mirror of
https://github.com/chipsec/chipsec
synced 2026-06-08 13:31:00 +00:00
brentholtsclaw
106 lines
4.7 KiB
Python
106 lines
4.7 KiB
Python
#CHIPSEC: Platform Security Assessment Framework
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#Copyright (c) 2010-2021, Intel Corporation
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#
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#This program is free software; you can redistribute it and/or
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#modify it under the terms of the GNU General Public License
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#as published by the Free Software Foundation; Version 2.
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#
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#This program is distributed in the hope that it will be useful,
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#but WITHOUT ANY WARRANTY; without even the implied warranty of
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#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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#GNU General Public License for more details.
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#
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#You should have received a copy of the GNU General Public License
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#along with this program; if not, write to the Free Software
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#Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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#
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#Contact information:
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#chipsec@intel.com
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#
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"""
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Checks for RTC memory locks. Since we do not know what RTC memory will be used for on a specific platform, we return WARNING (rather than FAILED) if the memory is not locked.
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"""
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from chipsec.module_common import BaseModule, ModuleResult, MTAG_BIOS, MTAG_HWCONFIG
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from chipsec.hal.cmos import CMOS
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TAGS = [MTAG_BIOS, MTAG_HWCONFIG]
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class rtclock(BaseModule):
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def __init__(self):
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BaseModule.__init__(self)
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self.cmos = CMOS(self.cs)
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self.user_request = False
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self.test_offset = 0x38
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self.test_value = 0xAA
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self.cs.set_scope({None: "8086.RTC"})
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def is_supported(self):
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if self.cs.is_core():
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return True
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self.res = ModuleResult.NOTAPPLICABLE
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return False
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def check_rtclock(self):
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self.logger.start_test( "Protected RTC memory locations" )
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ll = ul = 0
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check_config_regs = self.cs.read_register('RC') != 0xFFFFFFFF
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if check_config_regs:
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rc_reg = self.cs.read_register( 'RC' )
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self.cs.print_register( 'RC', rc_reg )
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ll = self.cs.get_register_field( 'RC', rc_reg, 'LL' )
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ul = self.cs.get_register_field( 'RC', rc_reg, 'UL' )
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elif self.user_request:
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self.logger.log_warning('Writing to CMOS to determine write protection (original values will be restored)')
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# Try to modify the low RTC memory regions.
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original_val = self.cmos.read_cmos_low(self.test_offset)
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self.cmos.write_cmos_low(self.test_offset, original_val ^ self.test_value)
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if original_val == self.cmos.read_cmos_low(self.test_offset):
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ll = 1
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else:
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self.logger.log_warning('Restoring original value')
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self.cmos.write_cmos_low(self.test_offset, original_val)
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# Try to modify the upper RTC memory regions.
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original_val = self.cmos.read_cmos_high(self.test_offset)
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self.cmos.write_cmos_high(self.test_offset, original_val ^ self.test_value)
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if original_val == self.cmos.read_cmos_high(self.test_offset):
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ul = 1
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else:
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self.logger.log_warning('Restoring original value')
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self.cmos.write_cmos_high(self.test_offset, original_val)
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else:
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self.logger.log_warn("Unable to test lock bits without attempting to modify CMOS.")
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self.logger.log("[*] Run chipsec_main manually with the following commandline flags.")
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self.logger.log("[*] python chipsec_main -m common.rtclock -a modify")
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return ModuleResult.WARNING
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if ll == 1: self.logger.log_good( "Protected bytes (0x38-0x3F) in low 128-byte bank of RTC memory are locked" )
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else: self.logger.log_bad( "Protected bytes (0x38-0x3F) in low 128-byte bank of RTC memory are not locked" )
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if ul == 1: self.logger.log_good( "Protected bytes (0x38-0x3F) in high 128-byte bank of RTC memory are locked" )
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else: self.logger.log_bad( "Protected bytes (0x38-0x3F) in high 128-byte bank of RTC memory are not locked" )
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if ll == 1 and ul == 1:
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res = ModuleResult.PASSED
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self.logger.log_passed( "Protected locations in RTC memory are locked" )
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else:
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res = ModuleResult.WARNING
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self.logger.log_warn( "Protected locations in RTC memory are accessible (BIOS may not be using them)" )
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return res
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# --------------------------------------------------------------------------
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# run( module_argv )
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# Required function: run here all tests from this module
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# --------------------------------------------------------------------------
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def run( self, module_argv ):
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if len(module_argv) >= 1:
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if module_argv[0].lower() == 'modify':
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self.user_request = True
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self.res = self.check_rtclock()
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return self.res
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