CAA Failure for CloudFlare DNS?

Question

We maintain a number of domains and requests certificates for CloudFront to S3 distributions, the zones are all hosted in CloudFlare and most of them passes CM validation without problems.  
  
But recently one of our domains are hitting this CAA failure, after successfully validating via DNS CNAME method. We know that CloudFlare adds their own CAA domains automatically, so AWS's option of leaving them blank may not work. We went ahead and added 4 CAA domains for amazon, but it still fails with **CAA Error** without further details on what we should do.  
  
What exactly is CM requiring for CAA? Or is it even CAA related?

x5inspire · Answer

Hi, so you only setting for "amazon.com"?  
  
How about amazontrust.com , awstrust.com , amazonaws.com?  
  
Can you share your screenshot from CloudFlare please?  I'm still having CAA error :(

iLake · Answer

Solved my own question, maybe it is CloudFlare who suddenly sets CAA automatically on the root domain and that's what prevents our CI pipeline from invoking ACM validation.  
  
So our problem is essentially a misconfiguration on wildcard subdomains, such that the line below is wrong
 `* CAA 0 issue amazon.com`
 and instead we should use

```
@ CAA 0 issuewild amazon.com
```

Edited by: iLake on Oct 22, 2019 12:15 AM

Ben Francom · Answer

Notice the difference between `@` versus `*` for the wildcard. It should be `@`.
Here is an example:
![Enter image description here](/media/postImages/original/IMDW-rBvRxS5OuS0la3ok0EQ)

After saving, it looks like so:
![Enter image description here](/media/postImages/original/IM2cPtr1hbQoyWh3DI8v5F6g)

Using `dig` on the cli, you should see something like so (notice `"amazon.com"` on the first line):

```
dig +short CAA benfran.com | sort
0 issue "amazon.com"
0 issue "comodoca.com"
0 issue "digicert.com; cansignhttpexchanges=yes"
0 issue "letsencrypt.org"
0 issue "pki.goog; cansignhttpexchanges=yes"
0 issuewild "comodoca.com"
0 issuewild "digicert.com; cansignhttpexchanges=yes"
0 issuewild "letsencrypt.org"
0 issuewild "pki.goog; cansignhttpexchanges=yes"
```
I only had to specify the one Amazon CA, "amazon.com" not all four. That aligns with the documentation too:

> ...a CAA record that specifies **one** of the following **four** Amazon CAs...

https://docs.aws.amazon.com/acm/latest/userguide/setup-caa.html

CAA Failure for CloudFlare DNS?

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