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fscrypt: remove filesystem specific build config option

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In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
This commit is contained in:
Chandan Rajendra 2018-12-12 15:20:12 +05:30 committed by Theodore Ts'o
parent 62230e0d70
commit 643fa9612b
31 changed files with 460 additions and 535 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/filesystems/fscrypt.rst
View File

@ -343,9 +343,9 @@ FS_IOC_SET_ENCRYPTION_POLICY can fail with the following errors:
- ``ENOTEMPTY``: the file is unencrypted and is a nonempty directory
- ``ENOTTY``: this type of filesystem does not implement encryption
- ``EOPNOTSUPP``: the kernel was not configured with encryption
support for this filesystem, or the filesystem superblock has not
support for filesystems, or the filesystem superblock has not
had encryption enabled on it. (For example, to use encryption on an
ext4 filesystem, CONFIG_EXT4_ENCRYPTION must be enabled in the
ext4 filesystem, CONFIG_FS_ENCRYPTION must be enabled in the
kernel config, and the superblock must have had the "encrypt"
feature flag enabled using ``tune2fs -O encrypt`` or ``mkfs.ext4 -O
encrypt``.)

2
arch/mips/configs/generic_defconfig
View File

@ -59,7 +59,7 @@ CONFIG_HID_MONTEREY=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_EXT4_ENCRYPTION=y
CONFIG_FS_ENCRYPTION=y
CONFIG_FANOTIFY=y
CONFIG_FUSE_FS=y
CONFIG_CUSE=y

2
arch/nds32/configs/defconfig
View File

@ -74,7 +74,7 @@ CONFIG_GENERIC_PHY=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_EXT4_ENCRYPTION=y
CONFIG_FS_ENCRYPTION=y
CONFIG_FUSE_FS=y
CONFIG_MSDOS_FS=y
CONFIG_VFAT_FS=y

2
arch/s390/configs/debug_defconfig
View File

@ -500,7 +500,6 @@ CONFIG_S390_AP_IOMMU=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_EXT4_ENCRYPTION=y
CONFIG_JBD2_DEBUG=y
CONFIG_JFS_FS=m
CONFIG_JFS_POSIX_ACL=y
@ -520,6 +519,7 @@ CONFIG_BTRFS_DEBUG=y
CONFIG_NILFS2_FS=m
CONFIG_FS_DAX=y
CONFIG_EXPORTFS_BLOCK_OPS=y
CONFIG_FS_ENCRYPTION=y
CONFIG_FANOTIFY=y
CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
CONFIG_QUOTA_NETLINK_INTERFACE=y

2
arch/s390/configs/performance_defconfig
View File

@ -497,7 +497,6 @@ CONFIG_S390_AP_IOMMU=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_EXT4_ENCRYPTION=y
CONFIG_JBD2_DEBUG=y
CONFIG_JFS_FS=m
CONFIG_JFS_POSIX_ACL=y
@ -515,6 +514,7 @@ CONFIG_BTRFS_FS_POSIX_ACL=y
CONFIG_NILFS2_FS=m
CONFIG_FS_DAX=y
CONFIG_EXPORTFS_BLOCK_OPS=y
CONFIG_FS_ENCRYPTION=y
CONFIG_FANOTIFY=y
CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
CONFIG_QUOTA_NETLINK_INTERFACE=y

5
fs/crypto/Kconfig
View File

@ -1,5 +1,5 @@
config FS_ENCRYPTION
tristate "FS Encryption (Per-file encryption)"
bool "FS Encryption (Per-file encryption)"
select CRYPTO
select CRYPTO_AES
select CRYPTO_CBC
@ -12,4 +12,5 @@ config FS_ENCRYPTION
Enable encryption of files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
decrypted pages in the page cache. Currently Ext4,
F2FS and UBIFS make use of this feature.

1
fs/crypto/fscrypt_private.h
View File

@ -12,7 +12,6 @@
#ifndef _FSCRYPT_PRIVATE_H
#define _FSCRYPT_PRIVATE_H
#define __FS_HAS_ENCRYPTION 1
#include <linux/fscrypt.h>
#include <crypto/hash.h>

15
fs/ext4/Kconfig
View File

@ -96,21 +96,6 @@ config EXT4_FS_SECURITY
If you are not using a security module that requires using
extended attributes for file security labels, say N.
config EXT4_ENCRYPTION
bool "Ext4 Encryption"
depends on EXT4_FS
select FS_ENCRYPTION
help
Enable encryption of ext4 files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
config EXT4_FS_ENCRYPTION
bool
default y
depends on EXT4_ENCRYPTION
config EXT4_DEBUG
bool "EXT4 debugging support"
depends on EXT4_FS

2
fs/ext4/dir.c
View File

@ -283,9 +283,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
done:
err = 0;
errout:
#ifdef CONFIG_EXT4_FS_ENCRYPTION
fscrypt_fname_free_buffer(&fstr);
#endif
brelse(bh);
return err;
}

