# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""A Python library to interact with TPM module for testing.
Background
- TPM stands for Trusted Platform Module, a piece of security device
- TPM specification is the work of Trusted Computing Group
- As of September 2011, the current TPM specification is version 1.2
Dependency
- This library depends on a C shared library called "libtspi.so", which
contains a set of APIs for interacting with TPM module
Notes:
- An exception is raised if it doesn't make logical sense to continue program
flow (e.g. I/O error prevents test case from executing)
- An exception is caught and then converted to an error code if the caller
expects to check for error code per API definition
"""
import datetime, logging
from autotest_lib.client.common_lib import smogcheck_ttci
# Use explicit import to make code more readable
from ctypes import c_uint, c_uint32, cdll, c_bool, Structure, POINTER, \
c_ubyte, c_byte, byref, c_uint16, cast, create_string_buffer, c_uint64, \
c_char_p, addressof, c_char, pointer
# TPM flags
# TODO(tgao): possible to import from trousers/src/include/tss/tss_defines.h?
TSS_KEY_AUTHORIZATION = c_uint32(0x00000001)
TSS_KEY_TSP_SRK = c_uint32(0x04000000)
TSS_POLICY_USAGE = c_uint32(0x00000001)
TSS_OBJECT_TYPE_RSAKEY = c_uint(0x02)
TSS_SECRET_MODE_SHA1 = c_uint32(0x00001000)
TSS_SECRET_MODE_PLAIN = c_uint32(0x00001800)
TSS_TPMCAP_PROP_MANUFACTURER = c_uint(0x12)
TSS_TPMCAP_PROPERTY = c_uint(0x13)
TSS_TPMCAP_VERSION = c_uint(0x14)
TSS_TPMCAP_VERSION_VAL = c_uint32(0x15)
TSS_TPMSTATUS_DISABLEOWNERCLEAR = c_uint32(0x00000001)
TSS_TPMSTATUS_DISABLEFORCECLEAR = c_uint32(0x00000002)
TSS_TPMSTATUS_PHYSICALSETDEACTIVATED = c_uint32(0x00000010)
TSS_TPMSTATUS_SETTEMPDEACTIVATED = c_uint32(0x00000011)
# TODO(tgao): possible to import from trousers/src/include/tss/tpm.h?
TPM_SHA1_160_HASH_LEN = c_uint(0x14)
# Path to TSPI shared library.
TSPI_C_LIB = "/usr/lib/libtspi.so.1"
# Valid operation of tpmSetActive(). Equivalent CLI commands:
# 'status' = tpm_setactive --well-known --status
# 'activate' = tpm_setactive --well-known --active
# 'deactivate' = tpm_setactive --well-known --inactive
# 'temp' = tpm_setactive --well-known --temp
TPM_SETACTIVE_OP = ['status', 'activate', 'deactivate', 'temp']
# Valid operation of tpmSetClearable(). Equivalent CLI commands:
# 'status' = tpm_setclearable --well-known --status
# 'owner' = tpm_setclearable --well-known --owner
# 'force' = tpm_setclearable --well-known --force
TPM_SETCLEARABLE_OP = ['status', 'owner', 'force']
# Secret mode for setPolicySecret()
TSS_SECRET_MODE = dict(sha1=TSS_SECRET_MODE_SHA1,
plain=TSS_SECRET_MODE_PLAIN)
class SmogcheckError(Exception):
"""Base class for all smogcheck API errors."""
class TpmVersion(Structure):
"""Defines TPM version string struct.
Declared in tss/tpm.h and named TPM_VERSION.
"""
_fields_ = [('major', c_ubyte),
('minor', c_ubyte),
('revMajor', c_ubyte),
('revMinor', c_ubyte)]
class TpmCapVersionInfo(Structure):
"""Defines TPM version info struct.
Declared in tss/tpm.h and named TPM_CAP_VERSION_INFO.
"""
_fields_ = [('tag', c_uint16),
('version', TpmVersion),
('specLevel', c_uint16),
('errataRev', c_ubyte),
('tpmVendorID', c_char*4),
('vendorSpecific', POINTER(c_ubyte))]
def InitVersionInfo(vi):
"""Utility method to allocate memory for TPM version info.
Args:
vi: a TpmCapVerisonInfo object, just created.
