[RFC][PATCH v3 4/6] eCryptfs: export global eCryptfs definitions to include/linux/ecryptfs.h

From: Roberto Sassu
Date: Mon Jan 24 2011 - 11:45:44 EST

Some eCryptfs specific definitions, such as the current version and the
authentication token structure, are moved to the new include file
'include/linux/ecryptfs.h', in order to be available for all kernel
subsystems.

Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxx>
Acked-by: Gianluca Ramunno <ramunno@xxxxxxxxx>
Acked-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxx>
---
fs/ecryptfs/ecryptfs_kernel.h | 109 +---------------------------------------
include/linux/ecryptfs.h | 113 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 114 insertions(+), 108 deletions(-)
create mode 100644 include/linux/ecryptfs.h

diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index dbc84ed..2e2242f 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -36,125 +36,18 @@
#include <linux/hash.h>
#include <linux/nsproxy.h>
#include <linux/backing-dev.h>
+#include <linux/ecryptfs.h>

-/* Version verification for shared data structures w/ userspace */
-#define ECRYPTFS_VERSION_MAJOR 0x00
-#define ECRYPTFS_VERSION_MINOR 0x04
-#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x03
-/* These flags indicate which features are supported by the kernel
- * module; userspace tools such as the mount helper read
- * ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine
- * how to behave. */
-#define ECRYPTFS_VERSIONING_PASSPHRASE 0x00000001
-#define ECRYPTFS_VERSIONING_PUBKEY 0x00000002
-#define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004
-#define ECRYPTFS_VERSIONING_POLICY 0x00000008
-#define ECRYPTFS_VERSIONING_XATTR 0x00000010
-#define ECRYPTFS_VERSIONING_MULTKEY 0x00000020
-#define ECRYPTFS_VERSIONING_DEVMISC 0x00000040
-#define ECRYPTFS_VERSIONING_HMAC 0x00000080
-#define ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION 0x00000100
-#define ECRYPTFS_VERSIONING_GCM 0x00000200
-#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
- | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
- | ECRYPTFS_VERSIONING_PUBKEY \
- | ECRYPTFS_VERSIONING_XATTR \
- | ECRYPTFS_VERSIONING_MULTKEY \
- | ECRYPTFS_VERSIONING_DEVMISC \
- | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
-#define ECRYPTFS_MAX_PASSWORD_LENGTH 64
-#define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH
-#define ECRYPTFS_SALT_SIZE 8
-#define ECRYPTFS_SALT_SIZE_HEX (ECRYPTFS_SALT_SIZE*2)
-/* The original signature size is only for what is stored on disk; all
- * in-memory representations are expanded hex, so it better adapted to
- * be passed around or referenced on the command line */
-#define ECRYPTFS_SIG_SIZE 8
-#define ECRYPTFS_SIG_SIZE_HEX (ECRYPTFS_SIG_SIZE*2)
-#define ECRYPTFS_PASSWORD_SIG_SIZE ECRYPTFS_SIG_SIZE_HEX
-#define ECRYPTFS_MAX_KEY_BYTES 64
-#define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
#define ECRYPTFS_DEFAULT_IV_BYTES 16
-#define ECRYPTFS_FILE_VERSION 0x03
#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
#define ECRYPTFS_DEFAULT_SEND_TIMEOUT HZ
#define ECRYPTFS_MAX_MSG_CTX_TTL (HZ*3)
-#define ECRYPTFS_MAX_PKI_NAME_BYTES 16
#define ECRYPTFS_DEFAULT_NUM_USERS 4
#define ECRYPTFS_MAX_NUM_USERS 32768
#define ECRYPTFS_XATTR_NAME "user.ecryptfs"

