DNS Certification Authority Authorization

CAA

Reading RFC 6844 you will find the definition of “DNS Certification Authority Authorization (CAA) Resource Record”.

You can read everything here: RFC 6844

So, what is CAA anyhow?

Certificate Authority

In a nutshell you are declaring which your Certificate Authority is for your domain.

It’s another way to verify that the certificate your site is announcing is in fact signed by the issuer that the certificate is showing.

So let’s see what my certificate is showing:

DNS

Now, let’s find out what my DNS is telling us:

# dig caa balaskas.gr

;; ANSWER SECTION:
balaskas.gr.        5938    IN  CAA 1 issue "letsencrypt.org"

Testing

You can also use the Qualys ssl server test:

https://www.ssllabs.com/ssltest/