Modified source engine (2017) developed by valve and leaked in 2020. Not for commercial purporses
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// basecode.cpp - written and placed in the public domain by Wei Dai
#include "pch.h"
#ifndef CRYPTOPP_IMPORTS
#include "basecode.h"
#include "fltrimpl.h"
#include <ctype.h>
NAMESPACE_BEGIN(CryptoPP)
void BaseN_Encoder::IsolatedInitialize(const NameValuePairs &parameters)
{
parameters.GetRequiredParameter("BaseN_Encoder", Name::EncodingLookupArray(), m_alphabet);
parameters.GetRequiredIntParameter("BaseN_Encoder", Name::Log2Base(), m_bitsPerChar);
if (m_bitsPerChar <= 0 || m_bitsPerChar >= 8)
throw InvalidArgument("BaseN_Encoder: Log2Base must be between 1 and 7 inclusive");
byte padding;
bool pad;
if (parameters.GetValue(Name::PaddingByte(), padding))
pad = parameters.GetValueWithDefault(Name::Pad(), true);
else
pad = false;
m_padding = pad ? padding : -1;
m_bytePos = m_bitPos = 0;
int i = 8;
while (i%m_bitsPerChar != 0)
i += 8;
m_outputBlockSize = i/m_bitsPerChar;
m_outBuf.New(m_outputBlockSize);
}
size_t BaseN_Encoder::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
FILTER_BEGIN;
while (m_inputPosition < length)
{
if (m_bytePos == 0)
memset(m_outBuf, 0, m_outputBlockSize);
{
unsigned int b = begin[m_inputPosition++], bitsLeftInSource = 8;
while (true)
{
assert(m_bitPos < m_bitsPerChar);
unsigned int bitsLeftInTarget = m_bitsPerChar-m_bitPos;
m_outBuf[m_bytePos] |= b >> (8-bitsLeftInTarget);
if (bitsLeftInSource >= bitsLeftInTarget)
{
m_bitPos = 0;
++m_bytePos;
bitsLeftInSource -= bitsLeftInTarget;
if (bitsLeftInSource == 0)
break;
b <<= bitsLeftInTarget;
b &= 0xff;
}
else
{
m_bitPos += bitsLeftInSource;
break;
}
}
}
assert(m_bytePos <= m_outputBlockSize);
if (m_bytePos == m_outputBlockSize)
{
int i;
for (i=0; i<m_bytePos; i++)
{
assert(m_outBuf[i] < (1 << m_bitsPerChar));
m_outBuf[i] = m_alphabet[m_outBuf[i]];
}
FILTER_OUTPUT(1, m_outBuf, m_outputBlockSize, 0);
m_bytePos = m_bitPos = 0;
}
}
if (messageEnd)
{
if (m_bitPos > 0)
++m_bytePos;
int i;
for (i=0; i<m_bytePos; i++)
m_outBuf[i] = m_alphabet[m_outBuf[i]];
if (m_padding != -1 && m_bytePos > 0)
{
memset(m_outBuf+m_bytePos, m_padding, m_outputBlockSize-m_bytePos);
m_bytePos = m_outputBlockSize;
}
FILTER_OUTPUT(2, m_outBuf, m_bytePos, messageEnd);
m_bytePos = m_bitPos = 0;
}
FILTER_END_NO_MESSAGE_END;
}
void BaseN_Decoder::IsolatedInitialize(const NameValuePairs &parameters)
{
parameters.GetRequiredParameter("BaseN_Decoder", Name::DecodingLookupArray(), m_lookup);
parameters.GetRequiredIntParameter("BaseN_Decoder", Name::Log2Base(), m_bitsPerChar);
if (m_bitsPerChar <= 0 || m_bitsPerChar >= 8)
throw InvalidArgument("BaseN_Decoder: Log2Base must be between 1 and 7 inclusive");
m_bytePos = m_bitPos = 0;
int i = m_bitsPerChar;
while (i%8 != 0)
i += m_bitsPerChar;
m_outputBlockSize = i/8;
m_outBuf.New(m_outputBlockSize);
}
size_t BaseN_Decoder::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
FILTER_BEGIN;
while (m_inputPosition < length)
{
unsigned int value;
value = m_lookup[begin[m_inputPosition++]];
if (value >= 256)
continue;
if (m_bytePos == 0 && m_bitPos == 0)
memset(m_outBuf, 0, m_outputBlockSize);
{
int newBitPos = m_bitPos + m_bitsPerChar;
if (newBitPos <= 8)
m_outBuf[m_bytePos] |= value << (8-newBitPos);
else
{
m_outBuf[m_bytePos] |= value >> (newBitPos-8);
m_outBuf[m_bytePos+1] |= value << (16-newBitPos);
}
m_bitPos = newBitPos;
while (m_bitPos >= 8)
{
m_bitPos -= 8;
++m_bytePos;
}
}
if (m_bytePos == m_outputBlockSize)
{
FILTER_OUTPUT(1, m_outBuf, m_outputBlockSize, 0);
m_bytePos = m_bitPos = 0;
}
}
if (messageEnd)
{
FILTER_OUTPUT(2, m_outBuf, m_bytePos, messageEnd);
m_bytePos = m_bitPos = 0;
}
FILTER_END_NO_MESSAGE_END;
}
void BaseN_Decoder::InitializeDecodingLookupArray(int *lookup, const byte *alphabet, unsigned int base, bool caseInsensitive)
{
std::fill(lookup, lookup+256, -1);
for (unsigned int i=0; i<base; i++)
{
if (caseInsensitive && isalpha(alphabet[i]))
{
assert(lookup[toupper(alphabet[i])] == -1);
lookup[toupper(alphabet[i])] = i;
assert(lookup[tolower(alphabet[i])] == -1);
lookup[tolower(alphabet[i])] = i;
}
else
{
assert(lookup[alphabet[i]] == -1);
lookup[alphabet[i]] = i;
}
}
}
void Grouper::IsolatedInitialize(const NameValuePairs &parameters)
{
m_groupSize = parameters.GetIntValueWithDefault(Name::GroupSize(), 0);
ConstByteArrayParameter separator, terminator;
if (m_groupSize)
parameters.GetRequiredParameter("Grouper", Name::Separator(), separator);
else
parameters.GetValue(Name::Separator(), separator);
parameters.GetValue(Name::Terminator(), terminator);
m_separator.Assign(separator.begin(), separator.size());
m_terminator.Assign(terminator.begin(), terminator.size());
m_counter = 0;
}
size_t Grouper::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
FILTER_BEGIN;
if (m_groupSize)
{
while (m_inputPosition < length)
{
if (m_counter == m_groupSize)
{
FILTER_OUTPUT(1, m_separator, m_separator.size(), 0);
m_counter = 0;
}
size_t len;
FILTER_OUTPUT2(2, len = STDMIN(length-m_inputPosition, m_groupSize-m_counter),
begin+m_inputPosition, len, 0);
m_inputPosition += len;
m_counter += len;
}
}
else
FILTER_OUTPUT(3, begin, length, 0);
if (messageEnd)
{
FILTER_OUTPUT(4, m_terminator, m_terminator.size(), messageEnd);
m_counter = 0;
}
FILTER_END_NO_MESSAGE_END
}
NAMESPACE_END
#endif