/* $OpenBSD: c_skey.c,v 1.14 2023/07/08 10:43:59 beck Exp $ */
/* 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/cast.h>
#include "cast_local.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;
	}
}
LCRYPTO_ALIAS(CAST_set_key);
