GuidesiOS mDocs Verifier SDKTutorial πŸŽ“

Learn how to build an iOS application that can verify an mDoc presented via a proximity workflow

Overview

In this tutorial we will use the iOS mDoc verifier SDK to build an iOS application that can verify an mDoc presented via a proximity workflow as per ISO 18013-5:

Tutorial Workflow

  1. The credential holder presents a QR code generated by their wallet application.
  2. The verifier uses their application to scan the QR code, connect with the wallet and request an mDoc for verification.
  3. The wallet application displays matching credentials to the holder and asks for consent to share them with the verifier.
  4. The verifier application receives the wallet’s response and verifies the provided credential.
  5. Verification results are displayed to the verifier.

The result will look something like this:

To achieve this, you will build the following capabilities into your iOS verifier application:

  • Initialize the SDK, so that your application can use its functions and classes.
  • Manage certificates, which enable your application to verify mDocs that were issued by trusted issuers.
  • Scan a QR code presented by a wallet application and establish a secure communication channel.
  • Send presentation requests to the wallet application, receive a presentation response and verify its content.
  • Display the results to the verifier app user.

Tutorial Steps

Prerequisites

Before we get started, let’s make sure you have everything you need.

Prior knowledge

  • The proximity verification workflow described in this tutorial is based on the ISO 18013-5 standard. If you are unfamiliar with this standard, refer to the following Docs for more information:

  • We assume you have experience developing iOS native apps in Swift.

If you need to get a verifier solution up and running quickly with minimal development resources and in-house domain expertise, talk to us about our white-label MATTR GO Verifier which might be a good fit for you.

Assets

  • As part of your onboarding process you should have been provided with access to the following assets:
    • ZIP file which includes the required framework: (MobileCredentialVerifierSDK-*version*.xcframework.zip).
    • Sample Verifier app: You can use this app for reference as we work through this tutorial.

This tutorial is only meant to be used with the most recent version of the iOS mDocs Verifier SDK.

Development environment

  • Xcode setup with either:
    • Local build settings if you are developing locally.
    • iOS developer account if you intend to publish your app.

Testing devices

As this tutorial implements a proximity presentation workflow, you will need two different mobile devices to test the end-to-end result:

  • Verifier device:
    • Supported iOS device to run the built Verifier application on, setup with:
      • Bluetooth access.
      • Available internet connection.
  • Holder device:
    • Mobile device with the MATTR GO Hold example app installed and setup with:
      • Biometric authentication.
      • Bluetooth access.
      • Available internet connection.

mDoc

  1. Download and install the MATTR GO Hold example app on your wallet testing device.
  2. Use the GO Hold example app to claim an mDoc by scanning the following QR code:
QR Code

Got everything? Let’s get going!

Environment setup

Tutorial Step 1

Perform the following steps to setup and configure your development environment:

Create a new project

Please follow the detailed instructions to Create a new Xcode Project and add your organization’s identifier.

Create a new project

Unzip the dependencies file

  1. Unzip the MobileCredentialVerifierSDK-*version*.xcframework.zip file.
  2. Drag the MobileCredentialVerifierSDK-*version*.xcframework folder into your project.
  3. Configure MobileCredentialVerifierSDK.xcframework to Embed & sign.

See Add existing files and folders for detailed instructions.

This should result in the the following framework being added to your project:

Framework added

Add Bluetooth permissions

The SDK requires access to the mobile device Bluetooth capabilities as part of the proximity presentation workflow. Configure these permissions in the Info tab of the Application target:

Privacy capabilities

Run the application

Select Run and make sure the application launches with a β€œHello, world!” text in the middle of the display, as shown in the following image:

Application ready

Nice work, your application is now all set to begin using the SDK!

Initialize the SDK

Tutorial Step 2

The first capability you will build into your app is to initialize the SDK so that your app can use SDK functions and classes. To achieve this, we need to import the MobilecredentialVerifierSDK framework and then initialize the MobileCredentialVerifier class.

