1# SPDX-License-Identifier:	GPL-2.0+
2#
3# Copyright (c) 2021 Alexandru Gagniuc <mr.nuke.me@gmail.com>
4
5"""
6Check hashes produced by mkimage against known values
7
8This test checks the correctness of mkimage's hashes. by comparing the mkimage
9output of a fixed data block with known good hashes.
10This test doesn't run the sandbox. It only checks the host tool 'mkimage'
11"""
12
13import os
14import pytest
15import u_boot_utils as util
16
17kernel_hashes = {
18    "sha512" : "f18c1486a2c29f56360301576cdfce4dfd8e8e932d0ed8e239a1f314b8ae1d77b2a58cd7fe32e4075e69448e623ce53b0b6aa6ce5626d2c189a5beae29a68d93",
19    "sha384" : "16e28976740048485d08d793d8bf043ebc7826baf2bc15feac72825ad67530ceb3d09e0deb6932c62a5a0e9f3936baf4",
20    "sha256" : "2955c56bc1e5050c111ba6e089e0f5342bb47dedf77d87e3f429095feb98a7e5",
21    "sha1"   : "652383e1a6d946953e1f65092c9435f6452c2ab7",
22    "md5"    : "4879e5086e4c76128e525b5fe2af55f1",
23    "crc32"  : "32eddfdf",
24    "crc16-ccitt" : "d4be"
25}
26
27class ReadonlyFitImage(object):
28    """ Helper to manipulate a FIT image on disk """
29    def __init__(self, cons, file_name):
30        self.fit = file_name
31        self.cons = cons
32        self.hashable_nodes = set()
33
34    def __fdt_list(self, path):
35        return util.run_and_log(self.cons, f'fdtget -l {self.fit} {path}')
36
37    def __fdt_get(self, node, prop):
38        val = util.run_and_log(self.cons, f'fdtget {self.fit} {node} {prop}')
39        return val.rstrip('\n')
40
41    def __fdt_get_sexadecimal(self, node, prop):
42        numbers = util.run_and_log(self.cons, f'fdtget -tbx {self.fit} {node} {prop}')
43
44        sexadecimal = ''
45        for num in numbers.rstrip('\n').split(' '):
46            sexadecimal += num.zfill(2)
47        return sexadecimal
48
49    def find_hashable_image_nodes(self):
50        for node in self.__fdt_list('/images').split():
51            # We only have known hashes for the kernel node
52            if 'kernel' not in node:
53                continue
54            self.hashable_nodes.add(f'/images/{node}')
55
56        return self.hashable_nodes
57
58    def verify_hashes(self):
59        for image in self.hashable_nodes:
60            algos = set()
61            for node in self.__fdt_list(image).split():
62                if "hash-" not in node:
63                    continue
64
65                raw_hash = self.__fdt_get_sexadecimal(f'{image}/{node}', 'value')
66                algo = self.__fdt_get(f'{image}/{node}', 'algo')
67                algos.add(algo)
68
69                good_hash = kernel_hashes[algo]
70                if good_hash != raw_hash:
71                    raise ValueError(f'{image} Borked hash: {algo}');
72
73            # Did we test all the hashes we set out to test?
74            missing_algos = kernel_hashes.keys() - algos
75            if (missing_algos):
76                raise ValueError(f'Missing hashes from FIT: {missing_algos}')
77
78
79@pytest.mark.buildconfigspec('hash')
80@pytest.mark.requiredtool('dtc')
81@pytest.mark.requiredtool('fdtget')
82@pytest.mark.requiredtool('fdtput')
83def test_mkimage_hashes(u_boot_console):
84    """ Test that hashes generated by mkimage are correct. """
85
86    def assemble_fit_image(dest_fit, its, destdir):
87        dtc_args = f'-I dts -O dtb -i {destdir}'
88        util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f', its, dest_fit])
89
90    def dtc(dts):
91        dtb = dts.replace('.dts', '.dtb')
92        util.run_and_log(cons, f'dtc {datadir}/{dts} -O dtb -o {tempdir}/{dtb}')
93
94    cons = u_boot_console
95    mkimage = cons.config.build_dir + '/tools/mkimage'
96    datadir = cons.config.source_dir + '/test/py/tests/vboot/'
97    tempdir = os.path.join(cons.config.result_dir, 'hashes')
98    os.makedirs(tempdir, exist_ok=True)
99
100    fit_file = f'{tempdir}/test.fit'
101    dtc('sandbox-kernel.dts')
102
103    # Create a fake kernel image -- Avoid zeroes or crc16 will be zero
104    with open(f'{tempdir}/test-kernel.bin', 'w') as fd:
105        fd.write(500 * chr(0xa5))
106
107    assemble_fit_image(fit_file, f'{datadir}/hash-images.its', tempdir)
108
109    fit = ReadonlyFitImage(cons, fit_file)
110    nodes = fit.find_hashable_image_nodes()
111    if len(nodes) == 0:
112        raise ValueError('FIT image has no "/image" nodes with "hash-..."')
113
114    fit.verify_hashes()
115