/*!\file netinet6/ah.h
 * Authentication Header.
 */

/*      $FreeBSD: src/sys/netinet6/ah.h,v 1.7 2002/04/19 04:46:22 suz Exp $     */
/*      $KAME: ah.h,v 1.16 2001/09/04 08:43:19 itojun Exp $     */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * RFC1826/2402 authentication header.
 */

#ifndef _NETINET6_AH_H_
#define _NETINET6_AH_H_

#if defined(_KERNEL) && !defined(_LKM)
#include "opt_inet.h"
#endif

struct ah {
        u_int8_t        ah_nxt;         /* Next Header */
        u_int8_t        ah_len;         /* Length of data, in 32bit */
        u_int16_t       ah_reserve;     /* Reserved for future use */
        u_int32_t       ah_spi;         /* Security parameter index */
        /* variable size, 32bit bound*/ /* Authentication data */
};

struct newah {
        u_int8_t        ah_nxt;         /* Next Header */
        u_int8_t        ah_len;         /* Length of data + 1, in 32bit */
        u_int16_t       ah_reserve;     /* Reserved for future use */
        u_int32_t       ah_spi;         /* Security parameter index */
        u_int32_t       ah_seq;         /* Sequence number field */
        /* variable size, 32bit bound*/ /* Authentication data */
};

#ifdef _KERNEL
struct secasvar;

struct ah_algorithm_state {
        struct secasvar *sav;
        void* foo;      /* per algorithm data - maybe */
};

struct ah_algorithm {
        int (*sumsiz) __P((struct secasvar *));
        int (*mature) __P((struct secasvar *));
        int keymin;     /* in bits */
        int keymax;     /* in bits */
        const char *name;
        int (*init) __P((struct ah_algorithm_state *, struct secasvar *));
        void (*update) __P((struct ah_algorithm_state *, caddr_t, size_t));
        void (*result) __P((struct ah_algorithm_state *, caddr_t));
};

#define AH_MAXSUMSIZE   16

extern const struct ah_algorithm *ah_algorithm_lookup __P((int));

/* cksum routines */
extern int ah_hdrlen __P((struct secasvar *));

extern size_t ah_hdrsiz __P((struct ipsecrequest *));
extern void ah4_input __P((struct mbuf *, int));
extern int ah4_output __P((struct mbuf *, struct ipsecrequest *));
extern int ah4_calccksum __P((struct mbuf *, caddr_t, size_t,
        const struct ah_algorithm *, struct secasvar *));
#endif /* _KERNEL */

#endif /* _NETINET6_AH_H_ */