Create the application structure

  1. Open the ContentView file in your new project and replace any existing code with the following:

    Swift
    import SwiftUI
    import MobileCredentialVerifierSDK
     
    struct ContentView: View {
        @ObservedObject var viewModel: VerifierViewModel = VerifierViewModel()
        // Verify mDocs - Step 4.4: Add the isPresentingResponseView variable
     
        var body: some View {
            NavigationStack {
                VStack(spacing: 20) {
                    // Manage certificates - Step 1.2: Add Certificate Management button
                    // Verify mDocs - Step 2.5: Add Scan QR Code button
                    // Verify mDocs - Step 4.3: Add View Response button
                }
                // Manage certificates - Step 1.3: Add navigation destination logic
            }
        }
         // Verify mDocs - Step 2.4: Create QRScannerView
    }
     
    class VerifierViewModel: ObservableObject {
        // Initialize SDK - Step 2.1: Add MobileCredentialVerifier var
        // Verify mDocs - Step 1.1: Create MobileCredentialRequest instance
        // Verify mDocs - Step 1.2: Create receivedDocuments variable
     
        init() {
          do {
                // Initialize SDK - Step 2.2: Initialize MobileCredentialVerifier SDK
     
          }
          catch {
              print(error.localizedDescription)
          }
        }
     
        // Verify mDocs - Step 3.1: Create setupProximityPresentationSession
        // Verify mDocs - Step 3.2: Create sendDeviceRequest function
    }
     
    // Manage certificates - Step 1.1: Create CertificateManagementView view
    // Verify mDocs - Step 4.1: Create MobileCredentialClaimListView view
    // Verify mDocs - Step 4.2: Create PresentationResponseView

    This will serve as the basic structure for your application. We will copy and paste different code snippets into specific locations in this codebase to achieve the different functionalities. These locations are indicated by comments that reference both the section and the step.

Initialize the MobileCredentialVerifier class

  1. Add the following code after the // Initialize SDK - Step 2.1: Add MobileCredentialVerifier var comment to create a variable that holds the mobileCredentialVerifier instance:

We recommend copying and pasting the comment text in Xcode search field (e.g. `// Initialize SDK

  • Step 2.1: Add MobileCredentialVerifier var`) to easily locate it in the code.
Swift
    var mobileCredentialVerifier: MobileCredentialVerifier
  1. Add the following code after the // Initialize SDK - Step 2.2: Initialize MobileCredentialVerifier SDK comment to initialize the SDK and create a new instance in the MobileCredentialVerifier variable:

    Swift
        mobileCredentialVerifier = MobileCredentialVerifier.shared
        try mobileCredentialVerifier.initialize()
  2. Run the app to make sure it compiles properly.

Manage certificates

Tutorial Step 3

Once the SDK is initialized, the next step is to build the capability for the application to manage certificates.

Tutorial Workflow

Every mDoc is signed by a series of certificates, referred to as a chain of trust. For your application to verify a presented mDoc it must validate it was signed using a root certificate (IACA) associated with a trusted issuer.

To enable this, your application can provide an interface for the user to manage (add, view and remove) certificates. We will achieve this by creating a new CertificateManagementView view and building certificate management capabilities into it.

Create the Certificate Management view

  1. Add the following code under the // Manage certificates - Step 1.1: Create CertificateManagementView view comment to create a new view where the user will manage certificates in the app.

    Swift
    struct CertificateManagementView: View {
        // Certificate Management ViewModel will handle the logic
        @ObservedObject var viewModel = CertificateManagementViewModel()
        // This var holds a pem string of a certificate to be added
        @State var certificateString = ""
     
        var body: some View {
            Form {
                Section(
                    header: Text("IACA Certificate").font(.headline),
                    footer: HStack {
                        Spacer()
                        Button("Add", action: {
                            // Manage Certificates - Step 2.6: Call addCertificate function
                        })
                        Spacer().frame(width: 30)
                        Button("Clear", action: {
                            certificateString = ""
                        })
                        .foregroundColor(.red)
                        .contentShape(Rectangle())
                        .frame(alignment: .trailing)
                    }
                ) {
                    TextField("IACA certificate string", text: $certificateString)
                }
     
