Ledger Flare app

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Please visit our website at zondax.ch

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This project contains the Flare app for Ledger Nano S+, Nano X, Stax and Flex.

• Ledger Nano S+/X, Stax and Flex Flare app
• Specs / Documentation
• C++ unit tests
• Zemu tests

ATTENTION

The app releases of this repository and the binaries you can build yourself with this repo are considered unvetted development releases, use with caution.

The releases provided by Ledger via Ledger Live have undergone Ledger's security assessment and thus are safe to use with real funds.

If you wish to use a development release, we recommend the following:

• Do not use in production
• Do not use a Ledger device with funds for development purposes
• Do use a separate and marked device that is used ONLY for development and testing

Nevertheless, this disclaimer does not apply to the client libraries provided in this repository.

Download and install a prerelease

Once the app is approved by Ledger, it will be available in their app store (Ledger Live). You can get builds generated by Github Actions from the release tab. THESE ARE UNVETTED DEVELOPMENT RELEASES

Download a release from here (https://github.com/Zondax/ledger-flare/releases). You only need installer.sh

If the file is not executable, run

chmod +x ./installer.sh

then run:

./installer.sh load

Development

Preconditions

• Be sure you checkout submodules too:

  git submodule update --init --recursive
  

• Install Docker CE

  • Instructions can be found here: https://docs.docker.com/install/

• We only officially support Ubuntu. Install the following packages:

  sudo apt update && apt-get -y install build-essential git wget cmake \
  libssl-dev libgmp-dev autoconf libtool
  

• Install node > v13.0. We typically recommend using n

• You will need python 3 and then run

  • make deps

• This project requires Ledger firmware 2.0

  • The current repository keeps track of Ledger's SDK but it is possible to override it by changing the git submodule.

Warning: Some IDEs may not use the same python interpreter or virtual environment as the one you used when running pip. If you see conan is not found, check that you installed the package in the same interpreter as the one that launches cmake.

How to build ?

We like clion or vscode but let's have some reproducible command line steps

• Building the app itself

  If you installed the what is described above, just run:

  make

Running tests

• Running rust tests (x64)

  If you installed the what is described above, just run:

  make rust_test

• Running C/C++ tests (x64)

  If you installed the what is described above, just run:

  make cpp_test

• Running device emulation+integration tests!!

   Use Zemu! Explained below!

• Running everything

  If you don't want to bother typing all those make commands by hand, you can skip them all!

  The only command you have to type is:

  make test_all

  This will initially run unit and integration tests (needs rust installed!), then install Zemu for you, clean the app's build files in case there's anything, proceed to build both application types and finally run the Zemu test suite.

How to test with Zemu?

What is Zemu?? Great you asked!! As part of this project, we are making public a beta version of our internal testing+emulation framework for Ledger apps.

Npm Package here: https://www.npmjs.com/package/@zondax/zemu

Repo here: https://github.com/Zondax/zemu

Let's go! First install everything:

At this moment, if you change the app you will need to run make before running the test again.

make zemu_install

Then you can run JS tests:

make zemu_test

To run a single specific test:

At the moment, the recommendation is to run from the IDE. Remember to run make if you change the app.

Using a real device

How to prepare your DEVELOPMENT! device:

You can use an emulated device for development. This is only required if you are using a physical device

Please do not use a Ledger device with funds for development purposes.

Have a separate and marked device that is used ONLY for development and testing

There are a few additional steps that increase reproducibility and simplify development:

1 - Ensure your device works in your OS

• In Linux hosts it might be necessary to adjust udev rules, etc.

  Refer to Ledger documentation: https://support.ledger.com/hc/en-us/articles/115005165269-Fix-connection-issues

2 - Set a test mnemonic

Many of our integration tests expect the device to be configured with a known test mnemonic.

• Plug your device while pressing the right button

• Your device will show "Recovery" in the screen

• Double click

• Run make dev_init. This will take about 2 minutes. The device will be initialized to:

  PIN: 5555
  Mnemonic: equip will roof matter pink blind book anxiety banner elbow sun young
  

3 - Add a development certificate

• Plug your device while pressing the right button

• Your device will show "Recovery" in the screen

• Click both buttons at the same time

• Enter your pin if necessary

• Run make dev_caS2. The device will receive a development certificate to avoid constant manual confirmations.

Loading into your development device

The Makefile will build the firmware in a docker container and leave the binary in the correct directory. this example is for NanoS+.

• Build

  make buildS2                # Builds the app
  

• Upload to a device The following command will upload the application to the ledger. Warning: The application will be deleted before uploading.

  make loadS2          # Builds and loads the app to the device
  

APDU Specifications

• APDU Protocol