Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756911Ab3IKSrT (ORCPT ); Wed, 11 Sep 2013 14:47:19 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:34315 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755986Ab3IKSrS convert rfc822-to-8bit (ORCPT ); Wed, 11 Sep 2013 14:47:18 -0400 Message-ID: <1378925224.26698.90.camel@localhost> Subject: Re: TPMs and random numbers From: David Safford To: Andy Lutomirski Cc: "H. Peter Anvin" , Leonidas Da Silva Barbosa , Ashley Lai , Rajiv Andrade , Marcel Selhorst , Sirrix AG , Linux Kernel Mailing List , Jeff Garzik , "Ted Ts'o" , Kent Yoder , David Safford , Mimi Zohar , "Johnston, DJ" Date: Wed, 11 Sep 2013 14:47:04 -0400 In-Reply-To: References: <1378920168.26698.64.camel@localhost> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.8.5 (3.8.5-2.fc19) Mime-Version: 1.0 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13091118-5806-0000-0000-000022B3D72E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1155 Lines: 28 On Wed, 2013-09-11 at 10:49 -0700, Andy Lutomirski wrote: > On Wed, Sep 11, 2013 at 10:22 AM, David Safford wrote: > >>On 09/09/2013 02:11 PM, H. Peter Anvin wrote: > > A TPM that has an excellent internal entropy source and is FIPS 140-2 > compliant with no bugs whatsoever may still use Dual_EC_DRBG, which > looks increasingly likely to be actively malicious. I don't know of any that do so (it's more complex and slower than the alternatives). > I'd be *much* happier if my system read a few hundred random bytes > from the TPM at startup and fed those bytes into the kernel's entropy > pool. This should IMO happen at startup as early as possible. I agree completely that the ideal case is a system with good entropy sources, including a TPM, and all these mixed as early as possible. But I also think that the existing (certified) TPMs are good enough for direct use. dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/