                Section(
                    header: Text("Stored Certificates").font(.headline)
                ) {
                    // Manage Certificates - Step 2.4: Display retrieved certificates
                }
            }
            .navigationBarTitle("Certificate Setting")
            .onAppear {
                // Manage Certificates - Step 2.3: Call getCertificates function
            }
        }
    }
     
    class CertificateManagementViewModel: ObservableObject {
     
        // Manage Certificates - Step 2.1: Add certificates variable
        // Manage Certificates - Step 2.2: Create getCertificates function
        // Manage Certificates - Step 2.5: Create addCertificate function
        // Manage Certificates - Step 2.7: Create removeCertificate function
    }
  2. Add the following code under the // Manage certificates - Step 1.2: Add Certificate Management button comment to add a new button for the user to select to navigate to the new CertificateManagementView:

    Swift
    NavigationLink("Certificate Management", value: "CertificateManagement")
        .font(.headline)
        .foregroundColor(.blue)
        .padding()
        .background(Color.gray.opacity(0.2))
        .cornerRadius(10)
  3. Add the following code under the // Manage certificates - Step 1.3: Add navigation destination logic comment to create the logic that associates the button with the correct view:

    Swift
    .navigationDestination(for: String.self) { value in
        switch value {
        case "CertificateManagement":
            CertificateManagementView(viewModel: CertificateManagementViewModel())
        // Verify mDocs - Step 2.6: Add QR code view destination
        // Verify mDocs - Step 4.6: Add Response view destination
        default:
            EmptyView()
        }
    }
  4. Run the app and select the Certificate Management button. You should see a result similar to the following:

As the user selects the Certificate Management button they are navigated to the new CertificateManagement view where they can see controls that would enable them to add, view and remove certificates. We will build these capabilities into the controls in the next step.

Add Certificate Management functionalities

Currently our CertificateManagementView view has no functionalities. Let’s fix this by adding the capabilities to add, view and remove certificates.

  1. Add the following code under the // Manage Certificates - Step 2.1: Add certificates variable comment to add a new certificates variable that will hold the certificates added to the application:

    Swift
        @Published var certificates: [TrustedCertificate] = []
        let mobileCredentialVerifier = MobileCredentialVerifier.shared
  2. Add the following code under the // Manage Certificates - Step 2.2: Create getCertificates function comment to create a new getCertificates function that calls the SDK getTrustedIssuerCertificates and enables the application to retrieve all certificates and display them to the user:

    Swift
        func getCertificates() {
            do {
                let fetchedCertificates = try mobileCredentialVerifier.getTrustedIssuerCertificates()
                // Updating the UI from the main thread
                DispatchQueue.main.async {
                    self.certificates = fetchedCertificates
                }
            } catch {
                print(error.localizedDescription)
            }
        }
  3. Add the following code under the // Manage Certificates - Step 2.3: Call getCertificates function comment to call the new getCertificates function from within the CertificateManagementView once the view is loaded:

    Swift
        viewModel.getCertificates()
  4. Add the following code under the // Manage Certificates - Step 2.4: Display retrieved certificates comment to iterate over retrieved certificates and display them to the user:

    Swift
            ForEach(viewModel.certificates, id: \.id) { certificate in
            Text("\(certificate.pem)")
                .frame(maxHeight: 100)
                // Manage Certificates - Step 2.8: Call removeCertificate function
    }
  5. Add the following code under the // Manage Certificates - Step 2.5: Create addCertificate function comment to create a new addCertificate function that calls the SDK addTrustedIssuerCertificates and enables the application to accept a string parameter and use it to add a new certificate:

    Swift
        func addCertificate(_ certificate: String) {
            Task {
                do {
                    _ = try await mobileCredentialVerifier.addTrustedIssuerCertificates(certificates: [certificate])
                    self.getCertificates()
                }
                catch {
                    print(error.localizedDescription)
                }
            }
        }
  6. Add the following code under the // Manage Certificates - Step 2.6: Call addCertificate function comment to call the new addCertificate function from within the CertificateManagementView once the user provides a string (which is stored in the certificateString variable) and selects the Add button:

