Greenworks

Encrypted App Tickets allow you to obtain authenticated Steam IDs from clients without network requests to Steam's API servers. They can be decrypted locally using your game's secret key.

1. Generate an Encrypted App Ticket

Use greenworks.getEncryptedAppTicket(user_data, success_callback, [error_callback]).

• user_data (String): Arbitrary UTF-8 encoded data to be encrypted into the ticket.
• success_callback: Receives the encrypted_ticket (Buffer).

2. Decrypt the Ticket

Use greenworks.decryptAppTicket(encrypted_ticket, decryption_key).

• encrypted_ticket (Buffer): The ticket to decrypt.
• decryption_key (Buffer): The secret key. Its length must match greenworks.EncryptedAppTicketSymmetricKeyLength.
• Returns: A Buffer representing the decrypted ticket if successful; otherwise null.

3. Inspect Decrypted Ticket Data

Once decrypted, use these methods to extract information:

• greenworks.isTicketForApp(decrypted_ticket, app_id): Returns Boolean indicating if the ticket is for the specified app_id.
• greenworks.getTicketAppId(decrypted_ticket): Returns the Integer App ID.
• greenworks.getTicketSteamId(decrypted_ticket): Returns a SteamID object.
• greenworks.getTicketIssueTime(decrypted_ticket): Returns an Integer representing the issue time.

var greenworks = require('./greenworks');

greenworks.init();

greenworks.getEncryptedAppTicket('test_content', function(ticket) {
  console.log("ticket: " + ticket.toString('hex'));
  
  // Specify the secret key (must be 32 bytes for symmetric key)
  var key = new Buffer(32);
  // TODO: initialize Buffer key with your game's secret key
  
  assert(key.length == greenworks.EncryptedAppTicketSymmetricKeyLength);
  
  var decrypted_app_ticket = greenworks.decryptAppTicket(ticket, key);
  if (decrypted_app_ticket) {
    console.log(greenworks.isTicketForApp(decrypted_app_ticket, greenworks.getAppId()));
    console.log(greenworks.getTicketAppId(decrypted_app_ticket));
    console.log(greenworks.getTicketSteamId(decrypted_app_ticket));
    console.log(greenworks.getTicketIssueTime(decrypted_app_ticket));
  }
}, function(err) { throw err; });

To use Greenworks in an NW.js application without building from source, follow these steps to arrange the required binaries and configuration files:

1. Download Greenworks Binaries: Download the release binaries from the releases page and unzip them to your project directory (<greenworks_path>).
2. Download Steamworks SDK: Download the Steamworks SDK and unzip it to a local directory (<steam_sdk_path>). Ensure the SDK version matches the version supported by your Greenworks prebuilt binaries.
3. Copy Steam API Library: Copy the appropriate Steam API library from <steam_sdk_path>/redistributable_bin/[win64|linux32|linux64|osx32] to <greenworks_path>/lib/.
   • Windows: steam_api.dll (or steam_api64.dll for 64-bit)
   • macOS: libsteam_api.dylib
   • Linux: libsteam_api.so
4. Copy Encrypted App Ticket Library: Copy the encrypted app ticket library from <steam_sdk_path>/public/steam/lib/[win32|win64|linux32|linux64|osx32] to <greenworks_path>/lib/.
   • Windows: sdkencryptedappticket.dll (or sdkencryptedappticket64.dll for 64-bit)
   • macOS: libsdkencryptedappticket.dylib
   • Linux: libsdkencryptedappticket.so
5. Configure AppID: Create a steam_appid.txt file containing your Steam AppID (use 480 for testing with the Steamworks example) in the <greenworks_path>/ directory. This is only required for development; Steam handles this automatically when launching a published game.

Important Architecture Note: Ensure the architecture of the Steam dynamic libraries matches both your OS and your NW.js version. For example, if using 64-bit NW.js on 64-bit Windows, use the win64 versions of the DLLs.

Greenworks requires the Steamworks SDK to function. Because of licensing restrictions, the SDK is not included in the Greenworks repository and must be provided by the developer.

Setup Steps

1. Download: Log in to the official Steamworks website and download the SDK.
2. Extract: Unzip the downloaded file.
3. Rename: Locate the extracted sdk subdirectory and rename it to steamworks_sdk.
4. Install: You can provide the SDK to Greenworks using one of two methods:
   • Manual Placement: Copy the steamworks_sdk directory into the <greenworks_src_dir>/deps/ folder.
   • Environment Variable: Set the STEAMWORKS_SDK_PATH environment variable to point to the absolute path of your steamworks_sdk directory.

Version Compatibility

Greenworks is designed to work with Steamworks SDK v1.41. If a newer version is released, ensure you download the version compatible with your specific Greenworks build.

Greenworks provides a P2P (Peer-to-Peer) networking interface based on Steamworks. You can send packets, manage sessions, and check connection states between users via their Steam IDs.

Sending Packets

Use greenworks.sendP2PPacket to transmit data. You must specify the recipient's steamId, the sendType (from the eP2PSendType enum), the data as a Buffer, and a nChannel number.

Receiving Packets

To check for incoming data, use greenworks.isP2PPacketAvailable(nChannel). If data is available, use greenworks.readP2PPacket(size, nChannel) to retrieve the Buffer and the steamIDRemote of the sender.

Session Management

• Accepting Sessions: When a user requests a connection, use greenworks.acceptP2PSessionWithUser(steamId) to establish the link.
• Checking State: Use greenworks.getP2PSessionState(steamIDUser) to get a result (boolean) and a connectionState object.
• Closing Sessions: Use greenworks.closeP2PSessionWithUser(steamIDUser) to end a session, or greenworks.closeP2PChannelWithUser(steamIDUser, nChannel) to close a specific channel.

Networking Environment

Use greenworks.isBehindNAT() to determine if the user is behind a NAT, which may affect P2P connectivity.

To receive chat messages from friends, you must first enable the listener using greenworks.setListenForFriendsMessage(true). Once enabled, you can listen for the game-connected-friend-chat-message event. Inside the listener, use greenworks.getFriendMessage to retrieve the actual message content.

// 1. Enable listening
greenworks.setListenForFriendsMessage(true);

// 2. Listen for the event
greenworks.on('game-connected-friend-chat-message', function(steam_id, message_id) {
  // Retrieve message content
  var info = greenworks.getFriendMessage(steam_id.getRawSteamID(), message_id, 2048);
  
  if (info.chatEntryType == greenworks.ChatEntryType.ChatMsg) {
    var message = info.message;
    console.log("Receive a message from " + steam_id.getPersonaName() + ": " + message);
    
    // 3. Reply to the message
    greenworks.replyToFriendMessage(steam_id.getRawSteamID(), "Hello, I received your message.");
  }
});