;;; smime.el --- S/MIME support library
-;; Copyright (c) 2000 Free Software Foundation, Inc.
+
+;; Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+;; 2009, 2010 Free Software Foundation, Inc.
;; Author: Simon Josefsson <simon@josefsson.org>
;; Keywords: SMIME X.509 PEM OpenSSL
-;; This file is not a part of GNU Emacs, but the same permissions apply.
+;; 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 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 3 of the License, 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.
+;; 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., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; This library perform S/MIME operations from within Emacs.
;;
;; Functions for fetching certificates from public repositories are
-;; provided, currently only from DNS. LDAP support (via EUDC) is planned.
+;; provided, currently from DNS and LDAP.
;;
;; It uses OpenSSL (tested with version 0.9.5a and 0.9.6) for signing,
;; encryption and decryption.
;; PKCSx or similar, it's intended to perform common operations
;; done on messages encoded in these formats. The terminology chosen
;; reflect this.
+;;
+;; The home of this file is in Gnus, but also available from
+;; http://josefsson.org/smime.html.
;;; Quick introduction:
;;
;; Now you should be able to sign messages! Create a buffer and write
;; something and run M-x smime-sign-buffer RET RET and you should see
-;; your message MIME armoured and a signature. Encryption, M-x
+;; your message MIME armored and a signature. Encryption, M-x
;; smime-encrypt-buffer, should also work.
;;
;; To be able to verify messages you need to build up trust with
;; that decision. One might think that this even influenced were I
;; store my keys, and one would probably be right. :-)
;;
+;; Update: Mathias Herberts sent the patch. However, it uses
+;; environment variables to pass the password to OpenSSL, which is
+;; slightly insecure. Hence a new todo: use a better -passin method.
+;;
+;; Cache password for e.g. 1h
+;;
;; Suggestions and comments are appreciated, mail me at simon@josefsson.org.
-;; <rant>
+;; begin rant
;;
;; I would include pointers to introductory text on concepts used in
;; this library here, but the material I've read are so horrible I
;; Also, I'm not going to mention anything about the wonders of
;; cryptopolitics. Oops, I just did.
;;
-;; </rant>
+;; end rant
;;; Revision history:
-;; version 0 not released
+;; 2000-06-05 initial version, committed to Gnus CVS contrib/
+;; 2000-10-28 retrieve certificates via DNS CERT RRs
+;; 2001-10-14 posted to gnu.emacs.sources
+;; 2005-02-13 retrieve certificates via LDAP
;;; Code:
+;; For Emacs <22.2 and XEmacs.
+(eval-and-compile
+ (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
(require 'dig)
+
+(if (locate-library "password-cache")
+ (require 'password-cache)
+ (require 'password))
+
(eval-when-compile (require 'cl))
+(eval-and-compile
+ (cond
+ ((fboundp 'replace-in-string)
+ (defalias 'smime-replace-in-string 'replace-in-string))
+ ((fboundp 'replace-regexp-in-string)
+ (defun smime-replace-in-string (string regexp newtext &optional literal)
+ "Replace all matches for REGEXP with NEWTEXT in STRING.
+If LITERAL is non-nil, insert NEWTEXT literally. Return a new
+string containing the replacements.
+
+This is a compatibility function for different Emacsen."
+ (replace-regexp-in-string regexp newtext string nil literal)))))
+
(defgroup smime nil
- "S/MIME configuration.")
+ "S/MIME configuration."
+ :group 'mime)
(defcustom smime-keys nil
- "Map mail addresses to a file containing Certificate (and private key).
-The file is assumed to be in PEM format and not encrypted."
+ "*Map mail addresses to a file containing Certificate (and private key).
+The file is assumed to be in PEM format. You can also associate additional
+certificates to be sent with every message to each address."
:type '(repeat (list (string :tag "Mail address")
- (file :tag "File name")))
+ (file :tag "File name")
+ (repeat :tag "Additional certificate files"
+ (file :tag "File name"))))
:group 'smime)
-(defcustom smime-CA-directory ""
- "Directory containing certificates for CAs you trust.
+(defcustom smime-CA-directory nil
+ "*Directory containing certificates for CAs you trust.
Directory should contain files (in PEM format) named to the X.509
-hash of the certificate."
+hash of the certificate. This can be done using OpenSSL such as:
+
+$ ln -s ca.pem `openssl x509 -noout -hash -in ca.pem`.0
+
+where `ca.pem' is the file containing a PEM encoded X.509 CA
+certificate."
