This is a wallet app for the Ledger Nano S and Ledger Blue that makes it possible to store your Nimiq-based assets on those devices.
A companion Javascript library is available to communicate with this app.
To learn how to use this library you can take look at the demo project.
To build and install the app on your Nano S or Blue you must set up the Ledger Nano S or Blue build environment. Please follow the Getting Started instructions at the Ledger Nano S github repository.
Alternatively, you can set up the Vagrant Virtualbox Ledger environment maintained here. This sets up an Ubuntu virtual machine with the Ledger build environment already set up. Note that if you are on a Mac, at the time of this writing this seems to be the only way to build and load the app.
The command to compile and load the app onto the device is:
$ make load
To remove the app from the device do:
$ make delete
The ./test directory contains files for testing the transaction parser and some printing utilities. To build and execute the tests run ./test.sh.
The operation to retrieve the public key implements an optional keypair verification method. Along with the request to retrieve the public key a small message is sent that is to be signed by the device. Back on the host the returned signature can be checked against the returned public key. This is to guard against incompatibility between the keypairs generated by the Ledger device and the ones expected by the Nimiq network, whatever the reason for this might be. The extra precaution prevents users from sending funds to an address they are not able to sign transactions for.