X-Git-Url: http://git.chise.org/gitweb/?a=blobdiff_plain;f=epa-file.el;h=2b47373b6d9c3e74ada9c40d7ff8038e3092e401;hb=24c376fab8b0785deeb6e1df796624a035090b20;hp=e2169991086689b435fc6995d20e0d878c51e0e3;hpb=d9a0c1d079435cd5041e28380e5236e9479f1a23;p=elisp%2Fepg.git

diff --git a/epa-file.el b/epa-file.el
index e216999..2b47373 100644
--- a/epa-file.el
+++ b/epa-file.el
@@ -1,4 +1,4 @@
-;;; epa-file.el --- the EasyPG Assistant hooks for transparent file encryption
+;;; epa-file.el --- the EasyPG Assistant, transparent file encryption
 ;; Copyright (C) 2006 Daiki Ueno
 
 ;; Author: Daiki Ueno <ueno@unixuser.org>
@@ -25,7 +25,7 @@
 
 (require 'epa)
 
-(defgroup 'epa-file
+(defgroup epa-file nil
   "The EasyPG Assistant hooks for transparent file encryption"
   :group 'epa)
 
@@ -33,39 +33,171 @@
   "Regexp which matches filenames to be encrypted with GnuPG."
   :type 'regexp
   :group 'epa-file)
+
+(defvar epa-file-handler
+  (cons epa-file-name-regexp 'epa-file-handler))
   
-(defvar epa-file nil)
+(defvar epa-file-passphrase-alist nil)
+
+(defun epa-file-passphrase-callback-function (context key-id file)
+  (if (eq key-id 'SYM)
+      (let ((entry (assoc file epa-file-passphrase-alist))
+	    passphrase)
+	(or (copy-sequence (cdr entry))
+	    (progn
+	      (unless entry
+		(setq entry (list file)
+		      epa-file-passphrase-alist (cons entry
+						 epa-file-passphrase-alist)))
+	      (setq passphrase (epg-passphrase-callback-function context
+								 key-id nil))
+	      (setcdr entry (copy-sequence passphrase))
+	      passphrase)))
+    (epg-passphrase-callback-function context key-id nil)))
+
+(defun epa-file-handler (operation &rest args)
+  (save-match-data
+    (let ((op (get operation 'epa-file)))
+      (if op
+	  (apply op args)
+	(epa-file-run-real-handler operation args)))))
+
+(defun epa-file-run-real-handler (operation args)
+  (let ((inhibit-file-name-handlers
+	 (cons 'epa-file-handler
+	       (and (eq inhibit-file-name-operation operation)
+		    inhibit-file-name-handlers)))
+	(inhibit-file-name-operation operation))
+    (apply operation args)))
+
+(defun epa-file-decode-and-insert (string file visit beg end replace)
+  (if (fboundp 'decode-coding-inserted-region)
+      (save-restriction
+	(narrow-to-region (point) (point))
+	(let ((multibyte enable-multibyte-characters))
+	  (set-buffer-multibyte nil)
+	  (insert string)
+	  (set-buffer-multibyte multibyte)
+	  (decode-coding-inserted-region
+	   (point-min) (point-max)
+	   (substring file 0 (string-match epa-file-name-regexp file))
+	   visit beg end replace)))
+    (insert (decode-coding-string string (or coding-system-for-read
+					     'undecided)))))
 
