--- /dev/null
+;;; plstore.el --- searchable, partially encrypted, persistent plist store -*- lexical-binding: t -*-
+;; Copyright (C) 2011 Free Software Foundation, Inc.
+
+;; Author: Daiki Ueno <ueno@unixuser.org>
+;; Keywords: PGP, 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 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.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary
+
+;; Creating:
+;;
+;; (setq store (plstore-open (expand-file-name "~/.emacs.d/auth.plist")))
+;; (plstore-put store "foo" '(:host "foo.example.org" :port 80) nil)
+;; (plstore-save store)
+;; ;; :user property is secret
+;; (plstore-put store "bar" '(:host "bar.example.org") '(:user "test"))
+;; (plstore-put store "baz" '(:host "baz.example.org") '(:user "test"))
+;; (plstore-save store) ;<= will ask passphrase via GPG
+;; (plstore-close store)
+;;
+;; Searching:
+;;
+;; (setq store (plstore-open (expand-file-name "~/.emacs.d/auth.plist")))
+;; (plstore-find store '(:host ("foo.example.org")))
+;; (plstore-find store '(:host ("bar.example.org"))) ;<= will ask passphrase via GPG
+;; (plstore-close store)
+;;
+
+;;; Code:
+
+(require 'epg)
+
+(defvar plstore-cache-passphrase-for-symmetric-encryption nil)
+(defvar plstore-passphrase-alist nil)
+
+(defun plstore-passphrase-callback-function (_context _key-id plstore)
+ (if plstore-cache-passphrase-for-symmetric-encryption
+ (let* ((file (file-truename (plstore--get-buffer plstore)))
+ (entry (assoc file plstore-passphrase-alist))
+ passphrase)
+ (or (copy-sequence (cdr entry))
+ (progn
+ (unless entry
+ (setq entry (list file)
+ plstore-passphrase-alist
+ (cons entry
+ plstore-passphrase-alist)))
+ (setq passphrase
+ (read-passwd (format "Passphrase for PLSTORE %s: "
+ (plstore--get-buffer plstore))))
+ (setcdr entry (copy-sequence passphrase))
+ passphrase)))
+ (read-passwd (format "Passphrase for PLSTORE %s: "
+ (plstore--get-buffer plstore)))))
+
+(defun plstore-progress-callback-function (_context _what _char current total
+ handback)
+ (if (= current total)
+ (message "%s...done" handback)
+ (message "%s...%d%%" handback
+ (if (> total 0) (floor (* (/ current (float total)) 100)) 0))))
+
+(defun plstore--get-buffer (this)
+ (aref this 0))
+
+(defun plstore--get-alist (this)
+ (aref this 1))
+
+(defun plstore--get-encrypted-data (this)
+ (aref this 2))
+
+(defun plstore--get-secret-alist (this)
+ (aref this 3))
+
+(defun plstore--get-merged-alist (this)
+ (aref this 4))
+
+(defun plstore--set-file (this file)
+ (aset this 0 file))
+
+(defun plstore--set-alist (this plist)
+ (aset this 1 plist))
+
+(defun plstore--set-encrypted-data (this encrypted-data)
+ (aset this 2 encrypted-data))
+
+(defun plstore--set-secret-alist (this secret-alist)
+ (aset this 3 secret-alist))
+
+(defun plstore--set-merged-alist (this merged-alist)
+ (aset this 4 merged-alist))
+
+(defun plstore-get-file (this)
+ (buffer-file-name (plstore--get-buffer this)))
+
+;;;###autoload
+(defun plstore-open (file)
+ "Create a plstore instance associated with FILE."
+ (let ((store (vector
+ (find-file-noselect file)
+ nil ;plist (plist)
+ nil ;encrypted data (string)
+ nil ;secret plist (plist)
+ nil ;merged plist (plist)
+ )))
+ (plstore-revert store)
+ store))
+
+(defun plstore-revert (plstore)
+ "Replace current data in PLSTORE with the file on disk."
+ (with-current-buffer (plstore--get-buffer plstore)
+ ;; make the buffer invisible from user
+ (rename-buffer (format " plstore %s" (buffer-file-name)))
+ (goto-char (point-min))
+ (when (looking-at ";;; public entries\n")
+ (forward-line)
+ (plstore--set-alist plstore (read (point-marker)))
+ (forward-sexp)
+ (forward-char)
+ (when (looking-at ";;; secret entries\n")
+ (forward-line)
+ (plstore--set-encrypted-data plstore (read (point-marker))))
+ (plstore--merge-secret plstore))))
+
+(defun plstore-close (plstore)
+ "Destroy a plstore instance PLSTORE."
