hmac_sha256_final(9)

💅 hmac_sha256_final(9) — like, the finale of your HMAC-SHA256 era

okay so this is a page from the Kernel API Manual bestie, and it's about the very last step of an HMAC-SHA256 computation. It's short, it's sweet, and it literally cleans up after itself. main character energy fr fr 🎀

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✨ NAME ✨

hmac_sha256_final — finish computing an HMAC-SHA256 value. that's it. that's the whole job. 💖

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🌸 SYNOPSIS 🌸

void hmac_sha256_final (struct hmac_sha256_ctx *ctx , u8 out[static
SHA256_DIGEST_SIZE] );

no cap, that's the whole signature. look at it. iconic. ✨

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🦋 ARGUMENTS 🦋

• ctx — the HMAC context you're about to finalize. ⚠️ heads up: it must have been initialized first, bestie, like you cannot skip that step, that's not a vibe.
• out — (output) the resulting HMAC-SHA256 value lands here. this is where the good stuff goes 💅

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💜 DESCRIPTION 💜

so after it's done finishing, this function zeroizes ctx. like, it scrubs it clean, poof, gone 🫶 which means the caller does not need to do it — that's you, you don't have to. it already ate. it already cleaned up. periodt.

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🌈 CONTEXT 🌈

Any context. literally any. no restrictions, we love a flexible icon 😌✨

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🔥 SEE ALSO 🔥

bestie there is a lot here and I'm not skipping a single one, we don't do that here 💀

Kernel file ./include/crypto/sha2.h

• struct sha224_ctx(9)
• sha224_init(9)
• sha224_update(9)
• sha224_final(9)
• sha224(9)
• struct hmac_sha224_key(9)
• struct hmac_sha224_ctx(9)
• hmac_sha224_preparekey(9)
• hmac_sha224_init(9)
• hmac_sha224_init_usingrawkey(9)
• hmac_sha224_update(9)
• hmac_sha224_final(9)
• hmac_sha224(9)
• hmac_sha224_usingrawkey(9)
• struct sha256_ctx(9)
• sha256_init(9)
• sha256_update(9)
• sha256_final(9)
• sha256(9)
• sha256_finup_2x(9)
• sha256_finup_2x_is_optimized(9)
• struct hmac_sha256_key(9)
• struct hmac_sha256_ctx(9)
• hmac_sha256_preparekey(9)
• hmac_sha256_init(9)
• hmac_sha256_init_usingrawkey(9)
• hmac_sha256_update(9)
• hmac_sha256(9)
• hmac_sha256_usingrawkey(9)
• struct sha384_ctx(9)
• sha384_init(9)
• sha384_update(9)
• sha384_final(9)
• sha384(9)
• struct hmac_sha384_key(9)
• struct hmac_sha384_ctx(9)
• hmac_sha384_preparekey(9)
• hmac_sha384_init(9)
• hmac_sha384_init_usingrawkey(9)
• hmac_sha384_update(9)
• hmac_sha384_final(9)
• hmac_sha384(9)
• hmac_sha384_usingrawkey(9)
• struct sha512_ctx(9)
• sha512_init(9)
• sha512_update(9)
• sha512_final(9)
• sha512(9)
• struct hmac_sha512_key(9)
• struct hmac_sha512_ctx(9)
• hmac_sha512_preparekey(9)
• hmac_sha512_init(9)
• hmac_sha512_init_usingrawkey(9)
• hmac_sha512_update(9)
• hmac_sha512_final(9)
• hmac_sha512(9)
• hmac_sha512_usingrawkey(9)

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🧚 and that's the whole page!! go forth and finalize your HMACs, you gorgeous kernel dev 💅✨

this lil beauty lives in ./include/crypto, it's the October 2026 edition of the Kernel API Manual, and yes hmac_sha256_final(9) is right there in the corner being all official 🎀 slay, bye!!