Session Token Rewards Contract

This contract is designed to facilitate the integration and functioning of the Session Token within the oxen network. The core of the codebase is now split into two components: the existing C++ codebase, which handles various service node responsibilities like uptime tracking, reward calculations, and other duties; and the new smart contract system, which includes the Session Token contract and this rewards contract.

The rewards contract manages the dynamics of nodes within the network. It handles various crucial operations such as the admission of node operators through stake deposits, broadcasting new node details across the network via events/logs, managing the exit of stakers with an associated unlock period, and the distribution of earned rewards. One of the key features of the rewards contract is its use of BLS signatures. This technology enables the aggregation of multiple signatures into a single, verifiable entity, ensuring that rewards are distributed only when a consensus (e.g., 95% agreement within the network) is achieved regarding the amount to be claimed.

Building and Tests

There are 3 testing frameworks in use,

• Javascript: Unit tests via Hardhat
• C++: Integration tests via RPC over a devnet (like a local hardhat node)
• Echidna: Fuzz testing of the smart contract over a devnet

Javascript

Contracts can be compiled and tested against unit tests run by executing:

yarn
yarn build
yarn test

C++

Integration tests require running a devnet first with the deployed smart contracts followed by running the C++ tests which will communicate with the given network. First setup the devnet:

make node         # Run the local devnet (note: This blocks the terminal)
make deploy-local # Deploy the smart contracts onto the devnet

Then execute the C++ tests by compilin and running, for example:

cd test/cpp/
cmake -B build -S .
cmake --build build --parallel --verbose

# Run the tests
./test/cpp/build/test/rewards_contract_Tests

Echidna

Get echidna and place it onto your path. Echidna also relies on slither a static analyzer that uses Python 3 and hence can be installed via python -m pip install slither-analyzer.

Fuzz testing may then be run by executing:

echidna . --contract ServiceNodeContributionEchidnaTest --config echidna.config.yml

# Or alternatively via the make target

make fuzz

We run Echidna in assertion testing mode which allows echidna to simulate multiple senders (because our contracts can potentially use multiple wallets). property testing mode simulates the transactions as if they were originating from the smart contract which is not as useful for testing our contracts.