From: David Howells Subject: Re: [PATCH v1.3 4/4] keys: add new key-type encrypted Date: Mon, 15 Nov 2010 16:18:54 +0000 Message-ID: <8268.1289837934@redhat.com> References: <1289694826.3257.82.camel@localhost.localdomain> <1289595738.2731.80.camel@localhost.localdomain> <1289404309-15955-5-git-send-email-zohar@linux.vnet.ibm.com> <1289404309-15955-1-git-send-email-zohar@linux.vnet.ibm.com> <26689.1289591135@redhat.com> <27900.1289597013@redhat.com> Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@linux-nfs.org, linux-crypto@vger.kernel.org, Jason Gunthorpe , James Morris , David Safford , Rajiv Andrade , Mimi Zohar To: Mimi Zohar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43694 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755275Ab0KOQTV (ORCPT ); Mon, 15 Nov 2010 11:19:21 -0500 In-Reply-To: <1289694826.3257.82.camel@localhost.localdomain> Sender: linux-crypto-owner@vger.kernel.org List-ID: Mimi Zohar wrote: > > I thought that might be the case. In which case, it might be better to > > allow someone to add a trusted key, supplying both encrypted and > > unencrypted versions of the data so that the TPM need not be consulted. > > You might want to mark such a key so that it can be seen when it is > > dumped. > > At least to me, the name 'trusted' implies some form of HW. In many ways, I think that the type and description describe the purpose of the key, not its source or derivation. > > But if you're going to use a user-defined key, you really need to prefix > > the description with something suitable. > > Agreed. So instead of: > keyctl add encrypted name "new master-key-name keylen" ring > > the description would be prefixed with the key type like: > keyctl add encrypted name "new trusted|user master-key-name keylen" ring I don't think you understood what I meant. If you look at the following function: +static struct key *request_master_key(struct encrypted_key_payload *epayload, + void **master_key, + unsigned int *master_keylen) +{ + struct key *mkey; + + mkey = request_trusted_key(epayload->master_desc, + master_key, master_keylen); + if (IS_ERR(mkey)) { + mkey = request_user_key(epayload->master_desc, + master_key, master_keylen); + if (IS_ERR(mkey)) { + pr_info("encrypted_key: trusted/user key %s not found", + epayload->master_desc); + return mkey; + } + } + dump_master_key(*master_key, *master_keylen); + return mkey; +} In the bit where you go for a user key (having failed to get a trusted key), you should prefix the description here (or in request_user_key()) with something like "trusted:". Then you don't need to change the user interface. David