FreeIPA Active Directory trust configuration issues

[iulian roman]

Hello,

I try to configure trust between a FreeIPA domain and Active Directory. They are both in different domains (ipa domain: ipadev.test.local , ad domain: iam.intern ) and use external DNS. I have configured/verified all prerequisites, but when I run ipa trust-add command, I get the following error:

ipa: ERROR: AD domain controller complains about communication sequence. It may mean unsynchronized time on both sides, for example

I have enabled debug for samba but I cannot make much sense from  the debug information in error.log :

s4_tevent: Added timed event "composite_trigger": 0x7f9324240e30
s4_tevent: Ending timer event 0x7f932424ed50 "composite_trigger"
s4_tevent: Running timer event 0x7f9324240e30 "composite_trigger"
s4_tevent: Ending timer event 0x7f9324240e30 "composite_trigger"
s4_tevent: Added timed event "connect_multi_timer": 0x7f9324240cc0
s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f9324403310
s4_tevent: Run immediate event "tevent_req_trigger": 0x7f9324403310
s4_tevent: Destroying timer event 0x7f9324240cc0 "connect_multi_timer"
Socket options:
        SO_KEEPALIVE = 0
        SO_REUSEADDR = 0
        SO_BROADCAST = 0
        TCP_NODELAY = 1
        TCP_KEEPCNT = 9
        TCP_KEEPIDLE = 300
        TCP_KEEPINTVL = 75
        IPTOS_LOWDELAY = 0
        IPTOS_THROUGHPUT = 0
        SO_REUSEPORT = 0
        SO_SNDBUF = 2626560
        SO_RCVBUF = 1061808
        SO_SNDLOWAT = 1
        SO_RCVLOWAT = 1
        SO_SNDTIMEO = 0
        SO_RCVTIMEO = 0
        TCP_QUICKACK = 1
        TCP_DEFER_ACCEPT = 0
s4_tevent: Added timed event "tevent_req_timedout": 0x7f932424ed50
s4_tevent: Schedule immediate event "tevent_queue_immediate_trigger": 0x7f9324240cc0
s4_tevent: Run immediate event "tevent_queue_immediate_trigger": 0x7f9324240cc0
s4_tevent: Destroying timer event 0x7f932424ed50 "tevent_req_timedout"
s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f932425c370
s4_tevent: Run immediate event "tevent_req_trigger": 0x7f932425c370
s4_tevent: Added timed event "tevent_req_timedout": 0x7f9324016970
Starting GENSEC mechanism spnego
SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT
s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f9324403310
s4_tevent: Run immediate event "tevent_req_trigger": 0x7f9324403310
s4_tevent: Destroying timer event 0x7f9324016970 "tevent_req_timedout"
s4_tevent: Destroying timer event 0x7f932401f730 "dcerpc_connect_timeout_handler"
[Tue Mar 09 09:51:12.685725 2021] [wsgi:error] [pid 29053:tid 140270172727040] [remote 10.30.214.119:36488] ipa: INFO: [jsonserver_session] cifs/[e-mail]: trust_add/1(u'IAM.INTERN', trust_type=u'ad', realm_admin=u'admin', realm_passwd=u'********', realm_server=u'10.30.201.46', version=u'2.232'): RemoteRetrieveError

Any idea what should I look into ?

[Alexander Bokovoy]

