Android Software Internals Quick Reference : A Field Manual and Security Reference Guide to Java-based Android Components

Use this handy field guide as a quick reference book and cheat sheet for all of the techniques you use or reference day to day. Covering up to Android 11, this Android Java programming reference guide focuses on non-UI elements with a security focus. You won’t see Android UI development, nor will you see low-level C or kernel techniques. Instead, this book focuses on easily digestible, useful, and interesting techniques in Java and the Android system. This reference guide was created out of the need for myself to jot down all the useful techniques I commonly reached for, and so I’m now sharing these techniques with you, whether you are an Android internals software engineer or security researcher. **What You Will Learn** * Discover the differences between and how to access application names, package names, IDs, and unique identifiers in Android * Quickly reference common techniques such as storage, the activity lifecycle, and permissions * Debug using the Android shell * Work with Android's obfuscation and encryption capabilities * Extract and decompile Android applications * Carry out Android reflection and dex class loading **Who This Book Is For** Programmers, developers, and admins with at least prior Android and Java experience. Table of Contents About the Author About the Technical Reviewer Chapter 1: Introduction What Is This Book What This Book Is Not Chapter 2: Android Versions Chapter 3: Fundamentals Android Sandbox Application Components Activities Services Broadcast Receivers Content Providers Manifest Permissions Context Application Context Activity Context The Activity Life Cycle onCreate() onStart() onResume() onPause() onStop() onRestart() Android Users Linux Users Android Users Chapter 4: Intents Starting Components Intent Attributes Core Attributes Additional Attributes Actions Categories Extras Flags Task Stack Intent Filters Chapter 5: Application Names, Android Package Name, and ID Java Package Name Package ID Retrieving Package ID Application ID Suffix and Flavor Application Name Retrieving Application Name Chapter 6: Storage Partitions External and Internal Storage Internal Storage External Storage Text Files Databases Shared Preferences File Providers Assets Folder Resources Chapter 7: Android Unique Identifiers Google Play Advertising ID Android ID (Secure Settings Android ID – SSAID) SIM Serial Number Phone Number IMEI and MEID Chapter 8: Obfuscation and Encryption Logging Standard Logging Final Constant Variables Using .isLoggable Dynamically Checking If Debuggable ProGuard Enabling ProGuard The ProGuard Mapping File The ProGuard Allow-List The Different Types of Keep Entry Points Example Rules Public Key/Certificate Pinning AES Encryption Chapter 9: Services, Launchers, and Components Long-Running Services Triggers Services IntentService, AlarmManager, and BootComplete Foreground Services JobScheduler Work Managers Threading AsyncTasks Battery and Security Effects on Long-Running Services Doze App Standby Buckets Modifying a Component’s State Statically Modifying Component State Dynamically Modifying Components Creating an Android Launcher Creating a Launcher Application Additional Functionality Chapter 10: Reflection and Class Loading Reflection Making an Instance of a Class .getDeclaredMethod Compared With .getMethod Static Methods Private Constructors Initialized Classes as Fields of Other Classes Class Loading Chapter 11: The Android Shell Running Commands Programmatically Chapter 12: Decompiling and Disassembling Android Applications Decompiled Java Disassembled Dalvik Bytecode (Smali) Extracting APKs from Running Devices Chapter 13: Closing Thoughts Index