PEP 484 Type Hints for pyUmbral

.gitignore

@@ -249,3 +249,4 @@ pytest.ini
 /tests/metrics/.benchmarks/
 tests/metrics/histograms/
 .circleci/execute_build.sh
+/monkeytype.sqlite3

mypy.ini

@@ -1,9 +1,10 @@
 [mypy]
 python_version=3.6
-verbosity=1
+verbosity=0
+ignore_missing_imports=True
 [mypy-umbral.*]
-disallow_untyped_defs=True
+disallow_untyped_defs=False
 check_untyped_defs=False
-disallow_untyped_calls=True
+disallow_untyped_calls=False
 [mypy-umbral.openssl]
 disallow_untyped_defs=False

tests/fixtures.py

@@ -0,0 +1,62 @@
+from collections import namedtuple
+
+import pytest
+
+from umbral import keys
+from umbral.curvebn import CurveBN
+from umbral.point import Point
+
+MockKeyPair = namedtuple('TestKeyPair', 'priv pub')
+
+
+parameters = [
+    # (N, M)
+    (1, 1),
+    (6, 1),
+    (6, 4),
+    (6, 6),
+    (50, 30)
+]
+
+wrong_parameters = [
+    # (N, M)
+    (-1, -1),   (-1, 0),    (-1, 5),
+    (0, -1),    (0, 0),     (0, 5),
+    (1, -1),    (1, 0),     (1, 5),
+    (5, -1),    (5, 0),     (5, 10)
+]
+
+
+@pytest.fixture(scope='function')
+def alices_keys():
+    delegating_priv = keys.UmbralPrivateKey.gen_key()
+    signing_priv = keys.UmbralPrivateKey.gen_key()
+    return delegating_priv, signing_priv
+
+
+@pytest.fixture(scope='function')
+def bobs_keys():
+    priv = keys.UmbralPrivateKey.gen_key()
+    pub = priv.get_pubkey()
+    return MockKeyPair(priv, pub)
+
+
+@pytest.fixture()
+def random_ec_point1():
+    yield Point.gen_rand()
+
+
+@pytest.fixture()
+def random_ec_point2():
+    yield Point.gen_rand()
+
+
+@pytest.fixture()
+def random_ec_curvebn1():
+    yield CurveBN.gen_rand()
+
+
+@pytest.fixture()
+def random_ec_curvebn2():
+    yield CurveBN.gen_rand()
+

umbral/_pre.py

@@ -1,20 +1,21 @@
+from typing import Optional
+
 from umbral.curvebn import CurveBN
-from umbral.config import default_params
 from umbral.keys import UmbralPublicKey
-from umbral.params import UmbralParameters
 
 
-def prove_cfrag_correctness(cfrag: "CapsuleFrag",
-                            kfrag: "KFrag",
-                            capsule: "Capsule",
-                            metadata: bytes = None
-                            ) -> "CorrectnessProof":
+def prove_cfrag_correctness(cfrag: 'CapsuleFrag',
+                            kfrag: 'KFrag',
+                            capsule: 'Capsule',
+                            metadata: Optional[bytes] = None
+                            ) -> 'CorrectnessProof':
+
     params = capsule._umbral_params
 
     rk = kfrag._bn_key
     t = CurveBN.gen_rand(params.curve)
     ####
-    ## Here are the formulaic constituents shared with `assess_cfrag_correctness`.
+    # Here are the formulaic constituents shared with `assess_cfrag_correctness`.
     ####
     e = capsule._point_e
     v = capsule._point_v
@@ -45,7 +46,7 @@ def prove_cfrag_correctness(cfrag: "CapsuleFrag",
         raise capsule.NotValid("Capsule verification failed.")
 
 
-def assess_cfrag_correctness(cfrag, capsule: "Capsule"):
+def assess_cfrag_correctness(cfrag: 'CapsuleFrag', capsule: 'Capsule') -> bool:
 
     correctness_keys = capsule.get_correctness_keys()
 
@@ -62,7 +63,7 @@ def assess_cfrag_correctness(cfrag, capsule: "Capsule"):
     params = capsule._umbral_params
 
     ####
-    ## Here are the formulaic constituents shared with `prove_cfrag_correctness`.
+    # Here are the formulaic constituents shared with `prove_cfrag_correctness`.
     ####
     e = capsule._point_e
     v = capsule._point_v
@@ -110,11 +111,11 @@ def assess_cfrag_correctness(cfrag, capsule: "Capsule"):
            & correct_rk_commitment
 
