Showmyip.com

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yann

Apr 3 2005, 02:33 PM

Hi,

It's maybe a new bee question, but how does showmyip.com manage to find the good ip address even through an anonymous proxy connection.

Do they use a java script on the site? or they do a X-Forwarded request?

All other ip sites shows my proxy address not my ISP address.

Thanks,

AgentOrange

Apr 3 2005, 05:48 PM

This isn't a stupid question per say, if this was possible i would want to know how to stop it...

However, I don't have a problem visiting this site anon. I am using FireFox, tor and privoxy, it is possible that privoxy is filtering something out... however from the privoxy logs its just filtering out some google add.

As far as java goes, you can't connect to another ip address other than loopback or the site that you got the java code from, unless you break out of the sandbox. There shouldn't be a way to bypass proxies with java... I browsed though the source and it doesn't look like there is any sneaky code. One thing I would be suspicious of is the site attempting to connect to other browser supported protocols such as gopher, in hopes that it might not be set to use a proxy. However it would be tricky to make a system like that fool proof.

ActiveX is even more strict than java when it comes to sockets, and there isn't any activeX content on that site.

It would be a security risk to have the ability to connect to another ip address. Java and activeX are so rich if you had this peace of the puzzle you could do a lot.

peace

eftex

Apr 16 2005, 07:11 AM

If you deativated javascript, java and ActiveX in your Browser it depents on which kind of Proxy you are using.

Anonymous - HTTP Proxy server does not send HTTP_X_FORWARDED_FOR variable to host, this improves privacy since your IP address cannot be logged.

High anonymity (elite proxy) - HTTP Servers of this type do not send HTTP_X_FORWARDED_FOR, HTTP_VIA and HTTP_PROXY_CONNECTION variables. Host doesn't even know you are using proxy server an of course it doesn't know your IP address.

Pro21

Apr 16 2005, 10:17 AM

IS not a stupid question !!
I had the same problem 3 years ago. I seen when i am using a proxy in my brower and if i am directly connectly to internet with this computer, the proxy doesn t work correctly ....
Work fine behind a nat router or anything else like that

Or you can use a software who check proxy and use them for you. It s a solution

showmyip

Aug 8 2005, 04:36 AM

We just have a smarter script to detect it, though truly anonymous proxies will not reveal it. We do not use javascript, nor java, nor any other protocols besides http or https - just plain PHP (version 4 at present).

st4n

Aug 12 2005, 12:33 AM

try to use

CODE

getenv("HTTP_X_FORWARDED_FOR")

function getip()
{
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");

else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");

else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");

else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];

else
$ip = "unknown";

return($ip);
}

(source from http://www.php.net/manual/de/function.getenv.php)

setthesun

Aug 12 2005, 03:43 PM

QUOTE(yann @ Apr 3 2005, 02:33 PM)

I'm testing some proxies though showmyip and it can not dedect. It must be related though your proxy check it with other proxies. Also check out that your browser using proxy for SSL connections.

IcedOut3E

Aug 12 2005, 05:56 PM

I tested it through hxxp://www.proxify.com/ and it didn't show my real IP. Maybe its different when you use a program or through your browser.

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