Apply the wildcard SSL certificate of Let’s Encrypt

Abstract

This article aims to introduce how to apply the wildcard SSL certificate provided by Let’s Encrypt.

Step 1. Download the certbot client

In the latest version of Let’s Encrypt, certbot client is used to deploy the SSL certificate. Download and give execute permission to the client file:

# Download certbot client
~$ wget https://dl.eff.org/certbot-auto

# Set execute permission
~$ chmod a+x certbot-auto

Step 2. Run the client

Assume that the Let’s Encrypt client certbot-auto is installed in the home directory(~/), run the client(Please use the correct domain instead of *.example.com):

~$ ./certbot-auto --server https://acme-v02.api.letsencrypt.org/directory -d "*.example.com"  --manual --preferred-challenges dns-01 certonly

Step 3. Add TXT record of the domain

Follow the guide and add TXT record of the domain in the provider administration background, the details will be given in the terminal.

Step 4. Reload and restart the proxy service

Restart and reload the proxy service apache or nginx on the server.