[CRYPTO] lib: table driven multiplications in GF(2^128)

A lot of cypher modes need multiplications in GF(2^128). LRW, ABL, GCM... I use functions from this library in my LRW implementation and I will also use them in my ABL (Arbitrary Block Length, an unencumbered (correct me if I am wrong, wide block cipher mode). Elements of GF(2^128) must be presented as u128 *, it encourages automatic and proper alignment. The library contains support for two different representations of GF(2^128), see the comment in gf128mul.h. There different levels of optimization (memory/speed tradeoff). The code is based on work by Dr Brian Gladman. Notable changes: - deletion of two optimization modes - change from u32 to u64 for faster handling on 64bit machines - support for 'bbe' representation in addition to the, already implemented, 'lle' representation. - move 'inline void' functions from header to 'static void' in the source file - update to use the linux coding style conventions The original can be found at: http://fp.gladman.plus.com/AES/modes.vc8.19-06-06.zip The copyright (and GPL statement) of the original author is preserved. Signed-off-by: Rik Snel <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
iegor · Dec 7, 2006 · c494e07 · c494e07
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commit c494e07
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diff --git a/crypto/Kconfig b/crypto/Kconfig
@@ -139,6 +139,16 @@ config CRYPTO_TGR192
 	  See also:
 	  <http://www.cs.technion.ac.il/~biham/Reports/Tiger/>.
 
+config CRYPTO_GF128MUL
+	tristate "GF(2^128) multiplication functions (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	help
+	  Efficient table driven implementation of multiplications in the
+	  field GF(2^128).  This is needed by some cypher modes. This
+	  option will be selected automatically if you select such a
+	  cipher mode.  Only select this option by hand if you expect to load
+	  an external module that requires these functions.
+
 config CRYPTO_ECB
 	tristate "ECB support"
 	select CRYPTO_BLKCIPHER

diff --git a/crypto/Makefile b/crypto/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_CRYPTO_SHA256) += sha256.o
 obj-$(CONFIG_CRYPTO_SHA512) += sha512.o
 obj-$(CONFIG_CRYPTO_WP512) += wp512.o
 obj-$(CONFIG_CRYPTO_TGR192) += tgr192.o
+obj-$(CONFIG_CRYPTO_GF128MUL) += gf128mul.o
 obj-$(CONFIG_CRYPTO_ECB) += ecb.o
 obj-$(CONFIG_CRYPTO_CBC) += cbc.o
 obj-$(CONFIG_CRYPTO_DES) += des.o