Setup

To use SSO with Spark (as of subversion r8551), a few things need to be configured.

At the login screen, click on 'Advanced' and go to the SSO tab.

Click on 'Use Single Sign-On via GSSAP'. If Spark reports what username it will use, this may be all you need to do.

If Spark was not able to determine a username to use, click on Ok and exit Spark. You will need to edit the spark.properties file.

There are 4 "hidden" properties you can add/edit in this file:

ssoMethod=string
ssoRealm=string
ssoKDC=string
ssoAdv=boolean

ssoMethod

Set ssoMethod to one of file, dns or manual. If not specified, the default is OS dependent. (On Windows its dns, on others its file)

Set to file to use a krb5.conf or krb5.ini (OS dependent) to determine the realm and KDC information. file is recommended for Unix installations or when a complex realm setup is needed, and DNS is not configured.

Set to dns to use DNS SRV records to determine the KDC information and TXT records to determine the realm. DNS is recommended for ease of administration, but requires additional setup from the default Windows AD DNS records.

Set to manual to use the ssoRealm and ssoKDC fields.

ssoRealm

Set this to the name of the realm to use when ssoMethod is manual.

ssoKDC

Set this to the KDC to use when ssoMethod is manual.

ssoAdv

Set this to true to allow setting the above options on the SSO tab of the advanced settings in the GUI. The default is false.

krb5.conf / krb5.ini

If you wish to use a krb5.conf or krb5.ini file, you can use the following example:

 [libdefaults]
     default_realm = EXAMPLE.COM

[realms]
    EXAMPLE.COM {
        kdc = kdc.example.com
        kdc = backupkdc.example.com
        admin_server = kdc.example.com
        default_domain = example.com
    }

[domain_realms]
    example.com = EXAMPLE.COM
    .example.com = EXAMPLE.COM

This file should be placed in either /etc/krb5.conf or C:\Windows\krb5.ini or in your OS specific location. For more details on this file syntax, see http://www.cmf.nrl.navy.mil/CCS/people/kenh/kerberos-faq.html#confdoc

DNS Records

To use DNS records, the following must be set up in your DNS zone:

SRV record

_kerberos._udp.example.com Should be a valid SRV record and point to the KDC for your realm.

TXT record

_kerberos.example.com Should be a valid TXT record and contain the name of your Kerberos realm.

Example:

_kerberos._udp.example.com     7200 IN SRV 0 0 88 kdc.example.com.
_kerberos._udp.example.com     7200 IN SRV 1 0 88 backupkdc.example.com.
_kerberos.example.com

Registry

You need to modify the registry to allow exporting the TGT for SSO to work. Modifying your registry is dangerous- make sure you have proper backups before making any changes to your registry.

Depending on the OS, the setting is in a different location:

For Windows 2003 and Windows 2000 SP4:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\Kerberos\Parameters

Value Name: allowtgtsessionkey

Value Type: REG_DWORD

Value: 0x01 ( default is 0 )

Here is the location of the registry setting on Windows XP SP2:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\Kerberos\

Value Name: allowtgtsessionkey

Value Type: REG_DWORD

Value: 0x01