Debugging why KRB5_KTNAME isn't working

Brian J. Murrell brian at
Thu Jan 27 14:25:32 EST 2022

On Thu, 2022-01-27 at 13:45 -0500, Ken Hornstein wrote:
> > 
> import_environment (default: see postconf -d output)

> Is that what you're using?

Yes.  That is the "for-purpose" mechanism that I alluded to earlier
which is why I posited that if smtpd was clearing the environment it
was doing so in violation of the specific mechanism that was supposed
to make this all work.

> It looks to me that if the variable isn't
> listed in the import_environment configuration entry, it doesn't make
> it very far and is removed by the function clean_env().

In my case, I am using the "name=value" variant so that KRB5_KTNAME is
supposed to be getting an explict value even, rather than relying on
the environment already having the variable set.

> (If you want to demonstrate to others how KRB5_KTNAME is supposed to
> work, just include the output of "env KRB5_KTNAME=/dev/stdout kinit"
> or
> some other Kerberos program).

Indeed.  I used as my example:

# KRB5_KTNAME=/etc/postfix/smtp.keytab klist -k
Keytab name: FILE:/etc/postfix/smtp.keytab
KVNO Principal
---- --------------------------------------------------------------------------
   1 smtp/ at EXAMPLE.COM


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