Single Sign-On Yii And Magento

Yii 1.1 General Discussion
1

How do we maintain Single Sign-On between Yii and Magento application.

we have two application

  1. test.com - yii application

  2. store.test.com magento application

both are deployed on same server, they also have same users and passwords, how do we maintain single -sign-on between these two sub-domains of yii and Magento