src/random.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2014 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifndef BITCOIN_RANDOM_H
   7 #define BITCOIN_RANDOM_H
   8
   9 #include "uint256.h"
  10
  11 #include <stdint.h>
  12
  13 /**
  14  * Seed OpenSSL PRNG with additional entropy data
  15  */
  16 void RandAddSeed();
  17 void RandAddSeedPerfmon();
  18
  19 /**
  20  * Functions to gather random data via the OpenSSL PRNG
  21  */
  22 void GetRandBytes(unsigned char* buf, int num);
  23 uint64_t GetRand(uint64_t nMax);
  24 int GetRandInt(int nMax);
  25 uint256 GetRandHash();
  26
  27 /**
  28  * Seed insecure_rand using the random pool.
  29  * @param Deterministic Use a deterministic seed
  30  */
  31 void seed_insecure_rand(bool fDeterministic = false);
  32
  33 /**
  34  * MWC RNG of George Marsaglia
  35  * This is intended to be fast. It has a period of 2^59.3, though the
  36  * least significant 16 bits only have a period of about 2^30.1.
  37  *
  38  * @return random value
  39  */
  40 extern uint32_t insecure_rand_Rz;
  41 extern uint32_t insecure_rand_Rw;
  42 static inline uint32_t insecure_rand(void)
  43 {
  44     insecure_rand_Rz = 36969 * (insecure_rand_Rz & 65535) + (insecure_rand_Rz >> 16);
  45     insecure_rand_Rw = 18000 * (insecure_rand_Rw & 65535) + (insecure_rand_Rw >> 16);
  46     return (insecure_rand_Rw << 16) + insecure_rand_Rz;
  47 }
  48
  49 #endif // BITCOIN_RANDOM_H