1 files changed, 152 insertions, 0 deletions

diff --git a/CryptoPP/ida.h b/CryptoPP/ida.h
new file mode 100644
index 000000000..8ebb4ec91
--- /dev/null
+++ b/CryptoPP/ida.h
@@ -0,0 +1,152 @@
+#ifndef CRYPTOPP_IDA_H
+#define CRYPTOPP_IDA_H
+
+#include "mqueue.h"
+#include "filters.h"
+#include "channels.h"
+#include <map>
+#include <vector>
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// base class for secret sharing and information dispersal
+class RawIDA : public AutoSignaling<Unflushable<Multichannel<Filter> > >
+{
+public:
+	RawIDA(BufferedTransformation *attachment=NULL)
+		{Detach(attachment);}
+
+	unsigned int GetThreshold() const {return m_threshold;}
+	void AddOutputChannel(word32 channelId);
+	void ChannelData(word32 channelId, const byte *inString, size_t length, bool messageEnd);
+	lword InputBuffered(word32 channelId) const;
+
+	void IsolatedInitialize(const NameValuePairs &parameters=g_nullNameValuePairs);
+	size_t ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking)
+	{
+		if (!blocking)
+			throw BlockingInputOnly("RawIDA");
+		ChannelData(StringToWord<word32>(channel), begin, length, messageEnd != 0);
+		return 0;
+	}
+
+protected:
+	virtual void FlushOutputQueues();
+	virtual void OutputMessageEnds();
+
+	unsigned int InsertInputChannel(word32 channelId);
+	unsigned int LookupInputChannel(word32 channelId) const;
+	void ComputeV(unsigned int);
+	void PrepareInterpolation();
+	void ProcessInputQueues();
+
+	typedef std::map<word32, unsigned int> InputChannelMap;
+	InputChannelMap m_inputChannelMap;
+	InputChannelMap::iterator m_lastMapPosition;
+	std::vector<MessageQueue> m_inputQueues;
+	std::vector<word32> m_inputChannelIds, m_outputChannelIds, m_outputToInput;
+	std::vector<std::string> m_outputChannelIdStrings;
+	std::vector<ByteQueue> m_outputQueues;
+	int m_threshold;
+	unsigned int m_channelsReady, m_channelsFinished;
+	std::vector<SecBlock<word32> > m_v;
+	SecBlock<word32> m_u, m_w, m_y;
+};
+
+/// a variant of Shamir's Secret Sharing Algorithm
+class SecretSharing : public CustomFlushPropagation<Filter>
+{
+public:
+	SecretSharing(RandomNumberGenerator &rng, int threshold, int nShares, BufferedTransformation *attachment=NULL, bool addPadding=true)
+		: m_rng(rng), m_ida(new OutputProxy(*this, true))
+	{
+		Detach(attachment);
+		IsolatedInitialize(MakeParameters("RecoveryThreshold", threshold)("NumberOfShares", nShares)("AddPadding", addPadding));
+	}
+
+	void IsolatedInitialize(const NameValuePairs &parameters=g_nullNameValuePairs);
+	size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
+	bool Flush(bool hardFlush, int propagation=-1, bool blocking=true) {return m_ida.Flush(hardFlush, propagation, blocking);}
+
+protected:
+	RandomNumberGenerator &m_rng;
+	RawIDA m_ida;
+	bool m_pad;
+};
+
+/// a variant of Shamir's Secret Sharing Algorithm
+class SecretRecovery : public RawIDA
+{
+public:
+	SecretRecovery(int threshold, BufferedTransformation *attachment=NULL, bool removePadding=true)
+		: RawIDA(attachment)
+		{IsolatedInitialize(MakeParameters("RecoveryThreshold", threshold)("RemovePadding", removePadding));}
+
+	void IsolatedInitialize(const NameValuePairs &parameters=g_nullNameValuePairs);
+
+protected:
+	void FlushOutputQueues();
+	void OutputMessageEnds();
+
+	bool m_pad;
+};
+
+/// a variant of Rabin's Information Dispersal Algorithm
+class InformationDispersal : public CustomFlushPropagation<Filter>
+{
+public:
+	InformationDispersal(int threshold, int nShares, BufferedTransformation *attachment=NULL, bool addPadding=true)
+		: m_ida(new OutputProxy(*this, true))
+	{
+		Detach(attachment);
+		IsolatedInitialize(MakeParameters("RecoveryThreshold", threshold)("NumberOfShares", nShares)("AddPadding", addPadding));
+	}
+
+	void IsolatedInitialize(const NameValuePairs &parameters=g_nullNameValuePairs);
+	size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
+	bool Flush(bool hardFlush, int propagation=-1, bool blocking=true) {return m_ida.Flush(hardFlush, propagation, blocking);}
+
+protected:
+	RawIDA m_ida;
+	bool m_pad;
+	unsigned int m_nextChannel;
+};
+
+/// a variant of Rabin's Information Dispersal Algorithm
+class InformationRecovery : public RawIDA
+{
+public:
+	InformationRecovery(int threshold, BufferedTransformation *attachment=NULL, bool removePadding=true)
+		: RawIDA(attachment)
+		{IsolatedInitialize(MakeParameters("RecoveryThreshold", threshold)("RemovePadding", removePadding));}
+
+	void IsolatedInitialize(const NameValuePairs &parameters=g_nullNameValuePairs);
+
+protected:
+	void FlushOutputQueues();
+	void OutputMessageEnds();
+
+	bool m_pad;
+	ByteQueue m_queue;
+};
+
+class PaddingRemover : public Unflushable<Filter>
+{
+public:
+	PaddingRemover(BufferedTransformation *attachment=NULL)
+		: m_possiblePadding(false) {Detach(attachment);}
+
+	void IsolatedInitialize(const NameValuePairs &parameters) {m_possiblePadding = false;}
+	size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
+
+	// GetPossiblePadding() == false at the end of a message indicates incorrect padding
+	bool GetPossiblePadding() const {return m_possiblePadding;}
+
+private:
+	bool m_possiblePadding;
+	lword m_zeroCount;
+};
+
+NAMESPACE_END
+
+#endif