test/py/tests/test_vboot.py - u-boot - Git at Google

 # SPDX-License-Identifier:	GPL-2.0+
 # Copyright (c) 2016, Google Inc.
 #
 # U-Boot Verified Boot Test

 """
 This tests verified boot in the following ways:

 For image verification:
 - Create FIT (unsigned) with mkimage
 - Check that verification shows that no keys are verified
 - Sign image
 - Check that verification shows that a key is now verified

 For configuration verification:
 - Corrupt signature and check for failure
 - Create FIT (with unsigned configuration) with mkimage
 - Check that image verification works
 - Sign the FIT and mark the key as 'required' for verification
 - Check that image verification works
 - Corrupt the signature
 - Check that image verification no-longer works

 Tests run with both SHA1 and SHA256 hashing.
 """

 import pytest
 import sys
 import struct
 import u_boot_utils as util

 @pytest.mark.boardspec('sandbox')
 @pytest.mark.buildconfigspec('fit_signature')
 @pytest.mark.requiredtool('dtc')
 @pytest.mark.requiredtool('fdtget')
 @pytest.mark.requiredtool('fdtput')
 @pytest.mark.requiredtool('openssl')
 def test_vboot(u_boot_console):
     """Test verified boot signing with mkimage and verification with 'bootm'.

     This works using sandbox only as it needs to update the device tree used
     by U-Boot to hold public keys from the signing process.

     The SHA1 and SHA256 tests are combined into a single test since the
     key-generation process is quite slow and we want to avoid doing it twice.
     """
     def dtc(dts):
         """Run the device tree compiler to compile a .dts file

         The output file will be the same as the input file but with a .dtb
         extension.

         Args:
             dts: Device tree file to compile.
         """
         dtb = dts.replace('.dts', '.dtb')
         util.run_and_log(cons, 'dtc %s %s%s -O dtb '
                          '-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))

     def run_bootm(sha_algo, test_type, expect_string, boots):
         """Run a 'bootm' command U-Boot.

         This always starts a fresh U-Boot instance since the device tree may
         contain a new public key.

         Args:
             test_type: A string identifying the test type.
             expect_string: A string which is expected in the output.
             sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
                     use.
             boots: A boolean that is True if Linux should boot and False if
                     we are expected to not boot
         """
         cons.restart_uboot()
         with cons.log.section('Verified boot %s %s' % (sha_algo, test_type)):
             output = cons.run_command_list(
                 ['sb load hostfs - 100 %stest.fit' % tmpdir,
                 'fdt addr 100',
                 'bootm 100'])
         assert(expect_string in ''.join(output))
         if boots:
             assert('sandbox: continuing, as we cannot run' in ''.join(output))

     def make_fit(its):
         """Make a new FIT from the .its source file.

         This runs 'mkimage -f' to create a new FIT.

         Args:
             its: Filename containing .its source.
         """
         util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f',
                                 '%s%s' % (datadir, its), fit])

     def sign_fit(sha_algo):
         """Sign the FIT

         Signs the FIT and writes the signature into it. It also writes the
         public key into the dtb.

         Args:
             sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
                     use.
         """
         cons.log.action('%s: Sign images' % sha_algo)
         util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
                                 '-r', fit])

     def replace_fit_totalsize(size):
         """Replace FIT header's totalsize with something greater.

         The totalsize must be less than or equal to FIT_SIGNATURE_MAX_SIZE.
         If the size is greater, the signature verification should return false.

         Args:
             size: The new totalsize of the header

         Returns:
             prev_size: The previous totalsize read from the header
         """
         total_size = 0
         with open(fit, 'r+b') as handle:
             handle.seek(4)
             total_size = handle.read(4)
             handle.seek(4)
             handle.write(struct.pack(">I", size))
         return struct.unpack(">I", total_size)[0]

     def test_with_algo(sha_algo):
         """Test verified boot with the given hash algorithm.

         This is the main part of the test code. The same procedure is followed
         for both hashing algorithms.

