From: Andy Lutomirski <luto@kernel.org>
To: David Howells <dhowells@redhat.com>, rusty@rustcorp.com.au
Cc: mmarek@suse.cz, mjg59@srcf.ucam.org, keyrings@linux-nfs.org,
dmitry.kasatkin@gmail.com, mcgrof@suse.com,
linux-kernel@vger.kernel.org, seth.forshee@canonical.com,
linux-security-module@vger.kernel.org, dwmw2@infradead.org
Subject: Re: [PATCH 0/8] MODSIGN: Use PKCS#7 for module signatures [ver #4]
Date: Tue, 19 May 2015 17:36:37 -0700 [thread overview]
Message-ID: <555BD715.40202@kernel.org> (raw)
In-Reply-To: <20150515123513.16723.96340.stgit@warthog.procyon.org.uk>
I'm not sure I want to get involved here, but...
On 05/15/2015 05:35 AM, David Howells wrote:
>
> Hi Rusty,
>
> Here's a set of patches that does the following:
>
> (1) Extracts both parts of an X.509 AuthorityKeyIdentifier (AKID) extension.
> We already extract the bit that can match the subjectKeyIdentifier (SKID)
> of the parent X.509 cert, but we currently ignore the bits that can match
> the issuer and serialNumber.
>
> Looks up an X.509 cert by issuer and serialNumber if those are provided in
> the AKID. If the keyIdentifier is also provided, checks that the
> subjectKeyIdentifier of the cert found matches that also.
>
> If no issuer and serialNumber are provided in the AKID, looks up an X.509
> cert by SKID using the AKID keyIdentifier.
>
> This allows module signing to be done with certificates that don't have an
> SKID by which they can be looked up.
I think this is way more complicated than it has to be. Can't we look
up certificates by their subjectPublicKeyInfo? Every public key has a
subjectPublicKeyInfo, and even key types that aren't X.509 at all have
something equivalent to that.
>
> (2) Makes use of the PKCS#7 facility to provide module signatures.
>
> sign-file is replaced with a program that generates a PKCS#7 message that
> has no X.509 certs embedded and that has detached data (the module
> content) and adds it onto the message with magic string and descriptor.
Why is PKCS#7 better than whatever we're using now?
>
> (3) The PKCS#7 message (and matching X.509 cert) supply all the information
> that is needed to select the X.509 cert to be used to verify the signature
> by standard means (including selection of digest algorithm and public key
> algorithm). No kernel-specific magic values are required.
I would take kernel-specific over PKCS#7 any day. PKCS#7 is severely
overcomplicated for what we're doing here.
--Andy
next prev parent reply other threads:[~2015-05-20 0:36 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-15 12:35 [PATCH 0/8] MODSIGN: Use PKCS#7 for module signatures [ver #4] David Howells
2015-05-15 12:35 ` [PATCH 1/8] X.509: Extract both parts of the AuthorityKeyIdentifier " David Howells
2015-05-15 12:35 ` [PATCH 2/8] X.509: Support X.509 lookup by Issuer+Serial form " David Howells
2015-05-15 12:35 ` [PATCH 3/8] PKCS#7: Allow detached data to be supplied for signature checking purposes " David Howells
2015-05-15 12:35 ` [PATCH 4/8] MODSIGN: Provide a utility to append a PKCS#7 signature to a module " David Howells
2015-05-20 0:50 ` Andy Lutomirski
2015-05-20 13:14 ` David Howells
2015-05-20 16:00 ` Andy Lutomirski
2015-05-15 12:36 ` [PATCH 5/8] MODSIGN: Use PKCS#7 messages as module signatures " David Howells
2015-05-15 12:36 ` [PATCH 6/8] sign-file: Add option to only create signature file " David Howells
2015-05-15 12:36 ` [PATCH 7/8] system_keyring.c doesn't need to #include module-internal.h " David Howells
