Update documentation of nginx configuration

- Avoid using "if" to check for file existence (use try_files instead)
- Replicate the behavior of the .htaccess files
- TODO: get static error pages to work

docs/en/installation/nginx.md

@@ -1,35 +1,97 @@
 # Nginx
 
-These instructions are also covered on the [Nginx Wiki](http://wiki.nginx.org/SilverStripe)
+These instructions are also covered in less detail on the
+[Nginx Wiki](http://wiki.nginx.org/SilverStripe).
 
-The prerequisite is that you have already installed Nginx and you are able to run PHP files via the FastCGI-wrapper from
-Nginx.
+The prerequisite is that you have already installed Nginx and you are
+able to run PHP files via the FastCGI-wrapper from Nginx.
 
-Now you need to setup a virtual host in Nginx with the following configuration settings:
+Now you need to set up a virtual host in Nginx with the following
+configuration settings:
 
 	server {
 		listen 80;
-	        server_name  yoursite.com;
 		
-	        root   /home/yoursite.com/httpdocs;
-	        index  index.html index.php;
+		# SSL configuration (optional, but recommended for security)
+		include ssl
 		
-	        if (!-f $request_filename) {
-	                rewrite ^/(.*?)(\?|$)(.*)$ /sapphire/main.php?url=$1&$3 last;
+		root /var/www/example.com;
+		index index.php index.html index.htm;
+		
+		server_name example.com;
+
+		include silverstripe3;
+		include htaccess;
 	}
 
-	        error_page  404  /sapphire/main.php;
+Here is the include file `silverstripe3`:
 
-	        location ~ \.php$ {
-	                fastcgi_pass   127.0.0.1:9000;
-	                fastcgi_index  index.php;
-	                fastcgi_param  SCRIPT_FILENAME  /home/yoursite.com/httpdocs$fastcgi_script_name;
+	location / {
+		try_files $uri @silverstripe;
+	}
+ 
+	location @silverstripe {
 		include fastcgi_params;
-	        }
+		
+		# Defend against arbitrary PHP code execution
+		# NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
+		# More info:
+		# https://nealpoole.com/blog/2011/04/setting-up-php-fastcgi-and-nginx-dont-trust-the-tutorials-check-your-configuration/
+		fastcgi_split_path_info ^(.+\.php)(/.+)$;
+		
+		fastcgi_param SCRIPT_FILENAME $document_root/sapphire/main.php;
+		fastcgi_param SCRIPT_NAME /sapphire/main.php;
+		fastcgi_param QUERY_STRING url=$uri&$args;
+		
+		fastcgi_pass unix:/var/run/php5-fpm.sock;
+		fastcgi_index index.php;
+		fastcgi_buffer_size 32k;
+		fastcgi_buffers 4 32k;
+		fastcgi_busy_buffers_size 64k;
 	}
 
 
-The above configuration will setup a new virtual host `yoursite.com` with rewrite rules suited for SilverStripe. The
-location block at the bottom will pass all php scripts to the FastCGI-wrapper.
+Here is the include file `htaccess`:
+
+	# Don't serve up any .htaccess files
+	location ~ /\.ht {
+		deny all;
+	}
+	
+	# Deny access to silverstripe-cache
+	location ~ ^/silverstripe-cache {
+		deny all;
+	}
+	
+	# Don't execute scripts in the assets
+	location ^~ /assets/ {
+		try_files $uri $uri/ =404;
+	}
+	
+	# cms & sapphire .htaccess rules
+	location ~ ^/(cms|sapphire|mysite)/.*\.(php|php[345]|phtml|inc)$ {
+		deny all;
+	}
+	location ~ ^/(cms|sapphire)/silverstripe_version$ {
+		deny all;
+	}
+	location ~ ^/sapphire/.*(main|static-main|rpc|tiny_mce_gzip)\.php$ {
+		allow all;
+	}
+
+Here is the optional include file `ssl`:
+
+	listen 443 ssl;
+	ssl_certificate server.crt;
+	ssl_certificate_key server.key;
+	ssl_session_timeout 5m;
+	ssl_protocols SSLv3 TLSv1;
+	ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv3:+EXP;
+
+The above configuration sets up a virtual host `example.com` with
+rewrite rules suited for SilverStripe. The location block named
+`@silverstripe` passes all php scripts to the FastCGI-wrapper via a Unix
+socket. This example is from a site running Ubuntu with the php5-fpm
+package.
 
 Now you can proceed with the SilverStripe installation normally.