oss-fuzz/projects/pyjwt/fuzz_jwt.py

65 lines
1.7 KiB
Python

#!/usr/bin/python3
# Copyright 2022 Google LLC
#
# 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 os
import sys
import atheris
import jwt
import json
from collections.abc import Mapping
def test_decoding(data):
"""Checks jwt decoding does not fail"""
fdp = atheris.FuzzedDataProvider(data)
s1 = fdp.ConsumeUnicodeNoSurrogates(1024)
try:
_ = jwt.decode(s1, algorithms=["HS256"])
except jwt.exceptions.PyJWTError:
pass
def test_roundtrip(data):
"""Check payload == decoded(encoded(payload))"""
fdp = atheris.FuzzedDataProvider(data)
try:
payload = json.loads(fdp.ConsumeUnicodeNoSurrogates(1024))
except:
return
# Only continue if correct type was created as payload.
if not isinstance(payload, Mapping):
return
key = "fuzzing"
jwt_message = jwt.encode(payload, key, algorithm="HS256")
decoded_payload = jwt.decode(jwt_message, key, algorithms=["HS256"])
assert decoded_payload == payload
def TestOneInput(data):
test_decoding(data)
test_roundtrip(data)
def main():
atheris.instrument_all()
atheris.Setup(sys.argv, TestOneInput, enable_python_coverage=True)
atheris.Fuzz()
if __name__ == "__main__":
main()