 
-def verify_kfrag(kfrag,
+def verify_kfrag(kfrag: 'KFrag',
                  delegating_pubkey: UmbralPublicKey,
-                 signing_pubkey,
+                 signing_pubkey: UmbralPublicKey,
                  receiving_pubkey: UmbralPublicKey
-                 ):
+                 ) -> bool:
 
 
     params = delegating_pubkey.params

umbral/config.py

@@ -1,6 +1,8 @@
+from typing import Optional, Type
 from warnings import warn
 
 from umbral.curve import Curve, SECP256K1
+from umbral.params import UmbralParameters
 
 
 class _CONFIG:
@@ -18,19 +20,19 @@ def __set_curve_by_default(cls):
         cls.set_curve(cls.__CURVE_TO_USE_IF_NO_DEFAULT_IS_SET_BY_USER)
 
     @classmethod
-    def params(cls):
+    def params(cls) -> UmbralParameters:
         if not cls.__params:
             cls.__set_curve_by_default()
         return cls.__params
 
     @classmethod
-    def curve(cls):
+    def curve(cls) -> Type[Curve]:
         if not cls.__curve:
             cls.__set_curve_by_default()
         return cls.__curve
 
     @classmethod
-    def set_curve(cls, curve: Curve=None):
+    def set_curve(cls, curve: Optional[Curve] = None) -> None:
         if cls.__curve:
             raise cls.UmbralConfigurationError(
                 "You can only set the default curve once.  Do it once and then leave it alone.")
@@ -42,13 +44,13 @@ def set_curve(cls, curve: Curve=None):
             cls.__params = UmbralParameters(curve)
 
 
-def set_default_curve(curve: Curve=None):
+def set_default_curve(curve: Optional[Curve] = None) -> None:
     return _CONFIG.set_curve(curve)
 
 
-def default_curve():
+def default_curve() -> Type[Curve]:
     return _CONFIG.curve()
 
 
-def default_params():
+def default_params() -> UmbralParameters:
     return _CONFIG.params()

umbral/curvebn.py

@@ -1,13 +1,11 @@
-import os
-
 from cryptography.hazmat.backends.openssl import backend
 from cryptography.hazmat.primitives import hashes
 
 from umbral import openssl
-from umbral.config import default_curve, default_params
+from umbral.config import default_curve
 from umbral.curve import Curve
-from umbral.utils import get_field_order_size_in_bytes
 from umbral.params import UmbralParameters
+from umbral.utils import get_field_order_size_in_bytes
 
 
 class CurveBN(object):
@@ -27,7 +25,7 @@ def __init__(self, bignum, curve: Curve):
         self.curve = curve
 
     @classmethod
-    def expected_bytes_length(cls, curve: Curve=None):
+    def expected_bytes_length(cls, curve: Curve=None) -> int:
         """
         Returns the size (in bytes) of a CurveBN given the curve.
         If no curve is provided, it uses the default.
@@ -36,7 +34,7 @@ def expected_bytes_length(cls, curve: Curve=None):
         return get_field_order_size_in_bytes(curve)
 
     @classmethod
-    def gen_rand(cls, curve: Curve=None):
+    def gen_rand(cls, curve: Curve=None) -> 'CurveBN':
         """
         Returns a CurveBN object with a cryptographically secure OpenSSL BIGNUM
         based on the given curve.
@@ -56,7 +54,7 @@ def gen_rand(cls, curve: Curve=None):
         return cls(new_rand_bn, curve)
 
     @classmethod
-    def from_int(cls, num, curve: Curve=None):
+    def from_int(cls, num: int, curve: Curve=None) -> 'CurveBN':
         """
         Returns a CurveBN object from a given integer on a curve.
         By default, the underlying OpenSSL BIGNUM has BN_FLG_CONSTTIME set for
@@ -67,7 +65,7 @@ def from_int(cls, num, curve: Curve=None):
         return cls(conv_bn, curve)
 
     @classmethod
-    def hash(cls, *crypto_items, params: UmbralParameters):
+    def hash(cls, *crypto_items, params: UmbralParameters) -> 'CurveBN':
         # TODO: Clean this in an upcoming cleanup of pyUmbral
         blake2b = hashes.Hash(hashes.BLAKE2b(64), backend=backend)
         for item in crypto_items:
@@ -101,7 +99,7 @@ def hash(cls, *crypto_items, params: UmbralParameters):
         return cls(bignum, params.curve)
 
