From patchwork Fri Feb 22 20:26:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10826955 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 8427C14E1 for ; Fri, 22 Feb 2019 20:26:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C91232841 for ; Fri, 22 Feb 2019 20:26:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6113B3294F; Fri, 22 Feb 2019 20:26:32 +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 D9E3B32841 for ; Fri, 22 Feb 2019 20:26:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727269AbfBVU0Y (ORCPT ); Fri, 22 Feb 2019 15:26:24 -0500 Received: from mail-qk1-f202.google.com ([209.85.222.202]:44585 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727287AbfBVU0Y (ORCPT ); Fri, 22 Feb 2019 15:26:24 -0500 Received: by mail-qk1-f202.google.com with SMTP id e9so2423684qka.11 for ; Fri, 22 Feb 2019 12:26:23 -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=QdqoL0K3zxFFGbmlyhBJxqAUmz+voVFPYJ0GB3SWvlY=; b=s1mHfRL+EDTU5WJMCV1wxupbcwVVB2OrrhGchRt5aCjj1ppa4myp4g5/p3mFBP/WCD rHK13sQYsXjNwu7nI+WX9gPhgpsfRreXtmCTw0dSyjYENcU6RFZI61hu0RFGVVDln9pt HOy26IrEpNsZeBRzUK2IJVRtdtTwvEKH3CHMLotGuKpPfZCSMMeXLIRlbG6vuU8BAKpq ui4n6yntzHt5j8jf0ulu04Hz0/KJ2rcBG/0t5PZ9rxU8hbMXHjUKwV7W/HP7fY1hqSxS DehwscNHkKhngiPM9A2H/57/h6oYyeQ+6BsfHHTVVFoiYzoK4EoP2XbXjFHTL1iLysmR u6ig== 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=QdqoL0K3zxFFGbmlyhBJxqAUmz+voVFPYJ0GB3SWvlY=; b=ouIKhZNge6Jnv0SdM/LdtL1sSyTuIaTmUjrRimxAwxXmnBIlYydxl7QFK1W8CdWQdX eSH8y7upzr2lpC1ZQpuJvO5CzeX/Lm8HLc1mfbR746Tb6NUY2+VW6T/INiOdpTMZr8tX j6av6yrxoFshAE00FVnG65Uyh7moT+S9Zo6sQQwgOOMOuUKGY7rqAX8rp6ItoAzk0B9E o6n381tbvzY6ZvvWIzRytJT+p/u7a9juWl87Qaxmv1LYyFZlKpqzXEGX4tvxXegObCSW xTVh1B9xnOOan/AuK/PH5wiAMVaouJ/whobitmvdL+KUbh4eEnruFWxq3YDDRjJ96IpE Cpyg== X-Gm-Message-State: AHQUAuZum4QCWbwQjqo6kH9GtTmic99GnJnnL9DFeNgeGyuj9FevGkh6 s/lfS/TAEi6FzKrq5GSl6vMnAjxv7Xhtw1YlR0QouQ== X-Google-Smtp-Source: AHgI3IZ6hRQOpgvZQ7RZTDBrH6MpRsUnwB5Cm2xa4JwoZXOgxyM0uZaoo6PmI7/4HwRZladXWq0OXWEQpbpV0NseTkt1eg== X-Received: by 2002:a37:d654:: with SMTP id t81mr3541286qki.4.1550867182796; Fri, 22 Feb 2019 12:26:22 -0800 (PST) Date: Fri, 22 Feb 2019 12:26:06 -0800 In-Reply-To: <20190222202606.160816-1-matthewgarrett@google.com> Message-Id: <20190222202606.160816-5-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 4/4] efi: Attempt to get the TCG2 event log in the boot stub 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 Right now we only attempt to obtain the SHA1-only event log. The protocol also supports a crypto agile log format, which contains digests for all algorithms in use. Attempt to obtain this first, and fall back to obtaining the older format if the system doesn't support it. This is lightly complicated by the event sizes being variable (as we don't know in advance which algorithms are in use), and the interface giving us back a pointer to the start of the final entry rather than a pointer to the end of the log - as a result, we need to parse the final entry to figure out its length in order to know how much data to copy up to the OS. Signed-off-by: Matthew Garrett --- drivers/firmware/efi/libstub/tpm.c | 50 ++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 17 deletions(-) diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index a90b0b8fc69a..523cd07c551c 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -59,7 +59,7 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) #endif -static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) { efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; @@ -69,6 +69,7 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) unsigned long first_entry_addr, last_entry_addr; size_t log_size, last_entry_size; efi_bool_t truncated; + int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2; void *tcg2_protocol = NULL; status = efi_call_early(locate_protocol, &tcg2_guid, NULL, @@ -76,14 +77,20 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) if (status != EFI_SUCCESS) return; - status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, - EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, - &log_location, &log_last_entry, &truncated); - if (status != EFI_SUCCESS) - return; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + + if (status != EFI_SUCCESS || !log_location) { + version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + if (status != EFI_SUCCESS || !log_location) + return; + + } - if (!log_location) - return; first_entry_addr = (unsigned long) log_location; /* @@ -98,8 +105,23 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) * We need to calculate its size to deduce the full size of * the logs. */ - last_entry_size = sizeof(struct tcpa_event) + - ((struct tcpa_event *) last_entry_addr)->event_size; + if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) { + /* + * The TCG2 log format has variable length entries, + * and the information to decode the hash algorithms + * back into a size is contained in the first entry - + * pass a pointer to the final entry (to calculate its + * size) and the first entry (so we know how long each + * digest is) + */ + last_entry_size = + __calc_tpm2_event_size((void *)last_entry_addr, + (void *)log_location, + false); + } else { + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *) last_entry_addr)->event_size; + } log_size = log_last_entry - log_location + last_entry_size; } @@ -116,7 +138,7 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) memset(log_tbl, 0, sizeof(*log_tbl) + log_size); log_tbl->size = log_size; - log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + log_tbl->version = version; memcpy(log_tbl->log, (void *) first_entry_addr, log_size); status = efi_call_early(install_configuration_table, @@ -128,9 +150,3 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) err_free: efi_call_early(free_pool, log_tbl); } - -void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) -{ - /* Only try to retrieve the logs in 1.2 format. */ - efi_retrieve_tpm2_eventlog_1_2(sys_table_arg); -}