54 lines
1.6 KiB
C++
54 lines
1.6 KiB
C++
/*
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* Copyright 2020 Google Inc.
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "libprotobuf-mutator/src/libfuzzer/libfuzzer_macro.h"
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#include "png_fuzz_proto.pb.h"
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template <typename Proto>
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using FuzzMutatorCallback = std::function<void(Proto*, unsigned int)>;
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template <typename Proto>
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struct PngProtoCBRegistration
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{
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PngProtoCBRegistration(FuzzMutatorCallback<Proto> const& _callback)
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{
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static protobuf_mutator::libfuzzer::PostProcessorRegistration<Proto> reg = {_callback};
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}
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};
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/// Custom mutation: Otherchunk unknown_type -> known_type
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static PngProtoCBRegistration<OtherChunk> addCustomChunk = {
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[](OtherChunk* message, unsigned int seed)
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{
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// Mutate with a probability of roughly 1/47
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// 47 has been chosen ad-hoc
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if (seed % 47 == 0)
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{
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// If otherChunk is unknown type, mutate
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// it to known type
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if (message->has_unknown_type())
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{
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// This is our custom mutation
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// We assume (k * 47 mod N) distribute
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// uniformly, where
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// - N is total number of known
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// chunks defined by png proto converter
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// - k is a factor of seed
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message->set_known_type(seed);
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}
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}
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}
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};
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