This patch adds the helper crypto_skcipher_driver_name which returns
the driver name of the alg object for a given tfm. This is needed by
ecryptfs.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As the size of an skcipher_request is variable, it's awkward to
zero it explicitly. This patch adds a helper to do that which
should be used when it is created on the stack.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
While converting ecryptfs over to skcipher I found that it needs
to pick a default key size if one isn't given. Rather than having
it poke into the guts of the algorithm to get max_keysize, let's
provide a helper that is meant to give a sane default (just in
case we ever get an algorithm that has no maximum key size).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a way for skcipher users to determine whether a key
is required by a transform.
Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the crypto skcipher interface which aims
to replace both blkcipher and ablkcipher.
It's very similar to the existing ablkcipher interface. The
main difference is the removal of the givcrypt interface. In
order to make the transition easier for blkcipher users, there
is a helper SKCIPHER_REQUEST_ON_STACK which can be used to place
a request on the stack for synchronous transforms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Change formal parameters to not clash with global names to
eliminate many W=2 warnings.
Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch finally makes the givencrypt/givdecrypt operations available
to users by adding crypto_skcipher_givencrypt and crypto_skcipher_givdecrypt.
A suite of helpers to allocate and fill in the request is also available.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Different block cipher modes have different requirements for intialisation
vectors. For example, CBC can use a simple randomly generated IV while
modes such as CTR must use an IV generation mechanisms that give a stronger
guarantee on the lack of collisions. Furthermore, disk encryption modes
have their own IV generation algorithms.
Up until now IV generation has been left to the users of the symmetric
key cipher API. This is inconvenient as the number of block cipher modes
increase because the user needs to be aware of which mode is supposed to
be paired with which IV generation algorithm.
Therefore it makes sense to integrate the IV generation into the crypto
API. This patch takes the first step in that direction by creating two
new ablkcipher operations, givencrypt and givdecrypt that generates an
IV before performing the actual encryption or decryption.
The operations are currently not exposed to the user. That will be done
once the underlying functionality has actually been implemented.
It also creates the underlying givcipher type. Algorithms that directly
generate IVs would use it instead of ablkcipher. All other algorithms
(including all existing ones) would generate a givcipher algorithm upon
registration. This givcipher algorithm will be constructed from the geniv
string that's stored in every algorithm. That string will locate a template
which is instantiated by the blkcipher/ablkcipher algorithm in question to
give a givcipher algorithm.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
