/* SCTP kernel implementation
* (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
*
* This file is part of the SCTP kernel implementation
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <[email protected]>
*
* Written or modified by:
* Vlad Yasevich <[email protected]>
*/

#ifndef __sctp_auth_h__
#define __sctp_auth_h__

#include <linux/list.h>
#include <linux/crypto.h>

struct sctp_endpoint;
struct sctp_association;
struct sctp_authkey;
struct sctp_hmacalgo;

/*
* Define a generic struct that will hold all the info
* necessary for an HMAC transform
*/
struct sctp_hmac {
__u16 hmac_id; /* one of the above ids */
char *hmac_name; /* name for loading */
__u16 hmac_len; /* length of the signature */
};

/* This is generic structure that containst authentication bytes used
* as keying material. It's a what is referred to as byte-vector all
* over SCTP-AUTH
*/
struct sctp_auth_bytes {
atomic_t refcnt;
__u32 len;
__u8 data[];
};

/* Definition for a shared key, weather endpoint or association */
struct sctp_shared_key {
struct list_head key_list;
__u16 key_id;
struct sctp_auth_bytes *key;
};

#define key_for_each(__key, __list_head) \
list_for_each_entry(__key, __list_head, key_list)

#define key_for_each_safe(__key, __tmp, __list_head) \
list_for_each_entry_safe(__key, __tmp, __list_head, key_list)

static inline void sctp_auth_key_hold(struct sctp_auth_bytes *key)
{
if (!key)
return;

atomic_inc(&key->refcnt);
}

void sctp_auth_key_put(struct sctp_auth_bytes *key);
struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp);
void sctp_auth_destroy_keys(struct list_head *keys);
int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp);
struct sctp_shared_key *sctp_auth_get_shkey(
const struct sctp_association *asoc,
__u16 key_id);
int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
struct sctp_association *asoc,
gfp_t gfp);
int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp);
void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[]);
struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id);
struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc);
void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
struct sctp_hmac_algo_param *hmacs);
int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
__be16 hmac_id);
int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc);
void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
struct sk_buff *skb,
struct sctp_auth_chunk *auth, gfp_t gfp);

/* API Helpers */
int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id);
int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
struct sctp_hmacalgo *hmacs);
int sctp_auth_set_key(struct sctp_endpoint *ep,
struct sctp_association *asoc,
struct sctp_authkey *auth_key);
int sctp_auth_set_active_key(struct sctp_endpoint *ep,
struct sctp_association *asoc,
__u16 key_id);
int sctp_auth_del_key_id(struct sctp_endpoint *ep,
struct sctp_association *asoc,
__u16 key_id);

#endif