7
fs/ext4/ext4.h
View File

@ -40,7 +40,6 @@
#include <linux/compat.h>
#endif
#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
#include <linux/fscrypt.h>
#include <linux/compiler.h>
@ -1326,7 +1325,7 @@ struct ext4_super_block {
#define EXT4_MF_FS_ABORTED 0x0002 /* Fatal error detected */
#define EXT4_MF_TEST_DUMMY_ENCRYPTION 0x0004
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
#define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
EXT4_MF_TEST_DUMMY_ENCRYPTION))
#else
@ -2051,7 +2050,7 @@ struct ext4_filename {
const struct qstr *usr_fname;
struct fscrypt_str disk_name;
struct dx_hash_info hinfo;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
struct fscrypt_str crypto_buf;
#endif
};
@ -2279,7 +2278,7 @@ extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
struct ext4_group_desc *gdp);
ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
static inline int ext4_fname_setup_filename(struct inode *dir,
const struct qstr *iname,
int lookup, struct ext4_filename *fname)

8
fs/ext4/inode.c
View File

@ -1150,7 +1150,7 @@ int do_journal_get_write_access(handle_t *handle,
return ret;
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
get_block_t *get_block)
{
@ -1302,7 +1302,7 @@ retry_journal:
/* In case writeback began while the page was unlocked */
wait_for_stable_page(page);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (ext4_should_dioread_nolock(inode))
ret = ext4_block_write_begin(page, pos, len,
ext4_get_block_unwritten);
@ -3104,7 +3104,7 @@ retry_journal:
/* In case writeback began while the page was unlocked */
wait_for_stable_page(page);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
ret = ext4_block_write_begin(page, pos, len,
ext4_da_get_block_prep);
#else
@ -3879,7 +3879,7 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
loff_t offset = iocb->ki_pos;
ssize_t ret;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
return 0;
#endif

4
fs/ext4/ioctl.c
View File

@ -210,7 +210,7 @@ journal_err_out:
return err;
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
static int uuid_is_zero(__u8 u[16])
{
int i;
@ -978,7 +978,7 @@ resizefs_out:
return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
int err, err2;
struct ext4_sb_info *sbi = EXT4_SB(sb);
handle_t *handle;

10
fs/ext4/namei.c
View File

@ -612,7 +612,7 @@ static struct stats dx_show_leaf(struct inode *dir,
{
if (show_names)
{
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
int len;
char *name;
struct fscrypt_str fname_crypto_str =
@ -984,7 +984,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
top = (struct ext4_dir_entry_2 *) ((char *) de +
dir->i_sb->s_blocksize -
EXT4_DIR_REC_LEN(0));
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
/* Check if the directory is encrypted */
if (IS_ENCRYPTED(dir)) {
err = fscrypt_get_encryption_info(dir);
@ -1047,7 +1047,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
}
errout:
brelse(bh);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
fscrypt_fname_free_buffer(&fname_crypto_str);
#endif
return count;
@ -1267,7 +1267,7 @@ static inline bool ext4_match(const struct ext4_filename *fname,
f.usr_fname = fname->usr_fname;
f.disk_name = fname->disk_name;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
f.crypto_buf = fname->crypto_buf;
#endif
return fscrypt_match_name(&f, de->name, de->name_len);
@ -1498,7 +1498,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
ext4_lblk_t block;
int retval;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
*res_dir = NULL;
#endif
frame = dx_probe(fname, dir, NULL, frames);

6
fs/ext4/page-io.c
View File

@ -66,7 +66,7 @@ static void ext4_finish_bio(struct bio *bio)
bio_for_each_segment_all(bvec, bio, i) {
struct page *page = bvec->bv_page;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
struct page *data_page = NULL;
#endif
struct buffer_head *bh, *head;
@ -78,7 +78,7 @@ static void ext4_finish_bio(struct bio *bio)
if (!page)
continue;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (!page->mapping) {
/* The bounce data pages are unmapped. */
data_page = page;
@ -111,7 +111,7 @@ static void ext4_finish_bio(struct bio *bio)
bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
local_irq_restore(flags);
if (!under_io) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (data_page)
fscrypt_restore_control_page(data_page);
#endif

2
fs/ext4/readpage.c
View File

@ -49,7 +49,7 @@
static inline bool ext4_bio_encrypted(struct bio *bio)
{
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
return unlikely(bio->bi_private != NULL);
#else
return false;

6
fs/ext4/super.c
View File

@ -1232,7 +1232,7 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
return try_to_free_buffers(page);
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
@ -1922,7 +1922,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
*journal_ioprio =
IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
} else if (token == Opt_test_dummy_encryption) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
ext4_msg(sb, KERN_WARNING,
"Test dummy encryption mode enabled");
@ -4167,7 +4167,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
sb->s_op = &ext4_sops;
sb->s_export_op = &ext4_export_ops;
sb->s_xattr = ext4_xattr_handlers;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
sb->s_cop = &ext4_cryptops;
#endif
#ifdef CONFIG_QUOTA

