platform_system_sepolicy/tools/fuzzer_bindings_check.py
Pawan Wagh a103fde7ea sepolicy: updating error message for fuzzer bindings
BUG: 249122938
Test: m
Change-Id: I562cc9207f821025180c647d4a07e433abb2cc6c
2022-09-28 19:38:31 +00:00

96 lines
4.3 KiB
Python

#!/usr/bin/env python3
#
# Copyright 2022 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import json
import sys
import os
import argparse
def check_file_exists(file_name):
if not os.path.exists(file_name):
sys.exit("File doesn't exist : {0}".format(file_name))
def read_bindings(binding_file):
check_file_exists(binding_file)
with open(binding_file) as jsonFile:
bindings = json.loads(jsonFile.read())
return bindings
def check_fuzzer_exists(context_file, bindings):
with open(context_file) as file:
for line in file:
# Ignore empty lines and comments
line = line.strip()
if line.startswith("#"):
logging.debug("Found a comment..skipping")
continue
tokens = line.split()
if len(tokens) == 0:
logging.debug("Skipping empty lines in service_contexts")
continue
# For a valid service_context file, there will be only two tokens
# First will be service name and second will be its label.
service_name = tokens[0]
if service_name not in bindings:
sys.exit("\nerror: Service '{0}' is being added, but we have no fuzzer on file for it. "
"Fuzzers are listed at $ANDROID_BUILD_TOP/system/sepolicy/build/soong/service_fuzzer_bindings.go \n\n"
"NOTE: automatic service fuzzers are currently not supported in Java (b/232439254) "
"and Rust (b/164122727). In this case, please ignore this for now and add an entry for your"
"new service in service_fuzzer_bindings.go \n\n"
"If you are writing a new service, it may be subject to attack from other "
"potentially malicious processes. A fuzzer can be written automatically "
"by adding these things: \n"
"- a cc_fuzz Android.bp entry \n"
"- a main file that constructs your service and calls 'fuzzService' \n\n"
"An examples can be found here: \n"
"- $ANDROID_BUILD_TOP/hardware/interfaces/vibrator/aidl/default/fuzzer.cpp \n"
"- https://source.android.com/docs/core/architecture/aidl/aidl-fuzzing \n\n"
"This is only ~30 lines of configuration. It requires dependency injection "
"for your service which is a good practice, and (in AOSP) you will get bugs "
"automatically filed on you. You will find out about issues without needing "
"to backport changes years later, and the system will automatically find ways "
"to reproduce difficult to solve issues for you. \n\n"
"This error can be bypassed by adding entry "
"for new service in $ANDROID_BUILD_TOP/system/sepolicy/build/soong/service_fuzzer_bindings.go \n\n"
"- Android Fuzzing and Security teams".format(service_name))
return
def validate_bindings(args):
bindings = read_bindings(args.bindings)
for file in args.srcs:
check_file_exists(file)
check_fuzzer_exists(file, bindings)
return
def get_args():
parser = argparse.ArgumentParser(description="Tool to check if fuzzer is "
"added for new services")
parser.add_argument('-b', help='Path to json file containing '
'"service":[fuzzers...] bindings.',
required=True, dest='bindings')
parser.add_argument('-s', '--list', nargs='+',
help='list of service_contexts files. Tool will check if '
'there is fuzzer for every service in the context '
'file.', required=True, dest='srcs')
parsed_args = parser.parse_args()
return parsed_args
if __name__ == "__main__":
args = get_args()
validate_bindings(args)