1 files changed, 238 insertions, 0 deletions

diff --git a/CryptoPP/basecode.cpp b/CryptoPP/basecode.cpp
new file mode 100644
index 000000000..0c98b2271
--- /dev/null
+++ b/CryptoPP/basecode.cpp
@@ -0,0 +1,238 @@
+// 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