Fix decryption upadding 2 (#13)

* fix unpad logic in videio segment decryption

* use cryptography instead of pycryptodome

* update dependencies

requirements.txt

@@ -1,11 +1,11 @@
 click==8.1.7
 requests==2.32.3
 m3u8==6.0.0
-pycryptodome==3.19.1
-inquirer==3.3.0
+cryptography==43.0.1
+inquirer==3.4.0
 tinydb==4.8.0
-pathvalidate==3.2.0
-typer[all]==0.12.3
-rich==13.7.1
-setuptools==72.1.0
+pathvalidate==3.2.1
+typer[all]==0.12.5
+rich==13.8.1
+setuptools==74.1.2
 pylibimport==1.9.2

util/m3u8_downloader.py

@@ -1,7 +1,10 @@
 import requests
 import m3u8
-from Crypto.Cipher import AES
-from Crypto.Util.Padding import unpad
+from cryptography.hazmat.primitives.ciphers import Cipher
+from cryptography.hazmat.primitives.ciphers.algorithms import AES
+from cryptography.hazmat.primitives.ciphers.modes import CBC as RFC8216MediaSegmentEncryptMode
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives.padding import PKCS7
 import time
 import inquirer
 from pathlib import Path
@@ -54,9 +57,15 @@ def __init__(self, api_client: NCP, progress_manager: ProgressManager, session_i
         # init manager
         self.m3u8_manager = M3U8Manager(f'{self.output}.ts', resume=self.resume)
 
+        # data load from session
         self.video_index = None
         self.target_video = None
-        self.key = None
+
+        # decrypt settings
+        self.algorithm = AES  # Decrypt algorithm
+        self.mode = RFC8216MediaSegmentEncryptMode  # Decrypt mode
+        self.unpadder = PKCS7(128)
+        self.key = None  # Decrypt key
 
         # init task progress
         self.task = self.progress_manager.add_task('Start downloading', total=None)
@@ -139,9 +148,16 @@ def __decrypt(self, content: bytes, media_sequence):
         please refer to RFC 8216, Section 5.2:
         https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis#section-5.2
         """
-        cipher = AES.new(self.key, AES.MODE_CBC, media_sequence.to_bytes(16, 'big'))
+        iv = media_sequence.to_bytes(16, 'big')
+        cipher = Cipher(self.algorithm(self.key), self.mode(iv), backend=default_backend())
+
+        decryptor = cipher.decryptor()
+        decrypted = decryptor.update(content) + decryptor.finalize()
+
+        unpadder = self.unpadder.unpadder()
+        unpadded = unpadder.update(decrypted) + unpadder.finalize()
 
-        return unpad(cipher.decrypt(content), AES.block_size, style='pkcs7')
+        return unpadded
 
     def __init_manager(self) -> None:
         """Initialize M3U8Manager"""