On ti, 09 maalis 2021, iulian roman via FreeIPA-users wrote:
> Hello,
>
> I try to configure trust between a FreeIPA domain and Active Directory.
> They are both in different domains (ipa domain: ipadev.test.local , ad
> domain: iam.intern ) and use external DNS. I have configured/verified
> all prerequisites, but when I run ipa trust-add command, I get the
> following error:
>
> ipa: ERROR: AD domain controller complains about communication sequence. It may mean unsynchronized time on both sides, for example
>
> I have enabled debug for samba but I cannot make much sense from  the debug information in error.log :
>
> s4_tevent: Added timed event "composite_trigger": 0x7f9324240e30
> s4_tevent: Ending timer event 0x7f932424ed50 "composite_trigger"
> s4_tevent: Running timer event 0x7f9324240e30 "composite_trigger"
> s4_tevent: Ending timer event 0x7f9324240e30 "composite_trigger"
> s4_tevent: Added timed event "connect_multi_timer": 0x7f9324240cc0
> s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f9324403310
> s4_tevent: Run immediate event "tevent_req_trigger": 0x7f9324403310
> s4_tevent: Destroying timer event 0x7f9324240cc0 "connect_multi_timer"
> Socket options:
>        SO_KEEPALIVE = 0
>        SO_REUSEADDR = 0
>        SO_BROADCAST = 0
>        TCP_NODELAY = 1
>        TCP_KEEPCNT = 9
>        TCP_KEEPIDLE = 300
>        TCP_KEEPINTVL = 75
>        IPTOS_LOWDELAY = 0
>        IPTOS_THROUGHPUT = 0
>        SO_REUSEPORT = 0
>        SO_SNDBUF = 2626560
>        SO_RCVBUF = 1061808
>        SO_SNDLOWAT = 1
>        SO_RCVLOWAT = 1
>        SO_SNDTIMEO = 0
>        SO_RCVTIMEO = 0
>        TCP_QUICKACK = 1
>        TCP_DEFER_ACCEPT = 0
> s4_tevent: Added timed event "tevent_req_timedout": 0x7f932424ed50
> s4_tevent: Schedule immediate event "tevent_queue_immediate_trigger": 0x7f9324240cc0
> s4_tevent: Run immediate event "tevent_queue_immediate_trigger": 0x7f9324240cc0
> s4_tevent: Destroying timer event 0x7f932424ed50 "tevent_req_timedout"
> s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f932425c370
> s4_tevent: Run immediate event "tevent_req_trigger": 0x7f932425c370
> s4_tevent: Added timed event "tevent_req_timedout": 0x7f9324016970
> Starting GENSEC mechanism spnego
> SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT
> s4_tevent: Schedule immediate event "tevent_req_trigger": 0x7f9324403310
> s4_tevent: Run immediate event "tevent_req_trigger": 0x7f9324403310
> s4_tevent: Destroying timer event 0x7f9324016970 "tevent_req_timedout"
> s4_tevent: Destroying timer event 0x7f932401f730 "dcerpc_connect_timeout_handler"
> [Tue Mar 09 09:51:12.685725 2021] [wsgi:error] [pid 29053:tid 140270172727040] [remote 10.30.214.119:36488] ipa: INFO: [jsonserver_session] cifs/[e-mail]: trust_add/1(u'IAM.INTERN', trust_type=u'ad', realm_admin=u'admin', realm_passwd=u'********', realm_server=u'10.30.201.46', version=u'2.232'): RemoteRetrieveError
>
> Any idea what should I look into ?

Couple notes.

0. It is unclear what is the OS, its version, Samba and IPA versions.
IPA API is said to be 2.232, so this is most likely FreeIPA 4.8
pre-releases, like 4.7.91 -- is this Ubuntu? If it is Ubuntu, then trust
to AD feature is not supported on Ubuntu. On the other hand, the version
in the IPA API call is the version sent by the client.

In your previous communication on this list you stated that your
deployment is

FreeIPA version: 4.7.4 on Ubuntu 18.04

This is *not supported* for trust to AD feature, at all.

If this is CentOS or RHEL 8 server, knowning exact distro version is
important because in RHEL 8.3 we've got rid of RC4 cipher in the default
configuration for Kerberos authentication. This is documented in the
RHEL 8.3 release notes.

1. The log above shows that you ran 'ipa trust-add' as cifs/...
principal, not as IPA 'admin'. Please fix and re-try.

kinit admin
  ipa trust-ad ...

2. The response sequence above states that when using AD administrator
'[e-mail]' credentials, we cannot really agree on the supported
  mechanism with a chosen AD DC.

Starting GENSEC mechanism spnego
    SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT

this might mean multiple things. For example, AD side doesn't have AES
ciphers enabled for this particular user and on IPA side system-wide
crypto policy prevents using RC4 cipher, as I said above. But it also
might mean you are running IPA server on Ubuntu and it could be a
combination of unsupported MIT/Heimdal mix in runtime.

[iulian roman]

Thank you for clarifications  Alexander.

OS version: Ubuntu 18.04.2 LTS
samba version : Version 4.7.6-Ubuntu
FreeIPA version: 4.7.4

If  I understand correctly does not make any sense to continue troubleshooting as long as AD trust is not supported with this OS version. I'll try to see what are the  OS alternatives I can use and which do properly support FreeIPA.

Interesting is that while running  the ipa trust-add command, there is no communication with the AD domain controller in tcpdump, so probably it is stopped even before contacting the DC due to incompatibility.

[François Cami]

On Tue, Mar 9, 2021 at 10:52 AM iulian roman via FreeIPA-users
 wrote:
> Thank you for clarifications  Alexander.
>
> OS version: Ubuntu 18.04.2 LTS
> samba version : Version 4.7.6-Ubuntu
> FreeIPA version: 4.7.4
>
> If  I understand correctly does not make any sense to continue troubleshooting as long as AD trust is not supported with this OS version. I'll try to see what are the  OS alternatives I can use and which do properly support FreeIPA.

