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