cbcmac.cpp
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#include "pch.h"
#ifndef CRYPTOPP_IMPORTS
#include "cbcmac.h"
NAMESPACE_BEGIN(CryptoPP)
void CBC_MAC_Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
{
AccessCipher().SetKey(key, length, params);
m_reg.CleanNew(AccessCipher().BlockSize());
m_counter = 0;
}
void CBC_MAC_Base::Update(const byte *input, size_t length)
{
unsigned int blockSize = AccessCipher().BlockSize();
while (m_counter && length)
{
m_reg[m_counter++] ^= *input++;
if (m_counter == blockSize)
ProcessBuf();
length--;
}
if (length >= blockSize)
{
size_t leftOver = AccessCipher().AdvancedProcessBlocks(m_reg, input, m_reg, length, BlockTransformation::BT_DontIncrementInOutPointers|BlockTransformation::BT_XorInput);
input += (length - leftOver);
length = leftOver;
}
while (length--)
{
m_reg[m_counter++] ^= *input++;
if (m_counter == blockSize)
ProcessBuf();
}
}
void CBC_MAC_Base::TruncatedFinal(byte *mac, size_t size)
{
ThrowIfInvalidTruncatedSize(size);
if (m_counter)
ProcessBuf();
memcpy(mac, m_reg, size);
memset(m_reg, 0, AccessCipher().BlockSize());
}
void CBC_MAC_Base::ProcessBuf()
{
AccessCipher().ProcessBlock(m_reg);
m_counter = 0;
}
NAMESPACE_END
#endif