Wildcard Certificates use Subject Alternative Names (SANs) to secure a domain and all of its first-level subdomains. For example, a certificate for *.example.com secures www.example.com, mail.example.com, blog.example.com etc.
A standard SSL Certificate would only secure www.example.com, requiring you to purchase an additional certificate for mail.example.com and so on.
Source: https://www.digicert.com/wildcard-ssl-certificates.htm
Generating CSR:
- Login to Plesk
- Navigate to the Websites & Domains tab, select the domain you want to secure and click on Secure Your Sites link.
- Click Add SSL Certificate button.
- On the next page enter the Certificate Name to easily recognize the certificate among others on the server and fill in the required information for the CSR code.
- Enter the FQDN for which the SSL will be activated (common name). The common name for Wildcard certificates should be represented with an asterisk in front of the domain ie. *.example.com
- Click Request button.
- A new record will be added to the list of SSL Certificates. Click on the newly created certificate to view the CSR code and RSA Private Key that were created.
- You can now proceed in submitting the CSR to the SSL vendor.
Importing SSL Certificate:
- Login to Plesk
- Navigate to the Websites & Domains tab, select the domain you want to secure and click on Secure Your Sites link.
- Select the SSL certificate that was created while generating the CSR code.
- On the next page, paste ‘SSL certificate’ code in Certificate field and ‘intermediate CAs’ in CA certificate field.
Note: depending on the file format customer has provided, you may need to convert the Intermediate CAs to PEM like PKCS#7 or P7B formats are not recognized by plesk. Use https://www.sslshopper.com/ssl-converter.html to convert such format.
- After both fields are populated, click Send Text button.
- Ensure import is successful and navigate back to Domain > Manage Hosting > Hosting Settings > tick SSL support check box > select Certificate Name dropdown and hit OK.
- Verify SSL certificate was installed correctly in https://www.sslshopper.com/ssl-checker.html