From patchwork Tue Jan 11 19:15:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 531195 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 BEA6AC433EF for ; Tue, 11 Jan 2022 19:16:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350476AbiAKTQU (ORCPT ); Tue, 11 Jan 2022 14:16:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350437AbiAKTQP (ORCPT ); Tue, 11 Jan 2022 14:16:15 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F301FC061748; Tue, 11 Jan 2022 11:16:14 -0800 (PST) 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 AEF8CB81D24; Tue, 11 Jan 2022 19:16:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC8AEC36AF2; Tue, 11 Jan 2022 19:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641928572; bh=5IIZ9LeYGLILbMWK68fPIjDJTM45GEp1gb0bOrKq7u0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jsk8a44vwD7cOePfRaWQa8CDuvRcTXpQTKEwc8Br9EqMrrR+wtIm/xsciks35iX+y eCuEhXlyQjCVPDl0GJzcp6HAm6qe2UI5eTNT0yxPMGxI08xBMmI0qLvTTryP2XkODz FgmCRhCH2SHNYo8uHSQpYSw6bYrkLYPpqoC7PqQlu+RmwUgynzpxgQmR8wFiRZCkWj GPwsFOEt/Z7zygumwMQ9M1ITACcRHZVH/HLD5BiFttgyohp51Wcq8jo1AvHEZ7VN+W KiEuedH/x9xX6QkHFJaWAmm7LHZ3lJ/vbsj40XNEQuf1f2H2VHXeNHiMFmR7gHBp9U qkBfKoE2P7k3w== From: Jeff Layton To: ceph-devel@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, idryomov@gmail.com, Eric Biggers Subject: [RFC PATCH v10 02/48] fscrypt: export fscrypt_base64url_encode and fscrypt_base64url_decode Date: Tue, 11 Jan 2022 14:15:22 -0500 Message-Id: <20220111191608.88762-3-jlayton@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220111191608.88762-1-jlayton@kernel.org> References: <20220111191608.88762-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org Ceph is going to add fscrypt support, but we still want encrypted filenames to be composed of printable characters, so we can maintain compatibility with clients that don't support fscrypt. We could just adopt fscrypt's current nokey name format, but that is subject to change in the future, and it also contains dirhash fields that we don't need for cephfs. Because of this, we're going to concoct our own scheme for encoding encrypted filenames. It's very similar to fscrypt's current scheme, but doesn't bother with the dirhash fields. The ceph encoding scheme will use base64 encoding as well, and we also want it to avoid characters that are illegal in filenames. Export the fscrypt base64 encoding/decoding routines so we can use them in ceph's fscrypt implementation. Acked-by: Eric Biggers Signed-off-by: Jeff Layton --- fs/crypto/fname.c | 8 ++++---- include/linux/fscrypt.h | 5 +++++ 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c index a9be4bc74a94..1e4233c95005 100644 --- a/fs/crypto/fname.c +++ b/fs/crypto/fname.c @@ -182,8 +182,6 @@ static int fname_decrypt(const struct inode *inode, static const char base64url_table[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; -#define FSCRYPT_BASE64URL_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) - /** * fscrypt_base64url_encode() - base64url-encode some binary data * @src: the binary data to encode @@ -198,7 +196,7 @@ static const char base64url_table[65] = * Return: the length of the resulting base64url-encoded string in bytes. * This will be equal to FSCRYPT_BASE64URL_CHARS(srclen). */ -static int fscrypt_base64url_encode(const u8 *src, int srclen, char *dst) +int fscrypt_base64url_encode(const u8 *src, int srclen, char *dst) { u32 ac = 0; int bits = 0; @@ -217,6 +215,7 @@ static int fscrypt_base64url_encode(const u8 *src, int srclen, char *dst) *cp++ = base64url_table[(ac << (6 - bits)) & 0x3f]; return cp - dst; } +EXPORT_SYMBOL_GPL(fscrypt_base64url_encode); /** * fscrypt_base64url_decode() - base64url-decode a string @@ -233,7 +232,7 @@ static int fscrypt_base64url_encode(const u8 *src, int srclen, char *dst) * Return: the length of the resulting decoded binary data in bytes, * or -1 if the string isn't a valid base64url string. */ -static int fscrypt_base64url_decode(const char *src, int srclen, u8 *dst) +int fscrypt_base64url_decode(const char *src, int srclen, u8 *dst) { u32 ac = 0; int bits = 0; @@ -256,6 +255,7 @@ static int fscrypt_base64url_decode(const char *src, int srclen, u8 *dst) return -1; return bp - dst; } +EXPORT_SYMBOL_GPL(fscrypt_base64url_decode); bool fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, u32 orig_len, u32 max_len, diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 91ea9477e9bd..671181d196a8 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 +/* len of resulting string (sans NUL terminator) after base64 encoding nbytes */ +#define FSCRYPT_BASE64URL_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) + #ifdef CONFIG_FS_ENCRYPTION /* @@ -305,6 +308,8 @@ void fscrypt_free_inode(struct inode *inode); int fscrypt_drop_inode(struct inode *inode); /* fname.c */ +int fscrypt_base64url_encode(const u8 *src, int len, char *dst); +int fscrypt_base64url_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);