Upgrade tooling (#400)

* upgrade tooling

* adds condition on nrfjprog

tools/deploy_partition.py

@@ -0,0 +1,244 @@
+#!/usr/bin/env python3
+# Copyright 2020-2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# Lint as: python3
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import argparse
+import datetime
+import hashlib
+import os
+import struct
+from typing import Any
+import uuid
+
+import colorama
+from tqdm.auto import tqdm
+
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives.asymmetric.utils import decode_dss_signature
+
+from fido2 import ctap
+from fido2 import hid
+from tockloader import tab
+from tools.configure import fatal, error, info, get_opensk_devices, get_private_key
+
+OPENSK_VID_PID = (0x1915, 0x521F)
+OPENSK_VENDOR_UPGRADE = 0x41
+OPENSK_VENDOR_UPGRADE_INFO = 0x42
+PAGE_SIZE = 0x1000
+KERNEL_SIZE = 0x20000
+APP_SIZE = 0x20000
+PARTITION_ADDRESS = {
+    "nrf52840dk_opensk_a": 0x20000,
+    "nrf52840dk_opensk_b": 0x60000,
+}
+ES256_ALGORITHM = -7
+ARCH = "thumbv7em-none-eabi"
+
+
+def create_metadata(firmware_image: bytes, partition_address: int) -> bytes:
+  """Creates the matching metadata for the given firmware.
+
+  The metadata consists of a timestamp, the expected address and a hash of
+  the image and the other properties in this metadata.
+
+  Args:
+    firmware_image: A byte array of kernel and app, padding to full length.
+    partition_address: The address to be written as a metadata property.
+
+  Returns:
+    A byte array consisting of 32B hash, 4B timestamp and 4B partition address
+    in little endian encoding.
+  """
+  t = datetime.datetime.utcnow().timestamp()
+  timestamp = struct.pack("<I", int(t))
+  partition_start = struct.pack("<I", partition_address)
+  sha256_hash = hashlib.sha256()
+  sha256_hash.update(firmware_image)
+  sha256_hash.update(timestamp)
+  sha256_hash.update(partition_start)
+  checksum = sha256_hash.digest()
+  return checksum + timestamp + partition_start
+
+
+def hash_message(message: bytes) -> bytes:
+  """Uses SHA256 to hash a message."""
+  sha256_hash = hashlib.sha256()
+  sha256_hash.update(message)
+  return sha256_hash.digest()
+
+
+def check_info(partition_address: int, authenticator: Any):
+  """Checks if the assumed upgrade info matches the authenticator's."""
+  try:
+    info("Reading upgrade info...")
+    result = authenticator.send_cbor(
+        OPENSK_VENDOR_UPGRADE_INFO,
+        data={},
+    )
+    if result[0x01] != partition_address:
+      fatal("Identifiers do not match.")
+  except ctap.CtapError as ex:
+    error(f"Failed to read OpenSK upgrade info (error: {ex}")
+
+
+def get_kernel(board: str) -> bytes:
+  """Reads the kernel binary from file."""
+  kernel_file = f"third_party/tock/target/{ARCH}/release/{board}.bin"
+  if not os.path.exists(kernel_file):
+    fatal(f"File not found: {kernel_file}")
+  with open(kernel_file, "rb") as firmware:
+    binary = firmware.read()
+  return binary
+
+
+def get_app(board: str) -> bytes:
+  """Reads the app binary for the given board from a TAB file."""
+  app_tab_path = "target/tab/ctap2.tab"
+  if not os.path.exists(app_tab_path):
+    fatal(f"File not found: {app_tab_path}")
+  app_tab = tab.TAB(app_tab_path)
+  if ARCH not in app_tab.get_supported_architectures():
+    fatal(f"Architecture not found: {ARCH}")
+  app_address = PARTITION_ADDRESS[board] + KERNEL_SIZE
+  return app_tab.extract_app(ARCH).get_binary(app_address)
+
+
+def pad_to(binary: bytes, length: int) -> bytes:
+  """Extends the given binary to the new length with a 0xFF padding."""
+  if len(binary) > length:
+    fatal(f"Binary size {len(binary)} exceeds flash partition {length}.")
+  padding = bytes([0xFF] * (length - len(binary)))
+  return binary + padding
+
+
+def generate_firmware_image(board: str) -> bytes:
+  """Creates binaries for kernel and app, to generate a full firmware image."""
+  kernel = get_kernel(board)
+  app = get_app(board)
+  return pad_to(kernel, KERNEL_SIZE) + pad_to(app, APP_SIZE)
+
+
+def load_priv_key(priv_key_file: argparse.FileType) -> Any:
+  """Loads the ECDSA private key from the specified file."""
+  priv_key = get_private_key(priv_key_file.read())
+  if not isinstance(priv_key, ec.EllipticCurvePrivateKey):
+    fatal("Private key must be an Elliptic Curve one.")
+  if not isinstance(priv_key.curve, ec.SECP256R1):
