smartbugs-curated/dataset/access_control/FibonacciBalance.sol

63 lines
1.8 KiB
Solidity

/*
* @source: https://github.com/sigp/solidity-security-blog
* @author: Suhabe Bugrara
* @vulnerable_at_lines: 31,38
*/
//added pragma version
pragma solidity ^0.4.0;
contract FibonacciBalance {
address public fibonacciLibrary;
// the current fibonacci number to withdraw
uint public calculatedFibNumber;
// the starting fibonacci sequence number
uint public start = 3;
uint public withdrawalCounter;
// the fibonancci function selector
bytes4 constant fibSig = bytes4(sha3("setFibonacci(uint256)"));
// constructor - loads the contract with ether
constructor(address _fibonacciLibrary) public payable {
fibonacciLibrary = _fibonacciLibrary;
}
function withdraw() {
withdrawalCounter += 1;
// calculate the fibonacci number for the current withdrawal user
// this sets calculatedFibNumber
// <yes> <report> ACCESS_CONTROL
require(fibonacciLibrary.delegatecall(fibSig, withdrawalCounter));
msg.sender.transfer(calculatedFibNumber * 1 ether);
}
// allow users to call fibonacci library functions
function() public {
// <yes> <report> ACCESS_CONTROL
require(fibonacciLibrary.delegatecall(msg.data));
}
}
// library contract - calculates fibonacci-like numbers;
contract FibonacciLib {
// initializing the standard fibonacci sequence;
uint public start;
uint public calculatedFibNumber;
// modify the zeroth number in the sequence
function setStart(uint _start) public {
start = _start;
}
function setFibonacci(uint n) public {
calculatedFibNumber = fibonacci(n);
}
function fibonacci(uint n) internal returns (uint) {
if (n == 0) return start;
else if (n == 1) return start + 1;
else return fibonacci(n - 1) + fibonacci(n - 2);
}
}