From patchwork Tue Aug 8 17:08:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346794 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BADAC04FDF for ; Tue, 8 Aug 2023 18:53:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231361AbjHHSx4 (ORCPT ); Tue, 8 Aug 2023 14:53:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231126AbjHHSxh (ORCPT ); Tue, 8 Aug 2023 14:53:37 -0400 Received: from box.fidei.email (box.fidei.email [71.19.144.250]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EECA15A8D8; Tue, 8 Aug 2023 10:08:17 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 82A338353E; Tue, 8 Aug 2023 13:08:17 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514497; bh=1CtPCyW+9LFbA9Iwks8XlKITZk9CwP+wFLt76MORpo0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wACjgxlnPyRb/0iqiMDNkZy37bXDBMBJsvVlG2FacwyVlYc9qtb9mHlA+chPR5CCK nrAJanEMkTZc0i4mwG87f4HTQ/7DsS7ukLWEk6ZuNrQrHCkU17vTHBGq/k+1HNSgXm 8NNger2nA3PUHxiIAyXx/SFEIjl/jryudKmxeSbI1IHwXUUn5PpY9lEVeTsklHjC8U BOZj8iDueetAIl1tyfYhJWYUUe3DyCRWSuU0yN3LkqIJmC1KA7Zh8JDEdFuL/mxC0q +2zguRoD0I/EEYsPYVLKcP6/B3oHCHaPGFq5FJi3OOx8WMT2qvuF5pY5KYoGrdkcyK bLFAYAXdyNJdQ== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 1/8] fscrypt: move inline crypt decision to info setup Date: Tue, 8 Aug 2023 13:08:01 -0400 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org setup_file_encryption_key() is doing a lot of things at the moment -- setting the crypt_info's inline encryption bit, finding and locking a master key, and calling the functions to get the appropriate prepared key for this info. Since setting the inline encryption bit has nothing to do with finding the master key, it's easy and hopefully clearer to select the encryption implementation in fscrypt_setup_encryption_info(), the main fscrypt_info setup function, instead of in setup_file_encryption_key() which will long-term only deal in setting up the prepared key for the info. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/keysetup.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 361f41ef46c7..b89c32ad19fb 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -443,10 +443,6 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, struct fscrypt_master_key *mk; int err; - err = fscrypt_select_encryption_impl(ci); - if (err) - return err; - err = fscrypt_policy_to_key_spec(&ci->ci_policy, &mk_spec); if (err) return err; @@ -580,6 +576,10 @@ fscrypt_setup_encryption_info(struct inode *inode, WARN_ON_ONCE(mode->ivsize > FSCRYPT_MAX_IV_SIZE); crypt_info->ci_mode = mode; + res = fscrypt_select_encryption_impl(crypt_info); + if (res) + goto out; + res = setup_file_encryption_key(crypt_info, need_dirhash_key, &mk); if (res) goto out; From patchwork Tue Aug 8 17:08:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346796 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 833A9C04FDF for ; Tue, 8 Aug 2023 18:54:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234037AbjHHSyC (ORCPT ); Tue, 8 Aug 2023 14:54:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233965AbjHHSxk (ORCPT ); Tue, 8 Aug 2023 14:53:40 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73D2A15A8EB; Tue, 8 Aug 2023 10:08:20 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id E804E83541; Tue, 8 Aug 2023 13:08:18 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514499; bh=Edga/P62JZ+8sSaGHQj3Tj7RpkRT2vBPCsbfD56+hHg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qwQ6BxbX4rA0D6dQ9t44S2CGb+Lz6n4owFdtU+bEPP0lG5PHHlLIR5TcTbAsGDQnH PQQ3qU+f83WMm1zXABKSxNrV1URzsGufkfKTPs4J1wS+uZgeQWxF/uIwTfXqcL8DXe 6ch8hWeuCqpd+FWHpccJyi7Un027XWZzV/MZVnIA/Vm1VwvAXJ1i5eXky/vbL/GDNQ rnWxz2Q4wTXO75n5c4AQHVaOhNtCGpEdByRrIjElv8iiTR+cQIs56qxdL77r0zMjcI lkpPmjYRnS+0QigypoNvKBvFM3QlPuiOr/2FXZRQDB3Bgb/o+XV5FR4cZGwYoWtmEt 4FsTFmD0dXSlA== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 2/8] fscrypt: split and rename setup_file_encryption_key() Date: Tue, 8 Aug 2023 13:08:02 -0400 Message-ID: <5d9a09398c5432545db73d8f91d6b63cbfd0ee6f.1691505830.git.sweettea-kernel@dorminy.me> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org At present, setup_file_encryption_key() does several things: it finds and locks the master key, and then calls into the appropriate functions to setup the prepared key for the fscrypt_info. The code is clearer to follow if these functions are divided. Thus, move calling the appropriate file key setup function into a new fscrypt_setup_file_key() function. After the file key setup functions are moved, the remaining function can take a const fscrypt_info, and is renamed find_and_lock_master_key() to precisely describe its action. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/keysetup.c | 77 ++++++++++++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 25 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index b89c32ad19fb..727d473b6b03 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -386,6 +386,43 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, return 0; } +/* + * Find or create the appropriate prepared key for an info. + */ +static int fscrypt_setup_file_key(struct fscrypt_info *ci, + struct fscrypt_master_key *mk, + bool need_dirhash_key) +{ + int err; + + if (!mk) { + if (ci->ci_policy.version != FSCRYPT_POLICY_V1) + return -ENOKEY; + + /* + * As a legacy fallback for v1 policies, search for the key in + * the current task's subscribed keyrings too. Don't move this + * to before the search of ->s_master_keys, since users + * shouldn't be able to override filesystem-level keys. + */ + return fscrypt_setup_v1_file_key_via_subscribed_keyrings(ci); + } + + switch (ci->ci_policy.version) { + case FSCRYPT_POLICY_V1: + err = fscrypt_setup_v1_file_key(ci, mk->mk_secret.raw); + break; + case FSCRYPT_POLICY_V2: + err = fscrypt_setup_v2_file_key(ci, mk, need_dirhash_key); + break; + default: + WARN_ON_ONCE(1); + err = -EINVAL; + break; + } + return err; +} + /* * Check whether the size of the given master key (@mk) is appropriate for the * encryption settings which a particular file will use (@ci). @@ -426,7 +463,7 @@ static bool fscrypt_valid_master_key_size(const struct fscrypt_master_key *mk, } /* - * Find the master key, then set up the inode's actual encryption key. + * Find and lock the master key. * * If the master key is found in the filesystem-level keyring, then it is * returned in *mk_ret with its semaphore read-locked. This is needed to ensure @@ -434,9 +471,8 @@ static bool fscrypt_valid_master_key_size(const struct fscrypt_master_key *mk, * multiple tasks may race to create an fscrypt_info for the same inode), and to * synchronize the master key being removed with a new inode starting to use it. */ -static int setup_file_encryption_key(struct fscrypt_info *ci, - bool need_dirhash_key, - struct fscrypt_master_key **mk_ret) +static int find_and_lock_master_key(const struct fscrypt_info *ci, + struct fscrypt_master_key **mk_ret) { struct super_block *sb = ci->ci_inode->i_sb; struct fscrypt_key_specifier mk_spec; @@ -466,17 +502,19 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, mk = fscrypt_find_master_key(sb, &mk_spec); } } + if (unlikely(!mk)) { if (ci->ci_policy.version != FSCRYPT_POLICY_V1) return -ENOKEY; /* - * As a legacy fallback for v1 policies, search for the key in - * the current task's subscribed keyrings too. Don't move this - * to before the search of ->s_master_keys, since users - * shouldn't be able to override filesystem-level keys. + * This might be the case of a v1 policy using a process + * subscribed keyring to get the key, so there may not be + * a relevant master key. */ - return fscrypt_setup_v1_file_key_via_subscribed_keyrings(ci); + + *mk_ret = NULL; + return 0; } down_read(&mk->mk_sem); @@ -491,21 +529,6 @@ static int setup_file_encryption_key(struct fscrypt_info *ci, goto out_release_key; } - switch (ci->ci_policy.version) { - case FSCRYPT_POLICY_V1: - err = fscrypt_setup_v1_file_key(ci, mk->mk_secret.raw); - break; - case FSCRYPT_POLICY_V2: - err = fscrypt_setup_v2_file_key(ci, mk, need_dirhash_key); - break; - default: - WARN_ON_ONCE(1); - err = -EINVAL; - break; - } - if (err) - goto out_release_key; - *mk_ret = mk; return 0; @@ -580,7 +603,11 @@ fscrypt_setup_encryption_info(struct inode *inode, if (res) goto out; - res = setup_file_encryption_key(crypt_info, need_dirhash_key, &mk); + res = find_and_lock_master_key(crypt_info, &mk); + if (res) + goto out; + + res = fscrypt_setup_file_key(crypt_info, mk, need_dirhash_key); if (res) goto out; From patchwork Tue Aug 8 17:08:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346797 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA701C04A94 for ; Tue, 8 Aug 2023 18:54:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232630AbjHHSyI (ORCPT ); Tue, 8 Aug 2023 14:54:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232599AbjHHSxp (ORCPT ); Tue, 8 Aug 2023 14:53:45 -0400 Received: from box.fidei.email (box.fidei.email [71.19.144.250]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20D3A15A8F7; Tue, 8 Aug 2023 10:08:22 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 5228583542; Tue, 8 Aug 2023 13:08:20 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514500; bh=h27qIlwt20auHIvCc2yPFpadI21oe/SGA4sS3MlQVqc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rzpIYSD9sdb3wJc1GaeXTq5KUF+0GD9VAueEiHJ5veD8j43AH5tu2CroRq0h8cWVt 0Cxep7fL3qCqjuuuB7UUb9Qw9LieZnpqotcnGb4ycgsX4Su8RKns8ARLHeL4NO3Ozc H65TVAHkyBkJ3ta+OJjcs3i7wMQSbNwGMjehzWRIMlSkllu0+uOh2Hlp+n9Q0Bd6vb WMesqFsUaouH2IgrDf6caD0UtYpmm2AKPM0WWlDjy4z4HuiVYP98XX5Z9LmZkdMD+Z 72vAxq2sKClKDImMqM+Pdzya7S/oWv8GdO1Edu3Mq6nGG20/nSzU+q724TIt/yNKvK uT60d5LeRDc/g== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 3/8] fscrypt: split setup_per_mode_enc_key() Date: Tue, 8 Aug 2023 13:08:03 -0400 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org At present, setup_per_mode_enc_key() tries to find, within an array of mode keys in the master key, an already prepared key, and if it doesn't find a pre-prepared key, sets up a new one. This caching is not super clear, at least to me, and splitting this function makes it clearer. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/keysetup.c | 61 +++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 24 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 727d473b6b03..06deac6f4487 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -184,34 +184,24 @@ int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key) return fscrypt_prepare_key(&ci->ci_enc_key, raw_key, ci); } -static int setup_per_mode_enc_key(struct fscrypt_info *ci, - struct fscrypt_master_key *mk, - struct fscrypt_prepared_key *keys, - u8 hkdf_context, bool include_fs_uuid) +static int setup_new_mode_prepared_key(struct fscrypt_master_key *mk, + struct fscrypt_prepared_key *prep_key, + const struct fscrypt_info *ci, + u8 hkdf_context, bool include_fs_uuid) { const struct inode *inode = ci->ci_inode; const struct super_block *sb = inode->i_sb; struct fscrypt_mode *mode = ci->ci_mode; const u8 mode_num = mode - fscrypt_modes; - struct fscrypt_prepared_key *prep_key; u8 mode_key[FSCRYPT_MAX_KEY_SIZE]; u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)]; unsigned int hkdf_infolen = 0; - int err; - - if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX)) - return -EINVAL; - - prep_key = &keys[mode_num]; - if (fscrypt_is_key_prepared(prep_key, ci)) { - ci->ci_enc_key = *prep_key; - return 0; - } + int err = 0; mutex_lock(&fscrypt_mode_key_setup_mutex); if (fscrypt_is_key_prepared(prep_key, ci)) - goto done_unlock; + goto