Botan 3.8.1
Crypto and TLS for C&
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 (std::string_view 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 ( 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 111 of file entropy_srcs.cpp.

111 {
112#if defined(BOTAN_HAS_SYSTEM_RNG)
113 if(name == "system_rng") {
114 return std::make_unique<System_RNG_EntropySource>();
115 }
116#endif
117
118#if defined(BOTAN_HAS_PROCESSOR_RNG)
119 if(name == "hwrng") {
121 return std::make_unique<Processor_RNG_EntropySource>();
122 }
123 }
124#endif
125
126#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
127 if(name == "rdseed") {
128 return std::make_unique<Intel_Rdseed>();
129 }
130#endif
131
132#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
133 if(name == "getentropy") {
134 return std::make_unique<Getentropy>();
135 }
136#endif
137
138#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
139 if(name == "system_stats") {
140 return std::make_unique<Win32_EntropySource>();
141 }
142#endif
143
144#if defined(BOTAN_HAS_JITTER_RNG)
145 if(name == "jitter_rng") {
146 return std::make_unique<Jitter_RNG_EntropySource>();
147 }
148#endif
149
151 return nullptr;
152}
#define BOTAN_UNUSED
Definition assert.h:120
virtual std::string name() const =0

References Botan::Processor_RNG::available(), BOTAN_UNUSED, and 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 21 of file getentropy.h.

21{ 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 25 of file getentropy.cpp.

25 {
27
28 if(::getentropy(buf.data(), buf.size()) == 0) {
29 rng.add_entropy(buf.data(), buf.size());
30 return buf.size() * 8;
31 }
32
33 return 0;
34}
std::vector< T, secure_allocator< T > > secure_vector
Definition secmem.h:65

References Botan::RandomNumberGenerator::add_entropy().


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