"""
vi.tpmVendorId = create_string_buffer(4) # Allocate 4 bytes
vendorDetail = create_string_buffer(64) # Allocate 64 bytes
vi.vendorSpecific = cast(pointer(vendorDetail), POINTER(c_ubyte))
def PrintVersionInfo(vi):
"""Utility method to print TPM version info.
Args:
vi: a TpmCapVerisonInfo object.
"""
logging.info(' TPM 1.2 Version Info:\n')
logging.info(' Chip Version: %d.%d.%d.%d.', vi.version.major,
vi.version.minor, vi.version.revMajor, vi.version.revMinor)
logging.info(' Spec Level: %d', vi.specLevel)
logging.info(' Errata Revision: %d', vi.errataRev)
vendorId = [i for i in vi.tpmVendorID if i]
logging.info(' TPM Vendor ID: %s', ''.join(vendorId))
# TODO(tgao): handle the case when there's no vendor specific data.
logging.info(' Vendor Specific data (first 4 bytes in Hex): '
'%.2x %.2x %.2x %.2x', vi.vendorSpecific[0],
vi.vendorSpecific[1], vi.vendorSpecific[2],
vi.vendorSpecific[3])
def PrintSelfTestResult(str_len, pResult):
"""Utility method to print TPM self test result.
Args:
str_len: an integer, length of string pointed to by pResult.
pResult: a c_char_p, pointer to result.
"""
out = []
for i in range(str_len):
if i and not i % 32:
out.append('\t')
if not i % 4:
out.append(' ')
b = pResult.value[i]
out.append('%02x' % ord(b))
logging.info(' TPM Test Results: %s', ''.join(out))
class TpmController(object):
"""Object to interact with TPM module for testing."""
def __init__(self):
"""Constructor.
Mandatory params:
hContext: a c_uint32, context object handle.
_contextSet: a boolean, True if TPM context is set.
hTpm: a c_uint32, TPM object handle.
hTpmPolicy: a c_uint32, TPM policy object handle.
tspi_lib: a shared library object (libtspi.so).
Raises:
SmogcheckError: if error initializing TpmController.
"""
self.hContext = c_uint32(0)
self._contextSet = False
self.hTpm = c_uint32(0)
self.hTpmPolicy = c_uint32(0)
logging.info('Attempt to load shared library %s', TSPI_C_LIB)
try:
self.tspi_lib = cdll.LoadLibrary(TSPI_C_LIB)
except OSError, e:
raise SmogcheckError('Error loading C library %s: %r' %
(TSPI_C_LIB, e))
logging.info('Successfully loaded shared library %s', TSPI_C_LIB)
def closeContext(self):
"""Closes TPM context and cleans up.
Returns:
an integer, 0 for success and -1 for error.
"""
if not self._contextSet:
logging.debug('TPM context NOT set.')
return 0
ret = -1
# Calling the pointer type without an argument creates a NULL pointer
if self.tspi_lib.Tspi_Context_FreeMemory(self.hContext,
POINTER(c_byte)()) != 0:
logging.error('Error freeing memory when closing TPM context')
else:
logging.debug('Tspi_Context_FreeMemory() success')
if self.tspi_lib.Tspi_Context_Close(self.hContext) != 0:
logging.error('Error closing TPM context')
else:
logging.debug('Tspi_Context_Close() success')
ret = 0
self._contextSet = False
return ret
def _closeContextObject(self, hObject):
"""Closes TPM context object.
Args:
hObject: an integer, basic object handle.
Raises:
SmogcheckError: if an error is encountered.
"""
if self.tspi_lib.Tspi_Context_CloseObject(self.hContext, hObject) != 0:
raise SmogcheckError('Error closing TPM context object')
logging.debug('Tspi_Context_CloseObject() success')
def setupContext(self):
"""Sets up tspi context for TPM access.
TPM context cannot be reused. Therefore, each new Tspi_* command would
require a new context to be set up before execution and closing that
context after execution (or error).
Raises:
SmogcheckError: if an error is encountered.
