void AdditiveCipherTemplate<S>::GenerateBlock(byte *outString, size_t length)
{
if (m_leftOver > 0)
{
const size_t len = STDMIN(m_leftOver, length);
memcpy(outString, PtrSub(KeystreamBufferEnd(), m_leftOver), len);
length -= len; m_leftOver -= len;
outString = PtrAdd(outString, len);
if (!length) {return;}
}
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
if (length >= bytesPerIteration)
{
const size_t iterations = length / bytesPerIteration;
policy.WriteKeystream(outString, iterations);
length -= iterations * bytesPerIteration;
outString = PtrAdd(outString, iterations * bytesPerIteration);
}
if (length > 0)
{
size_t bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration);
size_t bufferIterations = bufferByteSize / bytesPerIteration;
policy.WriteKeystream(PtrSub(KeystreamBufferEnd(), bufferByteSize), bufferIterations);
memcpy(outString, PtrSub(KeystreamBufferEnd(), bufferByteSize), length);
m_leftOver = bufferByteSize - length;
}
}
void AdditiveCipherTemplate<S>::ProcessData(byte *outString, const byte *inString, size_t length)
{
if (m_leftOver > 0)
{
size_t len = STDMIN(m_leftOver, length);
xorbuf(outString, inString, KeystreamBufferEnd()-m_leftOver, len);
length -= len;
m_leftOver -= len;
inString += len;
outString += len;
if (!length)
return;
}
CRYPTOPP_ASSERT(m_leftOver == 0);
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
if (policy.CanOperateKeystream() && length >= bytesPerIteration)
{
size_t iterations = length / bytesPerIteration;
unsigned int alignment = policy.GetAlignment();
KeystreamOperation operation = KeystreamOperation((IsAlignedOn(inString, alignment) * 2) | (int)IsAlignedOn(outString, alignment));
policy.OperateKeystream(operation, outString, inString, iterations);
inString += iterations * bytesPerIteration;
outString += iterations * bytesPerIteration;
length -= iterations * bytesPerIteration;
if (!length)
return;
}
size_t bufferByteSize = m_buffer.size();
size_t bufferIterations = bufferByteSize / bytesPerIteration;
while (length >= bufferByteSize)
{
policy.WriteKeystream(m_buffer, bufferIterations);
xorbuf(outString, inString, KeystreamBufferBegin(), bufferByteSize);
length -= bufferByteSize;
inString += bufferByteSize;
outString += bufferByteSize;
}
if (length > 0)
{
bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration);
bufferIterations = bufferByteSize / bytesPerIteration;
policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations);
xorbuf(outString, inString, KeystreamBufferEnd()-bufferByteSize, length);
m_leftOver = bufferByteSize - length;
}
}
inline void AdditiveCipherTemplate<S>::ProcessData(byte *outString, const byte *inString, unsigned int length)
{
if (m_leftOver > 0)
{
unsigned int len = STDMIN(m_leftOver, length);
xorbuf(outString, inString, KeystreamBufferEnd()-m_leftOver, len);
length -= len;
m_leftOver -= len;
inString += len;
outString += len;
}
if (!length)
return;
assert(m_leftOver == 0);
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
unsigned int alignment = policy.GetAlignment();
if (policy.CanOperateKeystream() && length >= bytesPerIteration && IsAlignedOn(outString, alignment))
{
if (IsAlignedOn(inString, alignment))
policy.OperateKeystream(XOR_KEYSTREAM, outString, inString, length / bytesPerIteration);
else
{
memcpy(outString, inString, length);
policy.OperateKeystream(XOR_KEYSTREAM_INPLACE, outString, outString, length / bytesPerIteration);
}
inString += length - length % bytesPerIteration;
outString += length - length % bytesPerIteration;
length %= bytesPerIteration;
if (!length)
return;
}
unsigned int bufferByteSize = GetBufferByteSize(policy);
