Commit Graph

12 Commits

Author SHA1 Message Date
Ondrej Mosnáček acb9b159c7 crypto: gf128mul - define gf128mul_x_* in gf128mul.h
The gf128mul_x_ble function is currently defined in gf128mul.c, because
it depends on the gf128mul_table_be multiplication table.

However, since the function is very small and only uses two values from
the table, it is better for it to be defined as inline function in
gf128mul.h. That way, the function can be inlined by the compiler for
better performance.

For consistency, the other gf128mul_x_* functions are also moved to the
header file. In addition, the code is rewritten to be constant-time.

After this change, the speed of the generic 'xts(aes)' implementation
increased from ~225 MiB/s to ~235 MiB/s (measured using 'cryptsetup
benchmark -c aes-xts-plain64' on an Intel system with CRYPTO_AES_X86_64
and CRYPTO_AES_NI_INTEL disabled).

Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Reviewd-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-05 21:58:35 +08:00
Eric Biggers 3ea996ddfb crypto: gf128mul - constify 4k and 64k multiplication tables
Constify the multiplication tables passed to the 4k and 64k
multiplication functions, as they are not modified by these functions.

Cc: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-09 18:34:16 +08:00
Eric Biggers f33fd64778 crypto: gf128mul - rename the byte overflow tables
Though the GF(2^128) byte overflow tables were named the "lle" and "bbe"
tables, they are not actually tied to these element formats
specifically, but rather to particular a "bit endianness".  For example,
the bbe table is actually used for both bbe and ble multiplication.
Therefore, rename the tables to "le" and "be" and update the comment to
explain this.

Cc: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-09 18:34:15 +08:00
Eric Biggers 2416e4fa98 crypto: gf128mul - remove xx() macro
The xx() macro serves no purpose and can be removed.

Cc: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-09 18:34:15 +08:00
Eric Biggers 63be5b53b6 crypto: gf128mul - fix some comments
Fix incorrect references to GF(128) instead of GF(2^128), as these are
two entirely different fields, and fix a few other incorrect comments.

Cc: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-03-09 18:34:14 +08:00
Alex Cope 75aa0a7caf crypto: gf128mul - Zero memory when freeing multiplication table
GF(2^128) multiplication tables are typically used for secret
information, so it's a good idea to zero them on free.

Signed-off-by: Alex Cope <alexcope@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-11-17 23:34:59 +08:00
Alex Cope d266f44b5b crypto: gf128mul - remove dead gf128mul_64k_lle code
This code is unlikely to be useful in the future because transforms
don't know how often keys will be changed, new algorithms are unlikely
to use lle representation, and tables should be replaced with
carryless multiplication instructions when available.

Signed-off-by: Alex Cope <alexcope@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-11-13 17:45:06 +08:00
Mathias Krause 625426633d crypto: gf128mul - fix call to memset()
In gf128mul_lle() and gf128mul_bbe() r isn't completely initialized with
zero because the size argument passed to memset() is the size of the
pointer, not the structure it points to.

Luckily there are no in-kernel users of those functions so the ABI
change implied by this fix should break no existing code.

Based on a patch by the PaX Team.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: PaX Team <pageexec@freemail.hu>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-07-08 17:21:21 +08:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Adrian-Ken Rueegsegger 8c882f6413 crypto: Fix dead links
Signed-off-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-03-04 14:43:52 +08:00
Rik Snel f19f5111c9 [CRYPTO] xts: XTS blockcipher mode implementation without partial blocks
XTS currently considered to be the successor of the LRW mode by the IEEE1619
workgroup. LRW was discarded, because it was not secure if the encyption key
itself is encrypted with LRW.

XTS does not have this problem. The implementation is pretty straightforward,
a new function was added to gf128mul to handle GF(128) elements in ble format.
Four testvectors from the specification
	http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
were added, and they verify on my system.

Signed-off-by: Rik Snel <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10 16:55:45 -07:00
Rik Snel c494e0705d [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 <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2006-12-06 18:38:55 -08:00