[Samba] Winbind messes up Kerberos tickets when renewing them

[Rowland Penny]

On Tue, 2021-12-21 at 21:18 +0100, Edwin Mackenzie-Owen via samba
wrote:
> Hi,
> 
> Winbind often messes up my Kerberos ticket when renewing it.
> This is the valid ticket:
> 
> $ klist
> Ticket cache: FILE:/tmp/krb5cc_1234567
> Default principal: exampleuser (at) SAMDOM.EXAMPLE.COM
> 
> Valid starting     Expires            Service principal
> 12/20/21 21:40:12  12/21/21 07:40:12 
> krbtgt/SAMDOM.EXAMPLE.COM (at) SAMDOM.EXAMPLE.COM
>         renew until 12/21/21 21:40:07
> 
> Winbind then creates a ticket with a weird principal that I can't use
> for SSO (sorry, I have only saved it in German):
> 
> $ klist
> Ticketzwischenspeicher: FILE:/tmp/krb5cc_1234567
> Standard-Principal: exampleuser\ (at) SAMDOM (at) SAMDOM.EXAMPLE.COM
> 
> Valid starting       Expires              Service principal
> 17.12.2021 20:05:24  18.12.2021 06:05:24  
> krbtgt/SAMDOM.EXAMPLE.COM (at) SAMDOM.EXAMPLE.COM
>         für Client exampleuser (at) SAMDOM.EXAMPLE.COM, erneuern bis
> 24.12.2021 15:05:24
> 
> My krb5.conf (auth_to_local is for SSH SSO):
> 
> [libdefaults]
>         default_realm = SAMDOM.EXAMPLE.COM
>         dns_lookup_realm = false
>         dns_lookup_kdc = true
>         default_ccache_name = FILE:/tmp/krb5cc_%{uid}
>         forwardable = true
> [realms]
>         SAMDOM.EXAMPLE.COM = {
>                 auth_to_local = RULE:[1:SAMDOM\$1]
>                 auth_to_local = DEFAULT
>         }
> [domain_realm]
>         .samdom.example.com = SAMDOM.EXAMPLE.COM

I do not have all that in krb5.conf (I just have the first 4 lines) and
it works for myself on Debian Buster using Samba 4.15.3
Perhaps it is a problem with the Samba from Arch ??

Rowland