[39619] in Kerberos
Re: krb5ccmachine
daemon@ATHENA.MIT.EDU (=?utf-8?q?Marek_Gre=C5=A1ko_via_Ke)
Mon Apr 27 14:13:14 2026
Date: Mon, 27 Apr 2026 18:12:40 +0000
To: Simo Sorce <simo@redhat.com>
Cc: kerberos@mit.edu
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Great analysis. I found out there are some ways of configuring gssd in /etc/nfs.conf. Mys current config for it states:
use-gss-proxy=1
There are available options
# cred-cache-directory=
# use-memcache=0
Would not one of these options solve my problem?
I think the memory cache woudl be better. Are there any culprits I am not aware of not to do it like this?
If the second option with cred directory is used, what is the recommended diretory in Fedora to use? Should I use /var/lib/nfs?
Thanks
Marek
Odoslané pomocou bezpečného emailu Proton Mail.
pondelok 27. apríla 2026, 19:33, Simo Sorce via Kerberos <kerberos@mit.edu> napísal/a:
> 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
> > > > >
> > > > > ________________________________________________
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> > > > >
> > >
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> > >
> >
> > ________________________________________________
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>
> --
> Simo Sorce
> Distinguished Engineer
> RHEL Crypto Team
> Red Hat, Inc
>
>
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