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
diff --git a/tests/suites/test_suite_bignum_mod.data b/tests/suites/test_suite_bignum_mod.data
index 5edb283..e0aa540 100644
--- a/tests/suites/test_suite_bignum_mod.data
+++ b/tests/suites/test_suite_bignum_mod.data
@@ -50,8 +50,29 @@
# END MERGE SLOT 6
# BEGIN MERGE SLOT 7
-Test mbedtls_mpi_residue_setup
-mpi_residue_setup:
+Test mbedtls_mpi_residue_setup #1 m > r
+mpi_residue_setup:"fe":"01":0
+
+Test mbedtls_mpi_residue_setup #2 r == m - 1
+mpi_residue_setup:"ff":"fe":0
+
+Test mbedtls_mpi_residue_setup #3 m->limbs > r-> limbs && m > r
+mpi_residue_setup:"000000000000000000000000000000007dfe5c6beb35a2d6":"fe":0
+
+Test mbedtls_mpi_residue_setup #4 m->limbs > r-> limbs && m > r
+mpi_residue_setup:"7ffffffffffffffffffffffffffffffffffffffffffffff1":"fe":0
+
+Test mbedtls_mpi_residue_setup #5 m->limbs > r-> limbs && m > r
+mpi_residue_setup:"7ffffffffffffffffffff000000000000000000000000000":"fe":-4
+
+Test mbedtls_mpi_residue_setup #6 m->limbs < r-> limbs && m > r
+mpi_residue_setup:"ff":"000000000000000000000000000000000000000000000001":-4
+
+Test mbedtls_mpi_residue_setup #7 r == m
+mpi_residue_setup:"fe":"fe":-4
+
+Test mbedtls_mpi_residue_setup #8 r > m
+mpi_residue_setup:"fe":"ff":-4
Test mbedtls_mpi_mod_io_neg
mpi_mod_io_neg:
diff --git a/tests/suites/test_suite_bignum_mod.function b/tests/suites/test_suite_bignum_mod.function
index 5a2d000..e4d7b41 100644
--- a/tests/suites/test_suite_bignum_mod.function
+++ b/tests/suites/test_suite_bignum_mod.function
@@ -81,52 +81,32 @@
/* BEGIN MERGE SLOT 7 */
/* BEGIN_CASE */
-void mpi_residue_setup( )
+void mpi_residue_setup( char * input_X, char * input_Y, int ret )
{
- #define RS_ONE 0
- #define RS_MAX_MIN1 1
- #define RS_MAX 2
- const char * s_data[ 3 ] = { "01", "fe", "ff" };
-
mbedtls_mpi_uint *N = NULL;
mbedtls_mpi_uint *R = NULL;
- mbedtls_mpi_uint *R_MAX = NULL;
- size_t n_limbs, r_limbs, r_max_limbs;
+ size_t n_limbs, r_limbs;
mbedtls_mpi_mod_modulus m;
mbedtls_mpi_mod_residue r;
- /* Allocate the memory for intermediate data structures */
- TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &N, &n_limbs, s_data[ RS_MAX_MIN1 ] ) );
- TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &R, &r_limbs, s_data[ RS_ONE ] ) );
- TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &R_MAX, &r_max_limbs, s_data[ RS_MAX ] ) );
-
mbedtls_mpi_mod_modulus_init( &m );
+ /* Allocate the memory for intermediate data structures */
+ TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &N, &n_limbs, input_X ) );
+ TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &R, &r_limbs, input_Y ) );
+
TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
MBEDTLS_MPI_MOD_EXT_REP_LE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
- TEST_EQUAL( 0, mbedtls_mpi_mod_residue_setup( &r, &m, R , r_limbs ) );
-
- /* Test for r-> limbs > m-> limbs */
- TEST_EQUAL( MBEDTLS_ERR_MPI_BAD_INPUT_DATA, mbedtls_mpi_mod_residue_setup( &r, &m, R , r_limbs + 1 ) );
-
- /* Test for r-> p > m-> p */
- TEST_EQUAL( MBEDTLS_ERR_MPI_BAD_INPUT_DATA, mbedtls_mpi_mod_residue_setup( &r, &m, R_MAX , r_max_limbs ) );
-
- /* Test for r-> p == m-> p */
- TEST_EQUAL( MBEDTLS_ERR_MPI_BAD_INPUT_DATA, mbedtls_mpi_mod_residue_setup( &r, &m, N , r_max_limbs ) );
+ TEST_EQUAL( ret, mbedtls_mpi_mod_residue_setup( &r, &m, R , r_limbs ) );
exit:
mbedtls_mpi_mod_modulus_free( &m );
mbedtls_free( N );
mbedtls_free( R );
- mbedtls_free( R_MAX );
-
- #undef RS_ONE
- #undef RS_MAX_MIN1
- #undef RS_MAX
}
/* END_CASE */
+
/* BEGIN_CASE */
void mpi_mod_io_neg( )
{