File: ida.h

package info (click to toggle)
libcrypto++ 5.6.4-8
  • links: PTS
  • area: main
  • in suites: buster
  • size: 11,896 kB
  • ctags: 13,256
  • sloc: cpp: 69,231; sh: 4,117; asm: 4,090; makefile: 373
file content (161 lines) | stat: -rw-r--r-- 5,444 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// ida.h - written and placed in the public domain by Wei Dai

//! \file ida.h
//! \brief Classes for Information Dispersal Algorithm (IDA)

#ifndef CRYPTOPP_IDA_H
#define CRYPTOPP_IDA_H

#include "cryptlib.h"
#include "mqueue.h"
#include "filters.h"
#include "channels.h"
#include "secblock.h"
#include "stdcpp.h"
#include "misc.h"

NAMESPACE_BEGIN(CryptoPP)

/// base class for secret sharing and information dispersal
class RawIDA : public AutoSignaling<Unflushable<Multichannel<Filter> > >
{
public:
	RawIDA(BufferedTransformation *attachment=NULL)
		: m_threshold (0), m_channelsReady(0), m_channelsFinished(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;
	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)), 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;
};

/// a variant of Rabin's Information Dispersal Algorithm
class InformationRecovery : public RawIDA
{
public:
	InformationRecovery(int threshold, BufferedTransformation *attachment=NULL, 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=NULL)
		: 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