Prerequisites

Here are the prerequisites to mobile SDK integration:

• Authentication keys
• REST API keys
• REST API server name
• Mobile SDK keys
• Signature keys
• Merchant server

Once these prerequisites are integrated, you are ready to integrate the Android and iOS SDKs.

Authentication keys

Three keys are needed for authenticating your exchanges with the payment gateway:

KEY	Description
Server to server key	For the calls to web services
Mobile SDK key	For creating a payment screen in your mobile application.
Signature key	For checking the integrity of the data returned in the IPN and/or JSON returned by the SDK during the transaction status verification stage.

Sign in to the Merchant Back Office

The keys are available in the Merchant Back Office. To access them, you must first connect to the Merchant Back Office. Users are identified with a login and password.

1. Sign in to the Merchant Back Office: https://secure.lyra.com/portal/

2. Enter your login.
3. Enter your password.
4. Click Login.

Finding the keys

From the Merchant Back Office, click on Other Actions. The following window will appear:

Click on Merchant Back Office to access your Merchant Back Office.

In the Settings > Shop menu, select your shop and go to the REST API keys tab.

The tab contains all the information required for authentication:

REST API keys

The REST payment Web Services use Basic HTTP authentication for securing the calls between the merchant server and the payment gateway servers (see Authentication phase for more information). In order to proceed to authentication, you need a login and a password.

They can be retrieved in the REST API Keys tab of the Merchant Back Office:

PARAMETER	Description
User	Username for building the header Authorization string.
Test password	Password for building the header Authorization string for test transactions (with test cards).
Production password	Password for building the header Authorization string for production transactions (with real cards).

For more information on the implementation, see Implementation using different programming languages.

REST API server name

The REST API server name parameter visible in the same screen is also required: this is the URL to which to send REST API requests. It is requested for the initialization of the mobile SDK.

Mobile SDK keys

The mobile SDK requires a key upon its initialization (i.e. the parameter passed when calling the Lyra.init method). Two keys are available in the Merchant Back Office in the REST API keys tab, Keys for the mobile SDK client section:

KEY	Description
Public test key	Public key for making test payments.
Public production key	Public key for making production payments.

The key is called 'public' because it is publicly visible in the source code of your mobile application.

Signature keys

There are two ways of retrieving the details of a newly created transaction:

Server notification (IPN)	Every time a transaction is created, we call the merchant server to notify it.
End of payment	When the payment is made, the same information is sent to the mobile SDK, which transmits it to your mobile application.

Both of these information flows can be intercepted or modified during transport. A hashing process is therefore used to allow the merchant to verify the authenticity and integrity of the received data and thus securely check the status of the transaction.

There are two keys for this purpose:

KEY	Description
HMAC SHA256 test key	Allows to confirm data authenticity for test transactions.
HMAC SHA256 production key	Allows to confirm data authenticity for production transactions.

For computing the key during IPN calls, go to Using the IPN (notification URL). For computing the key when checking the transaction result, go to the iOS and Android integration guides.

Merchant server

For payment security reasons and to avoid fraudulent transactions, the mobile SDK relies on a merchant server that must be provided by you.

This server responds to several needs:

• Confirm that the transactions to be transmitted to the payment gateway correspond to the purchases on your merchant website, and that the amounts and currencies are correct,
• Securely store your communication keys with the payment gateway,
• Receive instant notifications (IPN) from the payment gateway for each payment event (accepted, refused, etc.).

Merchant server example

In order to simplify your integration, we offer a ready-made sample implementation in Java Spring Boot.

Access to logs

If you want to view the logs, simply install the Heroku client and run the command: heroku logs -a [APPNAME], where “APPNAME” is the name you gave to your server during the deployment. For instance, if you called it ‘my-merchant-server’, the command to run will be:

heroku logs -a my-merchant-server

URL of the sample server

Once your server is deployed, your URL will be composed of the name that you will have given to it and the suffix: “.herokuapp.com/”.

For example, if you called your server "my-merchant-server", your URL will be: https://my-merchant-server.herokuapp.com/