/*	$OpenBSD: acss_skey.c,v 1.3 2009/08/07 00:05:04 martynas Exp $	*/
/*
 * Copyright (c) 2004 The OpenBSD project
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <openssl/acss.h>
#include <string.h>

static unsigned char reverse[] = {
	0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 
	0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, 
	0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 
	0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, 
	0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 
	0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, 
	0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 
	0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, 
	0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 
	0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, 
	0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 
	0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, 
	0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 
	0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, 
	0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 
	0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, 
	0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 
	0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, 
	0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 
	0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, 
	0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 
	0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, 
	0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 
	0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, 
	0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 
	0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, 
	0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 
	0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, 
	0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 
	0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, 
	0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 
	0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff 
};

static void
acss_seed(ACSS_KEY *key)
{
	int i;

	for (i = 0; i < ACSS_KEYSIZE; i++)
		key->seed[i] = reverse[key->data[i]];

	/* seed lfsrs */
	key->lfsr17 = key->seed[1]
		| (key->seed[0] << 9)
		| (1 << 8);	/* inject 1 at bit 9 */
	key->lfsr25 = key->seed[4]
		| (key->seed[3] << 8)
		| ((key->seed[2] & 0x1f) << 16)
		| ((key->seed[2] & 0xe0) << 17)
			| (1 << 21);	/* inject 1 at bit 22 */

	key->lfsrsum = 0;
}

void
acss_setkey(ACSS_KEY *key, const unsigned char *data, int enc, int mode)
{
	memcpy(key->data, data, sizeof(key->data));

	if (enc != -1)
		key->encrypt = enc;
	key->mode = mode;

	acss_seed(key);
}
