From: Herbert Xu Subject: Re: [PATCH v3 1/3] crypto: rsa - generalize ASN.1 sequences Date: Fri, 15 Apr 2016 22:38:51 +0800 Message-ID: <20160415143851.GK733@gondor.apana.org.au> References: <1459949826-11840-1-git-send-email-tudor-dan.ambarus@nxp.com> <1459949826-11840-2-git-send-email-tudor-dan.ambarus@nxp.com> <20160415135245.GA334@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-crypto@vger.kernel.org" , "tadeusz.struk@intel.com" , "smueller@chronox.de" , Cristian Stoica , Horia Ioan Geanta Neag To: Tudor-Dan Ambarus Return-path: Received: from helcar.hengli.com.au ([209.40.204.226]:56786 "EHLO helcar.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbcDOOi4 (ORCPT ); Fri, 15 Apr 2016 10:38:56 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: On Fri, Apr 15, 2016 at 02:32:42PM +0000, Tudor-Dan Ambarus wrote: > > On Wed, Apr 06, 2016 at 04:37:04PM +0300, Tudor Ambarus wrote: > > > This approach has the advantage that users can select specific > > > parser actions by using a general parser with function pointers > > > to specific actions. > > > > I don't understand why we need different parsing functions in the > > first place. Can't they just return raw integers always? > > > > You can then trivially convert the raw integers to MPI, no? > > We need different parsing functions so that we don't allocate duplicate buffers for the same data. > > You need to allocate buffers when getting the raw integers and you need to allocate other (duplicate) buffers when converting the raw integers to MPI. > > Using the proposed API each user can select the format of data he wants, eliminating the need of a double conversion (with its drawbacks: duplicate buffers, unnecessary cycles). The double allocation only happens with software RSA, right? I don't really think that is going to matter considering how slow it is, no? Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt