Registration with a third-party mobile app
Registration with third-party mobile application (also known as App2App) is possible using two-step registration.
Prerequisites
A number of properties need to be set up on the backend side, to be sure that it is properly configured. A two-step custom registration IDP with scripts for both init and complete steps needs to be set up. The third-party app needs to be installed on the device, and ready to receive and emit iOS Universal Links.
Flow overview
- App initiates custom registration with
initrequest (with empty data) Initresponses with JSON:sessionIdandapp link(the example of the response is shown in step 2 below)- App opens the third-party app using
app link. - Third-party app authenticates the user and navigates back to the app using the
app link. - App extracts
artefactIdfrom theapp linkand sends it to the backend along with thesessionId. - Registration finishes and the app receives an access or refresh token.
- Proceed with PIN creation flow.
Example of the flow
Your app needs to be able to receive Universal Links from the third-party app. Be sure to register the correct URL scheme.
Step 1
// identity provider is two-step IDP configured on the backend
userClient.registerUserWith(identityProvider: identityProvider, scopes: ["read"], delegate: self)
func userClient(_ userClient: UserClient, didReceiveCustomRegistrationInitChallenge challenge:
CustomRegistrationChallenge) {
// custom registration with init request (with empty data)
challenge.sender.respond(with: nil, to: challenge)
}
Step 2
func userClient(_ userClient: UserClient, didReceiveCustomRegistrationFinishChallenge challenge:
CustomRegistrationChallenge) {
// parse challenge of Init response JSON (example of Init response is shown below)
...
// do not respond for the challenge yet
// open third party app using app link taken from the response
...
}
Example of Init response:
{
"sessionID": "Njg3NTM0NTYzQzk4M0FGOTRGMDQyRjhGRjlDMDgxN0F8OGVhOTgzYWYtNzEzNC00ZTQwLT
"digidRequest": "https://app-preprod1.digid.nl/digid-app?app-app=eyAiSWNvbiI6Imh0dHB
}
Step 3
The app opens the third-party app using the app link.
Step 4
The third-party app authenticates the user and navigates back to the app using the app link.
Step 5
The app extracts data: artefactId from the app link and sends it to the backend along with the sessionId.
// data with with artefactId and sessionId
customRegistrationFinishChallenge.sender.respond(with: data, to: customRegistrationFinishChallenge)
Step 6
Registration finishes and the app receives an access or refresh token.
