Does Let's Encrypt Support Wildcard Certificates?

Yes, Let's Encrypt does support wildcard certificates. A wildcard certificate allows you to secure an unlimited number of subdomains for a specific domain with a single certificate. This makes it convenient and cost-effective for websites with multiple subdomains.

How Does a Wildcard Certificate Work?

A wildcard certificate is issued for the main domain and all its subdomains. The certificate includes a wildcard character (*) to represent all subdomains, ensuring that any subdomain under the same domain will be automatically covered by the same certificate.

How to Obtain a Wildcard Certificate from Let's Encrypt

To obtain a wildcard certificate from Let's Encrypt, you need to follow the ACMEv2 protocol and use compatible ACME clients or Certbot.

Step-by-Step Guide

Ensure you have a compatible client: You need to use a client that supports ACMEv2. Certbot supports this protocol and is one of the most popular choices. Install Certbot if you haven't already: Download and install Certbot from the official Let's Encrypt website. Generate a challenge type: For wildcards, the DNS-01 challenge is used. This means you need to have control over the DNS settings for your domain. Issue the Certificate: Use the following command to request a wildcard certificate:

certbot certonly --manual --preferred-challengesdns --email your_email@ --server  -d *

Replace Your_email@ with your email address. Replace with your actual domain name. The --manual flag indicates manual DNS configuration, and --preferred-challengesdns specifies the DNS challenge method.

Certbot will provide you with instructions on how to add a DNS TXT record for domain validation. Once you've added the record, Certbot will verify it and issue the wildcard certificate.

Renewing Your Certificate

Let's Encrypt certificates are valid for 90 days. It's crucial to renew them before they expire to maintain security for your domain. You can automate this process using Certbot's built-in renewal functionality.

Conclusion

By utilizing Let's Encrypt wildcard certificates, you can easily secure all your subdomains with a single certificate. This ensures encryption and security across your entire domain ecosystem. For detailed steps and additional resources, see the 'How To' section below.