Maui.Biometric

Provides a cross-platform implementation of biometric authentication.
Supports iOS, macOS, Android and Windows.
Continuation of the abandoned Plugin.Fingerprint in the MAUI ecosystem.

Usage

• Add NuGet package to your project:

<PackageReference Include="Oscore.Maui.Biometric" Version="1.0.0" />

• iOS - Add NSFaceIDUsageDescription to your Info.plist to describe the reason your app uses Face ID. (see Documentation). Otherwise the App will crash when you start a Face ID authentication on iOS 11.3+.

<key>NSFaceIDUsageDescription</key>
<string>Need your face to unlock secrets!</string>

• Android - Request the permission in AndroidManifest.xml

<uses-permission android:name="android.permission.USE_FINGERPRINT" android:maxSdkVersion="27" />
<uses-permission android:name="android.permission.USE_BIOMETRIC" android:minSdkVersion="28" />

• Add the following to your MauiProgram.cs CreateMauiApp method:

builder
    .UseMauiApp<App>()
+   .UseBiometricAuthentication()
    .ConfigureFonts(fonts =>
    {
        fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
        fonts.AddFont("OpenSans-Sed:nammibold.ttf", "OpenSansSemibold");
    });

• Use through BiometricAuthentication.Current or using IBiometricAuthentication from DI:

var result = await BiometricAuthentication.Current.AuthenticateAsync(
    new AuthenticationRequest(
        title: "Prove you have fingers!",
        reason: "Because without it you can't have access"));
if (result.Authenticated)
{
    // do secret stuff :)
}
else
{
    // not allowed to do secret stuff :(
}

Testing on Simulators

iOS

With the Hardware menu you can

• Toggle the enrollment status
• Trigger valid (⌘ ⌥ M) and invalid (⌘ ⌥ N) fingerprint sensor events

Android

• start the emulator (Android >= 6.0)
• open the settings app
• go to Security > Fingerprint, then follow the enrollment instructions
• when it asks for touch
• open command prompt
• telnet 127.0.0.1 <emulator-id> (adb devices prints "emulator-<emulator-id>")
• finger touch 1
• finger touch 1

Sending fingerprint sensor events for testing the plugin can be done with the telnet commands, too.

Note for Windows users: You have to enable telnet: Programs and Features > Add Windows Feature > Telnet Client

Links

• https://github.com/smstuebe/xamarin-fingerprint
• https://stackoverflow.com/questions/633132/is-ms-pl-microsoft-public-license-code-allowed-in-commercial-product

Legal information and credits

It was forked from the xamarin-fingerprint project.
xamarin-fingerprint is a project by Sven-Michael Stübe.
It was licensed under the MS-PL license.
This fork changes the license to MIT with attribution to the original license.