Self-Signed Packed Attestation

Does this look right for a self-signed packed attestation? If I got this
right, hopefully it’s a validation that the spec is readable.
https://gist.github.com/apowers313/5f484fd85da7a885b31c7dceecb7dd13


Note that the code that generated this attestation currently lives here
(the function is createPackedAttestation), although it is currently in the
embarrassing state of needing some clean-up / integration:
https://github.com/apowers313/webauthn-soft-authn/blob/master/soft-authn.js