:type '(choice (const :tag "none" nil)
directory)
:group 'smime)
-(defcustom smime-CA-file ""
- "Files containing certificates for CAs you trust.
-File should be in PEM format."
+(defcustom smime-CA-file nil
+ "*Files containing certificates for CAs you trust.
+File should contain certificates in PEM format."
+ :version "22.1"
:type '(choice (const :tag "none" nil)
file)
:group 'smime)
(defcustom smime-certificate-directory "~/Mail/certs/"
- "Directory containing other people's certificates.
+ "*Directory containing other people's certificates.
It should contain files named to the X.509 hash of the certificate,
-and the files themself should be in PEM format.
-The S/MIME library provide simple functionality for fetching
-certificates into this directory, so there is no need to populate it
-manually."
+and the files themself should be in PEM format."
+;The S/MIME library provide simple functionality for fetching
+;certificates into this directory, so there is no need to populate it
+;manually.
:type 'directory
:group 'smime)
-(defcustom smime-openssl-program
- (and (condition-case ()
+(defcustom smime-openssl-program
+ (and (condition-case ()
(eq 0 (call-process "openssl" nil nil nil "version"))
(error nil))
"openssl")
- "Name of OpenSSL binary."
+ "*Name of OpenSSL binary."
:type 'string
:group 'smime)
+;; OpenSSL option to select the encryption cipher
+
+(defcustom smime-encrypt-cipher "-des3"
+ "*Cipher algorithm used for encryption."
+ :version "22.1"
+ :type '(choice (const :tag "Triple DES" "-des3")
+ (const :tag "DES" "-des")
+ (const :tag "RC2 40 bits" "-rc2-40")
+ (const :tag "RC2 64 bits" "-rc2-64")
+ (const :tag "RC2 128 bits" "-rc2-128"))
+ :group 'smime)
+
+(defcustom smime-crl-check nil
+ "*Check revocation status of signers certificate using CRLs.
+Enabling this will have OpenSSL check the signers certificate
+against a certificate revocation list (CRL).
+
+For this to work the CRL must be up-to-date and since they are
+normally updated quite often (ie. several times a day) you
+probably need some tool to keep them up-to-date. Unfortunately
+Gnus cannot do this for you.
+
+The CRL should either be appended (in PEM format) to your
+`smime-CA-file' or be located in a file (also in PEM format) in
+your `smime-certificate-directory' named to the X.509 hash of the
+certificate with .r0 as file name extension.
+
+At least OpenSSL version 0.9.7 is required for this to work."
+ :type '(choice (const :tag "No check" nil)
+ (const :tag "Check certificate" "-crl_check")
+ (const :tag "Check certificate chain" "-crl_check_all"))
+ :group 'smime)
+
(defcustom smime-dns-server nil
- "DNS server to query certificates from.
+ "*DNS server to query certificates from.
If nil, use system defaults."
+ :version "22.1"
:type '(choice (const :tag "System defaults")
string)
- :group 'dig)
+ :group 'smime)
+
+(defcustom smime-ldap-host-list nil
+ "A list of LDAP hosts with S/MIME user certificates.
+If needed search base, binddn, passwd, etc. for the LDAP host
+must be set in `ldap-host-parameters-alist'."
+ :type '(repeat (string :tag "Host name"))
+ :version "23.1" ;; No Gnus
+ :group 'smime)
(defvar smime-details-buffer "*OpenSSL output*")
+;; Use mm-util?
+(eval-and-compile
+ (defalias 'smime-make-temp-file
+ (if (fboundp 'make-temp-file)
+ 'make-temp-file
+ (lambda (prefix &optional dir-flag) ;; Simple implementation
+ (expand-file-name
+ (make-temp-name prefix)
+ (if (fboundp 'temp-directory)
+ (temp-directory)
+ temporary-file-directory))))))
+
+;; Password dialog function
+(declare-function password-read-and-add "password-cache" (prompt &optional key))
+
+(defun smime-ask-passphrase (&optional cache-key)
+ "Asks the passphrase to unlock the secret key.
+If `cache-key' and `password-cache' is non-nil then cache the
+password under `cache-key'."
+ (let ((passphrase
+ (password-read-and-add
+ "Passphrase for secret key (RET for no passphrase): " cache-key)))
+ (if (string= passphrase "")
+ nil
+ passphrase)))
+
;; OpenSSL wrappers.
