Date: Sun, 14 Mar 1999 17:15:29 +1030 From: Greg Lehey <grog@lemis.com> To: Mark Murray <mark@grondar.za> Cc: hackers@FreeBSD.ORG Subject: Re: Randomness and vnodes Message-ID: <19990314171529.Z429@lemis.com> In-Reply-To: <199903140618.IAA64577@greenpeace.grondar.za>; from Mark Murray on Sun, Mar 14, 1999 at 08:18:44AM %2B0200 References: <199903131704.TAA97969@greenpeace.grondar.za> <19990314112807.K429@lemis.com> <199903140618.IAA64577@greenpeace.grondar.za>
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On Sunday, 14 March 1999 at 8:18:44 +0200, Mark Murray wrote: > Greg Lehey wrote: >> On Saturday, 13 March 1999 at 19:04:19 +0200, Mark Murray wrote: >>> Hi >>> >>> One for you filesystem types; of all the parts of a struct vnode, >>> which are the most dynamic? Which would be the most usable as >>> input for an entropy collector running in the namei cache? >>> >>> The ones I am most interested in are the simple types; pointers, >>> ints (short or long) or chars. Volatile would be good :-) >> >> Depends on how many bits you want. Most pointers will have the top 4 >> bits set and the bottom 2 bits cleared. Why do you want to use a >> vnode? > > I don't care, as long as there is some entropy. > > I want to add a entropy harvester into the namei cache, and if I can > also pass in some genuine junk, that helps things. > > For interrupts, the interrupt number is used; for the keyboard, scancodes; > the available environmental stuff in the namei cache is centred around > vnodes, so I'm looking for dirt in them. Heck - I may just xor the whole > thing into an int to get some junk if necessary. I don't think xoring would be very random, given the number of fields with predictable content. That's my main concern with using vnodes in the first place, but if you want to use them, you should at least divide and get a remainder. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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