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

#include <entropy_src.h>

Inheritance diagram for Botan::Entropy_Source:
Botan::Device_EntropySource Botan::Getentropy Botan::Intel_Rdrand Botan::Intel_Rdseed Botan::ProcWalking_EntropySource Botan::Win32_EntropySource

Public Member Functions

 Entropy_Source ()=default
 
 Entropy_Source (const Entropy_Source &other)=delete
 
 Entropy_Source (Entropy_Source &&other)=delete
 
virtual std::string name () const =0
 
Entropy_Sourceoperator= (const Entropy_Source &other)=delete
 
virtual size_t poll (RandomNumberGenerator &rng)=0
 
virtual ~Entropy_Source ()=default
 

Static Public Member Functions

static std::unique_ptr< Entropy_Sourcecreate (const std::string &type)
 

Detailed Description

Abstract interface to a source of entropy

Definition at line 25 of file entropy_src.h.

Constructor & Destructor Documentation

◆ Entropy_Source() [1/3]

Botan::Entropy_Source::Entropy_Source ( )
default

◆ Entropy_Source() [2/3]

Botan::Entropy_Source::Entropy_Source ( const Entropy_Source other)
delete

◆ Entropy_Source() [3/3]

Botan::Entropy_Source::Entropy_Source ( Entropy_Source &&  other)
delete

◆ ~Entropy_Source()

virtual Botan::Entropy_Source::~Entropy_Source ( )
virtualdefault

Member Function Documentation

◆ create()

std::unique_ptr< Entropy_Source > Botan::Entropy_Source::create ( const std::string &  type)
static

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, 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()

virtual std::string Botan::Entropy_Source::name ( ) const
pure virtual

◆ operator=()

Entropy_Source& Botan::Entropy_Source::operator= ( const Entropy_Source other)
delete

◆ poll()

virtual size_t Botan::Entropy_Source::poll ( RandomNumberGenerator rng)
pure virtual

Perform an entropy gathering poll

Parameters
rngwill be provided with entropy via calls to add_entropy
Returns
conservative estimate of actual entropy added to rng during poll

Implemented in Botan::ProcWalking_EntropySource, Botan::Device_EntropySource, Botan::Getentropy, Botan::Intel_Rdrand, Botan::Intel_Rdseed, and Botan::Win32_EntropySource.


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