From patchwork Tue Sep 27 16:49:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 12990969 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 5A69DC07E9D for ; Tue, 27 Sep 2022 16:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232447AbiI0QvN (ORCPT ); Tue, 27 Sep 2022 12:51:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233266AbiI0QuO (ORCPT ); Tue, 27 Sep 2022 12:50:14 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAAA35FDE3 for ; Tue, 27 Sep 2022 09:50:11 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id w10so9590989pll.11 for ; Tue, 27 Sep 2022 09:50:11 -0700 (PDT) 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; bh=Y5IIjhYcp6pllpBstUKppAn5vOER8d/5NeFiMFC+AZ4=; b=KtOFCJo06CDDr+BAxpO/ygHq6cEPoZynIvZgbfM1UHBzDuHQUJ5CbEi4ZoiG9svTxR pKrL9ectGlvt8OIUq4guOEuCs5QSQsuOcd71aO/aHyyn3G+JRcxLp4QddwkV6WaeekXJ p/dLQjZ0L0skPBXMyfxZMM9L8/y7cz6FrOn3c= 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; bh=Y5IIjhYcp6pllpBstUKppAn5vOER8d/5NeFiMFC+AZ4=; b=sirUceCUsg+NsJYOVxWbLgAAPmjbj4YvX47VEFbwBi13hP2mY1ShaT8L5Ub4FZKr3R 1xtfGPu332By4JYa5WEoJyFpHrnEP2PshmNKTTm6CS4NpB1x/4s3AmBEanRjhzLf0zAx 2R+9uE4DIxGVjbnncwQAJT22R06Q0LX6Zd0hcOTuo/TV4t7Sb6g/vEhMNvTnigcdfqSs ESmMSo+0dIZtZ/FRESIMorKcGwLm2lXqwSX2z1yywJpTzsbOCe/oaOBluvaGGOkyagir z2fIB7JSvSmfjWZm0+sfevR9zGCEwxLH27HwGzejR13mP/MFxSq7gmDE6bC9Uk0zW9pK IsBg== X-Gm-Message-State: ACrzQf0G+UfdgTFNgU62nXx6sTeiZAasAtNjolkI2HeFy+2/QRvKHWVf sJyb7ekNQLvK3q9gF9f+Nv9YPg== X-Google-Smtp-Source: AMsMyM4ctE5xgYsg5LsKG4IlQynNCZ/9CXt4peHvCFJnISdc8MiKkgtgmmifk2yFFB9mBJnY2OBKVA== X-Received: by 2002:a17:90a:1096:b0:202:c5a9:bf1e with SMTP id c22-20020a17090a109600b00202c5a9bf1emr5669884pja.3.1664297411430; Tue, 27 Sep 2022 09:50:11 -0700 (PDT) Received: from evgreen-glaptop.lan ([73.231.74.141]) by smtp.gmail.com with ESMTPSA id p13-20020a63950d000000b00434272fe870sm1753509pgd.88.2022.09.27.09.50.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Sep 2022 09:50:10 -0700 (PDT) From: Evan Green To: linux-kernel@vger.kernel.org Cc: linux-integrity@vger.kernel.org, apronin@chromium.org, dlunev@google.com, jarkko@kernel.org, Pavel Machek , Ben Boeckel , rjw@rjwysocki.net, corbet@lwn.net, linux-pm@vger.kernel.org, zohar@linux.ibm.com, Kees Cook , Eric Biggers , jejb@linux.ibm.com, gwendal@chromium.org, Matthew Garrett , Evan Green , Matthew Garrett , David Howells , Hao Wu , James Morris , Matthew Garrett , Paul Moore , "Serge E. Hallyn" , axelj , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v3 06/11] security: keys: trusted: Verify creation data Date: Tue, 27 Sep 2022 09:49:17 -0700 Message-Id: <20220927094559.v3.6.I6cdb522cb5ea28fcd1e35b4cd92cbd067f99269a@changeid> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220927164922.3383711-1-evgreen@chromium.org> References: <20220927164922.3383711-1-evgreen@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: keyrings@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 --- Source material for this change is at: https://patchwork.kernel.org/project/linux-pm/patch/20210220013255.1083202-9-matthewgarrett@google.com/ 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 8320cbac6f4009..438f8bc0a50582 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 a7ad83bc0e5396..c76a1b5a2e8471 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -703,6 +703,74 @@ 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 * @@ -728,8 +796,15 @@ 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);