hammerd/hammerd_api_demo.py

#!/usr/bin/env python3
# Copyright 2017 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Python wrapper of hammerd API."""

from __future__ import print_function

import ctypes
import time

import hammerd_api


PUBLIC_KEY_SIZE = 32


def main():
    """Demonstrates FirmwareUpdater usage."""
    updater = hammerd_api.FirmwareUpdater(0x18D1, 0x503C, usb_path="1-1.1")
    public_key = (ctypes.c_ubyte * PUBLIC_KEY_SIZE)()
    # Load EC image.
    with open("/lib/firmware/hammer.fw", "rb") as f:
        ec_image = f.read()
    updater.LoadEcImage(ec_image)

    print("Connect to base EC.")
    updater.TryConnectUsb()
    updater.SendFirstPdu()
    updater.SendDone()

    print("EC information:")
    print("PDU Response: %s" % updater.GetFirstResponsePdu().contents)
    print("RO: %s" % updater.GetSectionVersion(hammerd_api.SectionName.RO))
    print("RW: %s" % updater.GetSectionVersion(hammerd_api.SectionName.RW))

    print("Assume EC already in RW, send pairing challenge.")
    pair_manager = hammerd_api.PairManager()
    challenge_status = pair_manager.PairChallenge(updater.object, public_key)
    print("Challenge status: %d" % challenge_status)

    print("Jump back to RO.")
    updater.SendSubcommand(hammerd_api.UpdateExtraCommand.ImmediateReset)
    updater.CloseUsb()

    print("Inject all-zero entropy.")
    time.sleep(0.5)
    updater.TryConnectUsb()
    updater.SendSubcommand(hammerd_api.UpdateExtraCommand.StayInRO)
    updater.InjectEntropyWithPayload("\x00" * hammerd_api.ENTROPY_SIZE)
    updater.CloseUsb()


if __name__ == "__main__":
    main()