solidity | 一个小而全的合约项目案例

该合约主要实现以下几点

• 创建新合约
• 数字签名
  • solidity | 数字签名

该案例来自于我的 web3 项目 wordslabs 中的一部分。

代码

其主要思路如下

• ERC721 工厂类
  • 可以创建 ERC721 工厂
• 验证类
  • 可以进行数字签名

这里直接贴一下代码

• BookUtil.sol

pragma solidity ^0.8.1;

import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";

contract BookUtil {

    address immutable public signer = address(0xe16C1623c1AA7D919cd2241d8b36d9E79C1Be2A2);

    function vertify(bytes32 hash, bytes memory signature) public view returns (bool){
        return (signer == ECDSA.recover(hash, signature));
    }

}

• GameBook.sol

pragma solidity ^0.8.1;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";

interface functionContract {
    function utilAddress() external pure returns (address utilAddr);
    function vertify(bytes32 hash, bytes memory signature) external view returns (bool);
}

interface GameBookRule {

    struct Rule {
        uint256 amount;
        uint256 price;
        uint256 time;
        bytes32 hash;
        bytes signature;
    }

}

contract GameBook is ERC721 {

    using Address for address;

    address public immutable factory;
    address public immutable creator;

    uint256 public immutable originAmount;
    uint256 public immutable originMintPrice;

    mapping(address => uint256) public timeRecords;

    constructor(uint256 _originAmount, uint256 _price) ERC721("GameBook", "GB") {
        factory = msg.sender;
        creator = tx.origin;
        originAmount = _originAmount;
        originMintPrice = _price;
    }

    function mint(GameBookRule.Rule calldata rule) public payable {
        require(!_msgSender().isContract(), "gamebook: call to non-contract");
        address utilAddr = functionContract(factory).utilAddress();
        require(rule.time != timeRecords[_msgSender()], "gamebook: time is not valid");
        require(functionContract(utilAddr).vertify(rule.hash,rule.signature),"gamebook: vertify is fail");
        timeRecords[tx.origin] = rule.time;
    }

}

contract GameBookFactory is Context, Ownable {

    address public utilAddress;

    using Address for address;
    using EnumerableSet for EnumerableSet.AddressSet;
    EnumerableSet.AddressSet private _allGameBookAddrs;
    mapping(address => address) public GameBookCreatorInfos;
    mapping(address => uint256) public timeRecords;

    event eCreateGameBook(address creator, address gameBookAddr);

    constructor(address _utilAddress) Ownable(){
        utilAddress = _utilAddress;
    }

    function updateUtilAddr(address addr) public onlyOwner() {
        utilAddress = addr;
    }

    function createGameBook(GameBookRule.Rule calldata rule) external returns (address gameBookAddr) {
        require(!_msgSender().isContract(), "gamebook: call to non-contract");
        require(rule.time != timeRecords[_msgSender()], "gamebook: time is not valid");
        require(functionContract(utilAddress).vertify(rule.hash,rule.signature),"gamebook: vertify is fail");

        GameBook gameBook = new GameBook(rule.amount, rule.price);
        gameBookAddr = address(gameBook);
        if (!_allGameBookAddrs.contains(gameBookAddr)) {
            _allGameBookAddrs.add(gameBookAddr);
            emit eCreateGameBook(msg.sender, gameBookAddr);
        } else {
            revert("gamebook: create gamebook fail");
        }
        GameBookCreatorInfos[gameBookAddr] = _msgSender();
        timeRecords[_msgSender()] = rule.time;
    }

    function getAllGameBooks() public view returns (address[] memory){
        return _allGameBookAddrs.values();
    }

}

这里说一下，为什么 BookUtil 的验证不直接写在 GameBook 里面，而是采用合约调用的方式。

因为，我怕，万一后端被人攻克后，数字签名就形同虚设了，而这个时候，通过更换 GameBook 里面的数字签名地址，更换验证逻辑。

使用

先部署 BookUtil 得到合约地址为 0xd9145CCE52D386f254917e481eB44e9943F39138。

再部署 GameBookFactory 传入合约参数 0xd9145CCE52D386f254917e481eB44e9943F39138，最后部署的合约地址为 0x358AA13c52544ECCEF6B0ADD0f801012ADAD5eE3

执行 GameBookFactory 的 createGameBook,传入参数

["1000","100","10000","0xb42ca4636f721c7a331923e764587e98ec577cea1a185f60dfcc14dbb9bd900b","0x390d704d7ab732ce034203599ee93dd5d3cb0d4d1d7c600ac11726659489773d559b12d220f99f41d17651b0c1c6a669d346a397f8541760d6b32a5725378b241c"]

如下图所示

执行完成后，log 输入为

[
	{
		"from": "0x358AA13c52544ECCEF6B0ADD0f801012ADAD5eE3",
		"topic": "0xe91950a1c46aac78a2422f8326cc374e7a6c52b3952ca8f66badb714ced6a30a",
		"event": "eCreateGameBook",
		"args": {
			"0": "0x5B38Da6a701c568545dCfcB03FcB875f56beddC4",
			"1": "0x568864A892a1B25127018Be020d2AF585Dff6c96",
			"creator": "0x5B38Da6a701c568545dCfcB03FcB875f56beddC4",
			"gameBookAddr": "0x568864A892a1B25127018Be020d2AF585Dff6c96"
		}
	}
]

说明一个合约地址为 0x568864A892a1B25127018Be020d2AF585Dff6c96 的 ERC721 已经部署成功。

为了能在 remix 中调用 0x568864A892a1B25127018Be020d2AF585Dff6c96 中的方法。

选择 GameBook 合约然后输入合约地址，点击 At Address，就成功出现了。

调用 0x568864A892a1B25127018Be020d2AF585Dff6c96 合约的 mint 传入参数

["1000","100","10000","0xb42ca4636f721c7a331923e764587e98ec577cea1a185f60dfcc14dbb9bd900b","0x390d704d7ab732ce034203599ee93dd5d3cb0d4d1d7c600ac11726659489773d559b12d220f99f41d17651b0c1c6a669d346a397f8541760d6b32a5725378b241c"]

最后成功，调用一下各个合约的其他函数，都能正确的返回。