Capstone.js

Port of the Capstone disassembler framework for JavaScript/WASM. Powered by Emscripten.

Requirements: JavaScript environment with WebAssembly and BigInt support.

Notes: Capstone is a lightweight multi-architecture disassembly framework originally developed by Nguyen Anh Quynh and released under BSD license. More information about contributors and license terms can be found in the files CREDITS.TXT and LICENSE.TXT of the capstone submodule in this repository.

Installation

To add Capstone.js to your web application, include it with:

<script src="capstone.js"></script>

or install it with the NPM command:

npm install @alexaltea/capstone-js

Usage

// Input: Machine code bytes and offset where they are located
var buffer = [0x55, 0x31, 0xD2, 0x89, 0xE5, 0x8B, 0x45, 0x08];
var offset = 0x10000;

MCapstone().then((cs) => {
    // Initialize the decoder
    var d = new cs.Capstone(cs.ARCH_X86, cs.MODE_32);

    // Output: Array of cs.Instruction objects
    var instructions = d.disasm(buffer, offset);

    // Display results
    instructions.forEach((instr) => {
        console.log("0x%s:\t%s\t%s",
            instr.address.toString(16),
            instr.mnemonic,
            instr.op_str
        );
    });

    // Delete decoder
    d.close();
});

Building

To build the Capstone.js library:

1. Clone this repository including its submodules:

   git clone --recursive https://github.com/AlexAltea/capstone.js

2. Install the latest Python 3.x, CMake and the Emscripten SDK. Follow the corresponding instructions and make sure all environment variables are configured correctly.

3. Run the build script:

   python3 build.py

Build artifacts will be saved to dist.

[!TIP] Pass architecture names to produce a smaller, single-architecture bundle (e.g. python3 build.py x86), or python3 build.py --release to build every variant.