openssl/crypto/cast/c_skey.c

/* crypto/cast/c_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/cast.h>
#include "cast_lcl.h"
#include "cast_s.h"

#define CAST_exp(l,A,a,n) \
        A[n/4]=l; \
        a[n+3]=(l    )&0xff; \
        a[n+2]=(l>> 8)&0xff; \
        a[n+1]=(l>>16)&0xff; \
        a[n+0]=(l>>24)&0xff;

#define S4 CAST_S_table4
#define S5 CAST_S_table5
#define S6 CAST_S_table6
#define S7 CAST_S_table7

void CAST_set_key(CAST_KEY *key, int len, const unsigned char *data)
{
    CAST_LONG x[16];
    CAST_LONG z[16];
    CAST_LONG k[32];
    CAST_LONG X[4], Z[4];
    CAST_LONG l, *K;
    int i;

    for (i = 0; i < 16; i++)
        x[i] = 0;
    if (len > 16)
        len = 16;
    for (i = 0; i < len; i++)
        x[i] = data[i];
    if (len <= 10)
        key->short_key = 1;
    else
        key->short_key = 0;

    K = &k[0];
    X[0] = ((x[0] << 24) | (x[1] << 16) | (x[2] << 8) | x[3]) & 0xffffffffL;
    X[1] = ((x[4] << 24) | (x[5] << 16) | (x[6] << 8) | x[7]) & 0xffffffffL;
    X[2] = ((x[8] << 24) | (x[9] << 16) | (x[10] << 8) | x[11]) & 0xffffffffL;
    X[3] =
        ((x[12] << 24) | (x[13] << 16) | (x[14] << 8) | x[15]) & 0xffffffffL;

    for (;;) {
        l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
        CAST_exp(l, Z, z, 0);
        l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
        CAST_exp(l, Z, z, 4);
        l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
        CAST_exp(l, Z, z, 8);
        l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
        CAST_exp(l, Z, z, 12);

        K[0] = S4[z[8]] ^ S5[z[9]] ^ S6[z[7]] ^ S7[z[6]] ^ S4[z[2]];
        K[1] = S4[z[10]] ^ S5[z[11]] ^ S6[z[5]] ^ S7[z[4]] ^ S5[z[6]];
        K[2] = S4[z[12]] ^ S5[z[13]] ^ S6[z[3]] ^ S7[z[2]] ^ S6[z[9]];
        K[3] = S4[z[14]] ^ S5[z[15]] ^ S6[z[1]] ^ S7[z[0]] ^ S7[z[12]];

        l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
        CAST_exp(l, X, x, 0);
        l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
        CAST_exp(l, X, x, 4);
        l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
        CAST_exp(l, X, x, 8);
        l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
        CAST_exp(l, X, x, 12);

        K[4] = S4[x[3]] ^ S5[x[2]] ^ S6[x[12]] ^ S7[x[13]] ^ S4[x[8]];
        K[5] = S4[x[1]] ^ S5[x[0]] ^ S6[x[14]] ^ S7[x[15]] ^ S5[x[13]];
        K[6] = S4[x[7]] ^ S5[x[6]] ^ S6[x[8]] ^ S7[x[9]] ^ S6[x[3]];
        K[7] = S4[x[5]] ^ S5[x[4]] ^ S6[x[10]] ^ S7[x[11]] ^ S7[x[7]];

        l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
        CAST_exp(l, Z, z, 0);
        l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
        CAST_exp(l, Z, z, 4);
        l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
        CAST_exp(l, Z, z, 8);
        l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
        CAST_exp(l, Z, z, 12);

        K[8] = S4[z[3]] ^ S5[z[2]] ^ S6[z[12]] ^ S7[z[13]] ^ S4[z[9]];
        K[9] = S4[z[1]] ^ S5[z[0]] ^ S6[z[14]] ^ S7[z[15]] ^ S5[z[12]];
        K[10] = S4[z[7]] ^ S5[z[6]] ^ S6[z[8]] ^ S7[z[9]] ^ S6[z[2]];
        K[11] = S4[z[5]] ^ S5[z[4]] ^ S6[z[10]] ^ S7[z[11]] ^ S7[z[6]];

        l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
        CAST_exp(l, X, x, 0);
        l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
        CAST_exp(l, X, x, 4);
        l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
        CAST_exp(l, X, x, 8);
        l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
        CAST_exp(l, X, x, 12);

        K[12] = S4[x[8]] ^ S5[x[9]] ^ S6[x[7]] ^ S7[x[6]] ^ S4[x[3]];
        K[13] = S4[x[10]] ^ S5[x[11]] ^ S6[x[5]] ^ S7[x[4]] ^ S5[x[7]];
        K[14] = S4[x[12]] ^ S5[x[13]] ^ S6[x[3]] ^ S7[x[2]] ^ S6[x[8]];
        K[15] = S4[x[14]] ^ S5[x[15]] ^ S6[x[1]] ^ S7[x[0]] ^ S7[x[13]];
        if (K != k)
            break;
        K += 16;
    }

    for (i = 0; i < 16; i++) {
        key->data[i * 2] = k[i];
        key->data[i * 2 + 1] = ((k[i + 16]) + 16) & 0x1f;
    }
}