    Swift
        viewModel.addCertificate(certificateString)
  7. Add the following code under the // Manage Certificates - Step 2.7: Create removeCertificate function comment to create a new removeCertificate function that calls the SDK deleteTrustedIssuerCertificate and enables the application to remove a selected certificate:

    Swift
        func removeCertificate(_ certificateID: String) {
            do {
                try mobileCredentialVerifier.deleteTrustedIssuerCertificate(certificateId: certificateID)
                // Refresh the certificates list after deletion
                self.getCertificates()
            } catch {
                print(error.localizedDescription)
            }
        }
  8. Add the following code under the // Manage Certificates - Step 2.8: Call removeCertificate function comment to call the new removeCertificate function from within the CertificateManagementView once the user performs a swipe action on an individual certificate:

    Swift
    		.swipeActions(edge: .trailing) {
    	Button(role:. destructive) {
    		viewModel.removeCertificate(certificate.id)
    	} label: {
    		Image(systemName: "trash")
    	}
    }
  9. Run the app and perform the following instructions:

    1. Select the Manage Certificates button.

    2. Copy and paste the following text into the IACA Certificate text box.

      MIICYzCCAgmgAwIBAgIKXhjLoCkLWBxREDAKBggqhkjOPQQDAjA4MQswCQYDVQQG
      EwJBVTEpMCcGA1UEAwwgbW9udGNsaWZmLWRtdi5tYXR0cmxhYnMuY29tIElBQ0Ew
      HhcNMjQwMTE4MjMxNDE4WhcNMzQwMTE1MjMxNDE4WjA4MQswCQYDVQQGEwJBVTEp
      MCcGA1UEAwwgbW9udGNsaWZmLWRtdi5tYXR0cmxhYnMuY29tIElBQ0EwWTATBgcq
      hkjOPQIBBggqhkjOPQMBBwNCAASBnqobOh8baMW7mpSZaQMawj6wgM5e5nPd6HXp
      dB8eUVPlCMKribQ7XiiLU96rib/yQLH2k1CUeZmEjxoEi42xo4H6MIH3MBIGA1Ud
      EwEB/wQIMAYBAf8CAQAwDgYDVR0PAQH/BAQDAgEGMB0GA1UdDgQWBBRFZwEOI9yq
      232NG+OzNQzFKa/LxDAuBgNVHRIEJzAlhiNodHRwczovL21vbnRjbGlmZi1kbXYu
      bWF0dHJsYWJzLmNvbTCBgQYDVR0fBHoweDB2oHSgcoZwaHR0cHM6Ly9tb250Y2xp
      ZmYtZG12LnZpaS5hdTAxLm1hdHRyLmdsb2JhbC92Mi9jcmVkZW50aWFscy9tb2Jp
      bGUvaWFjYXMvMjk0YmExYmMtOTFhMS00MjJmLThhMTctY2IwODU0NWY0ODYwL2Ny
      bDAKBggqhkjOPQQDAgNIADBFAiAlZYQP95lGzVJfCykhcpCzpQ2LWE/AbjTGkcGI
      SNsu7gIhAJfP54a2hXz4YiQN4qJERlORjyL1Ru9M0/dtQppohFm6

You will need to copy this text from the device you are using to display this tutorial and paste it in the device where you are running the built application. There are several ways to achieve this on iOS devices, one of them is setting up a Universal Clipboard.

  1. Select the Add button. The new certificate should appear in the STORED CERTIFICATES area.

  2. Swipe left across the new certificate and select the Delete icon to remove it.

You should get a result similar to the following:

  1. When the user selects the Certificate Management button they are navigated to the CertificateManagement view.
  2. When the user adds the text and selects the Add button a new certificate is added and displayed in the STORED CERTIFICATES area.
  3. When the user swipes left and selects the Delete icon the certificate is removed.

