分类 Ethereum 下的文章 - 区块链中文技术社区

您正在查看: Ethereum 分类下的文章

检查签名对于给定的签名者和数据哈希是否有效

2024-07-29　 Surou　阅读　 Ethereum-新手教程　 0 评论

github: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/659f3063f82422cef820de746444e6f6cba6ca7c/contracts/utils/cryptography/SignatureChecker.sol

/**
     * @dev Checks if a signature is valid for a given signer and data hash. If the signer is a smart contract, the
     * signature is validated against that smart contract using ERC-1271, otherwise it's validated using `ECDSA.recover`.
     *
     * NOTE: Unlike ECDSA signatures, contract signatures are revocable, and the outcome of this function can thus
     * change through time. It could return true at block N and false at block N+1 (or the opposite).
     */
    function isValidSignatureNow(address signer, bytes32 hash, bytes memory signature) internal view returns (bool) {
        if (signer.code.length == 0) {
            (address recovered, ECDSA.RecoverError err, ) = ECDSA.tryRecover(hash, signature);
            return err == ECDSA.RecoverError.NoError && recovered == signer;
        } else {
            return isValidERC1271SignatureNow(signer, hash, signature);
        }
    }

测试例子

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.19;

import {SignatureChecker} from "@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol";

contract TestSignatureChecker {
    function verify(address _signer, bytes32 messageHash,  bytes memory _signature) external view returns(bool) {
        return SignatureChecker.isValidSignatureNow(_signer, messageHash, _signature);
    }
}

用于以太坊 RLP 解码的 Solidity 库

2024-07-29　 Surou　阅读　 Ethereum-开源推荐　 0 评论

安装

npm install solidity-rlp在项目目录中。请确保通过 npm 安装以便及时更新！
import "solidity-rlp/contracts/RLPReader.sol"在所需的智能合约中。

github: https://github.com/hamdiallam/Solidity-RLP.git

测试例子

import "solidity-rlp/contracts/RLPReader.sol"

contract SomeContract {

    // optional way to attach library functions to these data types.
    using RLPReader for RLPReader.RLPItem;
    using RLPReader for RLPReader.Iterator;
    using RLPReader for bytes;

    // lets assume that rlpBytes is an encoding of [[1, "nested"], 2, 0x<Address>]
    function someFunctionThatTakesAnEncodedItem(bytes memory rlpBytes) public {
        RLPReader.RLPItem[] memory ls = rlpBytes.toRlpItem().toList(); // must convert to an rlpItem first!

        RLPReader.RLPItem memory item = ls[0]; // the encoding of [1, "nested"].
        item.toList()[0].toUint(); // 1
        string(item.toList()[1].toBytes()); // "nested"

        ls[1].toUint(); // 2
        ls[2].toAddress(); // 0x<Address>
    }

    // lets assume rlpBytes is an encoding of [["sublist"]]
    function someFunctionThatDemonstratesIterators(bytes memory rlpBytes) public {
        RLPReader.Iterator memory iter = rlpBytes.toRlpItem().iterator();
        RLPReader.Iterator memory subIter = iter.next().iterator();

        // iter.hasNext() == false
        // string(subIter.next().toBytes()) == "sublist"
        // subIter.hasNext() == false
    }
}

参考

https://ethereum.stackexchange.com/questions/42732/how-to-rlp-encode-messages-in-solidity

Geth Clique共识下miner显示0x地址

2024-07-12　 Surou　阅读　 Ethereum-新手教程　 0 评论

问题

在Clique共识下，查看block

eth.getBlockByNumber(1000);

返回数据中miner为0x地址

miner: "0x0000000000000000000000000000000000000000",

解决

对于Clique共识查看某个区块的miner，通过getSignersAtHash查看

clique.getSignersAtHash("0xec6058d9364569e92a7e7c19889fa4daf86111ddf29dfcd6993be697b1cdd553")
["0x0eb7365be3c1fa53fe6ad8080c723def2a4cbb9f", "0x45d959f955e6ba85c03d1131e8e6efbf7061b6ec", "0x48f58ba03e2bfe0f84813184ba605c530ce333d5", "0x57fa14bde7440f47f3a9ddc854c1281d1b7a2fc5", "0x5cd8f88f97ead6f84957cf5a2c80db33da53a8c7"]

对于blockscout浏览器显示0x问题，需要首次启动前，修改docker-compose/envs/common-blockscout.env