edb614f985
Try app-internal key first (new format); on failure, signal the renderer to prompt for the old password and retry. Lets users import .mhu files that were exported with a custom password in v2.7.6 or earlier without downgrading.
96 lines
3.1 KiB
JavaScript
96 lines
3.1 KiB
JavaScript
const crypto = require('crypto');
|
|
|
|
const MAGIC = Buffer.from('MHU1');
|
|
const SALT_LEN = 16;
|
|
const IV_LEN = 12;
|
|
const TAG_LEN = 16;
|
|
const KEY_LEN = 32;
|
|
const ITERATIONS = 100_000;
|
|
const DIGEST = 'sha512';
|
|
const ALGO = 'aes-256-gcm';
|
|
|
|
// Fixed app-internal passphrase — backups are opaque without the app, which is
|
|
// enough protection for API keys stored locally. We keep the AES-GCM envelope
|
|
// (with random salt/iv) so each export is still distinct and authenticated.
|
|
const APP_PASSPHRASE = 'multi-hoster-upload::backup::v1';
|
|
|
|
function deriveKey(passphrase, salt) {
|
|
return crypto.pbkdf2Sync(passphrase, salt, ITERATIONS, KEY_LEN, DIGEST);
|
|
}
|
|
|
|
/**
|
|
* Encrypt a config object.
|
|
* Returns a Buffer: MHU1 | salt(16) | iv(12) | tag(16) | ciphertext
|
|
*/
|
|
function encrypt(config) {
|
|
const plaintext = Buffer.from(JSON.stringify(config), 'utf-8');
|
|
const salt = crypto.randomBytes(SALT_LEN);
|
|
const iv = crypto.randomBytes(IV_LEN);
|
|
const key = deriveKey(APP_PASSPHRASE, salt);
|
|
|
|
const cipher = crypto.createCipheriv(ALGO, key, iv);
|
|
const encrypted = Buffer.concat([cipher.update(plaintext), cipher.final()]);
|
|
const tag = cipher.getAuthTag();
|
|
|
|
plaintext.fill(0);
|
|
key.fill(0);
|
|
return Buffer.concat([MAGIC, salt, iv, tag, encrypted]);
|
|
}
|
|
|
|
/**
|
|
* Decrypt a .mhu buffer.
|
|
* Tries the app's built-in key first; if that fails and a user password is
|
|
* provided, falls back to legacy password-based decryption. Throws a special
|
|
* error with `needsPassword = true` if the app key fails and no password was
|
|
* given, so callers can prompt the user for the legacy password.
|
|
*/
|
|
function decrypt(buffer, userPassword) {
|
|
if (buffer.length < MAGIC.length + SALT_LEN + IV_LEN + TAG_LEN + 1) {
|
|
throw new Error('Ungültiges Backup-Format');
|
|
}
|
|
|
|
const magic = buffer.subarray(0, 4);
|
|
if (!magic.equals(MAGIC)) {
|
|
throw new Error('Keine gültige .mhu Backup-Datei');
|
|
}
|
|
|
|
let offset = MAGIC.length;
|
|
const salt = buffer.subarray(offset, offset += SALT_LEN);
|
|
const iv = buffer.subarray(offset, offset += IV_LEN);
|
|
const tag = buffer.subarray(offset, offset += TAG_LEN);
|
|
const ciphertext = buffer.subarray(offset);
|
|
|
|
const tryPassphrase = (passphrase) => {
|
|
const key = deriveKey(passphrase, salt);
|
|
const decipher = crypto.createDecipheriv(ALGO, key, iv);
|
|
decipher.setAuthTag(tag);
|
|
try {
|
|
const decrypted = Buffer.concat([decipher.update(ciphertext), decipher.final()]);
|
|
const result = JSON.parse(decrypted.toString('utf-8'));
|
|
decrypted.fill(0);
|
|
key.fill(0);
|
|
return result;
|
|
} catch {
|
|
key.fill(0);
|
|
return null;
|
|
}
|
|
};
|
|
|
|
// 1) Try the app-internal key (new format, no password required).
|
|
const fromApp = tryPassphrase(APP_PASSPHRASE);
|
|
if (fromApp) return fromApp;
|
|
|
|
// 2) Legacy format: user had set their own password.
|
|
if (userPassword) {
|
|
const fromUser = tryPassphrase(userPassword);
|
|
if (fromUser) return fromUser;
|
|
throw new Error('Falsches Passwort oder beschädigte Datei');
|
|
}
|
|
|
|
const err = new Error('Dieses Backup wurde mit einem Passwort verschlüsselt');
|
|
err.needsPassword = true;
|
|
throw err;
|
|
}
|
|
|
|
module.exports = { encrypt, decrypt };
|