From patchwork Wed Jan 20 18:28:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12033289 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=-19.2 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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C4335C433E9 for ; Wed, 20 Jan 2021 18:33:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A58C623403 for ; Wed, 20 Jan 2021 18:33:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404446AbhATSc6 (ORCPT ); Wed, 20 Jan 2021 13:32:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:51496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404400AbhATS3t (ORCPT ); Wed, 20 Jan 2021 13:29:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3D9E023405; Wed, 20 Jan 2021 18:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611167330; bh=lP+BXswxzEdVjx21+CaacBnDsvQXsNgV+lN33K9pes8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qMJyCncfo/p73BTxmnAAkODIGrNkIAxbKIWHNXPiJ/eWNbMEshlYTTCjcuIz89QoH pny7iiv66RNla4I7t9qECcpwS4T9/XVAy54y2fFhPLc2+igRmW56PnPaRqa4CVTtcq HWPh8XyZlrCaOxyuy9cmAmxDG/IgBoM4Vx01N1hLDU/ipEZ8OMxYALUYvzx5hPbcIF jIRPwjeAEh/QSvnxZipaSZH7kXwLXr9tw1huMPzcnLKkxkpTGonSwz7Sb/nLn1wmPP RwCc74X7OZ6QbC0Fd2spKJz9GoYdDiA/0VJchXjEpC43Xb/Cp0Dpc/j+fxlL4jWPiU 1iYq+LrZOau0A== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH v4 02/17] fscrypt: export fscrypt_base64_encode and fscrypt_base64_decode Date: Wed, 20 Jan 2021 13:28:32 -0500 Message-Id: <20210120182847.644850-3-jlayton@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210120182847.644850-1-jlayton@kernel.org> References: <20210120182847.644850-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Ceph will need to base64-encode some encrypted filenames, so make these routines, and FSCRYPT_BASE64_CHARS available to modules. Signed-off-by: Jeff Layton --- fs/crypto/fname.c | 34 ++++++++++++++++++++++++---------- include/linux/fscrypt.h | 5 +++++ 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index 6ca7d16593ff..32b1f50433ba 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -178,10 +178,8 @@ static int fname_decrypt(const struct inode *inode, static const char lookup_table[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,"; -#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) - /** - * base64_encode() - base64-encode some bytes + * fscrypt_base64_encode() - base64-encode some bytes * @src: the bytes to encode * @len: number of bytes to encode * @dst: (output) the base64-encoded string. Not NUL-terminated. @@ -191,7 +189,7 @@ static const char lookup_table[65] = * * Return: length of the encoded string */ -static int base64_encode(const u8 *src, int len, char *dst) +int fscrypt_base64_encode(const u8 *src, int len, char *dst) { int i, bits = 0, ac = 0; char *cp = dst; @@ -209,8 +207,20 @@ static int base64_encode(const u8 *src, int len, char *dst) *cp++ = lookup_table[ac & 0x3f]; return cp - dst; } +EXPORT_SYMBOL(fscrypt_base64_encode); -static int base64_decode(const char *src, int len, u8 *dst) +/** + * fscrypt_base64_decode() - base64-decode some bytes + * @src: the bytes to decode + * @len: number of bytes to decode + * @dst: (output) decoded binary data + * + * Decode an input string that was previously encoded using + * fscrypt_base64_encode. + * + * Return: length of the decoded binary data + */ +int fscrypt_base64_decode(const char *src, int len, u8 *dst) { int i, bits = 0, ac = 0; const char *p; @@ -232,6 +242,7 @@ static int base64_decode(const char *src, int len, u8 *dst) return -1; return cp - dst; } +EXPORT_SYMBOL(fscrypt_base64_decode); bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, u32 orig_len, u32 max_len, @@ -263,8 +274,9 @@ bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, int fscrypt_fname_alloc_buffer(u32 max_encrypted_len, struct fscrypt_str *crypto_str) { - const u32 max_encoded_len = BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX); u32 max_presented_len; + const u32 max_encoded_len = + FSCRYPT_BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX); max_presented_len = max(max_encoded_len, max_encrypted_len); @@ -342,7 +354,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode, offsetof(struct fscrypt_nokey_name, bytes)); BUILD_BUG_ON(offsetofend(struct fscrypt_nokey_name, bytes) != offsetof(struct fscrypt_nokey_name, sha256)); - BUILD_BUG_ON(BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX); + BUILD_BUG_ON(FSCRYPT_BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX) > NAME_MAX); if (hash) { nokey_name.dirhash[0] = hash; @@ -362,7 +374,8 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode, nokey_name.sha256); size = FSCRYPT_NOKEY_NAME_MAX; } - oname->len = base64_encode((const u8 *)&nokey_name, size, oname->name); + oname->len = fscrypt_base64_encode((const u8 *)&nokey_name, size, + oname->name); return 0; } EXPORT_SYMBOL(fscrypt_fname_disk_to_usr); @@ -436,14 +449,15 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, * user-supplied name */ - if (iname->len > BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX)) + if (iname->len > FSCRYPT_BASE64_CHARS(FSCRYPT_NOKEY_NAME_MAX)) return -ENOENT; fname->crypto_buf.name = kmalloc(FSCRYPT_NOKEY_NAME_MAX, GFP_KERNEL); if (fname->crypto_buf.name == NULL) return -ENOMEM; - ret = base64_decode(iname->name, iname->len, fname->crypto_buf.name); + ret = fscrypt_base64_decode(iname->name, iname->len, + fname->crypto_buf.name); if (ret < (int)offsetof(struct fscrypt_nokey_name, bytes[1]) || (ret > offsetof(struct fscrypt_nokey_name, sha256) && ret != FSCRYPT_NOKEY_NAME_MAX)) { diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 2ea1387bb497..e300f6145ddc 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -46,6 +46,9 @@ struct fscrypt_name { /* Maximum value for the third parameter of fscrypt_operations.set_context(). */ #define FSCRYPT_SET_CONTEXT_MAX_SIZE 40 +/* Calculate worst-case base64 encoding inflation */ +#define FSCRYPT_BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) + #ifdef CONFIG_FS_ENCRYPTION /* * fscrypt superblock flags @@ -207,6 +210,8 @@ void fscrypt_free_inode(struct inode *inode); int fscrypt_drop_inode(struct inode *inode); /* fname.c */ +int fscrypt_base64_encode(const u8 *src, int len, char *dst); +int fscrypt_base64_decode(const char *src, int len, u8 *dst); int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname, int lookup, struct fscrypt_name *fname);