APK Parser

A Dart library for analyzing and decoding Android APK files, providing functionality similar to the Java Apktool project. This implementation focuses on parsing Android binary XML (AXML) format, extracting resources, and providing detailed APK analysis.

Features

• APK Analysis: Fast analysis of APK files returning essential information as JSON
• AndroidManifest.xml Decoding: Converts binary XML format to readable XML text
• Resource Resolution: Resolves resource references (e.g., @string/app_name) to human-readable format
• Resource Extraction: Extracts resources (images, XML files) from APK files
• ARSC Parser: Parses Android resource table (resources.arsc) files
• Signature Analysis: Extracts and validates APK signing information (V2/V3 signatures)
• Architecture Detection: Identifies supported CPU architectures in the APK
• Icon Extraction: Extracts and exports application icons
• Cross-platform: Pure Dart implementation that works on all platforms

What it does

This library takes Android APK files as input and provides comprehensive analysis and decoding capabilities:

1. APK Analysis: The analyzeApk method returns a JSON object containing:

   • Package name and application name
   • Version information (name and code)
   • SDK version requirements (min and target)
   • List of permissions
   • Supported CPU architectures
   • Application icon (as base64-encoded PNG)
   • Certificate hashes for signature verification
   • Optional architecture filtering

2. Manifest Decoding: Reads the binary AndroidManifest.xml file and converts it to readable XML format

3. Resource Resolution: Resolves numeric resource IDs (like @0x7f020001) to human-readable names (like @drawable/icon)

4. Resource Extraction: Extracts and decodes resources like images, layouts, and other XML files from the APK

5. Signature Analysis: Parses and validates APK signing blocks (V2/V3) including:

   • Signature algorithms (RSA, ECDSA, DSA)
   • Certificate chains
   • SDK version requirements for signatures

Usage

import 'package:apk_parser/src/androlib/apk_parser.dart';

final parser = ApkParser();

// Analyze APK and get JSON output
final analysis = await parser.analyzeApk('path/to/app.apk');
print(analysis);

// Analyze with architecture filter
final arm64Analysis = await parser.analyzeApk(
  'path/to/app.apk',
  requiredArchitecture: 'arm64-v8a',
);

// Decode just the manifest
final manifestXml = await parser.decodeManifestToXmlText('path/to/app.apk');
print(manifestXml);

// Full decode with resource extraction
await parser.decode('path/to/app.apk', 'output/directory');

Command Line Interface

The library includes a CLI tool for quick APK analysis:

# Basic analysis
dart run bin/apktool.dart path/to/app.apk

# Analysis with architecture filter
dart run bin/apktool.dart --arch arm64-v8a path/to/app.apk

# Export app icon
dart run bin/apktool.dart --export-icon icon.png path/to/app.apk

Testing

Run tests with:

dart test

The test suite validates the library against real APK files and compares output with the original Java Apktool implementation. Tests cover:

• APK analysis accuracy
• Manifest decoding
• Resource resolution
• Icon extraction
• Architecture detection
• Signature parsing

Current Status

The library successfully implements all core APK analysis features and provides reliable results for most APK files. The implementation is actively maintained and tested against a variety of real-world APK files.

License

MIT