kernel/git/stable/linux-stable.git/fs/crypto/crypto.c, branch linux-5.0.y

fscrypt: add Adiantum support

2019-01-06T13:36:21+00:00

Add support for the Adiantum encryption mode to fscrypt. Adiantum is a tweakable, length-preserving encryption mode with security provably reducible to that of XChaCha12 and AES-256, subject to a security bound. It's also a true wide-block mode, unlike XTS. See the paper "Adiantum: length-preserving encryption for entry-level processors" (https://eprint.iacr.org/2018/720.pdf) for more details. Also see commit 059c2a4d8e16 ("crypto: adiantum - add Adiantum support"). On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and the NH hash function. These algorithms are fast even on processors without dedicated crypto instructions. Adiantum makes it feasible to enable storage encryption on low-end mobile devices that lack AES instructions; currently such devices are unencrypted. On ARM Cortex-A7, on 4096-byte messages Adiantum encryption is about 4 times faster than AES-256-XTS encryption; decryption is about 5 times faster. In fscrypt, Adiantum is suitable for encrypting both file contents and names. With filenames, it fixes a known weakness: when two filenames in a directory share a common prefix of >= 16 bytes, with CTS-CBC their encrypted filenames share a common prefix too, leaking information. Adiantum does not have this problem. Since Adiantum also accepts long tweaks (IVs), it's also safe to use the master key directly for Adiantum encryption rather than deriving per-file keys, provided that the per-file nonce is included in the IVs and the master key isn't used for any other encryption mode. This configuration saves memory and improves performance. A new fscrypt policy flag is added to allow users to opt-in to this configuration. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

Merge tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2018-06-11T17:16:13+00:00

Pull f2fs updates from Jaegeuk Kim: "In this round, we've mainly focused on discard, aka unmap, control along with fstrim for Android-specific usage model. In addition, we've fixed writepage flow which returned EAGAIN previously resulting in EIO of fsync(2) due to mapping's error state. In order to avoid old MM bug [1], we decided not to use __GFP_ZERO for the mapping for node and meta page caches. As always, we've cleaned up many places for future fsverity and symbol conflicts. Enhancements: - do discard/fstrim in lower priority considering fs utilization - split large discard commands into smaller ones for better responsiveness - add more sanity checks to address syzbot reports - add a mount option, fsync_mode=nobarrier, which can reduce # of cache flushes - clean up symbol namespace with modified function names - be strict on block allocation and IO control in corner cases Bug fixes: - don't use __GFP_ZERO for mappings - fix error reports in writepage to avoid fsync() failure - avoid selinux denial on CAP_RESOURCE on resgid/resuid - fix some subtle race conditions in GC/atomic writes/shutdown - fix overflow bugs in sanity_check_raw_super - fix missing bits on get_flags Clean-ups: - prepare the generic flow for future fsverity integration - fix some broken coding standard" [1] https://lkml.org/lkml/2018/4/8/661 * tag 'f2fs-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (79 commits) f2fs: fix to clear FI_VOLATILE_FILE correctly f2fs: let sync node IO interrupt async one f2fs: don't change wbc->sync_mode f2fs: fix to update mtime correctly fs: f2fs: insert space around that ':' and ', ' fs: f2fs: add missing blank lines after declarations fs: f2fs: changed variable type of offset "unsigned" to "loff_t" f2fs: clean up symbol namespace f2fs: make set_de_type() static f2fs: make __f2fs_write_data_pages() static f2fs: fix to avoid accessing cross the boundary f2fs: fix to let caller retry allocating block address disable loading f2fs module on PAGE_SIZE > 4KB f2fs: fix error path of move_data_page f2fs: don't drop dentry pages after fs shutdown f2fs: fix to avoid race during access gc_thread pointer f2fs: clean up with clear_radix_tree_dirty_tag f2fs: fix to don't trigger writeback during recovery f2fs: clear discard_wake earlier f2fs: let discard thread wait a little longer if dev is busy ...

