LIBKECCAK_CSHAKE_INITIALISE(3)

Hey bestie, welcome to LIBKECCAK_..._INITIALISE(3) from the Library Functions Manual ✨ this one's all about getting your cSHAKE sponge ready to slay.

💖 NAME 💖

libkeccak_cshake_initialise — initialise a sponge for cSHAKE hashing

✨ SYNOPSIS ✨

#include <libkeccak.h>

void libkeccak_cshake_initialise(struct libkeccak_state *restrict state,
                                 const void *n_text, size_t n_len, size_t n_bits, const char *n_suffix,
                                 const void *s_text, size_t s_len, size_t s_bits, const char *s_suffix);

Link with -lkeccak.

🧚 DESCRIPTION 🧚

Okay so, plot twist: the DESCRIPTION says the libkeccak_cshake_suffix() function shall be called immediately after the libkeccak_state_initialise(3) function (before libkeccak_update(3) or libkeccak_digest(3), or any variant of those functions), to provide the initialisation blocks, containing customisation data, to the Keccak sponge. I'm just relaying the lore, bestie 💅

The value of the state parameter shall be an initialised state to feed the initialisation blocks to.

• n_text — shall be the function-name bit-string, represented in raw bytes.
• n_len — shall be value no greater than the number of whole bytes in n_text.
• n_bits — shall be the number of bits in n_text sans the bytes covered by n_len, that is, the number of bits in n_text minus (nlen_*8).
• n_suffix — shall be either NULL or an appendix of bits to n_suffix (neither n_len nor n_bits shall count these), stored as a NUL-terminated string of the ASCII digits 1 and 0.

The value of the s_text parameter shall be the customisation bit-string, represented in raw bytes.

• s_len — shall be value no greater than the number of whole bytes in s_text.
• s_bits — shall be the number of bits in s_text sans the bytes covered by s_len, that is, the number of bits in s_text minus (nles_*8).
• s_suffix — shall be either NULL or an appendix of bits to s_suffix (neither s_len nor s_bits shall count these), stored as a NUL-terminated string of the ASCII digits 1 and 0.

For the n_suffix and s_suffix parameters, NULL is treated as the empty string 🫶

🎀 RETURN VALUES 🎀

The libkeccak_cshake_suffix() function does not return a value. No return value, periodt 💖

🌈 ERRORS 🌈

The libkeccak_cshake_suffix() function cannot fail. It's giving flawless, honestly ✨

👑 SEE ALSO 👑

• libkeccak_spec_cshake(3)
• libkeccak_generalised_spec_initialise(3)
• libkeccak_state_initialise(3)
• libkeccak_cshake_initialise(3)
• libkeccak_fast_update(3)
• libkeccak_zerocopy_update(3)
• libkeccak_update(3)
• libkeccak_fast_digest(3)
• libkeccak_zerocopy_digest(3)
• libkeccak_digest(3)

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xoxo, signing off from the LIBKECCAK manual 💖 page LIBKECCAK_..._INITIALISE(3) — no date in the footer, so we're keeping it mysterious 🎀