background.js

var defaultRgx =  ["<all_urls>","*://*/*","https://*.w3schools.com/*"].join('\n')
var theRegex = null;
var headersdo = {
		"content-security-policy":(x=>{return false}),
		"x-frame-options":(x=>{return false})
	}

function updateRegexpes()
{
	browser.storage.local.get(null, function(res) {
		var  regstr = (res.regstr_allowed || defaultRgx);
		browser.webRequest.onHeadersReceived.removeListener(setHeader)
		if(!res.is_disabled)
		{
			theRegex = new RegExp(
				regstr.split("\n").map(
					x=>x.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')	// Sanitize regex
						.replace(/(^<all_urls>|\\\*)/g,"(.*?)")	// Allow wildcards
						.replace(/^(.*)$/g,"^$1$")).join("|")	// User multi match
				)
			browser.webRequest.onHeadersReceived.addListener(
				setHeader,
				{urls :["<all_urls>"], types:["sub_frame","object"]},
				["blocking", "responseHeaders"]
			);
		}
	});
}

function setHeader(e) {
	return new Promise((resolve, reject)=>
	{
		browser.webNavigation.getFrame({tabId:e.tabId,frameId:e.parentFrameId})
		.then(parentFrame=>{
			if(parentFrame.url.match(theRegex))
			{
				e.responseHeaders=e.responseHeaders.filter(x=>(headersdo[x.name.toLowerCase()]||Array)())
			}
		  	resolve({responseHeaders: e.responseHeaders});
		})
	})
}
updateRegexpes();
var portFromCS;
function connected(p) {
	portFromCS = p;
	portFromCS.onMessage.addListener(function(m) {
			browser.storage.local.set(m,updateRegexpes);
	});
}
browser.runtime.onConnect.addListener(connected);
console.log("LOADED");