From patchwork Mon May 20 20:54:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10952349 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CCF9614C0 for ; Mon, 20 May 2019 20:55:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BC8A02871F for ; Mon, 20 May 2019 20:55:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B07C928896; Mon, 20 May 2019 20:55:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_HI,USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 387282871F for ; Mon, 20 May 2019 20:55:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726931AbfETUz1 (ORCPT ); Mon, 20 May 2019 16:55:27 -0400 Received: from mail-qt1-f202.google.com ([209.85.160.202]:38401 "EHLO mail-qt1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726855AbfETUzJ (ORCPT ); Mon, 20 May 2019 16:55:09 -0400 Received: by mail-qt1-f202.google.com with SMTP id 28so13226419qtw.5 for ; Mon, 20 May 2019 13:55:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=akrm/3bgh71I70hR0K09l3Kfzzk0aIwNcfCkA5T1H8s=; b=YBpxht9kl8QYDiQ4NThsO65nDKncBg5XXpPzCNuHbT4kR7k7m0qx2/e6WdDmMsY2LY 2iLbS1wFLp6/bGp5FJa/Eo9+dJu1YFPAi9sl9XwAPRy5XI699M8FGgE45AOooLuweR6O gha7bK5+MQaJxFFeJAk3iPUZltWJVWxqBNLcjgfb3Cu7FLGAHh+Mgx61RYJGcEls3wcv ioK5P59ZLO4RWWuJe8gEgYB0SLYIr0S0drSe5DfqZ8oE9wDAy6Hq5siXjpUcd4nlvldz jmEdqpWaXcU0TJhsFdE6Jlqwynd771VjOkcgUnAoBRH14294GeufY8URUrFX2A7JYt4O sBXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=akrm/3bgh71I70hR0K09l3Kfzzk0aIwNcfCkA5T1H8s=; b=mPr2yLoYRfboxpSRd4wvolaTogdU4nYQor9x8IikB4TvBc0zTPyCHvJeABlpZiVR+Q MsCV48s3b5UpFiQ3fpo0EVoDT2X0xzwThxpNJBKUCi08gN2SGCSc64a7EQ/rerNE2DQh L3p5GccYqdhVCL4l9bujmgWjQqB4e7Sw6hpe/kgIkJB6pxK6hdNtm5952DX9lBeP+KU6 /83s+o0wfVq3lLzKSZAn4RrEY9o8ZiEu5d0TS3b3NjLK1DxGvU57bcvHMfAGlZX2am4K urQ0YrSzJss/6rfa58ENi2Vv66ezTyEauJKFjv8+33e44xElBgQIv2VBcv57QZ/Keh9i OEZg== X-Gm-Message-State: APjAAAVNfUR6k+JhYUdueq7N8Ug134rb47lZ3BGCZKWbSumHdtTbuE4R Rw7s97XgG8vWvo8XdtBdl0eoW0tRvBiyCXW0CrUqmw== X-Google-Smtp-Source: APXvYqzKTMYg8rW5jVfSQPhysQn7BFeOUlYvYPTcDiKFgnvWNRdEhRqy390LZ8ffPMPH9cPbWXbojWbOAP680fBQu19y3w== X-Received: by 2002:aed:21ca:: with SMTP id m10mr60246543qtc.97.1558385708444; Mon, 20 May 2019 13:55:08 -0700 (PDT) Date: Mon, 20 May 2019 13:54:58 -0700 In-Reply-To: <20190520205501.177637-1-matthewgarrett@google.com> Message-Id: <20190520205501.177637-2-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190520205501.177637-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH V7 1/4] tpm: Abstract crypto agile event size calculations From: Matthew Garrett To: linux-integrity@vger.kernel.org Cc: peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, jgg@ziepe.ca, roberto.sassu@huawei.com, linux-efi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, tweek@google.com, bsz@semihalf.com, Matthew Garrett Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Matthew Garrett We need to calculate the size of crypto agile events in multiple locations, including in the EFI boot stub. The easiest way to do this is to put it in a header file as an inline and leave a wrapper to ensure we don't end up with multiple copies of it embedded in the existing code. Signed-off-by: Matthew Garrett --- drivers/char/tpm/eventlog/tpm2.c | 47 +--------------------- include/linux/tpm_eventlog.h | 68 ++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 46 deletions(-) diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c index f824563fc28d..1a977bdd3bd2 100644 --- a/drivers/char/tpm/eventlog/tpm2.c +++ b/drivers/char/tpm/eventlog/tpm2.c @@ -40,52 +40,7 @@ static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event, struct tcg_pcr_event *event_header) { - struct tcg_efi_specid_event_head *efispecid; - struct