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Diffstat (limited to 'tests/hazmat/primitives/test_hkdf.py')
-rw-r--r-- | tests/hazmat/primitives/test_hkdf.py | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/tests/hazmat/primitives/test_hkdf.py b/tests/hazmat/primitives/test_hkdf.py new file mode 100644 index 00000000..3d9dffda --- /dev/null +++ b/tests/hazmat/primitives/test_hkdf.py @@ -0,0 +1,85 @@ +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or +# implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from __future__ import absolute_import, division, print_function + +import pytest + +from cryptography import exceptions +from cryptography.hazmat.primitives import hashes +from cryptography.hazmat.primitives.kdf.hkdf import HKDF + + +@pytest.mark.hash +class TestHKDF(object): + def test_length_limit(self, backend): + big_length = 255 * (hashes.SHA256().digest_size // 8) + 1 + + with pytest.raises(ValueError): + HKDF( + hashes.SHA256(), + big_length, + salt=None, + info=None, + backend=backend + ) + + def test_already_finalized(self, backend): + hkdf = HKDF( + hashes.SHA256(), + 16, + salt=None, + info=None, + backend=backend + ) + + hkdf.derive('\x01' * 16) + + with pytest.raises(exceptions.AlreadyFinalized): + hkdf.derive('\x02' * 16) + + hkdf = HKDF( + hashes.SHA256(), + 16, + salt=None, + info=None, + backend=backend + ) + + hkdf.verify('\x01' * 16, 'gJ\xfb{\xb1Oi\xc5sMC\xb7\xe4@\xf7u') + + with pytest.raises(exceptions.AlreadyFinalized): + hkdf.verify('\x02' * 16, 'gJ\xfb{\xb1Oi\xc5sMC\xb7\xe4@\xf7u') + + def test_verify(self, backend): + hkdf = HKDF( + hashes.SHA256(), + 16, + salt=None, + info=None, + backend=backend + ) + + hkdf.verify('\x01' * 16, 'gJ\xfb{\xb1Oi\xc5sMC\xb7\xe4@\xf7u') + + def test_verify_invalid(self, backend): + hkdf = HKDF( + hashes.SHA256(), + 16, + salt=None, + info=None, + backend=backend + ) + + with pytest.raises(exceptions.InvalidKey): + hkdf.verify('\x02' * 16, 'gJ\xfb{\xb1Oi\xc5sMC\xb7\xe4@\xf7u') |