Enable third-party cookies and site data for certain domains

I want example.com to be able to write and read third-party cookies and site data but no other domain may access any other domain's cookies and site data. It is only possible to globally enable/disable third-party cookies and site data.

Ideally, I can even fine-tune access as in:

• example.com may access cookies and data of web.example.com
• example.com may access cookies of elpmaxe.com
• all other third-party access is blocked

Is there an extension that supports this? How to configure it? Open source preferred.

An incomplete workaround is to have a Chrome profile in which you:

• enable third party cookies and site data
• only visit example.com and the websites, of which it should be able to access their data
• accept that the other website will be able to read example.com's cookies and data

Solution 1:

You can do that easily with uMatrix.

This free and open-source browser extension is available:

• for Google Chrome, and all Chromium-based browsers (Chromium, Vivaldi...)
• for Firefox
• for Opera

Example: Check the "Cookie" column on this following screenshot.

• Green color = cookie authorized
• Red color = cookie blocked

Solution 2:

For me, the section "Sites that can always use cookies" worked:

I enabled the checkbox "All cookies, on this site only".