Book Image

Android Application Security Essentials

By : Pragati Rai
Book Image

Android Application Security Essentials

By: Pragati Rai

Overview of this book

In today's techno-savvy world, more and more parts of our lives are going digital, and all this information is accessible anytime and anywhere using mobile devices. It is of the utmost importance that you understand and implement security in your apps that will reduce the likelihood of hazards that will wreck your users' experience. "Android Application Security Essentials" takes a deep look into Android security from kernel to the application level, with practical hands-on examples, illustrations, and everyday use cases. This book will show you how to overcome the challenge of getting the security of your applications right. "Android Application Security Essentials" will show you how to secure your Android applications and data. It will equip you with tricks and tips that will come in handy as you develop your applications.We will start by learning the overall security architecture of the Android stack. Securing components with permissions, defining security in a manifest file, cryptographic algorithms and protocols on the Android stack, secure storage, security focused testing, and protecting enterprise data on your device is then also discussed in detail. You will also learn how to be security-aware when integrating newer technologies like NFC and mobile payments into your Android applications. At the end of this book, you will understand Android security at the system level all the way to the nitty-gritty details of application security for securing your Android applications.
Table of Contents (12 chapters)
11
Index

File


An application can use Android's filesystem to store and retrieve data as well. The java.io package provides this functionality. This package provides classes to write and read different data types from a file. By default, files created by applications are private to the application and cannot be accessed by other applications. Files persist reboots and application crashes; they are only removed when the application is uninstalled.

Creating a file

The following code snippet shows how to create a file. As I have said before, by default, all files are private to the application.

FileOutputStream fOut = openFileOutput("MyFile.txt", MODE_WORLD_READABLE);

The file MyFile.txt will be created in the /data/data/<application-path>/files/ directory. The preceding file is created as MODE_WORLD_READABLE, that means that other applications can read this file. The other options are MODE_WORLD_READABLE, MODE_PRIVATE, and MODE_APPEND that let other applications write to the file, keep it private...