out_unlock; BUILD_BUG_ON(sizeof(mode_num) != 1); BUILD_BUG_ON(sizeof(sb->s_uuid) != 16); @@ -229,16 +219,39 @@ static int setup_per_mode_enc_key(struct fscrypt_info *ci, goto out_unlock; err = fscrypt_prepare_key(prep_key, mode_key, ci); memzero_explicit(mode_key, mode->keysize); - if (err) - goto out_unlock; -done_unlock: - ci->ci_enc_key = *prep_key; - err = 0; + out_unlock: mutex_unlock(&fscrypt_mode_key_setup_mutex); return err; } +static int find_mode_prepared_key(struct fscrypt_info *ci, + struct fscrypt_master_key *mk, + struct fscrypt_prepared_key *keys, + u8 hkdf_context, bool include_fs_uuid) +{ + struct fscrypt_mode *mode = ci->ci_mode; + const u8 mode_num = mode - fscrypt_modes; + struct fscrypt_prepared_key *prep_key; + int err; + + if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX)) + return -EINVAL; + + prep_key = &keys[mode_num]; + if (fscrypt_is_key_prepared(prep_key, ci)) { + ci->ci_enc_key = *prep_key; + return 0; + } + err = setup_new_mode_prepared_key(mk, prep_key, ci, hkdf_context, + include_fs_uuid); + if (err) + return err; + + ci->ci_enc_key = *prep_key; + return 0; +} + /* * Derive a SipHash key from the given fscrypt master key and the given * application-specific information string. @@ -294,7 +307,7 @@ static int fscrypt_setup_iv_ino_lblk_32_key(struct fscrypt_info *ci, { int err; - err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_32_keys, + err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_32_keys, HKDF_CONTEXT_IV_INO_LBLK_32_KEY, true); if (err) return err; @@ -344,7 +357,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, * encryption key. This ensures that the master key is * consistently used only for HKDF, avoiding key reuse issues. */ - err = setup_per_mode_enc_key(ci, mk, mk->mk_direct_keys, + err = find_mode_prepared_key(ci, mk, mk->mk_direct_keys, HKDF_CONTEXT_DIRECT_KEY, false); } else if (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) { @@ -354,7 +367,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, * the IVs. This format is optimized for use with inline * encryption hardware compliant with the UFS standard. */ - err = setup_per_mode_enc_key(ci, mk, mk->mk_iv_ino_lblk_64_keys, + err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_64_keys, HKDF_CONTEXT_IV_INO_LBLK_64_KEY, true); } else if (ci->ci_policy.v2.flags & From patchwork Tue Aug 8 17:08:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346798 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68DCDC41513 for ; Tue, 8 Aug 2023 18:54:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233424AbjHHSyO (ORCPT ); Tue, 8 Aug 2023 14:54:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233406AbjHHSxu (ORCPT ); Tue, 8 Aug 2023 14:53:50 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED68963483; Tue, 8 Aug 2023 10:08:23 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 04F9883543; Tue, 8 Aug 2023 13:08:21 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514502; bh=wiexMjPw2AV0+ev+V2Ao2InY43w8oDJglvamG5Tr2Vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=INhyXvRdqBv1yVK2/AFyEGA3i3saH9PGG9OCGZlsaXQ3JXIunrc2APmXrMDvi4xkq lMh7rPV4iCAN08wmhAcpdgRa61jIr5EA+6sWga7omcbzQMNTLhaLY2RIK3wFwamAE+ BYdRpGLhNnPDy7cr2gY11sc2jIMwxTWS0z2Pt5dvskHRw72f6FvDgfHLjRfy33hpFs vgCZmW1Vfd5J4ZFUc4bcIveoO6f90ZjpnsrsvZJc8lHFHzuAmfd10fa+XgBbNWzvgx tmJhmHRIiOQ60GhMJxYsW7a1gIZB2DbbNMK2V4lB4wMq2GIiy85HFxCRkuDhga0cXV COXsFs6OZfTJw== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 4/8] fscrypt: move dirhash key setup away from IO key setup Date: Tue, 8 Aug 2023 13:08:04 -0400 Message-ID: <729a2735c32cd9ddd9fb61c716643a39d10ae189.1691505830.git.sweettea-kernel@dorminy.me> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The function named fscrypt_setup_v2_file_key() has as its main focus the setting up of the fscrypt_info's ci_enc_key member, the prepared key with which filenames or file contents are encrypted or decrypted. However, it currently also sets up the dirhash key, used by some directories, based on a parameter. There are no dependencies on setting up the dirhash key beyond having the master key locked, and it's clearer having fscrypt_setup_file_key() be only about setting up the prepared key for IO. Thus, move dirhash key setup to fscrypt_setup_encryption_info(), which calls out to each function setting up parts of the fscrypt_info, and stop passing the need_dirhash_key parameter around. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/keysetup.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 06deac6f4487..430e2455ea2d 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -343,8 +343,7 @@ static int fscrypt_setup_iv_ino_lblk_32_key(struct fscrypt_info *ci, } static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, - struct fscrypt_master_key *mk, - bool need_dirhash_key) + struct fscrypt_master_key *mk) { int err; @@ -386,25 +385,15 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, err = fscrypt_set_per_file_enc_key(ci, derived_key); memzero_explicit(derived_key, ci->ci_mode->keysize); } - if (err) - return err; - /* Derive a secret dirhash key for directories that need it. */ - if (need_dirhash_key) { - err = fscrypt_derive_dirhash_key(ci, mk); - if (err) - return err; - } - - return 0; + return err; } /* * Find or create the appropriate prepared key for an info. */ static int fscrypt_setup_file_key(struct fscrypt_info *ci, - struct fscrypt_master_key *mk, - bool need_dirhash_key) + struct fscrypt_master_key *mk) { int err; @@ -426,7 +415,7 @@ static int fscrypt_setup_file_key(struct fscrypt_info *ci, err = fscrypt_setup_v1_file_key(ci, mk->mk_secret.raw); break; case FSCRYPT_POLICY_V2: - err = fscrypt_setup_v2_file_key(ci, mk, need_dirhash_key); + err = fscrypt_setup_v2_file_key(ci, mk); break; default: