#!/usr/bin/env python3
import binascii
import sys
import netifaces
import Pyro4
import serpent

PORT = 5001
indexmap = {
    'bootloader': 0,
    'vendorheader': 1,
    'firmware': 2,
}


def get_trezor():
    from trezorlib.client import TrezorClient
    from trezorlib.transport_hid import HidTransport
    devices = HidTransport.enumerate()
    if len(devices) > 0:
        return TrezorClient(devices[0])
    else:
        raise Exception('No TREZOR found')


def get_path(index):
    return "10018'/%d'" % indexmap[index]


@Pyro4.expose
class KeyctlProxy(object):

    def get_commit(self, index, digest):
        digest = serpent.tobytes(digest)
        path = get_path(index)
        commit = None
        while commit is None:
            try:
                t = get_trezor()
                print('\n\n\nCommiting to hash %s with path %s:' % (binascii.hexlify(digest).decode(), path))
                commit = t.cosi_commit(t.expand_path(path), digest)
            except Exception as e:
                print(e)
                print('Trying again ...')
        pk = commit.pubkey
        R = commit.commitment
        print('Commitment sent!')
        return (pk, R)

    def get_signature(self, index, digest, global_R, global_pk):
        digest, global_R, global_pk = serpent.tobytes(digest), serpent.tobytes(global_R), serpent.tobytes(global_pk)
        path = get_path(index)
        signature = None
        while signature is None:
            try:
                t = get_trezor()
                print('\n\n\nSigning hash %s with path %s:' % (binascii.hexlify(digest).decode(), path))
                signature = t.cosi_sign(t.expand_path(path), digest, global_R, global_pk)
            except Exception as e:
                print(e)
                print('Trying again ...')
        sig = signature.signature
        print('Signature sent!')
        return sig


if __name__ == '__main__':
    if len(sys.argv) > 1:
        iface = sys.argv[1]
    else:
        print('Usage: keyctl-proxy interface')
        sys.exit(1)
    host = netifaces.ifaddresses(iface)[netifaces.AF_INET][0]['addr']
    daemon = Pyro4.Daemon(host=host, port=PORT)
    proxy = KeyctlProxy()
    uri = daemon.register(proxy, 'keyctl')
    print('keyctl-proxy running at URI: "%s"' % uri)
    daemon.requestLoop()