4
fs/ext4/sysfs.c
View File

@ -224,7 +224,7 @@ static struct attribute *ext4_attrs[] = {
EXT4_ATTR_FEATURE(lazy_itable_init);
EXT4_ATTR_FEATURE(batched_discard);
EXT4_ATTR_FEATURE(meta_bg_resize);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
EXT4_ATTR_FEATURE(encryption);
#endif
EXT4_ATTR_FEATURE(metadata_csum_seed);
@ -233,7 +233,7 @@ static struct attribute *ext4_feat_attrs[] = {
ATTR_LIST(lazy_itable_init),
ATTR_LIST(batched_discard),
ATTR_LIST(meta_bg_resize),
#ifdef CONFIG_EXT4_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
ATTR_LIST(encryption),
#endif
ATTR_LIST(metadata_csum_seed),

12
fs/f2fs/Kconfig
View File

@ -3,6 +3,7 @@ config F2FS_FS
depends on BLOCK
select CRYPTO
select CRYPTO_CRC32
select F2FS_FS_XATTR if FS_ENCRYPTION
help
F2FS is based on Log-structured File System (LFS), which supports
versatile "flash-friendly" features. The design has been focused on
@ -70,17 +71,6 @@ config F2FS_CHECK_FS
If you want to improve the performance, say N.
config F2FS_FS_ENCRYPTION
bool "F2FS Encryption"
depends on F2FS_FS
depends on F2FS_FS_XATTR
select FS_ENCRYPTION
help
Enable encryption of f2fs files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
config F2FS_IO_TRACE
bool "F2FS IO tracer"
depends on F2FS_FS

7
fs/f2fs/f2fs.h
View File

@ -24,7 +24,6 @@
#include <linux/quotaops.h>
#include <crypto/hash.h>
#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION)
#include <linux/fscrypt.h>
#ifdef CONFIG_F2FS_CHECK_FS
@ -1137,7 +1136,7 @@ enum fsync_mode {
FSYNC_MODE_NOBARRIER, /* fsync behaves nobarrier based on posix */
};
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
#define DUMMY_ENCRYPTION_ENABLED(sbi) \
(unlikely(F2FS_OPTION(sbi).test_dummy_encryption))
#else
@ -3470,7 +3469,7 @@ static inline bool f2fs_encrypted_file(struct inode *inode)
static inline void f2fs_set_encrypted_inode(struct inode *inode)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
file_set_encrypt(inode);
f2fs_set_inode_flags(inode);
#endif
@ -3549,7 +3548,7 @@ static inline void set_opt_mode(struct f2fs_sb_info *sbi, unsigned int mt)
static inline bool f2fs_may_encrypt(struct inode *inode)
{
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
umode_t mode = inode->i_mode;
return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode));

8
fs/f2fs/super.c
View File

@ -757,7 +757,7 @@ static int parse_options(struct super_block *sb, char *options)
kvfree(name);
break;
case Opt_test_dummy_encryption:
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (!f2fs_sb_has_encrypt(sbi)) {
f2fs_msg(sb, KERN_ERR, "Encrypt feature is off");
return -EINVAL;
@ -1390,7 +1390,7 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
seq_printf(seq, ",whint_mode=%s", "user-based");
else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS)
seq_printf(seq, ",whint_mode=%s", "fs-based");
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
if (F2FS_OPTION(sbi).test_dummy_encryption)
seq_puts(seq, ",test_dummy_encryption");
#endif
@ -2154,7 +2154,7 @@ static const struct super_operations f2fs_sops = {
.remount_fs = f2fs_remount,
};
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
{
return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
@ -3116,7 +3116,7 @@ try_onemore:
#endif
sb->s_op = &f2fs_sops;
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
sb->s_cop = &f2fs_cryptops;
#endif
sb->s_xattr = f2fs_xattr_handlers;

4
fs/f2fs/sysfs.c
View File

@ -431,7 +431,7 @@ F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
F2FS_GENERAL_RO_ATTR(features);
F2FS_GENERAL_RO_ATTR(current_reserved_blocks);
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
#endif
#ifdef CONFIG_BLK_DEV_ZONED
@ -492,7 +492,7 @@ static struct attribute *f2fs_attrs[] = {
};
static struct attribute *f2fs_feat_attrs[] = {
#ifdef CONFIG_F2FS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
ATTR_LIST(encryption),
#endif
#ifdef CONFIG_BLK_DEV_ZONED

