From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 10 Aug 1999 16:54:57 +0000 (+0000)
Subject: Eliminate use of krypt and the ".ky" file suffix.  Change all
X-Git-Tag: 20090517-FFI~4483
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=f7217eebf8c8715c61d09ea7fb7cb8fa4428ae87;p=mit-scheme.git

Eliminate use of krypt and the ".ky" file suffix.  Change all
encryption commands to use Blowfish, and also to be more paranoid
about eliminating passphrases and plaintext after use.
---

diff --git a/v7/src/edwin/comint.scm b/v7/src/edwin/comint.scm
index 9fb0164fd..b03863d6b 100644
--- a/v7/src/edwin/comint.scm
+++ b/v7/src/edwin/comint.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: comint.scm,v 1.28 1999/01/02 06:11:34 cph Exp $
+$Id: comint.scm,v 1.29 1999/08/10 16:54:57 cph Exp $
 
 Copyright (c) 1991-1999 Massachusetts Institute of Technology
 
@@ -227,7 +227,8 @@ String is not saved on comint input history list.
 Security bug: your string can still be temporarily recovered with
 \\[view-lossage]."
   ()
-  (lambda () (send-invisible (prompt-for-password "Non-echoed text: "))))
+  (lambda ()
+    (call-with-pass-phrase "Non-echoed text" send-invisible)))
 
 (define (send-invisible string)
   (process-send-string (current-process) string)
diff --git a/v7/src/edwin/dired.scm b/v7/src/edwin/dired.scm
index 1ab1f5e05..3291964ee 100644
--- a/v7/src/edwin/dired.scm
+++ b/v7/src/edwin/dired.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: dired.scm,v 1.169 1999/01/28 03:59:47 cph Exp $
+;;; $Id: dired.scm,v 1.170 1999/08/10 16:54:51 cph Exp $
 ;;;
 ;;; Copyright (c) 1986, 1989-1999 Massachusetts Institute of Technology
 ;;;
@@ -102,7 +102,7 @@ Space and Rubout can be used to move down and up by lines."
 (define-key 'dired #\~ 'dired-flag-backup-files)
 
 (define-key 'dired #\C 'dired-do-copy)
-(define-key 'dired #\K 'dired-krypt-file)
+(define-key 'dired #\K 'dired-encrypt/decrypt-file)
 (define-key 'dired #\R 'dired-do-rename)
 
 (define-key 'dired #\c-d 'dired-flag-file-deletion)
@@ -659,67 +659,31 @@ When renaming multiple or marked files, you specify a directory."
 		(mark-temporary! (cdr filename)))
 	      filenames)))
 
