# File lib/gapps_openid.rb, line 276
    def self.valid_chain?(chain)
      if chain.nil? or chain.empty?
        return false
      end
      cert = chain.shift
      if self.store.verify(cert)
        return true
      end
      if chain.empty? or not cert.verify(chain.first.public_key)
        return false
      end
      return self.valid_chain?(chain)
    end