sshd not working properly

Brian Inglis Brian.Inglis@SystematicSW.ab.ca
Fri Jan 17 13:41:58 GMT 2025


On 2025-01-17 05:51, Corinna Vinschen via Cygwin wrote:
> On Jan 17 11:59, Mario Emmenlauer via Cygwin wrote:
>>
>> On 04.09.24 12:11, Andy Wood via Cygwin wrote:
>>> Running "passwd -R" for 'other_user', as suggested by the subject of
>>> the post, fixed the problems for me.
>>>
>>> It looks like sshd isn't handling a login failure properly.
>>>
>>> On Tue, Sep 3, 2024 at 7:57 PM Jim McNamara via Cygwin
>>> <cygwin@cygwin.com> wrote:
>>>>
>>>>>> This looks like a bug. Can anyone help? Is there a work-around?
>>>>    Hi Andy,
>>>>
>>>> There was some chatter the last week or 2 on someone trying to get ssh to work. At the archive mailing list, you can read and see if that answers any of it.
>>>>
>>>> I thought the gist of it is that a cipher is being swapped out or something.
>>>>
>>>> Please read archives at the mailing list while you are waiting for a reply for the past week or 2 msgs.
>>>>
>>>> Also, the other person said they found out information in the release notes for cygwin that were kind of recent.
>>
>>
>> I am under the impression that there may be a misbehavior in more recent
>> Cygwin OpenSSH :-(
>>
>> I observe the same problem as Andy Wood was having, and found another
>> very recent identical report at https://serverfault.com/q/1168457/473559.
>> Their cases, as well as mine, seem to share, that OpenSSH can no longer
>> correctly authenticate as a user without having the plain text password
>> stored in the registry.
>>
>> In my case, this is exclusively limited to domain users. Local users
>> work correctly. I can see that at least one other report, the one at
>> Serverfault, is also for a domain user. Also, everything that is
>> reported at Serverfault applies basically identically to my case, i.e.
>> the connection being just dropped, and the only relevant message from
>> OpenSSH being "fatal: seteuid 4096: Function not implemented".
> 
> I just tested this on my local W11 24H2 Enterprise installation with
> Cygwin 3.5.5 and OpenSSH 9.9p1 installed as service under the SYSTEM
> account, and it works fine for me in a Windows domain with one 2019 and
> one 2022 Domain Server.
> 
> I tested with a user account in the administrators group as well as with
> a non-admin user account, and to both accounts I can login with pubkey
> authentication as expected.
> 
> The error message "seteuid 4096: Function not implemented" is weird.
> The internal implementation only uses documented functions.
> 
> Which Windows version are you running the service on exactly?
> 
> Do you have any other entries in the server-side Windows Log, which may
> be connected, especially inside the Security log.  Kerberos or so.
> 
> Other than that, it might be prudent to run sshd in a SYSTEM shell
> under strace.

Any chance the user is also running Windows sshd and tyhat has grabbed the port?

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry


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