From: David Howells <dhowells@redhat.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: dhowells@redhat.com, kyle@mcmartin.ca,
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: Thu, 31 May 2012 15:11:02 +0100 [thread overview]
Message-ID: <17249.1338473462@redhat.com> (raw)
In-Reply-To: <87r4u6w58c.fsf@rustcorp.com.au>
Rusty Russell <rusty@rustcorp.com.au> wrote:
> > That then adds 5 bytes to the magic string. Is that really so bad?
>
> Yes, because it's unnecessary.
I'm sorry Rusty, but this argument is disingenuous.
Yes, a length field in the file is unnecessary - BUT SO TOO is scanning! By
this argument, your idea is really so bad too. It's all about the trade off
one chooses to make. I do not accept your chosen trade off[*] as being the
best one.
David
[*] And, yes, it *is* a trade off: you are trading CPU time and permanently
resident kernel code space in order to save a tiny amount of disk
space[**].
[**] Assuming 512 byte blocks and a 5 byte size field, probably fewer than 1%
of modules will expand sufficiently to consume an extra block. Further,
making it a 2-byte binary field would make it even less intrusive, both
in the file and in the module verifier.
next prev parent reply other threads:[~2012-05-31 14:11 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-22 23:02 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 ` [PATCH 00/23] Crypto keys and module signing Rusty Russell
2012-05-23 14:20 ` David Howells
2012-05-24 12:04 ` 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
2012-05-24 14:00 ` David Howells
2012-05-27 5:41 ` Rusty Russell
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
2012-05-31 14:11 ` David Howells [this message]
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
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=17249.1338473462@redhat.com \
--to=dhowells@redhat.com \
--cc=keyrings@linux-nfs.org \
--cc=kyle@mcmartin.ca \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=rusty@rustcorp.com.au \
/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
Powered by JetHome