source-engine/thirdparty/openssl/crypto/des/fcrypt_b.c

/* crypto/des/fcrypt_b.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 <stdio.h>

/*
 * This version of crypt has been developed from my MIT compatible DES
 * library. The library is available at pub/Crypto/DES at ftp.psy.uq.oz.au
 * Eric Young (eay@cryptsoft.com)
 */

#define DES_FCRYPT
#include "des_locl.h"
#undef DES_FCRYPT

#undef PERM_OP
#define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
        (b)^=(t),\
        (a)^=((t)<<(n)))

#undef HPERM_OP
#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
        (a)=(a)^(t)^(t>>(16-(n))))\

void fcrypt_body(DES_LONG *out, DES_key_schedule *ks, DES_LONG Eswap0,
                 DES_LONG Eswap1)
{
    register DES_LONG l, r, t, u;
#ifdef DES_PTR
    register const unsigned char *des_SP = (const unsigned char *)DES_SPtrans;
#endif
    register DES_LONG *s;
    register int j;
    register DES_LONG E0, E1;

    l = 0;
    r = 0;

    s = (DES_LONG *)ks;
    E0 = Eswap0;
    E1 = Eswap1;

    for (j = 0; j < 25; j++) {
#ifndef DES_UNROLL
        register int i;

        for (i = 0; i < 32; i += 4) {
            D_ENCRYPT(l, r, i + 0); /* 1 */
            D_ENCRYPT(r, l, i + 2); /* 2 */
        }
#else
        D_ENCRYPT(l, r, 0);     /* 1 */
        D_ENCRYPT(r, l, 2);     /* 2 */
        D_ENCRYPT(l, r, 4);     /* 3 */
        D_ENCRYPT(r, l, 6);     /* 4 */
        D_ENCRYPT(l, r, 8);     /* 5 */
        D_ENCRYPT(r, l, 10);    /* 6 */
        D_ENCRYPT(l, r, 12);    /* 7 */
        D_ENCRYPT(r, l, 14);    /* 8 */
        D_ENCRYPT(l, r, 16);    /* 9 */
        D_ENCRYPT(r, l, 18);    /* 10 */
        D_ENCRYPT(l, r, 20);    /* 11 */
        D_ENCRYPT(r, l, 22);    /* 12 */
        D_ENCRYPT(l, r, 24);    /* 13 */
        D_ENCRYPT(r, l, 26);    /* 14 */
        D_ENCRYPT(l, r, 28);    /* 15 */
        D_ENCRYPT(r, l, 30);    /* 16 */
#endif

        t = l;
        l = r;
        r = t;
    }
    l = ROTATE(l, 3) & 0xffffffffL;
    r = ROTATE(r, 3) & 0xffffffffL;

    PERM_OP(l, r, t, 1, 0x55555555L);
    PERM_OP(r, l, t, 8, 0x00ff00ffL);
    PERM_OP(l, r, t, 2, 0x33333333L);
    PERM_OP(r, l, t, 16, 0x0000ffffL);
    PERM_OP(l, r, t, 4, 0x0f0f0f0fL);

    out[0] = r;
    out[1] = l;
}