Re: [PATCH v4 0/5] BLAKE2b generic implementation

[David Sterba <dsterba@suse.cz>]

On Fri, Oct 11, 2019 at 10:57:40AM -0700, Eric Biggers wrote:
> The choice of data lengths seems a bit unusual, as they include every length in
> two ranges but nothing in between.  Also, none of the lengths except 0 is a
> multiple of the blake2b block size.  Instead, maybe use something like
> [0, 1, 7, 15, 64, 247, 256]?

Just to clarify, do you mean the block size defined by BLAKE2B_BLOCKBYTES?
That's 128, so that makes 0 and 256 the multiples.

> Also, since the 4 variants share nearly all their code, it seems the tests would
> be just as effective in practice if we cut the test vectors down by 4x by
> distributing the key lengths among each variant.  Like:
> 
>           blake2b-160  blake2b-256  blake2b-384  blake2b-512
>          ---------------------------------------------------
> len=0   | klen=0       klen=1       klen=16      klen=32
> len=1   | klen=16      klen=32      klen=0       klen=1
> len=7   | klen=32      klen=0       klen=1       klen=16
> len=15  | klen=1       klen=16      klen=32      klen=0
> len=64  | klen=0       klen=1       klen=16      klen=32
> len=247 | klen=16      klen=32      klen=0       klen=1
> len=256 | klen=32      klen=0       klen=1       klen=16

That's clever. I assume the 32 key length refers to the default key,
right? That's 64 bytes (BLAKE2B_KEYBYTES), so I'll use that value.

> > Testing performed:
> > 
> > - compiled with SLUB_DEBUG and KASAN, plus crypto selftests
> >   CONFIG_CRYPTO_MANAGER2=y
> >   CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=n
> >   CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y
> > - module loaded, no errors reported from the tessuite
> > - (un)intentionally broken test values were detected
> > 
> > The test values were produced by b2sum, compiled from the reference
> > implementation. The generated values were cross-checked by pyblake2
> > based script (ie. not the same sources, built by distro).
> > 
> > The .h portion of testmgr is completely generated, so in case somebody feels
> > like reducing it in size, adding more keys, changing the formatting, it's easy
> > to do.
> 
> > 
> > In case the patches don't make it to the mailinglist, it's in git
> > 
> >   git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git dev/blake2b-v4
> 
> Can you please rebase this onto cryptodev/master?

Will do.

Thanks for the comments.