From patchwork Tue Jan 11 19:15:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12710444 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 B7FC0C433EF for ; Tue, 11 Jan 2022 19:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350760AbiAKTRv (ORCPT ); Tue, 11 Jan 2022 14:17:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350662AbiAKTRK (ORCPT ); Tue, 11 Jan 2022 14:17:10 -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 7DEC4C06175B; Tue, 11 Jan 2022 11:16:37 -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 23202B81D2A; Tue, 11 Jan 2022 19:16:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BD74C36AE9; Tue, 11 Jan 2022 19:16:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641928595; bh=fS2OSYWQAYU6dgNohiaAhLeUPSUAJMzPoZu/hFO+AI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kXty3floN225RpnXosZPfh2gge2xNcE0+spsNqG9YHCd+HkkelplEdTsxi2WFzsls ypiJyvF/krLVwffyivFe0nzyCuAuV9IS0dtK4WFH3m8fd97mj92G8b4ZO0HRUlOrp4 nWeuq0kR1pC7ePIPvo2y4uKxhwqINMqS2usWlKe0d3XBXhaBSolb8x0WS3pLuNr48G 4IsOhclVBkV1WQG1952xYL1L+Y+FA+BzZOTTTsx4Np2DQyUlaq4Ly98l3z19xC3XWp FWrV9ZAh8UjTk/hG6OQcBkhmH0hQa68w9aekvwJBK9PUWN/428LU2Gu5WqBGiBrAvD cfsMGp7JkDNVQ== From: Jeff Layton To: ceph-devel@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, idryomov@gmail.com Subject: [RFC PATCH v10 35/48] ceph: add infrastructure for file encryption and decryption Date: Tue, 11 Jan 2022 14:15:55 -0500 Message-Id: <20220111191608.88762-36-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: linux-fscrypt@vger.kernel.org ...and allow test_dummy_encryption to bypass content encryption if mounted with test_dummy_encryption=clear. Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 66 ++++++++++++++++++++++++++ fs/ceph/super.c | 8 ++++ fs/ceph/super.h | 1 + 4 files changed, 196 insertions(+) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 35137beb027b..5a87e7385d3f 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -251,3 +251,124 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, fscrypt_fname_free_buffer(&_tname); return ret; } + +int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num) +{ + struct ceph_mount_options *opt = ceph_inode_to_client(inode)->mount_options; + + if (opt->flags & CEPH_MOUNT_OPT_DUMMY_ENC_CLEAR) + return 0; + + dout("%s: len %u offs %u blk %llu\n", __func__, len, offs, lblk_num); + return fscrypt_decrypt_block_inplace(inode, page, len, offs, lblk_num); +} + +int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num, gfp_t gfp_flags) +{ + struct ceph_mount_options *opt = ceph_inode_to_client(inode)->mount_options; + + if (opt->flags & CEPH_MOUNT_OPT_DUMMY_ENC_CLEAR) + return 0; + + dout("%s: len %u offs %u blk %llu\n", __func__, len, offs, lblk_num); + return fscrypt_encrypt_block_inplace(inode, page, len, offs, lblk_num, gfp_flags); +} + +/** + * ceph_fscrypt_decrypt_pages - decrypt an array of pages + * @inode: pointer to inode associated with these pages + * @page: pointer to page array + * @off: offset into the file that the read data starts + * @len: max length to decrypt + * + * Decrypt an array of fscrypt'ed pages and return the amount of + * data decrypted. Any data in the page prior to the start of the + * first complete block in the read is ignored. Any incomplete + * crypto blocks at the end of the array are ignored (and should + * probably be zeroed by the caller). + * + * Returns the length of the decrypted data or a negative errno. + */ +int ceph_fscrypt_decrypt_pages(struct inode *inode, struct page **page, u64 off, int len) +{ + int i, num_blocks; + u64 baseblk = off >> CEPH_FSCRYPT_BLOCK_SHIFT; + int ret = 0; + + /* + * We can't deal with partial blocks on an encrypted file, so mask off + * the last bit. + */ + num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK); + + /* Decrypt each block */ + for (i = 0; i < num_blocks; ++i) { + int blkoff = i << CEPH_FSCRYPT_BLOCK_SHIFT; + int pgidx = blkoff >> PAGE_SHIFT; + unsigned int pgoffs = offset_in_page(blkoff); + int fret; + + fret = ceph_fscrypt_decrypt_block_inplace(inode, page[pgidx], + CEPH_FSCRYPT_BLOCK_SIZE, pgoffs, + baseblk + i); + if (fret < 0) { + if (ret == 0) + ret = fret; + break; + } + ret += CEPH_FSCRYPT_BLOCK_SIZE; + } + return ret; +} + +/** + * ceph_fscrypt_encrypt_pages - encrypt an array of pages + * @inode: pointer to inode associated with these pages + * @page: pointer to page array + * @off: offset into the file that the data starts + * @len: max length to encrypt + * @gfp: gfp flags to use for allocation + * + * Decrypt an array of cleartext pages and return the amount of + * data encrypted. Any data in the page prior to the start of the + * first complete block in the read is ignored. Any incomplete + * crypto blocks at the end of the array are