LIBKECCAK_SPEC_CHECK(3)

💅 LIBKECCAK_SPEC_CHECK(3) — validate hashing parameters 💅

okay so bestie, welcome to the Library Functions Manual page for libkeccak_spec_check — aka the vibe check for your Keccak spec 💖 this is LIBKECCAK_SPEC_CHECK(3), and we're about to make sure your hashing parameters are not a chaotic mess.

🌸 NAME 🌸

libkeccak_spec_check — validate hashing parameters. That's the whole name, no cap: it checks whether your spec is usable before you send it into the wild 🦋

✨ SYNOPSIS ✨

#include <libkeccak.h>

int libkeccak_spec_check(const struct libkeccak_spec *spec);

Link with -lkeccak. 🫶

💖 DESCRIPTION 💖

The libkeccak_spec_check() function validates the parameters of *spec, so that unusable configurations can be detected. It is recommended to call this function after calling libkeccak_spec_sha3(3), libkeccak_spec_cshake(3), libkeccak_spec_rawshake(3), libkeccak_spec_shake(3), or, especially, after setting the parameters manually for Keccak hashing. Basically: don't just yolo your custom values, let this icon do a quick check first 👑

Here's the struct in question:

       struct libkeccak_spec {
            long int bitrate;  /* bitrate (in bits) */
            long int capacity; /* capacity (in bits) */
            long int output;   /* output size (in bits) */
       };

🔥 RETURN VALUES 🔥

The libkeccak_spec_check() function returns 0 if the settings are usable. Otherwise it will return one of the following constants. Like, it's giving error-code menu 😭

• LIBKECCAK_SPEC_ERROR_BITRATE_NONPOSITIVE — the specified bitrate was non-positive.
• LIBKECCAK_SPEC_ERROR_BITRATE_MOD_8 — the specified bitrate was not equivalent to 0 modulus 8, that is, it was not in whole bytes.
• LIBKECCAK_SPEC_ERROR_CAPACITY_NONPOSITIVE — the specified capacity was non-positive.
• LIBKECCAK_SPEC_ERROR_CAPACITY_MOD_8 — the specified capacity was not equivalent to 0 modulus 8, that is, it was not in whole bytes.
• LIBKECCAK_SPEC_ERROR_OUTPUT_NONPOSITIVE — the specified output size was non-positive.
• LIBKECCAK_SPEC_ERROR_STATE_TOO_LARGE — the state size, that is the sum of the bitrate and the capacity, exceeded the supported limit (currently at 1600 bits).
• LIBKECCAK_SPEC_ERROR_STATE_MOD_25 — the state size, that is the sum of the bitrate and the capacity, in bits, was not equivalent to 0 modulus 25. Meaning the state size cannot cover all lanes equivalently.
• LIBKECCAK_SPEC_ERROR_WORD_NON_2_POTENT — the word size, that is the state size divided by 25, is not a power of 2.
• LIBKECCAK_SPEC_ERROR_WORD_MOD_8 — the word size, that is the state size divided by 25, is not equivalent to 0 modulus 8, that is, it is not in whole bytes.

Note that there may be more than one error. Only the first detected is returned. So yes, it's a "first problem wins" situation, no cap 💀

🎀 ERRORS 🎀

The libkeccak_spec_check() function cannot fail. Literally. It's just built different 💅

🦋 SEE ALSO 🦋

• libkeccak_spec_sha3(3)
• libkeccak_spec_cshake(3)
• libkeccak_spec_rawshake(3)
• libkeccak_spec_shake(3)
• libkeccak_generalised_spec_initialise(3)
• libkeccak_state_initialise(3)
• libkeccak_hmac_initialise(3)

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xoxo, your LIBKECCAK bestie 💖 this was LIBKECCAK_SPEC_CHECK(3) from the Library Functions Manual — source/version LIBKECCAK, page LIBKECCAK_SPEC_CHECK(3), and the footer didn't show a date so we're not making one up, periodt 🌈