/******************************************************************************
|  File Name : Dcm_App.c
|  Description: ��Ϸ�����崦��
 *****************************************************************************/

/******************************************************************************
 * Description:     : Include File Section 									
******************************************************************************/
#include "Dcm_Key.h"

/******************************************************************************
 * Description:     : Global Variable Definition Section 									
 ******************************************************************************/
 


/******************************************************************************
 * Description:     : Static Variable Definition Section 									
 ******************************************************************************/
 
 
 /******************************************************************************
 * Description:     : Write User Function Code								
 *****************************************************************************/
static const uint8 xorArray[4] = {0xAA,0x50,0x43,0x52};

uint32 GetSeed(void)
{
	return (GetTimerCnt());
	//return(0x0016CDB0);   test 
}

uint32 encypt(uint32 seed)
{
	uint8 i,data[8];
	uint32 seed_temp;
	seed_temp = seed;//(uint32)(data[0])<<24 | (uint32)(data[1])<<16 | (uint32)(data[2])<<8 | (uint32)(data[3]);
	if(seed_temp != 0)
	{
		for(i=0;i<35;i++)
		{
			if(seed_temp & 0x80000000)
			{
				if(seed_temp & 0x00000002)
				{
					seed_temp = ((seed_temp << 1)&0xFFFFFFFF);
					seed_temp = (seed_temp^0xDFAF30B5)&0xFFFFFFFF;
				}
				else
				{
					seed_temp = (seed_temp << 1)&0xFFFFFFFF;
					seed_temp = seed_temp^0x6F21EAAE;
				}
			}
			else
				seed_temp = (seed_temp << 1)&0xFFFFFFFF;	
		}
	}
	// data[0] = seed_temp>>24;
	// data[1] = seed_temp>>16;
	// data[2] = seed_temp>>8;
	// data[3] = seed_temp;
	// TransmitCAN_Message(0x701,8,data);
	return seed_temp;
}

uint32 SecurityLevel_1(uint32 Seed)
{
	return encypt(Seed);
}

uint32 SecurityLevel_3(uint32 Seed)
{
	SeedSec_t cal,key,seed;
	seed.word = Seed;
	cal.byte[0] = ((seed.byte[0]&0xF8)>>3)^xorArray[0];
	cal.byte[1] = ((seed.byte[1]&0xF8)>>3)^xorArray[1];
	cal.byte[2] = ((seed.byte[2]&0xF8)>>3)^xorArray[2];
	cal.byte[3] = ((seed.byte[3]&0xF8)>>3)^xorArray[3];
	
	key.byte[0] = ((cal.byte[3]&0x07)<<5)|(( cal.byte[0]&0xF8)>>3);
	key.byte[1] = ((cal.byte[0]&0x07)<<5)|(cal.byte[2]&0x1F); 
	key.byte[2] = (cal.byte[1]&0xF8)|((cal.byte[3]&0xE0)>>5);
	key.byte[3] = (cal.byte[2]&0xF8)|( cal.byte[1]&0x07);
	
	return( key.word );
}

uint32 SecurityLevel_11(uint32 Seed)
{
	SeedSec_t cal,key,seed,key_test;
	seed.word = Seed;
	cal.byte[0] = seed.byte[0]^xorArray[0];
	cal.byte[1] = seed.byte[1]^xorArray[1];
	cal.byte[2] = seed.byte[2]^xorArray[2];
	cal.byte[3] = seed.byte[3]^xorArray[3];
#if 0	
	key.byte[0] = ((cal.byte[2]&0x03)<<6)|(( cal.byte[3]&0xFC)>>2);
	key.byte[1] = ((cal.byte[3]&0x03)<<6)|(cal.byte[0]&0x3F); 
	key.byte[2] = (cal.byte[0]&0xFC)|((cal.byte[1]&0xC0)>>6);
	key.byte[3] = (cal.byte[1]&0xFC)|( cal.byte[2]&0x03);
#else	
	key.byte[3] = ((cal.byte[1]&0x03)<<6)|(( cal.byte[0]&0xFC)>>2);
	key.byte[2] = ((cal.byte[0]&0x03)<<6)|(cal.byte[3]&0x3F); 
	key.byte[1] = (cal.byte[3]&0xFC)|((cal.byte[2]&0xC0)>>6);
	key.byte[0] = (cal.byte[2]&0xFC)|( cal.byte[1]&0x03);
#endif	
	return( key.word );
}


 uint32 GENERIC_ALGORITHM(uint32 wSeed, uint8 SecurityLevel)
{    
    if(0x01==SecurityLevel){
    	return(SecurityLevel_1(wSeed));
    }
	else if(0x03==SecurityLevel){
    	return(SecurityLevel_3(wSeed));
    }
    else if(0x11==SecurityLevel){
    	return(SecurityLevel_11(wSeed));
    }
}