29 Aug
2015
29 Aug
'15
11:40 a.m.
I've just installed PuTTY on a new PC running Windows 10. When I attempt
to connect to my VPS console (on bellini) PuTTY immediately disconnects
with the message
"Disconnected: No support authentication methods available (server sent:
publickey,keyboard-interactive)"
I can connect to my VPS using PuTTY without any problems. I can also
connect to the console on bellini from my home Linux box (using openssh
on CentOS 6).
This was working (PuTTY, Windows 10) a couple of weeks ago - has
anything changed?
Thanks,
Mike
29 Aug
29 Aug
4:22 p.m.
Hi Mike,
On Sat, Aug 29, 2015 at 12:40:36PM +0100, Mike Zanker wrote:
I've just installed PuTTY on a new PC running
Windows 10. When I attempt
to connect to my VPS console (on bellini) PuTTY immediately disconnects
with the message
"Disconnected: No support authentication methods available (server sent:
publickey,keyboard-interactive)"
The logs on bitfolk's side show an authentication failure for your
user and then an authentication success. Presumably the success is
when you tried it from the Linux host. Although it seems to happen
at the same time down to the second as the failed connection, so
that's weird.
I can connect to my VPS using PuTTY without any
problems. I can also
connect to the console on bellini from my home Linux box (using openssh
on CentOS 6).
This was working (PuTTY, Windows 10) a couple of weeks ago - has
anything changed?
No, I don't think so. The sshd config on that host has not been
changed in several years. If this is a new PC then surely it's the
client end that has changed?
I'm afraid I don't know how to get debug info out of PuTTY, but my
first step if it were openssh would be running the client as ssh -v.
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
4:32 p.m.
On 29/08/2015 17:22, Andy Smith wrote:
The logs on bitfolk's side show an authentication
failure for your
user and then an authentication success. Presumably the success is
when you tried it from the Linux host. Although it seems to happen
at the same time down to the second as the failed connection, so
that's weird.
Yes, and I get the disconnection before I even have a chance to enter a
password. It appears to be saying that there's no authentication method
that the two sides can agree on, which shouldn't be the case as
keyboard-interactive is definitely enabled.
No, I don't think so. The sshd config on that host
has not been
changed in several years. If this is a new PC then surely it's the
client end that has changed?
Sorry, what I meant was that it worked on another new PC with Windows 10
a couple of weeks ago (in fact two PCs).
I'm afraid I don't know how to get debug info
out of PuTTY, but my
first step if it were openssh would be running the client as ssh -v.
I'll see what I can do, otherwise I'll just have to go via my Linux box
here.
Thanks,
Mike
5:03 p.m.
On Sat, Aug 29, 2015 at 05:32:06PM +0100, Mike Zanker wrote:
Right clicking the window title of the PuTTy client lets you see the
event log, which is the same (it seems) as ssh -v gives you.
Perhaps this helps?
If not, did you try to connect to some other ssh servers that you know
allow for password-based authentication, to see if this PuTTy client
(and/or its settings) gives you the password prompt.
Martijn.
I'm afraid
I don't know how to get debug info out of PuTTY, but my
first step if it were openssh would be running the client as ssh -v.
I'll see what I can do, otherwise I'll just have to go via my Linux box
here.
6:20 p.m.
On 29/08/2015 18:03, Martijn Grooten wrote:
Right clicking the window title of the PuTTy client
lets you see the
event log, which is the same (it seems) as ssh -v gives you.
Thanks for that - this is what I get:
2015-08-29 19:13:06 Looking up host "osprey.console.bitfolk.com"
2015-08-29 19:13:06 Connecting to 2001:ba8:0:1f1::8 port 22
2015-08-29 19:13:06 We claim version: SSH-2.0-PuTTY_Release_0.65
2015-08-29 19:13:06 Server version: SSH-2.0-OpenSSH_5.5p1 Debian-6+squeeze6
2015-08-29 19:13:06 We believe remote version has SSH-2 channel request bug
2015-08-29 19:13:06 Using SSH protocol version 2
2015-08-29 19:13:06 Doing Diffie-Hellman group exchange
2015-08-29 19:13:06 Doing Diffie-Hellman key exchange with hash SHA-256
2015-08-29 19:13:07 Host key fingerprint is:
2015-08-29 19:13:07 ssh-rsa 2048 <deleted>
2015-08-29 19:13:07 Initialised AES-256 SDCTR client->server encryption
2015-08-29 19:13:07 Initialised HMAC-SHA1 client->server MAC algorithm
2015-08-29 19:13:07 Initialised AES-256 SDCTR server->client encryption
2015-08-29 19:13:07 Initialised HMAC-SHA1 server->client MAC algorithm
2015-08-29 19:13:11 Attempting keyboard-interactive authentication
2015-08-29 19:13:11 Server refused keyboard-interactive authentication
2015-08-29 19:13:11 Disconnected: No supported authentication methods
available (server sent: publickey,keyboard-interactive)
If not, did you try to connect to some other ssh
servers that you know
allow for password-based authentication, to see if this PuTTy client
(and/or its settings) gives you the password prompt.
Yes - as I said in my original post I can connect to my VPS through
keyboard-interactive authentication without any problems (and my other
Linux servers).
Thanks,
Mike
30 Aug
30 Aug
9:34 p.m.
