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|
# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
import binascii
import os
import pytest
from cryptography.exceptions import AlreadyFinalized, _Reasons
from cryptography.hazmat.bindings._rust import openssl as rust_openssl
from cryptography.hazmat.primitives.ciphers import algorithms, base, modes
from ...doubles import DummyMode
from ...utils import load_nist_vectors, raises_unsupported_algorithm
from .utils import _load_all_params, generate_encrypt_test
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 32), modes.XTS(b"\x00" * 16)
),
skip_message="Does not support AES XTS",
)
class TestAESModeXTS:
def test_xts_vectors(self, backend, subtests):
# This list comprehension excludes any vector that does not have a
# data unit length that is divisible by 8. The NIST vectors include
# tests for implementations that support encryption of data that is
# not divisible modulo 8, but OpenSSL is not such an implementation.
vectors = [
x
for x in _load_all_params(
os.path.join("ciphers", "AES", "XTS", "tweak-128hexstr"),
["XTSGenAES128.rsp", "XTSGenAES256.rsp"],
load_nist_vectors,
)
if int(x["dataunitlen"]) / 8.0 == int(x["dataunitlen"]) // 8
]
for vector in vectors:
with subtests.test():
key = binascii.unhexlify(vector["key"])
tweak = binascii.unhexlify(vector["i"])
pt = binascii.unhexlify(vector["pt"])
ct = binascii.unhexlify(vector["ct"])
cipher = base.Cipher(
algorithms.AES(key), modes.XTS(tweak), backend
)
enc = cipher.encryptor()
computed_ct = enc.update(pt) + enc.finalize()
assert computed_ct == ct
dec = cipher.decryptor()
computed_pt = dec.update(ct) + dec.finalize()
assert computed_pt == pt
def test_xts_too_short(self, backend):
key = b"thirty_two_byte_keys_are_great!!"
tweak = b"\x00" * 16
cipher = base.Cipher(algorithms.AES(key), modes.XTS(tweak))
enc = cipher.encryptor()
with pytest.raises(ValueError):
enc.update(b"0" * 15)
@pytest.mark.supported(
only_if=lambda backend: not rust_openssl.CRYPTOGRAPHY_IS_LIBRESSL,
skip_message="duplicate key encryption error added in OpenSSL 1.1.1d",
)
def test_xts_no_duplicate_keys_encryption(self, backend):
key = bytes(range(16)) * 2
tweak = b"\x00" * 16
cipher = base.Cipher(algorithms.AES(key), modes.XTS(tweak))
with pytest.raises(ValueError, match="duplicated keys"):
cipher.encryptor()
def test_xts_unsupported_with_aes128_aes256_classes(self):
with pytest.raises(TypeError):
base.Cipher(algorithms.AES128(b"0" * 16), modes.XTS(b"\x00" * 16))
with pytest.raises(TypeError):
base.Cipher(algorithms.AES256(b"0" * 32), modes.XTS(b"\x00" * 16))
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.CBC(b"\x00" * 16)
),
skip_message="Does not support AES CBC",
)
class TestAESModeCBC:
test_cbc = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "CBC"),
[
"CBCGFSbox128.rsp",
"CBCGFSbox192.rsp",
"CBCGFSbox256.rsp",
"CBCKeySbox128.rsp",
"CBCKeySbox192.rsp",
"CBCKeySbox256.rsp",
"CBCVarKey128.rsp",
"CBCVarKey192.rsp",
"CBCVarKey256.rsp",
"CBCVarTxt128.rsp",
"CBCVarTxt192.rsp",
"CBCVarTxt256.rsp",
"CBCMMT128.rsp",
"CBCMMT192.rsp",
