Re: Gnus 5.10.6 problems with PGP/MIME (test cases)

[Daiki Ueno <ueno@unixuser.org>]

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>>>>> In <15566.1139355525@juniper.net> 
>>>>>	"Mark D. Baushke" <mdb@gnu.org> wrote:
> > See RFC3156, section 4:
> > 
> > 4.  OpenPGP encrypted data
> > 
> >    Before OpenPGP encryption, the data is written in MIME canonical
> >    format (body and headers).
> > 
> > Though I couldn't find the definition of "MIME canonical format", I
> > believe that it was intended to have CRLF line-ending.

> Hmmm... I also do not see the definition for "MIME canonical format"
> so I am not sure.

I found a clue in sylpheed-claws-users ML.
http://sourceforge.net/mailarchive/message.php?msg_id=1636575

  RFC 2045 (MIME) clearly says that CRLF is the normal line separator for
  MIME header fields. For body text, see RFC 2046 :
   
      The canonical form of any MIME "text" subtype MUST always represent a
      line break as a CRLF sequence.  Similarly, any occurrence of CRLF in
      MIME "text" MUST represent a line break.  Use of CR and LF outside of
      line break sequences is also forbidden.

> > > > For non-MIME encryption, line-ending conversion is not needed at all.
> > 
> > > I disagree. This is what started the debate in the first place.
> > 
> > > If I am sending a text message, then changing the line endings to CRLF
> > > as is done in pgg-gpg-encrypt-region should also tell the remote end
> > > that a text packet is coming rather than arbitrary binary data.
> > 
> > I doubt that it is really necessary to be a text packet.

Sorry, I misunderstood the problem.

Now my understanding is that, the problem is, unless --textmode is
specified, a sender and a receiver using non-MIME encryption have to
make an out-of-band agreement to specify line endings.  Right?

If so, --textmode is still needed for non-MIME encryption.  And also, if
"MIME canonical format" in RFC3156 is intended to have CRLF line
endings, specifying --textmode in PGP/MIME is harmless.

However, always specifying --textmode might not be a good idea.  Because
applications other than MUA will need encryption of raw binary data.

I attach a patch which allows users to select text-mode or binary-mode
by setting pgg-text-mode.


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Index: lisp/pgg-def.el
===================================================================
RCS file: /usr/local/cvsroot/gnus/lisp/pgg-def.el,v
retrieving revision 7.9
diff -u -r7.9 pgg-def.el
--- lisp/pgg-def.el	8 Feb 2006 04:17:15 -0000	7.9
+++ lisp/pgg-def.el	8 Feb 2006 07:54:38 -0000
@@ -83,6 +83,9 @@
 (defvar pgg-scheme nil
   "Current scheme of PGP implementation.")
 
+(defvar pgg-text-mode nil
+  "If t, inform the recipient that the input is text.")
+
 (defmacro pgg-truncate-key-identifier (key)
   `(if (> (length ,key) 8) (substring ,key 8) ,key))
 
Index: lisp/pgg-gpg.el
===================================================================
RCS file: /usr/local/cvsroot/gnus/lisp/pgg-gpg.el,v
retrieving revision 7.10
diff -u -r7.10 pgg-gpg.el
--- lisp/pgg-gpg.el	19 Jan 2006 11:53:12 -0000	7.10
+++ lisp/pgg-gpg.el	8 Feb 2006 07:54:38 -0000
@@ -185,7 +185,8 @@
 			    pgg-gpg-user-id))))
 	 (args
 	  (append
-	   (list "--batch" "--textmode" "--armor" "--always-trust" "--encrypt")
+	   (list "--batch" "--armor" "--always-trust" "--encrypt")
+	   (if pgg-text-mode (list "--textmode"))
 	   (if sign (list "--sign" "--local-user" pgg-gpg-user-id))
 	   (if recipients
 	       (apply #'nconc
@@ -213,7 +214,8 @@
 			 (pgg-read-passphrase
 			  "GnuPG passphrase for symmetric encryption: ")))
 	 (args
-	  (append (list "--batch" "--textmode" "--armor" "--symmetric" ))))
+	  (append (list "--batch" "--armor" "--symmetric" )
+		  (if pgg-text-mode (list "--textmode")))))
     (pgg-as-lbt start end 'CRLF
       (pgg-gpg-process-region start end passphrase pgg-gpg-program args))
     (pgg-process-when-success)))
@@ -277,9 +279,10 @@
 			  (format "GnuPG passphrase for %s: " pgg-gpg-user-id)
 			  pgg-gpg-user-id)))
 	 (args
-	  (list (if cleartext "--clearsign" "--detach-sign")
-		"--armor" "--batch" "--verbose"
-		"--local-user" pgg-gpg-user-id))
+	  (append (list (if cleartext "--clearsign" "--detach-sign")
+			"--armor" "--batch" "--verbose"
+			"--local-user" pgg-gpg-user-id)
+		  (if pgg-text-mode (list "--textmode"))))
 	 (inhibit-read-only t)
 	 buffer-read-only)
     (pgg-as-lbt start end 'CRLF

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Regards,
-- 
Daiki Ueno