WARN_ON_ONCE(1); @@ -620,10 +609,26 @@ fscrypt_setup_encryption_info(struct inode *inode, if (res) goto out; - res = fscrypt_setup_file_key(crypt_info, mk, need_dirhash_key); + res = fscrypt_setup_file_key(crypt_info, mk); if (res) goto out; + /* + * Derive a secret dirhash key for directories that need it. It + * should be impossible to set flags such that a v1 policy sets + * need_dirhash_key, but check it anyway. + */ + if (need_dirhash_key) { + if (WARN_ON_ONCE(policy->version == FSCRYPT_POLICY_V1)) { + res = -EINVAL; + goto out; + } + + res = fscrypt_derive_dirhash_key(crypt_info, mk); + if (res) + goto out; + } + /* * For existing inodes, multiple tasks may race to set ->i_crypt_info. * So use cmpxchg_release(). This pairs with the smp_load_acquire() in From patchwork Tue Aug 8 17:08:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346799 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4135DC001DB for ; Tue, 8 Aug 2023 18:54:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231405AbjHHSyY (ORCPT ); Tue, 8 Aug 2023 14:54:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231771AbjHHSyC (ORCPT ); Tue, 8 Aug 2023 14:54:02 -0400 Received: from box.fidei.email (box.fidei.email [71.19.144.250]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9042563496; Tue, 8 Aug 2023 10:08:27 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 6FB5683545; Tue, 8 Aug 2023 13:08:23 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514503; bh=hdt5Oxh1/yha851knbsYCyjKyvmap3vWBAAm6xQtpeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SThpj4J7KsjXb2OsnN1MSHv38Ssz365awdlZOjWB05HraW6GpzG6XdGlpAZPh1OY2 vcqDsMJGdfxpWQSxzfhgVw5KVn92lECigKpGZtYm/giuXgP2FudkawNJo3MzvQuf2+ lc66nYYF6Odm45u3LmSGTun+5c4SZX0yKxh4QT/4Pj8hRleUJaFcMJQTnD6sklL92F uNtjM1G2zYxL1aOHPHST1RpcupfK7qlHZSPYl6/zgVaiDkh3gkUHNY8srFRkdmJA0Q iMZhwPmhkWmxwkh++23/ENb4io5OYZl9V3MfTFD066CvqcWtRHik8LeY0f5o6Jh2Lw RNCy4M7HyUX/w== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 5/8] fscrypt: reduce special-casing of IV_INO_LBLK_32 Date: Tue, 8 Aug 2023 13:08:05 -0400 Message-ID: <542ea134771e2caa3043dfe48c2825d93495c626.1691505830.git.sweettea-kernel@dorminy.me> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Right now, the IV_INO_LBLK_32 policy is handled by its own function called in fscrypt_setup_v2_file_key(), different from all other policies which just call find_mode_prepared_key() with various parameters. The function additionally sets up the relevant inode hashing key in the master key, and uses it to hash the inode number if possible. This is not particularly relevant to setting up a prepared key, so this change tries to make it clear that every non-default policy uses basically the same setup mechanism for its prepared key. The other setup is moved to be called from the top crypt_info setup function. Signed-off-by: Sweet Tea Dorminy --- fs/crypto/keysetup.c | 62 +++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 30 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 430e2455ea2d..8b201b91c036 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -302,44 +302,30 @@ void fscrypt_hash_inode_number(struct fscrypt_info *ci, &mk->mk_ino_hash_key); } -static int fscrypt_setup_iv_ino_lblk_32_key(struct fscrypt_info *ci, - struct fscrypt_master_key *mk) +static int fscrypt_setup_ino_hash_key(struct fscrypt_master_key *mk) { int err; - err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_32_keys, - HKDF_CONTEXT_IV_INO_LBLK_32_KEY, true); - if (err) - return err; - /* pairs with smp_store_release() below */ - if (!smp_load_acquire(&mk->mk_ino_hash_key_initialized)) { + if (smp_load_acquire(&mk->mk_ino_hash_key_initialized)) + return 0; - mutex_lock(&fscrypt_mode_key_setup_mutex); + mutex_lock(&fscrypt_mode_key_setup_mutex); - if (mk->mk_ino_hash_key_initialized) - goto unlock; + if (mk->mk_ino_hash_key_initialized) + goto unlock; - err = fscrypt_derive_siphash_key(mk, - HKDF_CONTEXT_INODE_HASH_KEY, - NULL, 0, &mk->mk_ino_hash_key); - if (err) - goto unlock; - /* pairs with smp_load_acquire() above */ - smp_store_release(&mk->mk_ino_hash_key_initialized, true); + err = fscrypt_derive_siphash_key(mk, + HKDF_CONTEXT_INODE_HASH_KEY, + NULL, 0, &mk->mk_ino_hash_key); + if (err) + goto unlock; + /* pairs with smp_load_acquire() above */ + smp_store_release(&mk->mk_ino_hash_key_initialized, true); unlock: - mutex_unlock(&fscrypt_mode_key_setup_mutex); - if (err) - return err; - } + mutex_unlock(&fscrypt_mode_key_setup_mutex); - /* - * New inodes may not have an inode number assigned yet. - * Hashing their inode number is delayed until later. - */ - if (ci->ci_inode->i_ino) - fscrypt_hash_inode_number(ci, mk); - return 0; + return err; } static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, @@ -371,7 +357,9 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, true); } else if (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) { - err = fscrypt_setup_iv_ino_lblk_32_key(ci, mk); + err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_32_keys, + HKDF_CONTEXT_IV_INO_LBLK_32_KEY, + true); } else { u8 derived_key[FSCRYPT_MAX_KEY_SIZE]; @@ -629,6 +617,20 @@ fscrypt_setup_encryption_info(struct inode *inode, goto out; } + /* + * The IV_INO_LBLK_32 policy needs a hashed inode number, but new + * inodes may not have an inode number assigned yet. + */ + if (policy->version == FSCRYPT_POLICY_V2 && + (policy->v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) { + res = fscrypt_setup_ino_hash_key(mk); + if (res) + goto out; + + if (inode->i_ino) + fscrypt_hash_inode_number(crypt_info, mk); + } + /* * For existing inodes, multiple tasks may race to set ->i_crypt_info. * So use cmpxchg_release(). This pairs with the smp_load_acquire() in From patchwork Tue Aug 8 17:08:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346800 