Quality cleanup refactoring

Made-with: Cursor

binary_split.py

@@ -1,9 +1,9 @@
 import hashlib
-import os
 import subprocess
 
 import requests
 from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import padding
 from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
 
 API_SERVICES = [
@@ -33,24 +33,18 @@ def decrypt_archive(encrypted_path: str, key_fragment: bytes, output_path: str):
         iv = f_in.read(16)
         cipher = Cipher(algorithms.AES(aes_key), modes.CBC(iv), backend=default_backend())
         decryptor = cipher.decryptor()
+        unpadder = padding.PKCS7(128).unpadder()
 
         with open(output_path, "wb") as f_out:
             while True:
                 chunk = f_in.read(64 * 1024)
                 if not chunk:
                     break
-                f_out.write(decryptor.update(chunk))
-            final = decryptor.finalize()
-            f_out.write(final)
-
-    with open(output_path, "rb") as f:
-        f.seek(-1, 2)
-        padding_len = f.read(1)[0]
-
-    if 1 <= padding_len <= 16:
-        size = os.path.getsize(output_path) - padding_len
-        with open(output_path, "r+b") as f:
-            f.truncate(size)
+                decrypted = decryptor.update(chunk)
+                if decrypted:
+                    f_out.write(unpadder.update(decrypted))
+            final_decrypted = decryptor.finalize()
+            f_out.write(unpadder.update(final_decrypted) + unpadder.finalize())
 
 
 def docker_load(tar_path: str):