Move to function based Mod dispatch.

pyecsca/ec/curve.py

@@ -12,7 +12,7 @@
 
 from pyecsca.ec.coordinates import CoordinateModel, AffineCoordinateModel
 from pyecsca.ec.error import raise_unsatisified_assumption
-from pyecsca.ec.mod import Mod
+from pyecsca.ec.mod import Mod, mod
 from pyecsca.ec.model import CurveModel
 from pyecsca.ec.point import Point, InfinityPoint
 
@@ -37,12 +37,12 @@ class EllipticCurve:
 
     >>> from pyecsca.ec.coordinates import AffineCoordinateModel
     >>> affine = AffineCoordinateModel(curve.model)
-    >>> points_P = sorted(curve.affine_lift_x(Mod(5, curve.prime)), key=lambda p: int(p.y))
+    >>> points_P = sorted(curve.affine_lift_x(mod(5, curve.prime)), key=lambda p: int(p.y))
     >>> points_P  # doctest: +NORMALIZE_WHITESPACE
     [Point([x=5, y=31468013646237722594854082025316614106172411895747863909393730389177298123724] in shortw/affine),
      Point([x=5, y=84324075564118526167843364924090959423913731519542450286139900919689799730227] in shortw/affine)]
     >>> P = points_P[0]
-    >>> Q = Point(affine, x=Mod(106156966968002564385990772707119429362097710917623193504777452220576981858057, curve.prime), y=Mod(89283496902772247016522581906930535517715184283144143693965440110672128480043, curve.prime))
+    >>> Q = Point(affine, x=mod(106156966968002564385990772707119429362097710917623193504777452220576981858057, curve.prime), y=mod(89283496902772247016522581906930535517715184283144143693965440110672128480043, curve.prime))
     >>> curve.affine_add(P, Q)
     Point([x=110884201872336783252492544257507655322265785208411447156687491781308462893723, y=17851997459724035659875545393642578516937407971293368958749928013979790074156] in shortw/affine)
     >>> curve.affine_multiply(P, 10)
@@ -94,7 +94,7 @@ def __init__(
                 if value.n != prime:
                     raise ValueError(f"Parameter {name} has wrong modulus.")
             else:
-                value = Mod(value, prime)
+                value = mod(value, prime)
             self.parameters[name] = value
         self.neutral = neutral
         self.__validate_coord_assumptions()
@@ -147,9 +147,9 @@ def _execute_base_formulas(self, formulas: List[Module], *points: Point) -> Poin
         for line in formulas:
             exec(compile(line, "", mode="exec"), None, locls)  # exec is OK here, skipcq: PYL-W0122
         if not isinstance(locls["x"], Mod):
-            locls["x"] = Mod(locls["x"], self.prime)
+            locls["x"] = mod(locls["x"], self.prime)
         if not isinstance(locls["y"], Mod):
-            locls["y"] = Mod(locls["y"], self.prime)
+            locls["y"] = mod(locls["y"], self.prime)
         return Point(AffineCoordinateModel(self.model), x=locls["x"], y=locls["y"])
 
     def affine_add(self, one: Point, other: Point) -> Point:
@@ -234,9 +234,9 @@ def affine_neutral(self) -> Optional[Point]:
         for line in self.model.base_neutral:
             exec(compile(line, "", mode="exec"), None, locls)  # exec is OK here, skipcq: PYL-W0122
         if not isinstance(locls["x"], Mod):
-            locls["x"] = Mod(locls["x"], self.prime)
+            locls["x"] = mod(locls["x"], self.prime)
         if not isinstance(locls["y"], Mod):
-            locls["y"] = Mod(locls["y"], self.prime)
+            locls["y"] = mod(locls["y"], self.prime)
         return Point(AffineCoordinateModel(self.model), x=locls["x"], y=locls["y"])
 
