Add validation tests for mbedtls_mpi_{mod,mod_raw}_random
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_bignum_random.data b/tests/suites/test_suite_bignum_random.data
index b51254b..b486f38 100644
--- a/tests/suites/test_suite_bignum_random.data
+++ b/tests/suites/test_suite_bignum_random.data
@@ -263,3 +263,48 @@
MPI random mod=core: 0..2^256+1
mpi_mod_random_values:0:"010000000000000000000000000000000000000000000000000000000000000001"
+
+MPI random mod validation: 1 limb, good, 0..1
+mpi_mod_random_validation:0:"1":0:0
+
+MPI random mod validation: 1 limb, good, 1..3
+mpi_mod_random_validation:1:"3":0:0
+
+MPI random mod validation: 1 limb, good, 2..3
+mpi_mod_random_validation:2:"3":0:0
+
+MPI random mod validation: 1 limb, good, 3..5
+mpi_mod_random_validation:3:"5":0:0
+
+MPI random mod validation: 1 limb, good, 4..5
+mpi_mod_random_validation:4:"5":0:0
+
+MPI random mod validation: 1 limb, good, 5..7
+mpi_mod_random_validation:5:"7":0:0
+
+MPI random mod validation: 1 limb, good, 6..7
+mpi_mod_random_validation:6:"7":0:0
+
+MPI random mod validation: 1 limb, good, 0..0x123
+mpi_mod_random_validation:0:"123":0:0
+
+MPI random mod validation: 2+ limbs, good
+mpi_mod_random_validation:0:"01234567890123456789":0:0
+
+MPI random mod validation: 1 limb, output null
+mpi_mod_random_validation:0:"123":-1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+MPI random mod validation: 1 limb, output too large
+mpi_mod_random_validation:0:"123":1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+MPI random mod validation: 2+ limbs, output too small
+mpi_mod_random_validation:0:"01234567890123456789":-1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+MPI random mod validation: 2+ limbs, output too large
+mpi_mod_random_validation:0:"01234567890123456789":1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+MPI random mod validation: min == upper bound
+mpi_mod_random_validation:0x123:"123":-1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
+
+MPI random mod validation: min > upper bound
+mpi_mod_random_validation:0x124:"123":-1:MBEDTLS_ERR_MPI_BAD_INPUT_DATA
diff --git a/tests/suites/test_suite_bignum_random.function b/tests/suites/test_suite_bignum_random.function
index 4ee26ad..61db40d 100644
--- a/tests/suites/test_suite_bignum_random.function
+++ b/tests/suites/test_suite_bignum_random.function
@@ -387,6 +387,66 @@
/* END_CASE */
/* BEGIN_CASE */
+void mpi_mod_random_validation( int min, char *bound_hex,
+ int result_limbs_delta,
+ int expected_ret )
+{
+ mbedtls_mpi_uint *result_digits = NULL;
+ mbedtls_mpi_mod_modulus N;
+ mbedtls_mpi_mod_modulus_init( &N );
+
+ TEST_EQUAL( mbedtls_test_read_mpi_modulus( &N, bound_hex,
+ MBEDTLS_MPI_MOD_REP_MONTGOMERY ),
+ 0 );
+ size_t result_limbs = N.limbs + result_limbs_delta;
+ ASSERT_ALLOC( result_digits, result_limbs );
+ /* Build a reside that might not match the modulus, to test that
+ * the library function rejects that as expected. */
+ mbedtls_mpi_mod_residue result = {result_digits, result_limbs};
+
+ TEST_EQUAL( mbedtls_mpi_mod_random( &result, min, &N,
+ mbedtls_test_rnd_std_rand, NULL ),
+ expected_ret );
+ if( expected_ret == 0 )
+ {
+ /* Success should only be expected when the result has the same
+ * size as the modulus, otherwise it's a mistake in the test data. */
+ TEST_EQUAL( result_limbs, N.limbs );
+ /* Sanity check: check that the result is in range */
+ TEST_EQUAL( mbedtls_mpi_mod_raw_from_mont_rep( result_digits, &N ), 0 );
+ TEST_EQUAL( mbedtls_mpi_core_lt_ct( result_digits, N.p, N.limbs ),
+ 1 );
+ /* Check result >= min (changes result) */
+ TEST_EQUAL( mbedtls_mpi_core_sub_int( result_digits, result_digits, min,
+ result_limbs ),
+ 0 );
+ }
+
+ /* When the result has the right number of limbs, also test mod_raw
+ * (for which this is an unchecked precondition). */
+ if( result_limbs_delta == 0 )
+ {
+ TEST_EQUAL( mbedtls_mpi_mod_raw_random( result_digits, min, &N,
+ mbedtls_test_rnd_std_rand, NULL ),
+ expected_ret );
+ if( expected_ret == 0 )
+ {
+ TEST_EQUAL( mbedtls_mpi_mod_raw_from_mont_rep( result_digits, &N ), 0 );
+ TEST_EQUAL( mbedtls_mpi_core_lt_ct( result_digits, N.p, N.limbs ),
+ 1 );
+ TEST_EQUAL( mbedtls_mpi_core_sub_int( result_digits, result.p, min,
+ result_limbs ),
+ 0 );
+ }
+ }
+
+exit:
+ mbedtls_test_mpi_mod_modulus_free_with_limbs( &N );
+ mbedtls_free( result_digits );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
void mpi_random_fail( int min, data_t *bound_bytes, int expected_ret )
{
mbedtls_mpi upper_bound;