         Args:
             sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
                     use.
         """
         # Compile our device tree files for kernel and U-Boot. These are
         # regenerated here since mkimage will modify them (by adding a
         # public key) below.
         dtc('sandbox-kernel.dts')
         dtc('sandbox-u-boot.dts')

         # Build the FIT, but don't sign anything yet
         cons.log.action('%s: Test FIT with signed images' % sha_algo)
         make_fit('sign-images-%s.its' % sha_algo)
         run_bootm(sha_algo, 'unsigned images', 'dev-', True)

         # Sign images with our dev keys
         sign_fit(sha_algo)
         run_bootm(sha_algo, 'signed images', 'dev+', True)

         # Create a fresh .dtb without the public keys
         dtc('sandbox-u-boot.dts')

         cons.log.action('%s: Test FIT with signed configuration' % sha_algo)
         make_fit('sign-configs-%s.its' % sha_algo)
         run_bootm(sha_algo, 'unsigned config', '%s+ OK' % sha_algo, True)

         # Sign images with our dev keys
         sign_fit(sha_algo)
         run_bootm(sha_algo, 'signed config', 'dev+', True)

         cons.log.action('%s: Check signed config on the host' % sha_algo)

         util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
                                 '-k', dtb])

         # Replace header bytes
         bcfg = u_boot_console.config.buildconfig
         max_size = int(bcfg.get('config_fit_signature_max_size', 0x10000000), 0)
         existing_size = replace_fit_totalsize(max_size + 1)
         run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)
         cons.log.action('%s: Check overflowed FIT header totalsize' % sha_algo)

         # Replace with existing header bytes
         replace_fit_totalsize(existing_size)
         run_bootm(sha_algo, 'signed config', 'dev+', True)
         cons.log.action('%s: Check default FIT header totalsize' % sha_algo)

         # Increment the first byte of the signature, which should cause failure
         sig = util.run_and_log(cons, 'fdtget -t bx %s %s value' %
                                (fit, sig_node))
         byte_list = sig.split()
         byte = int(byte_list[0], 16)
         byte_list[0] = '%x' % (byte + 1)
         sig = ' '.join(byte_list)
         util.run_and_log(cons, 'fdtput -t bx %s %s value %s' %
                          (fit, sig_node, sig))

         run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)

         cons.log.action('%s: Check bad config on the host' % sha_algo)
         util.run_and_log_expect_exception(cons, [fit_check_sign, '-f', fit,
                 '-k', dtb], 1, 'Failed to verify required signature')

     cons = u_boot_console
     tmpdir = cons.config.result_dir + '/'
     tmp = tmpdir + 'vboot.tmp'
     datadir = cons.config.source_dir + '/test/py/tests/vboot/'
     fit = '%stest.fit' % tmpdir
     mkimage = cons.config.build_dir + '/tools/mkimage'
     fit_check_sign = cons.config.build_dir + '/tools/fit_check_sign'
     dtc_args = '-I dts -O dtb -i %s' % tmpdir
     dtb = '%ssandbox-u-boot.dtb' % tmpdir
     sig_node = '/configurations/conf@1/signature@1'

     # Create an RSA key pair
     public_exponent = 65537
     util.run_and_log(cons, 'openssl genpkey -algorithm RSA -out %sdev.key '
                      '-pkeyopt rsa_keygen_bits:2048 '
                      '-pkeyopt rsa_keygen_pubexp:%d '
                      '2>/dev/null'  % (tmpdir, public_exponent))

     # Create a certificate containing the public key
     util.run_and_log(cons, 'openssl req -batch -new -x509 -key %sdev.key -out '
                      '%sdev.crt' % (tmpdir, tmpdir))

     # Create a number kernel image with zeroes
     with open('%stest-kernel.bin' % tmpdir, 'w') as fd:
         fd.write(5000 * chr(0))

     try:
         # We need to use our own device tree file. Remember to restore it
         # afterwards.
         old_dtb = cons.config.dtb
         cons.config.dtb = dtb
         test_with_algo('sha1')
         test_with_algo('sha256')
     finally:
         # Go back to the original U-Boot with the correct dtb.
         cons.config.dtb = old_dtb
         cons.restart_uboot()
	# SPDX-License-Identifier: GPL-2.0+
	# Copyright (c) 2016, Google Inc.
	#
	# U-Boot Verified Boot Test

