C2DM Auth Error

I have a based application C2DMthat works fine, but lately I get Auth Error  although I get a RID (registration identifier) ​​and the message is sent. I recently read that the keys to log into the system expire (April 30), may bebecause of this I get this error. My question is, how can I recover Client Login Keys???? How to recover AUTH TOKEN????? Any help would be appreciated .... Thanks