Unfortunately the generic chaining hasn't been ported to all architectures
yet, and notably not s390.  So this patch restores the chainging that we've
been using previously which does work everywhere.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The scatterwalk infrastructure is used by algorithms so it needs to
move out of crypto for future users that may live in drivers/crypto
or asm/*/crypto.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

This patch changes gcm/authenc to return EBADMSG instead of EINVAL for
ICV mismatches.  This convention has already been adopted by IPsec.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The crypto_aead convention for ICVs is to include it directly in the
output.  If we decided to change this in future then we would make
the ICV (if the algorithm has an explicit one) available in the
request itself.

For now no algorithm needs this so this patch changes gcm to conform
to this convention.  It also adjusts the tcrypt aead tests to take
this into account.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

As it is authsize is an algorithm paramter which cannot be changed at
run-time.  This is inconvenient because hardware that implements such
algorithms would have to register each authsize that they support
separately.

Since authsize is a property common to all AEAD algorithms, we can add
a function setauthsize that sets it at run-time, just like setkey.

This patch does exactly that and also changes authenc so that authsize
is no longer a parameter of its template.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Add GCM/GMAC support to cryptoapi.

GCM (Galois/Counter Mode) is an AEAD mode of operations for any block cipher
with a block size of 16.  The typical example is AES-GCM.
Signed-off-by: NMikko Herranen <mh1@iki.fi>
Reviewed-by: NMika Kukkonen <mika.kukkonen@nsn.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>