From patchwork Fri Nov 11 23:16:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 13040922 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 15265C43219 for ; Fri, 11 Nov 2022 23:20:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234641AbiKKXUT (ORCPT ); Fri, 11 Nov 2022 18:20:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234545AbiKKXT4 (ORCPT ); Fri, 11 Nov 2022 18:19:56 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E06D83386 for ; Fri, 11 Nov 2022 15:19:51 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id k7so5376609pll.6 for ; Fri, 11 Nov 2022 15:19:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=lT6eX+hZD0ZTySUyAECYTCle2DEgzv1f+QjqPC3Dddk=; b=U2W25pAvqdkdkWLcokZmO7l4t8Bw+tkvFOixYVuwcikCJOh84eIQEtmWeKRV3H67Cl kkxJiMOaisdceUpyytoKvTfzcHeG1zNMnbI8yauLRuL0bHiOYiKgs6QRKMPhmj7br+cC RfbQaXDPPOrgB0ad6d6z+NtpYbMorkvaHf22o= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=lT6eX+hZD0ZTySUyAECYTCle2DEgzv1f+QjqPC3Dddk=; b=WWO8QMpFFcyL9XCxXWAERRoVE7vJyU8VgimUg+THr7OBX57iJExhhIC871VzkJBG4z MJku0kllTZ0yT5iwVXBkwKbfVGJmI8YQCuqaKMipWgip/wat4LET3RxZ3fjQ/55wxLq3 Mdlk4Lyzfo+O88VSLlPESqD8NMPkPx3LkgZDpyfXSQgsMHDNd1L4VFeReHmpv/X7GacS wQ+A2tA2IoEEF2FnJRNyCxyPtJmsRwPXH8y1P9i5A2gi3r+tb5C4RmGW/wkLZIeLnFCz GgDSpOnb5bMRby0Rzmp5XbUuYb7cp9hu3ipoFZ/kUMCZXtL4Bc2lAYNT8fiO/lG0MiY8 jd0w== X-Gm-Message-State: ANoB5plJm3CJVCe1+N0s0JbNEnch6aFCD99/52syk4qIqIRRqFyQHsrm 30nUjyycbg3N6s6BFkVP9vuAGw== X-Google-Smtp-Source: AA0mqf4p+IlUyIKh3j0vUMhqyQotcP0Ad7fK3S6VQzoCBIJimaKlPbs9tjtuMVYQHk1nqchFwy1AhQ== X-Received: by 2002:a17:902:9b97:b0:186:5f71:7939 with SMTP id y23-20020a1709029b9700b001865f717939mr4244136plp.162.1668208791108; Fri, 11 Nov 2022 15:19:51 -0800 (PST) Received: from evgreen-glaptop.lan ([98.45.28.95]) by smtp.gmail.com with ESMTPSA id x128-20020a623186000000b0056da2ad6503sm2106900pfx.39.2022.11.11.15.19.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Nov 2022 15:19:50 -0800 (PST) From: Evan Green To: linux-kernel@vger.kernel.org Cc: corbet@lwn.net, linux-integrity@vger.kernel.org, Eric Biggers , gwendal@chromium.org, dianders@chromium.org, apronin@chromium.org, Pavel Machek , Ben Boeckel , rjw@rjwysocki.net, jejb@linux.ibm.com, Kees Cook , dlunev@google.com, zohar@linux.ibm.com, Matthew Garrett , jarkko@kernel.org, linux-pm@vger.kernel.org, Evan Green , Matthew Garrett , David Howells , James Morris , Paul Moore , "Serge E. Hallyn" , axelj , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v5 06/11] security: keys: trusted: Verify creation data Date: Fri, 11 Nov 2022 15:16:31 -0800 Message-Id: <20221111151451.v5.6.I6cdb522cb5ea28fcd1e35b4cd92cbd067f99269a@changeid> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog In-Reply-To: <20221111231636.3748636-1-evgreen@chromium.org> References: <20221111231636.3748636-1-evgreen@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org If a loaded key contains creation data, ask the TPM to verify that creation data. This allows users like encrypted hibernate to know that the loaded and parsed creation data has not been tampered with. Suggested-by: Matthew Garrett Signed-off-by: Evan Green Reviewed-by: Kees