From c9619f0a17927086c49e4b443202be296d734a76 Mon Sep 17 00:00:00 2001 From: Yen Chi Hsuan Date: Mon, 27 Feb 2017 18:47:47 +0800 Subject: [aes] Add aes_cbc_encrypt Used in daisuki.net (#4738) --- youtube_dl/aes.py | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'youtube_dl') 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 -- cgit v1.2.3