splendorLee / libprotobuf-mutator_fuzzing_learning

Learn how to combine libprotobuf-mutator with libfuzzer & AFL++

libprotobuf-mutator_fuzzing_learning

Learn how to combine libprotobuf-mutator with libfuzzer & AFL++

Environment Settings

• Ubuntu Linux 20.04 64 bit
• Clang 11.0.1

Install Clang/LLVM & libfuzzer

• Follow the step in this article and add the toolchain's apt repository in Ubuntu.
• sudo apt-get install clang-11 libfuzzer-11-dev

Install libprotobuf-mutator

Follow the step in libprotobuf-mutator's readme

Install dependencies

sudo apt-get update
sudo apt-get install protobuf-compiler libprotobuf-dev binutils cmake \
  ninja-build liblzma-dev libz-dev pkg-config autoconf libtool

Compile and test everything:

cd libprotobuf-mutator
mkdir build
cd build
( A cmake command, check the below section )
ninja check # test, might took very long time
ninja # just build, use this if you don't want to wait too long
sudo ninja install # install

Notice
Use the following cmake command to build libprotobuf-mutator-libfuzzer.so.0 and libprotobuf-mutator.so.0 shared library

 cmake .. -GNinja -DCMAKE_C_COMPILER=clang-11 \ 
 -DCMAKE_CXX_COMPILER=clang++-11 \ 
 -DCMAKE_BUILD_TYPE=Debug \ 
 -DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON \ 
 -DBUILD_SHARED_LIBS=ON

To build static libraries, use the following cmake command:
( This will generate libraries that can be linked into shared libraries / normal program )

cmake .. -GNinja -DCMAKE_C_COMPILER=clang-11 \
-DCMAKE_CXX_COMPILER=clang++-11 \
-DCMAKE_BUILD_TYPE=Debug \
-DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON \
-DCMAKE_C_FLAGS="-fPIC" -DCMAKE_CXX_FLAGS="-fPIC"

How to upgrade the environment

• Upgrade Clang/LLVM & libfuzzer ( install a new version )
• Upgrade AFL++ ( git pull & rebuild )
• Upgrade libprotobuf-mutator ( git pull & rebuild )
  • Rebuild and re-install libprotobuf-mutator-libfuzzer.so.0 and libprotobuf-mutator.so.0.
  • Rebuild libprotobuf-mutator-libfuzzer.a and libprotobuf-mutator.a.
• Re-compile the protobuf with newer protoc and replace those *.cc & *.h with new ones.

FAQ

Q : I ran into this error message while building the binary : This file was generated by an old version of protoc.
A : The test.pb.cc and test.pb.h in this repo is generated with protoc v3.13.0.0, so if your protoc's version is newer, make sure to re-generate those two files with the original protobuf source code test.proto ( source code and steps to generate *.cc & *.h are all in 1_simple_protobuf ).

Learning

• Simple protobuf example
• libprotobuf + libfuzzer
• libprotobuf + libfuzzer ( custom mutator )
• How to combine libprotobuf-mutator and AFL++
• Handling input samples from AFL++ in custom mutator

Reference

• libprotobuf-mutator
• Deconstructing LibProtobuf/Mutator Fuzzing
• Custom Proto Mutation
• AFL++ custom mutator
• afl-libprotobuf-mutator

LICENSE