React Native Simple Biometrics

Overview

React Native Simple Biometrics is a straightforward and minimalistic React Native package designed to provide developers with an API for implementing user authentication using on-device biometrics. This library facilitates the quick verification of the app's user, ensuring that sensitive information is only accessible to authorized individuals, such as the phone owner or a trustee.

Installation

To get started with React Native Simple Biometrics, you can add it to your project using Yarn:

$ yarn add react-native-simple-biometrics

Minimum Requirements

• iOS target: 10.0
• Android minSdkVersion: 21

iOS Permission

To utilize the Face ID system on iOS devices, it is mandatory to include an entry in your iOS app's info.plist, explaining the valid reason for using biometrics:

<key>NSFaceIDUsageDescription</key>
<string>a valid reason to use biometrics</string>

When you call the authenticate function, iOS users will be automatically prompted for permission. For more granular control over when to request permissions, you can utilize the react-native-permissions package.

Usage

React Native Simple Biometrics offers two main methods:

1. canAuthenticate(options?: Options): Checks whether the device supports biometric authentication. Returns true if the hardware is available or if permission for Face ID (iOS) was granted.

Parameters

• options (optional): An object containing configuration options
  • allowDeviceCredentials (boolean, default: true): Whether to allow device credentials (passcode/password) as a fallback when biometric authentication is not available

Return Value

Returns a Promise that resolves to:

• true if authentication is possible with the specified options
• false if authentication is not possible

2. requestBioAuth(promptTitle: string, promptMessage: string, options?: Options): Initiates the biometric authentication process, displaying a user-friendly prompt with the specified title and message. This function can be used for user authentication.

Required Parameters

• promptTitle (string): The title displayed in the authentication dialog Must be a non-empty string Throws an error if not provided or empty
• promptMessage (string): The subtitle/reason for requesting authentication Must be a non-empty string Throws an error if not provided or empty Displays in the authentication dialog to explain why authentication is needed

Optional Parameters

• options (object, optional): Configuration options
  • allowDeviceCredentials (boolean, default: true): Whether to allow device credentials (passcode/password) as a fallback when biometric authentication is not available

Return Value

Returns a Promise that:

• Resolves to true when authentication is successful
• Rejects with an error when authentication fails or is cancelled

Here's a code snippet demonstrating how to use these methods:

import RNBiometrics from 'react-native-simple-biometrics';

// Check if biometric authentication is available, will fallback to device passcode by default if not
const can = await RNBiometrics.canAuthenticate();

if (can) {
  try {
    await RNBiometrics.requestBioAuth('prompt-title', 'prompt-message');
    // Code to execute when authenticated
    // ...
  } catch (error) {
    // Code to handle authentication failure
    // ...
  }
}

Credits

React Native Simple Biometrics is a simplified version of react-native-biometrics. If you require advanced features such as key generation, signatures, and more, consider using react-native-biometrics.