     @property
@@ -314,15 +314,15 @@ def decode_point(self, encoded: bytes) -> Point:
                 raise ValueError("Encoded point has bad length")
             coords = {}
             for var in sorted(self.coordinate_model.variables):
-                coords[var] = Mod(int.from_bytes(data[:coord_len], "big"), self.prime)
+                coords[var] = mod(int.from_bytes(data[:coord_len], "big"), self.prime)
                 data = data[coord_len:]
             return Point(self.coordinate_model, **coords)
         elif encoded[0] in (0x02, 0x03):
             if isinstance(self.coordinate_model, AffineCoordinateModel):
                 data = encoded[1:]
                 if len(data) != coord_len:
                     raise ValueError("Encoded point has bad length")
-                x = Mod(int.from_bytes(data, "big"), self.prime)
+                x = mod(int.from_bytes(data, "big"), self.prime)
                 loc = {**self.parameters, "x": x}
                 rhs = eval(compile(self.model.ysquared, "", mode="eval"), loc)  # eval is OK here, skipcq: PYL-W0123
                 if not rhs.is_residue():

pyecsca/ec/divpoly.py

@@ -8,7 +8,7 @@
 import networkx as nx
 
 from pyecsca.ec.curve import EllipticCurve
-from pyecsca.ec.mod import Mod
+from pyecsca.ec.mod import Mod, mod
 from pyecsca.ec.model import ShortWeierstrassModel
 
 has_pari = False
@@ -90,9 +90,9 @@ def a_invariants(curve: EllipticCurve) -> Tuple[Mod, ...]:
     :return: A tuple of 5 a-invariants (a1, a2, a3, a4, a6).
     """
     if isinstance(curve.model, ShortWeierstrassModel):
-        a1 = Mod(0, curve.prime)
-        a2 = Mod(0, curve.prime)
-        a3 = Mod(0, curve.prime)
+        a1 = mod(0, curve.prime)
+        a2 = mod(0, curve.prime)
+        a3 = mod(0, curve.prime)
         a4 = curve.parameters["a"]
         a6 = curve.parameters["b"]
         return a1, a2, a3, a4, a6

pyecsca/ec/formula/base.py

@@ -13,7 +13,7 @@
 from pyecsca.ec.context import ResultAction
 from pyecsca.ec import context
 from pyecsca.ec.error import UnsatisfiedAssumptionError, raise_unsatisified_assumption
-from pyecsca.ec.mod import Mod, SymbolicMod
+from pyecsca.ec.mod import Mod, SymbolicMod, mod
 from pyecsca.ec.op import CodeOp, OpType
 from pyecsca.misc.cfg import getconfig
 from pyecsca.misc.cache import sympify
@@ -191,7 +191,7 @@ def __validate_assumption_simple(self, lhs, rhs, field, params):
                 domain = FF(field)
                 numerator, denominator = expr.as_numer_denom()
                 val = int(domain.from_sympy(numerator) / domain.from_sympy(denominator))
-                params[lhs] = Mod(val, field)
+                params[lhs] = mod(val, field)
             _assumption_cache[cache_key] = params[lhs]
         return True
 
@@ -216,7 +216,7 @@ def __validate_assumption_generic(self, lhs, rhs, field, params, assumption_stri
         poly = Poly(numerator, symbols(param), domain=domain)
         roots = poly.ground_roots()
         for root in roots:
-            params[param] = Mod(int(domain.from_sympy(root)), field)
+            params[param] = mod(int(domain.from_sympy(root)), field)
             return
         raise UnsatisfiedAssumptionError(
             f"Unsatisfied assumption in the formula ({assumption_string}).\n"
@@ -274,7 +274,7 @@ def __call__(self, field: int, *points: Any, **params: Mod) -> Tuple[Any, ...]:
                         f"Bad stuff happened in op {op}, floats will pollute the results."
                     )
                 if not isinstance(op_result, Mod):
-                    op_result = Mod(op_result, field)
+                    op_result = mod(op_result, field)
                 if context.current is not None:
                     action.add_operation(op, op_result)
                 params[op.result] = op_result

pyecsca/ec/formula/switch_sign.py

@@ -7,7 +7,7 @@
 from pyecsca.ec.formula.base import Formula
 from pyecsca.ec.formula.graph import FormulaGraph, ConstantNode, CodeOpNode, CodeFormula
 from pyecsca.ec.point import Point
-from pyecsca.ec.mod import Mod
+from pyecsca.ec.mod import Mod, mod
 
 
 @public
@@ -59,7 +59,7 @@ def sign_test(output_signs: Dict[str, int], coordinate_model: Any):
             out_var = out[: out.index(ind)]
             if not out_var.isalpha():
                 continue
-            point_dict[out_var] = Mod(sign, p)
+            point_dict[out_var] = mod(sign, p)
         point = Point(coordinate_model, **point_dict)
         try:
             apoint = point.to_affine()
@@ -68,7 +68,7 @@ def sign_test(output_signs: Dict[str, int], coordinate_model: Any):
             if scale is None:
                 raise BadSignSwitch
             apoint = scale(p, point)[0]
-        if set(apoint.coords.values()) != {Mod(1, p)}:
+        if set(apoint.coords.values()) != {mod(1, p)}:
             raise BadSignSwitch
 
