esp-idf/tools/test_apps/security/secure_boot/pytest_secure_boot.py

219 lines
8.1 KiB
Python

# SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
# SPDX-License-Identifier: Unlicense OR CC0-1.0
from __future__ import print_function
import os
import struct
import zlib
import pytest
from pytest_embedded import Dut
# To prepare a runner for these tests,
# 1. Connect an FPGA with C3 image
# 2. Use a COM port for programming and export it as ESPPORT
# e.g export ESPPORT=/dev/ttyUSB0
# 3. Use another COM port for resetting efuses and connect its DTR pin to efuse reset pin on the FPGA board.
# Export it as EFUSEPORT
# e.g export EFUSEPORT=/dev/ttyUSB1
# 4. Run these tests
def corrupt_signature(signed_bootloader, seed=0, corrupt_sig=True, corrupt_crc=False, corrupt_single_block=None):
# type: (bytes, int, bool, bool, int) -> bytes
image = signed_bootloader[:-4096]
signature = signed_bootloader[-4096:]
sig_blocks = (signature[0:1216], signature[1216:2432], signature[2432:3648])
new_blocks = tuple(corrupt_sig_block(s, seed, corrupt_sig, corrupt_crc) for s in sig_blocks)
# if corrupt_single_block is None, corrupt all blocks
# otherwise, only corrupt the one with that index set
corr_sig_blocks = tuple(new_blocks[n] if corrupt_single_block in [None, n] else sig_blocks[n] for n in range(3))
return image + b''.join(corr_sig_blocks) + signature[3648:]
def corrupt_sig_block(sig_block, seed=0, corrupt_sig=True, corrupt_crc=False):
# type: (bytes, int, bool, bool) -> bytes
assert len(sig_block) == 1216
magic = sig_block[0]
assert magic in [0xe7, 0xff]
if magic != 0xe7:
return sig_block # not valid
data = sig_block[:812]
new_sig = sig = sig_block[812:1196]
crc = sig_block[1196:1200]
padding = sig_block[1200:1216]
if corrupt_sig:
corrupt_idx = seed % len(sig)
corrupt_delta = zlib.crc32(bytes(seed)) & 0xFF
if corrupt_delta == 0:
corrupt_delta = 1
new_byte = sig[corrupt_idx] ^ corrupt_delta
new_sig = sig[0:corrupt_idx] + bytes([new_byte]) + sig[corrupt_idx + 1:]
assert new_sig != sig
if not corrupt_crc:
crc = struct.pack('<I', zlib.crc32(data + new_sig) & 0xffffffff)
else:
crc = struct.pack('<I', zlib.crc32(crc))
result = data + new_sig + crc + padding
assert len(result) == len(sig_block)
return result
def dut_start_secure_app(dut: Dut) -> None:
dut.serial.erase_app_header()
dut.serial.reset_efuses()
dut.burn_wafer_version()
dut.serial.bootloader_flash(os.path.join(dut.app.binary_path, 'bootloader/bootloader.bin'))
dut.serial.partition_table_flash(os.path.join(dut.app.binary_path, 'partition_table/partition-table.bin'))
dut.serial.app_flash(os.path.join(dut.app.binary_path, 'secure_boot.bin'))
# Test secure boot flow.
# Correctly signed bootloader + correctly signed app should work
@pytest.mark.esp32c3
@pytest.mark.esp32s3
@pytest.mark.esp32p4
def test_examples_security_secure_boot(dut: Dut) -> None:
dut_start_secure_app(dut)
dut.expect('Secure Boot is enabled', timeout=10)
dut.serial.reset_efuses()
dut.burn_wafer_version()
# Test efuse key index and key block combination.
# Any key index can be written to any key block and should work
@pytest.mark.esp32c3
@pytest.mark.esp32s3
@pytest.mark.esp32p4
# Increasing the test timeout to 1200s as the test runs for 18 iterations
# and thus the default 600s timeout is not sufficient
@pytest.mark.timeout(1200)
def test_examples_security_secure_boot_key_combo(dut: Dut) -> None:
dut_start_secure_app(dut)
dut.expect('Secure Boot is enabled', timeout=10)
for index in range(3):
for block in range(6):
dut.serial.reset_efuses()
dut.burn_wafer_version()
dut.secure_boot_burn_en_bit()
dut.secure_boot_burn_digest('test_rsa_3072_key.pem', index, block)
dut.expect('Secure Boot is enabled', timeout=10)
dut.serial.reset_efuses()
dut.burn_wafer_version()
