aes_gcm_auth_update(9)

✨ aes_gcm_auth_update(9) ✨

okay so like, welcome to the Kernel API Manual bestie 🫶 this one's about aes_gcm_auth_update from the manual page aes_gcm_auth_update(9) — yes the name's in the title AND the manual name, it's giving main character energy 💅

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💖 NAME 💖

aes_gcm_auth_update — literally processes AES-GCM associated data incrementally, one little chunk at a time, no cap ✨

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🦋 SYNOPSIS 🦋

void aes_gcm_auth_update (struct aes_gcm_ctx *ctx , const u8 *ad ,
       size_t len );

like, that's the whole signature. short and iconic 🎀

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🌸 ARGUMENTS 🌸

• ctx — an AES-GCM context. your lil working space, your vibe holder 💜
• ad — the associated data. yes, that's the ad right there 🍓
• len — number of bytes provided. and listen, the caller has to make sure the total associated data length doesn't exceed GCM's limit of 2^61 - 1. that's a real number, respect it 🔥

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👑 DESCRIPTION 👑

IMPORTANT ⚠️ (like, actually important, not just me being dramatic): callers MUST NOT assume that any decrypted or associated data is authentic until the authentication tag has been verified. periodt. don't trust it till the tag says so 🙈

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💀 CONTEXT 💀

Any context. literally any. we're flexible like that 💅✨

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🌈 SEE ALSO 🌈

Kernel file ./include/crypto/aes-gcm.h, plus the whole squad:

• struct aes_gcm_key(9)
• struct aes_gcm_ctx(9)
• aes_gcm_preparekey(9)
• aes_gcm_encrypt(9)
• aes_gcm_decrypt(9)
• aes_gcm_init(9)
• aes_gcm_encrypt_update(9)
• aes_gcm_decrypt_update(9)
• aes_gcm_encrypt_final(9)
• aes_gcm_decrypt_final(9)

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and that's the page bestie, iykyk 🧚💖 this came from ./include/crypto and it's dated October 2026, signed off with aes_gcm_auth_update(9) — slay, go verify that tag before you trust anything, mwah 💋⭐