Modified source engine (2017) developed by valve and leaked in 2020. Not for commercial purporses
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

307 lines
9.3 KiB

// modes.cpp - originally written and placed in the public domain by Wei Dai
#include "pch.h"
#ifndef CRYPTOPP_IMPORTS
#include "modes.h"
#include "misc.h"
#if defined(CRYPTOPP_DEBUG)
#include "des.h"
#endif
NAMESPACE_BEGIN(CryptoPP)
#if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)
void Modes_TestInstantiations()
{
CFB_Mode<DES>::Encryption m0;
CFB_Mode<DES>::Decryption m1;
OFB_Mode<DES>::Encryption m2;
CTR_Mode<DES>::Encryption m3;
ECB_Mode<DES>::Encryption m4;
CBC_Mode<DES>::Encryption m5;
}
#endif
void CipherModeBase::ResizeBuffers()
{
m_register.New(m_cipher->BlockSize());
}
void CFB_ModePolicy::Iterate(byte *output, const byte *input, CipherDir dir, size_t iterationCount)
{
CRYPTOPP_ASSERT(input); CRYPTOPP_ASSERT(output);
CRYPTOPP_ASSERT(m_cipher->IsForwardTransformation());
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CRYPTOPP_ASSERT(m_temp.size() == BlockSize());
CRYPTOPP_ASSERT(iterationCount > 0);
const unsigned int s = BlockSize();
if (dir == ENCRYPTION)
{
m_cipher->ProcessAndXorBlock(m_register, input, output);
if (iterationCount > 1)
m_cipher->AdvancedProcessBlocks(output, PtrAdd(input,s), PtrAdd(output,s), (iterationCount-1)*s, 0);
memcpy(m_register, PtrAdd(output,(iterationCount-1)*s), s);
}
else
{
// make copy first in case of in-place decryption
memcpy(m_temp, PtrAdd(input,(iterationCount-1)*s), s);
if (iterationCount > 1)
m_cipher->AdvancedProcessBlocks(input, PtrAdd(input,s), PtrAdd(output,s), (iterationCount-1)*s, BlockTransformation::BT_ReverseDirection);
m_cipher->ProcessAndXorBlock(m_register, input, output);
memcpy(m_register, m_temp, s);
}
}
void CFB_ModePolicy::TransformRegister()
{
CRYPTOPP_ASSERT(m_cipher->IsForwardTransformation());
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CRYPTOPP_ASSERT(m_temp.size() == BlockSize());
const ptrdiff_t updateSize = BlockSize()-m_feedbackSize;
m_cipher->ProcessBlock(m_register, m_temp);
memmove_s(m_register, m_register.size(), PtrAdd(m_register.begin(),m_feedbackSize), updateSize);
memcpy_s(PtrAdd(m_register.begin(),updateSize), m_register.size()-updateSize, m_temp, m_feedbackSize);
}
void CFB_ModePolicy::CipherResynchronize(const byte *iv, size_t length)
{
CRYPTOPP_ASSERT(length == BlockSize());
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CopyOrZero(m_register, m_register.size(), iv, length);
TransformRegister();
}
void CFB_ModePolicy::SetFeedbackSize(unsigned int feedbackSize)
{
if (feedbackSize > BlockSize())
throw InvalidArgument("CFB_Mode: invalid feedback size");
m_feedbackSize = feedbackSize ? feedbackSize : BlockSize();
}
void CFB_ModePolicy::ResizeBuffers()
{
CipherModeBase::ResizeBuffers();
m_temp.New(BlockSize());
}
byte* CFB_ModePolicy::GetRegisterBegin()
{
CRYPTOPP_ASSERT(!m_register.empty());
CRYPTOPP_ASSERT(BlockSize() >= m_feedbackSize);
return PtrAdd(m_register.begin(), BlockSize() - m_feedbackSize);
}
void OFB_ModePolicy::WriteKeystream(byte *keystreamBuffer, size_t iterationCount)
{
CRYPTOPP_ASSERT(m_cipher->IsForwardTransformation());
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CRYPTOPP_ASSERT(iterationCount > 0);
const unsigned int s = BlockSize();
m_cipher->ProcessBlock(m_register, keystreamBuffer);
if (iterationCount > 1)
m_cipher->AdvancedProcessBlocks(keystreamBuffer, NULLPTR, PtrAdd(keystreamBuffer, s), s*(iterationCount-1), 0);
memcpy(m_register, PtrAdd(keystreamBuffer, (iterationCount-1)*s), s);
}
void OFB_ModePolicy::CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)
{
CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CRYPTOPP_ASSERT(length == BlockSize());
CopyOrZero(m_register, m_register.size(), iv, length);
}
void CTR_ModePolicy::SeekToIteration(lword iterationCount)
{
int carry=0;
for (int i=BlockSize()-1; i>=0; i--)
{
unsigned int sum = m_register[i] + (byte)iterationCount + carry;
m_counterArray[i] = byte(sum & 0xff);
carry = sum >> 8;
iterationCount >>= 8;
}
}
void CTR_ModePolicy::IncrementCounterBy256()
{
IncrementCounterByOne(m_counterArray, BlockSize()-1);
}
void CTR_ModePolicy::OperateKeystream(KeystreamOperation /*operation*/, byte *output, const byte *input, size_t iterationCount)
{
CRYPTOPP_ASSERT(m_cipher->IsForwardTransformation());
CRYPTOPP_ASSERT(m_counterArray.size() == BlockSize());
const unsigned int s = BlockSize();
