/** * Hachette main content script run in all frames * * Copyright (C) 2021 Wojtek Kosior * Copyright (C) 2021 jahoti * Redistribution terms are gathered in the `copyright' file. */ /* * IMPORTS_START * IMPORT handle_page_actions * IMPORT extract_signed * IMPORT sign_data * IMPORT gen_nonce * IMPORT is_privileged_url * IMPORT is_chrome * IMPORT is_mozilla * IMPORT start_activity_info_server * IMPORT csp_rule * IMPORT is_csp_header_name * IMPORT sanitize_csp_header * IMPORTS_END */ function extract_cookie_policy(cookie, min_time) { let best_result = {time: -1}; let policy = null; const extracted_signatures = []; for (const match of cookie.matchAll(/hachette-(\w*)=([^;]*)/g)) { const new_result = extract_signed(...match.slice(1, 3)); if (new_result.fail) continue; extracted_signatures.push(match[1]); if (new_result.time < Math.max(min_time, best_result.time)) continue; /* This should succeed - it's our self-produced valid JSON. */ const new_policy = JSON.parse(decodeURIComponent(new_result.data)); if (new_policy.url !== document.URL) continue; best_result = new_result; policy = new_policy; } return [policy, extracted_signatures]; } function extract_url_policy(url, min_time) { const [base_url, payload, anchor] = /^([^#]*)#?([^#]*)(#?.*)$/.exec(url).splice(1, 4); const match = /^hachette_([^_]+)_(.*)$/.exec(payload); if (!match) return [null, url]; const result = extract_signed(...match.slice(1, 3)); if (result.fail) return [null, url]; const original_url = base_url + anchor; const policy = result.time < min_time ? null : JSON.parse(decodeURIComponent(result.data)); return [policy.url === original_url ? policy : null, original_url]; } function employ_nonhttp_policy(policy) { if (!policy.allow) return; policy.nonce = gen_nonce(); const [base_url, target] = /^([^#]*)(#?.*)$/.exec(policy.url).slice(1, 3); const encoded_policy = encodeURIComponent(JSON.stringify(policy)); const payload = "hachette_" + sign_data(encoded_policy, new Date().getTime()).join("_"); const resulting_url = `${base_url}#${payload}${target}`; location.href = resulting_url; location.reload(); } /* * 1. When injecting some payload we need to sanitize CSP tags before * they reach the document. * 2. Only tags inside are considered valid by the browser and * need to be considered. * 3. We want to detach from document, wait until its completes * loading, sanitize it and re-attach . * 4. Browsers are eager to add 's that appear after `' but before * `'. Due to this behavior the `DOMContentLoaded' event is considered * unreliable (although it could still work properly, it is just problematic * to verify). * 5. We shall wait for anything to appear in or after and take that as * a sign has _really_ finished loading. */ function make_body_start_observer(DOM_element, waiting) { const observer = new MutationObserver(() => try_body_started(waiting)); observer.observe(DOM_element, {childList: true}); return observer; } function try_body_started(waiting) { const body = waiting.detached_html.querySelector("body"); if ((body && (body.firstChild || body.nextSibling)) || waiting.doc.documentElement.nextSibling) { finish_waiting(waiting); return true; } if (body && waiting.observers.length < 2) waiting.observers.push(make_body_start_observer(body, waiting)); } function finish_waiting(waiting) { waiting.observers.forEach(observer => observer.disconnect()); waiting.doc.removeEventListener("DOMContentLoaded", waiting.loaded_cb); setTimeout(waiting.callback, 0); } function _wait_for_head(doc, detached_html, callback) { const waiting = {doc, detached_html, callback, observers: []}; /* * For XML and SVG documents, instead of waiting for `', we wait * for the entire document to finish loading. */ if (doc instanceof HTMLDocument) { if (try_body_started(waiting)) return; waiting.observers = [make_body_start_observer(detached_html, waiting)]; } waiting.loaded_cb = () => finish_waiting(waiting); doc.addEventListener("DOMContentLoaded", waiting.loaded_cb); } function wait_for_head(doc, detached_html) { return new Promise(cb => _wait_for_head(doc, detached_html, cb)); } const blocked_str = "blocked"; function block_attribute(node, attr) { /* * Disabling attributes this way allows them to still be relatively * easily accessed in case they contain some useful data. */ const construct_name = [attr]; while (node.hasAttribute(construct_name.join(""))) construct_name.unshift(blocked_str); while (construct_name.length > 1) { construct_name.shift(); const name = construct_name.join(""); node.setAttribute(`${blocked_str}-${name}`, node.getAttribute(name)); } node.removeAttribute(attr); } function sanitize_meta(meta, policy) { const http_equiv = meta.getAttribute("http-equiv"); const value = meta.content; if (!value || !is_csp_header_name(http_equiv, true)) return; block_attribute(meta, "content"); if (is_csp_header_name(http_equiv, false)) meta.content = sanitize_csp_header({value}, policy).value; } function sanitize_script(script) { script.hachette_blocked_type = script.type; script.type = "text/plain"; } /* * Executed after script has been connected to the DOM, when it is no longer * eligible for being executed by the browser */ function desanitize_script(script, policy) { script.setAttribute("type", script.hachette_blocked_type); if (script.hachette_blocked_type === undefined) script.removeAttribute("type"); delete script.hachette_blocked_type; } function apply_hachette_csp_rules(doc, head, policy) { const meta = doc.createElement("meta"); meta.setAttribute("http-equiv", "Content-Security-Policy"); meta.setAttribute("content", csp_rule(policy.nonce)); head.append(meta); /* CSP is already in effect, we can remove the now. */ meta.remove(); } function sanitize_urls(element) { for (const attribute of [...element.attributes]) { if (/^(href|src|data)$/i.test(attribute.localName) && /^data:([^,;]*ml|unknown-content-type)/i.test(attribute.value)) block_attribute(element, attribute.localName); } } function start_data_urls_sanitizing(doc) { doc.querySelectorAll("*[href], *[src], *[data]").forEach(sanitize_urls); const mutation_handler = m => m.addedNodes.forEach(sanitize_urls); const mo = new MutationObserver(ms => ms.forEach(mutation_handler)); mo.observe(doc, {childList: true, subtree: true}); } function apply_intrinsics_sanitizing(root_element) { for (const subelem of root_element.querySelectorAll("*")) { [...subelem.attributes] .filter(a => /^on/i.test(a.localName)) .filter(a => /^javascript:/i.test(a.value)) .forEach(a => block_attribute(subelem, a.localName)); } } async function sanitize_document(doc, policy) { /* * Blocking of scripts that are in the DOM from the beginning. Needed for * Mozilla, harmless on Chromium. * Note that at least in SVG documents the `src' attr on `