From: Tudor-Dan Ambarus Subject: RE: [PATCH v3 1/3] crypto: rsa - generalize ASN.1 sequences Date: Fri, 15 Apr 2016 14:32:42 +0000 Message-ID: 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" Content-Transfer-Encoding: 8BIT Cc: "linux-crypto@vger.kernel.org" , "tadeusz.struk@intel.com" , "smueller@chronox.de" , Cristian Stoica , "Horia Ioan Geanta Neag" To: Herbert Xu Return-path: Received: from mail-db3on0074.outbound.protection.outlook.com ([157.55.234.74]:32448 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750921AbcDOOcp convert rfc822-to-8bit (ORCPT ); Fri, 15 Apr 2016 10:32:45 -0400 In-Reply-To: <20160415135245.GA334@gondor.apana.org.au> Content-Language: en-US Sender: linux-crypto-owner@vger.kernel.org List-ID: > 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). Thanks, ta