1# Copyright 2014 The Chromium OS Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5import hashlib, logging
6
7from autotest_lib.client.common_lib import error
8from autotest_lib.server.cros.faft.firmware_test import FirmwareTest
9
10
11class firmware_TPMExtend(FirmwareTest):
12    """Test to ensure TPM PCRs are extended correctly."""
13    version = 1
14
15    def initialize(self, host, cmdline_args):
16        super(firmware_TPMExtend, self).initialize(host, cmdline_args)
17        self.switcher.setup_mode('normal')
18        self.setup_usbkey(usbkey=True, host=False)
19
20    def _check_pcr(self, num, hash_obj):
21        """Returns true iff PCR |num| was extended with hashlib |hash_obj|."""
22        pcrs_file='/sys/class/*/tpm0/device/pcrs'
23        pcrs = '\n'.join(self.faft_client.system.run_shell_command_get_output(
24                        'cat %s' % pcrs_file))
25        logging.debug('Dumping PCRs read from device: \n%s', pcrs)
26        extended = hashlib.sha1('\0' * 20 + hash_obj.digest()[:20]).hexdigest()
27        spaced = ' '.join(extended[i:i+2] for i in xrange(0, len(extended), 2))
28        logging.debug('PCR %d should contain hash: %s', num, spaced)
29        return ('PCR-%.2d: %s' % (num, spaced.upper())) in pcrs
30
31    def run_once(self):
32        logging.info('Verifying HWID digest in PCR1')
33        hwid = self.faft_client.system.run_shell_command_get_output(
34                'crossystem hwid')[0]
35        logging.debug('HWID reported by device is: %s', hwid)
36        if not self._check_pcr(1, hashlib.sha256(hwid)):
37            error.TestFail('PCR1 was not extended with SHA256 digest of HWID!')
38
39        logging.info('Verifying bootmode digest in PCR0 in normal mode')
40        self.check_state((self.checkers.crossystem_checker, {
41                            'devsw_boot': '0',
42                            'mainfw_type': 'normal'
43                            }))
44        # dev_mode: 0, rec_mode: 0, keyblock_flags: "normal" (1)
45        if not self._check_pcr(0, hashlib.sha1(chr(0) + chr(0) + chr(1))):
46            error.TestFail('PCR0 was not extended with bootmode 0|0|1!')
47
48        logging.info('Verifying bootmode digest in PCR0 in recovery mode')
49        self.switcher.reboot_to_mode(to_mode='rec')
50        self.check_state((self.checkers.crossystem_checker, {
51                            'devsw_boot': '0',
52                            'mainfw_type': 'recovery'
53                            }))
54        # dev_mode: 0, rec_mode: 1, keyblock_flags: "unknown" (0)
55        if not self._check_pcr(0, hashlib.sha1(chr(0) + chr(1) + chr(0))):
56            error.TestFail('PCR0 was not extended with bootmode 0|1|0!')
57
58        logging.info('Transitioning to dev mode for next test')
59        self.switcher.reboot_to_mode(to_mode='dev')
60
61        logging.info('Verifying bootmode digest in PCR0 in developer mode')
62        self.check_state((self.checkers.crossystem_checker, {
63                            'devsw_boot': '1',
64                            'mainfw_type': 'developer'
65                            }))
66        # dev_mode: 1, rec_mode: 0, keyblock_flags: "normal" (1)
67        if not self._check_pcr(0, hashlib.sha1(chr(1) + chr(0) + chr(1))):
68            error.TestFail('PCR0 was not extended with bootmode 1|0|1!')
69
70        logging.info('Verifying bootmode digest in PCR0 in dev-recovery mode')
71        self.switcher.reboot_to_mode(to_mode='rec')
72        self.check_state((self.checkers.crossystem_checker, {
73                            'devsw_boot': '1',
74                            'mainfw_type': 'recovery'
75                            }))
76        # dev_mode: 1, rec_mode: 1, keyblock_flags: "unknown" (0)
77        if not self._check_pcr(0, hashlib.sha1(chr(1) + chr(1) + chr(0))):
78            error.TestFail('PCR0 was not extended with bootmode 1|1|0!')
79
80        logging.info('All done, returning to normal mode')
81        self.switcher.reboot_to_mode(to_mode='normal')
82