Apache: reverse proxy to process PHP from another server - php

I have the following setup:
Plain-Server: Delivering php-files as plain text
Proxy-Server: Asking the Plain-Server for the php file and parsing it.
Now my question: How do I configure the Proxy-Server (a fully configurable apache 2.2 with PHP 5.3) to interpret the plain php files from Plain-Server?
Example: Given a small php script "hello.php" on Plain-Server (accessible throw http://plainserver/hello.php):
<?php
echo "Hello World";
?>
Plain-Server only outputs it as plain text, no parsing of php-code.
On the Proxy-Server the file "hello.php" does not exist. But when requesting hello.php from Proxy-Server it should get the hello.php from Plain-Server with mod_proxy (Reverse Proxy). It should also parse and execute the php, saying only "Hello World".
The Reverse Proxy is already running, but the execution of php code not working. I tried mod_filter, but couldn't is work. Any ideas how to that?

You may consider instead sharing the php files from your source server via an nfs mount or something similar to your target server. Tricking the proxy server into doing what you ask seems like the long way around the barn?

I totally agree with jskaggz,
you could build some awfull tricks building some apps that fetch the remote page ,
dowload it into a local file and then redirect the user to that page that could be executed...
but there is a milion security issues and things that might go wrong with that...
Can't you just convert the 'plain server' to a php excuting server and do some traditional reverse proxying
on your 'proxy server'
maybe using mod_proxy:
http://www.apachetutor.org/admin/reverseproxies ?

Answered this on the ServerFault version of this thread: https://serverfault.com/a/399671/48061

Related

Requesting file via PHP fails, but succeeds in Python

The URL in question : http://www.roblox.com/asset/?id=149996624
When accessed in a browser, it will correctly download a file (which is an XML document). I wanted to get the file in php, and simply display its contents on a page.
$contents = file_get_contents("http://www.roblox.com/asset/?id=149996624");
The above is what I've tried using (as far as I know, the page does not expect any headers). I get a 500 HTTP error. However, in Python, the following code works and I receive the file.
r = requests.get("http://www.roblox.com/asset/?id=147781188")
I'm confused as to what the distinction is between how these two requests are sent. I am almost 100% it is not a header problem. I've also tried the cURL library in PHP to no avail. Nothing I've tried in PHP seems to succeed with the URL (with any valid id parameter); but Python is able to bring success nonchalantly.
Any insight as to why this issue may be happening would be great.
EDIT : I have already tried copying Python's headers into my PHP request.
EDIT2 : It also appears that there are two requests happening upon navigating to the link.
Is this on a linux/mac host by chance? If so you could use ngrep to see the differences on the request themselves on the wire. Something like the following should work
ngrep -t '^(GET) ' 'src host 127.0.0.1 and tcp and dst port 80'
EDIT - The problem is that your server is responding with a 302 and the PHP library is not following it automatically. Cheers!

How to view PHP or Apache error log online in a browser?

Is there a way to view the PHP error logs or Apache error logs in a web browser?
I find it inconvenient to ssh into multiple servers and run a "tail" command to follow the error logs. Is there some tool (preferably open source) that shows me the error logs online (streaming or non-streaming?
Thanks
A simple php code to read log and print:
<?php
exec('tail /var/log/apache2/error.log', $error_logs);
foreach($error_logs as $error_log) {
echo "<br />".$error_log;
}
?>
You can embed error_log php variable in html as per your requirement. The best part is tail command will load the latest errors which wont make too load on your server.
You can change tail to give output as you want
Ex. tail myfile.txt -n 100 // it will give last 100 lines
See What commercial and open source competitors are there to Splunk? and I would recommend https://github.com/tobi/clarity
Simple and easy tool.
Since everyone is suggesting clarity, I would also like to mention tailon. I wrote tailon as a more modern and secure alternative to clarity. It's still in its early stages of development, but the functionality you need is there. You may also use wtee, if you're only interested in following a single log file.
You good make a script that reads the error logs from apache2..
$apache_errorlog = file_get_contents('/var/log/apache2/error.log');
if its not working.. trying to get it with the php functions exec or shell_exec and the command 'cat /var/log/apache2/error.log'
EDIT: If you have multi servers(i quess with webservers on it) you can create a file on the machine, when you make a request to that script(hashed connection) you get the logs from that server
I recommend LogHappens: https://loghappens.com, it allows you to view the error log in web, and this is what it looks like:
LogHappens supports kinds of web server log format, it comes with parses for Apache and CakePHP, and you can write your own.
You can find it here: https://github.com/qijianjun/logHappens
It's open source and free, I forked it and do some work to make it work better in dev env or in public env. That is:
Support token for security, one can't access the site without the token in config.php
Support IP whitelists for security and privacy
Sopport config the interval between ajax requests
Support load static files from local (for local dev env)
I've found this solution https://code.google.com/p/php-tail/
It's working perfectly. I only needed to change the filesize, because I was getting an error first.
56 if($maxLength > $this->maxSizeToLoad) {
57 $maxLength = $this->maxSizeToLoad;
58 // return json_encode(array("size" => $fsize, "data" => array("ERROR: PHPTail attempted to load more (".round(($maxLength / 1048576), 2)."MB) then the maximum size (".round(($this->maxSizeToLoad / 1048576), 2) ."MB) of bytes into memory. You should lower the defaultUpdateTime to prevent this from happening. ")));
59 }
And I've added default size, but it's not needed
125 lastSize = <?php echo filesize($this->log) || 1000; ?>;
I know this question is a bit old, but (along with the lack of good choices) it gave me the idea to create this tiny (open source) web app. https://github.com/ToX82/logHappens. It can be used online, but I'd use an .htpasswd as a basic login system. I hope it helps.

