How to use passcode lock scene in my app?

Question

Actually, I building an app which contains local authentication.

My code so far:

func authenticateUser() {
        let authenticationContext = LAContext()
        var error: NSError?
        let reasonString = "Touch the Touch ID sensor to unlock."

        // Check if the device can evaluate the policy.
        if authenticationContext.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error: &error) {

            authenticationContext.evaluatePolicy( .deviceOwnerAuthenticationWithBiometrics, localizedReason: reasonString, reply: { (success, evalPolicyError) in

                if success {
                    print("success")
                } else {
                    if let evaluateError = error as NSError? {
                        // enter password using system UI 
                    }

                }
            })

        } else {
            print("toch id not available")
           // enter password using system UI
        }
    }

My problem is I want to use the passcode lock scene when the app doesn't has touch ID or invalid finger print.

Like below Image:

How can I do it?

You should be able to do that by using keychain I believe. – GoodSp33d Jul 06 '17 at 08:54 — GoodSp33d, Jul 06 '17 at 08:54

score 13 · Answer 1 · edited Jun 20 '20 at 09:12

You should use .deviceOwnerAuthentication instead of .deviceOwnerAuthenticationWithBiometrics to evaluate policy. With this parameter the system uses biometric authentication if available else it presents passcode screen. And if the biometric authentication is available but fails, a fallback button redirect to the passcode screen. See documentation :

If Touch ID or Face ID is available, enrolled, and not disabled, the user is asked for that first. Otherwise, they are asked to enter the device passcode.

Tapping the fallback button switches the authentication method to ask the user for the device passcode.

So your code will be:

func authenticateUser() {
        let authenticationContext = LAContext()
        var error: NSError?
        let reasonString = "Touch the Touch ID sensor to unlock."

        // Check if the device can evaluate the policy.
        if authenticationContext.canEvaluatePolicy(LAPolicy.deviceOwnerAuthentication, error: &error) {

            authenticationContext.evaluatePolicy( .deviceOwnerAuthentication, localizedReason: reasonString, reply: { (success, evalPolicyError) in

                if success {
                    print("success")
                } else {
                    // Handle evaluation failure or cancel
                }
            })

        } else {
            print("passcode not set")
        }
    }

So passcode code would come at // Handle evaluation failure or cancel place right? — shaqir saiyed, Mar 15 '19 at 11:55
This works great. For anyone using this method remember to import LocalAuthentication. — Marcy, Dec 25 '19 at 02:04

score 0 · Accepted Answer · answered Jul 06 '17 at 07:19

0

At this point, I am afraid that you cannot access this passcode lock screen into your app, it is related to the iOS itself. You might need to build your own custom view controller to look/behave as the passcode lock scene (with Touch ID). I would suggest to use a library for achieving this, personally, I've tried PasscodeLock and it works fine for me.

answered Jul 06 '17 at 07:19

Ahmad F

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is customizable passcode screen accpeted by apple ?! – shaqir saiyed Mar 15 '19 at 11:53
@shaqirsaiyed yes, I've used it in more than one app and it is acceptable. – Ahmad F Mar 15 '19 at 12:49
Hopefully someone can answer: I've tried PasscodeLock, and when I attempt to customize it, it seems you have to do the whole thing from scratch. Is this correct, or should the PlaceholderView load with all the buttons and labels in place? Right now I'm using the SwiftPasscodeLock Version. – Pleirosei Mar 30 '20 at 15:25

How to use passcode lock scene in my app?

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