V2 ACS challenge (Flows B, C)

This step is only required if the response from the initialisation API or the Auth API (Flow B) indicates the challengeRequired property is true, and the status is ACS_REQUIRED.

Inside this response will be another redirectUrl property.

There are two options:

  1. Perform a full browser redirect to ACS challenge page (If a merchantRedirectUrl was provided in the 3DS Initialisation API request body)

  2. Use an ACS challenge iframe

Option 1: Perform a full browser redirect

Use the redirectUrl in the response to perform a browser redirect, where the ACS challenge will be hosted.

Once the challenge is complete, the user will be redirected back to the merchant site.

The transID can be extracted from the URL parameters, appended to the merchant’s url. This is what the URL might look like:

https://merchantsite?result=SUCCESS&transID=6b65860e-a9ee-416d-b8a9-e6b674634470&threeDsStatus=ACS_COMPLETED

Please note : A merchantRedirectUrl must have been initially supplied in the initialisation API

Once the transID has been extracted from the url, it can be used to call the Result API

Option 2: Use an ACS challenge iframe

If a merchantRedirectUrl was not supplied, create an iframe to contain the ACS challenge.

Set up iframe html

Use the redirectUrl as the src property. This is what the iframe might look like:

<iframe src={redirectUrl} title="ACS" style="width: 100%; height: 100vh" ></iframe>

Note the iframe width and height

The default size of the challenge iframe will be full screen. However, if the acsWindowSize property was specified in the 3DS init call, then the iframe must have the same width and height as the acsWindowSize provided.

Create a POST message event Listener

The merchant site needs to know when the challenge is complete, and can proceed to call the 3DS Result. API. This done via a window.postMessage from the iframe.

Create an event listener on the page to receive this event. For security purposes, be sure to check the origin of the message is from the Netvalve domain.

const handlePostEvent = (event) => { if (event.origin === 'https://3dsecuresuite.uat.sandbox-netvalve.com') { const data = event.data; // Use the data to perform STEP 3 } }; // Be sure to attach the listener window.addEventListener('message', handlePostEvent, false);

Extract the message data

Inside the event.data is the following object. The expected status is ACS_COMPLETED

Once the message is received, whether success or fail, proceed to call the Result API.

Expected Properties and Values

result : 'SUCCESS' | 'ERROR' Use this for error handling. *Note - SUCCESS refers to the success of the 3DS initialization step. It does not mean 3DS values have been retrieved.

status : 'ACS_COMPLETED' | 'ERROR' | 'CALLBACK_PROCESSING_ERROR' | 'TIMEOUT' | 'INVALID_TRANS_ID' | 'MAX_IFRAME_RELOADS'

transID is the 3Ds transaction ID

providerErrorMessage will contain the error message from the 3DS provider, if any.

Proceed to fetch result