Reduced gas cost ( -3167gas )

[jayden-sudo]

With the code equivalent, executing ecZZ_mulmuladd_S_asm reduced gas cost by 3167 gas:

	Gas
Before	207633 gas
After	204466 gas

• Testing step:

  1. Open the file: /solidity/tests/WebAuthn_hardhat/test/Webauthn.js

  2. Uncomment line 80: let keyPair = ec.keyFromPrivate( "97ddae0f3a25b92268175400149d65d6887b9cefaf28ea2c078e05cdc15a3c01");

  3. Comment lines 82-83.

  4. npx hardhat test | grep gasused

     The purpose of using a fixed key is to perform gas tests with deterministic data.

list:

1. (uint[2] calldata rs,uint[2] calldata Q) -> (uint256 r,uint256 s,uint256 Qx,uint256 Qy) save 393 gas

2. if (rs[0] == 0 || rs[0] >= n || rs[1] == 0||rs[1]>=n) -> iszero(mul(mul(r, s), and(gt(n, r), gt(n, s)))) save 118 gas

3. Update ecAff_isOnCurve save 176 gas

4. uint[6] memory -> let pointer := mload(0x40) save 135 gas

5. if eq(y2,0) -> if iszero(y2) save 1170 gas

   ... and more

[jayden-sudo]

Additionally, Why did I submit code in the test path: The current code does not have a code format. In order to make it easier to review the code diffs in the submitted code, I did not format the code. However, for the sake of maintainability, I hope we can unify the style of the formal code (https://github.com/rdubois-crypto/FreshCryptoLib/blob/master/solidity) before making a formal code PR, for example, by using the "solidity.formatter": "forge" plugin. I hope this suggestion can be considered. Thank you.

[rdubois-crypto]

Those lines seems false:

• if iszero(add(scalar_u, scalar_v)), if u+v=0 modulo 2^256 will be incorrect, while not null because addition is performed modulo 2^256.

Please do not modify API, as the function are integrated elsewhere.

Could you use forge environment please ? There are tests vectors not assesed in hardhat (hardhat deprecated now).

[jayden-sudo]

got! thanks