On Thu, 12 Oct 2017, Michael Felt wrote: > On 08/10/2017 23:32, Michael Felt wrote: > > On 04/10/2017 11:07, Michael Felt wrote: > >> I do not often use X11 - but when I do I prefer to enable > >> X11forwarding, and when finished - turn it off. This is preferable, > >> imho, to having "clear" X11 processing when local - and otherwise > >> impossible when working remote. > >> > >> Working with openssh-7.5p2 I cannot figure out what (extra) I need to > >> do with sshd_config to get it working. > >> > >> I know that there is a security-fix starting with openssh-7.2 > >> (https://www.openssh.com/security.html, March 9, 2016) - and when I > >> load any version of openssh prior to Openssh-7.2 I get the expected > >> X11 behavior over an ssh(d) X11forwarding tunnel. > >> > >> So, what should I be looking at on my server or client-side. Is there > >> a different setting I should be using? I am still using the "putty" > >> setting of: MIT-Magic-Cookie-1. (I'll test, in a moment using > >> XDM-Authorization-1). However, the hint I am hoping for is the flag > >> to set for sshd (e.g., -ddddd) and what debug string - to see if > >> X11forwarding is attempted, and if so, why it is rejected by the sshd. > >> > >> Again - no changes to client-side - openssh-7.1 and earlier work, > >> openssh-7.2 and later do not. > >> > > If you need more verbose debug data - please say what you need > > specifically. > > No comments? Is the data in the wrong format? > > IMHO - any comment is better than no comment. If it will take time - I > will wait. But being held up because the data is wrong - and noone > saying so - is counterproductive. I took a look at it and can't see any obvious error, nor could I reproduce the failure with 7.6p1 locally. Looking at the server log: > debug3: receive packet: type 98 > debug1: server_input_channel_req: channel 0 request x11-req reply 1 > debug1: session_by_channel: session 0 channel 0 > debug1: session_input_channel_req: session 0 req x11-req sshd receives the request > 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, 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."); -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); + 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 || _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
