Enforce NULL context for hardcoded RNG
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index ccd4d42..f5b61f3 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -356,6 +356,18 @@
 }
 #endif
 
+#if defined(MBEDTLS_SSL_CONF_RNG)
+int rng_wrap( void *ctx, unsigned char *dst, size_t len )
+{
+    ((void) ctx);
+    ((void) dst);
+    ((void) len);
+    /* We don't expect test suites to use SSL functionality
+     * that would trigger the hardcoded RNG. */
+    return( -1 );
+}
+#endif /* MBEDTLS_SSL_CONF_RNG */
+
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 static int redirect_output( FILE** out_stream, const char* path )
 {