Add low level subtraction with modulus
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index b43add7..9a8e3ee 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -108,6 +108,16 @@
/* BEGIN MERGE SLOT 2 */
+void mbedtls_mpi_mod_raw_sub( mbedtls_mpi_uint *X,
+ const mbedtls_mpi_uint *A,
+ const mbedtls_mpi_uint *B,
+ const mbedtls_mpi_mod_modulus *N )
+{
+ mbedtls_mpi_uint c = mbedtls_mpi_core_sub( X, A, B, N->limbs );
+
+ (void) mbedtls_mpi_core_add_if( X, N->p, N->limbs, c );
+}
+
/* END MERGE SLOT 2 */
/* BEGIN MERGE SLOT 3 */