Reduce the size of mbedtls_mpi
Reduce the size of mbedtls_mpi from 3 words to 2 on most architectures.
This also reduces the code size significantly in bignum.o and ecp_curves.o,
with negligible variations in other modules.
This removes the ability to set MBEDTLS_MPI_MAX_LIMBS to a value >=65536,
but we don't support customizing this value anyway (it's always 10000).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index a4fa663..9acf778 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4512,12 +4512,13 @@
defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
/*
* Create an MPI from embedded constants
- * (assumes len is an exact multiple of sizeof(mbedtls_mpi_uint))
+ * (assumes len is an exact multiple of sizeof(mbedtls_mpi_uint) and
+ * len < 1048576)
*/
static inline void ecp_mpi_load(mbedtls_mpi *X, const mbedtls_mpi_uint *p, size_t len)
{
X->s = 1;
- X->n = len / sizeof(mbedtls_mpi_uint);
+ X->n = (unsigned short) (len / sizeof(mbedtls_mpi_uint));
X->p = (mbedtls_mpi_uint *) p;
}
#endif