[CRYPTO] lrw: Liskov Rivest Wagner, a tweakable narrow block cipher mode

Main module, this implements the Liskov Rivest Wagner block cipher mode
in the new blockcipher API. The implementation is based on ecb.c.

The LRW-32-AES specification I used can be found at:
http://grouper.ieee.org/groups/1619/email/pdf00017.pdf

It implements the optimization specified as optional in the
specification, and in addition it uses optimized multiplication
routines from gf128mul.c.

Since gf128mul.[ch] is not tested on bigendian, this cipher mode
may currently fail badly on bigendian machines.

Signed-off-by: Rik Snel <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index f941ffb..92ba249 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -168,6 +168,19 @@
 	  CBC: Cipher Block Chaining mode
 	  This block cipher algorithm is required for IPSec.
 
+config CRYPTO_LRW
+	tristate "LRW support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	select CRYPTO_BLKCIPHER
+	select CRYPTO_MANAGER
+	select CRYPTO_GF128MUL
+	help
+	  LRW: Liskov Rivest Wagner, a tweakable, non malleable, non movable
+	  narrow block cipher mode for dm-crypt.  Use it with cipher
+	  specification string aes-lrw-benbi, the key must be 256, 320 or 384.
+	  The first 128, 192 or 256 bits in the key are used for AES and the
+	  rest is used to tie each cipher block to its logical position.
+
 config CRYPTO_DES
 	tristate "DES and Triple DES EDE cipher algorithms"
 	select CRYPTO_ALGAPI