SSL_CTX_FREE(3SSL)

📦
version 4.0.3 · 14 versions
, in ubuntu stonking

💖 SSL_CTX_free 💖

okay bestie, this is the OpenSSL manual page for SSL_CTX_free — yes it's from the 3SSL section, iykyk — and honestly? it's giving "spring cleaning for your SSL context." let's get into it 🧹✨

🎀 NAME 🎀

SSL_CTX_free — free an allocated SSL_CTX object

like. it frees it. that's the whole job. and it does it immaculately. 💅

🌸 SYNOPSIS 🌸

#include <openssl/ssl.h>

void SSL_CTX_free(SSL_CTX *ctx);

that's it. one function, one argument, returns nothing. lowkey iconic in its simplicity. 🦋

✨ DESCRIPTION ✨

So here's the tea, bestie. SSL_CTX_free() does a little reference count thing:

  • it decrements the reference count of ctx
  • and removes the SSL_CTX object pointed to by ctx
  • and frees up the allocated memory — but ONLY if the reference count has reached 0

so if your refcount isn't at zero yet? the object stays. it's not over till the refcount says it's over. periodt. 💀

And because SSL_CTX is a whole main character holding onto a bunch of other stuff, it also calls the free()ing procedures for indirectly affected items, if applicable:

  • the session cache
  • the list of ciphers
  • the list of Client CAs
  • the certificates and keys

she's cleaning up after herself. we love a responsible queen. 👑

And if ctx is NULL? nothing is done. no crash, no drama, no nothing. a true gentleman. 🙈

⚠️ WARNINGS ⚠️

okay this part is important, don't scroll past it 🚨

If a session-remove callback is set — that's SSL_CTX_sess_set_remove_cb() — then that callback will be called for each session being freed from ctx's session cache.

Which means… (and hear me out) all corresponding sessions from an external session cache are removed as well. 😭

If that is not what you want — if you're sitting there like "bestie I did NOT consent to that" — then the user should explicitly unset the callback by calling:

SSL_CTX_sess_set_remove_cb(ctx, NULL)

…prior to calling SSL_CTX_free().

no cap: unset it first. order matters. do not skip this step. 🫶

🦋 RETURN VALUES 🦋

SSL_CTX_free() does not provide diagnostic information.

that's it. that's the whole section. she gives you nothing back. no return value to obsess over, no error code to decode. you just free her and move on. 💜

🌈 SEE ALSO 🌈

go read these too, they're part of the universe. ✨

Copyright 2000-2016 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>.

okay and that's the whole page, bestie 💖 remember: decrement, and only actually free at 0, and unset that remove callback if you don't want your external sessions ghosted.

this has been SSL_CTX_FREE(3SSL), from OpenSSL 4.0.3, dated 2026-09-29. slay, stay memory-safe, and don't leak. 🎀🦋💅

📦 where this page comes from