Random Number Generator

Random Number Generator. More...

Data Structures
struct	rand_cpu_ctx_t
	CPU random number generator context. More...

Functions
void	rand_cpu_init (rand_cpu_ctx_t *ctx)
	Initializes the random number generator.
uint64_t	rand_gen (void *buffer, uint64_t size)
	Fills a buffer with random bytes.
uint64_t	rdrand_do (uint32_t *value, uint8_t retries)
	Generates a random 32-bit unsigned integer using the RDRAND instruction.

Detailed Description

Random Number Generator.

The random number generator driver provides functions to generate random numbers for use in the kernel.

See also

RDRAND Instruction

Function Documentation

rand_cpu_init()

void rand_cpu_init

(

rand_cpu_ctx_t *

ctx

)

Initializes the random number generator.

Definition at line 28 of file rand.c.

References CPUID_ECX_RDRAND, cpuid_feature_info(), ERR, info, LOG_WARN, rdrand_do(), rand_cpu_ctx_t::rdrandAvail, smp_self_unsafe(), and UINT64_MAX.

rand_gen()

uint64_t rand_gen	(	void *	buffer,
		uint64_t	size
	)

Fills a buffer with random bytes.

If the RDRAND instruction is available and working, it will be used. Otherwise, a fallback time based RNG will be used.

Parameters

buffer	A pointer to the buffer to fill.
size	The number of bytes to fill.

Returns

On success, 0. On failure, ERR and errno is set.

Definition at line 61 of file rand.c.

References buffer, ERR, memcpy(), cpu_t::rand, rand_gen_fallback(), rdrand_do(), rand_cpu_ctx_t::rdrandAvail, smp_put(), and smp_self().

Referenced by key_generate().

rdrand_do()

uint64_t rdrand_do ( uint32_t *  value, uint8_t  retries  )

extern

Generates a random 32-bit unsigned integer using the RDRAND instruction.

Parameters

value	A pointer to store the generated random value.
retries	The number of retries to attempt if RDRAND fails.

Returns

On success, 0. On failure, ERR and errno is set.

Referenced by rand_cpu_init(), and rand_gen().