Write Up/Ethernaut - 블록체인 워게임18 Ethernaut - 5단계 (Token) // SPDX-License-Identifier: MIT pragma solidity ^0.6.0; contract Token { mapping(address => uint) balances; uint public totalSupply; constructor(uint _initialSupply) public { balances[msg.sender] = totalSupply = _initialSupply; } function transfer(address _to, uint _value) public returns (bool) { require(balances[msg.sender] - _value >= 0); balances[msg.sender] -= _value; balances[_to] += _value.. 2023. 11. 7. Ethernaut - 4단계 (Telephone) // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; contract Telephone { address public owner; constructor() { owner = msg.sender; } function changeOwner(address _owner) public { if (tx.origin != msg.sender) { owner = _owner; } } } Claim ownership of the contract below to complete this level. Things that might help See the "?" page above, section "Beyond the console" 이더넛 4단계 문제이다. 해당 문제는 msg.. 2023. 11. 7. Ethernaut - 3단계 (Coin Flip) // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; contract CoinFlip { uint256 public consecutiveWins; uint256 lastHash; uint256 FACTOR = 57896044618658097711785492504343953926634992332820282019728792003956564819968; constructor() { consecutiveWins = 0; } function flip(bool _guess) public returns (bool) { uint256 blockValue = uint256(blockhash(block.number - 1)); if (lastHash == blockValue).. 2023. 11. 7. Ethernaut - 2단계 (Fallout) // SPDX-License-Identifier: MIT pragma solidity ^0.6.0; import 'openzeppelin-contracts-06/math/SafeMath.sol'; contract Fallout { using SafeMath for uint256; mapping (address => uint) allocations; address payable public owner; /* constructor */ function Fal1out() public payable { owner = msg.sender; allocations[owner] = msg.value; } modifier onlyOwner { require( msg.sender == owner, "caller is no.. 2023. 11. 6. 이전 1 2 3 4 5 다음
