Luciano Balmaceda lbalmaceda

Secure CredentialsManager (v2)

We can enhance the existing manager to make it encrypt/decrypt the content before persisting it. Then as an extra improvement, we can ask for user authentication before allowing them to obtain the credentials.

APIs

API 18 introduces the algorithm I'm using to encrypt/decrypt.
API 21 introduces the Intent to call the LockScreen and wait for a cancel/pass signal.
API 23 introduces the protected keys, which means that in every key use we can ask for the user to be authenticated first.

The CredentialsManager usage can be divided in two:

Authenticated CredentialsManager

The simple credentials manager receives a pair of Credentials and perform:

Storage of the values (either 1 by 1 or all together in a single operation)
Retrieval of the values (either 1 by 1 or all together in a single operation)
Check for existing credentials
Check for valid credentials and renew them if required

Because the manager receives a Storage, which abstracts the logic of reading/writing stuff, how the values are persisted is up to that implementation. What it's missing is a security layer to encrypt the values before saving them, ask for authentication before retrieving them, or both of the previous.

CredentialsManager

Recently we introduced a helper class available here to handle Auth0 Credentials. Usage is simple: Once you create a new instance by passing an AuthenticationAPIClient (to renew credentials) and a Storage (to do persistance), you can call any of this 2 public methods:

saveCredentials: To synchronously save a pair of credentials in the storage. Will throw if the access_token or id_token is null, or if the expires_at date is missing.
getCredentials: To asynchronously get a pair of credentials from the storage.
- If no credentials were stored before the methods fails.
- If stored credentials have expired (expires_at > now) and no refresh_token was saved the method fails.
- If the call to renew the credentials using the refresh_token fails, the method fails.
In any other case, a valid pair of credentials is ret

Auth0 Fingerprint API

Create a new instance

The context is needed to access the check for availability

public class Auth0Fingerprint implements FingerprintManager.AuthenticationCallback {

  private final FingerprintManagerCompat manager;

	//Copyright 2017 - https://github.com/lbalmaceda
	//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 SOF

	#
	# Build configuration for Circle CI
	#

	machine:
	environment:
	ANDROID_HOME: /usr/local/android-sdk-linux
	GRADLE_OPTS: '-Dorg.gradle.jvmargs="-Xmx2048m -XX:+HeapDumpOnOutOfMemoryError"'
	_JAVA_OPTIONS: "-Xms512m -Xmx1024m"
	ANDROID_API_LEVEL: 25

	//This is the abstract AuthProvider, with permission handling.

	public abstract class AuthProvider implements PermissionProvider {

	public AuthProvider(@NonNull PermissionHandler handler) {
	this.handler = handler;
	}

	public void start(@NonNull Activity activity, @NonNull AuthCallback callback, int permissionRequestCode) {
	this.callback = callback;

	package com.lbalmaceda.genericsproject;

	import com.lbalmaceda.genericsproject.exceptions.BaseException;

	/**
	* Created by lbalmaceda on 6/21/16.
	*/
	public interface CustomCallback<T, U extends BaseException> {

	void onSuccess(T response);

	package com.lbalmaceda.genericsproject;

	import com.lbalmaceda.genericsproject.exceptions.BaseException;

	/**
	* Created by lbalmaceda on 6/21/16.
	*/
	public interface CustomCallback<T, U extends BaseException> {

	void onSuccess(T response);