OPENSSL_INIT_SSL(3SSL)

💖 OPENSSL_INIT_SSL(3SSL) — the girlies' guide to waking up OpenSSL 💖

okay bestie, pull up a chair 🪑 because we're talking about OPENSSL_init_ssl — that's the little glow-up function from the OpenSSL manuals. It's the one that gets libssl and libcrypto out of bed in the morning. ☀️

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✨ NAME ✨

OPENSSL_init_ssl — OpenSSL (libssl and libcrypto) initialisation. she's literally the alarm clock for the whole library bestie ⏰💅

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🌸 SYNOPSIS 🌸

#include <openssl/ssl.h>

int OPENSSL_init_ssl(uint64_t opts, const OPENSSL_INIT_SETTINGS *settings);

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🦋 DESCRIPTION 🦋

so here's the tea 🍵 During normal operation, OpenSSL (that's libssl and libcrypto, both of them, together, holding hands 🫶) allocates a bunch of resources at start up, and those resources absolutely MUST be freed on close down of the library. Not optional. Not a vibe. Must. 🚨

And on top of that, some resources get allocated on a per thread basis (so if your app is multi-threaded, yes, those too bestie), and those resources must be freed prior to the thread closing. no dangling, no leftovers, no mess 💀

But here's the iconic part: as of version 1.1.0, OpenSSL will automatically allocate all the resources it needs, so like… no explicit initialisation is required. she just handles it 💅 Same energy on the way out — she also automatically deinitialises as required. self-care queen 👑

However!! there are still situations where explicit initialisation is desirable or needed — for example when some nondefault initialisation is required. and that's where OPENSSL_init_ssl() comes in, serving looks ✨

Calling this function will explicitly initialise BOTH libcrypto and libssl. Both. no cap. If you want to explicitly initialise ONLY libcrypto, go check the OPENSSL_init_crypto(3) function instead, that's a different girl 💜

Also super important: numerous internal OpenSSL functions call OPENSSL_init_ssl(). So — and this is the part you cannot skip — in order to perform nondefault initialisation, OPENSSL_init_ssl() MUST be called by application code prior to any other OpenSSL function calls. before. first. no exceptions bestie 😭

The opts parameter specifies which aspects of libssl and libcrypto should be initialised. Valid options for libcrypto are described on the OPENSSL_init_crypto(3) page. And in addition to any libcrypto specific option, these libssl options can also be used 🎀:

• OPENSSL_INIT_NO_LOAD_SSL_STRINGS — suppresses automatic loading of the libssl error strings. This option is not a default option. Once selected, subsequent calls to OPENSSL_init_ssl() with the option OPENSSL_INIT_LOAD_SSL_STRINGS will be ignored. 🙈
• OPENSSL_INIT_LOAD_SSL_STRINGS — automatic loading of the libssl error strings. This option is a default option. Once selected, subsequent calls to OPENSSL_init_ssl() with the option OPENSSL_INIT_LOAD_SSL_STRINGS will be ignored. (yes, it says the same thing twice — that's what the page says, we're not editing the queen's words 💖)

OPENSSL_init_ssl() takes a settings parameter which can be used to set parameter values. See OPENSSL_init_crypto(3) for the details, she's got the lore 📖

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⭐ RETURN VALUES ⭐

The function OPENSSL_init_ssl() returns 1 on success or 0 on error. that's it, that's the whole binary mood 🌈

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🔥 SEE ALSO 🔥

• OPENSSL_init_crypto(3)

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👑 HISTORY 👑

The OPENSSL_init_ssl() function was added in OpenSSL 1.1.0. a true 1.1.0 era icon, iykyk ✨

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🎀 COPYRIGHT 🎀

Copyright 2016-2020 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>.

fr fr, read the license bestie, it's giving legally binding 💀

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and that's the page!! 🦋 this was version 4.0.3, dated 2026-09-29, and it's the OPENSSL_INIT_SSL(3SSL) manual page from OpenSSL. mwah 💋 go init responsibly, bestie 💖🌸✨