Table of Contents

Virtualmin SSL Issues

See also TLS/SSL Certificate Testing

For Webmin Alone

https://doxfer.webmin.com/Webmin/Let's_Encrypt

Webmin → Webmin → Webmin Configuration → SSL Encryption

:!: Requires HTTP server or DNS server hosting the domain

Install Service Certs

virtualmin install-service-cert --domain yourdomain.com --service webmin

Let's Encrypt

:!: Beware of rate limiting at Let's Encrypt. Don't run any more attempts than is absolutely necessary or you may have to wait an hour to try again.

  1. Edit the virtual server you want to SSL-enable
    1. Enable SSL feature
      • A self-signed certificate is automatically created and applied
      • You must have an accessible index.html or certbot will fail
  2. Configure Let's Encrypt SSL certificate
    1. Don't add mail.domain.tld
      1. Mail clients will still have to accept the host server's certificate anyway
      2. Use domain.tld or www.domain.tld as mail server
      3. Or just accept the server's cert
    2. List the desired SANs
      domain.tld
www.domain.tld
autoconfig.domain.tld
autodiscover.domain.tld
    3. Adjust the auto-renewal interval
      • The default (two months) is safe

Virtualmin → <domain> → Server Configuration → Manage SSL Certificate → Let’s Encrypt (tab)

Request certificate for → Domain names listed here → <list of Subject Alternative Names>

Months between automatic renewal → 2

Encrypt all Traffic for a Site

Virtualmin → <domain> → Services → Configure Website → Aliases and Redirects

Permanent URL redirects → From → / (slash)

Permanent URL redirects → To → https://www.yourdomainname.tld

Apply Let’s Encrypt SSL Cert to System Services

Most of the time, Virtualmin on newer host operating systems such as (Ubuntu 20.04) supports SNI. SNI presents the SSL certs of client domains based on the calling URI.
If you want SNI to function for a particular virtual server (domain), you must have configured SSL for that virtual server/domain.

:!: The matching domain name must be included in the SSL certificate.

Virtualmin → <domain> → Server Configuration → Manage SSL Certificate → Current Certificate (tab) → Copy to…