/*

 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <openssl/cast.h>

#include "cast_lcl.h"

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

{

    CAST_LONG l, r, t;

    const 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)

{

    CAST_LONG l, r, t;

    const 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;

}