Nano S uses uncompressed keys even on Segwit paths

[oriolpont]

Segwit transactions are supposed to use compressed keys only, and uncompressed ones will be made invalid in the future.

This issue has two sub-issues (probably related) namely:

• getWalletPublicKey() method always returns public keys in the uncompressed form: \x04+x_coord+y_coord

• getFirmwareVersion() method says that keys are uncompressed.

dongle = getDongle(True)
app = btchip(dongle)
app.getFirmwareVersion() 

replies that: {'specialVersion': 48, 'version': '1.1.18', 'compressedKeys': False} when used on the official app installed from the manager.

I initialized my Nano S by restoring my BIP39 mnemonic, segwit path, no passwords.

A quick inspection on the generated P2SH-P2WPKH addresses suggests that they indeed correspond to the compressed forms, and in at least one case the wallet spent from a compressed-key associated segwit input, but I have not systematically checked that.