ignored. + * + * Returns the length of the encrypted data or a negative errno. + */ +int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off, + int len, gfp_t gfp) +{ + int i, num_blocks; + u64 baseblk = off >> CEPH_FSCRYPT_BLOCK_SHIFT; + int ret = 0; + + /* + * We can't deal with partial blocks on an encrypted file, so mask off + * the last bit. + */ + num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK); + + /* Encrypt each block */ + for (i = 0; i < num_blocks; ++i) { + int blkoff = i << CEPH_FSCRYPT_BLOCK_SHIFT; + int pgidx = blkoff >> PAGE_SHIFT; + unsigned int pgoffs = offset_in_page(blkoff); + int fret; + + fret = ceph_fscrypt_encrypt_block_inplace(inode, page[pgidx], + CEPH_FSCRYPT_BLOCK_SIZE, pgoffs, + baseblk + i, gfp); + if (fret < 0) { + if (ret == 0) + ret = fret; + break; + } + ret += CEPH_FSCRYPT_BLOCK_SIZE; + } + return ret; +} diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index ab27a7ed62c3..b5d360085fe8 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -31,6 +31,10 @@ struct ceph_fscrypt_auth { u8 cfa_blob[FSCRYPT_SET_CONTEXT_MAX_SIZE]; } __packed; +#define CEPH_FSCRYPT_BLOCK_SHIFT 12 +#define CEPH_FSCRYPT_BLOCK_SIZE (_AC(1,UL) << CEPH_FSCRYPT_BLOCK_SHIFT) +#define CEPH_FSCRYPT_BLOCK_MASK (~(CEPH_FSCRYPT_BLOCK_SIZE-1)) + #define CEPH_FSCRYPT_AUTH_VERSION 1 static inline u32 ceph_fscrypt_auth_len(struct ceph_fscrypt_auth *fa) { @@ -83,6 +87,38 @@ static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_s int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, struct fscrypt_str *oname, bool *is_nokey); +static inline unsigned int ceph_fscrypt_blocks(u64 off, u64 len) +{ + /* crypto blocks cannot span more than one page */ + BUILD_BUG_ON(CEPH_FSCRYPT_BLOCK_SHIFT > PAGE_SHIFT); + + return ((off+len+CEPH_FSCRYPT_BLOCK_SIZE-1) >> CEPH_FSCRYPT_BLOCK_SHIFT) - + (off >> CEPH_FSCRYPT_BLOCK_SHIFT); +} + +/* + * If we have an encrypted inode then we must adjust the offset and + * range of the on-the-wire read to cover an entire encryption block. + * The copy will be done using the original offset and length, after + * we've decrypted the result. + */ +static inline void fscrypt_adjust_off_and_len(struct inode *inode, u64 *off, u64 *len) +{ + if (IS_ENCRYPTED(inode)) { + *len = ceph_fscrypt_blocks(*off, *len) * CEPH_FSCRYPT_BLOCK_SIZE; + *off &= CEPH_FSCRYPT_BLOCK_MASK; + } +} + +int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num); +int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num, gfp_t gfp_flags); +int ceph_fscrypt_decrypt_pages(struct inode *inode, struct page **page, u64 off, int len); +int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off, + int len, gfp_t gfp); #else /* CONFIG_FS_ENCRYPTION */ static inline void ceph_fscrypt_set_ops(struct super_block *sb) @@ -128,6 +164,36 @@ static inline int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscry oname->len = fname->name_len; return 0; } + +static inline void fscrypt_adjust_off_and_len(struct inode *inode, u64 *off, u64 *len) +{ +} + +static inline int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num) +{ + return 0; +} + +static inline int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num, gfp_t gfp_flags) +{ + return 0; +} + +static inline int ceph_fscrypt_decrypt_pages(struct inode *inode, struct page **page, + u64 off, int len) +{ + return 0; +} + +static inline int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, + u64 off, int len, gfp_t gfp) +{ + return 0; +} #endif /* CONFIG_FS_ENCRYPTION */ #endif diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 0b32d31c6fe0..10923d75a876 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -1076,6 +1076,14 @@ static int ceph_set_test_dummy_encryption(struct super_block *sb, struct fs_cont return -EEXIST; } + /* HACK: allow for cleartext "encryption" in files for testing */ + if (fsc->mount_options->test_dummy_encryption && + !strcmp(fsc->mount_options->test_dummy_encryption, "clear")) { + fsopt->flags |= CEPH_MOUNT_OPT_DUMMY_ENC_CLEAR; + kfree(fsc->mount_options->test_dummy_encryption); + fsc->mount_options->test_dummy_encryption = NULL; + } + err = fscrypt_set_test_dummy_encryption(sb, fsc->mount_options->test_dummy_encryption, &fsc->dummy_enc_policy); diff --git a/fs/ceph/super.h b/fs/ceph/super.h index c17622778720..4d2ccb51fe61 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -50,6 +50,7 @@ #define CEPH_MOUNT_OPT_ASYNC_DIROPS (1<<15) /* allow async directory ops */ #define CEPH_MOUNT_OPT_NOPAGECACHE (1<<16) /* bypass pagecache altogether */ #define CEPH_MOUNT_OPT_TEST_DUMMY_ENC (1<<17) /* enable dummy encryption (for testing) */ +#define CEPH_MOUNT_OPT_DUMMY_ENC_CLEAR (1<<18) /* don't actually encrypt content */ #define CEPH_MOUNT_OPT_DEFAULT \ (CEPH_MOUNT_OPT_DCACHE | \