hmac_sha512_preparekey(9)

💖 NAME 💖

okay so bestie, we're in the Kernel API Manual, and this page is hmac_sha512_preparekey(9).

hmac_sha512_preparekey — prepare a key for HMAC-SHA512. That's the whole vibe: you're getting the key structure set up so HMAC-SHA512 can do its thing. slay. ✨

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✨ SYNOPSIS ✨

Here's the signature, exactly as it lives in the manual, no edits bestie:

void hmac_sha512_preparekey (struct hmac_sha512_key *key , const u8
*raw_key , size_t raw_key_len );

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🎀 ARGUMENTS 🎀

• key — (output) the key structure to initialize. This is the struct you're handing over to get initialized.
• raw_key — the raw HMAC-SHA512 key.
• raw_key_len — the key length in bytes. All key lengths are supported. Literally all, no cap. 💅

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⚠️ NOTE ⚠️

real talk, bestie: the caller is responsible for zeroizing both the struct hmac_sha512_key and the raw key once they are no longer needed. Don't leave them lying around, okay? 🫶

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🌈 CONTEXT 🌈

Any context. That's it. Any context. iconic. 👑

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🦋 SEE ALSO 🦋

the whole cryptographic friend group is linked, no cap. Here's every single ref, because we do not skip refs:

• Kernel file ./include/crypto/sha2.h
• SHA-224 squad: struct sha224_ctx(9), sha224_init(9), sha224_update(9), sha224_final(9), sha224(9)
• HMAC-SHA-224 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)
• SHA-256 squad: 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-SHA-256 squad: 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 squad: struct sha384_ctx(9), sha384_init(9), sha384_update(9), sha384_final(9), sha384(9)
• HMAC-SHA-384 squad: 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 squad: struct sha512_ctx(9), sha512_init(9), sha512_update(9), sha512_final(9), sha512(9)
• HMAC-SHA-512 squad: struct hmac_sha512_key(9), struct hmac_sha512_ctx(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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source/version tag: ./include/crypto ✨ date: October 2026 ✨ and that's a wrap on hmac_sha512_preparekey(9) — byeee, go zeroize your secrets 💅