Letsencrypt + Multiple Vhosts Question

Hi,

I just set up a 2nd VPS dev server for some integration work. I have a freshly updated v123.09beta01 install that I need to configure for three Vhosts as follows: domain.com, sub1.domain.com, sub2.domain.com.

DNS records are fully configured for each with all three pointed to the same IP. Each Vhost will contain a separate and unique website sharing the same IP, but none will share the same webroot.

My question is:
Is there way to create and configure all three Vhosts to share a single Letsencrypt (default HTTPS only) cert? Or must a live cert be issued for each domain/subdomain independently?

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The reason I am asking is because once this project is completed, the client intends to submit a HSTS Preload request for browser inclusion, IE:

Code:

Strict-Transport-Security "max-age=31536000; includeSubdomains; preload";

That header looks pretty risky to me since the three sites will interact with shared assets and data, but I've been assured that there will be no third-party content or assets ever called.

This is the custom_config.inc entries that I have entered so far:

Code:

LETSENCRYPT_DETECT='y'
DUALCERTS='y'
KEYLENGTH='ec-256'

Are those sufficient?

Thanks for your help,

 

Thank you for your help @eva2000.