You have now built the capabilities required to manage certificates in your verifier applications. Now we can proceed to building the capabilities to handle the actual presentation workflow.

Verify mDocs

Tutorial Step 4

In this part we will build the components that enable a verifier app to verify an mDoc presented via a proximity workflow as per ISO 18013-5:

Tutorial Workflow

To achieve this, your application must be able to:

  1. Create a presentation request that defines the information required for verification.
  2. Scan and process a QR code created presented by a wallet application.
  3. Establish a secure connection with the wallet over Bluetooth, share the presentation request and receive a response.
  4. Verify the response and display the results to the verifier app user.

Create a presentation request

As a verifier, you can select what information you request for verification. Our application implements this by creating a MobileCredentialRequest instance to define the required information, and a new variable to hold the response from the wallet application.

  1. Add the following code under the Verify mDocs - Step 1.1: Create MobileCredentialRequest instance comment to define what information to request from the wallet application user:

    Swift
        let mobileCredentialRequest = MobileCredentialRequest(
            docType: "org.iso.18013.5.1.mDL",
            namespaces: [
                "org.iso.18013.5.1":  [
                    "family_name": false,
                    "given_name": false,
                    "birth_date": false
                ]
            ]
        )

    This object details:

    • The requested credential type (e.g. org.iso.18013.5.1.mDL).
    • The claims required for verification (e.g. family_name).
    • The requested namespace (e.g. org.iso.18013.5.1).
    • Whether or not the verifier intends to persist the claim value (true/false).

    For the verification to be successful, the presented credential must include the referenced claim against the specific namespace defined in the request. Our example requests the birth_date under the org.iso.18013.5.1 namespace. If a wallet responds to this request with a credential that includes a birth_date but rather under the org.iso.18013.5.1.US namespace, the claim will not be verified.

To simplify the tutorial, this is a hardcoded request. However, once you are comfortable with the basic functionalities you can create a UI in your verifier application that enables the user to create different requests on the fly by selecting different claims to include. See our GO Verify app as an example.

  1. Add the following code under the Verify mDocs - Step 1.2: Create receivedDocuments variable comment to create a new receivedDocuments variable that will hold the response from the wallet application:

    Swift
        @Published var receivedDocuments: [MobileCredentialPresentation] = []

Now your application has an existing request to share, and a variable to hold any incoming responses. We can now proceed to build the capabilities to send the request and handle the response.

Scan and process a QR code

Tutorial Workflow

As defined in ISO 18130-5, a proximity presentation workflow is always initiated by the holder (wallet application user), who must create a QR code for the verifier to scan in order to initiate the device engagement phase.

Tutorial Workflow

This means that your verifier application must be able to scan and process this QR code. For ease of implementation, we will use a third party framework to achieve this.

  1. Add camera usage permissions to the app target:
Camera permissions
  1. Add the CodeScanner library via Swift Package Manager.
Code scanner package
  1. Create a new swift file named QRScannerView and add the following code into it to implement the QR scanning capability:

    Swift
    import SwiftUI
    import CodeScanner
     
    struct QRScannerView: View {
     
        private let completionHandler: (String) -> Void
     
        init(completion: @escaping (String) -> Void) {
            completionHandler = completion
        }
     
        var body: some View {
            CodeScannerView(codeTypes: [.qr]) { result in
                switch result {
                case .failure(let error):
                    print(error.localizedDescription)
                case .success(let result):
                    print(result.string)
                    completionHandler(result.string)
                }
            }
        }
    }
  2. Back in the ContentView file, add the following code under the // Verify mDocs - Step 2.4: Create QRScannerView comment to create a new app view that the user will use to scan a QR code:

    Swift
        var codeScannerView: some View {
            QRScannerView(
                completion: { string in
                    // Verify mDocs - Step 3.3: Pass string from QR code to presentation session
                    // Verify mDocs - Step 4.5: Change isPresentingResponseView to true
                }
            )
        }
  3. Add the following code under the // Verify mDocs - Step 2.5: Add Scan QR Code button comment to add a new button for the user to select to navigate to the new QRScannerView:

