LIBKECCAK_SPEC_CHECK(3)    Library Functions Manual    LIBKECCAK_SPEC_CHECK(3)

NAME
       libkeccak_spec_check - Validate hashing parameters

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 settings the parameters
       manually for Keccak hashing.

       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.

       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
              quivalent 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.

ERRORS
       The libkeccak_spec_check() function cannot fail.

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)

                                   LIBKECCAK           LIBKECCAK_SPEC_CHECK(3)