Add support for directoryName subjectAltName

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index ed1dcaf..abdc5aa 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -289,6 +289,17 @@
                 *p++ = san->san.unstructured_name.p[i];
             }
             break;/* MBEDTLS_X509_SAN_RFC822_NAME */
+        case (MBEDTLS_X509_SAN_DIRECTORY_NAME):
+            ret = mbedtls_snprintf(p, n, "\ndirectoryName : ");
+            MBEDTLS_X509_SAFE_SNPRINTF;
+            ret = mbedtls_x509_dn_gets(p, n, &san->san.directory_name);
+            if (ret < 0) {
+                return ret;
+            }
+
+            p += ret;
+            n -= ret;
+            break;/* MBEDTLS_X509_SAN_DIRECTORY_NAME */
         default:
             /*
              * Should not happen.