diff -up openssl-1.0.2i/engines/e_chil.c.chil openssl-1.0.2i/engines/e_chil.c

--- openssl-1.0.2i/engines/e_chil.c.chil	2016-09-22 12:23:06.000000000 +0200

+++ openssl-1.0.2i/engines/e_chil.c	2016-09-22 13:49:32.532017102 +0200

@@ -1274,6 +1274,11 @@ static int hwcrhk_insert_card(const char

     UI *ui;

     void *callback_data = NULL;

     UI_METHOD *ui_method = NULL;

+    /* Despite what the documentation says prompt_info can be

+     * an empty string.

+     */

+    if (prompt_info && !*prompt_info)

+        prompt_info = NULL;

     if (cactx) {

         if (cactx->ui_method)