def test_symmetric(self):
for _ in range(1 << 8):
kek = urandom(32)
cek = urandom(32)
ukm = urandom(8)
wrapped = wrap_gost(ukm, kek, cek)
unwrapped = unwrap_gost(kek, wrapped)
self.assertEqual(unwrapped, cek)
def process_cms(
self,
content_info_raw,
prv_key_our,
curve_name,
keker,
plaintext_expected,
):
sbox = "Gost28147_tc26_ParamZ"
content_info, tail = ContentInfo().decode(content_info_raw)
self.assertSequenceEqual(tail, b"")
enveloped_data, tail = EnvelopedData().decode(
bytes(content_info["content"]))
self.assertSequenceEqual(tail, b"")
eci = enveloped_data["encryptedContentInfo"]
kari = enveloped_data["recipientInfos"][0]["kari"]
pub_key_their, tail = OctetString().decode(
bytes(kari["originator"]["originatorKey"]["publicKey"]), )
self.assertSequenceEqual(tail, b"")
ukm = bytes(kari["ukm"])
rek = kari["recipientEncryptedKeys"][0]
curve = GOST3410Curve(*CURVE_PARAMS[curve_name])
kek = keker(curve, prv_key_our, bytes(pub_key_their), ukm)
encrypted_key, tail = Gost2814789EncryptedKey().decode(
bytes(rek["encryptedKey"]), )
self.assertSequenceEqual(tail, b"")
key_wrapped = bytes(encrypted_key["encryptedKey"])
mac = bytes(encrypted_key["macKey"])
cek = unwrap_gost(kek, ukm + key_wrapped + mac, sbox=sbox)
ciphertext = bytes(eci["encryptedContent"])
encryption_params, tail = Gost2814789Parameters().decode(
bytes(eci["contentEncryptionAlgorithm"]["parameters"]))
self.assertSequenceEqual(tail, b"")
iv = bytes(encryption_params["iv"])
self.assertSequenceEqual(
cfb_decrypt(cek, ciphertext, iv, sbox=sbox, mesh=True),
plaintext_expected,
)
def test_invalid_length(self):
with self.assertRaises(ValueError):
unwrap_gost(urandom(32), urandom(41))
with self.assertRaises(ValueError):
unwrap_gost(urandom(32), urandom(45))
def process_cms(
self,
content_info_raw,
prv_key_our,
curve_name,
keker,
plaintext_expected,
):
sbox = "id-tc26-gost-28147-param-Z"
content_info, tail = ContentInfo().decode(
content_info_raw,
ctx={
"defines_by_path": [(
(
"content",
DecodePathDefBy(id_envelopedData),
"recipientInfos",
any,
"kari",
"originator",
"originatorKey",
"algorithm",
"algorithm",
),
((
("..", "publicKey"),
{
id_tc26_gost3410_2012_256: OctetString(),
id_tc26_gost3410_2012_512: OctetString(),
},
), ),
) for _ in (
id_tc26_gost3410_2012_256,
id_tc26_gost3410_2012_512,
)],
})
self.assertSequenceEqual(tail, b"")
self.assertIsNotNone(content_info["content"].defined)
_, enveloped_data = content_info["content"].defined
eci = enveloped_data["encryptedContentInfo"]
kari = enveloped_data["recipientInfos"][0]["kari"]
self.assertIsNotNone(
kari["originator"]["originatorKey"]["publicKey"].defined)
_, pub_key_their = kari["originator"]["originatorKey"][
"publicKey"].defined
ukm = bytes(kari["ukm"])
rek = kari["recipientEncryptedKeys"][0]
curve = CURVES[curve_name]
kek = keker(curve, prv_key_our, bytes(pub_key_their), ukm)
self.assertIsNotNone(rek["encryptedKey"].defined)
_, encrypted_key = rek["encryptedKey"].defined
key_wrapped = bytes(encrypted_key["encryptedKey"])
mac = bytes(encrypted_key["macKey"])
cek = unwrap_gost(kek, ukm + key_wrapped + mac, sbox=sbox)
ciphertext = bytes(eci["encryptedContent"])
self.assertIsNotNone(
eci["contentEncryptionAlgorithm"]["parameters"].defined)
_, encryption_params = eci["contentEncryptionAlgorithm"][
"parameters"].defined
iv = bytes(encryption_params["iv"])
self.assertSequenceEqual(
cfb_decrypt(cek, ciphertext, iv, sbox=sbox, mesh=True),
plaintext_expected,
)