[Refactor] Link Play TCP data transmission

- Code refactor of Link Play TCP data transmission for better security and scalability

latest version/core/util.py

@@ -1,9 +1,30 @@
 import hashlib
 import os
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
 from datetime import date
 from time import mktime
 
 
+def aes_gcm_128_encrypt(key, plaintext, associated_data):
+    iv = os.urandom(12)
+    encryptor = Cipher(
+        algorithms.AES(key),
+        modes.GCM(iv, min_tag_length=12),
+    ).encryptor()
+    encryptor.authenticate_additional_data(associated_data)
+    ciphertext = encryptor.update(plaintext) + encryptor.finalize()
+    return (iv, ciphertext, encryptor.tag)
+
+
+def aes_gcm_128_decrypt(key, associated_data, iv, ciphertext, tag):
+    decryptor = Cipher(
+        algorithms.AES(key),
+        modes.GCM(iv, tag, min_tag_length=12),
+    ).decryptor()
+    decryptor.authenticate_additional_data(associated_data)
+    return decryptor.update(ciphertext) + decryptor.finalize()
+
+
 def md5(code: str) -> str:
     # md5加密算法
     code = code.encode()