[[!tag kerberos howto]]

#### Why enable Kerberos on your system?

Convenience and security. With
[Kerberos](http://web.mit.edu/Kerberos/dialogue.html), a single
login grants access to all NetBSD web services. Configuration is easy
and you only have to do it once (sometimes less).

#### [[!toggle id="macosx" text="Mac OS X"]]
[[!toggleable id="macosx" text="""
OS X autodiscovers and uses the NETBSD.ORG KDC as defined in DNS.
To use Kerberized TNF services, log in with your Kerberos [[password]]:

`$ kinit <username>@NETBSD.ORG`

The right-hand side is a Kerberos realm, not a DNS domain. Case is significant!

##### A Keychain.app trick

To pop up a GUI password dialog:

`$ kinit <username>@NETBSD.ORG </dev/null`

Check "Remember this password in my keychain" to make future Kerberos
logins (sans input redirection) prompt-free.
"""]]

#### [[!toggle id="netbsd" text="NetBSD"]]
[[!toggleable id="netbsd" text="""
NetBSD needs to be configured to prevent Kerberos from being used
to log into _your_ system, and then to enable Kerberos.

7. Either disable Kerberos auth for `sshd`, `login`, etc. in
`/etc/pam.d`, or tell your relevant services not to use PAM.

   /!\ Disabling KerberosAuthentication in `/etc/ssh/sshd_config` does **NOT** prevent `sshd` from invoking `pam_krb5.so` and prompting for a Kerberos password -- oops. Since you probably do not have a host key in the realm NETBSD.ORG you have little to fear from ssh's KerberosAuthentication method -- nothing can get tickets to use your machine, because there is no host instance for your machine shared between the NetBSD kerberos server and your local keytab. So, the bottom line: turn off UsePAM for `sshd` or adjust your PAM configuration; don't worry about KerberosAuthentication or GSSAPIAuthentication in `sshd` itself.

7. Create `/etc/krb5.conf` containing only the line `[libdefaults]`.

NetBSD will now autodiscover and uses the NETBSD.ORG KDC as defined
in DNS. To use Kerberized TNF services, log in with your Kerberos
[[password]]:

`$ kinit <username>@NETBSD.ORG`

The right-hand side is a Kerberos realm, not a DNS domain. Case is significant!
"""]]

#### [[!toggle id="windows" text="Windows XP"]]
[[!toggleable id="windows" text="""

Windows does not provide an easy way to configure and use KDCs different from the one embedded into an Active Directory.

Therefore, to use [[Kerberos]], you should follow the following steps:

7. Download the [MIT Kerberos for Windows](http://web.mit.edu/Kerberos/dist/#kfw-3.2) installer. It is composed of different tools traditionally found with Kerberos distributions, like [[!template id=man name=kinit section=1]] or [[!template id=man name=klist section=1]], and a Network Identity Manager, an application used to manage credential caching of Kerberos tickets.

7. Install the package. Use the default provided options, then restart the computer.

7. The Network Identity Manager [(PDF)](http://web.mit.edu/kerberos/kfw-3.2/kfw-3.2.2/netidmgr_userdoc.pdf) should automatically start when you login. As there is no principal currently configured, it should open a dialog box to obtain the new credentials.

7. Enter your principal:

        Username: <username>
        Realm: NETBSD.ORG

7. Click `Ok`. After a few seconds, it should obtain the TGT for you from NetBSD.ORG KDC.

"""]]