crypto: ahash - remove support for nonzero alignmask

Currently, the ahash API checks the alignment of all key and result
buffers against the algorithm's declared alignmask, and for any
unaligned buf

crypto: ahash - remove support for nonzero alignmask

Currently, the ahash API checks the alignment of all key and result
buffers against the algorithm's declared alignmask, and for any
unaligned buffers it falls back to manually aligned temporary buffers.

This is virtually useless, however. First, since it does not apply to
the message, its effect is much more limited than e.g. is the case for
the alignmask for "skcipher". Second, the key and result buffers are
given as virtual addresses and cannot (in general) be DMA'ed into, so
drivers end up having to copy to/from them in software anyway. As a
result it's easy to use memcpy() or the unaligned access helpers.

The crypto_hash_walk_*() helper functions do use the alignmask to align
the message. But with one exception those are only used for shash
algorithms being exposed via the ahash API, not for native ahashes, and
aligning the message is not required in this case, especially now that
alignmask support has been removed from shash. The exception is the
n2_core driver, which doesn't set an alignmask.

In any case, no ahash algorithms actually set a nonzero alignmask
anymore. Therefore, remove support for it from ahash. The benefit is
that all the code to handle "misaligned" buffers in the ahash API goes
away, reducing the overhead of the ahash API.

This follows the same change that was made to shash.

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

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crypto: doc - use correct function name

The hashing API does not have a function called .finish()

Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.a

crypto: doc - use correct function name

The hashing API does not have a function called .finish()

Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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crypto: algapi - make unregistration functions return void

Some of the algorithm unregistration functions return -ENOENT when asked
to unregister a non-registered algorithm, while others always retu

crypto: algapi - make unregistration functions return void

Some of the algorithm unregistration functions return -ENOENT when asked
to unregister a non-registered algorithm, while others always return 0
or always return void. But no users check the return value, except for
two of the bulk unregistration functions which print a message on error
but still always return 0 to their caller, and crypto_del_alg() which
calls crypto_unregister_instance() which always returns 0.

Since unregistering a non-registered algorithm is always a kernel bug
but there isn't anything callers should do to handle this situation at
runtime, let's simplify things by making all the unregistration
functions return void, and moving the error message into
crypto_unregister_alg() and upgrading it to a WARN().

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

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crypto: doc - remove references to ARC4

arc4 is no longer considered secure, so it shouldn't be used, even as
just an example. Mention serpent and chacha20 instead.

Signed-off-by: Eric Biggers <eb

crypto: doc - remove references to ARC4

arc4 is no longer considered secure, so it shouldn't be used, even as
just an example. Mention serpent and chacha20 instead.

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

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crypto: skcipher - remove the "blkcipher" algorithm type

Now that all "blkcipher" algorithms have been converted to "skcipher",
remove the blkcipher algorithm type.

The skcipher (symmetric key ciph

crypto: skcipher - remove the "blkcipher" algorithm type

Now that all "blkcipher" algorithms have been converted to "skcipher",
remove the blkcipher algorithm type.

The skcipher (symmetric key cipher) algorithm type was introduced a few
years ago to replace both blkcipher and ablkcipher (synchronous and
asynchronous block cipher). The advantages of skcipher include:

- A much less confusing name, since none of these algorithm types have
ever actually been for raw block ciphers, but rather for all
length-preserving encryption modes including block cipher modes of
operation, stream ciphers, and other length-preserving modes.

- It unified blkcipher and ablkcipher into a single algorithm type
which supports both synchronous and asynchronous implementations.
Note, blkcipher already operated only on scatterlists, so the fact
that skcipher does too isn't a regression in functionality.

- Better type safety by using struct skcipher_alg, struct
crypto_skcipher, etc. instead of crypto_alg, crypto_tfm, etc.

- It sometimes simplifies the implementations of algorithms.

Also, the blkcipher API was no longer being tested.

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

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crypto: doc - clarify hash callbacks state machine

Add a note that it is perfectly legal to "abandon" a request object:
- call .init() and then (as many times) .update()
- _not_ call any of .final()

crypto: doc - clarify hash callbacks state machine

Add a note that it is perfectly legal to "abandon" a request object:
- call .init() and then (as many times) .update()
- _not_ call any of .final(), .finup() or .export() at any point in
future

Link: https://lkml.kernel.org/r/20180222114741.GA27631@gondor.apana.org.au
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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crypto: doc - convert crypto API documentation to Sphinx

With the conversion of the kernel crypto API DocBook to Sphinx, the
monolithic document is broken up into individual documents. The
documenta

crypto: doc - convert crypto API documentation to Sphinx

With the conversion of the kernel crypto API DocBook to Sphinx, the
monolithic document is broken up into individual documents. The
documentation is unchanged with the exception of a slight reordering to
keep the individual document parts self-contained.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

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