    Swift
    NavigationLink("Scan QR Code", value: "ScanQRCode")
        .font(.headline)
        .foregroundColor(.blue)
        .padding()
        .background(Color.gray.opacity(0.2))
        .cornerRadius(10)
  4. Add the following code under the // Verify mDocs - Step 2.6: Add QR code view destination comment to create the logic that associates the button with the correct view:

    Swift
        case "ScanQRCode":
            codeScannerView
  5. Run the app and select the Scan QR Code button. You should be navigated to the new QRScannerView where you can use the camera to scan a QR code.

Now we will build the logic that handles this QR code to establish a secure connection with the wallet application.

Exchange presentation request and response

Tutorial Workflow

Once the verifier has scanned the QR code presented by the wallet application, your application must retrieve the information from that QR code and use it to establish a secure connection between the verifier and holder devices.

The verifier then uses this secure connection to send a presentation request to which the holder wallet application responds with a presentation response. The SDK then verifies any mDocs included in the response and stored the verification results in a variable.

To achieve this, your application must use the SDK’s createProximityPresentationSession function that takes a string retrieved from the QR code and uses it to establish a proximity presentation session with the wallet application and initiate the presentation workflow.

  1. Add the following code under the // Verify mDocs - Step 3.1: Create setupProximityPresentationSession comment to create a new setupProximityPresentationSession function that:

    1. Retrieves the string from the QR code.
    2. Establishes a secure connection with the wallet application by creating a proximityPresentationSession instance.
    3. Sends a presentation request by calling the sendDeviceRequest function:
    Swift
        func setupProximityPresentationSession(_ string: String) {
            Task {
                do {
                    let _ = try await mobileCredentialVerifier.createProximityPresentationSession(
                        encodedDeviceEngagementString: string,
                        onSessionTerminated: { _ in print("Session Terminated") }
                    )
                    sendDeviceRequest()
                } catch {
                    print(error.localizedDescription)
                }
            }
        }

Your app cannot compile at this stage as we will only created the sendDeviceRequest function in the next step.

  1. Add the following code under the // Verify mDocs - Step 3.2: Create sendDeviceRequest function comment to create a new sendDeviceRequest function. This function calls the existing proximityPresentationSession instance requestMobileCredentials function, which:

    1. Accepts an array of MobileCredentialRequests.
    2. Sends the requests to the wallet application.
    3. Receives a response from the wallet application.
    4. Verifies any mDocs included in the response.
    5. Stores the verification results in the receivedDocuments variable:
    Swift
        func sendDeviceRequest() {
         Task { @MainActor in
             do {
     
                 // Refresh the list of received documents
                 if !receivedDocuments.isEmpty {
                     receivedDocuments = []
                 }
     
                 // Find the existing proximity presentation session.
                 let presentationSession = try? mobileCredentialVerifier.getCurrentProximityPresentationSession()
     
                 // Request mDocs
                 let deviceResponse = try await presentationSession?.requestMobileCredentials(
                     request: [mobileCredentialRequest]
                 )
     
                 // Assign new values from the response
                 receivedDocuments = deviceResponse?.credentials ?? []
                 // Terminate session after response is received (optional)
                 await presentationSession?.terminateSession()
             } catch {
                 print(error)
                 receivedDocuments = []
             }
         }
     }
  2. Add the following code under the // Verify mDocs - Step 3.3: Pass string from QR code to presentation session comment to pass the string retrieved from the scanned QR code to the presentation session function:

    Swift
    viewModel.setupProximityPresentationSession(string)

Now that we have the verification results stored, you can implement different business logics to handle the results.

For this tutorial, we will only display these results to the verifier app user, individually indicating the verification status of each claim included in the request.

Display verification results

Tutorial Workflow

We will now create a new view that is automatically displayed when verification results are available.

