void Safe2Decrypt_RIJ128(const Ipp8u* in,
Ipp8u* out,
int Nr,
const Ipp8u* RoundKey,
const void* sbox)
{
Ipp32u state[4];
int round=0;
UNREFERENCED_PARAMETER(sbox);
// copy input to the state array
TRANSPOSE((Ipp8u*)state, in);
// add the round key to the state before starting the rounds.
XorRoundKey((Ipp32u*)state, (Ipp32u*)(RoundKey+Nr*16));
// there will be Nr rounds
for(round=Nr-1;round>0;round--) {
invShiftRows(state);
invSubBytes((Ipp8u*)state);
XorRoundKey(state,(Ipp32u*)(RoundKey+round*16));
invMixColumns(state);
}
// last round
invShiftRows(state);
invSubBytes((Ipp8u*)state);
XorRoundKey(state,(Ipp32u*)(RoundKey+0*16));
// copy from the state to output
TRANSPOSE(out, (Ipp8u*)state);
}
/**
* @brief Decrypts 16 bytes of data.
*
* Based on Advanced Encryption Standard specification.
*
* @param dataToEncrypt Data to encrypt, must be at least 16 bytes in size.
* @param result Destination to store encrypted data, must be at least 16 bytes in size.
* @param numRounds Number of rounds.
* @param roundKey Round key.
*/
void ThreadMessageItemEncrypt::InverseCipher(unsigned char * dataToEncrypt,unsigned char * result, unsigned char numRounds, unsigned char * roundKey)
{
// Copy data into state for manipulation
for(size_t r = 0;r<EncryptKey::WORD_SIZE;r++)
{
for(size_t c = 0;c<EncryptKey::WORD_SIZE;c++)
{
state[r][c] = result[r+(c*EncryptKey::WORD_SIZE)];
}
}
// Perform decryption operations
XorRoundKey(numRounds,roundKey);
for(size_t r = numRounds-1; r>=1; r--)
{
ShiftRowsRight();
InverseSubBytes();
XorRoundKey(r,roundKey);
InverseMixColumns();
}
ShiftRowsRight();
InverseSubBytes();
XorRoundKey(0,roundKey);
// Copy state into data now that we have finished
for(int r = 0;r<EncryptKey::WORD_SIZE;r++)
{
for(int c = 0;c<EncryptKey::WORD_SIZE;c++)
{
result[r+(c*EncryptKey::WORD_SIZE)] = state[r][c];
}
}
}
