* OpenSSH: SSHD daemon (as SYSTEM) is partially broken
@ 2020-02-27 18:09 n0nc3
2020-02-27 19:34 ` Bill Stewart
0 siblings, 1 reply; 4+ messages in thread
From: n0nc3 @ 2020-02-27 18:09 UTC (permalink / raw)
To: cygwin
It appears Cygwin SSHD's functionality is partially broke in the later
versions, where SSHD runs as SYSTEM (no longer cyg_server).
On reboot, any attempt to SSH into the server *before* any previous logon
attempt (RDP/locally/etc) is quickly denied:
debug1: Offering public key: /home/<user>/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
Connection closed by <server_addr>
Once an RDP/local login is attempted, regardless of success/failure,
subsequent ssh attempts will progress to the password prompt which
eventually gets us in.
The Event Viewer shows the attached error message, relating to a NULL SID
and 0xC00000BB status.
ssh_as_first_login.txt
<http://cygwin.1069669.n5.nabble.com/file/t11987/ssh_as_first_login.txt>
It was a rather vanilla 'ssh-host-config' run to get it installed: strict
modes = no, no special ssh_/sshd_config settings at this point.
Running latest cygwin packages on Windows Server 2016 Standard:
CYGWIN_NT-10.0 <server_name> 3.1.4(0.340/5/3) 2020-02-19 08:49 x86_64 Cygwin
...
openssh 8.2p1-1 OK
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* Re: OpenSSH: SSHD daemon (as SYSTEM) is partially broken
2020-02-27 18:09 OpenSSH: SSHD daemon (as SYSTEM) is partially broken n0nc3
@ 2020-02-27 19:34 ` Bill Stewart
2020-02-27 23:10 ` TestUser1
0 siblings, 1 reply; 4+ messages in thread
From: Bill Stewart @ 2020-02-27 19:34 UTC (permalink / raw)
To: cygwin
On Thu, Feb 27, 2020 at 11:09 AM n0nc3 <pkoshar@compunetix.com> wrote:
It appears Cygwin SSHD's functionality is partially broke in the later
> versions, where SSHD runs as SYSTEM (no longer cyg_server).
>
> On reboot, any attempt to SSH into the server *before* any previous logon
> attempt (RDP/locally/etc) is quickly denied:
>
> debug1: Offering public key: /home/<user>/.ssh/id_rsa
> debug3: send_pubkey_test
> debug2: we sent a publickey packet, wait for reply
> Connection closed by <server_addr>
>
> Once an RDP/local login is attempted, regardless of success/failure,
> subsequent ssh attempts will progress to the password prompt which
> eventually gets us in.
>
This is a known issue on OS versions older than 8.1.
See thread starting with this message:
https://cygwin.com/ml/cygwin/2019-03/msg00087.html
My proposed workaround is this:
https://cygwin.com/ml/cygwin/2019-03/msg00113.html
Bill
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: OpenSSH: SSHD daemon (as SYSTEM) is partially broken
2020-02-27 19:34 ` Bill Stewart
@ 2020-02-27 23:10 ` TestUser1
2020-02-28 14:53 ` Bill Stewart
0 siblings, 1 reply; 4+ messages in thread
From: TestUser1 @ 2020-02-27 23:10 UTC (permalink / raw)
To: cygwin
So is this expected to work fine in my environment, Windows Server 2016 (OS
Version 10.0.14393), without the workaround?
Thanks!
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* Re: OpenSSH: SSHD daemon (as SYSTEM) is partially broken
2020-02-27 23:10 ` TestUser1
@ 2020-02-28 14:53 ` Bill Stewart
0 siblings, 0 replies; 4+ messages in thread
From: Bill Stewart @ 2020-02-28 14:53 UTC (permalink / raw)
To: cygwin
On Thu, Feb 27, 2020 at 4:10 PM TestUser1 wrote:
So is this expected to work fine in my environment, Windows Server 2016 (OS
> Version 10.0.14393), without the workaround?
>
I can't reproduce on Windows Server 8.1/Server 2012 R2 or later.
But you can certainly try the workaround.
Bill
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-02-28 14:53 UTC | newest]
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2020-02-27 18:09 OpenSSH: SSHD daemon (as SYSTEM) is partially broken n0nc3
2020-02-27 19:34 ` Bill Stewart
2020-02-27 23:10 ` TestUser1
2020-02-28 14:53 ` Bill Stewart
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