-#define RFC2440_CIPHER_DES3_EDE 0x02
-#define RFC2440_CIPHER_CAST_5 0x03
-#define RFC2440_CIPHER_BLOWFISH 0x04
-#define RFC2440_CIPHER_AES_128 0x07
-#define RFC2440_CIPHER_AES_192 0x08
-#define RFC2440_CIPHER_AES_256 0x09
-#define RFC2440_CIPHER_TWOFISH 0x0a
-#define RFC2440_CIPHER_CAST_6 0x0b
-
-#define RFC2440_CIPHER_RSA 0x01
-
-/**
- * For convenience, we may need to pass around the encrypted session
- * key between kernel and userspace because the authentication token
- * may not be extractable. For example, the TPM may not release the
- * private key, instead requiring the encrypted data and returning the
- * decrypted data.
- */
-struct ecryptfs_session_key {
-#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT 0x00000001
-#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT 0x00000002
-#define ECRYPTFS_CONTAINS_DECRYPTED_KEY 0x00000004
-#define ECRYPTFS_CONTAINS_ENCRYPTED_KEY 0x00000008
- u32 flags;
- u32 encrypted_key_size;
- u32 decrypted_key_size;
- u8 encrypted_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
- u8 decrypted_key[ECRYPTFS_MAX_KEY_BYTES];
-};
-
-struct ecryptfs_password {
- u32 password_bytes;
- s32 hash_algo;
- u32 hash_iterations;
- u32 session_key_encryption_key_bytes;
-#define ECRYPTFS_PERSISTENT_PASSWORD 0x01
-#define ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET 0x02
- u32 flags;
- /* Iterated-hash concatenation of salt and passphrase */
- u8 session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
- u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
- /* Always in expanded hex */
- u8 salt[ECRYPTFS_SALT_SIZE];
-};
-
-enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY};
-
-struct ecryptfs_private_key {
- u32 key_size;
- u32 data_len;
- u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
- char pki_type[ECRYPTFS_MAX_PKI_NAME_BYTES + 1];
- u8 data[];
-};
-
-/* May be a password or a private key */
-struct ecryptfs_auth_tok {
- u16 version; /* 8-bit major and 8-bit minor */
- u16 token_type;
-#define ECRYPTFS_ENCRYPT_ONLY 0x00000001
- u32 flags;
- struct ecryptfs_session_key session_key;
- u8 reserved[32];
- union {
- struct ecryptfs_password password;
- struct ecryptfs_private_key private_key;
- } token;
-} __attribute__ ((packed));
-
void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok);
extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size);
extern void ecryptfs_from_hex(char *dst, char *src, int dst_size);
diff --git a/include/linux/ecryptfs.h b/include/linux/ecryptfs.h
new file mode 100644
index 0000000..2224a8c
--- /dev/null
+++ b/include/linux/ecryptfs.h
@@ -0,0 +1,113 @@
+#ifndef _LINUX_ECRYPTFS_H
+#define _LINUX_ECRYPTFS_H
+
+/* Version verification for shared data structures w/ userspace */
+#define ECRYPTFS_VERSION_MAJOR 0x00
+#define ECRYPTFS_VERSION_MINOR 0x04
+#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x03
+/* These flags indicate which features are supported by the kernel
+ * module; userspace tools such as the mount helper read
+ * ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine
+ * how to behave. */
+#define ECRYPTFS_VERSIONING_PASSPHRASE 0x00000001
+#define ECRYPTFS_VERSIONING_PUBKEY 0x00000002
+#define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004
+#define ECRYPTFS_VERSIONING_POLICY 0x00000008
+#define ECRYPTFS_VERSIONING_XATTR 0x00000010
+#define ECRYPTFS_VERSIONING_MULTKEY 0x00000020
+#define ECRYPTFS_VERSIONING_DEVMISC 0x00000040
+#define ECRYPTFS_VERSIONING_HMAC 0x00000080
