sending mail: starttls and gnutls-cli sessions

sending mail: starttls and gnutls-cli sessions

[Marco Maggi]

Ciao,

  I want to send email through two remote servers, Gmail and
Poste.it, using  gnutls-cli for  authentication.  I am  on a
GNU+Linux system running Emacs 22.3.1 from the latest stable
Slackware package.

  I can successfully send mail through Gmail both using Gnus
and  using an  interactive  eshell session  in  which I  run
gnutls-cli directly and write  SMTP commands by hand.  Fine,
I know that it can work.

  When running the  eshell session for Gmail, I  do this: in
the eshell buffer

$ gnutls-cli --crlf --starttls --port 587 smtp.gmail.com

and the server replies with  a line of greetings; so I start
an SMTP dialogue and issue the STARTTLS SMTP command; now on
a xterm  I send a  SIGALRM signal to the  running gnutls-cli
process,  and  it establishes  the  encrypted bridge.   Then
everything  works.  I  assume that  this is  what  Gnus does
using the underlying libraries.

  Now with Poste.it I can  do the same on an eshell session,
but I have to leave out the "--starttls" option:

$ gnutls-cli --crlf --port 465 relay.poste.it

because  the  server  wants  the  encrypted  bridge  set  up
immediately.   Alternatively  I  can start  gnutls-cli  with
"--starttls" and immediately send  a SIGALRM to the process,
without waiting for server's greetings.

  Reading the  documentation of  Gnus and Smtpmail  I cannot
find a way to  select command line parameters for gnutls-cli
or to  tell it to  send SIGALRM immediately  without messing
with undocumented internal state of the libraries.

  I  see in  "starttls.el" that  a relevant  function  is be
`starttls-open-stream-gnutls'.  In the form:

(apply #'start-process name buffer
       starttls-gnutls-program "-s" host
       "-p" (if (integerp port) (int-to-string port) port)
       starttls-extra-arguments)

it  makes  use  of  the  "-s" option,  which  is  short  for
"--starttls".   So  the  way   to  go  is  to  send  SIGALRM
immediately.  Then the form:

    (while (and (processp process)
		(eq (process-status process) 'run)
		(save-excursion
		  (set-buffer buffer)
		  (goto-char old-max)
		  (not (setq done (re-search-forward
				   starttls-connect nil t)))))
      (accept-process-output process 0 100)
      (sit-for 0.1))

waits for  gnutls-cli text  telling that the  connection was
established ("Simple  Client Mode"); fine this  is should be
read correctly because I see it in the interactive session.

  So I have to turn  to "smtpmail.el", which is BIG!  Here I
guess  that  the problem  is  in `smtpmail-via-smtp',  which
seems  to   always  try  to  send  a   EHLO  command  before
considering a call to `starttls-negotiate'.

  My problem is that when `smtpmail-via-smtp' does:

(setq greeting (smtpmail-read-response process))

Gnus blocks waiting for  input that will never arrive, until
I stop it with C-g.

  What  to  do? Do  I  have to  send  a  feature request  to
someone?
-- Marco Maggi

Re: sending mail: starttls and gnutls-cli sessions

[Ted Zlatanov]

On Mon, 27 Apr 2009 12:27:06 +0200 Marco Maggi <marco.maggi-ipsu@poste.it> wrote: 

MM>   Now with Poste.it I can  do the same on an eshell session,
MM> but I have to leave out the "--starttls" option:

MM> $ gnutls-cli --crlf --port 465 relay.poste.it

MM> because  the  server  wants  the  encrypted  bridge  set  up
MM> immediately.   Alternatively  I  can start  gnutls-cli  with
MM> "--starttls" and immediately send  a SIGALRM to the process,
MM> without waiting for server's greetings.
...
MM>   My problem is that when `smtpmail-via-smtp' does:

MM> (setq greeting (smtpmail-read-response process))

MM> Gnus blocks waiting for  input that will never arrive, until
MM> I stop it with C-g.

MM>   What  to  do? Do  I  have to  send  a  feature request  to
MM> someone?

Can you write a shell script that will DTRT and open the connection?  If
yes, use that script to set up the tunnel and don't get Gnus involved
before the tunnel is running.

Ted

Re: sending mail: starttls and gnutls-cli sessions

[Marco Maggi]

"Ted Zlatanov" wrote:
> Can you write  a shell script that will  DTRT and open the
> connection?  If yes, use that  script to set up the tunnel
> and don't get Gnus involved before the tunnel is running.

I have a  shell script that can send  an email message using
an  encrypted session;  I will  try  to use  it through  the
`message-send-mail-function' interface.

In  the meantime  I filed  a  feature request  on the  Emacs
mailing list.
-- 
Marco Maggi