# Test secure boot key revoke.
# If a key is revoked, bootloader signed with that key should fail verification
@pytest.mark.esp32c3
@pytest.mark.esp32s3
@pytest.mark.esp32p4
def test_examples_security_secure_boot_key_revoke(dut: Dut) -> None:
dut_start_secure_app(dut)
dut.expect('Secure Boot is enabled', timeout=10)
for index in range(3):
dut.serial.reset_efuses()
dut.burn_wafer_version()
dut.secure_boot_burn_en_bit()
dut.serial.burn_efuse('SECURE_BOOT_KEY_REVOKE%d' % index, 1)
dut.secure_boot_burn_digest('test_rsa_3072_key.pem', index, 0)
dut.expect('secure boot verification failed', timeout=5)
dut.serial.reset_efuses()
dut.burn_wafer_version()
# Test bootloader signature corruption.
# Corrupt one byte at a time of bootloader signature and test that the verification fails
@pytest.mark.esp32c3
@pytest.mark.esp32s3
@pytest.mark.esp32p4
@pytest.mark.timeout(18000)
# Increasing the test timeout to 18000s as the test runs for 384 iterations
# and thus the default 600s timeout is not sufficient
def test_examples_security_secure_boot_corrupt_bl_sig(dut: Dut) -> None:
dut_start_secure_app(dut)
dut.expect('Secure Boot is enabled', timeout=10)
bootloader_bin = os.path.join(dut.app.binary_path, 'bootloader/bootloader.bin')
with open(bootloader_bin, 'rb') as f:
signed_bl = f.read()
seeds = range(0, 384)
max_seed = max(seeds)
for seed in seeds:
print('Case %d / %d' % (seed, max_seed))
corrupt_bl = corrupt_signature(signed_bl, seed=seed)
with open('corrupt_bl.bin', 'wb') as corrupt_file:
corrupt_file.write(corrupt_bl)
dut.serial.reset_efuses()
dut.burn_wafer_version()
dut.serial.bootloader_flash('corrupt_bl.bin')
dut.secure_boot_burn_en_bit()
dut.secure_boot_burn_digest('test_rsa_3072_key.pem', 0, 0)
# Though the order of flashing and burning efuse would not effect the test,
# if we flash bootlader before burning en bit, even with no_stub = True
# it still calls run_stub() and throws an error as it fails to start stub.
dut.expect('Signature Check Failed', timeout=10)
dut.serial.reset_efuses()
dut.burn_wafer_version()
# Test app signature corruption.
# Corrupt app signature, one byte at a time, and test that the verification fails
@pytest.mark.esp32c3
@pytest.mark.esp32s3
@pytest.mark.esp32p4
@pytest.mark.timeout(18000)
# Increasing the test timeout to 18000s as the test runs for 385 iterations
# and thus the default 600s timeout is not sufficient
def test_examples_security_secure_boot_corrupt_app_sig(dut: Dut) -> None:
dut_start_secure_app(dut)
dut.expect('Secure Boot is enabled', timeout=10)
app_bin = os.path.join(dut.app.binary_path, 'secure_boot.bin')
with open(app_bin, 'rb') as f:
signed_app = f.read()
seeds = range(0, 384)
max_seed = max(seeds)
for seed in seeds:
print('Case %d / %d' % (seed, max_seed))
corrupt_app = corrupt_signature(signed_app, seed=seed)
with open('corrupt_app.bin', 'wb') as corrupt_file:
corrupt_file.write(corrupt_app)
dut.serial.reset_efuses()
dut.burn_wafer_version()
dut.serial.app_flash('corrupt_app.bin')
dut.secure_boot_burn_en_bit()
dut.secure_boot_burn_digest('test_rsa_3072_key.pem', 0, 0)
dut.expect('Signature Check Failed', timeout=10)
dut.expect('image valid, signature bad', timeout=2)
print('Testing invalid CRC...')
# Valid signature but invalid CRC
dut.serial.reset_efuses()
dut.burn_wafer_version()
corrupt_app = corrupt_signature(signed_app, corrupt_sig=False, corrupt_crc=True)
with open('corrupt_app.bin', 'wb') as corrupt_file:
corrupt_file.write(corrupt_app)
dut.serial.app_flash('corrupt_app.bin')
dut.secure_boot_burn_en_bit()
dut.secure_boot_burn_digest('test_rsa_3072_key.pem', 0, 0)
dut.expect('Sig block 0 invalid: {}'.format('CRC mismatch' if dut.target == 'esp32p4' else 'Stored CRC ends'), timeout=2)
dut.expect('Secure boot signature verification failed', timeout=2)
dut.expect('No bootable app partitions in the partition table', timeout=2)