sha256_final(9)

💖 sha256_final — the Kernel API Manual's own "wrap it up bestie" moment 💖

okay so you're in the Kernel API Manual (yes, that one) and you've stumbled onto sha256_final(9), which is literally the last step of a SHA-256 digest. she's the finisher. the closer. the "ok we're done here" of the whole operation ✨

---

🌸 NAME 🌸

sha256_final — Finish computing a SHA-256 message digest

like bestie, the digest is done. she's cooked. serve her 🍓

---

✨ SYNOPSIS ✨

void sha256_final (struct sha256_ctx *ctx , u8 out[static
SHA256_DIGEST_SIZE] );

yes the line break in the middle is real, she's just built like that, no cap 💅

---

🎀 ARGUMENTS 🎀

• ctx — the context to finalize; must have been initialized. like, must. it's not optional, it's not a vibe, it's a requirement. this is the struct sha256_ctx you've been feeding this whole time 🫶
• out — (output) the resulting SHA-256 message digest. she writes the answer here. this is the moment. main character energy fr 🔥

---

🦋 DESCRIPTION 🦋

So after finishing, this zeroizes ctx. read that again. she wipes the context clean on her way out 🧹✨

Which means — and this is the good part — the caller does not need to do it. no cleanup arc for you, bestie, that's her job. you can just chill. she ate and left no crumbs 💀

---

🌈 CONTEXT 🌈

Any context. literally any. she's flexible like that 🙈

---

👑 SEE ALSO 👑

okay this list is long long, so buckle up buttercup, we're going on a tour of the whole sha2 header 🌸

Kernel file ./include/crypto/sha2.h 💜

SHA-224 crew:

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

HMAC-SHA-224 girlies:

• 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)

SHA-256 squad (your faves):

• struct sha256_ctx(9), sha256_init(9), sha256_update(9), sha256(9), sha256_finup_2x(9), sha256_finup_2x_is_optimized(9)

HMAC-SHA-256 crew:

• 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 babes:

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

HMAC-SHA-384 hive:

• 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)

SHA-512 icons:

• struct sha512_ctx(9), sha512_init(9), sha512_update(9), sha512_final(9), sha512(9)

HMAC-SHA-512 royalty:

• 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)

every single one. not me listing all of them. iykyk 😭💖

---

quick vibe check: ctx must have been initialized before you call this. don't be the person who skips sha256_init. that's not a look 🙈

---

⭐ okay that's the page!! brought to you by ./include/crypto, version dated October 2026, filed under sha256_final(9) — mwah, go hash something, bestie 💅🎀🧚‍♀️