diff options
Diffstat (limited to 'youtube_dl/aes.py')
| -rw-r--r-- | youtube_dl/aes.py | 43 |
1 files changed, 38 insertions, 5 deletions
diff --git a/youtube_dl/aes.py b/youtube_dl/aes.py index c5bb3c4ef..a94a41079 100644 --- a/youtube_dl/aes.py +++ b/youtube_dl/aes.py @@ -1,13 +1,25 @@ from __future__ import unicode_literals -import base64 from math import ceil +from .compat import compat_b64decode from .utils import bytes_to_intlist, intlist_to_bytes BLOCK_SIZE_BYTES = 16 +def pkcs7_padding(data): + """ + PKCS#7 padding + + @param {int[]} data cleartext + @returns {int[]} padding data + """ + + remaining_length = BLOCK_SIZE_BYTES - len(data) % BLOCK_SIZE_BYTES + return data + [remaining_length] * remaining_length + + def aes_ctr_decrypt(data, key, counter): """ Decrypt with aes in counter mode @@ -76,8 +88,7 @@ def aes_cbc_encrypt(data, key, iv): 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 + block = pkcs7_padding(block) mixed_block = xor(block, previous_cipher_block) encrypted_block = aes_encrypt(mixed_block, expanded_key) @@ -88,6 +99,28 @@ def aes_cbc_encrypt(data, key, iv): return encrypted_data +def aes_ecb_encrypt(data, key): + """ + Encrypt with aes in ECB mode. Using PKCS#7 padding + + @param {int[]} data cleartext + @param {int[]} key 16/24/32-Byte cipher key + @returns {int[]} encrypted data + """ + expanded_key = key_expansion(key) + block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) + + encrypted_data = [] + for i in range(block_count): + block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] + block = pkcs7_padding(block) + + encrypted_block = aes_encrypt(block, expanded_key) + encrypted_data += encrypted_block + + return encrypted_data + + def key_expansion(data): """ Generate key schedule @@ -180,7 +213,7 @@ def aes_decrypt_text(data, password, key_size_bytes): """ NONCE_LENGTH_BYTES = 8 - data = bytes_to_intlist(base64.b64decode(data.encode('utf-8'))) + data = bytes_to_intlist(compat_b64decode(data)) password = bytes_to_intlist(password.encode('utf-8')) key = password[:key_size_bytes] + [0] * (key_size_bytes - len(password)) @@ -303,7 +336,7 @@ def xor(data1, data2): def rijndael_mul(a, b): - if(a == 0 or b == 0): + if (a == 0 or b == 0): return 0 return RIJNDAEL_EXP_TABLE[(RIJNDAEL_LOG_TABLE[a] + RIJNDAEL_LOG_TABLE[b]) % 0xFF] |
