Check if pair is supported before transferring tokens

Cardinal-Cryptography · Nov 13, 2023 · ede52ca · ede52ca
1 parent 729444a
commit ede52ca
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Showing 2 changed files with 11 additions and 8 deletions.
diff --git a/azero/contracts/membrane/lib.rs b/azero/contracts/membrane/lib.rs
@@ -200,18 +200,19 @@ pub mod membrane {
             dest_receiver_address: [u8; 32],
         ) -> Result<(), MembraneError> {
             let sender = self.env().caller();
+
+            let dest_token_address = self
+                .supported_pairs
+                .get(src_token_address)
+                .ok_or(MembraneError::UnsupportedPair)?;
+
             self.transfer_from_tx(
                 src_token_address.into(),
                 sender,
                 self.env().account_id(),
                 amount,
             )?;
 
-            let dest_token_address = self
-                .supported_pairs
-                .get(src_token_address)
-                .ok_or(MembraneError::UnsupportedPair)?;
-
             self.env().emit_event(CrosschainTransferRequest {
                 dest_token_address,
                 amount,

diff --git a/eth/contracts/Membrane.sol b/eth/contracts/Membrane.sol
@@ -70,13 +70,15 @@ contract Membrane {
     address sender = msg.sender;
 
     IERC20 token = IERC20(bytes32ToAddress(srcTokenAddress));
-    // lock tokens in this contract
-    // message sender needs to give approval else this tx will revert
-    token.transferFrom(sender, address(this), amount);
 
+    // check if the token is supported
     bytes32 destTokenAddress = supportedPairs[srcTokenAddress];
     require(destTokenAddress != 0x0, "Unsupported pair");
 
+    // lock tokens in this contract
+    // message sender needs to give approval else this tx will revert
+    token.transferFrom(sender, address(this), amount);
+
     emit CrosschainTransferRequest(
                                    destTokenAddress,
                                    amount,