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rippled/include/xrpl/crypto/csprng.h
2024-06-20 13:57:14 -05:00

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C++

//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2012, 2013 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef RIPPLE_CRYPTO_RANDOM_H_INCLUDED
#define RIPPLE_CRYPTO_RANDOM_H_INCLUDED
#include <mutex>
#include <string>
#include <type_traits>
namespace ripple {
/** A cryptographically secure random number engine
The engine is thread-safe (it uses a lock to serialize
access) and will, automatically, mix in some randomness
from std::random_device.
Meets the requirements of UniformRandomNumberEngine
*/
class csprng_engine
{
private:
std::mutex mutex_;
public:
using result_type = std::uint64_t;
csprng_engine(csprng_engine const&) = delete;
csprng_engine&
operator=(csprng_engine const&) = delete;
csprng_engine(csprng_engine&&) = delete;
csprng_engine&
operator=(csprng_engine&&) = delete;
csprng_engine();
~csprng_engine();
/** Mix entropy into the pool */
void
mix_entropy(void* buffer = nullptr, std::size_t count = 0);
/** Generate a random integer */
result_type
operator()();
/** Fill a buffer with the requested amount of random data */
void
operator()(void* ptr, std::size_t count);
/* The smallest possible value that can be returned */
static constexpr result_type
min()
{
return std::numeric_limits<result_type>::min();
}
/* The largest possible value that can be returned */
static constexpr result_type
max()
{
return std::numeric_limits<result_type>::max();
}
};
/** The default cryptographically secure PRNG
Use this when you need to generate random numbers or
data that will be used for encryption or passed into
cryptographic routines.
This meets the requirements of UniformRandomNumberEngine
*/
csprng_engine&
crypto_prng();
} // namespace ripple
#endif