Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755176AbaJGSrO (ORCPT ); Tue, 7 Oct 2014 14:47:14 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:55320 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754388AbaJGSrN (ORCPT ); Tue, 7 Oct 2014 14:47:13 -0400 Message-ID: <5434352A.6080403@linux.vnet.ibm.com> Date: Tue, 07 Oct 2014 14:47:06 -0400 From: Stefan Berger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Jason Gunthorpe CC: Andy Lutomirski , Peter Huewe , keyrings@linux-nfs.org, jarkko.sakkinnen@linux.intel.com, "ksummit-discuss@lists.linuxfoundation.org" , "linux-kernel@vger.kernel.org" , LSM List , tpmdd-devel@lists.sourceforge.net, James Morris , linux-ima-devel@lists.sourceforge.net, trousers-tech@lists.sourceforge.net Subject: Re: [tpmdd-devel] [TrouSerS-tech] [Ksummit-discuss] TPM MiniSummit @ LinuxCon Europe References: <543428E1.7050702@linux.vnet.ibm.com> <20141007180209.GD10432@obsidianresearch.com> In-Reply-To: <20141007180209.GD10432@obsidianresearch.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14100718-1344-0000-0000-000004C0FE85 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/07/2014 02:02 PM, Jason Gunthorpe wrote: > On Tue, Oct 07, 2014 at 01:54:41PM -0400, Stefan Berger wrote: > >> Why add the complexity of swapping of authenticated sessions and keys >> into the kernel if you can handle this in userspace? You need a library >> that is aware of the number of key slots and slots for sessions in the >> TPM and swaps them in at out when applications need them. Trousers is >> such a library that was designed to cope with the limitations of the >> device and make its functionality available to all applications that >> want to access it. > How does trousers work with the kernel when the kernel is also using > TPM key slots for IMA/keyring/whatever? IIRC it only uses a single key slot and swaps all keys in and out of that one. If the kernel was to fill up all key (and sessions) slots, TSS would probably not work anymore. Another argument for the TSS is that you also wouldn't want applications to swap out each others keys and sessions and leave them out or assume that they would always cleanup if they do not currently need them. Regards, Stefan -- 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/