     @classmethod
-    def from_bytes(cls, data, curve: Curve=None):
+    def from_bytes(cls, data: bytes, curve: Curve=None) -> 'CurveBN':
         """
         Returns a CurveBN object from the given byte data that's within the size
         of the provided curve's order.
@@ -112,20 +110,20 @@ def from_bytes(cls, data, curve: Curve=None):
         num = int.from_bytes(data, 'big')
         return cls.from_int(num, curve)
 
-    def to_bytes(self):
+    def to_bytes(self) -> bytes:
         """
         Returns the CurveBN as bytes.
         """
         size = backend._lib.BN_num_bytes(self.curve.order)
         return int.to_bytes(int(self), size, 'big')
 
-    def __int__(self):
+    def __int__(self) -> int:
         """
         Converts the CurveBN to a Python int.
         """
         return backend._bn_to_int(self.bignum)
 
-    def __eq__(self, other):
+    def __eq__(self, other) -> bool:
         """
         Compares the two BIGNUMS or int.
         """
@@ -137,7 +135,7 @@ def __eq__(self, other):
         # -1 less than, 0 is equal to, 1 is greater than
         return not bool(backend._lib.BN_cmp(self.bignum, other.bignum))
 
-    def __pow__(self, other):
+    def __pow__(self, other) -> 'CurveBN':
         """
         Performs a BN_mod_exp on two BIGNUMS.
 
@@ -157,7 +155,7 @@ def __pow__(self, other):
 
         return CurveBN(power, self.curve)
 
-    def __mul__(self, other):
+    def __mul__(self, other) -> 'CurveBN':
         """
         Performs a BN_mod_mul between two BIGNUMS.
         """
@@ -173,7 +171,7 @@ def __mul__(self, other):
 
         return CurveBN(product, self.curve)
 
-    def __truediv__(self, other):
+    def __truediv__(self, other) -> 'CurveBN':
         """
         Performs a BN_div on two BIGNUMs (modulo the order of the curve).
 
@@ -193,7 +191,7 @@ def __truediv__(self, other):
 
         return CurveBN(product, self.curve)
 
-    def __add__(self, other):
+    def __add__(self, other) -> 'CurveBN':
         """
         Performs a BN_mod_add on two BIGNUMs.
         """
@@ -206,7 +204,7 @@ def __add__(self, other):
 
         return CurveBN(op_sum, self.curve)
 
-    def __sub__(self, other):
+    def __sub__(self, other) -> 'CurveBN':
         """
         Performs a BN_mod_sub on two BIGNUMS.
         """
@@ -219,7 +217,7 @@ def __sub__(self, other):
 
         return CurveBN(diff, self.curve)
 
-    def __invert__(self):
+    def __invert__(self) -> 'CurveBN':
         """
         Performs a BN_mod_inverse.
 
@@ -235,7 +233,7 @@ def __invert__(self):
 
         return CurveBN(inv, self.curve)
 
-    def __mod__(self, other):
+    def __mod__(self, other) -> 'CurveBN':
         """
         Performs a BN_nnmod on two BIGNUMS.
         """

umbral/dem.py

@@ -1,4 +1,6 @@
 import os
+from typing import Optional
+
 from cryptography.hazmat.primitives.ciphers.aead import ChaCha20Poly1305
 
 
@@ -7,7 +9,7 @@
 
 
 class UmbralDEM(object):
-    def __init__(self, symm_key: bytes):
+    def __init__(self, symm_key: bytes) -> None:
         """
         Initializes an UmbralDEM object. Requires a key to perform
         ChaCha20-Poly1305.
@@ -19,7 +21,7 @@ def __init__(self, symm_key: bytes):
 
         self.cipher = ChaCha20Poly1305(symm_key)
 
-    def encrypt(self, data: bytes, authenticated_data: bytes=None):
+    def encrypt(self, data: bytes, authenticated_data: Optional[bytes] = None) -> bytes:
         """
         Encrypts data using ChaCha20-Poly1305 with optional authenticated data.
         """
@@ -28,7 +30,7 @@ def encrypt(self, data: bytes, authenticated_data: bytes=None):
         # Ciphertext will be a 12 byte nonce, the ciphertext, and a 16 byte tag.
         return nonce + enc_data
 
-    def decrypt(self, ciphertext: bytes, authenticated_data: bytes=None):
+    def decrypt(self, ciphertext: bytes, authenticated_data: Optional[bytes] = None) -> bytes:
         """
         Decrypts data using ChaCha20-Poly1305 and validates the provided
         authenticated data.