LINE Thrift IDL Compiler

A comprehensive Thrift IDL extractor and compiler for LINE APK decompiled sources.

Features

• Complete Thrift IDL extraction from decompiled Java sources
• Automatic type resolution for obfuscated class names
• Response/Request mapping using toString() patterns
• Support for complex types (lists, maps, sets, enums)
• E2EE components extraction including LetterSealing
• Service method typing with proper request/response types

Installation

pip install -r requirements.txt

Usage

Basic Usage

python src/thrift_compiler.py

This will:

1. Parse all Java files in /workspaces/LINE/line_decompiled/sources
2. Extract enums, structs, and services
3. Generate line.thrift with complete Thrift IDL

Output Statistics

The compiler extracts:

• 2,014 structs with proper field definitions
• 508 enums with values
• 105 services with 421 methods
• 387 type aliases for obfuscated names

Architecture

Core Components

1. Enum Parser - Extracts Java enums with values
2. Struct Parser - Parses Thrift struct implementations with fields
3. Service Parser - Extracts service definitions and methods
4. Type Resolver - Maps obfuscated names to real types
5. Response/Request Mapper - Uses toString() patterns to identify types

Key Features

Obfuscated Name Resolution

Maps obfuscated class names (e.g., E0, X3) to actual types (e.g., GetContactsV3Response, DeleteOtherFromChatResponse) using:

• toString() method patterns
• StringBuilder patterns with field names

Field Type Resolution

• Handles primitive types (bool, byte, i16, i32, i64, string)
• Complex types (list, map, set) with nested type resolution
• Struct references with automatic aliasing

E2EE Support

Complete extraction of:

• E2EE services (E2eeKeyBackupService, E2eeTalkService)
• Key exchange methods and structs
• LetterSealing components
• Error codes and notification types

Project Structure

compiler/
├── src/
│   └── thrift_compiler.py    # Main compiler
├── docs/
│   └── API.md                 # API documentation
├── examples/
│   └── example_output.thrift  # Sample output
├── tests/
│   └── test_compiler.py       # Unit tests
├── README.md
└── requirements.txt

Example Output

enum TalkErrorCode {
  E2EE_INVALID_PROTOCOL = 81,
  E2EE_RETRY_ENCRYPT = 82,
  ...
}

struct GetContactsV3Response {
  1: list<i32> responses
}

service GroupTalkService {
  CancelChatInvitationResponse cancelChatInvitation(1: C12999i2 request),
  DeleteOtherFromChatResponse deleteOtherFromChat(1: W3 request),
  ...
}

Contributing

1. Fork the repository
2. Create your feature branch
3. Add tests for new functionality
4. Submit a pull request

License

This tool is for educational and research purposes only.