This script decodes Google News generated encoded, internal URLs for RSS items

decodeGoogleNewsUrl.ts

/**
 * This magically uses batchexecute protocol. It's not documented, but it works.
 * 
 * Licensed under: MIT License
 *
 * Copyright (c) 2024 Ruslan Gainutdinov
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
const fetchDecodedBatchExecute = (id: string) => {
  const s =
    '[[["Fbv4je","[\\"garturlreq\\",[[\\"en-US\\",\\"US\\",[\\"FINANCE_TOP_INDICES\\",\\"WEB_TEST_1_0_0\\"],null,null,1,1,\\"US:en\\",null,180,null,null,null,null,null,0,null,null,[1608992183,723341000]],\\"en-US\\",\\"US\\",1,[2,3,4,8],1,0,\\"655000234\\",0,0,null,0],\\"' +
    id +
    '\\"]",null,"generic"]]]';

  return fetch("https://news.google.com/_/DotsSplashUi/data/batchexecute?" + "rpcids=Fbv4je", {
    headers: {
      "Content-Type": "application/x-www-form-urlencoded;charset=utf-8",
      Referrer: "https://news.google.com/"
    },
    body: "f.req=" + encodeURIComponent(s),
    method: "POST"
  })
    .then(e => e.text())
    .then(s => {
      const header = '[\\"garturlres\\",\\"';
      const footer = '\\",';
      if (!s.includes(header)) {
        throw new Error("header not found: " + s);
      }
      const start = s.substring(s.indexOf(header) + header.length);
      if (!start.includes(footer)) {
        throw new Error("footer not found");
      }
      const url = start.substring(0, start.indexOf(footer));
      return url;
    });
};

/**
 * Google News started generate encoded, internal URLs for RSS items
 * https://news.google.com/rss/search?q=New%20York%20when%3A30d&hl=en-US&gl=US&ceid=US:en
 *
 * This script decodes URLs into original one, for example URL
 * https://news.google.com/__i/rss/rd/articles/CBMiSGh0dHBzOi8vdGVjaGNydW5jaC5jb20vMjAyMi8xMC8yNy9uZXcteW9yay1wb3N0LWhhY2tlZC1vZmZlbnNpdmUtdHdlZXRzL9IBAA?oc=5
 *
 * contains this
 * https://techcrunch.com/2022/10/27/new-york-post-hacked-offensive-tweets/
 *
 * In path after articles/ goes Base64 encoded binary data
 *
 * Format is the following:
 * <prefix> <len bytes> <URL bytes> <len bytes> <amp URL bytes> [<suffix>]
 *
 * <prefix> - 0x08, 0x13, 0x22
 * <suffix> - 0xd2, 0x01, 0x00 (sometimes missing??)
 * <len bytes> - formatted as 0x40 or 0x81 0x01 sometimes
 *
 *
 * https://news.google.com/rss/articles/CBMiqwFBVV95cUxNMTRqdUZpNl9hQldXbGo2YVVLOGFQdkFLYldlMUxUVlNEaElsYjRRODVUMkF3R1RYdWxvT1NoVzdUYS0xSHg3eVdpTjdVODQ5cVJJLWt4dk9vZFBScVp2ZmpzQXZZRy1ncDM5c2tRbXBVVHVrQnpmMGVrQXNkQVItV3h4dVQ1V1BTbjhnM3k2ZUdPdnhVOFk1NmllNTZkdGJTbW9NX0k5U3E2Tkk?oc=5
 * https://news.google.com/rss/articles/CBMidkFVX3lxTFB1QmFsSi1Zc3dLQkpNLThKTXExWXBGWlE0eERJQ2hLRENIOFJzRTlsRnM1NS1Hc2FlbjdIMlZ3eWNQa0JqeVYzZGs1Y0hKaUtTUko2dmJabUtVMWZob0lNSFNCa3NLQ05ROGh4cVZfVTYyUDVxc2c?oc=5
 * https://news.google.com/rss/articles/CBMiqwFBVV95cUxNMTRqdUZpNl9hQldXbGo2YVVLOGFQdkFLYldlMUxUVlNEaElsYjRRODVUMkF3R1RYdWxvT1NoVzdUYS0xSHg3eVdpTjdVODQ5cVJJLWt4dk9vZFBScVp2ZmpzQXZZRy1ncDM5c2tRbXBVVHVrQnpmMGVrQXNkQVItV3h4dVQ1V1BTbjhnM3k2ZUdPdnhVOFk1NmllNTZkdGJTbW9NX0k5U3E2Tkk?oc=5
 *
 * FIXME: What will happen if URL more than 255 bytes??
 *
 * Licensed under: MIT License
 *
 * Copyright (c) 2022 Ruslan Gainutdinov
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
export const decodeGoogleNewsUrl = async (sourceUrl: string) => {
  const url = new URL(sourceUrl);
  const path = url.pathname.split("/");
  if (
    url.hostname === "news.google.com" &&
    path.length > 1 &&
    path[path.length - 2] === "articles"
  ) {
    const base64 = path[path.length - 1];
    let str = atob(base64);

    const prefix = Buffer.from([0x08, 0x13, 0x22]).toString("binary");
    if (str.startsWith(prefix)) {
      str = str.substring(prefix.length);
    }

    const suffix = Buffer.from([0xd2, 0x01, 0x00]).toString("binary");
    if (str.endsWith(suffix)) {
      str = str.substring(0, str.length - suffix.length);
    }

    // One or two bytes to skip
    const bytes = Uint8Array.from(str, c => c.charCodeAt(0));
    const len = bytes.at(0)!;
    if (len >= 0x80) {
      str = str.substring(2, len + 2);
    } else {
      str = str.substring(1, len + 1);
    }

    if (str.startsWith("AU_yqL")) {
      // New style encoding, introduced in July 2024. Not yet known how to decode offline.
      const url = await fetchDecodedBatchExecute(base64);
      return url;
    }

    return str;
  } else {
    return sourceUrl;
  }
};