| 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
| ||
|
Date: Tue, 05 Nov 2013 19:31:58 -0800 From: Randy Dunlap <rdunlap@...radead.org> To: Rob Landley <rob@...dley.net>, Josh Boyer <jwboyer@...oraproject.org> CC: James Solner <solner@...atel-lucent.com>, David Howells <dhowells@...hat.com>, Rusty Russell <rusty@...tcorp.com.au>, "Linux-Kernel@...r. Kernel. Org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] Adding Documentation/module-signing.txt file On 11/05/13 14:54, Rob Landley wrote: > On 10/24/2013 07:08:33 PM, Josh Boyer wrote: >> On Thu, Oct 24, 2013 at 6:35 PM, James Solner <solner@...atel-lucent.com> wrote: >> > This patch adds the Documentation/module-signing.txt file that is >> > missing. There is a link to Documentation/module-signing.txt file >> > in init/Kconfig that references this file. >> > >> > Signed-off-by: James Solner <solner@...atel-lucent.com> >> >> Nak. Please see below. >> >> > --- >> > Documentation/module-signing.txt | 182 +++++++++++++++++++++++++++++++++++++++ >> > 1 file changed, 182 insertions(+) >> > create mode 100644 Documentation/module-signing.txt >> > >> > diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt >> > new file mode 100644 >> > index 0000000..b21e1f1 >> > --- /dev/null >> > +++ b/Documentation/module-signing.txt >> > @@ -0,0 +1,182 @@ >> > + ============================== >> > + KERNEL MODULE SIGNING FACILITY >> > + ============================== >> > + >> > +The module signing facility applies cryptographic signature checking to modules >> > +on module load, checking the signature against a ring of public keys compiled >> > +into the kernel. GPG is used to do the cryptographic work and determines the >> > +format of the signature and key data. The facility uses GPG's MPI library to >> > +handle the huge numbers involved. >> > + >> > +The signature checker in the kernel is capable of handling multiple keys of >> > +either DSA or RSA type, and can support any of MD5, RIPE-MD-160, SHA-1, >> > +SHA-224, SHA-256, SHA-384 and SHA-512 hashes - PROVIDED(!) the requisite >> > +algorithms are compiled into the kernel. >> > + >> > +(!) NOTE: Modules may only be verified initially with algorithms compiled into >> > +the kernel. Further algorithm modules may be loaded and used - but these must >> > +first pass a verification step using already loaded/compiled-in algorithms. >> > + >> > + >> > +===================== >> > +SUPPLYING PUBLIC KEYS >> > +===================== >> > + >> > +A set of public keys must be supplied at kernel image build time. This is done >> > +by taking a GPG public key file and placing it in the base of the kernel >> > +directory in a file called modsign.pub. >> > + >> > +For example, a throwaway key could be generated automatically by something like >> > +the following: >> > + >> > + cat >genkey <<EOF >> > + %pubring modsign.pub >> > + %secring modsign.sec >> > + Key-Type: RSA >> > + Key-Length: 4096 >> > + Name-Real: A. N. Other >> > + Name-Comment: Kernel Module GPG key >> > + %commit >> > + EOF >> > + gpg --homedir . --batch --gen-key genkey >> > + >> > +The above generates fresh keys using /dev/random. If there's insufficient data >> > +in /dev/random, more can be provided using the rngd program if there's a >> > +hardware random number generator available. >> > + >> > +Note that no GPG password is used in the above scriptlet. >> >> This is inaccurate and doesn't match how module signing is done today. >> The document you have here is a weird mix of the old RHEL style GPG >> signing and the current appended-signature x509 certificate signing. >> >> It needs to be updated to match the fact that x509 keys and signatures >> are used now. >> >> josh > > What's the current status of this? I'm collating my Documentation patch stack to submit upstream, and this is the most recent message on this one? > > (Googling for Documentation/module-signing.txt brings up dhowells tree on googlesource.com, so presumably something could be fished out of that, but maybe it's going upstream via Rusty's tree, or...?) > > *shrug* Just trying to keep tabs... There was a new version posted earlier today: http://marc.info/?l=linux-kernel&m=138369435917393&w=2 It still needs to be cleaned up IMO. -- ~Randy -- 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/
Powered by blists - more mailing lists