12
fs/ubifs/Kconfig
View File

@ -8,6 +8,7 @@ config UBIFS_FS
select CRYPTO_LZO if UBIFS_FS_LZO
select CRYPTO_DEFLATE if UBIFS_FS_ZLIB
select CRYPTO_HASH_INFO
select UBIFS_FS_XATTR if FS_ENCRYPTION
depends on MTD_UBI
help
UBIFS is a file system for flash devices which works on top of UBI.
@ -60,17 +61,6 @@ config UBIFS_FS_XATTR
If unsure, say Y.
config UBIFS_FS_ENCRYPTION
bool "UBIFS Encryption"
depends on UBIFS_FS_XATTR && BLOCK
select FS_ENCRYPTION
default n
help
Enable encryption of UBIFS files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
config UBIFS_FS_SECURITY
bool "UBIFS Security Labels"
depends on UBIFS_FS_XATTR

2
fs/ubifs/Makefile
View File

@ -6,6 +6,6 @@ ubifs-y += tnc.o master.o scan.o replay.o log.o commit.o gc.o orphan.o
ubifs-y += budget.o find.o tnc_commit.o compress.o lpt.o lprops.o
ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o debug.o
ubifs-y += misc.o
ubifs-$(CONFIG_UBIFS_FS_ENCRYPTION) += crypto.o
ubifs-$(CONFIG_FS_ENCRYPTION) += crypto.o
ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o
ubifs-$(CONFIG_UBIFS_FS_AUTHENTICATION) += auth.o

4
fs/ubifs/ioctl.c
View File

@ -185,7 +185,7 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
return err;
}
case FS_IOC_SET_ENCRYPTION_POLICY: {
#ifdef CONFIG_UBIFS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
struct ubifs_info *c = inode->i_sb->s_fs_info;
err = ubifs_enable_encryption(c);
@ -198,7 +198,7 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
#endif
}
case FS_IOC_GET_ENCRYPTION_POLICY: {
#ifdef CONFIG_UBIFS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
return fscrypt_ioctl_get_policy(file, (void __user *)arg);
#else
return -EOPNOTSUPP;

2
fs/ubifs/sb.c
View File

@ -748,7 +748,7 @@ int ubifs_read_superblock(struct ubifs_info *c)
goto out;
}
#ifndef CONFIG_UBIFS_FS_ENCRYPTION
#ifndef CONFIG_FS_ENCRYPTION
if (c->encrypted) {
ubifs_err(c, "file system contains encrypted files but UBIFS"
" was built without crypto support.");

2
fs/ubifs/super.c
View File

@ -2146,7 +2146,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
#ifdef CONFIG_UBIFS_FS_XATTR
sb->s_xattr = ubifs_xattr_handlers;
#endif
#ifdef CONFIG_UBIFS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
sb->s_cop = &ubifs_crypt_operations;
#endif

5
fs/ubifs/ubifs.h
View File

@ -43,7 +43,6 @@
#include <crypto/hash.h>
#include <crypto/algapi.h>
#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_UBIFS_FS_ENCRYPTION)
#include <linux/fscrypt.h>
#include "ubifs-media.h"
@ -142,7 +141,7 @@
*/
#define WORST_COMPR_FACTOR 2
#ifdef CONFIG_UBIFS_FS_ENCRYPTION
#ifdef CONFIG_FS_ENCRYPTION
#define UBIFS_CIPHER_BLOCK_SIZE FS_CRYPTO_BLOCK_SIZE
#else
#define UBIFS_CIPHER_BLOCK_SIZE 0
@ -2072,7 +2071,7 @@ int ubifs_decompress(const struct ubifs_info *c, const void *buf, int len,
#include "misc.h"
#include "key.h"
#ifndef CONFIG_UBIFS_FS_ENCRYPTION
#ifndef CONFIG_FS_ENCRYPTION
static inline int ubifs_encrypt(const struct inode *inode,
struct ubifs_data_node *dn,
unsigned int in_len, unsigned int *out_len,

4
include/linux/fs.h
View File

@ -698,7 +698,7 @@ struct inode {
struct fsnotify_mark_connector __rcu *i_fsnotify_marks;
#endif
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
#ifdef CONFIG_FS_ENCRYPTION
struct fscrypt_info *i_crypt_info;
#endif
@ -1403,7 +1403,7 @@ struct super_block {
void *s_security;
#endif
const struct xattr_handler **s_xattr;
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
#ifdef CONFIG_FS_ENCRYPTION
const struct fscrypt_operations *s_cop;
#endif
struct hlist_bl_head s_roots; /* alternate root dentries for NFS */

