aboutsummaryrefslogtreecommitdiff
path: root/youtube_dl/aes.py
diff options
context:
space:
mode:
Diffstat (limited to 'youtube_dl/aes.py')
-rw-r--r--youtube_dl/aes.py28
1 files changed, 28 insertions, 0 deletions
diff --git a/youtube_dl/aes.py b/youtube_dl/aes.py
index b8ff45481..c5bb3c4ef 100644
--- a/youtube_dl/aes.py
+++ b/youtube_dl/aes.py
@@ -60,6 +60,34 @@ def aes_cbc_decrypt(data, key, iv):
return decrypted_data
+def aes_cbc_encrypt(data, key, iv):
+ """
+ Encrypt with aes in CBC mode. Using PKCS#7 padding
+
+ @param {int[]} data cleartext
+ @param {int[]} key 16/24/32-Byte cipher key
+ @param {int[]} iv 16-Byte IV
+ @returns {int[]} encrypted data
+ """
+ expanded_key = key_expansion(key)
+ block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES))
+
+ encrypted_data = []
+ previous_cipher_block = iv
+ for i in range(block_count):
+ block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]
+ remaining_length = BLOCK_SIZE_BYTES - len(block)
+ block += [remaining_length] * remaining_length
+ mixed_block = xor(block, previous_cipher_block)
+
+ encrypted_block = aes_encrypt(mixed_block, expanded_key)
+ encrypted_data += encrypted_block
+
+ previous_cipher_block = encrypted_block
+
+ return encrypted_data
+
+
def key_expansion(data):
"""
Generate key schedule