Keychain certificate

My certificate (.p12 file) when imported to the keychain gives an error (This certificate has exp开发者_如何学运维ired) what should i do ?

This article should help you out.

If your certificate has expired, renew it at the iPhone Portal, download it, and double-click it to add it to your Keychain. If it's "signed by an unknown authority", download the "Apple Worldwide Developer Relations" certificate from the Certificates section of the iPhone Portal and double-click it to add it to your Keychain.