From patchwork Thu Aug 26 16:19:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 503437 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B8BCC4320E for ; Thu, 26 Aug 2021 16:20:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7726761101 for ; Thu, 26 Aug 2021 16:20:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243108AbhHZQVL (ORCPT ); Thu, 26 Aug 2021 12:21:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:44648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243091AbhHZQVG (ORCPT ); Thu, 26 Aug 2021 12:21:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B9F0D6108F; Thu, 26 Aug 2021 16:20:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629994819; bh=Yx7SW8C4gmOMhsq0PpESDd32cAYSfy7AD3A7RgWHKvs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cDZhj9eyqDjcbMWTaSqjmQZt9qVjO93R6luQpq5qU8O7N1+WuWYbGc/Br08rDPh+1 tprdfO179Vqf1Rbkg/b3uDqKGKJpr2Ncy7b0JxQ3+tljrTumRXIX7Ivt7wLN0R+xuv GMIdzwkSKtXYF/6wUrIrflDYAAEeyvL2Wcgn5wlLARaBylWu2WW7NLEAfT4yECFLsP u8A5LFSOTlMGftjiGzxBxRFVH/ocM7bC7HzgyAV1pdKzOE/GknaGTNKidJV1FXOf6X mLrzx705LbW/vIerxza5nyurofWsnDB9eTzhKlJHVRZs89iwIq4euShfeHtAyUoczr F6eYHb1MWhJkg== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, dhowells@redhat.com, xiubli@redhat.com, lhenriques@suse.de, khiremat@redhat.com, ebiggers@kernel.org Subject: [RFC PATCH v8 03/24] fscrypt: export fscrypt_fname_encrypt and fscrypt_fname_encrypted_size Date: Thu, 26 Aug 2021 12:19:53 -0400 Message-Id: <20210826162014.73464-4-jlayton@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210826162014.73464-1-jlayton@kernel.org> References: <20210826162014.73464-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org For ceph, we want to use our own scheme for handling filenames that are are longer than NAME_MAX after encryption and base64 encoding. This allows us to have a consistent view of the encrypted filenames for clients that don't support fscrypt and clients that do but that don't have the key. Currently, fs/crypto only supports encrypting filenames using fscrypt_setup_filename, but that also handles encoding nokey names. Ceph can't use that because it handles nokey names in a different way. Export fscrypt_fname_encrypt. Rename fscrypt_fname_encrypted_size to __fscrypt_fname_encrypted_size and add a new wrapper called fscrypt_fname_encrypted_size that takes an inode argument rather than a pointer to a fscrypt_policy union. Signed-off-by: Jeff Layton --- fs/crypto/fname.c | 32 +++++++++++++++++++++++++++----- fs/crypto/fscrypt_private.h | 9 +++------ fs/crypto/hooks.c | 6 +++--- include/linux/fscrypt.h | 4 ++++ 4 files changed, 37 insertions(+), 14 deletions(-) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 02555a31875a..7195b64aea77 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -130,6 +130,7 @@ int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, return 0; } +EXPORT_SYMBOL(fscrypt_fname_encrypt); /** * fname_decrypt() - decrypt a filename @@ -257,9 +258,9 @@ int fscrypt_base64url_decode(const char *src, int srclen, u8 *dst) } EXPORT_SYMBOL(fscrypt_base64url_decode); -bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, - u32 orig_len, u32 max_len, - u32 *encrypted_len_ret) +bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, + u32 orig_len, u32 max_len, + u32 *encrypted_len_ret) { int padding = 4 << (fscrypt_policy_flags(policy) & FSCRYPT_POLICY_FLAGS_PAD_MASK); @@ -273,6 +274,28 @@ bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, return true; } +/** + * fscrypt_fname_encrypted_size() - calculate length of encrypted filename + * @inode: parent inode of dentry name being encrypted + * @orig_len: length of the original filename + * @max_len: maximum length to return + * @encrypted_len_ret: where calculated length should be returned (on success) + * + * Filenames must be padded out to at least the end of an fscrypt block before + * encrypting them. This calculates the length of an encrypted filename. + * + * Return: false if the orig_len is shorter than max_len. Otherwise, true and + * fill out encrypted_len_ret with the length (up to max_len). + */ +bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len, + u32 max_len, u32 *encrypted_len_ret) +{ + return __fscrypt_fname_encrypted_size(&inode->i_crypt_info->ci_policy, + orig_len, max_len, + encrypted_len_ret); +} +EXPORT_SYMBOL(fscrypt_fname_encrypted_size); + /** * fscrypt_fname_alloc_buffer() - allocate a buffer for presented filenames * @max_encrypted_len: maximum length of encrypted filenames the buffer will be @@ -428,8 +451,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, return ret; if (fscrypt_has_encryption_key(dir)) { - if (!fscrypt_fname_encrypted_size(&dir->i_crypt_info->ci_policy, - iname->len, + if (!fscrypt_fname_encrypted_size(dir, iname->len, dir->i_sb->s_cop->max_namelen, &fname->crypto_buf.len)) return -ENAMETOOLONG; diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 3fa965eb3336..195de6d0db40 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -292,14 +292,11 @@ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, const struct fscrypt_info *ci); /* fname.c */ -int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, - u8 *out, unsigned int olen); -bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, - u32 orig_len, u32 max_len, - u32 *encrypted_len_ret); +bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, + u32 orig_len, u32 max_len, + u32 *encrypted_len_ret); /* hkdf.c */ - struct fscrypt_hkdf { struct crypto_shash *hmac_tfm; }; diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index a73b0376e6f3..e65c19aae041 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -228,9 +228,9 @@ int fscrypt_prepare_symlink(struct inode *dir, const char *target, * counting it (even though it is meaningless for ciphertext) is simpler * for now since filesystems will assume it is there and subtract it. */ - if (!fscrypt_fname_encrypted_size(policy, len, - max_len - sizeof(struct fscrypt_symlink_data), - &disk_link->len)) + if (!__fscrypt_fname_encrypted_size(policy, len, + max_len - sizeof(struct fscrypt_symlink_data), + &disk_link->len)) return -ENAMETOOLONG; disk_link->len += sizeof(struct fscrypt_symlink_data); diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 07144330f975..64281ba4be2b 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -210,8 +210,12 @@ void fscrypt_free_inode(struct inode *inode); int fscrypt_drop_inode(struct inode *inode); /* fname.c */ +int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, + u8 *out, unsigned int olen); int fscrypt_base64url_encode(const u8 *src, int len, char *dst); int fscrypt_base64url_decode(const char *src, int len, u8 *dst); +bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len, + u32 max_len, u32 *encrypted_len_ret); int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname, int lookup, struct fscrypt_name *fname);