crypto_aead_chunksize(9)

💅 crypto_aead_chunksize(9) — the Kernel API Manual, bestie edition ✨

okay so this page is crypto_aead_chunksize(9), straight out of the Kernel API Manual, and it's genuinely such a little icon — tiny page, huge lore. let's get into it 🎀

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✨ NAME ✨

crypto_aead_chunksize — obtain chunk size 🧚

like. it does exactly what it says on the tin. no notes.

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🌸 SYNOPSIS 🌸

unsigned int crypto_aead_chunksize (struct crypto_aead *tfm );

that's the whole vibe check right there — one function, one argument, returns an unsigned int. simple. clean. ate. 💅

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🦋 ARGUMENTS 🦋

• tfm — the cipher handle 💖 this is your little handle to the cipher, and yes you literally have to hand it over. it's giving "give me the keys" energy.

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🔥 DESCRIPTION 🔥

okay so here's the tea, and it's lowkey kind of weird but stay with me bestie 🫶

the block size is set to one for ciphers such as CCM. one!! a whole block size of one. iconic behaviour honestly.

but — and this is the part that matters — you still need to provide incremental updates in multiples of the underlying block size, because the IV does not have sub-block granularity. so even though the block size says one, you can't just go feral and send whatever arbitrary length you want. nope. multiples of the underlying block size only, queen. 👑

in this API, that whole concept is known as the chunk size. that's the name. that's the thing this function hands you. iykyk ✨

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⭐ RETURN ⭐

the chunk size, in bytes 💜 that's it. that's the whole return.

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🌈 SEE ALSO 🌈

• Kernel file ./include/crypto/internal/aead.h — go read it, it's right there, slay 📖

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💀 reminder bestie: multiples of the underlying block size. the IV does NOT have sub-block granularity. no cap. do not test this. do not come crying to me when your incremental updates are the wrong size. 🙈

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and that's the page!! short, sweet, and honestly kind of a bop 🌸 this one shipped in the ./include/crypto/internal corner of the kernel, in the edition dated October 2026 — so like, remember this moment, because we were all here for it 🫶💖✨