You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
74 lines
1.8 KiB
74 lines
1.8 KiB
// randpool.cpp - written and placed in the public domain by Wei Dai |
|
// RandomPool used to follow the design of randpool in PGP 2.6.x, |
|
// but as of version 5.5 it has been redesigned to reduce the risk |
|
// of reusing random numbers after state rollback (which may occur |
|
// when running in a virtual machine like VMware). |
|
|
|
#include "pch.h" |
|
|
|
#ifndef CRYPTOPP_IMPORTS |
|
|
|
#include "randpool.h" |
|
#include "aes.h" |
|
#include "sha.h" |
|
#include "hrtimer.h" |
|
#include <time.h> |
|
|
|
NAMESPACE_BEGIN(CryptoPP) |
|
|
|
RandomPool::RandomPool() |
|
: m_pCipher(new AES::Encryption), m_keySet(false) |
|
{ |
|
memset(m_key, 0, m_key.SizeInBytes()); |
|
memset(m_seed, 0, m_seed.SizeInBytes()); |
|
} |
|
|
|
void RandomPool::IncorporateEntropy(const byte *input, size_t length) |
|
{ |
|
SHA256 hash; |
|
hash.Update(m_key, 32); |
|
hash.Update(input, length); |
|
hash.Final(m_key); |
|
m_keySet = false; |
|
} |
|
|
|
void RandomPool::GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size) |
|
{ |
|
if (size > 0) |
|
{ |
|
if (!m_keySet) |
|
m_pCipher->SetKey(m_key, 32); |
|
|
|
Timer timer; |
|
TimerWord tw = timer.GetCurrentTimerValue(); |
|
CRYPTOPP_COMPILE_ASSERT(sizeof(tw) <= 16); |
|
*(TimerWord *)m_seed.data() += tw; |
|
|
|
time_t t = time(NULL); |
|
CRYPTOPP_COMPILE_ASSERT(sizeof(t) <= 8); |
|
|
|
// UBsan finding: signed integer overflow: 1876017710 + 1446085457 cannot be represented in type 'long int' |
|
// *(time_t *)(m_seed.data()+8) += t; |
|
assert(m_seed.size() >= 16); |
|
word64 tt1, tt2 = (word64)t; |
|
memcpy(&tt1, m_seed.data()+8, 8); |
|
memcpy(m_seed.data()+8, &(tt2 += tt1), 8); |
|
|
|
// Wipe the intermediates |
|
*((volatile TimerWord*)&tw) = 0; |
|
*((volatile word64*)&tt1) = 0; |
|
*((volatile word64*)&tt2) = 0; |
|
|
|
do |
|
{ |
|
m_pCipher->ProcessBlock(m_seed); |
|
size_t len = UnsignedMin(16, size); |
|
target.ChannelPut(channel, m_seed, len); |
|
size -= len; |
|
} while (size > 0); |
|
} |
|
} |
|
|
|
NAMESPACE_END |
|
|
|
#endif
|
|
|