KSDeviceAuthenticator

KSDeviceAuthenticator provides wrapper around LocalAuthentication.framework for authentication device using touchId , faceId and passcode.

Note: - Face ID authentication requires user's permission to be add in info.plist.

<key>NSFaceIDUsageDescription</key>
<string>This app requires Face ID permission to authenticate using Face recognition.</string>

Installation

CocoaPods

To be added soon

Manual

Drag and drop files from Sources folder into your project

Usage

Authenticate with biometric

KSDeviceAuthenticator.authenticateWithBioMetrics(reason: "") { (result) in

    switch result {
    case .success( _):
        print("Authentication Successful")
    case .failure(let error):
        print("Authentication Failed")
    }
}

• When reason specified as empty - default will be used based on the device. Ex. for iPhone X - "Confirm your face to authenticate.", For other devices - "Confirm your fingerprint to authenticate."

Can Authenticate with biometric

• Alternatively you can check before authentication by following. This will check that if device supports Touch ID or Face ID authentication and your app can use that as of now.

if KSDeviceAuthenticator.canAuthenticate() {

    KSDeviceAuthenticator.authenticateWithBioMetrics(reason: "") { (result) in
        // check result -> success or failure
    }
}

Check for Face ID

• Check if device supports face recognition or not.

if KSDeviceAuthenticator.shared.faceIDAvailable() {
    // device supports face id recognition.
}

Check for Touch ID

• Check if device supports touch id authentication or not.

if KSDeviceAuthenticator.shared.touchIDAvailable() {
    // device supports touch id authentication
}

Fallback Reason

• Fallback reason title will be shown when first authentication attempt is failed.
• You can give alternate authentication options like enter 'username & password' when user clicks on fallback button.
• Default reason is empty, which will hide fallback button.

KSDeviceAuthenticator.authenticateWithBioMetrics(reason: "Biometric Authentication", fallbackTitle: "Enter Credentials") { (result) in

    switch result {
    case .success( _):
        // proceed further

    case .failure(let error):

        switch error {
        case .fallback:

            print("Authentication Failed")

            // show alternatives on fallback button clicked
            // for ex. - enter username/email and password

        default:
            break
        }
    }
}

BiometryLockedout

• When biometry authentication is locked out after multiple failed attempts. You can unlock it by passcode authentication.
• Provide your own passcode authentication reason here, default will be used if not provided.

KSDeviceAuthenticator.authenticateWithPasscode(reason: message) { (result) in
    switch result {
    case .success( _):
        // passcode authentication success
    case .failure(let error):
        print(error.message())
    }
}

Error Handling

• There are various cases when biometric authentication can be failed.

1. fallback
   • Called when user clicks on provided fallback button.
2. biometryNotEnrolled
   • Called when no fingerprints or face is registered with the device.
   • You can show message to register a new face or fingerprint here.
   • Default message will be shown if not provided.
3. canceledByUser
   • Called when authentication canceled by user.
4. canceledBySystem
   • Called when authentication canceled by system when app goes into background or any other reason.
5. passcodeNotSet
   • Called when device passcode is not set and trying to use biometry authentication.
   • We can ask user to set device passcode here by opening Settings Application.
6. failed
   • Called when multiple failed attempts made by user.
   • You can show error message to user here.
   • Default message can be shown if not provided.
7. biometryLockedout
   • Called when more than 5 failed attempts made using biometric authentication. This will locked your biometry system.
   • You'll restrict user when this error is occured.
   • Aleternatively you can ask user to enter device passcode to unlock biometry.
8. biometryNotAvailable
   • Called when device does not support Face ID or Touch ID authentication.

Example

KSDeviceAuthenticator.authenticateWithBioMetrics(reason: "") { [weak self] (result) in

    switch result {
    case .success( _):

        // authentication successful
        self?.showLoginSucessAlert()

    case .failure(let error):

        switch error {

        // device does not support biometric (face id or touch id) authentication
        case .biometryNotAvailable:
            self?.showErrorAlert(message: error.message())

        // No biometry enrolled in this device, ask user to register fingerprint or face
        case .biometryNotEnrolled:
            self?.showGotoSettingsAlert(message: error.message())

        // show alternatives on fallback button clicked
        case .fallback:
            self?.txtUsername.becomeFirstResponder() // enter username password manually

        // Biometry is locked out now, because there were too many failed attempts.
        // Need to enter device passcode to unlock.
        case .biometryLockout:
            self?.showPasscodeAuthentication(message: error.message())

        // do nothing on canceled by system or user
        case .canceledBySystem, .canceledByUser:
            break

        // show error for any other reason
        default:
            self?.showErrorAlert(message: error.message())
        }
    }
}

Credits

https://github.com/rushisangani/BiometricAuthentication

License

KSDeviceAuthentication is released under the MIT license.