(defun smime-call-openssl-region (b e buf &rest args)
(4 (message "OpenSSL: An error occurred decrypting or verifying the message.") nil)
(t (error "Unknown OpenSSL exitcode") nil)))
+(defun smime-make-certfiles (certfiles)
+ (if certfiles
+ (append (list "-certfile" (expand-file-name (car certfiles)))
+ (smime-make-certfiles (cdr certfiles)))))
+
;; Sign+encrypt region
(defun smime-sign-region (b e keyfile)
"Sign region with certified key in KEYFILE.
If signing fails, the buffer is not modified. Region is assumed to
have proper MIME tags. KEYFILE is expected to contain a PEM encoded
-private key and certificate."
- (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*"))))
+private key and certificate as its car, and a list of additional
+certificates to include in its caar. If no additional certificates is
+included, KEYFILE may be the file containing the PEM encoded private
+key and certificate itself."
+ (smime-new-details-buffer)
+ (let* ((certfiles (and (cdr-safe keyfile) (cadr keyfile)))
+ (keyfile (or (car-safe keyfile) keyfile))
+ (buffer (generate-new-buffer " *smime*"))
+ (passphrase (smime-ask-passphrase (expand-file-name keyfile)))
+ (tmpfile (smime-make-temp-file "smime")))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" passphrase))
(prog1
- (when (smime-call-openssl-region b e buffer "smime" "-sign"
- "-signer" (expand-file-name keyfile))
+ (when (prog1
+ (apply 'smime-call-openssl-region b e (list buffer tmpfile)
+ "smime" "-sign" "-signer" (expand-file-name keyfile)
+ (append
+ (smime-make-certfiles certfiles)
+ (if passphrase
+ (list "-passin" "env:GNUS_SMIME_PASSPHRASE"))))
+ (if passphrase
+ (setenv "GNUS_SMIME_PASSPHRASE" "" t))
+ (with-current-buffer smime-details-buffer
+ (insert-file-contents tmpfile)
+ (delete-file tmpfile)))
(delete-region b e)
- (insert-buffer buffer)
+ (insert-buffer-substring buffer)
+ (goto-char b)
(when (looking-at "^MIME-Version: 1.0$")
(delete-region (point) (progn (forward-line 1) (point))))
t)
- (with-current-buffer (get-buffer-create smime-details-buffer)
+ (with-current-buffer smime-details-buffer
(goto-char (point-max))
- (insert-buffer buffer))
+ (insert-buffer-substring buffer))
(kill-buffer buffer))))
(defun smime-encrypt-region (b e certfiles)
If encryption fails, the buffer is not modified. Region is assumed to
have proper MIME tags. CERTFILES is a list of filenames, each file
is expected to contain of a PEM encoded certificate."
- (let ((buffer (generate-new-buffer (generate-new-buffer-name " *smime*"))))
+ (smime-new-details-buffer)
+ (let ((buffer (generate-new-buffer " *smime*"))
+ (tmpfile (smime-make-temp-file "smime")))
(prog1
- (when (apply 'smime-call-openssl-region b e buffer "smime" "-encrypt"
- (mapcar 'expand-file-name certfiles))
+ (when (prog1
+ (apply 'smime-call-openssl-region b e (list buffer tmpfile)
+ "smime" "-encrypt" smime-encrypt-cipher
+ (mapcar 'expand-file-name certfiles))
+ (with-current-buffer smime-details-buffer
+ (insert-file-contents tmpfile)
+ (delete-file tmpfile)))
(delete-region b e)
- (insert-buffer buffer)
+ (insert-buffer-substring buffer)
+ (goto-char b)
(when (looking-at "^MIME-Version: 1.0$")
(delete-region (point) (progn (forward-line 1) (point))))
t)
- (with-current-buffer (get-buffer-create smime-details-buffer)
+ (with-current-buffer smime-details-buffer
(goto-char (point-max))
- (insert-buffer buffer))
+ (insert-buffer-substring buffer))
(kill-buffer buffer))))
;; Sign+encrypt buffer
KEYFILE should contain a PEM encoded key and certificate."
(interactive)
(with-current-buffer (or buffer (current-buffer))
- (smime-sign-region
- (point-min) (point-max)
- (or keyfile
- (smime-get-key-by-email
- (completing-read "Sign using which signature? " smime-keys nil nil
- (and (listp (car-safe smime-keys))
- (caar smime-keys))))))))
+ (unless (smime-sign-region
+ (point-min) (point-max)
+ (if keyfile
+ keyfile
+ (smime-get-key-with-certs-by-email
+ (gnus-completing-read
+ &n
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