feat: Solidity verification of light client proofs with Plonk

[storojs72]

This PR adds Foundry project for verification the Plonk proofs of light client programs (epoch-change and inclusion) using Solidity contract from Sphinx artefacts.

The solidity folder now contains two subfolders:

• contracts (Foundry project with Solidity code);
• fixture-generator (Rust program for generating a so-called fixture - a JSON file with the encoded proof, public values and vk necessary for the verification).

Currently, executing Solidity verification should give tentatively following:

artemstorozhuk@Artems-MacBook-Pro aptos % cd solidity/contracts
artemstorozhuk@Artems-MacBook-Pro contracts % forge test
[⠊] Compiling...
[⠒] Compiling 9 files with Solc 0.8.26
[⠢] Solc 0.8.26 finished in 1.06s
Compiler run successful!

Ran 8 tests for test/test_lc_proofs.sol:SolidityVerificationTest
[PASS] testFail_FakeProofEpochChange() (gas: 8660281895700906415)
[PASS] testFail_FakeProofInclusion() (gas: 8660281895700906410)
[FAIL. Reason: assertion failed] testFail_FakePublicValuesEpochChange() (gas: 320971)
[FAIL. Reason: assertion failed] testFail_FakePublicValuesInclusion() (gas: 325381)
[FAIL. Reason: assertion failed] testFail_WrongVkValuesEpochChange() (gas: 2385538)
[FAIL. Reason: assertion failed] testFail_WrongVkValuesInclusion() (gas: 2385702)
[PASS] testValidEpochChangeProofPlonk() (gas: 318083)
[PASS] testValidInclusionProofPlonk() (gas: 318091)
Suite result: FAILED. 4 passed; 4 failed; 0 skipped; finished in 13.00ms (41.70ms CPU time)

Two positive tests that demonstrate Plonk verification of epoch-change and inclusion proofs at ~318k gas are successful and two negative tests if fake proofs are used are successful.

There are also additionally four negative tests - when fake public values or wrong vk are used - that are currently failed. That means essentially that current version of Plonk contract (e48c01ec tag from Sphinx) allows submitting those fake input. I have checked that in recent versions of SP1 (in v1.0.7-testnet) it is fixed, so we in theory should get those tests passing once forward porting latest SP1 changes to sphinx.

If you want to use custom fixture, you can regenerate it with fixture-generator program:

cd aptos
RUST_LOG=info RUSTFLAGS="-C target-cpu=native --cfg tokio_unstable" SHARD_SIZE=4194304 SHARD_BATCH_SIZE=0 cargo +nightly run --bin generate-fixture --features aptos --release -- --program <inclusion | epoch_change>

This will run either inclusion or epoch_change proving (depending on --program flag value) and will end up with fixture JSON file replaced the current one in aptos/solidity/contracts/src/plonk_fixtures.

We have set own private AWS S3 bucket (s3://sphinx-plonk-params) for Plonk parameters distribution. Anyone from us can use it via requesting the access from @samuelburnham. Also aws cli needs to be installed. I uploaded the valid artefacts for e48c01ec tag of Sphinx to AWS, so with recent commit they can now be downloaded by artifacts program from sphinx-contracts repository.

[wwared]

This looks very good! I haven't tested it locally yet but the code seems good to me.

We might want to merge argumentcomputer/sphinx#49 before this PR since that will require us to update the circuit artifacts

Docs are still a TODO, but that's fine for now

[wwared]

nit: We should eventually rename this to SphinxProofFixtureJson

[storojs72]

Docs are still a TODO, but that's fine for now

Yes, adding documentation, renaming SP1 -> Sphinx (in sphinx-contracts as well) and introducing CI for the Solidity testing are still a TODO