crypto: sm4 - export sm4 constant arrays

Export the constant arrays fk, ck, sbox of the SM4 algorithm, and
add the 'crypto_sm4_' prefix, where sbox is used in the SM4 NEON
implementation for the tbl/tbx instruction to replace the S-BOX,
and the fk, ck arrays are used in the SM4 CE implementation. Use
the sm4ekey instruction to speed up key expansion operations.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: arm64/sm4-ce - Make dependent on sm4 library instead of sm4-generic

SM4 library is abstracted from sm4-generic algorithm, sm4-ce can depend on
the SM4 library instead of sm4-generic, and some functions in sm4-generic
do not need to be exported.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: sm4 - create SM4 library based on sm4 generic code

Take the existing small footprint and mostly time invariant C code
and turn it into a SM4 library that can be used for non-performance
critical, casual use of SM4, and as a fallback for, e.g., SIMD code
that needs a secondary path that can be taken in contexts where the
SIMD unit is off limits.

Secondly, some codes have been optimized, such as unrolling small
times loop, removing unnecessary memory shifts, exporting sbox, fk,
ck arrays, and basic encryption and decryption functions.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: sm4 - export encrypt/decrypt routines to other drivers

In preparation of adding support for the SIMD based arm64 implementation
of arm64, which requires a fallback to non-SIMD code when invoked in
certain contexts, expose the generic SM4 encrypt and decrypt routines
to other drivers.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: sm4 - introduce SM4 symmetric cipher algorithm

Introduce the SM4 cipher algorithms (OSCCA GB/T 32907-2016).

SM4 (GBT.32907-2016) is a cryptographic standard issued by the
Organization of State Commercial Administration of China (OSCCA)
as an authorized cryptographic algorithms for the use within China.

SMS4 was originally created for use in protecting wireless
networks, and is mandated in the Chinese National Standard for
Wireless LAN WAPI (Wired Authentication and Privacy Infrastructure)
(GB.15629.11-2003).

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>