idea about modifying pam_krb5 use of krb5_verify_init_creds

[Russ Allbery]

Will Fiveash <will.fiveash at oracle.com> writes:

> People may have addressed this already but for Solaris when one has
> provisioned a krb5.keytab with a host princ and is using pam-krb5 in the
> pam.conf auth stack, if the hostname changes the pam-krb5 will fail to
> verify a user's initial krb cred unless there is a host service princ in
> the krb5.keytab that matches the new hostname.  What I'm thinking would
> be a better way for pam-krb5 to verify a user's initial krb cred is to
> use a service princ found in the existing keytab and call
> krb5_verify_init_creds() using that instead of using
> krb5_sname_to_princ().  In fact, pam-krb5 could get a list of all unique
> service princ names for the default realm in the keytab and call
> krb5_verify_init_creds() in a loop until either one succeeds or they all
> fail.  Thoughts?

My preference, rather than putting code into pam-krb5 to read the keytab,
would be for there to be some way to tell krb5_verify_init_creds to
internally switch to this behavior.

This seems similar to, although distinct from, the discussion a while back
(with patches by Luke Howard) to use principal canonicalization.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>