samba - Aug 2022 - Fixing dns_tkey_gssnegotiate: TKEY is unacceptable but stuck on check_spn_alias_collision

On 8/8/22 5:00 AM, L. van Belle via samba wrote:
> Can you run this script..
>
https://raw.githubusercontent.com/thctlo/samba4/master/samba-collect-debug-info.sh
> and post the content.
> Thanks,
>
> Greetz,
>
> Louis
>
>
Hi Louis,

I can't post the output of that script due to it showing a lot of 
internal information, but I can say :

--------------------------------------------------------------------
Hostname, dns, realm, etc is all fine.

There are only two interfaces lo0, eth0 and are configured correctly.

/etc/hosts has loopback and the IP address followed by short name and 
FQDN for this host

*/etc/resolve.conf is 127.0.0.1 and then the other DNS servers* *(*I 
think this is the problem*)*

Kerberos SRV _kerberos._tcp.ad.domain.net record(s) verified ok

'kinit Administrator' checked successfully.

Samba is running as an AD DC

/etc/krb5.conf is a COPY of /var/lib/samba/private/krb5.conf and looks fine

/etc/nsswitch.conf shows "files ldap" since I use nss-pam-ldap on this
host to resolve UID and GUI in AD

/etc/samba/smb.conf shows

[global]
 ?? ?netbios name = dc-2
 ?? ?realm = AD.DOMAIN.NET
 ?? ?server role = active directory domain controller
 ?? ?server services = s3fs, rpc, nbt, wrepl, ldap, cldap, kdc, drepl, 
winbindd, ntp_signd, kcc, dnsupdate
 ?? ?workgroup = AD
 ?? ?idmap_ldb:userfc2307? = yes
 ?? ?tls enabled? = yes
 ?? ?tls keyfile? = /etc/ssl/certs/dc-2.pem
 ?? ?tls certfile = /etc/ssl/certs/dc-2.pem
 ?? ?tls cafile?? = /etc/ssl/certs/dc-2.pem
 ?? ?ntlm auth = mschapv2-and-ntlmv2-only

[sysvol]
 ?? ?path = /var/lib/samba/sysvol
 ?? ?read only = No

[netlogon]
 ?? ?path = /var/lib/samba/sysvol/ad.domain.net/scripts
 ?? ?read only = No

This DC is not being used as a fileserver

Detected bind DLZ enabled..

Time verified ok, within the allowed 300sec margin.
Time offset is currently : -1 seconds

Packages are missing because I don't have dpkg.? Distro is slackware, I 
compiled samba myself.
--------------------------------------------------------------------

Given the above, let me include my /etc/named.conf

--------------------------------------------------------------------
options {
 ?? ?directory "/var/named";
 ?? ?/*
 ?? ? * If there is a firewall between you and nameservers you want
 ?? ? * to talk to, you might need to uncomment the query-source
 ?? ? * directive below.? Previous versions of BIND always asked
 ?? ? * questions using port 53, but BIND 8.1 uses an unprivileged
 ?? ? * port by default.
 ?? ? */
 ?? ?// query-source address * port 53;

 ?? ?tkey-gssapi-keytab "/var/lib/samba/bind-dns/dns.keytab";
 ?? ?minimal-responses yes;

//????? forwarders {
//????????????? x.x.x.x;
//????? };

};

//
// a caching only nameserver config
//
zone "." IN {
 ?? ?type hint;
 ?? ?file "caching-example/named.root";
};

zone "localhost" IN {
 ?? ?type master;
 ?? ?file "caching-example/localhost.zone";
 ?? ?allow-update { none; };
};

zone "0.0.127.in-addr.arpa" IN {
 ?? ?type master;
 ?? ?file "caching-example/named.local";
 ?? ?allow-update { none; };
};

include "/var/lib/samba/bind-dns/named.conf";
--------------------------------------------------------------------


Looking at the DNS servers in /etc/resolve.conf it occurred to me that 
using the loopback address wouldn't work, so I removed that, and it 
updated the dns against another domain controller without issue.

So, my question.? Is there any reason the local bind server with the DLZ 
plugin can't take kerberos authenticated updates?? Any thoughts on how 
to debug this?

Also,? samba_dnsupdate? --use-samba-tool works just fine, so, can I 
configure samba to use that internally when calling samba-dnsupdate with?

dns update command = /usr/sbin/samba_dnsupdate --use-samba-tool

Any disadvantages of doing it that way?

