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