Botan::Randpool Class Reference

#include <randpool.h>

Inheritance diagram for Botan::Randpool:

Public Member Functions
void	add_entropy (const byte input[], size_t length)
void	add_entropy_source (EntropySource *es)
void	clear ()
bool	is_seeded () const
std::string	name () const
byte	next_byte ()
secure_vector< byte >	random_vec (size_t bytes)
void	randomize (byte[], size_t)
	Randpool (BlockCipher *cipher, MessageAuthenticationCode *mac, size_t pool_blocks=32, size_t iterations_before_reseed=128)
void	reseed (size_t bits_to_collect)
	~Randpool ()

Static Public Member Functions
static RandomNumberGenerator *	make_rng ()

Detailed Description

Randpool

Definition at line 21 of file randpool.h.

Constructor & Destructor Documentation

Botan::Randpool::Randpool	(	BlockCipher *	cipher,
		MessageAuthenticationCode *	mac,
		size_t	pool_blocks = 32,
		size_t	iterations_before_reseed = 128
	)

Parameters

cipher	a block cipher to use
mac	a message authentication code to use
pool_blocks	how many cipher blocks to use for the pool
iterations_before_reseed	how many times we'll use the internal state to generate output before reseeding

Definition at line 169 of file randpool.cpp.

References Botan::BlockCipher::block_size(), Botan::Algorithm::name(), Botan::MessageAuthenticationCode::name(), Botan::Buffered_Computation::output_length(), and Botan::SymmetricAlgorithm::valid_keylength().

                                              :
   ITERATIONS_BEFORE_RESEED(iter_before_reseed),
   POOL_BLOCKS(pool_blocks),
   cipher(cipher_in),
   mac(mac_in)
   {
   const size_t BLOCK_SIZE = cipher->block_size();
   const size_t OUTPUT_LENGTH = mac->output_length();

   if(OUTPUT_LENGTH < BLOCK_SIZE ||
      !cipher->valid_keylength(OUTPUT_LENGTH) ||
      !mac->valid_keylength(OUTPUT_LENGTH))
      {
      delete cipher;
      delete mac;
      throw Internal_Error("Randpool: Invalid algorithm combination " +
                           cipher->name() + "/" + mac->name());
      }

   buffer.resize(BLOCK_SIZE);
   pool.resize(POOL_BLOCKS * BLOCK_SIZE);
   counter.resize(12);
   seeded = false;