JCC - LLVM IR to JavaCard Compiler

Compiles LLVM IR to JavaCard bytecode (CAP files). Any language with an LLVM frontend (C, Rust, etc.) can target JavaCard smart cards.

Quick Start

This project is working but has some rough edges. Please file an issue if you run into problems.

git clone https://github.com/CrystalPeakSecurity/jcc.git
cd jcc
./setup.sh              # installs prereqs, then guided toolchain setup
just test               # run tests
just sim examples/2048  # load a project in the simulator (stays running)

# in another terminal:
just run examples/2048  # runs a project's driver

Example

#include "jcc.h"

short count;

void process(APDU apdu, short len) {
    byte* buffer = apduGetBuffer(apdu);
    if (buffer[APDU_INS] == 0x01) {
        count++;
        buffer[0] = (byte)(count >> 8);
        buffer[1] = (byte)count;
        apduSetOutgoing(apdu);
        apduSetOutgoingLength(apdu, 2);
        apduSendBytes(apdu, 0, 2);
    }
}

Examples

jcc examples/minimal     # A minimal example
jcc examples/2048        # The game 2048
jcc examples/flappy      # Flappy Bird
jcc examples/rusty       # Flappy Bird - in rust!
jcc examples/apple       # Bad Apple
jcc examples/musicvideo  # A music video
jcc examples/doom        # DOOM renderer
jcc examples/wolf3d      # Wolfenstein 3D renderer

Additional examples and tests are in the examples/ directory.

Project Structure

• src/jcc/ - Compiler (LLVM IR parser, analysis, codegen, output)
• src/jcc/cli/ - CLI (jcc, jcc run-setup, jcc run-sim, jcc run-verify)
• src/jcc/cap/ - CAP file bytecode verifier
• src/jcc/driver/ - Simulator/card session management
• examples/ - Example applets with drivers
• tools/ - Development utilities

License

MIT