// ==UserScript==
// @name         KindleMangaDownloader
// @namespace    https://github.com/Timesient/manga-download-scripts
// @version      0.6
// @license      GPL-3.0
// @author       Timesient
// @description  Manga downloader for read.amazon.co.jp
// @icon         https://m.media-amazon.com/images/G/01/kfw/mobile/kindle_favicon.png
// @homepageURL  https://greasyfork.org/scripts/451870-kindlemangadownloader
// @supportURL   https://github.com/Timesient/manga-download-scripts/issues
// @match        https://read.amazon.co.jp/manga/*
// @require      https://unpkg.com/axios@0.27.2/dist/axios.min.js
// @require      https://unpkg.com/jszip@3.7.1/dist/jszip.min.js
// @require      https://unpkg.com/file-saver@2.0.5/dist/FileSaver.min.js
// @require      https://update.greasyfork.org/scripts/451810/1398192/ImageDownloaderLib.js
// @grant        GM_info
// @grant        GM_xmlhttpRequest
// ==/UserScript==
(async function(axios, JSZip, saveAs, ImageDownloader) {
'use strict';
// collect essential data
const { asin, revision, pageAmount } = await new Promise(resolve => {
const timer = setInterval(() => {
const target1 = document.querySelector('#requestData');
const target2 = document.querySelector('#bookInfo');
const target3 = document.querySelector('#pageInfoCurrentPage');
const target4 = document.querySelector('#pageInfoTotalPage');
if (target1 && target2 && target3 && target4 && parseInt(target3.textContent) !== 0 && parseInt(target4.textContent) !== 1) {
clearInterval(timer);
resolve({
asin: JSON.parse(target1.textContent).asin,
revision: JSON.parse(target2.textContent).contentGuid,
pageAmount: parseInt(target4.textContent)
});
}
}, 200);
});
// get book info and build parameters
const bookInfo = await axios.get(`https://read.amazon.co.jp/api/manga/open-next-book/${asin}`).then(res => res.data);
const params = {
version: '3.0',
asin,
contentType: 'FullBook',
revision,
fontFamily: 'Bookerly',
fontSize: 4.95,
lineHeight: 1.4,
dpi: 160,
height: 923,
width: 400,
maxNumberColumns: 2,
theme: 'dark',
packageType: 'TAR',
numPage: -1 * pageAmount,
skipPageCount: pageAmount,
startingPosition: 0,
token: bookInfo.karamelToken.token
}
// get pages
const pages = [].concat(
await getPages(params),
await getPages({ ...params, numPage: 1 }),
);
// setup ImageDownloader
ImageDownloader.init({
maxImageAmount: pages.length,
getImagePromises,
title: bookInfo.title
});
// collect promises of image
function getImagePromises(startNum, endNum) {
return pages
.slice(startNum - 1, endNum)
.map(page => getDecryptedImage(page)
.then(ImageDownloader.fulfillHandler)
.catch(ImageDownloader.rejectHandler)
)
}
// get decrypted image
async function getDecryptedImage(page) {
const src = `${page.baseUrl}/${page.url}?${page.authParameter}&token=${encodeURIComponent(bookInfo.karamelToken.token)}&expiration=${encodeURIComponent(bookInfo.karamelToken.expiresAt)}`;
const encryptedBuffer = await fetch(src).then(res => res.arrayBuffer());
const decryptedBuffer = await getDecryptedBuffer(encryptedBuffer, bookInfo.karamelToken);
return new Blob([decryptedBuffer]);
}
async function getDecryptedBuffer(t, e) {
const n = new TextDecoder('utf-8');
const o = new TextEncoder;
const r = n.decode(t);
const a = r.slice(0, 24);
const c = r.slice(24, 48);
const h = r.slice(48, r.length);
const l = base64StringToArrayBuffer(a);
const d = base64StringToArrayBuffer(c);
const u = base64StringToArrayBuffer(h);
const g = getKey(e);
const v = await window.crypto.subtle.importKey("raw", o.encode(g), { name: "PBKDF2" }, false, ["deriveBits", "deriveKey"]);
const p = await window.crypto.subtle.deriveKey({ name: "PBKDF2", salt: l, iterations: 1e3, hash: "SHA-256" }, v, { name: "AES-GCM", length: 128 }, false, ["decrypt"]);
return await window.crypto.subtle.decrypt({
name: "AES-GCM",
iv: d,
additionalData: o.encode(g.slice(0, 9)),
tagLength: 128
}, p, u);
}
function base64StringToArrayBuffer(base64) {
const origin = window.atob(base64);
const r###lt = new Uint8Array(origin.length);
for (let i = 0; i < origin.length; i++) {
r###lt[i] = origin.charCodeAt(i);
}
return r###lt.buffer;
}
function getKey(t) {
if (t.token.length < 100) throw new Error('error in getKey');
const i = t.expiresAt % 60;
return t.token.substring(i, i + 40);
}
// request pages from API
async function getPages(params) {
const apiURL = `https://read.amazon.co.jp/renderer/render?${new URLSearchParams(params)}`;
const tarString = await axios.get(apiURL).then(res => res.data.replaceAll('\u0000', ''));
const manifest = JSON.parse(`{` + tarString.match(/"cdnResources".*"acr"/)[0] + `: "acr content" }`);
return manifest.cdnResources.map(page => {
page.baseUrl = manifest.cdn.baseUrl;
page.authParameter = manifest.cdn.authParameter;
page.order = parseInt(page.url.replace('resource/rsrc', ''), 36);
return page;
}).sort((a, b) => a.order - b.order);
}
})(axios, JSZip, saveAs, ImageDownloader);