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author | Alexander Harkness <bearbin@gmail.com> | 2013-11-24 15:21:13 +0100 |
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committer | Alexander Harkness <bearbin@gmail.com> | 2013-11-24 15:21:13 +0100 |
commit | 3438e5d3ddf8444f0e31009ffbe8237ef3752c22 (patch) | |
tree | 7c2f76d5e9281c130e60fb932c4dda89a49863b6 /CryptoPP/eprecomp.cpp | |
parent | Moved source to src (diff) | |
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Diffstat (limited to 'CryptoPP/eprecomp.cpp')
-rw-r--r-- | CryptoPP/eprecomp.cpp | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/CryptoPP/eprecomp.cpp b/CryptoPP/eprecomp.cpp deleted file mode 100644 index a061cf6cd..000000000 --- a/CryptoPP/eprecomp.cpp +++ /dev/null @@ -1,112 +0,0 @@ -// eprecomp.cpp - written and placed in the public domain by Wei Dai - -#include "pch.h" - -#ifndef CRYPTOPP_IMPORTS - -#include "eprecomp.h" -#include "asn.h" - -NAMESPACE_BEGIN(CryptoPP) - -template <class T> void DL_FixedBasePrecomputationImpl<T>::SetBase(const DL_GroupPrecomputation<Element> &group, const Element &i_base) -{ - m_base = group.NeedConversions() ? group.ConvertIn(i_base) : i_base; - - if (m_bases.empty() || !(m_base == m_bases[0])) - { - m_bases.resize(1); - m_bases[0] = m_base; - } - - if (group.NeedConversions()) - m_base = i_base; -} - -template <class T> void DL_FixedBasePrecomputationImpl<T>::Precompute(const DL_GroupPrecomputation<Element> &group, unsigned int maxExpBits, unsigned int storage) -{ - assert(m_bases.size() > 0); - assert(storage <= maxExpBits); - - if (storage > 1) - { - m_windowSize = (maxExpBits+storage-1)/storage; - m_exponentBase = Integer::Power2(m_windowSize); - } - - m_bases.resize(storage); - for (unsigned i=1; i<storage; i++) - m_bases[i] = group.GetGroup().ScalarMultiply(m_bases[i-1], m_exponentBase); -} - -template <class T> void DL_FixedBasePrecomputationImpl<T>::Load(const DL_GroupPrecomputation<Element> &group, BufferedTransformation &bt) -{ - BERSequenceDecoder seq(bt); - word32 version; - BERDecodeUnsigned<word32>(seq, version, INTEGER, 1, 1); - m_exponentBase.BERDecode(seq); - m_windowSize = m_exponentBase.BitCount() - 1; - m_bases.clear(); - while (!seq.EndReached()) - m_bases.push_back(group.BERDecodeElement(seq)); - if (!m_bases.empty() && group.NeedConversions()) - m_base = group.ConvertOut(m_bases[0]); - seq.MessageEnd(); -} - -template <class T> void DL_FixedBasePrecomputationImpl<T>::Save(const DL_GroupPrecomputation<Element> &group, BufferedTransformation &bt) const -{ - DERSequenceEncoder seq(bt); - DEREncodeUnsigned<word32>(seq, 1); // version - m_exponentBase.DEREncode(seq); - for (unsigned i=0; i<m_bases.size(); i++) - group.DEREncodeElement(seq, m_bases[i]); - seq.MessageEnd(); -} - -template <class T> void DL_FixedBasePrecomputationImpl<T>::PrepareCascade(const DL_GroupPrecomputation<Element> &i_group, std::vector<BaseAndExponent<Element> > &eb, const Integer &exponent) const -{ - const AbstractGroup<T> &group = i_group.GetGroup(); - - Integer r, q, e = exponent; - bool fastNegate = group.InversionIsFast() && m_windowSize > 1; - unsigned int i; - - for (i=0; i+1<m_bases.size(); i++) - { - Integer::DivideByPowerOf2(r, q, e, m_windowSize); - std::swap(q, e); - if (fastNegate && r.GetBit(m_windowSize-1)) - { - ++e; - eb.push_back(BaseAndExponent<Element>(group.Inverse(m_bases[i]), m_exponentBase - r)); - } - else - eb.push_back(BaseAndExponent<Element>(m_bases[i], r)); - } - eb.push_back(BaseAndExponent<Element>(m_bases[i], e)); -} - -template <class T> T DL_FixedBasePrecomputationImpl<T>::Exponentiate(const DL_GroupPrecomputation<Element> &group, const Integer &exponent) const -{ - std::vector<BaseAndExponent<Element> > eb; // array of segments of the exponent and precalculated bases - eb.reserve(m_bases.size()); - PrepareCascade(group, eb, exponent); - return group.ConvertOut(GeneralCascadeMultiplication<Element>(group.GetGroup(), eb.begin(), eb.end())); -} - -template <class T> T - DL_FixedBasePrecomputationImpl<T>::CascadeExponentiate(const DL_GroupPrecomputation<Element> &group, const Integer &exponent, - const DL_FixedBasePrecomputation<T> &i_pc2, const Integer &exponent2) const -{ - std::vector<BaseAndExponent<Element> > eb; // array of segments of the exponent and precalculated bases - const DL_FixedBasePrecomputationImpl<T> &pc2 = static_cast<const DL_FixedBasePrecomputationImpl<T> &>(i_pc2); - eb.reserve(m_bases.size() + pc2.m_bases.size()); - PrepareCascade(group, eb, exponent); - pc2.PrepareCascade(group, eb, exponent2); - return group.ConvertOut(GeneralCascadeMultiplication<Element>(group.GetGroup(), eb.begin(), eb.end())); -} - -NAMESPACE_END - -#endif |