mbedtls/scripts/mbedtls_dev/bignum_common.py
Werner Lewis 99e8178fa7 Add module for bignum_core test generation
Separate file is added for classes used to generate cases for tests
in bignum_core.function. Common elements of the BignumOperation class
are added to classes in a new common file, for use across files.

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
2022-10-19 15:20:01 +01:00

111 lines
3.7 KiB
Python

"""Common features for bignum in test generation framework."""
# Copyright The Mbed TLS Contributors
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import itertools
import typing
from abc import abstractmethod
from typing import Iterator, List, Tuple, TypeVar
T = TypeVar('T') #pylint: disable=invalid-name
def hex_to_int(val: str) -> int:
return int(val, 16) if val else 0
def quote_str(val) -> str:
return "\"{}\"".format(val)
def bound_mpi8(val: int) -> int:
"""First number exceeding 8-byte limbs needed for given input value."""
return bound_mpi8_limbs(limbs_mpi8(val))
def bound_mpi4(val: int) -> int:
"""First number exceeding 4-byte limbs needed for given input value."""
return bound_mpi4_limbs(limbs_mpi4(val))
def bound_mpi8_limbs(limbs: int) -> int:
"""First number exceeding maximum of given 8-byte limbs."""
bits = 64 * limbs
return 1 << bits
def bound_mpi4_limbs(limbs: int) -> int:
"""First number exceeding maximum of given 4-byte limbs."""
bits = 32 * limbs
return 1 << bits
def limbs_mpi8(val: int) -> int:
"""Return the number of 8-byte limbs required to store value."""
return (val.bit_length() + 63) // 64
def limbs_mpi4(val: int) -> int:
"""Return the number of 4-byte limbs required to store value."""
return (val.bit_length() + 31) // 32
def combination_pairs(values: List[T]) -> List[Tuple[T, T]]:
"""Return all pair combinations from input values.
The return value is cast, as older versions of mypy are unable to derive
the specific type returned by itertools.combinations_with_replacement.
"""
return typing.cast(
List[Tuple[T, T]],
list(itertools.combinations_with_replacement(values, 2))
)
class OperationCommon:
"""Common features for bignum binary operations.
This adds functionality common in binary operation tests.
Attributes:
symbol: Symbol to use for the operation in case description.
input_values: List of values to use as test case inputs. These are
combined to produce pairs of values.
input_cases: List of tuples containing pairs of test case inputs. This
can be used to implement specific pairs of inputs.
"""
symbol = ""
input_values = [] # type: List[str]
input_cases = [] # type: List[Tuple[str, str]]
def __init__(self, val_a: str, val_b: str) -> None:
self.arg_a = val_a
self.arg_b = val_b
self.int_a = hex_to_int(val_a)
self.int_b = hex_to_int(val_b)
def arguments(self) -> List[str]:
return [quote_str(self.arg_a), quote_str(self.arg_b), self.result()]
@abstractmethod
def result(self) -> str:
"""Get the result of the operation.
This could be calculated during initialization and stored as `_result`
and then returned, or calculated when the method is called.
"""
raise NotImplementedError
@classmethod
def get_value_pairs(cls) -> Iterator[Tuple[str, str]]:
"""Generator to yield pairs of inputs.
Combinations are first generated from all input values, and then
specific cases provided.
"""
yield from combination_pairs(cls.input_values)
yield from cls.input_cases