X509_EXTENSION_SET_OBJECT(3ossl)

📦
version 3.5.9 · 8 versions
, in fedora 43, fedora 44

💅 X509_EXTENSION_SET_OBJECT — the ossl manual, bestie edition ✨

okay so. this is a page from the OpenSSL manuals, and it's literally called X509_EXTENSION_SET_OBJECT(3ossl). yes the name is long. no we're not shortening it. it's iconic like that. 🎀

✨ NAME ✨

so like, the whole friend group here is:

  • X509_EXTENSION_set_object
  • X509_EXTENSION_set_critical
  • X509_EXTENSION_set_data
  • X509_EXTENSION_create_by_NID
  • X509_EXTENSION_create_by_OBJ
  • X509_EXTENSION_get_object
  • X509_EXTENSION_get_critical
  • X509_EXTENSION_get_data

and they're all extension utility functions. that's the whole vibe. extensions. utility. slay. 💖

🌸 SYNOPSIS 🌸

okay here's the receipts, copy-pasted exactly, no notes:

int X509_EXTENSION_set_object(X509_EXTENSION *ex, const ASN1_OBJECT *obj);
int X509_EXTENSION_set_critical(X509_EXTENSION *ex, int crit);
int X509_EXTENSION_set_data(X509_EXTENSION *ex, ASN1_OCTET_STRING *data);

X509_EXTENSION *X509_EXTENSION_create_by_NID(X509_EXTENSION **ex,
                                             int nid, int crit,
                                             ASN1_OCTET_STRING *data);
X509_EXTENSION *X509_EXTENSION_create_by_OBJ(X509_EXTENSION **ex,
                                             const ASN1_OBJECT *obj, int crit,
                                             ASN1_OCTET_STRING *data);

ASN1_OBJECT *X509_EXTENSION_get_object(X509_EXTENSION *ex);
int X509_EXTENSION_get_critical(const X509_EXTENSION *ex);
ASN1_OCTET_STRING *X509_EXTENSION_get_data(X509_EXTENSION *ne);

(and yes, that last one really does say ne instead of ex. not a typo on my end bestie, we keep it EXACTLY as it is. 🙈)

🦋 DESCRIPTION 🦋

the setters, aka the glow-up crew 💅

  • X509_EXTENSION_set_object() sets the extension type of ex to obj. the obj pointer gets duplicated internally, so like… go ahead and free obj after you use it. she doesn't need it anymore, she made a copy. 🫶
  • X509_EXTENSION_set_critical() sets the criticality of ex to crit. if crit is zero, the extension is non-critical, otherwise it is critical. that's it. that's the whole personality. zero = chill, not-zero = main character energy. 👑
  • X509_EXTENSION_set_data() sets the data in extension ex to data. the data pointer is duplicated internally too. same deal, she copies, you move on. ✨

the creators, aka the builders 🧚

  • X509_EXTENSION_create_by_NID() creates an extension of type nid, with criticality crit, using data data. the created extension is returned and written to *ex, reusing or allocating a new extension if necessary.
⚠️ so *ex should either be NULL or a valid X509_EXTENSION structure — it must not be an uninitialised pointer. do not pass her a mystery box, bestie, that's how you get undefined behaviour and tears. 😭
  • X509_EXTENSION_create_by_OBJ() is identical to X509_EXTENSION_create_by_NID() except it creates an extension using obj instead of a NID. same girl, different outfit. 🌈

the getters, aka the read-only queens 👑

  • X509_EXTENSION_get_object() returns the extension type of ex as an ASN1_OBJECT pointer. the returned pointer is an internal value which must not be freed up. hands off, she's not yours. 💀
  • X509_EXTENSION_get_critical() returns the criticality of extension ex — it returns 1 for critical and 0 for non-critical. a simple girl. a binary icon. 💖
  • X509_EXTENSION_get_data() returns the data of extension ex. the returned pointer is an internal value which must not be freed up. same rule as before. look, don't touch. 🙈

📝 NOTES 📝

okay important lore drop. these functions manipulate the contents of an extension directly. most applications will want to parse or encode and add an extension instead — those apps should use the extension encode and decode functions like X509_add1_ext_i2d() and X509_get_ext_d2i(). lowkey that's the move for most of y'all. 💅

also: the data associated with an extension is the extension encoding in an ASN1_OCTET_STRING structure. that's the tea. 🍓

⭐ RETURN VALUES ⭐

  • X509_EXTENSION_set_object(), X509_EXTENSION_set_critical() and X509_EXTENSION_set_data() return 1 for success and 0 for failure. simple pass/fail, no nuance, no drama. ✨
  • X509_EXTENSION_create_by_NID() and X509_EXTENSION_create_by_OBJ() return an X509_EXTENSION pointer, or NULL if an error occurs. 😭
  • X509_EXTENSION_get_object() returns an ASN1_OBJECT pointer.
  • X509_EXTENSION_get_critical() returns 0 for non-critical and 1 for critical.
  • X509_EXTENSION_get_data() returns an ASN1_OCTET_STRING pointer.

👀 SEE ALSO 👀

go read her too, she's part of the squad. 🫶

Copyright 2015-2016 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 that's the whole page, you ate it, you understood it, we're so back. this was OpenSSL 3.5.9, dated 2026-09-29, and it's the X509_EXTENSION_SET_OBJECT(3ossl) manual through and through. go forth and set those extensions, bestie, no cap. 🎀💖✨🦋🌸

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