ProPolice: best way to fill canary

Jeremie Le Hen jeremie at
Sat Jul 9 08:15:52 GMT 2005

Hi Mike,

On Fri, Jul 08, 2005 at 07:22:13PM -0500, Mike Silbersack wrote:
> On Fri, 8 Jul 2005, Jeremie Le Hen wrote:
> >The second method requires to introduce the kern.arnd sysctl
> >(KERN_ARND).  FYI, note that NetBSD has kern.urandom (KERN_URND) and
> >they define KERN_ARND to be an alias to this.
> I don't see any problem with introducing such a sysctl, if it would make 
> the propolice patch simpler.

Thanks for you answer.  In that case, which sysctl should we use ?

	* OpenBSD's kern.arnd (KERN_ARND) which is a front-end to
	  the arc4random() function ?
	* NetBSD's kern.urandom (KERN_URND) which is using the rnd(4)
	  pseudo-device.  They also have KERN_ARND in sysctl.h, which
	  is no more than a #define of KERN_URND, for compatibility
	  with OpenBSD.

Usually, I noticed that FreeBSD used to be as close as possible with
NetBSD.  But I would like to hear the voice of a more experienced
hacker about this.

Best regards,
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >

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