("-")))
(pgg-gpg-process-region start end nil pgg-gpg-program args)
(with-current-buffer pgg-errors-buffer
(goto-char (point-min))
(while (re-search-forward "^gpg: \\(.*\\)\n" nil t)
(with-current-buffer pgg-output-buffer
(insert-buffer-substring pgg-errors-buffer
(match-beginning 1) (match-end 0)))
(delete-region (match-beginning 0) (match-end 0)))
(goto-char (point-min))
(re-search-forward "^\\[GNUPG:] GOODSIG\\>" nil t))))
(defun pgg-gpg-insert-key ()
"Insert public key at point."
(let* ((pgg-gpg-user-id (or pgg-gpg-user-id pgg-default-user-id))
(args (list "--batch" "--export" "--armor"
pgg-gpg-user-id)))
(pgg-gpg-process-region (point)(point) nil pgg-gpg-program args)
(insert-buffer-substring pgg-output-buffer)))
(defun pgg-gpg-snarf-keys-region (start end)
"Add all public keys in region between START and END to the keyring."
(let ((args '("--import" "--batch" "-")) status)
(pgg-gpg-process-region start end nil pgg-gpg-program args)
(set-buffer pgg-errors-buffer)
(goto-char (point-min))
(when (re-search-forward "^\\[GNUPG:] IMPORT_RES\\>" nil t)
(setq status (buffer-substring (match-end 0)
(progn (end-of-line)(point)))
status (vconcat (mapcar #'string-to-number (split-string status))))
(erase-buffer)
(insert (format "Imported %d key(s).
\tArmor contains %d key(s) [%d bad, %d old].\n"
(+ (aref status 2)
(aref status 10))
(aref status 0)
(aref status 1)
(+ (aref status 4)
(aref status 11)))
(if (zerop (aref status 9))
""
"\tSecret keys are imported.\n")))
(append-to-buffer pgg-output-buffer (point-min)(point-max))
(pgg-process-when-success)))
(provide 'pgg-gpg)
;;; arch-tag: 2aa5d5d8-93a0-4865-9312-33e29830e000
;;; pgg-gpg.el ends here