ocs_hcu_hmac(9)

📦 version 7.3.1, in nixpkgs unstable

💖 ocs_hcu_hmac — Kernel API Manual ✨

okay so bestie, welcome to the Kernel API Manual entry for ocs_hcu_hmac(9) — literally the function whose whole entire job is computing an HMAC. that's it. that's the vibe. no cap. 🎀

🌸 NAME 🌸

ocs_hcu_hmac — compute HMAC. yes ghoul, it does exactly what the name says, main character energy from the very first line 💅

✨ SYNOPSIS ✨

int ocs_hcu_hmac (struct ocs_hcu_dev *hcu_dev , enum ocs_hcu_algo algo ,
const u8 *key , size_t key_len , const struct ocs_hcu_dma_list *dma_list
, u8 *dgst , size_t dgst_len );

look at that signature. it's giving seven-whole-parameters. she's thorough, she's precise, she does not skip a single argument 🔥

🦋 ARGUMENTS 🦋

okay so let's go through every single one of these, because nobody's getting left out on my watch 🫶

  • hcu_dev — the OCS HCU device to use. this is your hardware bestie, the one actually doing the work 💪
  • algo — the hash algorithm to use with HMAC. it's an enum ocs_hcu_algo, so pick your fave, but like... actually pick the right one 🙈
  • key — the key to use. the secret ingredient. the whole personality of the HMAC tbh 🔑
  • key_len — the length of key. it's a size_t, and yes you do have to get it right ⭐
  • dma_list — the OCS DMA list mapping the input data to process. it's a const struct ocs_hcu_dma_list *, so the data's already mapped and ready to slay 🌈
  • dgst — the buffer where to save the computed HMAC. this is where the finished product lands, so make sure it's got room 💖
  • dgst_len — the length of dgst. again with the size_t. again: get it right, bestie 😭

👑 RETURN 👑

  • 0 on success
  • negative error code otherwise

that's literally it. zero is the slay outcome, anything negative means something went sideways and you should probably look into it 💀

🧚 SEE ALSO 🧚

the kernel file for all of this lives at ./drivers/crypto/intel/keembay/ocs-hcu.c — highly recommend a lil scroll if ur nosy like me 👀

and the whole friend group, in order:

iykyk, that's the whole squad 🎀

real talk though: this page is from the ./drivers/crypto/intel/keembay directory, dated October 2026, and the page itself is ocs_hcu_hmac(9). so like, cite me properly if you're quoting me in ur writeup bestie 💜

mwah, go forth and compute those HMACs responsibly 🍓✨

📦 where this page comes from