-;;;; Krypt File
+;;;; Encrypt/Decrypt File
 
-(define-command dired-krypt-file
-  "Krypt/unkrypt a file.  If the file ends in KY, assume it is already
-krypted and unkrypt it.  Otherwise, krypt it."
-  '()
-  (lambda ()
-    (load-option 'krypt)
+(define-command dired-encrypt/decrypt-file
+  "Encrypt/Decrypt a file.
+Decrypts if the file's suffix is recognized as a known encryption type.
+Otherwise encrypts using Blowfish.
+Prefix arg means treat the plaintext file as binary data (ignored on unix)."
+  "P"
+  (lambda (binary-plaintext?)
     (let ((pathname (dired-current-pathname)))
-      (if (and (pathname-type pathname)
-	       (string=? (pathname-type pathname) "KY"))
-	  (dired-decrypt-file pathname)
-	  (dired-encrypt-file pathname)))))
-
-(define (dired-decrypt-file pathname)
-  (let ((the-encrypted-file
-	 (with-input-from-file pathname
-	   (lambda ()
-	     (read-string (char-set)))))
-	(password
-	 (prompt-for-password "Password: ")))
-    (let ((the-string
-	   (decrypt the-encrypted-file password
-		    (lambda ()
-		      (editor-beep)
-		      (message "krypt: Password error!")
-		      'FAIL)
-		    (lambda (x)
-		      x
-		      (editor-beep)
-		      (message "krypt: Checksum error!")
-		      'FAIL))))
-      (if (not (eq? the-string 'FAIL))
-	  (let ((new-name (pathname-new-type pathname false)))
-	    (with-output-to-file new-name
-	      (lambda ()
-		(write-string the-string)))
-	    (delete-file pathname)
-	    (dired-redisplay new-name))))))
-
-(define (dired-encrypt-file pathname)
-  (let ((the-file-string
-	 (with-input-from-file pathname
-	   (lambda ()
-	     (read-string (char-set)))))
-	(password
-	 (prompt-for-confirmed-password)))
-    (let ((the-encrypted-string
-	   (encrypt the-file-string password)))
-      (let ((new-name
-	     (pathname-new-type
-	      pathname
-	      (let ((old-type (pathname-type pathname)))
-		(if (not old-type)
-		    "KY"
-		    (string-append old-type ".KY"))))))
-	(with-output-to-file new-name
-	  (lambda ()
-	    (write-string the-encrypted-string)))
-	(delete-file pathname)
-	(dired-redisplay new-name)))))
+      (let ((type (pathname-type pathname)))
+	(cond ((equal? "bf" type)
+	       (dired-blowfish-decrypt-file pathname binary-plaintext?))
+	      (else
+	       (dired-blowfish-encrypt-file pathname binary-plaintext?)))))))
+
+(define (dired-blowfish-encrypt-file from binary-plaintext?)
+  (let ((to (string-append (->namestring from) ".bf")))
+    (blowfish-encrypt-file from to binary-plaintext? #t)
+    (dired-redisplay to)))
+
+(define (dired-blowfish-decrypt-file from binary-plaintext?)
+  (let ((to (pathname-new-type from #f)))
+    (blowfish-decrypt-file from to binary-plaintext? #t)
+    (dired-redisplay to)))
 
 ;;;; List Directory
 
diff --git a/v7/src/edwin/dosfile.scm b/v7/src/edwin/dosfile.scm
index 3da58f043..188b62345 100644
--- a/v7/src/edwin/dosfile.scm
+++ b/v7/src/edwin/dosfile.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: dosfile.scm,v 1.29 1999/08/09 18:19:15 cph Exp $
+;;; $Id: dosfile.scm,v 1.30 1999/08/10 16:54:41 cph Exp $
 ;;;
 ;;; Copyright (c) 1994-1999 Massachusetts Institute of Technology
 ;;;
@@ -495,20 +495,14 @@ Switches may be concatenated, e.g. `-lt' is equivalent to `-l -t'."
      . ,(lambda (pathname mark visit?)
 	  visit?
 	  (read-compressed-file "gzip -d" pathname mark)))
-    (,(read/write-encrypted-file? #f)
-     . ,(lambda (pathname mark visit?)
-	  visit?
-	  (read-encrypted-file pathname mark)))))
+    ,@(os-independent/read-file-methods)))
 
 (define (os/write-file-methods)
   `((,read/write-compressed-file?
      . ,(lambda (region pathname visit?)
 	  visit?
 	  (write-compressed-file "gzip" region pathname)))
-    (,(read/write-encrypted-file? #t)
-     . ,(lambda (region pathname visit?)
-	  visit?
-	  (write-encrypted-file region pathname)))))
+    ,@(os-independent/write-file-methods)))
 
 (define (os/alternate-pathnames group pathname)
   (if (dos/fs-long-filenames? pathname)
@@ -516,14 +510,7 @@ Switches may be concatenated, e.g. `-lt' is equivalent to `-l -t'."
 		       (not (equal? "gz" (pathname-type pathname))))
 		  (list (string-append (->namestring pathname) ".gz"))
 		  '())
-	      (if (and (ref-variable enable-encrypted-files group)
-		       (not (equal? "bf" (pathname-type pathname))))
-		  (list (string-append (->namestring pathname) ".bf"))
-		  '())
-	      (if (and (ref-variable enable-encrypted-files group)
-		       (not (equal? "ky" (pathname-type pathname))))
-		  (list (string-append (->namestring pathname) ".ky"))
-		  '()))
+	      (os-independent/alternate-pathnames group pathname))
       '()))
 