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5273C41513 for ; Tue, 8 Aug 2023 18:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233922AbjHHSyX (ORCPT ); Tue, 8 Aug 2023 14:54:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234204AbjHHSyB (ORCPT ); Tue, 8 Aug 2023 14:54:01 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 802EC1A77F; Tue, 8 Aug 2023 10:08:27 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id DE4EA83546; Tue, 8 Aug 2023 13:08:24 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514505; bh=aTSgRaKoyZXOKio0Qeto3AOD8EsEQ5Vi7X+iufCiWwk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bDrukw0alMlnR3CHpwMq69UsKZ26hp5nasovN7kaZdb5DVR40QL02hIk1fdi5995w bxoUHFOoJnyv+3cpFncJ8elwVT22eBETo/JwDq48f4u2k2TTiMAAbMZO0eRxhPu5rb cgXGuLIzSTSIyXtKMlsNX/NTUI0X/6iyv9xsWOw5AMKcz8Dq5kLZotM0Ll25EujIdw Gj3A2MPzL+9ER4Op1AoB9yofPvW74fWQUZKXq1oC8h98lExwIDQ+HkHct7zJUzEuTp MTQB5sFfiz3oTnYeCrSoe2ZjgQvC7kW6E+I2xhjsfLQItX8zboChn8kn3IMi5cuklZ +yI7kH02Q9VbA== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 6/8] fscrypt: move all the shared mode key setup deeper Date: Tue, 8 Aug 2023 13:08:06 -0400 Message-ID: <953985195b4cce824ed64ee68827558544e93dcc.1691505830.git.sweettea-kernel@dorminy.me> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Currently, fscrypt_setup_v2_file_key() has a set of ifs which encode various information about how to set up a new mode key if necessary for a shared-key policy (DIRECT or IV_INO_LBLK_*). This is somewhat awkward -- this information is only needed at the point that we need to setup a new key, which is not the common case; the setup details are recorded as function parameters relatively far from where they're actually used; and at the point we use the parameters, we can derive the information equally well. So this moves mode and policy checking as deep into the callstack as possible. mk_prepared_key_for_mode_policy() deals with the array lookup within a master key. And fill_hkdf_info_for mode_key() deals with filling in the hkdf info as necessary for a particular policy. These seem a little clearer in broad strokes, emphasizing the similarities between the policies, but it does spread out the information on how the key is derived for a particular policy more. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/keysetup.c | 131 +++++++++++++++++++++++++++++-------------- 1 file changed, 88 insertions(+), 43 deletions(-) diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 8b201b91c036..7dd12c1821dd 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -13,6 +13,17 @@ #include "fscrypt_private.h" +#define MAX_MODE_KEY_HKDF_INFO_SIZE 17 + +/* + * Constant defining the various policy flags which require a non-default key + * policy. + */ +#define FSCRYPT_POLICY_FLAGS_KEY_MASK \ + (FSCRYPT_POLICY_FLAG_DIRECT_KEY \ + | FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 \ + | FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) + struct fscrypt_mode fscrypt_modes[] = { [FSCRYPT_MODE_AES_256_XTS] = { .friendly_name = "AES-256-XTS", @@ -184,20 +195,83 @@ int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key) return fscrypt_prepare_key(&ci->ci_enc_key, raw_key, ci); } +static struct fscrypt_prepared_key * +mk_prepared_key_for_mode_policy(struct fscrypt_master_key *mk, + union fscrypt_policy *policy, + struct fscrypt_mode *mode) +{ + const u8 mode_num = mode - fscrypt_modes; + + switch (policy->v2.flags & FSCRYPT_POLICY_FLAGS_KEY_MASK) { + case FSCRYPT_POLICY_FLAG_DIRECT_KEY: + return &mk->mk_direct_keys[mode_num]; + case FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64: + return &mk->mk_iv_ino_lblk_64_keys[mode_num]; + case FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32: + return &mk->mk_iv_ino_lblk_32_keys[mode_num]; + default: + return ERR_PTR(-EINVAL); + } +} + +static size_t +fill_hkdf_info_for_mode_key(const struct fscrypt_info *ci, + u8 hkdf_info[MAX_MODE_KEY_HKDF_INFO_SIZE]) +{ + const u8 mode_num = ci->ci_mode - fscrypt_modes; + const struct super_block *sb = ci->ci_inode->i_sb; + u8 hkdf_infolen = 0; + + hkdf_info[hkdf_infolen++] = mode_num; + if (!(ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY)) { + memcpy(&hkdf_info[hkdf_infolen], &sb->s_uuid, + sizeof(sb->s_uuid)); + hkdf_infolen += sizeof(sb->s_uuid); + } + return hkdf_infolen; +} + static int setup_new_mode_prepared_key(struct fscrypt_master_key *mk, struct fscrypt_prepared_key *prep_key, - const struct fscrypt_info *ci, - u8 hkdf_context, bool include_fs_uuid) + const struct fscrypt_info *ci) { const struct inode *inode = ci->ci_inode; const struct super_block *sb = inode->i_sb; + unsigned int policy_flags = fscrypt_policy_flags(&ci->ci_policy); struct fscrypt_mode *mode = ci->ci_mode; const u8 mode_num = mode - fscrypt_modes; u8 mode_key[FSCRYPT_MAX_KEY_SIZE]; u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)]; unsigned int hkdf_infolen = 0; + u8 hkdf_context = 0; int err = 0; + switch (policy_flags & FSCRYPT_POLICY_FLAGS_KEY_MASK) { + case FSCRYPT_POLICY_FLAG_DIRECT_KEY: + hkdf_context = HKDF_CONTEXT_DIRECT_KEY; + break; + case FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64: + hkdf_context = HKDF_CONTEXT_IV_INO_LBLK_64_KEY; + break; + case FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32: + hkdf_context = HKDF_CONTEXT_IV_INO_LBLK_32_KEY; + break; + } + + /* + * For DIRECT_KEY policies: instead of deriving per-file encryption + * keys, the per-file nonce will be included in all the IVs. But + * unlike v1 policies, for v2 policies in this case we don't encrypt + * with the master key directly but rather derive a per-mode encryption + * key. This ensures that the master key is consistently used only for + * HKDF, avoiding key reuse issues. + * + * For