key_create_or_update(9)

📦 version 7.3.1, in nixpkgs unstable

✨ key_create_or_update ✨

okay so this is a page from the Kernel API Manual (yes, the kernel has lore too 💅) and it's all about key_create_or_update — the function that either updates a key or creates one and instantiates it. literally both jobs in one icon, we love a multitasking main character 🫶

🌸 SYNOPSIS 🌸

key_ref_t key_create_or_update (key_ref_t keyring_ref , const char *type
, const char *description , const void *payload , size_t plen ,
key_perm_t perm , unsigned long flags );

that's the whole signature bestie, take it in 🧚

🎀 ARGUMENTS 🎀

  • keyring_ref — a pointer to the destination keyring, and it's got the possession flag riding along with it 💖
  • type — the type of key, like what kind of key we're dealing with ✨
  • description — the searchable description for the key, this is how you'll find it later, no cap 🔍
  • payload — the data used to instantiate or update the key 🍓
  • plen — the length of payload, keep it honest 📏
  • perm — the permissions mask for a new key 🔐
  • flags — the quota flags for a new key 💫

🦋 DESCRIPTION 🦋

here's the vibe: it searches the destination keyring for a key with the same description. if one turns up, bestie, it gets updated. if not, it creates and instantiates a brand new one and makes a link to it from that keyring. it's giving "find or create", periodt 👑

if perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be concocted — like it just whips one up for you, iconic 🧪✨

and now the return tea ☕ it returns a pointer to the new key if it's successful. but if things go sideways:

  • -ENODEV — the key type wasn't available 😭
  • -ENOTDIR — the thing you gave it wasn't a keyring, awkward 💀
  • -EACCES — the caller isn't permitted to modify the keyring, or the LSM did not permit creation of the key 🙈
on success, the possession flag from the keyring ref will be tacked on to the key ref before it's returned. so cute, it carries the flag with it 🌈

👑 SEE ALSO 👑

the kernel file ./security/keys/key.c (iykyk) plus all these faves:

and that's the page, bestie! 🎀 this one lives in ./security/keys and it's dated October 2026 — go off, future manual ⭐💜

📦 where this page comes from