openssh unix dev - Jan 2015 - Variable substitution in UserKnownHostsFile configuration option

Dear OpenSSH developers,

Do you find it a good idea if variable substitution is implemented in
UserKnownHostsFile the same way it is done for IdentityFile? In
ssh_config I would like to write something like

UserKnownHostsFile ~/keys/%r/known_hosts

Thanks!

-- 
With best regards,
Dmitry

On Sat 2015-01-10 09:10:38 -0500, Dmitry Katsubo wrote:
> Do you find it a good idea if variable substitution is implemented in
> UserKnownHostsFile the same way it is done for IdentityFile? In
> ssh_config I would like to write something like
>
> UserKnownHostsFile ~/keys/%r/known_hosts
%r is the remote username, right?  so this would be useful if you wanted
a different known_hosts file for example.net depending on whether you
were logging in as foo at example.net or bar at example.net.  is that right?
if so, it seems like a pretty strange use case.  can you come up with a
better rationale for the variable substitution?

In the abstract, it seems like a reasonable suggestion, but the specific
example you're offering isn't particularly compelling.

        --dkg

On 16/01/2015 01:46, Daniel Kahn Gillmor wrote:
> %r is the remote username, right?  so this would be useful if you wanted
> a different known_hosts file for example.net depending on whether you
> were logging in as foo at example.net or bar at example.net.  is that
right?
> if so, it seems like a pretty strange use case.  can you come up with a
> better rationale for the variable substitution?
> 
> In the abstract, it seems like a reasonable suggestion, but the specific
> example you're offering isn't particularly compelling.
I agree, this feature usecase sounds a bit weird. In my case I am using
OpenSSH compiled with Cygwin for Win32 and I need to specify in
etc/ssh_config something like this:

UserKnownHostsFile /cygdrive/c/Users/%u/.ssh/known_hosts

Currently I can only specify the location of IdentityFile.

-- 
With best regards,
Dmitry