From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:55876 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727329AbeIRDBy (ORCPT ); Mon, 17 Sep 2018 23:01:54 -0400 From: David Howells In-Reply-To: References: <153685389564.14766.11306559824641824935.stgit@warthog.procyon.org.uk> <153685392942.14766.3347355712333618914.stgit@warthog.procyon.org.uk> <20180914041831.GY19965@ZenIV.linux.org.uk> To: Trond Myklebust Cc: dhowells@redhat.com, "viro@ZenIV.linux.org.uk" , "linux-kernel@vger.kernel.org" , "linux-afs@lists.infradead.org" , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH 04/10] iov_iter: Add mapping and discard iterator types MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <5763.1537219964.1@warthog.procyon.org.uk> Date: Mon, 17 Sep 2018 22:32:44 +0100 Message-ID: <5764.1537219964@warthog.procyon.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Trond Myklebust wrote: > Another question that is relevant for most networked filesystems > (including AFS, I believe), is how will you deal with encryption of the > data you are transmitting? Encrypting and decrypting in-place directly > in the page cache or in a userspace O_DIRECT mapped buffer might not be > the best and most secure option, so won't you find yourself wanting to > copy the data anyway? For kAFS, the interface between kAFS and AF_RXRPC takes an iterator. Currently, encryption is done in place on the sk_buffs inside AF_RXRPC, but the goal I have in mind is to use the crypto operation to replace the copy between sk_buff and buffer. This is tricky, however, as the encrypted payload contains metadata as well as data and on reception I have to read the metadata to find out how much data there actually is. David