[39618] in Kerberos
Re: krb5ccmachine
daemon@ATHENA.MIT.EDU (Simo Sorce via Kerberos)
Mon Apr 27 13:32:24 2026
Message-ID: <e19616d1a6bfc5e932cb71d4a33d961d3c91a73b.camel@redhat.com>
To: kerberos@mit.edu
Date: Mon, 27 Apr 2026 13:30:57 -0400
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From: Simo Sorce via Kerberos <kerberos@mit.edu>
Reply-To: Simo Sorce <simo@redhat.com>
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Gssproxy never stores caches in /tmp, that file is more likely created
by rpc.gssd the NFS Client daemon that handles GSSAPI authentication.
rpc.gssd is sadly stuck in time and forces the use of the FILE: ccache
through most of its code, which is why we intercept it with gssproxy
for some operations with user ccaches only.
HTH,
Simo.
On Mon, 2026-04-27 at 17:02 +0000, Marek Greško via Kerberos wrote:
> Hello,
>
> so for klist it seems it is generated by gssproxy, because there is nfs/ ticket.
>
> Regarding gssproxy.conf I have the file /etc/gssproxy/99-network-fs-clients.conf containing:
>
> [service/network-fs-clients]
> mechs = krb5
> cred_store = keytab:/etc/krb5.keytab
> cred_store = ccache:FILE:/var/lib/gssproxy/clients/krb5cc_%U
> cred_store = client_keytab:/var/lib/gssproxy/clients/%U.keytab
> cred_usage = initiate
> allow_any_uid = yes
> trusted = yes
> euid = 0
> min_lifetime = 60
>
> But apparently it is not using the path. I also did not find how to specify path for machine ccache. Even better, if I could convince machine ccache to be also stored in KCM. Is it possible?
>
> Thanks
>
> Marek
>
>
>
>
> Odoslané pomocou bezpečného emailu Proton Mail.
>
> pondelok 27. apríla 2026, 16:19, Christian, Mark <mark.christian@intel.com> napísal/a:
>
> > On Mon, 2026-04-27 at 04:38 +0000, Marek Greško wrote:
> > > Hello,
> > >
> > > the
> > > kinit -c /tmp/krb5ccmachine_EXAMPLE.COM
> > > asks for password. Which password? What should I expect thereafter to
> > > happen?
> >
> > Sorry I meant for you to use klist, not kinit:
> >
> > % klist -c /tmp/krb5ccmachine_EXAMPLE.COM
> >
> > >
> > > I also asked AI to help me on the original issue. It thinks it is
> > > related to gssproxy and most probably it is right. It stated there is
> > > not nuch to do and I should accept the current state. But I feel a
> > > little bit unhappy, since it creates file with predictable name in
> > > the /tmp and it could be a security risk.
> >
> > see man gssproxy.conf for details on howto configure the location of
> > cred_store / ccache.
> >
> > Mark
> >
> >
> > >
> > > Thanks
> > >
> > > Marek
> > >
> > >
> > >
> > > Odoslané pomocou bezpečného emailu Proton Mail.
> > >
> > > piatok 24. apríla 2026, 16:02, Christian, Mark
> > > <mark.christian@intel.com> napísal/a:
> > >
> > > > On Fri, 2026-04-24 at 10:44 +0000, Marek Greško via Kerberos wrote:
> > > > > Hello,
> > > > >
> > > > > I have configured kerberos client on Fedora 43. I configured
> > > > > kerberos
> > > > > to use KCM: ccache. Users ccaches are in KCM, but I always see
> > > > > the
> > > > > file /tmp/krb5ccmachine_EXAMPLE.COM created. Why is this file
> > > > > created?
> > > >
> > > > Perhaps related to your kerberos NFS configuration? Inspect the
> > > > cache,
> > > > kinit -c /tmp/krb5ccmachine_EXAMPLE.COM, doing so might clue you
> > > > in.
> > > >
> > > > Mark
> > > >
> > > > > What mechanism does not use KCM and how could it be convinced to
> > > > > do
> > > > > so?
> > > > >
> > > > > Thanks
> > > > >
> > > > > Marek
> > > > > ________________________________________________
> > > > > Kerberos mailing list Kerberos@mit.edu
> > > > > https://mailman.mit.edu/mailman/listinfo/kerberos
> > > >
> > > > ________________________________________________
> > > > Kerberos mailing list Kerberos@mit.edu
> > > > https://mailman.mit.edu/mailman/listinfo/kerberos
> > > >
> >
> > ________________________________________________
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> >
>
> ________________________________________________
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--
Simo Sorce
Distinguished Engineer
RHEL Crypto Team
Red Hat, Inc
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