BiometricAuthenticator

Usage

To run the example project, clone the repo, and run pod install from the Example directory first.

First things first, any application that plans on authenticating with Face ID must inclue the NSFaceIDUsageDescription key in the app's Info.plist file. From within in the plist editor in xcode, add a new row and start typing out the following: Privacy - Face ID Usage Description (Xcode should autocomplete) followed by your usage string.

Invoking the authentication prompt can be as easy as:

import BiometricAuthenticator

let bioAuth = BiometricAuthenticator()

if bioAuth.isTouchIdEnabledOnDevice() || bioAuth.isFaceIdEnabledOnDevice() {
    bioAuth.authenticate(localizedReason: "Let's authenticate with biometrics!", successBlock: {
        // oh boy it worked!
    }, failureBlock: { (error) in
        if let error = error {
            switch error {
            default:
            // use the LAError code to handle the different error scenarios
            print("error: \(error.code)")
            }
        }
    })
}

The BiometricAuthenticator can also determine if the current device has biometric capabilities and whether or not the biometric feature has been enabled.

import BiometricAuthenticator

let bioAuth = BiometricAuthenticator()

// check if the feature exists on the device
if bioAuth.isTouchIdSupportedOnDevice() {
    // check if the feature is enabled
    if bioAuth.isTouchIdEnabledOnDevice() {
        // Hooray! We can authenticate using Touch ID!
    }
}

// check if the feature exists on the device
if bioAuth.isFaceIdSupportedOnDevice() {
    // check if the feature is enabled
    if bioAuth.isFaceIdEnabledOnDevice() {
        // Hooray! We can authenticate using Face ID!
    }
}

Or if you'd rather just check for feature enablement directly:

import BiometricAuthenticator

let bioAuth = BiometricAuthenticator()

if bioAuth.isTouchIdEnabledOnDevice() {
    ...
}

if bioAuth.isFaceIdEnabledOnDevice() {
    ...
}

Handling Authentication Errors

The BiometricAuthenticator relies on the Local Authentication module's provided error codes. The relevant error codes are below with a bit about what they cover.

appCancel - The application cancelled the biometric prompt

authenticationFailed - The provided fingerprint or face was not recognized by iOS

biometryLockout - Authentication could not continue because the user has been locked out of biometric authentication, due to failing authentication too many times.

biometryNotAvailable - Authentication could not start because the device does not support biometric authentication.

biometryNotEnrolled - Authentication could not start because the user has not enrolled in biometric authentication.

passcodeNotSet - Authentication could not start because the passcode is not set on the device.

systemCancel - Authentication was canceled by the system (can be caused by another application taking foreground while the authentication dialog was up)

userCancel - User cancelled by clicking the cancel option in the authentication dialog.

userFallback - Authentication was canceled because the user tapped the fallback button in the authentication dialog, but no fallback is available for the authentication policy.

Requirements

Xcode 8+, iOS 9.0+

Installation

BiometricAuthenticator is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'BiometricAuthenticator'

Author

Chris Corea, [email protected]

License

BiometricAuthenticator is available under the MIT license. See the LICENSE file for more info.