crypto_shash_setkey(9)

✨ crypto_shash_setkey(9) ✨

okay so bestie, welcome to the Kernel API Manual 💖 we're doing crypto_shash_setkey(9) today and it's literally gonna be so easy, i promise 🫶

---

🌸 NAME 🌸

crypto_shash_setkey — set key for message digest 🔑

---

🎀 SYNOPSIS 🎀

int crypto_shash_setkey (struct crypto_shash *tfm , const u8 *key ,
       unsigned int keylen );

---

🦋 ARGUMENTS 🦋

• tfm — the cipher handle 💅 that's your main character right there
• key — the buffer holding the key 🔑 like the actual key bytes live here
• keylen — length of the key in bytes, not vibes, bytes ✨

---

👑 DESCRIPTION 👑

so basically: the key you the caller provided gets set for the keyed message digest cipher 💖 that's it, that's the plot.

but here's the thing bestie, listen — the cipher handle has to point to a keyed message digest cipher, or this function will not succeed. no cap. if it's not keyed, this whole thing is a no 🚫

---

🌈 CONTEXT 🌈

Softirq or process context. so yes, both, depending. iykyk ⭐

---

💜 RETURN 💜

0 if the setting of the key was successful 🎉; < 0 if an error occurred 😭

fr fr check the return value, don't just assume it slayed 🙈

---

🍓 SEE ALSO 🍓

Kernel file ./include/crypto/hash.h 🌸 Message Digest Algorithm Definitions(9), struct ahash_alg(9), struct shash_alg(9), Asynchronous Message Digest API(9), crypto_alloc_ahash(9), crypto_free_ahash(9), crypto_has_ahash(9), crypto_ahash_blocksize(9), crypto_ahash_digestsize(9), crypto_ahash_statesize(9), crypto_ahash_reqtfm(9), crypto_ahash_reqsize(9), crypto_ahash_setkey(9), crypto_ahash_finup(9), crypto_ahash_final(9), crypto_ahash_digest(9), crypto_ahash_export(9), crypto_ahash_import(9), crypto_ahash_init(9), crypto_ahash_update(9), Asynchronous Hash Request Handle(9), ahash_request_set_tfm(9), ahash_request_alloc(9), ahash_request_free(9), ahash_request_set_callback(9), ahash_request_set_crypt(9), ahash_request_set_virt(9), Synchronous Message Digest API(9), crypto_alloc_shash(9), crypto_free_shash(9), crypto_shash_blocksize(9), crypto_shash_digestsize(9), crypto_shash_descsize(9), crypto_shash_digest(9), crypto_shash_tfm_digest(9), crypto_shash_export(9), crypto_shash_import(9), crypto_shash_init(9), crypto_shash_finup(9), crypto_shash_update(9), crypto_shash_final(9) 🧚

that's a lot of links bestie but they're all right there, go click around, it's giving study session 📚✨

---

and that's the whole page!! 💅 this one came from ./include/crypto, October 2026, and it's crypto_shash_setkey(9) — mwah, go set some keys, you're gonna ate it up 🔥👑🎀