void SHARK::Base::UncheckedSetKey(CipherDir dir, const byte *key, unsigned int keyLen, unsigned int rounds)
{
AssertValidKeyLength(keyLen);
AssertValidRounds(rounds);
m_rounds = rounds;
m_roundKeys.New(m_rounds+1);
// concatenate key enought times to fill a
for (unsigned int i=0; i<(m_rounds+1)*8; i++)
((byte *)m_roundKeys.begin())[i] = key[i%keyLen];
SHARK::Encryption e;
e.InitForKeySetup();
byte IV[8] = {0,0,0,0,0,0,0,0};
CFB_Mode_ExternalCipher::Encryption cfb(e, IV);
cfb.ProcessString((byte *)m_roundKeys.begin(), (m_rounds+1)*8);
ConditionalByteReverse(BIG_ENDIAN_ORDER, m_roundKeys.begin(), m_roundKeys.begin(), (m_rounds+1)*8);
m_roundKeys[m_rounds] = SHARKTransform(m_roundKeys[m_rounds]);
if (dir == DECRYPTION)
{
unsigned int i;
// transform encryption round keys into decryption round keys
for (i=0; i<m_rounds/2; i++)
std::swap(m_roundKeys[i], m_roundKeys[m_rounds-i]);
for (i=1; i<m_rounds; i++)
m_roundKeys[i] = SHARKTransform(m_roundKeys[i]);
}
#ifdef IS_LITTLE_ENDIAN
m_roundKeys[0] = ByteReverse(m_roundKeys[0]);
m_roundKeys[m_rounds] = ByteReverse(m_roundKeys[m_rounds]);
#endif
}
// construct an SHARKEncryption object with fixed round keys, to be used to initialize actual round keys
SHARKEncryption::SHARKEncryption()
: SHARKBase(DEFAULT_ROUNDS)
{
for (unsigned int i=0; i<DEFAULT_ROUNDS; i++)
roundkeys[i] = cbox[0][i];
roundkeys[DEFAULT_ROUNDS] = SHARKTransform(cbox[0][DEFAULT_ROUNDS]);
#ifdef IS_LITTLE_ENDIAN
roundkeys[0] = byteReverse(roundkeys[0]);
roundkeys[DEFAULT_ROUNDS] = byteReverse(roundkeys[DEFAULT_ROUNDS]);
#endif
}
// construct an SHARK_Enc object with fixed round keys, to be used to initialize actual round keys
void SHARK::Enc::InitForKeySetup()
{
m_rounds = DEFAULT_ROUNDS;
m_roundKeys.New(DEFAULT_ROUNDS+1);
for (unsigned int i=0; i<DEFAULT_ROUNDS; i++)
m_roundKeys[i] = cbox[0][i];
m_roundKeys[DEFAULT_ROUNDS] = SHARKTransform(cbox[0][DEFAULT_ROUNDS]);
#ifdef IS_LITTLE_ENDIAN
m_roundKeys[0] = ByteReverse(m_roundKeys[0]);
m_roundKeys[m_rounds] = ByteReverse(m_roundKeys[m_rounds]);
#endif
}
void SHARKBase::InitEncryptionRoundKeys(const byte *key, unsigned int keyLen, unsigned int rounds, word64 *roundkeys)
{
// concatenate key enought times to fill a
for (unsigned int i=0; i<(rounds+1)*8; i++)
((byte *)roundkeys)[i] = key[i%keyLen];
SHARKEncryption e;
byte IV[8] = {0,0,0,0,0,0,0,0};
CFBEncryption cfb(e, IV);
cfb.ProcessString((byte *)roundkeys, (rounds+1)*8);
#ifdef IS_LITTLE_ENDIAN
byteReverse(roundkeys, roundkeys, (rounds+1)*8);
#endif
roundkeys[rounds] = SHARKTransform(roundkeys[rounds]);
}
SHARKDecryption::SHARKDecryption(const byte *key, unsigned int keyLen, unsigned int rounds)
: SHARKBase(rounds)
{
InitEncryptionRoundKeys(key, keyLen, rounds, roundkeys);
unsigned int i;
// transform encryption round keys into decryption round keys
for (i=0; i<rounds/2; i++)
std::swap(roundkeys[i], roundkeys[rounds-i]);
for (i=1; i<rounds; i++)
roundkeys[i] = SHARKTransform(roundkeys[i]);
#ifdef IS_LITTLE_ENDIAN
roundkeys[0] = byteReverse(roundkeys[0]);
roundkeys[rounds] = byteReverse(roundkeys[rounds]);
#endif
}