	"""
	This tests verified boot in the following ways:

	For image verification:
	- Create FIT (unsigned) with mkimage
	- Check that verification shows that no keys are verified
	- Sign image
	- Check that verification shows that a key is now verified

	For configuration verification:
	- Corrupt signature and check for failure
	- Create FIT (with unsigned configuration) with mkimage
	- Check that image verification works
	- Sign the FIT and mark the key as 'required' for verification
	- Check that image verification works
	- Corrupt the signature
	- Check that image verification no-longer works

	Tests run with both SHA1 and SHA256 hashing.
	"""

	import pytest
	import sys
	import struct
	import u_boot_utils as util

	@pytest.mark.boardspec('sandbox')
	@pytest.mark.buildconfigspec('fit_signature')
	@pytest.mark.requiredtool('dtc')
	@pytest.mark.requiredtool('fdtget')
	@pytest.mark.requiredtool('fdtput')
	@pytest.mark.requiredtool('openssl')
	def test_vboot(u_boot_console):
	"""Test verified boot signing with mkimage and verification with 'bootm'.

	This works using sandbox only as it needs to update the device tree used
	by U-Boot to hold public keys from the signing process.

	The SHA1 and SHA256 tests are combined into a single test since the
	key-generation process is quite slow and we want to avoid doing it twice.
	"""
	def dtc(dts):
	"""Run the device tree compiler to compile a .dts file

	The output file will be the same as the input file but with a .dtb
	extension.

	Args:
	dts: Device tree file to compile.
	"""
	dtb = dts.replace('.dts', '.dtb')
	util.run_and_log(cons, 'dtc %s %s%s -O dtb '
	'-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))

	def run_bootm(sha_algo, test_type, expect_string, boots):
	"""Run a 'bootm' command U-Boot.

	This always starts a fresh U-Boot instance since the device tree may
	contain a new public key.

	Args:
	test_type: A string identifying the test type.
	expect_string: A string which is expected in the output.
	sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
	use.
	boots: A boolean that is True if Linux should boot and False if
	we are expected to not boot
	"""
	cons.restart_uboot()
	with cons.log.section('Verified boot %s %s' % (sha_algo, test_type)):
	output = cons.run_command_list(
	['sb load hostfs - 100 %stest.fit' % tmpdir,
	'fdt addr 100',
	'bootm 100'])
	assert(expect_string in ''.join(output))
	if boots:
	assert('sandbox: continuing, as we cannot run' in ''.join(output))

	def make_fit(its):
	"""Make a new FIT from the .its source file.

	This runs 'mkimage -f' to create a new FIT.

	Args:
	its: Filename containing .its source.
	"""
	util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f',
	'%s%s' % (datadir, its), fit])

	def sign_fit(sha_algo):
	"""Sign the FIT

	Signs the FIT and writes the signature into it. It also writes the
	public key into the dtb.

	Args:
	sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
	use.
	"""
	cons.log.action('%s: Sign images' % sha_algo)
	util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
	'-r', fit])

	def replace_fit_totalsize(size):
	"""Replace FIT header's totalsize with something greater.

	The totalsize must be less than or equal to FIT_SIGNATURE_MAX_SIZE.
	If the size is greater, the signature verification should return false.

	Args:
	size: The new totalsize of the header

	Returns:
	prev_size: The previous totalsize read from the header
	"""
	total_size = 0
	with open(fit, 'r+b') as handle:
	handle.seek(4)
	total_size = handle.read(4)
	handle.seek(4)
	handle.write(struct.pack(">I", size))
	return struct.unpack(">I", total_size)[0]

	def test_with_algo(sha_algo):
	"""Test verified boot with the given hash algorithm.

	This is the main part of the test code. The same procedure is followed
	for both hashing algorithms.

