svn commit: r230230 - head/sys/dev/random

[Andrey Chernov]

On Mon, Jan 16, 2012 at 08:18:10PM +0000, David Schultz wrote:
> Author: das
> Date: Mon Jan 16 20:18:10 2012
> New Revision: 230230
> URL: http://svn.freebsd.org/changeset/base/230230
> 
> Log:
>   Generate a warning if the kernel's arc4random() is seeded with bogus entropy.

While you are here, could you review/commit my patch to fix bad 31bit
arc4rand() seeding, please?

--- yarrow.c.bak	2011-09-26 07:35:48.000000000 +0400
+++ yarrow.c	2012-01-18 10:13:47.000000000 +0400
@@ -59,6 +59,8 @@ static void reseed(u_int);
 /* The reseed thread mutex */
 struct mtx random_reseed_mtx;
 
+static arc4rand_seeded = 0;
+
 /* Process a single stochastic event off the harvest queue */
 void
 random_process_event(struct harvest *event)
@@ -261,6 +263,11 @@ reseed(u_int fastslow)
 
 	/* Release the reseed mutex */
 	mtx_unlock(&random_reseed_mtx);
+
+	if (!arc4rand_seeded) {
+		arc4rand_seeded = 1;
+		arc4rand(NULL, 0, 1);
+	}
 }
 
 /* Internal function to return processed entropy from the PRNG */

-- 
http://ache.vniz.net/