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63 lines
1.4 KiB
63 lines
1.4 KiB
// randpool.cpp - written and placed in the public domain by Wei Dai |
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// RandomPool used to follow the design of randpool in PGP 2.6.x, |
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// but as of version 5.5 it has been redesigned to reduce the risk |
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// of reusing random numbers after state rollback (which may occur |
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// when running in a virtual machine like VMware). |
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#include "pch.h" |
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#ifndef CRYPTOPP_IMPORTS |
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#include "randpool.h" |
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#include "aes.h" |
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#include "sha.h" |
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#include "hrtimer.h" |
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#include <time.h> |
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NAMESPACE_BEGIN(CryptoPP) |
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RandomPool::RandomPool() |
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: m_pCipher(new AES::Encryption), m_keySet(false) |
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{ |
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memset(m_key, 0, m_key.SizeInBytes()); |
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memset(m_seed, 0, m_seed.SizeInBytes()); |
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} |
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void RandomPool::IncorporateEntropy(const byte *input, size_t length) |
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{ |
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SHA256 hash; |
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hash.Update(m_key, 32); |
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hash.Update(input, length); |
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hash.Final(m_key); |
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m_keySet = false; |
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} |
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void RandomPool::GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size) |
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{ |
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if (size > 0) |
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{ |
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if (!m_keySet) |
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m_pCipher->SetKey(m_key, 32); |
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Timer timer; |
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TimerWord tw = timer.GetCurrentTimerValue(); |
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CRYPTOPP_COMPILE_ASSERT(sizeof(tw) <= 16); |
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*(TimerWord *)m_seed.data() += tw; |
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time_t t = time(NULL); |
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CRYPTOPP_COMPILE_ASSERT(sizeof(t) <= 8); |
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*(time_t *)(m_seed.data()+8) += t; |
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do |
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{ |
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m_pCipher->ProcessBlock(m_seed); |
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size_t len = UnsignedMin(16, size); |
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target.ChannelPut(channel, m_seed, len); |
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size -= len; |
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} while (size > 0); |
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} |
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} |
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NAMESPACE_END |
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#endif
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