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
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
"""
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))