// basecode.cpp - written and placed in the public domain by Wei Dai#include "pch.h"#include "basecode.h"#include "fltrimpl.h"#include <ctype.h>NAMESPACE_BEGIN(CryptoPP)void BaseN_Encoder::IsolatedInitialize(const NameValuePairs &parameters){	parameters.GetRequiredParameter("BaseN_Encoder", "EncodingLookupArray", m_alphabet);	parameters.GetRequiredIntParameter("BaseN_Encoder", "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("PaddingByte", padding))		pad = parameters.GetValueWithDefault("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);}unsigned int BaseN_Encoder::Put2(const byte *begin, unsigned int 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", "DecodingLookupArray", m_lookup);	parameters.GetRequiredIntParameter("BaseN_Decoder", "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);}unsigned int BaseN_Decoder::Put2(const byte *begin, unsigned int 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("GroupSize", 0);	ConstByteArrayParameter separator, terminator;	if (m_groupSize)		parameters.GetRequiredParameter("Grouper", "Separator", separator);	parameters.GetValue("Terminator", terminator);	m_separator.Assign(separator.begin(), separator.size());	m_terminator.Assign(terminator.begin(), terminator.size());	m_counter = 0;}unsigned int Grouper::Put2(const byte *begin, unsigned int 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;			}			unsigned int 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);	FILTER_END_NO_MESSAGE_END}NAMESPACE_END