/*
 ***************************************************************************
 * Ralink Tech Inc.
 * 4F, No. 2 Technology 5th Rd.
 * Science-based Industrial Park
 * Hsin-chu, Taiwan, R.O.C.
 *
 * (c) Copyright 2002-2004, Ralink Technology, Inc.
 *
 * All rights reserved. Ralink's source code is an unpublished work and the
 * use of a copyright notice does not imply otherwise. This source code
 * contains confidential trade secret material of Ralink Tech. Any attemp
 * or participation in deciphering, decoding, reverse engineering or in any
 * way altering the source code is stricitly prohibited, unless the prior
 * written consent of Ralink Technology, Inc. is obtained.
 ***************************************************************************

	Module Name:
	rtmp_wep.c

	Abstract:

	Revision History:
	Who			When			What
	--------	----------		----------------------------------------------
	Paul Wu		10-28-02		Initial
*/

#include	"rt_config.h"

UINT FCSTAB_32[256] = 
{
	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba,
	0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
	0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
	0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
	0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec,
	0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
	0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
	0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940,
	0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116,
	0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
	0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
	0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a,
	0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818,
	0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
	0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 
	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 
	0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 
	0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 
	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 
	0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 
	0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 
	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 
	0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 
	0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 
	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 
	0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 
	0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 
	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 
	0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 
	0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 
	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 
	0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 
	0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 
	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 
	0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 
	0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 
	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 
	0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 
	0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 
	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 
	0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 
	0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 
	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 
	0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 
	0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 
	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 
	0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 
	0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 
	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 
	0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 
	0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 
	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 
	0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 
	0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 
	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 
	0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 
	0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 
	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d 
}; 

/*
UCHAR   WEPKEY[] = {
		//IV
		0x00, 0x11, 0x22, 
		//WEP KEY
		0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC 
	};
 */

/*
	========================================================================

	Routine	Description:
		Init WEP function.	
		
	Arguments:
      pAd		Pointer to our adapter
		pKey        Pointer to the WEP KEY
		KeyId		   WEP Key ID
		KeyLen      the length of WEP KEY
		pDest       Pointer to the destination which Encryption data will store in.
		
	Return Value:
		None

	IRQL = DISPATCH_LEVEL
	
	Note:
	
	========================================================================
*/
VOID	RTMPInitWepEngine(
	IN	PRTMP_ADAPTER	pAd,	
	IN	PUCHAR			pKey,
	IN	UCHAR			KeyId,
	IN	UCHAR			KeyLen, 
	IN OUT	PUCHAR		pDest)
{
	UINT i;
	UCHAR   WEPKEY[] = {
		//IV
		0x00, 0x11, 0x22, 
		//WEP KEY
		0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC 
	};

	pAd->PrivateInfo.FCSCRC32 = PPPINITFCS32;   //Init crc32.

#ifdef CONFIG_STA_SUPPORT
    if (pAd->StaCfg.bCkipOn && (pAd->StaCfg.CkipFlag & 0x10) && (pAd->OpMode == OPMODE_STA))
    {
        ARCFOUR_INIT(&pAd->PrivateInfo.WEPCONTEXT, pKey, KeyLen);  //INIT SBOX, KEYLEN+3(IV)
        NdisMoveMemory(pDest, pKey, 3);  //Append Init Vector
    }
    else
#endif // CONFIG_STA_SUPPORT //
    {
		NdisMoveMemory(WEPKEY + 3, pKey, KeyLen);

        for(i = 0; i < 3; i++)
			WEPKEY[i] = RandomByte(pAd);   //Call mlme RandomByte() function.
		ARCFOUR_INIT(&pAd->PrivateInfo.WEPCONTEXT, WEPKEY, KeyLen + 3);  //INIT SBOX, KEYLEN+3(IV)

		NdisMoveMemory(pDest, WEPKEY, 3);  //Append Init Vector 
    }
	*(pDest+3) = (KeyId << 6);       //Append KEYID 
	
}

/*
	========================================================================

	Routine	Description:
		Encrypt transimitted data		
		
	Arguments:
      pAd		Pointer to our adapter
      pSrc        Pointer to the transimitted source data that will be encrypt
      pDest       Pointer to the destination where entryption data will be store in.
      Len			Indicate the length of the source data
		
	Return Value:
      None
		        
	IRQL = DISPATCH_LEVEL

	Note:
	
