System Administration Guide: Naming and Directory Services (NIS+)

Limiting Access to the Passwd Column to NIS+ Owners and Administrators

This task describes how to limit read access to the password-related columns of the passwd table to the entry owner and the table administrators, without affecting the read access of other authenticated principals (including applications) to the remaining columns of the passwd table.

This task establishes the following rights:

                         Nobody  Owner   Group  World
Table Level Rights:      ----    rmcd    rmcd   ----
Passwd Column Rights:    ----    rm--    rmcd   ----
Shadow Column Rights:    ----    rm--    rmcd   ----

ProcedureHow to Limit Read Access to the Passwd Column

Use NIS+ commands to modify passwd.org_dir to restrict access to the passwd column for owners and administrators.

Before You Begin

The NIS+ principal performing this task must have modify rights to the passwd table.

  1. Log in to the domain's master server.

    The examples in this task use the root master server, rootmaster.

  2. Check the current table and column permissions.

    Use the niscat -o command.

    rootmaster# niscat -o passwd.org_dir

    This task assumes the existing permissions are:

    Access Rights    : ----rmcdrmcdr---
    Columns          :       
                         [0]  Name              : name
                               Access Rights : r-----------r---
                         [1]  Name              : passwd
                               Access Rights : -----m----------
                         [2]  Name              : uid
                               Access Rights : r-----------r---
                         [3]  Name              : gid
                               Access Rights : r-----------r---
                         [4]  Name              : gcos
                               Access Rights : r----m------r---
                         [5]  Name              : home
                               Access Rights : r-----------r---
                         [6]  Name              : shell
                               Access Rights : r-----------r---
                         [7]  Name              : shadow
                               Access Rights : r-----------r---

    If your permissions are different, you may need to use a different syntax. For instructions, see Chapter 15, Administering NIS+ Access Rights.

  3. Change the table permissions.

    Use the nischmod command to change the table's object-level permissions to ---- rmcdrmcd ----

    rootmaster# nischmod og=rmcd,nw= passwd.org_dir
  4. Change the column permissions.

    Use the nistbladm command with the -u option to change the permissions of the passwd and shadow columns to:

    passwd ---- rm-- ---- ----
    shadow ---- r--- ---- ----
    rootmaster# nistbladm -u passwd=o+r, shadow=o+r passwd.org_dir
  5. Verify the new permissions.

    Use the niscat -o command, as you did in Step 2. The permissions should look the same as they do in that step's output.