/*
 * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *
 * File: tkip.c
 *
 * Purpose: Implement functions for 802.11i TKIP
 *
 * Author: Jerry Chen
 *
 * Date: Mar. 11, 2003
 *
 * Functions:
 *      TKIPvMixKey - Get TKIP RC4 Key from TK,TA, and TSC
 *
 * Revision History:
 *
 */

#include "tmacro.h"
#include "tkip.h"

/*---------------------  Static Definitions -------------------------*/

/*---------------------  Static Classes  ----------------------------*/

/*---------------------  Static Variables  --------------------------*/

/*---------------------  Static Functions  --------------------------*/

/*---------------------  Export Variables  --------------------------*/

/*---------------------  Static Definitions -------------------------*/

/*---------------------  Static Classes  ----------------------------*/

/*---------------------  Static Variables  --------------------------*/

/* The Sbox is reduced to 2 16-bit wide tables, each with 256 entries. */
/* The 2nd table is the same as the 1st but with the upper and lower   */
/* bytes swapped. To allow an endian tolerant implementation, the byte */
/* halves have been expressed independently here.                      */
static const unsigned char TKIP_Sbox_Lower[256] = {
	0xA5, 0x84, 0x99, 0x8D, 0x0D, 0xBD, 0xB1, 0x54,
	0x50, 0x03, 0xA9, 0x7D, 0x19, 0x62, 0xE6, 0x9A,
	0x45, 0x9D, 0x40, 0x87, 0x15, 0xEB, 0xC9, 0x0B,
	0xEC, 0x67, 0xFD, 0xEA, 0xBF, 0xF7, 0x96, 0x5B,
	0xC2, 0x1C, 0xAE, 0x6A, 0x5A, 0x41, 0x02, 0x4F,
	0x5C, 0xF4, 0x34, 0x08, 0x93, 0x73, 0x53, 0x3F,
	0x0C, 0x52, 0x65, 0x5E, 0x28, 0xA1, 0x0F, 0xB5,
	0x09, 0x36, 0x9B, 0x3D, 0x26, 0x69, 0xCD, 0x9F,
	0x1B, 0x9E, 0x74, 0x2E, 0x2D, 0xB2, 0xEE, 0xFB,
	0xF6, 0x4D, 0x61, 0xCE, 0x7B, 0x3E, 0x71, 0x97,
	0xF5, 0x68, 0x00, 0x2C, 0x60, 0x1F, 0xC8, 0xED,
	0xBE, 0x46, 0xD9, 0x4B, 0xDE, 0xD4, 0xE8, 0x4A,
	0x6B, 0x2A, 0xE5, 0x16, 0xC5, 0xD7, 0x55, 0x94,
	0xCF, 0x10, 0x06, 0x81, 0xF0, 0x44, 0xBA, 0xE3,
	0xF3, 0xFE, 0xC0, 0x8A, 0xAD, 0xBC, 0x48, 0x04,
	0xDF, 0xC1, 0x75, 0x63, 0x30, 0x1A, 0x0E, 0x6D,
	0x4C, 0x14, 0x35, 0x2F, 0xE1, 0xA2, 0xCC, 0x39,
	0x57, 0xF2, 0x82, 0x47, 0xAC, 0xE7, 0x2B, 0x95,
	0xA0, 0x98, 0xD1, 0x7F, 0x66, 0x7E, 0xAB, 0x83,
	0xCA, 0x29, 0xD3, 0x3C, 0x79, 0xE2, 0x1D, 0x76,
	0x3B, 0x56, 0x4E, 0x1E, 0xDB, 0x0A, 0x6C, 0xE4,
	0x5D, 0x6E, 0xEF, 0xA6, 0xA8, 0xA4, 0x37, 0x8B,
	0x32, 0x43, 0x59, 0xB7, 0x8C, 0x64, 0xD2, 0xE0,
	0xB4, 0xFA, 0x07, 0x25, 0xAF, 0x8E, 0xE9, 0x18,
	0xD5, 0x88, 0x6F, 0x72, 0x24, 0xF1, 0xC7, 0x51,
	0x23, 0x7C, 0x9C, 0x21, 0xDD, 0xDC, 0x86, 0x85,
	0x90, 0x42, 0xC4, 0xAA, 0xD8, 0x05, 0x01, 0x12,
	0xA3, 0x5F, 0xF9, 0xD0, 0x91, 0x58, 0x27, 0xB9,
	0x38, 0x13, 0xB3, 0x33, 0xBB, 0x70, 0x89, 0xA7,
	0xB6, 0x22, 0x92, 0x20, 0x49, 0xFF, 0x78, 0x7A,
	0x8F, 0xF8, 0x80, 0x17, 0xDA, 0x31, 0xC6, 0xB8,
	0xC3, 0xB0, 0x77, 0x11, 0xCB, 0xFC, 0xD6, 0x3A
};

