Sui only supports ECDSA Secp256r1 signatures natively, this is a problem because certificate authorities use a wide range of algorithm. For example, Let' Encrypt (most used certificate authority) uses ECDSA Secp384r1, we spent a lot of time trying to verify the signature for a real domain before realizing this.
To get around this, we had to use self-signed certificates using openssl, which defeat the point because the certificate authority can no longer be trusted, but technically it works the same.

A better approach would be to implement a dns resolver that communicates with the smart contract, this is what ENS did (https://github.com/ensdomains/ens-contracts/blob/staging/contracts/resolvers/profiles/DNSResolver.sol).
Unfortunaly SuiNS don't yet have this capability and it would have been impossible to implement it in 24h.

Major challenges we ran into:

• We didn't have time to write parsing logic for X.509 certificates in Sui. This should be straightforward but tedious (see https://github.com/lapo-luchini/asn1js for a javascript parser).
• We didn't have time to properly connect the frontend with the smart contract.

These two issues makes the project unusable for now but the bulk of the skeleton is there.