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#!/usr/bin/env python
# Copyright (c) 2011 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Makes sure that all EXE and DLL files in the provided directory were built
correctly.
In essense it runs a subset of BinScope tests ensuring that binaries have
/NXCOMPAT, /DYNAMICBASE and /SAFESEH.
"""
import json
import os
import optparse
import sys
# Find /third_party/pefile based on current directory and script path.
sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..',
'third_party', 'pefile'))
import pefile
PE_FILE_EXTENSIONS = ['.exe', '.dll']
DYNAMICBASE_FLAG = 0x0040
NXCOMPAT_FLAG = 0x0100
NO_SEH_FLAG = 0x0400
MACHINE_TYPE_AMD64 = 0x8664
# Please do not add your file here without confirming that it indeed doesn't
# require /NXCOMPAT and /DYNAMICBASE. Contact cpu@chromium.org or your local
# Windows guru for advice.
EXCLUDED_FILES = ['chrome_frame_mini_installer.exe',
'mini_installer.exe',
'wow_helper.exe',
'xinput1_3.dll' # Microsoft DirectX redistributable.
]
def IsPEFile(path):
return (os.path.isfile(path) and
os.path.splitext(path)[1].lower() in PE_FILE_EXTENSIONS and
os.path.basename(path) not in EXCLUDED_FILES)
def main(options, args):
directory = args[0]
pe_total = 0
pe_passed = 0
failures = []
for file in os.listdir(directory):
path = os.path.abspath(os.path.join(directory, file))
if not IsPEFile(path):
continue
pe = pefile.PE(path, fast_load=True)
pe.parse_data_directories(directories=[
pefile.DIRECTORY_ENTRY['IMAGE_DIRECTORY_ENTRY_LOAD_CONFIG']])
pe_total = pe_total + 1
success = True
# Check for /DYNAMICBASE.
if pe.OPTIONAL_HEADER.DllCharacteristics & DYNAMICBASE_FLAG:
if options.verbose:
print "Checking %s for /DYNAMICBASE... PASS" % path
else:
success = False
print "Checking %s for /DYNAMICBASE... FAIL" % path
# Check for /NXCOMPAT.
if pe.OPTIONAL_HEADER.DllCharacteristics & NXCOMPAT_FLAG:
if options.verbose:
print "Checking %s for /NXCOMPAT... PASS" % path
else:
success = False
print "Checking %s for /NXCOMPAT... FAIL" % path
# Check for /SAFESEH. Binaries should meet one of the following
# criteria:
# 1) Have no SEH table as indicated by the DLL characteristics
# 2) Have a LOAD_CONFIG section containing a valid SEH table
# 3) Be a 64-bit binary, in which case /SAFESEH isn't required
#
# Refer to the following MSDN article for more information:
# http://msdn.microsoft.com/en-us/library/9a89h429.aspx
if (pe.OPTIONAL_HEADER.DllCharacteristics & NO_SEH_FLAG or
(hasattr(pe, "DIRECTORY_ENTRY_LOAD_CONFIG") and
pe.DIRECTORY_ENTRY_LOAD_CONFIG.struct.SEHandlerCount > 0 and
pe.DIRECTORY_ENTRY_LOAD_CONFIG.struct.SEHandlerTable != 0) or
pe.FILE_HEADER.Machine == MACHINE_TYPE_AMD64):
if options.verbose:
print "Checking %s for /SAFESEH... PASS" % path
else:
success = False
print "Checking %s for /SAFESEH... FAIL" % path
# ASLR is weakened on Windows 64-bit when the ImageBase is below 4GB
# (because the loader will never be rebase the image above 4GB).
if pe.FILE_HEADER.Machine == MACHINE_TYPE_AMD64:
if pe.OPTIONAL_HEADER.ImageBase <= 0xFFFFFFFF:
print("Checking %s ImageBase (0x%X < 4GB)... FAIL" %
(path, pe.OPTIONAL_HEADER.ImageBase))
success = False
elif options.verbose:
print("Checking %s ImageBase (0x%X > 4GB)... PASS" %
(path, pe.OPTIONAL_HEADER.ImageBase))
# Update tally.
if success:
pe_passed = pe_passed + 1
else:
failures.append(path)
print "Result: %d files found, %d files passed" % (pe_total, pe_passed)
if options.json:
with open(options.json, 'w') as f:
json.dump(failures, f)
if pe_passed != pe_total:
sys.exit(1)
if __name__ == '__main__':
usage = "Usage: %prog [options] DIRECTORY"
option_parser = optparse.OptionParser(usage=usage)
option_parser.add_option("-v", "--verbose", action="store_true",
default=False, help="Print debug logging")
option_parser.add_option("--json", help="Path to JSON output file")
options, args = option_parser.parse_args()
if not args:
option_parser.print_help()
sys.exit(0)
main(options, args)
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