I have use mkcert to create infinites *.dev.net subdomains & localhost with valid HTTPS/SSL certs (Windows 10 XAMPP & Linux Debian 10 Apache2)
I create the certs on Windows with mkcert v1.4.0 (execute CMD as Administrator):
mkcert -install
mkcert localhost "*.dev.net"
This create in Windows 10 this files (I will install it first in Windows 10 XAMPP)
localhost+1.pem
localhost+1-key.pem
Overwrite the XAMPP default certs:
copy "localhost+1.pem" C:\xampp\apache\conf\ssl.crt\server.crt
copy "localhost+1-key.pem" C:\xampp\apache\conf\ssl.key\server.key
Now, in Apache2 for Debian 10, activate SSL & vhost_alias
a2enmod vhosts_alias
a2enmod ssl
a2ensite default-ssl
systemctl restart apache2
For vhost_alias add this Apache2 config:
nano /etc/apache2/sites-available/999-vhosts_alias.conf
With this content:
<VirtualHost *:80>
UseCanonicalName Off
ServerAlias *.dev.net
VirtualDocumentRoot "/var/www/html/%0/"
</VirtualHost>
Add the site:
a2ensite 999-vhosts_alias
Copy the certs to /root/mkcert by SSH and let overwrite the Debian ones:
systemctl stop apache2
mv /etc/ssl/certs/ssl-cert-snakeoil.pem /etc/ssl/certs/ssl-cert-snakeoil.pem.bak
mv /etc/ssl/private/ssl-cert-snakeoil.key /etc/ssl/private/ssl-cert-snakeoil.key.bak
cp "localhost+1.pem" /etc/ssl/certs/ssl-cert-snakeoil.pem
cp "localhost+1-key.pem" /etc/ssl/private/ssl-cert-snakeoil.key
chown root:ssl-cert /etc/ssl/private/ssl-cert-snakeoil.key
chmod 640 /etc/ssl/private/ssl-cert-snakeoil.key
systemctl start apache2
Edit the SSL config
nano /etc/apache2/sites-enabled/default-ssl.conf
At the start edit the file with this content:
<IfModule mod_ssl.c>
<VirtualHost *:443>
UseCanonicalName Off
ServerAlias *.dev.net
ServerAdmin webmaster@localhost
# DocumentRoot /var/www/html/
VirtualDocumentRoot /var/www/html/%0/
...
Last restart:
systemctl restart apache2
NOTE: donĀ“t forget to create the folders for your subdomains in /var/www/html/
/var/www/html/subdomain1.dev.net
/var/www/html/subdomain2.dev.net
/var/www/html/subdomain3.dev.net