Move secret key tweak functions to secret keys module (#1464)

squeaknode/core/secret_keys.py

@@ -0,0 +1,48 @@
+# MIT License
+#
+# Copyright (c) 2020 Jonathan Zernik
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+from squeak.core.elliptic import generate_random_scalar
+from squeak.core.elliptic import scalar_difference
+from squeak.core.elliptic import scalar_from_bytes
+from squeak.core.elliptic import scalar_sum
+from squeak.core.elliptic import scalar_to_bytes
+
+
+DATA_KEY_LENGTH = 32
+
+
+def generate_tweak():
+    tweak = generate_random_scalar()
+    return scalar_to_bytes(tweak)
+
+
+def add_tweak(n, tweak):
+    n_int = scalar_from_bytes(n)
+    tweak_int = scalar_from_bytes(tweak)
+    sum_int = scalar_sum(n_int, tweak_int)
+    return scalar_to_bytes(sum_int)
+
+
+def subtract_tweak(n, tweak):
+    n_int = scalar_from_bytes(n)
+    tweak_int = scalar_from_bytes(tweak)
+    sum_int = scalar_difference(n_int, tweak_int)
+    return scalar_to_bytes(sum_int)

squeaknode/core/squeak_core.py

@@ -38,6 +38,9 @@ from squeaknode.core.peer_address import PeerAddress
 from squeaknode.core.received_offer import ReceivedOffer
 from squeaknode.core.received_payment import ReceivedPayment
 from squeaknode.core.received_payment_stream import ReceivedPaymentsStream
+from squeaknode.core.secret_keys import add_tweak
+from squeaknode.core.secret_keys import generate_tweak
+from squeaknode.core.secret_keys import subtract_tweak
 from squeaknode.core.sent_offer import SentOffer
 from squeaknode.core.sent_payment import SentPayment
 from squeaknode.core.squeak_profile import SqueakProfile
@@ -46,9 +49,6 @@ from squeaknode.core.squeaks import get_decrypted_content
 from squeaknode.core.squeaks import get_hash
 from squeaknode.core.squeaks import get_payment_point_of_secret_key
 from squeaknode.core.squeaks import make_squeak_with_block
-from squeaknode.core.util import add_tweak
-from squeaknode.core.util import generate_tweak
-from squeaknode.core.util import subtract_tweak
 from squeaknode.lightning.lnd_lightning_client import LNDLightningClient
 
 

squeaknode/core/util.py

@@ -23,11 +23,6 @@ import random
 
 from bitcoin.base58 import Base58ChecksumError
 from bitcoin.wallet import CBitcoinAddressError
-from squeak.core.elliptic import generate_random_scalar
-from squeak.core.elliptic import scalar_difference
-from squeak.core.elliptic import scalar_from_bytes
-from squeak.core.elliptic import scalar_sum
-from squeak.core.elliptic import scalar_to_bytes
 from squeak.core.signing import CSqueakAddress
 
 
@@ -46,25 +41,6 @@ def generate_ping_nonce() -> int:
     return random.SystemRandom().getrandbits(64)
 
 
-def generate_tweak():
-    tweak = generate_random_scalar()
-    return scalar_to_bytes(tweak)
-
-
-def add_tweak(n, tweak):
-    n_int = scalar_from_bytes(n)
-    tweak_int = scalar_from_bytes(tweak)
-    sum_int = scalar_sum(n_int, tweak_int)
-    return scalar_to_bytes(sum_int)
-
-
-def subtract_tweak(n, tweak):
-    n_int = scalar_from_bytes(n)
-    tweak_int = scalar_from_bytes(tweak)
-    sum_int = scalar_difference(n_int, tweak_int)
-    return scalar_to_bytes(sum_int)
-
-
 def is_address_valid(address: str) -> bool:
     if not address:
         return False

tests/core/test_secret_keys.py

@@ -0,0 +1,44 @@
+# MIT License
+#
+# Copyright (c) 2020 Jonathan Zernik
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+import pytest
+from squeak.core.elliptic import generate_secret_key
+
+from squeaknode.core.secret_keys import add_tweak
+from squeaknode.core.secret_keys import generate_tweak
+from squeaknode.core.secret_keys import subtract_tweak
+
+
+@pytest.fixture
+def secret_key():
+    yield generate_secret_key()
+
+
+@pytest.fixture
+def tweak():
+    yield generate_tweak()
+
+
+def test_add_subtract_tweak(secret_key, tweak):
+    tweaked_secret_key = add_tweak(secret_key, tweak)
+    untweaked_secret_key = subtract_tweak(tweaked_secret_key, tweak)
+
+    assert untweaked_secret_key == secret_key