Re-implement server TLS support.

STLS in pop3d is already working.

* include/mailutils/sys/tls-stream.h: New header.
* include/mailutils/tls.h (mu_tls_stream_create)
(mu_tls_stream_create_client)
(mu_tls_stream_create_client_from_tcp): Remove.
(mu_tls_server_stream_create, mu_tls_client_stream_create): New
protos.
* libmu_auth/tls.c: Rewrite.

* imap4d/util.c: Use mu_tls_server_stream_create.
* libproto/pop/mbox.c: Use mu_tls_server_stream_create/
mu_tls_client_stream_create.
* libproto/pop/pop3_stls.c: Use mu_tls_client_stream_create.
* libproto/imap/folder.c: Use mu_tls_client_stream_create.

* pop3d/capa.c (pop3d_capa): CAPA is allowed in both states.
* pop3d/extra.c (pop3d_setio): Rewrite.

@@ -893,7 +893,7 @@ imap4d_init_tls_server ()
   mu_stream_t stream;
   int rc;
  
-  rc = mu_tls_stream_create (&stream, istream, ostream, 0);
+  rc = mu_tls_server_stream_create (&stream, istream, ostream, 0);
   if (rc)
     return 0;
 

@@ -34,5 +34,6 @@ sysinclude_HEADERS = \
  streamref.h\
  streamtrans.h\
  stream.h\
+ tls-stream.h\
  pop3.h\
  nntp.h

+/* 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/>. */
+
+#ifndef _MAILUTILS_SYS_TLS_STREAM_H
+# define _MAILUTILS_SYS_TLS_STREAM_H
+
+# include <mailutils/types.h>
+# include <mailutils/stream.h>
+# include <mailutils/sys/stream.h>
+
+enum _mu_tls_stream_state
+  {
+    state_init,
+    state_open,
+    state_closed,
+    state_destroyed
+  };
+
+struct _mu_tls_io_stream
+{
+  struct _mu_stream stream;
+  mu_stream_t transport;
+  struct _mu_tls_stream *up;
+};
+
+struct _mu_tls_stream
+{
+  struct _mu_stream stream;
+  enum _mu_tls_stream_state state;
+  gnutls_session session;
+  int tls_err;
+  mu_stream_t transport[2];
+};
+
+struct _mu_tls_stream_s
+{
+  struct _mu_stream stream;
+  enum _mu_tls_stream_state state;
+  gnutls_session session;
+  int tls_err;
+  mu_stream_t transport;
+};
+
+#endif

@@ -36,15 +36,12 @@ struct mu_tls_module_config
 
 extern int mu_tls_module_init (enum mu_gocs_op, void *);
 
-extern int mu_tls_stream_create (mu_stream_t *stream, 
+extern int mu_tls_server_stream_create (mu_stream_t *stream, 
 			 	        mu_stream_t strin, mu_stream_t strout,
 				        int flags);
-extern int mu_tls_stream_create_client (mu_stream_t *stream,
+extern int mu_tls_client_stream_create (mu_stream_t *stream,
 					mu_stream_t strin, mu_stream_t strout,
 					int flags);
-extern int mu_tls_stream_create_client_from_tcp (mu_stream_t *stream,
-						 mu_stream_t tcp_str,
-						 int flags);
 
 extern int mu_check_tls_environment (void);
 extern int mu_init_tls_libs (void);

@@ -688,10 +688,12 @@ folder_imap_open (mu_folder_t folder, int flags)
 	      CHECK_EAGAIN (f_imap, status);
 	      CHECK_ERROR_CLOSE (folder, f_imap, status);
 
-	      status = mu_tls_stream_create_client_from_tcp (&newstr, folder->stream, 0);
+	      status = mu_tls_client_stream_create (&newstr, 
+	                                            folder->stream,
+	                                            folder->stream, 0);
 	      if (status != 0)
 		{
-		  mu_error ("folder_imap_open: mu_tls_stream_create_client_from_tcp: %s",
+		  mu_error ("folder_imap_open: mu_tls_client_stream_create: %s",
 			    mu_strerror (status));
 		  return status;
 		}

@@ -824,8 +824,11 @@ pop_open (mu_mailbox_t mbox, int flags)
       /* Create the networking stack.  */
       if (mbox->stream == NULL)
 	{
-	  status = mu_tcp_stream_create (&mbox->stream, host, port, mbox->flags);
+	  status = mu_tcp_stream_create (&mbox->stream, host, port,
+					 mbox->flags);
 	  CHECK_ERROR (mpd, status);
+	  /* FIXME: How to configure the buffer size? */
+	  mu_stream_set_buffer (mbox->stream, mu_buffer_line, 1024);
 