	========================================================================
*/
VOID	RTMPEncryptData(
	IN	PRTMP_ADAPTER	pAd,	
	IN	PUCHAR			pSrc,
	IN	PUCHAR			pDest,
	IN	UINT			Len)
{
	pAd->PrivateInfo.FCSCRC32 = RTMP_CALC_FCS32(pAd->PrivateInfo.FCSCRC32, pSrc, Len);
	ARCFOUR_ENCRYPT(&pAd->PrivateInfo.WEPCONTEXT, pDest, pSrc, Len);
}


/*
	========================================================================

	Routine	Description:
		Decrypt received WEP data	
		
	Arguments:
		pAdapter		Pointer to our adapter
		pSrc        Pointer to the received data
		Len         the length of the received data
		
	Return Value:
		TRUE        Decrypt WEP data success
		FALSE       Decrypt WEP data failed
		
	Note:
	
	========================================================================
*/
BOOLEAN	RTMPSoftDecryptWEP(
	IN PRTMP_ADAPTER 	pAd,
	IN PUCHAR			pData,
	IN ULONG			DataByteCnt,
	IN PCIPHER_KEY		pGroupKey)
{
	UINT	trailfcs;
	UINT    crc32;
	UCHAR	KeyIdx;
	UCHAR   WEPKEY[] = {
		//IV
		0x00, 0x11, 0x22, 
		//WEP KEY
		0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC 
	};
	UCHAR 	*pPayload = (UCHAR *)pData + LENGTH_802_11;
	ULONG	payload_len = DataByteCnt - LENGTH_802_11;

	NdisMoveMemory(WEPKEY, pPayload, 3);    //Get WEP IV
	
	KeyIdx = (*(pPayload + 3) & 0xc0) >> 6;
	if (pGroupKey[KeyIdx].KeyLen == 0)
		return (FALSE);

	NdisMoveMemory(WEPKEY + 3, pGroupKey[KeyIdx].Key, pGroupKey[KeyIdx].KeyLen);	
	ARCFOUR_INIT(&pAd->PrivateInfo.WEPCONTEXT, WEPKEY, pGroupKey[KeyIdx].KeyLen + 3);
	ARCFOUR_DECRYPT(&pAd->PrivateInfo.WEPCONTEXT, pPayload, pPayload + 4, payload_len - 4);
	NdisMoveMemory(&trailfcs, pPayload + payload_len - 8, 4);
	crc32 = RTMP_CALC_FCS32(PPPINITFCS32, pPayload, payload_len - 8);  //Skip last 4 bytes(FCS).
	crc32 ^= 0xffffffff;             /* complement */

    if(crc32 != cpu2le32(trailfcs))
    {
		DBGPRINT(RT_DEBUG_TRACE, ("! WEP Data CRC Error !\n"));	 //CRC error.
		return (FALSE);
	}
	return (TRUE);
}

/*
	========================================================================

	Routine	Description:
		The Stream Cipher Encryption Algorithm "ARCFOUR" initialize		
		
	Arguments:
	   Ctx         Pointer to ARCFOUR CONTEXT (SBOX)
		pKey        Pointer to the WEP KEY
		KeyLen      Indicate the length fo the WEP KEY
		
	Return Value:
	   None
		
	IRQL = DISPATCH_LEVEL
	
	Note:
	
	========================================================================
*/
VOID	ARCFOUR_INIT(
	IN	PARCFOURCONTEXT	Ctx,
	IN	PUCHAR			pKey,
	IN	UINT			KeyLen)
{
	UCHAR	t, u;
	UINT	keyindex;
	UINT	stateindex;
	PUCHAR	state;
	UINT	counter;
	
	state = Ctx->STATE;
	Ctx->X = 0;
	Ctx->Y = 0;
	for (counter = 0; counter < 256; counter++)
		state[counter] = (UCHAR)counter;
	keyindex = 0;
	stateindex = 0;
	for (counter = 0; counter < 256; counter++)
	{
		t = state[counter];
		stateindex = (stateindex + pKey[keyindex] + t) & 0xff;
		u = state[stateindex];
		state[stateindex] = t;
		state[counter] = u;
		if (++keyindex >= KeyLen)
			keyindex = 0;
	}
}

/*
	========================================================================

	Routine	Description:
		Get bytes from ARCFOUR CONTEXT (S-BOX)				
		
	Arguments:
	   Ctx         Pointer to ARCFOUR CONTEXT (SBOX)
		
	Return Value:
	   UCHAR  - the value of the ARCFOUR CONTEXT (S-BOX)		
		
	Note:
	
