From patchwork Tue Sep 12 11:11:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gstir X-Patchwork-Id: 13381460 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 1E450CA0ECF for ; Tue, 12 Sep 2023 11:12:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234667AbjILLMd (ORCPT ); Tue, 12 Sep 2023 07:12:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234886AbjILLLs (ORCPT ); Tue, 12 Sep 2023 07:11:48 -0400 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 697C41717 for ; Tue, 12 Sep 2023 04:11:42 -0700 (PDT) Received: by mail-ej1-x62b.google.com with SMTP id a640c23a62f3a-986d8332f50so731631966b.0 for ; Tue, 12 Sep 2023 04:11:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sigma-star.at; s=google; t=1694517101; x=1695121901; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=WMxyxYMtu219LMB4VQwtAfAzEA7xWrv4p6+B3IeeMCg=; b=RB9Md7NlopPy6qhyoTLIEklGGL7AteMsFTzJ2pObAafH1jAv3ApAAoF98dEr+Z8inr ZGB7RqZB1AL9mlKGNDnB4Zivw/+qBj4ENDjiR5ZEo+P2t3SzOKv8uJrVruwcz6BIWz3p +Li9EQB958qRO1g4km5Esobef25kpP13b1aemfcY2bqDbjGG4NIGK3kQuFqvcU/iUu0H 1FIf6sesuYNfMHKgn6pxFasSCPdeCR7/1TtVqOwgTfGcfAdku1QdjWNUBVLochlfwGlw 6ssTQRfLmCf1f1+nBJvXw2ZoFRQ3AhF3hbu3/tGGe87CM4dx3trmP9uEQC0pFxDpMUd6 TZuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694517101; x=1695121901; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=WMxyxYMtu219LMB4VQwtAfAzEA7xWrv4p6+B3IeeMCg=; b=s23jrgNS8apzxCprIqHrWW8Mm0eARJDDWTww4Qy6IrAoxpDlrJF2hhYwsJ3NP+QPp5 b5XHHModpMZpBSIAY6JU8U0TBA7LLYcv1MnEaPBoDalvG7fVcn5+Xczy43YaIyDatFAL OGT6jQLCHCd41NzM9WN6h1KjU8aqzUi4Kj4IeueP+L9/hu67OigLeXP1XVs7AcrTib0r l44BAiC4U6MaTb0XlLwuyb/+ug0UUDd8a4GxtmqL37eh8QgONmr0RRXxrQu2W73lJVwK hVKOnjCzvpOhZlIeJpD4hV8sXVR/8GbMNU8BzU3SfrrKCIAB4fNeLVHjfGyw2Al/JdQ1 wkhA== X-Gm-Message-State: AOJu0Ywg8aGdjUfB8reOf4IqfrBXLh4nEyGDCVSd5Mdx2D12SPuecSCj tlFG8OGiNGhrD0hfXH0wIJV90g== X-Google-Smtp-Source: AGHT+IGVIXpipGIV3RcKzH1lIoBGyC+f3uy72Hr8eeCBPxmUGKKb6/6xig/ZZuHGDB1u6QZuTruK9g== X-Received: by 2002:a17:906:2895:b0:9a1:b967:aca9 with SMTP id o21-20020a170906289500b009a1b967aca9mr9945956ejd.63.1694517100748; Tue, 12 Sep 2023 04:11:40 -0700 (PDT) Received: from localhost ([82.150.214.1]) by smtp.gmail.com with UTF8SMTPSA id rp6-20020a170907888600b009a9fbeb15f2sm6393915ejc.62.2023.09.12.04.11.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Sep 2023 04:11:40 -0700 (PDT) From: David Gstir To: Mimi Zohar , James Bottomley , Jarkko Sakkinen , Herbert Xu , "David S. Miller" Cc: David Gstir , Shawn Guo , Jonathan Corbet , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Ahmad Fatoum , sigma star Kernel Team , David Howells , Li Yang , Paul Moore , James Morris , "Serge E. Hallyn" , "Paul E. McKenney" , Randy Dunlap , Catalin Marinas , "Rafael J. Wysocki" , Tejun Heo , "Steven Rostedt (Google)" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 0/3] DCP as trusted keys backend Date: Tue, 12 Sep 2023 13:11:11 +0200 Message-ID: <20230912111115.24274-1-david@sigma-star.at> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org This is a revival of the previous patch set submitted by Richard Weinberger: https://lore.kernel.org/linux-integrity/20210614201620.30451-1-richard@nod.at/ v1 -> v2: - Revive and rebase to latest version - Include review comments from Ahmad Fatoum The Data CoProcessor (DCP) is an IP core built into many NXP SoCs such as i.mx6ull. Similar to the CAAM engine used in more powerful SoCs, DCP can AES- encrypt/decrypt user data using a unique, never-disclosed, device-specific key. Unlike CAAM though, it cannot directly wrap and unwrap blobs in hardware. As DCP offers only the bare minimum feature set and a blob mechanism needs aid from software. A blob in this case is a piece of sensitive data (e.g. a key) that is encrypted and authenticated using the device-specific key so that unwrapping can only be done on the hardware where the blob was wrapped. This patch series adds a DCP based, trusted-key backend and is similar in spirit to the one by Ahmad Fatoum [0] that does the same for CAAM. It is of interest for similar use cases as the CAAM patch set, but for lower end devices, where CAAM is not available. Because constructing and parsing the blob has to happen in software, we needed to decide on a blob format and chose the following: struct dcp_blob_fmt { __u8 fmt_version; __u8 blob_key[AES_KEYSIZE_128]; __u8 nonce[AES_KEYSIZE_128]; __le32 payload_len; __u8 payload[]; } __packed; The `fmt_version` is currently 1. The encrypted key is stored in the payload area. It is AES-128-GCM encrypted using `blob_key` and `nonce`, GCM auth tag is attached at the end of the payload (`payload_len` does not include the size of the auth tag). The `blob_key` itself is encrypted in AES-128-ECB mode by DCP using the OTP or UNIQUE device key. A new `blob_key` and `nonce` are generated randomly, when sealing/exporting the DCP blob. This patchset was tested with dm-crypt on an i.MX6ULL board. [0] https://lore.kernel.org/keyrings/20220513145705.2080323-1-a.fatoum@pengutronix.de/ David Gstir (3): crypto: mxs-dcp: Add support for hardware provided keys KEYS: trusted: Introduce support for NXP DCP-based trusted keys doc: trusted-encrypted: add DCP as new trust source .../admin-guide/kernel-parameters.txt | 13 + .../security/keys/trusted-encrypted.rst | 85 +++++ MAINTAINERS | 9 + drivers/crypto/mxs-dcp.c | 107 +++++- include/keys/trusted_dcp.h | 13 + include/soc/fsl/dcp.h | 19 ++ security/keys/trusted-keys/Kconfig | 9 +- security/keys/trusted-keys/Makefile | 2 + security/keys/trusted-keys/trusted_core.c | 6 +- security/keys/trusted-keys/trusted_dcp.c | 313 ++++++++++++++++++ 10 files changed, 563 insertions(+), 13 deletions(-) create mode 100644 include/keys/trusted_dcp.h create mode 100644 include/soc/fsl/dcp.h create mode 100644 security/keys/trusted-keys/trusted_dcp.c