Centrify

Tips for finding Knowledge Articles

  • - Enter just a few key words related to your question or problem
  • - Add Key words to refine your search as necessary
  • - Do not use punctuation
  • - Search is not case sensitive
  • - Avoid non-descriptive filler words like "how", "the", "what", etc.
  • - If you do not find what you are looking for the first time,reduce the number of key words you enter and try searching again.
  • - Minimum supported Internet Explorer version is IE9
Home  >
article

KB-3023: User who is not Zone-enabled can SSH/SSO into a machine

Authentication Service ,  

12 April,16 at 11:08 AM

All versions of Centrify DirectControl running stock Open-SSH/Centrify OpenSSH.
 
Problem:
 
A user has a local Unix account name that matches their AD account name. This user is not zone-enabled but can ssh and SSO into a machine with their AD account. 
Even if the local account is locked in /etc/passwd, login works. 
 
What steps should be taken to prevent it?
 
Cause:
 
With SSO and GSSAPI authentication enabled, stock sshd is using the Kerberos ticket and principal to send over from ssh/putty and validate the user because the credentials are good. Centrify's sshd and Kerberos library have the same behavior as the open source implementations.  Using Centrify's sshd will not help.
 
Resolution:
 
Option #1 
 
On the server, add/change the line in /etc/centrifydc/centrifydc.conf
adclient.krb5.autoedit: false
 
This will stop adclient from deleting and changing /etc/krb5.conf when join or leave.
 
Then, edit /etc/krb5.conf, in the section [realm], add a subsection auth_to_local_names, something like this:
 
[realms]
DOMAIN.COM = {
 kdc = domain.domain.com:88
 master_kdc = domain.domain.com:88
 kpasswd = domain.domain.com:464
 kpasswd_server = domain.domain.com:464
 kdc = domain.domain.com:88
 master_kdc = domain.domain.com:88
 kpasswd = domain.domain.com:464
 kpasswd_server = domain.domain.com:464
 auto_to_local_names = {
   local_user = NOUSER
 }
}
 
where local_user is the local_user that you want to stop SSO from the same AD user.
 
Centrify will fix our Kerberos library to honor .k5login first, but that is planned for the next maintenance release as any fix to low level MIT Kerberos library has its own implications.
 
Option #2
 
1. Download the following two files:
 
- krb5_conf.pl
- add_auth.sh
 
Place these files in the same directory.
 
2. backup /etc/krb5.conf
 
3. ./add_auth.sh > /tmp/krb5.conf
 
4. cp /tmp/krb5.conf /etc/krb5.conf
 
Update /etc/centrifydc/centrifydc.conf, add or edit the line to
adclient.krb5.autoedit: false
 

Still have questions? Click here to log a technical support case, or collaborate with your peers in Centrify's Online Community.

Related Articles

 articleKB-6041: How to show current license type in use by adclient articleKB-7417: How to troubleshoot when a user show up in Show Effective Users but adquery for the user shows the status as zoneEnabled:false? articleKB-6040: How to change the license type in use after adclient successful joined to the AD? articleKB-6073: How to join the Linux/Unix Centrify Server to Active Directory with specific Computer Role? articleKB-6056: How to report the group policy settings that are in effect for the local computer? articleKB-6038: How to specify the license type to use when joining the server to AD using adjoin? articleKB-3029: Running adquery shows the user's shell as '/sbin/nologin' and user can't login articleKB-3038: How to add an AD user into a Centrify Zone. articleKB-20210: Common Questions Regarding Centrify DirectControl and CoreOS