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cordova-plugin-touch-id

Cordova TouchID Plugin

by Eddy Verbruggen

0. Index

  1. Description
  2. Screenshot
  3. Installation
    1. Automatically (CLI / Plugman)
    2. Manually
  4. Usage
  5. Security++
  6. License

1. Description

Scan the fingerprint of your user with the TouchID sensor (iPhone 5S).

  • Compatible with Cordova Plugman.
  • Minimum iOS version is 8 (error callbacks will be gracefully invoked on lower versions).
  • Requires a fingerprint scanner, so an iPhone 5S or newer is required.

2. Screenshot

Distorted a bit because I created it back when Apple had not yet released the SDK and they're not a fan of developers posting screenshots of unreleased features.

ScreenShot

3. Installation

Automatically (CLI / Plugman)

Compatible with Cordova Plugman, compatible with PhoneGap 3.0 CLI, here's how it works with the CLI (backup your project first!):

From npm:

$ cordova plugin add cordova-plugin-touch-id
$ cordova prepare

The latest, from the master repo:

$ cordova plugin add https://github.com/EddyVerbruggen/cordova-plugin-touch-id
$ cordova prepare

TouchID.js is brought in automatically. There is no need to change or add anything in your html.

Manually

1. Add the following xml to your config.xml in the root directory of your www folder:

<feature name="TouchID">
  <param name="ios-package" value="TouchID" />
</feature>

You'll need to add the LocalAuthentication.framework and Security.framework to your project. Click your project, Build Phases, Link Binary With Libraries, search for and add the frameworks.

2. Grab a copy of TouchID.js, add it to your project and reference it in index.html:

<script type="text/javascript" src="js/TouchID.js"></script>

3. Download the source files and copy them to your project.

iOS: Copy the two .h and two .m files to platforms/ios/<ProjectName>/Plugins

4. Usage

First you'll want to check whether or not the user has a configured fingerprint scanner. You can use this to show a 'log in with your fingerprint' button next to a username/password login form.

window.plugins.touchid.isAvailable(
  function(msg) {alert('ok: ' + msg)},    // success handler: TouchID available 
  function(msg) {alert('not ok: ' + msg)} // error handler: no TouchID available 
);

If the onSuccess handler was called, you can scan the fingerprint. There are two options: verifyFingerprint and verifyFingerprintWithCustomPasswordFallback. The first method will offer a fallback option called 'enter passcode' which shows the default passcode UI when pressed. The second method will offer a fallback option called 'enter password' (not passcode) which allows you to provide your own password dialog.

window.plugins.touchid.verifyFingerprint(
  'Scan your fingerprint please', // this will be shown in the native scanner popup 
   function(msg) {alert('ok: ' + msg)}, // success handler: fingerprint accepted 
   function(msg) {alert('not ok: ' + JSON.stringify(msg))} // error handler with errorcode and localised reason 
);

The errorhandler of the method above can receive an error code of -2 which means the user pressed the 'enter password' fallback.

window.plugins.touchid.verifyFingerprintWithCustomPasswordFallback(
  'Scan your fingerprint please', // this will be shown in the native scanner popup 
   function(msg) {alert('ok: ' + msg)}, // success handler: fingerprint accepted 
   function(msg) {alert('not ok: ' + JSON.stringify(msg))} // error handler with errorcode and localised reason 
);

This will render a button labelled 'Enter password' in case the fingerprint is not recognized. If you want to provide your own label ('Enter PIN' perhaps), you can use awkwardly named function (added in version 3.1.0):

window.plugins.touchid.verifyFingerprintWithCustomPasswordFallbackAndEnterPasswordLabel(
  'Scan your fingerprint please', // this will be shown in the native scanner popup 
  'Enter PIN', // this will become the 'Enter password' button label 
   function(msg) {alert('ok: ' + msg)}, // success handler: fingerprint accepted 
   function(msg) {alert('not ok: ' + JSON.stringify(msg))} // error handler with errorcode and localised reason 
);

You can copy-paste these lines of code for a quick test:

<button onclick="window.plugins.touchid.isAvailable(function(msg) {alert('ok: ' + msg)}, function(msg) {alert('not ok: ' + msg)})">Touch ID available?</button>
<button onclick="window.plugins.touchid.verifyFingerprint('Scan your fingerprint please', function(msg) {alert('ok: ' + msg)}, function(msg) {alert('not ok: ' + JSON.stringify(msg))})">Scan fingerprint</button>

5. Security++

Since iOS9 it's possible to check whether or not the list of enrolled fingerprints changed since the last time you checked it. It's recommended you add this check so you can counter hacker attacks to your app. See this article for more details.

So instead of checking the fingerprint after isAvailable add another check. In case didFingerprintDatabaseChange returns true you probably want to re-authenticate your user before accepting valid fingerprints again.

window.plugins.touchid.isAvailable(
  function(available) {
    if (available) {
      window.plugins.touchid.didFingerprintDatabaseChange(
        function(changed) {
          if (changed) {
            // re-auth the user by asking for his credentials before allowing a fingerprint scan again 
          } else {
            // call the fingerprint scanner 
          }
        }
      );
    }
  }
);

6. License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.