static const unsigned char TKIP_Sbox_Upper[256] = {
	0xC6, 0xF8, 0xEE, 0xF6, 0xFF, 0xD6, 0xDE, 0x91,
	0x60, 0x02, 0xCE, 0x56, 0xE7, 0xB5, 0x4D, 0xEC,
	0x8F, 0x1F, 0x89, 0xFA, 0xEF, 0xB2, 0x8E, 0xFB,
	0x41, 0xB3, 0x5F, 0x45, 0x23, 0x53, 0xE4, 0x9B,
	0x75, 0xE1, 0x3D, 0x4C, 0x6C, 0x7E, 0xF5, 0x83,
	0x68, 0x51, 0xD1, 0xF9, 0xE2, 0xAB, 0x62, 0x2A,
	0x08, 0x95, 0x46, 0x9D, 0x30, 0x37, 0x0A, 0x2F,
	0x0E, 0x24, 0x1B, 0xDF, 0xCD, 0x4E, 0x7F, 0xEA,
	0x12, 0x1D, 0x58, 0x34, 0x36, 0xDC, 0xB4, 0x5B,
	0xA4, 0x76, 0xB7, 0x7D, 0x52, 0xDD, 0x5E, 0x13,
	0xA6, 0xB9, 0x00, 0xC1, 0x40, 0xE3, 0x79, 0xB6,
	0xD4, 0x8D, 0x67, 0x72, 0x94, 0x98, 0xB0, 0x85,
	0xBB, 0xC5, 0x4F, 0xED, 0x86, 0x9A, 0x66, 0x11,
	0x8A, 0xE9, 0x04, 0xFE, 0xA0, 0x78, 0x25, 0x4B,
	0xA2, 0x5D, 0x80, 0x05, 0x3F, 0x21, 0x70, 0xF1,
	0x63, 0x77, 0xAF, 0x42, 0x20, 0xE5, 0xFD, 0xBF,
	0x81, 0x18, 0x26, 0xC3, 0xBE, 0x35, 0x88, 0x2E,
	0x93, 0x55, 0xFC, 0x7A, 0xC8, 0xBA, 0x32, 0xE6,
	0xC0, 0x19, 0x9E, 0xA3, 0x44, 0x54, 0x3B, 0x0B,
	0x8C, 0xC7, 0x6B, 0x28, 0xA7, 0xBC, 0x16, 0xAD,
	0xDB, 0x64, 0x74, 0x14, 0x92, 0x0C, 0x48, 0xB8,
	0x9F, 0xBD, 0x43, 0xC4, 0x39, 0x31, 0xD3, 0xF2,
	0xD5, 0x8B, 0x6E, 0xDA, 0x01, 0xB1, 0x9C, 0x49,
	0xD8, 0xAC, 0xF3, 0xCF, 0xCA, 0xF4, 0x47, 0x10,
	0x6F, 0xF0, 0x4A, 0x5C, 0x38, 0x57, 0x73, 0x97,
	0xCB, 0xA1, 0xE8, 0x3E, 0x96, 0x61, 0x0D, 0x0F,
	0xE0, 0x7C, 0x71, 0xCC, 0x90, 0x06, 0xF7, 0x1C,
	0xC2, 0x6A, 0xAE, 0x69, 0x17, 0x99, 0x3A, 0x27,
	0xD9, 0xEB, 0x2B, 0x22, 0xD2, 0xA9, 0x07, 0x33,
	0x2D, 0x3C, 0x15, 0xC9, 0x87, 0xAA, 0x50, 0xA5,
	0x03, 0x59, 0x09, 0x1A, 0x65, 0xD7, 0x84, 0xD0,
	0x82, 0x29, 0x5A, 0x1E, 0x7B, 0xA8, 0x6D, 0x2C
};

//STKIPKeyManagement  sTKIPKeyTable[MAX_TKIP_KEY];

/*---------------------  Static Functions  --------------------------*/
unsigned int tkip_sbox(unsigned int index);
unsigned int rotr1(unsigned int a);

/*---------------------  Export Variables  --------------------------*/

/************************************************************/
/* tkip_sbox()                                              */
/* Returns a 16 bit value from a 64K entry table. The Table */
/* is synthesized from two 256 entry byte wide tables.      */
/************************************************************/
unsigned int tkip_sbox(unsigned int index)
{
	unsigned int index_low;
	unsigned int index_high;
	unsigned int left, right;

	index_low = (index % 256);
	index_high = ((index >> 8) % 256);

	left = TKIP_Sbox_Lower[index_low] + (TKIP_Sbox_Upper[index_low] * 256);
	right = TKIP_Sbox_Upper[index_high] + (TKIP_Sbox_Lower[index_high] * 256);

	return left ^ right;
};

unsigned int rotr1(unsigned int a)
{
	unsigned int b;

	if ((a & 0x01) == 0x01)
		b = (a >> 1) | 0x8000;
	else
		b = (a >> 1) & 0x7fff;

	b = b % 65536;
	return b;
}

/*
 * Description: Calculate RC4Key fom TK, TA, and TSC
 *
 * Parameters:
 *  In:
 *      pbyTKey         - TKey
 *      pbyTA           - TA
 *      dwTSC           - TSC
 *  Out:
 *      pbyRC4Key       - RC4Key
 *
 * Return Value: none
 *
 */
void TKIPvMixKey(
	unsigned char *pbyTKey,
	unsigned char *pbyTA,
	unsigned short wTSC15_0,
	unsigned long dwTSC47_16,
	unsigned char *pbyRC4Key
)
{
	unsigned int p1k[5];
	unsigned int tsc0, tsc1, tsc2;
	unsigned int ppk0, ppk1, ppk2, ppk3, ppk4, ppk5;
	unsigned long int pnl, pnh;

	int i, j;

	pnl = wTSC15_0;
	pnh = dwTSC47_16;

	tsc0 = (unsigned int)((pnh >> 16) % 65536); /* msb */
	tsc1 = (unsigned int)(pnh % 65536);
	tsc2 = (unsigned int)(pnl % 65536); /* lsb */