fscrypt: use a common logging function

2018-05-20T20:21:05+00:00

Use a common function for fscrypt warning and error messages so that all the messages are consistently ratelimited, include the "fscrypt:" prefix, and include the filesystem name if applicable. Also fix up a few of the log messages to be more descriptive. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: remove stale comment from fscrypt_d_revalidate()

2018-05-20T20:21:01+00:00

Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: remove error messages for skcipher_request_alloc() failure

2018-05-20T20:21:00+00:00

skcipher_request_alloc() can only fail due to lack of memory, and in that case the memory allocator will have already printed a detailed error message. Thus, remove the redundant error messages from fscrypt. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: clean up after fscrypt_prepare_lookup() conversions

2018-05-20T20:20:59+00:00

Now that all filesystems have been converted to use fscrypt_prepare_lookup(), we can remove the fscrypt_set_d_op() and fscrypt_set_encrypted_dentry() functions as well as un-export fscrypt_d_ops. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: use unbound workqueue for decryption

2018-05-20T20:20:58+00:00

Improve fscrypt read performance by switching the decryption workqueue from bound to unbound. With the bound workqueue, when multiple bios completed on the same CPU, they were decrypted on that same CPU. But with the unbound queue, they are now decrypted in parallel on any CPU. Although fscrypt read performance can be tough to measure due to the many sources of variation, this change is most beneficial when decryption is slow, e.g. on CPUs without AES instructions. For example, I timed tarring up encrypted directories on f2fs. On x86 with AES-NI instructions disabled, the unbound workqueue improved performance by about 25-35%, using 1 to NUM_CPUs jobs with 4 or 8 CPUs available. But with AES-NI enabled, performance was unchanged to within ~2%. I also did the same test on a quad-core ARM CPU using xts-speck128-neon encryption. There performance was usually about 10% better with the unbound workqueue, bringing it closer to the unencrypted speed. The unbound workqueue may be worse in some cases due to worse locality, but I think it's still the better default. dm-crypt uses an unbound workqueue by default too, so this change makes fscrypt match. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

fscrypt: allow synchronous bio decryption

2018-05-02T21:30:57+00:00

Currently, fscrypt provides fscrypt_decrypt_bio_pages() which decrypts a bio's pages asynchronously, then unlocks them afterwards. But, this assumes that decryption is the last "postprocessing step" for the bio, so it's incompatible with additional postprocessing steps such as authenticity verification after decryption. Therefore, rename the existing fscrypt_decrypt_bio_pages() to fscrypt_enqueue_decrypt_bio(). Then, add fscrypt_decrypt_bio() which decrypts the pages in the bio synchronously without unlocking the pages, nor setting them Uptodate; and add fscrypt_enqueue_decrypt_work(), which enqueues work on the fscrypt_read_workqueue. The new functions will be used by filesystems that support both fscrypt and fs-verity. Signed-off-by: Eric Biggers Signed-off-by: Jaegeuk Kim

fscrypt: trim down fscrypt.h includes

2018-01-12T03:06:19+00:00

fscrypt.h included way too many other headers, given that it is included by filesystems both with and without encryption support. Trim down the includes list by moving the needed includes into more appropriate places, and removing the unneeded ones. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o

Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt

2017-11-14T19:35:15+00:00

Pull fscrypt updates from Ted Ts'o: "Lots of cleanups, mostly courtesy by Eric Biggers" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: lock mutex before checking for bounce page pool fscrypt: add a documentation file for filesystem-level encryption ext4: switch to fscrypt_prepare_setattr() ext4: switch to fscrypt_prepare_lookup() ext4: switch to fscrypt_prepare_rename() ext4: switch to fscrypt_prepare_link() ext4: switch to fscrypt_file_open() fscrypt: new helper function - fscrypt_prepare_setattr() fscrypt: new helper function - fscrypt_prepare_lookup() fscrypt: new helper function - fscrypt_prepare_rename() fscrypt: new helper function - fscrypt_prepare_link() fscrypt: new helper function - fscrypt_file_open() fscrypt: new helper function - fscrypt_require_key() fscrypt: remove unneeded empty fscrypt_operations structs fscrypt: remove ->is_encrypted() fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED() fs, fscrypt: add an S_ENCRYPTED inode flag fscrypt: clean up include file mess