1#!/usr/bin/env python3
2#
3# Copyright 2022 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#     http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17import logging
18import json
19import sys
20import os
21import argparse
22
23def check_file_exists(file_name):
24  if not os.path.exists(file_name):
25    sys.exit("File doesn't exist : {0}".format(file_name))
26
27def read_bindings(binding_file):
28  check_file_exists(binding_file)
29  with open(binding_file) as jsonFile:
30   bindings = json.loads(jsonFile.read())
31  return bindings
32
33def check_fuzzer_exists(context_file, bindings):
34  with open(context_file) as file:
35    for line in file:
36       # Ignore empty lines and comments
37       line = line.strip()
38       if line.startswith("#"):
39         logging.debug("Found a comment..skipping")
40         continue
41
42       tokens = line.split()
43       if len(tokens) == 0:
44         logging.debug("Skipping empty lines in service_contexts")
45         continue
46
47       # For a valid service_context file, there will be only two tokens
48       # First will be service name and second will be its label.
49       service_name = tokens[0]
50       if service_name not in bindings:
51         sys.exit("\nerror: Service '{0}' is being added, but we have no fuzzer on file for it. "
52                  "Fuzzers are listed at $ANDROID_BUILD_TOP/system/sepolicy/build/soong/service_fuzzer_bindings.go \n\n"
53                  "NOTE: automatic service fuzzers are currently not supported in Java (b/232439254) "
54                  "and Rust (b/164122727). In this case, please ignore this for now and add an entry for your"
55                  "new service in service_fuzzer_bindings.go \n\n"
56                  "If you are writing a new service, it may be subject to attack from other "
57                  "potentially malicious processes. A fuzzer can be written automatically "
58                  "by adding these things: \n"
59                  "- a cc_fuzz Android.bp entry \n"
60                  "- a main file that constructs your service and calls 'fuzzService' \n\n"
61                  "An examples can be found here: \n"
62                  "- $ANDROID_BUILD_TOP/hardware/interfaces/vibrator/aidl/default/fuzzer.cpp \n"
63                  "- https://source.android.com/docs/core/architecture/aidl/aidl-fuzzing \n\n"
64                  "This is only ~30 lines of configuration. It requires dependency injection "
65                  "for your service which is a good practice, and (in AOSP) you will get bugs "
66                  "automatically filed on you. You will find out about issues without needing "
67                  "to backport changes years later, and the system will automatically find ways "
68                  "to reproduce difficult to solve issues for you. \n\n"
69                  "This error can be bypassed by adding entry "
70                  "for new service in $ANDROID_BUILD_TOP/system/sepolicy/build/soong/service_fuzzer_bindings.go \n\n"
71                  "- Android Fuzzing and Security teams".format(service_name))
72  return
73
74def validate_bindings(args):
75  bindings = read_bindings(args.bindings)
76  for file in args.srcs:
77    check_file_exists(file)
78    check_fuzzer_exists(file, bindings)
79  return
80
81def get_args():
82  parser =  argparse.ArgumentParser(description="Tool to check if fuzzer is "
83                                                "added for new services")
84  parser.add_argument('-b', help='Path to json file containing '
85                                 '"service":[fuzzers...] bindings.',
86                      required=True, dest='bindings')
87  parser.add_argument('-s', '--list', nargs='+',
88                      help='list of service_contexts files. Tool will check if '
89                           'there is fuzzer for every service in the context '
90                           'file.', required=True, dest='srcs')
91  parsed_args = parser.parse_args()
92  return parsed_args
93
94if __name__ == "__main__":
95  args = get_args()
96  validate_bindings(args)
97