Simplify logic and document test_cases_for_values
Explain what's going on in BignumModRawConvertRep.test_case_for_values.
Simplify the logic and the interdependencies related to limb sizes:
* Montgomery is the special case, so base the decisions on it.
* As soon as we've encountered one limb size, no matter what it is,
give up.
No behavior change, other than changing the numbering of test cases (which
previously included more skipped test cases).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index 4628bff..21add3b 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -134,17 +134,32 @@
@classmethod
def test_cases_for_values(cls, rep: bignum_common.ModulusRepresentation,
n: str, a: str) -> Iterator[test_case.TestCase]:
+ """Emit test cases for the given values (if any).
+
+ This may emit no test cases if a isn't valid for the modulus n,
+ or multiple test cases if rep requires different data depending
+ on the limb size.
+ """
for bil in cls.limb_sizes:
test_object = cls(n, a, bits_in_limb=bil)
test_object.set_representation(rep)
- #Filters out the duplicate
- if rep == bignum_common.ModulusRepresentation.OPT_RED:
+ # The class is set to having separate test cases for each limb
+ # size, because the Montgomery representation requires it.
+ # But other representations don't require it. So for other
+ # representations, emit a single test case with no dependency
+ # on the limb size.
+ if rep is not bignum_common.ModulusRepresentation.MONTGOMERY:
test_object.dependencies = []
- if bil == 64:
- continue
if test_object.is_valid:
yield test_object.create_test_case()
+ if rep is not bignum_common.ModulusRepresentation.MONTGOMERY:
+ # A single test case (emitted, or skipped due to invalidity)
+ # is enough, since this test case doesn't depend on the
+ # limb size.
+ break
+ # The parent class doesn't support non-bignum parameters. So we override
+ # test generation, in order to have the representation as a parameter.
@classmethod
def generate_function_tests(cls) -> Iterator[test_case.TestCase]: