/* crypto/idea/i_skey.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/crypto.h>

#include <openssl/idea.h>

#include "idea_lcl.h"

static IDEA_INT inverse(unsigned int xin);

void idea_set_encrypt_key(const unsigned char *key, IDEA_KEY_SCHEDULE *ks)

#ifdef OPENSSL_FIPS

{

    fips_cipher_abort(IDEA);

    private_idea_set_encrypt_key(key, ks);

}

void private_idea_set_encrypt_key(const unsigned char *key,

                                  IDEA_KEY_SCHEDULE *ks)

#endif

{

    int i;

    register IDEA_INT *kt, *kf, r0, r1, r2;

    kt = &(ks->data[0][0]);

    n2s(key, kt[0]);

    n2s(key, kt[1]);

    n2s(key, kt[2]);

    n2s(key, kt[3]);

    n2s(key, kt[4]);

    n2s(key, kt[5]);

    n2s(key, kt[6]);

    n2s(key, kt[7]);

    kf = kt;

    kt += 8;

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

        r2 = kf[1];

        r1 = kf[2];

        *(kt++) = ((r2 << 9) | (r1 >> 7)) & 0xffff;

        r0 = kf[3];

        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;

        r1 = kf[4];

        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;

        r0 = kf[5];

        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;

        r1 = kf[6];

        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;

        r0 = kf[7];

        *(kt++) = ((r1 << 9) | (r0 >> 7)) & 0xffff;

        r1 = kf[0];

        if (i >= 5)

            break;

        *(kt++) = ((r0 << 9) | (r1 >> 7)) & 0xffff;

        *(kt++) = ((r1 << 9) | (r2 >> 7)) & 0xffff;

        kf += 8;

    }

}

void idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)

{

    int r;

    register IDEA_INT *fp, *tp, t;

    tp = &(dk->data[0][0]);

    fp = &(ek->data[8][0]);

    for (r = 0; r < 9; r++) {

        *(tp++) = inverse(fp[0]);

        *(tp++) = ((int)(0x10000L - fp[2]) & 0xffff);

        *(tp++) = ((int)(0x10000L - fp[1]) & 0xffff);

        *(tp++) = inverse(fp[3]);

        if (r == 8)

            break;

        fp -= 6;

        *(tp++) = fp[4];

        *(tp++) = fp[5];

    }

    tp = &(dk->data[0][0]);

    t = tp[1];

    tp[1] = tp[2];

    tp[2] = t;

    t = tp[49];

    tp[49] = tp[50];

    tp[50] = t;

}

/* taken directly from the 'paper' I'll have a look at it later */

static IDEA_INT inverse(unsigned int xin)

{

    long n1, n2, q, r, b1, b2, t;

    if (xin == 0)

        b2 = 0;

    else {

        n1 = 0x10001;

        n2 = xin;

        b2 = 1;

        b1 = 0;

        do {

            r = (n1 % n2);

            q = (n1 - r) / n2;

            if (r == 0) {

                if (b2 < 0)

                    b2 = 0x10001 + b2;

            } else {

                n1 = n2;

                n2 = r;

                t = b2;

                b2 = b1 - q * b2;

                b1 = t;

            }

        } while (r != 0);

    }

    return ((IDEA_INT) b2);

}