Android Security Cookbook

Android Security Cookbook

Overview of this book

Android Security Cookbook discusses many common vulnerabilities and security related shortcomings in Android applications and operating systems. The book breaks down and enumerates the processes used to exploit and remediate these vulnerabilities in the form of detailed recipes and walkthroughs. The book also teaches readers to use an Android Security Assessment Framework called Drozer and how to develop plugins to customize the framework. Other topics covered include how to reverse-engineer Android applications to find common vulnerabilities, and how to find common memory corruption vulnerabilities on ARM devices. In terms of application protection this book will show various hardening techniques to protect application components, the data stored, secure networking. In summary, Android Security Cookbook provides a practical analysis into many areas of Android application and operating system security and gives the reader the required skills to analyze the security of their Android devices.

Android Security Cookbook

Credits

About the Authors

About the Reviewers

www.PacktPub.com

Preface

Free Chapter

Android Development Tools

Introduction

Installing the Android Development Tools (ADT)

Installing the Java Development Kit (JDK)

Updating the API sources

Alternative installation of the ADT

Installing the Native Development Kit (NDK)

Emulating Android

Creating Android Virtual Devices (AVDs)

Using the Android Debug Bridge (ADB) to interact with the AVDs

Copying files off/onto an AVD

Installing applications onto the AVDs via ADB

Engaging with Application Security

Introduction

Inspecting application certificates and signatures

Signing Android applications

Verifying application signatures

Inspecting the AndroidManifest.xml file

Interacting with the activity manager via ADB

Extracting application resources via ADB

Android Security Assessment Tools

Introduction

Installing and setting up Santoku

Setting up drozer

Running a drozer session

Enumerating installed packages

Enumerating activities

Enumerating content providers

Enumerating services

Enumerating broadcast receivers

Determining application attack surfaces

Launching activities

Writing a drozer module – a device enumeration module

Writing an application certificate enumerator

Exploiting Applications

Introduction

Information disclosure via logcat

Inspecting network traffic

Passive intent sniffing via the activity manager

Attacking services

Attacking broadcast receivers

Enumerating vulnerable content providers

Extracting data from vulnerable content providers

Inserting data into content providers

Enumerating SQL-injection vulnerable content providers

Exploiting debuggable applications

Man-in-the-middle attacks on applications

Protecting Applications

Introduction

Securing application components

Protecting components with custom permissions

Protecting content provider paths

Defending against the SQL-injection attack

Application signature verification (anti-tamper)

Tamper protection by detecting the installer, emulator, and debug flag

Removing all log messages with ProGuard

Advanced code obfuscation with DexGuard

Reverse Engineering Applications

Introduction

Compiling from Java to DEX

Decompiling DEX files

Interpreting the Dalvik bytecode

Decompiling DEX to Java

Decompiling the application's native libraries

Debugging the Android processes using the GDB server

Secure Networking

Introduction

Validating self-signed SSL certificates

Using StrongTrustManager from the OnionKit library

SSL pinning

Native Exploitation and Analysis

Introduction

Inspecting file permissions

Cross-compiling native executables

Exploitation of race condition vulnerabilities

Stack memory corruption exploitation

Automated native Android fuzzing

Encryption and Developing Device Administration Policies

Introduction

Using cryptography libraries

Generating a symmetric encryption key

Securing SharedPreferences data

Password-based encryption

Encrypting a database with SQLCipher

Android KeyStore provider

Setting up device administration policies

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Generating a symmetric encryption key

A symmetric key describes a key that is used for both encryption and decryption. To create cryptographically secure encryption keys in general, we use securely generated pseudorandom numbers. This recipe demonstrates how to correctly initialize the SecureRandom class and how to use it to initialize an Advanced Encryption Standard (AES) encryption key. AES is the preferred encryption standard to DES, and typically used with key sizes 128 bit and 256 bit.

Note

There are no code differences whether you are using Bouncy Castle or Spongy Castle, as noted in the previous recipe.

How to do it...

Let's create a secure encryption key.

Write the following function to generate a symmetric AES encryption key:

public static SecretKey generateAESKey(int keysize)
      throws NoSuchAlgorithmException {
    final SecureRandom random = new SecureRandom();

    final KeyGenerator generator = KeyGenerator.getInstance("AES");
    generator.init(keysize, random);
    return generator...

Android Security Cookbook

Android Security Cookbook

Overview of this book

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Android Security Cookbook

Generating a symmetric encryption key

Note

How to do it...