Reentrancy protection

Author: rhlsthrm

contracts/LedgerChannel.sol

@@ -163,17 +163,27 @@ contract LedgerChannel {
     }
 
     function LCOpenTimeout(bytes32 _lcID) public {
-        require(msg.sender == Channels[_lcID].partyAddresses[0] && Channels[_lcID].isOpen == false);
-        require(now > Channels[_lcID].LCopenTimeout);
+        require(msg.sender == Channels[_lcID].partyAddresses[0], "Request not sent by channel party A");
+        require(Channels[_lcID].isOpen == false, "Channel has been joined");
+        require(now > Channels[_lcID].LCopenTimeout, "Channel timeout has not expire");
+
+        // reentrancy protection
+        uint256 ethbalanceA = Channels[_lcID].ethBalances[0];
+        uint256 tokenbalanceA = Channels[_lcID].erc20Balances[0];
+
+        Channels[_lcID].ethBalances[0] = 0;
+        Channels[_lcID].ethBalances[1] = 0;
+        Channels[_lcID].erc20Balances[0] = 0;
+        Channels[_lcID].erc20Balances[1] = 0;
 
         if(Channels[_lcID].initialDeposit[0] != 0) {
-            Channels[_lcID].partyAddresses[0].transfer(Channels[_lcID].ethBalances[0]);
+            Channels[_lcID].partyAddresses[0].transfer(ethbalanceA);
         } 
         if(Channels[_lcID].initialDeposit[1] != 0) {
-            require(Channels[_lcID].token.transfer(Channels[_lcID].partyAddresses[0], Channels[_lcID].erc20Balances[0]),"CreateChannel: token transfer failure");
+            require(Channels[_lcID].token.transfer(Channels[_lcID].partyAddresses[0], tokenbalanceA),"CreateChannel: token transfer failure");
         }
 
-        emit DidLCClose(_lcID, 0, Channels[_lcID].ethBalances[0], Channels[_lcID].erc20Balances[0], 0, 0);
+        emit DidLCClose(_lcID, 0, ethbalanceA, tokenbalanceA, 0, 0);
 
         // only safe to delete since no action was taken on this channel
         delete Channels[_lcID];