Authentication

When you have a multiplayer game, often you need to store information about your player for later games, keep game stats or communicate with your friends. For all these use cases, you often need a way to uniquely identify a user. Being able to tell users appart is called authentication. There are several methods available, some examples include:

  • Ask the user for username and password
  • Use a third party oath or openid identity provider, such as facebook, twitter, google
  • Use a third party service such as playfab, gamelift or steam
  • Use the device id, very popular method in mobile
  • Use Google Play in android
  • Use Game Center in ios
  • Use a web service in your website

Trying to write a comprehensive authentication framework that cover all these is very complex. There is no one size fit all, and we would quickly end up with bloated code.

Instead, Mirror does not perform authentication, but we provide hooks you can use to implement any of these.

Here is an example of how to implement simple username/password authentication:

1) Select your NetworkManager gameobject in the unity editor. 2) In the inspector, under Spawn Info, disable Auto Create Player 3) Call AddPlayer in your client to pass the credentials. 4) Override the OnServerAddPlayer method and validate the user’s credential.

For example this would be part of your NetworkManager class:

class MyGameNetworkManager : NetworkManager {

    class CredentialsMessage : MessageBase
    {
        // use whatever credentials make sense for your game
        // for example,  you might want to pass the accessToken if using oauth
        public string username;
        public string password;
    }

    // this gets called in your client after 
    // it has connected to the server,  
    public override void OnClientConnect(NetworkConnection conn)
    {
        base.OnClientConnect(conn);

        var msg = new CredentialsMessage()
        {
            // perhaps get the username and password
            // from textboxes instead
            username = "Joe",
            password = "Gaba Gaba"
        };

        ClientScene.AddPlayer(conn, MessagePacker.Pack(msg));
    }

    // this gets called in your server when the 
    // client requests to add a player.
    public override void OnServerAddPlayer(NetworkConnection conn, AddPlayerMessage extraMessage)
    {
        var msg = MessagePacker.Unpack<CredentialsMessage>(extraMessage.value);

        // check the credentials by calling your web server, database table, playfab api, or any method appropriate.
        if (msg.username == "Joe" && msg.password == "Gaba Gaba")
        {
            // proceed to regular add player
            base.OnServerAddPlayer(conn, extraMessage);
        }
        else
        {
            conn.Disconnect();
        }
    }
}

Warning

By default Mirror uses Telepathy, which is not encrypted. The above code sample works, but if you want to do authentication through Mirror, we highly recommend you use a transport that supports encryption.