From c9619f0a17927086c49e4b443202be296d734a76 Mon Sep 17 00:00:00 2001 From: Yen Chi Hsuan Date: Mon, 27 Feb 2017 18:47:47 +0800 Subject: [PATCH] [aes] Add aes_cbc_encrypt Used in daisuki.net (#4738) --- test/test_aes.py | 9 ++++++++- youtube_dl/aes.py | 28 ++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletion(-) diff --git a/test/test_aes.py b/test/test_aes.py index 54078a66d..78a28751b 100644 --- a/test/test_aes.py +++ b/test/test_aes.py @@ -8,7 +8,7 @@ import sys import unittest sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__)))) -from youtube_dl.aes import aes_decrypt, aes_encrypt, aes_cbc_decrypt, aes_decrypt_text +from youtube_dl.aes import aes_decrypt, aes_encrypt, aes_cbc_decrypt, aes_cbc_encrypt, aes_decrypt_text from youtube_dl.utils import bytes_to_intlist, intlist_to_bytes import base64 @@ -34,6 +34,13 @@ class TestAES(unittest.TestCase): decrypted = intlist_to_bytes(aes_cbc_decrypt(data, self.key, self.iv)) self.assertEqual(decrypted.rstrip(b'\x08'), self.secret_msg) + def test_cbc_encrypt(self): + data = bytes_to_intlist(self.secret_msg) + encrypted = intlist_to_bytes(aes_cbc_encrypt(data, self.key, self.iv)) + self.assertEqual( + encrypted, + b"\x97\x92+\xe5\x0b\xc3\x18\x91ky9m&\xb3\xb5@\xe6'\xc2\x96.\xc8u\x88\xab9-[\x9e|\xf1\xcd") + def test_decrypt_text(self): password = intlist_to_bytes(self.key).decode('utf-8') encrypted = base64.b64encode( 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 -- 2.40.0