Botan::Win32_EntropySource Class Reference

#include <es_win32.h>

Inheritance diagram for Botan::Win32_EntropySource:

Public Member Functions
std::string	name () const override
size_t	poll (RandomNumberGenerator &rng) override

Static Public Member Functions
static std::unique_ptr< Entropy_Source >	create (std::string_view type)

Detailed Description

Win32 Entropy Source

Definition at line 18 of file es_win32.h.

Member Function Documentation

create()

std::unique_ptr< Entropy_Source > Botan::Entropy_Source::create ( std::string_view type )

staticinherited

Return a new entropy source of a particular type, or null Each entropy source may require substantial resources (eg, a file handle or socket instance), so try to share them among multiple RNGs, or just use the preconfigured global list accessed by Entropy_Sources::global_sources()

Definition at line 110 of file entropy_srcs.cpp.

                                                                        {
#if defined(BOTAN_HAS_SYSTEM_RNG)
   if(name == "system_rng") {
      return std::make_unique<System_RNG_EntropySource>();
   }
#endif
 
#if defined(BOTAN_HAS_PROCESSOR_RNG)
   if(name == "hwrng") {
      if(Processor_RNG::available()) {
         return std::make_unique<Processor_RNG_EntropySource>();
      }
   }
#endif
 
#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
   if(name == "rdseed") {
      return std::make_unique<Intel_Rdseed>();
   }
#endif
 
#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
   if(name == "getentropy") {
      return std::make_unique<Getentropy>();
   }
#endif
 
#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
   if(name == "system_stats") {
      return std::make_unique<Win32_EntropySource>();
   }
#endif
 
#if defined(BOTAN_HAS_JITTER_RNG)
   if(name == "jitter_rng") {
      return std::make_unique<Jitter_RNG_EntropySource>();
   }
#endif
 
   BOTAN_UNUSED(name);
   return nullptr;
}

References Botan::Processor_RNG::available(), BOTAN_UNUSED, and Botan::Entropy_Source::name().

Referenced by Botan::Entropy_Sources::Entropy_Sources().

name()

std::string Botan::Win32_EntropySource::name ( ) const

inlineoverridevirtual

Returns

name identifying this entropy source

Implements Botan::Entropy_Source.

Definition at line 20 of file es_win32.h.

{ return "system_stats"; }

poll()

size_t Botan::Win32_EntropySource::poll ( RandomNumberGenerator & rng )

overridevirtual

Perform an entropy gathering poll

Parameters

rng	will be provided with entropy via calls to add_entropy

Returns

conservative estimate of actual entropy added to rng during poll

Implements Botan::Entropy_Source.

Definition at line 15 of file es_win32.cpp.

                                                           {
   rng.add_entropy_T(::GetTickCount());
   rng.add_entropy_T(::GetMessagePos());
   rng.add_entropy_T(::GetMessageTime());
   rng.add_entropy_T(::GetInputState());
 
   rng.add_entropy_T(::GetCurrentProcessId());
   rng.add_entropy_T(::GetCurrentThreadId());
 
   SYSTEM_INFO sys_info;
   ::GetSystemInfo(&sys_info);
   rng.add_entropy_T(sys_info);
 
   MEMORYSTATUSEX mem_info;
   ::GlobalMemoryStatusEx(&mem_info);
   rng.add_entropy_T(mem_info);
 
   POINT point;
   ::GetCursorPos(&point);
   rng.add_entropy_T(point);
 
   ::GetCaretPos(&point);
   rng.add_entropy_T(point);
 
   /*
   Potential other sources to investigate
 
   GetProductInfo
   GetComputerNameExA
   GetSystemFirmwareTable
   GetVersionExA
   GetProcessorSystemCycleTime
   GetProcessHandleCount(GetCurrentProcess())
   GetThreadTimes(GetCurrentThread())
   QueryThreadCycleTime
   QueryIdleProcessorCycleTime
   QueryUnbiasedInterruptTime
   */
 
   // We assume all of the above is basically junk
   return 0;
}

References Botan::RandomNumberGenerator::add_entropy_T().

---

The documentation for this class was generated from the following files:

• src/lib/entropy/win32_stats/es_win32.h
• src/lib/entropy/win32_stats/es_win32.cpp