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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-05 15:15:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-05 15:15:32 -0700 |
| commit | fd59ccc53062964007beda8787ffd9cd93968d63 (patch) | |
| tree | a2d2dd5cf5d456f7e1a1427e2a062d1a530e0ca4 /Documentation/filesystems | |
| parent | 6567af78acd18a1f9dec99f27f1b7ba9d270074b (diff) | |
| parent | e1cc40e5d42acb1d99652babb17e6a5ee4247409 (diff) | |
Merge tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt
Pull fscrypt updates from Ted Ts'o:
"Add bunch of cleanups, and add support for the Speck128/256
algorithms.
Yes, Speck is contrversial, but the intention is to use them only for
the lowest end Android devices, where the alternative *really* is no
encryption at all for data stored at rest"
* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
fscrypt: log the crypto algorithm implementations
fscrypt: add Speck128/256 support
fscrypt: only derive the needed portion of the key
fscrypt: separate key lookup from key derivation
fscrypt: use a common logging function
fscrypt: remove internal key size constants
fscrypt: remove unnecessary check for non-logon key type
fscrypt: make fscrypt_operations.max_namelen an integer
fscrypt: drop empty name check from fname_decrypt()
fscrypt: drop max_namelen check from fname_decrypt()
fscrypt: don't special-case EOPNOTSUPP from fscrypt_get_encryption_info()
fscrypt: don't clear flags on crypto transform
fscrypt: remove stale comment from fscrypt_d_revalidate()
fscrypt: remove error messages for skcipher_request_alloc() failure
fscrypt: remove unnecessary NULL check when allocating skcipher
fscrypt: clean up after fscrypt_prepare_lookup() conversions
fs, fscrypt: only define ->s_cop when FS_ENCRYPTION is enabled
fscrypt: use unbound workqueue for decryption
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/fscrypt.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index cfbc18f0d9c9..48b424de85bb 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -191,11 +191,21 @@ Currently, the following pairs of encryption modes are supported: - AES-256-XTS for contents and AES-256-CTS-CBC for filenames - AES-128-CBC for contents and AES-128-CTS-CBC for filenames +- Speck128/256-XTS for contents and Speck128/256-CTS-CBC for filenames It is strongly recommended to use AES-256-XTS for contents encryption. AES-128-CBC was added only for low-powered embedded devices with crypto accelerators such as CAAM or CESA that do not support XTS. +Similarly, Speck128/256 support was only added for older or low-end +CPUs which cannot do AES fast enough -- especially ARM CPUs which have +NEON instructions but not the Cryptography Extensions -- and for which +it would not otherwise be feasible to use encryption at all. It is +not recommended to use Speck on CPUs that have AES instructions. +Speck support is only available if it has been enabled in the crypto +API via CONFIG_CRYPTO_SPECK. Also, on ARM platforms, to get +acceptable performance CONFIG_CRYPTO_SPECK_NEON must be enabled. + New encryption modes can be added relatively easily, without changes to individual filesystems. However, authenticated encryption (AE) modes are not currently supported because of the difficulty of dealing |