On 13/10/2017 13:40, Michael Felt wrote:
debug3: send packet: type 4
sshd sends a SSH2_MSG_DEBUG back to client, probably indicating
why the request failed
debug3: send packet: type 100
sshd sends SSH2_MSG_CHANNEL_FAILURE.
The debug message would probably give you the reason it fails. You could
try to wheedle it out of PuTTY,
I'll try an iptrace trace - to see what putty is masking with XXXXX.
apply the patch below to have it shown
at LogLevel=debug3 or try to guess which of one of likely ones it is
from session.c:session_setup_x11fwd()
packet_send_debug("X11 forwarding disabled in user configuration
file.");
packet_send_debug("X11 forwarding disabled in server configuration
file.");
packet_send_debug("No xauth program; cannot forward with spoofing.");
packet_send_debug("Can't get IP address for X11 DISPLAY.");
My 'quess' is that it somehow related to 'auth' - as there was a
security-fix for auth that was introduced in version 7.2 (as I
mentioned before: https://www.openssh.com/security.html, March 9,
2016) and https://www.openssh.com/txt/release-7.2p2
* sshd(8): sanitise X11 authentication credentials to avoid xauth
command injection when X11Forwarding is enabled.
My guess is that AIX is still sending either one of '\n', '\r', or
even both.
-d
diff --git a/packet.c b/packet.c
index f114ea52..5dda4243 100644
--- a/packet.c
+++ b/packet.c
@@ -1774,6 +1774,8 @@ ssh_packet_send_debug(struct ssh *ssh, const
char *fmt,...)
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
+ debug3("sending debug message: %s", buf);
+
Will also try this!
This verifies it is xauth related:
debug3: sending debug message: No xauth program; cannot forward with
spoofing.
so, added an extra debug - and this is what I see:
debug1: session_input_channel_req: session 0 req x11-req
debug3: setup_x11fwd: xauth_location == /usr/X11R6/bin/xauth
debug3: sending debug message: No xauth program; cannot forward with
spoofing.
but the xauth_location should be:
# which xauth
/usr/bin/X11/xauth
and fyi:
# ls -l /usr/bin/X11
lrwxrwxrwx 1 bin bin 16 Aug 31 17:40 /usr/bin/X11
-> /usr/lpp/X11/bin
# ls -ld /usr/X11R6
drwxr-xr-x 2 bin bin 256 Aug 29 12:16 /usr/X11R6
# ls -l /usr/X11R6
total 0
lrwxrwxrwx 1 bin bin 19 Aug 31 17:40 lib ->
/usr/lpp/X11/lib/R6
so, obviously - the stat() calls for /usr/X11R6/bin/xauth return -1.
# ls -l /usr/X11R6/bin/xauth
ls: 0653-341 The file /usr/X11R6/bin/xauth does not exist.
And, I expect noone from IBM has ever said anything - as they still use
OpenSSH-6.0 as a base, although they are also using OpenSSH-7.1, both of
which are not affected by the fix for OpenSSH-7.2.
Studying further - but maybe you already know what needs to be done.
if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
(r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
(r = sshpkt_put_cstring(ssh, buf)) != 0 ||
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