Date: Sun, 2 Feb 2003 17:16:05 +0300 From: "Andrey A. Chernov" <ache@nagual.pp.ru> To: Tim Robbins <tjr@FreeBSD.ORG> Cc: Kris Kennaway <kris@obsecurity.org>, current@FreeBSD.ORG Subject: Re: rand() is broken Message-ID: <20030202141605.GA64157@nagual.pp.ru> In-Reply-To: <20030202140223.GA63836@nagual.pp.ru> References: <20030202070644.GA9987@rot13.obsecurity.org> <20030202090422.GA59750@nagual.pp.ru> <20030202091106.GA72723@rot13.obsecurity.org> <20030202102621.GA60900@nagual.pp.ru> <20030202123035.GB62977@nagual.pp.ru> <20030203001735.A30440@dilbert.robbins.dropbear.id.au> <20030202134225.GA63673@nagual.pp.ru> <20030202140223.GA63836@nagual.pp.ru>
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On Sun, Feb 02, 2003 at 17:02:23 +0300, Andrey A. Chernov wrote:
>
> I'll produce and send it a bit later.
Here it is.
--- stdlib/rand.c.old Sat Jan 4 20:39:19 2003
+++ stdlib/rand.c Sun Feb 2 17:06:08 2003
@@ -72,10 +72,13 @@
*/
long hi, lo, x;
+ /* Can't be initialized with 0, so use another value. */
+ if (*ctx == 0)
+ *ctx = 123459876;
hi = *ctx / 127773;
lo = *ctx % 127773;
x = 16807 * lo - 2836 * hi;
- if (x <= 0)
+ if (x < 0)
x += 0x7fffffff;
return ((*ctx = x) % ((u_long)RAND_MAX + 1));
#endif /* !USE_WEAK_SEEDING */
@@ -86,8 +89,10 @@
rand_r(unsigned int *ctx)
{
u_long val = (u_long) *ctx;
- *ctx = do_rand(&val);
- return (int) *ctx;
+ int r = do_rand(&val);
+
+ *ctx = (unsigned int) val;
+ return (r);
}
--- stdlib/random.c.old Sun Mar 24 23:42:48 2002
+++ stdlib/random.c Sun Feb 2 17:09:19 2003
@@ -236,10 +236,13 @@
*/
long hi, lo;
+ /* Can't be initialized with 0, so use another value. */
+ if (x == 0)
+ x = 123459876;
hi = x / 127773;
lo = x % 127773;
x = 16807 * lo - 2836 * hi;
- if (x <= 0)
+ if (x < 0)
x += 0x7fffffff;
return (x);
#endif /* !USE_WEAK_SEEDING */
--
Andrey A. Chernov
http://ache.pp.ru/
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