Our Prophet (saas) stated that those allied with Hazrat Mahdi(pbuh) are his friends

ADNAN OKTAR: Our Prophet (saas) says, "I have good news for the ones who communicate with the Qaim Mahdi from my Ahl al-Bayt, who ally with his allies… " that is to say, those who ally with his friends, "… and who become enemies to his enemies…" that is to say who oppose his enemies, "… before his appearance, while my son, the Mahdi is in hiding." He says, "These people are my fellows, my beloved ones and they are the noblest ones of my nation -the Islamic nation- on the Last Day." So I am also giving you this good news. Look, he says that he (our Prophet (saas)) has good news for those in communication with Qaim (pbuh) who are allies to his allies and hostile to his enemies. First, he says that these people are his friends. In other words, what our Prophet (saas) says in summary is that he is pleased with them and that they are pleased with him as well. 

http://en.a9.com.tr/watch/216880/Adnan-Oktarin-Sohbetle