/* crypto/modes/wrap128.c */

/*

 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL

 * project.

 */

/* ====================================================================

 * Copyright (c) 2013 The OpenSSL 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. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 */

#include "cryptlib.h"

#include <openssl/modes.h>

static const unsigned char default_iv[] = {

    0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,

};

/*

 * Input size limit: lower than maximum of standards but far larger than

 * anything that will be used in practice.

 */

#define CRYPTO128_WRAP_MAX (1UL << 31)

size_t CRYPTO_128_wrap(void *key, const unsigned char *iv,

                       unsigned char *out,

                       const unsigned char *in, size_t inlen,

                       block128_f block)

{

    unsigned char *A, B[16], *R;

    size_t i, j, t;

    if ((inlen & 0x7) || (inlen < 8) || (inlen > CRYPTO128_WRAP_MAX))

        return 0;

    A = B;

    t = 1;

    memmove(out + 8, in, inlen);

    if (!iv)

        iv = default_iv;

    memcpy(A, iv, 8);

    for (j = 0; j < 6; j++) {

        R = out + 8;

        for (i = 0; i < inlen; i += 8, t++, R += 8) {

            memcpy(B + 8, R, 8);

            block(B, B, key);

            A[7] ^= (unsigned char)(t & 0xff);

            if (t > 0xff) {

                A[6] ^= (unsigned char)((t >> 8) & 0xff);

                A[5] ^= (unsigned char)((t >> 16) & 0xff);

                A[4] ^= (unsigned char)((t >> 24) & 0xff);

            }

            memcpy(R, B + 8, 8);

        }

    }

    memcpy(out, A, 8);

    return inlen + 8;

}

size_t CRYPTO_128_unwrap(void *key, const unsigned char *iv,

                         unsigned char *out,

                         const unsigned char *in, size_t inlen,

                         block128_f block)

{

    unsigned char *A, B[16], *R;

    size_t i, j, t;

    inlen -= 8;

    if ((inlen & 0x7) || (inlen < 16) || (inlen > CRYPTO128_WRAP_MAX))

        return 0;

    A = B;

    t = 6 * (inlen >> 3);

    memcpy(A, in, 8);

    memmove(out, in + 8, inlen);

    for (j = 0; j < 6; j++) {

        R = out + inlen - 8;

        for (i = 0; i < inlen; i += 8, t--, R -= 8) {

            A[7] ^= (unsigned char)(t & 0xff);

            if (t > 0xff) {

                A[6] ^= (unsigned char)((t >> 8) & 0xff);

                A[5] ^= (unsigned char)((t >> 16) & 0xff);

                A[4] ^= (unsigned char)((t >> 24) & 0xff);

            }

            memcpy(B + 8, R, 8);

            block(B, B, key);

            memcpy(R, B + 8, 8);

        }

    }

    if (!iv)

        iv = default_iv;

    if (memcmp(A, iv, 8)) {

        OPENSSL_cleanse(out, inlen);

        return 0;

    }

    return inlen;

}