path: root/libhashsum_init_shake_hasher.c

/* See LICENSE file for copyright and license details. */
#include "common.h"
#ifdef SUPPORT_SHAKE


int
libhashsum_init_shake_hasher(struct libhashsum_hasher *this, size_t hcapbits, size_t hashbits)
{
	struct libkeccak_spec spec;

	if (hcapbits == 128U) {
		this->algorithm = LIBHASHSUM_SHAKE128;
		this->algorithm_string = "SHAKE128";
	} else if (hcapbits == 256U) {
		this->algorithm = LIBHASHSUM_SHAKE256;
		this->algorithm_string = "SHAKE256";
	} else if (hcapbits == 512U) {
		this->algorithm = LIBHASHSUM_SHAKE512;
		this->algorithm_string = "SHAKE512";
	} else {
		errno = EINVAL;
		return -1;
	}

	if (hashbits == 0U) {
		hashbits = hcapbits;
	} else if (hashbits > (size_t)LONG_MAX) {
		errno = EINVAL;
		return -1;
	}

	if (hashbits != hcapbits) {
		sprintf(this->state.keccak.algostr, "%s[n=%zu]", this->algorithm_string, hashbits);
		this->algorithm_string = this->state.keccak.algostr;
	}

	libkeccak_spec_shake(&spec, (long int)hcapbits, (long int)hashbits);
	return libhashsum_init_keccak__(this, hashbits, &spec, 1U, LIBKECCAK_SHAKE_SUFFIX);
}


#else
int
libhashsum_init_shake_hasher(struct libhashsum_hasher *this, size_t hcapbits, size_t hashbits)
{
	(void) this;
	(void) hcapbits;
	(void) hashbits;
	errno = ENOSYS;
	return -1;
}
#endif