 #ifdef WITH_TLS
 	  if (mpd->pops)
@@ -836,19 +839,18 @@ pop_open (mu_mailbox_t mbox, int flags)
 	      CHECK_EAGAIN (mpd, status);
 	      CHECK_ERROR_CLOSE (mbox, mpd, status);
 
-	      status = mu_tls_stream_create_client_from_tcp (&newstr, mbox->stream, 0);
+	      status = mu_tls_client_stream_create (&newstr, 
+	                                            mbox->stream, 
+	                                            mbox->stream, 0);
 	      if (status != 0)
 		{
-		  mu_error ("pop_open: mu_tls_stream_create_client_from_tcp: %s",
+		  mu_error ("pop_open: mu_tls_client_stream_create: %s",
 			    mu_strerror (status));
 		  return status;
 		}
 	      mbox->stream = newstr;
 	    }
 #endif /* WITH_TLS */
-
-	  /* Using the awkward mu_stream_t buffering.  */
-	  mu_stream_setbufsiz (mbox->stream, BUFSIZ);
 	}
       else
 	{

@@ -66,7 +66,9 @@ mu_pop3_stls (mu_pop3_t pop3)
         MU_POP3_CHECK_EAGAIN (pop3, status);
         mu_pop3_debug_ack (pop3);
         MU_POP3_CHECK_OK (pop3);
-        status = mu_tls_stream_create_client_from_tcp (&tls_stream, pop3->carrier, 0);
+        status = mu_tls_client_stream_create (&tls_stream, 
+                                              pop3->carrier, 
+                                              pop3->carrier, 0);
         MU_POP3_CHECK_ERROR (pop3, status);
         pop3->carrier = tls_stream; 
         pop3->state = MU_POP3_STLS_CONNECT;

@@ -32,9 +32,6 @@ pop3d_capa (char *arg)
   if (strlen (arg) != 0)
     return ERR_BAD_ARGS;
 
-  if (state != initial_state && state != TRANSACTION)
-    return ERR_WRONG_STATE;
-
   pop3d_outf ("+OK Capability list follows\n");
   pop3d_outf ("TOP\n");
   pop3d_outf ("USER\n");

@@ -126,6 +126,14 @@ pop3d_abquit (int reason)
   exit (code);
 }
 
+/* Keeps the *real* output stream.  Ostream is a RFC822 filter built over
+   real_ostream, or even over a TLS stream, which in turn is based on this
+   real_ostream.
+   FIXME: This is sorta kludge: we could use MU_IOCTL_GET_TRANSPORT call
+   to retrieve the bottom-level stream, if filter streams supported it.
+*/
+static mu_stream_t real_ostream;
+
 void
 pop3d_setio (FILE *in, FILE *out)
 {
@@ -136,14 +144,17 @@ pop3d_setio (FILE *in, FILE *out)
   if (!out)
     pop3d_abquit (ERR_NO_OFILE);
 
-  if (mu_stdio_stream_create (&istream, fileno (in), MU_STREAM_NO_CLOSE))
+  if (mu_stdio_stream_create (&istream, fileno (in),
+			      MU_STREAM_READ | MU_STREAM_NO_CLOSE))
     pop3d_abquit (ERR_NO_IFILE);
   mu_stream_set_buffer (istream, mu_buffer_line, 1024);
   
-  if (mu_stdio_stream_create (&str, fileno (out), MU_STREAM_NO_CLOSE))
+  if (mu_stdio_stream_create (&str, fileno (out),
+			      MU_STREAM_WRITE | MU_STREAM_NO_CLOSE))
     pop3d_abquit (ERR_NO_OFILE);
+  real_ostream = str;
   if (mu_filter_create (&ostream, str, "rfc822", MU_FILTER_ENCODE,
-			MU_STREAM_WRITE|MU_STREAM_NO_CLOSE))
+			MU_STREAM_WRITE | MU_STREAM_NO_CLOSE))
     pop3d_abquit (ERR_NO_IFILE);
   mu_stream_set_buffer (ostream, mu_buffer_line, 1024);
 }
@@ -155,7 +166,7 @@ pop3d_init_tls_server ()
   mu_stream_t stream;
   int rc;
 
-  rc = mu_tls_stream_create (&stream, istream, ostream, 0);
+  rc = mu_tls_server_stream_create (&stream, istream, real_ostream, 0);
   if (rc)
     return 0;
 
@@ -167,7 +178,12 @@ pop3d_init_tls_server ()
       return 0;
     }
   
-  istream = ostream = stream;
+  istream = stream;
+  mu_stream_destroy (&ostream);
+  if (mu_filter_create (&ostream, stream, "rfc822", MU_FILTER_ENCODE,
+			MU_STREAM_WRITE | MU_STREAM_NO_CLOSE))
+    pop3d_abquit (ERR_NO_IFILE);
+  mu_stream_set_buffer (ostream, mu_buffer_line, 1024);
   return 1;
 }
 #endif