Seeking assistance with pubkey authentication problem on Windows OS

[Manoj K. Ampalam]

Please file an issue at https://github.com/PowerShell/Win32-OpenSSH. The
Windows fork is not part of the main OpenSSH project yet.

Otherwise, you may work around your issue by getting rid of this
configuration line:
AuthorizedKeysFile %h\.ssh\authorized_keys

It would default to %userprofile%\.ssh\authorized_keys.


On Wed, Dec 14, 2016 at 7:34 AM, Peter_Lawrence at belgocontrol.be <
Peter_Lawrence at belgocontrol.be> wrote:

> Hello.
>
> I did a bit more digging in the debug information and I have isolated the
> problem, which looks like it comes directly from the source code.
> The ssh-agent.log shows the following entries during my ssh connection
> attempt from the Linux machine to the Windows machine running a Win64
> OpenSSH:
>
> 5772 16:13:37 990 debug1: trying public key file
> C:\Users\LAW/.ssh\authorized_keys
> 5772 16:13:37 990 debug1: given public key is not mapped to user LAW
> (profile:C:\Users\LAW)
>
> My sshd_config file has been set with the following entry:
> AuthorizedKeysFile .ssh\authorized_keys
>
> I have noticed that if I was to either use the line
> AuthorizedKeysFile %h\.ssh\authorized_keys
> or
> AuthorizedKeysFile C:\Users\LAW\.ssh\authorized_keys
> the ssh-agent.log shows a debug entry now saying
> trying public key file C:\Users\LAW/C:\Users\LAW\.ssh\authorized_keys
>
> Having had a dig around in the source-code for OpenSSH, the culprit is the
> subroutine
> expand_authorized_keys
> in the file auth.c
> which returns a char pointer called ret given by snprintf(ret,
> sizeof(ret), "%s/%s", pw->pw_dir, file)
> You can see here that the formatting "%s/%s" is causing the insertion of a
> forward-slash in the public key filename used in the windows environment;
> to this extent, the authorized_keys file will never be found in the windows
> environment.
>
> Would it suffice if I rebuild the Win64 OpenSSH executables with the
> correction snprintf(ret, sizeof(ret), "%s\\%s", pw->pw_dir, file), or
> should I wait for an official build with this correction?
>
>
> Yours sincerely,
> Peter.
>
> ___________________________________________________________
>
> Dr. Peter E. Lawrence  BSc(Ma & Comp Sc)(Hons) MSc(Ma Sc)(Res) PhD(Ma Sc)
> Analyst & Software Engineer
> BELGOCONTROL (CANAC)
> Tervuursesteenweg 303
> B - 1820 Steenokkerzeel
> Tel: [Office]:  +32 2 206 2588
>        [GSM]:   +32 4 701 80752
> Email: law at belgocontrol.be
> Web:  www.belgocontrol.be
>
>
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