Constify the input parameter to UI_method_get_*

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2204)

crypto/ui/ui_lib.c

@@ -647,44 +647,43 @@ int UI_method_set_prompt_constructor(UI_METHOD *method,
     return -1;
 }
 
-int (*UI_method_get_opener(UI_METHOD *method)) (UI *)
+int (*UI_method_get_opener(const UI_METHOD *method)) (UI *)
 {
     if (method != NULL)
         return method->ui_open_session;
     return NULL;
 }
 
-int (*UI_method_get_writer(UI_METHOD *method)) (UI *, UI_STRING *)
+int (*UI_method_get_writer(const UI_METHOD *method)) (UI *, UI_STRING *)
 {
     if (method != NULL)
         return method->ui_write_string;
     return NULL;
 }
 
-int (*UI_method_get_flusher(UI_METHOD *method)) (UI *)
+int (*UI_method_get_flusher(const UI_METHOD *method)) (UI *)
 {
     if (method != NULL)
         return method->ui_flush;
     return NULL;
 }
 
-int (*UI_method_get_reader(UI_METHOD *method)) (UI *, UI_STRING *)
+int (*UI_method_get_reader(const UI_METHOD *method)) (UI *, UI_STRING *)
 {
     if (method != NULL)
         return method->ui_read_string;
     return NULL;
 }
 
-int (*UI_method_get_closer(UI_METHOD *method)) (UI *)
+int (*UI_method_get_closer(const UI_METHOD *method)) (UI *)
 {
     if (method != NULL)
         return method->ui_close_session;
     return NULL;
 }
 
-char *(*UI_method_get_prompt_constructor(UI_METHOD *method)) (UI *,
-                                                              const char *,
-                                                              const char *)
+char *(*UI_method_get_prompt_constructor(const UI_METHOD *method))
+    (UI *, const char *, const char *)
 {
     if (method != NULL)
         return method->ui_construct_prompt;

include/openssl/ui.h

@@ -284,14 +284,13 @@ int UI_method_set_prompt_constructor(UI_METHOD *method,
                                                                   *object_desc,
                                                                   const char
                                                                   *object_name));
-int (*UI_method_get_opener(UI_METHOD *method)) (UI *);
-int (*UI_method_get_writer(UI_METHOD *method)) (UI *, UI_STRING *);
-int (*UI_method_get_flusher(UI_METHOD *method)) (UI *);
-int (*UI_method_get_reader(UI_METHOD *method)) (UI *, UI_STRING *);
-int (*UI_method_get_closer(UI_METHOD *method)) (UI *);
-char *(*UI_method_get_prompt_constructor(UI_METHOD *method)) (UI *,
-                                                              const char *,
-                                                              const char *);
+int (*UI_method_get_opener(const UI_METHOD *method)) (UI *);
+int (*UI_method_get_writer(const UI_METHOD *method)) (UI *, UI_STRING *);
+int (*UI_method_get_flusher(const UI_METHOD *method)) (UI *);
+int (*UI_method_get_reader(const UI_METHOD *method)) (UI *, UI_STRING *);
+int (*UI_method_get_closer(const UI_METHOD *method)) (UI *);
+char *(*UI_method_get_prompt_constructor(const UI_METHOD *method))
+    (UI *, const char *, const char *);
 
 /*
  * The following functions are helpers for method writers to access relevant