	========================================================================
*/
UCHAR	ARCFOUR_BYTE(
	IN	PARCFOURCONTEXT		Ctx)
{
  UINT x;
  UINT y;
  UCHAR sx, sy;
  PUCHAR state;
  
  state = Ctx->STATE;
  x = (Ctx->X + 1) & 0xff;
  sx = state[x];
  y = (sx + Ctx->Y) & 0xff;
  sy = state[y];
  Ctx->X = x;
  Ctx->Y = y;
  state[y] = sx;
  state[x] = sy;

  return(state[(sx + sy) & 0xff]);
  
}

/*
	========================================================================

	Routine	Description:
		The Stream Cipher Decryption Algorithm 		
		
	Arguments:
		Ctx         Pointer to ARCFOUR CONTEXT (SBOX)
		pDest			Pointer to the Destination 
		pSrc        Pointer to the Source data
		Len         Indicate the length of the Source data
		
	Return Value:
		None
		
	Note:
	
	========================================================================
*/
VOID	ARCFOUR_DECRYPT(
	IN	PARCFOURCONTEXT	Ctx,
	IN	PUCHAR			pDest, 
	IN	PUCHAR			pSrc,
	IN	UINT			Len)
{
	UINT i;

	for (i = 0; i < Len; i++)
		pDest[i] = pSrc[i] ^ ARCFOUR_BYTE(Ctx);
}

/*
	========================================================================

	Routine	Description:
		The Stream Cipher Encryption Algorithm 		
		
	Arguments:
		Ctx         Pointer to ARCFOUR CONTEXT (SBOX)
		pDest			Pointer to the Destination 
		pSrc        Pointer to the Source data
		Len         Indicate the length of the Source dta
		
	Return Value:
		None
		        
	IRQL = DISPATCH_LEVEL

	Note:
	
	========================================================================
*/
VOID	ARCFOUR_ENCRYPT(
	IN	PARCFOURCONTEXT	Ctx,
	IN	PUCHAR			pDest,
	IN	PUCHAR			pSrc,
	IN	UINT			Len)
{
	UINT i;

	for (i = 0; i < Len; i++)
		pDest[i] = pSrc[i] ^ ARCFOUR_BYTE(Ctx);
}

/*
	========================================================================

	Routine	Description:
		The Stream Cipher Encryption Algorithm which conform to the special requirement to encrypt  GTK.
		
	Arguments:
		Ctx         Pointer to ARCFOUR CONTEXT (SBOX)
		pDest			Pointer to the Destination 
		pSrc        Pointer to the Source data
		Len         Indicate the length of the Source dta
		
		
	========================================================================
*/

VOID	WPAARCFOUR_ENCRYPT(
	IN	PARCFOURCONTEXT	Ctx,
	IN	PUCHAR			pDest,
	IN	PUCHAR			pSrc,
	IN	UINT			Len)
{
	UINT i;
        //discard first 256 bytes
	for (i = 0; i < 256; i++)
            ARCFOUR_BYTE(Ctx);
    
	for (i = 0; i < Len; i++)
		pDest[i] = pSrc[i] ^ ARCFOUR_BYTE(Ctx);
}


/*
	========================================================================

	Routine	Description:
		Calculate a new FCS given the current FCS and the new data.
		
	Arguments:
		Fcs	      the original FCS value
		Cp          pointer to the data which will be calculate the FCS
		Len         the length of the data
		
	Return Value:
		UINT - FCS 32 bits
		        
	IRQL = DISPATCH_LEVEL

	Note:
	
	========================================================================
*/
UINT	RTMP_CALC_FCS32(
	IN	UINT	Fcs,
	IN	PUCHAR	Cp,
	IN	INT		Len)
{
	while (Len--)
	   Fcs = (((Fcs) >> 8) ^ FCSTAB_32[((Fcs) ^ (*Cp++)) & 0xff]);

	return (Fcs); 
} 


/*
	========================================================================

	Routine	Description:
		Get last FCS and encrypt it to the destination				
		
	Arguments:
		pDest			Pointer to the Destination 
		
	Return Value:
		None
		
	Note:
	
	========================================================================
*/
VOID	RTMPSetICV(
	IN	PRTMP_ADAPTER	pAd,
	IN	PUCHAR	pDest)
{
	pAd->PrivateInfo.FCSCRC32 ^= 0xffffffff;             /* complement */
	pAd->PrivateInfo.FCSCRC32 = cpu2le32(pAd->PrivateInfo.FCSCRC32);
	
	ARCFOUR_ENCRYPT(&pAd->PrivateInfo.WEPCONTEXT, pDest, (PUCHAR) &pAd->PrivateInfo.FCSCRC32, 4);
}

