Verification of special offers (REST API)

You can execute the verification of special offers on the game server-side by using Game of Whales. In order to do this, you are just enough of using a value from payload property.

The payload is a special offer's data encrypted by using a secret key. The key can be taken from Payload Key field on Game Settings page. Game of Whales uses AES-256-CTR encryption algorithm with "hex" output encoding.

Payload structure

The payload has the following attributes:

Example:

{
        "camp": "camp42",
        "custom": {
            "str": "abc",
            "num": 123,
            "flag": true
        },
        "product": "item_01",
        "priceFactor": 2,
        "countFactor": 1,
        "finishedAt": 1550264340000,
        "redeemable": true,
        "activatedAt": 1550219230037,
        "user": "1234-5678-....-4321",
        "now": 1550219230037
}

Use case

The use case of using payload is as follows:

1. A client (your game’s code) receives a special offer from Game of Whales server and shows the offer in the game’s shop.

2. When a player tries to use the special offer, the client sends a request to your game server for applying this action on server-side and passes the payload.

3. The server decrypts the payload by using the secret key. The secret key can be taken in your game settings page on Game Of Whales service.

4. Server-side validation is processing:

5. If point 4 is successful, the special offer can be applied to the player.

This case can be applied only if you want the validation process to be made on server-side.

Example of decryption on the server-side

(for nodejs)

	decrypt = (encrypted, secretKey) => {
	            const crypto = require('crypto'),
	                decipher = crypto.createDecipher("AES-256-CTR", secretKey);
            
	            let decrypted = decipher.update(encrypted, 'hex', 'utf8');
	            decrypted += decipher.final('utf8');
          
	            return decrypted;

	        };