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>
128bit is a common blocksize in linux kernel cryptography, so it helps to
centralize some common operations.
The code, while mostly trivial, is based on a header file mode_hdr.h in
http://fp.gladman.plus.com/AES/modes.vc8.19-06-06.zip
The original copyright (and GPL statement) of the original author,
Dr Brian Gladman, is preserved.
Signed-off-by: Rik Snel <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The existing digest user interface is inadequate for support asynchronous
operations. For one it doesn't return a value to indicate success or
failure, nor does it take a per-operation descriptor which is essential
for the issuing of requests while other requests are still outstanding.
This patch is the first in a series of steps to remodel the interface
for asynchronous operations.
For the ease of transition the new interface will be known as "hash"
while the old one will remain as "digest".
This patch also changes sg_next to allow chaining.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds two block cipher algorithms, CBC and ECB. These
are implemented as templates on top of existing single-block cipher
algorithms. They invoke the single-block cipher through the new
encrypt_one/decrypt_one interface.
This also optimises the in-place encryption and decryption to remove
the cost of an IV copy each round.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the new type of block ciphers. Unlike current cipher
algorithms which operate on a single block at a time, block ciphers
operate on an arbitrarily long linear area of data. As it is block-based,
it will skip any data remaining at the end which cannot form a block.
The block cipher has one major difference when compared to the existing
block cipher implementation. The sg walking is now performed by the
algorithm rather than the cipher mid-layer. This is needed for drivers
that directly support sg lists. It also improves performance for all
algorithms as it reduces the total number of indirect calls by one.
In future the existing cipher algorithm will be converted to only have
a single-block interface. This will be done after all existing users
have switched over to the new block cipher type.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch prepares the scatterwalk code for use by the new block cipher
type.
Firstly it halves the size of scatter_walk on 32-bit platforms. This
is important as we allocate at least two of these objects on the stack
for each block cipher operation.
It also exports the symbols since the block cipher code can be built as
a module.
Finally there is a hack in scatterwalk_unmap that relies on progress
being made. Unfortunately, for hardware crypto we can't guarantee
progress to be made since the hardware can fail.
So this also gets rid of the hack by not advancing the address returned
by scatterwalk_map.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds two new operations for the simple cipher that encrypts or
decrypts a single block at a time. This will be the main interface after
the existing block operations have moved over to the new block ciphers.
It also adds the crypto_cipher type which is currently only used on the
new operations but will be extended to setkey as well once existing users
have been converted to use block ciphers where applicable.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the crypto_type structure which will be used for all new
crypto algorithm types, beginning with block ciphers.
The primary purpose of this abstraction is to allow different crypto_type
objects for crypto algorithms of the same type, in particular, there will
be a different crypto_type objects for asynchronous algorithms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the helpers crypto_get_attr_alg and crypto_alloc_instance
which can be used by simple one-argument templates like hmac to process
input parameters and allocate instances.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that the tfm is passed directly to setkey instead of the ctx, we no
longer need to pass the &tfm->crt_flags pointer.
This patch also gets rid of a few unnecessary checks on the key length
for ciphers as the cipher layer guarantees that the key length is within
the bounds specified by the algorithm.
Rather than testing dia_setkey every time, this patch does it only once
during crypto_alloc_tfm. The redundant check from crypto_digest_setkey
is also removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Spawns lock a specific crypto algorithm in place. They can then be used
with crypto_spawn_tfm to allocate a tfm for that algorithm. When the base
algorithm of a spawn is deregistered, all its spawns will be automatically
removed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
A crypto_template generates a crypto_alg object when given a set of
parameters. this patch adds the basic data structure fo templates
and code to handle their registration/deregistration.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The crypto API is made up of the part facing users such as IPsec and the
low-level part which is used by cryptographic entities such as algorithms.
This patch splits out the latter so that the two APIs are more clearly
delineated. As a bonus the low-level API can now be modularised if all
algorithms are built as modules.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch splits up the twofish crypto routine into a common part ( key
setup ) which will be uses by all twofish crypto modules ( generic-c , i586
assembler and x86_64 assembler ) and generic-c part. It also creates a new
header file which will be used by all 3 modules.
This eliminates all code duplication.
Correctness was verified with the tcrypt module and automated test scripts.
Signed-off-by: Joachim Fritschi <jfritschi@freenet.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
