surfrand: Random number generator based on SURF

Data Structures
struct	surfrand

Functions
void	surfrand_init (struct surfrand *c, const uint32 *data, unsigned words)
uint32	surfrand_uint32 (struct surfrand *c)
double	surfrand_double (struct surfrand *c)
void	surfrand_fill (struct surfrand *c, unsigned char *buf, unsigned len)
uint32	surfrand_uniform (struct surfrand *c, uint32 bound)

Detailed Description

Function Documentation

surfrand_double()

double surfrand_double

(

struct surfrand *

c

)

Output a random double precision floating-point number in the range 0-1.

This routine uses two calls to surfrand_uint32 to fill all the precision of a double precision floating-point with randomness.

References surfrand_uint32().

surfrand_fill()

void surfrand_fill	(	struct surfrand *	c,
		unsigned char *	buf,
		unsigned	len
	)

Fill the buffer with random data

References surfrand_uint32().

surfrand_init()

void surfrand_init	(	struct surfrand *	c,
		const uint32 *	data,
		unsigned	words
	)

Initialize the surfrand structure.

Initializes the seed in c from the input data, and sets the counter to zero. If more than SURF_SEED_U32 bytes of input data is given, the extra data is merged into the seed. If less, the given data is repeated until the seed is filled.

The counter is treated as a giant multi-word integer, and is incremented once each time data is generated. This makes the theoretical period of this generator 8*2^32^12 or >10^116.

References counter, left, seed, and SURF_SEED_U32.

Referenced by surfrand_uniform().

surfrand_uint32()

uint32 surfrand_uint32

(

struct surfrand *

c

)

Output an random unsigned 32-bit integer.

All the bits in the output integer are equally random.

References generated, and left.

Referenced by surfrand_double(), surfrand_fill(), and surfrand_uniform().

surfrand_uniform()

uint32 surfrand_uniform	(	struct surfrand *	c,
		uint32	bound
	)

Generate a uniformly distributed random number less than bound.

The result is masked against bias by regenerating the result if it would cause bias.

References obuf_putc(), obuf_putxw(), outbuf, surfrand_init(), and surfrand_uint32().

Referenced by dns_random().