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authorJason A. Donenfeld <Jason@zx2c4.com>2018-08-07 02:22:25 -0400
committerHerbert Xu <herbert@gondor.apana.org.au>2018-09-03 23:35:03 -0400
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:
191 191
192- AES-256-XTS for contents and AES-256-CTS-CBC for filenames 192- AES-256-XTS for contents and AES-256-CTS-CBC for filenames
193- AES-128-CBC for contents and AES-128-CTS-CBC for filenames 193- AES-128-CBC for contents and AES-128-CTS-CBC for filenames
194- Speck128/256-XTS for contents and Speck128/256-CTS-CBC for filenames
195 194
196It is strongly recommended to use AES-256-XTS for contents encryption. 195It is strongly recommended to use AES-256-XTS for contents encryption.
197AES-128-CBC was added only for low-powered embedded devices with 196AES-128-CBC was added only for low-powered embedded devices with
198crypto accelerators such as CAAM or CESA that do not support XTS. 197crypto accelerators such as CAAM or CESA that do not support XTS.
199 198
200Similarly, Speck128/256 support was only added for older or low-end
201CPUs which cannot do AES fast enough -- especially ARM CPUs which have
202NEON instructions but not the Cryptography Extensions -- and for which
203it would not otherwise be feasible to use encryption at all. It is
204not recommended to use Speck on CPUs that have AES instructions.
205Speck support is only available if it has been enabled in the crypto
206API via CONFIG_CRYPTO_SPECK. Also, on ARM platforms, to get
207acceptable performance CONFIG_CRYPTO_SPECK_NEON must be enabled.
208
209New encryption modes can be added relatively easily, without changes 199New encryption modes can be added relatively easily, without changes
210to individual filesystems. However, authenticated encryption (AE) 200to individual filesystems. However, authenticated encryption (AE)
211modes are not currently supported because of the difficulty of dealing 201modes are not currently supported because of the difficulty of dealing