 ;;;; Compressed Files
@@ -583,77 +570,4 @@ filename suffix \".gz\"."
 			    "[unknown]"
 			    write-compressed-file
 			    (list region pathname)))
-  (append-message "done"))
-
-;;;; Encrypted files
-
-(define-variable enable-encrypted-files
-  "If true, encrypted files are automatically decrypted when read,
-and recrypted when written.  An encrypted file is identified by the
-filename suffixes \".bf\" and \".ky\"."
-  #t
-  boolean?)
-
-(define ((read/write-encrypted-file? write?) group pathname)
-  (and (ref-variable enable-encrypted-files group)
-       (or (and (equal? "bf" (pathname-type pathname))
-		(blowfish-available?)
-		(or write? (blowfish-file? pathname)))
-	   (equal? "ky" (pathname-type pathname)))))
-
-(define (read-encrypted-file pathname mark)
-  (let ((password (prompt-for-password "Pass phrase"))
-	(type (pathname-type pathname)))
-    (message "Decrypting file " (->namestring pathname) "...")
-    (cond ((equal? "bf" type)
-	   (call-with-binary-input-file pathname
-	     (lambda (input)
-	       (call-with-output-mark mark
-		 (lambda (output)
-		   (blowfish-encrypt-port input output (md5 password)
-					  (read-blowfish-file-header input)
-					  #f))))))
-	  ((or (equal? "ky" type) (equal? "KY" type))
-	   (insert-string (let ((the-encrypted-file
-				 (call-with-binary-input-file pathname
-				   (lambda (port)
-				     (read-string (char-set) port)))))
-			    (decrypt the-encrypted-file password
-				     (lambda () 
-				       (kill-buffer (mark-buffer mark))
-				       (editor-error "krypt: Password error!"))
-				     (lambda (x) 
-				       (editor-beep)
-				       (message "krypt: Checksum error!")
-				       x)))
-			  mark)))
-    ;; Disable auto-save here since we don't want to
-    ;; auto-save the unencrypted contents of the 
-    ;; encrypted file.
-    (define-variable-local-value! (mark-buffer mark)
-	(ref-variable-object auto-save-default)
-      #f)
-    (append-message "done")))
-
-(define (write-encrypted-file region pathname)
-  (let ((password (prompt-for-confirmed-password))
-	(type (pathname-type pathname)))
-    (message "Encrypting file " (->namestring pathname) "...")
-    (cond ((equal? "bf" type)
-	   (let ((input
-		  (make-buffer-input-port (region-start region)
-					  (region-end region))))
-	     (call-with-binary-output-file pathname
-	       (lambda (output)
-		 (blowfish-encrypt-port input output (md5 password)
-					(write-blowfish-file-header output)
-					#t)))))
-	  ((or (equal? "ky" type) (equal? "KY" type))
-	   (let ((the-encrypted-file
-		  (encrypt (extract-string (region-start region)
-					   (region-end region))
-			   password)))
-	     (call-with-binary-output-file pathname
-	       (lambda (port)
-		 (write-string the-encrypted-file port))))))
-    (append-message "done")))
\ No newline at end of file
+  (append-message "done"))
\ No newline at end of file
diff --git a/v7/src/edwin/edwin.pkg b/v7/src/edwin/edwin.pkg
index e37fc4763..5651d041c 100644
--- a/v7/src/edwin/edwin.pkg
+++ b/v7/src/edwin/edwin.pkg
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: edwin.pkg,v 1.238 1999/05/13 03:06:39 cph Exp $
+$Id: edwin.pkg,v 1.239 1999/08/10 16:54:44 cph Exp $
 
