1 # Copyright (c) 2016, Google Inc.
3 # SPDX-License-Identifier: GPL-2.0+
5 # U-Boot Verified Boot Test
8 This tests verified boot in the following ways:
10 For image verification:
11 - Create FIT (unsigned) with mkimage
12 - Check that verification shows that no keys are verified
14 - Check that verification shows that a key is now verified
16 For configuration verification:
17 - Corrupt signature and check for failure
18 - Create FIT (with unsigned configuration) with mkimage
19 - Check that image verification works
20 - Sign the FIT and mark the key as 'required' for verification
21 - Check that image verification works
22 - Corrupt the signature
23 - Check that image verification no-longer works
25 Tests run with both SHA1 and SHA256 hashing.
30 import u_boot_utils as util
32 @pytest.mark.boardspec('sandbox')
33 @pytest.mark.buildconfigspec('fit_signature')
34 @pytest.mark.requiredtool('dtc')
35 @pytest.mark.requiredtool('fdtget')
36 @pytest.mark.requiredtool('fdtput')
37 @pytest.mark.requiredtool('openssl')
38 def test_vboot(u_boot_console):
39 """Test verified boot signing with mkimage and verification with 'bootm'.
41 This works using sandbox only as it needs to update the device tree used
42 by U-Boot to hold public keys from the signing process.
44 The SHA1 and SHA256 tests are combined into a single test since the
45 key-generation process is quite slow and we want to avoid doing it twice.
48 """Run the device tree compiler to compile a .dts file
50 The output file will be the same as the input file but with a .dtb
54 dts: Device tree file to compile.
56 dtb = dts.replace('.dts', '.dtb')
57 util.run_and_log(cons, 'dtc %s %s%s -O dtb '
58 '-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))
60 def run_bootm(sha_algo, test_type, expect_string, boots):
61 """Run a 'bootm' command U-Boot.
63 This always starts a fresh U-Boot instance since the device tree may
64 contain a new public key.
67 test_type: A string identifying the test type.
68 expect_string: A string which is expected in the output.
69 sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
71 boots: A boolean that is True if Linux should boot and False if
72 we are expected to not boot
75 with cons.log.section('Verified boot %s %s' % (sha_algo, test_type)):
76 output = cons.run_command_list(
77 ['sb load hostfs - 100 %stest.fit' % tmpdir,
80 assert(expect_string in ''.join(output))
82 assert('sandbox: continuing, as we cannot run' in ''.join(output))
85 """Make a new FIT from the .its source file.
87 This runs 'mkimage -f' to create a new FIT.
90 its: Filename containing .its source.
92 util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f',
93 '%s%s' % (datadir, its), fit])
95 def sign_fit(sha_algo):
98 Signs the FIT and writes the signature into it. It also writes the
99 public key into the dtb.
102 sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
105 cons.log.action('%s: Sign images' % sha_algo)
106 util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
109 def test_with_algo(sha_algo):
110 """Test verified boot with the given hash algorithm.
112 This is the main part of the test code. The same procedure is followed
113 for both hashing algorithms.
116 sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
119 # Compile our device tree files for kernel and U-Boot. These are
120 # regenerated here since mkimage will modify them (by adding a
122 dtc('sandbox-kernel.dts')
123 dtc('sandbox-u-boot.dts')
125 # Build the FIT, but don't sign anything yet
126 cons.log.action('%s: Test FIT with signed images' % sha_algo)
127 make_fit('sign-images-%s.its' % sha_algo)
128 run_bootm(sha_algo, 'unsigned images', 'dev-', True)
130 # Sign images with our dev keys
132 run_bootm(sha_algo, 'signed images', 'dev+', True)
134 # Create a fresh .dtb without the public keys
135 dtc('sandbox-u-boot.dts')
137 cons.log.action('%s: Test FIT with signed configuration' % sha_algo)
138 make_fit('sign-configs-%s.its' % sha_algo)
139 run_bootm(sha_algo, 'unsigned config', '%s+ OK' % sha_algo, True)
141 # Sign images with our dev keys
143 run_bootm(sha_algo, 'signed config', 'dev+', True)
145 cons.log.action('%s: Check signed config on the host' % sha_algo)
147 util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
150 # Increment the first byte of the signature, which should cause failure
151 sig = util.run_and_log(cons, 'fdtget -t bx %s %s value' %
153 byte_list = sig.split()
154 byte = int(byte_list[0], 16)
155 byte_list[0] = '%x' % (byte + 1)
156 sig = ' '.join(byte_list)
157 util.run_and_log(cons, 'fdtput -t bx %s %s value %s' %
158 (fit, sig_node, sig))
160 run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)
162 cons.log.action('%s: Check bad config on the host' % sha_algo)
163 util.run_and_log_expect_exception(cons, [fit_check_sign, '-f', fit,
164 '-k', dtb], 1, 'Failed to verify required signature')
166 cons = u_boot_console
167 tmpdir = cons.config.result_dir + '/'
168 tmp = tmpdir + 'vboot.tmp'
169 datadir = cons.config.source_dir + '/test/py/tests/vboot/'
170 fit = '%stest.fit' % tmpdir
171 mkimage = cons.config.build_dir + '/tools/mkimage'
172 fit_check_sign = cons.config.build_dir + '/tools/fit_check_sign'
173 dtc_args = '-I dts -O dtb -i %s' % tmpdir
174 dtb = '%ssandbox-u-boot.dtb' % tmpdir
175 sig_node = '/configurations/conf@1/signature@1'
177 # Create an RSA key pair
178 public_exponent = 65537
179 util.run_and_log(cons, 'openssl genpkey -algorithm RSA -out %sdev.key '
180 '-pkeyopt rsa_keygen_bits:2048 '
181 '-pkeyopt rsa_keygen_pubexp:%d '
182 '2>/dev/null' % (tmpdir, public_exponent))
184 # Create a certificate containing the public key
185 util.run_and_log(cons, 'openssl req -batch -new -x509 -key %sdev.key -out '
186 '%sdev.crt' % (tmpdir, tmpdir))
188 # Create a number kernel image with zeroes
189 with open('%stest-kernel.bin' % tmpdir, 'w') as fd:
190 fd.write(5000 * chr(0))
193 # We need to use our own device tree file. Remember to restore it
195 old_dtb = cons.config.dtb
196 cons.config.dtb = dtb
197 test_with_algo('sha1')
198 test_with_algo('sha256')
200 # Go back to the original U-Boot with the correct dtb.
201 cons.config.dtb = old_dtb