react-native-local-auth

Authenticate users with Touch ID, with optional fallback to passcode (if TouchID is unavailable or not enrolled). Most of the code and documentation is originally from react-native-touch-id, but together with naoufal we decided that fallback to passcode didn't belong in react-native-touch-id.

Documentation

- UI
- Install
- Usage
- Errors
- License

UI

If TouchID is supported and enrolled (in this gif, 1st touch fails, 2nd succeeds)

!Touch ID

If TouchID is not supported or not enrolled, you can fallback to device passcode

!fallback to passcode

Install

``shell
npm i --save react-native-local-auth
`

$3

First link the library to your project. There's excellent documentation on how to do this in the React Native Docs.

#### Android

1. Open up android/app/src/main/java/[...]/MainActivity.java
- Add import io.tradle.reactlocalauth.LocalAuthPackage; to the imports at the top of the file
- Add new LocalAuthPackage() to the list returned by the getPackages() method
2. Append the following lines to android/settings.gradle:
`
include ':react-native-local-auth'
project(':react-native-local-auth').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-local-auth/android')
`
3. Insert the following lines inside the dependencies block in android/app/build.gradle:
`
compile project(':react-native-local-auth')
`

Usage

`js
var LocalAuth = require('react-native-local-auth')

var YourComponent = React.createClass({
_pressHandler() {
LocalAuth.authenticate({
reason: 'this is a secure area, please authenticate yourself',
fallbackToPasscode: true, // fallback to passcode on cancel
suppressEnterPassword: true // disallow Enter Password fallback
})
.then(success => {
AlertIOS.alert('Authenticated Successfully')
})
.catch(error => {
AlertIOS.alert('Authentication Failed', error.message)
})
},

render() {
return (

...


Authenticate with Touch ID / Passcode



)
}
})
`

$3


check if Touch ID is supported.
Returns a Promise object.

Errors

There are various reasons why authenticating with Touch ID or device passcode may fail. Whenever authentication fails, LocalAuth.authenticate will return an error code representing the reason.

Below is a list of error codes that can be returned:

| Code | Description |
|---|---|
| LAErrorAuthenticationFailed | Authentication was not successful because the user failed to provide valid credentials. |
| LAErrorUserCancel | Authentication was canceled by the user—for example, the user tapped Cancel in the dialog. |
| LAErrorUserFallback | Authentication was canceled because the user tapped the fallback button (Enter Password). |
| LAErrorSystemCancel | Authentication was canceled by system—for example, if another application came to foreground while the authentication dialog was up. |
| LAErrorPasscodeNotSet | Authentication could not start because the passcode is not set on the device. |
| LAErrorTouchIDNotAvailable | Authentication could not start because Touch ID is not available on the device |
| LAErrorTouchIDNotEnrolled | Authentication could not start because Touch ID has no enrolled fingers. |
| RCTTouchIDUnknownError | Could not authenticate for an unknown reason. |
| RCTTouchIDNotSupported` | Device does not support Touch ID. |

_More information on errors can be found in Apple's Documentation._

License

ISC. react-native-touch-id license also included.