From patchwork Thu Apr 18 23:29:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 10908197 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8D70C1390 for ; Thu, 18 Apr 2019 23:31:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7FEC428D6F for ; Thu, 18 Apr 2019 23:31:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 741FD28D85; Thu, 18 Apr 2019 23:31:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD10728D6F for ; Thu, 18 Apr 2019 23:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726823AbfDRXbD (ORCPT ); Thu, 18 Apr 2019 19:31:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:58940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726399AbfDRXa0 (ORCPT ); Thu, 18 Apr 2019 19:30:26 -0400 Received: from ebiggers-linuxstation.mtv.corp.google.com (unknown [104.132.1.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 49F0D217F9; Thu, 18 Apr 2019 23:30:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555630225; bh=umE80bY8b0NLW/IR4dcLhpvY2ps7d7P4zaqDFrbjfbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0Lit++IpbKFpPqC1dkNANbiP2XPB1wgKNueSb6doNDleVa15RfoXxhWjC0yWl0NhZ mI7DjIdVDegYgStgihwKy7Hp6rkN5fq59Hd99pC5g388YFJH9RFBE7PXFVBLixnA9Y BjG5uQ8Nmge453vvN9J1NR4conzug85nZMfQxxwM= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: Satya Tangirala , linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Paul Crowley Subject: [PATCH v5 02/16] fscrypt: use FSCRYPT_ prefix for uapi constants Date: Thu, 18 Apr 2019 16:29:09 -0700 Message-Id: <20190418232923.250800-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog In-Reply-To: <20190418232923.250800-1-ebiggers@kernel.org> References: <20190418232923.250800-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Biggers Prefix all filesystem encryption UAPI constants except the ioctl numbers with "FSCRYPT_" rather than with "FS_". This namespaces the constants more appropriately and makes it clear that they are related specifically to the filesystem encryption feature, and to the 'fscrypt_*' structures. With some of the old names like "FS_POLICY_FLAGS_VALID", it was not immediately clear that the constant had anything to do with encryption. This is also useful because we'll be adding more encryption-related constants, e.g. for the policy version, and we'd otherwise have to choose whether to use unclear names like FS_POLICY_V1 or inconsistent names like FS_ENCRYPTION_POLICY_V1. For source compatibility with existing userspace programs, keep the old names defined as aliases to the new names. Finally, as long as new names are being defined anyway, I skipped defining new names for the fscrypt mode numbers that aren't actually used: INVALID (0), AES_256_GCM (2), AES_256_CBC (3), SPECK128_256_XTS (7), and SPECK128_256_CTS (8). Signed-off-by: Eric Biggers --- Documentation/filesystems/fscrypt.rst | 36 +++++++-------- include/uapi/linux/fscrypt.h | 66 +++++++++++++++++---------- 2 files changed, 61 insertions(+), 41 deletions(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 08c23b60e0164..4f9df6ba669e5 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -223,9 +223,10 @@ a little endian number, except that: is encrypted with AES-256 where the AES-256 key is the SHA-256 hash of the file's data encryption key. -- In the "direct key" configuration (FS_POLICY_FLAG_DIRECT_KEY set in - the fscrypt_policy), the file's nonce is also appended to the IV. - Currently this is only allowed with the Adiantum encryption mode. +- In the "direct key" configuration (FSCRYPT_POLICY_FLAG_DIRECT_KEY + set in the fscrypt_policy), the file's nonce is also appended to the + IV. Currently this is only allowed with the Adiantum encryption + mode. Filenames encryption -------------------- @@ -272,14 +273,14 @@ empty directory or verifies that a directory or regular file already has the specified encryption policy. It takes in a pointer to a :c:type:`struct fscrypt_policy`, defined as follows:: - #define FS_KEY_DESCRIPTOR_SIZE 8 + #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8 struct fscrypt_policy { __u8 version; __u8 contents_encryption_mode; __u8 filenames_encryption_mode; __u8 flags; - __u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; + __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; }; This structure must be initialized as follows: @@ -288,18 +289,17 @@ This structure must be initialized as follows: - ``contents_encryption_mode`` and ``filenames_encryption_mode`` must be set to constants from ```` which identify the - encryption modes to use. If unsure, use - FS_ENCRYPTION_MODE_AES_256_XTS (1) for ``contents_encryption_mode`` - and FS_ENCRYPTION_MODE_AES_256_CTS (4) for - ``filenames_encryption_mode``. + encryption modes to use. If unsure, use FSCRYPT_MODE_AES_256_XTS + (1) for ``contents_encryption_mode`` and FSCRYPT_MODE_AES_256_CTS + (4) for ``filenames_encryption_mode``. - ``flags`` must contain a value from ```` which identifies the amount of NUL-padding to use when encrypting - filenames. If unsure, use FS_POLICY_FLAGS_PAD_32 (0x3). - In addition, if the chosen encryption modes are both - FS_ENCRYPTION_MODE_ADIANTUM, this can contain - FS_POLICY_FLAG_DIRECT_KEY to specify that the master key should be - used directly, without key derivation. + filenames. If