diff options
Diffstat (limited to 'pyecsca/ec/point.py')
| -rw-r--r-- | pyecsca/ec/point.py | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/pyecsca/ec/point.py b/pyecsca/ec/point.py index b39cef7..280d746 100644 --- a/pyecsca/ec/point.py +++ b/pyecsca/ec/point.py @@ -5,7 +5,7 @@ from typing import Mapping, TYPE_CHECKING from public import public from .context import ResultAction -from .coordinates import AffineCoordinateModel, CoordinateModel, EFDCoordinateModel +from .coordinates import AffineCoordinateModel, CoordinateModel from .mod import Mod, Undefined from .op import CodeOp @@ -44,7 +44,9 @@ class Point: def __init__(self, model: CoordinateModel, **coords: Mod): if not set(model.variables) == set(coords.keys()): - raise ValueError(f"Wrong coordinate values for coordinate model, expected {model.variables} got {coords.keys()}.") + raise ValueError( + f"Wrong coordinate values for coordinate model, expected {model.variables} got {coords.keys()}." + ) self.coordinate_model = model self.coords = coords field = None @@ -82,7 +84,9 @@ class Point: pass result_variables = set(map(lambda x: x.result, ops)) if not result_variables.issuperset(affine_model.variables): - raise NotImplementedError(f"Coordinate model does have affine mapping function ({result_variables})") + raise NotImplementedError( + f"Coordinate model does have affine mapping function ({result_variables})" + ) result = {} locls = {**self.coords} for op in ops: @@ -98,7 +102,10 @@ class Point: return action.exit(Point(affine_model, **result)) def to_model( - self, coordinate_model: CoordinateModel, curve: "EllipticCurve" + self, + coordinate_model: CoordinateModel, + curve: "EllipticCurve", + randomized: bool = False, ) -> "Point": """Convert an affine point into a given coordinate model, if possible.""" if not isinstance(self.coordinate_model, AffineCoordinateModel): @@ -122,10 +129,18 @@ class Point: continue result = {} for var in coordinate_model.variables: - if var in locls: # Try this first. - result[var] = Mod(locls[var], curve.prime) if not isinstance(locls[var], Mod) else locls[var] + if var in locls: + result[var] = ( + Mod(locls[var], curve.prime) + if not isinstance(locls[var], Mod) + else locls[var] + ) else: raise NotImplementedError + if randomized: + lmbd = Mod.random(curve.prime) + for var, value in result.items(): + result[var] = value * lmbd**coordinate_model.homogweights[var] return action.exit(Point(coordinate_model, **result)) def equals_affine(self, other: "Point") -> bool: @@ -183,7 +198,13 @@ class Point: return self.coords == other.coords def __hash__(self): - return hash((self.coordinate_model, tuple(self.coords.keys()), tuple(self.coords.values()))) + return hash( + ( + self.coordinate_model, + tuple(self.coords.keys()), + tuple(self.coords.values()), + ) + ) def __str__(self): args = ", ".join([f"{key}={val}" for key, val in self.coords.items()]) @@ -205,7 +226,8 @@ class InfinityPoint(Point): return InfinityPoint(AffineCoordinateModel(self.coordinate_model.curve_model)) def to_model( - self, coordinate_model: CoordinateModel, curve: "EllipticCurve" + self, coordinate_model: CoordinateModel, curve: "EllipticCurve", + randomized: bool = False ) -> "InfinityPoint": return InfinityPoint(coordinate_model) |