Bug 2103327

Summary:	Generate AES SHA-2 HMAC keys on deployed IPA instances in FIPS mode
Product:	Red Hat Enterprise Linux 9	Reporter:	Abhijit Roy <abroy>
Component:	krb5	Assignee:	Julien Rische <jrische>
Status:	CLOSED MIGRATED	QA Contact:	Michal Polovka <mpolovka>
Severity:	high	Docs Contact:	Filip Hanzelka <fhanzelk>
Priority:	unspecified
Version:	9.0	CC:	abokovoy, afarley, apeddire, asosedki, cilmar, dchen, ekeck, fhanzelk, frenaud, jrische, kemyers, kurathod, mralph, pkulkarn, rcritten, tmihinto, tscherf, vmishra, vvanhaft
Target Milestone:	rc	Keywords:	MigratedToJIRA, Triaged
Target Release:	---	Flags:	jrische: needinfo- pm-rhel: mirror+
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Known Issue
Doc Text:	.Adding a RHEL 9 replica in FIPS mode to an IdM deployment in FIPS mode that was initialized with RHEL 8.6 or earlier fails The default RHEL 9 FIPS cryptographic policy aiming to comply with FIPS 140-3 does not allow the use of the AES HMAC-SHA1 encryption types' key derivation function as defined by RFC3961, section 5.1. This constraint is a blocker when adding a RHEL 9 Identity Management (IdM) replica in FIPS mode to a RHEL 8 IdM environment in FIPS mode in which the first server was installed on a RHEL 8.6 system or earlier. This is because there are no common encryption types between RHEL 9 and the previous RHEL versions, which commonly use the AES HMAC-SHA1 encryption types but do not use the AES HMAC-SHA2 encryption types. You can view the encryption type of your IdM master key by entering the following command on the server: [subs="quotes"] ---- # kadmin.local getprinc K/M \| grep -E '^Key:' ---- For more information, see the link:https://access.redhat.com/solutions/7003853[AD Domain Users unable to login in to the FIPS-compliant environment] KCS solution.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-09-18 19:54:01 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Abhijit Roy 2022-07-02 08:50:29 UTC

Description of problem:

The RHEL 9 client configured for FIPS fails to join an IPA realm if the IPA server was created in FIPS.

The RHEL 9 client NOT configured for FIPS will successfully join an IPA realm if the IPA server was created in FIPS.

The RHEL 9 client configured for FIPS will successfully an IPA realm of the IPA server was not created it FIPS.

Version-Release number of selected component (if applicable):

ipa-client-4.9.8-7.el9_0.x86_64

How reproducible:

To replicate the problem, follow the following instructions.  I have replicated this issue many times. We have hundreds of nodes set with FIPS enabled.  Only the RHEL 9.0 systems will not join the IPA realm.

1.  Create a RHEL 9.0 system
2.  Enable FIPS:  fips-mode-setup --enable
3.  Reboot
4.  login
5.  ipa-client-setup -N (enter username, password, etc.)
6.  The node fails to join the IPA realm
7.  Disable FIPS: fips-mode-setup --disable
6. Reboot
7.  Login
8.  ipa-client-setup -N (enter username, password, etc.)
9.  Node joins the IPA realm with no error.

Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:

Comment 3 Florence Blanc-Renaud 2022-07-03 15:13:26 UTC

Hi @abroy 

I was not able to reproduce the issue. I configured a RHEL 9 server in FIPS mode, then ran ipa-server-install, then configured a client machine in FIPS mode, and ran ipa-client-install. Both machines were installed with RHEL 9 and ipa 4.9.8-7.el9_0. The client installation succeeds with admin or a user member of the admins group.

Can you provide the server sos report as well as the client sos report, or link to a customer case?

Comment 6 Florence Blanc-Renaud 2022-07-07 09:07:06 UTC

In the linked case, the customer has a RHEL 8.6 server, and that is a completely different setup. This should have been mentioned in the BZ description.

With this specific config, the issue can be reproduced:
1. install a 8.6 server in FIPS mode
2. install a 9.0 client in FIPS mode
The installation fails when the client tries to obtain a kerberos TGT with the principal provided to  ipa-client-install --principal XXX:

In krb5kdc.log on the master:
Jul 07 04:58:20 master.testrelm.test krb5kdc[6251](info): AS_REQ (2 etypes {aes256-cts-hmac-sha384-192(20), aes128-cts-hmac-sha256-128(19)}) 10.0.192.183: BAD_ENCRYPTION_TYPE: admin for krbtgt/TESTRELM.TEST, KDC has no support for encryption type

On the master:
[root@master ~]# cat /etc/krb5.conf.d/crypto-policies 
[libdefaults]
permitted_enctypes = aes256-cts-hmac-sha1-96 aes256-cts-hmac-sha384-192 aes128-cts-hmac-sha1-96 aes128-cts-hmac-sha256-128

On the client:
# cat /etc/krb5.conf.d/crypto-policies 
[libdefaults]
permitted_enctypes = aes256-cts-hmac-sha384-192 aes128-cts-hmac-sha256-128


Moving the issue to krb5 component for further analysis.

Comment 7 Julien Rische 2022-07-08 16:19:34 UTC

A FIPS-enabled RHEL9 client will fail to authenticate against any RHEL8 IPA server (FIPS or non-FIPS) because none of the encryption types supported by IPA on RHEL8 are allowed on RHEL9 in FIPS mode, which aims to comply with FIPS 140-3, a newer and more strict version of the standard (more information in bug 2039684).

Fixing this issue is not trivial, because it requires to update user passwords and to add new keys to all services and import these new keys to service keytabs.

We are planning to provide batch script to automate this process as much as possible.

Comment 19 Ding-Yi Chen 2023-01-23 07:59:27 UTC

The encrypt type aes256-cts-hmac-sha1-96 was used.

It is the default for RHEL 8 because:

1. HMAC-SHA1 is approved in CMVP
2. AES SHA-1 HMAC encryption types remain essential for interoperability with Active Directory because they are the "best" ones MIT Kerberos has in common with AD [2].


However, FIPS mode in RHEL 9 does not contain HMAC-SHA1-96

~~~
mac = AEAD HMAC-SHA2-256 HMAC-SHA2-384 HMAC-SHA2-512

group = SECP256R1 SECP384R1 SECP521R1 \
    FFDHE-2048 FFDHE-3072 FFDHE-4096 FFDHE-6144 FFDHE-8192
~~~

Also Bug 2006843 - Disable SHA-1 in FIPS policy

That's why it failed.

The workaround will be using FIPS:AD-SUPPORT because 

~~~
...
# This subpolicy is provided for enabling aes256-cts-hmac-sha1-96,
# the strongest Kerberos encryption type interoperable with Active Directory.

cipher@kerberos = AES-256-CBC+
mac@kerberos = HMAC-SHA1+
~~~




1. https://csrc.nist.gov/publications/detail/sp/800-140c/rev-1/final
2. https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-kile/b3fa11e2-a878-4734-a9e2-2d77a5a06108

Comment 55 RHEL Program Management 2023-09-18 19:51:50 UTC

Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug.

Comment 56 RHEL Program Management 2023-09-18 19:54:01 UTC

This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there.

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