  1. Add the following code under the // Verify mDocs - Step 4.1: Create MobileCredentialClaimListView view comment to create a new MobileCredentialClaimListView view that parses all claims from the presented mDocs and displays them to the verifier app user:

    Swift
    struct MobileCredentialClaimListView: View {
        let claims: [MobileCredentialDataTypes.NameSpace: [MobileCredentialDataTypes.ElementID: Any]]
        var body: some View {
            Form {
                ForEach(claims.keys.sorted(), id: \.self) { namespace in
                    Section(header: Text(namespace).font(.title2)) {
                        ForEach(claims[namespace]!.sorted(by: { $0.key < $1.key }), id: \.key) { key, value in
                            HStack {
                                Text(key)
                                Spacer()
                                Text(String(describing: value))
                            }
                        }
                    }
                }
            }
        }
    }

Your app cannot compile at this stage until we complete all steps of this section.

  1. Add the following code under the // Verify mDocs - Step 4.2: Create PresentationResponseView comment to create a new PresentationResponseView view that displays verified and failed claims as soon as the receivedDocuments variable is not empty:

    Swift
    struct PresentationResponseView: View {
        @Binding var receivedDocuments: [MobileCredentialPresentation]
     
        var body: some View {
            if receivedDocuments.isEmpty {
                VStack(spacing: 40) {
                    Text("Waiting for response...")
                        .font(.title3)
                    ProgressView()
                        .progressViewStyle(.circular)
                        .scaleEffect(2)
                }
            } else {
                ForEach(receivedDocuments, id: \.docType) { doc in
                    Text(doc.verificationResult.verified ? "Verified" : "Failed")
                        .foregroundStyle(doc.verificationResult.verified ? Color.green : Color.red)
                        .font(.title)
                        .bold()
                    Text("Received claims").font(.title3.bold())
                    MobileCredentialClaimListView(claims: doc.claims ?? [:])
                }
     
                ForEach(receivedDocuments, id: \.docType) { doc in
                    Text("Failed claims").font(.title3.bold())
                    MobileCredentialClaimListView(claims: doc.claimErrors ?? [:])
                }
            .padding(10)
            }
        }
    }
  2. Add the following code under the // Verify mDocs - Step 4.3: Add View Response button comment to add a new View Response button that the user can use to manually navigate to the new PresentationResponseView view if required:

    Swift
    NavigationLink("View Response", value: "ViewResponse")
        .font(.headline)
        .foregroundColor(.blue)
        .padding()
        .background(Color.gray.opacity(0.2))
        .cornerRadius(10)
        .navigationTitle("Main Menu")
        .navigationBarTitleDisplayMode(.inline)
        .navigationDestination(isPresented: $isPresentingResponseView) {
            PresentationResponseView(receivedDocuments: $viewModel.receivedDocuments)
        }
        .navigationDestination(for: String.self) { value in
            switch value {
            case "CertificateManagement":
                CertificateManagementView(viewModel: CertificateManagementViewModel())
            case "ScanQRCode":
                codeScannerView
            case "ViewResponse":
                PresentationResponseView(receivedDocuments: $viewModel.receivedDocuments)
            default:
                EmptyView()
            }
        }

Your app cannot compile at this stage until we complete all steps of this section.

  1. Add the following code under the // Verify mDocs - Step 4.4: Add the isPresentingResponseView variable comment to add a new isPresentingResponseView variable that is used to indicate whether or not the response view should be displayed.

    Swift
    @State private var isPresentingResponseView = false
  2. Add the following code under the // Verify mDocs - Step 4.5: Change isPresentingResponseView to true comment to change the isPresentingResponseView variable to true, indicating the verifier app should navigate to the PresentationResponseView view.