Cook --- Source material for this change is at: https://patchwork.kernel.org/project/linux-pm/patch/20210220013255.1083202-9-matthewgarrett@google.com/ (no changes since v3) Changes in v3: - Changed funky tag to suggested-by (Kees). Matthew, holler if you want something different. Changes in v2: - Adjust hash len by 2 due to new ASN.1 storage, and add underflow check. include/linux/tpm.h | 1 + security/keys/trusted-keys/trusted_tpm2.c | 77 ++++++++++++++++++++++- 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 70134e6551745f..9c2ee3e30ffa5d 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -224,6 +224,7 @@ enum tpm2_command_codes { TPM2_CC_SELF_TEST = 0x0143, TPM2_CC_STARTUP = 0x0144, TPM2_CC_SHUTDOWN = 0x0145, + TPM2_CC_CERTIFYCREATION = 0x014A, TPM2_CC_NV_READ = 0x014E, TPM2_CC_CREATE = 0x0153, TPM2_CC_LOAD = 0x0157, diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 3d84c3d41bdee1..402933f8c99ede 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -730,6 +730,74 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip, return rc; } +/** + * tpm2_certify_creation() - execute a TPM2_CertifyCreation command + * + * @chip: TPM chip to use + * @payload: the key data in clear and encrypted form + * @blob_handle: the loaded TPM handle of the key + * + * Return: 0 on success + * -EINVAL on tpm error status + * < 0 error from tpm_send or tpm_buf_init + */ +static int tpm2_certify_creation(struct tpm_chip *chip, + struct trusted_key_payload *payload, + u32 blob_handle) +{ + struct tpm_header *head; + struct tpm_buf buf; + int rc; + + rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CERTIFYCREATION); + if (rc) + return rc; + + /* Use TPM_RH_NULL for signHandle */ + tpm_buf_append_u32(&buf, 0x40000007); + + /* Object handle */ + tpm_buf_append_u32(&buf, blob_handle); + + /* Auth */ + tpm_buf_append_u32(&buf, 9); + tpm_buf_append_u32(&buf, TPM2_RS_PW); + tpm_buf_append_u16(&buf, 0); + tpm_buf_append_u8(&buf, 0); + tpm_buf_append_u16(&buf, 0); + + /* Qualifying data */ + tpm_buf_append_u16(&buf, 0); + + /* Creation data hash */ + if (payload->creation_hash_len < 2) { + rc = -EINVAL; + goto out; + } + + tpm_buf_append_u16(&buf, payload->creation_hash_len - 2); + tpm_buf_append(&buf, payload->creation_hash + 2, + payload->creation_hash_len - 2); + + /* signature scheme */ + tpm_buf_append_u16(&buf, TPM_ALG_NULL); + + /* creation ticket */ + tpm_buf_append(&buf, payload->tk, payload->tk_len); + + rc = tpm_transmit_cmd(chip, &buf, 6, "certifying creation data"); + if (rc) + goto out; + + head = (struct tpm_header *)buf.data; + + if (be32_to_cpu(head->return_code) != TPM2_RC_SUCCESS) + rc = -EINVAL; +out: + tpm_buf_destroy(&buf); + return rc; +} + /** * tpm2_unseal_trusted() - unseal the payload of a trusted key * @@ -755,8 +823,15 @@ int tpm2_unseal_trusted(struct tpm_chip *chip, goto out; rc = tpm2_unseal_cmd(chip, payload, options, blob_handle); - tpm2_flush_context(chip, blob_handle); + if (rc) + goto flush; + + if (payload->creation_len) + rc = tpm2_certify_creation(chip, payload, blob_handle); + +flush: + tpm2_flush_context(chip, blob_handle); out: tpm_put_ops(chip);