ext-cryptopp/ida.cpp
2006-12-22 15:03:42 +00:00

422 lines
11 KiB
C++

// ida.cpp - written and placed in the public domain by Wei Dai
#include "pch.h"
#include "ida.h"
#include "algebra.h"
#include "gf2_32.h"
#include "polynomi.h"
#include <functional>
#include "polynomi.cpp"
ANONYMOUS_NAMESPACE_BEGIN
static const CryptoPP::GF2_32 field;
NAMESPACE_END
using namespace std;
NAMESPACE_BEGIN(CryptoPP)
void RawIDA::IsolatedInitialize(const NameValuePairs &parameters)
{
if (!parameters.GetIntValue("RecoveryThreshold", m_threshold))
throw InvalidArgument("RawIDA: missing RecoveryThreshold argument");
if (m_threshold <= 0)
throw InvalidArgument("RawIDA: RecoveryThreshold must be greater than 0");
m_lastMapPosition = m_inputChannelMap.end();
m_channelsReady = 0;
m_channelsFinished = 0;
m_w.New(m_threshold);
m_y.New(m_threshold);
m_inputQueues.reserve(m_threshold);
m_outputChannelIds.clear();
m_outputChannelIdStrings.clear();
m_outputQueues.clear();
word32 outputChannelID;
if (parameters.GetValue("OutputChannelID", outputChannelID))
AddOutputChannel(outputChannelID);
else
{
int nShares = parameters.GetIntValueWithDefault("NumberOfShares", m_threshold);
for (int i=0; i<nShares; i++)
AddOutputChannel(i);
}
}
unsigned int RawIDA::InsertInputChannel(word32 channelId)
{
if (m_lastMapPosition != m_inputChannelMap.end())
{
if (m_lastMapPosition->first == channelId)
goto skipFind;
++m_lastMapPosition;
if (m_lastMapPosition != m_inputChannelMap.end() && m_lastMapPosition->first == channelId)
goto skipFind;
}
m_lastMapPosition = m_inputChannelMap.find(channelId);
skipFind:
if (m_lastMapPosition == m_inputChannelMap.end())
{
if (m_inputChannelIds.size() == m_threshold)
return m_threshold;
m_lastMapPosition = m_inputChannelMap.insert(InputChannelMap::value_type(channelId, (unsigned int)m_inputChannelIds.size())).first;
m_inputQueues.push_back(MessageQueue());
m_inputChannelIds.push_back(channelId);
if (m_inputChannelIds.size() == m_threshold)
PrepareInterpolation();
}
return m_lastMapPosition->second;
}
unsigned int RawIDA::LookupInputChannel(word32 channelId) const
{
map<word32, unsigned int>::const_iterator it = m_inputChannelMap.find(channelId);
if (it == m_inputChannelMap.end())
return m_threshold;
else
return it->second;
}
void RawIDA::ChannelData(word32 channelId, const byte *inString, size_t length, bool messageEnd)
{
int i = InsertInputChannel(channelId);
if (i < m_threshold)
{
lword size = m_inputQueues[i].MaxRetrievable();
m_inputQueues[i].Put(inString, length);
if (size < 4 && size + length >= 4)
{
m_channelsReady++;
if (m_channelsReady == m_threshold)
ProcessInputQueues();
}
if (messageEnd)
{
m_inputQueues[i].MessageEnd();
if (m_inputQueues[i].NumberOfMessages() == 1)
{
m_channelsFinished++;
if (m_channelsFinished == m_threshold)
{
m_channelsReady = 0;
for (i=0; i<m_threshold; i++)
m_channelsReady += m_inputQueues[i].AnyRetrievable();
ProcessInputQueues();
}
}
}
}
}
lword RawIDA::InputBuffered(word32 channelId) const
{
int i = LookupInputChannel(channelId);
return i < m_threshold ? m_inputQueues[i].MaxRetrievable() : 0;
}
void RawIDA::ComputeV(unsigned int i)
{
if (i >= m_v.size())
{
m_v.resize(i+1);
m_outputToInput.resize(i+1);
}
m_outputToInput[i] = LookupInputChannel(m_outputChannelIds[i]);
if (m_outputToInput[i] == m_threshold && i * m_threshold <= 1000*1000)
{
m_v[i].resize(m_threshold);
PrepareBulkPolynomialInterpolationAt(field, m_v[i].begin(), m_outputChannelIds[i], &(m_inputChannelIds[0]), m_w.begin(), m_threshold);
}
}
void RawIDA::AddOutputChannel(word32 channelId)
{
m_outputChannelIds.push_back(channelId);
