.TH LIBKECCAK_HMAC_INITIALISE 3 LIBKECCAK
.SH NAME
libkeccak_hmac_initialise - Initialise HMAC-hashing state
.SH SYNOPSIS
.nf
#include <libkeccak.h>

int libkeccak_hmac_initialise(struct libkeccak_hmac_state *\fIstate\fP, const struct libkeccak_spec *\fIspec\fP,
                              const void *\fIkey\fP, size_t \fIkey_length\fP);
.fi
.PP
Link with
.IR -lkeccak .
.SH DESCRIPTION
The
.BR libkeccak_hmac_initialise ()
function initialises
.I *state
and sets the algorithm tuning parameters to
those specified by
.IR *spec ,
and the key to
.I key
of length
.IR key_length .
.SH RETURN VALUES
The
.BR libkeccak_hmac_initialise ()
function returns 0 upon successful completion.
On error, -1 is returned and
.I errno
is set to describe the error.
.SH ERRORS
The
.BR libkeccak_hmac_initialise ()
function may fail for any specified for the functions
.BR malloc (3)
and
.BR realloc (3).
.SH SEE ALSO
.BR libkeccak_hmac_create (3),
.BR libkeccak_hmac_destroy (3),
.BR libkeccak_hmac_fast_destroy (3),
.BR libkeccak_hmac_copy (3),
.BR libkeccak_spec_cshake (3),
.BR libkeccak_spec_sha3 (3),
.BR libkeccak_spec_shake (3),
.BR libkeccak_spec_rawshake (3),
.BR libkeccak_spec_check (3),
.BR libkeccak_generalised_spec_initialise (3),
.BR libkeccak_state_initialise (3)