void AuthenticatedSymmetricCipherBase::ProcessData(byte *outString, const byte *inString, size_t length)
{
m_totalMessageLength += length;
if (m_state >= State_IVSet && m_totalMessageLength > MaxMessageLength())
throw InvalidArgument(AlgorithmName() + ": message length exceeds maximum");
reswitch:
switch (m_state)
{
case State_Start:
case State_KeySet:
throw BadState(AlgorithmName(), "ProcessData", "setting key and IV");
case State_AuthFooter:
throw BadState(AlgorithmName(), "ProcessData was called after footer input has started");
case State_IVSet:
AuthenticateLastHeaderBlock();
m_bufferedDataLength = 0;
m_state = AuthenticationIsOnPlaintext()==IsForwardTransformation() ? State_AuthUntransformed : State_AuthTransformed;
goto reswitch;
case State_AuthUntransformed:
AuthenticateData(inString, length);
AccessSymmetricCipher().ProcessData(outString, inString, length);
break;
case State_AuthTransformed:
AccessSymmetricCipher().ProcessData(outString, inString, length);
AuthenticateData(outString, length);
break;
default:
CRYPTOPP_ASSERT(false);
}
}
void TF_EncryptorBase::Encrypt(RandomNumberGenerator &rng, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs ¶meters) const
{
if (plaintextLength > FixedMaxPlaintextLength())
{
if (FixedMaxPlaintextLength() < 1)
throw InvalidArgument(AlgorithmName() + ": this key is too short to encrypt any messages");
else
throw InvalidArgument(AlgorithmName() + ": message length of " + IntToString(plaintextLength) + " exceeds the maximum of " + IntToString(FixedMaxPlaintextLength()) + " for this public key");
}
SecByteBlock paddedBlock(PaddedBlockByteLength());
GetMessageEncodingInterface().Pad(rng, plaintext, plaintextLength, paddedBlock, PaddedBlockBitLength(), parameters);
GetTrapdoorFunctionInterface().ApplyRandomizedFunction(rng, Integer(paddedBlock, paddedBlock.size())).Encode(ciphertext, FixedCiphertextLength());
}
void CCM_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs ¶ms)
{
BlockCipher &blockCipher = AccessBlockCipher();
blockCipher.SetKey(userKey, keylength, params);
if (blockCipher.BlockSize() != REQUIRED_BLOCKSIZE)
throw InvalidArgument(AlgorithmName() + ": block size of underlying block cipher is not 16");
m_digestSize = params.GetIntValueWithDefault(Name::DigestSize(), DefaultDigestSize());
if (m_digestSize % 2 > 0 || m_digestSize < 4 || m_digestSize > 16)
throw InvalidArgument(AlgorithmName() + ": DigestSize must be 4, 6, 8, 10, 12, 14, or 16");
m_buffer.Grow(2*REQUIRED_BLOCKSIZE);
m_L = 8;
}
bool BufferedTransformation::ChannelMessageSeriesEnd(const std::string &channel, int propagation, bool blocking)
{
if (channel.empty())
return MessageSeriesEnd(propagation, blocking);
else
throw NoChannelSupport(AlgorithmName());
}
bool BufferedTransformation::ChannelFlush(const std::string &channel, bool completeFlush, int propagation, bool blocking)
{
if (channel.empty())
return Flush(completeFlush, propagation, blocking);
else
throw NoChannelSupport(AlgorithmName());
}
size_t BufferedTransformation::ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking)
{
if (channel.empty())
return Put2(begin, length, messageEnd, blocking);
else
throw NoChannelSupport(AlgorithmName());
}
byte * BufferedTransformation::ChannelCreatePutSpace(const std::string &channel, size_t &size)
{
if (channel.empty())
return CreatePutSpace(size);
else
throw NoChannelSupport(AlgorithmName());
}
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 TF_EncryptorBase::Encrypt(RandomNumberGenerator &rng, const byte *plaintext, unsigned int plaintextLength, byte *ciphertext, const NameValuePairs ¶meters) const
{
if (plaintextLength > FixedMaxPlaintextLength())
throw InvalidArgument(AlgorithmName() + ": message too long for this public key");
