From patchwork Fri Feb 22 20:26:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10826951 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 06B791805 for ; Fri, 22 Feb 2019 20:26:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EDAC03293A for ; Fri, 22 Feb 2019 20:26:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EBE0E328CC; Fri, 22 Feb 2019 20:26:18 +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 5FC513294E for ; Fri, 22 Feb 2019 20:26:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726975AbfBVU0R (ORCPT ); Fri, 22 Feb 2019 15:26:17 -0500 Received: from mail-pg1-f201.google.com ([209.85.215.201]:57342 "EHLO mail-pg1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726955AbfBVU0Q (ORCPT ); Fri, 22 Feb 2019 15:26:16 -0500 Received: by mail-pg1-f201.google.com with SMTP id d3so2458702pgv.23 for ; Fri, 22 Feb 2019 12:26:15 -0800 (PST) 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=PIskTotTS30my00PpyuDNjp7J1bfei86ZvMSyGFT+Tk=; b=rB/3gxjtk7QInhP1fGU8s+7yNH6+fpF0d5AA0bKpDTTw8lDg0EsawLZWApduXgPYNg 8Pp6j6FKF6wRBUiPMKzRMczZu9t5SRqDs0T1Z5bo3/ARbTqLGK0waiVl8xMr+1pT+4GK ahvQH0BMa6XLYz+5fmSqFHxEGyDIZ8sgviV3I68okHCOSlkUAJxihw6Ce9WsNogzu5Kd 1NTw+nHvBqWbsHu0YN2DhmC0lU5ReT4DLgrsQpyfYXQKQ49jxjyYhybtMlfQ2wqE20n1 eQ0VE1cdXUmhXRuJE8i73SWMG+RuWeScAXSDX6CK9xbiZAGY6qVC1B5hoX7pcov4F6n4 nRWw== 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=PIskTotTS30my00PpyuDNjp7J1bfei86ZvMSyGFT+Tk=; b=Zf3TTVWIjHZhrt5LJbH3sGAwqUx+9GUTPNu8ZTbCbjUZHfzup1LIOpXR70cN380mNw cAYSVykPD/gldjdvPThLJkEiaMZw3+pLhUZ8rHYDMGouxmhTi5FAKxAGABxIWBZx0AvN ZUVcq0oIEpK+EYqmCOB0CzLoKA1rnQY7rY4E83O8dTcMLAEQlbIAlSHoO+GZYpE9Wt58 gIpOQT+8QAH/Cxt0xCJAi3NHUScdIMak/L1LBMdG7ujOze4jDaewRUvhGmTslPiep5Pw SzLdN7Q9VwLIK/VVKhLC/sEUJa34+g6aNIfgXGJa2sLX4GScwCNYhjROsqtUN+P/4OCO Tmuw== X-Gm-Message-State: AHQUAubFiJHmv/dJcA1YnsQrCPJlDR3kLEVahadCB7beq1KXm5dCjAeb qKE/nSdTAffQ3ebVP91dRm8Yfe43l7+7rjaXsmE74A== X-Google-Smtp-Source: AHgI3IbrUQQy7H+Rwm147t40V6tiYOdDt8xad6imXP9blhPLdeTT8QyWUi2atbMieXcz40bMPiRoSjJNMxNHsA0Vw4GD9Q== X-Received: by 2002:a17:902:bc49:: with SMTP id t9mr1867783plz.70.1550867174986; Fri, 22 Feb 2019 12:26:14 -0800 (PST) Date: Fri, 22 Feb 2019 12:26:03 -0800 In-Reply-To: <20190222202606.160816-1-matthewgarrett@google.com> Message-Id: <20190222202606.160816-2-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190222202606.160816-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.rc0.258.g878e2cd30e-goog Subject: [PATCH V4 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, 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 d8b77133a83a..dc12e1cbd03a 100644 --- a/drivers/char/tpm/eventlog/tpm2.c +++ b/drivers/char/tpm/eventlog/tpm2.c @@ -40,52 +40,7 @@ static 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; + 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 f47342361e87..09c19d506b69 100644 --- a/include/linux/tpm_eventlog.h +++ b/include/linux/tpm_eventlog.h @@ -117,4 +117,72 @@ struct tcg_pcr_event2_head { struct tpm2_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