    Swift
    isPresentingResponseView = true
  3. Add the following code under the // Verify mDocs - Step 4.6: Add Response view destination comment to create the logic that associates the button with the correct view:

    Swift
        case "ViewResponse":
            PresentationResponseView(receivedDocuments: $viewModel.receivedDocuments)

Test the end-to-end workflow

Tutorial Step 5

  1. Run the app.

    1. Select the Certificate Management button.

    2. Copy and paste the following text into the IACA Certificate text box.

      MIICYzCCAgmgAwIBAgIKXhjLoCkLWBxREDAKBggqhkjOPQQDAjA4MQswCQYDVQQG
      EwJBVTEpMCcGA1UEAwwgbW9udGNsaWZmLWRtdi5tYXR0cmxhYnMuY29tIElBQ0Ew
      HhcNMjQwMTE4MjMxNDE4WhcNMzQwMTE1MjMxNDE4WjA4MQswCQYDVQQGEwJBVTEp
      MCcGA1UEAwwgbW9udGNsaWZmLWRtdi5tYXR0cmxhYnMuY29tIElBQ0EwWTATBgcq
      hkjOPQIBBggqhkjOPQMBBwNCAASBnqobOh8baMW7mpSZaQMawj6wgM5e5nPd6HXp
      dB8eUVPlCMKribQ7XiiLU96rib/yQLH2k1CUeZmEjxoEi42xo4H6MIH3MBIGA1Ud
      EwEB/wQIMAYBAf8CAQAwDgYDVR0PAQH/BAQDAgEGMB0GA1UdDgQWBBRFZwEOI9yq
      232NG+OzNQzFKa/LxDAuBgNVHRIEJzAlhiNodHRwczovL21vbnRjbGlmZi1kbXYu
      bWF0dHJsYWJzLmNvbTCBgQYDVR0fBHoweDB2oHSgcoZwaHR0cHM6Ly9tb250Y2xp
      ZmYtZG12LnZpaS5hdTAxLm1hdHRyLmdsb2JhbC92Mi9jcmVkZW50aWFscy9tb2Jp
      bGUvaWFjYXMvMjk0YmExYmMtOTFhMS00MjJmLThhMTctY2IwODU0NWY0ODYwL2Ny
      bDAKBggqhkjOPQQDAgNIADBFAiAlZYQP95lGzVJfCykhcpCzpQ2LWE/AbjTGkcGI
      SNsu7gIhAJfP54a2hXz4YiQN4qJERlORjyL1Ru9M0/dtQppohFm6

You will need to copy this text from the device you are using to display this tutorial and paste it in the device where you are running the built application. There are several ways to achieve this on iOS devices, one of them is setting up a Universal Clipboard.

  1. Select the Add button.
  2. Return to the app main screen.
  3. Open your wallet testing device and launch the GO Hold example app.
  4. Select the Wallet button.
  5. Locate the mDoc claimed earlier in this tutorial and select the share button to display a QR code.
  6. Use your verifier testing device and select the Scan QR Code button.
  7. Use the verifier testing device to scan the QR code displayed on the wallet testing device.
  8. Use the wallet testing device to consent to sharing the information with the verifier.
  9. Use the verifier testing device and select the View response button.

You should see a result similar to the following:

  1. The verifier app user adds a new certificate to the app. This is the certificate associated with the issuer of the mDoc we are about to verify.
  2. The wallet app user creates a QR code to initiate the proximity presentation workflow.
  3. The verifier app scans the QR code, establishes a secure connection and sends a presentation request.
  4. The wallet app user reviews the presentation request and agrees to share matching mDocs with the verifier.
  5. The verifier app receives the mDocs included in the presentation response.
  6. The verifier app user views the verification results.

Congratulations! Your verifier application can now verify mDocs presented via a proximity presentation workflow, as per ISO 18013-5.

Summary

You have just used the iOS mDoc verifier SDK to build an iOS application that can verify an mDoc presented via a proximity workflow as per ISO 18013-5:

Tutorial Workflow

This was achieved by building the following capabilities into the application:

  • Initialize the SDK, so that your application can use its functions and classes.
  • Manage certificates, which enable your application to verify mDocs that were issued by trusted issuers.
  • Scan a QR code presented by a wallet application and establish a secure communication channel.
  • Send presentation requests to the wallet application, receive a presentation response and verify its content.
  • Display the results to the verifier app user.

What’s next?

  • You can check out the iOS mDoc verifier SDK Docs to learn more about available functions and classes.