From patchwork Mon Dec 23 07:46:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herbert Xu X-Patchwork-Id: 11307815 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F2F17138C for ; Mon, 23 Dec 2019 07:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D282F20709 for ; Mon, 23 Dec 2019 07:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725880AbfLWHqc (ORCPT ); Mon, 23 Dec 2019 02:46:32 -0500 Received: from helcar.hmeau.com ([216.24.177.18]:56834 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725810AbfLWHqc (ORCPT ); Mon, 23 Dec 2019 02:46:32 -0500 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtps (Exim 4.89 #2 (Debian)) id 1ijIQ5-0008A0-Sy; Mon, 23 Dec 2019 15:46:25 +0800 Received: from herbert by gondobar with local (Exim 4.89) (envelope-from ) id 1ijIQ3-0001tn-QZ; Mon, 23 Dec 2019 15:46:23 +0800 Date: Mon, 23 Dec 2019 15:46:23 +0800 From: Herbert Xu To: Eric Biggers Cc: Linux Kernel Mailing List , "Theodore Y. Ts'o" , Jaegeuk Kim , Chandan Rajendra , linux-fscrypt@vger.kernel.org Subject: [v3 PATCH] fscrypt: Allow modular crypto algorithms Message-ID: <20191223074623.you4ivf2yuxk4ad2@gondor.apana.org.au> References: <20191221143020.hbgeixvlmzt7nh54@gondor.apana.org.au> <20191221234428.GA551@zzz.localdomain> <20191222084155.n4mbomsw6pl4c7kv@gondor.apana.org.au> <20191222164545.GA157733@zzz.localdomain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20191222164545.GA157733@zzz.localdomain> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On Sun, Dec 22, 2019 at 10:45:45AM -0600, Eric Biggers wrote: > > Okay, this approach looks fine. But can you rename the option to something more > self-explanatory like FS_ENCRYPTION_ALGS, and add a comment? Like: > > # Filesystems supporting encryption must select this if FS_ENCRYPTION. This > # allows the algorithms to be built as modules when all the filesystems are. Sure, here's a third revision. ---8<--- The commit 643fa9612bf1 ("fscrypt: remove filesystem specific build config option") removed modular support for fs/crypto. This causes the Crypto API to be built-in whenever fscrypt is enabled. This makes it very difficult for me to test modular builds of the Crypto API without disabling fscrypt which is a pain. As fscrypt is still evolving and it's developing new ties with the fs layer, it's hard to build it as a module for now. However, the actual algorithms are not required until a filesystem is mounted. Therefore we can allow them to be built as modules. Signed-off-by: Herbert Xu diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig index ff5a1746cbae..02df95b44331 100644 --- a/fs/crypto/Kconfig +++ b/fs/crypto/Kconfig @@ -2,13 +2,8 @@ config FS_ENCRYPTION bool "FS Encryption (Per-file encryption)" select CRYPTO - select CRYPTO_AES - select CRYPTO_CBC - select CRYPTO_ECB - select CRYPTO_XTS - select CRYPTO_CTS - select CRYPTO_SHA512 - select CRYPTO_HMAC + select CRYPTO_HASH + select CRYPTO_SKCIPHER select KEYS help Enable encryption of files and directories. This @@ -16,3 +11,15 @@ config FS_ENCRYPTION efficient since it avoids caching the encrypted and decrypted pages in the page cache. Currently Ext4, F2FS and UBIFS make use of this feature. + +# Filesystems supporting encryption must select this if FS_ENCRYPTION. This +# allows the algorithms to be built as modules when all the filesystems are. +config FS_ENCRYPTION_ALGS + tristate + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_CTS + select CRYPTO_ECB + select CRYPTO_HMAC + select CRYPTO_SHA512 + select CRYPTO_XTS diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig index ef42ab040905..930793456d3a 100644 --- a/fs/ext4/Kconfig +++ b/fs/ext4/Kconfig @@ -10,6 +10,7 @@ config EXT3_FS select CRC16 select CRYPTO select CRYPTO_CRC32C + select FS_ENCRYPTION_ALGS if FS_ENCRYPTION help This config option is here only for backward compatibility. ext3 filesystem is now handled by the ext4 driver. diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig index 652fd2e2b23d..599fb9194c6a 100644 --- a/fs/f2fs/Kconfig +++ b/fs/f2fs/Kconfig @@ -6,6 +6,7 @@ config F2FS_FS select CRYPTO select CRYPTO_CRC32 select F2FS_FS_XATTR if FS_ENCRYPTION + select FS_ENCRYPTION_ALGS if FS_ENCRYPTION help F2FS is based on Log-structured File System (LFS), which supports versatile "flash-friendly" features. The design has been focused on diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig index 69932bcfa920..45d3d207fb99 100644 --- a/fs/ubifs/Kconfig +++ b/fs/ubifs/Kconfig @@ -12,6 +12,7 @@ config UBIFS_FS select CRYPTO_ZSTD if UBIFS_FS_ZSTD select CRYPTO_HASH_INFO select UBIFS_FS_XATTR if FS_ENCRYPTION + select FS_ENCRYPTION_ALGS if FS_ENCRYPTION depends on MTD_UBI help UBIFS is a file system for flash devices which works on top of UBI.