From patchwork Wed May 4 23:20:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 12838905 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 2B328C433FE for ; Wed, 4 May 2022 23:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353875AbiEEABb (ORCPT ); Wed, 4 May 2022 20:01:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1382648AbiEDXZO (ORCPT ); Wed, 4 May 2022 19:25:14 -0400 Received: from mail-pj1-x102f.google.com (mail-pj1-x102f.google.com [IPv6:2607:f8b0:4864:20::102f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AAE04EA34 for ; Wed, 4 May 2022 16:21:36 -0700 (PDT) Received: by mail-pj1-x102f.google.com with SMTP id cq17-20020a17090af99100b001dc0386cd8fso2551875pjb.5 for ; Wed, 04 May 2022 16:21:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=oSCDp+BlWHOAe2tqoHinPSSzUxabaz3SWirbYWgZ7iE=; b=AK96nFD2jq9As8QRqe4ZZgrKB3muSxd4UKPDu0PiPgxZCEkF09YM3a/lbxSE2Aolhc 8/11YUs8xGSuIa13K4FNjPmrXP32NRaFX2/fqhw5ycNjYisg1PBFJZiM4dKkwgF7l4SI 8V/qwibG9N2Kolpq0e2PDsUZD0WN7jb8AqoT4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=oSCDp+BlWHOAe2tqoHinPSSzUxabaz3SWirbYWgZ7iE=; b=bIyL7BS3l9gIHZRazu1skmYdgbJmUkUDhOhzo+12082bt7gBEb9JLhGYL63rCq9rNh +eqGIO4EwA5tjprVEzCmMZj5GEMjQCzQcU2jpiZvG0gpptUwS9RqPJpjK4GPkH0Xkb5+ vkxcO8muodUQNMdoQYthdN9j9mw37zfRsxUbmUtQ5M9y/b/lDb+QumcZq33xCw5pKxqZ QhgTeRXhqVXU02DLH/okmN4d42VJ3qc+flhf2X4psb3bEDOM+UnU6BiEi5fasPui/YoX 2eSEMyJ94odp9tjivrTs19/ZxDBJV6UiPsEcMRL/QZE326M6cU7v6G5ibEBmZu0cqo/X /TtA== X-Gm-Message-State: AOAM531GsfNFraaiMLfQeGLbyO2idopFdYoUSDru7kdinbdZLVPE4Bhk ZGsVwxYKToUTSGzJTwjVdIHnQQ== X-Google-Smtp-Source: ABdhPJyWCNX/I16qyW4fvcathhxcuAgJ0GjSbW0c5vLuKr3I6Bnp2rIZfhNKLxSoEtDyFcQM2HOpmw== X-Received: by 2002:a17:902:7e01:b0:15e:caea:d6 with SMTP id b1-20020a1709027e0100b0015ecaea00d6mr4372912plm.33.1651706495884; Wed, 04 May 2022 16:21:35 -0700 (PDT) Received: from evgreen-glaptop.lan ([98.47.98.87]) by smtp.gmail.com with ESMTPSA id q12-20020a170902f78c00b0015e8d4eb2d6sm1901pln.288.2022.05.04.16.21.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 May 2022 16:21:35 -0700 (PDT) From: Evan Green To: linux-kernel@vger.kernel.org Cc: Matthew Garrett , dlunev@google.com, zohar@linux.ibm.com, jejb@linux.ibm.com, linux-integrity@vger.kernel.org, corbet@lwn.net, rjw@rjwysocki.net, gwendal@chromium.org, jarkko@kernel.org, linux-pm@vger.kernel.org, Matthew Garrett , Matthew Garrett , Evan Green , David Howells , James Morris , "Serge E. Hallyn" , keyrings@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH 04/10] security: keys: trusted: Allow storage of PCR values in creation data Date: Wed, 4 May 2022 16:20:56 -0700 Message-Id: <20220504161439.4.I32591db064b6cdc91850d777f363c9d05c985b39@changeid> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220504232102.469959-1-evgreen@chromium.org> References: <20220504232102.469959-1-evgreen@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Matthew Garrett When TPMs generate keys, they can also generate some information describing the state of the PCRs at creation time. This data can then later be certified by the TPM, allowing verification of the PCR values. This allows us to determine the state of the system at the time a key was generated. Add an additional argument to the trusted key creation options, allowing the user to provide the set of PCRs that should have their values