when deciding whether to enable keystroke timing obfuscation,

only consider enabling it when a channel with a tty is open.

Avoids turning on the obfucation when X11 forwarding only is in use,
which slows it right down. Reported by Roger Marsh

diff --git a/usr.bin/ssh/channels.c b/usr.bin/ssh/channels.c
index 1b310e3..7c611bc 100644 (file)
--- a/usr.bin/ssh/channels.c
+++ b/usr.bin/ssh/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.433 2023/09/04 00:01:46 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.434 2023/11/15 22:51:49 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -886,6 +886,23 @@ channel_still_open(struct ssh *ssh)
        return 0;
 }
 
+/* Returns true if a channel with a TTY is open. */
+int
+channel_tty_open(struct ssh *ssh)
+{
+       u_int i;
+       Channel *c;
+
+       for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
+               c = ssh->chanctxt->channels[i];
+               if (c == NULL || c->type != SSH_CHANNEL_OPEN)
+                       continue;
+               if (c->client_tty)
+                       return 1;
+       }
+       return 0;
+}
+
 /* Returns the id of an open channel suitable for keepaliving */
 int
 channel_find_open(struct ssh *ssh)

diff --git a/usr.bin/ssh/channels.h b/usr.bin/ssh/channels.h
index 7cfba92..b8c8883 100644 (file)
--- a/usr.bin/ssh/channels.h
+++ b/usr.bin/ssh/channels.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.h,v 1.152 2023/09/04 00:01:46 djm Exp $ */
+/* $OpenBSD: channels.h,v 1.153 2023/11/15 22:51:49 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -337,6 +337,7 @@ int  channel_output_poll(struct ssh *);
 int      channel_not_very_much_buffered_data(struct ssh *);
 void     channel_close_all(struct ssh *);
 int      channel_still_open(struct ssh *);
+int     channel_tty_open(struct ssh *);
 const char *channel_format_extended_usage(const Channel *);
 char   *channel_open_message(struct ssh *);
 int     channel_find_open(struct ssh *);

diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index deebbba..ffa0fac 100644 (file)
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.400 2023/10/12 02:12:53 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.401 2023/11/15 22:51:49 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -580,7 +580,7 @@ obfuscate_keystroke_timing(struct ssh *ssh, struct timespec *timeout,
        if (options.obscure_keystroke_timing_interval <= 0)
                return 1;       /* disabled in config */
 
-       if (!channel_still_open(ssh) || quit_pending) {
+       if (!channel_tty_open(ssh) || quit_pending) {
                /* Stop if no channels left of we're waiting for one to close */
                stop_reason = "no active channels";
        } else if (ssh_packet_is_rekeying(ssh)) {