From 290502bee239062499297916bb7d21d205e99d62 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 28 Feb 2013 00:39:37 -0800 Subject: eCryptfs: allow userspace messaging to be disabled 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 Signed-off-by: Tyler Hicks --- fs/ecryptfs/ecryptfs_kernel.h | 40 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 38 insertions(+), 2 deletions(-) (limited to 'fs/ecryptfs/ecryptfs_kernel.h') diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index cfb4b9fed520..a9df69efadc2 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -172,6 +172,19 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24 #define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32) +#ifdef CONFIG_ECRYPT_FS_MESSAGING +# define ECRYPTFS_VERSIONING_MASK_MESSAGING (ECRYPTFS_VERSIONING_DEVMISC \ + | ECRYPTFS_VERSIONING_PUBKEY) +#else +# define ECRYPTFS_VERSIONING_MASK_MESSAGING 0 +#endif + +#define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \ + | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \ + | ECRYPTFS_VERSIONING_XATTR \ + | ECRYPTFS_VERSIONING_MULTKEY \ + | ECRYPTFS_VERSIONING_MASK_MESSAGING \ + | ECRYPTFS_VERSIONING_FILENAME_ENCRYPTION) struct ecryptfs_key_sig { struct list_head crypt_stat_list; char keysig[ECRYPTFS_SIG_SIZE_HEX + 1]; @@ -399,7 +412,9 @@ struct ecryptfs_daemon { struct hlist_node euid_chain; }; +#ifdef CONFIG_ECRYPT_FS_MESSAGING extern struct mutex ecryptfs_daemon_hash_mux; +#endif static inline size_t ecryptfs_lower_header_size(struct ecryptfs_crypt_stat *crypt_stat) @@ -604,6 +619,7 @@ int ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode); +#ifdef CONFIG_ECRYPT_FS_MESSAGING int ecryptfs_process_response(struct ecryptfs_daemon *daemon, struct ecryptfs_message *msg, u32 seq); int ecryptfs_send_message(char *data, int data_len, @@ -612,6 +628,24 @@ int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, struct ecryptfs_message **emsg); int ecryptfs_init_messaging(void); void ecryptfs_release_messaging(void); +#else +static inline int ecryptfs_init_messaging(void) +{ + return 0; +} +static inline void ecryptfs_release_messaging(void) +{ } +static inline int ecryptfs_send_message(char *data, int data_len, + struct ecryptfs_msg_ctx **msg_ctx) +{ + return -ENOTCONN; +} +static inline int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx, + struct ecryptfs_message **emsg) +{ + return -ENOMSG; +} +#endif void ecryptfs_write_header_metadata(char *virt, @@ -649,12 +683,11 @@ int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs, size_t offset_in_page, size_t size, struct inode *ecryptfs_inode); struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index); -int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon); -int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon); int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, size_t *length_size); int ecryptfs_write_packet_length(char *dest, size_t size, size_t *packet_size_length); +#ifdef CONFIG_ECRYPT_FS_MESSAGING int ecryptfs_init_ecryptfs_miscdev(void); void ecryptfs_destroy_ecryptfs_miscdev(void); int ecryptfs_send_miscdev(char *data, size_t data_size, @@ -663,6 +696,9 @@ int ecryptfs_send_miscdev(char *data, size_t data_size, void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx); int ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, struct file *file); +int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon); +int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon); +#endif int ecryptfs_init_kthread(void); void ecryptfs_destroy_kthread(void); int ecryptfs_privileged_open(struct file **lower_file, -- cgit v1.2.3