path: root/init.c

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


/**
 * Initial state for SHA-1 and SHA-0
 */
static const uint32_t H[] = {
	0x67452301UL, 0xEFCDAB89UL, 0x98BADCFEUL, 0x10325476UL, 0xC3D2E1F0UL
};


/**
 * Initialise a state
 * 
 * @param   state      The state that should be initialised
 * @param   algorithm  The hashing algorithm
 * @return             Zero on success, -1 on error
 */
int
libsha1_init(struct libsha1_state *restrict state, enum libsha1_algorithm algorithm)
{
	memset(state, 0, sizeof(*state));
	state->message_size = 0;
	state->algorithm = algorithm;

	/* Set initial hash values. */
	switch (algorithm) {
	case LIBSHA1_0:
	case LIBSHA1_1:
		memcpy(state->h, H, sizeof(H)); break;
	default:
		errno = EINVAL;
		return -1;
	}

	return 0;
}