Chapter 12. Managing Kerberos principal aliases for users, hosts, and services

When you create a new user, host, or service, a Kerberos principal in the following format is automatically added:

  • user_name@REALM
  • host/host_name@REALM
  • service_name/host_name@REALM

Administrators can enable users, hosts, or services to authenticate against Kerberos applications using an alias. This is beneficial in the following scenarios:

  • The user name changed and the user wants to log in using both the previous and new user name.
  • The user needs to log in using the email address even if the IdM Kerberos realm differs from the email domain.

Note that if you rename a user, the object keeps the aliases and the previous canonical principal name.

12.1. Adding a Kerberos principal alias

You can associate alias names with existing Kerberos principals in an Identity Management (IdM) environment. This enhances security and simplifies authentication processes within the IdM domain.

Procedure

  • To add the alias name useralias to the account user, enter: 

    # ipa user-add-principal <user> <useralias>
--------------------------------
Added new aliases to user "user"
--------------------------------
         User login: user
    Principal alias: user@IDM.EXAMPLE.COM, useralias@IDM.EXAMPLE.COM

    To add an alias to a host or service, use the ipa host-add-principal or ipa service-add-principal command respectively instead.

    If you use an alias name to authenticate, use the -C option with the kinit command: 

    # kinit -C <useralias>
Password for <user>@IDM.EXAMPLE.COM:

12.2. Removing a Kerberos principal alias

You can remove alias names associated with Kerberos principals in their Identity Management (IdM) environment.

Procedure

  • To remove the alias useralias from the account user, enter: 

    # ipa user-remove-principal <user> <useralias>
--------------------------------
Removed aliases from user "user"
--------------------------------
  User login: user
  Principal alias: user@IDM.EXAMPLE.COM

    To remove an alias from a host or service, use the ipa host-remove-principal or ipa service-remove-principal command respectively instead.

    Note that you cannot remove the canonical principal name: 

    # ipa user-show <user>
  User login: user
  ...
  Principal name: user@IDM.EXAMPLE.COM
  ...

# ipa user-remove-principal user user
ipa: ERROR: invalid 'krbprincipalname': at least one value equal to the canonical principal name must be present

12.3. Adding a Kerberos enterprise principal alias

You can associate enterprise principal alias names with existing Kerberos enterprise principals in an Identity Management (IdM) environment. Enterprise principal aliases can use any domain suffix except for user principal name (UPN) suffixes, NetBIOS names, or domain names of trusted Active Directory forest domains.

Note

When adding or removing enterprise principal aliases, escape the @ symbol using two backslashes (\\). Otherwise, the shell interprets the @ symbol as part of the Kerberos realm name and leads to the following error: 

ipa: ERROR: The realm for the principal does not match the realm for this IPA server

Procedure

  • To add the enterprise principal alias user@example.com to the user account: 

    # ipa user-add-principal <user> <user\\@example.com>
--------------------------------
Added new aliases to user "user"
--------------------------------
         User login: user
    Principal alias: user@IDM.EXAMPLE.COM, user\@example.com@IDM.EXAMPLE.COM

    To add an enterprise alias to a host or service, use the ipa host-add-principal or ipa service-add-principal command respectively instead.

    If you use an enterprise principal name to authenticate, use the -E option with the kinit command: 

    # kinit -E <user@example.com>
Password for user\@example.com@IDM.EXAMPLE.COM:

12.4. Removing a Kerberos enterprise principal alias

You can remove enterprise principal alias names associated with Kerberos enterprise principals in their Identity Management (IdM) environment.

Note

When adding or removing enterprise principal aliases, escape the @ symbol using two backslashes (\\). Otherwise, the shell interprets the @ symbol as part of the Kerberos realm name and leads to the following error: 

ipa: ERROR: The realm for the principal does not match the realm for this IPA server

Procedure

  • To remove the enterprise principal alias user@example.com from the account user, enter: 

    # ipa user-remove-principal <user> <user\\@example.com>
--------------------------------
Removed aliases from user "user"
--------------------------------
  User login: user
  Principal alias: user@IDM.EXAMPLE.COM

    To remove an alias from a host or service, use the ipa host-remove-principal or ipa service-remove-principal command respectively instead.