From b4b1d4be3ed9e9da8217921e9be8b6c8c3cecc91 Mon Sep 17 00:00:00 2001
From: rzhxeo <rzhxeot7z81b4700@mailcatch.com>
Date: Wed, 3 Jun 2015 00:00:29 +0200
Subject: [PATCH] [aes.py] Use Crypto.Cipher.AES if available

---
 youtube_dl/aes.py | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/youtube_dl/aes.py b/youtube_dl/aes.py
index 7817adcfd..459a76457 100644
--- a/youtube_dl/aes.py
+++ b/youtube_dl/aes.py
@@ -2,6 +2,10 @@ from __future__ import unicode_literals
 
 import base64
 from math import ceil
+try:
+    from Crypto.Cipher import AES
+except:
+    pass
 
 from .utils import bytes_to_intlist, intlist_to_bytes
 
@@ -18,6 +22,12 @@ def aes_ctr_decrypt(data, key, counter):
                                returns the next counter block
     @returns {int[]}           decrypted data
     """
+    if 'AES' in globals():
+        obj = AES.new(intlist_to_bytes(key), AES.MODE_CTR,
+                      counter = lambda: intlist_to_bytes(counter.next_value()))
+        decrypted_data = obj.decrypt(intlist_to_bytes(data))
+        return bytes_to_intlist(decrypted_data)
+
     expanded_key = key_expansion(key)
     block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES))
 
@@ -43,15 +53,20 @@ def aes_cbc_decrypt(data, key, iv):
     @param {int[]} iv          16-Byte IV
     @returns {int[]}           decrypted data
     """
-    expanded_key = key_expansion(key)
     block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES))
+    data += [0] * (block_count * BLOCK_SIZE_BYTES - len(data))
+
+    if 'AES' in globals():
+        obj = AES.new(intlist_to_bytes(key), AES.MODE_CBC, intlist_to_bytes(iv))
+        decrypted_data = obj.decrypt(intlist_to_bytes(data))
+        return bytes_to_intlist(decrypted_data)
+
+    expanded_key = key_expansion(key)
 
     decrypted_data = []
     previous_cipher_block = iv
     for i in range(block_count):
         block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]
-        block += [0] * (BLOCK_SIZE_BYTES - len(block))
-
         decrypted_block = aes_decrypt(block, expanded_key)
         decrypted_data += xor(decrypted_block, previous_cipher_block)
         previous_cipher_block = block