u-boot/test/py/tests/test_fit_hashes.py
Alexandru Gagniuc 01e1e2a966 test/py: Check hashes produced by mkimage against known values
Target code and mkimage share the same hashing infrastructure. If one
is wrong, it's very likely that both are wrong in the same way. Thus
testing won't catch hash regressions. This already happened in
commit 92055e138f ("image: Drop if/elseif hash selection in
calculate_hash()"). None of the tests caught that CRC32 was broken.

Instead of testing hash_calculate() against itself, create a FIT with
containing a kernel with pre-calculated hashes. Then check the hashes
produced against the known good hashes.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2021-10-05 08:50:15 -04:00

111 lines
4 KiB
Python

# SPDX-License-Identifier: GPL-2.0+
#
# Copyright (c) 2021 Alexandru Gagniuc <mr.nuke.me@gmail.com>
"""
Check hashes produced by mkimage against known values
This test checks the correctness of mkimage's hashes. by comparing the mkimage
output of a fixed data block with known good hashes.
This test doesn't run the sandbox. It only checks the host tool 'mkimage'
"""
import pytest
import u_boot_utils as util
kernel_hashes = {
"sha512" : "f18c1486a2c29f56360301576cdfce4dfd8e8e932d0ed8e239a1f314b8ae1d77b2a58cd7fe32e4075e69448e623ce53b0b6aa6ce5626d2c189a5beae29a68d93",
"sha384" : "16e28976740048485d08d793d8bf043ebc7826baf2bc15feac72825ad67530ceb3d09e0deb6932c62a5a0e9f3936baf4",
"sha256" : "2955c56bc1e5050c111ba6e089e0f5342bb47dedf77d87e3f429095feb98a7e5",
"sha1" : "652383e1a6d946953e1f65092c9435f6452c2ab7",
"md5" : "4879e5086e4c76128e525b5fe2af55f1",
"crc32" : "32eddfdf",
"crc16-ccitt" : "d4be"
}
class ReadonlyFitImage(object):
""" Helper to manipulate a FIT image on disk """
def __init__(self, cons, file_name):
self.fit = file_name
self.cons = cons
self.hashable_nodes = set()
def __fdt_list(self, path):
return util.run_and_log(self.cons, f'fdtget -l {self.fit} {path}')
def __fdt_get(self, node, prop):
val = util.run_and_log(self.cons, f'fdtget {self.fit} {node} {prop}')
return val.rstrip('\n')
def __fdt_get_sexadecimal(self, node, prop):
numbers = util.run_and_log(self.cons, f'fdtget -tbx {self.fit} {node} {prop}')
sexadecimal = ''
for num in numbers.rstrip('\n').split(' '):
sexadecimal += num.zfill(2)
return sexadecimal
def find_hashable_image_nodes(self):
for node in self.__fdt_list('/images').split():
# We only have known hashes for the kernel node
if 'kernel' not in node:
continue
self.hashable_nodes.add(f'/images/{node}')
return self.hashable_nodes
def verify_hashes(self):
for image in self.hashable_nodes:
algos = set()
for node in self.__fdt_list(image).split():
if "hash-" not in node:
continue
raw_hash = self.__fdt_get_sexadecimal(f'{image}/{node}', 'value')
algo = self.__fdt_get(f'{image}/{node}', 'algo')
algos.add(algo)
good_hash = kernel_hashes[algo]
if good_hash != raw_hash:
raise ValueError(f'{image} Borked hash: {algo}');
# Did we test all the hashes we set out to test?
missing_algos = kernel_hashes.keys() - algos
if (missing_algos):
raise ValueError(f'Missing hashes from FIT: {missing_algos}')
@pytest.mark.buildconfigspec('hash')
@pytest.mark.requiredtool('dtc')
@pytest.mark.requiredtool('fdtget')
@pytest.mark.requiredtool('fdtput')
def test_mkimage_hashes(u_boot_console):
""" Test that hashes generated by mkimage are correct. """
def assemble_fit_image(dest_fit, its, destdir):
dtc_args = f'-I dts -O dtb -i {destdir}'
util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f', its, dest_fit])
def dtc(dts):
dtb = dts.replace('.dts', '.dtb')
util.run_and_log(cons, f'dtc {datadir}/{dts} -O dtb -o {tempdir}/{dtb}')
cons = u_boot_console
mkimage = cons.config.build_dir + '/tools/mkimage'
datadir = cons.config.source_dir + '/test/py/tests/vboot/'
tempdir = cons.config.result_dir
fit_file = f'{tempdir}/test.fit'
dtc('sandbox-kernel.dts')
# Create a fake kernel image -- Avoid zeroes or crc16 will be zero
with open(f'{tempdir}/test-kernel.bin', 'w') as fd:
fd.write(500 * chr(0xa5))
assemble_fit_image(fit_file, f'{datadir}/hash-images.its', tempdir)
fit = ReadonlyFitImage(cons, fit_file)
nodes = fit.find_hashable_image_nodes()
if len(nodes) == 0:
raise ValueError('FIT image has no "/image" nodes with "hash-..."')
fit.verify_hashes()