When DCERPC clients use Kerberos authentication, they use a service
ticket to host/domain.controller because in Active Directory any
service on the host is an alias to the machine account object.
In FreeIPA each Kerberos service has own keys so host/.. and cifs/..
do not share the same keys. It means Samba suite needs to have access to
host/.. keytab entries to validate incoming DCERPC requests.
Unfortunately, MIT Kerberos has no means to operate on multiple keytabs
at the same time and Samba doesn't implement this either. We cannot use
GSS-Proxy as well because Samba daemons are running under root.
As a workaround, copy missing aes256 and aes128 keys from the host
keytab. SMB protocol doesn't use other encryption types and we don't
have rc4-hmac for the host either.
Fixes: https://pagure.io/freeipa/issue/3999
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>
d631e008cc