void AdditiveCipherTemplate<S>::Resynchronize(const byte *iv, int length)
{
PolicyInterface &policy = this->AccessPolicy();
m_leftOver = 0;
m_buffer.New(GetBufferByteSize(policy));
policy.CipherResynchronize(m_buffer, iv, this->ThrowIfInvalidIVLength(length));
}
void AdditiveCipherTemplate<S>::Resynchronize(const byte *iv)
{
PolicyInterface &policy = this->AccessPolicy();
m_leftOver = 0;
m_buffer.New(GetBufferByteSize(policy));
policy.CipherResynchronize(m_buffer, iv);
}
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;
}
}
void AdditiveCipherTemplate<S>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
{
PolicyInterface &policy = this->AccessPolicy();
policy.CipherSetKey(params, key, length);
m_leftOver = 0;
m_buffer.New(GetBufferByteSize(policy));
if (this->IsResynchronizable())
policy.CipherResynchronize(m_buffer, this->GetIVAndThrowIfInvalid(params));
}
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;
}
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;
}
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;
}
}
void AdditiveCipherTemplate<S>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
{
PolicyInterface &policy = this->AccessPolicy();
policy.CipherSetKey(params, key, length);
m_leftOver = 0;
unsigned int bufferByteSize = policy.CanOperateKeystream() ? GetBufferByteSize(policy) : RoundUpToMultipleOf(1024U, GetBufferByteSize(policy));
m_buffer.New(bufferByteSize);
if (this->IsResynchronizable())
{
size_t ivLength;
const byte *iv = this->GetIVAndThrowIfInvalid(params, ivLength);
policy.CipherResynchronize(m_buffer, iv, ivLength);
}
}
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;
}
}
