def test_invalid_key(self, backend):
kdf = KBKDFCMAC(
algorithms.AES,
Mode.CounterMode,
32,
4,
4,
CounterLocation.BeforeFixed,
b"label",
b"context",
None,
backend=backend,
)
key = kdf.derive(self._KEY_MATERIAL)
kdf = KBKDFCMAC(
algorithms.AES,
Mode.CounterMode,
32,
4,
4,
CounterLocation.BeforeFixed,
b"label",
b"context",
None,
backend=backend,
)
with pytest.raises(InvalidKey):
kdf.verify(self._KEY_MATERIAL2, key)
def test_already_finalized(self, backend):
kdf = KBKDFCMAC(
algorithms.AES,
Mode.CounterMode,
32,
4,
4,
CounterLocation.BeforeFixed,
b"label",
b"context",
None,
backend=backend,
)
kdf.derive(self._KEY_MATERIAL)
with pytest.raises(AlreadyFinalized):
kdf.derive(self._KEY_MATERIAL2)
kdf = KBKDFCMAC(
algorithms.AES,
Mode.CounterMode,
32,
4,
4,
CounterLocation.BeforeFixed,
b"label",
b"context",
None,
backend=backend,
)
key = kdf.derive(self._KEY_MATERIAL)
with pytest.raises(AlreadyFinalized):
kdf.verify(self._KEY_MATERIAL, key)
kdf = KBKDFCMAC(
algorithms.AES,
Mode.CounterMode,
32,
4,
4,
CounterLocation.BeforeFixed,
b"label",
b"context",
None,
backend=backend,
)
kdf.verify(self._KEY_MATERIAL, key)
with pytest.raises(AlreadyFinalized):
kdf.verify(self._KEY_MATERIAL, key)