 Copyright (c) 1989-1999 Massachusetts Institute of Technology
 
@@ -444,6 +444,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   (files "prompt")
   (parent (edwin))
   (export (edwin)
+	  call-with-confirmed-pass-phrase
+	  call-with-pass-phrase
 	  completion-message
 	  edwin-command$exit-minibuffer
 	  edwin-command$exit-minibuffer-yes-or-no
@@ -467,10 +469,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 	  prompt-for-command
 	  prompt-for-completed-string
 	  prompt-for-confirmation?
-	  prompt-for-confirmed-password
 	  prompt-for-key
 	  prompt-for-number
-	  prompt-for-password
 	  prompt-for-string
 	  prompt-for-string-table-name
 	  prompt-for-string-table-value
@@ -652,12 +652,12 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 	  edwin-command$dired-do-copy
 	  edwin-command$dired-do-deletions
 	  edwin-command$dired-do-rename
+	  edwin-command$dired-encrypt/decrypt-file
 	  edwin-command$dired-find-file
 	  edwin-command$dired-find-file-other-window
 	  edwin-command$dired-flag-auto-save-files
 	  edwin-command$dired-flag-backup-files
 	  edwin-command$dired-flag-file-deletion
-	  edwin-command$dired-krypt-file
 	  edwin-command$dired-mark
 	  edwin-command$dired-next-line
 	  edwin-command$dired-other-window
diff --git a/v7/src/edwin/filcom.scm b/v7/src/edwin/filcom.scm
index 95d64d2fd..9d3cf86ba 100644
--- a/v7/src/edwin/filcom.scm
+++ b/v7/src/edwin/filcom.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: filcom.scm,v 1.203 1999/08/09 18:19:24 cph Exp $
+;;; $Id: filcom.scm,v 1.204 1999/08/10 16:54:34 cph Exp $
 ;;;
 ;;; Copyright (c) 1986, 1989-1999 Massachusetts Institute of Technology
 ;;;
@@ -613,41 +613,22 @@ Prompts for the plaintext and ciphertext filenames.
 Prefix arg means treat the plaintext file as binary data.
 Deletes the plaintext file after encryption."
   (lambda ()
-    (if (not (blowfish-available?))
-	(editor-error "Blowfish encryption not supported on this system"))
+    (guarantee-blowfish-available)
     (let ((from (prompt-for-existing-file "Encrypt file (plaintext)" #f)))
       (let ((to
 	     (prompt-for-file
 	      "Encrypt file to (ciphertext)"
 	      (list (string-append (->namestring from) ".bf")))))
 	(list from to (command-argument)))))
-  (lambda (from to binary?)
-    (if (or (not (file-exists? to))
-	    (prompt-for-yes-or-no?
-	     (string-append "File "
-			    (->namestring to)
-			    " already exists; overwrite")))
-	(begin
-	  (let ((password (prompt-for-confirmed-password)))
-	    ((if binary?
-		 call-with-binary-input-file
-		 call-with-input-file)
-	     from
-	     (lambda (input)
-	       (call-with-binary-output-file to
-		 (lambda (output)
-		   (blowfish-encrypt-port input output (md5 password)
-					  (write-blowfish-file-header output)
-					  #t))))))
-	  (delete-file from)))))
+  (lambda (from to binary-plaintext?)
+    (blowfish-encrypt-file from to binary-plaintext? #t)))
 
