SYNCHRONOUS MESSAGE DIGEST API(9)

💖 Synchronous Message Digest API 💖

okay so bestie, welcome to the Kernel API Manual — this is the Synchronous Message Digest API, and it's lowkey iconic 💅✨

Real talk: the synchronous message digest API is the one you use with ciphers of type CRYPTO_ALG_TYPE_SHASH (they're listed as type "shash" in /proc/crypto, iykyk) 🦋

The message digest API can literally maintain state information for you, the caller — main character energy fr fr 🫶

And yes, the synchronous message digest API can store user-related context in its shash_desc request data structure, no cap 🎀

💅 SEE ALSO 💅

bestie, here's the whole reading list — every single one, periodt:

• 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)
• crypto_alloc_shash(9)
• crypto_free_shash(9)
• crypto_shash_blocksize(9)
• crypto_shash_digestsize(9)
• crypto_shash_descsize(9)
• crypto_shash_setkey(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)

okay that's the whole page, bestie 🫶 — signed off from ./include/crypto, dated October 2026, with the footer still serving Synchronous ...e Digest API(9) realness 💅✨