Fuzzing OpenSSL

Requirements

• honggfuzz
• clang-5.0 or newer
• openssl 1.1.0 (or the github's master branch)
• libressl/boringssl should work as well, though they might require more specific building instructions

Preparation (for OpenSSL 1.1.0/master)

1. Compile honggfuzz
2. Unpack/Clone OpenSSL

$ git clone --depth=1 https://github.com/openssl/openssl.git
$ mv openssl openssl-master

3. Use compile_hfuzz_openssl_master.sh to configure OpenSSL

$ cd openssl-master
$ <honggfuzz_dir>/examples/openssl/compile_hfuzz_openssl_master.sh [enable-asan|enable-msan|enable-ubsan]

4. Compile OpenSSL

$ make -j$(nproc)

5. Prepare fuzzing binaries

The make.sh script will compile honggfuzz and libFuzzer binaries. Syntax:

<honggfuzz_dir>/examples/openssl/make.sh <directory-with-open/libre/boring-ssl> [address|memory|undefined]

$ cd ..
$ <honggfuzz_dir>/examples/openssl/make.sh openssl-master address

Fuzzing

$ <honggfuzz_dir>/honggfuzz --input corpus_server/ -- ./openssl-master.address.server
$ <honggfuzz_dir>/honggfuzz --input corpus_client/ -- ./openssl-master.address.client
$ <honggfuzz_dir>/honggfuzz --input corpus_x509/ -- ./openssl-master.address.x509
$ <honggfuzz_dir>/honggfuzz --input corpus_privkey/ -- ./openssl-master.address.privkey