cnstr_shdsc_aead_givencap(9)

📦 version 7.3.1, in nixpkgs unstable

💅 cnstr_shdsc_aead_givencap 💅

okay so bestie, welcome to the Kernel API Manual entry for cnstr_shdsc_aead_givencap — literally the function that builds you an IPSec ESP encapsulation shared descriptor (non-protocol flavoured ✨) with a HW-generated initialization vector. no cap, that's the whole NAME section, she's lowkey iconic.

✨ SYNOPSIS ✨

void cnstr_shdsc_aead_givencap (u32 * const desc , struct alginfo *cdata
, struct alginfo *adata , unsigned int ivsize , unsigned int icvsize ,
const bool is_rfc3686 , u32 *nonce , const u32 ctx1_iv_off , const bool
is_qi , int era );

void, bestie. she returns nothing. she just builds. main character energy fr fr 🫶

🎀 ARGUMENTS 🎀

  • desc — pointer to the buffer used for descriptor construction. this is where the magic gets written, she's the canvas 💖
  • cdata — pointer to block cipher transform definitions. valid algorithm values are one of OP_ALG_ALGSEL_{AES, DES, 3DES} ANDed with OP_ALG_AAI_CBC or OP_ALG_AAI_CTR_MOD128. that's the whole list, don't come for me 🌸
  • adata — pointer to authentication transform definitions. heads up queen: a split key is required for SEC Era < 6, and in that case the size of the split key is specified here. valid algorithm values are one of OP_ALG_ALGSEL_{MD5, SHA1, SHA224, SHA256, SHA384, SHA512} ANDed with OP_ALG_AAI_HMAC_PRECOMP. slay 💅
  • ivsize — initialization vector size. literally the size of the IV 🦋
  • icvsize — integrity check value (ICV) size, and yes it can be truncated or full, your call ✨
  • is_rfc3686 — true when ctr(aes) is wrapped by the rfc3686 template. a little bool doing a big job 👑
  • nonce — pointer to the rfc3686 nonce 🎀
  • ctx1_iv_off — IV offset in the CONTEXT1 register. it's const u32, so don't even think about it 🔥
  • is_qi — true when called from caam/qi ⭐
  • era — SEC Era. just... the era. know your era bestie 💜

🌈 SEE ALSO 🌈

the kernel file she lives in:

./drivers/crypto/caam/caamalg_desc.c

and her whole friend group, all iconics, all (9):

go read them. iykyk 📚

okay that's the whole page, mwah 💋 — signed off from ./drivers/crypto/caam, dated October 2026, and the queen herself is cnstr_shdsc_aead_givencap(9). periodt 🧚‍♀️💖

📦 where this page comes from