IntelliJ Forgotten master key

decode.ts

// @ts-expect-error
import * as dpapi from 'win-dpapi';
import crypto from 'node:crypto';
import fs from 'node:fs/promises';

function rot13(txt:string) {
  return txt.replace(/[a-z]/gi, c =>
    "NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm"
      [ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".indexOf(c) ] );
}

const builtInEncryptionKey = Buffer.from(rot13('HUWirUxtD29hMzyaVSAyLj=='), 'base64');

function decryptAes(encrypted: Buffer) {
  const ivLen = encrypted.readUInt32BE();
  const iv = encrypted.slice(4, ivLen + 4);
  const data = encrypted.slice(ivLen + 4);

  const decipher = crypto.createDecipheriv(
    'aes-128-cbc',
    builtInEncryptionKey,
    iv,
  );
  return decipher.update(data, undefined, 'utf8') + decipher.final('utf8');
}

function decryptSecret(secret: string) {
  const secretBin = Buffer.from(secret, 'base64');
  return dpapi.unprotectData(secretBin, null, 'LocalMachine') as Buffer;
}

async function getDirectories(path: string) {
  const found = [];
  for (const file of await fs.readdir(path)) {
    if ((await fs.stat(`${path}${file}`)).isDirectory())
      found.push(`${path}${file}`);
  }
  return found;
}

async function fileExists(filename: string) {
  try {
    await fs.access(filename);
    return true;
  } catch (err: any) {
    if (err.code === 'ENOENT') {
      return 'File does not exist';
    }
    return `Error reading file: ${err.code}`;
  }
}

const appDir = `${process.env.APPDATA}\\JetBrains\\`;
getDirectories(appDir).then(async (apps) => {
  for (const app of apps) {
    if (app.endsWith('consentOptions')) continue;
    const appName = app.slice(appDir.length);
    const exists = await fileExists(`${app}\\c.pwd`);
    if (exists !== true) {
      console.error(`${appName}: c.pwd does not exist : ${exists}`);
      continue;
    }
    let secret = '';
    try {
      const fileData = await fs.readFile(`${app}\\c.pwd`, 'utf8');
      const metaData = Object.fromEntries(
        fileData
          .split('\n')
          .map((line) => line.split(':').map((x) => x.trim())),
      );
      if (metaData.encryption !== 'CRYPT_32') {
        console.error(
          `${appName}: unknown encryption type : ${metaData.encryption}`,
        );
        continue;
      }
      secret = metaData.value.split(' ')[1];
    } catch (err) {
      console.error(`${appName}: Error reading c.pwd`, err);
      continue;
    }
    try {
      console.log(`${appName} decrypted : ${decryptAes(decryptSecret(secret))}`);
    } catch (err) {
      console.error(`${appName}: Error decrypting secret`, err);
    }
  }
});