Block requests via intermediate host names at nginx

Question

I have a setup where users are supposed to send requests to A.com. Requests are sent to a CDN which further sends request to A-reader.com, and A-reader routes the request to nginx.

I want A-reader to be accessible only via CDN, so, the aim is to block any request where original request url is not A.com. If any user types A-reader.com/<anything> in browser address bar, requests should be blocked at nginx

Is this possible?

score 1 · Accepted Answer · edited May 23 '17 at 10:27

Yes - You can use the nginx http referrer module - http://nginx.org/en/docs/http/ngx_http_referer_module.html

In your case, since you only want to allow A.com, the configuration should be something like:

valid_referers *.A.com;
if ($invalid_referer) {
    return 403;
}

You'll have to customize the valid referral list to match your domain.

Alternatively, you can do regex matching on $http_referer:

 if ($http_referer ~* (babes|click|diamond|forsale|girl|jewelry|love|nudit|poker|porn))
    {  return 403;   }

(HTTP referer from https://calomel.org/nginx.html via How to block referral spam using Nginx?)

Thanks. I ended up using a similar approach. I used $host header instead, and it worked for me — patentfox, Apr 24 '15 at 06:28

Block requests via intermediate host names at nginx

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