unsigned int bufferIterations = policy.GetIterationsToBuffer();
while (length >= bufferByteSize)
{
policy.WriteKeystream(m_buffer, bufferIterations);
xorbuf(outString, inString, KeystreamBufferBegin(), bufferByteSize);
length -= bufferByteSize;
inString += bufferByteSize;
outString += bufferByteSize;
}
if (length > 0)
{
policy.WriteKeystream(m_buffer, bufferIterations);
xorbuf(outString, inString, KeystreamBufferBegin(), length);
m_leftOver = bytesPerIteration - length;
}
}
byte AdditiveCipherTemplate<S>::GenerateByte()
{
PolicyInterface &policy = this->AccessPolicy();
if (m_leftOver == 0)
{
policy.WriteKeystream(m_buffer, policy.GetIterationsToBuffer());
m_leftOver = policy.GetBytesPerIteration();
}
return *(KeystreamBufferEnd()-m_leftOver--);
}
void AdditiveCipherTemplate<S>::GenerateBlock(byte *outString, size_t length)
{
if (m_leftOver > 0)
{
size_t len = STDMIN(m_leftOver, length);
memcpy(outString, KeystreamBufferEnd()-m_leftOver, len);
length -= len;
m_leftOver -= len;
outString += len;
if (!length)
return;
}
CRYPTOPP_ASSERT(m_leftOver == 0);
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
if (length >= bytesPerIteration)
{
size_t iterations = length / bytesPerIteration;
policy.WriteKeystream(outString, iterations);
outString += iterations * bytesPerIteration;
length -= iterations * bytesPerIteration;
}
if (length > 0)
{
size_t bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration);
size_t bufferIterations = bufferByteSize / bytesPerIteration;
policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations);
memcpy(outString, KeystreamBufferEnd()-bufferByteSize, length);
m_leftOver = bufferByteSize - length;
}
}
void AdditiveCipherTemplate<BASE>::Seek(lword position)
{
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
policy.SeekToIteration(position / bytesPerIteration);
position %= bytesPerIteration;
if (position > 0)
{
policy.WriteKeystream(KeystreamBufferEnd()-bytesPerIteration, 1);
m_leftOver = bytesPerIteration - (unsigned int)position;
}
else
m_leftOver = 0;
}
void AdditiveCipherTemplate<BASE>::Seek(lword position)
{
PolicyInterface &policy = this->AccessPolicy();
word32 bytesPerIteration = policy.GetBytesPerIteration();
policy.SeekToIteration(position / bytesPerIteration);
position %= bytesPerIteration;
if (position > 0)
{
policy.WriteKeystream(PtrSub(KeystreamBufferEnd(), bytesPerIteration), 1);
m_leftOver = bytesPerIteration - static_cast<word32>(position);
}
else
m_leftOver = 0;
}
void AdditiveCipherTemplate<S>::GenerateBlock(byte *outString, size_t length)
{
if (m_leftOver > 0)
{
size_t len = STDMIN(m_leftOver, length);
memcpy(outString, KeystreamBufferEnd()-m_leftOver, len);
length -= len;
m_leftOver -= len;
outString += len;
if (!length)
return;
}
assert(m_leftOver == 0);
PolicyInterface &policy = this->AccessPolicy();
unsigned int bytesPerIteration = policy.GetBytesPerIteration();
if (length >= bytesPerIteration)
{
size_t iterations = length / bytesPerIteration;
policy.WriteKeystream(outString, iterations);
outString += iterations * bytesPerIteration;
length -= iterations * bytesPerIteration;
if (!length)
return;
}
unsigned int bufferByteSize = GetBufferByteSize(policy);
unsigned int bufferIterations = policy.GetIterationsToBuffer();
while (length >= bufferByteSize)
{
policy.WriteKeystream(m_buffer, bufferIterations);
memcpy(outString, KeystreamBufferBegin(), bufferByteSize);
length -= bufferByteSize;
outString += bufferByteSize;
}
if (length > 0)
{
policy.WriteKeystream(m_buffer, bufferIterations);
memcpy(outString, KeystreamBufferBegin(), length);
m_leftOver = bytesPerIteration - length;
}
}