Hinder unwanted optimisations
We want this function to be constant time. Make it less likely that the
compiler optimises it.
Signed-off-by: Janos Follath <janos.follath@arm.com>
diff --git a/library/bignum_core.c b/library/bignum_core.c
index f66739d..8374f3a 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -859,7 +859,7 @@
mbedtls_ct_condition_t mbedtls_mpi_core_check_zero_ct(const mbedtls_mpi_uint *A,
size_t limbs)
{
- mbedtls_mpi_uint bits = 0;
+ volatile mbedtls_mpi_uint bits = 0;
for (size_t i = 0; i < limbs; i++) {
bits |= A[i];