def test_copy(self):
m = MAC(self.k, b"foo")
c = m.copy()
m.update(b"barbaz")
c.update(b"bar")
c.update(b"baz")
self.assertSequenceEqual(m.digest(), c.digest())
def wrap_gost(ukm, kek, cek, sbox=DEFAULT_SBOX):
"""28147-89 key wrapping
:param ukm: UKM
:type ukm: bytes, 8 bytes
:param kek: key encryption key
:type kek: bytes, 32 bytes
:param cek: content encryption key
:type cek: bytes, 32 bytes
:returns: wrapped key
:rtype: bytes, 44 bytes
"""
cek_mac = MAC(kek, data=cek, iv=ukm, sbox=sbox).digest()[:4]
cek_enc = ecb_encrypt(kek, cek, sbox=sbox)
return ukm + cek_enc + cek_mac
def unwrap_gost(kek, data, sbox=DEFAULT_SBOX):
"""28147-89 key unwrapping
:param kek: key encryption key
:type kek: bytes, 32 bytes
:param data: wrapped key
:type data: bytes, 44 bytes
:returns: unwrapped CEK
:rtype: 32 bytes
"""
if len(data) != 44:
raise ValueError("Invalid data length")
ukm, cek_enc, cek_mac = data[:8], data[8:8 + 32], data[-4:]
cek = ecb_decrypt(kek, cek_enc, sbox=sbox)
if MAC(kek, data=cek, iv=ukm, sbox=sbox).digest()[:4] != cek_mac:
raise ValueError("Invalid MAC")
return cek
def test_parts(self):
m = MAC(self.k)
m.update(b"foo")
m.update(b"bar")
self.assertSequenceEqual(m.digest(), MAC(self.k, b"foobar").digest())
def test_13x(self):
self.assertSequenceEqual(
MAC(self.k, 13 * b"x").hexdigest(),
"917ee1f1a668fbd3",
)
def test_128U(self):
self.assertSequenceEqual(
MAC(self.k, 128 * b"U").hexdigest(),
"1a06d1bad74580ef",
)
def test_abc(self):
self.assertSequenceEqual(
MAC(self.k, b"abc").hexdigest(),
"28661e40805b1ff9",
)
def test_a(self):
self.assertSequenceEqual(
MAC(self.k, b"a").hexdigest(),
"bd5d3b5b2b7b57af",
)