hmac_sha512_final(9)

💅 hmac_sha512_final(9) — from the Kernel API Manual, bestie

Okay so real talk, the header says hmac_sha512_final(9) and the manual is the Kernel API Manual, and today we're learning how to finish an HMAC-SHA512 value. Last step of the vibe, the closing act, the final rose ceremony 🌹✨

---

🌸 NAME 🌸

hmac_sha512_final — wrap it up and finish computing an HMAC-SHA512 value 💖

---

✨ SYNOPSIS ✨

void hmac_sha512_final (struct hmac_sha512_ctx *ctx , u8 out[static
SHA512_DIGEST_SIZE] );

That's the whole thing. Short, sweet, iconic. Periodt. 👑

---

🎀 ARGUMENTS 🎀

• ctx — the HMAC context you're finalizing. Heads up though: it must have been initialized first. No init, no service, that's the rule 🙈
• out — this one's an output param, so it's where the resulting HMAC-SHA512 value lands. It's u8 out[static SHA512_DIGEST_SIZE], so the size is right there in the signature — no guessing, iykyk 💅

---

🦋 DESCRIPTION 🦋

So you've been updating and updating and now you're done, and this function is the grand finale 🎆

And here's the cute part that lowkey slays: after finishing, this zeroizes ctx. The way that means the caller does not need to do it. She cleans up after herself. Self-care, honestly 🧖‍♀️✨

---

🌈 CONTEXT 🌈

Any context. Literally any. No restrictions, no drama, we love a flexible queen 🫶

---

💜 SEE ALSO 💜

Kernel file ./include/crypto/sha2.h — and bestie, the friend group here is huge, so buckle up 🎢

The SHA-224 corner:

• struct sha224_ctx(9)
• sha224_init(9)
• sha224_update(9)
• sha224_final(9)
• sha224(9)

HMAC-224, the whole squad:

• 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)

Now the SHA-256 crew:

• 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)

HMAC-256, back at it:

• 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)

SHA-384 said hi:

• struct sha384_ctx(9)
• sha384_init(9)
• sha384_update(9)
• sha384_final(9)
• sha384(9)

HMAC-384, matching energy:

• 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)

And our own family, SHA-512, main character energy:

• 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(9)
• hmac_sha512_usingrawkey(9)

---

Reminder bestie: ctx has to be initialized before you call this, and this function zeroizes it for you afterward, so don't double-clean 💀

---

🍓 Sign-off 🍓

Source path is ./include/crypto, dated October 2026 — that's the whole footer, and honestly it's giving "signed, sealed, delivered" 💌 Go forth and finalize, queen 👑✨