From: Eric Biggers Subject: [RFC PATCH 02/25] fscrypt: use FSCRYPT_ prefix for uapi constants Date: Mon, 23 Oct 2017 14:40:35 -0700 Message-ID: <20171023214058.128121-3-ebiggers3@gmail.com> References: <20171023214058.128121-1-ebiggers3@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Ryo Hashimoto , Gwendal Grignou , "Theodore Y . Ts'o" , Eric Biggers , linux-api@vger.kernel.org, Nick Desaulniers , linux-f2fs-devel@lists.sourceforge.net, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, Michael Halcrow , Sarthak Kukreti , linux-fsdevel@vger.kernel.org, Jaegeuk Kim , linux-ext4@vger.kernel.org To: linux-fscrypt@vger.kernel.org Return-path: In-Reply-To: <20171023214058.128121-1-ebiggers3@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net List-Id: linux-ext4.vger.kernel.org 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_VERSION_* or inconsistent names like FS_ENCRYPTION_POLICY_VERSION_*. For source compatibility with older userspace programs, keep the old names defined as aliases to the new ones. (It's debatable whether we really need this, though; the filesystem encryption API is new enough that most if not all programs that are using it have to declare it themselves anyway.) Signed-off-by: Eric Biggers --- Documentation/filesystems/fscrypt.rst | 14 ++++----- include/uapi/linux/fscrypt.h | 59 ++++++++++++++++++++++++----------- 2 files changed, 47 insertions(+), 26 deletions(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 776ddc655f79..f12956f3f1f8 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -251,14 +251,14 @@ 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: @@ -274,7 +274,7 @@ This structure must be initialized as follows: - ``flags`` must be set to a value from ```` which identifies the amount of NUL-padding to use when encrypting - filenames. If unsure, use FS_POLICY_FLAGS_PAD_32 (0x3). + filenames. If unsure, use FSCRYPT_POLICY_FLAGS_PAD_32 (0x3). - ``master_key_descriptor`` specifies how to find the master key in the keyring; see `Adding keys`_. It is up to userspace to choose a @@ -374,11 +374,11 @@ 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; }; @@ -533,7 +533,7 @@ 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 { @@ -541,7 +541,7 @@ 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 c09209fc42ea..26c381a40279 100644 --- a/include/uapi/linux/fscrypt.h +++ b/include/uapi/linux/fscrypt.h @@ -7,30 +7,31 @@ * 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_FLAGS_VALID 0x03 +/* 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_FLAGS_VALID 0x03 /* 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 FSCRYPT_MODE_INVALID 0 +#define FSCRYPT_MODE_AES_256_XTS 1 +#define FSCRYPT_MODE_AES_256_GCM 2 +#define FSCRYPT_MODE_AES_256_CBC 3 +#define FSCRYPT_MODE_AES_256_CTS 4 +#define FSCRYPT_MODE_AES_128_CBC 5 +#define FSCRYPT_MODE_AES_128_CTS 6 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) @@ -38,16 +39,36 @@ 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_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_FLAGS_VALID FSCRYPT_POLICY_FLAGS_VALID +#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE +#define FS_ENCRYPTION_MODE_INVALID FSCRYPT_MODE_INVALID +#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS +#define FS_ENCRYPTION_MODE_AES_256_GCM FSCRYPT_MODE_AES_256_GCM +#define FS_ENCRYPTION_MODE_AES_256_CBC FSCRYPT_MODE_AES_256_CBC +#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_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 */ -- 2.15.0.rc0.271.g36b669edcc-goog ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot