Certificate Policy DNS
Validate and generate CAA records for Let’s Encrypt, DigiCert, wildcard issuance, and incident reporting so certificate policy is explicit before you publish it.
Checks CAA flags, tag semantics, and common operational mistakes.
Generates a ready-to-publish zone-file line for BIND or PowerDNS workflows.
Shows Cloudflare-style flag, tag, and value fields for quick copying.
Presets
Use issue for normal certificates, issuewild for wildcard-only authorization, and iodef for incident reports.
Verdict
Only letsencrypt.org is authorized to issue non-wildcard certificates for this hostname.
CAA reduces certificate issuance ambiguity by explicitly naming which certificate authorities may issue for a hostname.
Many teams add issue records but forget issuewild, leaving wildcard policy undefined or overly broad.
Clear CAA policy makes certificate automation, audits, and incident handling easier to reason about.
CAA records use the format flags tag "value". In a zone file they are published as name TTL IN CAA flags tag "value".
The most common tags are:
Flag 128 sets the issuer-critical bit. If that bit is present and a CA does not understand the property, it must refuse issuance.
It explicitly forbids certificate issuance for the hostname scope covered by that record.
Only if your wildcard issuance policy differs from normal certificate issuance. Otherwise issue may be enough.
It tells certificate authorities where to send incident or mis-issuance reports, usually via mailto: or https:.
No. CAA controls who may issue certificates, but domain validation still has to succeed.