2015-05-15 12:36 ` [PATCH 8/8] MODSIGN: Extract the blob PKCS#7 signature verifier from module signing " David Howells
2015-05-15 13:46 ` [PATCH 0/8] MODSIGN: Use PKCS#7 for module signatures " David Woodhouse
2015-05-15 16:52 ` [PATCH 1/4] modsign: Abort modules_install when signing fails David Woodhouse
2015-05-19 1:29 ` Mimi Zohar
2015-05-19 6:40 ` Woodhouse, David
2015-05-19 11:45 ` Mimi Zohar
2015-05-19 12:57 ` Woodhouse, David
2015-05-19 13:54 ` Mimi Zohar
2015-05-15 16:53 ` [PATCH 2/4] modsign: Allow external signing key to be specified David Woodhouse
2015-05-15 16:53 ` [PATCH 3/4] modsign: Allow password to be specified for signing key David Woodhouse
2015-05-19 1:37 ` Mimi Zohar
2015-05-15 16:54 ` [PATCH 4/4] modsign: Allow signing key to be PKCS#11 David Woodhouse
2015-05-15 19:07 ` sign-file and detached PKCS#7 firmware signatures David Howells
2015-05-18 23:13 ` Luis R. Rodriguez
2015-05-19 9:25 ` David Howells
2015-05-19 16:19 ` Luis R. Rodriguez
2015-05-19 16:48 ` David Howells
2015-05-19 18:21 ` Luis R. Rodriguez
2015-05-19 18:35 ` Luis R. Rodriguez
2015-05-19 18:47 ` David Howells
2015-05-19 20:12 ` Luis R. Rodriguez
2015-05-19 20:29 ` David Howells
2015-05-15 22:51 ` [PATCH 0/8] MODSIGN: Use PKCS#7 for module signatures [ver #4] Rusty Russell
2015-05-18 12:43 ` [PATCH 4/4] modsign: Allow signing key to be PKCS#11 David Howells
2015-05-19 14:45 ` [PATCH 9/8] modsign: Abort modules_install when signing fails David Woodhouse
2015-05-19 14:45 ` [PATCH 10/8] modsign: Allow password to be specified for signing key David Woodhouse
2015-05-19 15:50 ` Petko Manolov
2015-05-19 16:15 ` David Woodhouse
2015-05-19 16:34 ` Petko Manolov
2015-05-19 18:39 ` Mimi Zohar
2015-05-19 18:48 ` David Howells
2015-05-19 19:14 ` Mimi Zohar
2015-05-19 20:04 ` David Woodhouse
2015-05-19 14:46 ` [PATCH 11/8] modsign: Allow signing key to be PKCS#11 David Woodhouse
2015-05-19 14:46 ` [PATCH 12/8] modsign: Allow external signing key to be specified David Woodhouse
2015-05-19 14:47 ` [PATCH 13/8] modsign: Extract signing cert from CONFIG_MODULE_SIG_KEY if needed David Woodhouse
2015-05-19 15:36 ` [PATCH 10/8] modsign: Allow password to be specified for signing key David Howells
2015-05-20 0:36 ` Andy Lutomirski [this message]
2015-05-20 13:36 ` [PATCH 0/8] MODSIGN: Use PKCS#7 for module signatures [ver #4] David Howells
2015-05-20 15:56 ` Andy Lutomirski
2015-05-20 16:21 ` Petko Manolov
2015-05-20 16:41 ` Andy Lutomirski
2015-05-20 16:55 ` Petko Manolov
2015-05-21 21:38 ` Luis R. Rodriguez
2015-05-21 21:44 ` Andy Lutomirski
2015-05-21 21:59 ` Luis R. Rodriguez
2015-05-21 22:06 ` Andy Lutomirski
2015-05-21 22:16 ` Luis R. Rodriguez
2015-05-21 22:24 ` Andy Lutomirski
2015-05-21 22:31 ` Luis R. Rodriguez
2015-05-21 22:47 ` Andy Lutomirski
2015-05-21 23:01 ` Luis R. Rodriguez
2015-05-21 23:09 ` Andy Lutomirski
2015-05-22 7:56 ` David Howells
2015-05-22 12:42 ` Mimi Zohar
2015-05-22 7:49 ` David Howells
2015-05-22 7:48 ` David Howells
2015-05-22 12:28 ` Mimi Zohar
2015-05-24 10:52 ` Petko Manolov
2015-05-21 13:59 ` David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=555BD715.40202@kernel.org \
--to=luto@kernel.org \
--cc=dhowells@redhat.com \
--cc=dmitry.kasatkin@gmail.com \
--cc=dwmw2@infradead.org \
--cc=keyrings@linux-nfs.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mcgrof@suse.com \
--cc=mjg59@srcf.ucam.org \
--cc=mmarek@suse.cz \
--cc=rusty@rustcorp.com.au \
--cc=seth.forshee@canonical.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).