From patchwork Fri Aug 24 16:16:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 10575589 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 2F86214BD for ; Fri, 24 Aug 2018 16:24:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 21E722CA5B for ; Fri, 24 Aug 2018 16:24:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 204082CA71; Fri, 24 Aug 2018 16:24:38 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI 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 B02122CA69 for ; Fri, 24 Aug 2018 16:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728237AbeHXT7w (ORCPT ); Fri, 24 Aug 2018 15:59:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:41502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727618AbeHXT6w (ORCPT ); Fri, 24 Aug 2018 15:58:52 -0400 Received: from sol.localdomain (c-67-185-97-198.hsd1.wa.comcast.net [67.185.97.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3A8592159F; Fri, 24 Aug 2018 16:23:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1535127810; bh=xLQOyqOdBZE9OaHvzop6bdy6Jv/N6ypKdUom9H1RQIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kOQdVjW3k5Ry9mPyhdGxppJ8fYzLL8vDlhh4UlyDh8AD0sCQby3usRYS/nxr4wQ3l nXs7m31khQFULtgRbEtZ16CLZSD7En3qNAnkXZqcfwAv3sMl/Tx0m0/skg0iNVDGQC LT8Jfo2e/X0CyD47vCkruE/LUBsmVMNm7X4wdFeM= From: Eric Biggers To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: linux-integrity@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org, Mimi Zohar , Dmitry Kasatkin , Michael Halcrow , Victor Hsieh Subject: [RFC PATCH 06/10] fs-verity: add CRC-32C support Date: Fri, 24 Aug 2018 09:16:38 -0700 Message-Id: <20180824161642.1144-7-ebiggers@kernel.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180824161642.1144-1-ebiggers@kernel.org> References: <20180824161642.1144-1-ebiggers@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Biggers Add CRC-32C support to fs-verity, to provide a faster alternative to SHA-256 for users who want integrity-only (not authenticity), i.e. who want to detect only accidental corruption, not malicious changes. CRC-32C is chosen over CRC-32 because the CRC-32C polynomial is believed to provide slightly better error-detection properties; and CRC-32C is just as fast (or can be just as fast) as CRC-32, or even faster e.g. on some x86 processors that have a CRC-32C instruction but not CRC-32. We use "crc32c" from the crypto API, so the polynomial convention is bitwise little-endian, the digest is bytewise little-endian, and the CRC bits are inverted at the beginning and end (which is desirable). Signed-off-by: Eric Biggers --- fs/verity/hash_algs.c | 4 ++++ include/uapi/linux/fsverity.h | 1 + 2 files changed, 5 insertions(+) diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c index e16d767070fec..3fd4bba7c4aa6 100644 --- a/fs/verity/hash_algs.c +++ b/fs/verity/hash_algs.c @@ -23,6 +23,10 @@ struct fsverity_hash_alg fsverity_hash_algs[] = { .digest_size = 64, .cryptographic = true, }, + [FS_VERITY_ALG_CRC32C] = { + .name = "crc32c", + .digest_size = 4, + }, }; /* diff --git a/include/uapi/linux/fsverity.h b/include/uapi/linux/fsverity.h index 64846763f7aef..b1afd205bbf87 100644 --- a/include/uapi/linux/fsverity.h +++ b/include/uapi/linux/fsverity.h @@ -29,6 +29,7 @@ struct fsverity_digest { /* Supported hash algorithms */ #define FS_VERITY_ALG_SHA256 1 #define FS_VERITY_ALG_SHA512 2 +#define FS_VERITY_ALG_CRC32C 3 /* for integrity only */ /* Metadata stored near the end of verity files, after the Merkle tree */ /* This structure is 64 bytes long */