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optimize ECB/CBC modes

pull/2/head
weidai 2007-05-05 15:26:05 +00:00
parent 3dfcdf8c44
commit 3bc56fe4c4
1 changed files with 18 additions and 29 deletions
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47
modes.cpp
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@ -94,51 +94,40 @@ void BlockOrientedCipherModeBase::UncheckedSetKey(const byte *key, unsigned int
void BlockOrientedCipherModeBase::ProcessData(byte *outString, const byte *inString, size_t length)
{
if (!length)
return;
unsigned int s = BlockSize();
assert(length % s == 0);
unsigned int alignment = m_cipher->BlockAlignment();
bool inputAlignmentOk = !RequireAlignedInput() || IsAlignedOn(inString, alignment);
if (IsAlignedOn(outString, alignment))
{
if (inputAlignmentOk)
ProcessBlocks(outString, inString, length / s);
else
{
memcpy(outString, inString, length);
ProcessBlocks(outString, outString, length / s);
}
}
if (!RequireAlignedInput() || IsAlignedOn(inString, m_cipher->BlockAlignment()))
ProcessBlocks(outString, inString, length / s);
else
{
while (length)
do
{
if (inputAlignmentOk)
ProcessBlocks(m_buffer, inString, 1);
else
{
memcpy(m_buffer, inString, s);
ProcessBlocks(m_buffer, m_buffer, 1);
}
memcpy(outString, m_buffer, s);
memcpy(m_buffer, inString, s);
ProcessBlocks(outString, m_buffer, 1);
inString += s;
outString += s;
length -= s;
}
} while (length > 0);
}
}
void CBC_Encryption::ProcessBlocks(byte *outString, const byte *inString, size_t numberOfBlocks)
{
unsigned int blockSize = BlockSize();
while (numberOfBlocks--)
xorbuf(m_register, inString, blockSize);
while (--numberOfBlocks)
{
xorbuf(m_register, inString, blockSize);
m_cipher->ProcessBlock(m_register);
memcpy(outString, m_register, blockSize);
m_cipher->ProcessBlock(m_register, outString);
inString += blockSize;
xorbuf(m_register, inString, outString, blockSize);
outString += blockSize;
}
m_cipher->ProcessBlock(m_register);
memcpy(outString, m_register, blockSize);
}
void CBC_CTS_Encryption::ProcessLastBlock(byte *outString, const byte *inString, size_t length)
@ -171,14 +160,14 @@ void CBC_CTS_Encryption::ProcessLastBlock(byte *outString, const byte *inString,
void CBC_Decryption::ProcessBlocks(byte *outString, const byte *inString, size_t numberOfBlocks)
{
unsigned int blockSize = BlockSize();
while (numberOfBlocks--)
do
{
memcpy(m_temp, inString, blockSize);
memcpy(m_temp, inString, blockSize); // make copy in case we're doing in place decryption
m_cipher->ProcessAndXorBlock(m_temp, m_register, outString);
m_register.swap(m_temp);
inString += blockSize;
outString += blockSize;
}
} while (--numberOfBlocks);
}
void CBC_CTS_Decryption::ProcessLastBlock(byte *outString, const byte *inString, size_t length)