/* crypto/cast/c_enc.c */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * 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 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 acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 OR 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.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <openssl/cast.h>

#include "cast_lcl.h"

void CAST_encrypt(CAST_LONG *data, const CAST_KEY *key)

{

    register CAST_LONG l, r, t;

    const register CAST_LONG *k;

    k = &(key->data[0]);

    l = data[0];

    r = data[1];

    E_CAST(0, k, l, r, +, ^, -);

    E_CAST(1, k, r, l, ^, -, +);

    E_CAST(2, k, l, r, -, +, ^);

    E_CAST(3, k, r, l, +, ^, -);

    E_CAST(4, k, l, r, ^, -, +);

    E_CAST(5, k, r, l, -, +, ^);

    E_CAST(6, k, l, r, +, ^, -);

    E_CAST(7, k, r, l, ^, -, +);

    E_CAST(8, k, l, r, -, +, ^);

    E_CAST(9, k, r, l, +, ^, -);

    E_CAST(10, k, l, r, ^, -, +);

    E_CAST(11, k, r, l, -, +, ^);

    if (!key->short_key) {

        E_CAST(12, k, l, r, +, ^, -);

        E_CAST(13, k, r, l, ^, -, +);

        E_CAST(14, k, l, r, -, +, ^);

        E_CAST(15, k, r, l, +, ^, -);

    }

    data[1] = l & 0xffffffffL;

    data[0] = r & 0xffffffffL;

}

void CAST_decrypt(CAST_LONG *data, const CAST_KEY *key)

{

    register CAST_LONG l, r, t;

    const register CAST_LONG *k;

    k = &(key->data[0]);

    l = data[0];

    r = data[1];

    if (!key->short_key) {

        E_CAST(15, k, l, r, +, ^, -);

        E_CAST(14, k, r, l, -, +, ^);

        E_CAST(13, k, l, r, ^, -, +);

        E_CAST(12, k, r, l, +, ^, -);

    }

    E_CAST(11, k, l, r, -, +, ^);

    E_CAST(10, k, r, l, ^, -, +);

    E_CAST(9, k, l, r, +, ^, -);

    E_CAST(8, k, r, l, -, +, ^);

    E_CAST(7, k, l, r, ^, -, +);

    E_CAST(6, k, r, l, +, ^, -);

    E_CAST(5, k, l, r, -, +, ^);

    E_CAST(4, k, r, l, ^, -, +);

    E_CAST(3, k, l, r, +, ^, -);

    E_CAST(2, k, r, l, -, +, ^);

    E_CAST(1, k, l, r, ^, -, +);

    E_CAST(0, k, r, l, +, ^, -);

    data[1] = l & 0xffffffffL;

    data[0] = r & 0xffffffffL;

}

void CAST_cbc_encrypt(const unsigned char *in, unsigned char *out,

                      long length, const CAST_KEY *ks, unsigned char *iv,

                      int enc)

{

    register CAST_LONG tin0, tin1;

    register CAST_LONG tout0, tout1, xor0, xor1;

    register long l = length;

    CAST_LONG tin[2];

    if (enc) {

        n2l(iv, tout0);

        n2l(iv, tout1);

        iv -= 8;

        for (l -= 8; l >= 0; l -= 8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin0 ^= tout0;

            tin1 ^= tout1;

            tin[0] = tin0;

            tin[1] = tin1;

            CAST_encrypt(tin, ks);

            tout0 = tin[0];

            tout1 = tin[1];

            l2n(tout0, out);

            l2n(tout1, out);

        }

        if (l != -8) {

            n2ln(in, tin0, tin1, l + 8);

            tin0 ^= tout0;

            tin1 ^= tout1;

            tin[0] = tin0;

            tin[1] = tin1;

            CAST_encrypt(tin, ks);

            tout0 = tin[0];

            tout1 = tin[1];

            l2n(tout0, out);

            l2n(tout1, out);

        }

        l2n(tout0, iv);

        l2n(tout1, iv);

    } else {

        n2l(iv, xor0);

        n2l(iv, xor1);

        iv -= 8;

        for (l -= 8; l >= 0; l -= 8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin[0] = tin0;

            tin[1] = tin1;

            CAST_decrypt(tin, ks);

            tout0 = tin[0] ^ xor0;

            tout1 = tin[1] ^ xor1;

            l2n(tout0, out);

            l2n(tout1, out);

            xor0 = tin0;

            xor1 = tin1;

        }

        if (l != -8) {

            n2l(in, tin0);

            n2l(in, tin1);

            tin[0] = tin0;

            tin[1] = tin1;

            CAST_decrypt(tin, ks);

            tout0 = tin[0] ^ xor0;

            tout1 = tin[1] ^ xor1;

            l2nn(tout0, tout1, out, l + 8);

            xor0 = tin0;

            xor1 = tin1;

        }

        l2n(xor0, iv);

        l2n(xor1, iv);

    }

    tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;

    tin[0] = tin[1] = 0;

}