Use unchecked arithmetic for the ryRecover function

Signed-off-by: Pascal Marco Caversaccio <pascal.caversaccio@hotmail.ch>
OpenZeppelin · Jun 2, 2023 · 1aa24a1 · 1aa24a1
1 parent 30256fa
commit 1aa24a1
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/contracts/utils/cryptography/ECDSA.sol b/contracts/utils/cryptography/ECDSA.sol
@@ -98,9 +98,12 @@ library ECDSA {
      * _Available since v4.3._
      */
     function tryRecover(bytes32 hash, bytes32 r, bytes32 vs) internal pure returns (address, RecoverError) {
-        bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
-        uint8 v = uint8((uint256(vs) >> 255) + 27);
-        return tryRecover(hash, v, r, s);
+        unchecked {
+            bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
+            // We do not check for an overflow here since the shift operation results in 0 or 1.
+            uint8 v = uint8((uint256(vs) >> 255) + 27);
+            return tryRecover(hash, v, r, s);
+        }
     }
 
     /**