Yul based wrapper for ECDSA

[Vectorized]

The OpenZeppelin library has a convenient wrapper over the ecrecover function to ensure that the signature is valid and non-malleable.

However, most of the time, users only need check whether the signature is valid, without throwing or getting error codes.

I'd suggest a Yul based wrapper that simply returns an address.
If the address doesn't match the signer, the signature is simply treated as invalid.

The implementation at #247 should save you about 700 gas over OpenZeppelin's version.

Let me know your opinions.

[sehgalaayu]

I wanna try this!

[MukeshVermaLegit]

Hi @Vectorized @transmissions11,

This PR (#433) implements the Yul-based ECDSA wrapper discussed in #244, focusing on gas efficiency, malformed signature tolerance, and low-level assembly optimization compared to OpenZeppelin’s version.

Key points:

Gas savings: ~700–13k gas per recovery (see benchmarks in PR description)
Security: Malleability check (s <= n/2) and graceful failure for malformed signatures
Implementation: Direct Yul logic for reduced overhead
Testing: Full Forge test suite covering correctness, malleability rejection, and fallback on invalid inputs

Would love your feedback to move this forward.