-# Copyright (c) 2013, Google Inc.
-#
# SPDX-License-Identifier: GPL-2.0+
+# Copyright (c) 2016, Google Inc.
#
# U-Boot Verified Boot Test
For configuration verification:
- Corrupt signature and check for failure
- Create FIT (with unsigned configuration) with mkimage
-- Check that image veriication works
+- Check that image verification works
- Sign the FIT and mark the key as 'required' for verification
- Check that image verification works
- Corrupt the signature
Tests run with both SHA1 and SHA256 hashing.
"""
+import struct
import pytest
-import sys
import u_boot_utils as util
-
+import vboot_forge
+
+TESTDATA = [
+ ['sha1', '', None, False],
+ ['sha1', '', '-E -p 0x10000', False],
+ ['sha1', '-pss', None, False],
+ ['sha1', '-pss', '-E -p 0x10000', False],
+ ['sha256', '', None, False],
+ ['sha256', '', '-E -p 0x10000', False],
+ ['sha256', '-pss', None, False],
+ ['sha256', '-pss', '-E -p 0x10000', False],
+ ['sha256', '-pss', None, True],
+ ['sha256', '-pss', '-E -p 0x10000', True],
+]
+
+@pytest.mark.boardspec('sandbox')
@pytest.mark.buildconfigspec('fit_signature')
-def test_vboot(u_boot_console):
+@pytest.mark.requiredtool('dtc')
+@pytest.mark.requiredtool('fdtget')
+@pytest.mark.requiredtool('fdtput')
+@pytest.mark.requiredtool('openssl')
+@pytest.mark.parametrize("sha_algo,padding,sign_options,required", TESTDATA)
+def test_vboot(u_boot_console, sha_algo, padding, sign_options, required):
"""Test verified boot signing with mkimage and verification with 'bootm'.
This works using sandbox only as it needs to update the device tree used
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
+ """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.
dts: Device tree file to compile.
"""
dtb = dts.replace('.dts', '.dtb')
- util.cmd(cons, 'dtc %s %s%s -O dtb '
- '-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))
+ util.run_and_log(cons, 'dtc %s %s%s -O dtb '
+ '-o %s%s' % (dtc_args, datadir, dts, tmpdir, dtb))
- def run_bootm(test_type, expect_string):
+ 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
+ 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.cleanup_spawn()
- cons.ensure_spawned()
- cons.log.action('%s: Test Verified Boot Run: %s' % (algo, test_type))
- output = cons.run_command_list(
- ['sb load hostfs - 100 %stest.fit' % tmpdir,
- 'fdt addr 100',
- 'bootm 100'])
- assert(expect_string in output)
+ cons.restart_uboot()
+ with cons.log.section('Verified boot %s %s' % (sha_algo, test_type)):
+ output = cons.run_command_list(
+ ['host 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)
+ else:
+ assert('sandbox: continuing, as we cannot run'
+ not in ''.join(output))
def make_fit(its):
- """Make a new FIT from the .its source file
+ """Make a new FIT from the .its source file.
This runs 'mkimage -f' to create a new FIT.
Args:
- its: Filename containing .its source
+ its: Filename containing .its source.
"""
util.run_and_log(cons, [mkimage, '-D', dtc_args, '-f',
'%s%s' % (datadir, its), fit])
- def sign_fit():
+ def sign_fit(sha_algo, options):
"""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.
+ options: Options to provide to mkimage.
"""
- cons.log.action('%s: Sign images' % algo)
- util.run_and_log(cons, [mkimage, '-F', '-k', tmpdir, '-K', dtb,
- '-r', fit])
+ args = [mkimage, '-F', '-k', tmpdir, '-K', dtb, '-r', fit]
+ if options:
+ args += options.split(' ')
+ cons.log.action('%s: Sign images' % sha_algo)
+ util.run_and_log(cons, args)
- def test_with_algo(sha):
- """Test verified boot with the given hash algorithm
+ def replace_fit_totalsize(size):
+ """Replace FIT header's totalsize with something greater.
- This is the main part of the test code. The same procedure is followed
- for both hashing algorithms.
+ 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 create_rsa_pair(name):
+ """Generate a new RSA key paid and certificate
Args:
- sha: Either 'sha1' or 'sha256', to select the algorithm to use
+ name: Name of of the key (e.g. 'dev')
"""
- global algo
+ public_exponent = 65537
+ util.run_and_log(cons, 'openssl genpkey -algorithm RSA -out %s%s.key '
+ '-pkeyopt rsa_keygen_bits:2048 '
+ '-pkeyopt rsa_keygen_pubexp:%d' %
+ (tmpdir, name, public_exponent))
- algo = sha
+ # Create a certificate containing the public key
+ util.run_and_log(cons, 'openssl req -batch -new -x509 -key %s%s.key '
+ '-out %s%s.crt' % (tmpdir, name, tmpdir, name))
+
+ def test_with_algo(sha_algo, padding, sign_options):
+ """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.
- # Compile our device tree files for kernel and U-Boot
+ Args:
+ sha_algo: Either 'sha1' or 'sha256', to select the algorithm to
+ use.
+ padding: Either '' or '-pss', to select the padding to use for the
+ rsa signature algorithm.
+ sign_options: Options to mkimage when signing a fit image.
