linux/kernel/module-internal.h

/* Module internals
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

extern int mod_verify_sig(const void *mod, unsigned long *_modlen);
module: signature checking hook We do a very simple search for a particular string appended to the module (which is cache-hot and about to be SHA'd anyway). There's both a config option and a boot parameter which control whether we accept or fail with unsigned modules and modules that are signed with an unknown key. If module signing is enabled, the kernel will be tainted if a module is loaded that is unsigned or has a signature for which we don't have the key. (Useful feedback and tweaks by David Howells <dhowells@redhat.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> 2012-09-26 09:09:40 +00:00			`/* Module internals`
			`*`
			`* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.`
			`* Written by David Howells (dhowells@redhat.com)`
			`*`
			`* This program is free software; you can redistribute it and/or`
			`* modify it under the terms of the GNU General Public Licence`
			`* as published by the Free Software Foundation; either version`
			`* 2 of the Licence, or (at your option) any later version.`
			`*/`

MODSIGN: Move the magic string to the end of a module and eliminate the search Emit the magic string that indicates a module has a signature after the signature data instead of before it. This allows module_sig_check() to be made simpler and faster by the elimination of the search for the magic string. Instead we just need to do a single memcmp(). This works because at the end of the signature data there is the fixed-length signature information block. This block then falls immediately prior to the magic number. From the contents of the information block, it is trivial to calculate the size of the signature data and thus the size of the actual module data. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2012-10-20 00:19:29 +00:00			`extern int mod_verify_sig(const void mod, unsigned long _modlen);`