Signature Validation
One of the most notable differences between various types of accounts to be built is different signature schemes. We expect accounts to support the EIP-1271 standard.
OpenZeppelin Libraries
The
@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol
library provides a way to verify signatures for different
account implementations. We strongly encourage you to use this library whenever you need to check that a signature of an account is correct.
Adding the library to your project
npm add @openzeppelin/contracts
Example of using the library
pragma solidity ^0.8.0;
import { SignatureChecker } from "@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol";
contract TestSignatureChecker {
using SignatureChecker for address;
function isValidSignature(
address _address,
bytes32 _hash,
bytes memory _signature
) public pure returns (bool) {
return _address.isValidSignatureNow(_hash, _signature);
}
}
Verifying AA signatures
Our SDK provides two methods within utils to verify the signature of an account:
isMessageSignatureCorrect and isTypedDataSignatureCorrect.
import { utils, EIP712Signer } from "zksync-ethers";
const isValidMessageSignature = await utils.isMessageSignatureCorrect(provider, ADDRESS, message, messageSignature);
const isValidTypesSignature = await utils.isTypedDataSignatureCorrect(provider, ADDRESS, await eip712Signer.getDomain(), utils.EIP712_TYPES, EIP712Signer.getSignInput(tx), typedSignature);
Currently these methods only support verifying ECDSA signatures, but very soon they will support EIP1271 signature verification as well.
Both of these methods return true or false depending on whether the message signature is correct.
It is not recommended to use the ethers.js library to verify user signatures.
Validating Secp256r1 Signatures
The P256Verify precompile
is available to validate secp256r1 signatures.
address constant P256 = 0x0000000000000000000000000000000000000100;
/**
* input[ 0: 32] = signed data hash
* input[ 32: 64] = signature r
* input[ 64: 96] = signature s
* input[ 96:128] = public key x
* input[128:160] = public key y
*/
bytes memory input = abi.encodePacked(
hash,
rs[0],
rs[1],
pubKey[0],
pubKey[1]
);
(bool __, bytes memory output) = P256.staticcall(input);
// if signature is valid:
// output = 0x0000000000000000000000000000000000000000000000000000000000000001
// if signature is NOT valid:
// output.length == 0
You can find a more in-depth example showing how it can be used in the "Signing Transactions with WebAuthn" tutorial.