/*
 ***************************************************************************
 * Ralink Tech Inc.
 * 5F, No. 36 Taiyuan St.
 * Jhubei City
 * Hsinchu County 302, Taiwan, R.O.C.
 *
 * (c) Copyright 2002-2008, Ralink Technology, Inc.
 *
 * 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.,                                       * 
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             * 
 *                                                                       * 
 *************************************************************************

	Module Name:
	rtmp_wep.c

	Abstract:

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

#include    "rt_config.h"

ULONG 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:
      pAdapter      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

    Note:
    
    ========================================================================
*/
VOID    RTMPInitWepEngine(
    IN  PRTMP_ADAPTER   pAdapter,   
    IN  PUCHAR          pKey,
    IN  UCHAR           KeyId,
    IN  UCHAR           KeyLen, 
    IN OUT  PUCHAR      pDest)
{
    UINT i;

    pAdapter->PrivateInfo.FCSCRC32 = PPPINITFCS32;   //Init crc32.
    NdisMoveMemory(WEPKEY + 3, pKey, KeyLen);

    for(i = 0; i < 3; i++)
        WEPKEY[i] = RandomByte(pAdapter);   //Call mlme RandomByte() function.
    ARCFOUR_INIT(&pAdapter->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:
      pAdapter      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
        
    Note:
    
    ========================================================================
*/
VOID    RTMPEncryptData(
    IN  PRTMP_ADAPTER   pAdapter,   
    IN  PUCHAR          pSrc,
    IN  PUCHAR          pDest,
    IN  UINT            Len)
{
    pAdapter->PrivateInfo.FCSCRC32 = RTMP_CALC_FCS32(pAdapter->PrivateInfo.FCSCRC32, pSrc, Len);
    ARCFOUR_ENCRYPT(&pAdapter->PrivateInfo.WEPCONTEXT, pDest, pSrc, Len);
}

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

    Routine Description:
		Decrypt received 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	RTMPDecryptData(
	IN	PRTMP_ADAPTER	pAdapter,
	IN	PUCHAR			pSrc,
	IN	UINT			Len)
{
	ULONG	trailfcs;
	ULONG   crc32;
	UCHAR	KeyIdx;

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

	NdisMoveMemory(WEPKEY + 3, pAdapter->SharedKey[KeyIdx].Key, pAdapter->SharedKey[KeyIdx].KeyLen);	
	ARCFOUR_INIT(&pAdapter->PrivateInfo.WEPCONTEXT, WEPKEY, pAdapter->SharedKey[KeyIdx].KeyLen + 3);
	ARCFOUR_DECRYPT(&pAdapter->PrivateInfo.WEPCONTEXT, pSrc, pSrc + 4, Len - 4);
	NdisMoveMemory(&trailfcs, pSrc + Len - 8, 4);
	crc32 = RTMP_CALC_FCS32(PPPINITFCS32, pSrc, Len - 8);  //Skip last 4 bytes(FCS).
	crc32 ^= 0xffffffff;             /* complement */
#ifndef BIG_ENDIAN
	if(crc32 != trailfcs)
#else
    if(crc32 != SWAP32(trailfcs))
#endif
    {
		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
        
    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
        
    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:
        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:
        ULONG - FCS 32 bits
        
    Note:
    
    ========================================================================
*/
ULONG   RTMP_CALC_FCS32(
    IN  ULONG   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   pAdapter,
    IN  PUCHAR  pDest)
{
    pAdapter->PrivateInfo.FCSCRC32 ^= 0xffffffff;             /* complement */
    
#ifdef BIG_ENDIAN
    pAdapter->PrivateInfo.FCSCRC32 = SWAP32(pAdapter->PrivateInfo.FCSCRC32);
#endif
    
    ARCFOUR_ENCRYPT(&pAdapter->PrivateInfo.WEPCONTEXT, pDest, (PUCHAR) &pAdapter->PrivateInfo.FCSCRC32, 4);
}