unsure, use FSCRYPT_POLICY_FLAGS_PAD_32 (0x3). In + addition, if the chosen encryption modes are both + FSCRYPT_MODE_ADIANTUM, this can contain + FSCRYPT_POLICY_FLAG_DIRECT_KEY to specify that the master key should + be used directly, without key derivation. - ``master_key_descriptor`` specifies how to find the master key in the keyring; see `Adding keys`_. It is up to userspace to choose a @@ -399,11 +399,11 @@ followed by the 16-character lower case hex representation of the ``master_key_descriptor`` that was set in the encryption policy. The key payload must conform to the following structure:: - #define FS_MAX_KEY_SIZE 64 + #define FSCRYPT_MAX_KEY_SIZE 64 struct fscrypt_key { u32 mode; - u8 raw[FS_MAX_KEY_SIZE]; + u8 raw[FSCRYPT_MAX_KEY_SIZE]; u32 size; }; @@ -572,7 +572,7 @@ much confusion if an encryption policy were to be added to or removed from anything other than an empty directory.) The struct is defined as follows:: - #define FS_KEY_DESCRIPTOR_SIZE 8 + #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8 #define FS_KEY_DERIVATION_NONCE_SIZE 16 struct fscrypt_context { @@ -580,7 +580,7 @@ as follows:: u8 contents_encryption_mode; u8 filenames_encryption_mode; u8 flags; - u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; + u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; }; diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h index 193339cb53fdb..f9b99cc028bc6 100644 --- a/include/uapi/linux/fscrypt.h +++ b/include/uapi/linux/fscrypt.h @@ -8,34 +8,30 @@ * File system encryption support */ /* Policy provided via an ioctl on the topmost directory */ -#define FS_KEY_DESCRIPTOR_SIZE 8 +#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8 -#define FS_POLICY_FLAGS_PAD_4 0x00 -#define FS_POLICY_FLAGS_PAD_8 0x01 -#define FS_POLICY_FLAGS_PAD_16 0x02 -#define FS_POLICY_FLAGS_PAD_32 0x03 -#define FS_POLICY_FLAGS_PAD_MASK 0x03 -#define FS_POLICY_FLAG_DIRECT_KEY 0x04 /* use master key directly */ -#define FS_POLICY_FLAGS_VALID 0x07 +/* Encryption policy flags */ +#define FSCRYPT_POLICY_FLAGS_PAD_4 0x00 +#define FSCRYPT_POLICY_FLAGS_PAD_8 0x01 +#define FSCRYPT_POLICY_FLAGS_PAD_16 0x02 +#define FSCRYPT_POLICY_FLAGS_PAD_32 0x03 +#define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03 +#define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04 /* use master key directly */ +#define FSCRYPT_POLICY_FLAGS_VALID 0x07 /* Encryption algorithms */ -#define FS_ENCRYPTION_MODE_INVALID 0 -#define FS_ENCRYPTION_MODE_AES_256_XTS 1 -#define FS_ENCRYPTION_MODE_AES_256_GCM 2 -#define FS_ENCRYPTION_MODE_AES_256_CBC 3 -#define FS_ENCRYPTION_MODE_AES_256_CTS 4 -#define FS_ENCRYPTION_MODE_AES_128_CBC 5 -#define FS_ENCRYPTION_MODE_AES_128_CTS 6 -#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* Removed, do not use. */ -#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* Removed, do not use. */ -#define FS_ENCRYPTION_MODE_ADIANTUM 9 +#define FSCRYPT_MODE_AES_256_XTS 1 +#define FSCRYPT_MODE_AES_256_CTS 4 +#define FSCRYPT_MODE_AES_128_CBC 5 +#define FSCRYPT_MODE_AES_128_CTS 6 +#define FSCRYPT_MODE_ADIANTUM 9 struct fscrypt_policy { __u8 version; __u8 contents_encryption_mode; __u8 filenames_encryption_mode; __u8 flags; - __u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE]; + __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; }; #define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy) @@ -43,16 +39,40 @@ struct fscrypt_policy { #define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy) /* Parameters for passing an encryption key into the kernel keyring */ -#define FS_KEY_DESC_PREFIX "fscrypt:" -#define FS_KEY_DESC_PREFIX_SIZE 8 +#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:" +#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8 /* Structure that userspace passes to the kernel keyring */ -#define FS_MAX_KEY_SIZE 64 +#define FSCRYPT_MAX_KEY_SIZE 64 struct fscrypt_key { __u32 mode; - __u8 raw[FS_MAX_KEY_SIZE]; + __u8 raw[FSCRYPT_MAX_KEY_SIZE]; __u32 size; }; +/**********************************************************************/ + +/* old names; don't add anything new here! */ +#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE +#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4 +#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8 +#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16 +#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32 +#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK +#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY +#define FS_POLICY_FLAGS_VALID FSCRYPT_POLICY_FLAGS_VALID +#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS +#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */ +#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS +#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC +#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS +#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* removed */ +#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* removed */ +#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM +#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX +#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE +#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE #endif /* _UAPI_LINUX_FSCRYPT_H */