 

pyecsca/ec/mod/base.py

@@ -1,5 +1,6 @@
 import random
 import secrets
+from abc import ABC
 from functools import lru_cache, wraps
 
 from public import public
@@ -123,7 +124,7 @@ def __repr__(self):
 
 
 @public
-class Mod:
+class Mod(ABC):
     """
     An element x of ℤₙ.
 
@@ -134,8 +135,8 @@ class Mod:
 
     Has all the usual special methods that upcast integers automatically:
 
-    >>> a = Mod(3, 5)
-    >>> b = Mod(2, 5)
+    >>> a = mod(3, 5)
+    >>> b = mod(2, 5)
     >>> a + b
     0
     >>> a * 2
@@ -163,21 +164,9 @@ class Mod:
     n: Any
     __slots__ = ("x", "n")
 
-    def __new__(cls, *args, **kwargs) -> "Mod":
-        if cls != Mod:
-            return cls.__new__(cls, *args, **kwargs)
-        if not _mod_classes:
-            raise ValueError("Cannot find any working Mod class.")
-        selected_class = getconfig().ec.mod_implementation
-        if selected_class not in _mod_classes:
-            # Fallback to something
-            for fallback in _mod_order:
-                if fallback in _mod_classes:
-                    selected_class = fallback
-                    break
-        return _mod_classes[selected_class].__new__(
-            _mod_classes[selected_class], *args, **kwargs
-        )
+    def __init__(self, x, n):
+        self.x = x
+        self.n = n
 
     @_check
     def __add__(self, other) -> "Mod":
@@ -269,7 +258,7 @@ def random(cls, n: int) -> "Mod":
         :return: The random :py:class:`Mod`.
         """
         with RandomModAction(n) as action:
-            return action.exit(cls(secrets.randbelow(n), n))
+            return action.exit(mod(secrets.randbelow(n), n))
 
     def __pow__(self, n) -> "Mod":
         return NotImplemented
@@ -288,8 +277,7 @@ def __new__(cls, *args, **kwargs):
         return object.__new__(cls)
 
     def __init__(self):
-        self.x = None
-        self.n = None
+        super().__init__(None, None)
 
     def __add__(self, other):
         return NotImplemented
@@ -359,3 +347,17 @@ def __hash__(self):
 
     def __pow__(self, n):
         return NotImplemented
+
+
+@public
+def mod(x, n) -> Mod:
+    if not _mod_classes:
+        raise ValueError("Cannot find any working Mod class.")
+    selected_class = getconfig().ec.mod_implementation
+    if selected_class not in _mod_classes:
+        # Fallback to something
+        for fallback in _mod_order:
+            if fallback in _mod_classes:
+                selected_class = fallback
+                break
+    return _mod_classes[selected_class](x, n)

pyecsca/ec/mod/flint.py

@@ -56,9 +56,6 @@ class FlintMod(Mod):
         _ctx: flint.fmpz_mod_ctx
         __slots__ = ("x", "_ctx")
 
-        def __new__(cls, *args, **kwargs):
-            return object.__new__(cls)
-
         def __init__(
             self,
             x: Union[int, flint.fmpz_mod],

pyecsca/ec/mod/gmp.py

@@ -44,9 +44,6 @@ class GMPMod(Mod):
         n: gmpy2.mpz
         __slots__ = ("x", "n")
 
-        def __new__(cls, *args, **kwargs):
-            return object.__new__(cls)
-
         def __init__(
             self,
             x: Union[int, gmpy2.mpz],

pyecsca/ec/mod/raw.py

@@ -15,9 +15,6 @@ class RawMod(Mod):
     n: int
     __slots__ = ("x", "n")
 
-    def __new__(cls, *args, **kwargs):
-        return object.__new__(cls)
-
     def __init__(self, x: int, n: int):
         self.x = x % n
         self.n = n
@@ -115,6 +112,6 @@ def __pow__(self, n) -> "RawMod":
         return RawMod(pow(self.x, n, self.n), self.n)
 
