/* $OpenBSD: crypto.h,v 1.20 2010/10/19 07:47:34 mikeb Exp $     */
/* $EOM: crypto.h,v 1.12 2000/10/15 21:56:41 niklas Exp $        */

/*
 * Copyright (c) 1998 Niels Provos.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * This code was written under funding by Ericsson Radio Systems.
 */

#ifndef _CRYPTO_H_
#define _CRYPTO_H_

#include <openssl/des.h>
#include <blf.h>
#include <openssl/cast.h>

#include <openssl/aes.h>

#define USE_32BIT
#if defined (USE_64BIT)

#define XOR64(x,y) *(u_int64_t *)(x) ^= *(u_int64_t *)(y);
#define SET64(x,y) *(u_int64_t *)(x) = *(u_int64_t *)(y);

#elif defined (USE_32BIT)

#define XOR64(x,y) *(u_int32_t *)(x) ^= *(u_int32_t *)(y); \
   *(u_int32_t *)((u_int8_t *)(x) + 4) ^= *(u_int32_t *)((u_int8_t *)(y) + 4);
#define SET64(x,y) *(u_int32_t *)(x) = *(u_int32_t *)(y); \
   *(u_int32_t *)((u_int8_t *)(x) + 4) = *(u_int32_t *)((u_int8_t *)(y) + 4);

#else

#define XOR8(x,y,i) (x)[i] ^= (y)[i];
#define XOR64(x,y) XOR8(x,y,0); XOR8(x,y,1); XOR8(x,y,2); XOR8(x,y,3); \
   XOR8(x,y,4); XOR8(x,y,5); XOR8(x,y,6); XOR8(x,y,7);
#define SET8(x,y,i) (x)[i] = (y)[i];
#define SET64(x,y) SET8(x,y,0); SET8(x,y,1); SET8(x,y,2); SET8(x,y,3); \
   SET8(x,y,4); SET8(x,y,5); SET8(x,y,6); SET8(x,y,7);

#endif                          /* USE_64BIT */

#define SET_32BIT_BIG(x,y) (x)[3]= (y); (x)[2]= (y) >> 8; \
    (x)[1] = (y) >> 16; (x)[0]= (y) >> 24;
#define GET_32BIT_BIG(x) (u_int32_t)(x)[3] | ((u_int32_t)(x)[2] << 8) | \
    ((u_int32_t)(x)[1] << 16)| ((u_int32_t)(x)[0] << 24);

/*
 * This is standard for all block ciphers we use at the moment.
 * Keep MAXBLK uptodate.
 */
#define BLOCKSIZE       8
#define MAXBLK          AES_BLOCK_SIZE

struct keystate {
        struct crypto_xf *xf;   /* Back pointer */
        u_int8_t        iv[MAXBLK];     /* Next IV to use */
        u_int8_t        iv2[MAXBLK];
        u_int8_t       *riv, *liv;
        union {
                DES_key_schedule desks[3];
                blf_ctx         blfks;
                CAST_KEY        castks;
                AES_KEY         aesks[2];
        }               keydata;
};

#define ks_des  keydata.desks
#define ks_blf  keydata.blfks
#define ks_cast keydata.castks
#define ks_aes  keydata.aesks

/*
 * Information about the cryptotransform.
 *
 * XXX - In regards to the IV (Initialization Vector) the drafts are
 * completely fucked up and specify a MUST as how it is derived, so
 * we also have to provide for that. I just don't know where.
 * Furthermore is this enum needed at all?  It seems to be Oakley IDs
 * only anyhow, and we already have defines for that in ipsec_doi.h.
 */
enum transform {
        DES_CBC = 1,            /* This is a MUST */
        IDEA_CBC = 2,           /* Licensed, DONT use */
        BLOWFISH_CBC = 3,
        RC5_R16_B64_CBC = 4,    /* Licensed, DONT use */
        TRIPLEDES_CBC = 5,      /* This is a SHOULD */
        CAST_CBC = 6,
        AES_CBC = 7
};

enum cryptoerr {
        EOKAY,                  /* No error */
        ENOCRYPTO,              /* A none crypto related error, see errno */
        EWEAKKEY,               /* A weak key was found in key setup */
        EKEYLEN                 /* The key length was invalid for the cipher */
};

struct crypto_xf {
        enum transform  id;     /* Oakley ID */
        char           *name;   /* Transform Name */
        u_int16_t       keymin, keymax; /* Possible Keying Bytes */
        u_int16_t       blocksize;      /* Need to keep IV in the state */
        struct keystate *state; /* Key information, can also be passed sep. */
        enum cryptoerr  (*init)(struct keystate *, u_int8_t *, u_int16_t);
        void            (*encrypt)(struct keystate *, u_int8_t *, u_int16_t);
        void            (*decrypt)(struct keystate *, u_int8_t *, u_int16_t);
};

extern struct keystate *crypto_clone_keystate(struct keystate *);
extern void     crypto_decrypt(struct keystate *, u_int8_t *, u_int16_t);
extern void     crypto_encrypt(struct keystate *, u_int8_t *, u_int16_t);
extern struct crypto_xf *crypto_get(enum transform);
extern struct keystate *crypto_init(struct crypto_xf *, u_int8_t *, u_int16_t,
                    enum cryptoerr *);
extern void     crypto_init_iv(struct keystate *, u_int8_t *, size_t);
extern void     crypto_update_iv(struct keystate *);

#endif                          /* _CRYPTO_H_ */