incorporated into the creation data. From: Matthew Garrett Signed-off-by: Matthew Garrett Signed-off-by: Evan Green --- Matthew's original version of this patch is at: https://patchwork.kernel.org/patch/12096503/ .../security/keys/trusted-encrypted.rst | 4 +++ include/keys/trusted-type.h | 1 + security/keys/trusted-keys/trusted_tpm1.c | 9 +++++++ security/keys/trusted-keys/trusted_tpm2.c | 25 +++++++++++++++++-- 4 files changed, 37 insertions(+), 2 deletions(-) diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst index f614dad7de12f9..7215b067bf128f 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -170,6 +170,10 @@ Usage:: policyhandle= handle to an authorization policy session that defines the same policy and with the same hash algorithm as was used to seal the key. + creationpcrs= hex integer representing the set of PCR values to be + included in the PCR creation data. The bit corresponding + to each PCR should be 1 to be included, 0 to be ignored. + TPM2 only. "keyctl print" returns an ascii hex copy of the sealed key, which is in standard TPM_STORED_DATA format. The key length for new keys are always in bytes. diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h index 8a793ae1ad9f70..b3ac4afe8ba987 100644 --- a/include/keys/trusted-type.h +++ b/include/keys/trusted-type.h @@ -54,6 +54,7 @@ struct trusted_key_options { uint32_t policydigest_len; unsigned char policydigest[MAX_DIGEST_SIZE]; uint32_t policyhandle; + uint32_t creation_pcrs; }; struct trusted_key_ops { diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index aa108bea6739b3..2975827c01bec0 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -713,6 +713,7 @@ enum { Opt_hash, Opt_policydigest, Opt_policyhandle, + Opt_creationpcrs, }; static const match_table_t key_tokens = { @@ -725,6 +726,7 @@ static const match_table_t key_tokens = { {Opt_hash, "hash=%s"}, {Opt_policydigest, "policydigest=%s"}, {Opt_policyhandle, "policyhandle=%s"}, + {Opt_creationpcrs, "creationpcrs=%s"}, {Opt_err, NULL} }; @@ -858,6 +860,13 @@ static int getoptions(char *c, struct trusted_key_payload *pay, return -EINVAL; opt->policyhandle = handle; break; + case Opt_creationpcrs: + if (!tpm2) + return -EINVAL; + res = kstrtoint(args[0].from, 16, &opt->creation_pcrs); + if (res < 0) + return -EINVAL; + break; default: return -EINVAL; } diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index 296a00f872ba40..b7ddb78e644d17 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -290,7 +290,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip, struct tpm_buf buf; u32 hash; u32 flags; - int i; + int i, j; int rc; for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { @@ -359,7 +359,28 @@ int tpm2_seal_trusted(struct tpm_chip *chip, tpm_buf_append_u16(&buf, 0); /* creation PCR */ - tpm_buf_append_u32(&buf, 0); + if (options->creation_pcrs) { + /* One bank */ + tpm_buf_append_u32(&buf, 1); + /* Which bank to use */ + tpm_buf_append_u16(&buf, hash); + /* Length of the PCR bitmask */ + tpm_buf_append_u8(&buf, 3); + /* PCR bitmask */ + for (i = 0; i < 3; i++) { + char tmp = 0; + + for (j = 0; j < 8; j++) { + char bit = (i * 8) + j; + + if (options->creation_pcrs & (1 << bit)) + tmp |= (1 << j); + } + tpm_buf_append_u8(&buf, tmp); + } + } else { + tpm_buf_append_u32(&buf, 0); + } if (buf.flags & TPM_BUF_OVERFLOW) { rc = -E2BIG;