/* * Copyright (C) 2020 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ class RequestBuilder { constructor() { this._extraHeadersSupported = null; this._onBeforeSendHeadersExtraInfoSpec = ['blocking', 'requestHeaders', 'extraHeaders']; this._textEncoder = new TextEncoder(); this._ruleIds = new Set(); } async prepare() { try { await this._clearDynamicRules(); } catch (e) { // NOP } } async fetchAnonymous(url, init) { if (isObject(chrome.declarativeNetRequest)) { return await this._fetchAnonymousDeclarative(url, init); } const originURL = this._getOriginURL(url); const modifications = [ ['cookie', null], ['origin', {name: 'Origin', value: originURL}] ]; return await this._fetchModifyHeaders(url, init, modifications); } // Private async _fetchModifyHeaders(url, init, modifications) { const matchURL = this._getMatchURL(url); let done = false; const callback = (details) => { if (done || details.url !== url) { return {}; } done = true; const requestHeaders = details.requestHeaders; this._modifyHeaders(requestHeaders, modifications); return {requestHeaders}; }; const filter = { urls: [matchURL], types: ['xmlhttprequest'] }; let needsCleanup = false; try { this._onBeforeSendHeadersAddListener(callback, filter); needsCleanup = true; } catch (e) { // NOP } try { return await fetch(url, init); } finally { if (needsCleanup) { try { chrome.webRequest.onBeforeSendHeaders.removeListener(callback); } catch (e) { // NOP } } } } _onBeforeSendHeadersAddListener(callback, filter) { const extraInfoSpec = this._onBeforeSendHeadersExtraInfoSpec; for (let i = 0; i < 2; ++i) { try { chrome.webRequest.onBeforeSendHeaders.addListener(callback, filter, extraInfoSpec); if (this._extraHeadersSupported === null) { this._extraHeadersSupported = true; } break; } catch (e) { // Firefox doesn't support the 'extraHeaders' option and will throw the following error: // Type error for parameter extraInfoSpec (Error processing 2: Invalid enumeration value "extraHeaders") for webRequest.onBeforeSendHeaders. if (this._extraHeadersSupported !== null || !`${e.message}`.includes('extraHeaders')) { throw e; } } // addListener failed; remove 'extraHeaders' from extraInfoSpec. this._extraHeadersSupported = false; const index = extraInfoSpec.indexOf('extraHeaders'); if (index >= 0) { extraInfoSpec.splice(index, 1); } } } _getMatchURL(url) { const url2 = new URL(url); return `${url2.protocol}//${url2.host}${url2.pathname}`; } _getOriginURL(url) { const url2 = new URL(url); return `${url2.protocol}//${url2.host}`; } _modifyHeaders(headers, modifications) { modifications = new Map(modifications); for (let i = 0, ii = headers.length; i < ii; ++i) { const header = headers[i]; const name = header.name.toLowerCase(); const modification = modifications.get(name); if (typeof modification === 'undefined') { continue; } modifications.delete(name); if (modification === null) { headers.splice(i, 1); --i; --ii; } else { headers[i] = modification; } } for (const header of modifications.values()) { if (header !== null) { headers.push(header); } } } async _clearDynamicRules() { if (!isObject(chrome.declarativeNetRequest)) { return; } const rules = this._getDynamicRules(); if (rules.length === 0) { return; } const removeRuleIds = []; for (const {id} of rules) { removeRuleIds.push(id); } await this._updateDynamicRules({removeRuleIds}); } async _fetchAnonymousDeclarative(url, init) { const id = this._getNewRuleId(); const originUrl = this._getOriginURL(url); url = encodeURI(decodeURI(url)); this._ruleIds.add(id); try { const addRules = [{ id, priority: 1, condition: { urlFilter: `|${this._escapeDnrUrl(url)}|`, resourceTypes: ['xmlhttprequest'] }, action: { type: 'modifyHeaders', requestHeaders: [ { operation: 'remove', header: 'Cookie' }, { operation: 'set', header: 'Origin', value: originUrl } ], responseHeaders: [ { operation: 'remove', header: 'Set-Cookie' } ] } }]; await this._updateDynamicRules({addRules}); try { return await fetch(url, init); } finally { await this._tryUpdateDynamicRules({removeRuleIds: [id]}); } } finally { this._ruleIds.delete(id); } } _getDynamicRules() { return new Promise((resolve, reject) => { chrome.declarativeNetRequest.getDynamicRules((result) => { const e = chrome.runtime.lastError; if (e) { reject(new Error(e.message)); } else { resolve(result); } }); }); } _updateDynamicRules(options) { return new Promise((resolve, reject) => { chrome.declarativeNetRequest.updateDynamicRules(options, () => { const e = chrome.runtime.lastError; if (e) { reject(new Error(e.message)); } else { resolve(); } }); }); } async _tryUpdateDynamicRules(options) { try { await this._updateDynamicRules(options); return true; } catch (e) { return false; } } _getNewRuleId() { let id = 1; while (this._ruleIds.has(id)) { const pre = id; ++id; if (id === pre) { throw new Error('Could not generate an id'); } } return id; } _escapeDnrUrl(url) { return url.replace(/[|*^]/g, (char) => this._urlEncodeUtf8(char)); } _urlEncodeUtf8(text) { const array = this._textEncoder.encode(text); let result = ''; for (const byte of array) { result += `%${byte.toString(16).toUpperCase().padStart(2, '0')}`; } return result; } }