416
include/linux/fscrypt.h
View File

@ -2,9 +2,8 @@
/*
* fscrypt.h: declarations for per-file encryption
*
* Filesystems that implement per-file encryption include this header
* file with the __FS_HAS_ENCRYPTION set according to whether that filesystem
* is being built with encryption support or not.
* Filesystems that implement per-file encryption must include this header
* file.
*
* Copyright (C) 2015, Google, Inc.
*
@ -15,6 +14,8 @@
#define _LINUX_FSCRYPT_H
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#define FS_CRYPTO_BLOCK_SIZE 16
@ -42,11 +43,410 @@ struct fscrypt_name {
/* Maximum value for the third parameter of fscrypt_operations.set_context(). */
#define FSCRYPT_SET_CONTEXT_MAX_SIZE 28
#if __FS_HAS_ENCRYPTION
#include <linux/fscrypt_supp.h>
#else
#include <linux/fscrypt_notsupp.h>
#endif
#ifdef CONFIG_FS_ENCRYPTION
/*
* fscrypt superblock flags
*/
#define FS_CFLG_OWN_PAGES (1U << 1)
/*
* crypto operations for filesystems
*/
struct fscrypt_operations {
unsigned int flags;
const char *key_prefix;
int (*get_context)(struct inode *, void *, size_t);
int (*set_context)(struct inode *, const void *, size_t, void *);
bool (*dummy_context)(struct inode *);
bool (*empty_dir)(struct inode *);
unsigned int max_namelen;
};
struct fscrypt_ctx {
union {
struct {
struct page *bounce_page; /* Ciphertext page */
struct page *control_page; /* Original page */
} w;
struct {
struct bio *bio;
struct work_struct work;
} r;
struct list_head free_list; /* Free list */
};
u8 flags; /* Flags */
};
static inline bool fscrypt_has_encryption_key(const struct inode *inode)
{
return (inode->i_crypt_info != NULL);
}
static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
{
return inode->i_sb->s_cop->dummy_context &&
inode->i_sb->s_cop->dummy_context(inode);
}
/* crypto.c */
extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
unsigned int, unsigned int,
u64, gfp_t);
extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
unsigned int, u64);
static inline struct page *fscrypt_control_page(struct page *page)
{
return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
}
extern void fscrypt_restore_control_page(struct page *);
/* policy.c */
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
extern int fscrypt_inherit_context(struct inode *, struct inode *,
void *, bool);
/* keyinfo.c */
extern int fscrypt_get_encryption_info(struct inode *);
extern void fscrypt_put_encryption_info(struct inode *);
/* fname.c */
extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
int lookup, struct fscrypt_name *);
static inline void fscrypt_free_filename(struct fscrypt_name *fname)
{
kfree(fname->crypto_buf.name);
}
extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
struct fscrypt_str *);
extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
const struct fscrypt_str *, struct fscrypt_str *);
#define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE 32
/* Extracts the second-to-last ciphertext block; see explanation below */
#define FSCRYPT_FNAME_DIGEST(name, len) \
((name) + round_down((len) - FS_CRYPTO_BLOCK_SIZE - 1, \
FS_CRYPTO_BLOCK_SIZE))
#define FSCRYPT_FNAME_DIGEST_SIZE FS_CRYPTO_BLOCK_SIZE
/**
* fscrypt_digested_name - alternate identifier for an on-disk filename
*
* When userspace lists an encrypted directory without access to the key,
* filenames whose ciphertext is longer than FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE
* bytes are shown in this abbreviated form (base64-encoded) rather than as the
* full ciphertext (base64-encoded). This is necessary to allow supporting
* filenames up to NAME_MAX bytes, since base64 encoding expands the length.
*
* To make it possible for filesystems to still find the correct directory entry
* despite not knowing the full on-disk name, we encode any filesystem-specific
* 'hash' and/or 'minor_hash' which the filesystem may need for its lookups,
* followed by the second-to-last ciphertext block of the filename. Due to the
* use of the CBC-CTS encryption mode, the second-to-last ciphertext block
* depends on the full plaintext. (Note that ciphertext stealing causes the
* last two blocks to appear "flipped".) This makes accidental collisions very
* unlikely: just a 1 in 2^128 chance for two filenames to collide even if they
* share the same filesystem-specific hashes.
*
* However, this scheme isn't immune to intentional collisions, which can be
* created by anyone able to create arbitrary plaintext filenames and view them
* without the key. Making the "digest" be a real cryptographic hash like
* SHA-256 over the full ciphertext would prevent this, although it would be
* less efficient and harder to implement, especially since the filesystem would
* need to calculate it for each directory entry examined during a search.
*/
struct fscrypt_digested_name {
u32 hash;
u32 minor_hash;
u8 digest[FSCRYPT_FNAME_DIGEST_SIZE];
};
/**
* fscrypt_match_name() - test whether the given name matches a directory entry
* @fname: the name being searched for
* @de_name: the name from the directory entry
* @de_name_len: the length of @de_name in bytes
*
* Normally @fname->disk_name will be set, and in that case we simply compare
* that to the name stored in the directory entry. The only exception is that
* if we don't have the key for an encrypted directory and a filename in it is
* very long, then we won't have the full disk_name and we'll instead need to
* match against the fscrypt_digested_name.
*
