Skip to content
Navigation Menu
Toggle navigation
Sign in
In this repository
All GitHub Enterprise
↵
Jump to
↵
No suggested jump to results
In this repository
All GitHub Enterprise
↵
Jump to
↵
In this organization
All GitHub Enterprise
↵
Jump to
↵
In this repository
All GitHub Enterprise
↵
Jump to
↵
Sign in
Reseting focus
You signed in with another tab or window.
Reload
to refresh your session.
You signed out in another tab or window.
Reload
to refresh your session.
You switched accounts on another tab or window.
Reload
to refresh your session.
Dismiss alert
{{ message }}
mariux64
/
linux
Public
Notifications
You must be signed in to change notification settings
Fork
0
Star
0
Code
Issues
2
Pull requests
0
Actions
Projects
0
Wiki
Security
Insights
Additional navigation options
Code
Issues
Pull requests
Actions
Projects
Wiki
Security
Insights
Files
3dbb5eb
Documentation
arch
block
crypto
drivers
firmware
fs
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs
cachefiles
ceph
cifs
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs
efivarfs
efs
exofs
exportfs
ext2
ext3
ext4
Kconfig
Makefile
acl.c
acl.h
balloc.c
bitmap.c
block_validity.c
crypto.c
crypto_fname.c
crypto_key.c
crypto_policy.c
dir.c
ext4.h
ext4_crypto.h
ext4_extents.h
ext4_jbd2.c
ext4_jbd2.h
extents.c
extents_status.c
extents_status.h
file.c
fsync.c
hash.c
ialloc.c
indirect.c
inline.c
inode.c
ioctl.c
mballoc.c
mballoc.h
migrate.c
mmp.c
move_extent.c
namei.c
page-io.c
readpage.c
resize.c
super.c
symlink.c
truncate.h
xattr.c
xattr.h
xattr_security.c
xattr_trusted.c
xattr_user.c
f2fs
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2
jffs2
jfs
kernfs
lockd
logfs
minix
ncpfs
nfs
nfs_common
nfsd
nilfs2
nls
notify
ntfs
ocfs2
omfs
openpromfs
overlayfs
proc
pstore
qnx4
qnx6
quota
ramfs
reiserfs
romfs
squashfs
sysfs
sysv
tracefs
ubifs
udf
ufs
xfs
Kconfig
Kconfig.binfmt
Makefile
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
coredump.c
dax.c
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fhandle.c
file.c
file_table.c
filesystems.c
fs-writeback.c
fs_pin.c
fs_struct.c
inode.c
internal.h
ioctl.c
libfs.c
locks.c
mbcache.c
mount.h
mpage.c
namei.c
namespace.c
no-block.c
nsfs.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr.c
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README
REPORTING-BUGS
Breadcrumbs
linux
/
fs
/
ext4
/
crypto.c
Blame
Blame
Latest commit
History
History
475 lines (423 loc) · 12.4 KB
Breadcrumbs
linux
/
fs
/
ext4
/
crypto.c
Top
File metadata and controls
Code
Blame
475 lines (423 loc) · 12.4 KB
Raw
/* * linux/fs/ext4/crypto.c * * Copyright (C) 2015, Google, Inc. * * This contains encryption functions for ext4 * * Written by Michael Halcrow, 2014. * * Filename encryption additions * Uday Savagaonkar, 2014 * Encryption policy handling additions * Ildar Muslukhov, 2014 * * This has not yet undergone a rigorous security audit. * * The usage of AES-XTS should conform to recommendations in NIST * Special Publication 800-38E and IEEE P1619/D16. */ #include <crypto/hash.h> #include <crypto/sha.h> #include <keys/user-type.h> #include <keys/encrypted-type.h> #include <linux/crypto.h> #include <linux/ecryptfs.h> #include <linux/gfp.h> #include <linux/kernel.h> #include <linux/key.h> #include <linux/list.h> #include <linux/mempool.