From patchwork Wed Apr 27 19:12:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 566797 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 F3BC3C433F5 for ; Wed, 27 Apr 2022 19:16:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232871AbiD0TTy (ORCPT ); Wed, 27 Apr 2022 15:19:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233259AbiD0TTQ (ORCPT ); Wed, 27 Apr 2022 15:19:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7ADE369CA for ; Wed, 27 Apr 2022 12:13:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6CDE7B82929 for ; Wed, 27 Apr 2022 19:13:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9707AC385A9; Wed, 27 Apr 2022 19:13:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651086816; bh=t8pc+tEK8OUvwug35XJRJGMtLe5QP5Z9BQBlzDDEy+g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Du6e5IV0RBd76OTea7n4RwAJkEw+BFtJyqwRfXMIuXonjzVXh5FZfpUDrtCH83LRw q8C10BITAhGXrn0mrGjj179dp+HHpc+AfqpU3/+dsY1UTZmNRlB04YtUijxEe/Imp3 vMD2BXEFyi1k0l8bItxnW3e+QKQIfwcihJj8FBe6NaT49lkHlNTsfgrNTo7tMgOgpQ EH4+b4D4FRT6iyZQdK0FIkJ2k6WdxWC0AjhD4IsWy/3riWqXfDGwCf/Avd1HV79Aqd sdOTK9RFjtJYuuITYSjeSJbnFzYtxixheprTyoPQossZYxGb9Lxdjz+Od1kGu+1h0T C6wAVknz602uw== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: xiubli@redhat.com, lhenriques@suse.de, idryomov@gmail.com Subject: [PATCH v14 27/64] ceph: add helpers for converting names for userland presentation Date: Wed, 27 Apr 2022 15:12:37 -0400 Message-Id: <20220427191314.222867-28-jlayton@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220427191314.222867-1-jlayton@kernel.org> References: <20220427191314.222867-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org Define a new ceph_fname struct that we can use to carry information about encrypted dentry names. Add helpers for working with these objects, including ceph_fname_to_usr which formats an encrypted filename for userland presentation. Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 41 ++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 921e62f860c4..7e1f66b35095 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -234,3 +234,79 @@ int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentr dout("base64-encoded ciphertext name = %.*s\n", elen, buf); return elen; } + +/** + * ceph_fname_to_usr - convert a filename for userland presentation + * @fname: ceph_fname to be converted + * @tname: temporary name buffer to use for conversion (may be NULL) + * @oname: where converted name should be placed + * @is_nokey: set to true if key wasn't available during conversion (may be NULL) + * + * Given a filename (usually from the MDS), format it for presentation to + * userland. If @parent is not encrypted, just pass it back as-is. + * + * Otherwise, base64 decode the string, and then ask fscrypt to format it + * for userland presentation. + * + * Returns 0 on success or negative error code on error. + */ +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + int ret; + struct fscrypt_str _tname = FSTR_INIT(NULL, 0); + struct fscrypt_str iname; + + if (!IS_ENCRYPTED(fname->dir)) { + oname->name = fname->name; + oname->len = fname->name_len; + return 0; + } + + /* Sanity check that the resulting name will fit in the buffer */ + if (fname->name_len > FSCRYPT_BASE64URL_CHARS(NAME_MAX)) + return -EIO; + + ret = __fscrypt_prepare_readdir(fname->dir); + if (ret) + return ret; + + /* + * Use the raw dentry name as sent by the MDS instead of + * generating a nokey name via fscrypt. + */ + if (!fscrypt_has_encryption_key(fname->dir)) { + memcpy(oname->name, fname->name, fname->name_len); + oname->len = fname->name_len; + if (is_nokey) + *is_nokey = true; + return 0; + } + + if (fname->ctext_len == 0) { + int declen; + + if (!tname) { + ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); + if (ret) + return ret; + tname = &_tname; + } + + declen = fscrypt_base64url_decode(fname->name, fname->name_len, tname->name); + if (declen <= 0) { + ret = -EIO; + goto out; + } + iname.name = tname->name; + iname.len = declen; + } else { + iname.name = fname->ctext; + iname.len = fname->ctext_len; + } + + ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); +out: + fscrypt_fname_free_buffer(&_tname); + return ret; +} diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 8abf10604722..f231d6e3ba0f 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -13,6 +13,14 @@ struct ceph_fs_client; struct ceph_acl_sec_ctx; struct ceph_mds_request; +struct ceph_fname { + struct inode *dir; + char *name; // b64 encoded, possibly hashed + unsigned char *ctext; // binary crypttext (if any) + u32 name_len; // length of name buffer + u32 ctext_len; // length of crypttext +}; + struct ceph_fscrypt_auth { __le32 cfa_version; __le32 cfa_blob_len; @@ -69,6 +77,22 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as); int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentry, char *buf); +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (!IS_ENCRYPTED(parent)) + return 0; + return fscrypt_fname_alloc_buffer(NAME_MAX, fname); +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (IS_ENCRYPTED(parent)) + fscrypt_fname_free_buffer(fname); +} + +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey); + #else /* CONFIG_FS_ENCRYPTION */ static inline void ceph_fscrypt_set_ops(struct super_block *sb) @@ -97,6 +121,23 @@ static inline int ceph_encode_encrypted_fname(const struct inode *parent, { return -EOPNOTSUPP; } + +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + return 0; +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ +} + +static inline int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + oname->name = fname->name; + oname->len = fname->name_len; + return 0; +} #endif /* CONFIG_FS_ENCRYPTION */ #endif