* Return: %true if the name matches, otherwise %false.
*/
static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len)
{
if (unlikely(!fname->disk_name.name)) {
const struct fscrypt_digested_name *n =
(const void *)fname->crypto_buf.name;
if (WARN_ON_ONCE(fname->usr_fname->name[0] != '_'))
return false;
if (de_name_len <= FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE)
return false;
return !memcmp(FSCRYPT_FNAME_DIGEST(de_name, de_name_len),
n->digest, FSCRYPT_FNAME_DIGEST_SIZE);
}
if (de_name_len != fname->disk_name.len)
return false;
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
}
/* bio.c */
extern void fscrypt_decrypt_bio(struct bio *);
extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
struct bio *bio);
extern void fscrypt_pullback_bio_page(struct page **, bool);
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
/* hooks.c */
extern int fscrypt_file_open(struct inode *inode, struct file *filp);
extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir);
extern int __fscrypt_prepare_rename(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry,
unsigned int flags);
extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry);
extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
unsigned int max_len,
struct fscrypt_str *disk_link);
extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
unsigned int len,
struct fscrypt_str *disk_link);
extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
unsigned int max_size,
struct delayed_call *done);
#else /* !CONFIG_FS_ENCRYPTION */
static inline bool fscrypt_has_encryption_key(const struct inode *inode)
{
return false;
}
static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
{
return false;
}
/* crypto.c */
static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
{
}
static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode,
gfp_t gfp_flags)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
{
return;
}
static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
struct page *page,
unsigned int len,
unsigned int offs,
u64 lblk_num, gfp_t gfp_flags)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline int fscrypt_decrypt_page(const struct inode *inode,
struct page *page,
unsigned int len, unsigned int offs,
u64 lblk_num)
{
return -EOPNOTSUPP;
}
static inline struct page *fscrypt_control_page(struct page *page)
{
WARN_ON_ONCE(1);
return ERR_PTR(-EINVAL);
}
static inline void fscrypt_restore_control_page(struct page *page)
{
return;
}
/* policy.c */
static inline int fscrypt_ioctl_set_policy(struct file *filp,
const void __user *arg)
{
return -EOPNOTSUPP;
}
static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
{
return -EOPNOTSUPP;
}
static inline int fscrypt_has_permitted_context(struct inode *parent,
struct inode *child)
{
return 0;
}
static inline int fscrypt_inherit_context(struct inode *parent,
struct inode *child,
void *fs_data, bool preload)
{
return -EOPNOTSUPP;
}
/* keyinfo.c */
static inline int fscrypt_get_encryption_info(struct inode *inode)
{
return -EOPNOTSUPP;
}
static inline void fscrypt_put_encryption_info(struct inode *inode)
{
return;
}
/* fname.c */
static inline int fscrypt_setup_filename(struct inode *dir,
const struct qstr *iname,
int lookup, struct fscrypt_name *fname)
{
if (IS_ENCRYPTED(dir))
return -EOPNOTSUPP;
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
}
static inline void fscrypt_free_filename(struct fscrypt_name *fname)
{
return;
}
static inline int fscrypt_fname_alloc_buffer(const struct inode *inode,
u32 max_encrypted_len,
struct fscrypt_str *crypto_str)
{
return -EOPNOTSUPP;
}
static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
{
return;
}
static inline int fscrypt_fname_disk_to_usr(struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
struct fscrypt_str *oname)
{
return -EOPNOTSUPP;
}
static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len)
{
/* Encryption support disabled; use standard comparison */
if (de_name_len != fname->disk_name.len)
return false;
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
}
/* bio.c */
static inline void fscrypt_decrypt_bio(struct bio *bio)
{
}
static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
struct bio *bio)
{
}
static inline void fscrypt_pullback_bio_page(struct page **page, bool restore)
{
return;
}
static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
return -EOPNOTSUPP;
}
/* hooks.c */
static inline int fscrypt_file_open(struct inode *inode, struct file *filp)
{
if (IS_ENCRYPTED(inode))
return -EOPNOTSUPP;
return 0;
}
static inline int __fscrypt_prepare_link(struct inode *inode,
struct inode *dir)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_rename(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry,
unsigned int flags)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_lookup(struct inode *dir,
struct dentry *dentry)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_symlink(struct inode *dir,
unsigned int len,
unsigned int max_len,
struct fscrypt_str *disk_link)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_encrypt_symlink(struct inode *inode,
const char *target,
unsigned int len,
struct fscrypt_str *disk_link)
{
return -EOPNOTSUPP;
}
static inline const char *fscrypt_get_symlink(struct inode *inode,
const void *caddr,
unsigned int max_size,
struct delayed_call *done)
{
return ERR_PTR(-EOPNOTSUPP);
}
#endif /* !CONFIG_FS_ENCRYPTION */
/**
* fscrypt_require_key - require an inode's encryption key

