diff options
Diffstat (limited to 'pyecsca/ec/params.py')
| -rw-r--r-- | pyecsca/ec/params.py | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/pyecsca/ec/params.py b/pyecsca/ec/params.py index f92b2ca..2ec9706 100644 --- a/pyecsca/ec/params.py +++ b/pyecsca/ec/params.py @@ -1,5 +1,5 @@ import json -from sympy import Poly, PythonFiniteField, symbols, sympify +from sympy import Poly, FF, symbols, sympify from astunparse import unparse from io import RawIOBase, BufferedIOBase from os.path import join @@ -11,6 +11,7 @@ from public import public from .coordinates import AffineCoordinateModel, CoordinateModel from .curve import EllipticCurve +from .error import UnsatisfiedAssumptionError from .mod import Mod from .model import (CurveModel, ShortWeierstrassModel, MontgomeryModel, EdwardsModel, TwistedEdwardsModel) @@ -133,17 +134,17 @@ def _create_params(curve, coords, infty): exec(compiled, None, alocals) for param, value in alocals.items(): if params[param] != value: - raise ValueError( + raise UnsatisfiedAssumptionError( f"Coordinate model {coord_model} has an unsatisifed assumption on the {param} parameter (= {value}).") except NameError: - k = PythonFiniteField(field) + k = FF(field) assumption_string = unparse(assumption) lhs, rhs = assumption_string.split(" = ") expr = sympify(f"{rhs} - {lhs}") for curve_param, value in params.items(): expr = expr.subs(curve_param, k(value)) if len(expr.free_symbols) > 1 or (param := str(expr.free_symbols.pop())) not in coord_model.parameters: - raise ValueError(f"This coordinate model couldn't be loaded due to unsupported asusmption ({assumption_string}).") + raise ValueError(f"This coordinate model couldn't be loaded due to an unsupported assumption ({assumption_string}).") poly = Poly(expr, symbols(param), domain=k) roots = poly.ground_roots() for root in roots.keys(): @@ -151,7 +152,7 @@ def _create_params(curve, coords, infty): params[param] = Mod(int(root), field) break else: - raise ValueError(f"Coordinate model {coord_model} has an unsatisifed assumption on the {param} parameter (0 = {expr}).") + raise UnsatisfiedAssumptionError(f"Coordinate model {coord_model} has an unsatisifed assumption on the {param} parameter (0 = {expr}).") # Construct the point at infinity infinity: Point @@ -238,20 +239,25 @@ def load_params(file: Union[str, Path, BinaryIO], coords: str, infty: bool = Tru return _create_params(curve, coords, infty) + @public def get_category(category: str, coords: Union[str, Callable[[str], str]], infty: Union[bool, Callable[[str], bool]] = True) -> DomainParameterCategory: """ + Retrieve a category from the std-curves database at https://github.com/J08nY/std-curves. - :param category: - :param coords: - :param infty: - :return: + :param category: The category to retrieve. + :param coords: The name of the coordinate system to use. Can be a callable that takes + as argument the name of the curve and produces the coordinate system to use for that curve. + :param infty: Whether to use the special :py:class:InfinityPoint (`True`) or try to use the + point at infinity of the coordinate system. Can be a callable that takes + as argument the name of the curve and returns the infinity option to use for that curve. + :return: The category. """ listing = resource_listdir(__name__, "std") categories = list(entry for entry in listing if resource_isdir(__name__, join("std", entry))) if category not in categories: - raise ValueError("Category {} not found.".format(category)) + raise ValueError(f"Category {category} not found.") json_path = join("std", category, "curves.json") with resource_stream(__name__, json_path) as f: return load_category(f, coords, infty) @@ -273,7 +279,7 @@ def get_params(category: str, name: str, coords: str, infty: bool = True) -> Dom listing = resource_listdir(__name__, "std") categories = list(entry for entry in listing if resource_isdir(__name__, join("std", entry))) if category not in categories: - raise ValueError("Category {} not found.".format(category)) + raise ValueError(f"Category {category} not found.") json_path = join("std", category, "curves.json") with resource_stream(__name__, json_path) as f: category_json = json.load(f) @@ -281,6 +287,6 @@ def get_params(category: str, name: str, coords: str, infty: bool = True) -> Dom if curve["name"] == name: break else: - raise ValueError("Curve {} not found in category {}.".format(name, category)) + raise ValueError(f"Curve {name} not found in category {category}.") return _create_params(curve, coords, infty) |