IPNS contenthash decoding strips first character from peer ID

[eth-limo]

Ethers Version

6.9.1

Search Terms

ipns, contenthash

Describe the Problem

When attempting to decode a contentHash record set to an IPNS peer ID, the first character is stripped, resulting in an unparsable IPNS pointer:

For example (esteroids.eth):

Wrong: ipns://2D3KooWKrB93pwXDdeyz2WRMwcSBny5ECjA1JasB4GTo4ijUUtf

Should be: ipns://12D3KooWKrB93pwXDdeyz2WRMwcSBny5ECjA1JasB4GTo4ijUUtf

Code Snippet

const { ethers } = require("ethers");

const provider = new ethers.JsonRpcProvider(process.env.ETH_RPC_ENDPOINT);

async function lookup(ens) {
  let hostname = ens
  var res = await provider.getResolver(hostname);
  var contentHash = await res.getContentHash();
  var address = await res.getAddress();

  var output = JSON.stringify({
    resolver: res,
    address: address,
    contentHash: contentHash,
  });
  console.log(output);
}

lookup("esteroids.eth");

Contract ABI

No response

Errors

No response

Environment

node.js (v12 or newer)

Environment (Other)

No response

[ricmoo]

Thanks! I’ll look into this right away.

[ricmoo]

The problem is that Base58 is more an encoding for numeric data, not binary data, so as a result the leading-0's are getting trimmer (while in base-58, the character "1" is used to indicate the value 0). Looking into the best way to remedy this.

Most protocols that use Base58 as a result tend to specify a bit width to pad to.

I'll update shortly. :)

[ricmoo]

Useful resource: https://medium.com/concerning-pharo/understanding-base58-encoding-23e673e37ff6

I've made the change and am just waiting for the CI to complete.

[ricmoo]

Fixed in v6.9.2.

Thanks! :)

[eth-limo]

Fixed in v6.9.2.

Thanks! :)

Thank you so much @ricmoo! I'll open a new issue if I run into anything else.