How to programmatically check support of 'Face Id' and 'Touch Id'

Question

I've integrated LocalAuthentication for my app security purpose, which has been supporting 'Touch Id' based supporting. But now, apple has recently added 'Face Id' based authentication also.

How can I check, which type of authentication is supported by a device. Touch Id or Face Id?

Answer 1

With Xcode 9, Look at LocalAuthentication -> LAContext -> LABiometryType.

LABiometryType is a enum with values as in attached image

You can check which authentication type supported by device between Touch ID and FaceID or none.

Edit:

Apple have updated values for this enum LABiometryType. none is deprecated now.

Answer 2

I've been struggling to get this to work and found that I needed to use a single instance of the LAContext and needed to call the LAContextInstance.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) before getting the biometryType. Here is my final code with support for older iOS versions:

import LocalAuthentication

static func biometricType() -> BiometricType {
    let authContext = LAContext()
    if #available(iOS 11, *) {
        let _ = authContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
        switch(authContext.biometryType) {
        case .none:
            return .none
        case .touchID:
            return .touch
        case .faceID:
            return .face
        }
    } else {
        return authContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) ? .touch : .none
    }
}

enum BiometricType {
    case none
    case touch
    case face
}

Answer 3

As I am a big fan of extension. I phrase this answer a little differently. Essense is the same. This is a drop-in extension.

import LocalAuthentication

extension LAContext {
    enum BiometricType: String {
        case none
        case touchID
        case faceID
    }

    var biometricType: BiometricType {
        var error: NSError?

        guard self.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
            // Capture these recoverable error thru Crashlytics
            return .none
        }

        if #available(iOS 11.0, *) {
            switch self.biometryType {
            case .none:
                return .none
            case .touchID:
                return .touchID
            case .faceID:
                return .faceID
            }
        } else {
            return  self.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) ? .touchID : .none
        }
    }
}

Use like this:

var currentType = LAContext().biometricType

Answer 4

Objective C :)

/** Only interesting devices are enumerated here. To change view constraints depending
 on screen height. Or the top notch for iPhone X
 */
typedef NS_ENUM(NSUInteger, BPDeviceType) {
    BPDeviceTypeUnknown,
    BPDeviceTypeiPhone4,
    BPDeviceTypeiPhone5,
    BPDeviceTypeiPhone6,
    BPDeviceTypeiPhone6Plus,
    BPDeviceTypeiPhone7,
    BPDeviceTypeiPhone7Plus,
    BPDeviceTypeiPhoneX,
    BPDeviceTypeiPad
};

+ (BPDeviceType)getDeviceType {
    double screenHeight = [[UIScreen mainScreen] bounds].size.height;
    if(UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad)
    {
        return BPDeviceTypeiPad;

    } else if (UI_USER_INTERFACE_IDIOM()== UIUserInterfaceIdiomPhone)
    {
        if (@available(iOS 11, *)) {
            UIEdgeInsets insets = [UIApplication sharedApplication].delegate.window.safeAreaInsets;
            if (insets.top > 0) {
                return BPDeviceTypeiPhoneX;
            }
        }

        if(screenHeight == 480) {
            return BPDeviceTypeiPhone4;
        } else if (screenHeight == 568) {
            return BPDeviceTypeiPhone5;
        } else if (screenHeight == 667) {
            return BPDeviceTypeiPhone6;
        } else if (screenHeight == 736) {
            return BPDeviceTypeiPhone6Plus;
        }
    }
    return BPDeviceTypeUnknown;
}

+ (BOOL) isBiometricIDAvailable {
    if (![LAContext class]) return NO;

    LAContext *myContext = [[LAContext alloc] init];
    NSError *authError = nil;
    if (![myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) {
        NSLog(@"%@", [authError localizedDescription]);
        return NO;
    }
    return YES;
}

+ (BOOL) isTouchIDAvailable {
    if (![LAContext class]) return NO;

    LAContext *myContext = [[LAContext alloc] init];
    NSError *authError = nil;
    if (![myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) {
        NSLog(@"%@", [authError localizedDescription]);
        return NO;
        // if (authError.code == LAErrorTouchIDNotAvailable) {}
    }

    if (@available(iOS 11.0, *)) {
        if (myContext.biometryType == LABiometryTypeTouchID){
            return YES;
        } else {
            return NO;
        }
    } else {
        return YES;
    }
}

+ (BOOL) supportFaceID {
    return [BPDeviceInfo getDeviceType] == BPDeviceTypeiPhoneX;
}

+ (BOOL) isFaceIDAvailable {
    if (![LAContext class]) return NO;

    LAContext *myContext = [[LAContext alloc] init];
    NSError *authError = nil;
    if (![myContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&authError]) {
        NSLog(@"%@", [authError localizedDescription]);
        return NO;
    }

    if (@available(iOS 11.0, *)) {
        if (myContext.biometryType == LABiometryTypeFaceID){
            return YES;
        } else {
            return NO;
        }
    } else {
        return NO;
    }
}