Using PHP on non-supportive server

I have a rather complicated scenario that I have never really had to deal with before. I am creating a website that will be hosted on a web-server without PHP support. But I need to call a PHP script that returns a Flash Slideshow. Is there any way that I can do this? Here is the bit of PHP code that I need to call to return the Flash Slideshow.
<?php
//include slideshow.php to access the Insert_Slideshow function
include "http://mywebsite/slideshow.php";
//insert the slideshow.swf flash file into the web page
//tell slideshow.swf to get the slideshow's data from sample.php created in the first step
//set the slideshow's width to 320 pixels and the height to 240
echo Insert_Slideshow ( "http://mywebsite/slideshow.swf", "http://mywebsite/sample.php", 600, 500 );
?>
To run PHP on your server (not another server) you will definitely need to install a PHP processor.
However since you have a hard-coded URL in there, it looks as though the PHP code is just some kind of utility function for inserting a flash movie.
Run the PHP code on your local computer (for example) and see what HTML it generates, and if it always generates that same HTML, why not just copy it and use that in your website.
You could have the PHP script execute on a PHP enabled webserver somewhere else and include it in an iframe on the page without PHP support. That would be quite ugly, tho.
Although you obviously can't run PHP on a server that doesn't have it, if your slideshow doesn't change frequently perhaps you could run your PHP script on another machine, capture the output, then upload that to your web host.
This is not possible. If you need to call a PHP script, its obvious that you need PHP installed on the web server.

Hacked, what does this piece of code do?

WARNING: This is a possible exploit. Do not run directly on your server if you're not sure what to do with this.
http://pastehtml.com/view/1b1m2r6.txt
I believe this was uploaded via an insecure upload script. How do I decode and uncompress this code? Running it in the browser might execute it as a shell script, open up a port or something.
I can do a base64 decode online but i couldn't really decompress it.
So there's a string. It's gzipped and base64 encoded, and the code decodes the base64 and then uncompresses it.
When that's done, I am resulted with this:
<? eval(base64_decode('...')); ?>
Another layer of base64, which is 720440 bytes long.
Now, base64 decoding that, we have 506961 bytes of exploit code.
I'm still examining the code, and will update this answer when I have more understanding. The code is huge.
Still reading through the code, and the (very well-done) exploit allows these tools to be exposed to the hacker:
TCP backdoor setup
unauthorised shell access
reading of all htpasswd, htaccess, password and configuration files
log wiping
MySQL access (read, write)
append code to all files matching a name pattern (mass exploit)
RFI/LFI scanner
UDP flooding
kernel information
This is probably a professional PHP-based server-wide exploit toolkit, and seeing as it's got a nice HTML interface and the whole lot, it could be easily used by a pro hacker, or even a script kiddie.
This exploit is called c99shell (thanks Yi Jiang) and it turns out to have been quite popular, being talked about and running for a few years already. There are many results on Google for this exploit.
Looking at Delan's decoded source, it appears to be a full-fledged backdoor providing a web interface that can be used to control the server in various ways. Telling fragments from the source:
echo '<center>Are you sure you want to install an IP:Port proxy on this
website/server?<br />
or
<b>Mass Code Injection:</b><br><br>
Use this to add PHP to the end of every .php page in the directory specified.
or
echo "<br><b>UDP Flood</b><br>Completed with $pakits (" .
round(($pakits*65)/1024, 2) . " MB) packets averaging ".
round($pakits/$exec_time, 2) . " packets per second \n";
or
if (!$fp) {echo "Can't get /etc/passwd for password-list.";}
I'd advise you to scrub that server and reinstall everything from scratch.
I know Delan Azabani has done this, but just so you actually know how he got the data out:
Just in case you're wondering how to decompress this, use base64 -d filename > output to parse base64 strings and gunzip file.name.gz to parse gzipped data.
The trick is in recognising that what you've got is base64 or gunzip and decompressing the right bits.
This way it goes absolutely nowhere near a JS parser or PHP parser.
First, replace the eval with an echo to see what code it would execute if you'd let it.
Send the output of that script to another file, say, test2.php.
In that file, do the same trick again. Run it, and it will output the complete malicious program (it's quite a beast), ~4k lines of hacker's delight.
This is code for php shell.
to decode this
replace replace eval("?>". with print(
run this
php5 file.php > file2.php
then replace eval with print and run in browser. http://loclhost/file2.php

