crypto: digest: Fix digesting over memory chunks > 4096 bytes ...

There are two different cases that are handled in digest_file_window:

 a) the file to digest is memmappable (e.g. /dev/mem)
 b) it isn't (e.g. files in /)

In both cases a file is digested in hunks of (up to) 4096 bytes. After
each hunk in b) the buffer that is fed to digest_update() is then
overwritten using read() to get the next hunk to digest. In case a)
however it was forgotten to step forward in the buffer and instead the
same data was handed to digest_update() again and again.

So to fix that increase buffer by the number of bytes already digested
for case a) which is characterized by flags == 0.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

whole tree: remove trailing whitespaces ...

Signed-off-by: Du Huanpeng <u74147@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: add digest_alloc_by_algo() ...

In barebox the function digest_alloc() allocates a digest based on a string.
When a subsystem already uses an integer value to identify a digest it makes no
sense to create a string and pass it to digest_alloc(), where it is parsed
again. This patch adds the possibility to get a digest by an enum.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: digest: mark signature argument as const ...

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: prepare to allow multiple digest driver ...

This will allow to have hw driver or asm optimised driver.

Use a priority level to determine which one to use at runtime.
The generic one will be 0.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: allow algo to specify their length at runtime ...

such as RSA as we load a DER key we will detect the key size
at runtime and so the algo length.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

command: add generic digest command ...

That can be used for digest calculation and verify

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: add digest callback ...

Combination of @init and @update and @final. This function
effectively behaves as the entire chain of operations, @init,
@update and @final issued in sequence. This is added for hardware
which cannot do even the @finup, but can only do the whole
transformation in one run.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: add verify callback ...

this will allow to compare a md with the original one

When calling this do not call final

For RSA_SIGN verification final does not exist only verify
as final will be for signing

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: digest: digest_file_window/digest_file/digest_file_by_name drop key params ...

expect the key to be set before calling

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: digest: digest_file_window: check every digest_xxx return ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: digest: Fix coding style ...

When declaring pointer data or a function that returns a pointer type, the
preferred use of '*' is adjacent to the data name or function name and not
adjacent to the type name.

Fix the remaining occurences in crypto/

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

crypto: digest: Make string arguments const ...

Most string arguments for keys and filenames can be const. Change
that.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

command: add hmac sum supportfor md5, sha1, sha224, sha256, sha384, sha512 ...

pass the key via -h param

barebox@barebox sandbox:/ sha256sum -h test /dev/fd0
c297473e9bb221c5dc51d47ad75c76095f1bdc4ca9dff1d5931c2e22bf11a0de  /dev/fd0 0x00000000 ... 0xffffffffffffffff

use the same idea as openssl command

$ openssl dgst -sha256 -hmac "test" TODO
HMAC-SHA256(TODO)= c297473e9bb221c5dc51d47ad75c76095f1bdc4ca9dff1d5931c2e22bf11a0de

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: make it multi-instance ...

Now you need to call digest_alloc and when you finish to use it digest_free.

We need this for upcomming aes encryption support and secure boot
as we will need multiple instance of the same digest.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: introduce digest_{init/update/final/length} ...

This will allow to move from a one at a time digest to a multi-instance
with too much impact on the code using it

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

digest: move digest.c to crypto ...

with not the rest of the implementation

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>