# File lib/omniauth/strategies/windows_live/windowslivelogin.rb, line 1067 def derive(secret, prefix) begin fatal("Nil/empty secret.") if (secret.nil? or secret.empty?) key = prefix + secret key = OpenSSL::Digest::SHA256.digest(key) return key[0..15] rescue Exception => e debug("Error: derive: #{e}") return end end