Botan::ANSI_X931_RNG Class Reference

#include <x931_rng.h>

Inheritance diagram for Botan::ANSI_X931_RNG:

List of all members.

Public Member Functions
void	add_entropy (const byte[], u32bit)
void	add_entropy_source (EntropySource *)
	ANSI_X931_RNG (BlockCipher *cipher, RandomNumberGenerator *rng)
void	clear ()
bool	is_seeded () const
std::string	name () const
byte	next_byte ()
void	randomize (byte[], u32bit)
void	reseed (u32bit poll_bits)
	~ANSI_X931_RNG ()
Static Public Member Functions
static RandomNumberGenerator *	make_rng ()

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Detailed Description

ANSI X9.31 RNG

Definition at line 19 of file x931_rng.h.

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Constructor & Destructor Documentation

Botan::ANSI_X931_RNG::ANSI_X931_RNG	(	BlockCipher *	cipher,
		RandomNumberGenerator *	rng
	)

Parameters:

	cipher	the block cipher to use in this PRNG
	rng	the underlying PRNG for generating inputs (eg, an HMAC_RNG)

Definition at line 132 of file x931_rng.cpp.

References Botan::BlockCipher::BLOCK_SIZE, and Botan::MemoryRegion< T >::resize().

   {
   if(!prng_in || !cipher_in)
      throw Invalid_Argument("ANSI_X931_RNG constructor: NULL arguments");

   cipher = cipher_in;
   prng = prng_in;

   R.resize(cipher->BLOCK_SIZE);
   position = 0;
   }

Botan::ANSI_X931_RNG::~ANSI_X931_RNG

(

)

Definition at line 148 of file x931_rng.cpp.

   {
   delete cipher;
   delete prng;
   }

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Member Function Documentation

void Botan::ANSI_X931_RNG::add_entropy	(	const	in[],
		u32bit	length
	)			[virtual]

Add entropy to this RNG.

Parameters:

	in	a byte array containg the entropy to be added
	length	the length of the byte array in

Implements Botan::RandomNumberGenerator.

Definition at line 94 of file x931_rng.cpp.

References Botan::RandomNumberGenerator::add_entropy().

   {
   prng->add_entropy(input, length);
   rekey();
   }

void Botan::ANSI_X931_RNG::add_entropy_source

(

EntropySource *

source

)

[virtual]

Add this entropy source to the RNG object

Parameters:

source

the entropy source which will be retained and used by RNG

Implements Botan::RandomNumberGenerator.

Definition at line 86 of file x931_rng.cpp.

References Botan::RandomNumberGenerator::add_entropy_source().

   {
   prng->add_entropy_source(src);
   }

void Botan::ANSI_X931_RNG::clear

(

)

[virtual]

Clear all internally held values of this RNG.

Implements Botan::RandomNumberGenerator.

Definition at line 111 of file x931_rng.cpp.

References Botan::MemoryRegion< T >::clear(), Botan::RandomNumberGenerator::clear(), Botan::BlockCipher::clear(), and Botan::MemoryRegion< T >::destroy().

   {
   cipher->clear();
   prng->clear();
   R.clear();
   V.destroy();

   position = 0;
   }

bool Botan::ANSI_X931_RNG::is_seeded

(

)

const [virtual]

Check whether this RNG is seeded.

Returns:

true if this RNG was already seeded, false otherwise.

Reimplemented from Botan::RandomNumberGenerator.

Definition at line 103 of file x931_rng.cpp.

References Botan::MemoryRegion< T >::size().

Referenced by randomize().

   {
   return (V.size() > 0);
   }

RandomNumberGenerator * Botan::RandomNumberGenerator::make_rng

(

)

[static, inherited]

Create a seeded and active RNG object for general application use

Definition at line 29 of file rng.cpp.

   {
#if defined(BOTAN_HAS_AUTO_SEEDING_RNG)
   return new AutoSeeded_RNG;
#endif

   throw Algorithm_Not_Found("RandomNumberGenerator::make_rng - no RNG found");
   }

std::string Botan::ANSI_X931_RNG::name

(

)

const [virtual]

Return the name of this object

Implements Botan::RandomNumberGenerator.

Definition at line 124 of file x931_rng.cpp.

References Botan::SymmetricAlgorithm::name().

Referenced by randomize().

   {
   return "X9.31(" + cipher->name() + ")";
   }

byte Botan::RandomNumberGenerator::next_byte

(

)

[inherited]

Return a random byte

Returns:

random byte

Definition at line 19 of file rng.cpp.

References Botan::RandomNumberGenerator::randomize().

Referenced by Botan::random_prime().

   {
   byte out;
   this->randomize(&out, 1);
   return out;
   }

void Botan::ANSI_X931_RNG::randomize	(	byte	output[],
		u32bit	length
	)			[virtual]

Randomize a byte array.

Parameters:

	output	the byte array to hold the random output.
	length	the length of the byte array output.

Implements Botan::RandomNumberGenerator.

Definition at line 17 of file x931_rng.cpp.

References Botan::copy_mem(), is_seeded(), name(), and Botan::MemoryRegion< T >::size().

   {
   if(!is_seeded())
      throw PRNG_Unseeded(name());

   while(length)
      {
      if(position == R.size())
         update_buffer();

      const u32bit copied = std::min(length, R.size() - position);

      copy_mem(out, R + position, copied);
      out += copied;
      length -= copied;
      position += copied;
      }
   }

void Botan::ANSI_X931_RNG::reseed

(

u32bit

bits_to_collect

)

[virtual]

Seed this RNG using the entropy sources it contains.

Parameters:

bits_to_collect

is the number of bits of entropy to attempt to gather from the entropy sources

Implements Botan::RandomNumberGenerator.

Definition at line 77 of file x931_rng.cpp.

References Botan::RandomNumberGenerator::reseed().

   {
   prng->reseed(poll_bits);
   rekey();
   }

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

• src/rng/x931_rng/x931_rng.h
• src/rng/x931_rng/x931_rng.cpp