如何在Solidity中连接2个字符串并编码Keccak256

Question

我正在研究一个智能合约，它有一个merkle树函数

基本上，我从firebase函数传递证据，该函数接收用户保留的地址和令牌的n°的输入，并将证据作为输出提供给执行智能合约函数的前端。

我唯一需要弄清楚的是leaf计算，在firebase函数上，它是通过对数组中的字符串keccak256进行编码而组成的，该字符串由eth地址与保留令牌的数量(0x32807d0e84edb04a57482c3769fe192617520373+3(连接而成，而在智能合约中，叶是用keccak256(abi.incodepacked(0x32807d0e84edb04a57482c3769fe1926175203733，3(计算的，它没有通过验证。。。

我认为这两种计算方法在某些方面不同，你能帮我吗？

我将粘贴两个函数的代码：

溶解度

// 1. Address check, if the proof is valid
function isPrivateListed(
uint256 _addressReservedTokens,
bytes32[] memory _proof
) public view returns (bool) {
bytes32 leaf = keccak256(abi.encodePacked(msg.sender, _addressReservedTokens);
return MerkleProof.verify(_proof, privateListRoot, leaf);
}

// 2. Mint function called from the front-end
function privateMint(
uint256 _mintAmount,
uint256 _addressReservedTokens,
bytes32[] calldata proof
) public payable {
require(privateOpen, "The private mint is not opened");
require(
isPrivateListed(_addressReservedTokens, proof),
"you are not in the private list"
);
uint256 supply = totalSupply();
require(supply + _mintAmount <= maxSupply, "max NFT limit exceeded");
uint256 owned = addressMintedBalance[msg.sender];
require(
owned + _mintAmount <= _addressReservedTokens,
"You have less nft reserved"
);
for (uint256 i = 1; i <= _mintAmount; i++) {
_safeMint(msg.sender, supply + i);
addressMintedBalance[msg.sender]++;
}
}

防火墙功能

// 1. Get parameters from the function called from client side
const walletAddress = data.walletAddress;
let whitelistAddresses = [
'0x38207d0e84edb04a57482c3769fe1926175203733',
'0x943926a8ff0000350d0b879a658fa52bcd4fca186',
];
// 2. Create a new array of `leafNodes` by hashing all indexes of the `whitelistAddresses`
// using `keccak256`. Then creates a Merkle Tree object using keccak256 as the algorithm.
const leafNodes = whitelistAddresses.map((addr) => keccak256(addr));
const merkleTree = new MerkleTree(leafNodes, keccak256, {
sortPairs: true,
});
// 3. Get root hash of the `merkleeTree` in hexadecimal format (0x)
const rootHash = merkleTree.getRoot();
const rootHashHex = merkleTree.getHexRoot();
// ***** ***** ***** CLIENT-SIDE ***** ***** ***** //
const claimingAddress = keccak256(walletAddress);
const hexProof = merkleTree.getHexProof(claimingAddress);
const verifyProof = merkleTree.verify(hexProof, claimingAddress, rootHash);

Answer 1

在solidity中，您正在散列一个(20+32(字节的元素

bytes32 leaf = keccak256(abi.encodePacked(msg.sender, _addressReservedTokens);

由于msg.sender是20个字节，_addressReservedTokens是32个字节，因此abi.encodePacked()的输出大致如下：

0x38207d0e84edb04a57482c3769fe1926175203730000000000000000000000000000000000000000000000000000000000000003

这与firebase使用的0x38207d0e84edb04a57482c3769fe1926175203733明显不同。

此外，我不确定js-keccak256是将该值解释为字符串还是字节(在solidity中是字节(。

最好的解决方案可能是更改js代码。您可以使用ethers编写正确的whitelistAddresses，请参阅此处https://ethereum.stackexchange.com/questions/119990/how-to-mimic-abi-encodepacked-in-ethers