Date:   Fri, 25 Jan 2019 18:00:09 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     David Howells <dhowells@redhat.com>,
        Tudor Ambarus <tudor-dan.ambarus@nxp.com>,
        "David S. Miller" <davem@davemloft.net>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Horia =?utf-8?Q?Geant=C4=83?= <horia.geanta@nxp.com>,
        Aymen Sghaier <aymen.sghaier@nxp.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Gary Hook <gary.hook@amd.com>,
        Giovanni Cabiddu <giovanni.cabiddu@intel.com>,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        keyrings@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, qat-linux@intel.com
Subject: Re: [RFC PATCH v2] akcipher: Introduce verify_rsa/verify for public
 key algorithms
Message-ID: <20190125100009.i2ggpc7k7qvzayvj@gondor.apana.org.au>
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On Fri, Jan 18, 2019 at 11:41:00PM +0300, Vitaly Chikunov wrote:
>
> a) RSA verify works differently (is it just disguised encrypt),
> b) We have separate wrapper module for it (pkcs1pad). Thus:
> 
> Old API can not be removed. In other words, we can not replace
> .verify_rsa with .verify in these drivers or PKCS1 will not work.
> 
> We can replace .verify_rsa with .verify in pkcs1pad, but there is no
> need for that if we stay with two API calls, which we can't avoid.

I think having two API calls during a transition period is fine.
But it must not be the long-term outcome.

In order to keep existing drivers working, I think we should make
the API wrap the legacy verify_rsa and implement verify directly
on top of it.  IOW the driver remains unchanged for now but the
crypto API code should provide a verify API that is implemented
on top of the driver's verify_rsa call.

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