STRUCT AES_CMAC_KEY(9)

✨ struct aes_cmac_key(9) ✨

okay bestie so this is a page from the Kernel API Manual and it's literally all about struct aes_cmac_key — no cap, that's the whole vibe 💅

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🌸 NAME 🌸

struct aes_cmac_key — the prepared key for AES-CMAC or AES-XCBC-MAC 🎀

Like, it's the key, but prepared, y'know? It's giving "I've already done my skincare routine" energy. ✨

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🦋 SYNOPSIS 🦋

struct aes_cmac_key {
    struct aes_enckey aes;
    union {
      u8 b[AES_BLOCK_SIZE];
      __be64 w[2];
    } k_final[2];
 };

ok so that's the whole struct, copied exactly, don't come for me 😭 keep it character-for-character bestie.

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👑 Members 👑

• aes — the AES key for cipher block chaining. that's her. the main character key 🔥
• k_final — the finalization subkeys for the final block, and the way this works is so specific so listen up 🫶: k_final[0] (that's CMAC K1, XCBC-MAC K2) gets used if it's a full block. and k_final[1] (that's CMAC K2, XCBC-MAC K3) gets used if it's a partial block. yes bestie, [0] for full, [1] for partial, write it down 📝

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🌈 SEE ALSO 🌈

go look at the kernel file ./include/crypto/aes-cbc-macs.h — it's got the whole friend group in there:

• aes_cmac_zeroize_key(9)
• struct aes_cmac_ctx(9)
• aes_cmac_zeroize_ctx(9)
• aes_cmac_preparekey(9)
• aes_xcbcmac_preparekey(9)
• aes_cmac_init(9)
• aes_cmac_update(9)
• aes_cmac_final(9)
• aes_cmac(9)

literally the whole squad, iykyk 💖

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🧚 and that's the page!! sourced from ./include/crypto, dated October 2026 — mwah, iconic, periodt. bye bestie, go prep those keys 💅⭐🍓