FingerLock
FingerLock is a library designed to make fingerprint authentication an easy task for Android developers.
Note: this library is powered by material-dialogs, depending on this library will automatically depend on Material Dialogs.
Check the related post on Medium.
Gradle Dependency
Repository
repositories {
maven { url "https://jitpack.io" }
}Dependencies
Core
The core module contains the core class FingerLock to perform full fingerprint authentication.
dependencies {
// ... other dependencies here
compile 'com.github.aitorvs.fingerlock:core:1.0.0'
}Fingerprint Dialog Extension
The dialog extension module is powered by material-dialogs library and provides an out-of-the-box-ready material authentication dialog based on the design guidelines on fingerprint authentication.
dependencies {
// ... other dependencies here
compile 'com.github.aitorvs.fingerlock:dialog:1.0.0'
}Manifest
The library requires the USE_FINGERPRINT permission. Just add the following to your AndroidManifest.xml file
<uses-permission android:name="android.permission.USE_FINGERPRINT"/>
Core
The core module requires Android M and above and also a device supporting fingerprint sensor. If you target devices before M or not having fingerprint sensors, use the dialog extension.
(Core) FingerLock in 4 steps
1. Implement the FingerLockResultCallback inside your Activity/Fragment
public class MainActivity extends AppCompatActivity
implements FingerLockResultCallback {
//...
}2. Initialize the library (e.g. inside onCreate() method)
@Override
protected void onCreate(Bundle savedInstanceState) {
private FingerLockManager mFingerLockManager;
// ... Some code here
// returns a manager object to manage the fingerprint authentication
mFingerLockManager = FingerLock.initialize(this, KEY_NAME);
}3. Start the fingerprint scanning
It is as simple as calling the start() method.
@Override
protected void onCreate(Bundle savedInstanceState) {
// ... Some code here
mButton = (Button) findViewById(R.id.button_authenticate);
mButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mFingerLockManager.start();
}
});
// ... Some more code here
}4. Handle the callbacks
Library is ready
@Override
public void onFingerLockReady() {
// Called right after registration if the device supports fingerprint authentication.
// This is normally a good place to call mFingerLockManager.start()
}This method is called when the library finishes the registration process successfully.
This is normally a good place to call start() so start the fingerprint(s) scanning process.
Fingerprint(s) Scanning
@Override
public void onFingerLockScanning(boolean invalidKey) {
// Called to notify the fingerprint scanning is started successfully as a result of mFingerLockManager.start()
// The 'invalidKey' parameter will be true when the key is no longer valid. This happens when
// the user disables the lock screen, resets or adds a new fingerprint after the key was created (i.e. mFingerLockManager.register())
}The callback onFingerLockScanning(boolean) is called when the library has started
scanning for fingerprint(s) to authenticate the user. The input parameter invalidKey flags when the key provided
during registration is no longer valid. Either because the user disabled the lock screen, device reset or
a new fingerprint was added.
For security purposes it is recommended to stop scanning fingerpring(s) calling stop() and
fallback to any other type of authentication (i.e. password) that authenticates the user and let
them use fingerprint the next time.
Authenticated
@Override
public void onFingerLockAuthenticationSucceeded() {
// Called when the user fingerprint has been correctly authenticated
}This method is called upon successful fingerprint authentication.
Error
The callback provides error events that may happen throughout the fingerprint authentication process.
@Override
public void onFingerLockError(@FingerLock.FingerLockErrorState int errorType, Exception e) {
// Called every time there's an error at any stage during the authentication
switch (errorType) {
case FingerLock.FINGERPRINT_PERMISSION_DENIED:
// USE_PERMISSION is denied by the user, fallback to password authentication
break;
case FingerLock.FINGERPRINT_ERROR_HELP:
// there's some kind of recoverable error that can be solved. Call e.getMessage()
// to get help about the error
break;
case FingerLock.FINGERPRINT_NOT_RECOGNIZED:
// The fingerprint was not recognized, try another one
break;
case FingerLock.FINGERPRINT_NOT_SUPPORTED:
// Fingerprint authentication is not supported by the device. Fallback to password
// authentication
break;
case FingerLock.FINGERPRINT_REGISTRATION_NEEDED:
// There are no fingerprints registered in this device.
