Explain why we check 65535 (not USHORT_MAX)
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index a8422b1..eb372cf 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -224,6 +224,12 @@
/** Total number of limbs in \c p. */
unsigned short MBEDTLS_PRIVATE(n);
+ /* Make sure that MBEDTLS_MPI_MAX_LIMBS fits in n.
+ * Use the same limit value on all platforms so that we don't have to
+ * think about different behavior on the rare platforms where
+ * unsigned short can store values larger than the minimum required by
+ * the C language, which is 65535.
+ */
#if MBEDTLS_MPI_MAX_LIMBS > 65535
#error "MBEDTLS_MPI_MAX_LIMBS > 65535 is not supported"
#endif