Botan 3.0.0-alpha0
Crypto and TLS for C&
Public Member Functions | Static Public Member Functions | List of all members
Botan::Getentropy Class Referencefinal

#include <getentropy.h>

Inheritance diagram for Botan::Getentropy:
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

Entropy source using the getentropy(2) system call first introduced in OpenBSD 5.6 and added to Solaris 11.3.

Definition at line 19 of file getentropy.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 90 of file entropy_srcs.cpp.

91 {
92#if defined(BOTAN_HAS_SYSTEM_RNG)
93 if(name == "system_rng")
94 {
95 return std::make_unique<System_RNG_EntropySource>();
96 }
97#endif
98
99#if defined(BOTAN_HAS_PROCESSOR_RNG)
100 if(name == "hwrng")
101 {
103 {
104 return std::make_unique<Processor_RNG_EntropySource>();
105 }
106 }
107#endif
108
109#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
110 if(name == "rdseed")
111 {
112 return std::make_unique<Intel_Rdseed>();
113 }
114#endif
115
116#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
117 if(name == "getentropy")
118 {
119 return std::make_unique<Getentropy>();
120 }
121#endif
122
123#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
124 if(name == "system_stats")
125 {
126 return std::make_unique<Win32_EntropySource>();
127 }
128#endif
129
131 return nullptr;
132 }
#define BOTAN_UNUSED(...)
Definition: assert.h:141
virtual std::string name() const =0
static bool available()

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

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

◆ name()

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

Implements Botan::Entropy_Source.

Definition at line 22 of file getentropy.h.

22{ return "getentropy"; }

◆ poll()

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

Gather 256 bytes entropy from getentropy(2). Note that maximum buffer size is limited to 256 bytes. On OpenBSD this does neither block nor fail.

Implements Botan::Entropy_Source.

Definition at line 24 of file getentropy.cpp.

25 {
26 secure_vector<uint8_t> buf(256);
27
28 if(::getentropy(buf.data(), buf.size()) == 0)
29 {
30 rng.add_entropy(buf.data(), buf.size());
31 return buf.size() * 8;
32 }
33
34 return 0;
35 }

References Botan::RandomNumberGenerator::add_entropy().


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