diff options
author | Igor Pavlov <ipavlov@users.sourceforge.net> | 2007-01-20 03:00:00 +0300 |
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committer | Kornel LesiĆski <kornel@geekhood.net> | 2016-05-28 02:15:49 +0300 |
commit | d9666cf046a8453b33b3e2fbf4d82295a9f87df3 (patch) | |
tree | c722ed19b844b53042aec0c1d7d2f8381140a5ed /CPP/7zip/Crypto/Hash/RandGen.cpp | |
parent | 804edc5756fede54dbb1aefda6d39d306111938d (diff) |
4.44 beta
Diffstat (limited to 'CPP/7zip/Crypto/Hash/RandGen.cpp')
-rwxr-xr-x | CPP/7zip/Crypto/Hash/RandGen.cpp | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/CPP/7zip/Crypto/Hash/RandGen.cpp b/CPP/7zip/Crypto/Hash/RandGen.cpp new file mode 100755 index 00000000..480e04ca --- /dev/null +++ b/CPP/7zip/Crypto/Hash/RandGen.cpp @@ -0,0 +1,78 @@ +// RandGen.cpp + +#include "StdAfx.h" + +#include <stdio.h> + +#include "Windows/Synchronization.h" + +#include "RandGen.h" + +// This is not very good random number generator. +// Please use it only for salt. +// First genrated data block depends from timer. +// Other genrated data blocks depend from previous state +// Maybe it's possible to restore original timer vaue from generated value. + +void CRandomGenerator::Init() +{ + NCrypto::NSha1::CContext hash; + hash.Init(); + + #ifdef _WIN32 + DWORD w = ::GetCurrentProcessId(); + hash.Update((const Byte *)&w, sizeof(w)); + w = ::GetCurrentThreadId(); + hash.Update((const Byte *)&w, sizeof(w)); + #endif + + for (int i = 0; i < 1000; i++) + { + #ifdef _WIN32 + LARGE_INTEGER v; + if (::QueryPerformanceCounter(&v)) + hash.Update((const Byte *)&v.QuadPart, sizeof(v.QuadPart)); + #endif + + DWORD tickCount = ::GetTickCount(); + hash.Update((const Byte *)&tickCount, sizeof(tickCount)); + + for (int j = 0; j < 100; j++) + { + hash.Final(_buff); + hash.Init(); + hash.Update(_buff, NCrypto::NSha1::kDigestSize); + } + } + hash.Final(_buff); + _needInit = false; +} + +static NWindows::NSynchronization::CCriticalSection g_CriticalSection; + +void CRandomGenerator::Generate(Byte *data, unsigned int size) +{ + g_CriticalSection.Enter(); + if (_needInit) + Init(); + while (size > 0) + { + NCrypto::NSha1::CContext hash; + + hash.Init(); + hash.Update(_buff, NCrypto::NSha1::kDigestSize); + hash.Final(_buff); + + hash.Init(); + UInt32 salt = 0xF672ABD1; + hash.Update((const Byte *)&salt, sizeof(salt)); + hash.Update(_buff, NCrypto::NSha1::kDigestSize); + Byte buff[NCrypto::NSha1::kDigestSize]; + hash.Final(buff); + for (unsigned int i = 0; i < NCrypto::NSha1::kDigestSize && size > 0; i++, size--) + *data++ = buff[i]; + } + g_CriticalSection.Leave(); +} + +CRandomGenerator g_RandomGenerator; |