	Args:
	sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
	use.
	"""
	# Compile our device tree files for kernel and U-Boot. These are
	# regenerated here since mkimage will modify them (by adding a
	# public key) below.
	dtc('sandbox-kernel.dts')
	dtc('sandbox-u-boot.dts')

	# Build the FIT, but don't sign anything yet
	cons.log.action('%s: Test FIT with signed images' % sha_algo)
	make_fit('sign-images-%s.its' % sha_algo)
	run_bootm(sha_algo, 'unsigned images', 'dev-', True)

	# Sign images with our dev keys
	sign_fit(sha_algo)
	run_bootm(sha_algo, 'signed images', 'dev+', True)

	# Create a fresh .dtb without the public keys
	dtc('sandbox-u-boot.dts')

	cons.log.action('%s: Test FIT with signed configuration' % sha_algo)
	make_fit('sign-configs-%s.its' % sha_algo)
	run_bootm(sha_algo, 'unsigned config', '%s+ OK' % sha_algo, True)

	# Sign images with our dev keys
	sign_fit(sha_algo)
	run_bootm(sha_algo, 'signed config', 'dev+', True)

	cons.log.action('%s: Check signed config on the host' % sha_algo)

	util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
	'-k', dtb])

	# Replace header bytes
	bcfg = u_boot_console.config.buildconfig
	max_size = int(bcfg.get('config_fit_signature_max_size', 0x10000000), 0)
	existing_size = replace_fit_totalsize(max_size + 1)
	run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)
	cons.log.action('%s: Check overflowed FIT header totalsize' % sha_algo)

	# Replace with existing header bytes
	replace_fit_totalsize(existing_size)
	run_bootm(sha_algo, 'signed config', 'dev+', True)
	cons.log.action('%s: Check default FIT header totalsize' % sha_algo)

	# Increment the first byte of the signature, which should cause failure
	sig = util.run_and_log(cons, 'fdtget -t bx %s %s value' %
	(fit, sig_node))
	byte_list = sig.split()
	byte = int(byte_list[0], 16)
	byte_list[0] = '%x' % (byte + 1)
	sig = ' '.join(byte_list)
	util.run_and_log(cons, 'fdtput -t bx %s %s value %s' %
	(fit, sig_node, sig))

	run_bootm(sha_algo, 'Signed config with bad hash', 'Bad Data Hash', False)

	cons.log.action('%s: Check bad config on the host' % sha_algo)
	util.run_and_log_expect_exception(cons, [fit_check_sign, '-f', fit,
	'-k', dtb], 1, 'Failed to verify required signature')

	cons = u_boot_console
	tmpdir = cons.config.result_dir + '/'
	tmp = tmpdir + 'vboot.tmp'
	datadir = cons.config.source_dir + '/test/py/tests/vboot/'
	fit = '%stest.fit' % tmpdir
	mkimage = cons.config.build_dir + '/tools/mkimage'
	fit_check_sign = cons.config.build_dir + '/tools/fit_check_sign'
	dtc_args = '-I dts -O dtb -i %s' % tmpdir
	dtb = '%ssandbox-u-boot.dtb' % tmpdir
	sig_node = '/configurations/conf@1/signature@1'

	# Create an RSA key pair
	public_exponent = 65537
	util.run_and_log(cons, 'openssl genpkey -algorithm RSA -out %sdev.key '
	'-pkeyopt rsa_keygen_bits:2048 '
	'-pkeyopt rsa_keygen_pubexp:%d '
	'2>/dev/null' % (tmpdir, public_exponent))

	# Create a certificate containing the public key
	util.run_and_log(cons, 'openssl req -batch -new -x509 -key %sdev.key -out '
	'%sdev.crt' % (tmpdir, tmpdir))

	# Create a number kernel image with zeroes
	with open('%stest-kernel.bin' % tmpdir, 'w') as fd:
	fd.write(5000 * chr(0))

	try:
	# We need to use our own device tree file. Remember to restore it
	# afterwards.
	old_dtb = cons.config.dtb
	cons.config.dtb = dtb
	test_with_algo('sha1')
	test_with_algo('sha256')
	finally:
	# Go back to the original U-Boot with the correct dtb.
	cons.config.dtb = old_dtb
	cons.restart_uboot()