From bf473c641f35ce2bc833ef3f985daee198b5d8e4 Mon Sep 17 00:00:00 2001
From: KOSASIH <kosasihg88@gmail.com>
Date: Sun, 21 Jul 2024 20:16:12 +0700
Subject: [PATCH] Create crypto.js

---
 utils/crypto.js | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 utils/crypto.js

diff --git a/utils/crypto.js b/utils/crypto.js
new file mode 100644
index 0000000..50367fd
--- /dev/null
+++ b/utils/crypto.js
@@ -0,0 +1,54 @@
+import { createHash } from 'crypto';
+import { randomBytes } from 'crypto';
+import { scrypt } from 'scrypt-js';
+import { ed25519 } from 'ed25519';
+
+const MESSAGE_ENCRYPTION_KEY = process.env.MESSAGE_ENCRYPTION_KEY;
+const KEY_DERIVATION_SALT = process.env.KEY_DERIVATION_SALT;
+
+class Crypto {
+  static async deriveKey(password) {
+    // Derive a key from a password using scrypt
+    const derivedKey = await scrypt(password, KEY_DERIVATION_SALT, 16384, 8, 1);
+    return derivedKey.toString('hex');
+  }
+
+  static async encrypt(data, key) {
+    // Encrypt data using AES-256-GCM
+    const iv = randomBytes(12);
+    const cipher = createCipher('aes-256-gcm', key);
+    const encrypted = Buffer.concat([cipher.update(data), cipher.final()]);
+    return `${iv.toString('hex')}:${encrypted.toString('hex')}`;
+  }
+
+  static async decrypt(encrypted, key) {
+    // Decrypt data using AES-256-GCM
+    const [ivHex, encryptedHex] = encrypted.split(':');
+    const iv = Buffer.from(ivHex, 'hex');
+    const encryptedBuffer = Buffer.from(encryptedHex, 'hex');
+    const decipher = createDecipher('aes-256-gcm', key);
+    decipher.setAuthTag(encryptedBuffer.slice(-16));
+    const decrypted = Buffer.concat([decipher.update(encryptedBuffer.slice(0, -16)), decipher.final()]);
+    return decrypted.toString();
+  }
+
+  static async sign(data, privateKey) {
+    // Sign data using Ed25519
+    const signature = ed25519.sign(data, privateKey);
+    return signature.toString('hex');
+  }
+
+  static async verify(data, signature, publicKey) {
+    // Verify a signature using Ed25519
+    return ed25519.verify(data, signature, publicKey);
+  }
+
+  static async hash(data) {
+    // Hash data using SHA-512
+    const hash = createHash('sha512');
+    hash.update(data);
+    return hash.digest('hex');
+  }
+}
+
+export default Crypto;