O Route53 suporta curingas (do FAQ do Route53 ):
Q. Does Amazon Route 53 support wildcard entries? If so, what record types support them?
Yes. To make it even easier for you to configure DNS settings for your domain, Amazon Route 53 supports wildcard entries for all record types, except NS records. A wildcard entry is a record in a DNS zone that will match requests for any domain name based on the configuration you set. For example, a wildcard DNS record such as *.example.com will match queries for www.example.com and subdomain.example.com.
Você precisará obter um certificado SSL curinga separadamente e hospedá-lo em qualquer servidor que aceite essas solicitações.