From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2C97EE49B1 for ; Tue, 22 Aug 2023 18:59:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229971AbjHVS7l (ORCPT ); Tue, 22 Aug 2023 14:59:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229560AbjHVS7j (ORCPT ); Tue, 22 Aug 2023 14:59:39 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 228DE137; Tue, 22 Aug 2023 11:59:38 -0700 (PDT) Received: by linux.microsoft.com (Postfix, from userid 1152) id A770E2126CD0; Tue, 22 Aug 2023 11:59:37 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A770E2126CD0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1692730777; bh=qJbjN14Eu6Dgb/Zj3Nv5uz34X4Pg/6WqJE0DfmFfXYs=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=WRgd4M8FCxtTxbpA5azLSv9g9tPTEmihEafyGrt20LiLj36if2cLx6baiIjujrYO3 N97CuHZ1m3z0C48z+z+yInzyT6tgj/l4q4cVYuYe0LD0jZzZlFINB//gDTouIA2DXy uTl0l9kSffwtL+/vMEEk63gTyaYxf/f9wvzxU8P0= Received: from localhost (localhost [127.0.0.1]) by linux.microsoft.com (Postfix) with ESMTP id A336330705C5; Tue, 22 Aug 2023 11:59:37 -0700 (PDT) Date: Tue, 22 Aug 2023 11:59:37 -0700 (PDT) From: Shyam Saini To: Sumit Garg cc: Jerome Forissier , Ulf Hansson , linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, op-tee@lists.trustedfirmware.org, linux-scsi@vger.kernel.org, =?ISO-8859-15?Q?Alex_Benn=E9e?= , Tomas Winkler , Linus Walleij , Arnd Bergmann , Ilias Apalodimas , Tyler Hicks , "Srivatsa S . Bhat" , Paul Moore , Allen Pais Subject: Re: [RFC, PATCH 1/1] rpmb: add Replay Protected Memory Block (RPMB) driver In-Reply-To: Message-ID: References: <20230722014037.42647-1-shyamsaini@linux.microsoft.com> <20230722014037.42647-2-shyamsaini@linux.microsoft.com> <94728786-b41b-1467-63c1-8e2d5acfa5e4@linaro.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="656392-984032877-1692730777=:12353" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --656392-984032877-1692730777=:12353 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT Hi Sumit, > On Mon, 21 Aug 2023 at 15:19, Jerome Forissier > wrote: >> >> >> >> On 8/17/23 01:31, Shyam Saini wrote: >>> >>> Hi Ulf, >>> >>>> On Sat, 22 Jul 2023 at 03:41, Shyam Saini >>>> wrote: >>>>> >>>>> From: Alex Bennée >>>>> >>>>> [This is patch 1 from [1] Alex's submission and this RPMB layer was >>>>> originally proposed by [2]Thomas Winkler ] >>>>> >>>>> A number of storage technologies support a specialised hardware >>>>> partition designed to be resistant to replay attacks. The underlying >>>>> HW protocols differ but the operations are common. The RPMB partition >>>>> cannot be accessed via standard block layer, but by a set of specific >>>>> commands: WRITE, READ, GET_WRITE_COUNTER, and PROGRAM_KEY. Such a >>>>> partition provides authenticated and replay protected access, hence >>>>> suitable as a secure storage. >>>>> >>>>> The initial aim of this patch is to provide a simple RPMB Driver which >>>>> can be accessed by Linux's optee driver to facilitate fast-path for >>>>> RPMB access to optee OS(secure OS) during the boot time. [1] Currently, >>>>> Optee OS relies on user-tee supplicant to access eMMC RPMB partition. >>>>> >>>>> A TEE device driver can claim the RPMB interface, for example, via >>>>> class_interface_register(). The RPMB driver provides a series of >>>>> operations for interacting with the device. >>>> >>>> I don't quite follow this. More exactly, how will the TEE driver know >>>> what RPMB device it should use? >>> >>> I don't have complete code to for this yet, but i think OP-TEE driver >>> should register with RPMB subsystem and then we can have eMMC/UFS/NVMe >>> specific implementation for RPMB operations. >>> >>> Linux optee driver can handle RPMB frames and pass it to RPMB subsystem >>> > > It would be better to have this OP-TEE use case fully implemented. So > that we can justify it as a valid user for this proposed RPMB > subsystem. If you are looking for any further suggestions then please > let us know. I was looking into UFS/NVMe user-space utils, it seems we may have to adapt rpmb frame data structure in optee-os to to handle NVMe/UFS specific bits. For nvme rpmb data frame, I think we would need an extra "target" member in rpmb data frame structure, as NVMe can support upto 7 RPMB units, see [1] "struct rpmb_data_frame_t" UFS may support upto 3 or 4 RPMB regions. So even if we use CID to uniquely identify RPMB device either from eMMC/NVMe/UFS, we still need identify which RPMB target/unit in case if the device is NVMe, and which RPMB region if the device UFS. Also both NVMe/UFS utils have two extra RPMB operations implemented, Although new request/response operation than eMMC spec: 1) Authenticated Device Configuration Block Write 2) Authenticated Device Configuration Block Read see [2] enum rpmb_request/response_type and [3]enum rpmb_op_type do we need those implemented as well ? Please let me know what you think about these. [1] https://github.com/linux-nvme/nvme-cli/blob/master/nvme-rpmb.c#L252 [2] https://github.com/linux-nvme/nvme-cli/blob/master/nvme-rpmb.c#L230 [3] https://github.com/westerndigitalcorporation/ufs-utils/blob/dev/ufs_rpmb.c#L27 >>> [1] U-Boot has mmc specific implementation >>> >>> I think OPTEE-OS has CFG_RPMB_FS_DEV_ID option >>> CFG_RPMB_FS_DEV_ID=1 for /dev/mmcblk1rpmb, >> >> Correct. Note that tee-supplicant will ignore this device ID if --rmb-cid >> is given and use the specified RPMB instead (the CID is a non-ambiguous way >> to identify a RPMB device). >> >>> but in case if a >>> system has multiple RPMB devices such as UFS/eMMC/NVMe, one them >>> should be declared as secure storage and optee should access that one only. >> >> Indeed, that would be an equivalent of tee-supplicant's --rpmb-cid. >> >>> Sumit, do you have suggestions for this ? >> > > I would suggest having an OP-TEE secure DT property that would provide > the RPMB CID which is allocated to the secure world. > > -Sumit > >> >> -- >> Jerome > --656392-984032877-1692730777=:12353--