This patch makes chainiv avoid spinning by postponing requests on lock
contention if the user allows the use of asynchronous algorithms. If
a synchronous algorithm is requested then we behave as before.
This should improve IPsec performance on SMP when two CPUs attempt to
transmit over the same SA. Currently one of them will spin doing nothing
waiting for the other CPU to finish its encryption. This patch makes it
postpone the request and get on with other work.
If only one CPU is transmitting for a given SA, then we will process
the request synchronously as before.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that seqiv supports AEAD algorithms it needs to select the AEAD option.
Thanks to Erez Zadok for pointing out the problem.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
It's better to return silently than crash and burn when someone feeds us
a zero length. In particular the null digest algorithm when used as part
of authenc will do that to us.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We need to allow setkey on digest_null if it is to be used directly by
authenc instead of through hmac.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a null blkcipher algorithm called ecb(cipher_null) for
backwards compatibility. Previously the null algorithm when used by
IPsec copied the data byte by byte. This new algorithm optimises that
to a straight memcpy which lets us better measure inherent overheads in
our IPsec code.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds 7 test vectors to tcrypt for CCM.
The test vectors are from rfc 3610.
There are about 10 more test vectors in RFC 3610
and 4 or 5 more in NIST. I can add these as time permits.
I also needed to set authsize. CCM has a prerequisite of
authsize.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds Counter with CBC-MAC (CCM) support.
RFC 3610 and NIST Special Publication 800-38C were referenced.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes crypto_alloc_aead always return algorithms that is
capable of generating their own IVs through givencrypt and givdecrypt.
All existing AEAD algorithms already do. New ones must either supply
their own or specify a generic IV generator with the geniv field.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds support for using seqiv with AEAD algorithms. This is
useful for those AEAD algorithms that performs authentication before
encryption because the IV generated by the underlying encryption algorithm
won't be available for authentication.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch creates the infrastructure to help the construction of IV
generator templates that wrap around AEAD algorithms by adding an IV
generator to them. This is useful for AEAD algorithms with no built-in
IV generator or to replace their built-in generator.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Some algorithms always require manual IV construction. For instance,
the generic CCM algorithm requires the first byte of the IV to be manually
constructed. Such algorithms are always used by other algorithms equipped
with their own IV generators and do not need IV generation per se.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch implements the givencrypt function for authenc. It simply
calls the givencrypt operation on the underlying cipher instead of encrypt.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the underlying givcrypt operations for aead and associated
support elements. The rationale is identical to that of the skcipher
givcrypt operations, i.e., sometimes only the algorithm knows how the
IV should be generated.
A new request type aead_givcrypt_request is added which contains an
embedded aead_request structure with two new elements to support this
operation. The new elements are seq and giv. The seq field should
contain a strictly increasing 64-bit integer which may be used by
certain IV generators as an input value. The giv field will be used
to store the generated IV. It does not need to obey the alignment
requirements of the algorithm because it's not used during the operation.
The existing iv field must still be available as it will be used to store
intermediate IVs and the output IV if chaining is desired.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This generator generates an IV based on a sequence number by xoring it
with a salt. This algorithm is mainly useful for CTR and similar modes.
This patch also sets it as the default IV generator for ctr.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch converts the gcm algorithm over to crypto_grab_skcipher
which is a prerequisite for IV generation.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the gcm_base template which takes a block cipher
parameter instead of cipher. This allows the user to specify a
specific CTR implementation.
This also fixes a leak of the cipher algorithm that was previously
looked up but never freed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch converts the authenc algorithm over to crypto_grab_skcipher
which is a prerequisite for IV generation.
This patch also changes authenc to set its ASYNC status depending on
the ASYNC status of the underlying skcipher.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch makes crypto_alloc_ablkcipher/crypto_grab_skcipher always
return algorithms that are capable of generating their own IVs through
givencrypt and givdecrypt. Each algorithm may specify its default IV
generator through the geniv field.
For algorithms that do not set the geniv field, the blkcipher layer will
pick a default. Currently it's chainiv for synchronous algorithms and
eseqiv for asynchronous algorithms. Note that if these wrappers do not
work on an algorithm then that algorithm must specify its own geniv or
it can't be used at all.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This generator generates an IV based on a sequence number by xoring it
with a salt and then encrypting it with the same key as used to encrypt
the plain text. This algorithm requires that the block size be equal
to the IV size. It is mainly useful for CBC.
It has one noteworthy property that for IPsec the IV happens to lie
just before the plain text so the IV generation simply increases the
number of encrypted blocks by one. Therefore the cost of this generator
is entirely dependent on the speed of the underlying cipher.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The chain IV generator is the one we've been using in the IPsec stack.
It simply starts out with a random IV, then uses the last block of each
encrypted packet's cipher text as the IV for the next packet.
It can only be used by synchronous ciphers since we have to make sure
that we don't start the encryption of the next packet until the last
one has completed.
It does have the advantage of using very little CPU time since it doesn't
have to generate anything at all.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch creates the infrastructure to help the construction of givcipher
templates that wrap around existing blkcipher/ablkcipher algorithms by adding
an IV generator to them.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
If the underlying algorithm specifies a specific geniv algorithm then
we should use it for the cryptd version as well.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the geniv field which indicates the default IV
generator for each algorithm. It should point to a string that is not
freed as long as the algorithm is registered.
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>
