cnstr_shdsc_skcipher_decap(9)

💅 cnstr_shdsc_skcipher_decap — skcipher decapsulation shared descriptor

okay so bestie, welcome to cnstr_shdsc_skcipher_decap(9) from the Kernel API Manual 🎀 — this is the little function that builds you a skcipher decapsulation shared descriptor, and honestly? it's giving "quietly doing the lord's work in the CAAM driver" energy. ✨

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✨ NAME ✨

cnstr_shdsc_skcipher_decap — skcipher decapsulation shared descriptor 🌸

no cap, that's literally what it is.

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🦋 SYNOPSIS 🦋

void cnstr_shdsc_skcipher_decap (u32 * const desc , struct alginfo
       *cdata , unsigned int ivsize , const bool is_rfc3686 , const u32
       ctx1_iv_off );

she takes five arguments and returns nothing (void) — she's a builder, not a talker, and we respect that 💅

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👑 ARGUMENTS 👑

• desc — pointer to the buffer you're using for descriptor construction. yes bestie, she needs somewhere to live, hand her a buffer 🫶
• cdata — pointer to the 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. iykyk, it's a whole ANDed situation, don't fight it ✨
  • also OP_ALG_ALGSEL_CHACHA20 — she's on the list too 🔥
• ivsize — initialization vector size. how big is your IV, bestie? 💖
• is_rfc3686 — true when ctr(aes) is wrapped by the rfc3686 template. so like, only flex the true when that wrapping is happening, mmkay? 🌈
• ctx1_iv_off — the IV offset in the CONTEXT1 register. that's her little home address in the register, no big deal ⭐

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🌟 SEE ALSO 🌟

the kernel file she lives in, for the curious girlies:

./drivers/crypto/caam/caamalg_desc.c

and her whole friend group, periodt 💀:

cnstr_shdsc_aead_null_encap(9), cnstr_shdsc_aead_null_decap(9), cnstr_shdsc_aead_encap(9), cnstr_shdsc_aead_decap(9), cnstr_shdsc_aead_givencap(9), cnstr_shdsc_gcm_encap(9), cnstr_shdsc_gcm_decap(9), cnstr_shdsc_rfc4106_encap(9), cnstr_shdsc_rfc4106_decap(9), cnstr_shdsc_rfc4543_encap(9), cnstr_shdsc_rfc4543_decap(9), cnstr_shdsc_chachapoly(9), cnstr_shdsc_skcipher_encap(9), cnstr_shdsc_xts_skcipher_encap(9), cnstr_shdsc_xts_skcipher_decap(9)

like, the whole squad showed up 🧚‍♀️

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and that's the whole page, bestie — no notes, she ate 💖

sourced straight from ./drivers/crypto/caam in the October 2026 edition of the Kernel API Manual. mwah 💋 mark your calendars, the docs are dated and iconic ✨🎀