UI_CREATE_METHOD(3SSL)

📦

version 4.0.3 · 14 versions

💖 UI_CREATE_METHOD(3SSL) 💖

okay so bestie, this is the OpenSSL 3SSL manual page for UI_METHOD and its whole little friend group of functions — UI_create_method, UI_destroy_method, UI_method_set_opener, UI_method_set_writer, UI_method_set_flusher, UI_method_set_reader, UI_method_set_closer, UI_method_set_data_duplicator, UI_method_set_prompt_constructor, UI_method_set_ex_data, UI_method_get_opener, UI_method_get_writer, UI_method_get_flusher, UI_method_get_reader, UI_method_get_closer, UI_method_get_data_duplicator, UI_method_get_data_destructor, UI_method_get_prompt_constructor, and UI_method_get_ex_data. It's giving "user interface method creation and destruction" ✨ — basically how you invent your own way of talking to a human, on purpose, deliberately, and you slay it.

✨ SYNOPSIS ✨

like, first you gotta say the magic words:

#include <openssl/ui.h>

typedef struct ui_method_st UI_METHOD;

UI_METHOD *UI_create_method(const char *name);
void UI_destroy_method(UI_METHOD *ui_method);
int UI_method_set_opener(UI_METHOD *method, int (*opener) (UI *ui));
int UI_method_set_writer(UI_METHOD *method,
                         int (*writer) (UI *ui, UI_STRING *uis));
int UI_method_set_flusher(UI_METHOD *method, int (*flusher) (UI *ui));
int UI_method_set_reader(UI_METHOD *method,
                         int (*reader) (UI *ui, UI_STRING *uis));
int UI_method_set_closer(UI_METHOD *method, int (*closer) (UI *ui));
int UI_method_set_data_duplicator(UI_METHOD *method,
                                  void *(*duplicator) (UI *ui, void *ui_data),
                                  void (*destructor)(UI *ui, void *ui_data));
int UI_method_set_prompt_constructor(UI_METHOD *method,
                                     char *(*prompt_constructor) (UI *ui,
                                                                  const char
                                                                  *object_desc,
                                                                  const char
                                                                  *object_name));
int UI_method_set_ex_data(UI_METHOD *method, int idx, void *data);
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 *);
void *(*UI_method_get_data_duplicator(const UI_METHOD *method)) (UI *, void *);
void (*UI_method_get_data_destructor(const UI_METHOD *method)) (UI *, void *);
const void *UI_method_get_ex_data(const UI_METHOD *method, int idx);

🌸 DESCRIPTION 🌸

A method is literally just a little bag of functions that implement the low-level of the User Interface. That's it. That's the vibe. And the functions in the bag are:

an opener — this one takes a reference to a UI and starts a session. like, opening a channel to a tty, or creating a dialog box. girlboss entrance energy 💅
a writer — this one takes a reference to a UI and a UI String, and writes the string where it belongs. maybe to the tty, maybe as a field label in a dialog box. ⚠️ note note note: this gets fed all strings associated with a UI, one after the other, so you better take care which ones it actually uses. no cap.
a flusher — this one takes a reference to a UI, and flushes everything that's been output so far. for example, if the method builds up a dialog box, this is what you use to actually display it and accept input, ended with a pressed button. iconic behavior.
a reader — this one takes a reference to a UI and a UI string, and reads off the given prompt. maybe from the tty, maybe from a field in a dialog box. ⚠️ again: it gets fed all strings associated with a UI, one after the other, so take care which ones it actually uses.
a closer — this one takes a reference to a UI, and closes the session. maybe by closing the channel to the tty, maybe by destroying a dialog box. bye bestie 🫶

All of these functions are expected to return 0 on error, 1 on success, or -1 on out-off-band events — for example if some prompting has been cancelled (by pressing Ctrl+C, for example). Only the flusher or the reader are expected to return -1. If it comes back from any of the other functions, it's treated as if 0 was returned. 🫠

Regarding the writer and the reader: don't assume the former should only write and don't assume the latter should only read. It fully depends on the needs of the method. read that again. it's giving plot twist.

For example, a typical tty reader wouldn't write the prompts in the write, but would rather do so in the reader — because of the sequential nature of prompting on a tty. (This is how the UI_OpenSSL() method does it. 👑) In contrast, a method that builds up a dialog box would add all prompt text in the writer, have all input read in the flusher and store the results in some temporary buffer, and finally have the reader just fetch those results. two completely different girls, both valid.

The central function that uses these method functions is UI_process(), and it does it in five steps:

Open the session using the opener function if that one's defined. If an error occurs, jump to 5.
For every UI String associated with the UI, call the writer function if that one's defined. If an error occurs, jump to 5.
Flush everything using the flusher function if that one's defined. If an error occurs, jump to 5.
For every UI String associated with the UI, call the reader function if that one's defined. If an error occurs, jump to 5.
Close the session using the closer function if that one's defined.

UI_create_method() creates a new UI method with a given name. ✨ brand new baby method

UI_destroy_method() destroys the given UI method ui_method. rip to that method, she lived 💀

UI_method_set_opener(), UI_method_set_writer(), UI_method_set_flusher(), UI_method_set_reader() and UI_method_set_closer() set the five main method functions to the given function pointer.

UI_method_set_data_duplicator() sets the user data duplicator and destructor. See UI_dup_user_data(3).

UI_method_set_prompt_constructor() sets the prompt constructor. See UI_construct_prompt(3).

UI_method_set_ex_data() sets application specific data with a given EX_DATA index. See CRYPTO_get_ex_new_index(3) for general information on how to get that index.

UI_method_get_opener(), UI_method_get_writer(), UI_method_get_flusher(), UI_method_get_reader(), UI_method_get_closer(), UI_method_get_data_duplicator(), UI_method_get_data_destructor() and UI_method_get_prompt_constructor() return the different method functions.

UI_method_get_ex_data() returns the application data previously stored with UI_method_set_ex_data().

🔥 RETURN VALUES 🔥

okay so here's the receipts:

UI_create_method() returns a UI_METHOD pointer on success, NULL on error.
UI_method_set_opener(), UI_method_set_writer(), UI_method_set_flusher(), UI_method_set_reader(), UI_method_set_closer(), UI_method_set_data_duplicator() and UI_method_set_prompt_constructor() return 0 on success, -1 if the given method is NULL.
UI_method_set_ex_data() returns 1 on success and 0 on error (because CRYPTO_set_ex_data() does so). not her fault, she's just matching energy.
UI_method_get_opener(), UI_method_get_writer(), UI_method_get_flusher(), UI_method_get_reader(), UI_method_get_closer(), UI_method_get_data_duplicator(), UI_method_get_data_destructor() and UI_method_get_prompt_constructor() return the requested function pointer if it's set in the method, otherwise NULL.
UI_method_get_ex_data() returns a pointer to the application specific data associated with the method.

🦋 SEE ALSO 🦋

🎀 HISTORY 🎀

The UI_method_set_data_duplicator(), UI_method_get_data_duplicator() and UI_method_get_data_destructor() functions were added in OpenSSL 1.1.1. vintage but make it fashion ✨

💜 COPYRIGHT 💜

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

and that's the whole page bestie, no notes 💅 this was UI_CREATE_METHOD(3SSL) from OpenSSL 4.0.3, dated 2026-09-29 — go forth and build your own user interface method, you absolute main character 👑✨

📦 where this page comes from

ubuntu stonking: libssl-doc 4.0.3-1ubuntu1 · Apache-2.0
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-11-03: a language model's rewrite of the original, under its terms