"CBCMMT256.rsp",
],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda iv, **kwargs: modes.CBC(binascii.unhexlify(iv)),
)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.ECB()
),
skip_message="Does not support AES ECB",
)
class TestAESModeECB:
test_ecb = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "ECB"),
[
"ECBGFSbox128.rsp",
"ECBGFSbox192.rsp",
"ECBGFSbox256.rsp",
"ECBKeySbox128.rsp",
"ECBKeySbox192.rsp",
"ECBKeySbox256.rsp",
"ECBVarKey128.rsp",
"ECBVarKey192.rsp",
"ECBVarKey256.rsp",
"ECBVarTxt128.rsp",
"ECBVarTxt192.rsp",
"ECBVarTxt256.rsp",
"ECBMMT128.rsp",
"ECBMMT192.rsp",
"ECBMMT256.rsp",
],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda **kwargs: modes.ECB(),
)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.OFB(b"\x00" * 16)
),
skip_message="Does not support AES OFB",
)
class TestAESModeOFB:
test_ofb = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "OFB"),
[
"OFBGFSbox128.rsp",
"OFBGFSbox192.rsp",
"OFBGFSbox256.rsp",
"OFBKeySbox128.rsp",
"OFBKeySbox192.rsp",
"OFBKeySbox256.rsp",
"OFBVarKey128.rsp",
"OFBVarKey192.rsp",
"OFBVarKey256.rsp",
"OFBVarTxt128.rsp",
"OFBVarTxt192.rsp",
"OFBVarTxt256.rsp",
"OFBMMT128.rsp",
"OFBMMT192.rsp",
"OFBMMT256.rsp",
],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda iv, **kwargs: modes.OFB(binascii.unhexlify(iv)),
)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.CFB(b"\x00" * 16)
),
skip_message="Does not support AES CFB",
)
class TestAESModeCFB:
test_cfb = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "CFB"),
[
"CFB128GFSbox128.rsp",
"CFB128GFSbox192.rsp",
"CFB128GFSbox256.rsp",
"CFB128KeySbox128.rsp",
"CFB128KeySbox192.rsp",
"CFB128KeySbox256.rsp",
"CFB128VarKey128.rsp",
"CFB128VarKey192.rsp",
"CFB128VarKey256.rsp",
"CFB128VarTxt128.rsp",
"CFB128VarTxt192.rsp",
"CFB128VarTxt256.rsp",
"CFB128MMT128.rsp",
"CFB128MMT192.rsp",
"CFB128MMT256.rsp",
],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda iv, **kwargs: modes.CFB(binascii.unhexlify(iv)),
)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.CFB8(b"\x00" * 16)
),
skip_message="Does not support AES CFB8",
)
class TestAESModeCFB8:
test_cfb8 = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "CFB"),
[
"CFB8GFSbox128.rsp",
"CFB8GFSbox192.rsp",
"CFB8GFSbox256.rsp",
"CFB8KeySbox128.rsp",
"CFB8KeySbox192.rsp",
"CFB8KeySbox256.rsp",
"CFB8VarKey128.rsp",
"CFB8VarKey192.rsp",
"CFB8VarKey256.rsp",
"CFB8VarTxt128.rsp",
"CFB8VarTxt192.rsp",
"CFB8VarTxt256.rsp",
"CFB8MMT128.rsp",
"CFB8MMT192.rsp",
"CFB8MMT256.rsp",
],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda iv, **kwargs: modes.CFB8(binascii.unhexlify(iv)),
)
@pytest.mark.supported(
only_if=lambda backend: backend.cipher_supported(
algorithms.AES(b"\x00" * 16), modes.CTR(b"\x00" * 16)
),
skip_message="Does not support AES CTR",
)
class TestAESModeCTR:
test_ctr = generate_encrypt_test(
load_nist_vectors,
os.path.join("ciphers", "AES", "CTR"),
["aes-128-ctr.txt", "aes-192-ctr.txt", "aes-256-ctr.txt"],
lambda key, **kwargs: algorithms.AES(binascii.unhexlify(key)),
lambda iv, **kwargs: modes.CTR(binascii.unhexlify(iv)),
)
