generate_tlsa

ai.intodns/scanner · Verify this server

Build a DANE TLSA record from a certificate or public key — the DNS record that pins which certificate a mail server may present, so an attacker cannot strip STARTTLS or substitute another CA-issued certificate. Paste the PEM (a CERTIFICATE or PUBLIC KEY block) as `pem`; the hash is computed here because a language model cannot hash. Never send a private key: none is needed and the request is refused if one is present. The three numbers: `usage` 3 (DANE-EE) pins the end-entity key and needs no CA, `selector` 1 hashes the SubjectPublicKeyInfo, `matching` 1 is SHA-256 — the 3 1 1 profile recommended for SMTP, because it survives certificate renewal as long as the key is reused. `host` must be the mail server hostname from the MX record, not the domain. Two things break DANE and both are reported: a TLSA record in a zone without DNSSEC proves nothing and is ignored, and DANE fails closed, so installing a new certificate before the matching record has propagated stops mail from every sender that validates. Returns the record, the hash, what each number means, and the DNS entry.