diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/dev/rnd.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c index 7d915b6fa57..b501e726c67 100644 --- a/sys/dev/rnd.c +++ b/sys/dev/rnd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: rnd.c,v 1.16 1997/01/15 22:33:53 kstailey Exp $ */ +/* $OpenBSD: rnd.c,v 1.17 1997/02/04 03:03:18 dm Exp $ */ /* * random.c -- A strong random number generator @@ -311,7 +311,8 @@ struct arc4_stream { #define ENT_TTY 0x300 static struct random_bucket random_state; -struct arc4_stream arc4random_state; +static int arc4random_uninitialized = 2; +static struct arc4_stream arc4random_state; static u_int32_t random_pool[POOLWORDS]; static struct timer_rand_state mouse_timer_state; static struct timer_rand_state extract_timer_state; @@ -330,6 +331,7 @@ void add_timer_randomness __P((struct random_bucket *, struct timer_rand_state *, u_int)); static __inline int extract_entropy __P((struct random_bucket *, char *, int)); void arc4_init __P((struct arc4_stream *, u_char *, int)); +static __inline void arc4_stir (struct arc4_stream *); static __inline u_char arc4_getbyte __P((struct arc4_stream *)); /* Arcfour random stream generator. This code is derived from section @@ -380,9 +382,22 @@ arc4_getbyte (struct arc4_stream *as) return (as->s[(si + sj) & 0xff]); } +static inline void +arc4maybeinit (void) +{ + if (arc4random_uninitialized) { + if (arc4random_uninitialized > 1 + || random_state.entropy_count >= 128) { + arc4random_uninitialized--; + arc4_stir (&arc4random_state); + } + } +} + u_int32_t arc4random (void) { + arc4maybeinit (); return ((arc4_getbyte (&arc4random_state) << 24) | (arc4_getbyte (&arc4random_state) << 16) | (arc4_getbyte (&arc4random_state) << 8) @@ -737,6 +752,7 @@ randomread(dev, uio, ioflag) { u_char *cp = (u_char *) buf; u_char *end = cp + n; + arc4maybeinit (); while (cp < end) *cp++ = arc4_getbyte (&arc4random_state); break; @@ -767,14 +783,12 @@ randomselect(dev, rw, p) static __inline void arc4_stir (struct arc4_stream *as) { - int rsec = random_state.entropy_count >> 3; - u_int buf[2 + POOLWORDS]; - int n = min (sizeof(buf) - 2 * sizeof (u_int), rsec); + u_char buf[256]; microtime ((struct timeval *) buf); - get_random_bytes (buf + 2, n); - arc4_init (&arc4random_state, (u_char *) buf, - 2 * sizeof (u_int) + n); + get_random_bytes (buf + sizeof (struct timeval), + sizeof (buf) - sizeof (struct timeval)); + arc4_init (&arc4random_state, buf, sizeof (buf)); } int |