Hi,
2015-08-29 19:13:11 Disconnected: No supported
authentication methods
available (server sent: publickey,keyboard-interactive)
it looks like your client doesn't support the "password" method and the
server doesn't support keyboard-interactive.
Theses are different method and not compatible. I think password is
required by the spec but keyboard-interactive is optional.
http://fixunix.com/ssh/73976-difference-between-password-keyboard-interacti…
http://www.snailbook.com/faq/keyboard-interactive.auto.html
The "Client Configuration" and "Server Configuration" sections here
might be useful:
https://support.ssh.com/manuals/server-admin/44/User_Authentication_with_Ke…
Regards,
@ndy
--
andyjpb(a)ashurst.eu.org
http://www.ashurst.eu.org/
0290 DA75 E982 7D99 A51F E46A 387A 7695 7EBA 75FF
9:40 p.m.
On 30/08/2015 22:34, Andy Bennett wrote:
it looks like your client doesn't support the
"password" method and the
server doesn't support keyboard-interactive.
The server *does* support keyboard-interactive, though, because it works
fine via openssh from my Linux servers. It's just PuTTY that doesn't
seem to be able to negotiate it with this particular server.
Mike
9:42 p.m.
On Sun, Aug 30, 2015 at 10:40:05PM +0100, Mike Zanker wrote:
Did you check if keyboard-interactive is enabled by the client, under
Connection->SSH->Auth?
I took the liberty to see if I could reproduce this (from Win7 and with
a slightly older PuTTy client) and I could when I unticked that box.
Perhaps on Windows 10 and/or newer PuTTy clients it's disabled by
default.
Martijn.
it looks like
your client doesn't support the "password" method and the
server doesn't support keyboard-interactive.
The server *does* support keyboard-interactive, though, because it works
fine via openssh from my Linux servers. It's just PuTTY that doesn't
seem to be able to negotiate it with this particular server.
10:43 p.m.
On 30/08/2015 22:42, Martijn Grooten wrote:
Did you check if keyboard-interactive is enabled by
the client, under
Connection->SSH->Auth?
I took the liberty to see if I could reproduce this (from Win7 and with
a slightly older PuTTy client) and I could when I unticked that box.
Perhaps on Windows 10 and/or newer PuTTy clients it's disabled by
default.
Yes, it's enabled. If you look at the debug log I posted it actually
says "Attempting keyboard-interactive authentication". It's the server
that refuses it.
Mike
31 Aug
31 Aug
4:44 a.m.
Hi Mike,
On Sat, Aug 29, 2015 at 07:20:04PM +0100, Mike Zanker wrote:
2015-08-29 19:13:11 Attempting keyboard-interactive
authentication
2015-08-29 19:13:11 Server refused keyboard-interactive authentication
What time zone are the above log entries in please? Because
interestingly I see absolutely nothing related to you trying to log
in, around 19:13 UTC nor 18:13 UTC that day.
I do see something at 11:24 UTC that day though.
Do you have a password saved in PuTTY or are you typing it each
time?
Thing is as far as I know, "Server refused keyboard-interactive
authentication" just means you got the password wrong…
You may have to ask on a PuTTY list about this.
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
4:56 a.m.
On Mon, Aug 31, 2015 at 04:44:39AM +0000, Andy Smith wrote:
interestingly I see absolutely nothing related to you
trying to log
in, around 19:13 UTC nor 18:13 UTC that day.
It seems I can replicate the problem in putty on Ubuntu, and nothing
is logged on the server, so that explains why I couldn't see
anything.
That would be with putty package version 0.63-4ubuntu0.1.
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
5:28 a.m.
On Mon, Aug 31, 2015 at 04:56:45AM +0000, Andy Smith wrote:
It seems I can replicate the problem in putty on
Ubuntu, and nothing
is logged on the server, so that explains why I couldn't see
anything.
If I force IPv4 rather than Auto or IPv6 then it works. I suspect
this is a bug in PuTTY, because openssh from same host is working
fine on v4 and v6 alike.
So there's a workaround: force IPv4 in the "Connection" part of
PuTTY,
Cheers,
Andy
--
http://bitfolk.com/ -- No-nonsense VPS hosting
7:38 a.m.
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On 31/08/2015 06:28, Andy Smith wrote:
If I force IPv4 rather than Auto or IPv6 then it
works. I suspect
this is a bug in PuTTY, because openssh from same host is working
fine on v4 and v6 alike.
So there's a workaround: force IPv4 in the "Connection" part of
PuTTY,
Hi Andy - snap! Late last night I had to connect to work using Cisco
VPN, which has the side-effect of disabling IPv6 on the network
interface. I gave PuTTY one more shot and noticed it was working - it
stopped working again when I disconnected the VPN.
Thanks for your help in diagnosing this.
Cheers,
Mike
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7:47 a.m.
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On 31/08/2015 06:28, Andy Smith wrote:
If I force IPv4 rather than Auto or IPv6 then it
works. I suspect
this is a bug in PuTTY, because openssh from same host is working
fine on v4 and v6 alike.
Interestingly, though, PuTTY works fine over IPv6 to my VPS. That's
running CentOS 5.
I think Windows 10 has something to do with it, though, because I've
been using PuTTY to the VPS console ever since I've been a customer
and have had IPv6 all that time.
Mike
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13 comments
4 participants
participants (4)
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Andy Bennett -
Andy Smith -
Martijn Grooten -
Mike Zanker