#include "keywd.h"
#include "MD5.h" 
#include "Flash.h"


extern const u16 CRC16_Table[256];
/*****************************************************************************
 * Function      : create_keywd
 * Description   : none
 * Input         : u8* keyid  
 * Output        : None
 * Return        : 
 * Others        : 
 * Record
 * 1.Date        : 20170314
 *   Author      : barry
 *   Modification: Created function

*****************************************************************************/
bool create_keywd(u8* keyid)
{
    u8 un_id[12];
    u8 md5_id[16];
    u16 crc = 0;
    u8 index = 0;

    if (!read_unique_id(un_id))
    {
        return FALSE;
    }

    MD5_code(un_id, md5_id, sizeof(un_id));

    for (u16 i = 0; i < KEY_LEN; i++)
    {
        keyid[i] = rand()%255;
    }

    for (u32 i = 0; i < KEY_LEN; i++)
    {
        if ((i % 32) == 0)
        {
             keyid[i]  = md5_id[index++];

            if (index >= 16)
            {
                break;
            }
        }
    }

    crc =  GetCRC16(keyid,  KEY_LEN -2);

    keyid[KEY_LEN -2] = (u8)(crc %256);
    keyid[KEY_LEN -1] = (u8)(crc /256);

    return TRUE;
}

/*****************************************************************************
 * Function      : set_key_word
 * Description   : none
 * Input         : void  
 * Output        : None
 * Return        : 
 * Others        : 
 * Record
 * 1.Date        : 20170314
 *   Author      : barry
 *   Modification: Created function

*****************************************************************************/
bool set_key_word(void)
{
    u8 keyid[KEY_LEN];
    
    for (u32 i = 0; i < KEY_LEN; i++)
    {
        if (*((u8*)(FLASH_KEY_ADDRESS + i)) != 0xFF)
        {
            return FALSE;
        }
    }

    if ( create_keywd(keyid))
    {
        if (STM32_FlashPageErase(FLASH_KEY_ADDRESS) == FLH_SUCCESS)
        {
            if (STM32_FlashWrite( FLASH_KEY_ADDRESS,  keyid, KEY_LEN) == FLH_SUCCESS)
            {
                return TRUE;
            }
        }  

        return FALSE;
    }
    else
    {
        return FALSE;
    }
}

/*****************************************************************************
 * Function      : check_passwd
 * Description   : none
 * Input         : void  
 * Output        : None
 * Return        : 
 * Others        : 
 * Record
 * 1.Date        : 20170314
 *   Author      : barry
 *   Modification: Created function

*****************************************************************************/
bool check_passwd(void)
{ 
    u8 unid[12];
    
    u8 MD5_ID[16];
    u8 passwd[16];

    u8 temp;

    u8 index = 0;

    u16 crc16 = 0xFFFF;
    u16 crc_read = 0;
    bool new_flash_area = TRUE; 
     
    if ( read_unique_id(unid))
    {
        MD5_code(unid, MD5_ID, sizeof(unid)); 
    }
    else
    {
        return FALSE;
    }

   for (u16 i = 0; i < KEY_LEN -2; i++)
   {
      temp = *((u8*)(FLASH_KEY_ADDRESS + i));

      if (temp != 0xFF)
      {
        new_flash_area = FALSE;
      }
      
      crc16 = (crc16 >> 8 ) ^ CRC16_Table[(crc16 ^ temp) & 0xFF];

      if ( (i % 32) == 0)
      {
            if (index < sizeof(passwd))
            {
                passwd[index++] = temp;
            }
      }
   }
   crc16 ^= 0xFFFF;
   
   crc_read = *((u8*)(FLASH_KEY_ADDRESS + KEY_LEN - 2)) + *((u8*)(FLASH_KEY_ADDRESS + KEY_LEN - 1))*256;
   
   if (new_flash_area == TRUE)
   {
        return set_key_word();
   }
   else
   {
        if (crc_read == crc16)
        {
            if (cmp_datas(passwd, MD5_ID, 16))
            {
                return TRUE;
            }
        }

        return FALSE;   
   }
}