diff options
| -rw-r--r-- | lib/randutils.c | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/lib/randutils.c b/lib/randutils.c index 09dd26186..ceeb474ef 100644 --- a/lib/randutils.c +++ b/lib/randutils.c @@ -99,32 +99,40 @@ void random_get_bytes(void *buf, size_t nbytes) unsigned char *cp = (unsigned char *)buf; #ifdef HAVE_GETRANDOM + errno = 0; while (getrandom(buf, nbytes, 0) < 0) { if (errno == EINTR) continue; break; } -#else - size_t n = nbytes; - int fd = random_get_fd(); - int lose_counter = 0; - - if (fd >= 0) { - while (n > 0) { - ssize_t x = read(fd, cp, n); - if (x <= 0) { - if (lose_counter++ > 16) - break; - continue; + if (errno == ENOSYS) + /* + * We've been built against headers that support getrandom, + * but the running kernel does not. + * Fallback to reading from /dev/{u,}random as before + */ +#endif + { + size_t n = nbytes; + int fd = random_get_fd(); + int lose_counter = 0; + + if (fd >= 0) { + while (n > 0) { + ssize_t x = read(fd, cp, n); + if (x <= 0) { + if (lose_counter++ > 16) + break; + continue; + } + n -= x; + cp += x; + lose_counter = 0; } - n -= x; - cp += x; - lose_counter = 0; - } - close(fd); + close(fd); + } } -#endif /* * We do this all the time, but this is the only source of * randomness if /dev/random/urandom is out to lunch. |