From: Rusty Russell <rusty@rustcorp.com.au>
To: David Howells <dhowells@redhat.com>, kyle@mcmartin.ca
Cc: linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, keyrings@linux-nfs.org
Subject: Re: [PATCH 00/23] Crypto keys and module signing
Date: Wed, 23 May 2012 22:21:28 +0930 [thread overview]
Message-ID: <87obpfxdpr.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20120522230218.24007.3556.stgit@warthog.procyon.org.uk>
On Wed, 23 May 2012 00:02:19 +0100, David Howells <dhowells@redhat.com> wrote:
> The extended module file format is as follows:
>
> The module signature is appended to the end of the module file, followed by
> "@mod_size@\n@sig_size@\nThis Is A Crypto Signed Module".
>
> The EOF must follow the magic string directly, so nothing further must be
> appended to the file.
>
> mod_size and sig_size are left-aligned decimal numbers, space-padded to 8
> characters. mod_size is the size of the module payload part of the file and
> sig_size is the size of the signature blob.
Hi David,
That's pretty weird. Why not put the "@This Is A Crypto Signed
Module\n" before the signature? Then module-size is implied: everything
before that signature. The signature size is implied: everything after
that signature.
In fact, I'd modify this slightly, to allow multiple signatures.
This would work nicely with a deterministic strip. Find the signatures
backward, and truncate as they fail.
If you want to be super-paranoid, scan for that signature before
signing the module.
Cheers,
Rusty.
next prev parent reply other threads:[~2012-05-23 12:54 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-22 23:02 [PATCH 00/23] Crypto keys and module signing David Howells
2012-05-22 23:02 ` [PATCH 01/23] Guard check in module loader against integer overflow David Howells
2012-05-22 23:02 ` [PATCH 02/23] KEYS: Move the key config into security/keys/Kconfig David Howells
2012-05-22 23:02 ` [PATCH 03/23] KEYS: Announce key type (un)registration David Howells
2012-05-22 23:02 ` [PATCH 04/23] KEYS: Reorganise keys Makefile David Howells
2012-05-22 23:02 ` [PATCH 05/23] KEYS: Create a key type that can be used for general cryptographic operations David Howells
2012-05-22 23:03 ` [PATCH 06/23] KEYS: Add signature verification facility David Howells
2012-05-22 23:03 ` [PATCH 07/23] KEYS: Asymmetric public-key algorithm crypto key subtype David Howells
2012-05-22 23:03 ` [PATCH 08/23] KEYS: RSA signature verification algorithm David Howells
2012-05-22 23:03 ` [PATCH 09/23] Fix signature verification for shorter signatures David Howells
2012-05-22 23:03 ` [PATCH 10/23] PGPLIB: PGP definitions (RFC 4880) David Howells
2012-05-22 23:03 ` [PATCH 11/23] PGPLIB: Basic packet parser David Howells
2012-05-22 23:03 ` [PATCH 12/23] PGPLIB: Signature parser David Howells
2012-05-22 23:03 ` [PATCH 13/23] KEYS: PGP data parser David Howells
2012-05-22 23:04 ` [PATCH 14/23] KEYS: PGP-based public key signature verification David Howells
2012-05-22 23:04 ` [PATCH 15/23] KEYS: PGP format signature parser David Howells
2012-05-22 23:04 ` [PATCH 16/23] KEYS: Provide a function to load keys from a PGP keyring blob David Howells
2012-05-22 23:04 ` [PATCH 17/23] MODSIGN: Provide gitignore and make clean rules for extra files David Howells
2012-05-22 23:04 ` [PATCH 18/23] MODSIGN: Provide Documentation and Kconfig options David Howells
2012-05-22 23:04 ` [PATCH 19/23] MODSIGN: Sign modules during the build process David Howells
2012-05-22 23:04 ` [PATCH 20/23] MODSIGN: Provide module signing public keys to the kernel David Howells
2012-05-22 23:05 ` [PATCH 21/23] MODSIGN: Module signature verification David Howells
2012-05-22 23:05 ` [PATCH 22/23] MODSIGN: Automatically generate module signing keys if missing David Howells
2012-05-22 23:05 ` [PATCH 23/23] MODSIGN: Panic the kernel if FIPS is enabled upon module signing failure David Howells
2012-05-23 12:51 ` Rusty Russell [this message]
2012-05-23 14:20 ` [PATCH 00/23] Crypto keys and module signing David Howells
2012-05-24 12:04 ` Rusty Russell
2012-05-24 14:00 ` David Howells
2012-05-27 5:41 ` Rusty Russell
2012-05-31 14:11 ` David Howells
2012-05-31 15:35 ` Josh Boyer
2012-06-04 1:16 ` Rusty Russell
2012-06-04 13:38 ` Josh Boyer
2012-06-05 0:23 ` Rusty Russell
2012-06-22 1:53 ` Greg KH
2012-06-22 3:29 ` Lucas De Marchi
2012-06-22 4:05 ` Rusty Russell
2012-06-22 11:03 ` David Howells
2012-06-23 0:20 ` Rusty Russell
2012-05-25 11:15 ` Kasatkin, Dmitry
2012-05-25 11:37 ` David Howells
2012-05-25 13:08 ` Mimi Zohar
2012-05-25 13:53 ` David Howells
2012-05-25 14:40 ` Mimi Zohar
2012-05-25 12:18 ` David Howells
2012-05-25 15:42 ` David Howells
2012-06-04 1:31 ` Rusty Russell
2012-06-04 12:47 ` Mimi Zohar
2012-06-05 1:05 ` Rusty Russell
2012-06-05 11:39 ` Mimi Zohar
2012-06-05 13:37 ` David Howells
2012-06-05 14:36 ` Kasatkin, Dmitry
2012-06-05 13:35 ` David Howells
2012-06-10 5:47 ` Rusty Russell
2012-06-11 8:30 ` Kasatkin, Dmitry
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