DNS-PERSIST-01: Safer Wildcard Certificates
💬 This is a comment on DNS-PERSIST-01: A New Model for DNS-based Challenge Validation The Source of Truth Connecting to a website? Sending an email? Which server1 you reach depends on DNS records. And CAA or SSHFP records establish trust for public key cryptographic protocols. DNS records are the source of truth. DNS API Tokens Currently, wildcard certificates with Let’s Encrypt require to write an arbitrary string in a DNS record, for every single certificate renewed or issued. In practice, this often involves sharing a write API token to change the DNS. This is risky: should an attacker obtain the token, they can do a lot of damage: hijack traffic (and get valid certificates for it), receive and send emails using the corresponding domain… ...