@pytest.mark.parametrize(
"mode",
[
modes.CBC(bytearray(b"\x00" * 16)),
modes.CTR(bytearray(b"\x00" * 16)),
modes.OFB(bytearray(b"\x00" * 16)),
modes.CFB(bytearray(b"\x00" * 16)),
modes.CFB8(bytearray(b"\x00" * 16)),
modes.XTS(bytearray(b"\x00" * 16)),
# Add a dummy mode for coverage of the cipher_supported check.
DummyMode(),
],
)
def test_buffer_protocol_alternate_modes(mode, backend):
data = bytearray(b"sixteen_byte_msg")
key = algorithms.AES(bytearray(os.urandom(32)))
if not backend.cipher_supported(key, mode):
pytest.skip(f"AES in {mode.name} mode not supported")
cipher = base.Cipher(key, mode, backend)
enc = cipher.encryptor()
ct = enc.update(data) + enc.finalize()
dec = cipher.decryptor()
pt = dec.update(ct) + dec.finalize()
assert pt == data
@pytest.mark.parametrize(
"mode",
[
modes.ECB(),
modes.CBC(bytearray(b"\x00" * 16)),
modes.CTR(bytearray(b"\x00" * 16)),
modes.OFB(bytearray(b"\x00" * 16)),
modes.CFB(bytearray(b"\x00" * 16)),
modes.CFB8(bytearray(b"\x00" * 16)),
],
)
@pytest.mark.parametrize("alg_cls", [algorithms.AES128, algorithms.AES256])
def test_alternate_aes_classes(mode, alg_cls, backend):
alg = alg_cls(b"0" * (alg_cls.key_size // 8))
if not backend.cipher_supported(alg, mode):
pytest.skip(f"AES in {mode.name} mode not supported")
data = bytearray(b"sixteen_byte_msg")
cipher = base.Cipher(alg, mode, backend)
enc = cipher.encryptor()
ct = enc.update(data) + enc.finalize()
dec = cipher.decryptor()
pt = dec.update(ct) + dec.finalize()
assert pt == data
def test_reset_nonce(backend):
data = b"helloworld" * 10
nonce = b"\x00" * 16
nonce_alt = b"\xee" * 16
cipher = base.Cipher(
algorithms.AES(b"\x00" * 16),
modes.CTR(nonce),
)
cipher_alt = base.Cipher(
algorithms.AES(b"\x00" * 16),
modes.CTR(nonce_alt),
)
enc = cipher.encryptor()
ct1 = enc.update(data)
assert len(ct1) == len(data)
for _ in range(2):
enc.reset_nonce(nonce)
assert enc.update(data) == ct1
# Reset the nonce to a different value
# and check it matches with a different context
enc_alt = cipher_alt.encryptor()
ct2 = enc_alt.update(data)
enc.reset_nonce(nonce_alt)
assert enc.update(data) == ct2
enc_alt.finalize()
enc.finalize()
with pytest.raises(AlreadyFinalized):
enc.reset_nonce(nonce)
dec = cipher.decryptor()
assert dec.update(ct1) == data
for _ in range(2):
dec.reset_nonce(nonce)
assert dec.update(ct1) == data
# Reset the nonce to a different value
# and check it matches with a different context
dec_alt = cipher_alt.decryptor()
dec.reset_nonce(nonce_alt)
assert dec.update(ct2) == dec_alt.update(ct2)
dec_alt.finalize()
dec.finalize()
with pytest.raises(AlreadyFinalized):
dec.reset_nonce(nonce)
def test_reset_nonce_invalid_mode(backend):
iv = b"\x00" * 16
c = base.Cipher(
algorithms.AES(b"\x00" * 16),
modes.CBC(iv),
)
enc = c.encryptor()
with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_CIPHER):
enc.reset_nonce(iv)
dec = c.decryptor()
with raises_unsupported_algorithm(_Reasons.UNSUPPORTED_CIPHER):
dec.reset_nonce(iv)
|