-(defun epa-find-file ()
-  (when (string-match epa-file-name-regexp (buffer-file-name))
-    (if (= (buffer-size) 0)
+(defvar last-coding-system-used)
+(defun epa-file-insert-file-contents (file &optional visit beg end replace)
+  (barf-if-buffer-read-only)
+  (if (and visit (or beg end))
+      (error "Attempt to visit less than an entire file"))
+  (setq file (expand-file-name file))
+  (let ((local-copy (epa-file-run-real-handler #'file-local-copy (list file)))
+	(context (epg-make-context))
+	string length entry)
+    (if visit
+	(setq buffer-file-name file))
+    (epg-context-set-passphrase-callback
+     context
+     (cons #'epa-file-passphrase-callback-function
+	   file))
+    (unwind-protect
 	(progn
-	  (set-auto-mode)
-	  (hack-local-variables)
-	  (auto-save-mode nil))
-      (goto-char (point-min))
-      (insert (epg-decrypt-file (epg-make-context)
-				(expand-file-name (buffer-file-name))
-				nil))
-      (delete-region (point) (point-max)))
-    (make-local-variable 'epa-file)
-    (setq epa-file (buffer-file-name))))
-
-(defun epa-write-file ()
-  (when epa-file
-    (write-region
-     (epg-encrypt-string
-      (epg-make-context)
-      (buffer-string)
-      (mapcar (lambda (key)
-		(epg-sub-key-id
-		 (car (epg-key-sub-key-list key))))
-	      (epa-select-keys
-		 "Select recipents for encryption.
-If no one is selected, symmetric encryption will be performed.  ")))
-     nil (expand-file-name (buffer-file-name)))
-    (set-buffer-modified-p nil)
-    t))
+	  (if replace
+	      (goto-char (point-min)))
+	  (condition-case error
+	      (setq string (epg-decrypt-file context file nil))
+	    (error
+	     (if (setq entry (assoc file epa-file-passphrase-alist))
+		 (setcdr entry nil))
+	     (signal 'file-error
+		     (cons "Opening input file" (cdr error)))))
+	  (if (or beg end)
+	      (setq string (substring string (or beg 0) end)))
+	  (save-excursion
+	    (save-restriction
+	      (narrow-to-region (point) (point))
+	      (epa-file-decode-and-insert string file visit beg end replace)
+	      (setq length (- (point-max) (point-min))))
+	    (if replace
+		(delete-region (point) (point-max)))))
+      (if (and local-copy
+	       (file-exists-p local-copy))
+	  (delete-file local-copy)))
+    (list file length)))
+(put 'insert-file-contents 'epa-file 'epa-file-insert-file-contents)
+
+(defun epa-file-write-region (start end file &optional append visit lockname
+				    mustbenew)
+  (if append
+      (error "Can't append to the file."))
+  (setq file (expand-file-name file))
+  (let* ((coding-system (or coding-system-for-write
+			    (if (boundp 'last-coding-system-used)
+				(condition-case nil
+				    (write-region (point-min) (point-max) "/")
+				  (error last-coding-system-used))
+			      buffer-file-coding-system)))
+	 (context (epg-make-context))
+	 (coding-system-for-write 'binary)
+	 string entry)
+    (epg-context-set-passphrase-callback
+     context
+     (cons #'epa-file-passphrase-callback-function
+	   file))
+    (condition-case error
+	(setq string
+	      (epg-encrypt-string
+	       context
+	       (if (stringp start)
+		   (encode-coding-string start coding-system)
+		 (encode-coding-string (buffer-substring start end)
+				       coding-system))
+	       (unless (assoc file epa-file-passphrase-alist)
+		 (epa-select-keys
+		  context
+		  "Select recipents for encryption.
+If no one is selected, symmetric encryption will be performed.  "))))
+      (error
+       (if (setq entry (assoc file epa-file-passphrase-alist))
+	   (setcdr entry nil))
+       (signal 'file-error (cons "Opening output file" (cdr error)))))
+    (epa-file-run-real-handler
+     #'write-region
+     (list string nil file append visit lockname mustbenew))
+    (if (boundp 'last-coding-system-used)
+	(setq last-coding-system-used coding-system))
+    (if (eq visit t)
+	(progn
+	  (setq buffer-file-name file)
+	  (set-visited-file-modtime))
+      (if (stringp visit)
+	  (progn
+	    (set-visited-file-modtime)
+	    (setq buffer-file-name visit))))
+    (if (or (eq visit t)
+	    (eq visit nil)
+	    (stringp visit))
+	(message "Wrote %s" buffer-file-name))))
+(put 'write-region 'epa-file 'epa-file-write-region)
+
+;;;###autoload
+(defun epa-file-enable ()
+  (interactive)
+  (if (memq epa-file-handler file-name-handler-alist)
+      (message "`epa-file' already enabled")
+    (setq file-name-handler-alist
+	  (cons epa-file-handler file-name-handler-alist))
+    (message "`epa-file' enabled")))
+
+;;;###autoload
+(defun epa-file-disable ()
+  (interactive)
+  (if (memq epa-file-handler file-name-handler-alist)
+      (progn
+	(setq file-name-handler-alist
+	      (delq epa-file-handler file-name-handler-alist))
+	(message "`epa-file' disabled"))
+    (message "`epa-file' already disabled")))
 
 (provide 'epa-file)