m_outputChannelIdStrings.push_back(WordToString(channelId));
m_outputQueues.push_back(ByteQueue());
if (m_inputChannelIds.size() == m_threshold)
ComputeV((unsigned int)m_outputChannelIds.size() - 1);
}
void RawIDA::PrepareInterpolation()
{
assert(m_inputChannelIds.size() == m_threshold);
PrepareBulkPolynomialInterpolation(field, m_w.begin(), &(m_inputChannelIds[0]), m_threshold);
for (unsigned int i=0; i<m_outputChannelIds.size(); i++)
ComputeV(i);
}
void RawIDA::ProcessInputQueues()
{
bool finished = (m_channelsFinished == m_threshold);
int i;
while (finished ? m_channelsReady > 0 : m_channelsReady == m_threshold)
{
m_channelsReady = 0;
for (i=0; i<m_threshold; i++)
{
MessageQueue &queue = m_inputQueues[i];
queue.GetWord32(m_y[i]);
if (finished)
m_channelsReady += queue.AnyRetrievable();
else
m_channelsReady += queue.NumberOfMessages() > 0 || queue.MaxRetrievable() >= 4;
}
for (i=0; (unsigned int)i<m_outputChannelIds.size(); i++)
{
if (m_outputToInput[i] != m_threshold)
m_outputQueues[i].PutWord32(m_y[m_outputToInput[i]]);
else if (m_v[i].size() == m_threshold)
m_outputQueues[i].PutWord32(BulkPolynomialInterpolateAt(field, m_y.begin(), m_v[i].begin(), m_threshold));
else
{
m_u.resize(m_threshold);
PrepareBulkPolynomialInterpolationAt(field, m_u.begin(), m_outputChannelIds[i], &(m_inputChannelIds[0]), m_w.begin(), m_threshold);
m_outputQueues[i].PutWord32(BulkPolynomialInterpolateAt(field, m_y.begin(), m_u.begin(), m_threshold));
}
}
}
if (m_outputChannelIds.size() > 0 && m_outputQueues[0].AnyRetrievable())
FlushOutputQueues();
if (finished)
{
OutputMessageEnds();
m_channelsReady = 0;
m_channelsFinished = 0;
m_v.clear();
vector<MessageQueue> inputQueues;
vector<word32> inputChannelIds;
inputQueues.swap(m_inputQueues);
inputChannelIds.swap(m_inputChannelIds);
m_inputChannelMap.clear();
m_lastMapPosition = m_inputChannelMap.end();
for (i=0; i<m_threshold; i++)
{
inputQueues[i].GetNextMessage();
inputQueues[i].TransferAllTo(*AttachedTransformation(), WordToString(inputChannelIds[i]));
}
}
}
void RawIDA::FlushOutputQueues()
{
for (unsigned int i=0; i<m_outputChannelIds.size(); i++)
m_outputQueues[i].TransferAllTo(*AttachedTransformation(), m_outputChannelIdStrings[i]);
}
void RawIDA::OutputMessageEnds()
{
if (GetAutoSignalPropagation() != 0)
{
for (unsigned int i=0; i<m_outputChannelIds.size(); i++)
AttachedTransformation()->ChannelMessageEnd(m_outputChannelIdStrings[i], GetAutoSignalPropagation()-1);
}
}
// ****************************************************************
void SecretSharing::IsolatedInitialize(const NameValuePairs &parameters)
{
m_pad = parameters.GetValueWithDefault("AddPadding", true);
m_ida.IsolatedInitialize(parameters);
}
size_t SecretSharing::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
if (!blocking)
throw BlockingInputOnly("SecretSharing");
SecByteBlock buf(UnsignedMin(256, length));
unsigned int threshold = m_ida.GetThreshold();
while (length > 0)
{
size_t len = STDMIN(length, buf.size());
m_ida.ChannelData(0xffffffff, begin, len, false);
for (unsigned int i=0; i<threshold-1; i++)
{
m_rng.GenerateBlock(buf, len);
m_ida.ChannelData(i, buf, len, false);
}
length -= len;
begin += len;
}
if (messageEnd)
{
m_ida.SetAutoSignalPropagation(messageEnd-1);
if (m_pad)
{
SecretSharing::Put(1);
while (m_ida.InputBuffered(0xffffffff) > 0)
SecretSharing::Put(0);
}
m_ida.ChannelData(0xffffffff, NULL, 0, true);
for (unsigned int i=0; i<m_ida.GetThreshold()-1; i++)
m_ida.ChannelData(i, NULL, 0, true);
}
return 0;
}
void SecretRecovery::IsolatedInitialize(const NameValuePairs &parameters)
{
