void AuthenticatedSymmetricCipherBase::Update(const byte *input, size_t length)
{
if (length == 0)
return;
switch (m_state)
{
case State_Start:
case State_KeySet:
throw BadState(AlgorithmName(), "Update", "setting key and IV");
case State_IVSet:
AuthenticateData(input, length);
m_totalHeaderLength += length;
break;
case State_AuthUntransformed:
case State_AuthTransformed:
AuthenticateLastConfidentialBlock();
m_bufferedDataLength = 0;
m_state = State_AuthFooter;
// fall through
case State_AuthFooter:
AuthenticateData(input, length);
m_totalFooterLength += length;
break;
default:
CRYPTOPP_ASSERT(false);
}
}
void AuthenticatedSymmetricCipherBase::TruncatedFinal(byte *mac, size_t macSize)
{
if (m_totalHeaderLength > MaxHeaderLength())
throw InvalidArgument(AlgorithmName() + ": header length of " + IntToString(m_totalHeaderLength) + " exceeds the maximum of " + IntToString(MaxHeaderLength()));
if (m_totalFooterLength > MaxFooterLength())
{
if (MaxFooterLength() == 0)
throw InvalidArgument(AlgorithmName() + ": additional authenticated data (AAD) cannot be input after data to be encrypted or decrypted");
else
throw InvalidArgument(AlgorithmName() + ": footer length of " + IntToString(m_totalFooterLength) + " exceeds the maximum of " + IntToString(MaxFooterLength()));
}
switch (m_state)
{
case State_Start:
case State_KeySet:
throw BadState(AlgorithmName(), "TruncatedFinal", "setting key and IV");
case State_IVSet:
AuthenticateLastHeaderBlock();
m_bufferedDataLength = 0;
// fall through
case State_AuthUntransformed:
case State_AuthTransformed:
AuthenticateLastConfidentialBlock();
m_bufferedDataLength = 0;
// fall through
case State_AuthFooter:
AuthenticateLastFooterBlock(mac, macSize);
m_bufferedDataLength = 0;
break;
default:
CRYPTOPP_ASSERT(false);
}
m_state = State_KeySet;
}
