67 lines
2.2 KiB
Solidity
67 lines
2.2 KiB
Solidity
|
// SPDX-License-Identifier: GPL-3.0-or-later
|
||
|
|
pragma solidity ^0.8.17;
|
||
|
|
import "@openzeppelin/contracts/utils/Strings.sol";
|
||
|
|
|
||
|
|
/// @title On-chain storage to save a precious memory of you life
|
||
|
|
/// @author Challenge inspired by CCTF, coded by six
|
||
|
|
/// @notice The flag should return when the data is on-chain.
|
||
|
|
contract PMC_Sol_Challenge {
|
||
|
|
// Declare everything needed in the contract
|
||
|
|
address private admin = 0x5B38Da6a701c568545dCfcB03FcB875f56beddC4;
|
||
|
|
uint160 door = 0;
|
||
|
|
event contractStart(address indexed _admin);
|
||
|
|
uint256 public pin;
|
||
|
|
string private start;
|
||
|
|
string private data;
|
||
|
|
string private end;
|
||
|
|
string private flag;
|
||
|
|
string private result;
|
||
|
|
bytes32 private data_store;
|
||
|
|
uint private data_set;
|
||
|
|
string private ds_to_Str;
|
||
|
|
|
||
|
|
// O, that is nasty!
|
||
|
|
constructor(address O) payable {
|
||
|
|
emit contractStart(admin);
|
||
|
|
admin = 0==0?O:0x0000000000000000000000000000000000000000;
|
||
|
|
pin = block.number + block.timestamp; // "Random" pin
|
||
|
|
start = "PMC{";
|
||
|
|
data_set = 0;
|
||
|
|
end = ".NiceTry}";
|
||
|
|
}
|
||
|
|
|
||
|
|
/// @notice Mod
|
||
|
|
function callAddMod() public pure returns(uint){
|
||
|
|
return addmod(4, 5, 3);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// @notice Only the central admin should be able to store his life memory in bytes32.
|
||
|
|
function store_me_on_chain(bytes32 _data) public returns (string memory) {
|
||
|
|
require(msg.sender == admin, 'Not admin');
|
||
|
|
data_store = _data;
|
||
|
|
data_set = asmbl();
|
||
|
|
ds_to_Str = Strings.toString(data_set);
|
||
|
|
return data = string("den_who_is_dan_");
|
||
|
|
}
|
||
|
|
|
||
|
|
/// @notice Generate number
|
||
|
|
function asmbl() public view returns (uint8 b) {
|
||
|
|
assembly {
|
||
|
|
let c := add(27, 16)
|
||
|
|
mstore(0x80, c)
|
||
|
|
{ let d := add(sload(c), 255) b := d }
|
||
|
|
b := add(b, c) }
|
||
|
|
}
|
||
|
|
|
||
|
|
/// @notice The admin wants to check the data is on chain and return the flag if is!
|
||
|
|
function is_it_on_chain(uint256 _pin) external returns (string memory) {
|
||
|
|
require(msg.sender == admin, 'Not admin');
|
||
|
|
require(pin == _pin, 'Wrong pin');
|
||
|
|
require(data_set > 1, 'Nothing in the on-chain storage');
|
||
|
|
flag = string.concat(start,data,ds_to_Str,end);
|
||
|
|
return flag;
|
||
|
|
}
|
||
|
|
|
||
|
|
fallback() external {}
|
||
|
|
}
|