Multisite domain mapping with SSL redirects to main domain

Question

I created a fresh install of WordPress using Apache24 (on FreeBSD, not that that should make a difference), say using maindomain.com. I created an SSL certificate with Let's Encrypt and everything works fine, DNS pointing at my server's IP.

I then enabled the Multisite functionality using subdirectories. I created another site, located at https://maindomain.com/site1. Everything works correctly, with the different sites using the 2 different themes I installed and activated.

I also created another SSL certificate for site1.com, and pointed the DNS for that url to my server's IP as well.

I have set up 2 separate Apache configuration files, one for each virtual host, each pointing to the respective SSL certificate files (located in separate directories). At this point everything works correctly (main site and second site in the subdirectory).

Now I can't get site1.com to work correctly. When I go to the site administration page for site1, into the info tab and change the Site Address (URL) to site1.com, navigation to site1.com redirects me to maindomain.com.

My .htaccess file is standard:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

My Apache config file (in sites-available, and symlinked to sites-enabled) is also pretty standard:

<VirtualHost *:443>
  ServerName www.site1.com
  ServerAlias site1.com

  SSLEngine on
  SSLCertificateFile "/usr/local/etc/letsencrypt/live/site1.com/cert.pem"
  SSLCertificateKeyFile "/usr/local/etc/letsencrypt/live/site1.com/privkey.pem"
  SSLCertificateChainFile "/usr/local/etc/letsencrypt/live/site1.com/fullchain.pem"

  <FilesMatch "\.(cgi|shtml|phtml|php)$">
    SSLOptions +StdEnvVars
  </FilesMatch>

  BrowserMatch "MSIE [2-5]" nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0
  CustomLog "/var/log/httpd-ssl_request.log" "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"

  <Directory "/usr/local/www/apache24/data/">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Require all granted
  </Directory>

  ErrorLog "/var/log/site1.com.ssl-error.log"
  CustomLog "/var/log/site1.com.ssl-access_log" combined
</VirtualHost>

<VirtualHost *:80>
   ServerName www.site1.com
   ServerAlias site1.com

   Redirect permanent / https://site1.com/
</VirtualHost>

Answer 1

I have a strong suspicion that this had to do with me needing to clear the cache and cookies. I am also pretty sure that you can't use SSL certificates that were generated independently.

I ended up disabling SSL everywhere, getting the sites to map properly to the URLs, generating the certificates (first in manual mode, then in webroot mode), and then enabling SSL again.