	/* Phase 1, step 1 */
	p1k[0] = tsc1;
	p1k[1] = tsc0;
	p1k[2] = (unsigned int)(pbyTA[0] + (pbyTA[1]*256));
	p1k[3] = (unsigned int)(pbyTA[2] + (pbyTA[3]*256));
	p1k[4] = (unsigned int)(pbyTA[4] + (pbyTA[5]*256));

	/* Phase 1, step 2 */
	for (i = 0; i < 8; i++) {
		j = 2 * (i & 1);
		p1k[0] = (p1k[0] + tkip_sbox((p1k[4] ^ ((256*pbyTKey[1+j]) + pbyTKey[j])) % 65536)) % 65536;
		p1k[1] = (p1k[1] + tkip_sbox((p1k[0] ^ ((256*pbyTKey[5+j]) + pbyTKey[4+j])) % 65536)) % 65536;
		p1k[2] = (p1k[2] + tkip_sbox((p1k[1] ^ ((256*pbyTKey[9+j]) + pbyTKey[8+j])) % 65536)) % 65536;
		p1k[3] = (p1k[3] + tkip_sbox((p1k[2] ^ ((256*pbyTKey[13+j]) + pbyTKey[12+j])) % 65536)) % 65536;
		p1k[4] = (p1k[4] + tkip_sbox((p1k[3] ^ (((256*pbyTKey[1+j]) + pbyTKey[j]))) % 65536)) % 65536;
		p1k[4] = (p1k[4] + i) % 65536;
	}
	/* Phase 2, Step 1 */
	ppk0 = p1k[0];
	ppk1 = p1k[1];
	ppk2 = p1k[2];
	ppk3 = p1k[3];
	ppk4 = p1k[4];
	ppk5 = (p1k[4] + tsc2) % 65536;

	/* Phase2, Step 2 */
	ppk0 = ppk0 + tkip_sbox((ppk5 ^ ((256*pbyTKey[1]) + pbyTKey[0])) % 65536);
	ppk1 = ppk1 + tkip_sbox((ppk0 ^ ((256*pbyTKey[3]) + pbyTKey[2])) % 65536);
	ppk2 = ppk2 + tkip_sbox((ppk1 ^ ((256*pbyTKey[5]) + pbyTKey[4])) % 65536);
	ppk3 = ppk3 + tkip_sbox((ppk2 ^ ((256*pbyTKey[7]) + pbyTKey[6])) % 65536);
	ppk4 = ppk4 + tkip_sbox((ppk3 ^ ((256*pbyTKey[9]) + pbyTKey[8])) % 65536);
	ppk5 = ppk5 + tkip_sbox((ppk4 ^ ((256*pbyTKey[11]) + pbyTKey[10])) % 65536);

	ppk0 = ppk0 + rotr1(ppk5 ^ ((256*pbyTKey[13]) + pbyTKey[12]));
	ppk1 = ppk1 + rotr1(ppk0 ^ ((256*pbyTKey[15]) + pbyTKey[14]));
	ppk2 = ppk2 + rotr1(ppk1);
	ppk3 = ppk3 + rotr1(ppk2);
	ppk4 = ppk4 + rotr1(ppk3);
	ppk5 = ppk5 + rotr1(ppk4);

	/* Phase 2, Step 3 */
	pbyRC4Key[0] = (tsc2 >> 8) % 256;
	pbyRC4Key[1] = (((tsc2 >> 8) % 256) | 0x20) & 0x7f;
	pbyRC4Key[2] = tsc2 % 256;
	pbyRC4Key[3] = ((ppk5 ^ ((256*pbyTKey[1]) + pbyTKey[0])) >> 1) % 256;

	pbyRC4Key[4] = ppk0 % 256;
	pbyRC4Key[5] = (ppk0 >> 8) % 256;

	pbyRC4Key[6] = ppk1 % 256;
	pbyRC4Key[7] = (ppk1 >> 8) % 256;

	pbyRC4Key[8] = ppk2 % 256;
	pbyRC4Key[9] = (ppk2 >> 8) % 256;

	pbyRC4Key[10] = ppk3 % 256;
	pbyRC4Key[11] = (ppk3 >> 8) % 256;

	pbyRC4Key[12] = ppk4 % 256;
	pbyRC4Key[13] = (ppk4 >> 8) % 256;

	pbyRC4Key[14] = ppk5 % 256;
	pbyRC4Key[15] = (ppk5 >> 8) % 256;
}