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authorJason A. Donenfeld <Jason@zx2c4.com>2018-08-07 08:22:25 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2018-09-04 11:35:03 +0800
commit578bdaabd015b9b164842c3e8ace9802f38e7ecc (patch)
tree6a1b6134e2377490812b7aa27620f2330e94576e /Documentation/filesystems
parent9dbe3072c6b1f28000961e34497237d0e3d13318 (diff)
crypto: speck - remove Speck
These are unused, undesired, and have never actually been used by anybody. The original authors of this code have changed their mind about its inclusion. While originally proposed for disk encryption on low-end devices, the idea was discarded [1] in favor of something else before that could really get going. Therefore, this patch removes Speck. [1] https://marc.info/?l=linux-crypto-vger&m=153359499015659 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Eric Biggers <ebiggers@google.com> Cc: stable@vger.kernel.org Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/fscrypt.rst10
1 files changed, 0 insertions, 10 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
index 48b424de85bb..cfbc18f0d9c9 100644
--- a/Documentation/filesystems/fscrypt.rst
+++ b/Documentation/filesystems/fscrypt.rst
@@ -191,21 +191,11 @@ 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