/*      $OpenBSD: dh.h,v 1.10 2017/11/08 13:33:49 patrick Exp $ */

/*
 * Copyright (c) 2010-2013 Reyk Floeter <reyk@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _DH_H_
#define _DH_H_

enum group_type {
        GROUP_MODP      = 0,
        GROUP_EC2N      = 1,
        GROUP_ECP       = 2
};

struct group_id {
        enum group_type  type;
        u_int            id;
        int              bits;
        char            *prime;
        char            *generator;
        int              nid;
};

struct group {
        int              id;
        struct group_id *spec;

        void            *dh;
        void            *ec;

        int             (*init)(struct group *);
        int             (*getlen)(struct group *);
        int             (*secretlen)(struct group *);
        int             (*exchange)(struct group *, u_int8_t *);
        int             (*shared)(struct group *, u_int8_t *, u_int8_t *);
};

#define DH_MAXSZ        1024    /* 8192 bits */

void             group_init(void);
void             group_free(struct group *);
struct group    *group_get(u_int32_t);

int              dh_getlen(struct group *);
int              dh_secretlen(struct group *);
int              dh_create_exchange(struct group *, u_int8_t *);
int              dh_create_shared(struct group *, u_int8_t *, u_int8_t *);

#endif /* _DH_H_ */