forked from mirrors/linux
290502bee2
When the userspace messaging (for the less common case of userspace key wrap/unwrap via ecryptfsd) is not needed, allow eCryptfs to build with it removed. This saves on kernel code size and reduces potential attack surface by removing the /dev/ecryptfs node. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
105 lines
3.8 KiB
C
105 lines
3.8 KiB
C
#ifndef _LINUX_ECRYPTFS_H
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#define _LINUX_ECRYPTFS_H
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/* Version verification for shared data structures w/ userspace */
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#define ECRYPTFS_VERSION_MAJOR 0x00
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#define ECRYPTFS_VERSION_MINOR 0x04
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#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x03
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/* These flags indicate which features are supported by the kernel
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* module; userspace tools such as the mount helper read the feature
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* bits from a sysfs handle in order to determine how to behave. */
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#define ECRYPTFS_VERSIONING_PASSPHRASE 0x00000001
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#define ECRYPTFS_VERSIONING_PUBKEY 0x00000002
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#define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004
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#define ECRYPTFS_VERSIONING_POLICY 0x00000008
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#define ECRYPTFS_VERSIONING_XATTR 0x00000010
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#define ECRYPTFS_VERSIONING_MULTKEY 0x00000020
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#define ECRYPTFS_VERSIONING_DEVMISC 0x00000040
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#define ECRYPTFS_VERSIONING_HMAC 0x00000080
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#define ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION 0x00000100
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#define ECRYPTFS_VERSIONING_GCM 0x00000200
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#define ECRYPTFS_MAX_PASSWORD_LENGTH 64
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#define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH
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#define ECRYPTFS_SALT_SIZE 8
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#define ECRYPTFS_SALT_SIZE_HEX (ECRYPTFS_SALT_SIZE*2)
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/* The original signature size is only for what is stored on disk; all
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* in-memory representations are expanded hex, so it better adapted to
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* be passed around or referenced on the command line */
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#define ECRYPTFS_SIG_SIZE 8
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#define ECRYPTFS_SIG_SIZE_HEX (ECRYPTFS_SIG_SIZE*2)
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#define ECRYPTFS_PASSWORD_SIG_SIZE ECRYPTFS_SIG_SIZE_HEX
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#define ECRYPTFS_MAX_KEY_BYTES 64
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#define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
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#define ECRYPTFS_FILE_VERSION 0x03
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#define ECRYPTFS_MAX_PKI_NAME_BYTES 16
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#define RFC2440_CIPHER_DES3_EDE 0x02
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#define RFC2440_CIPHER_CAST_5 0x03
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#define RFC2440_CIPHER_BLOWFISH 0x04
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#define RFC2440_CIPHER_AES_128 0x07
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#define RFC2440_CIPHER_AES_192 0x08
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#define RFC2440_CIPHER_AES_256 0x09
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#define RFC2440_CIPHER_TWOFISH 0x0a
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#define RFC2440_CIPHER_CAST_6 0x0b
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#define RFC2440_CIPHER_RSA 0x01
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/**
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* For convenience, we may need to pass around the encrypted session
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* key between kernel and userspace because the authentication token
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* may not be extractable. For example, the TPM may not release the
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* private key, instead requiring the encrypted data and returning the
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* decrypted data.
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*/
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struct ecryptfs_session_key {
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#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT 0x00000001
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#define ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT 0x00000002
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#define ECRYPTFS_CONTAINS_DECRYPTED_KEY 0x00000004
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#define ECRYPTFS_CONTAINS_ENCRYPTED_KEY 0x00000008
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u32 flags;
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u32 encrypted_key_size;
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u32 decrypted_key_size;
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u8 encrypted_key[ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES];
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u8 decrypted_key[ECRYPTFS_MAX_KEY_BYTES];
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};
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struct ecryptfs_password {
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u32 password_bytes;
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s32 hash_algo;
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u32 hash_iterations;
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u32 session_key_encryption_key_bytes;
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#define ECRYPTFS_PERSISTENT_PASSWORD 0x01
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#define ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET 0x02
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u32 flags;
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/* Iterated-hash concatenation of salt and passphrase */
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u8 session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
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u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
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/* Always in expanded hex */
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u8 salt[ECRYPTFS_SALT_SIZE];
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};
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enum ecryptfs_token_types {ECRYPTFS_PASSWORD, ECRYPTFS_PRIVATE_KEY};
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struct ecryptfs_private_key {
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u32 key_size;
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u32 data_len;
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u8 signature[ECRYPTFS_PASSWORD_SIG_SIZE + 1];
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char pki_type[ECRYPTFS_MAX_PKI_NAME_BYTES + 1];
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u8 data[];
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};
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/* May be a password or a private key */
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struct ecryptfs_auth_tok {
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u16 version; /* 8-bit major and 8-bit minor */
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u16 token_type;
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#define ECRYPTFS_ENCRYPT_ONLY 0x00000001
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u32 flags;
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struct ecryptfs_session_key session_key;
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u8 reserved[32];
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union {
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struct ecryptfs_password password;
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struct ecryptfs_private_key private_key;
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} token;
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} __attribute__ ((packed));
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#endif /* _LINUX_ECRYPTFS_H */
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