bignum_mod: Adjusted input checking for `mbedtls_mpi_mod_residue_setup()`
This patch adjusts the logic of the size checking of the method,
and refactors the tests. Documentation has also been updated.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/library/bignum_mod.c b/library/bignum_mod.c
index 6c13b4b..770e633 100644
--- a/library/bignum_mod.c
+++ b/library/bignum_mod.c
@@ -39,7 +39,7 @@
mbedtls_mpi_uint *p,
size_t p_limbs )
{
- if( p_limbs > m->limbs || !mbedtls_mpi_core_lt_ct( p, m->p, m->limbs ) )
+ if( p_limbs > m->limbs || !mbedtls_mpi_core_lt_ct( p, m->p, p_limbs ) )
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
r->limbs = m->limbs;
diff --git a/library/bignum_mod.h b/library/bignum_mod.h
index 9378aab..4a01dfc 100644
--- a/library/bignum_mod.h
+++ b/library/bignum_mod.h
@@ -75,16 +75,17 @@
/** Setup a residue structure.
*
- * \param[out] r The address of residue to setup. The size is determined by
- * \p m.
- * (In particular, it must have at least as many limbs as the
- * modulus \p m.)
+ * \param[out] r The address of residue to setup. The resulting structure's
+ * size is determined by \p m.
* \param[in] m The address of the modulus related to \p r.
* \param[in] p The address of the limb array storing the value of \p r.
* The memory pointed to by \p p will be used by \p r and must
* not be modified in any way until after
- * mbedtls_mpi_mod_residue_release() is called.
- * \param p_limbs The number of limbs of \p p.
+ * mbedtls_mpi_mod_residue_release() is called. The data
+ * pointed by p should be compatible (in terms of size/endianness)
+ * with the representation used in \p m.
+ * \param p_limbs The number of limbs of \p p. It must have at most as
+ * many limbs as the modulus \p m.)
*
* \return \c 0 if successful.
* \return #MBEDTLS_ERR_MPI_BAD_INPUT_DATA if \p p_limbs is less than the