amdl/src/downloader/keygen.ts

48 lines
2.2 KiB
TypeScript

import { LicenseType, Session } from "node-widevine";
import { env } from "../config.js";
import { appleMusicApi } from "../api/index.js";
import { dataUriToBuffer } from "data-uri-to-buffer";
import * as log from "../log.js";
import fs from "node:fs";
import * as psshTools from "pssh-tools";
export async function getWidevineDecryptionKey(psshDataUri: string, trackId: string): Promise<void> {
let pssh = Buffer.from(dataUriToBuffer(psshDataUri).buffer);
const privateKey = Buffer.from(env.WIDEVINE_PRIVATE_KEY, "base64");
const identifierBlob = Buffer.from(env.WIDEVINE_CLIENT_ID, "base64");
let session = new Session({ privateKey, identifierBlob }, pssh);
let challenge: Buffer;
try {
challenge = session.createLicenseRequest(LicenseType.STREAMING);
} catch (err) {
// for some reason, if gotten from a webplayback manifest, the pssh is in a completely different format
// well, somewhat. we have to rebuild the pssh
const rebuiltPssh = psshTools.widevine.encodePssh({
contentId: "Hiiii", // lol?? i don't know what this is, random slop go!!!!
dataOnly: false,
keyIds: [Buffer.from(dataUriToBuffer(psshDataUri).buffer).toString("hex")]
});
log.warn("pssh was invalid, treating it as raw data");
log.warn("this should not error, unless the pssh data is invalid, too");
pssh = Buffer.from(rebuiltPssh, "base64");
session = new Session({ privateKey, identifierBlob }, pssh);
challenge = session.createLicenseRequest(LicenseType.STREAMING);
}
const response = await appleMusicApi.getWidevineLicense(
trackId,
psshDataUri,
challenge.toString("base64")
);
if (typeof response?.license !== "string") { throw "license is missing or not a string! sign that authentication failed (unsupported codec?)"; }
const license = session.parseLicense(Buffer.from(response.license, "base64"));
if (license.length === 0) { throw "license(s) failed to be parsed. this could be an error for invalid data! (e.x. pssh/challenge)"; }
log.info(license);
fs.writeFileSync("license", response.license, { encoding: "utf-8" });
}