From: Milan Broz Subject: Re: [dm-crypt] cryptsetup with arc4 cipher Date: Wed, 05 Aug 2009 15:09:59 +0200 Message-ID: <4A7984A7.40109@redhat.com> References: <87zlaf3zl0.wl@obsidian.enotty.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: dm-crypt@saout.de, linux-crypto@vger.kernel.org To: Stelios Bounanos Return-path: Received: from mx2.redhat.com ([66.187.237.31]:60922 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932737AbZHENKa (ORCPT ); Wed, 5 Aug 2009 09:10:30 -0400 In-Reply-To: <87zlaf3zl0.wl@obsidian.enotty.net> Sender: linux-crypto-owner@vger.kernel.org List-ID: Stelios Bounanos wrote: > I was surprised to see arc4 perform so badly, particularly since > "openssl speed" results tell a very different story. I decided to do > some simple benchmarking of my own but I can't seem to get cryptsetup to > work with arc4: > > # cryptsetup luksFormat --align-payload=512 -q -c arc4 /dev/sda4 key > # cryptsetup luksOpen -d key /dev/sda4 ctest > Command failed: No key available with this passphrase. > > The above commands work fine with aes. I can see arc4 in /proc/crypto. > > Any ideas? There is apparently some problem in kernel, not sure if dm-crypt or crypto api one, This ARC4 configuration is allowed (no errors) but produces something more like random generator:-) one sector device: # dmsetup create x --table "0 1 crypt arc4-cbc-plain 0123456789abcdef 0 /dev/sdb 0" # sha256sum /dev/mapper/x d37afeeb57a60b69715edd99f2a1523e77f6be51a1c61c56efc91ed691c90dfc /dev/mapper/x # sha256sum /dev/mapper/x fdc87e8e9f158d26e58c5b48c80375b56cc24d0c088872f4aacc7e19fb5c5599 /dev/mapper/x Not sure what's wrong yet... Milan -- mbroz@redhat.com