linux-kernel - Re: Should we automatically generate a module signing key at all?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1432067105.3277.95.camel@infradead.org>
Date:	Tue, 19 May 2015 21:25:05 +0100
From:	David Woodhouse <dwmw2@...radead.org>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andy Lutomirski <luto@...nel.org>,
	David Howells <dhowells@...hat.com>,
	Michal Marek <mmarek@...e.cz>,
	Abelardo Ricart III <aricart@...nix.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Sedat Dilek <sedat.dilek@...il.com>, keyrings@...ux-nfs.org,
	Rusty Russell <rusty@...tcorp.com.au>,
	LSM List <linux-security-module@...r.kernel.org>,
	Borislav Petkov <bp@...en8.de>, Jiri Kosina <jkosina@...e.cz>
Subject: Re: Should we automatically generate a module signing key at all?

On Tue, 2015-05-19 at 13:05 -0700, Andy Lutomirski wrote:
> > I appreciate why that's a problem in your scenario, but it's a valid and
> > useful feature of signatures, and I don't think we can just abandon it.
> 
> True, but I'd consider that use case (running a kernel built on a
> development machine) to be more in line with unsigned use or long-term
> (maybe medium-term) signing keys.
> 
> IOW, for this use case, running scripts/generate_module_signing_key or
> whatever and configuring accordingly seems entirely reasonable to me.
> Or you could just turn off forced module signature verification since
> keeping the signing key in plaintext on your machine mostly negates
> any benefit of verifying signatures on that machine at runtime.

Perhaps so (although it's ignoring use cases where the build tree is
somewhere secure and internal and I'm deploying to a server which is
more accessible).

But we already *fixed* the problem of generating the signing key
automatically. The in-tree signing_key.{priv,x509} are always transient
auto-generated files now, and the ambiguity is gone. As a side-effect of
what I was already doing to enable PKCS#11. It was mostly just a
documentation change.

So I'm not sure I see the point of ditching it, now that it's working.

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@...el.com                              Intel Corporation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/