## iOS Swift advanced setup

In this guide, you'll find an overview and best practices for enabling advanced features and using built in functions for biometric authentication (passkeys) and step-up.

## Passkeys authentication (iOS 15+)

Passkeys provide a seamless, passwordless login experience using WebAuthn and platform-level biometric authentication.

**Prerequisites**

1. **iOS Version**: Ensure your project targets **iOS 15 or later** to support the necessary WebAuthn APIs.
2. **Associated Domain**: Configure your app's associated domains to enable passkeys functionality.
3. **Frontegg SDK Version**: Use Frontegg iOS SDK version **1.2.24 or later**.


### Configure associated domains in Xcode

1. Open your project in **Xcode**
2. Go to your **target** settings
3. Open the **Signing & Capabilities** tab
4. Click the **+ Capability** button and add **Associated Domains**
5. Under **Associated Domains**, click the **+** and add: `webcredentials:your-domain.com`. For example, if your domain is `https://example.com`, use `webcredentials:example.com`.


### Host the `.well-known/webauthn` file

1. On your server, create a JSON file at the following location: `https://your-domain.com/.well-known/webauthn`.
2. Use the structure below:


br

```json
{
  "origins": [
    "https://your-domain.com",
    "https://subdomain.your-domain.com"
  ]
}
```

1. Ensure this file is publicly accessible (HTTP 200 OK).


### Test domain association

Verify that your associated domain configuration works using Apple's [Associated Domains Validator](https://developer.apple.com/contact/request/associated-domains).

### Register passkeys

Call this method from your app to enable passkeys registration for a user:


```swift
import FronteggSwift

func registerPasskeys() {
    if #available(iOS 15.0, *) {
        FronteggAuth.shared.registerPasskeys()
    } else {
        print("Passkeys are only supported on iOS 15 or later.")
    }
}
```

### Login with passkeys

To log users in using a stored passkey:

br

```swift
import FronteggSwift

func loginWithPasskeys() {
    if #available(iOS 15.0, *) {
        FronteggAuth.shared.loginWithPasskeys { result in
            switch result {
            case .success(let user):
                print("User logged in: \(user)")
            case .failure(let error):
                print("Error logging in: \(error)")
            }
        }
    } else {
        print("Passkeys are only supported on iOS 15 or later.")
    }
}
```

## Step-up authentication

Step-Up Authentication allows you to temporarily elevate a user's authentication level to perform sensitive actions. This is useful for operations like updating credentials, accessing confidential data, or performing secure transactions.

#### `stepUp` -

Starts the step-up authentication flow. This will usually trigger a secondary authentication method ( e.g. biometric, MFA, etc).

`maxAge` (optional): How long the elevated session is considered valid, in seconds.

`completion`: A closure called after authentication finishes. If step-up fails, it receives an error.

br

```
Task {
    await FronteggAuth.shared.stepUp(maxAge: 300) { error in
        if let error = error {
            print("Step-up failed: \(error.localizedDescription)")
            return
        }

        // Authentication successful, continue with the secure action
        self.performSensitiveAction()
    }
}
```

#### `isSteppedUp` -

This method hecks whether the user has recently completed a step-up authentication and whether it is still valid.


```
let isSteppedUp = FronteggAuth.shared.isSteppedUp(maxAge: 300) // 300 seconds = 5 minutes

if isSteppedUp {
    // Proceed with secure operation
} else {
    // Trigger step-up flow
}
```

br
**Example**

br

```
func performSensitiveFlow() {
    let isElevated = FronteggAuth.shared.isSteppedUp(maxAge: 300)

    if isElevated {
        performSensitiveAction()
    } else {
        Task {
            await FronteggAuth.shared.stepUp(maxAge: 300) { error in
                if let error = error {
                    showAlert("Authentication Failed", message: error.localizedDescription)
                    return
                }
                performSensitiveAction()
            }
        }
    }
}

func performSensitiveAction() {
    // Proceed with a high-security task
    print("Secure action performed.")
}
```

## Logout after reinstall

To force logout when a user reinstalls the app, update your `Frontegg.plist` file:


```xml
<plist version="1.0">
  <dict>
    <key>keepUserLoggedInAfterReinstall</key>
    <false/>
    ...
  </dict>
</plist>
```

br
By default `keepUserLoggedInAfterReinstall` is `true`.