lisp/epg-config.el

   1 ;;; epg-config.el --- configuration of the EasyPG Library
   2
   3 ;; Copyright (C) 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4
   5 ;; Author: Daiki Ueno <ueno@unixuser.org>
   6 ;; Keywords: PGP, GnuPG
   7 ;; Package: epg
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Code:
  25
  26 (defconst epg-package-name "epg"
  27   "Name of this package.")
  28
  29 (defconst epg-version-number "1.0.0"
  30   "Version number of this package.")
  31
  32 (defconst epg-bug-report-address "ueno@unixuser.org"
  33   "Report bugs to this address.")
  34
  35 (defgroup epg ()
  36   "The EasyPG library."
  37   :version "23.1"
  38   :group 'data)
  39
  40 (defcustom epg-gpg-program "gpg"
  41   "The `gpg' executable."
  42   :group 'epg
  43   :type 'string)
  44
  45 (defcustom epg-gpgsm-program "gpgsm"
  46   "The `gpgsm' executable."
  47   :group 'epg
  48   :type 'string)
  49
  50 (defcustom epg-gpg-home-directory nil
  51   "The directory which contains the configuration files of `epg-gpg-program'."
  52   :group 'epg
  53   :type '(choice (const :tag "Default" nil) directory))
  54
  55 (defcustom epg-passphrase-coding-system nil
  56   "Coding system to use with messages from `epg-gpg-program'."
  57   :group 'epg
  58   :type 'symbol)
  59
  60 (defcustom epg-debug nil
  61   "If non-nil, debug output goes to the \" *epg-debug*\" buffer.
  62 Note that the buffer name starts with a space."
  63   :group 'epg
  64   :type 'boolean)
  65
  66 (defconst epg-gpg-minimum-version "1.4.3")
  67
  68 ;;;###autoload
  69 (defun epg-configuration ()
  70   "Return a list of internal configuration parameters of `epg-gpg-program'."
  71   (let (config groups type args)
  72     (with-temp-buffer
  73       (apply #'call-process epg-gpg-program nil (list t nil) nil
  74              (append (if epg-gpg-home-directory
  75                          (list "--homedir" epg-gpg-home-directory))
  76                      '("--with-colons" "--list-config")))
  77       (goto-char (point-min))
  78       (while (re-search-forward "^cfg:\\([^:]+\\):\\(.*\\)" nil t)
  79         (setq type (intern (match-string 1))
  80               args (match-string 2))
  81         (cond
  82          ((eq type 'group)
  83           (if (string-match "\\`\\([^:]+\\):" args)
  84                   (setq groups
  85                         (cons (cons (downcase (match-string 1 args))
  86                                     (delete "" (split-string
  87                                                 (substring args
  88                                                            (match-end 0))
  89                                                 ";")))
  90                               groups))
  91             (if epg-debug
  92                 (message "Invalid group configuration: %S" args))))
  93          ((memq type '(pubkey cipher digest compress))
  94           (if (string-match "\\`\\([0-9]+\\)\\(;[0-9]+\\)*" args)
  95               (setq config
  96                     (cons (cons type
  97                                 (mapcar #'string-to-number
  98                                         (delete "" (split-string args ";"))))
  99                           config))
 100             (if epg-debug
 101                 (message "Invalid %S algorithm configuration: %S"
 102                          type args))))
 103          (t
 104           (setq config (cons (cons type args) config))))))
 105     (if groups
 106         (cons (cons 'groups groups) config)
 107       config)))
 108
 109 (defun epg-config--parse-version (string)
 110   (let ((index 0)
 111         version)
 112     (while (eq index (string-match "\\([0-9]+\\)\\.?" string index))
 113       (setq version (cons (string-to-number (match-string 1 string))
 114                           version)
 115             index (match-end 0)))
 116     (nreverse version)))
 117
 118 (defun epg-config--compare-version (v1 v2)
 119   (while (and v1 v2 (= (car v1) (car v2)))
 120     (setq v1 (cdr v1) v2 (cdr v2)))
 121   (- (or (car v1) 0) (or (car v2) 0)))
 122
 123 ;;;###autoload
 124 (defun epg-check-configuration (config &optional minimum-version)
 125   "Verify that a sufficient version of GnuPG is installed."
 126   (let ((entry (assq 'version config))
 127         version)
 128     (unless (and entry
 129                  (stringp (cdr entry)))
 130       (error "Undetermined version: %S" entry))
 131     (setq version (epg-config--parse-version (cdr entry))
 132           minimum-version (epg-config--parse-version
 133                            (or minimum-version
 134                                epg-gpg-minimum-version)))
 135     (unless (>= (epg-config--compare-version version minimum-version) 0)
 136       (error "Unsupported version: %s" (cdr entry)))))
 137
 138 ;;;###autoload
 139 (defun epg-expand-group (config group)
 140   "Look at CONFIG and try to expand GROUP."
 141   (let ((entry (assq 'groups config)))
 142     (if (and entry
 143              (setq entry (assoc (downcase group) (cdr entry))))
 144         (cdr entry))))
 145
 146 (provide 'epg-config)
 147
 148 ;; arch-tag: 9aca7cb8-5f63-4bcb-84ee-46fd2db0763f
 149 ;;; epg-config.el ends here