m_pad = parameters.GetValueWithDefault("RemovePadding", true);
RawIDA::IsolatedInitialize(CombinedNameValuePairs(parameters, MakeParameters("OutputChannelID", (word32)0xffffffff)));
}
void SecretRecovery::FlushOutputQueues()
{
if (m_pad)
m_outputQueues[0].TransferTo(*AttachedTransformation(), m_outputQueues[0].MaxRetrievable()-4);
else
m_outputQueues[0].TransferTo(*AttachedTransformation());
}
void SecretRecovery::OutputMessageEnds()
{
if (m_pad)
{
PaddingRemover paddingRemover(new Redirector(*AttachedTransformation()));
m_outputQueues[0].TransferAllTo(paddingRemover);
}
if (GetAutoSignalPropagation() != 0)
AttachedTransformation()->MessageEnd(GetAutoSignalPropagation()-1);
}
// ****************************************************************
void InformationDispersal::IsolatedInitialize(const NameValuePairs &parameters)
{
m_nextChannel = 0;
m_pad = parameters.GetValueWithDefault("AddPadding", true);
m_ida.IsolatedInitialize(parameters);
}
size_t InformationDispersal::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
if (!blocking)
throw BlockingInputOnly("InformationDispersal");
while (length--)
{
m_ida.ChannelData(m_nextChannel, begin, 1, false);
begin++;
m_nextChannel++;
if (m_nextChannel == m_ida.GetThreshold())
m_nextChannel = 0;
}
if (messageEnd)
{
m_ida.SetAutoSignalPropagation(messageEnd-1);
if (m_pad)
InformationDispersal::Put(1);
for (word32 i=0; i<m_ida.GetThreshold(); i++)
m_ida.ChannelData(i, NULL, 0, true);
}
return 0;
}
void InformationRecovery::IsolatedInitialize(const NameValuePairs &parameters)
{
m_pad = parameters.GetValueWithDefault("RemovePadding", true);
RawIDA::IsolatedInitialize(parameters);
}
void InformationRecovery::FlushOutputQueues()
{
while (m_outputQueues[0].AnyRetrievable())
{
for (unsigned int i=0; i<m_outputChannelIds.size(); i++)
m_outputQueues[i].TransferTo(m_queue, 1);
}
if (m_pad)
m_queue.TransferTo(*AttachedTransformation(), m_queue.MaxRetrievable()-4*m_threshold);
else
m_queue.TransferTo(*AttachedTransformation());
}
void InformationRecovery::OutputMessageEnds()
{
if (m_pad)
{
PaddingRemover paddingRemover(new Redirector(*AttachedTransformation()));
m_queue.TransferAllTo(paddingRemover);
}
if (GetAutoSignalPropagation() != 0)
AttachedTransformation()->MessageEnd(GetAutoSignalPropagation()-1);
}
size_t PaddingRemover::Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
{
if (!blocking)
throw BlockingInputOnly("PaddingRemover");
const byte *const end = begin + length;
if (m_possiblePadding)
{
size_t len = find_if(begin, end, bind2nd(not_equal_to<byte>(), 0)) - begin;
m_zeroCount += len;
begin += len;
if (begin == end)
return 0;
AttachedTransformation()->Put(1);
while (m_zeroCount--)
AttachedTransformation()->Put(0);
AttachedTransformation()->Put(*begin++);
m_possiblePadding = false;
}
#if defined(_MSC_VER) && !defined(__MWERKS__) && (_MSC_VER <= 1300)
// VC60 and VC7 workaround: built-in reverse_iterator has two template parameters, Dinkumware only has one
typedef reverse_bidirectional_iterator<const byte *, const byte> RevIt;
#elif defined(_RWSTD_NO_CLASS_PARTIAL_SPEC)
typedef reverse_iterator<const byte *, random_access_iterator_tag, const byte> RevIt;
#else
typedef reverse_iterator<const byte *> RevIt;
#endif
const byte *x = find_if(RevIt(end), RevIt(begin), bind2nd(not_equal_to<byte>(), 0)).base();
if (x != begin && *(x-1) == 1)
{
AttachedTransformation()->Put(begin, x-begin-1);
m_possiblePadding = true;
m_zeroCount = end - x;
}
else
AttachedTransformation()->Put(begin, end-begin);
if (messageEnd)
{
m_possiblePadding = false;
Output(0, begin, length, messageEnd, blocking);
}
return 0;
}
NAMESPACE_END