/*\
 * RRAND RNG - Ruptor's Fast True Random Number Generator, v2.0 based on RUPT64x2-512/2
 * http://cryptolib.com/crypto/rrand
 * Copyright (c) 1992-2010 Marcos el Ruptor
 * Released to public domain.
\*/

#ifndef _RRAND_H
#define _RRAND_H

#ifdef __cplusplus
extern "C" {
#endif

#ifndef _STD_TYPES
	#define _STD_TYPES
	#define uchar			unsigned char
	#define uint			unsigned int
	#define ulong			unsigned long int
	#if (defined(_MSC_VER) && defined(_M_IX86))||defined(INTEL_COMPILER)||defined(__WATCOMC__)
		#define ulonglong	unsigned __int64
	#else
		#define ulonglong	unsigned long long
	#endif
#endif

#define RRAND_SIZE 64	/* 16 is actually more than enough for 512-bit security, but we are paranoid */

/* although the ability to support separate states is provided, it is advised to use the same state for all PRNG instances, threads, and if possible, processes */

typedef struct _rrand_state
{
	ulonglong		pool[RRAND_SIZE], d0, d1, r;	/* RUPT state */
	uint			offset;							/* r % RRAND_SIZE */
}
rrand_state;

/**
 * \brief			[incremental] RRAND state initialization, slow refill with a large amount of entropy, not absolutely necessary to call, advised to call before generating large secret keys and every few ms in a separate thread
 *
 * \param rr		RRAND state to be reseeded
 */
void rrand_init (rrand_state * const rr);

/**
 * \brief			RRAND 64-bit random number generation function, fast, ~12 CPB on x64, ~45 CPB on x86 C2D
 *
 * \param vr		RRAND state
 *
 * \return			A random unsigned long long
 */
ulonglong rrand (void * const vr);

#ifdef __cplusplus
}
#endif

#endif /* rrand.h */