 (define-command decrypt-file
   "Decrypt a file with the blowfish encryption algorithm.
 Prompts for the ciphertext and plaintext filenames.
 Prefix arg means treat the plaintext file as binary data."
   (lambda ()
-    (if (not (blowfish-available?))
-	(editor-error "Blowfish encryption not supported on this system"))
+    (guarantee-blowfish-available)
     (let ((from (prompt-for-existing-file "Decrypt file (ciphertext)" #f)))
       (let ((to
 	     (prompt-for-file
@@ -655,23 +636,80 @@ Prefix arg means treat the plaintext file as binary data."
 	      (and (pathname-type from)
 		   (list (pathname-new-type from #f))))))
 	(list from to (command-argument)))))
-  (lambda (from to binary?)
-    (if (or (not (file-exists? to))
-	    (prompt-for-yes-or-no?
-	     (string-append "File "
-			    (->namestring to)
-			    " already exists; overwrite")))
-	(let ((password (prompt-for-password "Pass phrase")))
-	  (call-with-binary-input-file from
-	    (lambda (input)
-	      ((if binary?
-		   call-with-binary-output-file
-		   call-with-output-file)
-	       to
-	       (lambda (output)
-		 (blowfish-encrypt-port input output (md5 password)
-					(read-blowfish-file-header input)
-					#f)))))))))
+  (lambda (from to binary-plaintext?)
+    (blowfish-decrypt-file from to binary-plaintext? #f)))
+
+(define (guarantee-blowfish-available)
+  (if (not (blowfish-available?))
+      (editor-error "Blowfish encryption not supported on this system.")))
+
+(define (blowfish-encrypt-file from to binary-plaintext? delete-plaintext?)
+  (guarantee-blowfish-available)
+  (and (or (not (file-exists? to))
+	   (prompt-for-yes-or-no?
+	    (string-append "File "
+			   (->namestring to)
+			   " already exists; overwrite")))
+       (begin
+	 ((if binary-plaintext?
+	      call-with-binary-input-file
+	      call-with-input-file)
+	  from
+	  (lambda (input)
+	    (%blowfish-encrypt-file to input)))
+	 (let ((t (file-modification-time-indirect from)))
+	   (set-file-times! to t t))
+	 (set-file-modes! to (file-modes from))
+	 (if delete-plaintext? (delete-file from))
+	 #t)))
+
+(define (blowfish-decrypt-file from to binary-plaintext? delete-ciphertext?)
+  (guarantee-blowfish-available)
+  (and (or (not (file-exists? to))
+	   (prompt-for-yes-or-no?
+	    (string-append "File "
+			   (->namestring to)
+			   " already exists; overwrite")))
+       (begin
+	 ((if binary-plaintext?
+	      call-with-binary-output-file
+	      call-with-output-file)
+	  to
+	  (lambda (output)
+	    (%blowfish-decrypt-file from output)))
+	 (let ((t (file-modification-time-indirect from)))
+	   (set-file-times! to t t))
+	 (set-file-modes! to (file-modes from))
+	 (if delete-ciphertext? (delete-file from))
+	 #t)))
+
+(define (%blowfish-encrypt-file pathname input)
+  (call-with-binary-output-file pathname
+    (lambda (output)
+      (call-with-sensitive-string (call-with-confirmed-pass-phrase md5)
+	(lambda (key-string)
+	  (blowfish-encrypt-port input output key-string
+				 (write-blowfish-file-header output)
+				 #t))))))
+
+(define (%blowfish-decrypt-file pathname output)
+  (call-with-binary-input-file pathname
+    (lambda (input)
+      (call-with-sensitive-string (call-with-pass-phrase "Pass phrase" md5)
+	(lambda (key-string)
+	  (blowfish-encrypt-port input output key-string
+				 (read-blowfish-file-header input)
+				 #f))))))
+
+(define (call-with-sensitive-string string receiver)
+  (dynamic-wind (lambda ()
+		  unspecific)
+		(lambda ()
+		  (receiver string))
+		(lambda ()
+		  (string-fill! string #\NUL)
+		  (set! string)
+		  unspecific)))
 
 ;;;; Prompting
 
diff --git a/v7/src/edwin/fileio.scm b/v7/src/edwin/fileio.scm
index 31742857e..f7f5d1a14 100644
--- a/v7/src/edwin/fileio.scm
+++ b/v7/src/edwin/fileio.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: fileio.scm,v 1.145 1999/01/14 18:24:58 cph Exp $
+;;; $Id: fileio.scm,v 1.146 1999/08/10 16:54:37 cph Exp $
 ;;;
 ;;; Copyright (c) 1986, 1989-1999 Massachusetts Institute of Technology
 ;;;
@@ -22,6 +22,58 @@
 
 (declare (usual-integrations))
 
