This Gist is based on Self Signed Certificate with Custom Root CA gist.
It adds the use of AWS KMS to generate and decrypt the Root CA private key, so that this key does not need to be stored in plaintext. Instead, the key is stored encrypted, and is being decrypted using AWS KMS only when needed.
Create symmetic CMK (customer-managed key) and give it an alias of alias/root-ca-encrypting-key
that will be used later
to reference to it: