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Diffstat (limited to 'botan/src/rng/rng.h')
-rw-r--r-- | botan/src/rng/rng.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/botan/src/rng/rng.h b/botan/src/rng/rng.h new file mode 100644 index 0000000..41904db --- /dev/null +++ b/botan/src/rng/rng.h @@ -0,0 +1,103 @@ +/* +* RandomNumberGenerator +* (C) 1999-2009 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#ifndef BOTAN_RANDOM_NUMBER_GENERATOR_H__ +#define BOTAN_RANDOM_NUMBER_GENERATOR_H__ + +#include <botan/entropy_src.h> +#include <botan/exceptn.h> +#include <string> + +namespace Botan { + +/** +* This class represents a random number (RNG) generator object. +*/ +class BOTAN_DLL RandomNumberGenerator + { + public: + /** + * Create a seeded and active RNG object for general application use + */ + static RandomNumberGenerator* make_rng(); + + /** + * Randomize a byte array. + * @param output the byte array to hold the random output. + * @param length the length of the byte array output. + */ + virtual void randomize(byte output[], u32bit length) = 0; + + /** + * Return a random byte + * @return random byte + */ + byte next_byte(); + + /** + * Check whether this RNG is seeded. + * @return true if this RNG was already seeded, false otherwise. + */ + virtual bool is_seeded() const { return true; } + + /** + * Clear all internally held values of this RNG. + */ + virtual void clear() throw() = 0; + + /** + * Return the name of this object + */ + virtual std::string name() const = 0; + + /** + * Seed this RNG using the entropy sources it contains. + * @param bits_to_collect is the number of bits of entropy to + attempt to gather from the entropy sources + */ + virtual void reseed(u32bit bits_to_collect) = 0; + + /** + * Add this entropy source to the RNG object + * @param source the entropy source which will be retained and used by RNG + */ + virtual void add_entropy_source(EntropySource* source) = 0; + + /** + * Add entropy to this RNG. + * @param in a byte array containg the entropy to be added + * @param length the length of the byte array in + */ + virtual void add_entropy(const byte in[], u32bit length) = 0; + + RandomNumberGenerator() {} + virtual ~RandomNumberGenerator() {} + private: + RandomNumberGenerator(const RandomNumberGenerator&) {} + RandomNumberGenerator& operator=(const RandomNumberGenerator&) + { return (*this); } + }; + +/* +* Null Random Number Generator +*/ +class BOTAN_DLL Null_RNG : public RandomNumberGenerator + { + public: + void randomize(byte[], u32bit) { throw PRNG_Unseeded("Null_RNG"); } + void clear() throw() {} + std::string name() const { return "Null_RNG"; } + + void reseed(u32bit) {} + bool is_seeded() const { return false; } + void add_entropy(const byte[], u32bit) {} + void add_entropy_source(EntropySource* es) { delete es; } + }; + +} + +#endif |