Goldfinger

Description

Android library to simplify Biometric authentication implementation.

Table of contents

• Requirements
• Getting started
• Usage
• Rx module
• Configuration
• Known issues
• Contributing
• License
• Credits

Requirements

The project requires a minimum API version 14.

Important

This version is compatible with androidx.biometric. If you do not want to use androidx.biometric, feel free to use older version of Goldfinger.

Getting started

Add mavenCentral

To include Goldfinger in your project, you have to add buildscript dependencies in your project level build.gradle:

buildscript {
    repositories {
        mavenCentral()
    }
}

Add dependency

implementation 'com.infinum:goldfinger:2.2.0'

Usage

Initialize

Goldfinger.Builder(context).build()

Check prerequisites

if (goldfinger.canAuthenticate(@AuthenticatorTypes int authenticators)) {
  /* Authenticate */
}

Build params

PromptParams are directly linked to BiometricPrompt.PromptInfo so be sure to read which parameters are required.

Goldfinger.PromptParams params = new Goldfinger.PromptParams.Builder(activity)
  .title("Title")
  .negativeButtonText("Cancel")
  .description("Description")
  .subtitle("Subtitle")
  .build();

I also suggest looking at ValidateUtils class to understand what is allowed by the Biometric library.

Authenticate

goldfinger.authenticate(params, new Goldfinger.Callback() {
    @Override
    public void onError(@NonNull Exception e) {
        /* Critical error happened */
    }

    @Override
    public void onResult(@NonNull Goldfinger.Result result) {
        /* Result received */
    }
});

You can see all Goldfinger methods here.

Rx module

Goldfinger has separate Rx module in case you want to use reactive approach.

Add dependencies

implementation 'com.infinum:goldfinger:2.2.0'
implementation 'com.infinum:goldfinger-rx:2.2.0'

Initialize

RxGoldfinger.Builder(context).build()

Authenticate

goldfinger.authenticate(params).subscribe(new DisposableObserver<Goldfinger.Result>() {

  @Override
  public void onComplete() {
    /* Biometrics authentication is finished */
  }

  @Override
  public void onError(Throwable e) {
    /* Critical error happened */
  }

  @Override
  public void onNext(Goldfinger.Result result) {
    /* Result received */
  }
});

You can see all RxGoldfinger methods here.

Configuration

If you don’t like default implementations, you can easily modify them using Goldfinger.Builder object.

Goldfinger.Builder(context)
  .logEnabled(true)
  .cipherFactory(factory)
  .cipherCrypter(crypter)
  .build()

Important: Both Factory and Crypter should use same object type. If MacFactory is used, be sure to also provide MacCrypter!

Factory (Cipher, Mac, Signature)

Factory class should be used to create Cipher/Mac/Signature which will be used internally when CryptoObject is created.

new CipherFactory() {
  @Nullable
  @Override
  public Cipher createEncryptionCrypter(String key) {
     /* Create Cipher for encryption */
  }

  @Nullable
  @Override
  public Cipher createDecryptionCrypter(String key) {
    /* Create Cipher for decryption */
  }
};

Goldfinger will default to AesCipherFactory if other implementation is not provided.

Crypter (Cipher, Mac, Signature)

Crypter class should be used to encrypt/decrypt data with Cipher/Mac/Signature which was created with Factory above.

new CipherCrypter() {
  @Nullable
  @Override
  public String encrypt(@NonNull Cipher crypter, @NonNull String value) {
    /* Encrypt data with given crypter */
  }

  @Nullable
  @Override
  public String decrypt(@NonNull Cipher crypter, @NonNull String value) {
    /* Decrypt data with given crypter */
  }
};

Goldfinger will default to Base64CipherCrypter if other implementation is not provided.

Logging

Logging is off by default. You can enable it by calling Goldfinger.Builder(context).logEnabled(true).

Known issues

• Android Oreo does not throw KeyPermanentlyInvalidatedException - Link

Contributing

We believe that the community can help us improve and build better a product. Please refer to our contributing guide to learn about the types of contributions we accept and the process for submitting them.

To ensure that our community remains respectful and professional, we defined a code of conduct that we expect all contributors to follow.

We appreciate your interest and look forward to your contributions.

License

Copyright 2018 Infinum

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Credits

Maintained and sponsored by Infinum.