[PATCH 1/5] lib: add crypt subsystem

[Steffen Jaeckel]

Hi Simon,

thanks for taking the time to review.

On 4/21/21 9:14 AM, Simon Glass wrote:
> On Tue, 13 Apr 2021 at 10:16, Steffen Jaeckel
> <jaeckel-floss at eyet-services.de> wrote:
>>
>> Add the basic functionality required to support the standard crypt
>> format.
>> The files crypt-sha256.c and crypt-sha512.c originate from libxcrypt and
>> their formatting is therefor retained.
>> The integration is done via a crypt_compare() function in crypt.c.
>>
>> ```
>> libxcrypt $ git describe --long --always --all
>> tags/v4.4.17-0-g6b110bc
>> ```
>>
>> Signed-off-by: Steffen Jaeckel <jaeckel-floss at eyet-services.de>
>> ---
>>
>>  include/crypt.h          |  13 ++
>>  lib/Kconfig              |   1 +
>>  lib/Makefile             |   1 +
>>  lib/crypt/Kconfig        |  29 ++++
>>  lib/crypt/Makefile       |  10 ++
>>  lib/crypt/alg-sha256.h   |  17 ++
>>  lib/crypt/alg-sha512.h   |  17 ++
>>  lib/crypt/crypt-port.h   |  28 ++++
>>  lib/crypt/crypt-sha256.c | 313 +++++++++++++++++++++++++++++++++++++
>>  lib/crypt/crypt-sha512.c | 328 +++++++++++++++++++++++++++++++++++++++
>>  lib/crypt/crypt.c        |  73 +++++++++
>>  11 files changed, 830 insertions(+)
>>  create mode 100644 include/crypt.h
>>  create mode 100644 lib/crypt/Kconfig
>>  create mode 100644 lib/crypt/Makefile
>>  create mode 100644 lib/crypt/alg-sha256.h
>>  create mode 100644 lib/crypt/alg-sha512.h
>>  create mode 100644 lib/crypt/crypt-port.h
>>  create mode 100644 lib/crypt/crypt-sha256.c
>>  create mode 100644 lib/crypt/crypt-sha512.c
>>  create mode 100644 lib/crypt/crypt.c
> 
> This seems to use errno - is that necessary? Also are there any simple
> unit tests we could usefully bring over?

Regarding errno - that's the way how libxcrypt works internally, I'm not
sure whether we should really touch this ... the default crypt_alg_rn()
function has a void return type, so either we have to keep using errno
or we have to change the return type...

Regarding unit tests - good idea, I'll have a look.