hmac_sha512(9)

✨ hmac_sha512 ✨

okay so bestie, welcome to the hmac_sha512(9) page — that's a section 9 kernel API manual entry, iykyk 💅. Buckle up, this one's a whole mood.

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💖 NAME 💖

hmac_sha512 — computes an HMAC-SHA512 in one single shot, using a key you already prepped 🎀

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🦋 SYNOPSIS 🦋

void hmac_sha512 (const struct hmac_sha512_key *key , const u8 *data ,
size_t data_len , u8 out[static SHA512_DIGEST_SIZE] );

like… look at that signature. it's giving "I know exactly what I'm doing" 💅

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🌸 ARGUMENTS 🌸

• key — the prepared HMAC key, bestie. prepared is the whole vibe here — it's already been through the prep step, so don't come at it with a raw key 🫶
• data — the message data. yes, the actual stuff you're authenticating ✨
• data_len — how long that data is, counted in bytes 🔥
• out — (output) the resulting HMAC-SHA512 value gets dropped right in here 👑

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🧚 DESCRIPTION 🧚

So here's the tea: if you're only using the key once, bestie, consider hmac_sha512_usingrawkey instead. That's literally the whole note 🍓. Otherwise, you're in the right place — this function does the HMAC-SHA512 computation in one shot with that prepared key.

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⭐ CONTEXT ⭐

Any context. like, any. no gatekeeping, no restrictions, no vibe check needed — you can call this from wherever 💀✨

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🌈 SEE ALSO 🌈

the whole crypto family reunion, fr fr — go say hi to all of them 👑:

• 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_final(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_usingrawkey(9)

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and that's the page!! 🫶✨ this lil masterpiece lives over in ./include/crypto, dated October 2026 — mwah, iconic, no notes 💜🎀