Files
chipsec-chipsec/chipsec/modules/common/spi_access.py
T
2020-06-29 09:32:09 -07:00

100 lines
3.8 KiB
Python

#CHIPSEC: Platform Security Assessment Framework
#Copyright (c) 2010-2020, Intel Corporation
#
#This program is free software; you can redistribute it and/or
#modify it under the terms of the GNU General Public License
#as published by the Free Software Foundation; Version 2.
#
#This program is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
#GNU General Public License for more details.
#
#You should have received a copy of the GNU General Public License
#along with this program; if not, write to the Free Software
#Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
#Contact information:
#chipsec@intel.com
#
#
# Authors:
# Yuriy Bulygin
# Erik Bjorge
#
"""
Checks SPI Flash Region Access Permissions programmed in the Flash Descriptor
"""
from chipsec.module_common import BaseModule, ModuleResult, MTAG_BIOS
from chipsec.hal.spi import SPI, GBE, PLATFORM_DATA, ME, FLASH_DESCRIPTOR
TAGS = [MTAG_BIOS]
class spi_access(BaseModule):
def __init__(self):
BaseModule.__init__(self)
self.spi = SPI( self.cs )
def is_supported(self):
return True
##
# Displays the SPI Regions Access Permissions
def check_flash_access_permissions(self):
res = ModuleResult.PASSED
fdv = self.cs.read_register_field( 'HSFS', 'FDV' ) == 1
frap = self.cs.read_register( 'FRAP' )
brwa = self.cs.get_register_field( 'FRAP', frap, 'BRWA' )
# Informational
# State of Flash Descriptor Valid bit
if not fdv:
self.logger.log("[*] Flash Descriptor Valid bit is not set")
# CPU/Software access to Platform Data region (platform specific)
if brwa & (1 << PLATFORM_DATA):
self.logger.log("[*] Software has write access to Platform Data region in SPI flash (it's platform specific)")
# Warnings
# CPU/Software access to GBe region
if brwa & (1 << GBE):
res = ModuleResult.WARNING
self.logger.log_warning("Software has write access to GBe region in SPI flash")
# Failures
# CPU/Software access to Flash Descriptor region (Read Only)
if brwa & (1 << FLASH_DESCRIPTOR):
res = ModuleResult.FAILED
self.logger.log_bad("Software has write access to SPI flash descriptor")
# CPU/Software access to Intel ME region (Read Only)
if brwa & (1 << ME):
res = ModuleResult.FAILED
self.logger.log_bad("Software has write access to Management Engine (ME) region in SPI flash")
if fdv:
if ModuleResult.PASSED == res: self.logger.log_passed_check("SPI Flash Region Access Permissions in flash descriptor look ok")
elif ModuleResult.FAILED == res: self.logger.log_failed_check("SPI Flash Region Access Permissions are not programmed securely in flash descriptor")
elif ModuleResult.WARNING == res: self.logger.log_warn_check("Certain SPI flash regions are writeable by software")
else:
res = ModuleResult.WARNING
self.logger.log_warn_check("Either flash descriptor is not valid or not present on this system")
return res
# --------------------------------------------------------------------------
# run( module_argv )
# Required function: run here all tests from this module
# --------------------------------------------------------------------------
def run( self, module_argv ):
self.logger.start_test( "SPI Flash Region Access Control" )
self.spi.display_SPI_Ranges_Access_Permissions()
self.res = self.check_flash_access_permissions()
return self.res