N-12: Constant Could be Used to Denote ETH on L2s

Signed-off-by: bennett <[email protected]>
across-protocol · Nov 8, 2024 · 813bf95 · 813bf95
1 parent 3df9450
commit 813bf95
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Showing 2 changed files with 9 additions and 3 deletions.
diff --git a/contracts/chain-adapters/ZkStack_Adapter.sol b/contracts/chain-adapters/ZkStack_Adapter.sol
@@ -21,6 +21,9 @@ import { BridgeHubInterface } from "../interfaces/ZkStackBridgeHub.sol";
 contract ZkStack_Adapter is AdapterInterface {
     using SafeERC20 for IERC20;
 
+    // The ZkSync bridgehub contract treats address(1) to represent ETH.
+    address private constant ETH_TOKEN_ADDRESS = address(1);
+
     // We need to pay a base fee to the operator to include our L1 --> L2 transaction.
     // https://docs.zksync.io/build/developer-reference/l1-l2-interoperability#l1-to-l2-gas-estimation-for-transactions
 
@@ -73,7 +76,7 @@ contract ZkStack_Adapter is AdapterInterface {
         L1_GAS_TO_L2_GAS_PER_PUB_DATA_LIMIT = _l1GasToL2GasPerPubDataLimit;
         SHARED_BRIDGE = BRIDGE_HUB.sharedBridge();
         address gasToken = BRIDGE_HUB.baseToken(CHAIN_ID);
-        if (gasToken != address(1)) {
+        if (gasToken != ETH_TOKEN_ADDRESS) {
             revert ETHGasTokenRequired();
         }
     }

diff --git a/contracts/chain-adapters/ZkStack_CustomGasToken_Adapter.sol b/contracts/chain-adapters/ZkStack_CustomGasToken_Adapter.sol
@@ -36,6 +36,9 @@ interface FunderInterface {
 contract ZkStack_CustomGasToken_Adapter is AdapterInterface {
     using SafeERC20 for IERC20;
 
+    // The ZkSync bridgehub contract treats address(1) to represent ETH.
+    address private constant ETH_TOKEN_ADDRESS = address(1);
+
     // We need to pay a base fee to the operator to include our L1 --> L2 transaction.
     // https://docs.zksync.io/build/developer-reference/l1-l2-interoperability#l1-to-l2-gas-estimation-for-transactions
 
@@ -96,7 +99,7 @@ contract ZkStack_CustomGasToken_Adapter is AdapterInterface {
         L1_GAS_TO_L2_GAS_PER_PUB_DATA_LIMIT = _l1GasToL2GasPerPubDataLimit;
         SHARED_BRIDGE = BRIDGE_HUB.sharedBridge();
         CUSTOM_GAS_TOKEN = BRIDGE_HUB.baseToken(CHAIN_ID);
-        if (CUSTOM_GAS_TOKEN == address(1)) {
+        if (CUSTOM_GAS_TOKEN == ETH_TOKEN_ADDRESS) {
             revert ETHGasTokenNotAllowed();
         }
     }
@@ -164,7 +167,7 @@ contract ZkStack_CustomGasToken_Adapter is AdapterInterface {
                     refundRecipient: L2_REFUND_ADDRESS,
                     secondBridgeAddress: BRIDGE_HUB.sharedBridge(),
                     secondBridgeValue: amount,
-                    secondBridgeCalldata: _secondBridgeCalldata(to, address(1), amount)
+                    secondBridgeCalldata: _secondBridgeCalldata(to, ETH_TOKEN_ADDRESS, amount)
                 })
             );
         } else if (l1Token == CUSTOM_GAS_TOKEN) {