Thanks for the help!
Matt

On Mon, 2022-08-08 at 08:40 -0700, Matthew Schumacher via samba
wrote:
> On 8/8/22 5:00 AM, L. van Belle via samba wrote:
> > Can you run this script..
> >
https://raw.githubusercontent.com/thctlo/samba4/master/samba-collect-debug-info.sh
> > and post the content.
> > Thanks,
> > 
> > Greetz,
> > 
> > Louis
> > 
> > 
> Hi Louis,
> 
> I can't post the output of that script due to it showing a lot of 
> internal information, but I can say :
Did you miss this:

Please check this and if required, sanitise it.
> 
> --------------------------------------------------------------------
> Hostname, dns, realm, etc is all fine.
> 
> There are only two interfaces lo0, eth0 and are configured correctly.
> 
> /etc/hosts has loopback and the IP address followed by short name
> and 
> FQDN for this host
> 
> */etc/resolve.conf is 127.0.0.1 and then the other DNS servers* *(*I 
> think this is the problem*)*
You should be using the DC's ipaddress as the nameserver.
> 
> Kerberos SRV _kerberos._tcp.ad.domain.net record(s) verified ok
> 
> 'kinit Administrator' checked successfully.
> 
> Samba is running as an AD DC
> 
> /etc/krb5.conf is a COPY of /var/lib/samba/private/krb5.conf and
> looks fine
> 
> /etc/nsswitch.conf shows "files ldap" since I use nss-pam-ldap on
> this 
> host to resolve UID and GUI in AD
> 
> /etc/samba/smb.conf shows
> 
> [global]
>      netbios name = dc-2
>      realm = AD.DOMAIN.NET
>      server role = active directory domain controller
>      server services = s3fs, rpc, nbt, wrepl, ldap, cldap, kdc,
> drepl, 
> winbindd, ntp_signd, kcc, dnsupdate
>      workgroup = AD
>      idmap_ldb:userfc2307  = yes
>      tls enabled  = yes
>      tls keyfile  = /etc/ssl/certs/dc-2.pem
>      tls certfile = /etc/ssl/certs/dc-2.pem
>      tls cafile   = /etc/ssl/certs/dc-2.pem
>      ntlm auth = mschapv2-and-ntlmv2-only
> 
> [sysvol]
>      path = /var/lib/samba/sysvol
>      read only = No
> 
> [netlogon]
>      path = /var/lib/samba/sysvol/ad.domain.net/scripts
>      read only = No
> 
> This DC is not being used as a fileserver
> 
> Detected bind DLZ enabled..
> 
> Time verified ok, within the allowed 300sec margin.
> Time offset is currently : -1 seconds
> 
> Packages are missing because I don't have dpkg.  Distro is slackware,
> I 
> compiled samba myself.
You could use winbind instead of ldap, but you would probably need to
create the required links.
> --------------------------------------------------------------------
> 
> Given the above, let me include my /etc/named.conf
> 
> --------------------------------------------------------------------
> options {
>      directory "/var/named";
>      /*
>       * If there is a firewall between you and nameservers you want
>       * to talk to, you might need to uncomment the query-source
>       * directive below.  Previous versions of BIND always asked
>       * questions using port 53, but BIND 8.1 uses an unprivileged
>       * port by default.
>       */
>      // query-source address * port 53;
> 
>      tkey-gssapi-keytab "/var/lib/samba/bind-dns/dns.keytab";
>      minimal-responses yes;
> 
> //      forwarders {
> //              x.x.x.x;
> //      };
You need to set the 'forwarders'
> 
> };
> 
> //
> // a caching only nameserver config
> //
> zone "." IN {
>      type hint;
>      file "caching-example/named.root";
> };
> 
> zone "localhost" IN {
>      type master;
>      file "caching-example/localhost.zone";
>      allow-update { none; };
> };
> 
> zone "0.0.127.in-addr.arpa" IN {
>      type master;
>      file "caching-example/named.local";
>      allow-update { none; };
> };
> 
> include "/var/lib/samba/bind-dns/named.conf";
> --------------------------------------------------------------------
> 
> 
> Looking at the DNS servers in /etc/resolve.conf it occurred to me
> that 
> using the loopback address wouldn't work, so I removed that, and it 
> updated the dns against another domain controller without issue.
> 
> So, my question.  Is there any reason the local bind server with the
> DLZ 
> plugin can't take kerberos authenticated updates?  Any thoughts on
> how 
> to debug this?
Are you sure it isn't working now that you have fixed /etc/resolv.conf
?
> 
> Also,  samba_dnsupdate  --use-samba-tool works just fine, so, can I 
> configure samba to use that internally when calling samba-dnsupdate
> with?
> 
> dns update command = /usr/sbin/samba_dnsupdate --use-samba-tool
> 
> Any disadvantages of doing it that way?
None what so ever.

Rowland