Start introducing test_cas NULL-terminated list
diff --git a/include/mbedtls/certs.h b/include/mbedtls/certs.h
index e2e9f77..d3c92a0 100644
--- a/include/mbedtls/certs.h
+++ b/include/mbedtls/certs.h
@@ -30,10 +30,14 @@
 extern "C" {
 #endif
 
-/* Concatenation of all available CA certificates */
+/* Concatenation of all CA certificates in PEM format if available */
 extern const char   test_ca_list[];
 extern const size_t test_ca_list_len;
 
+/* List of all CA certificates, terminated by NULL */
+extern const char * test_cas[];
+extern const size_t test_cas_len[];
+
 /*
  * Convenience for users who just want a certificate:
  * RSA by default, or ECDSA if RSA is not available