Botan::Entropy_Sources Class Reference

#include <entropy_src.h>

Public Member Functions
void	add_source (std::unique_ptr< Entropy_Source > src)
std::vector< std::string >	enabled_sources () const
	Entropy_Sources ()=default
	Entropy_Sources (const Entropy_Sources &other)=delete
	Entropy_Sources (const std::vector< std::string > &sources)
	Entropy_Sources (Entropy_Sources &&other)=delete
Entropy_Sources &	operator= (const Entropy_Sources &other)=delete
size_t	poll (RandomNumberGenerator &rng, size_t bits, std::chrono::milliseconds timeout)
size_t	poll_just (RandomNumberGenerator &rng, std::string_view src)

Static Public Member Functions
static Entropy_Sources &	global_sources ()

Detailed Description

Definition at line 55 of file entropy_src.h.

Constructor & Destructor Documentation

Entropy_Sources() [1/4]

Botan::Entropy_Sources::Entropy_Sources ( )

default

Entropy_Sources() [2/4]

Botan::Entropy_Sources::Entropy_Sources ( const std::vector< std::string > & sources )

explicit

Definition at line 199 of file entropy_srcs.cpp.

                                                                    {
   for(auto&& src_name : sources) {
      add_source(Entropy_Source::create(src_name));
   }
}

References add_source(), and Botan::Entropy_Source::create().

Entropy_Sources() [3/4]

Botan::Entropy_Sources::Entropy_Sources ( const Entropy_Sources & other )

delete

Entropy_Sources() [4/4]

Botan::Entropy_Sources::Entropy_Sources ( Entropy_Sources && other )

delete

Member Function Documentation

add_source()

void Botan::Entropy_Sources::add_source

(

std::unique_ptr< Entropy_Source >

src

)

Definition at line 153 of file entropy_srcs.cpp.

                                                                  {
   if(src) {
      m_srcs.push_back(std::move(src));
   }
}

Referenced by Entropy_Sources().

enabled_sources()

std::vector< std::string > Botan::Entropy_Sources::enabled_sources

(

)

const

Definition at line 159 of file entropy_srcs.cpp.

                                                            {
   std::vector<std::string> sources;
   sources.reserve(m_srcs.size());
   for(const auto& src : m_srcs) {
      sources.push_back(src->name());
   }
   return sources;
}

global_sources()

Entropy_Sources & Botan::Entropy_Sources::global_sources ( )

static

Definition at line 205 of file entropy_srcs.cpp.

                                                 {
   static Entropy_Sources global_entropy_sources(BOTAN_ENTROPY_DEFAULT_SOURCES);
 
   return global_entropy_sources;
}

References BOTAN_ENTROPY_DEFAULT_SOURCES.

Referenced by Botan::AutoSeeded_RNG::AutoSeeded_RNG().

operator=()

Entropy_Sources & Botan::Entropy_Sources::operator= ( const Entropy_Sources & other )

delete

poll()

size_t Botan::Entropy_Sources::poll	(	RandomNumberGenerator &	rng,
		size_t	bits,
		std::chrono::milliseconds	timeout )

Poll all sources to collect bits of entropy with a timeout. Entropy collection is aborted as soon as either the requested number of bits are obtained or the timeout runs out. If the target system does not provide a clock, the timeout is ignored.

Note that the timeout is cooperative. If the poll() method of an entropy source blocks forever, this invocation will potentially also block.

Returns

the number of bits collected from the entropy sources

Definition at line 168 of file entropy_srcs.cpp.

                                                                                                        {
#if defined(BOTAN_TARGET_OS_HAS_SYSTEM_CLOCK)
   typedef std::chrono::system_clock clock;
   auto timeout_expired = [to = clock::now() + timeout] { return clock::now() > to; };
#else
   auto timeout_expired = [] { return false; };
#endif
 
   size_t bits_collected = 0;
 
   for(auto& src : m_srcs) {
      bits_collected += src->poll(rng);
 
      if(bits_collected >= poll_bits || timeout_expired()) {
         break;
      }
   }
 
   return bits_collected;
}

Referenced by Botan::RandomNumberGenerator::reseed().

poll_just()

size_t Botan::Entropy_Sources::poll_just	(	RandomNumberGenerator &	rng,
		std::string_view	src )

Poll just a single named source. Ordinally only used for testing

Definition at line 189 of file entropy_srcs.cpp.

                                                                                    {
   for(auto& src : m_srcs) {
      if(src->name() == the_src) {
         return src->poll(rng);
      }
   }
 
   return 0;
}

---

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

• src/lib/entropy/entropy_src.h
• src/lib/entropy/entropy_srcs.cpp