Hello the List,
We have a workaround, but it is not entirely satisfactory, we change
/etc/pam.d/password-auth-ac
password requisite pam_pwquality.so try_first_pass local_users_only
retry=3 authtok_type=
password sufficient pam_unix.so sha512 shadow try_first_pass
use_authtok
#password sufficient pam_sss.so use_authtok
password sufficient pam_krb5.so chpw_prompt=true use_authok # fix for
password reset
This allows a user to reset a password if expired, but gives them shell
rather than disconnecting. New ssh connections now require 2FA.
We're now quite certain it's a bug in sssd & pam_sss
Regards,
Aaron
From: Aaron Hicks [mailto:aaron.hicks@nesi.org.nz]
Sent: Friday, 24 November 2017 4:57 PM
To: 'FreeIPA users list' <freeipa-users(a)lists.fedorahosted.org
Cc: 'Sumit Bose' <sbose(a)redhat.com
Subject: RE: [Freeipa-users] Re: Expired passwords and
generating an OTP
token
Hello the list,
It's here:
https://pagure.io/SSSD/sssd/blob/master/f/src/providers/ipa/ipa_auth.c#_395
SSSD is not doing its job properly when a user has an expired password and
an OTP token, and they should reset their password at the ssh prompt.
When a user has an expired password it should ignore the OTP token during
password reset process, and then disconnect.
The condition where an expired or compromised temporary password is obtained
by an unauthorised entity means that as long as the unauthorised entity does
not have the OTP token secret, the worst they can do is reset your password.
This condition is escaped when someone, either the user, a helpdesk agent,
or an admin, resets the password to something the unauthorised entity
doesn't know.
The case of the unauthorised entity having both the password and OTP token
is already recognised as a compromised state, so the code doesn't need to
protect us from that.
Regards,
Aaron
From: Aaron Hicks [mailto:aaron.hicks@nesi.org.nz]
Sent: Thursday, 23 November 2017 5:44 PM
To: 'FreeIPA users list' <freeipa-users(a)lists.fedorahosted.org
<mailto:freeipa-users@lists.fedorahosted.org>
Cc:
'Sumit Bose' <sbose(a)redhat.com <mailto:sbose@redhat.com>
Subject: Re: [Freeipa-users] Re: Expired passwords and
generating an OTP
token
Progress,
We made Pam use kinit username when a user had an expired password, and this
allowed users to reset passwords at the ssh prompt.
However passwd remains broken on all the hosts, regardless of their auth
indicator.
Aaron
Get Outlook for iOS <
https://aka.ms/o0ukef
_____
From: Aaron Hicks <aaron.hicks(a)nesi.org.nz <mailto:aaron.hicks@nesi.org.nz
Sent: Thursday, November 23, 2017
4:25:12 PM
To: 'FreeIPA users list'
Cc: 'Sumit Bose'
Subject: RE: [Freeipa-users] Re: Expired passwords and generating an OTP
token
Hello the list,
The next bit of information is that the passwd command itself is broken when
a user has a OTP token set.
$ passwd
Changing password for user otpuser1.
Current Password:
passwd: Authentication token manipulation error
$ passwd
Changing password for user otpuser1.
Current Password:
passwd: Authentication token manipulation error
$ passwd
Changing password for user otpuser1.
Current Password:
passwd: Authentication token manipulation error
$ passwd
Changing password for user otpuser1.
Current Password:
passwd: Authentication token manipulation error
These were with the user's valid-not-expired password, and with
passwordOTPCODE
The Current Password: prompt fails.
Regards,
Aaron
From: Aaron Hicks [mailto:aaron.hicks@nesi.org.nz]
Sent: Thursday, 23 November 2017 3:44 PM
To: 'FreeIPA users list' <freeipa-users(a)lists.fedorahosted.org
<mailto:freeipa-users@lists.fedorahosted.org>
Cc:
'Sumit Bose' <sbose(a)redhat.com <mailto:sbose@redhat.com>
Subject: RE: [Freeipa-users] Re: Expired passwords and
generating an OTP
token
Hello the list,
We've kept at this today and this is what we think we are seeing:
* Preauth is detecting that a user has an expired password and a
token, so discards the token and just asks for password
* Password check succeeds and hands to the password change process
(maybe using /etc/pam.d/passwd and /etc/pam.d/system-auth)
* BUT the Current Password: check fails because it doesn't preauth to
check if the password is expired
* AND because the password is expired passwordOTPCODE is not valid
either
Similarly, accounts with expired passwords can't authenticate against the
API because their password is expired. Which would at least allow our
customer management system to disable or delete their OTP token so they can
reset their passwords.
In addition to this, users are not able to reset passwords at the ssh login
on hosts where 2FA is not enabled either! So this seems to be narrowing down
on the bits of pam and sssd uset to authenticate the password change
process.
An interesting note is, kinit does not require OTPCODE.
Finally, no users do not have access to the FreeIPA web interface or a host
without 2FA. The 2FA secured host is to be their lander node into our
network.
Regards,
Aaron
From: Aaron Hicks [mailto:aaron.hicks@nesi.org.nz]
Sent: Thursday, 23 November 2017 10:33 AM
To: 'FreeIPA users list' <freeipa-users(a)lists.fedorahosted.org
<mailto:freeipa-users@lists.fedorahosted.org>
Cc:
'Sumit Bose' <sbose(a)redhat.com <mailto:sbose@redhat.com>
Subject: RE: [Freeipa-users] Re: Expired passwords and
generating an OTP
token
Hello the List,
A couple of new things to this problem, when a user has an expired password
and a valid OTP token, the password reset process is broken on all machines
at the ssh prompt. Even the ones that do not require 2FA.
Feedback so far form Sumit indicates this is incorrect behaviour.
As an attempt to get around this, I've tried adding a permission to the
helpdesk role that would allow them to manage OTP tokens. I'll submit
another thread on that.
Regards,
Aaron
From: Aaron Hicks [mailto:aaron.hicks@nesi.org.nz]
Sent: Thursday, 23 November 2017 6:31 AM
To: Sumit Bose <sbose(a)redhat.com <mailto:sbose@redhat.com>
Cc: 'FreeIPA users list'
<freeipa-users(a)lists.fedorahosted.org
<mailto:freeipa-users@lists.fedorahosted.org> >; 'Sumit Bose'
<sbose(a)redhat.com <mailto:sbose@redhat.com>
Subject:
Re: [Freeipa-users] Re: Expired passwords and generating an OTP
token
Hi Sumit,
I sent those to you directly as I wasn't comfortable posting them to the
list.
Regards,
Aaron
Get Outlook for iOS <
https://aka.ms/o0ukef
_____
From: Sumit Bose <sbose(a)redhat.com <mailto:sbose@redhat.com>
Sent: Wednesday, November 22, 2017 10:19:34 PM
To: Aaron Hicks
Cc: 'FreeIPA users list'; 'Sumit Bose'
Subject: Re: [Freeipa-users] Re: Expired passwords and generating an OTP
token
On Wed, Nov 22, 2017 at 09:21:52PM +1300, Aaron Hicks wrote:
Hi Sumit,
Here is /etc/pam.d/password-auth I missed that it was an include, an that
you
wanted it too, again it's as installed bt CentOS 7.4 and
ipa-client-install
ok, the PAM configuration looks good. Can you send me the PAM related
messages form /var/log/secure or the journal which cover the failed
attempt? And additionally the SSSD logs with debug_level=9 from the same
time. Most important would be sssd_pam.log, sssd_domain.name.log and
krb5_child-log.
bye,
Sumit