231
include/linux/fscrypt_notsupp.h
View File

@ -1,231 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* fscrypt_notsupp.h
*
* This stubs out the fscrypt functions for filesystems configured without
* encryption support.
*
* Do not include this file directly. Use fscrypt.h instead!
*/
#ifndef _LINUX_FSCRYPT_H
#error "Incorrect include of linux/fscrypt_notsupp.h!"
#endif
#ifndef _LINUX_FSCRYPT_NOTSUPP_H
#define _LINUX_FSCRYPT_NOTSUPP_H
static inline bool fscrypt_has_encryption_key(const struct inode *inode)
{
return false;
}
static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
{
return false;
}
/* crypto.c */
static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
{
}
static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode,
gfp_t gfp_flags)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
{
return;
}
static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
struct page *page,
unsigned int len,
unsigned int offs,
u64 lblk_num, gfp_t gfp_flags)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline int fscrypt_decrypt_page(const struct inode *inode,
struct page *page,
unsigned int len, unsigned int offs,
u64 lblk_num)
{
return -EOPNOTSUPP;
}
static inline struct page *fscrypt_control_page(struct page *page)
{
WARN_ON_ONCE(1);
return ERR_PTR(-EINVAL);
}
static inline void fscrypt_restore_control_page(struct page *page)
{
return;
}
/* policy.c */
static inline int fscrypt_ioctl_set_policy(struct file *filp,
const void __user *arg)
{
return -EOPNOTSUPP;
}
static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
{
return -EOPNOTSUPP;
}
static inline int fscrypt_has_permitted_context(struct inode *parent,
struct inode *child)
{
return 0;
}
static inline int fscrypt_inherit_context(struct inode *parent,
struct inode *child,
void *fs_data, bool preload)
{
return -EOPNOTSUPP;
}
/* keyinfo.c */
static inline int fscrypt_get_encryption_info(struct inode *inode)
{
return -EOPNOTSUPP;
}
static inline void fscrypt_put_encryption_info(struct inode *inode)
{
return;
}
/* fname.c */
static inline int fscrypt_setup_filename(struct inode *dir,
const struct qstr *iname,
int lookup, struct fscrypt_name *fname)
{
if (IS_ENCRYPTED(dir))
return -EOPNOTSUPP;
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
}
static inline void fscrypt_free_filename(struct fscrypt_name *fname)
{
return;
}
static inline int fscrypt_fname_alloc_buffer(const struct inode *inode,
u32 max_encrypted_len,
struct fscrypt_str *crypto_str)
{
return -EOPNOTSUPP;
}
static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
{
return;
}
static inline int fscrypt_fname_disk_to_usr(struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
struct fscrypt_str *oname)
{
return -EOPNOTSUPP;
}
static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len)
{
/* Encryption support disabled; use standard comparison */
if (de_name_len != fname->disk_name.len)
return false;
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
}
/* bio.c */
static inline void fscrypt_decrypt_bio(struct bio *bio)
{
}
static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
struct bio *bio)
{
}
static inline void fscrypt_pullback_bio_page(struct page **page, bool restore)
{
return;
}
static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
return -EOPNOTSUPP;
}
/* hooks.c */
static inline int fscrypt_file_open(struct inode *inode, struct file *filp)
{
if (IS_ENCRYPTED(inode))
return -EOPNOTSUPP;
return 0;
}
static inline int __fscrypt_prepare_link(struct inode *inode,
struct inode *dir)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_rename(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry,
unsigned int flags)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_lookup(struct inode *dir,
struct dentry *dentry)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_prepare_symlink(struct inode *dir,
unsigned int len,
unsigned int max_len,
struct fscrypt_str *disk_link)
{
return -EOPNOTSUPP;
}
static inline int __fscrypt_encrypt_symlink(struct inode *inode,
const char *target,
unsigned int len,
struct fscrypt_str *disk_link)
{
return -EOPNOTSUPP;
}
static inline const char *fscrypt_get_symlink(struct inode *inode,
const void *caddr,
unsigned int max_size,
struct delayed_call *done)
{
return ERR_PTR(-EOPNOTSUPP);
}
#endif /* _LINUX_FSCRYPT_NOTSUPP_H */

