nimbus-eth2/nfuzz
Jacek Sieka a7a65bce42
disentangle eth2 types from the ssz library (#2785)
* reorganize ssz dependencies

This PR continues the work in
https://github.com/status-im/nimbus-eth2/pull/2646,
https://github.com/status-im/nimbus-eth2/pull/2779 as well as past
issues with serialization and type, to disentangle SSZ from eth2 and at
the same time simplify imports and exports with a structured approach.

The principal idea here is that when a library wants to introduce SSZ
support, they do so via 3 files:

* `ssz_codecs` which imports and reexports `codecs` - this covers the
basic byte conversions and ensures no overloads get lost
* `xxx_merkleization` imports and exports `merkleization` to specialize
and get access to `hash_tree_root` and friends
* `xxx_ssz_serialization` imports and exports `ssz_serialization` to
specialize ssz for a specific library

Those that need to interact with SSZ always import the `xxx_` versions
of the modules and never `ssz` itself so as to keep imports simple and
safe.

This is similar to how the REST / JSON-RPC serializers are structured in
that someone wanting to serialize spec types to REST-JSON will import
`eth2_rest_serialization` and nothing else.

* split up ssz into a core library that is independendent of eth2 types
* rename `bytes_reader` to `codec` to highlight that it contains coding
and decoding of bytes and native ssz types
* remove tricky List init overload that causes compile issues
* get rid of top-level ssz import
* reenable merkleization tests
* move some "standard" json serializers to spec
* remove `ValidatorIndex` serialization for now
* remove test_ssz_merkleization
* add tests for over/underlong byte sequences
* fix broken seq[byte] test - seq[byte] is not an SSZ type

There are a few things this PR doesn't solve:

* like #2646 this PR is weak on how to handle root and other
dontSerialize fields that "sometimes" should be computed - the same
problem appears in REST / JSON-RPC etc

* Fix a build problem on macOS

* Another way to fix the macOS builds

Co-authored-by: Zahary Karadjov <zahary@gmail.com>
2021-08-18 20:57:58 +02:00
..
README.md update nim-beacon-chain to nimbus-eth2 in beacon_chain/, ncli/, tests/, and README.md (#1843) 2020-10-08 19:02:05 +00:00
libnfuzz.h [WIP] Fake bls at runtime (#735) 2020-03-05 13:52:10 +01:00
libnfuzz.nim disentangle eth2 types from the ssz library (#2785) 2021-08-18 20:57:58 +02:00

README.md

Introduction

libnfuzz is a wrapper library that exports to C, a set of fuzzing test cases written in Nim and making use of nimbus-eth2.

Building

To build the wrapper library (for more details follow first the instructions from nimbus-eth2):

git clone https://github.com/status-im/nimbus-eth2.git
cd nimbus-eth2
make
# static library
make libnfuzz.a
# dynamic loaded library
make libnfuzz.so

Default, the library is build with the minimal config. To select a specific config you can instead run:

# build with mainnet config
make libnfuzz.a NIMFLAGS="-d:const_preset=mainnet"

For the library to be useful for fuzzing with libFuzzer (e.g. for integration with beacon-fuzz) we can pass additional Nim arguments, e.g.:

make libnfuzz.a NIMFLAGS="--cc:clang --passC:'-fsanitize=fuzzer-no-link' --passL='-fsanitize=fuzzer'"

To disable BLS verification on deserialization of SSZ objects add -d:ssz_testing to the NIMFLAGS.

Other useful options might include: --clang.path:<path>, --clang.exe:<exe>, --clang.linkerexe:<exe>, -d:const_preset=mainnet

It might also deem useful to lower the log level, e.g. by adding -d:chronicles_log_level=fatal.

Usage

There is a libnfuzz.h file provided for easy including in C or C++ projects.

It is most important that before any of the exported tests are called, the NimMain() call is done first. Additionally, all following library calls need to be done from the same thread as from where the original NimMain() call was done.