"""
if self._contextSet:
logging.debug('TPM context already set.')
return
if self.tspi_lib.Tspi_Context_Create(byref(self.hContext)) != 0:
raise SmogcheckError('Error creating tspi context')
logging.info('Created tspi context = 0x%x', self.hContext.value)
if self.tspi_lib.Tspi_Context_Connect(self.hContext,
POINTER(c_uint16)()) != 0:
raise SmogcheckError('Error connecting to tspi context')
logging.info('Connected to tspi context')
if self.tspi_lib.Tspi_Context_GetTpmObject(self.hContext,
byref(self.hTpm)) != 0:
raise SmogcheckError('Error getting TPM object from tspi context')
logging.info('Got tpm object from tspi context = 0x%x', self.hTpm.value)
self._contextSet = True
def _getTpmStatus(self, flag, bValue):
"""Wrapper function to call Tspi_TPM_GetStatus().
Args:
flag: a c_uint, TPM status info flag, values defined in C header file
"tss/tss_defines.h".
bValue: a c_bool, place holder for specific TPM flag bit value (0/1).
Raises:
SmogcheckError: if an error is encountered.
"""
result = self.tspi_lib.Tspi_TPM_GetStatus(self.hTpm, flag,
byref(bValue))
if result != 0:
msg = ('Error (0x%x) getting status for flag 0x%x' %
(result, flag.value))
raise SmogcheckError(msg)
logging.info('Tspi_TPM_GetStatus(): success for flag 0x%x',
flag.value)
def _setTpmStatus(self, flag, bValue):
"""Wrapper function to call Tspi_TPM_GetStatus().
Args:
flag: a c_uint, TPM status info flag.
bValue: a c_bool, place holder for specific TPM flag bit value (0/1).
Raises:
SmogcheckError: if an error is encountered.
"""
result = self.tspi_lib.Tspi_TPM_SetStatus(self.hTpm, flag, bValue)
if result != 0:
msg = ('Error (0x%x) setting status for flag 0x%x' %
(result, flag.value))
raise SmogcheckError(msg)
logging.info('Tspi_TPM_SetStatus(): success for flag 0x%x',
flag.value)
def getPolicyObject(self, hTpm=None, hPolicy=None):
"""Get TPM policy object.
Args:
hTpm: a c_uint, TPM object handle.
hPolicy: a c_uint, TPM policy object handle.
Raises:
SmogcheckError: if an error is encountered.
"""
if hTpm is None:
hTpm = self.hTpm
if hPolicy is None:
hPolicy = self.hTpmPolicy
logging.debug('Tspi_GetPolicyObject(): hTpm = 0x%x, hPolicy = 0x%x',
hTpm.value, hPolicy.value)
result = self.tspi_lib.Tspi_GetPolicyObject(hTpm, TSS_POLICY_USAGE,
byref(hPolicy))
if result != 0:
msg = 'Error (0x%x) getting TPM policy object' % result
raise SmogcheckError(msg)
logging.debug('Tspi_GetPolicyObject() success hTpm = 0x%x, '
'hPolicy = 0x%x', hTpm.value, hPolicy.value)
def setPolicySecret(self, hPolicy=None, pSecret=None, secret_mode=None):
"""Sets TPM policy secret.
Args:
hPolicy: a c_uint, TPM policy object handle.
pSecret: a pointer to a byte array, which holds the TSS secret.
secret_mode: a string, valid values are keys of TSS_SECRET_MODE.
Raises:
SmogcheckError: if an error is encountered.
"""
if hPolicy is None:
hPolicy = self.hTpmPolicy
if pSecret is None:
raise SmogcheckError('setPolicySecret(): pSecret cannot be None')
if secret_mode is None or secret_mode not in TSS_SECRET_MODE:
raise SmogcheckError('setPolicySecret(): invalid secret_mode')
logging.debug('Tspi_Policy_SetSecret(): hPolicy = 0x%x, secret_mode '
'(%r) = %r', hPolicy.value, secret_mode,
TSS_SECRET_MODE[secret_mode])
result = self.tspi_lib.Tspi_Policy_SetSecret(
hPolicy, TSS_SECRET_MODE[secret_mode], TPM_SHA1_160_HASH_LEN,
pSecret)
if result != 0:
msg = 'Error (0x%x) setting TPM policy secret' % result
raise SmogcheckError(msg)
logging.debug('Tspi_Policy_SetSecret() success, hPolicy = 0x%x',
hPolicy.value)
def getTpmVersion(self):
"""Gets TPM version info.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_version.c
Downloaded from:
http://sourceforge.net/projects/trousers/files/tpm-tools/1.3.4/\
tpm-tools-1.3.4.tar.gz
Raises:
SmogcheckError: if an error is encountered.
