LIBKECCAK_...AST_UPDATE(3)

🌸 NAME 🌸

Okay bestie, this is libkeccak_hmac_fast_update(3) from the Library Functions Manual, and it's here to partially HMAC-hash a message without erasure.

• libkeccak_hmac_fast_update — partially HMAC-hash a message without erasure

✨ SYNOPSIS ✨

#include <libkeccak.h>

int libkeccak_hmac_fast_update(struct libkeccak_state *state, const void *msg, size_t msglen);

Link with -lkeccak.

💖 DESCRIPTION 💖

So libkeccak_hmac_fast_update() continues (or starts) HMAC-hashing a message. The current state of the hashing is stored in *state, and it gets updated. The message specified by the msg parameter, with the byte-size specified by the msglen parameter, will be hashed. 🫶

The libkeccak_hmac_fast_update() function may reallocate the state's message chunk buffer. When doing so, it attempts to do so as securely as possible, rather than as fast as possible.

🎀 RETURN VALUES 🎀

The libkeccak_hmac_fast_update() function returns 0 upon successful completion. On error, -1 is returned and errno is set to describe the error. Periodt. 💅

🔥 ERRORS 🔥

Okay, plot twist time: the ERRORS section says the libkeccak_hmac_fast_update() function may reallocate the state's message chunk buffer. When doing so, it attempts to do so as quickly as possible, rather than ensuring that the information in the old allocation is securely removed if a new allocation is required. It also drops realloc(3). Yes bestie, that is what it says — I'm just relaying the text 💀.

🦋 NOTES 🦋

Neither parameter may be NULL or 0. That's the note, fr fr.

🌈 SEE ALSO 🌈

• libkeccak_hmac_create(3)
• libkeccak_hmac_initialise(3)
• libkeccak_hmac_fast_digest(3)
• libkeccak_hmac_update(3)

💅 Cute little sign-off: the source/version in the footer is LIBKECCAK, and the date slot in the original footer is blank — no date was printed, so I'm not inventing one. Byeee 🫶✨