Universal SSL
By default, Cloudflare issues — and renews — free, unshared, publicly trusted SSL certificates to all Cloudflare domains.When you change your authoritative nameservers to point to Cloudflare, this process happens automatically and between 15 minutes to 24 hours of domain activation. Provisioning time depends on certain security checks and other requirements mandated by Certificate Authorities (CA).
If you do not use Cloudflare for your authoritative nameservers (a CNAME setup), you will need to perform the additional steps described in Enable Universal SSL .