+;;;; Encrypted files
+
+(define-variable enable-encrypted-files
+  "If true, encrypted files are automatically decrypted when read,
+and recrypted when written.  An encrypted file is identified by the
+filename suffix \".bf\"."
+  #t
+  boolean?)
+
+(define ((read/write-encrypted-file? write?) group pathname)
+  (and (ref-variable enable-encrypted-files group)
+       (equal? "bf" (pathname-type pathname))
+       (blowfish-available?)
+       (or write? (blowfish-file? pathname))
+       #t))
+
+(define (read-encrypted-file pathname mark)
+  (let ((m (string-append "Decrypting file " (->namestring pathname) "...")))
+    (message m)
+    (call-with-output-mark mark
+      (lambda (output)
+	(%blowfish-decrypt-file pathname output)))
+    ;; Disable auto-save here since we don't want to auto-save the
+    ;; unencrypted contents of the encrypted file.
+    (local-set-variable! auto-save-default #f (mark-buffer mark))
+    (message m "done")))
+
+(define (write-encrypted-file region pathname)
+  (let ((m (string-append "Encrypting file " (->namestring pathname) "...")))
+    (message m)
+    (%blowfish-decrypt-file pathname
+			    (make-buffer-input-port (region-start region)
+						    (region-end region)))
+    (message m "done")))
+
+(define (os-independent/read-file-methods)
+  (list (cons (read/write-encrypted-file? #f)
+	      (lambda (pathname mark visit?)
+		visit?
+		(read-encrypted-file pathname mark)))))
+
+(define (os-independent/write-file-methods)
+  (list (cons (read/write-encrypted-file? #t)
+	      (lambda (region pathname visit?)
+		visit?
+		(write-encrypted-file region pathname)))))
+
+(define (os-independent/alternate-pathnames group pathname)
+  (if (ref-variable enable-encrypted-files group)
+      (list (string-append (->namestring pathname) ".bf"))
+      '()))
+
 ;;;; Special File I/O Methods
 
 (define (r/w-file-methods? objects)
diff --git a/v7/src/edwin/rmail.scm b/v7/src/edwin/rmail.scm
index 7795b61ba..3c8cd9b54 100644
--- a/v7/src/edwin/rmail.scm
+++ b/v7/src/edwin/rmail.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: rmail.scm,v 1.62 1999/05/13 03:06:43 cph Exp $
+;;; $Id: rmail.scm,v 1.63 1999/08/10 16:54:54 cph Exp $
 ;;;
 ;;; Copyright (c) 1991-1999 Massachusetts Institute of Technology
 ;;;
@@ -670,7 +670,8 @@ This variable is ignored if rmail-pop-procedure is #F."
 (define saved-pop-passwords '())
 
 (define (prompt-for-pop-server-password server)
-  (prompt-for-password (string-append "Password for POP server " server)))
+  (call-with-pass-phrase (string-append "Password for POP server " server)
+			 string-copy))
 
 ;;;; Moving around
 
diff --git a/v7/src/edwin/unix.scm b/v7/src/edwin/unix.scm
index b02dc3b2e..5a17be79d 100644
--- a/v7/src/edwin/unix.scm
+++ b/v7/src/edwin/unix.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;; $Id: unix.scm,v 1.97 1999/08/09 18:19:19 cph Exp $
+;;; $Id: unix.scm,v 1.98 1999/08/10 16:54:48 cph Exp $
 ;;;
 ;;; Copyright (c) 1989-1999 Massachusetts Institute of Technology
 ;;;
@@ -238,7 +238,7 @@ Includes the new backup.  Must be > 0."
 	      result))))))
 
 (define os/encoding-pathname-types
-  '("Z" "gz" "bz2" "KY" "ky" "bf"))
+  '("Z" "gz" "bz2" "bf"))
 
 (define unix/backup-suffixes
   (cons "~"
@@ -350,10 +350,7 @@ Includes the new backup.  Must be > 0."
 		   (read-compressed-file "bzip2 -d" pathname mark))
 		  ((equal? "Z" type)
 		   (read-compressed-file "uncompress" pathname mark))))))
-    (,(read/write-encrypted-file? #f)
-     . ,(lambda (pathname mark visit?)
-	  visit?
-	  (read-encrypted-file pathname mark)))))
+    ,@(os-independent/read-file-methods)))
 
 (define (os/write-file-methods)
   `((,read/write-compressed-file?
@@ -366,21 +363,16 @@ Includes the new backup.  Must be > 0."
 		   (write-compressed-file "bzip2" region pathname))
 		  ((equal? "Z" type)
 		   (write-compressed-file "compress" region pathname))))))
-    (,(read/write-encrypted-file? #t)
-     . ,(lambda (region pathname visit?)
-	  visit?
-	  (write-encrypted-file region pathname)))))
+    ,@(os-independent/write-file-methods)))
 