const unsigned int inputIncrement = input ? s : 0;
while (iterationCount)
{
const byte lsb = m_counterArray[s-1];
const size_t blocks = UnsignedMin(iterationCount, 256U-lsb);
m_cipher->AdvancedProcessBlocks(m_counterArray, input, output, blocks*s, BlockTransformation::BT_InBlockIsCounter|BlockTransformation::BT_AllowParallel);
if ((m_counterArray[s-1] = byte(lsb + blocks)) == 0)
IncrementCounterBy256();
output = PtrAdd(output, blocks*s);
input = PtrAdd(input, blocks*inputIncrement);
iterationCount -= blocks;
}
}
void CTR_ModePolicy::CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)
{
CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
CRYPTOPP_ASSERT(length == BlockSize());
CopyOrZero(m_register, m_register.size(), iv, length);
m_counterArray.Assign(m_register.begin(), m_register.size());
}
void BlockOrientedCipherModeBase::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &params)
{
m_cipher->SetKey(key, length, params);
ResizeBuffers();
if (IsResynchronizable())
{
size_t ivLength;
const byte *iv = GetIVAndThrowIfInvalid(params, ivLength);
Resynchronize(iv, (int)ivLength);
}
}
void BlockOrientedCipherModeBase::ResizeBuffers()
{
CipherModeBase::ResizeBuffers();
m_buffer.New(BlockSize());
}
void ECB_OneWay::ProcessData(byte *outString, const byte *inString, size_t length)
{
CRYPTOPP_ASSERT(length%BlockSize()==0);
m_cipher->AdvancedProcessBlocks(inString, NULLPTR, outString, length, BlockTransformation::BT_AllowParallel);
}
void CBC_Encryption::ProcessData(byte *outString, const byte *inString, size_t length)
{
CRYPTOPP_ASSERT(length%BlockSize()==0);
CRYPTOPP_ASSERT(m_register.size() == BlockSize());
if (!length) return;
const unsigned int blockSize = BlockSize();
m_cipher->AdvancedProcessBlocks(inString, m_register, outString, blockSize, BlockTransformation::BT_XorInput);
if (length > blockSize)
m_cipher->AdvancedProcessBlocks(PtrAdd(inString,blockSize), outString, PtrAdd(outString,blockSize), length-blockSize, BlockTransformation::BT_XorInput);
memcpy(m_register, PtrAdd(outString, length - blockSize), blockSize);
}
size_t CBC_CTS_Encryption::ProcessLastBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)
{
CRYPTOPP_UNUSED(outLength);
const size_t used = inLength;
const unsigned int blockSize = BlockSize();
if (inLength <= blockSize)
{
if (!m_stolenIV)
throw InvalidArgument("CBC_Encryption: message is too short for ciphertext stealing");
// steal from IV
memcpy(outString, m_register, inLength);
outString = m_stolenIV;
}
else
{
// steal from next to last block
xorbuf(m_register, inString, blockSize);
m_cipher->ProcessBlock(m_register);
inString = PtrAdd(inString, blockSize);
inLength -= blockSize;
memcpy(PtrAdd(outString, blockSize), m_register, inLength);
}
// output last full ciphertext block
xorbuf(m_register, inString, inLength);
m_cipher->ProcessBlock(m_register);
memcpy(outString, m_register, blockSize);
return used;
}
void CBC_Decryption::ResizeBuffers()
{
BlockOrientedCipherModeBase::ResizeBuffers();
m_temp.New(BlockSize());
}
void CBC_Decryption::ProcessData(byte *outString, const byte *inString, size_t length)
{
CRYPTOPP_ASSERT(length%BlockSize()==0);
if (!length) {return;}
// save copy now in case of in-place decryption
const unsigned int blockSize = BlockSize();
memcpy(m_temp, PtrAdd(inString,length-blockSize), blockSize);
if (length > blockSize)
m_cipher->AdvancedProcessBlocks(PtrAdd(inString,blockSize), inString, PtrAdd(outString,blockSize), length-blockSize, BlockTransformation::BT_ReverseDirection|BlockTransformation::BT_AllowParallel);
m_cipher->ProcessAndXorBlock(inString, m_register, outString);
m_register.swap(m_temp);
}
size_t CBC_CTS_Decryption::ProcessLastBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)
{
CRYPTOPP_UNUSED(outLength);
const byte *pn1, *pn2;
const size_t used = inLength;
const bool stealIV = inLength <= BlockSize();
const unsigned int blockSize = BlockSize();
if (stealIV)
{
pn1 = inString;
pn2 = m_register;
}
else
{
pn1 = PtrAdd(inString, blockSize);
pn2 = inString;
inLength -= blockSize;
}
// decrypt last partial plaintext block
memcpy(m_temp, pn2, blockSize);
m_cipher->ProcessBlock(m_temp);
xorbuf(m_temp, pn1, inLength);
if (stealIV)
{
memcpy(outString, m_temp, inLength);
}
else
{
memcpy(PtrAdd(outString, blockSize), m_temp, inLength);
// decrypt next to last plaintext block
memcpy(m_temp, pn1, inLength);
m_cipher->ProcessBlock(m_temp);
xorbuf(outString, m_temp, m_register, blockSize);
}
return used;
}
NAMESPACE_END
#endif