Sun Cluster Data Service for NFS Guide for Solaris OS

ProcedureHow to Create Kerberos Principals

The following steps create the required Kerberos principals and keytab entries in the KDC database. For each cluster node, the keytab entries for which service principals are created depend on the version of Solaris that is running on the cluster node.

The principal for the “nfs” service over the logical hostname is created on one node only and then added manually to the default Kerberos keytab file on each cluster node. The Kerberos configuration file krb5.conf and the keytab file krb5.keytab must be stored as individual copies on each cluster node and must not be shared on a global file system.

  1. On each cluster node, log in to the KDC server as the administrator and create the host principal for each cluster node.

    Note that, with Solaris 8, you must create both host and root principals for each cluster node.

    Principals must be created using the fully qualified domain names.

    Add these entries to the default keytab file on each node. These steps can be greatly simplified with the use of cluster console utilities (see cconsole(1M)) .

    The following example creates the root and host entries. Perform this step on all cluster nodes, substituting the physical hostname of each cluster node for the hostname in the example.


    # kadmin -p  username/admin
    Enter Password:
    kadmin: addprinc -randkey host/phys-red-1.mydept.company.com
    Principal "host/phys-red-1.mydept.company.com@ACME.COM" created.

    kadmin: addprinc -randkey root/phys-red-1.mydept.company.com
    Principal "root/phys-red-1.mydept.company.com@ACME.COM" created.

    kadmin: ktadd host/phys-red-1.mydept.company.com
    Entry for principal host/phys-red-1.mydept.company.com with kvno 2, 
    encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5/krb5.keytab.

    kadmin: ktadd root/phys-red-1.mydept.company.com
    Entry for principal root/phys-red-1.mydept.company.com with kvno 2, 
    encryption type DES-CBC-CRC added to keytab WRFILE:/etc/krb5/krb5.keytab.

    kadmin: quit
    #
  2. On one cluster node, create the principal for the Sun Cluster HA for NFS service for the logical hostnames which provide Sun Cluster HA for NFS service.

    Principals must be created using the fully qualified domain names. Perform this step on only one cluster node.


    # kadmin -p  username/admin
    Enter Password:
    kadmin: addprinc -randkey nfs/relo-red-1.mydept.company.com
    Principal "nfs/relo-red-1.mydept.company.com@ACME.COM" created.

    kadmin: ktadd -k /var/tmp/keytab.hanfs nfs/relo-red-1.mydept.company.com
    Entry for principal nfs/relo-red-1.mydept.company.com with kvno 3, 
    encryption type DES-CBC-CRC added to keytab WRFILE:/var/tmp/keytab.hanfs.

    kadmin: quit
    #

    In the above example, relo-red-1 is the logical hostname used with Sun Cluster HA for NFS.

  3. Securely copy the keytab database /var/tmp/keytab.hanfs specified in Step 2 to the rest of the cluster nodes.

    Do not use insecure copying methods such as regular ftp or rcp, and so forth. For additional security, you can use the cluster private interconnect to copy the database.

    The following example copies the database.


    # scp /var/tmp/keytab.hanfs clusternode2-priv:/var/tmp/keytab.hanfs
    # scp /var/tmp/keytab.hanfs clusternode3-priv:/var/tmp/keytab.hanfs
    
  4. On all cluster nodes, add the keytab entry for the “nfs” service over logical hostname to the local keytab database.

    The following example uses the ktutil(1M) command to add the entry. Remove the temporary keytab file /var/tmp/keytab.hanfs on all cluster nodes after it has been added to the default keytab database /etc/krb5/krb5.keytab.


    # ktutil
    ktutil: rkt /etc/krb5/krb5.keytab
    ktutil: rkt /var/tmp/keytab.hanfs
    ktutil: wkt /etc/krb5/krb5.keytab
    ktutil: quit#
    # rm /var/tmp/keytab.hanfs
    
  5. Verify the Kerberos client configuration.

    List the default keytab entries on each cluster node and make sure that the key version number (KVNO) for the “nfs” service principal is the same on all cluster nodes.


    # klist -k
    Keytab name: FILE:/etc/krb5/krb5.keytab
    KVNO Principal
    ---- ---------------------------------
    2    host/phys-red-1.mydept.company.com@ACME.COM
    2    root/phys-red-1.mydept.company.com@ACME.COM
    3    nfs/relo-red-1.mydept.company.com@ACME.COM

    On all cluster nodes, the principal for the “nfs” service over the logical host must have the same KVNO number. In the above example, the principal for the “nfs” service over the logical host is nfs/relo-red-1.mydept.company.com@ACME.COM, and the KVNO is 3.

  6. (Solaris 9 only) The user credentials database gsscred must be up-to-date for all users who access secure NFS services from the cluster.

    Build the user credential database by running the following command on all cluster nodes.


    # gsscred -m kerberos_v5 -a
    

    See gsscred(1M) man pages for details.

    Note that the above approach builds the user credentials database only once. Some other mechanism must be employed, for example, cron(1M), to keep the local copy of this database up-to-date with changes in the user population.

    This step is not necessary for Solaris release 10.