NGINX X-Frame-Options allow only from single page

Question

I am trying to setup my vHost to allow iframes from only one subdomain of our network. Before we had:

add_header X-Frame-Options "SAMEORIGIN"; on all our pages.

To accomplish what I want to do I tried:

add_header X-Frame-Options https://somewebsite.com;

This ends up allowing iframes as wanted but it allows them from every domain not just from https://somewebsite.com.

How can I deny iframes from all external pages but allow them from one subdomain?

Side info:

both sites run on the same machine.

Solution

The RFC for the X-Frame-Options header states that valid options for the header are:

• DENY
• SAMEORIGIN
• ALLOW-FROM <uri>

So, first off you need to add ALLOW-FROM then specify the URI of your subdomain. Something like this:

ALLOW-FROM https://subdomain.example.com/

Comments

[Flatron]

I added add_header X-Frame-Options "ALLOW-FROM https://sub.example.com"; to my vHost configuration file. This ends in the same behaviour as before --> iframing is allowed from any domain. Does the used Browser have an effect on this. I am using Google Chrome (48.0.2564.103)

[heavyd]

See the table at the bottom of this page. Apparently Chrome does not support ALLOW-FROM.

[BDN]

How can I enable multiple URI only?