/*******************************************************************************
* Function Name : AES_keyschedule_dec
* Description : According to key computes the expanded key (expkey) for AES128
* decryption.
* Input : key: user key (128 bits / 16 bytes)
* Output : expkey: expanded key (320 bits / 40 bytes)
* Return : None
*******************************************************************************/
void AES_keyschedule_dec(ot_u32* key, ot_u32* expkey) {
#if (AES_USEHW == ENABLED)
#elif (AES_USEFAST == ENABLED)
register ot_u32* local_pointer;// = expkey;
register int i; // = 0;
register ot_u32 copy0;
register ot_u32 copy1;
register ot_u32 copy2;
register ot_u32 copy3;
AES_keyschedule_enc(key,expkey);
local_pointer = expkey;
local_pointer[0] = key[0];
local_pointer[1] = key[1];
local_pointer[2] = key[2];
local_pointer[3] = key[3];
for (i = 1; i <10; i++) {
local_pointer += 4;
copy0 = local_pointer[0];
copy1 = local_pointer[1];
copy2 = local_pointer[2];
copy3 = local_pointer[3];
local_pointer[0] = dec_table[Sbox[byte0(copy0)]] ^
rot1(dec_table[Sbox[byte1(copy0)]]) ^
rot2(dec_table[Sbox[byte2(copy0)]]) ^
rot3(dec_table[Sbox[byte3(copy0)]]);
local_pointer[1] = dec_table[Sbox[byte0(copy1)]] ^
rot1(dec_table[Sbox[byte1(copy1)]]) ^
rot2(dec_table[Sbox[byte2(copy1)]]) ^
rot3(dec_table[Sbox[byte3(copy1)]]);
local_pointer[2] = dec_table[Sbox[byte0(copy2)]] ^
rot1(dec_table[Sbox[byte1(copy2)]]) ^
rot2(dec_table[Sbox[byte2(copy2)]]) ^
rot3(dec_table[Sbox[byte3(copy2)]]);
local_pointer[3] = dec_table[Sbox[byte0(copy3)]] ^
rot1(dec_table[Sbox[byte1(copy3)]]) ^
rot2(dec_table[Sbox[byte2(copy3)]]) ^
rot3(dec_table[Sbox[byte3(copy3)]]);
}
#elif (AES_USELITE == ENABLED)
AES_keyschedule_enc(key, exp);
#endif
}
/*******************************************************************************
* Function Name : WMBus_AppliEncrypt
* Description : Does key expension before encryption starts
* and put the data stream back into payload buffer
* Input : - input_pointer: input payload address
* - input pointer: encryption key
* - int: length
* Output : None
* Return : None
*******************************************************************************/
uint8_t WMBus_AppliEncrypt(u8 *key, unsigned char *payload, int length)
{
/*******************************************************/
/* AES CTR ENCRYPTION */
/*******************************************************/
/* Encryption key scheduling, to be done once */
AES_keyschedule_enc((u8*)key,(u32*)exp_key);
/* encryption starts here*/
encrypt_pdu_cbc((u32*)exp_key,payload,length,payload);
return(CipherBlocklen);
}
/*******************************************************************************
* Function Name : AES_keyschedule_dec
* Description : According to key computes the expanded key (expkey) for AES128
* decryption.
* Input : key: user key
* Output : expkey: expanded key
* Return : None
*******************************************************************************/
void AES_keyschedule_dec(u8* key, u32* expkey)
{
register u32* local_pointer = expkey;
register int i = 0;
register u32 copy0;
register u32 copy1;
register u32 copy2;
register u32 copy3;
AES_keyschedule_enc(key,expkey);
local_pointer[0] = *key;
local_pointer[0] =local_pointer[0]<<8;
local_pointer[0] |= *(key+1);
local_pointer[0] =local_pointer[0]<<8;
local_pointer[0] |= *(key+2);
local_pointer[0] =local_pointer[0]<<8;
local_pointer[0] |= *(key+3);
local_pointer[1] = *(key+4);
local_pointer[1] =local_pointer[1]<<8;
local_pointer[1] |= *(key+5);
local_pointer[1] =local_pointer[1]<<8;
local_pointer[1] |= *(key+6);
local_pointer[1] =local_pointer[1]<<8;
local_pointer[1] |= *(key+7);
local_pointer[2] = *(key+8);
local_pointer[2] =local_pointer[2]<<8;
local_pointer[2] |= *(key+9);
local_pointer[2] =local_pointer[2]<<8;
local_pointer[2] |= *(key+10);
local_pointer[2] =local_pointer[2]<<8;
local_pointer[2] |= *(key+11);
local_pointer[3] = *(key+12);
local_pointer[3] =local_pointer[3]<<8;
local_pointer[3] |= *(key+13);
local_pointer[3] =local_pointer[3]<<8;
local_pointer[3] |= *(key+14);
local_pointer[3] =local_pointer[3]<<8;
local_pointer[3] |= *(key+15);
// local_pointer[0] = key[0];
// local_pointer[1] = key[1];
// local_pointer[2] = key[2];
// local_pointer[3] = key[3];
for (i = 1; i <10; i++)
{
local_pointer += 4;
copy0 = local_pointer[0];
copy1 = local_pointer[1];
copy2 = local_pointer[2];
copy3 = local_pointer[3];
local_pointer[0] = dec_table[Sbox[byte0(copy0)]] ^
rot1(dec_table[Sbox[byte1(copy0)]]) ^
rot2(dec_table[Sbox[byte2(copy0)]]) ^
rot3(dec_table[Sbox[byte3(copy0)]]);
local_pointer[1] = dec_table[Sbox[byte0(copy1)]] ^
rot1(dec_table[Sbox[byte1(copy1)]]) ^
rot2(dec_table[Sbox[byte2(copy1)]]) ^
rot3(dec_table[Sbox[byte3(copy1)]]);
local_pointer[2] = dec_table[Sbox[byte0(copy2)]] ^
rot1(dec_table[Sbox[byte1(copy2)]]) ^
rot2(dec_table[Sbox[byte2(copy2)]]) ^
rot3(dec_table[Sbox[byte3(copy2)]]);
local_pointer[3] = dec_table[Sbox[byte0(copy3)]] ^
rot1(dec_table[Sbox[byte1(copy3)]]) ^
rot2(dec_table[Sbox[byte2(copy3)]]) ^
rot3(dec_table[Sbox[byte3(copy3)]]);
}
}
/*******************************************************************************
* Function Name : AES_keyschedule_dec
* Description : According to key computes the expanded key (expkey) for AES128
* decryption.
* Input : key: user key
* Output : expkey: expanded key
* Return : None
*******************************************************************************/
void AES_keyschedule_dec(u32* key, u32* exp)
{
AES_keyschedule_enc(key, exp);
}
