From: Eric Biggers <ebiggers@xxxxxxxxxx>
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 <ebiggers@xxxxxxxxxx>
---
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 ``<linux/fs.h>`` 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
