lbrycrd/src/random.h
Wladimir J. van der Laan 7cad849299 sanity: Move OS random to sanity check function
Move the OS random test to a sanity check function that is called every
time bitcoind is initialized.

Keep `src/test/random_tests.cpp` for the case that later random tests
are added, and keep a rudimentary test that just calls the sanity check.
2017-02-22 08:02:50 +01:00

66 lines
1.8 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_RANDOM_H
#define BITCOIN_RANDOM_H
#include "uint256.h"
#include <stdint.h>
/* Seed OpenSSL PRNG with additional entropy data */
void RandAddSeed();
/**
* Functions to gather random data via the OpenSSL PRNG
*/
void GetRandBytes(unsigned char* buf, int num);
uint64_t GetRand(uint64_t nMax);
int GetRandInt(int nMax);
uint256 GetRandHash();
/**
* Function to gather random data from multiple sources, failing whenever any
* of those source fail to provide a result.
*/
void GetStrongRandBytes(unsigned char* buf, int num);
/**
* Fast randomness source. This is seeded once with secure random data, but
* is completely deterministic and insecure after that.
* This class is not thread-safe.
*/
class FastRandomContext {
public:
explicit FastRandomContext(bool fDeterministic=false);
uint32_t rand32() {
Rz = 36969 * (Rz & 65535) + (Rz >> 16);
Rw = 18000 * (Rw & 65535) + (Rw >> 16);
return (Rw << 16) + Rz;
}
uint32_t Rz;
uint32_t Rw;
};
/* Number of random bytes returned by GetOSRand.
* When changing this constant make sure to change all call sites, and make
* sure that the underlying OS APIs for all platforms support the number.
* (many cap out at 256 bytes).
*/
static const ssize_t NUM_OS_RANDOM_BYTES = 32;
/** Get 32 bytes of system entropy. Do not use this in application code: use
* GetStrongRandBytes instead.
*/
void GetOSRand(unsigned char *ent32);
/** Check that OS randomness is available and returning the requested number
* of bytes.
*/
bool Random_SanityCheck();
#endif // BITCOIN_RANDOM_H