diff options
| -rw-r--r-- | util/nvmutil/nvmutil.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 4eb013be..af6c8e19 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -381,6 +381,7 @@ static ushort hextonum(char ch_s); static ushort rhex(void); #if !defined(HAVE_ARC4RANDOM_BUF) || \ (HAVE_ARC4RANDOM_BUF) < 1 +static ushort read_urandom(void); static ulong entropy_jitter(void); #endif static void write_mac_part(size_t partnum); @@ -1370,6 +1371,11 @@ rhex(void) struct timeval tv; ulong mix; static ulong counter = 0; + ushort r; + + r = read_urandom(); + if (r < 16) + return r; gettimeofday(&tv, NULL); @@ -1391,6 +1397,38 @@ rhex(void) return (ushort)(mix & 0xf); } +static ushort +read_urandom(void) +{ + static int fd = -1; + static ssize_t n = -1; + + static u8 r[12]; + + if (fd < 0) { + + fd = open("/dev/urandom", O_RDONLY); + + if (fd < 0) + return 16; + } + + if (n < 0) { + + n = rw_file_exact(fd, r, 12, 0, IO_READ, + LOOP_EAGAIN, LOOP_EINTR, 2, OFF_ERR); + + if (n == 0) + n = -1; + if (n < 0) + return 16; + + --n; + } + + return r[n--] & 0xf; +} + static ulong entropy_jitter(void) { |