CODEWITHSUNDEEP
php
Simon
Simon

Reputation: 23159

what is the usage of the following function?

Take a look to this function please

function CheckHost()
{
    $url = parse_url($_SERVER['HTTP_REFERER']);
    $host = $url['host'];
    if($host == $_SERVER['SERVER_NAME'])
        return true;
    return false;
}

i saw it somewhere, but can't understand it's usage.

is it for security reasons, or what?(as i see, it just verify is the last request from the same server as the script)

Thanks for attention

Upvotes: 1

Views: 64

Answers (4)

Christian Smorra
Christian Smorra

Reputation: 1754

It checks whether the referer is equal to the script location, basically its function is probably to prevent hotlinking.

Upvotes: 0

rook
rook

Reputation: 67004

This can be used for CSRF protection. The Referer will always be of a differnt domain and thus CheckHost() will return false.

Upvotes: 0

GrandmasterB
GrandmasterB

Reputation: 3455

It looks like its checking to see that the referrer is the same host name as the request. This is probably used for something like preventing other sites from directly linking to images or other content.

Upvotes: 0

BoltClock
BoltClock

Reputation: 724592

I suppose it's a simple check against cross-site request forgeries (CSRFs), or as others say, hotlinking. The PHP script calling this function would have to be executed on every HTTP request to the server in order to check for hotlinking, though.

Upvotes: 2

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