rlm@1: // RandGen.cpp
rlm@1: 
rlm@1: #include "StdAfx.h"
rlm@1: 
rlm@1: #include <stdio.h>
rlm@1: #include "Windows/Synchronization.h"
rlm@1: #include "RandGen.h"
rlm@1: 
rlm@1: #ifndef _WIN32
rlm@1: #include <unistd.h>
rlm@1: #define USE_POSIX_TIME
rlm@1: #define USE_POSIX_TIME2
rlm@1: #endif
rlm@1: 
rlm@1: #ifdef USE_POSIX_TIME
rlm@1: #include <time.h>
rlm@1: #ifdef USE_POSIX_TIME2
rlm@1: #include <sys/time.h>
rlm@1: #endif
rlm@1: #endif
rlm@1: 
rlm@1: // This is not very good random number generator.
rlm@1: // Please use it only for salt.
rlm@1: // First generated data block depends from timer and processID.
rlm@1: // Other generated data blocks depend from previous state
rlm@1: // Maybe it's possible to restore original timer value from generated value.
rlm@1: 
rlm@1: void CRandomGenerator::Init()
rlm@1: {
rlm@1:   NCrypto::NSha1::CContext hash;
rlm@1:   hash.Init();
rlm@1: 
rlm@1:   #ifdef _WIN32
rlm@1:   DWORD w = ::GetCurrentProcessId();
rlm@1:   hash.Update((const Byte *)&w, sizeof(w));
rlm@1:   w = ::GetCurrentThreadId();
rlm@1:   hash.Update((const Byte *)&w, sizeof(w));
rlm@1:   #else
rlm@1:   pid_t pid = getpid();
rlm@1:   hash.Update((const Byte *)&pid, sizeof(pid));
rlm@1:   pid = getppid();
rlm@1:   hash.Update((const Byte *)&pid, sizeof(pid));
rlm@1:   #endif
rlm@1: 
rlm@1:   for (int i = 0; i < 1000; i++)
rlm@1:   {
rlm@1:     #ifdef _WIN32
rlm@1:     LARGE_INTEGER v;
rlm@1:     if (::QueryPerformanceCounter(&v))
rlm@1:       hash.Update((const Byte *)&v.QuadPart, sizeof(v.QuadPart));
rlm@1:     #endif
rlm@1: 
rlm@1:     #ifdef USE_POSIX_TIME
rlm@1:     #ifdef USE_POSIX_TIME2
rlm@1:     timeval v;
rlm@1:     if (gettimeofday(&v, 0) == 0)
rlm@1:     {
rlm@1:       hash.Update((const Byte *)&v.tv_sec, sizeof(v.tv_sec));
rlm@1:       hash.Update((const Byte *)&v.tv_usec, sizeof(v.tv_usec));
rlm@1:     }
rlm@1:     #endif
rlm@1:     time_t v2 = time(NULL);
rlm@1:     hash.Update((const Byte *)&v2, sizeof(v2));
rlm@1:     #endif
rlm@1: 
rlm@1:     DWORD tickCount = ::GetTickCount();
rlm@1:     hash.Update((const Byte *)&tickCount, sizeof(tickCount));
rlm@1:     
rlm@1:     for (int j = 0; j < 100; j++)
rlm@1:     {
rlm@1:       hash.Final(_buff);
rlm@1:       hash.Init();
rlm@1:       hash.Update(_buff, NCrypto::NSha1::kDigestSize);
rlm@1:     }
rlm@1:   }
rlm@1:   hash.Final(_buff);
rlm@1:   _needInit = false;
rlm@1: }
rlm@1: 
rlm@1: static NWindows::NSynchronization::CCriticalSection g_CriticalSection;
rlm@1: 
rlm@1: void CRandomGenerator::Generate(Byte *data, unsigned int size)
rlm@1: {
rlm@1:   g_CriticalSection.Enter();
rlm@1:   if (_needInit)
rlm@1:     Init();
rlm@1:   while (size > 0)
rlm@1:   {
rlm@1:     NCrypto::NSha1::CContext hash;
rlm@1:     
rlm@1:     hash.Init();
rlm@1:     hash.Update(_buff, NCrypto::NSha1::kDigestSize);
rlm@1:     hash.Final(_buff);
rlm@1:     
rlm@1:     hash.Init();
rlm@1:     UInt32 salt = 0xF672ABD1;
rlm@1:     hash.Update((const Byte *)&salt, sizeof(salt));
rlm@1:     hash.Update(_buff, NCrypto::NSha1::kDigestSize);
rlm@1:     Byte buff[NCrypto::NSha1::kDigestSize];
rlm@1:     hash.Final(buff);
rlm@1:     for (unsigned int i = 0; i < NCrypto::NSha1::kDigestSize && size > 0; i++, size--)
rlm@1:       *data++ = buff[i];
rlm@1:   }
rlm@1:   g_CriticalSection.Leave();
rlm@1: }
rlm@1: 
rlm@1: CRandomGenerator g_RandomGenerator;