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/random.h> #include <linux/scatterlist.h> #include <linux/spinlock_types.h> #include "ext4_extents.h" #include "xattr.h" /* Encryption added and removed here! (L: */ static unsigned int num_prealloc_crypto_pages = 32; static unsigned int num_prealloc_crypto_ctxs = 128; module_param(num_prealloc_crypto_pages, uint, 0444); MODULE_PARM_DESC(num_prealloc_crypto_pages, "Number of crypto pages to preallocate"); module_param(num_prealloc_crypto_ctxs, uint, 0444); MODULE_PARM_DESC(num_prealloc_crypto_ctxs, "Number of crypto contexts to preallocate"); static mempool_t *ext4_bounce_page_pool; static LIST_HEAD(ext4_free_crypto_ctxs); static DEFINE_SPINLOCK(ext4_crypto_ctx_lock); static struct kmem_cache *ext4_crypto_ctx_cachep; struct kmem_cache *ext4_crypt_info_cachep; /** * ext4_release_crypto_ctx() - Releases an encryption context * @ctx: The encryption context to release. * * If the encryption context was allocated from the pre-allocated pool, returns * it to that pool. Else, frees it. * * If there's a bounce page in the context, this frees that. */ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx) { unsigned long flags; if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page) mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool); ctx->w.bounce_page = NULL; ctx->w.control_page = NULL; if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) { kmem_cache_free(ext4_crypto_ctx_cachep, ctx); } else { spin_lock_irqsave(&ext4_crypto_ctx_lock, flags); list_add(&ctx->free_list, &ext4_free_crypto_ctxs); spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags); } } /** * ext4_get_crypto_ctx() - Gets an encryption context * @inode: The inode for which we are doing the crypto * * Allocates and initializes an encryption context. * * Return: An allocated and initialized encryption context on success; error * value or NULL otherwise. */ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) { struct ext4_crypto_ctx *ctx = NULL; int res = 0; unsigned long flags; struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; if (ci == NULL) return ERR_PTR(-ENOKEY); /* * We first try getting the ctx from a free list because in * the common case the ctx will have an allocated and * initialized crypto tfm, so it's probably a worthwhile * optimization. For the bounce page, we first try getting it * from the kernel allocator because that's just about as fast * as getting it from a list and because a cache of free pages * should generally be a "last resort" option for a filesystem * to be able to do its job. */ spin_lock_irqsave(&ext4_crypto_ctx_lock, flags); ctx = list_first_entry_or_null(&ext4_free_crypto_ctxs, struct ext4_crypto_ctx, free_list); if (ctx) list_del(&ctx->free_list); spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags); if (!ctx) { ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS); if (!ctx) { res = -ENOMEM; goto out; } ctx->flags |= EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL; } else { ctx->flags &= ~EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL; } ctx->flags &= ~EXT4_WRITE_PATH_FL; out: if (res) { if (!IS_ERR_OR_NULL(ctx)) ext4_release_crypto_ctx(ctx); ctx = ERR_PTR(res); } return ctx; } struct workqueue_struct *ext4_read_workqueue; static DEFINE_MUTEX(crypto_init); /** * ext4_exit_crypto() - Shutdown the ext4 encryption system */ void ext4_exit_crypto(void) { struct ext4_crypto_ctx *pos, *n; list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) kmem_cache_free(ext4_crypto_ctx_cachep, pos); INIT_LIST_HEAD(&ext4_free_crypto_ctxs); if (ext4_bounce_page_pool) mempool_destroy(ext4_bounce_page_pool); ext4_bounce_page_pool = NULL; if (ext4_read_workqueue) destroy_workqueue(ext4_read_workqueue); ext4_read_workqueue = NULL; if (ext4_crypto_ctx_cachep) kmem_cache_destroy(ext4_crypto_ctx_cachep); ext4_crypto_ctx_cachep = NULL; if (ext4_crypt_info_cachep) kmem_cache_destroy(ext4_crypt_info_cachep); ext4_crypt_info_cachep = NULL; } /** * ext4_init_crypto() - Set up for ext4 encryption. * * We only