import { createCipheriv, createDecipheriv, randomBytes, pbkdf2Sync } from 'crypto';
import { readFileSync, writeFileSync, existsSync, mkdirSync } from 'fs';
import { homedir } from 'os';
import { join } from 'path';
import type { GameData } from '../types.js';
const ALGORITHM = 'aes-256-gcm';
const SALT_LENGTH = 32;
const IV_LENGTH = 16;
const AUTH_TAG_LENGTH = 16;
const KEY_LENGTH = 32;
const ITERATIONS = 100000;
export class CryptoStorage {
private gameDir: string;
private dataFile: string;
private keyFile: string;
constructor() {
this.gameDir = join(homedir(), '.mcp-idle-game');
this.dataFile = join(this.gameDir, 'player_data.enc');
this.keyFile = join(this.gameDir, 'key.enc');
if (!existsSync(this.gameDir)) {
mkdirSync(this.gameDir, { recursive: true });
}
}
private deriveKey(password: string, salt: Buffer): Buffer {
return pbkdf2Sync(password, salt, ITERATIONS, KEY_LENGTH, 'sha256');
}
private encrypt(data: string, key: Buffer): Buffer {
const iv = randomBytes(IV_LENGTH);
const cipher = createCipheriv(ALGORITHM, key, iv);
const encrypted = Buffer.concat([
cipher.update(data, 'utf8'),
cipher.final()
]);
const authTag = cipher.getAuthTag();
return Buffer.concat([iv, authTag, encrypted]);
}
private decrypt(encryptedData: Buffer, key: Buffer): string {
const iv = encryptedData.subarray(0, IV_LENGTH);
const authTag = encryptedData.subarray(IV_LENGTH, IV_LENGTH + AUTH_TAG_LENGTH);
const encrypted = encryptedData.subarray(IV_LENGTH + AUTH_TAG_LENGTH);
const decipher = createDecipheriv(ALGORITHM, key, iv);
decipher.setAuthTag(authTag);
return decipher.update(encrypted) + decipher.final('utf8');
}
async initialize(password: string): Promise<void> {
if (existsSync(this.keyFile)) {
throw new Error('Game already initialized. Use load() instead.');
}
const salt = randomBytes(SALT_LENGTH);
const key = this.deriveKey(password, salt);
// Store salt with encrypted marker
const keyData = Buffer.concat([salt]);
writeFileSync(this.keyFile, keyData);
// Create initial empty game data
const initialData: GameData = {
player: {
name: '',
equipment: {
weapon: null,
shield: null,
armor: null,
accessory: null,
item1: null,
item2: null
},
inventory: [],
itemInventory: [],
gold: 0,
state: 'idle'
},
version: '0.1.0'
};
await this.save(initialData, password);
}
async save(data: GameData, password: string): Promise<void> {
if (!existsSync(this.keyFile)) {
throw new Error('Game not initialized. Use initialize() first.');
}
const keyData = readFileSync(this.keyFile);
const salt = keyData.subarray(0, SALT_LENGTH);
const key = this.deriveKey(password, salt);
const jsonData = JSON.stringify(data, null, 2);
const encrypted = this.encrypt(jsonData, key);
writeFileSync(this.dataFile, encrypted);
}
async load(password: string): Promise<GameData> {
if (!existsSync(this.keyFile) || !existsSync(this.dataFile)) {
throw new Error('No save data found. Use initialize() first.');
}
const keyData = readFileSync(this.keyFile);
const salt = keyData.subarray(0, SALT_LENGTH);
const key = this.deriveKey(password, salt);
const encryptedData = readFileSync(this.dataFile);
const decrypted = this.decrypt(encryptedData, key);
return JSON.parse(decrypted) as GameData;
}
exists(): boolean {
return existsSync(this.keyFile) && existsSync(this.dataFile);
}
getSaveLocation(): string {
return this.gameDir;
}
}
