Move bignum flag for negative zero into test_info

Add accessors ready for protection with test_info mutex.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
This commit is contained in:
Paul Elliott 2023-11-03 18:44:57 +00:00
parent 5c498f355d
commit c7a1e9936a
5 changed files with 57 additions and 25 deletions

View file

@ -77,30 +77,22 @@ void mbedtls_test_mpi_mod_modulus_free_with_limbs(mbedtls_mpi_mod_modulus *N);
*
* - This function guarantees that if \p s begins with '-' then the sign
* bit of the result will be negative, even if the value is 0.
* When this function encounters such a "negative 0", it
* increments #mbedtls_test_case_uses_negative_0.
* - The size of the result is exactly the minimum number of limbs needed
* to fit the digits in the input. In particular, this function constructs
* a bignum with 0 limbs for an empty string, and a bignum with leading 0
* limbs if the string has sufficiently many leading 0 digits.
* This is important so that the "0 (null)" and "0 (1 limb)" and
* "leading zeros" test cases do what they claim.
* When this function encounters such a "negative 0", it calls
* mbedtls_test_increment_case_uses_negative_0().
* - The size of the result is exactly the minimum number of limbs needed to fit
* the digits in the input. In particular, this function constructs a bignum
* with 0 limbs for an empty string, and a bignum with leading 0 limbs if the
* string has sufficiently many leading 0 digits. This is important so that
* the "0 (null)" and "0 (1 limb)" and "leading zeros" test cases do what they
* claim.
*
* \param[out] X The MPI object to populate. It must be initialized.
* \param[in] s The null-terminated hexadecimal string to read from.
* \param[out] X The MPI object to populate. It must be initialized.
* \param[in] s The null-terminated hexadecimal string to read from.
*
* \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
*/
int mbedtls_test_read_mpi(mbedtls_mpi *X, const char *s);
/** Nonzero if the current test case had an input parsed with
* mbedtls_test_read_mpi() that is a negative 0 (`"-"`, `"-0"`, `"-00"`, etc.,
* constructing a result with the sign bit set to -1 and the value being
* all-limbs-0, which is not a valid representation in #mbedtls_mpi but is
* tested for robustness).
*/
extern unsigned mbedtls_test_case_uses_negative_0;
#endif /* MBEDTLS_BIGNUM_C */
#endif /* TEST_BIGNUM_HELPERS_H */