PREAUTH support from Oswald Buddenhagen <ossi@kde.org>

Added Tunnel directive to allow the user to specify a shell command to run
to set up an IMAP connection in place of a TCP socket (eg., to run over
an SSH session).

config.c

@@ -230,6 +230,13 @@ load_config (const char *where)
 	    else
 		global.copy_deleted_to = strdup (val);
 	}
+	else if (!strcasecmp ("Tunnel", cmd))
+	{
+	    if (*cur)
+		(*cur)->tunnel = strdup (val);
+	    else
+		global.tunnel = strdup (val);
+	}
 	else if (!strcasecmp ("Expunge", cmd))
 	{
 	    if (*cur)

configure.in

@@ -1,5 +1,5 @@
 AC_INIT(isync.h)
-AM_INIT_AUTOMAKE(isync,0.8)
+AM_INIT_AUTOMAKE(isync,0.9)
 AM_PROG_CC_STDC
 AC_ARG_WITH(ssl-dir, [  --with-ssl-dir=DIR	location where openssl is insalled],
 	[if test -d $withval/lib; then

imap.c

@@ -179,7 +179,7 @@ socket_read (Socket_t * sock, char *buf, size_t len)
     if (sock->use_ssl)
 	return SSL_read (sock->ssl, buf, len);
 #endif
-    return read (sock->fd, buf, len);
+    return read (sock->rdfd, buf, len);
 }
 
 static int
@@ -189,7 +189,7 @@ socket_write (Socket_t * sock, char *buf, size_t len)
     if (sock->use_ssl)
 	return SSL_write (sock->ssl, buf, len);
 #endif
-    return write (sock->fd, buf, len);
+    return write (sock->wrfd, buf, len);
 }
 
 static void
@@ -455,8 +455,8 @@ imap_exec (imap_t * imap, const char *fmt, ...)
 		imap->ns_shared = parse_list (cmd, 0);
 	    }
 	    else if (!strcmp ("OK", arg) || !strcmp ("BAD", arg) ||
-		     !strcmp ("NO", arg) || !strcmp ("PREAUTH", arg) ||
+		     !strcmp ("NO", arg) || !strcmp ("BYE", arg) ||
-		     !strcmp ("BYE", arg))
+		     !strcmp ("PREAUTH", arg))
 	    {
 		parse_response_code (imap, cmd);
 	    }
@@ -554,13 +554,15 @@ imap_exec (imap_t * imap, const char *fmt, ...)
  * mailbox.
  */
 imap_t *
-imap_open (config_t * box, unsigned int minuid, imap_t * imap)
+imap_open (config_t * box, unsigned int minuid, imap_t * imap, int flags)
 {
   int ret;
   int s;
   struct sockaddr_in addr;
   struct hostent *he;
+  char *arg, *rsp;
   int reuse = 0;
+  int preauth = 0;
 #if HAVE_LIBSSL
   int use_ssl = 0;
 #endif
@@ -611,6 +613,47 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
   {
     /* open connection to IMAP server */
 
+    if (box->tunnel)
+    {
+      int a[2];
+      int b[2];
+
+      printf ("Executing: %s...", box->tunnel);
+      fflush (stdout);
+
+      if (pipe (a))
+      {
+      }
+      if (pipe (b))
+      {
+      }
+
+      if (fork () == 0)
+      {
+	if (dup2 (a[0],0))
+	{
+	  _exit(127);
+	}
+	close (a[1]);
+	if (dup2 (b[1],1))
+	{
+	  _exit (127);
+	}
+	close (b[0]);
+	execl ("/bin/sh","sh","-c", box->tunnel);
+	_exit (127);
+      }
+
+      close (a[0]);
+      close (b[1]);
+
+      imap->sock->rdfd = b[0];
+      imap->sock->wrfd = a[1];
+
+      puts ("ok");
+    }
+    else
+    {
       memset (&addr, 0, sizeof (addr));
       addr.sin_port = htons (box->port);
       addr.sin_family = AF_INET;
@@ -639,11 +682,38 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
       }
       puts ("ok");
 
