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 def test_vboot(u_boot_console):
35 """Test verified boot signing with mkimage and verification with 'bootm'.
37 This works using sandbox only as it needs to update the device tree used
38 by U-Boot to hold public keys from the signing process.
40 The SHA1 and SHA256 tests are combined into a single test since the
41 key-generation process is quite slow and we want to avoid doing it twice.
44 """Run the device tree compiler to compile a .dts file
46 The output file will be the same as the input file but with a .dtb
50 dts: Device tree file to compile.
52 dtb = dts.replace('.dts', '.dtb')
53 util.cmd(cons, 'dtc %s %s%s -O dtb '
54 '-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))
56 def run_bootm(test_type, expect_string):
57 """Run a 'bootm' command U-Boot.
59 This always starts a fresh U-Boot instance since the device tree may
60 contain a new public key.
63 test_type: A string identifying the test type
64 expect_string: A string which is expected in the output
68 cons.log.action('%s: Test Verified Boot Run: %s' % (algo, test_type))
69 output = cons.run_command_list(
70 ['sb load hostfs - 100 %stest.fit' % tmpdir,
73 assert(expect_string in output)
76 """Make a new FIT from the .its source file.
78 This runs 'mkimage -f' to create a new FIT.
81 its: Filename containing .its source.
83 util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f',
84 '%s%s' % (datadir, its), fit])
89 Signs the FIT and writes the signature into it. It also writes the
90 public key into the dtb.
92 cons.log.action('%s: Sign images' % algo)
93 util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
96 def test_with_algo(sha):
97 """Test verified boot with the given hash algorithm.
99 This is the main part of the test code. The same procedure is followed
100 for both hashing algorithms.
103 sha: Either 'sha1' or 'sha256', to select the algorithm to use
109 # Compile our device tree files for kernel and U-Boot. These are
110 # regenerated here since mkimage will modify them (by adding a
112 dtc('sandbox-kernel.dts')
113 dtc('sandbox-u-boot.dts')
115 # Build the FIT, but don't sign anything yet
116 cons.log.action('%s: Test FIT with signed images' % algo)
117 make_fit('sign-images-%s.its' % algo)
118 run_bootm('unsigned images', 'dev-')
120 # Sign images with our dev keys
122 run_bootm('signed images', 'dev+')
124 # Create a fresh .dtb without the public keys
125 dtc('sandbox-u-boot.dts')
127 cons.log.action('%s: Test FIT with signed configuration' % algo)
128 make_fit('sign-configs-%s.its' % algo)
129 run_bootm('unsigned config', '%s+ OK' % algo)
131 # Sign images with our dev keys
133 run_bootm('signed config', 'dev+')
135 cons.log.action('%s: Check signed config on the host' % algo)
137 util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
140 # Increment the first byte of the signature, which should cause failure
141 sig = util.cmd(cons, 'fdtget -t bx %s %s value' % (fit, sig_node))
142 byte_list = sig.split()
143 byte = int(byte_list[0], 16)
144 byte_list[0] = '%x' % (byte + 1)
145 sig = ' '.join(byte_list)
146 util.cmd(cons, 'fdtput -t bx %s %s value %s' % (fit, sig_node, sig))
148 run_bootm('Signed config with bad hash', 'Bad Data Hash')
150 cons.log.action('%s: Check bad config on the host' % algo)
151 util.run_and_log_expect_exception(cons, [fit_check_sign, '-f', fit,
152 '-k', dtb], 1, 'Failed to verify required signature')
154 cons = u_boot_console
155 tmpdir = cons.config.result_dir + '/'
156 tmp = tmpdir + 'vboot.tmp'
157 datadir = cons.config.source_dir + '/test/py/tests/vboot/'
158 fit = '%stest.fit' % tmpdir
159 mkimage = cons.config.build_dir + '/tools/mkimage'
160 fit_check_sign = cons.config.build_dir + '/tools/fit_check_sign'
161 dtc_args = '-I dts -O dtb -i %s' % tmpdir
162 dtb = '%ssandbox-u-boot.dtb' % tmpdir
163 sig_node = '/configurations/conf@1/signature@1'
165 # Create an RSA key pair
166 public_exponent = 65537
167 util.cmd(cons, 'openssl genpkey -algorithm RSA -out %sdev.key '
168 '-pkeyopt rsa_keygen_bits:2048 '
169 '-pkeyopt rsa_keygen_pubexp:%d '
170 '2>/dev/null' % (tmpdir, public_exponent))
172 # Create a certificate containing the public key
173 util.cmd(cons, 'openssl req -batch -new -x509 -key %sdev.key -out '
174 '%sdev.crt' % (tmpdir, tmpdir))
176 # Create a number kernel image with zeroes
177 with open('%stest-kernel.bin' % tmpdir, 'w') as fd:
178 fd.write(5000 * chr(0))
181 # We need to use our own device tree file. Remember to restore it
183 old_dtb = cons.config.dtb
184 cons.config.dtb = dtb
185 test_with_algo('sha1')
186 test_with_algo('sha256')
188 cons.config.dtb = old_dtb