upstream: Don't send IUTF8 to servers that don't like them.

Some SSH servers eg "ConfD" drop the connection if the client sends the
new IUTF8 (RFC8160) terminal mode even if it's not set.  Add a bug bit
for such servers and avoid sending IUTF8 to them.  ok djm@

OpenBSD-Commit-ID: 26425855402d870c3c0a90491e72e2a8a342ceda

3 files changed, 15 insertions, 6 deletions

diff --git a/compat.c b/compat.c
index 89b302cca..861e9e21f 100644
--- a/compat.c
+++ b/compat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: compat.c,v 1.105 2018/01/23 05:27:21 djm Exp $ */
+/* $OpenBSD: compat.c,v 1.106 2018/02/16 04:43:11 dtucker Exp $ */
 /*
  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
  *
@@ -126,6 +126,8 @@ compat_datafellows(const char *version)
                   "WinSCP_release_5.7.3,"
                   "WinSCP_release_5.7.4",
                                         SSH_OLD_DHGEX },
+                { "ConfD-*",
+                                        SSH_BUG_UTF8TTYMODE },
                 { NULL,                 0 }
         };
 
diff --git a/compat.h b/compat.h
index 246e6ee4c..4fee3495a 100644
--- a/compat.h
+++ b/compat.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: compat.h,v 1.50 2018/01/23 05:27:21 djm Exp $ */
+/* $OpenBSD: compat.h,v 1.51 2018/02/16 04:43:11 dtucker Exp $ */
 
 /*
  * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
@@ -32,7 +32,7 @@
 #define SSH_PROTO_1_PREFERRED   0x02
 #define SSH_PROTO_2             0x04
 
-/* #define unused               0x00000001 */
+#define SSH_BUG_UTF8TTYMODE     0x00000001
 /* #define unused               0x00000002 */
 /* #define unused               0x00000004 */
 /* #define unused               0x00000008 */
diff --git a/ttymodes.c b/ttymodes.c
index 845139635..f9fdb92de 100644
--- a/ttymodes.c
+++ b/ttymodes.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ttymodes.c,v 1.32 2017/04/30 23:26:54 djm Exp $ */
+/* $OpenBSD: ttymodes.c,v 1.33 2018/02/16 04:43:11 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -56,6 +56,7 @@
 #include "log.h"
 #include "compat.h"
 #include "buffer.h"
+#include "compat.h"
 
 #define TTY_OP_END              0
 /*
@@ -308,9 +309,15 @@ tty_make_modes(int fd, struct termios *tiop)
         buffer_put_char(&buf, OP); \
         buffer_put_int(&buf, special_char_encode(tio.c_cc[NAME]));
 
+#define SSH_TTYMODE_IUTF8 42  /* for SSH_BUG_UTF8TTYMODE */
+
 #define TTYMODE(NAME, FIELD, OP) \
-        buffer_put_char(&buf, OP); \
-        buffer_put_int(&buf, ((tio.FIELD & NAME) != 0));
+        if (OP == SSH_TTYMODE_IUTF8 && (datafellows & SSH_BUG_UTF8TTYMODE)) { \
+                debug3("%s: SSH_BUG_UTF8TTYMODE", __func__); \
+        } else { \
+                buffer_put_char(&buf, OP); \
+                buffer_put_int(&buf, ((tio.FIELD & NAME) != 0)); \
+        }
 
 #include "ttymodes.h"