tcg_event_field *event_field; - void *marker; - void *marker_start; - u32 halg_size; - size_t size; - u16 halg; - int i; - int j; - - marker = event; - marker_start = marker; - marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type) - + sizeof(event->count); - - efispecid = (struct tcg_efi_specid_event_head *)event_header->event; - - /* Check if event is malformed. */ - if (event->count > efispecid->num_algs) - return 0; - - for (i = 0; i < event->count; i++) { - halg_size = sizeof(event->digests[i].alg_id); - memcpy(&halg, marker, halg_size); - marker = marker + halg_size; - for (j = 0; j < efispecid->num_algs; j++) { - if (halg == efispecid->digest_sizes[j].alg_id) { - marker += - efispecid->digest_sizes[j].digest_size; - break; - } - } - /* Algorithm without known length. Such event is unparseable. */ - if (j == efispecid->num_algs) - return 0; - } - - event_field = (struct tcg_event_field *)marker; - marker = marker + sizeof(event_field->event_size) - + event_field->event_size; - size = marker - marker_start; - - if ((event->event_type == 0) && (event_field->event_size == 0)) - return 0; - - return size; + return __calc_tpm2_event_size(event, event_header); } static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos) diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h index 81519f163211..6a86144e13f1 100644 --- a/include/linux/tpm_eventlog.h +++ b/include/linux/tpm_eventlog.h @@ -112,4 +112,72 @@ struct tcg_pcr_event2_head { struct tpm_digest digests[]; } __packed; +/** + * __calc_tpm2_event_size - calculate the size of a TPM2 event log entry + * @event: Pointer to the event whose size should be calculated + * @event_header: Pointer to the initial event containing the digest lengths + * + * The TPM2 event log format can contain multiple digests corresponding to + * separate PCR banks, and also contains a variable length of the data that + * was measured. This requires knowledge of how long each digest type is, + * and this information is contained within the first event in the log. + * + * We calculate the length by examining the number of events, and then looking + * at each event in turn to determine how much space is used for events in + * total. Once we've done this we know the offset of the data length field, + * and can calculate the total size of the event. + * + * Return: size of the event on success, <0 on failure + */ + +static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, + struct tcg_pcr_event *event_header) +{ + struct tcg_efi_specid_event_head *efispecid; + struct tcg_event_field *event_field; + void *marker; + void *marker_start; + u32 halg_size; + size_t size; + u16 halg; + int i; + int j; + + marker = event; + marker_start = marker; + marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type) + + sizeof(event->count); + + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; + + /* Check if event is malformed. */ + if (event->count > efispecid->num_algs) + return 0; + + for (i = 0; i < event->count; i++) { + halg_size = sizeof(event->digests[i].alg_id); + memcpy(&halg, marker, halg_size); + marker = marker + halg_size; + for (j = 0; j < efispecid->num_algs; j++) { + if (halg == efispecid->digest_sizes[j].alg_id) { + marker += + efispecid->digest_sizes[j].digest_size; + break; + } + } + /* Algorithm without known length. Such event is unparseable. */ + if (j == efispecid->num_algs) + return 0; + } + + event_field = (struct tcg_event_field *)marker; + marker = marker + sizeof(event_field->event_size) + + event_field->event_size; + size = marker - marker_start; + + if ((event->event_type == 0) && (event_field->event_size == 0)) + return 0; + + return size; +} #endif