IV_INO_LBLK policies: encryption keys are derived from + * (master_key, mode_num, filesystem_uuid), and inode number is + * included in the IVs. This format is optimized for use with inline + * encryption hardware compliant with the UFS standard. + */ + mutex_lock(&fscrypt_mode_key_setup_mutex); if (fscrypt_is_key_prepared(prep_key, ci)) @@ -205,13 +279,9 @@ static int setup_new_mode_prepared_key(struct fscrypt_master_key *mk, BUILD_BUG_ON(sizeof(mode_num) != 1); BUILD_BUG_ON(sizeof(sb->s_uuid) != 16); - BUILD_BUG_ON(sizeof(hkdf_info) != 17); - hkdf_info[hkdf_infolen++] = mode_num; - if (include_fs_uuid) { - memcpy(&hkdf_info[hkdf_infolen], &sb->s_uuid, - sizeof(sb->s_uuid)); - hkdf_infolen += sizeof(sb->s_uuid); - } + BUILD_BUG_ON(sizeof(hkdf_info) != MAX_MODE_KEY_HKDF_INFO_SIZE); + hkdf_infolen = fill_hkdf_info_for_mode_key(ci, hkdf_info); + err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf, hkdf_context, hkdf_info, hkdf_infolen, mode_key, mode->keysize); @@ -225,10 +295,8 @@ static int setup_new_mode_prepared_key(struct fscrypt_master_key *mk, return err; } -static int find_mode_prepared_key(struct fscrypt_info *ci, - struct fscrypt_master_key *mk, - struct fscrypt_prepared_key *keys, - u8 hkdf_context, bool include_fs_uuid) +static int setup_mode_prepared_key(struct fscrypt_info *ci, + struct fscrypt_master_key *mk) { struct fscrypt_mode *mode = ci->ci_mode; const u8 mode_num = mode - fscrypt_modes; @@ -238,13 +306,15 @@ static int find_mode_prepared_key(struct fscrypt_info *ci, if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX)) return -EINVAL; - prep_key = &keys[mode_num]; + prep_key = mk_prepared_key_for_mode_policy(mk, &ci->ci_policy, mode); + if (IS_ERR(prep_key)) + return PTR_ERR(prep_key); + if (fscrypt_is_key_prepared(prep_key, ci)) { ci->ci_enc_key = *prep_key; return 0; } - err = setup_new_mode_prepared_key(mk, prep_key, ci, hkdf_context, - include_fs_uuid); + err = setup_new_mode_prepared_key(mk, prep_key, ci); if (err) return err; @@ -333,33 +403,8 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci, { int err; - if (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) { - /* - * DIRECT_KEY: instead of deriving per-file encryption keys, the - * per-file nonce will be included in all the IVs. But unlike - * v1 policies, for v2 policies in this case we don't encrypt - * with the master key directly but rather derive a per-mode - * encryption key. This ensures that the master key is - * consistently used only for HKDF, avoiding key reuse issues. - */ - err = find_mode_prepared_key(ci, mk, mk->mk_direct_keys, - HKDF_CONTEXT_DIRECT_KEY, false); - } else if (ci->ci_policy.v2.flags & - FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) { - /* - * IV_INO_LBLK_64: encryption keys are derived from (master_key, - * mode_num, filesystem_uuid), and inode number is included in - * the IVs. This format is optimized for use with inline - * encryption hardware compliant with the UFS standard. - */ - err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_64_keys, - HKDF_CONTEXT_IV_INO_LBLK_64_KEY, - true); - } else if (ci->ci_policy.v2.flags & - FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) { - err = find_mode_prepared_key(ci, mk, mk->mk_iv_ino_lblk_32_keys, - HKDF_CONTEXT_IV_INO_LBLK_32_KEY, - true); + if (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAGS_KEY_MASK) { + err = setup_mode_prepared_key(ci, mk); } else { u8 derived_key[FSCRYPT_MAX_KEY_SIZE]; From patchwork Tue Aug 8 17:08:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346793 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3F26C04A94 for ; Tue, 8 Aug 2023 18:53:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233920AbjHHSxz (ORCPT ); Tue, 8 Aug 2023 14:53:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230341AbjHHSxh (ORCPT ); Tue, 8 Aug 2023 14:53:37 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1B2B59DDE; Tue, 8 Aug 2023 10:08:27 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 43D9083548; Tue, 8 Aug 2023 13:08:26 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514506; bh=7drZ0l6Y2HJEyfI+hq9L95dlOmYukpvQLi6KbbkW+9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ioB74QxU1WzPuBaFzaTeeMdXRsKj3KWpaPQkCjnkkd0935iiGWwqetMUfgWR7e7wj mX9Fhp2shbG2uvnpVeF42J0qQkaqUkY8rBCTzwKyuRrE7Hvj6FWQkNnHJJEZIcnSVD hYklfHcq39BPdmpz6RjKLrmQYdOWdVkfSfswzJV6+4R64r761JU0KGJdIEEo+OHLOv h72rYrT0j9QgvOyMcQF5ieYkYdA6KzIp+U/Xv+q38qzFmUfe8K26y+Bh7a2NiTcjSZ mQUO3/Y6/G+N2iTraBndeq20X8Xz7N4NORHTurl2qDSTi2K10Z/OL5RxjbSF+z41U0 hAcLIxktYFOZw== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 7/8] fscrypt: make infos have a pointer to prepared keys Date: Tue, 8 Aug 2023 13:08:07 -0400 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Adding a layer of indirection between infos and prepared keys makes everything clearer at the cost of another pointer. Now everyone sharing a prepared key within a direct key or a master key have the same pointer to the single prepared key. Followups move information from the crypt_info into the prepared key, which ends up reducing memory usage slightly. Additionally, it makes asynchronous freeing of prepared keys possible later. So this change makes crypt_info->ci_enc_key a pointer and updates all users thereof. