smtp_starttls.c 2.65 KB
/* GNU Mailutils -- a suite of utilities for electronic mail
   Copyright (C) 2010 Free Software Foundation, Inc.

   This library is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   This library 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <errno.h>
#include <stdlib.h>
#include <mailutils/errno.h>
#include <mailutils/list.h>
#include <mailutils/smtp.h>
#include <mailutils/stream.h>
#include <mailutils/sys/smtp.h>
#include <mailutils/tls.h>

static int
smtp_swap_streams (mu_smtp_t smtp, mu_stream_t *streams)
{
  int rc;
  
  if (MU_SMTP_FISSET (smtp, _MU_SMTP_TRACE))
    rc = mu_stream_ioctl (smtp->carrier, MU_IOCTL_SWAP_STREAM, streams);
  else if (streams[0] != streams[1])
    rc = EINVAL;
  else
    {
      mu_stream_t str = streams[0];
      streams[0] = streams[1] = smtp->carrier;
      smtp->carrier = str;
      rc = 0;
    }
  return rc;
}

int
mu_smtp_starttls (mu_smtp_t smtp)
{
#ifdef WITH_TLS
  int status;
  mu_stream_t tlsstream, streams[2];
  
  if (!smtp)
    return EINVAL;
  if (MU_SMTP_FISSET (smtp, _MU_SMTP_ERR))
    return MU_ERR_FAILURE;
  if (MU_SMTP_FISSET (smtp, _MU_SMTP_TLS))
    return MU_ERR_SEQ;
  if (smtp->state != MU_SMTP_MAIL)
    return MU_ERR_SEQ;

  status = mu_smtp_write (smtp, "STARTTLS\r\n");
  MU_SMTP_CHECK_ERROR (smtp, status);
  status = mu_smtp_response (smtp);
  MU_SMTP_CHECK_ERROR (smtp, status);
  if (smtp->replcode[0] == '4')
    return EAGAIN;
  else if (smtp->replcode[0] != '2')
    return MU_ERR_FAILURE;

  mu_stream_flush (smtp->carrier);
  streams[0] = streams[1] = NULL;
  status = smtp_swap_streams (smtp, streams);
  MU_SMTP_CHECK_ERROR (smtp, status);
  
  status = mu_tls_client_stream_create (&tlsstream,
					streams[0], streams[1], 0);
  MU_SMTP_CHECK_ERROR (smtp, status);
  status = mu_stream_open (tlsstream);
  if (status)
    {
      mu_stream_destroy (&tlsstream);
      return status;
    }
  streams[0] = streams[1] = tlsstream;
  status = smtp_swap_streams (smtp, streams);
  MU_SMTP_CHECK_ERROR (smtp, status);
  /* Invalidate the capability list */
  mu_list_destroy (&smtp->capa);
  return 0;
#else
  return ENOTSUP;
#endif
}