"""
uiResultLen = c_uint32(0)
pResult = c_char_p()
offset = c_uint64(0)
versionInfo = TpmCapVersionInfo()
InitVersionInfo(versionInfo)
logging.debug('Successfully set up tspi context: hTpm = %r', self.hTpm)
result = self.tspi_lib.Tspi_TPM_GetCapability(
self.hTpm, TSS_TPMCAP_VERSION_VAL, 0, POINTER(c_byte)(),
byref(uiResultLen), byref(pResult))
if result != 0:
msg = 'Error (0x%x) getting TPM capability, pResult = %r' % (
result, pResult.value)
raise SmogcheckError(msg)
logging.info('Successfully received TPM capability: '
'uiResultLen = %d, pResult=%r', uiResultLen.value,
pResult.value)
result = self.tspi_lib.Trspi_UnloadBlob_CAP_VERSION_INFO(
byref(offset), pResult, cast(byref(versionInfo),
POINTER(c_byte)))
if result != 0:
msg = 'Error (0x%x) unloading TPM CAP version info' % result
raise SmogcheckError(msg)
PrintVersionInfo(versionInfo)
def runTpmSelfTest(self):
"""Executes TPM self test.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_selftest.c
Raises:
SmogcheckError: if an error is encountered.
"""
uiResultLen = c_uint32(0)
pResult = c_char_p()
self.setupContext()
logging.debug('Successfully set up tspi context: hTpm = 0x%x',
self.hTpm.value)
result = self.tspi_lib.Tspi_TPM_SelfTestFull(self.hTpm)
if result != 0:
self.closeContext()
raise SmogcheckError('Error (0x%x) with TPM self test' % result)
logging.info('Successfully executed TPM self test: hTpm = 0x%x',
self.hTpm.value)
result = self.tspi_lib.Tspi_TPM_GetTestResult(
self.hTpm, byref(uiResultLen), byref(pResult))
if result != 0:
self.closeContext()
raise SmogcheckError('Error (0x%x) getting test results' % result)
logging.info('TPM self test results: uiResultLen = %d, pResult=%r',
uiResultLen.value, pResult.value)
PrintSelfTestResult(uiResultLen.value, pResult)
self.closeContext()
def takeTpmOwnership(self):
"""Take TPM ownership.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_takeownership.c
Raises:
SmogcheckError: if an error is encountered.
"""
hSrk = c_uint32(0) # TPM Storage Root Key
hSrkPolicy = c_uint32(0)
# Defaults each byte value to 0x00
well_known_secret = create_string_buffer(20)
pSecret = c_char_p(addressof(well_known_secret))
self.setupContext()
logging.debug('Successfully set up tspi context: hTpm = 0x%x',
self.hTpm.value)
try:
self.getPolicyObject()
self.setPolicySecret(pSecret=pSecret, secret_mode='sha1')
except SmogcheckError:
if hSrk != 0:
self._closeContextObject(hSrk)
self.closeContext()
raise # re-raise
flag = TSS_KEY_TSP_SRK.value | TSS_KEY_AUTHORIZATION.value
result = self.tspi_lib.Tspi_Context_CreateObject(
self.hContext, TSS_OBJECT_TYPE_RSAKEY, flag, byref(hSrk))
if result != 0:
raise SmogcheckError('Error (0x%x) creating context object' %
result)
logging.debug('hTpm = 0x%x, flag = 0x%x, hSrk = 0x%x',
self.hTpm.value, flag, hSrk.value) # DEBUG
try:
self.getPolicyObject(hTpm=hSrk, hPolicy=hSrkPolicy)
self.setPolicySecret(hPolicy=hSrkPolicy, pSecret=pSecret,
secret_mode='sha1')
except SmogcheckError:
if hSrk != 0:
self._closeContextObject(hSrk)
self.closeContext()
raise # re-raise
logging.debug('Successfully set up SRK policy: secret = %r, '
'hSrk = 0x%x, hSrkPolicy = 0x%x',
well_known_secret.value, hSrk.value, hSrkPolicy.value)
start_time = datetime.datetime.now()
result = self.tspi_lib.Tspi_TPM_TakeOwnership(self.hTpm, hSrk,
c_uint(0))
end_time = datetime.datetime.now()
if result != 0:
logging.info('Tspi_TPM_TakeOwnership error')
self._closeContextObject(hSrk)
self.closeContext()
raise SmogcheckError('Error (0x%x) taking TPM ownership' % result)
logging.info('Successfully took TPM ownership')
self._closeContextObject(hSrk)
self.closeContext()
return smogcheck_ttci.computeTimeElapsed(end_time, start_time)
def clearTpm(self):
"""Return TPM to default state.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_clear.c
Raises:
SmogcheckError: if an error is encountered.
