Start extracting WormholeGUID lib

contracts/common/LibWormholeGUID.sol

@@ -0,0 +1,11 @@
+pragma solidity >=0.7.6;
+
+struct WormholeGUID {
+  bytes32 sourceDomain;
+  bytes32 targetDomain;
+  address receiver;
+  address operator;
+  uint128 amount;
+  uint64 nonce;
+  uint64 timestamp;
+}

contracts/l1/L1DAITokenWormholeBridge.sol

@@ -85,8 +85,33 @@ contract L1DAIWormholeBridge is OVM_CrossDomainEnabled {
   }
 
   function finalizeFlush(bytes32 targetDomain, uint256 daiToFlush) external {
+    // can be called only by l2 counterpart
     // settle on join
     // update state root
     // emit event
   }
+
+  function prove(
+    WormholeGUID calldata guid,
+    uint256 maxFee,
+    L2MessageInclusionProof calldata proof
+  ) external {
+    // Optimism State Inclusion Proof
+    require(
+      ovmStateCommitmentChain.insideFraudProofWindow(proof.stateRootBatchHeader) == false &&
+        ovmStateCommitmentChain.verifyStateCommitment(
+          proof.stateRoot,
+          proof.stateRootBatchHeader,
+          proof.stateRootProof
+        ),
+      "WormholeOptimismStorageAuth/state-inclusion"
+    );
+    bytes32 hash = // Validate storage was set on L2 bridge
+    require(
+      verifyStorageProof(guid.getHash(), proof),
+      "WormholeOptimismStorageAuth/storage-inclusion"
+    );
+
+    join.mint(guid, msg.sender, maxFee);
+  }
 }

contracts/l2/L2DAIWormholeBridge.sol

@@ -30,16 +30,6 @@ interface IL1WormholeBridge {
   function finalizeFlush(bytes32 targetDomain, uint256 daiToFlush) external;
 }
 
-struct WormholeGUID {
-  bytes32 sourceDomain;
-  bytes32 targetDomain;
-  address receiver;
-  address operator;
-  uint128 amount;
-  uint64 nonce;
-  uint64 timestamp;
-}
-
 // Mint tokens on L2 after locking funds on L1.
 // Burn tokens on L1 and send a message to unlock tokens on L1 to L1 counterpart
 // Note: when bridge is closed it will still process in progress messages