Just to avoid your wasting some time on that search: Alexander listed
them in his previous email.

François
> Interesting is that while running  the ipa trust-add command, there is no communication with the AD domain controller in tcpdump, so probably it is stopped even before contacting the DC due to incompatibility.
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[Alexander Bokovoy]

On ti, 09 maalis 2021, iulian roman via FreeIPA-users wrote:
> Thank you for clarifications  Alexander.
>
> OS version: Ubuntu 18.04.2 LTS
> samba version : Version 4.7.6-Ubuntu
> FreeIPA version: 4.7.4
>
> If I understand correctly does not make any sense to continue
> troubleshooting as long as AD trust is not supported with this OS
> version. I'll try to see what are the  OS alternatives I can use and
> which do properly support FreeIPA.

Han Boetes (Han on #freeipa) did build Samba against MIT Keberos some
time ago to experiment with a similar stuff but he runs IPA DC on Fedora
and only needs Samba domain members on Ubuntu:
https://launchpad.net/~hboetes/+archive/ubuntu/samba-mit-kerberos

I do not really recommend running IPA DCs on Ubuntu/Debian at the moment
if you need trust to Active Directory. This mode is not tested by anyone
in FreeIPA upstream development team and bugs reported would not be
fixed.

Since this year, if you need RHEL, you can run RHEL in production as a
part of the RHEL Developer program as well. It has some limitations
(only 16 instances of RHEL machines can be done by a single RHEL
Developer account and it is all self-support unless you buy additional
support on top of it) but it is a viable option.

On the other hand, Fedora gives you another option, including up to date
FreeIPA versions.
> Interesting is that while running  the ipa trust-add command, there is
> no communication with the AD domain controller in tcpdump, so probably
> it is stopped even before contacting the DC due to incompatibility.

Correct.

[iulian roman]

> On ti, 09 maalis 2021, iulian roman via FreeIPA-users wrote:
>
> Han Boetes (Han on #freeipa) did build Samba against MIT Keberos some
> time ago to experiment with a similar stuff but he runs IPA DC on Fedora
> and only needs Samba domain members on Ubuntu:
> https://launchpad.net/~hboetes/+archive/ubuntu/samba-mit-kerberos
>
> I do not really recommend running IPA DCs on Ubuntu/Debian at the moment
> if you need trust to Active Directory. This mode is not tested by anyone
> in FreeIPA upstream development team and bugs reported would not be
> fixed.
>
> Since this year, if you need RHEL, you can run RHEL in production as a
> part of the RHEL Developer program as well. It has some limitations
> (only 16 instances of RHEL machines can be done by a single RHEL
> Developer account and it is all self-support unless you buy additional
> support on top of it) but it is a viable option.

Thanks again for the information. Do you recommend a specific RHEL7 minor version which is fully supported and integrated  with Idm/IPA ?
> On the other hand, Fedora gives you another option, including up to date
> FreeIPA versions.
>
> Correct.

[Alexander Bokovoy]

On ke, 10 maalis 2021, iulian roman via FreeIPA-users wrote:
> > On ti, 09 maalis 2021, iulian roman via FreeIPA-users wrote:
> >
> > Han Boetes (Han on #freeipa) did build Samba against MIT Keberos some
> > time ago to experiment with a similar stuff but he runs IPA DC on Fedora
> > and only needs Samba domain members on Ubuntu:
> > https://launchpad.net/~hboetes/+archive/ubuntu/samba-mit-kerberos
> >
> > I do not really recommend running IPA DCs on Ubuntu/Debian at the moment
> > if you need trust to Active Directory. This mode is not tested by anyone
> > in FreeIPA upstream development team and bugs reported would not be
> > fixed.
> >
> > Since this year, if you need RHEL, you can run RHEL in production as a
> > part of the RHEL Developer program as well. It has some limitations
> > (only 16 instances of RHEL machines can be done by a single RHEL
> > Developer account and it is all self-support unless you buy additional
> > support on top of it) but it is a viable option.
>
> Thanks again for the information. Do you recommend a specific RHEL7
> minor version which is fully supported and integrated  with Idm/IPA ?

FreeIPA is packaged in RHEL as RHEL Identity Management. It is part of
RHEL itself and if you have RHEL subscription, you have support for RHEL
IdM. When RHEL subscription is valid, it applies to all supported RHEL
series but what can be asked for differs by which phase a specific RHEL
version is in.

The following page explains RHEL life cycle phases:
https://access.redhat.com/support/policy/updates/errata

If you are switching to IPA in RHEL, I'd suggest you to look at RHEL 8,
not RHEL 7. RHEL 7 is in maintenance support 2 phase that has a number
of limitations for updates.