call this when we start accessing encrypted files, since it * results in memory getting allocated that wouldn't otherwise be used. * * Return: Zero on success, non-zero otherwise. */ int ext4_init_crypto(void) { int i, res = -ENOMEM; mutex_lock(&crypto_init); if (ext4_read_workqueue) goto already_initialized; ext4_read_workqueue = alloc_workqueue("ext4_crypto", WQ_HIGHPRI, 0); if (!ext4_read_workqueue) goto fail; ext4_crypto_ctx_cachep = KMEM_CACHE(ext4_crypto_ctx, SLAB_RECLAIM_ACCOUNT); if (!ext4_crypto_ctx_cachep) goto fail; ext4_crypt_info_cachep = KMEM_CACHE(ext4_crypt_info, SLAB_RECLAIM_ACCOUNT); if (!ext4_crypt_info_cachep) goto fail; for (i = 0; i < num_prealloc_crypto_ctxs; i++) { struct ext4_crypto_ctx *ctx; ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS); if (!ctx) { res = -ENOMEM; goto fail; } list_add(&ctx->free_list, &ext4_free_crypto_ctxs); } ext4_bounce_page_pool = mempool_create_page_pool(num_prealloc_crypto_pages, 0); if (!ext4_bounce_page_pool) { res = -ENOMEM; goto fail; } already_initialized: mutex_unlock(&crypto_init); return 0; fail: ext4_exit_crypto(); mutex_unlock(&crypto_init); return res; } void ext4_restore_control_page(struct page *data_page) { struct ext4_crypto_ctx *ctx = (struct ext4_crypto_ctx *)page_private(data_page); set_page_private(data_page, (unsigned long)NULL); ClearPagePrivate(data_page); unlock_page(data_page); ext4_release_crypto_ctx(ctx); } /** * ext4_crypt_complete() - The completion callback for page encryption * @req: The asynchronous encryption request context * @res: The result of the encryption operation */ static void ext4_crypt_complete(struct crypto_async_request *req, int res) { struct ext4_completion_result *ecr = req->data; if (res == -EINPROGRESS) return; ecr->res = res; complete(&ecr->completion); } typedef enum { EXT4_DECRYPT = 0, EXT4_ENCRYPT, } ext4_direction_t; static int ext4_page_crypto(struct ext4_crypto_ctx *ctx, struct inode *inode, ext4_direction_t rw, pgoff_t index, struct page *src_page, struct page *dest_page) { u8 xts_tweak[EXT4_XTS_TWEAK_SIZE]; struct ablkcipher_request *req = NULL; DECLARE_EXT4_COMPLETION_RESULT(ecr); struct scatterlist dst, src; struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; struct crypto_ablkcipher *tfm = ci->ci_ctfm; int res = 0; req = ablkcipher_request_alloc(tfm, GFP_NOFS); if (!req) { printk_ratelimited(KERN_ERR "%s: crypto_request_alloc() failed\n", __func__); return -ENOMEM; } ablkcipher_request_set_callback( req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, ext4_crypt_complete, &ecr); BUILD_BUG_ON(EXT4_XTS_TWEAK_SIZE < sizeof(index)); memcpy(xts_tweak, &index, sizeof(index)); memset(&xts_tweak[sizeof(index)], 0, EXT4_XTS_TWEAK_SIZE - sizeof(index)); sg_init_table(&dst, 1); sg_set_page(&dst, dest_page, PAGE_CACHE_SIZE, 0); sg_init_table(&src, 1); sg_set_page(&src, src_page, PAGE_CACHE_SIZE, 0); ablkcipher_request_set_crypt(req, &src, &dst, PAGE_CACHE_SIZE, xts_tweak); if (rw == EXT4_DECRYPT) res = crypto_ablkcipher_decrypt(req); else res = crypto_ablkcipher_encrypt(req); if (res == -EINPROGRESS || res == -EBUSY) { BUG_ON(req->base.data != &ecr); wait_for_completion(&ecr.completion); res = ecr.res; } ablkcipher_request_free(req); if (res) { printk_ratelimited( KERN_ERR "%s: crypto_ablkcipher_encrypt() returned %d\n", __func__, res); return res; } return 0; } static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx) { ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, GFP_NOWAIT); if (ctx->w.bounce_page == NULL) return ERR_PTR(-ENOMEM); ctx->flags |= EXT4_WRITE_PATH_FL; return ctx->w.bounce_page; } /** * ext4_encrypt() - Encrypts a page * @inode: The inode for which the