 (define (os/alternate-pathnames group pathname)
-  (let ((filename (->namestring pathname)))
-    `(,@(if (ref-variable enable-compressed-files group)
-	    (map (lambda (suffix) (string-append filename "." suffix))
-		 unix/compressed-file-suffixes)
-	    '())
-      ,@(if (ref-variable enable-encrypted-files group)
-	    (map (lambda (suffix) (string-append filename "." suffix))
-		 unix/encrypted-file-suffixes)
-	    '()))))
+  (if (ref-variable enable-compressed-files group)
+      (append (map (let ((filename (->namestring pathname)))
+		     (lambda (suffix)
+		       (string-append filename "." suffix)))
+		   unix/compressed-file-suffixes)
+	      (os-independent/alternate-pathnames group pathname))
+      '()))
 
 ;;;; Compressed Files
 
@@ -444,84 +436,6 @@ of the filename suffixes \".gz\", \".bz2\", or \".Z\"."
 			    (list region pathname)))
   (append-message "done"))
 
-;;;; Encrypted files
-
-(define-variable enable-encrypted-files
-  "If #T, encrypted files are automatically decrypted when read,
-and recrypted when written.  An encrypted file is identified by the
-filename suffixes \".bf\" and \".ky\"."
-  #t
-  boolean?)
-
-(define ((read/write-encrypted-file? write?) group pathname)
-  (and (ref-variable enable-encrypted-files group)
-       (let ((type (pathname-type pathname)))
-	 (and (member type unix/encrypted-file-suffixes)
-	      (if (equal? "bf" type)
-		  (and (blowfish-available?)
-		       (or write? (blowfish-file? pathname)))
-		  #t)))))
-
-(define unix/encrypted-file-suffixes
-  '("bf" "ky" "KY"))
-
-(define (read-encrypted-file pathname mark)
-  (let ((password (prompt-for-password "Pass phrase"))
-	(type (pathname-type pathname)))
-    (message "Decrypting file " (->namestring pathname) "...")
-    (cond ((equal? "bf" type)
-	   (call-with-binary-input-file pathname
-	     (lambda (input)
-	       (call-with-output-mark mark
-		 (lambda (output)
-		   (blowfish-encrypt-port input output (md5 password)
-					  (read-blowfish-file-header input)
-					  #f))))))
-	  ((or (equal? "ky" type) (equal? "KY" type))
-	   (insert-string (let ((the-encrypted-file
-				 (call-with-binary-input-file pathname
-				   (lambda (port)
-				     (read-string (char-set) port)))))
-			    (decrypt the-encrypted-file password
-				     (lambda () 
-				       (kill-buffer (mark-buffer mark))
-				       (editor-error "krypt: Password error!"))
-				     (lambda (x) 
-				       (editor-beep)
-				       (message "krypt: Checksum error!")
-				       x)))
-			  mark)))
-    ;; Disable auto-save here since we don't want to
-    ;; auto-save the unencrypted contents of the 
-    ;; encrypted file.
-    (define-variable-local-value! (mark-buffer mark)
-	(ref-variable-object auto-save-default)
-      #f)
-    (append-message "done")))
-
-(define (write-encrypted-file region pathname)
-  (let ((password (prompt-for-confirmed-password))
-	(type (pathname-type pathname)))
-    (message "Encrypting file " (->namestring pathname) "...")
-    (cond ((equal? "bf" type)
-	   (let ((input
-		  (make-buffer-input-port (region-start region)
-					  (region-end region))))
-	     (call-with-binary-output-file pathname
-	       (lambda (output)
-		 (blowfish-encrypt-port input output (md5 password)
-					(write-blowfish-file-header output)
-					#t)))))
-	  ((or (equal? "ky" type) (equal? "KY" type))
-	   (let ((the-encrypted-file
-		  (encrypt (extract-string (region-start region)
-					   (region-end region))
-			   password)))
-	     (call-with-binary-output-file pathname
-	       (lambda (port)
-		 (write-string the-encrypted-file port))))))
-    (append-message "done")))
-
 ;;;; Dired customization
 
 (define-variable dired-listing-switches