+#define ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION 0x00000100
+#define ECRYPTFS_VERSIONING_GCM 0x00000200
+#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \
+ | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \
+ | ECRYPTFS_VERSIONING_PUBKEY \
+ | ECRYPTFS_VERSIONING_XATTR \
+ | ECRYPTFS_VERSIONING_MULTKEY \
+ | ECRYPTFS_VERSIONING_DEVMISC \
+ | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION)
+#define ECRYPTFS_MAX_PASSWORD_LENGTH 64
+#define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH
+#define ECRYPTFS_SALT_SIZE 8
+#define ECRYPTFS_SALT_SIZE_HEX (ECRYPTFS_SALT_SIZE*2)
+/* The original signature size is only for what is stored on disk; all
+ * in-memory representations are expanded hex, so it better adapted to
+ * be passed around or referenced on the command line */
+#define ECRYPTFS_SIG_SIZE 8
+#define ECRYPTFS_SIG_SIZE_HEX (ECRYPTFS_SIG_SIZE*2)
+#define ECRYPTFS_PASSWORD_SIG_SIZE ECRYPTFS_SIG_SIZE_HEX
+#define ECRYPTFS_MAX_KEY_BYTES 64
+#define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
+#define ECRYPTFS_FILE_VERSION 0x03
+#define ECRYPTFS_MAX_PKI_NAME_BYTES 16
+
+#define RFC2440_CIPHER_DES3_EDE 0x02
+#define RFC2440_CIPHER_CAST_5 0x03
+#define RFC2440_CIPHER_BLOWFISH 0x04
+#define RFC2440_CIPHER_AES_128 0x07
+#define RFC2440_CIPHER_AES_192 0x08
+#define RFC2440_CIPHER_AES_256 0x09
+#define RFC2440_CIPHER_TWOFISH 0x0a
+#define RFC2440_CIPHER_CAST_6 0x0b
+
+#define RFC2440_CIPHER_RSA 0x01
+
+/**
+ * For convenience, we may need to pass around the encrypted session
+ * key between kernel and userspace because the authentication token
+ * may not be extractable. For example, the TPM may not release the
+ * private key, instead requiring the encrypted data and returning the
+ * decrypted data.
+ */
+struct ecryptfs_session_key {
+#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT 0x00000001
+#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT 0x00000002
+#define ECRYPTFS_CONTAINS_DECRYPTED_KEY 0x00000004
+#define ECRYPTFS_CONTAINS_ENCRYPTED_KEY 0x00000008
+ u32 flags;
+ u32 encrypted_key_size;
+ u32 decrypted_key_size;
+ u8 encrypted_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
+ u8 decrypted_key[ECRYPTFS_MAX_KEY_BYTES];
+};
+
+struct ecryptfs_password {
+ u32 password_bytes;
+ s32 hash_algo;
+ u32 hash_iterations;
+ u32 session_key_encryption_key_bytes;
+#define ECRYPTFS_PERSISTENT_PASSWORD 0x01
+#define ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET 0x02
+ u32 flags;
+ /* Iterated-hash concatenation of salt and passphrase */
+ u8 session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
+ u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
+ /* Always in expanded hex */
+ u8 salt[ECRYPTFS_SALT_SIZE];
+};
+
+enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY};
+
+struct ecryptfs_private_key {
+ u32 key_size;
+ u32 data_len;
+ u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
+ char pki_type[ECRYPTFS_MAX_PKI_NAME_BYTES + 1];
+ u8 data[];
+};
+
+/* May be a password or a private key */
+struct ecryptfs_auth_tok {
+ u16 version; /* 8-bit major and 8-bit minor */
+ u16 token_type;
+#define ECRYPTFS_ENCRYPT_ONLY 0x00000001
+ u32 flags;
+ struct ecryptfs_session_key session_key;
+ u8 reserved[32];
+ union {
+ struct ecryptfs_password password;
+ struct ecryptfs_private_key private_key;
+ } token;
+} __attribute__ ((packed));
+
+#endif /* _LINUX_ECRYPTFS_H */
--
1.7.3.4

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