encryption should take place * @plaintext_page: The page to encrypt. Must be locked. * * Allocates a ciphertext page and encrypts plaintext_page into it using the ctx * encryption context. * * Called on the page write path. The caller must call * ext4_restore_control_page() on the returned ciphertext page to * release the bounce buffer and the encryption context. * * Return: An allocated page with the encrypted content on success. Else, an * error value or NULL. */ struct page *ext4_encrypt(struct inode *inode, struct page *plaintext_page) { struct ext4_crypto_ctx *ctx; struct page *ciphertext_page = NULL; int err; BUG_ON(!PageLocked(plaintext_page)); ctx = ext4_get_crypto_ctx(inode); if (IS_ERR(ctx)) return (struct page *) ctx; /* The encryption operation will require a bounce page. */ ciphertext_page = alloc_bounce_page(ctx); if (IS_ERR(ciphertext_page)) goto errout; ctx->w.control_page = plaintext_page; err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, plaintext_page->index, plaintext_page, ciphertext_page); if (err) { ciphertext_page = ERR_PTR(err); errout: ext4_release_crypto_ctx(ctx); return ciphertext_page; } SetPagePrivate(ciphertext_page); set_page_private(ciphertext_page, (unsigned long)ctx); lock_page(ciphertext_page); return ciphertext_page; } /** * ext4_decrypt() - Decrypts a page in-place * @ctx: The encryption context. * @page: The page to decrypt. Must be locked. * * Decrypts page in-place using the ctx encryption context. * * Called from the read completion callback. * * Return: Zero on success, non-zero otherwise. */ int ext4_decrypt(struct ext4_crypto_ctx *ctx, struct page *page) { BUG_ON(!PageLocked(page)); return ext4_page_crypto(ctx, page->mapping->host, EXT4_DECRYPT, page->index, page, page); } /* * Convenience function which takes care of allocating and * deallocating the encryption context */ int ext4_decrypt_one(struct inode *inode, struct page *page) { int ret; struct ext4_crypto_ctx *ctx = ext4_get_crypto_ctx(inode); if (!ctx) return -ENOMEM; ret = ext4_decrypt(ctx, page); ext4_release_crypto_ctx(ctx); return ret; } int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex) { struct ext4_crypto_ctx *ctx; struct page *ciphertext_page = NULL; struct bio *bio; ext4_lblk_t lblk = ex->ee_block; ext4_fsblk_t pblk = ext4_ext_pblock(ex); unsigned int len = ext4_ext_get_actual_len(ex); int err = 0; BUG_ON(inode->i_sb->s_blocksize != PAGE_CACHE_SIZE); ctx = ext4_get_crypto_ctx(inode); if (IS_ERR(ctx)) return PTR_ERR(ctx); ciphertext_page = alloc_bounce_page(ctx); if (IS_ERR(ciphertext_page)) { err = PTR_ERR(ciphertext_page); goto errout; } while (len--) { err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, lblk, ZERO_PAGE(0), ciphertext_page); if (err) goto errout; bio = bio_alloc(GFP_KERNEL, 1); if (!bio) { err = -ENOMEM; goto errout; } bio->bi_bdev = inode->i_sb->s_bdev; bio->bi_iter.bi_sector = pblk; err = bio_add_page(bio, ciphertext_page, inode->i_sb->s_blocksize, 0); if (err) { bio_put(bio); goto errout; } err = submit_bio_wait(WRITE, bio); bio_put(bio); if (err) goto errout; } err = 0; errout: ext4_release_crypto_ctx(ctx); return err; } bool ext4_valid_contents_enc_mode(uint32_t mode) { return (mode == EXT4_ENCRYPTION_MODE_AES_256_XTS); } /** * ext4_validate_encryption_key_size() - Validate the encryption key size * @mode: The key mode. * @size: The key size to validate. * * Return: The validated key size for @mode. Zero if invalid. */ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size) { if (size == ext4_encryption_key_size(mode)) return size; return 0; }
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
You can’t perform that action at this time.