def test_cbc_symmetric(self):
for _ in range(100):
pt = pad2(urandom(randint(0, 16 * 2)), 16)
iv = urandom(8 * 2)
ciph = GOST3412Magma(urandom(32))
ct = cbc_encrypt(ciph.encrypt, 8, pt, iv)
self.assertSequenceEqual(cbc_decrypt(ciph.decrypt, 8, ct, iv), pt)
def cbc_encrypt(key, data, iv=8 * b"\x00", pad=True, sbox=DEFAULT_SBOX, mesh=False):
""" CBC encryption mode of operation
:param bytes key: encryption key
:param bytes data: plaintext
:param iv: initialization vector
:type iv: bytes, BLOCKSIZE length
:type bool pad: perform ISO/IEC 7816-4 padding
:param sbox: S-box parameters to use
:type sbox: str, SBOXES'es key
:param bool mesh: enable key meshing
:returns: ciphertext
:rtype: bytes
34.13-2015 padding method 2 is used.
"""
validate_key(key)
validate_iv(iv)
validate_sbox(sbox)
if not data:
raise ValueError("No data supplied")
if pad:
data = pad2(data, BLOCKSIZE)
if len(data) % BLOCKSIZE != 0:
raise ValueError("Data is not blocksize aligned")
ciphertext = [iv]
for i in xrange(0, len(data), BLOCKSIZE):
if mesh and i >= MESH_MAX_DATA and i % MESH_MAX_DATA == 0:
key, _ = meshing(key, iv, sbox=sbox)
ciphertext.append(ns2block(encrypt(sbox, key, block2ns(
strxor(ciphertext[-1], data[i:i + BLOCKSIZE])
))))
return b"".join(ciphertext)
def test_symmetric(self):
for _ in range(100):
for blocksize in (8, 16):
data = urandom(randint(0, blocksize * 3))
self.assertSequenceEqual(
unpad2(pad2(data, blocksize), blocksize),
data,
)
def __init__(self, blockcipher, pad=None, unpad=None):
self.enc = blockcipher.encrypt
self.dec = blockcipher.decrypt
self.blen = blockcipher.blen
if pad == None:
self.padding = lambda x: gost3413.pad2(x, self.blen)
else:
self.padding = pad
if unpad == None:
self.unpadding = lambda x: gost3413.unpad2(x, self.blen)
else:
self.unpadding = unpad
def test_ecb_symmetric(self):
for _ in range(100):
pt = pad2(urandom(randint(0, 16 * 2)), 16)
ciph = GOST3412Kuznechik(urandom(32))
ct = ecb_encrypt(ciph.encrypt, 16, pt)
self.assertSequenceEqual(ecb_decrypt(ciph.decrypt, 16, ct), pt)
