PHP file security on webserver

问题:

I'm slowly learning PHP, MySQL, along with some HTML, using localhost as my webserver. However, I'm starting to wonder how my .php files are going to be secured if I put this actually on the Internet.

I have a webpage at localhost/app.php that includes a form, some PHP code, and some MySQL queries. The MySQL credential information is located one directory above where app.php is located, but how do I prevent from strangers accessing the contents of app.php, including MySQL data structure, commands I'm using, etc. When you view the source code in a browser, you only see the HTML part of it, but couldn't someone download app.php and look into the actual file if he wanted to?

What's the proper way of constructing the file structure? Links or comments are greatly appreciated! TIA!

回答1:

Well, if you're using the .php extension, then Apache will serve up the parsed version -- echo and print will output but your variables won't.

If you're still concerned there's a few ways of making your files more secure.

• Apache aliasing is common -- it lets you have one directory act like it's another. In this case, you'd alias your PHP directory to some directory on your domain. If your file structure is /home/user/my_files/, you might alias my_files to be www.my-domain.com/files. The script would not be accessible there to the requests, but it would be accessible to something on the server.
• Symbolic links or symlinks can accomplish the same as the above.
• simply place the config files somewhere else and directly reference them. Generally not a good idea as it is hard-coding file locations, but it is an option.
• the CodeIgniter method: in your index.php have define( 'IN_APPLICATION', 1 ); in your config files have if( !defined( 'IN_APPLICATION' ) ) die( 'No direct script access allowed' );

回答2:

No. the php is parsed if the page is requested over HTTP. The person would have to know a vulnerability in your app, Apache or PHP or have some other access such as FTP.

You can move the files out of your wwwroot and reference them elsewhere. Also, never name your include files as .inc. always name them `.php.

回答3:

Try to download the .php file on your localhost. You'll find that all you get is HTML code. This is because of how a server works. Here is an example with a php file

1. Client (usually a web browser) sends a HTTP request to the server, i.e:

   GET /app.php HTTP/1.1

2. The server takes the request and processes it. In the case of a php file, the server should process the php file into HTML.

3. The HTML is returned to the client.

If you are using Apache, and want to make sure that the php files are being processed, make sure these rules are in your apache2.conf:

LoadModule php5_module modules/libphp5.so
AddHandler php5-script .php
AddType text/html .php

And, just for fun, if you did ever want to expose your php source, add this line to apache2.conf:

AddType application/x-httpd-php-source .phps

To be secure, make sure that your mySQL configuration files and anything else you don't want public are stored outside the directory you are serving up. The apache docs are a great resource for understanding how all this works.

回答4:

While there is not a direct problem with doing this, (many applications do this, and since the source cannot be seen without hacking your site), many applications solve this using a 'frontcontroller'. A frontcontroller is used a lot in MVC structured (Model, View Controller) applications.

A typical structure is like this:

app/ (applications, controllers and views)
lib/ (libraries, generic logic)
config/ (your configurations)
web/ (your webproot, only for css, images, javascript etc.)
web/index.php (your frontcontroller)

By only exposing index.php and placing all php and sensitive files outside of your webroot they will not be accessable for anyone from the web.