204
include/linux/fscrypt_supp.h
View File

@ -1,204 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* fscrypt_supp.h
*
* Do not include this file directly. Use fscrypt.h instead!
*/
#ifndef _LINUX_FSCRYPT_H
#error "Incorrect include of linux/fscrypt_supp.h!"
#endif
#ifndef _LINUX_FSCRYPT_SUPP_H
#define _LINUX_FSCRYPT_SUPP_H
#include <linux/mm.h>
#include <linux/slab.h>
/*
* fscrypt superblock flags
*/
#define FS_CFLG_OWN_PAGES (1U << 1)
/*
* crypto operations for filesystems
*/
struct fscrypt_operations {
unsigned int flags;
const char *key_prefix;
int (*get_context)(struct inode *, void *, size_t);
int (*set_context)(struct inode *, const void *, size_t, void *);
bool (*dummy_context)(struct inode *);
bool (*empty_dir)(struct inode *);
unsigned int max_namelen;
};
struct fscrypt_ctx {
union {
struct {
struct page *bounce_page; /* Ciphertext page */
struct page *control_page; /* Original page */
} w;
struct {
struct bio *bio;
struct work_struct work;
} r;
struct list_head free_list; /* Free list */
};
u8 flags; /* Flags */
};
static inline bool fscrypt_has_encryption_key(const struct inode *inode)
{
return (inode->i_crypt_info != NULL);
}
static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
{
return inode->i_sb->s_cop->dummy_context &&
inode->i_sb->s_cop->dummy_context(inode);
}
/* crypto.c */
extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
unsigned int, unsigned int,
u64, gfp_t);
extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
unsigned int, u64);
static inline struct page *fscrypt_control_page(struct page *page)
{
return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
}
extern void fscrypt_restore_control_page(struct page *);
/* policy.c */
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
extern int fscrypt_inherit_context(struct inode *, struct inode *,
void *, bool);
/* keyinfo.c */
extern int fscrypt_get_encryption_info(struct inode *);
extern void fscrypt_put_encryption_info(struct inode *);
/* fname.c */
extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
int lookup, struct fscrypt_name *);
static inline void fscrypt_free_filename(struct fscrypt_name *fname)
{
kfree(fname->crypto_buf.name);
}
extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
struct fscrypt_str *);
extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
const struct fscrypt_str *, struct fscrypt_str *);
#define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE 32
/* Extracts the second-to-last ciphertext block; see explanation below */
#define FSCRYPT_FNAME_DIGEST(name, len) \
((name) + round_down((len) - FS_CRYPTO_BLOCK_SIZE - 1, \
FS_CRYPTO_BLOCK_SIZE))
#define FSCRYPT_FNAME_DIGEST_SIZE FS_CRYPTO_BLOCK_SIZE
/**
* fscrypt_digested_name - alternate identifier for an on-disk filename
*
* When userspace lists an encrypted directory without access to the key,
* filenames whose ciphertext is longer than FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE
* bytes are shown in this abbreviated form (base64-encoded) rather than as the
* full ciphertext (base64-encoded). This is necessary to allow supporting
* filenames up to NAME_MAX bytes, since base64 encoding expands the length.
*
* To make it possible for filesystems to still find the correct directory entry
* despite not knowing the full on-disk name, we encode any filesystem-specific
* 'hash' and/or 'minor_hash' which the filesystem may need for its lookups,
* followed by the second-to-last ciphertext block of the filename. Due to the
* use of the CBC-CTS encryption mode, the second-to-last ciphertext block
* depends on the full plaintext. (Note that ciphertext stealing causes the
* last two blocks to appear "flipped".) This makes accidental collisions very
* unlikely: just a 1 in 2^128 chance for two filenames to collide even if they
* share the same filesystem-specific hashes.
*
* However, this scheme isn't immune to intentional collisions, which can be
* created by anyone able to create arbitrary plaintext filenames and view them
* without the key. Making the "digest" be a real cryptographic hash like
* SHA-256 over the full ciphertext would prevent this, although it would be
* less efficient and harder to implement, especially since the filesystem would
* need to calculate it for each directory entry examined during a search.
*/
struct fscrypt_digested_name {
u32 hash;
u32 minor_hash;
u8 digest[FSCRYPT_FNAME_DIGEST_SIZE];
};
/**
* fscrypt_match_name() - test whether the given name matches a directory entry
* @fname: the name being searched for
* @de_name: the name from the directory entry
* @de_name_len: the length of @de_name in bytes
*
* Normally @fname->disk_name will be set, and in that case we simply compare
* that to the name stored in the directory entry. The only exception is that
* if we don't have the key for an encrypted directory and a filename in it is
* very long, then we won't have the full disk_name and we'll instead need to
* match against the fscrypt_digested_name.
*
* Return: %true if the name matches, otherwise %false.
*/
static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len)
{
if (unlikely(!fname->disk_name.name)) {
const struct fscrypt_digested_name *n =
(const void *)fname->crypto_buf.name;
if (WARN_ON_ONCE(fname->usr_fname->name[0] != '_'))
return false;
if (de_name_len <= FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE)
return false;
return !memcmp(FSCRYPT_FNAME_DIGEST(de_name, de_name_len),
n->digest, FSCRYPT_FNAME_DIGEST_SIZE);
}
if (de_name_len != fname->disk_name.len)
return false;
return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
}
/* bio.c */
extern void fscrypt_decrypt_bio(struct bio *);
extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
struct bio *bio);
extern void fscrypt_pullback_bio_page(struct page **, bool);
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
/* hooks.c */
extern int fscrypt_file_open(struct inode *inode, struct file *filp);
extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir);
extern int __fscrypt_prepare_rename(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry,
unsigned int flags);
extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry);
extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
unsigned int max_len,
struct fscrypt_str *disk_link);
extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
unsigned int len,
struct fscrypt_str *disk_link);
extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
unsigned int max_size,
struct delayed_call *done);
#endif /* _LINUX_FSCRYPT_SUPP_H */