This guide explains how to generate a certificate signing request (CSR) for a domain name and all its subdomains with a Web Hosting (excluding free hosting of type Starter), thus allowing you to encrypt the connection to your domain name and all its subdomains via a single SSL certificate.

Preamble

• The configuration allows for a "named site" and a "backup site"; to ensure this works without conflict, make sure that the wildcard and your specific subdomains do not overlap on the same web hosting:
  • DNS Level the priority is natural: if a specific subdomain exists (e.g., private.domain.xyz), it is the one that is requested; otherwise, the request is redirected to the wildcard (*.domain.xyz).
  • Server Level it is necessary to be vigilant: if the wildcard and the specific subdomain are on the same server, it is the software implementation (Apache) that decides; Apache processes requests according to the evaluation order of the configuration files.
  • The risk: if the wildcard is evaluated first, it "captures" all the traffic, making your specific subdomain inaccessible, even if it exists elsewhere.
  • Therefore, do not place the wildcard on the same hosting as a more specific overlapping subdomain.

Setting up a Wildcard Certificate

1. Add an alias domain with an asterisk *

To add an alias of type * to your website:

1. Click here to access the management of your site on the Infomaniak Manager (need help?).
2. Click directly on the name assigned to the site concerned:
   
3. Click on the chevron ‍ to expand the Domains section of this site.
4. Click on the Add a Domain button:
   
5. Enter the domain name to be added in this form:
   • *.domain.xyz (the asterisk is mandatory, followed by a dot, then the domain name of the website which is domain.xyz in this example)
6. Click on the Confirm button to complete the procedure:
   

2. Install or update an SSL certificate

Example of updating the existing certificate to include the * wildcard subdomain:

1. Click here to access the management of your site on the Infomaniak Manager (need help?).
2. Click directly on the name assigned to the site concerned.
3. Click on SSL Certificate in the left sidebar menu.
4. Click on the action menu ⋮ located on the right.
5. Click on Update the certificate:
   
6. Make sure the recently added subdomain is selected.
7. Click on the Install button at the bottom:
   
8. Wait for the creation or update to complete.