From patchwork Tue Aug 23 22:25:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 12952688 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 487BBC38145 for ; Tue, 23 Aug 2022 22:26:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233998AbiHWW0z (ORCPT ); Tue, 23 Aug 2022 18:26:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234036AbiHWW0R (ORCPT ); Tue, 23 Aug 2022 18:26:17 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAF9288DC8 for ; Tue, 23 Aug 2022 15:26:09 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id u22so14043415plq.12 for ; Tue, 23 Aug 2022 15:26:09 -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; bh=h89V1jB8raz93s1UBdB755/qSlB/lATdkVzyb86xPlg=; b=nUlTu7qh1+o9COlB+JNxnTLFZQTa21AWzmc5sREQt16+4GKZCIQRkcyAEa9vEdLjFC MLZN9LcUOkjMGlexXqOKvML0eL7cxFfEybdFjI4Golhz8r3+DMqZvh8D2yrr+i813YdN D3AF/4liowxe+gcSd9iEKQUzpVAGnA7uWp0BE= 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; bh=h89V1jB8raz93s1UBdB755/qSlB/lATdkVzyb86xPlg=; b=6tpKRU1Jqu+iGiXyL3eqgY1+qGmjZBD3F/nXF2Tlyw/g0rB9cpc4V6k4dev/OeHhCU TMOAKFLMrxv8odSH3HBnOQ3wgU4mOsvc917WD3dHIIf4EuzHRGwFF+OeUiE3Y83MNe1N bbJc2tpT032FZ/uF4Cq161N8qPT4QZmZbrZiZHwv8NJrAxD/guK253I4q/isVPCFXywO YvsoevC5tRELXVvDjMIbjJQgAP7g69RP+UoidPKd/R0lwl+O1mlj52LPY/FmZVQkOdsT 6Oe7TR2bXSaqRODWkVPLKCG3NNKGXsXbkAYv4XYBbFSwgNrFP+83m9te0E3GDiIEL+kB Wtzg== X-Gm-Message-State: ACgBeo3gVJUwLtm8CQKBKRBWHkazJxMBCvXOws67YIItdHxw7aTuHBYj k+iaZ9WLakS2rLGMBZlFuSGNbg== X-Google-Smtp-Source: AA6agR6HauYb0XBAWZ9hxasy/RS63+xeO6/mMszxWoZRfjFzB6BGPJ5MpePgHRrY3xKu2KtNxa7bXA== X-Received: by 2002:a17:90a:e7c2:b0:1f5:85ab:938c with SMTP id kb2-20020a17090ae7c200b001f585ab938cmr5289101pjb.133.1661293569204; Tue, 23 Aug 2022 15:26:09 -0700 (PDT) Received: from evgreen-glaptop.lan ([98.45.66.167]) by smtp.gmail.com with ESMTPSA id f76-20020a62384f000000b0052f20d70845sm11256292pfa.150.2022.08.23.15.26.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 15:26:08 -0700 (PDT) From: Evan Green To: linux-kernel@vger.kernel.org Cc: gwendal@chromium.org, Eric Biggers , Matthew Garrett , jarkko@kernel.org, zohar@linux.ibm.com, linux-integrity@vger.kernel.org, Pavel Machek , apronin@chromium.org, dlunev@google.com, rjw@rjwysocki.net, linux-pm@vger.kernel.org, corbet@lwn.net, jejb@linux.ibm.com, Matthew Garrett , Matthew Garrett , Evan Green , David Howells , James Morris , Paul Moore , "Serge E. Hallyn" , keyrings@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v2 04/10] security: keys: trusted: Allow storage of PCR values in creation data Date: Tue, 23 Aug 2022 15:25:20 -0700 Message-Id: <20220823152108.v2.4.I32591db064b6cdc91850d777f363c9d05c985b39@changeid> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220823222526.1524851-1-evgreen@chromium.org> References: <20220823222526.1524851-1-evgreen@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: 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/ (no changes since v1) .../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 0bfb4c33974890..dc9e11bb4824da 100644 --- a/Documentation/security/keys/trusted-encrypted.rst +++ b/Documentation/security/keys/trusted-encrypted.rst @@ -199,6 +199,10 @@ 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 209086fed240a5..8523d41507b2a4 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 1f166d4fa307a9..1d1470b880ca01 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -389,7 +389,7 @@ 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++) { @@ -458,7 +458,28 @@ 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;