+ (kill-buffer (plstore--get-buffer plstore)))
+
+(defun plstore--merge-secret (plstore)
+ (let ((alist (plstore--get-secret-alist plstore))
+ modified-alist
+ modified-plist
+ modified-entry
+ entry
+ plist
+ placeholder)
+ (plstore--set-merged-alist
+ plstore
+ (copy-tree (plstore--get-alist plstore)))
+ (setq modified-alist (plstore--get-merged-alist plstore))
+ (while alist
+ (setq entry (car alist)
+ alist (cdr alist)
+ plist (cdr entry)
+ modified-entry (assoc (car entry) modified-alist)
+ modified-plist (cdr modified-entry))
+ (while plist
+ (setq placeholder
+ (plist-member
+ modified-plist
+ (intern (concat ":secret-"
+ (substring (symbol-name (car plist)) 1)))))
+ (if placeholder
+ (setcar placeholder (car plist)))
+ (setq modified-plist
+ (plist-put modified-plist (car plist) (car (cdr plist))))
+ (setq plist (nthcdr 2 plist)))
+ (setcdr modified-entry modified-plist))))
+
+(defun plstore--decrypt (plstore)
+ (if (plstore--get-encrypted-data plstore)
+ (let ((context (epg-make-context 'OpenPGP))
+ plain)
+ (epg-context-set-passphrase-callback
+ context
+ (cons #'plstore-passphrase-callback-function
+ plstore))
+ (epg-context-set-progress-callback
+ context
+ (cons #'plstore-progress-callback-function
+ (format "Decrypting %s" (plstore-get-file plstore))))
+ (setq plain
+ (epg-decrypt-string context
+ (plstore--get-encrypted-data plstore)))
+ (plstore--set-secret-alist plstore (car (read-from-string plain)))
+ (plstore--merge-secret plstore)
+ (plstore--set-encrypted-data plstore nil))))
+
+(defun plstore--match (entry keys skip-if-secret-found)
+ (let ((result t) key-name key-value prop-value secret-name)
+ (while keys
+ (setq key-name (car keys)
+ key-value (car (cdr keys))
+ prop-value (plist-get (cdr entry) key-name))
+ (unless (member prop-value key-value)
+ (if skip-if-secret-found
+ (progn
+ (setq secret-name
+ (intern (concat ":secret-"
+ (substring (symbol-name key-name) 1))))
+ (if (plist-member (cdr entry) secret-name)
+ (setq result 'secret)
+ (setq result nil
+ keys nil)))
+ (setq result nil
+ keys nil)))
+ (setq keys (nthcdr 2 keys)))
+ result))
+
+(defun plstore-find (plstore keys)
+ "Perform search on PLSTORE with KEYS.
+KEYS is a plist."
+ (let (entries alist entry match decrypt plist)
+ ;; First, go through the merged plist alist and collect entries
+ ;; matched with keys.
+ (setq alist (plstore--get-merged-alist plstore))
+ (while alist
+ (setq entry (car alist)
+ alist (cdr alist)
+ match (plstore--match entry keys t))
+ (if (eq match 'secret)
+ (setq decrypt t)
+ (when match
+ (setq plist (cdr entry))
+ (while plist
+ (if (string-match "\\`:secret-" (symbol-name (car plist)))
+ (setq decrypt t
+ plist nil))
+ (setq plist (nthcdr 2 plist)))
+ (setq entries (cons entry entries)))))
+ ;; Second, decrypt the encrypted plist and try again.
+ (when decrypt
+ (setq entries nil)
+ (plstore--decrypt plstore)
+ (setq alist (plstore--get-merged-alist plstore))
+ (while alist
+ (setq entry (car alist)
+ alist (cdr alist)
+ match (plstore--match entry keys nil))
+ (if match
+ (setq entries (cons entry entries)))))
+ (nreverse entries)))
+
+(defun plstore-get (plstore name)
+ "Get an entry with NAME in PLSTORE."
+ (let ((entry (assoc name (plstore--get-merged-alist plstore)))
+ plist)
+ (setq plist (cdr entry))
+ (while plist
+ (if (string-match "\\`:secret-" (symbol-name (car plist)))
+ (progn
+ (plstore--decrypt plstore)
+ (setq entry (assoc name (plstore--get-merged-alist plstore))
+ plist nil))
+ (setq plist (nthcdr 2 plist))))
+ entry))
+
+(defun plstore-put (plstore name keys secret-keys)
+ "Put an entry with NAME in PLSTORE.
+KEYS is a plist containing non-secret data.
+SECRET-KEYS is a plist containing secret data."
+ (let (entry
+ plist
+ secret-plist
+ symbol)
+ (if secret-keys
+ (plstore--decrypt plstore))
+ (while secret-keys
+ (setq symbol
+ (intern (concat ":secret-"
+ (substring (symbol-name (car secret-keys)) 1))))
+ (setq plist (plist-put plist symbol t)
+ secret-plist (plist-put secret-plist
+ (car secret-keys) (car (cdr secret-keys)))
+ secret-keys (nthcdr 2 secret-keys)))
+ (while keys
+ (setq symbol
+ (intern (concat ":secret-"
+ (substring (symbol-name (car keys)) 1))))
+ (setq plist (plist-put plist (car keys) (car (cdr keys)))
+ keys (nthcdr 2 keys)))
+ (setq entry (assoc name (plstore--get-alist plstore)))
+ (if entry
+ (setcdr entry plist)
+ (plstore--set-alist
+ plstore
+ (cons (cons name plist) (plstore--get-alist plstore))))
+ (when secret-plist
+ (setq entry (assoc name (plstore--get-secret-alist plstore)))
+ (if entry
+ (setcdr entry secret-plist)
+ (plstore--set-secret-alist
+ plstore
+ (cons (cons name secret-plist) (plstore--get-secret-alist plstore)))))
+ (plstore--merge-secret plstore)))
+
+(defvar pp-escape-newlines)
+(defun plstore-save (plstore)
+ "Save the contents of PLSTORE associated with a FILE."
+ (with-current-buffer (plstore--get-buffer plstore)
+ (erase-buffer)
+ (insert ";;; public entries\n" (pp-to-string (plstore--get-alist plstore)))
+ (if (plstore--get-secret-alist plstore)
+ (let ((context (epg-make-context 'OpenPGP))
+ (pp-escape-newlines nil)
+ cipher)
+ (epg-context-set-armor context t)
+ (epg-context-set-passphrase-callback
+ context
+ (cons #'plstore-passphrase-callback-function
+ plstore))
+ (setq cipher (epg-encrypt-string context
+ (pp-to-string
+ (plstore--get-secret-alist plstore))
+ nil))
+ (insert ";;; secret entries\n" (pp-to-string cipher))))
+ (save-buffer)))
+
+(provide 'plstore)
+
+;;; plstore.el ends here
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