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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
commit | 19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch) | |
tree | d59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/basic/random-util.h | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/basic/random-util.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/basic/random-util.h b/src/basic/random-util.h new file mode 100644 index 0000000..3e8c288 --- /dev/null +++ b/src/basic/random-util.h @@ -0,0 +1,33 @@ +/* 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); |