From: Sebastian Siewior Subject: Re: [PATCH 2/2] salsa20_i586: Salsa20 stream cipher algorithm (i586 version) Date: Fri, 7 Dec 2007 19:44:32 +0100 Message-ID: <20071207184432.GE24292@Chamillionaire.breakpoint.cc> References: <20071205214947.GA20246@Chamillionaire.breakpoint.cc> Reply-To: Sebastian Siewior Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Cc: Herbert Xu , Linux Crypto To: Tan Swee Heng Return-path: Received: from Chamillionaire.breakpoint.cc ([85.10.199.196]:52709 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753904AbXLGSof (ORCPT ); Fri, 7 Dec 2007 13:44:35 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: * Tan Swee Heng | 2007-12-08 01:02:04 [+0800]: >Hi Sebastian, Hi, >On Dec 6, 2007 5:49 AM, Sebastian Siewior wrote: >> The patch is a large one. Do you thing all those comments are requried >> or helping to understand what is going on? >Actually no, I don't think the comments outside of the functions are >that helpful. But let me explain why I left them in there: > >The assembly code was written by Bernstein 2 years ago in 2005 (see >). Since then I >suppose folks have vetted the code. These folks may want reassurance >that I did not corrupt it when adding indentations. By leaving the >comments and extraneous functions intact, I was HOPING they can verify >it with "diff -b". Yes, I saw this, there are very identical. They released test vectors to verify an implementation. >> Besides that, I saw the keysetup routine is also included in assembly. >> Is the computed key any different from the C version? *I* would prefer >> to share the keysetup code with the C version because it is not a >> performace critical part. >The keysetup() should be the same as the C version... except that I've >previously modified the C version to use key length in bytes while the >assembly version uses bits! :-) I could change the C code back. But I >personally prefer to use the assembly version since it was distributed >as a "self-contained and complete solution" in Bernstein's >"salsa20.s". I would go for the smaller files. That's why merged the AES code earlier. >Hope is a fickle thing. I just tried "diff -b" and it did not work as >I hoped. My removal of ".globl _ECRYPT_* " confuses diff. That being >the case, I will go with everyone's wish to remove the extraneous >comments. As for folks who want to verify that I did not corrupt the >assembly code, I will also provide the script I used to automate the >process. (I will do all these in a separate post.) I would not mind modifing the source code for the greated good :) Should you make a mistake than the test vectors should detect them. After all, you modified the C version and s/keysize/bits. >Swee Heng Sebastian