void intel_AES_dec128(UCHAR *cipherText,UCHAR *plainText,UCHAR *key,size_t numBlocks)
{
DEFINE_ROUND_KEYS
sAesData aesData;
aesData.in_block = cipherText;
aesData.out_block = plainText;
aesData.expanded_key = expandedKey;
aesData.num_blocks = numBlocks;
iDecExpandKey128(key,expandedKey);
iDec128(&aesData);
}
void tDecAES::m_init(nOperationModeAES opmode, const u8 key[], nKeyLengthAES keylen,
bool useFastASM)
{
// Set fields.
m_opmode = opmode;
m_keylen = keylen;
m_useASM = useFastASM;
m_expandedKey = NULL;
// Check the opmode.
switch (opmode)
{
case kOpModeECB: break;
case kOpModeCBC: break;
default: throw eInvalidArgument("The opmode parameter is not valid!");
}
// Check the keylen.
switch (keylen)
{
case k128bit: break;
case k192bit: break;
case k256bit: break;
default: throw eInvalidArgument("The keylen parameter is not valid!");
}
// Fast ASM setup:
if (m_useASM)
{
m_expandedKey = s_aligned_malloc(256, 16);
switch (keylen)
{
case k128bit:
{
u8* key_copy = new u8[16];
memcpy(key_copy, key, 16);
iDecExpandKey128(key_copy, m_expandedKey);
delete [] key_copy;
break;
}
case k192bit:
{
u8* key_copy = new u8[24];
memcpy(key_copy, key, 24);
iDecExpandKey192(key_copy, m_expandedKey);
delete [] key_copy;
break;
}
case k256bit:
{
u8* key_copy = new u8[32];
memcpy(key_copy, key, 32);
iDecExpandKey256(key_copy, m_expandedKey);
delete [] key_copy;
break;
}
default: throw eInvalidArgument("The keylen parameter is not valid!");
}
}
// Fallback setup:
else
{
int keybits;
int expectedNr;
switch (keylen)
{
case k128bit: keybits = 128; expectedNr = 10; break;
case k192bit: keybits = 192; expectedNr = 12; break;
case k256bit: keybits = 256; expectedNr = 14; break;
default: throw eInvalidArgument("The keylen parameter is not valid!");
}
m_Nr = rijndaelKeySetupDec(m_rk, key, keybits);
if (m_Nr != expectedNr)
throw eImpossiblePath();
}
}