-	imap->sock->fd = s;
+      imap->sock->rdfd = s;
+      imap->sock->wrfd = s;
+    }
   }
 
   do
   {
+    /* read the greeting string */
+    if (buffer_gets (imap->buf, &rsp))
+    {
+      puts ("Error, no greeting response");
+      ret = -1;
+      break;
+    }
+    if (Verbose)
+      puts (rsp);
+    arg = next_arg (&rsp);
+    if (!arg || *arg != '*' || (arg = next_arg (&rsp)) == NULL)
+    {
+      puts ("Error, invalid greeting response");
+      ret = -1;
+      break;
+    }
+    if (!strcmp ("PREAUTH", arg))
+      preauth = 1;
+    else if (strcmp ("OK", arg) != 0)
+    {
+      puts ("Error, unknown greeting response");
+      ret = -1;
+      break;
+    }
+
     /* if we are reusing the existing connection, we can skip the
      * authentication steps.
      */
@@ -691,7 +761,7 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
 	}
 
 	imap->sock->ssl = SSL_new (SSLContext);
-		SSL_set_fd (imap->sock->ssl, imap->sock->fd);
+	SSL_set_fd (imap->sock->ssl, imap->sock->rdfd);
 	ret = SSL_connect (imap->sock->ssl);
 	if (ret <= 0)
 	{
@@ -721,6 +791,8 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
 	break;
 #endif
 
+      if (!preauth)
+      {
 	puts ("Logging in...");
 #if HAVE_LIBSSL
 	if (imap->have_cram)
@@ -754,6 +826,7 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
 	    break;
 	  }
 	}
+      }
 
       /* get NAMESPACE info */
       if (box->use_namespace && imap->have_namespace)
@@ -773,9 +846,7 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap)
 
     fputs ("Selecting mailbox... ", stdout);
     fflush (stdout);
-	if (
+    if ((ret = imap_exec (imap, "SELECT \"%s%s\"", imap->prefix, box->box)))
-	    (ret =
-	     imap_exec (imap, "SELECT \"%s%s\"", imap->prefix, box->box)))
       break;
     printf ("%d messages, %d recent\n", imap->count, imap->recent);
 
@@ -804,7 +875,9 @@ imap_close (imap_t * imap)
   if (imap)
   {
     imap_exec (imap, "LOGOUT");
-	close (imap->sock->fd);
+    close (imap->sock->rdfd);
+    if (imap->sock->rdfd != imap->sock->wrfd)
+      close (imap->sock->wrfd);
     free (imap->sock);
     free (imap->buf);
     free_message (imap->msgs);

isync.1

@@ -16,7 +16,7 @@
 \"  along with this program; if not, write to the Free Software
 \"  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 ..
-.TH isync 1 "2002 Jan 16"
+.TH isync 1 "2002 Apr 19"
 ..
 .SH NAME
 isync - synchronize IMAP4 and maildir mailboxes
@@ -224,6 +224,11 @@ is 0, the maximum file size is
 .B unlimited.
 ..
 .TP
+\fBTunnel\fR \fIcommand\fR
+Specify a command to run to establish a connection rather than opening a TCP
+socket.  This allows you to run an IMAP session over an SSH tunnel, for
+example.
+.TP
 \fBUseNamespace\fR \fIyes|no\fR
 Selects whether
 .B isync

isync.h

@@ -30,7 +30,8 @@
 
 typedef struct
 {
-    int fd;
+    int rdfd;	/* read filedes */
+    int wrfd;	/* write filedes */
 #if HAVE_LIBSSL
     SSL *ssl;
     unsigned int use_ssl:1;
@@ -61,6 +62,7 @@ struct config
     char *box;
     char *alias;
     char *copy_deleted_to;
+    char *tunnel;
     unsigned int max_messages;
     off_t max_size;
     config_t *next;
@@ -119,7 +121,8 @@ typedef struct _list list_t;
 #define NIL	(void*)0x1
 #define LIST	(void*)0x2
 
-struct _list {
+struct _list
+{
     char *val;
     list_t *next;
     list_t *child;
@@ -187,7 +190,7 @@ int imap_copy_message (imap_t * imap, unsigned int uid, const char *mailbox);
 int imap_fetch_message (imap_t *, unsigned int, int);
 int imap_set_flags (imap_t *, unsigned int, unsigned int);
 int imap_expunge (imap_t *);
-imap_t *imap_open (config_t *, unsigned int, imap_t *);
+imap_t *imap_open (config_t *, unsigned int, imap_t *, int);
 int imap_append_message (imap_t *, int, message_t *);
 
 mailbox_t *maildir_open (const char *, int flags);

isyncrc.sample

@@ -40,3 +40,13 @@ Host host.play.com
 # use a non-default port for this connection
 Port 6789
 Alias personal
+
+
+###
+### Remote mailbox over a SSH tunnel
+###
+
+Mailbox /home/me/Mail/remote
+Host host.remote.com
+Tunnel "ssh -q host.remote.com /usr/sbin/imapd"
+Alias remote

main.c

@@ -292,7 +292,7 @@ main (int argc, char **argv)
 		break;
 	    }
 
-	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap);
+	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap, 0);
 	    if (!imap)
 	    {
 		fprintf (stderr, "%s: skipping mailbox due to IMAP error\n",