╭╯ ECDSA256

Introduction

This library provides functionality for ECDSA verification over any 256-bit curve.

For more information about the logic behind the contract implementation, please refer to the OpenZeppelin documentation, particularly the verifySolidity function.

Functions

To use the ECDSA256 library, you need to import it.

import "@solarity/solidity-lib/libs/crypto/ECDSA256.sol";

And optionally bind it to the type with the using statement.

using ECDSA256 for *;

verify

function verify(
    EC256.Curve memory ec,
    bytes32 hashedMessage_,
    bytes memory signature_,
    bytes memory pubKey_
) internal view returns (bool);

Description

The function to verify the ECDSA signature.

Parameters:

Name	Type	Description
ec	struct EC256.Curve	The 256-bit curve parameters
hashedMessage	bytes32	The already hashed message to be verified
signature	bytes	The ECDSA signature. Equals to bytes(r) + bytes(s)
pubKey	bytes	The full public key of a signer. Equals to bytes(x) + bytes(y). Note that signatures only from the lower part of the curve are accepted. If your s > n / 2, change it to s = n - s

Example

function verifySECP256r1(
    bytes memory message_,
    bytes memory signature_,
    bytes memory pubKey_
) external view returns (bool) {
    EC256.Curve memory curveParams_ =
    EC256.Curve({
        a: 0xFFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFC,
        b: 0x5AC635D8AA3A93E7B3EBBD55769886BC651D06B0CC53B0F63BCE3C3E27D2604B,
        gx: 0x6B17D1F2E12C4247F8BCE6E563A440F277037D812DEB33A0F4A13945D898C296,
        gy: 0x4FE342E2FE1A7F9B8EE7EB4A7C0F9E162BCE33576B315ECECBB6406837BF51F5,
        p: 0xFFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFF,
        n: 0xFFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551
    });

    return curveParams_.verify(sha256(message_), signature_, pubKey_);
}