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author | Lennart Poettering <lennart@poettering.net> | 2018-11-07 18:40:26 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2018-11-08 09:44:27 +0100 |
commit | 94d457e8d936555b3b1ae25592d0624746994166 (patch) | |
tree | 747d7158616103180c7c93ac4e0fed6a0c68f1cf /src/basic | |
parent | random-util: fix indentation (diff) | |
download | systemd-94d457e8d936555b3b1ae25592d0624746994166.tar.xz systemd-94d457e8d936555b3b1ae25592d0624746994166.zip |
random-util: change high_quality_required bool parameter into a flags parameter
No change in behaviour, just some refactoring.
Diffstat (limited to 'src/basic')
-rw-r--r-- | src/basic/random-util.c | 18 | ||||
-rw-r--r-- | src/basic/random-util.h | 10 |
2 files changed, 15 insertions, 13 deletions
diff --git a/src/basic/random-util.c b/src/basic/random-util.c index b6d1cfd1ca..d7543d388a 100644 --- a/src/basic/random-util.c +++ b/src/basic/random-util.c @@ -65,19 +65,17 @@ int rdrand64(uint64_t *ret) { #endif } -int genuine_random_bytes(void *p, size_t n, bool high_quality_required) { +int genuine_random_bytes(void *p, size_t n, RandomFlags flags) { static int have_syscall = -1; _cleanup_close_ int fd = -1; size_t already_done = 0; int r; - /* Gathers some randomness from the kernel. This call will never block. If - * high_quality_required, it will always return some data from the kernel, - * regardless of whether the random pool is fully initialized or not. - * Otherwise, it will return success if at least some random bytes were - * successfully acquired, and an error if the kernel has no entropy whatsover - * for us. */ + /* Gathers some randomness from the kernel. This call will never block. If RANDOM_EXTEND_WITH_PSEUDO is unset, + * it will always return some data from the kernel, regardless of whether the random pool is fully initialized + * or not. Otherwise, it will return success if at least some random bytes were successfully acquired, and an + * error if the kernel has no entropy whatsover for us. */ /* Use the getrandom() syscall unless we know we don't have it. */ if (have_syscall != 0 && !HAS_FEATURE_MEMORY_SANITIZER) { @@ -86,7 +84,7 @@ int genuine_random_bytes(void *p, size_t n, bool high_quality_required) { have_syscall = true; if ((size_t) r == n) return 0; - if (!high_quality_required) { + if (FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) { /* Fill in the remaining bytes using pseudorandom values */ pseudo_random_bytes((uint8_t*) p + r, n - r); return 0; @@ -110,7 +108,7 @@ int genuine_random_bytes(void *p, size_t n, bool high_quality_required) { * a best-effort basis. */ have_syscall = true; - if (!high_quality_required) { + if (FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) { uint64_t u; size_t k; @@ -207,7 +205,7 @@ void pseudo_random_bytes(void *p, size_t n) { void random_bytes(void *p, size_t n) { - if (genuine_random_bytes(p, n, false) >= 0) + if (genuine_random_bytes(p, n, RANDOM_EXTEND_WITH_PSEUDO) >= 0) return; /* If for some reason some user made /dev/urandom unavailable to us, or the kernel has no entropy, use a PRNG instead. */ diff --git a/src/basic/random-util.h b/src/basic/random-util.h index 0429ea5e52..6328f661d2 100644 --- a/src/basic/random-util.h +++ b/src/basic/random-util.h @@ -5,9 +5,13 @@ #include <stddef.h> #include <stdint.h> -int genuine_random_bytes(void *p, size_t n, bool high_quality_required); /* 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. */ +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 */ +} 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); |