S3 Serving Files Under Custom Subdomain w/ SSL

1. In the ACM request a cert for your subdomain and do the dns verification (Important: the cert has to be in the same region as your Cloudflare Distribution)
2. Create an S3 Bucket and give it this policy

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": "*",
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::oselot-docs/*",
            "Condition": {
                "StringEquals": {
                    "s3:ExistingObjectTag/public": "yes"
                }
            }
        }
    ]
}

3. Create a CloudFlare distro with the bucket as the origin, and add your subdomain as a CNAME. Choose the cert you just created
4. Point your subdomain to the subdomain at the cloudflare distro subdomain