"""
logging.debug('Successfully set up tspi context: hTpm = %r', self.hTpm)
result = self.tspi_lib.Tspi_TPM_ClearOwner(self.hTpm, True)
if result != 0:
raise SmogcheckError('Error (0x%x) clearing TPM' % result)
logging.info('Successfully cleared TPM')
def setTpmActive(self, op):
"""Change TPM active state.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_activate.c
Args:
op: a string, desired operation. Valid values are defined in
TPM_SETACTIVE_OP.
Raises:
SmogcheckError: if an error is encountered.
"""
bValue = c_bool()
# Defaults each byte value to 0x00
well_known_secret = create_string_buffer(20)
pSecret = c_char_p(addressof(well_known_secret))
if op not in TPM_SETACTIVE_OP:
msg = ('Invalid op (%s) for tpmSetActive(). Valid values are %r' %
(op, TPM_SETACTIVE_OP))
raise SmogcheckError(msg)
logging.debug('Successfully set up tspi context: hTpm = %r', self.hTpm)
if op == 'status':
self.getPolicyObject()
self.setPolicySecret(pSecret=pSecret, secret_mode='sha1')
self._getTpmStatus(
TSS_TPMSTATUS_PHYSICALSETDEACTIVATED, bValue)
logging.info('Persistent Deactivated Status: %s', bValue.value)
self._getTpmStatus(
TSS_TPMSTATUS_SETTEMPDEACTIVATED, bValue)
logging.info('Volatile Deactivated Status: %s', bValue.value)
elif op == 'activate':
self._setTpmStatus(
TSS_TPMSTATUS_PHYSICALSETDEACTIVATED, False)
logging.info('Successfully activated TPM')
elif op == 'deactivate':
self._setTpmStatus(
TSS_TPMSTATUS_PHYSICALSETDEACTIVATED, True)
logging.info('Successfully deactivated TPM')
elif op == 'temp':
self._setTpmStatus(
TSS_TPMSTATUS_SETTEMPDEACTIVATED, True)
logging.info('Successfully deactivated TPM for current boot')
def setTpmClearable(self, op):
"""Disable TPM clear operations.
Implementation based on tpm-tools-1.3.4/src/tpm_mgmt/tpm_clearable.c
Args:
op: a string, desired operation. Valid values are defined in
TPM_SETCLEARABLE_OP.
Raises:
SmogcheckError: if an error is encountered.
"""
bValue = c_bool()
# Defaults each byte value to 0x00
well_known_secret = create_string_buffer(20)
pSecret = c_char_p(addressof(well_known_secret))
if op not in TPM_SETCLEARABLE_OP:
msg = ('Invalid op (%s) for tpmSetClearable(). Valid values are %r'
% (op, TPM_SETCLEARABLE_OP))
raise SmogcheckError(msg)
logging.debug('Successfully set up tspi context: hTpm = %r', self.hTpm)
if op == 'status':
self.getPolicyObject()
self.setPolicySecret(pSecret=pSecret, secret_mode='sha1')
self._getTpmStatus(
TSS_TPMSTATUS_DISABLEOWNERCLEAR, bValue)
logging.info('Owner Clear Disabled: %s', bValue.value)
self._getTpmStatus(
TSS_TPMSTATUS_DISABLEFORCECLEAR, bValue)
logging.info('Force Clear Disabled: %s', bValue.value)
elif op == 'owner':
self.getPolicyObject()
self.setPolicySecret(pSecret=pSecret, secret_mode='sha1')
self._setTpmStatus(
TSS_TPMSTATUS_DISABLEOWNERCLEAR, False)
logging.info('Successfully disabled Owner Clear')
elif op == 'force':
self._setTpmStatus(
TSS_TPMSTATUS_DISABLEFORCECLEAR, True)
logging.info('Successfully disabled Force Clear')