// Go to Settings -> Security -> Fingerprint and register at least one
break;
case FingerLock.FINGERPRINT_UNRECOVERABLE_ERROR:
// Unrecoverable internal error occurred. Unregister and register back
break;
}
}Dialog extension
The dialog extension module provides an out-of-the-box-ready material design dialog implementation that follows the design rules for fingerprint authentication and handles the core library module for you. The dialog extension automatically falls back to password authentication when the device does not support fingerprint authentication.
public class MainActivity extends AppCompatActivity implements FingerprintDialog.Callback {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// show fingerprint dialog
FingerprintDialog.show(MainActivity.this, KEY_NAME, REQUEST_CODE);
}
@Override
public void onFingerprintDialogAuthenticated() {
// Authentication is successful
}
@Override
public void onFingerprintDialogVerifyPassword(final FingerprintDialog dialog, final String password) {
// Password verification has been requested. Use this method to verify the `password` passed
// as parameter against your backend
// Simulate exchange with backend
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
dialog.notifyPasswordValidation(password.equals("aitorvs"));
}
}, 1500);
}
@Override
public void onFingerprintDialogStageUpdated(FingerprintDialog dialog, FingerprintDialog.Stage stage) {
Log.d(TAG, "Dialog stage: " + stage.name());
}
public enum Stage {
FINGERPRINT, // fingerprint authentication allowed
KEY_INVALIDATED, // key invalidated, password to be required
PASSWORD // password authentication selected by the user
}
@Override
public void onFingerprintDialogCancelled() {
Toast.makeText(this, R.string.dialog_cancelled, Toast.LENGTH_SHORT).show();
}
}(Dialog) FingerLock in 3 steps
1. Implement the dialog callbacks
public class MainActivity extends AppCompatActivity
implements FingerprintDialog.Callback {
//...Looooots of code here
}2. Create and show the dialog
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// create and show the fingerprint dialog using the Builder
new FingerprintDialog.Builder()
.with(MainActivity.this) // context, must call
.setKeyName(KEY_NAME) // String key name, must call
.setRequestCode(69) // request code identifier, must call
.show(); // show the dialog
}Additionally, one could also call setCancelable(Boolean) in the builder
to set the dialog as cancelable or not. This call is optional and default
value is set to true.
3. Handle callbacks
Authenticated
@Override
public void onFingerprintDialogAuthenticated() {
// Authentication is successful
}Verify password
@Override
public void onFingerprintDialogVerifyPassword(final FingerprintDialog dialog, final String password) {
// Password verification has been requested. Use this method to verify the `password` passed
// as parameter against your backend
// Simulate exchange with backend
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
dialog.notifyPasswordValidation(password.equals("aitorvs"));
}
}, 1500);
}Called when password verification is required. Either because triggered automatically when the provided key is no longer valid or because the user required so.
Once the password is verified, notify the dialog calling dialog.notifyPasswordValidation(boolean).
State updated
@Override
public void onFingerprintDialogStageUpdated(FingerprintDialog dialog, FingerprintDialog.Stage stage) {
Log.d(TAG, "Dialog stage: " + stage.name());
}Method called at every internal stage change. Possible states are:
public enum Stage {
FINGERPRINT, // fingerprint authentication allowed
KEY_INVALIDATED, // key invalidated, password to be required
PASSWORD // password authentication selected by the user
}It is normally not necessary to act on any of the stages.
Authentication cancelled
Called when the user cancels the authentication dialog.
@Override
public void onFingerprintDialogCancelled() {
Toast.makeText(this, R.string.dialog_cancelled, Toast.LENGTH_SHORT).show();
}License
The MIT License (MIT)
Copyright (c) 2016 Aitor Viana Sanchez
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.