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/crypto.c | 2 +- fs/crypto/fname.c | 4 ++-- fs/crypto/fscrypt_private.h | 2 +- fs/crypto/inline_crypt.c | 4 ++-- fs/crypto/keysetup.c | 16 +++++++++++----- fs/crypto/keysetup_v1.c | 2 +- 6 files changed, 18 insertions(+), 12 deletions(-) diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 6a837e4b80dc..9f3bda18c797 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -108,7 +108,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, DECLARE_CRYPTO_WAIT(wait); struct scatterlist dst, src; struct fscrypt_info *ci = inode->i_crypt_info; - struct crypto_skcipher *tfm = ci->ci_enc_key.tfm; + struct crypto_skcipher *tfm = ci->ci_enc_key->tfm; int res = 0; if (WARN_ON_ONCE(len <= 0)) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 6eae3f12ad50..edb78cd1b0e7 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -101,7 +101,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, struct skcipher_request *req = NULL; DECLARE_CRYPTO_WAIT(wait); const struct fscrypt_info *ci = inode->i_crypt_info; - struct crypto_skcipher *tfm = ci->ci_enc_key.tfm; + struct crypto_skcipher *tfm = ci->ci_enc_key->tfm; union fscrypt_iv iv; struct scatterlist sg; int res; @@ -158,7 +158,7 @@ static int fname_decrypt(const struct inode *inode, DECLARE_CRYPTO_WAIT(wait); struct scatterlist src_sg, dst_sg; const struct fscrypt_info *ci = inode->i_crypt_info; - struct crypto_skcipher *tfm = ci->ci_enc_key.tfm; + struct crypto_skcipher *tfm = ci->ci_enc_key->tfm; union fscrypt_iv iv; int res; diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 2d63da48635a..20b8ea1e3518 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -198,7 +198,7 @@ struct fscrypt_prepared_key { struct fscrypt_info { /* The key in a form prepared for actual encryption/decryption */ - struct fscrypt_prepared_key ci_enc_key; + struct fscrypt_prepared_key *ci_enc_key; /* True if ci_enc_key should be freed when this fscrypt_info is freed */ bool ci_owns_key; diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index 8bfb3ce86476..2063f7941ce6 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -273,7 +273,7 @@ void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode, ci = inode->i_crypt_info; fscrypt_generate_dun(ci, first_lblk, dun); - bio_crypt_set_ctx(bio, ci->ci_enc_key.blk_key, dun, gfp_mask); + bio_crypt_set_ctx(bio, ci->ci_enc_key->blk_key, dun, gfp_mask); } EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx); @@ -360,7 +360,7 @@ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, * uses the same pointer. I.e., there's currently no need to support * merging requests where the keys are the same but the pointers differ. */ - if (bc->bc_key != inode->i_crypt_info->ci_enc_key.blk_key) + if (bc->bc_key != inode->i_crypt_info->ci_enc_key->blk_key) return false; fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun); diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 7dd12c1821dd..4f04999ecfd1 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -192,7 +192,11 @@ void fscrypt_destroy_prepared_key(struct super_block *sb, int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key) { ci->ci_owns_key = true; - return fscrypt_prepare_key(&ci->ci_enc_key, raw_key, ci); + ci->ci_enc_key = kzalloc(sizeof(*ci->ci_enc_key), GFP_KERNEL); + if (!ci->ci_enc_key) + return -ENOMEM; + + return fscrypt_prepare_key(ci->ci_enc_key, raw_key, ci); } static struct fscrypt_prepared_key * @@ -311,14 +315,14 @@ static int setup_mode_prepared_key(struct fscrypt_info *ci, return PTR_ERR(prep_key); if (fscrypt_is_key_prepared(prep_key, ci)) { - ci->ci_enc_key = *prep_key; + ci->ci_enc_key = prep_key; return 0; } err = setup_new_mode_prepared_key(mk, prep_key, ci); if (err) return err; - ci->ci_enc_key = *prep_key; + ci->ci_enc_key = prep_key; return 0; } @@ -582,9 +586,11 @@ static void put_crypt_info(struct fscrypt_info *ci) if (ci->ci_direct_key) fscrypt_put_direct_key(ci->ci_direct_key); - else if (ci->ci_owns_key) + else if (ci->ci_owns_key) { fscrypt_destroy_prepared_key(ci->ci_inode->i_sb, - &ci->ci_enc_key); + ci->ci_enc_key); + kfree_sensitive(ci->ci_enc_key); + } mk = ci->ci_master_key; if (mk) { diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c index 75dabd9b27f9..e1d761e8067f 100644 --- a/fs/crypto/keysetup_v1.c +++ b/fs/crypto/keysetup_v1.c @@ -259,7 +259,7 @@ static int setup_v1_file_key_direct(struct fscrypt_info *ci, if (IS_ERR(dk)) return PTR_ERR(dk); ci->ci_direct_key = dk; - ci->ci_enc_key = dk->dk_key; + ci->ci_enc_key = &dk->dk_key; return 0; } From patchwork Tue Aug 8 17:08:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346795 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E92E3C04A94 for ; Tue, 8 Aug 2023 18:54:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232769AbjHHSx7 (ORCPT ); Tue, 8 Aug 2023 14:53:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231354AbjHHSxi (ORCPT ); Tue, 8 Aug 2023 14:53:38 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 189AE5FDC2; Tue, 8 Aug 2023 10:08:28 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 9F66183533; Tue, 8 Aug 2023 13:08:27 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514507; bh=00y/3vVJG+zulZ5j0qomwBwj0hM9Ucvwq7H2Bzn4niw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZlYo6r2Sad3YVQFkp5bpVzks59EFOuYZdqrTx1JSck66n1JWf7E3DC+0pVjwp/27C DwGxyyhvNqOndzcoBCCE0wv4cjPFa3+yws1+gk5zppWgIoX7zfNWqUCwOorquJjsbS 2ntkd6RanBdwJ6fY8C8eKfOg8+gtxVOJNZiRoPx1fZa8ggaAHsMsa9N5WUtwZp+eCS bgTczNzGa8cAZDbtUMfBinwfugUlGMhFWymVyIo0ojM/yxJ+kKXg9h19S9HWOMyka/ ayiIaIguhHg1kIn+nsEHipxFjA7w9hpDnOCiMcuzpMMV3HbtT1TDJZ+X0GN57jjwUQ dZY7fEhk5Msrw== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Sweet Tea Dorminy Subject: [PATCH v6 8/8] fscrypt: make prepared keys record their type Date: Tue, 8 Aug 2023 13:08:08 -0400 Message-ID: <64c47243cea5a8eca15538b51f88c0a6d53799cf.1691505830.git.sweettea-kernel@dorminy.me> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Right now fscrypt_infos have two fields dedicated solely to recording what type of prepared key the info has: whether it solely owns the prepared key, or has borrowed it from a master key, or from a direct key. The ci_direct_key field is only used for v1 direct key policies, recording the direct key that needs to have its refcount