Functions for retrieving uniformly distributed numbers from our PRNGs. More...

#include "lib/crypt_ops/crypto_rand.h"
#include "lib/log/util_bug.h"

Macros
#define	IMPLEMENT_RAND_UNSIGNED(type, maxval, limit, fill_stmt)

Functions
unsigned	crypto_rand_uint (unsigned limit)

int	crypto_rand_int (unsigned int max)

int	crypto_rand_int_range (unsigned int min, unsigned int max)

uint64_t	crypto_rand_uint64_range (uint64_t min, uint64_t max)

time_t	crypto_rand_time_range (time_t min, time_t max)

uint64_t	crypto_rand_uint64 (uint64_t max)

double	crypto_rand_double (void)

unsigned	crypto_fast_rng_get_uint (crypto_fast_rng_t *rng, unsigned limit)

uint64_t	crypto_fast_rng_get_uint64 (crypto_fast_rng_t *rng, uint64_t limit)

uint32_t	crypto_fast_rng_get_u32 (crypto_fast_rng_t *rng)

uint64_t	crypto_fast_rng_uint64_range (crypto_fast_rng_t *rng, uint64_t min, uint64_t max)

double	crypto_fast_rng_get_double (crypto_fast_rng_t *rng)

Detailed Description

Functions for retrieving uniformly distributed numbers from our PRNGs.

Definition in file crypto_rand_numeric.c.

Macro Definition Documentation

◆ IMPLEMENT_RAND_UNSIGNED

#define IMPLEMENT_RAND_UNSIGNED	(	type,
		maxval,
		limit,
		fill_stmt )

Value:

  do {                                                                  \
    type val;                                                           \
    type cutoff;                                                        \
    tor_assert((limit) > 0);                                            \
                                                                        \
    /* We ignore any values that are >= 'cutoff,' to avoid biasing */   \
    /* the distribution with clipping at the upper end of the type's */ \
    /* range. */                                                        \
    cutoff = (maxval) - ((maxval)%(limit));                             \
    while (1) {                                                         \
      fill_stmt;                                                        \
      if (val < cutoff)                                                 \
        return val % (limit);                                           \
    }                                                                   \
  } while (0)

Implementation macro: yields code that returns a uniform unbiased random number between 0 and limit. "type" is the type of the number to return; "maxval" is the largest possible value of "type"; and "fill_stmt" is a code snippet that fills an object named "val" with random bits.

Definition at line 17 of file crypto_rand_numeric.c.

Referenced by crypto_fast_rng_get_uint(), crypto_fast_rng_get_uint64(), crypto_rand_uint(), and crypto_rand_uint64().

Function Documentation

◆ crypto_fast_rng_get_double()

double crypto_fast_rng_get_double ( crypto_fast_rng_t * rng )

As crypto_rand_get_double() but extract the result from a crypto_fast_rng_t.

Definition at line 188 of file crypto_rand_numeric.c.

◆ crypto_fast_rng_get_u32()

uint32_t crypto_fast_rng_get_u32 ( crypto_fast_rng_t * rng )

As crypto_rand_u32, but extract the result from a crypto_fast_rng_t.

Definition at line 161 of file crypto_rand_numeric.c.

Referenced by genpareto_sample(), geometric_sample(), log_logistic_sample(), logistic_sample(), random_uniform_01(), and weibull_sample().

◆ crypto_fast_rng_get_uint()

unsigned crypto_fast_rng_get_uint	(	crypto_fast_rng_t *	rng,
		unsigned	limit )

As crypto_rand_uint, but extract the result from a crypto_fast_rng_t

Definition at line 139 of file crypto_rand_numeric.c.

Referenced by circuit_reset_sendme_randomness(), and extend_info_pick_orport().

◆ crypto_fast_rng_get_uint64()

uint64_t crypto_fast_rng_get_uint64	(	crypto_fast_rng_t *	rng,
		uint64_t	limit )

As crypto_rand_uint64, but extract the result from a crypto_fast_rng_t.

Definition at line 150 of file crypto_rand_numeric.c.

Referenced by circpad_machine_sample_delay(), and crypto_fast_rng_uint64_range().

◆ crypto_fast_rng_uint64_range()

uint64_t crypto_fast_rng_uint64_range	(	crypto_fast_rng_t *	rng,
		uint64_t	min,
		uint64_t	max )

As crypto_rand_uint64_range(), but extract the result from a crypto_fast_rng_t.

Definition at line 173 of file crypto_rand_numeric.c.

Referenced by circpad_machine_sample_delay().

◆ crypto_rand_double()

double crypto_rand_double ( void )

Return a pseudorandom double d, chosen uniformly from the range 0.0 <= d < 1.0.

Definition at line 126 of file crypto_rand_numeric.c.

Referenced by rep_hist_format_hs_stats().

◆ crypto_rand_int()

int crypto_rand_int ( unsigned int max )

Return a pseudorandom integer, chosen uniformly from the values between 0 and max-1 inclusive. max must be between 1 and INT_MAX+1, inclusive.

Definition at line 52 of file crypto_rand_numeric.c.

Referenced by channelpadding_get_channel_idle_timeout(), channelpadding_get_circuits_available_timeout(), channelpadding_get_netflow_inactive_timeout_ms(), check_dns_honesty_callback(), choose_array_element_by_weight(), circuit_build_times_shuffle_and_store_array(), client_get_random_intro(), crypto_rand_int_range(), origin_circuit_new(), router_initialize_tls_context(), smartlist_choose(), smartlist_shuffle(), and update_consensus_networkstatus_fetch_time_impl().

◆ crypto_rand_int_range()

int crypto_rand_int_range	(	unsigned int	min,
		unsigned int	max )

Return a pseudorandom integer, chosen uniformly from the values i such that min <= i < max.

min MUST be in range [0, max). max MUST be in range (min, INT_MAX].

Definition at line 71 of file crypto_rand_numeric.c.

Referenced by check_dns_honesty_callback(), crypto_random_hostname(), get_layer2_hs_guard_lifetime(), initialize_pow_defenses(), next_random_exponential_delay(), rotate_pow_seeds(), router_initialize_tls_context(), service_intro_point_new(), and upload_descriptor_to_all().

◆ crypto_rand_time_range()

time_t crypto_rand_time_range	(	time_t	min,
		time_t	max )

As crypto_rand_int_range, but supports time_t.

Definition at line 95 of file crypto_rand_numeric.c.

Referenced by randomize_time().

◆ crypto_rand_uint()

unsigned crypto_rand_uint ( unsigned limit )

Return a pseudorandom integer chosen uniformly from the values between 0 and limit-1 inclusive. limit must be strictly greater than 0, and less than UINT_MAX.

Definition at line 39 of file crypto_rand_numeric.c.

Referenced by clip_dns_fuzzy_ttl(), and crypto_rand_int().

◆ crypto_rand_uint64()

uint64_t crypto_rand_uint64 ( uint64_t max )

Return a pseudorandom 64-bit integer, chosen uniformly from the values between 0 and max-1 inclusive.

Definition at line 106 of file crypto_rand_numeric.c.

Referenced by choose_array_element_by_weight(), crypto_rand_time_range(), and crypto_rand_uint64_range().

◆ crypto_rand_uint64_range()

uint64_t crypto_rand_uint64_range	(	uint64_t	min,
		uint64_t	max )

As crypto_rand_int_range, but supports uint64_t.

Definition at line 85 of file crypto_rand_numeric.c.

Macros

Functions