This commit modifies the WebAuthn library to accept non-calldata Q

parameters (since it is common for those to either be read from storage or immutables). An overload is provided to maintain backwards compatibility. Co-authored-by: Nicholas Rodrigues Lordello <[email protected]> Co-authored-by: Mikhail Mikheev <mikhail@safe@global>
rdubois-crypto · Dec 13, 2023 · 1b450b9 · 1b450b9
1 parent e2830cb
commit 1b450b9
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Showing 2 changed files with 19 additions and 4 deletions.
diff --git a/solidity/src/FCL_Webauthn.sol b/solidity/src/FCL_Webauthn.sol
@@ -92,14 +92,27 @@ library FCL_WebAuthn {
         uint256 clientChallengeDataOffset,
         uint256[2] calldata rs,
         uint256[2] calldata Q
+    ) internal view returns (bool) {
+        return checkSignature(authenticatorData, authenticatorDataFlagMask, clientData, clientChallenge, clientChallengeDataOffset, rs, Q[0], Q[1]);
+    }
+
+    function  checkSignature (
+        bytes calldata authenticatorData,
+        bytes1 authenticatorDataFlagMask,
+        bytes calldata clientData,
+        bytes32 clientChallenge,
+        uint256 clientChallengeDataOffset,
+        uint256[2] calldata rs,
+        uint256 Qx,
+        uint256 Qy
     ) internal view returns (bool) {
         // Let the caller check if User Presence (0x01) or User Verification (0x04) are set
 
         bytes32 message = FCL_WebAuthn.WebAuthn_format(
             authenticatorData, authenticatorDataFlagMask, clientData, clientChallenge, clientChallengeDataOffset, rs
         );
 
-        bool result = FCL_ecdsa_utils.ecdsa_verify(message, rs, Q);
+        bool result = FCL_ecdsa_utils.ecdsa_verify(message, rs, Qx, Qy);
 
         return result;
     }

diff --git a/solidity/src/FCL_ecdsa_utils.sol b/solidity/src/FCL_ecdsa_utils.sol
@@ -35,14 +35,12 @@ library FCL_ecdsa_utils {
      * @dev ECDSA verification, given , signature, and public key.
      */
 
-    function ecdsa_verify(bytes32 message, uint256[2] calldata rs, uint256[2] calldata Q) internal view returns (bool) {
+    function ecdsa_verify(bytes32 message, uint256[2] calldata rs, uint256 Qx, uint256 Qy) internal view returns (bool) {
         uint256 r = rs[0];
         uint256 s = rs[1];
         if (r == 0 || r >= FCL_Elliptic_ZZ.n || s == 0 || s >= FCL_Elliptic_ZZ.n) {
             return false;
         }
-        uint256 Qx = Q[0];
-        uint256 Qy = Q[1];
         if (!FCL_Elliptic_ZZ.ecAff_isOnCurve(Qx, Qy)) {
             return false;
         }
@@ -60,6 +58,10 @@ library FCL_ecdsa_utils {
         return x1 == 0;
     }
 
+    function ecdsa_verify(bytes32 message, uint256[2] calldata rs, uint256[2] calldata Q) internal view returns (bool) {
+        return ecdsa_verify(message, rs, Q[0], Q[1]);
+    }
+
     function ec_recover_r1(uint256 h, uint256 v, uint256 r, uint256 s) internal view returns (address)
     {
          if (r == 0 || r >= FCL_Elliptic_ZZ.n || s == 0 || s >= FCL_Elliptic_ZZ.n) {