template <class T, class BASE> byte * IteratedHashBase<T, BASE>::CreateUpdateSpace(size_t &size)
{
unsigned int blockSize = this->BlockSize();
unsigned int num = ModPowerOf2(m_countLo, blockSize);
size = blockSize - num;
return (byte *)DataBuf() + num;
}
inline T1 RoundDownToMultipleOf(const T1 &n, const T2 &m)
{
if (IsPowerOf2(m))
return n - ModPowerOf2(n, m);
else
return n - n%m;
}
template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte *input, size_t len)
{
HashWordType oldCountLo = m_countLo, oldCountHi = m_countHi;
if ((m_countLo = oldCountLo + HashWordType(len)) < oldCountLo)
m_countHi++; // carry from low to high
m_countHi += (HashWordType)SafeRightShift<8*sizeof(HashWordType)>(len);
if (m_countHi < oldCountHi || SafeRightShift<2*8*sizeof(HashWordType)>(len) != 0)
throw HashInputTooLong(this->AlgorithmName());
unsigned int blockSize = this->BlockSize();
unsigned int num = ModPowerOf2(oldCountLo, blockSize);
T* dataBuf = this->DataBuf();
byte* data = (byte *)dataBuf;
if (num != 0) // process left over data
{
if (num+len >= blockSize)
{
memcpy(data+num, input, blockSize-num);
HashBlock(dataBuf);
input += (blockSize-num);
len -= (blockSize-num);
num = 0;
// drop through and do the rest
}
else
{
memcpy(data+num, input, len);
return;
}
}
// now process the input data in blocks of blockSize bytes and save the leftovers to m_data
if (len >= blockSize)
{
if (input == data)
{
assert(len == blockSize);
HashBlock(dataBuf);
return;
}
else if (IsAligned<T>(input))
{
size_t leftOver = HashMultipleBlocks((T *)input, len);
input += (len - leftOver);
len = leftOver;
}
else
do
{ // copy input first if it's not aligned correctly
memcpy(data, input, blockSize);
HashBlock(dataBuf);
input+=blockSize;
len-=blockSize;
} while (len >= blockSize);
}
if (len && data != input)
memcpy(data, input, len);
}
template <class T, class BASE> byte * IteratedHashBase<T, BASE>::CreateUpdateSpace(unsigned int &size)
{
unsigned int blockSize = BlockSize();
unsigned int num = ModPowerOf2(m_countLo, blockSize);
size = blockSize - num;
return (byte *)m_data.begin() + num;
}
template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte *input, unsigned int len)
{
HashWordType tmp = m_countLo;
if ((m_countLo = tmp + len) < tmp)
m_countHi++; // carry from low to high
m_countHi += SafeRightShift<8*sizeof(HashWordType)>(len);
unsigned int blockSize = BlockSize();
unsigned int num = ModPowerOf2(tmp, blockSize);
if (num != 0) // process left over data
{
if ((num+len) >= blockSize)
{
memcpy((byte *)m_data.begin()+num, input, blockSize-num);
HashBlock(m_data);
input += (blockSize-num);
len-=(blockSize - num);
num=0;
// drop through and do the rest
}
else
{
memcpy((byte *)m_data.begin()+num, input, len);
return;
}
}
// now process the input data in blocks of blockSize bytes and save the leftovers to m_data
if (len >= blockSize)
{
if (input == (byte *)m_data.begin())
{
assert(len == blockSize);
HashBlock(m_data);
return;
}
else if (IsAligned<T>(input))
{
unsigned int leftOver = HashMultipleBlocks((T *)input, len);
input += (len - leftOver);
len = leftOver;
}
else
do
{ // copy input first if it's not aligned correctly
memcpy(m_data, input, blockSize);
HashBlock(m_data);
input+=blockSize;
len-=blockSize;
} while (len >= blockSize);
}
memcpy(m_data, input, len);
}
template <class T, class BASE> void IteratedHashBase<T, BASE>::PadLastBlock(unsigned int lastBlockSize, byte padFirst)
{
unsigned int blockSize = BlockSize();
unsigned int num = ModPowerOf2(m_countLo, blockSize);
((byte *)m_data.begin())[num++]=padFirst;
if (num <= lastBlockSize)
memset((byte *)m_data.begin()+num, 0, lastBlockSize-num);
else
{
memset((byte *)m_data.begin()+num, 0, blockSize-num);
HashBlock(m_data);
memset(m_data, 0, lastBlockSize);
}
}
template <class T, class BASE> void IteratedHashBase<T, BASE>::PadLastBlock(unsigned int lastBlockSize, byte padFirst)
{
unsigned int blockSize = this->BlockSize();
unsigned int num = ModPowerOf2(m_countLo, blockSize);
T* dataBuf = this->DataBuf();
byte* data = (byte *)dataBuf;
data[num++] = padFirst;
if (num <= lastBlockSize)
memset(data+num, 0, lastBlockSize-num);
else
{
memset(data+num, 0, blockSize-num);
HashBlock(dataBuf);
memset(data, 0, lastBlockSize);
}
}
inline bool IsAlignedOn(const void *p, unsigned int alignment)
{
return alignment==1 || (IsPowerOf2(alignment) ? ModPowerOf2((size_t)p, alignment) == 0 : (size_t)p % alignment == 0);
}
