Initial commit

.gitignore

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+/node_modules
+.DS_Store

LICENSE

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+MIT License
+
+Copyright (c) 2024 Vitaly Gashkov <vitalygashkov@vk.com>
+
+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.

README.md

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+# Crunchys
+
+A utility to extract secrets from Crunchyroll mobile app
+
+## Prerequisites
+
+- [Node.js](https://nodejs.org/en)
+- [jadx](https://github.com/skylot/jadx)
+
+## Installation
+
+```bash
+npm i crunchys
+```
+
+## Usage
+
+#### Library
+
+```js
+import { extractSecrets } from 'crunchys';
+
+const { id, secret, encoded, header } = await extractSecrets();
+
+// Do something with the extracted secrets
+```
+
+#### Command-line interface
+
+```bash
+npx crunchys
+```
+
+## License
+
+MIT

crunchys-cli.js

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+import { extractSecrets } from './crunchys';
+
+(async () => {
+  await extractSecrets();
+})();

crunchys.d.ts

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+export function extractSecrets(): Promise<{
+  // Crunchyroll app ID
+  id: string;
+  // Crunchyroll app secret
+  secret: string;
+  // Base64 encoded `id:secret` string
+  encoded: string;
+  // Basic `Authorization` header to access Crunchyroll mobile APIs
+  header: string;
+}>;

crunchys.js

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+const { join, basename } = require('node:path');
+const { createWriteStream } = require('node:fs');
+const { readdir, readFile, rm } = require('node:fs/promises');
+const { execSync } = require('node:child_process');
+const { Readable } = require('node:stream');
+
+const downloadLatestApk = async () => {
+  const source = 'https://www.apk20.com/apk/com.crunchyroll.crunchyroid/download/';
+  const page = await fetch(source);
+  const html = await page.text();
+  const url = html.split('<link rel="canonical" href="')[1]?.split('"')[0];
+  const id = url.split('/').reverse().at(0);
+  const downloadUrl = `https://srv01.apk20.com/com.crunchyroll.crunchyroid.${id}.xapk`;
+  const fileName = basename(downloadUrl);
+  const response = await fetch(downloadUrl);
+  if (response.ok && response.body) {
+    const filePath = join(process.cwd(), fileName);
+    const writer = createWriteStream(filePath);
+    Readable.fromWeb(response.body).pipe(writer);
+    await new Promise((resolve) => writer.on('finish', resolve));
+  }
+  return join(process.cwd(), fileName);
+};
+
+const decompileApk = (apkPath) => {
+  try {
+    execSync(`jadx ${apkPath}`, { stdio: 'inherit' });
+  } catch (error) {
+    console.error(error);
+  }
+  return apkPath.replace('.xapk', '');
+};
+
+const findConfigurationImpl = async (sourcesDir) => {
+  const entries = await readdir(sourcesDir, { withFileTypes: true });
+  for (const entry of entries) {
+    if (!entry.isDirectory()) continue;
+    const moduleDir = join(sourcesDir, entry.name);
+    const moduleEntries = await readdir(moduleDir, { withFileTypes: true });
+    for (const moduleFile of moduleEntries) {
+      if (moduleFile.isDirectory()) continue;
+      const moduleFilePath = join(moduleDir, moduleFile.name);
+      const moduleContents = await readFile(moduleFilePath, 'utf8');
+      if (moduleContents.includes(' ConfigurationImpl.kt')) {
+        return moduleContents;
+      }
+    }
+  }
+};
+
+const parseSecrets = (contents) => {
+  const lines = contents.split('\n');
+  const startIndex = lines.findIndex((line) => line.includes('https://sso.crunchyroll.com'));
+  const endIndex = lines.findIndex((line) => line.includes('CR-AndroidMobile-SSAI-Prod'));
+  const results = lines
+    .slice(startIndex, endIndex)
+    .map((line) => line.replaceAll(';', ''))
+    .map((line) => line.replaceAll('"', ''))
+    .map((line) => line.split('= ')[1])
+    .map((line) => line.trim());
+  const [, , id, secret] = results;
+  const encoded = Buffer.from(`${id}:${secret}`).toString('base64');
+  const header = `Basic ${encoded}`;
+  return { id, secret, encoded, header };
+};
+
+export const extractSecrets = async ({ cleanup = true } = {}) => {
+  console.log('Downloading latest APK...');
+  const apkPath = await downloadLatestApk();
+
+  console.log('Decompiling APK...');
+  const decompiledDir = decompileApk(apkPath);
+
+  console.log('Searching for secrets...');
+  const sourcesDir = join(decompiledDir, 'sources');
+  const configurationImpl = await findConfigurationImpl(sourcesDir);
+
+  console.log('Parsing secrets...');
+  const { id, secret, encoded, header } = parseSecrets(configurationImpl);
+
+  console.log(`Cleaning up files...`);
+  if (cleanup) await rm(apkPath, { recursive: true, force: true });
+  if (cleanup) await rm(decompiledDir, { recursive: true, force: true });
+
+  console.log(`ID: ${id}`);
+  console.log(`Secret: ${secret}`);
+  console.log(`Encoded ID with secret: ${encoded}`);
+
+  return { id, secret, encoded, header };
+};

package-lock.json

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+{
+  "name": "crunchys",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "crunchys",
+      "version": "1.0.0",
+      "license": "MIT",
+      "bin": {
+        "crunchys": "cli.js"
+      },
+      "devDependencies": {
+        "typescript": "^5.8.2"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "5.8.2",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.8.2.tgz",
+      "integrity": "sha512-aJn6wq13/afZp/jT9QZmwEjDqqvSGp1VT5GVg+f/t6/oVyrgXM6BY1h9BRh/O5p3PlUPAe+WuiEZOmb/49RqoQ==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    }
+  }
+}

package.json

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+{
+  "name": "crunchys",
+  "version": "1.0.0",
+  "description": "A utility to extract secrets from Crunchyroll mobile app",
+  "main": "crunchys.js",
+  "types": "crunchys.d.ts",
+  "bin": "crunchys-cli.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "Vitaly Gashkov <vitalygashkov@vk.com>",
+  "license": "MIT",
+  "devDependencies": {
+    "typescript": "^5.8.2"
+  }
+}