openssh unix dev - Apr 2014 - environment logged by debug3 (-vvv)

When using debug3 one gets all kinds of lovely environment information -
debug3: Ignored env TMPDIR
debug3: Ignored env TERM_PROGRAM_VERSION
debug3: Ignored env Apple_PubSub_Socket_Render
debug3: Ignored env __CHECKFIX1436934
debug3: Ignored env TERM_PROGRAM
debug3: Ignored env TERM_SESSION_ID
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env TERM
debug3: Ignored env DISPLAY
debug3: Ignored env __CF_USER_TEXT_ENCODING
debug3: Ignored env SHELL
debug3: Ignored env HOME
debug3: Ignored env LOGNAME
debug3: Ignored env USER
debug3: Ignored env PATH
debug3: Ignored env SHLVL
debug3: Ignored env PWD
debug3: Ignored env OLDPWD
debug3: Ignored env _

However, it appears to be limited to telling the user which variables are being
ignored. It would be useful to see what variables are impacting the session as
well, such as KRB5CCNAME and any X11/DISPLAY related variables, spelled out, as
well.

Thanks!

On Sun, 27 Apr 2014, Eric Melville wrote:
> However, it appears to be limited to telling the user which variables
> are being ignored. It would be useful to see what variables are
> impacting the session as well, such as KRB5CCNAME and any X11/DISPLAY
> related variables, spelled out, as well.
If you run with 'ssh -vv' (i.e. less than three 'v' options)
then you
won't see the 'Ignored' lines and will just see the
'Sending' lines.
>     if (!matched) {
>         debug3("Ignored env %s", name);
>         free(name);
>         continue;
>     }
>
>     debug("Sending env %s = %s", name, val);
This only applies to environment variables that are explicitly passed.
Some are implicitly passed ($TERM) and others are implicitly set by
forwarding and authentication ($DISPLAY, $SSH_AUTH_SOCK, $KRB5CCNAME).

The ones that are implicitly set are done by the server, so there are
no easy ways for the client to see what the server is setting them to.
If you run a server in debug mode ('sshd -ddd') then you'll see
everything the server sets.

-d