Token Service Overview

The Token Service is a public-facing API used for Proof of Identity in SteelShield. It authenticates game clients and issues SteelShield Tokens that are used to authorize game traffic.

How SteelShield Tokens work

Before a game client can connect to a SteelShield-protected server with Proof of Identity enabled, it must first fetch a SteelShield Token by authenticating via the game's authentication backend (e.g. a username/password account system). The backend issues a signed JSON Web Token (JWT) to the game client to clearly identify it. The public key used for the JWT's signature is shared between the game author and GameFabric.

The game client submits the JWT to the Token Service for signature verification. If the verification passes, the response includes a valid SteelShield Token.

The returned SteelShield Token is then prepended to all network packets sent by the game client to the game server. SteelShield intercepts this traffic and validates the issued SteelShield Token.

Should the SteelShield Token be missing, or not match one issued respectively, then the network packet is dropped by the SteelShield service and is never received by the game server.

With this, large DDoS attacks from botnets or via reflection attacks are stopped before reaching the game server as they do not get through the authentication process to receive a valid SteelShield Token which allows their traffic to pass through.

While an attacker can perform the authentication process and then use their SteelShield Token in an attack, the SteelShield Token would be able to be traced back to that individual's account, and the user banned.

Validity/Rollover

A SteelShield Token is only considered valid for a single connection with a game server and expires after some amount of time. It needs to be rolled over at an interval in order to ensure that a stolen token can not be used in future DDoS attacks. Our recommendation is every 15 minutes which is also implemented in the Unreal Engine Plugin.

Where to go from here

• Managing Token Services: how to create and edit Token Services in the GameFabric UI.
• Authentication Types: details about the different authentication methods.
• Token Service API Reference: details on how to fetch SteelShield Tokens via the Token Service.
• GameFabric API Reference: the full GameFabric API specification, including the Token Service provisioning endpoints.