From 0705335b9395481c2977f3e55bb0a75c0b66edb3 Mon Sep 17 00:00:00 2001 From: Wilson Cusack Date: Mon, 22 Apr 2024 10:37:31 -0400 Subject: [PATCH] add warning --- README.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/README.md b/README.md index b29ad2b..afd85e3 100644 --- a/README.md +++ b/README.md @@ -4,6 +4,9 @@ Webauthn-sol is a Solidity library for verifying WebAuthn authentication asserti This library is optimized for Ethereum layer 2 rollup chains but will work on all EVM chains. Signature verification always attempts to use the [RIP-7212 precompile](https://github.com/ethereum/RIPs/blob/master/RIPS/rip-7212.md) and, if this fails, falls back to using [FreshCryptoLib](https://github.com/rdubois-crypto/FreshCryptoLib/blob/master/solidity/src/FCL_ecdsa.sol#L40). +> [!IMPORTANT] +> FreshCryptoLib uses the `ModExp` precompile (`address(0x05)`), which is not supported on some chains, such as [Polygon zkEVM](https://www.rollup.codes/polygon-zkevm#precompiled-contracts). This library will not work on such chains, unless they support the RIP-7212 precompile. + Code excerpts ```solidity