Botan  2.8.0
Crypto and TLS for C++11
Public Member Functions | Static Public Member Functions | List of all members
Botan::Win32_EntropySource Class Referencefinal

#include <es_win32.h>

Inheritance diagram for Botan::Win32_EntropySource:
Botan::Entropy_Source

Public Member Functions

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

Static Public Member Functions

static std::unique_ptr< Entropy_Sourcecreate (const std::string &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 ( const std::string &  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 63 of file entropy_srcs.cpp.

References BOTAN_UNUSED, Botan::Entropy_Source::name(), and Botan::OS::running_in_privileged_state().

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

64  {
65 #if defined(BOTAN_HAS_SYSTEM_RNG)
66  if(name == "system_rng" || name == "win32_cryptoapi")
67  {
68  return std::unique_ptr<Entropy_Source>(new System_RNG_EntropySource);
69  }
70 #endif
71 
72 #if defined(BOTAN_HAS_ENTROPY_SRC_RDRAND)
73  if(name == "rdrand")
74  {
75  return std::unique_ptr<Entropy_Source>(new Intel_Rdrand);
76  }
77 #endif
78 
79 #if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
80  if(name == "rdseed")
81  {
82  return std::unique_ptr<Entropy_Source>(new Intel_Rdseed);
83  }
84 #endif
85 
86 #if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
87  if(name == "getentropy")
88  {
89  return std::unique_ptr<Entropy_Source>(new Getentropy);
90  }
91 #endif
92 
93 #if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM)
94  if(name == "dev_random")
95  {
96  return std::unique_ptr<Entropy_Source>(new Device_EntropySource(BOTAN_SYSTEM_RNG_POLL_DEVICES));
97  }
98 #endif
99 
100 #if defined(BOTAN_HAS_ENTROPY_SRC_PROC_WALKER)
101  if(name == "proc_walk" && OS::running_in_privileged_state() == false)
102  {
103  const std::string root_dir = BOTAN_ENTROPY_PROC_FS_PATH;
104  if(!root_dir.empty())
105  return std::unique_ptr<Entropy_Source>(new ProcWalking_EntropySource(root_dir));
106  }
107 #endif
108 
109 #if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
110  if(name == "system_stats")
111  {
112  return std::unique_ptr<Entropy_Source>(new Win32_EntropySource);
113  }
114 #endif
115 
117  return std::unique_ptr<Entropy_Source>();
118  }
virtual std::string name() const =0
bool running_in_privileged_state()
Definition: os_utils.cpp:83
#define BOTAN_UNUSED(...)
Definition: assert.h:142

◆ name()

std::string Botan::Win32_EntropySource::name ( ) const
inlineoverridevirtual
Returns
name identifying this entropy source

Implements Botan::Entropy_Source.

Definition at line 21 of file es_win32.h.

21 { return "system_stats"; }

◆ poll()

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

Win32 poll using stats functions including Tooltip32

Implements Botan::Entropy_Source.

Definition at line 20 of file es_win32.cpp.

References Botan::RandomNumberGenerator::add_entropy_T(), and TOOLHELP32_ITER.

21  {
22  const size_t POLL_TARGET = 128;
23  const size_t EST_ENTROPY_HEAP_INFO = 4;
24  const size_t EST_ENTROPY_THREAD_INFO = 2;
25 
26  /*
27  First query a bunch of basic statistical stuff
28  */
29  rng.add_entropy_T(::GetTickCount());
30  rng.add_entropy_T(::GetMessagePos());
31  rng.add_entropy_T(::GetMessageTime());
32  rng.add_entropy_T(::GetInputState());
33 
34  rng.add_entropy_T(::GetCurrentProcessId());
35  rng.add_entropy_T(::GetCurrentThreadId());
36 
37  SYSTEM_INFO sys_info;
38  ::GetSystemInfo(&sys_info);
39  rng.add_entropy_T(sys_info);
40 
41  MEMORYSTATUSEX mem_info;
42  ::GlobalMemoryStatusEx(&mem_info);
43  rng.add_entropy_T(mem_info);
44 
45  POINT point;
46  ::GetCursorPos(&point);
47  rng.add_entropy_T(point);
48 
49  ::GetCaretPos(&point);
50  rng.add_entropy_T(point);
51 
52  /*
53  Now use the Tooltip library to iterate through various objects on
54  the system, including processes, threads, and heap objects.
55  */
56 
57  HANDLE snapshot = ::CreateToolhelp32Snapshot(TH32CS_SNAPALL, 0);
58  size_t collected = 0;
59 
60 #define TOOLHELP32_ITER(DATA_TYPE, FUNC_FIRST, FUNC_NEXT) \
61  if(collected < POLL_TARGET) \
62  { \
63  DATA_TYPE info; \
64  info.dwSize = sizeof(DATA_TYPE); \
65  if(FUNC_FIRST(snapshot, &info)) \
66  { \
67  do \
68  { \
69  rng.add_entropy_T(info); \
70  collected += EST_ENTROPY_THREAD_INFO; \
71  if(collected >= POLL_TARGET) \
72  break; \
73  } while(FUNC_NEXT(snapshot, &info)); \
74  } \
75  }
76 
77  TOOLHELP32_ITER(MODULEENTRY32, ::Module32First, ::Module32Next);
78  TOOLHELP32_ITER(PROCESSENTRY32, ::Process32First, ::Process32Next);
79  TOOLHELP32_ITER(THREADENTRY32, ::Thread32First, ::Thread32Next);
80 
81 #undef TOOLHELP32_ITER
82 
83  if(collected < POLL_TARGET)
84  {
85  HEAPLIST32 heap_list;
86  heap_list.dwSize = sizeof(HEAPLIST32);
87 
88  if(::Heap32ListFirst(snapshot, &heap_list))
89  {
90  do
91  {
92  rng.add_entropy_T(heap_list);
93 
94  HEAPENTRY32 heap_entry;
95  heap_entry.dwSize = sizeof(HEAPENTRY32);
96  if(::Heap32First(&heap_entry,
97  heap_list.th32ProcessID,
98  heap_list.th32HeapID))
99  {
100  do
101  {
102  rng.add_entropy_T(heap_entry);
103  collected += EST_ENTROPY_HEAP_INFO;
104  if(collected >= POLL_TARGET)
105  break;
106  } while(::Heap32Next(&heap_entry));
107  }
108 
109  if(collected >= POLL_TARGET)
110  break;
111 
112  } while(::Heap32ListNext(snapshot, &heap_list));
113  }
114  }
115 
116  ::CloseHandle(snapshot);
117 
118  return collected;
119  }
#define TOOLHELP32_ITER(DATA_TYPE, FUNC_FIRST, FUNC_NEXT)

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