Date:   Sat, 11 Mar 2023 16:06:16 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     linux-crypto@vger.kernel.org, ebiggers@kernel.org,
        James Bottomley <James.Bottomley@hansenpartnership.com>
Subject: Re: [PATCH v2] crypto: lib - implement library version of AES in CFB
 mode
Message-ID: <ZAw2eHDQELdiVXcZ@gondor.apana.org.au>
References: <20230217144348.1537615-1-ardb@kernel.org>
 <Y/L6rSGDidhhWq2v@gondor.apana.org.au>
 <CAMj1kXE8ZjVh=hLVgnRGr8cJpkqzRHsVxuq3dm1P=Aqc1QpcXg@mail.gmail.com>
 <ZAsDT00Jgs2p6luL@gondor.apana.org.au>
 <CAMj1kXHhF7CyeGV2QHu6MRVQNKo1EHFkshewOfptEOdJ5znJDA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAMj1kXHhF7CyeGV2QHu6MRVQNKo1EHFkshewOfptEOdJ5znJDA@mail.gmail.com>
Precedence: bulk

On Fri, Mar 10, 2023 at 05:18:05PM +0100, Ard Biesheuvel wrote:
>
> Does that mean you are bringing back blkcipher? I think that would the
> right thing to do tbh, although it might make sense to enhance
> skcipher (and aead) to support this.

I haven't gone into that kind of detail yet but my first impression
is that it would be the analogue of shash and skcipher would simply
wrap around it just like ahash wraps around shash.

> Could we perhaps update struct skcipher_request so it can describe
> virtually mapped address ranges, but permit this only for synchronous
> implementations? Then, we could update the skcipher walker code to
> produce a single walk step covering the entire range, and just use the
> provided virtual addresses directly, rather than going through a
> mapping interface?

Since skcipher doesn't actually need to carry any state with it
I'd like to avoid having an skcipher_request at all.  So it would
look pretty much like the existing crypto_cipher interface except
with the addition of length and IV.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt