Commit Graph

5 Commits

Author SHA1 Message Date
Herbert Xu
b3c16bfc6a crypto: skcipher - Add skcipher_ialg_simple helper
This patch introduces the skcipher_ialg_simple helper which fetches
the crypto_alg structure from a simple skcipher instance's spawn.

This allows us to remove the third argument from the function
skcipher_alloc_instance_simple.

In doing so the reference count to the algorithm is now maintained
by the Crypto API and the caller no longer needs to drop the alg
refcount.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-12-27 18:18:04 +08:00
Eric Biggers
c4741b2305 crypto: run initcalls for generic implementations earlier
Use subsys_initcall for registration of all templates and generic
algorithm implementations, rather than module_init.  Then change
cryptomgr to use arch_initcall, to place it before the subsys_initcalls.

This is needed so that when both a generic and optimized implementation
of an algorithm are built into the kernel (not loadable modules), the
generic implementation is registered before the optimized one.
Otherwise, the self-tests for the optimized implementation are unable to
allocate the generic implementation for the new comparison fuzz tests.

Note that on arm, a side effect of this change is that self-tests for
generic implementations may run before the unaligned access handler has
been installed.  So, unaligned accesses will crash the kernel.  This is
arguably a good thing as it makes it easier to detect that type of bug.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-18 22:15:03 +08:00
Eric Biggers
21f3ca6cd5 crypto: ofb - convert to skcipher_alloc_instance_simple()
The OFB template just wraps a single block cipher algorithm, so simplify
it by converting it to use skcipher_alloc_instance_simple().

Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-11 14:16:58 +08:00
Eric Biggers
b3e3e2db7d crypto: ofb - fix handling partial blocks and make thread-safe
Fix multiple bugs in the OFB implementation:

1. It stored the per-request state 'cnt' in the tfm context, which can be
   used by multiple threads concurrently (e.g. via AF_ALG).
2. It didn't support messages not a multiple of the block cipher size,
   despite being a stream cipher.
3. It didn't set cra_blocksize to 1 to indicate it is a stream cipher.

To fix these, set the 'chunksize' property to the cipher block size to
guarantee that when walking through the scatterlist, a partial block can
only occur at the end.  Then change the implementation to XOR a block at
a time at first, then XOR the partial block at the end if needed.  This
is the same way CTR and CFB are implemented.  As a bonus, this also
improves performance in most cases over the current approach.

Fixes: e497c51896 ("crypto: ofb - add output feedback mode")
Cc: <stable@vger.kernel.org> # v4.20+
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-01-11 14:16:57 +08:00
Gilad Ben-Yossef
e497c51896 crypto: ofb - add output feedback mode
Add a generic version of output feedback mode. We already have support of
several hardware based transformations of this mode and the needed test
vectors but we somehow missed adding a generic software one. Fix this now.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-09-28 12:46:26 +08:00