/*      $OpenBSD: xform.c,v 1.16 2001/08/28 12:20:43 ben Exp $  */
/*-
 * The authors of this code are John Ioannidis (ji@tla.org),
 * Angelos D. Keromytis (kermit@csd.uch.gr),
 * Niels Provos (provos@physnet.uni-hamburg.de) and
 * Damien Miller (djm@mindrot.org).
 *
 * This code was written by John Ioannidis for BSD/OS in Athens, Greece,
 * in November 1995.
 *
 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
 * by Angelos D. Keromytis.
 *
 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
 * and Niels Provos.
 *
 * Additional features in 1999 by Angelos D. Keromytis.
 *
 * AES XTS implementation in 2008 by Damien Miller
 *
 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
 * Angelos D. Keromytis and Niels Provos.
 *
 * Copyright (C) 2001, Angelos D. Keromytis.
 *
 * Copyright (C) 2008, Damien Miller
 * Copyright (c) 2014 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by John-Mark Gurney
 * under sponsorship of the FreeBSD Foundation and
 * Rubicon Communications, LLC (Netgate).
 *
 * Permission to use, copy, and modify this software with or without fee
 * is hereby granted, provided that this entire notice is included in
 * all copies of any software which is or includes a copy or
 * modification of this software.
 * You may use this code under the GNU public license if you so wish. Please
 * contribute changes back to the authors under this freer than GPL license
 * so that we may further the use of strong encryption without limitations to
 * all.
 *
 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
 * PURPOSE.
 */

#include <sys/types.h>
#include <crypto/camellia/camellia.h>
#include <opencrypto/xform_enc.h>

struct camellia_cbc_ctx {
        camellia_ctx state;
        char iv[CAMELLIA_BLOCK_LEN];
};

static  int cml_setkey(void *, const uint8_t *, int);
static  void cml_encrypt(void *, const uint8_t *, uint8_t *);
static  void cml_decrypt(void *, const uint8_t *, uint8_t *);
static  void cml_encrypt_multi(void *, const uint8_t *, uint8_t *, size_t);
static  void cml_decrypt_multi(void *, const uint8_t *, uint8_t *, size_t);
static  void cml_reinit(void *, const uint8_t *, size_t);

/* Encryption instances */
const struct enc_xform enc_xform_camellia = {
        .type = CRYPTO_CAMELLIA_CBC,
        .name = "Camellia-CBC",
        .ctxsize = sizeof(struct camellia_cbc_ctx),
        .blocksize = CAMELLIA_BLOCK_LEN,
        .ivsize = CAMELLIA_BLOCK_LEN,
        .minkey = CAMELLIA_MIN_KEY,
        .maxkey = CAMELLIA_MAX_KEY,
        .setkey = cml_setkey,
        .reinit = cml_reinit,
        .encrypt = cml_encrypt,
        .decrypt = cml_decrypt,
        .encrypt_multi = cml_encrypt_multi,
        .decrypt_multi = cml_decrypt_multi,
};

/*
 * Encryption wrapper routines.
 */
static void
cml_encrypt(void *vctx, const uint8_t *in, uint8_t *out)
{
        struct camellia_cbc_ctx *ctx = vctx;

        for (u_int i = 0; i < CAMELLIA_BLOCK_LEN; i++)
                out[i] = in[i] ^ ctx->iv[i];
        camellia_encrypt(&ctx->state, out, out);
        memcpy(ctx->iv, out, CAMELLIA_BLOCK_LEN);
}

static void
cml_decrypt(void *vctx, const uint8_t *in, uint8_t *out)
{
        struct camellia_cbc_ctx *ctx = vctx;
        char block[CAMELLIA_BLOCK_LEN];

        memcpy(block, in, CAMELLIA_BLOCK_LEN);
        camellia_decrypt(&ctx->state, in, out);
        for (u_int i = 0; i < CAMELLIA_BLOCK_LEN; i++)
                out[i] ^= ctx->iv[i];
        memcpy(ctx->iv, block, CAMELLIA_BLOCK_LEN);
        explicit_bzero(block, sizeof(block));
}

static void
cml_encrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len)
{
        struct camellia_cbc_ctx *ctx = vctx;

        KASSERT(len % CAMELLIA_BLOCK_LEN == 0, ("%s: invalid length",
            __func__));
        while (len > 0) {
                for (u_int i = 0; i < CAMELLIA_BLOCK_LEN; i++)
                        out[i] = in[i] ^ ctx->iv[i];
                camellia_encrypt(&ctx->state, out, out);
                memcpy(ctx->iv, out, CAMELLIA_BLOCK_LEN);
                out += CAMELLIA_BLOCK_LEN;
                in += CAMELLIA_BLOCK_LEN;
                len -= CAMELLIA_BLOCK_LEN;
        }
}

static void
cml_decrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len)
{
        struct camellia_cbc_ctx *ctx = vctx;
        char block[CAMELLIA_BLOCK_LEN];

        KASSERT(len % CAMELLIA_BLOCK_LEN == 0, ("%s: invalid length",
            __func__));
        while (len > 0) {
                memcpy(block, in, CAMELLIA_BLOCK_LEN);
                camellia_decrypt(&ctx->state, in, out);
                for (u_int i = 0; i < CAMELLIA_BLOCK_LEN; i++)
                        out[i] ^= ctx->iv[i];
                memcpy(ctx->iv, block, CAMELLIA_BLOCK_LEN);
                out += CAMELLIA_BLOCK_LEN;
                in += CAMELLIA_BLOCK_LEN;
                len -= CAMELLIA_BLOCK_LEN;
        }
        explicit_bzero(block, sizeof(block));
}

static int
cml_setkey(void *vctx, const uint8_t *key, int len)
{
        struct camellia_cbc_ctx *ctx = vctx;

        if (len != 16 && len != 24 && len != 32)
                return (EINVAL);

        camellia_set_key(&ctx->state, key, len * 8);
        return (0);
}

static void
cml_reinit(void *vctx, const uint8_t *iv, size_t iv_len)
{
        struct camellia_cbc_ctx *ctx = vctx;

        KASSERT(iv_len == sizeof(ctx->iv), ("%s: bad IV length", __func__));
        memcpy(ctx->iv, iv, sizeof(ctx->iv));
}