ida.h

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// ida.h - originally written and placed in the public domain by Wei Dai
 
 
#ifndef CRYPTOPP_IDA_H
#define CRYPTOPP_IDA_H
 
#include "cryptlib.h"
#include "mqueue.h"
#include "filters.h"
#include "channels.h"
#include "secblock.h"
#include "gf2_32.h"
#include "stdcpp.h"
#include "misc.h"
 
NAMESPACE_BEGIN(CryptoPP)
 
 
class RawIDA : public AutoSignaling<Unflushable<Multichannel<Filter> > >
{
public:
        RawIDA(BufferedTransformation *attachment=NULLPTR)
                : m_channelsReady(0), m_channelsFinished(0), m_threshold (0)
                        {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;
        std::vector<SecBlock<word32> > m_v;
        SecBlock<word32> m_u, m_w, m_y;
        const GF2_32 m_gf32;
        unsigned int m_channelsReady, m_channelsFinished;
        int m_threshold;
};
 
class SecretSharing : public CustomFlushPropagation<Filter>
{
public:
        SecretSharing(RandomNumberGenerator &rng, int threshold, int nShares, BufferedTransformation *attachment=NULLPTR, 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;
};
 
class SecretRecovery : public RawIDA
{
public:
        SecretRecovery(int threshold, BufferedTransformation *attachment=NULLPTR, 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;
};
 
 
class InformationDispersal : public CustomFlushPropagation<Filter>
{
public:
        InformationDispersal(int threshold, int nShares, BufferedTransformation *attachment=NULLPTR, bool addPadding=true)
                : m_ida(new OutputProxy(*this, true)), m_pad(false), m_nextChannel(0)
        {
                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;
};
 
class InformationRecovery : public RawIDA
{
public:
        InformationRecovery(int threshold, BufferedTransformation *attachment=NULLPTR, bool removePadding=true)
                : RawIDA(attachment), m_pad(false)
                {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=NULLPTR)
                : m_possiblePadding(false), m_zeroCount(0) {Detach(attachment);}
 
        void IsolatedInitialize(const NameValuePairs &parameters)
                {CRYPTOPP_UNUSED(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