crypto: algapi - use common mechanism for inheriting flags

The flag CRYPTO_ALG_ASYNC is "inherited" in the sense that when a
template is instantiated, the template will have CRYPTO_ALG_ASYNC set if
any of the algorithms it uses has CRYPTO_ALG_ASYNC set.

We'd like to add a second flag (CRYPTO_ALG_ALLOCATES_MEMORY) that gets
"inherited" in the same way. This is difficult because the handling of
CRYPTO_ALG_ASYNC is hardcoded everywhere. Address this by:

- Add CRYPTO_ALG_INHERITED_FLAGS, which contains the set of flags that
have these inheritance semantics.

- Add crypto_algt_inherited_mask(), for use by template ->create()
methods. It returns any of these flags that the user asked to be
unset and thus must be passed in the 'mask' to crypto_grab_*().

- Also modify crypto_check_attr_type() to handle computing the 'mask'
so that most templates can just use this.

- Make crypto_grab_*() propagate these flags to the template instance
being created so that templates don't have to do this themselves.

Make crypto/simd.c propagate these flags too, since it "wraps" another
algorithm, similar to a template.

Based on a patch by Mikulas Patocka <mpatocka@redhat.com>
(https://lore.kernel.org/r/alpine.LRH.2.02.2006301414580.30526@file01.intranet.prod.int.rdu2.redhat.com).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: geniv - remove unneeded arguments from aead_geniv_alloc()

The type and mask arguments to aead_geniv_alloc() are always 0, so
remove them.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: geniv - simply error handling in aead_geniv_alloc()

Simplify the error handling in aead_geniv_alloc() by taking advantage of
crypto_grab_aead() now handling an ERR_PTR() name and by taking
advantage of crypto_drop_aead() now accepting (as a no-op) a spawn that
hasn't been grabbed yet.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: geniv - convert to new way of freeing instances

Convert the "seqiv" template to the new way of freeing instances where a
->free() method is installed to the instance struct itself. Also remove
the unused implementation of the old way of freeing instances from the
"echainiv" template, since it's already using the new way too.

In doing this, also simplify the code by making the helper function
aead_geniv_alloc() install the ->free() method, instead of making seqiv
and echainiv do this themselves. This is analogous to how
skcipher_alloc_instance_simple() works.

This will allow removing support for the old way of freeing instances.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: aead - pass instance to crypto_grab_aead()

Initializing a crypto_aead_spawn currently requires:

1. Set spawn->base.inst to point to the instance.
2. Call crypto_grab_aead().

But there's no reason for these steps to be separate, and in fact this
unneeded complication has caused at least one bug, the one fixed by
commit 6db43410179b ("crypto: adiantum - initialize crypto_spawn::inst")

So just make crypto_grab_aead() take the instance as an argument.

To keep the function calls from getting too unwieldy due to this extra
argument, also introduce a 'mask' variable into the affected places
which weren't already using one.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: aead - Split out geniv into its own module

If aead is built as a module along with cryptomgr, it creates a
dependency loop due to the dependency chain aead => crypto_null =>
cryptomgr => aead.

This is due to the presence of the AEAD geniv code. This code is
not really part of the AEAD API but simply support code for IV
generators such as seqiv. This patch moves the geniv code into
its own module thus breaking the dependency loop.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>