Answer 5

Here is one more way via the property (for example, on your access instance).

import LocalAuthentication


enum BiometricType {
    case none
    case touchID
    case faceID
}

var biometricType: BiometricType {
    get {
        let context = LAContext()
        var error: NSError?

        guard context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
            print(error?.localizedDescription ?? "")
            return .none
        }

        if #available(iOS 11.0, *) {
            switch context.biometryType {
            case .none:
                return .none
            case .typeTouchID:
                return .touchID
            case .typeFaceID:
                return .faceID
            }
        } else {
            return  .touchID
        }
    }
}

Answer 6

Face ID is available from iOS 11 and iPhone X comes with iOS 11 by default. In the LocalAuth framework they have added a 'biometryType' property which can give you ability to detect whether Face ID is available on device.

/// checks if face id is avaiable on device
func faceIDAvailable() -> Bool {
    if #available(iOS 11.0, *) {
        let context = LAContext()
        return (context.canEvaluatePolicy(LAPolicy.deviceOwnerAuthentication, error: nil) && context.biometryType == .faceID)
    }
    return false
}

Answer 7

Here is my "helper class", it includes passcode also

enum BiometryType: String {
    case none = "None"
    case faceID = "Face ID"
    case touchID = "Touch ID"
    case passcode = "Passcode"
}


var biometryType: BiometryType {
    let myContext = LAContext()

    let hasAuthenticationBiometrics = myContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
    let hasAuthentication = myContext.canEvaluatePolicy(.deviceOwnerAuthentication, error: nil)

    if #available(iOS 11.0, *) {
        if hasAuthentication {
            if hasAuthenticationBiometrics {
                switch myContext.biometryType {
                case .none: return .none
                case .faceID: return .faceID
                case .touchID: return .touchID
                }
            } else {
                return .passcode
            }
        } else {
            return .none
        }
    } else {
        if hasAuthentication {
            if hasAuthenticationBiometrics {
                return .touchID
            } else {
                return .passcode
            }
        } else {
            return .none
        }
    }
}

Answer 8

I made a singleton class for local authentication as it helps to initialise an instance one time using static property for the entire application.

import Foundation
import LocalAuthentication

public class LocalAuthManager: NSObject {

    public static let shared = LocalAuthManager()
    private let context = LAContext()
    private let reason = "Your Request Message"
    private var error: NSError?

    enum BiometricType: String {
        case none
        case touchID
        case faceID
    }

    private override init() {

    }

    // check type of local authentication device currently support
    var biometricType: BiometricType {
        guard self.context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) else {
            return .none
        }

        if #available(iOS 11.0, *) {
            switch context.biometryType {
            case .none:
                return .none
            case .touchID:
                return .touchID
            case .faceID:
                return .faceID
            }
        } else {
            return self.context.canEvaluatePolicy(.deviceOwnerAuthentication, error: nil) ? .touchID : .none
        }
    }
}

Implementation:

func checkAuth() {
     let authType = LocalAuthManager.shared.biometricType
        switch authType {
        case .none:
            print("Device not registered with TouchID/FaceID")
        case .touchID:
            print("Device support TouchID")
        case .faceID:
            print("Device support FaceID")
        }
 }

Answer 9

This code builds without warnings on Xcode 9.2-9.4 (see comments for 9.1):

@objc let biometricsAuthPolicy = LAPolicy.deviceOwnerAuthenticationWithBiometrics

@objc func supportsFaceID() -> Bool {
    if #available(iOS 11.0, *) {
        return biometryType() == .faceID // return biometryType() == .typeFaceID for Xcode 9.1
    }
    return false
}

@objc func supportsTouchID() -> Bool {
    if #available(iOS 11.0, *) {
        return biometryType() == .touchID // return biometryType() == .typeTouchID for Xcode 9.1
    }

    let context = LAContext()
    return context.canEvaluatePolicy(biometricsAuthPolicy, error: nil)
}

@objc @available(iOS 11.0, *)
func biometryType() -> LABiometryType {
    var error: NSError?
    let context = LAContext()

    guard context.canEvaluatePolicy(biometricsAuthPolicy, error: &error) else {
        if #available(iOS 11.2, *) {
            return .none
        }
        return LABiometryType.LABiometryNone // return LABiometryType.none for Xcode 9.1
    }

    return context.biometryType
}

Answer 10

From @Markicevic extension, but ignoring cases where user is not enrolled, etc...

extension LAContext {

enum BiometricType: String {
    case none = ""
    case touchID = "Touch ID"
    case faceID = "Face ID"
}

static var biometricType: BiometricType {
    var error: NSError?

    let context = LAContext()

    _ = context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error)

    if error?.code == LAError.Code.touchIDNotAvailable.rawValue {
        return .none
    }

    if #available(iOS 11.0, *) {
        switch context.biometryType {
        case .none:
            return .none
        case .touchID:
            return .touchID
        case .faceID:
            return .faceID
        }
    } else {
        return  context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil) ? .touchID : .none
    }
}

}