Add tests for valid NULL in ccm_free()
diff --git a/tests/suites/test_suite_ccm.function b/tests/suites/test_suite_ccm.function
index 1886339..16f9f8e 100644
--- a/tests/suites/test_suite_ccm.function
+++ b/tests/suites/test_suite_ccm.function
@@ -530,3 +530,12 @@
     return;
 }
 /* END_CASE */
+
+/* BEGIN_CASE */
+void ccm_valid_param( )
+{
+    TEST_VALID_PARAM( mbedtls_ccm_free( NULL ) );
+exit:
+    return;
+}
+/* END_CASE */