Custom Ecto.Type for WebAuthn cose keys.

Use this type for the :public_key field in an Ecto schema.

Example

defmodule MyApp.Authentication.UserKey do
  use Ecto.Schema
  import Ecto.Changeset
  alias MyApp.Accounts.User
  alias WebauthnComponents.CoseKey

  @primary_key {:id, :binary_id, autogenerate: true}
  @foreign_key_type :binary_id
  @derive {Jason.Encoder, only: [:key_id, :public_key, :label, :last_used]}
  schema "user_keys" do
    field :label, :string, default: "default"
    field :key_id, :binary
    field :public_key, CoseKey
    belongs_to :user, User
    field :last_used, :utc_datetime

    timestamps()
  end

  ...
end