From: Stephan Mueller Subject: Re: crypto: user - Allow get request with empty driver name Date: Thu, 20 Nov 2014 14:07:33 +0100 Message-ID: <6473728.hPvPq1YETa@tachyon.chronox.de> References: <5365136.g8vbXlhRyC@tachyon.chronox.de> <20141120074526.GB29544@gondor.apana.org.au> <20141120080406.GV6390@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: Herbert Xu , Daniel Borkmann , quentin.gouchet-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, LKML , linux-crypto-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ABI/API To: Steffen Klassert Return-path: In-Reply-To: <20141120080406.GV6390-opNxpl+3fjRBDgjK7y7TUQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-crypto.vger.kernel.org Am Donnerstag, 20. November 2014, 09:04:06 schrieb Steffen Klassert: Hi Steffen, > On Thu, Nov 20, 2014 at 03:45:26PM +0800, Herbert Xu wrote: > > On Thu, Nov 20, 2014 at 08:11:42AM +0100, Steffen Klassert wrote: > > > I think this is not sufficient, crypto_alg_match() will now return the > > > first algorithm in crypto_alg_list that matches cra_name. We would need > > > to extend crypto_alg_match() to return the algorithm with the highest > > > priority in that case. > > > > It doesn't really matter because all implementations must provide > > exactly the same set of parameters for a given algorithm so it's > > good enough for what Stephan wants to do. > > Ok, I see. > > > But yes an interface to grab the highest priority algorithm would > > be useful too so patches are welcome :) > > Should be not too hard to return the highest priority algorithm > instead of the first match with the existing interface, I'll see > what I can do. I think that for the purpose of using crypto-user in an AF_ALG scenario, even searching for the highest priporty will not necessarily give you the reference to the cipher used in AF_ALG. In the time between AF_ALG initialized a cipher and the time crypto-user is called, a new driver could register that may have even a higher priority than the one driver currently active for AF_ALG. Therefore, from my perspective of AF_ALG and considering that all drivers of the same name should be identical, I would not suggest add more code to resolve the highest priority as I do not see the value of it. -- Ciao Stephan