<!DOCTYPE HTML> <html> <head> <meta charset="utf-8"> <meta http-equiv="Content-Security-Policy" content= "img-src 'none'; script-src 'unsafe-inline'; report-uri http://www.example.com; frame-ancestors https:; sandbox allow-scripts"> <title>Bug 663570 - Implement Content Security Policy via meta tag</title> </head> <body> <!-- try to load an image which is forbidden by meta CSP --> <img id="testimage" src="http://mochi.test:8888/tests/image/test/mochitest/blue.png"></img> <script type="application/javascript"> var myImg = document.getElementById("testimage"); myImg.onload = function(e) { window.parent.postMessage({result: "img-loaded"}, "*"); }; myImg.onerror = function(e) { window.parent.postMessage({result: "img-blocked"}, "*"); }; </script> </body> </html>