PR: 2192

Submitted By: Jaroslav Imrich <jaroslav.imrich@disig.sk>

The prompt_info and wrong_info parameters can be empty strings which
can produce confusing prompts. Treat empty string same as NULL.

engines/e_chil.c

@@ -1201,6 +1201,11 @@ static int hwcrhk_get_pass(const char *prompt_info,
 	pem_password_cb *callback = NULL;
 	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)
                 {
@@ -1302,8 +1307,10 @@ static int hwcrhk_insert_card(const char *prompt_info,
 		{
 		char answer;
 		char buf[BUFSIZ];
-
-		if (wrong_info)
+		/* Despite what the documentation says wrong_info can be
+	 	 * an empty string.
+		 */
+		if (wrong_info && *wrong_info)
 			BIO_snprintf(buf, sizeof(buf)-1,
 				"Current card: \"%s\"\n", wrong_info);
 		ok = UI_dup_info_string(ui, buf);