# SPDX-License-Identifier: GPL-2.0+
# Copyright (c) 2018, Bootlin
# Author: Miquel Raynal <miquel.raynal@bootlin.com>
import os.path
import pytest
import u_boot_utils
import re
import time
"""
Test the TPMv2.x related commands. You must have a working hardware setup in
order to do these tests.
Notes:
* These tests will prove the password mechanism. The TPM chip must be cleared of
any password.
* Commands like pcr_setauthpolicy and pcr_resetauthpolicy are not implemented
here because they would fail the tests in most cases (TPMs do not implement them
and return an error).
"""
updates = 0
def force_init(u_boot_console, force=False):
"""When a test fails, U-Boot is reset. Because TPM stack must be initialized
after each reboot, we must ensure these lines are always executed before
trying any command or they will fail with no reason. Executing 'tpm init'
twice will spawn an error used to detect that the TPM was not reset and no
initialization code should be run.
"""
output = u_boot_console.run_command('tpm init')
if force or not 'Error' in output:
u_boot_console.run_command('echo --- start of init ---')
u_boot_console.run_command('tpm startup TPM2_SU_CLEAR')
u_boot_console.run_command('tpm self_test full')
u_boot_console.run_command('tpm clear TPM2_RH_LOCKOUT')
output = u_boot_console.run_command('echo $?')
if not output.endswith('0'):
u_boot_console.run_command('tpm clear TPM2_RH_PLATFORM')
u_boot_console.run_command('echo --- end of init ---')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_init(u_boot_console):
"""Init the software stack to use TPMv2 commands."""
u_boot_console.run_command('tpm init')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_startup(u_boot_console):
"""Execute a TPM2_Startup command.
Initiate the TPM internal state machine.
"""
u_boot_console.run_command('tpm startup TPM2_SU_CLEAR')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_self_test_full(u_boot_console):
"""Execute a TPM2_SelfTest (full) command.
Ask the TPM to perform all self tests to also enable full capabilities.
"""
u_boot_console.run_command('tpm self_test full')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_continue_self_test(u_boot_console):
"""Execute a TPM2_SelfTest (continued) command.
Ask the TPM to finish its self tests (alternative to the full test) in order
to enter a fully operational state.
"""
u_boot_console.run_command('tpm self_test continue')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_clear(u_boot_console):
"""Execute a TPM2_Clear command.
Ask the TPM to reset entirely its internal state (including internal
configuration, passwords, counters and DAM parameters). This is half of the
TAKE_OWNERSHIP command from TPMv1.
Use the LOCKOUT hierarchy for this. The LOCKOUT/PLATFORM hierarchies must
not have a password set, otherwise this test will fail. ENDORSEMENT and
PLATFORM hierarchies are also available.
"""
u_boot_console.run_command('tpm clear TPM2_RH_LOCKOUT')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
u_boot_console.run_command('tpm clear TPM2_RH_PLATFORM')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_change_auth(u_boot_console):
"""Execute a TPM2_HierarchyChangeAuth command.
Ask the TPM to change the owner, ie. set a new password: 'unicorn'
Use the LOCKOUT hierarchy for this. ENDORSEMENT and PLATFORM hierarchies are
also available.
"""
force_init(u_boot_console)
u_boot_console.run_command('tpm change_auth TPM2_RH_LOCKOUT unicorn')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
u_boot_console.run_command('tpm clear TPM2_RH_LOCKOUT unicorn')
output = u_boot_console.run_command('echo $?')
u_boot_console.run_command('tpm clear TPM2_RH_PLATFORM')
assert output.endswith('0')
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_get_capability(u_boot_console):
"""Execute a TPM_GetCapability command.
Display one capability. In our test case, let's display the default DAM
lockout counter that should be 0 since the CLEAR:
- TPM_CAP_TPM_PROPERTIES = 0x6
- TPM_PT_LOCKOUT_COUNTER (1st parameter) = PTR_VAR + 14
There is no expected default values because it would depend on the chip
used. We can still save them in order to check they have changed later.
"""
force_init(u_boot_console)
ram = u_boot_utils.find_ram_base(u_boot_console)
read_cap = u_boot_console.run_command('tpm get_capability 0x6 0x20e 0x200 1') #0x%x 1' % ram)
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
assert 'Property 0x0000020e: 0x00000000' in read_cap
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_dam_parameters(u_boot_console):
"""Execute a TPM2_DictionaryAttackParameters command.
Change Dictionary Attack Mitigation (DAM) parameters. Ask the TPM to change:
- Max number of failed authentication before lockout: 3
- Time before the failure counter is automatically decremented: 10 sec
- Time after a lockout failure before it can be attempted again: 0 sec
For an unknown reason, the DAM parameters must be changed before changing
the authentication, otherwise the lockout will be engaged after the first
failed authentication attempt.
"""
force_init(u_boot_console)
ram = u_boot_utils.find_ram_base(u_boot_console)
# Set the DAM parameters to known values
u_boot_console.run_command('tpm dam_parameters 3 10 0')
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
# Check the values have been saved
read_cap = u_boot_console.run_command('tpm get_capability 0x6 0x20f 0x%x 3' % ram)
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
assert 'Property 0x0000020f: 0x00000003' in read_cap
assert 'Property 0x00000210: 0x0000000a' in read_cap
assert 'Property 0x00000211: 0x00000000' in read_cap
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_pcr_read(u_boot_console):
"""Execute a TPM2_PCR_Read command.
Perform a PCR read of the 0th PCR. Must be zero.
"""
force_init(u_boot_console)
ram = u_boot_utils.find_ram_base(u_boot_console) + 1024
read_pcr = u_boot_console.run_command('tpm pcr_read 0 0x%x' % ram)
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
# Save the number of PCR updates
str = re.findall(r'\d+ known updates', read_pcr)[0]
global updates
updates = int(re.findall(r'\d+', str)[0])
# Check the output value
assert 'PCR #0 content' in read_pcr
assert '00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00' in read_pcr
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_pcr_extend(u_boot_console):
"""Execute a TPM2_PCR_Extend command.
Perform a PCR extension with a known hash in memory (zeroed since the board
must have been rebooted).
No authentication mechanism is used here, not protecting against packet
replay, yet.
"""
force_init(u_boot_console)
ram = u_boot_utils.find_ram_base(u_boot_console) + 1024
u_boot_console.run_command('tpm pcr_extend 0 0x%x' % ram)
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
read_pcr = u_boot_console.run_command('tpm pcr_read 0 0x%x' % ram)
output = u_boot_console.run_command('echo $?')
assert output.endswith('0')
assert 'f5 a5 fd 42 d1 6a 20 30 27 98 ef 6e d3 09 97 9b' in read_pcr
assert '43 00 3d 23 20 d9 f0 e8 ea 98 31 a9 27 59 fb 4b' in read_pcr
str = re.findall(r'\d+ known updates', read_pcr)[0]
new_updates = int(re.findall(r'\d+', str)[0])
assert (updates + 1) == new_updates
@pytest.mark.buildconfigspec('cmd_tpm_v2')
def test_tpm2_cleanup(u_boot_console):
"""Ensure the TPM is cleared from password or test related configuration."""
force_init(u_boot_console, True)