Ard Biesheuvel 5fb8ef2580 crypto: chacha - move existing library code into lib/crypto
Currently, our generic ChaCha implementation consists of a permute
function in lib/chacha.c that operates on the 64-byte ChaCha state
directly [and which is always included into the core kernel since it
is used by the /dev/random driver], and the crypto API plumbing to
expose it as a skcipher.

In order to support in-kernel users that need the ChaCha streamcipher
but have no need [or tolerance] for going through the abstractions of
the crypto API, let's expose the streamcipher bits via a library API
as well, in a way that permits the implementation to be superseded by
an architecture specific one if provided.

So move the streamcipher code into a separate module in lib/crypto,
and expose the init() and crypt() routines to users of the library.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-11-17 09:02:39 +08:00

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# SPDX-License-Identifier: GPL-2.0
comment "Crypto library routines"
config CRYPTO_LIB_AES
tristate
config CRYPTO_LIB_ARC4
tristate
config CRYPTO_ARCH_HAVE_LIB_CHACHA
tristate
help
Declares whether the architecture provides an arch-specific
accelerated implementation of the ChaCha library interface,
either builtin or as a module.
config CRYPTO_LIB_CHACHA_GENERIC
tristate
select CRYPTO_ALGAPI
help
This symbol can be depended upon by arch implementations of the
ChaCha library interface that require the generic code as a
fallback, e.g., for SIMD implementations. If no arch specific
implementation is enabled, this implementation serves the users
of CRYPTO_LIB_CHACHA.
config CRYPTO_LIB_CHACHA
tristate "ChaCha library interface"
depends on CRYPTO_ARCH_HAVE_LIB_CHACHA || !CRYPTO_ARCH_HAVE_LIB_CHACHA
select CRYPTO_LIB_CHACHA_GENERIC if CRYPTO_ARCH_HAVE_LIB_CHACHA=n
help
Enable the ChaCha library interface. This interface may be fulfilled
by either the generic implementation or an arch-specific one, if one
is available and enabled.
config CRYPTO_LIB_DES
tristate
config CRYPTO_LIB_SHA256
tristate