From patchwork Fri May 17 21:39:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10948651 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 367F513AD for ; Fri, 17 May 2019 21:39:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 269E42847E for ; Fri, 17 May 2019 21:39:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1A04C28481; Fri, 17 May 2019 21:39:27 +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 8688A2847E for ; Fri, 17 May 2019 21:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729559AbfEQVjZ (ORCPT ); Fri, 17 May 2019 17:39:25 -0400 Received: from mail-ot1-f74.google.com ([209.85.210.74]:50048 "EHLO mail-ot1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729549AbfEQVjZ (ORCPT ); Fri, 17 May 2019 17:39:25 -0400 Received: by mail-ot1-f74.google.com with SMTP id n21so3988910otq.16 for ; Fri, 17 May 2019 14:39:24 -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=NMhZkopB0GpdYEYudYKJxS5gWiq2qdR7lapWfQjPHn0=; b=SVK7SiPj/V3msfc/agSdMuR9LrKkbFO1/ab3d9PXzQ9M9qUO3aPHl1n+vK96HAVeYn 10FDapu3hsEc9f/lfnMM4yCzlTVLdAf8Io0hozKJedsHhMkFNdzRmwPLD7M5kF3BbRNh gZukKztYKQeYm0ODATLLWCMn5cGKaWUPFoVr4zsqqSnqFwKrNCAmlZRK0Ki3BetJfqWr iJzmDtWMc9m8BvjrBxCwRcD4Amc6ZjaYJV8uGUlEyxUAL86OUonvxSnbCnbt50l7ySsW VqPcjco2lRSQjKT5iwzITTrgLfmIRMk+DDCiZHEGs4D+o/CcMrPh79iD6v/CK6fU/DkF 3H2Q== 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=NMhZkopB0GpdYEYudYKJxS5gWiq2qdR7lapWfQjPHn0=; b=fA7QqHRmW46btEm6caU9S31HBWgyumrc3keYD0G9IrFHWkvuwGfxKrmNp0QE+7s3Da BYwXsmlLct7dX8ATwwvwDtHVZGbX2of1m7iNCJMRK6hVSgHhKksFzpxXdHJNASYuN0Zt OUMvj/JkQ5ykzIsG26jXta+cSmfSX2ZUM8NTy642UNASgZmkYQ2Dz/zswmjn7aZYTW6J gNhj4lKh4hc3dQav+Qz3zHEUVZy5RW+9VZD1tDdlLRj3ykDbP3HPgPRkl9k5T7jdCq+I qJMIJI2VBoRnIgTQwCsCrQzpQQ0QeOCbJnT7s6qq5HiSiVbPuHTIjmFSiervOBngoCId wX1w== X-Gm-Message-State: APjAAAW/BGTcZ/BXA2M1iT4ZroGJi8EJy4IZW8BhcnU510ek+H9Uuq5w MkupzMuPz1x8jBICn7gKVUxysUmu/MQ/QeCQVeotZQ== X-Google-Smtp-Source: APXvYqx5qlxXPSzsxfB4hCYJ9cYilyQiRVQHXdTQs11EVxGGS+4U4FmM3CEY9rrsh4jWlBe/H/N/BWdBWq09Pglde5Ca3w== X-Received: by 2002:aca:c353:: with SMTP id t80mr15750329oif.75.1558129164259; Fri, 17 May 2019 14:39:24 -0700 (PDT) Date: Fri, 17 May 2019 14:39:15 -0700 In-Reply-To: <20190517213918.26045-1-matthewgarrett@google.com> Message-Id: <20190517213918.26045-2-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190517213918.26045-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH V6 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 Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- 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