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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
commit19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch)
treed59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/basic/random-util.h
parentInitial commit. (diff)
downloadsystemd-d54215faec6264b9021f699873239ee9e4d99e5b.tar.xz
systemd-d54215faec6264b9021f699873239ee9e4d99e5b.zip
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/basic/random-util.h')
-rw-r--r--src/basic/random-util.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/src/basic/random-util.h b/src/basic/random-util.h
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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);