SecByteBlock paddedBlock(PaddedBlockByteLength());
GetMessageEncodingInterface().Pad(rng, plaintext, plaintextLength, paddedBlock, PaddedBlockBitLength(), parameters);
GetTrapdoorFunctionInterface().ApplyRandomizedFunction(rng, Integer(paddedBlock, paddedBlock.size())).Encode(ciphertext, FixedCiphertextLength());
}
void StreamTransformation::ProcessLastBlock(byte *outString, const byte *inString, size_t length)
{
CRYPTOPP_ASSERT(MinLastBlockSize() == 0); // this function should be overridden otherwise
if (length == MandatoryBlockSize())
ProcessData(outString, inString, length);
else if (length != 0)
throw NotImplemented(AlgorithmName() + ": this object doesn't support a special last block");
}
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;
}
void AuthenticatedSymmetricCipherBase::Resynchronize(const byte *iv, int length)
{
if (m_state < State_KeySet)
throw BadState(AlgorithmName(), "Resynchronize", "key is set");
m_bufferedDataLength = 0;
m_totalHeaderLength = m_totalMessageLength = m_totalFooterLength = 0;
m_state = State_KeySet;
Resync(iv, this->ThrowIfInvalidIVLength(length));
m_state = State_IVSet;
}
DecodingResult TF_DecryptorBase::Decrypt(RandomNumberGenerator &rng, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs ¶meters) const
{
if (ciphertextLength != FixedCiphertextLength())
throw InvalidArgument(AlgorithmName() + ": ciphertext length of " + IntToString(ciphertextLength) + " doesn't match the required length of " + IntToString(FixedCiphertextLength()) + " for this key");
SecByteBlock paddedBlock(PaddedBlockByteLength());
Integer x = GetTrapdoorFunctionInterface().CalculateInverse(rng, Integer(ciphertext, ciphertextLength));
if (x.ByteCount() > paddedBlock.size())
x = Integer::Zero(); // don't return false here to prevent timing attack
x.Encode(paddedBlock, paddedBlock.size());
return GetMessageEncodingInterface().Unpad(paddedBlock, PaddedBlockBitLength(), plaintext, parameters);
}
void CCM_Base::AuthenticateLastHeaderBlock()
{
byte *cbcBuffer = CBC_Buffer();
const BlockCipher &cipher = GetBlockCipher();
if (m_aadLength != m_totalHeaderLength)
throw InvalidArgument(AlgorithmName() + ": header length doesn't match that given in SpecifyDataLengths");
if (m_bufferedDataLength > 0)
{
xorbuf(cbcBuffer, m_buffer, m_bufferedDataLength);
cipher.ProcessBlock(cbcBuffer);
m_bufferedDataLength = 0;
}
}
void CCM_Base::UncheckedSpecifyDataLengths(lword headerLength, lword messageLength, lword /*footerLength*/)
{
if (m_state != State_IVSet)
throw BadState(AlgorithmName(), "SpecifyDataLengths", "or after State_IVSet");
m_aadLength = headerLength;
m_messageLength = messageLength;
byte *cbcBuffer = CBC_Buffer();
const BlockCipher &cipher = GetBlockCipher();
cbcBuffer[0] = byte(64*(headerLength>0) + 8*((m_digestSize-2)/2) + (m_L-1)); // flag
PutWord<word64>(true, BIG_ENDIAN_ORDER, cbcBuffer+REQUIRED_BLOCKSIZE-8, m_messageLength);
memcpy(cbcBuffer+1, m_buffer+1, REQUIRED_BLOCKSIZE-1-m_L);
cipher.ProcessBlock(cbcBuffer);
if (headerLength>0)
{
CRYPTOPP_ASSERT(m_bufferedDataLength == 0);
if (headerLength < ((1<<16) - (1<<8)))
{
PutWord<word16>(true, BIG_ENDIAN_ORDER, m_buffer, (word16)headerLength);
m_bufferedDataLength = 2;
}
else if (headerLength < (W64LIT(1)<<32))
{
m_buffer[0] = 0xff;
m_buffer[1] = 0xfe;
PutWord<word32>(false, BIG_ENDIAN_ORDER, m_buffer+2, (word32)headerLength);
m_bufferedDataLength = 6;
}
else
{
m_buffer[0] = 0xff;
m_buffer[1] = 0xff;
PutWord<word64>(false, BIG_ENDIAN_ORDER, m_buffer+2, headerLength);
m_bufferedDataLength = 10;
}
}
}
Base::Result Processor::createResult(int user_id) {
return Base::Result(AlgorithmName(),user_id, penalty_judge_->OveralPenalty(), 0 /*TODO*/);
}
