Capacitor Native Biometric

Use biometrics confirm device owner presence or authenticate users. A couple of methods are provided to handle user credentials. These are securely stored using Keychain (iOS) and Keystore (Android).

Installation

• npm i capacitor-native-biometric

Usage

import { Plugins } from "@capacitor/core";

const { NativeBiometric } = Plugins;

// Check if biometrics are available and which type is supported
Plugins.NativeBiometric.isAvailable().then(
  (result: AvailableResult) => {
    const isAvailable = result.isAvailable;
    const isFaceId = result.biometryType == BiometryType.FACE_ID;

    if (isAvailable) {
      // Get user's credentials
      Plugins.NativeBiometric.getCredentials({
        server: "www.example.com",
      }).then((credentials: Credentials) => {
        // Authenticate using biometrics before logging the user in
        Plugins.NativeBiometric.verifyIdentity({
          reason: "For easy log in",
          title: "Log in",
          subtitle: "Maybe add subtitle here?",
          description: "Maybe a description too?",
        }).then(
          () => {
            // Authentication successful
            this.login(credentials.username, credentials.password);
          },
          (error) => {
            // Failed to authenticate
          }
        );
      });
    }
  },
  (error) => {
    // Couldn't check availability
  }
);

// Save user's credentials
Plugins.NativeBiometric.setCredentials({
  username: "username",
  password: "password",
  server: "www.example.com",
}).then();

// Delete user's credentials
Plugins.NativeBiometric.deleteCredentials({
  server: "www.example.com",
}).then();

Methods

Method	Default	Type	Description
isAvailable()		Promise<AvailableOptions>	Gets available biometrics
verifyIdentity(options?: BiometricOptions)		Promise<any>	Shows biometric prompt
setCredentials(options: SetCredentialOptions)		Promise<any>	Securely stores user's credentials in Keychain (iOS) or encypts them using Keystore (Android)
getCredentials(options: GetCredentialOptions)		Promise<Credentials>	Retrieves user's credentials if any
deleteCredentials(options: DeleteCredentialOptions)		Promise<any>	Removes user's credentials if any

Interfaces

AvailableOptions

Properties	Default	Type	Description
isAvailable		boolean	Specifies if the devices has biometric enrollment
biometryType		BiometricType	Specifies if the available biometric hardware on the device

BiometryType - enum

Properties	Description
NONE	There is no biometry available
TOUCH_ID	TouchID is available (iOS)
FACE_ID	FaceID is available (iOS)
FINGERPRINT	Fingerprint is available (Android)
FACE_AUTHENTICATION	Face Authentication is available (Android)
IRIS_AUTHENTICATION	Iris Authentication is available (Android)

BiometricOptions

Properties	Default	Type	Description
reason?	"For biometric authentication"	string	Reason for requesting authentication in iOS. Displays in the authentication dialog presented to the user.
title?	"Authenticate"	string	Title for the Android prompt
subtitle?		string	Subtitle for the Android prompt
description?		string	Description for the Android prompt
negativeButtonText?	"Cancel"	string	Text for the negative button displayed on Android

SetCredentialOptions

Properties	Default	Type	Description
username		string	The string used as the alias at the time of loggin in. It doesn't have to be a username. For example if you're using email to log in your users then provide the email.
password		string	The users' password
server		string	Any string to identify the credentials object with

GetCredentialOptions

Properties	Default	Type	Description
server		string	The string used to identify the credentials object when setting the credentials

DeleteCredentialOptions

Properties	Default	Type	Description
server		string	The string used to identify the credentials object when setting the credentials

Face ID (iOS)

To use FaceID Make sure to provide a value for NSFaceIDUsageDescription, otherwise your app may crash on iOS devices with FaceID.

This value is just the reason for using FaceID. You can add something like the following example to App/info.plist:

<key>NSFaceIDUsageDescription</key>
<string>For an easier and faster log in.</string>

Biometric (Android)

To use android's BiometricPrompt api you must add the following permission to your AndroidManifest.xml:

<uses-permission android:name="android.permission.USE_BIOMETRIC">

And register the plugin by adding it to you MainActivity's onCreate:

import com.epicshaggy.biometric.NativeBiometric;

public class MainActivity extends BridgeActivity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Initializes the Bridge
    this.init(savedInstanceState, new ArrayList<Class<? extends Plugin>>() {{
      // Additional plugins you've installed go here
      // Ex: add(TotallyAwesomePlugin.class);
      add(NativeBiometric.class);
    }});
  }
}

Notes

Hasn't been tested on Android API level 22 or lower.