/*

 * iSNS authentication functions

 *

 * Copyright (C) 2007 Olaf Kirch <olaf.kirch@oracle.com>

 */

#include <stdlib.h>

#include <string.h>

#include <libisns/isns.h>

#include <libisns/attrs.h>

#include <libisns/message.h>

#include <libisns/util.h>

/* We impose an artificial limit on the size of

 * the size of the authenticator

 */

#define ISNS_SPISTR_MAX         512

int

isns_authblock_decode(buf_t *bp, struct isns_authblk *auth)

{

	unsigned int	avail = buf_avail(bp);

	if (!buf_get32(bp, &auth->iab_bsd)

	 || !buf_get32(bp, &auth->iab_length)

	 || !buf_get64(bp, &auth->iab_timestamp)

	 || !buf_get32(bp, &auth->iab_spi_len))

		 return 0;

	/* Make sure the length specified by the auth block

	 * is reasonable. */

	if (auth->iab_length < ISNS_AUTHBLK_SIZE

	 || auth->iab_length > avail)

		return 0;

	/* This chops off any data trailing the auth block.

	 * It also makes sure that we detect if iab_length

	 * exceeds the amount of available data. */

	if (!buf_truncate(bp, auth->iab_length - ISNS_AUTHBLK_SIZE))

		return 0;

	auth->iab_spi = buf_head(bp);

	if (!buf_pull(bp, auth->iab_spi_len))

		return 0;

	auth->iab_sig = buf_head(bp);

	auth->iab_sig_len = buf_avail(bp);

	return 1;

}

int

isns_authblock_encode(buf_t *bp, const struct isns_authblk *auth)

{

	if (!buf_put32(bp, auth->iab_bsd)

	 || !buf_put32(bp, auth->iab_length)

	 || !buf_put64(bp, auth->iab_timestamp)

	 || !buf_put32(bp, auth->iab_spi_len)

	 || !buf_put(bp, auth->iab_spi, auth->iab_spi_len)

	 || !buf_put(bp, auth->iab_sig, auth->iab_sig_len))

		return 0;

	return 1;

}