shadps4-emu/ext-cryptopp
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Cleanup XTS mode

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This commit is contained in:
Jeffrey Walton 2020-04-11 11:40:37 -04:00
parent e007e98501
commit d855d26b56
No known key found for this signature in database
GPG Key ID: B36AB348921B1838
1 changed files with 16 additions and 9 deletions
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25
xts.cpp
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@ -63,7 +63,7 @@ inline void XorBuffer(byte *output, const byte *input, const byte *mask, size_t
CRYPTOPP_ASSERT(count >= 16 && (count % 16 == 0));
#if defined(CRYPTOPP_DISABLE_ASM)
xorbuf(output, input, mask, count);
xorbuf(output, input, mask, count);
#elif defined(__SSE2__) || defined(_M_X64)
for (size_t i=0; i<count; i+=16)
@ -247,10 +247,9 @@ void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t len
const unsigned int blockSize = GetBlockCipher().BlockSize();
const size_t parallelSize = blockSize*ParallelBlocks;
size_t i = 0;
// encrypt the data unit, optimal size at a time
for ( ; i+parallelSize<=length; i+=parallelSize)
while (length >= parallelSize)
{
// If this fires the GF_Double'ing below is not in sync
CRYPTOPP_ASSERT(ParallelBlocks == 4);
@ -261,29 +260,37 @@ void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t len
GF_Double(m_xregister+3*blockSize, m_xregister+2*blockSize, blockSize);
// merge the tweak into the input block
XorBuffer(m_xworkspace, inString+i, m_xregister, parallelSize);
XorBuffer(m_xworkspace, inString, m_xregister, parallelSize);
// encrypt one block, merge the tweak into the output block
GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister, outString+i, parallelSize, BlockTransformation::BT_AllowParallel);
GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister, outString, parallelSize, BlockTransformation::BT_AllowParallel);
// m_xregister[0] always points to the next tweak.
GF_Double(m_xregister+0, m_xregister+(ParallelBlocks-1)*blockSize, blockSize);
GF_Double(m_xregister+0, m_xregister+3*blockSize, blockSize);
inString += parallelSize;
outString += parallelSize;
length -= parallelSize;
}
// encrypt the data unit, blocksize at a time
for ( ; i<length; i+=blockSize)
while (length)
{
// merge the tweak into the input block
XorBuffer(m_xworkspace, inString+i, m_xregister, blockSize);
XorBuffer(m_xworkspace, inString, m_xregister, blockSize);
// encrypt one block
GetBlockCipher().ProcessBlock(m_xworkspace);
// merge the tweak into the output block
XorBuffer(outString+i, m_xworkspace, m_xregister, blockSize);
XorBuffer(outString, m_xworkspace, m_xregister, blockSize);
// Multiply T by alpha
GF_Double(m_xregister, blockSize);
inString += blockSize;
outString += blockSize;
length -= blockSize;
}
}