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/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
typedef enum RandomFlags {
RANDOM_EXTEND_WITH_PSEUDO = 1 << 0, /* If we can't get enough genuine randomness, but some, fill up the rest with pseudo-randomness */
RANDOM_BLOCK = 1 << 1, /* Rather block than return crap randomness (only if the kernel supports that) */
RANDOM_DONT_DRAIN = 1 << 2, /* If we can't get any randomness at all, return early with -EAGAIN */
RANDOM_ALLOW_RDRAND = 1 << 3, /* Allow usage of the CPU RNG */
} RandomFlags;
int genuine_random_bytes(void *p, size_t n, RandomFlags flags); /* returns "genuine" randomness, optionally filled upwith pseudo random, if not enough is available */
void pseudo_random_bytes(void *p, size_t n); /* returns only pseudo-randommess (but possibly seeded from something better) */
void random_bytes(void *p, size_t n); /* returns genuine randomness if cheaply available, and pseudo randomness if not. */
void initialize_srand(void);
static inline uint64_t random_u64(void) {
uint64_t u;
random_bytes(&u, sizeof(u));
return u;
}
static inline uint32_t random_u32(void) {
uint32_t u;
random_bytes(&u, sizeof(u));
return u;
}
int rdrand(unsigned long *ret);
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