Good news. Let’s Encrypt has officially announced on July 6, 2017 that from January 2018 Wildcard SSL certificates will be issued.
A wildcard certificate can secure any number of subdomains of a base domain (e.g. *.example.com). This allows administrators to use a single certificate and key pair for a domain and all of its subdomains, which can make HTTPS deployment significantly easier.
Wildcard certificates will be offered free of charge via our upcoming ACME v2 API endpoint. We will initially only support base domain validation via DNS for wildcard certificates, but may explore additional validation options over time. We encourage people to ask any questions they might have about wildcard certificate support on our community forums.
Meanwhile, Let’s Encrypt is well and readily used. With its API it is very easy to issue new and inexpensive SSL certificates. Last month Let’s Encrypt reached another milestone. More than 100,000,000 certificates have been issued since the start. With the new Wildcard certificate, one thing is sure: A lot of certificates will be added on top of that. Go for next 100,000,000!