Stellar Ledger

This crate allows for interaction with Ledger devices, and exposes the following functions:

• get_app_configuration
• get_public_key
• sign_transaction_hash
• sign_transaction
• sign_blob

Tests

There are several unit tests in lib.rs, as well as integration-like tests in the emulator_tests.rs file. emulator_tests.rs uses testcontainers-rs to spin up a docker container running a Ledger emulator called Speculos.

Resources

• LedgerHQ/ledger-live/../hw-app-str is javascript implementation of the API for interacting with the Stellar app on Ledger devices. We used this as a reference when building the stellar-ledger crate.
• The communication protocol used by Ledger devices expects commands to be sent as Application Protocol Data Units (APDU).
  • More information about how APDUs are structured can be found here https://github.com/LedgerHQ/app-stellar/blob/develop/docs/APDU.md.
  • The list of commands that the Stellar App on Ledger devices currently supports can be found here https://github.com/LedgerHQ/app-stellar/blob/develop/docs/COMMANDS.md.
• The Ledger emulator we're using for integration-style tests is LedgerHQ's Speculos.
• The testing setup was also partially based on Zondax's Zemu testing framework, which makes use of Speculos.
• To connect with a real ledger device, we use Zondax's ledger-rs crate.
• To connect with the emulated ledger (Speculos), we created a custom EmulatorHttpTransport that can connect to the emulated ledger via HTTP. This is based on Zondax's ledger-transport-zemu crate (which has since been deprecated).