def test_derive_key_from_label():
umbral_keying_material = keys.UmbralKeyingMaterial()
label = b"my_healthcare_information"
priv_key1 = umbral_keying_material.derive_privkey_by_label(label)
assert type(priv_key1) == keys.UmbralPrivateKey
pub_key1 = priv_key1.get_pubkey()
assert type(pub_key1) == keys.UmbralPublicKey
# Check that key derivation is reproducible
priv_key2 = umbral_keying_material.derive_privkey_by_label(label)
pub_key2 = priv_key2.get_pubkey()
assert priv_key1.bn_key == priv_key2.bn_key
assert pub_key1 == pub_key2
# A salt can be used too, but of course it affects the derived key
salt = b"optional, randomly generated salt"
priv_key3 = umbral_keying_material.derive_privkey_by_label(label,
salt=salt)
assert priv_key3.bn_key != priv_key1.bn_key
# Different labels on the same master secret create different keys
label = b"my_tax_information"
priv_key4 = umbral_keying_material.derive_privkey_by_label(label)
pub_key4 = priv_key4.get_pubkey()
assert priv_key1.bn_key != priv_key4.bn_key
def test_keying_material_serialization():
umbral_keying_material = keys.UmbralKeyingMaterial()
encoded_key = umbral_keying_material.to_bytes()
decoded_key = keys.UmbralKeyingMaterial.from_bytes(encoded_key)
assert umbral_keying_material.keying_material == decoded_key.keying_material
def test_keying_material_serialization_with_encryption():
umbral_keying_material = keys.UmbralKeyingMaterial()
encoded_key = umbral_keying_material.to_bytes(password=b'test')
decoded_key = keys.UmbralKeyingMaterial.from_bytes(encoded_key,
password=b'test')
assert umbral_keying_material.keying_material == decoded_key.keying_material