+ """
+ # 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' % algo)
- make_fit('sign-images-%s.its' % algo)
- run_bootm('unsigned images', 'dev-')
+ cons.log.action('%s: Test FIT with signed images' % sha_algo)
+ make_fit('sign-images-%s%s.its' % (sha_algo, padding))
+ run_bootm(sha_algo, 'unsigned images', 'dev-', True)
# Sign images with our dev keys
- sign_fit()
- run_bootm('signed images', 'dev+')
+ sign_fit(sha_algo, sign_options)
+ 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' % algo)
- make_fit('sign-configs-%s.its' % algo)
- run_bootm('unsigned config', '%s+ OK' % algo)
+ cons.log.action('%s: Test FIT with signed configuration' % sha_algo)
+ make_fit('sign-configs-%s%s.its' % (sha_algo, padding))
+ run_bootm(sha_algo, 'unsigned config', '%s+ OK' % sha_algo, True)
# Sign images with our dev keys
- sign_fit()
- run_bootm('signed config', 'dev+')
-
- cons.log.action('%s: Check signed config on the host' % algo)
-
- util.run_and_log(cons, [fit_check_sign, '-f', fit, '-k', tmpdir,
- '-k', dtb])
+ sign_fit(sha_algo, sign_options)
+ 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', dtb])
+
+ # Make sure that U-Boot checks that the config is in the list of hashed
+ # nodes. If it isn't, a security bypass is possible.
+ with open(fit, 'rb') as fd:
+ root, strblock = vboot_forge.read_fdt(fd)
+ root, strblock = vboot_forge.manipulate(root, strblock)
+ with open(fit, 'w+b') as fd:
+ vboot_forge.write_fdt(root, strblock, fd)
+ util.run_and_log_expect_exception(
+ cons, [fit_check_sign, '-f', fit, '-k', dtb],
+ 1, 'Failed to verify required signature')
+
+ run_bootm(sha_algo, 'forged config', 'Bad Data Hash', False)
+
+ # Create a new properly signed fit and replace header bytes
+ make_fit('sign-configs-%s%s.its' % (sha_algo, padding))
+ sign_fit(sha_algo, sign_options)
+ 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.cmd(cons, 'fdtget -t bx %s %s value' % (fit, sig_node))
+ 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 = ['%x' % (byte + 1)] + byte_list[1:]
+ byte_list[0] = '%x' % (byte + 1)
sig = ' '.join(byte_list)
- util.cmd(cons, 'fdtput -t bx %s %s value %s' % (fit, sig_node, sig))
+ 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')
+
+ def test_required_key(sha_algo, padding, sign_options):
+ """Test verified boot with the given hash algorithm.
+
+ This function tests if U-Boot rejects an image when a required key isn't
+ used to sign a FIT.
- run_bootm('Signed config with bad hash', 'Bad Data Hash')
+ Args:
+ sha_algo: Either 'sha1' or 'sha256', to select the algorithm to use
+ padding: Either '' or '-pss', to select the padding to use for the
+ rsa signature algorithm.
+ sign_options: Options to mkimage when signing a fit image.
+ """
+ # 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')
- cons.log.action('%s: Check bad config on the host' % algo)
- util.run_and_log_expect_exception(cons, [fit_check_sign, '-f', fit,
- '-k', dtb], 1, 'Failed to verify required signature')
+ cons.log.action('%s: Test FIT with configs images' % sha_algo)
+
+ # Build the FIT with prod key (keys required) and sign it. This puts the
+ # signature into sandbox-u-boot.dtb, marked 'required'
+ make_fit('sign-configs-%s%s-prod.its' % (sha_algo, padding))
+ sign_fit(sha_algo, sign_options)
+
+ # Build the FIT with dev key (keys NOT required). This adds the
+ # signature into sandbox-u-boot.dtb, NOT marked 'required'.
+ make_fit('sign-configs-%s%s.its' % (sha_algo, padding))
+ sign_fit(sha_algo, sign_options)
+
+ # So now sandbox-u-boot.dtb two signatures, for the prod and dev keys.
+ # Only the prod key is set as 'required'. But FIT we just built has
+ # a dev signature only (sign_fit() overwrites the FIT).
+ # Try to boot the FIT with dev key. This FIT should not be accepted by
+ # U-Boot because the prod key is required.
+ run_bootm(sha_algo, 'required key', '', False)
cons = u_boot_console
tmpdir = cons.config.result_dir + '/'
- tmp = tmpdir + 'vboot.tmp'
- datadir = 'test/py/tests/vboot/'
+ 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.cmd(cons, 'openssl genpkey -algorithm RSA -out %sdev.key '
- '-pkeyopt rsa_keygen_bits:2048 '
- '-pkeyopt rsa_keygen_pubexp:%d '
- '2>/dev/null' % (tmpdir, public_exponent))
+ sig_node = '/configurations/conf-1/signature'
- # Create a certificate containing the public key
- util.cmd(cons, 'openssl req -batch -new -x509 -key %sdev.key -out '
- '%sdev.crt' % (tmpdir, tmpdir))
+ create_rsa_pair('dev')
+ create_rsa_pair('prod')
# Create a number kernel image with zeroes
with open('%stest-kernel.bin' % tmpdir, 'w') as fd:
- fd.write(5000 * chr(0))
+ fd.write(500 * 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')
+ if required:
+ test_required_key(sha_algo, padding, sign_options)
+ else:
+ test_with_algo(sha_algo, padding, sign_options)
finally:
+ # Go back to the original U-Boot with the correct dtb.
cons.config.dtb = old_dtb
+ cons.restart_uboot()
projects / oweals / u-boot.git / blobdiff