 
-from pyecsca.ec.mod.base import _mod_classes
+from pyecsca.ec.mod.base import _mod_classes  # noqa
 
 _mod_classes["python"] = RawMod

pyecsca/ec/mod/symbolic.py

@@ -26,9 +26,6 @@ class SymbolicMod(Mod):
     n: int
     __slots__ = ("x", "n")
 
-    def __new__(cls, *args, **kwargs):
-        return object.__new__(cls)
-
     def __init__(self, x: Expr, n: int):
         self.x = x
         self.n = n
@@ -117,6 +114,6 @@ def __pow__(self, n) -> "SymbolicMod":
         return self.__class__(pow(self.x, n), self.n)
 
 
-from pyecsca.ec.mod.base import _mod_classes
+from pyecsca.ec.mod.base import _mod_classes  # noqa
 
 _mod_classes["symbolic"] = SymbolicMod

pyecsca/ec/mod/test.pyx

@@ -1,7 +1,11 @@
-import cython
+cdef class Test:
+    def __init__(self):
+        print("here")
 
+cdef class SubTest(Test):
+    def __init__(self):
+        print("sub init")
 
-@cython.cclass
-class Test:
-    def __new__(cls, *args, **kwargs):
-        pass
+cdef class OtherTest(Test):
+    def __init__(self):
+        print("other init")

pyecsca/ec/params.py

@@ -18,7 +18,7 @@
 from pyecsca.ec.coordinates import AffineCoordinateModel, CoordinateModel
 from pyecsca.ec.curve import EllipticCurve
 from pyecsca.ec.error import raise_unsatisified_assumption
-from pyecsca.ec.mod import Mod
+from pyecsca.ec.mod import Mod, mod
 from pyecsca.ec.model import (
     CurveModel,
     ShortWeierstrassModel,
@@ -189,7 +189,7 @@ def _create_params(curve, coords, infty):
     else:
         raise ValueError("Unknown curve model.")
     params = {
-        name: Mod(int(curve["params"][name]["raw"], 16), field) for name in param_names
+        name: mod(int(curve["params"][name]["raw"], 16), field) for name in param_names
     }
 
     # Check coordinate model name and assumptions
@@ -233,7 +233,7 @@ def _create_params(curve, coords, infty):
                 poly = Poly(numerator, symbols(param), domain=k)
                 roots = poly.ground_roots()
                 for root in roots:
-                    params[param] = Mod(int(k.from_sympy(root)), field)
+                    params[param] = mod(int(k.from_sympy(root)), field)
                     break
                 else:
                     raise_unsatisified_assumption(
@@ -258,16 +258,16 @@ def _create_params(curve, coords, infty):
                 )
             value = ilocals[coordinate]
             if isinstance(value, int):
-                value = Mod(value, field)
+                value = mod(value, field)
             infinity_coords[coordinate] = value
         infinity = Point(coord_model, **infinity_coords)
     elliptic_curve = EllipticCurve(model, coord_model, field, infinity, params)  # type: ignore[arg-type]
     if "generator" not in curve:
         raise ValueError("Cannot construct curve, missing generator.")
     affine = Point(
         AffineCoordinateModel(model),
-        x=Mod(int(curve["generator"]["x"]["raw"], 16), field),
-        y=Mod(int(curve["generator"]["y"]["raw"], 16), field),
+        x=mod(int(curve["generator"]["x"]["raw"], 16), field),
+        y=mod(int(curve["generator"]["y"]["raw"], 16), field),
     )
     if not isinstance(coord_model, AffineCoordinateModel):
         generator = affine.to_model(coord_model, elliptic_curve)

pyecsca/ec/point.py

@@ -6,7 +6,7 @@
 
 from pyecsca.ec.context import ResultAction
 from pyecsca.ec.coordinates import AffineCoordinateModel, CoordinateModel
-from pyecsca.ec.mod import Mod, Undefined
+from pyecsca.ec.mod import Mod, Undefined, mod
 from pyecsca.ec.op import CodeOp
 
 
@@ -131,7 +131,7 @@ def to_model(
             for var in coordinate_model.variables:
                 if var in locls:
                     result[var] = (
-                        Mod(locls[var], curve.prime)
+                        mod(locls[var], curve.prime)
                         if not isinstance(locls[var], Mod)
                         else locls[var]
                     )