reduced when the crypt_info is freed. However, now that crypt_info->ci_enc_key is a pointer to the authoritative prepared key -- embedded in the direct key, in this case, we no longer need to keep a full pointer to the direct key -- we can use container_of() to go from the prepared key to its surrounding direct key. The key ownership information doesn't change during the lifetime of a prepared key. Since at worst there's a prepared key per info, and at best many infos share a single prepared key, it can be slightly more efficient to store this ownership info in the prepared key instead of in the fscrypt_info, especially since we can squash both fields down into a single enum. Signed-off-by: Sweet Tea Dorminy Reviewed-by: Josef Bacik --- fs/crypto/fscrypt_private.h | 31 +++++++++++++++++++++++-------- fs/crypto/keysetup.c | 21 +++++++++++++-------- fs/crypto/keysetup_v1.c | 7 +++++-- 3 files changed, 41 insertions(+), 18 deletions(-) diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 20b8ea1e3518..e2acd8894ea7 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -174,18 +174,39 @@ struct fscrypt_symlink_data { char encrypted_path[]; } __packed; +/** + * enum fscrypt_prepared_key_type - records a prepared key's ownership + * + * @FSCRYPT_KEY_PER_INFO: this prepared key is allocated for a specific info + * and is never shared. + * @FSCRYPT_KEY_DIRECT_V1: this prepared key is embedded in a fscrypt_direct_key + * used in v1 direct key policies. + * @FSCRYPT_KEY_MASTER_KEY: this prepared key is a per-mode and policy key, + * part of a fscrypt_master_key, shared between all + * users of this master key having this mode and + * policy. + */ +enum fscrypt_prepared_key_type { + FSCRYPT_KEY_PER_INFO = 1, + FSCRYPT_KEY_DIRECT_V1, + FSCRYPT_KEY_MASTER_KEY, +} __packed; + /** * struct fscrypt_prepared_key - a key prepared for actual encryption/decryption * @tfm: crypto API transform object * @blk_key: key for blk-crypto + * @type: records the ownership type of the prepared key * - * Normally only one of the fields will be non-NULL. + * Normally only one of @tfm and @blk_key will be non-NULL, although it is + * possible if @type is FSCRYPT_KEY_MASTER_KEY. */ struct fscrypt_prepared_key { struct crypto_skcipher *tfm; #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT struct blk_crypto_key *blk_key; #endif + enum fscrypt_prepared_key_type type; }; /* @@ -233,12 +254,6 @@ struct fscrypt_info { */ struct list_head ci_master_key_link; - /* - * If non-NULL, then encryption is done using the master key directly - * and ci_enc_key will equal ci_direct_key->dk_key. - */ - struct fscrypt_direct_key *ci_direct_key; - /* * This inode's hash key for filenames. This is a 128-bit SipHash-2-4 * key. This is only set for directories that use a keyed dirhash over @@ -641,7 +656,7 @@ static inline int fscrypt_require_key(struct inode *inode) /* keysetup_v1.c */ -void fscrypt_put_direct_key(struct fscrypt_direct_key *dk); +void fscrypt_put_direct_key(struct fscrypt_prepared_key *prep_key); int fscrypt_setup_v1_file_key(struct fscrypt_info *ci, const u8 *raw_master_key); diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index 4f04999ecfd1..a19650f954e2 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -191,11 +191,11 @@ void fscrypt_destroy_prepared_key(struct super_block *sb, /* Given a per-file encryption key, set up the file's crypto transform object */ int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key) { - ci->ci_owns_key = true; ci->ci_enc_key = kzalloc(sizeof(*ci->ci_enc_key), GFP_KERNEL); if (!ci->ci_enc_key) return -ENOMEM; + ci->ci_enc_key->type = FSCRYPT_KEY_PER_INFO; return fscrypt_prepare_key(ci->ci_enc_key, raw_key, ci); } @@ -290,7 +290,8 @@ static int setup_new_mode_prepared_key(struct fscrypt_master_key *mk, hkdf_context, hkdf_info, hkdf_infolen, mode_key, mode->keysize); if (err) - goto out_unlock; + return err; + prep_key->type = FSCRYPT_KEY_MASTER_KEY; err = fscrypt_prepare_key(prep_key, mode_key, ci); memzero_explicit(mode_key, mode->keysize); @@ -584,12 +585,16 @@ static void put_crypt_info(struct fscrypt_info *ci) if (!ci) return; - if (ci->ci_direct_key) - fscrypt_put_direct_key(ci->ci_direct_key); - else if (ci->ci_owns_key) { - fscrypt_destroy_prepared_key(ci->ci_inode->i_sb, - ci->ci_enc_key); - kfree_sensitive(ci->ci_enc_key); + if (ci->ci_enc_key) { + enum fscrypt_prepared_key_type type = ci->ci_enc_key->type; + + if (type == FSCRYPT_KEY_DIRECT_V1) + fscrypt_put_direct_key(ci->ci_enc_key); + if (type == FSCRYPT_KEY_PER_INFO) { + fscrypt_destroy_prepared_key(ci->ci_inode->i_sb, + ci->ci_enc_key); + kfree_sensitive(ci->ci_enc_key); + } } mk = ci->ci_master_key; diff --git a/fs/crypto/keysetup_v1.c b/fs/crypto/keysetup_v1.c index e1d761e8067f..1e785cedead0 100644 --- a/fs/crypto/keysetup_v1.c +++ b/fs/crypto/keysetup_v1.c @@ -160,8 +160,11 @@ static void free_direct_key(struct fscrypt_direct_key *dk) } } -void fscrypt_put_direct_key(struct fscrypt_direct_key *dk) +void fscrypt_put_direct_key(struct fscrypt_prepared_key *prep_key) { + struct fscrypt_direct_key *dk = + container_of(prep_key, struct fscrypt_direct_key, dk_key); + if (!refcount_dec_and_lock(&dk->dk_refcount, &fscrypt_direct_keys_lock)) return; hash_del(&dk->dk_node); @@ -235,6 +238,7 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key) dk->dk_sb = ci->ci_inode->i_sb; refcount_set(&dk->dk_refcount, 1); dk->dk_mode = ci->ci_mode; + dk->dk_key.type = FSCRYPT_KEY_DIRECT_V1; err = fscrypt_prepare_key(&dk->dk_key, raw_key, ci); if (err) goto err_free_dk; @@ -258,7 +262,6 @@ static int setup_v1_file_key_direct(struct fscrypt_info *ci, dk = fscrypt_get_direct_key(ci, raw_master_key); if (IS_ERR(dk)) return PTR_ERR(dk); - ci->ci_direct_key = dk; ci->ci_enc_key = &dk->dk_key; return 0; }