GWT with -noserver

I'm making a GWT project that uses PHP to connect to a DB2 database. When I compile the project and deploy it to the server (copy the contents of the WAR directory over), it works fine, obviously in hosted mode I run into the SOP issue since GWT is on port 8888 while the php script is running on port 80.
I'm trying to get the -noserver option to work but I must be missing something.. I went back and created the basic sample app from the command line (webApplicationCreator -out /home/mike/gwt/sample1)
I edited the build.xml to include the -noserver and -port 80 arguements for devmode. I want my app to be hosted at localhost/sample1 so I edited the -startupUrl to the whole URL I want to use: http://localhost/sample1/sample1.html
I compiled (ant), copied over the sample1.html, sample1.css from war to the webserver sample1 directory, and the (md5).gwt.rpc, clear.cache.gif, sample1.nocache.js and hosted.html files from the war/sample1 to sample1/sample1 directory as described in the GWT documentation (no history.html file was created).
I then run ant devmode from the project directory (/home/mike/gwt/sample1)
I can get to the sample1.html page, but when I click the button to send the name to the server it returns with
Remote Procedure Call - Failure
Server replies:
An error occurred while attempting to contact the server. Please check your network connection and try again.
I turned on firebug and it's returning a 404 for http://localhost/sample1/sample1/greet. This is where I'm stuck.. this file obviously doesn't exist on my webserver.. but why? Isn't this something that is supposed to be getting compiled by GWT?
Can anyone give me a hand? Thanks!
So, basically you've copied over the client-side of a client/server application. When your GWT client application attempts to make a Remote Procedure Call (RPC) to the server to a greeting service that is part of the initial sample, it can't find that service.
If you wanted to copy that service over, you'd need to have a Java application server, copy over the GreetingService, the web.xml that references it and possibly a few other things (I'd have to check in more detail). That doesn't sound like what you actually want, so either you'll want to build a GWT-RPC service in PHP that responds to that URL, or remove the reference in the GWT code to RPC call to the greeting service.
With a PHP back-end, you're probably not going to use GWT-RPC, I'm guessing that you're more likely to use JSON or XML, and if that's the case, then I'd go with removing the RPC call altogether for now.
Does this all make sense? Feel free to ask for further clarification.
To solve the SOP issue, I used the HttpProxyServlet to proxy the HTTP requests to my webserver through the development server.
Download httpProxyPackage.jar, copy it into WEB-INF/lib/, and configure it like so in WEB-INF/web.xml (this is for the StockWatcher tutorial, assuming your web root is the folder that contains the StockWatcher directory):
<servlet>
<servlet-name>jsonStockData</servlet-name>
<servlet-class>com.jsos.httpproxy.HttpProxyServlet</servlet-class>
<init-param>
<param-name>host</param-name>
<param-value>http://localhost/StockWatcher/war/stockPrices.php</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>jsonStockData</servlet-name>
<!--
http://127.0.0.1:8888/stockPrices.php in dev mode
http://gwt/StockWatcher/war/stockPrices.php in prod mode
-->
<url-pattern>/stockPrices.php</url-pattern>
</servlet-mapping>
Then redefine your JSON URL as:
GWT.getHostPageBaseURL() + "stockPrices.php?q=";
instead of:
GWT.getModuleBaseURL() + "stockPrices.php?q=";
It’s maybe not the best way, but if it can get someone else started… There was another way using php-cgi, but I didn’t have it installed.

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