OPENSSL_CONFIG(3SSL)

📦
version 4.0.3 · 14 versions
, in ubuntu stonking

💖 OPENSSL_CONFIG — the OPENSSL_config(3SSL) manual page, bestie edition ✨

okay so welcome to the OPENSSL_CONFIG(3SSL) page 💅 this one's from the OpenSSL fam, and it's about the lil "just configure OpenSSL for me" helpers. Spoiler: they're deprecated, and we're gonna talk about why. Sit with me 🫶

🌸 NAME 🌸

OPENSSL_config, OPENSSL_no_config — simple OpenSSL configuration functions. Like, simple simple. Call-it-and-forget-it simple.

✨ SYNOPSIS ✨

#include <openssl/conf.h>

okay so heads up bestie, the way that these functions are deprecated since OpenSSL 1.1.0, you can hide them entirely by defining OPENSSL_API_COMPAT with a suitable version value — go peek at openssl_user_macros(7) for the deets:

void OPENSSL_config(const char *appname);
void OPENSSL_no_config(void);

💜 DESCRIPTION 💜

OPENSSL_config() configures OpenSSL using the standard openssl.cnf, and it reads from the application section appname. If appname is NULL, then the default section, openssl_conf, gets used instead. And here's the tea: errors are silently ignored 😭 like, no scream, no warning, nothing. Also, multiple calls have no effect — call it once, call it five times, same vibe. Periodt.

OPENSSL_no_config() disables configuration. Fr fr. If you call it before OPENSSL_config(), then no configuration takes place. That's it. That's the whole job. ✨

and if the application is built with OPENSSL_LOAD_CONF defined, then a call to OpenSSL_add_all_algorithms() will implicitly call OPENSSL_config() first. sneaky lil side effect, iykyk 👑

🎀 NOTES 🎀

The OPENSSL_config() function is designed to be a very simple "call it and forget it" function. It is however much better than nothing. 💅

but listen — applications which need finer control over their configuration functionality should use the configuration functions such as CONF_modules_load() directly. This function is deprecated and its use should be avoided 🚫 Applications should instead call CONF_modules_load() during initialization — that is, before starting any threads. get it done early, bestie, no main-character chaos later 💀

🌈 ENVIRONMENT 🌈

  • OPENSSL_CONF — the path to the config file. Ignored in set-user-ID and set-group-ID programs. so don't go trusting it in those lil privilege-swapped moments fr.

🦋 RETURN VALUES 🦋

Neither OPENSSL_config() nor OPENSSL_no_config() return a value. Void. Empty. Nothing to catch. 💀 no return code to check, so act accordingly.

⭐ SEE ALSO ⭐

👑 HISTORY 👑

The OPENSSL_no_config() and OPENSSL_config() functions were deprecated in OpenSSL 1.1.0 by OPENSSL_init_crypto(). yeah, they got replaced. it happens to the best of us 🥲

Copyright 2004-2025 The OpenSSL Project Authors. All Rights Reserved.

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!! 🎀 this was OPENSSL_CONFIG(3SSL), version 4.0.3, dated 2026-09-29 — noted and slayed ✨ go forth and call CONF_modules_load() instead, mwah 💅💜

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