+    fatal("Private key must use Secp256r1 curve.")
+  if priv_key.key_size != 256:
+    fatal("Private key must be 256 bits long.")
+  info("Private key is valid.")
+  return priv_key
+
+
+def sign_firmware(data: bytes, priv_key: Any) -> bytes:
+  """Signs the data with the passed key and returns the signature bytes."""
+  signature_der = priv_key.sign(data, ec.ECDSA(hashes.SHA256()))
+  (r, s) = decode_dss_signature(signature_der)
+  return r.to_bytes(32, "big") + s.to_bytes(32, "big")
+
+
+def main(args):
+  colorama.init()
+
+  firmware_image = generate_firmware_image(args.board)
+  partition_address = PARTITION_ADDRESS[args.board]
+  metadata = create_metadata(firmware_image, partition_address)
+
+  if not args.priv_key:
+    fatal("Please pass in a private key file using --private-key.")
+  priv_key = load_priv_key(args.priv_key)
+  signed_data = firmware_image + metadata[32:40]
+  signature = {
+      "alg": ES256_ALGORITHM,
+      "signature": sign_firmware(signed_data, priv_key)
+  }
+
+  for authenticator in tqdm(get_opensk_devices(args.batch)):
+    # If the device supports it, wink to show which device we upgrade.
+    if authenticator.device.capabilities & hid.CAPABILITY.WINK:
+      authenticator.device.wink()
+    aaguid = uuid.UUID(bytes=authenticator.get_info().aaguid)
+    info(f"Upgrading OpenSK device AAGUID {aaguid} ({authenticator.device}).")
+
+    try:
+      check_info(partition_address, authenticator)
+      offset = 0
+      for offset in range(0, len(firmware_image), PAGE_SIZE):
+        page = firmware_image[offset:][:PAGE_SIZE]
+        info(f"Writing at offset 0x{offset:08X}...")
+        cbor_data = {1: offset, 2: page, 3: hash_message(page)}
+        authenticator.send_cbor(
+            OPENSK_VENDOR_UPGRADE,
+            data=cbor_data,
+        )
+
+      info("Writing metadata...")
+      cbor_data = {2: metadata, 3: hash_message(metadata), 4: signature}
+      authenticator.send_cbor(
+          OPENSK_VENDOR_UPGRADE,
+          data=cbor_data,
+      )
+    except ctap.CtapError as ex:
+      message = "Failed to upgrade OpenSK"
+      if ex.code.value == ctap.CtapError.ERR.INVALID_COMMAND:
+        error(f"{message} (unsupported command).")
+      elif ex.code.value == ctap.CtapError.ERR.INVALID_PARAMETER:
+        error(f"{message} (invalid parameter, maybe a wrong byte array size?).")
+      elif ex.code.value == ctap.CtapError.ERR_INTEGRITY_FAILURE:
+        error(f"{message} (hashes or signature don't match).")
+      elif ex.code.value == 0xF2:  # VENDOR_INTERNAL_ERROR
+        error(f"{message} (internal conditions not met).")
+      elif ex.code.value == 0xF3:  # VENDOR_HARDWARE_FAILURE
+        error(f"{message} (internal hardware error).")
+      else:
+        error(f"{message} (unexpected error: {ex}")
+
+
+if __name__ == "__main__":
+  # Make sure the current working directory is the right one before running
+  os.chdir(os.path.realpath(os.path.dirname(__file__)))
+  os.chdir("..")
+
+  parser = argparse.ArgumentParser()
+  parser.add_argument(
+      "--batch",
+      default=False,
+      action="store_true",
+      help=(
+          "When batch processing is used, all plugged OpenSK devices will "
+          "be programmed the same way. Otherwise (default) only the first seen "
+          "device will be programmed."),
+  )
+  parser.add_argument(
+      "--board",
+      type=str,
+      choices=["nrf52840dk_opensk_a", "nrf52840dk_opensk_b"],
+      dest="board",
+      help=("Binary file containing the compiled firmware."),
+  )
+  parser.add_argument(
+      "--private-key",
+      type=argparse.FileType("rb"),
+      default="crypto_data/opensk_upgrade.key",
+      dest="priv_key",
+      help=("PEM file for signing the firmware."),
+  )
+  main(parser.parse_args())

tools/perform_upgrade.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Creates a signature key and configures the public key.
+# The device will not be locked down for testing purposes.
+# Generates the binary and upgrades OpenSK.
+# To be run from the OpenSK base path.
+
+set -e
+
+BOARD="$1"
+
+./deploy.py --board=$BOARD --opensk --programmer=none
+python3 -m tools.deploy_partition --board=$BOARD
+if nrfjprog --reset --family NRF52 ; then
+  echo "Upgrade finished!"
+else
+  echo "Please replug OpenSK to reboot"
+fi