Force SSL on your PHP site
#Force SSL on entire site
RewriteEngine On
RewriteBase /
RewriteCond %{ENV:HTTPS} !on [NC]
RewriteRule ^(.*)$ https://(YOURDOMAIN)/$1 [R,L]
#Force SSL on a specific directory
RewriteEngine On
RewriteBase /
RewriteCond %{ENV:HTTPS} !on [NC]
RewriteRule ^DIRNAME/(.*)$ https://YOURDOMAIN/DIRNAME/$1 [R,L]